fs/btrfs/inode.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/bio.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/file.h>
  23 #include <linux/fs.h>
  24 #include <linux/pagemap.h>
  25 #include <linux/highmem.h>
  26 #include <linux/time.h>
  27 #include <linux/init.h>
  28 #include <linux/string.h>
  29 #include <linux/backing-dev.h>
  30 #include <linux/mpage.h>
  31 #include <linux/swap.h>
  32 #include <linux/writeback.h>
  33 #include <linux/statfs.h>
  34 #include <linux/compat.h>
  35 #include <linux/bit_spinlock.h>
  36 #include <linux/xattr.h>
  37 #include <linux/posix_acl.h>
  38 #include <linux/falloc.h>
  39 #include <linux/slab.h>
  40 #include <linux/ratelimit.h>
  41 #include <linux/mount.h>
  42 #include "compat.h"
  43 #include "ctree.h"
  44 #include "disk-io.h"
  45 #include "transaction.h"
  46 #include "btrfs_inode.h"
  47 #include "ioctl.h"
  48 #include "print-tree.h"
  49 #include "ordered-data.h"
  50 #include "xattr.h"
  51 #include "tree-log.h"
  52 #include "volumes.h"
  53 #include "compression.h"
  54 #include "locking.h"
  55 #include "free-space-cache.h"
  56 #include "inode-map.h"
  57
  58 struct btrfs_iget_args {
  59         u64 ino;
  60         struct btrfs_root *root;
  61 };
  62
  63 static const struct inode_operations btrfs_dir_inode_operations;
  64 static const struct inode_operations btrfs_symlink_inode_operations;
  65 static const struct inode_operations btrfs_dir_ro_inode_operations;
  66 static const struct inode_operations btrfs_special_inode_operations;
  67 static const struct inode_operations btrfs_file_inode_operations;
  68 static const struct address_space_operations btrfs_aops;
  69 static const struct address_space_operations btrfs_symlink_aops;
  70 static const struct file_operations btrfs_dir_file_operations;
  71 static struct extent_io_ops btrfs_extent_io_ops;
  72
  73 static struct kmem_cache *btrfs_inode_cachep;
  74 struct kmem_cache *btrfs_trans_handle_cachep;
  75 struct kmem_cache *btrfs_transaction_cachep;
  76 struct kmem_cache *btrfs_path_cachep;
  77 struct kmem_cache *btrfs_free_space_cachep;
  78
  79 #define S_SHIFT 12
  80 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
  81         [S_IFREG >> S_SHIFT]    = BTRFS_FT_REG_FILE,
  82         [S_IFDIR >> S_SHIFT]    = BTRFS_FT_DIR,
  83         [S_IFCHR >> S_SHIFT]    = BTRFS_FT_CHRDEV,
  84         [S_IFBLK >> S_SHIFT]    = BTRFS_FT_BLKDEV,
  85         [S_IFIFO >> S_SHIFT]    = BTRFS_FT_FIFO,
  86         [S_IFSOCK >> S_SHIFT]   = BTRFS_FT_SOCK,
  87         [S_IFLNK >> S_SHIFT]    = BTRFS_FT_SYMLINK,
  88 };
  89
  90 static int btrfs_setsize(struct inode *inode, loff_t newsize);
  91 static int btrfs_truncate(struct inode *inode);
  92 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
  93 static noinline int cow_file_range(struct inode *inode,
  94                                    struct page *locked_page,
  95                                    u64 start, u64 end, int *page_started,
  96                                    unsigned long *nr_written, int unlock);
  97 static noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
  98                                 struct btrfs_root *root, struct inode *inode);
  99
 100 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
 101                                      struct inode *inode,  struct inode *dir,
 102                                      const struct qstr *qstr)
 103 {
 104         int err;
 105
 106         err = btrfs_init_acl(trans, inode, dir);
 107         if (!err)
 108                 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
 109         return err;
 110 }
 111
 112 /*
 113  * this does all the hard work for inserting an inline extent into
 114  * the btree.  The caller should have done a btrfs_drop_extents so that
 115  * no overlapping inline items exist in the btree
 116  */
 117 static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
 118                                 struct btrfs_root *root, struct inode *inode,
 119                                 u64 start, size_t size, size_t compressed_size,
 120                                 int compress_type,
 121                                 struct page **compressed_pages)
 122 {
 123         struct btrfs_key key;
 124         struct btrfs_path *path;
 125         struct extent_buffer *leaf;
 126         struct page *page = NULL;
 127         char *kaddr;
 128         unsigned long ptr;
 129         struct btrfs_file_extent_item *ei;
 130         int err = 0;
 131         int ret;
 132         size_t cur_size = size;
 133         size_t datasize;
 134         unsigned long offset;
 135
 136         if (compressed_size && compressed_pages)
 137                 cur_size = compressed_size;
 138
 139         path = btrfs_alloc_path();
 140         if (!path)
 141                 return -ENOMEM;
 142
 143         path->leave_spinning = 1;
 144
 145         key.objectid = btrfs_ino(inode);
 146         key.offset = start;
 147         btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
 148         datasize = btrfs_file_extent_calc_inline_size(cur_size);
 149
 150         inode_add_bytes(inode, size);
 151         ret = btrfs_insert_empty_item(trans, root, path, &key,
 152                                       datasize);
 153         if (ret) {
 154                 err = ret;
 155                 goto fail;
 156         }
 157         leaf = path->nodes[0];
 158         ei = btrfs_item_ptr(leaf, path->slots[0],
 159                             struct btrfs_file_extent_item);
 160         btrfs_set_file_extent_generation(leaf, ei, trans->transid);
 161         btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
 162         btrfs_set_file_extent_encryption(leaf, ei, 0);
 163         btrfs_set_file_extent_other_encoding(leaf, ei, 0);
 164         btrfs_set_file_extent_ram_bytes(leaf, ei, size);
 165         ptr = btrfs_file_extent_inline_start(ei);
 166
 167         if (compress_type != BTRFS_COMPRESS_NONE) {
 168                 struct page *cpage;
 169                 int i = 0;
 170                 while (compressed_size > 0) {
 171                         cpage = compressed_pages[i];
 172                         cur_size = min_t(unsigned long, compressed_size,
 173                                        PAGE_CACHE_SIZE);
 174
 175                         kaddr = kmap_atomic(cpage);
 176                         write_extent_buffer(leaf, kaddr, ptr, cur_size);
 177                         kunmap_atomic(kaddr);
 178
 179                         i++;
 180                         ptr += cur_size;
 181                         compressed_size -= cur_size;
 182                 }
 183                 btrfs_set_file_extent_compression(leaf, ei,
 184                                                   compress_type);
 185         } else {
 186                 page = find_get_page(inode->i_mapping,
 187                                      start >> PAGE_CACHE_SHIFT);
 188                 btrfs_set_file_extent_compression(leaf, ei, 0);
 189                 kaddr = kmap_atomic(page);
 190                 offset = start & (PAGE_CACHE_SIZE - 1);
 191                 write_extent_buffer(leaf, kaddr + offset, ptr, size);
 192                 kunmap_atomic(kaddr);
 193                 page_cache_release(page);
 194         }
 195         btrfs_mark_buffer_dirty(leaf);
 196         btrfs_free_path(path);
 197
 198         /*
 199          * we're an inline extent, so nobody can
 200          * extend the file past i_size without locking
 201          * a page we already have locked.
 202          *
 203          * We must do any isize and inode updates
 204          * before we unlock the pages.  Otherwise we
 205          * could end up racing with unlink.
 206          */
 207         BTRFS_I(inode)->disk_i_size = inode->i_size;
 208         ret = btrfs_update_inode(trans, root, inode);
 209
 210         return ret;
 211 fail:
 212         btrfs_free_path(path);
 213         return err;
 214 }
 215
 216
 217 /*
 218  * conditionally insert an inline extent into the file.  This
 219  * does the checks required to make sure the data is small enough
 220  * to fit as an inline extent.
 221  */
 222 static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
 223                                  struct btrfs_root *root,
 224                                  struct inode *inode, u64 start, u64 end,
 225                                  size_t compressed_size, int compress_type,
 226                                  struct page **compressed_pages)
 227 {
 228         u64 isize = i_size_read(inode);
 229         u64 actual_end = min(end + 1, isize);
 230         u64 inline_len = actual_end - start;
 231         u64 aligned_end = (end + root->sectorsize - 1) &
 232                         ~((u64)root->sectorsize - 1);
 233         u64 hint_byte;
 234         u64 data_len = inline_len;
 235         int ret;
 236
 237         if (compressed_size)
 238                 data_len = compressed_size;
 239
 240         if (start > 0 ||
 241             actual_end >= PAGE_CACHE_SIZE ||
 242             data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
 243             (!compressed_size &&
 244             (actual_end & (root->sectorsize - 1)) == 0) ||
 245             end + 1 < isize ||
 246             data_len > root->fs_info->max_inline) {
 247                 return 1;
 248         }
 249
 250         ret = btrfs_drop_extents(trans, inode, start, aligned_end,
 251                                  &hint_byte, 1);
 252         if (ret)
 253                 return ret;
 254
 255         if (isize > actual_end)
 256                 inline_len = min_t(u64, isize, actual_end);
 257         ret = insert_inline_extent(trans, root, inode, start,
 258                                    inline_len, compressed_size,
 259                                    compress_type, compressed_pages);
 260         if (ret && ret != -ENOSPC) {
 261                 btrfs_abort_transaction(trans, root, ret);
 262                 return ret;
 263         } else if (ret == -ENOSPC) {
 264                 return 1;
 265         }
 266
 267         btrfs_delalloc_release_metadata(inode, end + 1 - start);
 268         btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
 269         return 0;
 270 }
 271
 272 struct async_extent {
 273         u64 start;
 274         u64 ram_size;
 275         u64 compressed_size;
 276         struct page **pages;
 277         unsigned long nr_pages;
 278         int compress_type;
 279         struct list_head list;
 280 };
 281
 282 struct async_cow {
 283         struct inode *inode;
 284         struct btrfs_root *root;
 285         struct page *locked_page;
 286         u64 start;
 287         u64 end;
 288         struct list_head extents;
 289         struct btrfs_work work;
 290 };
 291
 292 static noinline int add_async_extent(struct async_cow *cow,
 293                                      u64 start, u64 ram_size,
 294                                      u64 compressed_size,
 295                                      struct page **pages,
 296                                      unsigned long nr_pages,
 297                                      int compress_type)
 298 {
 299         struct async_extent *async_extent;
 300
 301         async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
 302         BUG_ON(!async_extent); /* -ENOMEM */
 303         async_extent->start = start;
 304         async_extent->ram_size = ram_size;
 305         async_extent->compressed_size = compressed_size;
 306         async_extent->pages = pages;
 307         async_extent->nr_pages = nr_pages;
 308         async_extent->compress_type = compress_type;
 309         list_add_tail(&async_extent->list, &cow->extents);
 310         return 0;
 311 }
 312
 313 /*
 314  * we create compressed extents in two phases.  The first
 315  * phase compresses a range of pages that have already been
 316  * locked (both pages and state bits are locked).
 317  *
 318  * This is done inside an ordered work queue, and the compression
 319  * is spread across many cpus.  The actual IO submission is step
 320  * two, and the ordered work queue takes care of making sure that
 321  * happens in the same order things were put onto the queue by
 322  * writepages and friends.
 323  *
 324  * If this code finds it can't get good compression, it puts an
 325  * entry onto the work queue to write the uncompressed bytes.  This
 326  * makes sure that both compressed inodes and uncompressed inodes
 327  * are written in the same order that pdflush sent them down.
 328  */
 329 static noinline int compress_file_range(struct inode *inode,
 330                                         struct page *locked_page,
 331                                         u64 start, u64 end,
 332                                         struct async_cow *async_cow,
 333                                         int *num_added)
 334 {
 335         struct btrfs_root *root = BTRFS_I(inode)->root;
 336         struct btrfs_trans_handle *trans;
 337         u64 num_bytes;
 338         u64 blocksize = root->sectorsize;
 339         u64 actual_end;
 340         u64 isize = i_size_read(inode);
 341         int ret = 0;
 342         struct page **pages = NULL;
 343         unsigned long nr_pages;
 344         unsigned long nr_pages_ret = 0;
 345         unsigned long total_compressed = 0;
 346         unsigned long total_in = 0;
 347         unsigned long max_compressed = 128 * 1024;
 348         unsigned long max_uncompressed = 128 * 1024;
 349         int i;
 350         int will_compress;
 351         int compress_type = root->fs_info->compress_type;
 352
 353         /* if this is a small write inside eof, kick off a defrag */
 354         if ((end - start + 1) < 16 * 1024 &&
 355             (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
 356                 btrfs_add_inode_defrag(NULL, inode);
 357
 358         actual_end = min_t(u64, isize, end + 1);
 359 again:
 360         will_compress = 0;
 361         nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
 362         nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
 363
 364         /*
 365          * we don't want to send crud past the end of i_size through
 366          * compression, that's just a waste of CPU time.  So, if the
 367          * end of the file is before the start of our current
 368          * requested range of bytes, we bail out to the uncompressed
 369          * cleanup code that can deal with all of this.
 370          *
 371          * It isn't really the fastest way to fix things, but this is a
 372          * very uncommon corner.
 373          */
 374         if (actual_end <= start)
 375                 goto cleanup_and_bail_uncompressed;
 376
 377         total_compressed = actual_end - start;
 378
 379         /* we want to make sure that amount of ram required to uncompress
 380          * an extent is reasonable, so we limit the total size in ram
 381          * of a compressed extent to 128k.  This is a crucial number
 382          * because it also controls how easily we can spread reads across
 383          * cpus for decompression.
 384          *
 385          * We also want to make sure the amount of IO required to do
 386          * a random read is reasonably small, so we limit the size of
 387          * a compressed extent to 128k.
 388          */
 389         total_compressed = min(total_compressed, max_uncompressed);
 390         num_bytes = (end - start + blocksize) & ~(blocksize - 1);
 391         num_bytes = max(blocksize,  num_bytes);
 392         total_in = 0;
 393         ret = 0;
 394
 395         /*
 396          * we do compression for mount -o compress and when the
 397          * inode has not been flagged as nocompress.  This flag can
 398          * change at any time if we discover bad compression ratios.
 399          */
 400         if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
 401             (btrfs_test_opt(root, COMPRESS) ||
 402              (BTRFS_I(inode)->force_compress) ||
 403              (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS))) {
 404                 WARN_ON(pages);
 405                 pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
 406                 if (!pages) {
 407                         /* just bail out to the uncompressed code */
 408                         goto cont;
 409                 }
 410
 411                 if (BTRFS_I(inode)->force_compress)
 412                         compress_type = BTRFS_I(inode)->force_compress;
 413
 414                 ret = btrfs_compress_pages(compress_type,
 415                                            inode->i_mapping, start,
 416                                            total_compressed, pages,
 417                                            nr_pages, &nr_pages_ret,
 418                                            &total_in,
 419                                            &total_compressed,
 420                                            max_compressed);
 421
 422                 if (!ret) {
 423                         unsigned long offset = total_compressed &
 424                                 (PAGE_CACHE_SIZE - 1);
 425                         struct page *page = pages[nr_pages_ret - 1];
 426                         char *kaddr;
 427
 428                         /* zero the tail end of the last page, we might be
 429                          * sending it down to disk
 430                          */
 431                         if (offset) {
 432                                 kaddr = kmap_atomic(page);
 433                                 memset(kaddr + offset, 0,
 434                                        PAGE_CACHE_SIZE - offset);
 435                                 kunmap_atomic(kaddr);
 436                         }
 437                         will_compress = 1;
 438                 }
 439         }
 440 cont:
 441         if (start == 0) {
 442                 trans = btrfs_join_transaction(root);
 443                 if (IS_ERR(trans)) {
 444                         ret = PTR_ERR(trans);
 445                         trans = NULL;
 446                         goto cleanup_and_out;
 447                 }
 448                 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 449
 450                 /* lets try to make an inline extent */
 451                 if (ret || total_in < (actual_end - start)) {
 452                         /* we didn't compress the entire range, try
 453                          * to make an uncompressed inline extent.
 454                          */
 455                         ret = cow_file_range_inline(trans, root, inode,
 456                                                     start, end, 0, 0, NULL);
 457                 } else {
 458                         /* try making a compressed inline extent */
 459                         ret = cow_file_range_inline(trans, root, inode,
 460                                                     start, end,
 461                                                     total_compressed,
 462                                                     compress_type, pages);
 463                 }
 464                 if (ret <= 0) {
 465                         /*
 466                          * inline extent creation worked or returned error,
 467                          * we don't need to create any more async work items.
 468                          * Unlock and free up our temp pages.
 469                          */
 470                         extent_clear_unlock_delalloc(inode,
 471                              &BTRFS_I(inode)->io_tree,
 472                              start, end, NULL,
 473                              EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
 474                              EXTENT_CLEAR_DELALLOC |
 475                              EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
 476
 477                         btrfs_end_transaction(trans, root);
 478                         goto free_pages_out;
 479                 }
 480                 btrfs_end_transaction(trans, root);
 481         }
 482
 483         if (will_compress) {
 484                 /*
 485                  * we aren't doing an inline extent round the compressed size
 486                  * up to a block size boundary so the allocator does sane
 487                  * things
 488                  */
 489                 total_compressed = (total_compressed + blocksize - 1) &
 490                         ~(blocksize - 1);
 491
 492                 /*
 493                  * one last check to make sure the compression is really a
 494                  * win, compare the page count read with the blocks on disk
 495                  */
 496                 total_in = (total_in + PAGE_CACHE_SIZE - 1) &
 497                         ~(PAGE_CACHE_SIZE - 1);
 498                 if (total_compressed >= total_in) {
 499                         will_compress = 0;
 500                 } else {
 501                         num_bytes = total_in;
 502                 }
 503         }
 504         if (!will_compress && pages) {
 505                 /*
 506                  * the compression code ran but failed to make things smaller,
 507                  * free any pages it allocated and our page pointer array
 508                  */
 509                 for (i = 0; i < nr_pages_ret; i++) {
 510                         WARN_ON(pages[i]->mapping);
 511                         page_cache_release(pages[i]);
 512                 }
 513                 kfree(pages);
 514                 pages = NULL;
 515                 total_compressed = 0;
 516                 nr_pages_ret = 0;
 517
 518                 /* flag the file so we don't compress in the future */
 519                 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
 520                     !(BTRFS_I(inode)->force_compress)) {
 521                         BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
 522                 }
 523         }
 524         if (will_compress) {
 525                 *num_added += 1;
 526
 527                 /* the async work queues will take care of doing actual
 528                  * allocation on disk for these compressed pages,
 529                  * and will submit them to the elevator.
 530                  */
 531                 add_async_extent(async_cow, start, num_bytes,
 532                                  total_compressed, pages, nr_pages_ret,
 533                                  compress_type);
 534
 535                 if (start + num_bytes < end) {
 536                         start += num_bytes;
 537                         pages = NULL;
 538                         cond_resched();
 539                         goto again;
 540                 }
 541         } else {
 542 cleanup_and_bail_uncompressed:
 543                 /*
 544                  * No compression, but we still need to write the pages in
 545                  * the file we've been given so far.  redirty the locked
 546                  * page if it corresponds to our extent and set things up
 547                  * for the async work queue to run cow_file_range to do
 548                  * the normal delalloc dance
 549                  */
 550                 if (page_offset(locked_page) >= start &&
 551                     page_offset(locked_page) <= end) {
 552                         __set_page_dirty_nobuffers(locked_page);
 553                         /* unlocked later on in the async handlers */
 554                 }
 555                 add_async_extent(async_cow, start, end - start + 1,
 556                                  0, NULL, 0, BTRFS_COMPRESS_NONE);
 557                 *num_added += 1;
 558         }
 559
 560 out:
 561         return ret;
 562
 563 free_pages_out:
 564         for (i = 0; i < nr_pages_ret; i++) {
 565                 WARN_ON(pages[i]->mapping);
 566                 page_cache_release(pages[i]);
 567         }
 568         kfree(pages);
 569
 570         goto out;
 571
 572 cleanup_and_out:
 573         extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
 574                                      start, end, NULL,
 575                                      EXTENT_CLEAR_UNLOCK_PAGE |
 576                                      EXTENT_CLEAR_DIRTY |
 577                                      EXTENT_CLEAR_DELALLOC |
 578                                      EXTENT_SET_WRITEBACK |
 579                                      EXTENT_END_WRITEBACK);
 580         if (!trans || IS_ERR(trans))
 581                 btrfs_error(root->fs_info, ret, "Failed to join transaction");
 582         else
 583                 btrfs_abort_transaction(trans, root, ret);
 584         goto free_pages_out;
 585 }
 586
 587 /*
 588  * phase two of compressed writeback.  This is the ordered portion
 589  * of the code, which only gets called in the order the work was
 590  * queued.  We walk all the async extents created by compress_file_range
 591  * and send them down to the disk.
 592  */
 593 static noinline int submit_compressed_extents(struct inode *inode,
 594                                               struct async_cow *async_cow)
 595 {
 596         struct async_extent *async_extent;
 597         u64 alloc_hint = 0;
 598         struct btrfs_trans_handle *trans;
 599         struct btrfs_key ins;
 600         struct extent_map *em;
 601         struct btrfs_root *root = BTRFS_I(inode)->root;
 602         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 603         struct extent_io_tree *io_tree;
 604         int ret = 0;
 605
 606         if (list_empty(&async_cow->extents))
 607                 return 0;
 608
 609
 610         while (!list_empty(&async_cow->extents)) {
 611                 async_extent = list_entry(async_cow->extents.next,
 612                                           struct async_extent, list);
 613                 list_del(&async_extent->list);
 614
 615                 io_tree = &BTRFS_I(inode)->io_tree;
 616
 617 retry:
 618                 /* did the compression code fall back to uncompressed IO? */
 619                 if (!async_extent->pages) {
 620                         int page_started = 0;
 621                         unsigned long nr_written = 0;
 622
 623                         lock_extent(io_tree, async_extent->start,
 624                                          async_extent->start +
 625                                          async_extent->ram_size - 1);
 626
 627                         /* allocate blocks */
 628                         ret = cow_file_range(inode, async_cow->locked_page,
 629                                              async_extent->start,
 630                                              async_extent->start +
 631                                              async_extent->ram_size - 1,
 632                                              &page_started, &nr_written, 0);
 633
 634                         /* JDM XXX */
 635
 636                         /*
 637                          * if page_started, cow_file_range inserted an
 638                          * inline extent and took care of all the unlocking
 639                          * and IO for us.  Otherwise, we need to submit
 640                          * all those pages down to the drive.
 641                          */
 642                         if (!page_started && !ret)
 643                                 extent_write_locked_range(io_tree,
 644                                                   inode, async_extent->start,
 645                                                   async_extent->start +
 646                                                   async_extent->ram_size - 1,
 647                                                   btrfs_get_extent,
 648                                                   WB_SYNC_ALL);
 649                         kfree(async_extent);
 650                         cond_resched();
 651                         continue;
 652                 }
 653
 654                 lock_extent(io_tree, async_extent->start,
 655                             async_extent->start + async_extent->ram_size - 1);
 656
 657                 trans = btrfs_join_transaction(root);
 658                 if (IS_ERR(trans)) {
 659                         ret = PTR_ERR(trans);
 660                 } else {
 661                         trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 662                         ret = btrfs_reserve_extent(trans, root,
 663                                            async_extent->compressed_size,
 664                                            async_extent->compressed_size,
 665                                            0, alloc_hint, &ins, 1);
 666                         if (ret)
 667                                 btrfs_abort_transaction(trans, root, ret);
 668                         btrfs_end_transaction(trans, root);
 669                 }
 670
 671                 if (ret) {
 672                         int i;
 673                         for (i = 0; i < async_extent->nr_pages; i++) {
 674                                 WARN_ON(async_extent->pages[i]->mapping);
 675                                 page_cache_release(async_extent->pages[i]);
 676                         }
 677                         kfree(async_extent->pages);
 678                         async_extent->nr_pages = 0;
 679                         async_extent->pages = NULL;
 680                         unlock_extent(io_tree, async_extent->start,
 681                                       async_extent->start +
 682                                       async_extent->ram_size - 1);
 683                         if (ret == -ENOSPC)
 684                                 goto retry;
 685                         goto out_free; /* JDM: Requeue? */
 686                 }
 687
 688                 /*
 689                  * here we're doing allocation and writeback of the
 690                  * compressed pages
 691                  */
 692                 btrfs_drop_extent_cache(inode, async_extent->start,
 693                                         async_extent->start +
 694                                         async_extent->ram_size - 1, 0);
 695
 696                 em = alloc_extent_map();
 697                 BUG_ON(!em); /* -ENOMEM */
 698                 em->start = async_extent->start;
 699                 em->len = async_extent->ram_size;
 700                 em->orig_start = em->start;
 701
 702                 em->block_start = ins.objectid;
 703                 em->block_len = ins.offset;
 704                 em->bdev = root->fs_info->fs_devices->latest_bdev;
 705                 em->compress_type = async_extent->compress_type;
 706                 set_bit(EXTENT_FLAG_PINNED, &em->flags);
 707                 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
 708
 709                 while (1) {
 710                         write_lock(&em_tree->lock);
 711                         ret = add_extent_mapping(em_tree, em);
 712                         write_unlock(&em_tree->lock);
 713                         if (ret != -EEXIST) {
 714                                 free_extent_map(em);
 715                                 break;
 716                         }
 717                         btrfs_drop_extent_cache(inode, async_extent->start,
 718                                                 async_extent->start +
 719                                                 async_extent->ram_size - 1, 0);
 720                 }
 721
 722                 ret = btrfs_add_ordered_extent_compress(inode,
 723                                                 async_extent->start,
 724                                                 ins.objectid,
 725                                                 async_extent->ram_size,
 726                                                 ins.offset,
 727                                                 BTRFS_ORDERED_COMPRESSED,
 728                                                 async_extent->compress_type);
 729                 BUG_ON(ret); /* -ENOMEM */
 730
 731                 /*
 732                  * clear dirty, set writeback and unlock the pages.
 733                  */
 734                 extent_clear_unlock_delalloc(inode,
 735                                 &BTRFS_I(inode)->io_tree,
 736                                 async_extent->start,
 737                                 async_extent->start +
 738                                 async_extent->ram_size - 1,
 739                                 NULL, EXTENT_CLEAR_UNLOCK_PAGE |
 740                                 EXTENT_CLEAR_UNLOCK |
 741                                 EXTENT_CLEAR_DELALLOC |
 742                                 EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
 743
 744                 ret = btrfs_submit_compressed_write(inode,
 745                                     async_extent->start,
 746                                     async_extent->ram_size,
 747                                     ins.objectid,
 748                                     ins.offset, async_extent->pages,
 749                                     async_extent->nr_pages);
 750
 751                 BUG_ON(ret); /* -ENOMEM */
 752                 alloc_hint = ins.objectid + ins.offset;
 753                 kfree(async_extent);
 754                 cond_resched();
 755         }
 756         ret = 0;
 757 out:
 758         return ret;
 759 out_free:
 760         kfree(async_extent);
 761         goto out;
 762 }
 763
 764 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
 765                                       u64 num_bytes)
 766 {
 767         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 768         struct extent_map *em;
 769         u64 alloc_hint = 0;
 770
 771         read_lock(&em_tree->lock);
 772         em = search_extent_mapping(em_tree, start, num_bytes);
 773         if (em) {
 774                 /*
 775                  * if block start isn't an actual block number then find the
 776                  * first block in this inode and use that as a hint.  If that
 777                  * block is also bogus then just don't worry about it.
 778                  */
 779                 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
 780                         free_extent_map(em);
 781                         em = search_extent_mapping(em_tree, 0, 0);
 782                         if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
 783                                 alloc_hint = em->block_start;
 784                         if (em)
 785                                 free_extent_map(em);
 786                 } else {
 787                         alloc_hint = em->block_start;
 788                         free_extent_map(em);
 789                 }
 790         }
 791         read_unlock(&em_tree->lock);
 792
 793         return alloc_hint;
 794 }
 795
 796 /*
 797  * when extent_io.c finds a delayed allocation range in the file,
 798  * the call backs end up in this code.  The basic idea is to
 799  * allocate extents on disk for the range, and create ordered data structs
 800  * in ram to track those extents.
 801  *
 802  * locked_page is the page that writepage had locked already.  We use
 803  * it to make sure we don't do extra locks or unlocks.
 804  *
 805  * *page_started is set to one if we unlock locked_page and do everything
 806  * required to start IO on it.  It may be clean and already done with
 807  * IO when we return.
 808  */
 809 static noinline int cow_file_range(struct inode *inode,
 810                                    struct page *locked_page,
 811                                    u64 start, u64 end, int *page_started,
 812                                    unsigned long *nr_written,
 813                                    int unlock)
 814 {
 815         struct btrfs_root *root = BTRFS_I(inode)->root;
 816         struct btrfs_trans_handle *trans;
 817         u64 alloc_hint = 0;
 818         u64 num_bytes;
 819         unsigned long ram_size;
 820         u64 disk_num_bytes;
 821         u64 cur_alloc_size;
 822         u64 blocksize = root->sectorsize;
 823         struct btrfs_key ins;
 824         struct extent_map *em;
 825         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
 826         int ret = 0;
 827
 828         BUG_ON(btrfs_is_free_space_inode(inode));
 829         trans = btrfs_join_transaction(root);
 830         if (IS_ERR(trans)) {
 831                 extent_clear_unlock_delalloc(inode,
 832                              &BTRFS_I(inode)->io_tree,
 833                              start, end, locked_page,
 834                              EXTENT_CLEAR_UNLOCK_PAGE |
 835                              EXTENT_CLEAR_UNLOCK |
 836                              EXTENT_CLEAR_DELALLOC |
 837                              EXTENT_CLEAR_DIRTY |
 838                              EXTENT_SET_WRITEBACK |
 839                              EXTENT_END_WRITEBACK);
 840                 return PTR_ERR(trans);
 841         }
 842         trans->block_rsv = &root->fs_info->delalloc_block_rsv;
 843
 844         num_bytes = (end - start + blocksize) & ~(blocksize - 1);
 845         num_bytes = max(blocksize,  num_bytes);
 846         disk_num_bytes = num_bytes;
 847         ret = 0;
 848
 849         /* if this is a small write inside eof, kick off defrag */
 850         if (num_bytes < 64 * 1024 &&
 851             (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
 852                 btrfs_add_inode_defrag(trans, inode);
 853
 854         if (start == 0) {
 855                 /* lets try to make an inline extent */
 856                 ret = cow_file_range_inline(trans, root, inode,
 857                                             start, end, 0, 0, NULL);
 858                 if (ret == 0) {
 859                         extent_clear_unlock_delalloc(inode,
 860                                      &BTRFS_I(inode)->io_tree,
 861                                      start, end, NULL,
 862                                      EXTENT_CLEAR_UNLOCK_PAGE |
 863                                      EXTENT_CLEAR_UNLOCK |
 864                                      EXTENT_CLEAR_DELALLOC |
 865                                      EXTENT_CLEAR_DIRTY |
 866                                      EXTENT_SET_WRITEBACK |
 867                                      EXTENT_END_WRITEBACK);
 868
 869                         *nr_written = *nr_written +
 870                              (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
 871                         *page_started = 1;
 872                         goto out;
 873                 } else if (ret < 0) {
 874                         btrfs_abort_transaction(trans, root, ret);
 875                         goto out_unlock;
 876                 }
 877         }
 878
 879         BUG_ON(disk_num_bytes >
 880                btrfs_super_total_bytes(root->fs_info->super_copy));
 881
 882         alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
 883         btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
 884
 885         while (disk_num_bytes > 0) {
 886                 unsigned long op;
 887
 888                 cur_alloc_size = disk_num_bytes;
 889                 ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
 890                                            root->sectorsize, 0, alloc_hint,
 891                                            &ins, 1);
 892                 if (ret < 0) {
 893                         btrfs_abort_transaction(trans, root, ret);
 894                         goto out_unlock;
 895                 }
 896
 897                 em = alloc_extent_map();
 898                 BUG_ON(!em); /* -ENOMEM */
 899                 em->start = start;
 900                 em->orig_start = em->start;
 901                 ram_size = ins.offset;
 902                 em->len = ins.offset;
 903
 904                 em->block_start = ins.objectid;
 905                 em->block_len = ins.offset;
 906                 em->bdev = root->fs_info->fs_devices->latest_bdev;
 907                 set_bit(EXTENT_FLAG_PINNED, &em->flags);
 908
 909                 while (1) {
 910                         write_lock(&em_tree->lock);
 911                         ret = add_extent_mapping(em_tree, em);
 912                         write_unlock(&em_tree->lock);
 913                         if (ret != -EEXIST) {
 914                                 free_extent_map(em);
 915                                 break;
 916                         }
 917                         btrfs_drop_extent_cache(inode, start,
 918                                                 start + ram_size - 1, 0);
 919                 }
 920
 921                 cur_alloc_size = ins.offset;
 922                 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
 923                                                ram_size, cur_alloc_size, 0);
 924                 BUG_ON(ret); /* -ENOMEM */
 925
 926                 if (root->root_key.objectid ==
 927                     BTRFS_DATA_RELOC_TREE_OBJECTID) {
 928                         ret = btrfs_reloc_clone_csums(inode, start,
 929                                                       cur_alloc_size);
 930                         if (ret) {
 931                                 btrfs_abort_transaction(trans, root, ret);
 932                                 goto out_unlock;
 933                         }
 934                 }
 935
 936                 if (disk_num_bytes < cur_alloc_size)
 937                         break;
 938
 939                 /* we're not doing compressed IO, don't unlock the first
 940                  * page (which the caller expects to stay locked), don't
 941                  * clear any dirty bits and don't set any writeback bits
 942                  *
 943                  * Do set the Private2 bit so we know this page was properly
 944                  * setup for writepage
 945                  */
 946                 op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
 947                 op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
 948                         EXTENT_SET_PRIVATE2;
 949
 950                 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
 951                                              start, start + ram_size - 1,
 952                                              locked_page, op);
 953                 disk_num_bytes -= cur_alloc_size;
 954                 num_bytes -= cur_alloc_size;
 955                 alloc_hint = ins.objectid + ins.offset;
 956                 start += cur_alloc_size;
 957         }
 958         ret = 0;
 959 out:
 960         btrfs_end_transaction(trans, root);
 961
 962         return ret;
 963 out_unlock:
 964         extent_clear_unlock_delalloc(inode,
 965                      &BTRFS_I(inode)->io_tree,
 966                      start, end, locked_page,
 967                      EXTENT_CLEAR_UNLOCK_PAGE |
 968                      EXTENT_CLEAR_UNLOCK |
 969                      EXTENT_CLEAR_DELALLOC |
 970                      EXTENT_CLEAR_DIRTY |
 971                      EXTENT_SET_WRITEBACK |
 972                      EXTENT_END_WRITEBACK);
 973
 974         goto out;
 975 }
 976
 977 /*
 978  * work queue call back to started compression on a file and pages
 979  */
 980 static noinline void async_cow_start(struct btrfs_work *work)
 981 {
 982         struct async_cow *async_cow;
 983         int num_added = 0;
 984         async_cow = container_of(work, struct async_cow, work);
 985
 986         compress_file_range(async_cow->inode, async_cow->locked_page,
 987                             async_cow->start, async_cow->end, async_cow,
 988                             &num_added);
 989         if (num_added == 0) {
 990                 btrfs_add_delayed_iput(async_cow->inode);
 991                 async_cow->inode = NULL;
 992         }
 993 }
 994
 995 /*
 996  * work queue call back to submit previously compressed pages
 997  */
 998 static noinline void async_cow_submit(struct btrfs_work *work)
 999 {
1000         struct async_cow *async_cow;
1001         struct btrfs_root *root;
1002         unsigned long nr_pages;
1003
1004         async_cow = container_of(work, struct async_cow, work);
1005
1006         root = async_cow->root;
1007         nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1008                 PAGE_CACHE_SHIFT;
1009
1010         if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1011             5 * 1024 * 1024 &&
1012             waitqueue_active(&root->fs_info->async_submit_wait))
1013                 wake_up(&root->fs_info->async_submit_wait);
1014
1015         if (async_cow->inode)
1016                 submit_compressed_extents(async_cow->inode, async_cow);
1017 }
1018
1019 static noinline void async_cow_free(struct btrfs_work *work)
1020 {
1021         struct async_cow *async_cow;
1022         async_cow = container_of(work, struct async_cow, work);
1023         if (async_cow->inode)
1024                 btrfs_add_delayed_iput(async_cow->inode);
1025         kfree(async_cow);
1026 }
1027
1028 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1029                                 u64 start, u64 end, int *page_started,
1030                                 unsigned long *nr_written)
1031 {
1032         struct async_cow *async_cow;
1033         struct btrfs_root *root = BTRFS_I(inode)->root;
1034         unsigned long nr_pages;
1035         u64 cur_end;
1036         int limit = 10 * 1024 * 1024;
1037
1038         clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1039                          1, 0, NULL, GFP_NOFS);
1040         while (start < end) {
1041                 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1042                 BUG_ON(!async_cow); /* -ENOMEM */
1043                 async_cow->inode = igrab(inode);
1044                 async_cow->root = root;
1045                 async_cow->locked_page = locked_page;
1046                 async_cow->start = start;
1047
1048                 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
1049                         cur_end = end;
1050                 else
1051                         cur_end = min(end, start + 512 * 1024 - 1);
1052
1053                 async_cow->end = cur_end;
1054                 INIT_LIST_HEAD(&async_cow->extents);
1055
1056                 async_cow->work.func = async_cow_start;
1057                 async_cow->work.ordered_func = async_cow_submit;
1058                 async_cow->work.ordered_free = async_cow_free;
1059                 async_cow->work.flags = 0;
1060
1061                 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1062                         PAGE_CACHE_SHIFT;
1063                 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1064
1065                 btrfs_queue_worker(&root->fs_info->delalloc_workers,
1066                                    &async_cow->work);
1067
1068                 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1069                         wait_event(root->fs_info->async_submit_wait,
1070                            (atomic_read(&root->fs_info->async_delalloc_pages) <
1071                             limit));
1072                 }
1073
1074                 while (atomic_read(&root->fs_info->async_submit_draining) &&
1075                       atomic_read(&root->fs_info->async_delalloc_pages)) {
1076                         wait_event(root->fs_info->async_submit_wait,
1077                           (atomic_read(&root->fs_info->async_delalloc_pages) ==
1078                            0));
1079                 }
1080
1081                 *nr_written += nr_pages;
1082                 start = cur_end + 1;
1083         }
1084         *page_started = 1;
1085         return 0;
1086 }
1087
1088 static noinline int csum_exist_in_range(struct btrfs_root *root,
1089                                         u64 bytenr, u64 num_bytes)
1090 {
1091         int ret;
1092         struct btrfs_ordered_sum *sums;
1093         LIST_HEAD(list);
1094
1095         ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1096                                        bytenr + num_bytes - 1, &list, 0);
1097         if (ret == 0 && list_empty(&list))
1098                 return 0;
1099
1100         while (!list_empty(&list)) {
1101                 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1102                 list_del(&sums->list);
1103                 kfree(sums);
1104         }
1105         return 1;
1106 }
1107
1108 /*
1109  * when nowcow writeback call back.  This checks for snapshots or COW copies
1110  * of the extents that exist in the file, and COWs the file as required.
1111  *
1112  * If no cow copies or snapshots exist, we write directly to the existing
1113  * blocks on disk
1114  */
1115 static noinline int run_delalloc_nocow(struct inode *inode,
1116                                        struct page *locked_page,
1117                               u64 start, u64 end, int *page_started, int force,
1118                               unsigned long *nr_written)
1119 {
1120         struct btrfs_root *root = BTRFS_I(inode)->root;
1121         struct btrfs_trans_handle *trans;
1122         struct extent_buffer *leaf;
1123         struct btrfs_path *path;
1124         struct btrfs_file_extent_item *fi;
1125         struct btrfs_key found_key;
1126         u64 cow_start;
1127         u64 cur_offset;
1128         u64 extent_end;
1129         u64 extent_offset;
1130         u64 disk_bytenr;
1131         u64 num_bytes;
1132         int extent_type;
1133         int ret, err;
1134         int type;
1135         int nocow;
1136         int check_prev = 1;
1137         bool nolock;
1138         u64 ino = btrfs_ino(inode);
1139
1140         path = btrfs_alloc_path();
1141         if (!path) {
1142                 extent_clear_unlock_delalloc(inode,
1143                              &BTRFS_I(inode)->io_tree,
1144                              start, end, locked_page,
1145                              EXTENT_CLEAR_UNLOCK_PAGE |
1146                              EXTENT_CLEAR_UNLOCK |
1147                              EXTENT_CLEAR_DELALLOC |
1148                              EXTENT_CLEAR_DIRTY |
1149                              EXTENT_SET_WRITEBACK |
1150                              EXTENT_END_WRITEBACK);
1151                 return -ENOMEM;
1152         }
1153
1154         nolock = btrfs_is_free_space_inode(inode);
1155
1156         if (nolock)
1157                 trans = btrfs_join_transaction_nolock(root);
1158         else
1159                 trans = btrfs_join_transaction(root);
1160
1161         if (IS_ERR(trans)) {
1162                 extent_clear_unlock_delalloc(inode,
1163                              &BTRFS_I(inode)->io_tree,
1164                              start, end, locked_page,
1165                              EXTENT_CLEAR_UNLOCK_PAGE |
1166                              EXTENT_CLEAR_UNLOCK |
1167                              EXTENT_CLEAR_DELALLOC |
1168                              EXTENT_CLEAR_DIRTY |
1169                              EXTENT_SET_WRITEBACK |
1170                              EXTENT_END_WRITEBACK);
1171                 btrfs_free_path(path);
1172                 return PTR_ERR(trans);
1173         }
1174
1175         trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1176
1177         cow_start = (u64)-1;
1178         cur_offset = start;
1179         while (1) {
1180                 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1181                                                cur_offset, 0);
1182                 if (ret < 0) {
1183                         btrfs_abort_transaction(trans, root, ret);
1184                         goto error;
1185                 }
1186                 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1187                         leaf = path->nodes[0];
1188                         btrfs_item_key_to_cpu(leaf, &found_key,
1189                                               path->slots[0] - 1);
1190                         if (found_key.objectid == ino &&
1191                             found_key.type == BTRFS_EXTENT_DATA_KEY)
1192                                 path->slots[0]--;
1193                 }
1194                 check_prev = 0;
1195 next_slot:
1196                 leaf = path->nodes[0];
1197                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1198                         ret = btrfs_next_leaf(root, path);
1199                         if (ret < 0) {
1200                                 btrfs_abort_transaction(trans, root, ret);
1201                                 goto error;
1202                         }
1203                         if (ret > 0)
1204                                 break;
1205                         leaf = path->nodes[0];
1206                 }
1207
1208                 nocow = 0;
1209                 disk_bytenr = 0;
1210                 num_bytes = 0;
1211                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1212
1213                 if (found_key.objectid > ino ||
1214                     found_key.type > BTRFS_EXTENT_DATA_KEY ||
1215                     found_key.offset > end)
1216                         break;
1217
1218                 if (found_key.offset > cur_offset) {
1219                         extent_end = found_key.offset;
1220                         extent_type = 0;
1221                         goto out_check;
1222                 }
1223
1224                 fi = btrfs_item_ptr(leaf, path->slots[0],
1225                                     struct btrfs_file_extent_item);
1226                 extent_type = btrfs_file_extent_type(leaf, fi);
1227
1228                 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1229                     extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1230                         disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1231                         extent_offset = btrfs_file_extent_offset(leaf, fi);
1232                         extent_end = found_key.offset +
1233                                 btrfs_file_extent_num_bytes(leaf, fi);
1234                         if (extent_end <= start) {
1235                                 path->slots[0]++;
1236                                 goto next_slot;
1237                         }
1238                         if (disk_bytenr == 0)
1239                                 goto out_check;
1240                         if (btrfs_file_extent_compression(leaf, fi) ||
1241                             btrfs_file_extent_encryption(leaf, fi) ||
1242                             btrfs_file_extent_other_encoding(leaf, fi))
1243                                 goto out_check;
1244                         if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1245                                 goto out_check;
1246                         if (btrfs_extent_readonly(root, disk_bytenr))
1247                                 goto out_check;
1248                         if (btrfs_cross_ref_exist(trans, root, ino,
1249                                                   found_key.offset -
1250                                                   extent_offset, disk_bytenr))
1251                                 goto out_check;
1252                         disk_bytenr += extent_offset;
1253                         disk_bytenr += cur_offset - found_key.offset;
1254                         num_bytes = min(end + 1, extent_end) - cur_offset;
1255                         /*
1256                          * force cow if csum exists in the range.
1257                          * this ensure that csum for a given extent are
1258                          * either valid or do not exist.
1259                          */
1260                         if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1261                                 goto out_check;
1262                         nocow = 1;
1263                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1264                         extent_end = found_key.offset +
1265                                 btrfs_file_extent_inline_len(leaf, fi);
1266                         extent_end = ALIGN(extent_end, root->sectorsize);
1267                 } else {
1268                         BUG_ON(1);
1269                 }
1270 out_check:
1271                 if (extent_end <= start) {
1272                         path->slots[0]++;
1273                         goto next_slot;
1274                 }
1275                 if (!nocow) {
1276                         if (cow_start == (u64)-1)
1277                                 cow_start = cur_offset;
1278                         cur_offset = extent_end;
1279                         if (cur_offset > end)
1280                                 break;
1281                         path->slots[0]++;
1282                         goto next_slot;
1283                 }
1284
1285                 btrfs_release_path(path);
1286                 if (cow_start != (u64)-1) {
1287                         ret = cow_file_range(inode, locked_page, cow_start,
1288                                         found_key.offset - 1, page_started,
1289                                         nr_written, 1);
1290                         if (ret) {
1291                                 btrfs_abort_transaction(trans, root, ret);
1292                                 goto error;
1293                         }
1294                         cow_start = (u64)-1;
1295                 }
1296
1297                 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1298                         struct extent_map *em;
1299                         struct extent_map_tree *em_tree;
1300                         em_tree = &BTRFS_I(inode)->extent_tree;
1301                         em = alloc_extent_map();
1302                         BUG_ON(!em); /* -ENOMEM */
1303                         em->start = cur_offset;
1304                         em->orig_start = em->start;
1305                         em->len = num_bytes;
1306                         em->block_len = num_bytes;
1307                         em->block_start = disk_bytenr;
1308                         em->bdev = root->fs_info->fs_devices->latest_bdev;
1309                         set_bit(EXTENT_FLAG_PINNED, &em->flags);
1310                         while (1) {
1311                                 write_lock(&em_tree->lock);
1312                                 ret = add_extent_mapping(em_tree, em);
1313                                 write_unlock(&em_tree->lock);
1314                                 if (ret != -EEXIST) {
1315                                         free_extent_map(em);
1316                                         break;
1317                                 }
1318                                 btrfs_drop_extent_cache(inode, em->start,
1319                                                 em->start + em->len - 1, 0);
1320                         }
1321                         type = BTRFS_ORDERED_PREALLOC;
1322                 } else {
1323                         type = BTRFS_ORDERED_NOCOW;
1324                 }
1325
1326                 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1327                                                num_bytes, num_bytes, type);
1328                 BUG_ON(ret); /* -ENOMEM */
1329
1330                 if (root->root_key.objectid ==
1331                     BTRFS_DATA_RELOC_TREE_OBJECTID) {
1332                         ret = btrfs_reloc_clone_csums(inode, cur_offset,
1333                                                       num_bytes);
1334                         if (ret) {
1335                                 btrfs_abort_transaction(trans, root, ret);
1336                                 goto error;
1337                         }
1338                 }
1339
1340                 extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1341                                 cur_offset, cur_offset + num_bytes - 1,
1342                                 locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
1343                                 EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
1344                                 EXTENT_SET_PRIVATE2);
1345                 cur_offset = extent_end;
1346                 if (cur_offset > end)
1347                         break;
1348         }
1349         btrfs_release_path(path);
1350
1351         if (cur_offset <= end && cow_start == (u64)-1) {
1352                 cow_start = cur_offset;
1353                 cur_offset = end;
1354         }
1355
1356         if (cow_start != (u64)-1) {
1357                 ret = cow_file_range(inode, locked_page, cow_start, end,
1358                                      page_started, nr_written, 1);
1359                 if (ret) {
1360                         btrfs_abort_transaction(trans, root, ret);
1361                         goto error;
1362                 }
1363         }
1364
1365 error:
1366         if (nolock) {
1367                 err = btrfs_end_transaction_nolock(trans, root);
1368         } else {
1369                 err = btrfs_end_transaction(trans, root);
1370         }
1371         if (!ret)
1372                 ret = err;
1373
1374         if (ret && cur_offset < end)
1375                 extent_clear_unlock_delalloc(inode,
1376                              &BTRFS_I(inode)->io_tree,
1377                              cur_offset, end, locked_page,
1378                              EXTENT_CLEAR_UNLOCK_PAGE |
1379                              EXTENT_CLEAR_UNLOCK |
1380                              EXTENT_CLEAR_DELALLOC |
1381                              EXTENT_CLEAR_DIRTY |
1382                              EXTENT_SET_WRITEBACK |
1383                              EXTENT_END_WRITEBACK);
1384
1385         btrfs_free_path(path);
1386         return ret;
1387 }
1388
1389 /*
1390  * extent_io.c call back to do delayed allocation processing
1391  */
1392 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1393                               u64 start, u64 end, int *page_started,
1394                               unsigned long *nr_written)
1395 {
1396         int ret;
1397         struct btrfs_root *root = BTRFS_I(inode)->root;
1398
1399         if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) {
1400                 ret = run_delalloc_nocow(inode, locked_page, start, end,
1401                                          page_started, 1, nr_written);
1402         } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC) {
1403                 ret = run_delalloc_nocow(inode, locked_page, start, end,
1404                                          page_started, 0, nr_written);
1405         } else if (!btrfs_test_opt(root, COMPRESS) &&
1406                    !(BTRFS_I(inode)->force_compress) &&
1407                    !(BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS)) {
1408                 ret = cow_file_range(inode, locked_page, start, end,
1409                                       page_started, nr_written, 1);
1410         } else {
1411                 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1412                         &BTRFS_I(inode)->runtime_flags);
1413                 ret = cow_file_range_async(inode, locked_page, start, end,
1414                                            page_started, nr_written);
1415         }
1416         return ret;
1417 }
1418
1419 static void btrfs_split_extent_hook(struct inode *inode,
1420                                     struct extent_state *orig, u64 split)
1421 {
1422         /* not delalloc, ignore it */
1423         if (!(orig->state & EXTENT_DELALLOC))
1424                 return;
1425
1426         spin_lock(&BTRFS_I(inode)->lock);
1427         BTRFS_I(inode)->outstanding_extents++;
1428         spin_unlock(&BTRFS_I(inode)->lock);
1429 }
1430
1431 /*
1432  * extent_io.c merge_extent_hook, used to track merged delayed allocation
1433  * extents so we can keep track of new extents that are just merged onto old
1434  * extents, such as when we are doing sequential writes, so we can properly
1435  * account for the metadata space we'll need.
1436  */
1437 static void btrfs_merge_extent_hook(struct inode *inode,
1438                                     struct extent_state *new,
1439                                     struct extent_state *other)
1440 {
1441         /* not delalloc, ignore it */
1442         if (!(other->state & EXTENT_DELALLOC))
1443                 return;
1444
1445         spin_lock(&BTRFS_I(inode)->lock);
1446         BTRFS_I(inode)->outstanding_extents--;
1447         spin_unlock(&BTRFS_I(inode)->lock);
1448 }
1449
1450 /*
1451  * extent_io.c set_bit_hook, used to track delayed allocation
1452  * bytes in this file, and to maintain the list of inodes that
1453  * have pending delalloc work to be done.
1454  */
1455 static void btrfs_set_bit_hook(struct inode *inode,
1456                                struct extent_state *state, int *bits)
1457 {
1458
1459         /*
1460          * set_bit and clear bit hooks normally require _irqsave/restore
1461          * but in this case, we are only testing for the DELALLOC
1462          * bit, which is only set or cleared with irqs on
1463          */
1464         if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1465                 struct btrfs_root *root = BTRFS_I(inode)->root;
1466                 u64 len = state->end + 1 - state->start;
1467                 bool do_list = !btrfs_is_free_space_inode(inode);
1468
1469                 if (*bits & EXTENT_FIRST_DELALLOC) {
1470                         *bits &= ~EXTENT_FIRST_DELALLOC;
1471                 } else {
1472                         spin_lock(&BTRFS_I(inode)->lock);
1473                         BTRFS_I(inode)->outstanding_extents++;
1474                         spin_unlock(&BTRFS_I(inode)->lock);
1475                 }
1476
1477                 spin_lock(&root->fs_info->delalloc_lock);
1478                 BTRFS_I(inode)->delalloc_bytes += len;
1479                 root->fs_info->delalloc_bytes += len;
1480                 if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1481                         list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1482                                       &root->fs_info->delalloc_inodes);
1483                 }
1484                 spin_unlock(&root->fs_info->delalloc_lock);
1485         }
1486 }
1487
1488 /*
1489  * extent_io.c clear_bit_hook, see set_bit_hook for why
1490  */
1491 static void btrfs_clear_bit_hook(struct inode *inode,
1492                                  struct extent_state *state, int *bits)
1493 {
1494         /*
1495          * set_bit and clear bit hooks normally require _irqsave/restore
1496          * but in this case, we are only testing for the DELALLOC
1497          * bit, which is only set or cleared with irqs on
1498          */
1499         if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1500                 struct btrfs_root *root = BTRFS_I(inode)->root;
1501                 u64 len = state->end + 1 - state->start;
1502                 bool do_list = !btrfs_is_free_space_inode(inode);
1503
1504                 if (*bits & EXTENT_FIRST_DELALLOC) {
1505                         *bits &= ~EXTENT_FIRST_DELALLOC;
1506                 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1507                         spin_lock(&BTRFS_I(inode)->lock);
1508                         BTRFS_I(inode)->outstanding_extents--;
1509                         spin_unlock(&BTRFS_I(inode)->lock);
1510                 }
1511
1512                 if (*bits & EXTENT_DO_ACCOUNTING)
1513                         btrfs_delalloc_release_metadata(inode, len);
1514
1515                 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1516                     && do_list)
1517                         btrfs_free_reserved_data_space(inode, len);
1518
1519                 spin_lock(&root->fs_info->delalloc_lock);
1520                 root->fs_info->delalloc_bytes -= len;
1521                 BTRFS_I(inode)->delalloc_bytes -= len;
1522
1523                 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1524                     !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1525                         list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1526                 }
1527                 spin_unlock(&root->fs_info->delalloc_lock);
1528         }
1529 }
1530
1531 /*
1532  * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1533  * we don't create bios that span stripes or chunks
1534  */
1535 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1536                          size_t size, struct bio *bio,
1537                          unsigned long bio_flags)
1538 {
1539         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1540         struct btrfs_mapping_tree *map_tree;
1541         u64 logical = (u64)bio->bi_sector << 9;
1542         u64 length = 0;
1543         u64 map_length;
1544         int ret;
1545
1546         if (bio_flags & EXTENT_BIO_COMPRESSED)
1547                 return 0;
1548
1549         length = bio->bi_size;
1550         map_tree = &root->fs_info->mapping_tree;
1551         map_length = length;
1552         ret = btrfs_map_block(map_tree, READ, logical,
1553                               &map_length, NULL, 0);
1554         /* Will always return 0 or 1 with map_multi == NULL */
1555         BUG_ON(ret < 0);
1556         if (map_length < length + size)
1557                 return 1;
1558         return 0;
1559 }
1560
1561 /*
1562  * in order to insert checksums into the metadata in large chunks,
1563  * we wait until bio submission time.   All the pages in the bio are
1564  * checksummed and sums are attached onto the ordered extent record.
1565  *
1566  * At IO completion time the cums attached on the ordered extent record
1567  * are inserted into the btree
1568  */
1569 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1570                                     struct bio *bio, int mirror_num,
1571                                     unsigned long bio_flags,
1572                                     u64 bio_offset)
1573 {
1574         struct btrfs_root *root = BTRFS_I(inode)->root;
1575         int ret = 0;
1576
1577         ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1578         BUG_ON(ret); /* -ENOMEM */
1579         return 0;
1580 }
1581
1582 /*
1583  * in order to insert checksums into the metadata in large chunks,
1584  * we wait until bio submission time.   All the pages in the bio are
1585  * checksummed and sums are attached onto the ordered extent record.
1586  *
1587  * At IO completion time the cums attached on the ordered extent record
1588  * are inserted into the btree
1589  */
1590 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1591                           int mirror_num, unsigned long bio_flags,
1592                           u64 bio_offset)
1593 {
1594         struct btrfs_root *root = BTRFS_I(inode)->root;
1595         return btrfs_map_bio(root, rw, bio, mirror_num, 1);
1596 }
1597
1598 /*
1599  * extent_io.c submission hook. This does the right thing for csum calculation
1600  * on write, or reading the csums from the tree before a read
1601  */
1602 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1603                           int mirror_num, unsigned long bio_flags,
1604                           u64 bio_offset)
1605 {
1606         struct btrfs_root *root = BTRFS_I(inode)->root;
1607         int ret = 0;
1608         int skip_sum;
1609         int metadata = 0;
1610
1611         skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1612
1613         if (btrfs_is_free_space_inode(inode))
1614                 metadata = 2;
1615
1616         if (!(rw & REQ_WRITE)) {
1617                 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1618                 if (ret)
1619                         return ret;
1620
1621                 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1622                         return btrfs_submit_compressed_read(inode, bio,
1623                                                     mirror_num, bio_flags);
1624                 } else if (!skip_sum) {
1625                         ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1626                         if (ret)
1627                                 return ret;
1628                 }
1629                 goto mapit;
1630         } else if (!skip_sum) {
1631                 /* csum items have already been cloned */
1632                 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1633                         goto mapit;
1634                 /* we're doing a write, do the async checksumming */
1635                 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1636                                    inode, rw, bio, mirror_num,
1637                                    bio_flags, bio_offset,
1638                                    __btrfs_submit_bio_start,
1639                                    __btrfs_submit_bio_done);
1640         }
1641
1642 mapit:
1643         return btrfs_map_bio(root, rw, bio, mirror_num, 0);
1644 }
1645
1646 /*
1647  * given a list of ordered sums record them in the inode.  This happens
1648  * at IO completion time based on sums calculated at bio submission time.
1649  */
1650 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1651                              struct inode *inode, u64 file_offset,
1652                              struct list_head *list)
1653 {
1654         struct btrfs_ordered_sum *sum;
1655
1656         list_for_each_entry(sum, list, list) {
1657                 btrfs_csum_file_blocks(trans,
1658                        BTRFS_I(inode)->root->fs_info->csum_root, sum);
1659         }
1660         return 0;
1661 }
1662
1663 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1664                               struct extent_state **cached_state)
1665 {
1666         if ((end & (PAGE_CACHE_SIZE - 1)) == 0)
1667                 WARN_ON(1);
1668         return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1669                                    cached_state, GFP_NOFS);
1670 }
1671
1672 /* see btrfs_writepage_start_hook for details on why this is required */
1673 struct btrfs_writepage_fixup {
1674         struct page *page;
1675         struct btrfs_work work;
1676 };
1677
1678 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1679 {
1680         struct btrfs_writepage_fixup *fixup;
1681         struct btrfs_ordered_extent *ordered;
1682         struct extent_state *cached_state = NULL;
1683         struct page *page;
1684         struct inode *inode;
1685         u64 page_start;
1686         u64 page_end;
1687         int ret;
1688
1689         fixup = container_of(work, struct btrfs_writepage_fixup, work);
1690         page = fixup->page;
1691 again:
1692         lock_page(page);
1693         if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1694                 ClearPageChecked(page);
1695                 goto out_page;
1696         }
1697
1698         inode = page->mapping->host;
1699         page_start = page_offset(page);
1700         page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1701
1702         lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1703                          &cached_state);
1704
1705         /* already ordered? We're done */
1706         if (PagePrivate2(page))
1707                 goto out;
1708
1709         ordered = btrfs_lookup_ordered_extent(inode, page_start);
1710         if (ordered) {
1711                 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1712                                      page_end, &cached_state, GFP_NOFS);
1713                 unlock_page(page);
1714                 btrfs_start_ordered_extent(inode, ordered, 1);
1715                 btrfs_put_ordered_extent(ordered);
1716                 goto again;
1717         }
1718
1719         ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1720         if (ret) {
1721                 mapping_set_error(page->mapping, ret);
1722                 end_extent_writepage(page, ret, page_start, page_end);
1723                 ClearPageChecked(page);
1724                 goto out;
1725          }
1726
1727         btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1728         ClearPageChecked(page);
1729         set_page_dirty(page);
1730 out:
1731         unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
1732                              &cached_state, GFP_NOFS);
1733 out_page:
1734         unlock_page(page);
1735         page_cache_release(page);
1736         kfree(fixup);
1737 }
1738
1739 /*
1740  * There are a few paths in the higher layers of the kernel that directly
1741  * set the page dirty bit without asking the filesystem if it is a
1742  * good idea.  This causes problems because we want to make sure COW
1743  * properly happens and the data=ordered rules are followed.
1744  *
1745  * In our case any range that doesn't have the ORDERED bit set
1746  * hasn't been properly setup for IO.  We kick off an async process
1747  * to fix it up.  The async helper will wait for ordered extents, set
1748  * the delalloc bit and make it safe to write the page.
1749  */
1750 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1751 {
1752         struct inode *inode = page->mapping->host;
1753         struct btrfs_writepage_fixup *fixup;
1754         struct btrfs_root *root = BTRFS_I(inode)->root;
1755
1756         /* this page is properly in the ordered list */
1757         if (TestClearPagePrivate2(page))
1758                 return 0;
1759
1760         if (PageChecked(page))
1761                 return -EAGAIN;
1762
1763         fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
1764         if (!fixup)
1765                 return -EAGAIN;
1766
1767         SetPageChecked(page);
1768         page_cache_get(page);
1769         fixup->work.func = btrfs_writepage_fixup_worker;
1770         fixup->page = page;
1771         btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
1772         return -EBUSY;
1773 }
1774
1775 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
1776                                        struct inode *inode, u64 file_pos,
1777                                        u64 disk_bytenr, u64 disk_num_bytes,
1778                                        u64 num_bytes, u64 ram_bytes,
1779                                        u8 compression, u8 encryption,
1780                                        u16 other_encoding, int extent_type)
1781 {
1782         struct btrfs_root *root = BTRFS_I(inode)->root;
1783         struct btrfs_file_extent_item *fi;
1784         struct btrfs_path *path;
1785         struct extent_buffer *leaf;
1786         struct btrfs_key ins;
1787         u64 hint;
1788         int ret;
1789
1790         path = btrfs_alloc_path();
1791         if (!path)
1792                 return -ENOMEM;
1793
1794         path->leave_spinning = 1;
1795
1796         /*
1797          * we may be replacing one extent in the tree with another.
1798          * The new extent is pinned in the extent map, and we don't want
1799          * to drop it from the cache until it is completely in the btree.
1800          *
1801          * So, tell btrfs_drop_extents to leave this extent in the cache.
1802          * the caller is expected to unpin it and allow it to be merged
1803          * with the others.
1804          */
1805         ret = btrfs_drop_extents(trans, inode, file_pos, file_pos + num_bytes,
1806                                  &hint, 0);
1807         if (ret)
1808                 goto out;
1809
1810         ins.objectid = btrfs_ino(inode);
1811         ins.offset = file_pos;
1812         ins.type = BTRFS_EXTENT_DATA_KEY;
1813         ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
1814         if (ret)
1815                 goto out;
1816         leaf = path->nodes[0];
1817         fi = btrfs_item_ptr(leaf, path->slots[0],
1818                             struct btrfs_file_extent_item);
1819         btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1820         btrfs_set_file_extent_type(leaf, fi, extent_type);
1821         btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
1822         btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
1823         btrfs_set_file_extent_offset(leaf, fi, 0);
1824         btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1825         btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
1826         btrfs_set_file_extent_compression(leaf, fi, compression);
1827         btrfs_set_file_extent_encryption(leaf, fi, encryption);
1828         btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1829
1830         btrfs_unlock_up_safe(path, 1);
1831         btrfs_set_lock_blocking(leaf);
1832
1833         btrfs_mark_buffer_dirty(leaf);
1834
1835         inode_add_bytes(inode, num_bytes);
1836
1837         ins.objectid = disk_bytenr;
1838         ins.offset = disk_num_bytes;
1839         ins.type = BTRFS_EXTENT_ITEM_KEY;
1840         ret = btrfs_alloc_reserved_file_extent(trans, root,
1841                                         root->root_key.objectid,
1842                                         btrfs_ino(inode), file_pos, &ins);
1843 out:
1844         btrfs_free_path(path);
1845
1846         return ret;
1847 }
1848
1849 /*
1850  * helper function for btrfs_finish_ordered_io, this
1851  * just reads in some of the csum leaves to prime them into ram
1852  * before we start the transaction.  It limits the amount of btree
1853  * reads required while inside the transaction.
1854  */
1855 /* as ordered data IO finishes, this gets called so we can finish
1856  * an ordered extent if the range of bytes in the file it covers are
1857  * fully written.
1858  */
1859 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
1860 {
1861         struct inode *inode = ordered_extent->inode;
1862         struct btrfs_root *root = BTRFS_I(inode)->root;
1863         struct btrfs_trans_handle *trans = NULL;
1864         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1865         struct extent_state *cached_state = NULL;
1866         int compress_type = 0;
1867         int ret;
1868         bool nolock;
1869
1870         nolock = btrfs_is_free_space_inode(inode);
1871
1872         if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
1873                 ret = -EIO;
1874                 goto out;
1875         }
1876
1877         if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
1878                 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
1879                 ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1880                 if (!ret) {
1881                         if (nolock)
1882                                 trans = btrfs_join_transaction_nolock(root);
1883                         else
1884                                 trans = btrfs_join_transaction(root);
1885                         if (IS_ERR(trans))
1886                                 return PTR_ERR(trans);
1887                         trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1888                         ret = btrfs_update_inode_fallback(trans, root, inode);
1889                         if (ret) /* -ENOMEM or corruption */
1890                                 btrfs_abort_transaction(trans, root, ret);
1891                 }
1892                 goto out;
1893         }
1894
1895         lock_extent_bits(io_tree, ordered_extent->file_offset,
1896                          ordered_extent->file_offset + ordered_extent->len - 1,
1897                          0, &cached_state);
1898
1899         if (nolock)
1900                 trans = btrfs_join_transaction_nolock(root);
1901         else
1902                 trans = btrfs_join_transaction(root);
1903         if (IS_ERR(trans)) {
1904                 ret = PTR_ERR(trans);
1905                 trans = NULL;
1906                 goto out_unlock;
1907         }
1908         trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1909
1910         if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
1911                 compress_type = ordered_extent->compress_type;
1912         if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1913                 BUG_ON(compress_type);
1914                 ret = btrfs_mark_extent_written(trans, inode,
1915                                                 ordered_extent->file_offset,
1916                                                 ordered_extent->file_offset +
1917                                                 ordered_extent->len);
1918         } else {
1919                 BUG_ON(root == root->fs_info->tree_root);
1920                 ret = insert_reserved_file_extent(trans, inode,
1921                                                 ordered_extent->file_offset,
1922                                                 ordered_extent->start,
1923                                                 ordered_extent->disk_len,
1924                                                 ordered_extent->len,
1925                                                 ordered_extent->len,
1926                                                 compress_type, 0, 0,
1927                                                 BTRFS_FILE_EXTENT_REG);
1928                 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
1929                                    ordered_extent->file_offset,
1930                                    ordered_extent->len);
1931         }
1932
1933         if (ret < 0) {
1934                 btrfs_abort_transaction(trans, root, ret);
1935                 goto out_unlock;
1936         }
1937
1938         add_pending_csums(trans, inode, ordered_extent->file_offset,
1939                           &ordered_extent->list);
1940
1941         ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
1942         if (!ret || !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1943                 ret = btrfs_update_inode_fallback(trans, root, inode);
1944                 if (ret) { /* -ENOMEM or corruption */
1945                         btrfs_abort_transaction(trans, root, ret);
1946                         goto out_unlock;
1947                 }
1948         }
1949         ret = 0;
1950 out_unlock:
1951         unlock_extent_cached(io_tree, ordered_extent->file_offset,
1952                              ordered_extent->file_offset +
1953                              ordered_extent->len - 1, &cached_state, GFP_NOFS);
1954 out:
1955         if (root != root->fs_info->tree_root)
1956                 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
1957         if (trans) {
1958                 if (nolock)
1959                         btrfs_end_transaction_nolock(trans, root);
1960                 else
1961                         btrfs_end_transaction(trans, root);
1962         }
1963
1964         if (ret)
1965                 clear_extent_uptodate(io_tree, ordered_extent->file_offset,
1966                                       ordered_extent->file_offset +
1967                                       ordered_extent->len - 1, NULL, GFP_NOFS);
1968
1969         /*
1970          * This needs to be dont to make sure anybody waiting knows we are done
1971          * upating everything for this ordered extent.
1972          */
1973         btrfs_remove_ordered_extent(inode, ordered_extent);
1974
1975         /* once for us */
1976         btrfs_put_ordered_extent(ordered_extent);
1977         /* once for the tree */
1978         btrfs_put_ordered_extent(ordered_extent);
1979
1980         return ret;
1981 }
1982
1983 static void finish_ordered_fn(struct btrfs_work *work)
1984 {
1985         struct btrfs_ordered_extent *ordered_extent;
1986         ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
1987         btrfs_finish_ordered_io(ordered_extent);
1988 }
1989
1990 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
1991                                 struct extent_state *state, int uptodate)
1992 {
1993         struct inode *inode = page->mapping->host;
1994         struct btrfs_root *root = BTRFS_I(inode)->root;
1995         struct btrfs_ordered_extent *ordered_extent = NULL;
1996         struct btrfs_workers *workers;
1997
1998         trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
1999
2000         ClearPagePrivate2(page);
2001         if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2002                                             end - start + 1, uptodate))
2003                 return 0;
2004
2005         ordered_extent->work.func = finish_ordered_fn;
2006         ordered_extent->work.flags = 0;
2007
2008         if (btrfs_is_free_space_inode(inode))
2009                 workers = &root->fs_info->endio_freespace_worker;
2010         else
2011                 workers = &root->fs_info->endio_write_workers;
2012         btrfs_queue_worker(workers, &ordered_extent->work);
2013
2014         return 0;
2015 }
2016
2017 /*
2018  * when reads are done, we need to check csums to verify the data is correct
2019  * if there's a match, we allow the bio to finish.  If not, the code in
2020  * extent_io.c will try to find good copies for us.
2021  */
2022 static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
2023                                struct extent_state *state, int mirror)
2024 {
2025         size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
2026         struct inode *inode = page->mapping->host;
2027         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2028         char *kaddr;
2029         u64 private = ~(u32)0;
2030         int ret;
2031         struct btrfs_root *root = BTRFS_I(inode)->root;
2032         u32 csum = ~(u32)0;
2033
2034         if (PageChecked(page)) {
2035                 ClearPageChecked(page);
2036                 goto good;
2037         }
2038
2039         if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
2040                 goto good;
2041
2042         if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
2043             test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
2044                 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
2045                                   GFP_NOFS);
2046                 return 0;
2047         }
2048
2049         if (state && state->start == start) {
2050                 private = state->private;
2051                 ret = 0;
2052         } else {
2053                 ret = get_state_private(io_tree, start, &private);
2054         }
2055         kaddr = kmap_atomic(page);
2056         if (ret)
2057                 goto zeroit;
2058
2059         csum = btrfs_csum_data(root, kaddr + offset, csum,  end - start + 1);
2060         btrfs_csum_final(csum, (char *)&csum);
2061         if (csum != private)
2062                 goto zeroit;
2063
2064         kunmap_atomic(kaddr);
2065 good:
2066         return 0;
2067
2068 zeroit:
2069         printk_ratelimited(KERN_INFO "btrfs csum failed ino %llu off %llu csum %u "
2070                        "private %llu\n",
2071                        (unsigned long long)btrfs_ino(page->mapping->host),
2072                        (unsigned long long)start, csum,
2073                        (unsigned long long)private);
2074         memset(kaddr + offset, 1, end - start + 1);
2075         flush_dcache_page(page);
2076         kunmap_atomic(kaddr);
2077         if (private == 0)
2078                 return 0;
2079         return -EIO;
2080 }
2081
2082 struct delayed_iput {
2083         struct list_head list;
2084         struct inode *inode;
2085 };
2086
2087 /* JDM: If this is fs-wide, why can't we add a pointer to
2088  * btrfs_inode instead and avoid the allocation? */
2089 void btrfs_add_delayed_iput(struct inode *inode)
2090 {
2091         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2092         struct delayed_iput *delayed;
2093
2094         if (atomic_add_unless(&inode->i_count, -1, 1))
2095                 return;
2096
2097         delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
2098         delayed->inode = inode;
2099
2100         spin_lock(&fs_info->delayed_iput_lock);
2101         list_add_tail(&delayed->list, &fs_info->delayed_iputs);
2102         spin_unlock(&fs_info->delayed_iput_lock);
2103 }
2104
2105 void btrfs_run_delayed_iputs(struct btrfs_root *root)
2106 {
2107         LIST_HEAD(list);
2108         struct btrfs_fs_info *fs_info = root->fs_info;
2109         struct delayed_iput *delayed;
2110         int empty;
2111
2112         spin_lock(&fs_info->delayed_iput_lock);
2113         empty = list_empty(&fs_info->delayed_iputs);
2114         spin_unlock(&fs_info->delayed_iput_lock);
2115         if (empty)
2116                 return;
2117
2118         down_read(&root->fs_info->cleanup_work_sem);
2119         spin_lock(&fs_info->delayed_iput_lock);
2120         list_splice_init(&fs_info->delayed_iputs, &list);
2121         spin_unlock(&fs_info->delayed_iput_lock);
2122
2123         while (!list_empty(&list)) {
2124                 delayed = list_entry(list.next, struct delayed_iput, list);
2125                 list_del(&delayed->list);
2126                 iput(delayed->inode);
2127                 kfree(delayed);
2128         }
2129         up_read(&root->fs_info->cleanup_work_sem);
2130 }
2131
2132 enum btrfs_orphan_cleanup_state {
2133         ORPHAN_CLEANUP_STARTED  = 1,
2134         ORPHAN_CLEANUP_DONE     = 2,
2135 };
2136
2137 /*
2138  * This is called in transaction commit time. If there are no orphan
2139  * files in the subvolume, it removes orphan item and frees block_rsv
2140  * structure.
2141  */
2142 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
2143                               struct btrfs_root *root)
2144 {
2145         struct btrfs_block_rsv *block_rsv;
2146         int ret;
2147
2148         if (atomic_read(&root->orphan_inodes) ||
2149             root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
2150                 return;
2151
2152         spin_lock(&root->orphan_lock);
2153         if (atomic_read(&root->orphan_inodes)) {
2154                 spin_unlock(&root->orphan_lock);
2155                 return;
2156         }
2157
2158         if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
2159                 spin_unlock(&root->orphan_lock);
2160                 return;
2161         }
2162
2163         block_rsv = root->orphan_block_rsv;
2164         root->orphan_block_rsv = NULL;
2165         spin_unlock(&root->orphan_lock);
2166
2167         if (root->orphan_item_inserted &&
2168             btrfs_root_refs(&root->root_item) > 0) {
2169                 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
2170                                             root->root_key.objectid);
2171                 BUG_ON(ret);
2172                 root->orphan_item_inserted = 0;
2173         }
2174
2175         if (block_rsv) {
2176                 WARN_ON(block_rsv->size > 0);
2177                 btrfs_free_block_rsv(root, block_rsv);
2178         }
2179 }
2180
2181 /*
2182  * This creates an orphan entry for the given inode in case something goes
2183  * wrong in the middle of an unlink/truncate.
2184  *
2185  * NOTE: caller of this function should reserve 5 units of metadata for
2186  *       this function.
2187  */
2188 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
2189 {
2190         struct btrfs_root *root = BTRFS_I(inode)->root;
2191         struct btrfs_block_rsv *block_rsv = NULL;
2192         int reserve = 0;
2193         int insert = 0;
2194         int ret;
2195
2196         if (!root->orphan_block_rsv) {
2197                 block_rsv = btrfs_alloc_block_rsv(root);
2198                 if (!block_rsv)
2199                         return -ENOMEM;
2200         }
2201
2202         spin_lock(&root->orphan_lock);
2203         if (!root->orphan_block_rsv) {
2204                 root->orphan_block_rsv = block_rsv;
2205         } else if (block_rsv) {
2206                 btrfs_free_block_rsv(root, block_rsv);
2207                 block_rsv = NULL;
2208         }
2209
2210         if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2211                               &BTRFS_I(inode)->runtime_flags)) {
2212 #if 0
2213                 /*
2214                  * For proper ENOSPC handling, we should do orphan
2215                  * cleanup when mounting. But this introduces backward
2216                  * compatibility issue.
2217                  */
2218                 if (!xchg(&root->orphan_item_inserted, 1))
2219                         insert = 2;
2220                 else
2221                         insert = 1;
2222 #endif
2223                 insert = 1;
2224                 atomic_dec(&root->orphan_inodes);
2225         }
2226
2227         if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2228                               &BTRFS_I(inode)->runtime_flags))
2229                 reserve = 1;
2230         spin_unlock(&root->orphan_lock);
2231
2232         /* grab metadata reservation from transaction handle */
2233         if (reserve) {
2234                 ret = btrfs_orphan_reserve_metadata(trans, inode);
2235                 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
2236         }
2237
2238         /* insert an orphan item to track this unlinked/truncated file */
2239         if (insert >= 1) {
2240                 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
2241                 if (ret && ret != -EEXIST) {
2242                         clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2243                                   &BTRFS_I(inode)->runtime_flags);
2244                         btrfs_abort_transaction(trans, root, ret);
2245                         return ret;
2246                 }
2247                 ret = 0;
2248         }
2249
2250         /* insert an orphan item to track subvolume contains orphan files */
2251         if (insert >= 2) {
2252                 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
2253                                                root->root_key.objectid);
2254                 if (ret && ret != -EEXIST) {
2255                         btrfs_abort_transaction(trans, root, ret);
2256                         return ret;
2257                 }
2258         }
2259         return 0;
2260 }
2261
2262 /*
2263  * We have done the truncate/delete so we can go ahead and remove the orphan
2264  * item for this particular inode.
2265  */
2266 int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
2267 {
2268         struct btrfs_root *root = BTRFS_I(inode)->root;
2269         int delete_item = 0;
2270         int release_rsv = 0;
2271         int ret = 0;
2272
2273         spin_lock(&root->orphan_lock);
2274         if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2275                                &BTRFS_I(inode)->runtime_flags))
2276                 delete_item = 1;
2277
2278         if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
2279                                &BTRFS_I(inode)->runtime_flags))
2280                 release_rsv = 1;
2281         spin_unlock(&root->orphan_lock);
2282
2283         if (trans && delete_item) {
2284                 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
2285                 BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
2286         }
2287
2288         if (release_rsv) {
2289                 btrfs_orphan_release_metadata(inode);
2290                 atomic_dec(&root->orphan_inodes);
2291         }
2292
2293         return 0;
2294 }
2295
2296 /*
2297  * this cleans up any orphans that may be left on the list from the last use
2298  * of this root.
2299  */
2300 int btrfs_orphan_cleanup(struct btrfs_root *root)
2301 {
2302         struct btrfs_path *path;
2303         struct extent_buffer *leaf;
2304         struct btrfs_key key, found_key;
2305         struct btrfs_trans_handle *trans;
2306         struct inode *inode;
2307         u64 last_objectid = 0;
2308         int ret = 0, nr_unlink = 0, nr_truncate = 0;
2309
2310         if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
2311                 return 0;
2312
2313         path = btrfs_alloc_path();
2314         if (!path) {
2315                 ret = -ENOMEM;
2316                 goto out;
2317         }
2318         path->reada = -1;
2319
2320         key.objectid = BTRFS_ORPHAN_OBJECTID;
2321         btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
2322         key.offset = (u64)-1;
2323
2324         while (1) {
2325                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2326                 if (ret < 0)
2327                         goto out;
2328
2329                 /*
2330                  * if ret == 0 means we found what we were searching for, which
2331                  * is weird, but possible, so only screw with path if we didn't
2332                  * find the key and see if we have stuff that matches
2333                  */
2334                 if (ret > 0) {
2335                         ret = 0;
2336                         if (path->slots[0] == 0)
2337                                 break;
2338                         path->slots[0]--;
2339                 }
2340
2341                 /* pull out the item */
2342                 leaf = path->nodes[0];
2343                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2344
2345                 /* make sure the item matches what we want */
2346                 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
2347                         break;
2348                 if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
2349                         break;
2350
2351                 /* release the path since we're done with it */
2352                 btrfs_release_path(path);
2353
2354                 /*
2355                  * this is where we are basically btrfs_lookup, without the
2356                  * crossing root thing.  we store the inode number in the
2357                  * offset of the orphan item.
2358                  */
2359
2360                 if (found_key.offset == last_objectid) {
2361                         printk(KERN_ERR "btrfs: Error removing orphan entry, "
2362                                "stopping orphan cleanup\n");
2363                         ret = -EINVAL;
2364                         goto out;
2365                 }
2366
2367                 last_objectid = found_key.offset;
2368
2369                 found_key.objectid = found_key.offset;
2370                 found_key.type = BTRFS_INODE_ITEM_KEY;
2371                 found_key.offset = 0;
2372                 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
2373                 ret = PTR_RET(inode);
2374                 if (ret && ret != -ESTALE)
2375                         goto out;
2376
2377                 if (ret == -ESTALE && root == root->fs_info->tree_root) {
2378                         struct btrfs_root *dead_root;
2379                         struct btrfs_fs_info *fs_info = root->fs_info;
2380                         int is_dead_root = 0;
2381
2382                         /*
2383                          * this is an orphan in the tree root. Currently these
2384                          * could come from 2 sources:
2385                          *  a) a snapshot deletion in progress
2386                          *  b) a free space cache inode
2387                          * We need to distinguish those two, as the snapshot
2388                          * orphan must not get deleted.
2389                          * find_dead_roots already ran before us, so if this
2390                          * is a snapshot deletion, we should find the root
2391                          * in the dead_roots list
2392                          */
2393                         spin_lock(&fs_info->trans_lock);
2394                         list_for_each_entry(dead_root, &fs_info->dead_roots,
2395                                             root_list) {
2396                                 if (dead_root->root_key.objectid ==
2397                                     found_key.objectid) {
2398                                         is_dead_root = 1;
2399                                         break;
2400                                 }
2401                         }
2402                         spin_unlock(&fs_info->trans_lock);
2403                         if (is_dead_root) {
2404                                 /* prevent this orphan from being found again */
2405                                 key.offset = found_key.objectid - 1;
2406                                 continue;
2407                         }
2408                 }
2409                 /*
2410                  * Inode is already gone but the orphan item is still there,
2411                  * kill the orphan item.
2412                  */
2413                 if (ret == -ESTALE) {
2414                         trans = btrfs_start_transaction(root, 1);
2415                         if (IS_ERR(trans)) {
2416                                 ret = PTR_ERR(trans);
2417                                 goto out;
2418                         }
2419                         printk(KERN_ERR "auto deleting %Lu\n",
2420                                found_key.objectid);
2421                         ret = btrfs_del_orphan_item(trans, root,
2422                                                     found_key.objectid);
2423                         BUG_ON(ret); /* -ENOMEM or corruption (JDM: Recheck) */
2424                         btrfs_end_transaction(trans, root);
2425                         continue;
2426                 }
2427
2428                 /*
2429                  * add this inode to the orphan list so btrfs_orphan_del does
2430                  * the proper thing when we hit it
2431                  */
2432                 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
2433                         &BTRFS_I(inode)->runtime_flags);
2434
2435                 /* if we have links, this was a truncate, lets do that */
2436                 if (inode->i_nlink) {
2437                         if (!S_ISREG(inode->i_mode)) {
2438                                 WARN_ON(1);
2439                                 iput(inode);
2440                                 continue;
2441                         }
2442                         nr_truncate++;
2443                         ret = btrfs_truncate(inode);
2444                 } else {
2445                         nr_unlink++;
2446                 }
2447
2448                 /* this will do delete_inode and everything for us */
2449                 iput(inode);
2450                 if (ret)
2451                         goto out;
2452         }
2453         /* release the path since we're done with it */
2454         btrfs_release_path(path);
2455
2456         root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
2457
2458         if (root->orphan_block_rsv)
2459                 btrfs_block_rsv_release(root, root->orphan_block_rsv,
2460                                         (u64)-1);
2461
2462         if (root->orphan_block_rsv || root->orphan_item_inserted) {
2463                 trans = btrfs_join_transaction(root);
2464                 if (!IS_ERR(trans))
2465                         btrfs_end_transaction(trans, root);
2466         }
2467
2468         if (nr_unlink)
2469                 printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
2470         if (nr_truncate)
2471                 printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
2472
2473 out:
2474         if (ret)
2475                 printk(KERN_CRIT "btrfs: could not do orphan cleanup %d\n", ret);
2476         btrfs_free_path(path);
2477         return ret;
2478 }
2479
2480 /*
2481  * very simple check to peek ahead in the leaf looking for xattrs.  If we
2482  * don't find any xattrs, we know there can't be any acls.
2483  *
2484  * slot is the slot the inode is in, objectid is the objectid of the inode
2485  */
2486 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
2487                                           int slot, u64 objectid)
2488 {
2489         u32 nritems = btrfs_header_nritems(leaf);
2490         struct btrfs_key found_key;
2491         int scanned = 0;
2492
2493         slot++;
2494         while (slot < nritems) {
2495                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
2496
2497                 /* we found a different objectid, there must not be acls */
2498                 if (found_key.objectid != objectid)
2499                         return 0;
2500
2501                 /* we found an xattr, assume we've got an acl */
2502                 if (found_key.type == BTRFS_XATTR_ITEM_KEY)
2503                         return 1;
2504
2505                 /*
2506                  * we found a key greater than an xattr key, there can't
2507                  * be any acls later on
2508                  */
2509                 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
2510                         return 0;
2511
2512                 slot++;
2513                 scanned++;
2514
2515                 /*
2516                  * it goes inode, inode backrefs, xattrs, extents,
2517                  * so if there are a ton of hard links to an inode there can
2518                  * be a lot of backrefs.  Don't waste time searching too hard,
2519                  * this is just an optimization
2520                  */
2521                 if (scanned >= 8)
2522                         break;
2523         }
2524         /* we hit the end of the leaf before we found an xattr or
2525          * something larger than an xattr.  We have to assume the inode
2526          * has acls
2527          */
2528         return 1;
2529 }
2530
2531 /*
2532  * read an inode from the btree into the in-memory inode
2533  */
2534 static void btrfs_read_locked_inode(struct inode *inode)
2535 {
2536         struct btrfs_path *path;
2537         struct extent_buffer *leaf;
2538         struct btrfs_inode_item *inode_item;
2539         struct btrfs_timespec *tspec;
2540         struct btrfs_root *root = BTRFS_I(inode)->root;
2541         struct btrfs_key location;
2542         int maybe_acls;
2543         u32 rdev;
2544         int ret;
2545         bool filled = false;
2546
2547         ret = btrfs_fill_inode(inode, &rdev);
2548         if (!ret)
2549                 filled = true;
2550
2551         path = btrfs_alloc_path();
2552         if (!path)
2553                 goto make_bad;
2554
2555         path->leave_spinning = 1;
2556         memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
2557
2558         ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
2559         if (ret)
2560                 goto make_bad;
2561
2562         leaf = path->nodes[0];
2563
2564         if (filled)
2565                 goto cache_acl;
2566
2567         inode_item = btrfs_item_ptr(leaf, path->slots[0],
2568                                     struct btrfs_inode_item);
2569         inode->i_mode = btrfs_inode_mode(leaf, inode_item);
2570         set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
2571         inode->i_uid = btrfs_inode_uid(leaf, inode_item);
2572         inode->i_gid = btrfs_inode_gid(leaf, inode_item);
2573         btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
2574
2575         tspec = btrfs_inode_atime(inode_item);
2576         inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2577         inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2578
2579         tspec = btrfs_inode_mtime(inode_item);
2580         inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2581         inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2582
2583         tspec = btrfs_inode_ctime(inode_item);
2584         inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
2585         inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);
2586
2587         inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
2588         BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
2589         inode->i_version = btrfs_inode_sequence(leaf, inode_item);
2590         inode->i_generation = BTRFS_I(inode)->generation;
2591         inode->i_rdev = 0;
2592         rdev = btrfs_inode_rdev(leaf, inode_item);
2593
2594         BTRFS_I(inode)->index_cnt = (u64)-1;
2595         BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
2596 cache_acl:
2597         /*
2598          * try to precache a NULL acl entry for files that don't have
2599          * any xattrs or acls
2600          */
2601         maybe_acls = acls_after_inode_item(leaf, path->slots[0],
2602                                            btrfs_ino(inode));
2603         if (!maybe_acls)
2604                 cache_no_acl(inode);
2605
2606         btrfs_free_path(path);
2607
2608         switch (inode->i_mode & S_IFMT) {
2609         case S_IFREG:
2610                 inode->i_mapping->a_ops = &btrfs_aops;
2611                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2612                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
2613                 inode->i_fop = &btrfs_file_operations;
2614                 inode->i_op = &btrfs_file_inode_operations;
2615                 break;
2616         case S_IFDIR:
2617                 inode->i_fop = &btrfs_dir_file_operations;
2618                 if (root == root->fs_info->tree_root)
2619                         inode->i_op = &btrfs_dir_ro_inode_operations;
2620                 else
2621                         inode->i_op = &btrfs_dir_inode_operations;
2622                 break;
2623         case S_IFLNK:
2624                 inode->i_op = &btrfs_symlink_inode_operations;
2625                 inode->i_mapping->a_ops = &btrfs_symlink_aops;
2626                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2627                 break;
2628         default:
2629                 inode->i_op = &btrfs_special_inode_operations;
2630                 init_special_inode(inode, inode->i_mode, rdev);
2631                 break;
2632         }
2633
2634         btrfs_update_iflags(inode);
2635         return;
2636
2637 make_bad:
2638         btrfs_free_path(path);
2639         make_bad_inode(inode);
2640 }
2641
2642 /*
2643  * given a leaf and an inode, copy the inode fields into the leaf
2644  */
2645 static void fill_inode_item(struct btrfs_trans_handle *trans,
2646                             struct extent_buffer *leaf,
2647                             struct btrfs_inode_item *item,
2648                             struct inode *inode)
2649 {
2650         btrfs_set_inode_uid(leaf, item, inode->i_uid);
2651         btrfs_set_inode_gid(leaf, item, inode->i_gid);
2652         btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
2653         btrfs_set_inode_mode(leaf, item, inode->i_mode);
2654         btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
2655
2656         btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
2657                                inode->i_atime.tv_sec);
2658         btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
2659                                 inode->i_atime.tv_nsec);
2660
2661         btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
2662                                inode->i_mtime.tv_sec);
2663         btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
2664                                 inode->i_mtime.tv_nsec);
2665
2666         btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
2667                                inode->i_ctime.tv_sec);
2668         btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
2669                                 inode->i_ctime.tv_nsec);
2670
2671         btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
2672         btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
2673         btrfs_set_inode_sequence(leaf, item, inode->i_version);
2674         btrfs_set_inode_transid(leaf, item, trans->transid);
2675         btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
2676         btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
2677         btrfs_set_inode_block_group(leaf, item, 0);
2678 }
2679
2680 /*
2681  * copy everything in the in-memory inode into the btree.
2682  */
2683 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
2684                                 struct btrfs_root *root, struct inode *inode)
2685 {
2686         struct btrfs_inode_item *inode_item;
2687         struct btrfs_path *path;
2688         struct extent_buffer *leaf;
2689         int ret;
2690
2691         path = btrfs_alloc_path();
2692         if (!path)
2693                 return -ENOMEM;
2694
2695         path->leave_spinning = 1;
2696         ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
2697                                  1);
2698         if (ret) {
2699                 if (ret > 0)
2700                         ret = -ENOENT;
2701                 goto failed;
2702         }
2703
2704         btrfs_unlock_up_safe(path, 1);
2705         leaf = path->nodes[0];
2706         inode_item = btrfs_item_ptr(leaf, path->slots[0],
2707                                     struct btrfs_inode_item);
2708
2709         fill_inode_item(trans, leaf, inode_item, inode);
2710         btrfs_mark_buffer_dirty(leaf);
2711         btrfs_set_inode_last_trans(trans, inode);
2712         ret = 0;
2713 failed:
2714         btrfs_free_path(path);
2715         return ret;
2716 }
2717
2718 /*
2719  * copy everything in the in-memory inode into the btree.
2720  */
2721 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
2722                                 struct btrfs_root *root, struct inode *inode)
2723 {
2724         int ret;
2725
2726         /*
2727          * If the inode is a free space inode, we can deadlock during commit
2728          * if we put it into the delayed code.
2729          *
2730          * The data relocation inode should also be directly updated
2731          * without delay
2732          */
2733         if (!btrfs_is_free_space_inode(inode)
2734             && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID) {
2735                 btrfs_update_root_times(trans, root);
2736
2737                 ret = btrfs_delayed_update_inode(trans, root, inode);
2738                 if (!ret)
2739                         btrfs_set_inode_last_trans(trans, inode);
2740                 return ret;
2741         }
2742
2743         return btrfs_update_inode_item(trans, root, inode);
2744 }
2745
2746 static noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
2747                                 struct btrfs_root *root, struct inode *inode)
2748 {
2749         int ret;
2750
2751         ret = btrfs_update_inode(trans, root, inode);
2752         if (ret == -ENOSPC)
2753                 return btrfs_update_inode_item(trans, root, inode);
2754         return ret;
2755 }
2756
2757 /*
2758  * unlink helper that gets used here in inode.c and in the tree logging
2759  * recovery code.  It remove a link in a directory with a given name, and
2760  * also drops the back refs in the inode to the directory
2761  */
2762 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2763                                 struct btrfs_root *root,
2764                                 struct inode *dir, struct inode *inode,
2765                                 const char *name, int name_len)
2766 {
2767         struct btrfs_path *path;
2768         int ret = 0;
2769         struct extent_buffer *leaf;
2770         struct btrfs_dir_item *di;
2771         struct btrfs_key key;
2772         u64 index;
2773         u64 ino = btrfs_ino(inode);
2774         u64 dir_ino = btrfs_ino(dir);
2775
2776         path = btrfs_alloc_path();
2777         if (!path) {
2778                 ret = -ENOMEM;
2779                 goto out;
2780         }
2781
2782         path->leave_spinning = 1;
2783         di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2784                                     name, name_len, -1);
2785         if (IS_ERR(di)) {
2786                 ret = PTR_ERR(di);
2787                 goto err;
2788         }
2789         if (!di) {
2790                 ret = -ENOENT;
2791                 goto err;
2792         }
2793         leaf = path->nodes[0];
2794         btrfs_dir_item_key_to_cpu(leaf, di, &key);
2795         ret = btrfs_delete_one_dir_name(trans, root, path, di);
2796         if (ret)
2797                 goto err;
2798         btrfs_release_path(path);
2799
2800         ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
2801                                   dir_ino, &index);
2802         if (ret) {
2803                 printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
2804                        "inode %llu parent %llu\n", name_len, name,
2805                        (unsigned long long)ino, (unsigned long long)dir_ino);
2806                 btrfs_abort_transaction(trans, root, ret);
2807                 goto err;
2808         }
2809
2810         ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
2811         if (ret) {
2812                 btrfs_abort_transaction(trans, root, ret);
2813                 goto err;
2814         }
2815
2816         ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
2817                                          inode, dir_ino);
2818         if (ret != 0 && ret != -ENOENT) {
2819                 btrfs_abort_transaction(trans, root, ret);
2820                 goto err;
2821         }
2822
2823         ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
2824                                            dir, index);
2825         if (ret == -ENOENT)
2826                 ret = 0;
2827 err:
2828         btrfs_free_path(path);
2829         if (ret)
2830                 goto out;
2831
2832         btrfs_i_size_write(dir, dir->i_size - name_len * 2);
2833         inode_inc_iversion(inode);
2834         inode_inc_iversion(dir);
2835         inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
2836         ret = btrfs_update_inode(trans, root, dir);
2837 out:
2838         return ret;
2839 }
2840
2841 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
2842                        struct btrfs_root *root,
2843                        struct inode *dir, struct inode *inode,
2844                        const char *name, int name_len)
2845 {
2846         int ret;
2847         ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
2848         if (!ret) {
2849                 btrfs_drop_nlink(inode);
2850                 ret = btrfs_update_inode(trans, root, inode);
2851         }
2852         return ret;
2853 }
2854
2855
2856 /* helper to check if there is any shared block in the path */
2857 static int check_path_shared(struct btrfs_root *root,
2858                              struct btrfs_path *path)
2859 {
2860         struct extent_buffer *eb;
2861         int level;
2862         u64 refs = 1;
2863
2864         for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2865                 int ret;
2866
2867                 if (!path->nodes[level])
2868                         break;
2869                 eb = path->nodes[level];
2870                 if (!btrfs_block_can_be_shared(root, eb))
2871                         continue;
2872                 ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len,
2873                                                &refs, NULL);
2874                 if (refs > 1)
2875                         return 1;
2876         }
2877         return 0;
2878 }
2879
2880 /*
2881  * helper to start transaction for unlink and rmdir.
2882  *
2883  * unlink and rmdir are special in btrfs, they do not always free space.
2884  * so in enospc case, we should make sure they will free space before
2885  * allowing them to use the global metadata reservation.
2886  */
2887 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
2888                                                        struct dentry *dentry)
2889 {
2890         struct btrfs_trans_handle *trans;
2891         struct btrfs_root *root = BTRFS_I(dir)->root;
2892         struct btrfs_path *path;
2893         struct btrfs_inode_ref *ref;
2894         struct btrfs_dir_item *di;
2895         struct inode *inode = dentry->d_inode;
2896         u64 index;
2897         int check_link = 1;
2898         int err = -ENOSPC;
2899         int ret;
2900         u64 ino = btrfs_ino(inode);
2901         u64 dir_ino = btrfs_ino(dir);
2902
2903         /*
2904          * 1 for the possible orphan item
2905          * 1 for the dir item
2906          * 1 for the dir index
2907          * 1 for the inode ref
2908          * 1 for the inode ref in the tree log
2909          * 2 for the dir entries in the log
2910          * 1 for the inode
2911          */
2912         trans = btrfs_start_transaction(root, 8);
2913         if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
2914                 return trans;
2915
2916         if (ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
2917                 return ERR_PTR(-ENOSPC);
2918
2919         /* check if there is someone else holds reference */
2920         if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
2921                 return ERR_PTR(-ENOSPC);
2922
2923         if (atomic_read(&inode->i_count) > 2)
2924                 return ERR_PTR(-ENOSPC);
2925
2926         if (xchg(&root->fs_info->enospc_unlink, 1))
2927                 return ERR_PTR(-ENOSPC);
2928
2929         path = btrfs_alloc_path();
2930         if (!path) {
2931                 root->fs_info->enospc_unlink = 0;
2932                 return ERR_PTR(-ENOMEM);
2933         }
2934
2935         /* 1 for the orphan item */
2936         trans = btrfs_start_transaction(root, 1);
2937         if (IS_ERR(trans)) {
2938                 btrfs_free_path(path);
2939                 root->fs_info->enospc_unlink = 0;
2940                 return trans;
2941         }
2942
2943         path->skip_locking = 1;
2944         path->search_commit_root = 1;
2945
2946         ret = btrfs_lookup_inode(trans, root, path,
2947                                 &BTRFS_I(dir)->location, 0);
2948         if (ret < 0) {
2949                 err = ret;
2950                 goto out;
2951         }
2952         if (ret == 0) {
2953                 if (check_path_shared(root, path))
2954                         goto out;
2955         } else {
2956                 check_link = 0;
2957         }
2958         btrfs_release_path(path);
2959
2960         ret = btrfs_lookup_inode(trans, root, path,
2961                                 &BTRFS_I(inode)->location, 0);
2962         if (ret < 0) {
2963                 err = ret;
2964                 goto out;
2965         }
2966         if (ret == 0) {
2967                 if (check_path_shared(root, path))
2968                         goto out;
2969         } else {
2970                 check_link = 0;
2971         }
2972         btrfs_release_path(path);
2973
2974         if (ret == 0 && S_ISREG(inode->i_mode)) {
2975                 ret = btrfs_lookup_file_extent(trans, root, path,
2976                                                ino, (u64)-1, 0);
2977                 if (ret < 0) {
2978                         err = ret;
2979                         goto out;
2980                 }
2981                 BUG_ON(ret == 0); /* Corruption */
2982                 if (check_path_shared(root, path))
2983                         goto out;
2984                 btrfs_release_path(path);
2985         }
2986
2987         if (!check_link) {
2988                 err = 0;
2989                 goto out;
2990         }
2991
2992         di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
2993                                 dentry->d_name.name, dentry->d_name.len, 0);
2994         if (IS_ERR(di)) {
2995                 err = PTR_ERR(di);
2996                 goto out;
2997         }
2998         if (di) {
2999                 if (check_path_shared(root, path))
3000                         goto out;
3001         } else {
3002                 err = 0;
3003                 goto out;
3004         }
3005         btrfs_release_path(path);
3006
3007         ref = btrfs_lookup_inode_ref(trans, root, path,
3008                                 dentry->d_name.name, dentry->d_name.len,
3009                                 ino, dir_ino, 0);
3010         if (IS_ERR(ref)) {
3011                 err = PTR_ERR(ref);
3012                 goto out;
3013         }
3014         BUG_ON(!ref); /* Logic error */
3015         if (check_path_shared(root, path))
3016                 goto out;
3017         index = btrfs_inode_ref_index(path->nodes[0], ref);
3018         btrfs_release_path(path);
3019
3020         /*
3021          * This is a commit root search, if we can lookup inode item and other
3022          * relative items in the commit root, it means the transaction of
3023          * dir/file creation has been committed, and the dir index item that we
3024          * delay to insert has also been inserted into the commit root. So
3025          * we needn't worry about the delayed insertion of the dir index item
3026          * here.
3027          */
3028         di = btrfs_lookup_dir_index_item(trans, root, path, dir_ino, index,
3029                                 dentry->d_name.name, dentry->d_name.len, 0);
3030         if (IS_ERR(di)) {
3031                 err = PTR_ERR(di);
3032                 goto out;
3033         }
3034         BUG_ON(ret == -ENOENT);
3035         if (check_path_shared(root, path))
3036                 goto out;
3037
3038         err = 0;
3039 out:
3040         btrfs_free_path(path);
3041         /* Migrate the orphan reservation over */
3042         if (!err)
3043                 err = btrfs_block_rsv_migrate(trans->block_rsv,
3044                                 &root->fs_info->global_block_rsv,
3045                                 trans->bytes_reserved);
3046
3047         if (err) {
3048                 btrfs_end_transaction(trans, root);
3049                 root->fs_info->enospc_unlink = 0;
3050                 return ERR_PTR(err);
3051         }
3052
3053         trans->block_rsv = &root->fs_info->global_block_rsv;
3054         return trans;
3055 }
3056
3057 static void __unlink_end_trans(struct btrfs_trans_handle *trans,
3058                                struct btrfs_root *root)
3059 {
3060         if (trans->block_rsv == &root->fs_info->global_block_rsv) {
3061                 btrfs_block_rsv_release(root, trans->block_rsv,
3062                                         trans->bytes_reserved);
3063                 trans->block_rsv = &root->fs_info->trans_block_rsv;
3064                 BUG_ON(!root->fs_info->enospc_unlink);
3065                 root->fs_info->enospc_unlink = 0;
3066         }
3067         btrfs_end_transaction(trans, root);
3068 }
3069
3070 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
3071 {
3072         struct btrfs_root *root = BTRFS_I(dir)->root;
3073         struct btrfs_trans_handle *trans;
3074         struct inode *inode = dentry->d_inode;
3075         int ret;
3076         unsigned long nr = 0;
3077
3078         trans = __unlink_start_trans(dir, dentry);
3079         if (IS_ERR(trans))
3080                 return PTR_ERR(trans);
3081
3082         btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);
3083
3084         ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3085                                  dentry->d_name.name, dentry->d_name.len);
3086         if (ret)
3087                 goto out;
3088
3089         if (inode->i_nlink == 0) {
3090                 ret = btrfs_orphan_add(trans, inode);
3091                 if (ret)
3092                         goto out;
3093         }
3094
3095 out:
3096         nr = trans->blocks_used;
3097         __unlink_end_trans(trans, root);
3098         btrfs_btree_balance_dirty(root, nr);
3099         return ret;
3100 }
3101
3102 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
3103                         struct btrfs_root *root,
3104                         struct inode *dir, u64 objectid,
3105                         const char *name, int name_len)
3106 {
3107         struct btrfs_path *path;
3108         struct extent_buffer *leaf;
3109         struct btrfs_dir_item *di;
3110         struct btrfs_key key;
3111         u64 index;
3112         int ret;
3113         u64 dir_ino = btrfs_ino(dir);
3114
3115         path = btrfs_alloc_path();
3116         if (!path)
3117                 return -ENOMEM;
3118
3119         di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3120                                    name, name_len, -1);
3121         if (IS_ERR_OR_NULL(di)) {
3122                 if (!di)
3123                         ret = -ENOENT;
3124                 else
3125                         ret = PTR_ERR(di);
3126                 goto out;
3127         }
3128
3129         leaf = path->nodes[0];
3130         btrfs_dir_item_key_to_cpu(leaf, di, &key);
3131         WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
3132         ret = btrfs_delete_one_dir_name(trans, root, path, di);
3133         if (ret) {
3134                 btrfs_abort_transaction(trans, root, ret);
3135                 goto out;
3136         }
3137         btrfs_release_path(path);
3138
3139         ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
3140                                  objectid, root->root_key.objectid,
3141                                  dir_ino, &index, name, name_len);
3142         if (ret < 0) {
3143                 if (ret != -ENOENT) {
3144                         btrfs_abort_transaction(trans, root, ret);
3145                         goto out;
3146                 }
3147                 di = btrfs_search_dir_index_item(root, path, dir_ino,
3148                                                  name, name_len);
3149                 if (IS_ERR_OR_NULL(di)) {
3150                         if (!di)
3151                                 ret = -ENOENT;
3152                         else
3153                                 ret = PTR_ERR(di);
3154                         btrfs_abort_transaction(trans, root, ret);
3155                         goto out;
3156                 }
3157
3158                 leaf = path->nodes[0];
3159                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3160                 btrfs_release_path(path);
3161                 index = key.offset;
3162         }
3163         btrfs_release_path(path);
3164
3165         ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3166         if (ret) {
3167                 btrfs_abort_transaction(trans, root, ret);
3168                 goto out;
3169         }
3170
3171         btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3172         inode_inc_iversion(dir);
3173         dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3174         ret = btrfs_update_inode(trans, root, dir);
3175         if (ret)
3176                 btrfs_abort_transaction(trans, root, ret);
3177 out:
3178         btrfs_free_path(path);
3179         return ret;
3180 }
3181
3182 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
3183 {
3184         struct inode *inode = dentry->d_inode;
3185         int err = 0;
3186         struct btrfs_root *root = BTRFS_I(dir)->root;
3187         struct btrfs_trans_handle *trans;
3188         unsigned long nr = 0;
3189
3190         if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
3191             btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
3192                 return -ENOTEMPTY;
3193
3194         trans = __unlink_start_trans(dir, dentry);
3195         if (IS_ERR(trans))
3196                 return PTR_ERR(trans);
3197
3198         if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
3199                 err = btrfs_unlink_subvol(trans, root, dir,
3200                                           BTRFS_I(inode)->location.objectid,
3201                                           dentry->d_name.name,
3202                                           dentry->d_name.len);
3203                 goto out;
3204         }
3205
3206         err = btrfs_orphan_add(trans, inode);
3207         if (err)
3208                 goto out;
3209
3210         /* now the directory is empty */
3211         err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
3212                                  dentry->d_name.name, dentry->d_name.len);
3213         if (!err)
3214                 btrfs_i_size_write(inode, 0);
3215 out:
3216         nr = trans->blocks_used;
3217         __unlink_end_trans(trans, root);
3218         btrfs_btree_balance_dirty(root, nr);
3219
3220         return err;
3221 }
3222
3223 /*
3224  * this can truncate away extent items, csum items and directory items.
3225  * It starts at a high offset and removes keys until it can't find
3226  * any higher than new_size
3227  *
3228  * csum items that cross the new i_size are truncated to the new size
3229  * as well.
3230  *
3231  * min_type is the minimum key type to truncate down to.  If set to 0, this
3232  * will kill all the items on this inode, including the INODE_ITEM_KEY.
3233  */
3234 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
3235                                struct btrfs_root *root,
3236                                struct inode *inode,
3237                                u64 new_size, u32 min_type)
3238 {
3239         struct btrfs_path *path;
3240         struct extent_buffer *leaf;
3241         struct btrfs_file_extent_item *fi;
3242         struct btrfs_key key;
3243         struct btrfs_key found_key;
3244         u64 extent_start = 0;
3245         u64 extent_num_bytes = 0;
3246         u64 extent_offset = 0;
3247         u64 item_end = 0;
3248         u64 mask = root->sectorsize - 1;
3249         u32 found_type = (u8)-1;
3250         int found_extent;
3251         int del_item;
3252         int pending_del_nr = 0;
3253         int pending_del_slot = 0;
3254         int extent_type = -1;
3255         int ret;
3256         int err = 0;
3257         u64 ino = btrfs_ino(inode);
3258
3259         BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
3260
3261         path = btrfs_alloc_path();
3262         if (!path)
3263                 return -ENOMEM;
3264         path->reada = -1;
3265
3266         if (root->ref_cows || root == root->fs_info->tree_root)
3267                 btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
3268
3269         /*
3270          * This function is also used to drop the items in the log tree before
3271          * we relog the inode, so if root != BTRFS_I(inode)->root, it means
3272          * it is used to drop the loged items. So we shouldn't kill the delayed
3273          * items.
3274          */
3275         if (min_type == 0 && root == BTRFS_I(inode)->root)
3276                 btrfs_kill_delayed_inode_items(inode);
3277
3278         key.objectid = ino;
3279         key.offset = (u64)-1;
3280         key.type = (u8)-1;
3281
3282 search_again:
3283         path->leave_spinning = 1;
3284         ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3285         if (ret < 0) {
3286                 err = ret;
3287                 goto out;
3288         }
3289
3290         if (ret > 0) {
3291                 /* there are no items in the tree for us to truncate, we're
3292                  * done
3293                  */
3294                 if (path->slots[0] == 0)
3295                         goto out;
3296                 path->slots[0]--;
3297         }
3298
3299         while (1) {
3300                 fi = NULL;
3301                 leaf = path->nodes[0];
3302                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3303                 found_type = btrfs_key_type(&found_key);
3304
3305                 if (found_key.objectid != ino)
3306                         break;
3307
3308                 if (found_type < min_type)
3309                         break;
3310
3311                 item_end = found_key.offset;
3312                 if (found_type == BTRFS_EXTENT_DATA_KEY) {
3313                         fi = btrfs_item_ptr(leaf, path->slots[0],
3314                                             struct btrfs_file_extent_item);
3315                         extent_type = btrfs_file_extent_type(leaf, fi);
3316                         if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3317                                 item_end +=
3318                                     btrfs_file_extent_num_bytes(leaf, fi);
3319                         } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3320                                 item_end += btrfs_file_extent_inline_len(leaf,
3321                                                                          fi);
3322                         }
3323                         item_end--;
3324                 }
3325                 if (found_type > min_type) {
3326                         del_item = 1;
3327                 } else {
3328                         if (item_end < new_size)
3329                                 break;
3330                         if (found_key.offset >= new_size)
3331                                 del_item = 1;
3332                         else
3333                                 del_item = 0;
3334                 }
3335                 found_extent = 0;
3336                 /* FIXME, shrink the extent if the ref count is only 1 */
3337                 if (found_type != BTRFS_EXTENT_DATA_KEY)
3338                         goto delete;
3339
3340                 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3341                         u64 num_dec;
3342                         extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
3343                         if (!del_item) {
3344                                 u64 orig_num_bytes =
3345                                         btrfs_file_extent_num_bytes(leaf, fi);
3346                                 extent_num_bytes = new_size -
3347                                         found_key.offset + root->sectorsize - 1;
3348                                 extent_num_bytes = extent_num_bytes &
3349                                         ~((u64)root->sectorsize - 1);
3350                                 btrfs_set_file_extent_num_bytes(leaf, fi,
3351                                                          extent_num_bytes);
3352                                 num_dec = (orig_num_bytes -
3353                                            extent_num_bytes);
3354                                 if (root->ref_cows && extent_start != 0)
3355                                         inode_sub_bytes(inode, num_dec);
3356                                 btrfs_mark_buffer_dirty(leaf);
3357                         } else {
3358                                 extent_num_bytes =
3359                                         btrfs_file_extent_disk_num_bytes(leaf,
3360                                                                          fi);
3361                                 extent_offset = found_key.offset -
3362                                         btrfs_file_extent_offset(leaf, fi);
3363
3364                                 /* FIXME blocksize != 4096 */
3365                                 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
3366                                 if (extent_start != 0) {
3367                                         found_extent = 1;
3368                                         if (root->ref_cows)
3369                                                 inode_sub_bytes(inode, num_dec);
3370                                 }
3371                         }
3372                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3373                         /*
3374                          * we can't truncate inline items that have had
3375                          * special encodings
3376                          */
3377                         if (!del_item &&
3378                             btrfs_file_extent_compression(leaf, fi) == 0 &&
3379                             btrfs_file_extent_encryption(leaf, fi) == 0 &&
3380                             btrfs_file_extent_other_encoding(leaf, fi) == 0) {
3381                                 u32 size = new_size - found_key.offset;
3382
3383                                 if (root->ref_cows) {
3384                                         inode_sub_bytes(inode, item_end + 1 -
3385                                                         new_size);
3386                                 }
3387                                 size =
3388                                     btrfs_file_extent_calc_inline_size(size);
3389                                 btrfs_truncate_item(trans, root, path,
3390                                                     size, 1);
3391                         } else if (root->ref_cows) {
3392                                 inode_sub_bytes(inode, item_end + 1 -
3393                                                 found_key.offset);
3394                         }
3395                 }
3396 delete:
3397                 if (del_item) {
3398                         if (!pending_del_nr) {
3399                                 /* no pending yet, add ourselves */
3400                                 pending_del_slot = path->slots[0];
3401                                 pending_del_nr = 1;
3402                         } else if (pending_del_nr &&
3403                                    path->slots[0] + 1 == pending_del_slot) {
3404                                 /* hop on the pending chunk */
3405                                 pending_del_nr++;
3406                                 pending_del_slot = path->slots[0];
3407                         } else {
3408                                 BUG();
3409                         }
3410                 } else {
3411                         break;
3412                 }
3413                 if (found_extent && (root->ref_cows ||
3414                                      root == root->fs_info->tree_root)) {
3415                         btrfs_set_path_blocking(path);
3416                         ret = btrfs_free_extent(trans, root, extent_start,
3417                                                 extent_num_bytes, 0,
3418                                                 btrfs_header_owner(leaf),
3419                                                 ino, extent_offset, 0);
3420                         BUG_ON(ret);
3421                 }
3422
3423                 if (found_type == BTRFS_INODE_ITEM_KEY)
3424                         break;
3425
3426                 if (path->slots[0] == 0 ||
3427                     path->slots[0] != pending_del_slot) {
3428                         if (root->ref_cows &&
3429                             BTRFS_I(inode)->location.objectid !=
3430                                                 BTRFS_FREE_INO_OBJECTID) {
3431                                 err = -EAGAIN;
3432                                 goto out;
3433                         }
3434                         if (pending_del_nr) {
3435                                 ret = btrfs_del_items(trans, root, path,
3436                                                 pending_del_slot,
3437                                                 pending_del_nr);
3438                                 if (ret) {
3439                                         btrfs_abort_transaction(trans,
3440                                                                 root, ret);
3441                                         goto error;
3442                                 }
3443                                 pending_del_nr = 0;
3444                         }
3445                         btrfs_release_path(path);
3446                         goto search_again;
3447                 } else {
3448                         path->slots[0]--;
3449                 }
3450         }
3451 out:
3452         if (pending_del_nr) {
3453                 ret = btrfs_del_items(trans, root, path, pending_del_slot,
3454                                       pending_del_nr);
3455                 if (ret)
3456                         btrfs_abort_transaction(trans, root, ret);
3457         }
3458 error:
3459         btrfs_free_path(path);
3460         return err;
3461 }
3462
3463 /*
3464  * taken from block_truncate_page, but does cow as it zeros out
3465  * any bytes left in the last page in the file.
3466  */
3467 static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
3468 {
3469         struct inode *inode = mapping->host;
3470         struct btrfs_root *root = BTRFS_I(inode)->root;
3471         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3472         struct btrfs_ordered_extent *ordered;
3473         struct extent_state *cached_state = NULL;
3474         char *kaddr;
3475         u32 blocksize = root->sectorsize;
3476         pgoff_t index = from >> PAGE_CACHE_SHIFT;
3477         unsigned offset = from & (PAGE_CACHE_SIZE-1);
3478         struct page *page;
3479         gfp_t mask = btrfs_alloc_write_mask(mapping);
3480         int ret = 0;
3481         u64 page_start;
3482         u64 page_end;
3483
3484         if ((offset & (blocksize - 1)) == 0)
3485                 goto out;
3486         ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
3487         if (ret)
3488                 goto out;
3489
3490         ret = -ENOMEM;
3491 again:
3492         page = find_or_create_page(mapping, index, mask);
3493         if (!page) {
3494                 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3495                 goto out;
3496         }
3497
3498         page_start = page_offset(page);
3499         page_end = page_start + PAGE_CACHE_SIZE - 1;
3500
3501         if (!PageUptodate(page)) {
3502                 ret = btrfs_readpage(NULL, page);
3503                 lock_page(page);
3504                 if (page->mapping != mapping) {
3505                         unlock_page(page);
3506                         page_cache_release(page);
3507                         goto again;
3508                 }
3509                 if (!PageUptodate(page)) {
3510                         ret = -EIO;
3511                         goto out_unlock;
3512                 }
3513         }
3514         wait_on_page_writeback(page);
3515
3516         lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
3517         set_page_extent_mapped(page);
3518
3519         ordered = btrfs_lookup_ordered_extent(inode, page_start);
3520         if (ordered) {
3521                 unlock_extent_cached(io_tree, page_start, page_end,
3522                                      &cached_state, GFP_NOFS);
3523                 unlock_page(page);
3524                 page_cache_release(page);
3525                 btrfs_start_ordered_extent(inode, ordered, 1);
3526                 btrfs_put_ordered_extent(ordered);
3527                 goto again;
3528         }
3529
3530         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
3531                           EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
3532                           0, 0, &cached_state, GFP_NOFS);
3533
3534         ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
3535                                         &cached_state);
3536         if (ret) {
3537                 unlock_extent_cached(io_tree, page_start, page_end,
3538                                      &cached_state, GFP_NOFS);
3539                 goto out_unlock;
3540         }
3541
3542         ret = 0;
3543         if (offset != PAGE_CACHE_SIZE) {
3544                 kaddr = kmap(page);
3545                 memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
3546                 flush_dcache_page(page);
3547                 kunmap(page);
3548         }
3549         ClearPageChecked(page);
3550         set_page_dirty(page);
3551         unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
3552                              GFP_NOFS);
3553
3554 out_unlock:
3555         if (ret)
3556                 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
3557         unlock_page(page);
3558         page_cache_release(page);
3559 out:
3560         return ret;
3561 }
3562
3563 /*
3564  * This function puts in dummy file extents for the area we're creating a hole
3565  * for.  So if we are truncating this file to a larger size we need to insert
3566  * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
3567  * the range between oldsize and size
3568  */
3569 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
3570 {
3571         struct btrfs_trans_handle *trans;
3572         struct btrfs_root *root = BTRFS_I(inode)->root;
3573         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3574         struct extent_map *em = NULL;
3575         struct extent_state *cached_state = NULL;
3576         u64 mask = root->sectorsize - 1;
3577         u64 hole_start = (oldsize + mask) & ~mask;
3578         u64 block_end = (size + mask) & ~mask;
3579         u64 last_byte;
3580         u64 cur_offset;
3581         u64 hole_size;
3582         int err = 0;
3583
3584         if (size <= hole_start)
3585                 return 0;
3586
3587         while (1) {
3588                 struct btrfs_ordered_extent *ordered;
3589                 btrfs_wait_ordered_range(inode, hole_start,
3590                                          block_end - hole_start);
3591                 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
3592                                  &cached_state);
3593                 ordered = btrfs_lookup_ordered_extent(inode, hole_start);
3594                 if (!ordered)
3595                         break;
3596                 unlock_extent_cached(io_tree, hole_start, block_end - 1,
3597                                      &cached_state, GFP_NOFS);
3598                 btrfs_put_ordered_extent(ordered);
3599         }
3600
3601         cur_offset = hole_start;
3602         while (1) {
3603                 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
3604                                 block_end - cur_offset, 0);
3605                 if (IS_ERR(em)) {
3606                         err = PTR_ERR(em);
3607                         break;
3608                 }
3609                 last_byte = min(extent_map_end(em), block_end);
3610                 last_byte = (last_byte + mask) & ~mask;
3611                 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3612                         u64 hint_byte = 0;
3613                         hole_size = last_byte - cur_offset;
3614
3615                         trans = btrfs_start_transaction(root, 3);
3616                         if (IS_ERR(trans)) {
3617                                 err = PTR_ERR(trans);
3618                                 break;
3619                         }
3620
3621                         err = btrfs_drop_extents(trans, inode, cur_offset,
3622                                                  cur_offset + hole_size,
3623                                                  &hint_byte, 1);
3624                         if (err) {
3625                                 btrfs_abort_transaction(trans, root, err);
3626                                 btrfs_end_transaction(trans, root);
3627                                 break;
3628                         }
3629
3630                         err = btrfs_insert_file_extent(trans, root,
3631                                         btrfs_ino(inode), cur_offset, 0,
3632                                         0, hole_size, 0, hole_size,
3633                                         0, 0, 0);
3634                         if (err) {
3635                                 btrfs_abort_transaction(trans, root, err);
3636                                 btrfs_end_transaction(trans, root);
3637                                 break;
3638                         }
3639
3640                         btrfs_drop_extent_cache(inode, hole_start,
3641                                         last_byte - 1, 0);
3642
3643                         btrfs_update_inode(trans, root, inode);
3644                         btrfs_end_transaction(trans, root);
3645                 }
3646                 free_extent_map(em);
3647                 em = NULL;
3648                 cur_offset = last_byte;
3649                 if (cur_offset >= block_end)
3650                         break;
3651         }
3652
3653         free_extent_map(em);
3654         unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
3655                              GFP_NOFS);
3656         return err;
3657 }
3658
3659 static int btrfs_setsize(struct inode *inode, loff_t newsize)
3660 {
3661         struct btrfs_root *root = BTRFS_I(inode)->root;
3662         struct btrfs_trans_handle *trans;
3663         loff_t oldsize = i_size_read(inode);
3664         int ret;
3665
3666         if (newsize == oldsize)
3667                 return 0;
3668
3669         if (newsize > oldsize) {
3670                 truncate_pagecache(inode, oldsize, newsize);
3671                 ret = btrfs_cont_expand(inode, oldsize, newsize);
3672                 if (ret)
3673                         return ret;
3674
3675                 trans = btrfs_start_transaction(root, 1);
3676                 if (IS_ERR(trans))
3677                         return PTR_ERR(trans);
3678
3679                 i_size_write(inode, newsize);
3680                 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
3681                 ret = btrfs_update_inode(trans, root, inode);
3682                 btrfs_end_transaction(trans, root);
3683         } else {
3684
3685                 /*
3686                  * We're truncating a file that used to have good data down to
3687                  * zero. Make sure it gets into the ordered flush list so that
3688                  * any new writes get down to disk quickly.
3689                  */
3690                 if (newsize == 0)
3691                         set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
3692                                 &BTRFS_I(inode)->runtime_flags);
3693
3694                 /* we don't support swapfiles, so vmtruncate shouldn't fail */
3695                 truncate_setsize(inode, newsize);
3696                 ret = btrfs_truncate(inode);
3697         }
3698
3699         return ret;
3700 }
3701
3702 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
3703 {
3704         struct inode *inode = dentry->d_inode;
3705         struct btrfs_root *root = BTRFS_I(inode)->root;
3706         int err;
3707
3708         if (btrfs_root_readonly(root))
3709                 return -EROFS;
3710
3711         err = inode_change_ok(inode, attr);
3712         if (err)
3713                 return err;
3714
3715         if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
3716                 err = btrfs_setsize(inode, attr->ia_size);
3717                 if (err)
3718                         return err;
3719         }
3720
3721         if (attr->ia_valid) {
3722                 setattr_copy(inode, attr);
3723                 inode_inc_iversion(inode);
3724                 err = btrfs_dirty_inode(inode);
3725
3726                 if (!err && attr->ia_valid & ATTR_MODE)
3727                         err = btrfs_acl_chmod(inode);
3728         }
3729
3730         return err;
3731 }
3732
3733 void btrfs_evict_inode(struct inode *inode)
3734 {
3735         struct btrfs_trans_handle *trans;
3736         struct btrfs_root *root = BTRFS_I(inode)->root;
3737         struct btrfs_block_rsv *rsv, *global_rsv;
3738         u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
3739         unsigned long nr;
3740         int ret;
3741
3742         trace_btrfs_inode_evict(inode);
3743
3744         truncate_inode_pages(&inode->i_data, 0);
3745         if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
3746                                btrfs_is_free_space_inode(inode)))
3747                 goto no_delete;
3748
3749         if (is_bad_inode(inode)) {
3750                 btrfs_orphan_del(NULL, inode);
3751                 goto no_delete;
3752         }
3753         /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
3754         btrfs_wait_ordered_range(inode, 0, (u64)-1);
3755
3756         if (root->fs_info->log_root_recovering) {
3757                 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3758                                  &BTRFS_I(inode)->runtime_flags));
3759                 goto no_delete;
3760         }
3761
3762         if (inode->i_nlink > 0) {
3763                 BUG_ON(btrfs_root_refs(&root->root_item) != 0);
3764                 goto no_delete;
3765         }
3766
3767         rsv = btrfs_alloc_block_rsv(root);
3768         if (!rsv) {
3769                 btrfs_orphan_del(NULL, inode);
3770                 goto no_delete;
3771         }
3772         rsv->size = min_size;
3773         global_rsv = &root->fs_info->global_block_rsv;
3774
3775         btrfs_i_size_write(inode, 0);
3776
3777         /*
3778          * This is a bit simpler than btrfs_truncate since
3779          *
3780          * 1) We've already reserved our space for our orphan item in the
3781          *    unlink.
3782          * 2) We're going to delete the inode item, so we don't need to update
3783          *    it at all.
3784          *
3785          * So we just need to reserve some slack space in case we add bytes when
3786          * doing the truncate.
3787          */
3788         while (1) {
3789                 ret = btrfs_block_rsv_refill_noflush(root, rsv, min_size);
3790
3791                 /*
3792                  * Try and steal from the global reserve since we will
3793                  * likely not use this space anyway, we want to try as
3794                  * hard as possible to get this to work.
3795                  */
3796                 if (ret)
3797                         ret = btrfs_block_rsv_migrate(global_rsv, rsv, min_size);
3798
3799                 if (ret) {
3800                         printk(KERN_WARNING "Could not get space for a "
3801                                "delete, will truncate on mount %d\n", ret);
3802                         btrfs_orphan_del(NULL, inode);
3803                         btrfs_free_block_rsv(root, rsv);
3804                         goto no_delete;
3805                 }
3806
3807                 trans = btrfs_start_transaction(root, 0);
3808                 if (IS_ERR(trans)) {
3809                         btrfs_orphan_del(NULL, inode);
3810                         btrfs_free_block_rsv(root, rsv);
3811                         goto no_delete;
3812                 }
3813
3814                 trans->block_rsv = rsv;
3815
3816                 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
3817                 if (ret != -EAGAIN)
3818                         break;
3819
3820                 nr = trans->blocks_used;
3821                 btrfs_end_transaction(trans, root);
3822                 trans = NULL;
3823                 btrfs_btree_balance_dirty(root, nr);
3824         }
3825
3826         btrfs_free_block_rsv(root, rsv);
3827
3828         if (ret == 0) {
3829                 trans->block_rsv = root->orphan_block_rsv;
3830                 ret = btrfs_orphan_del(trans, inode);
3831                 BUG_ON(ret);
3832         }
3833
3834         trans->block_rsv = &root->fs_info->trans_block_rsv;
3835         if (!(root == root->fs_info->tree_root ||
3836               root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
3837                 btrfs_return_ino(root, btrfs_ino(inode));
3838
3839         nr = trans->blocks_used;
3840         btrfs_end_transaction(trans, root);
3841         btrfs_btree_balance_dirty(root, nr);
3842 no_delete:
3843         clear_inode(inode);
3844         return;
3845 }
3846
3847 /*
3848  * this returns the key found in the dir entry in the location pointer.
3849  * If no dir entries were found, location->objectid is 0.
3850  */
3851 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
3852                                struct btrfs_key *location)
3853 {
3854         const char *name = dentry->d_name.name;
3855         int namelen = dentry->d_name.len;
3856         struct btrfs_dir_item *di;
3857         struct btrfs_path *path;
3858         struct btrfs_root *root = BTRFS_I(dir)->root;
3859         int ret = 0;
3860
3861         path = btrfs_alloc_path();
3862         if (!path)
3863                 return -ENOMEM;
3864
3865         di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
3866                                     namelen, 0);
3867         if (IS_ERR(di))
3868                 ret = PTR_ERR(di);
3869
3870         if (IS_ERR_OR_NULL(di))
3871                 goto out_err;
3872
3873         btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
3874 out:
3875         btrfs_free_path(path);
3876         return ret;
3877 out_err:
3878         location->objectid = 0;
3879         goto out;
3880 }
3881
3882 /*
3883  * when we hit a tree root in a directory, the btrfs part of the inode
3884  * needs to be changed to reflect the root directory of the tree root.  This
3885  * is kind of like crossing a mount point.
3886  */
3887 static int fixup_tree_root_location(struct btrfs_root *root,
3888                                     struct inode *dir,
3889                                     struct dentry *dentry,
3890                                     struct btrfs_key *location,
3891                                     struct btrfs_root **sub_root)
3892 {
3893         struct btrfs_path *path;
3894         struct btrfs_root *new_root;
3895         struct btrfs_root_ref *ref;
3896         struct extent_buffer *leaf;
3897         int ret;
3898         int err = 0;
3899
3900         path = btrfs_alloc_path();
3901         if (!path) {
3902                 err = -ENOMEM;
3903                 goto out;
3904         }
3905
3906         err = -ENOENT;
3907         ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
3908                                   BTRFS_I(dir)->root->root_key.objectid,
3909                                   location->objectid);
3910         if (ret) {
3911                 if (ret < 0)
3912                         err = ret;
3913                 goto out;
3914         }
3915
3916         leaf = path->nodes[0];
3917         ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
3918         if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
3919             btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
3920                 goto out;
3921
3922         ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
3923                                    (unsigned long)(ref + 1),
3924                                    dentry->d_name.len);
3925         if (ret)
3926                 goto out;
3927
3928         btrfs_release_path(path);
3929
3930         new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
3931         if (IS_ERR(new_root)) {
3932                 err = PTR_ERR(new_root);
3933                 goto out;
3934         }
3935
3936         if (btrfs_root_refs(&new_root->root_item) == 0) {
3937                 err = -ENOENT;
3938                 goto out;
3939         }
3940
3941         *sub_root = new_root;
3942         location->objectid = btrfs_root_dirid(&new_root->root_item);
3943         location->type = BTRFS_INODE_ITEM_KEY;
3944         location->offset = 0;
3945         err = 0;
3946 out:
3947         btrfs_free_path(path);
3948         return err;
3949 }
3950
3951 static void inode_tree_add(struct inode *inode)
3952 {
3953         struct btrfs_root *root = BTRFS_I(inode)->root;
3954         struct btrfs_inode *entry;
3955         struct rb_node **p;
3956         struct rb_node *parent;
3957         u64 ino = btrfs_ino(inode);
3958 again:
3959         p = &root->inode_tree.rb_node;
3960         parent = NULL;
3961
3962         if (inode_unhashed(inode))
3963                 return;
3964
3965         spin_lock(&root->inode_lock);
3966         while (*p) {
3967                 parent = *p;
3968                 entry = rb_entry(parent, struct btrfs_inode, rb_node);
3969
3970                 if (ino < btrfs_ino(&entry->vfs_inode))
3971                         p = &parent->rb_left;
3972                 else if (ino > btrfs_ino(&entry->vfs_inode))
3973                         p = &parent->rb_right;
3974                 else {
3975                         WARN_ON(!(entry->vfs_inode.i_state &
3976                                   (I_WILL_FREE | I_FREEING)));
3977                         rb_erase(parent, &root->inode_tree);
3978                         RB_CLEAR_NODE(parent);
3979                         spin_unlock(&root->inode_lock);
3980                         goto again;
3981                 }
3982         }
3983         rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
3984         rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
3985         spin_unlock(&root->inode_lock);
3986 }
3987
3988 static void inode_tree_del(struct inode *inode)
3989 {
3990         struct btrfs_root *root = BTRFS_I(inode)->root;
3991         int empty = 0;
3992
3993         spin_lock(&root->inode_lock);
3994         if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
3995                 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
3996                 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
3997                 empty = RB_EMPTY_ROOT(&root->inode_tree);
3998         }
3999         spin_unlock(&root->inode_lock);
4000
4001         /*
4002          * Free space cache has inodes in the tree root, but the tree root has a
4003          * root_refs of 0, so this could end up dropping the tree root as a
4004          * snapshot, so we need the extra !root->fs_info->tree_root check to
4005          * make sure we don't drop it.
4006          */
4007         if (empty && btrfs_root_refs(&root->root_item) == 0 &&
4008             root != root->fs_info->tree_root) {
4009                 synchronize_srcu(&root->fs_info->subvol_srcu);
4010                 spin_lock(&root->inode_lock);
4011                 empty = RB_EMPTY_ROOT(&root->inode_tree);
4012                 spin_unlock(&root->inode_lock);
4013                 if (empty)
4014                         btrfs_add_dead_root(root);
4015         }
4016 }
4017
4018 void btrfs_invalidate_inodes(struct btrfs_root *root)
4019 {
4020         struct rb_node *node;
4021         struct rb_node *prev;
4022         struct btrfs_inode *entry;
4023         struct inode *inode;
4024         u64 objectid = 0;
4025
4026         WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4027
4028         spin_lock(&root->inode_lock);
4029 again:
4030         node = root->inode_tree.rb_node;
4031         prev = NULL;
4032         while (node) {
4033                 prev = node;
4034                 entry = rb_entry(node, struct btrfs_inode, rb_node);
4035
4036                 if (objectid < btrfs_ino(&entry->vfs_inode))
4037                         node = node->rb_left;
4038                 else if (objectid > btrfs_ino(&entry->vfs_inode))
4039                         node = node->rb_right;
4040                 else
4041                         break;
4042         }
4043         if (!node) {
4044                 while (prev) {
4045                         entry = rb_entry(prev, struct btrfs_inode, rb_node);
4046                         if (objectid <= btrfs_ino(&entry->vfs_inode)) {
4047                                 node = prev;
4048                                 break;
4049                         }
4050                         prev = rb_next(prev);
4051                 }
4052         }
4053         while (node) {
4054                 entry = rb_entry(node, struct btrfs_inode, rb_node);
4055                 objectid = btrfs_ino(&entry->vfs_inode) + 1;
4056                 inode = igrab(&entry->vfs_inode);
4057                 if (inode) {
4058                         spin_unlock(&root->inode_lock);
4059                         if (atomic_read(&inode->i_count) > 1)
4060                                 d_prune_aliases(inode);
4061                         /*
4062                          * btrfs_drop_inode will have it removed from
4063                          * the inode cache when its usage count
4064                          * hits zero.
4065                          */
4066                         iput(inode);
4067                         cond_resched();
4068                         spin_lock(&root->inode_lock);
4069                         goto again;
4070                 }
4071
4072                 if (cond_resched_lock(&root->inode_lock))
4073                         goto again;
4074
4075                 node = rb_next(node);
4076         }
4077         spin_unlock(&root->inode_lock);
4078 }
4079
4080 static int btrfs_init_locked_inode(struct inode *inode, void *p)
4081 {
4082         struct btrfs_iget_args *args = p;
4083         inode->i_ino = args->ino;
4084         BTRFS_I(inode)->root = args->root;
4085         return 0;
4086 }
4087
4088 static int btrfs_find_actor(struct inode *inode, void *opaque)
4089 {
4090         struct btrfs_iget_args *args = opaque;
4091         return args->ino == btrfs_ino(inode) &&
4092                 args->root == BTRFS_I(inode)->root;
4093 }
4094
4095 static struct inode *btrfs_iget_locked(struct super_block *s,
4096                                        u64 objectid,
4097                                        struct btrfs_root *root)
4098 {
4099         struct inode *inode;
4100         struct btrfs_iget_args args;
4101         args.ino = objectid;
4102         args.root = root;
4103
4104         inode = iget5_locked(s, objectid, btrfs_find_actor,
4105                              btrfs_init_locked_inode,
4106                              (void *)&args);
4107         return inode;
4108 }
4109
4110 /* Get an inode object given its location and corresponding root.
4111  * Returns in *is_new if the inode was read from disk
4112  */
4113 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4114                          struct btrfs_root *root, int *new)
4115 {
4116         struct inode *inode;
4117
4118         inode = btrfs_iget_locked(s, location->objectid, root);
4119         if (!inode)
4120                 return ERR_PTR(-ENOMEM);
4121
4122         if (inode->i_state & I_NEW) {
4123                 BTRFS_I(inode)->root = root;
4124                 memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
4125                 btrfs_read_locked_inode(inode);
4126                 if (!is_bad_inode(inode)) {
4127                         inode_tree_add(inode);
4128                         unlock_new_inode(inode);
4129                         if (new)
4130                                 *new = 1;
4131                 } else {
4132                         unlock_new_inode(inode);
4133                         iput(inode);
4134                         inode = ERR_PTR(-ESTALE);
4135                 }
4136         }
4137
4138         return inode;
4139 }
4140
4141 static struct inode *new_simple_dir(struct super_block *s,
4142                                     struct btrfs_key *key,
4143                                     struct btrfs_root *root)
4144 {
4145         struct inode *inode = new_inode(s);
4146
4147         if (!inode)
4148                 return ERR_PTR(-ENOMEM);
4149
4150         BTRFS_I(inode)->root = root;
4151         memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
4152         set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
4153
4154         inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
4155         inode->i_op = &btrfs_dir_ro_inode_operations;
4156         inode->i_fop = &simple_dir_operations;
4157         inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
4158         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4159
4160         return inode;
4161 }
4162
4163 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
4164 {
4165         struct inode *inode;
4166         struct btrfs_root *root = BTRFS_I(dir)->root;
4167         struct btrfs_root *sub_root = root;
4168         struct btrfs_key location;
4169         int index;
4170         int ret = 0;
4171
4172         if (dentry->d_name.len > BTRFS_NAME_LEN)
4173                 return ERR_PTR(-ENAMETOOLONG);
4174
4175         if (unlikely(d_need_lookup(dentry))) {
4176                 memcpy(&location, dentry->d_fsdata, sizeof(struct btrfs_key));
4177                 kfree(dentry->d_fsdata);
4178                 dentry->d_fsdata = NULL;
4179                 /* This thing is hashed, drop it for now */
4180                 d_drop(dentry);
4181         } else {
4182                 ret = btrfs_inode_by_name(dir, dentry, &location);
4183         }
4184
4185         if (ret < 0)
4186                 return ERR_PTR(ret);
4187
4188         if (location.objectid == 0)
4189                 return NULL;
4190
4191         if (location.type == BTRFS_INODE_ITEM_KEY) {
4192                 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4193                 return inode;
4194         }
4195
4196         BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
4197
4198         index = srcu_read_lock(&root->fs_info->subvol_srcu);
4199         ret = fixup_tree_root_location(root, dir, dentry,
4200                                        &location, &sub_root);
4201         if (ret < 0) {
4202                 if (ret != -ENOENT)
4203                         inode = ERR_PTR(ret);
4204                 else
4205                         inode = new_simple_dir(dir->i_sb, &location, sub_root);
4206         } else {
4207                 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
4208         }
4209         srcu_read_unlock(&root->fs_info->subvol_srcu, index);
4210
4211         if (!IS_ERR(inode) && root != sub_root) {
4212                 down_read(&root->fs_info->cleanup_work_sem);
4213                 if (!(inode->i_sb->s_flags & MS_RDONLY))
4214                         ret = btrfs_orphan_cleanup(sub_root);
4215                 up_read(&root->fs_info->cleanup_work_sem);
4216                 if (ret)
4217                         inode = ERR_PTR(ret);
4218         }
4219
4220         return inode;
4221 }
4222
4223 static int btrfs_dentry_delete(const struct dentry *dentry)
4224 {
4225         struct btrfs_root *root;
4226         struct inode *inode = dentry->d_inode;
4227
4228         if (!inode && !IS_ROOT(dentry))
4229                 inode = dentry->d_parent->d_inode;
4230
4231         if (inode) {
4232                 root = BTRFS_I(inode)->root;
4233                 if (btrfs_root_refs(&root->root_item) == 0)
4234                         return 1;
4235
4236                 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
4237                         return 1;
4238         }
4239         return 0;
4240 }
4241
4242 static void btrfs_dentry_release(struct dentry *dentry)
4243 {
4244         if (dentry->d_fsdata)
4245                 kfree(dentry->d_fsdata);
4246 }
4247
4248 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
4249                                    struct nameidata *nd)
4250 {
4251         struct dentry *ret;
4252
4253         ret = d_splice_alias(btrfs_lookup_dentry(dir, dentry), dentry);
4254         if (unlikely(d_need_lookup(dentry))) {
4255                 spin_lock(&dentry->d_lock);
4256                 dentry->d_flags &= ~DCACHE_NEED_LOOKUP;
4257                 spin_unlock(&dentry->d_lock);
4258         }
4259         return ret;
4260 }
4261
4262 unsigned char btrfs_filetype_table[] = {
4263         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
4264 };
4265
4266 static int btrfs_real_readdir(struct file *filp, void *dirent,
4267                               filldir_t filldir)
4268 {
4269         struct inode *inode = filp->f_dentry->d_inode;
4270         struct btrfs_root *root = BTRFS_I(inode)->root;
4271         struct btrfs_item *item;
4272         struct btrfs_dir_item *di;
4273         struct btrfs_key key;
4274         struct btrfs_key found_key;
4275         struct btrfs_path *path;
4276         struct list_head ins_list;
4277         struct list_head del_list;
4278         int ret;
4279         struct extent_buffer *leaf;
4280         int slot;
4281         unsigned char d_type;
4282         int over = 0;
4283         u32 di_cur;
4284         u32 di_total;
4285         u32 di_len;
4286         int key_type = BTRFS_DIR_INDEX_KEY;
4287         char tmp_name[32];
4288         char *name_ptr;
4289         int name_len;
4290         int is_curr = 0;        /* filp->f_pos points to the current index? */
4291
4292         /* FIXME, use a real flag for deciding about the key type */
4293         if (root->fs_info->tree_root == root)
4294                 key_type = BTRFS_DIR_ITEM_KEY;
4295
4296         /* special case for "." */
4297         if (filp->f_pos == 0) {
4298                 over = filldir(dirent, ".", 1,
4299                                filp->f_pos, btrfs_ino(inode), DT_DIR);
4300                 if (over)
4301                         return 0;
4302                 filp->f_pos = 1;
4303         }
4304         /* special case for .., just use the back ref */
4305         if (filp->f_pos == 1) {
4306                 u64 pino = parent_ino(filp->f_path.dentry);
4307                 over = filldir(dirent, "..", 2,
4308                                filp->f_pos, pino, DT_DIR);
4309                 if (over)
4310                         return 0;
4311                 filp->f_pos = 2;
4312         }
4313         path = btrfs_alloc_path();
4314         if (!path)
4315                 return -ENOMEM;
4316
4317         path->reada = 1;
4318
4319         if (key_type == BTRFS_DIR_INDEX_KEY) {
4320                 INIT_LIST_HEAD(&ins_list);
4321                 INIT_LIST_HEAD(&del_list);
4322                 btrfs_get_delayed_items(inode, &ins_list, &del_list);
4323         }
4324
4325         btrfs_set_key_type(&key, key_type);
4326         key.offset = filp->f_pos;
4327         key.objectid = btrfs_ino(inode);
4328
4329         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4330         if (ret < 0)
4331                 goto err;
4332
4333         while (1) {
4334                 leaf = path->nodes[0];
4335                 slot = path->slots[0];
4336                 if (slot >= btrfs_header_nritems(leaf)) {
4337                         ret = btrfs_next_leaf(root, path);
4338                         if (ret < 0)
4339                                 goto err;
4340                         else if (ret > 0)
4341                                 break;
4342                         continue;
4343                 }
4344
4345                 item = btrfs_item_nr(leaf, slot);
4346                 btrfs_item_key_to_cpu(leaf, &found_key, slot);
4347
4348                 if (found_key.objectid != key.objectid)
4349                         break;
4350                 if (btrfs_key_type(&found_key) != key_type)
4351                         break;
4352                 if (found_key.offset < filp->f_pos)
4353                         goto next;
4354                 if (key_type == BTRFS_DIR_INDEX_KEY &&
4355                     btrfs_should_delete_dir_index(&del_list,
4356                                                   found_key.offset))
4357                         goto next;
4358
4359                 filp->f_pos = found_key.offset;
4360                 is_curr = 1;
4361
4362                 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
4363                 di_cur = 0;
4364                 di_total = btrfs_item_size(leaf, item);
4365
4366                 while (di_cur < di_total) {
4367                         struct btrfs_key location;
4368
4369                         if (verify_dir_item(root, leaf, di))
4370                                 break;
4371
4372                         name_len = btrfs_dir_name_len(leaf, di);
4373                         if (name_len <= sizeof(tmp_name)) {
4374                                 name_ptr = tmp_name;
4375                         } else {
4376                                 name_ptr = kmalloc(name_len, GFP_NOFS);
4377                                 if (!name_ptr) {
4378                                         ret = -ENOMEM;
4379                                         goto err;
4380                                 }
4381                         }
4382                         read_extent_buffer(leaf, name_ptr,
4383                                            (unsigned long)(di + 1), name_len);
4384
4385                         d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
4386                         btrfs_dir_item_key_to_cpu(leaf, di, &location);
4387
4388
4389                         /* is this a reference to our own snapshot? If so
4390                          * skip it.
4391                          *
4392                          * In contrast to old kernels, we insert the snapshot's
4393                          * dir item and dir index after it has been created, so
4394                          * we won't find a reference to our own snapshot. We
4395                          * still keep the following code for backward
4396                          * compatibility.
4397                          */
4398                         if (location.type == BTRFS_ROOT_ITEM_KEY &&
4399                             location.objectid == root->root_key.objectid) {
4400                                 over = 0;
4401                                 goto skip;
4402                         }
4403                         over = filldir(dirent, name_ptr, name_len,
4404                                        found_key.offset, location.objectid,
4405                                        d_type);
4406
4407 skip:
4408                         if (name_ptr != tmp_name)
4409                                 kfree(name_ptr);
4410
4411                         if (over)
4412                                 goto nopos;
4413                         di_len = btrfs_dir_name_len(leaf, di) +
4414                                  btrfs_dir_data_len(leaf, di) + sizeof(*di);
4415                         di_cur += di_len;
4416                         di = (struct btrfs_dir_item *)((char *)di + di_len);
4417                 }
4418 next:
4419                 path->slots[0]++;
4420         }
4421
4422         if (key_type == BTRFS_DIR_INDEX_KEY) {
4423                 if (is_curr)
4424                         filp->f_pos++;
4425                 ret = btrfs_readdir_delayed_dir_index(filp, dirent, filldir,
4426                                                       &ins_list);
4427                 if (ret)
4428                         goto nopos;
4429         }
4430
4431         /* Reached end of directory/root. Bump pos past the last item. */
4432         if (key_type == BTRFS_DIR_INDEX_KEY)
4433                 /*
4434                  * 32-bit glibc will use getdents64, but then strtol -
4435                  * so the last number we can serve is this.
4436                  */
4437                 filp->f_pos = 0x7fffffff;
4438         else
4439                 filp->f_pos++;
4440 nopos:
4441         ret = 0;
4442 err:
4443         if (key_type == BTRFS_DIR_INDEX_KEY)
4444                 btrfs_put_delayed_items(&ins_list, &del_list);
4445         btrfs_free_path(path);
4446         return ret;
4447 }
4448
4449 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
4450 {
4451         struct btrfs_root *root = BTRFS_I(inode)->root;
4452         struct btrfs_trans_handle *trans;
4453         int ret = 0;
4454         bool nolock = false;
4455
4456         if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
4457                 return 0;
4458
4459         if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
4460                 nolock = true;
4461
4462         if (wbc->sync_mode == WB_SYNC_ALL) {
4463                 if (nolock)
4464                         trans = btrfs_join_transaction_nolock(root);
4465                 else
4466                         trans = btrfs_join_transaction(root);
4467                 if (IS_ERR(trans))
4468                         return PTR_ERR(trans);
4469                 if (nolock)
4470                         ret = btrfs_end_transaction_nolock(trans, root);
4471                 else
4472                         ret = btrfs_commit_transaction(trans, root);
4473         }
4474         return ret;
4475 }
4476
4477 /*
4478  * This is somewhat expensive, updating the tree every time the
4479  * inode changes.  But, it is most likely to find the inode in cache.
4480  * FIXME, needs more benchmarking...there are no reasons other than performance
4481  * to keep or drop this code.
4482  */
4483 int btrfs_dirty_inode(struct inode *inode)
4484 {
4485         struct btrfs_root *root = BTRFS_I(inode)->root;
4486         struct btrfs_trans_handle *trans;
4487         int ret;
4488
4489         if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
4490                 return 0;
4491
4492         trans = btrfs_join_transaction(root);
4493         if (IS_ERR(trans))
4494                 return PTR_ERR(trans);
4495
4496         ret = btrfs_update_inode(trans, root, inode);
4497         if (ret && ret == -ENOSPC) {
4498                 /* whoops, lets try again with the full transaction */
4499                 btrfs_end_transaction(trans, root);
4500                 trans = btrfs_start_transaction(root, 1);
4501                 if (IS_ERR(trans))
4502                         return PTR_ERR(trans);
4503
4504                 ret = btrfs_update_inode(trans, root, inode);
4505         }
4506         btrfs_end_transaction(trans, root);
4507         if (BTRFS_I(inode)->delayed_node)
4508                 btrfs_balance_delayed_items(root);
4509
4510         return ret;
4511 }
4512
4513 /*
4514  * This is a copy of file_update_time.  We need this so we can return error on
4515  * ENOSPC for updating the inode in the case of file write and mmap writes.
4516  */
4517 static int btrfs_update_time(struct inode *inode, struct timespec *now,
4518                              int flags)
4519 {
4520         struct btrfs_root *root = BTRFS_I(inode)->root;
4521
4522         if (btrfs_root_readonly(root))
4523                 return -EROFS;
4524
4525         if (flags & S_VERSION)
4526                 inode_inc_iversion(inode);
4527         if (flags & S_CTIME)
4528                 inode->i_ctime = *now;
4529         if (flags & S_MTIME)
4530                 inode->i_mtime = *now;
4531         if (flags & S_ATIME)
4532                 inode->i_atime = *now;
4533         return btrfs_dirty_inode(inode);
4534 }
4535
4536 /*
4537  * find the highest existing sequence number in a directory
4538  * and then set the in-memory index_cnt variable to reflect
4539  * free sequence numbers
4540  */
4541 static int btrfs_set_inode_index_count(struct inode *inode)
4542 {
4543         struct btrfs_root *root = BTRFS_I(inode)->root;
4544         struct btrfs_key key, found_key;
4545         struct btrfs_path *path;
4546         struct extent_buffer *leaf;
4547         int ret;
4548
4549         key.objectid = btrfs_ino(inode);
4550         btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
4551         key.offset = (u64)-1;
4552
4553         path = btrfs_alloc_path();
4554         if (!path)
4555                 return -ENOMEM;
4556
4557         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4558         if (ret < 0)
4559                 goto out;
4560         /* FIXME: we should be able to handle this */
4561         if (ret == 0)
4562                 goto out;
4563         ret = 0;
4564
4565         /*
4566          * MAGIC NUMBER EXPLANATION:
4567          * since we search a directory based on f_pos we have to start at 2
4568          * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
4569          * else has to start at 2
4570          */
4571         if (path->slots[0] == 0) {
4572                 BTRFS_I(inode)->index_cnt = 2;
4573                 goto out;
4574         }
4575
4576         path->slots[0]--;
4577
4578         leaf = path->nodes[0];
4579         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4580
4581         if (found_key.objectid != btrfs_ino(inode) ||
4582             btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
4583                 BTRFS_I(inode)->index_cnt = 2;
4584                 goto out;
4585         }
4586
4587         BTRFS_I(inode)->index_cnt = found_key.offset + 1;
4588 out:
4589         btrfs_free_path(path);
4590         return ret;
4591 }
4592
4593 /*
4594  * helper to find a free sequence number in a given directory.  This current
4595  * code is very simple, later versions will do smarter things in the btree
4596  */
4597 int btrfs_set_inode_index(struct inode *dir, u64 *index)
4598 {
4599         int ret = 0;
4600
4601         if (BTRFS_I(dir)->index_cnt == (u64)-1) {
4602                 ret = btrfs_inode_delayed_dir_index_count(dir);
4603                 if (ret) {
4604                         ret = btrfs_set_inode_index_count(dir);
4605                         if (ret)
4606                                 return ret;
4607                 }
4608         }
4609
4610         *index = BTRFS_I(dir)->index_cnt;
4611         BTRFS_I(dir)->index_cnt++;
4612
4613         return ret;
4614 }
4615
4616 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
4617                                      struct btrfs_root *root,
4618                                      struct inode *dir,
4619                                      const char *name, int name_len,
4620                                      u64 ref_objectid, u64 objectid,
4621                                      umode_t mode, u64 *index)
4622 {
4623         struct inode *inode;
4624         struct btrfs_inode_item *inode_item;
4625         struct btrfs_key *location;
4626         struct btrfs_path *path;
4627         struct btrfs_inode_ref *ref;
4628         struct btrfs_key key[2];
4629         u32 sizes[2];
4630         unsigned long ptr;
4631         int ret;
4632         int owner;
4633
4634         path = btrfs_alloc_path();
4635         if (!path)
4636                 return ERR_PTR(-ENOMEM);
4637
4638         inode = new_inode(root->fs_info->sb);
4639         if (!inode) {
4640                 btrfs_free_path(path);
4641                 return ERR_PTR(-ENOMEM);
4642         }
4643
4644         /*
4645          * we have to initialize this early, so we can reclaim the inode
4646          * number if we fail afterwards in this function.
4647          */
4648         inode->i_ino = objectid;
4649
4650         if (dir) {
4651                 trace_btrfs_inode_request(dir);
4652
4653                 ret = btrfs_set_inode_index(dir, index);
4654                 if (ret) {
4655                         btrfs_free_path(path);
4656                         iput(inode);
4657                         return ERR_PTR(ret);
4658                 }
4659         }
4660         /*
4661          * index_cnt is ignored for everything but a dir,
4662          * btrfs_get_inode_index_count has an explanation for the magic
4663          * number
4664          */
4665         BTRFS_I(inode)->index_cnt = 2;
4666         BTRFS_I(inode)->root = root;
4667         BTRFS_I(inode)->generation = trans->transid;
4668         inode->i_generation = BTRFS_I(inode)->generation;
4669
4670         if (S_ISDIR(mode))
4671                 owner = 0;
4672         else
4673                 owner = 1;
4674
4675         key[0].objectid = objectid;
4676         btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
4677         key[0].offset = 0;
4678
4679         key[1].objectid = objectid;
4680         btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
4681         key[1].offset = ref_objectid;
4682
4683         sizes[0] = sizeof(struct btrfs_inode_item);
4684         sizes[1] = name_len + sizeof(*ref);
4685
4686         path->leave_spinning = 1;
4687         ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
4688         if (ret != 0)
4689                 goto fail;
4690
4691         inode_init_owner(inode, dir, mode);
4692         inode_set_bytes(inode, 0);
4693         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4694         inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4695                                   struct btrfs_inode_item);
4696         memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
4697                              sizeof(*inode_item));
4698         fill_inode_item(trans, path->nodes[0], inode_item, inode);
4699
4700         ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
4701                              struct btrfs_inode_ref);
4702         btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
4703         btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
4704         ptr = (unsigned long)(ref + 1);
4705         write_extent_buffer(path->nodes[0], name, ptr, name_len);
4706
4707         btrfs_mark_buffer_dirty(path->nodes[0]);
4708         btrfs_free_path(path);
4709
4710         location = &BTRFS_I(inode)->location;
4711         location->objectid = objectid;
4712         location->offset = 0;
4713         btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);
4714
4715         btrfs_inherit_iflags(inode, dir);
4716
4717         if (S_ISREG(mode)) {
4718                 if (btrfs_test_opt(root, NODATASUM))
4719                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
4720                 if (btrfs_test_opt(root, NODATACOW) ||
4721                     (BTRFS_I(dir)->flags & BTRFS_INODE_NODATACOW))
4722                         BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
4723         }
4724
4725         insert_inode_hash(inode);
4726         inode_tree_add(inode);
4727
4728         trace_btrfs_inode_new(inode);
4729         btrfs_set_inode_last_trans(trans, inode);
4730
4731         btrfs_update_root_times(trans, root);
4732
4733         return inode;
4734 fail:
4735         if (dir)
4736                 BTRFS_I(dir)->index_cnt--;
4737         btrfs_free_path(path);
4738         iput(inode);
4739         return ERR_PTR(ret);
4740 }
4741
4742 static inline u8 btrfs_inode_type(struct inode *inode)
4743 {
4744         return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
4745 }
4746
4747 /*
4748  * utility function to add 'inode' into 'parent_inode' with
4749  * a give name and a given sequence number.
4750  * if 'add_backref' is true, also insert a backref from the
4751  * inode to the parent directory.
4752  */
4753 int btrfs_add_link(struct btrfs_trans_handle *trans,
4754                    struct inode *parent_inode, struct inode *inode,
4755                    const char *name, int name_len, int add_backref, u64 index)
4756 {
4757         int ret = 0;
4758         struct btrfs_key key;
4759         struct btrfs_root *root = BTRFS_I(parent_inode)->root;
4760         u64 ino = btrfs_ino(inode);
4761         u64 parent_ino = btrfs_ino(parent_inode);
4762
4763         if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4764                 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
4765         } else {
4766                 key.objectid = ino;
4767                 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
4768                 key.offset = 0;
4769         }
4770
4771         if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4772                 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
4773                                          key.objectid, root->root_key.objectid,
4774                                          parent_ino, index, name, name_len);
4775         } else if (add_backref) {
4776                 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
4777                                              parent_ino, index);
4778         }
4779
4780         /* Nothing to clean up yet */
4781         if (ret)
4782                 return ret;
4783
4784         ret = btrfs_insert_dir_item(trans, root, name, name_len,
4785                                     parent_inode, &key,
4786                                     btrfs_inode_type(inode), index);
4787         if (ret == -EEXIST)
4788                 goto fail_dir_item;
4789         else if (ret) {
4790                 btrfs_abort_transaction(trans, root, ret);
4791                 return ret;
4792         }
4793
4794         btrfs_i_size_write(parent_inode, parent_inode->i_size +
4795                            name_len * 2);
4796         inode_inc_iversion(parent_inode);
4797         parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
4798         ret = btrfs_update_inode(trans, root, parent_inode);
4799         if (ret)
4800                 btrfs_abort_transaction(trans, root, ret);
4801         return ret;
4802
4803 fail_dir_item:
4804         if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
4805                 u64 local_index;
4806                 int err;
4807                 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4808                                  key.objectid, root->root_key.objectid,
4809                                  parent_ino, &local_index, name, name_len);
4810
4811         } else if (add_backref) {
4812                 u64 local_index;
4813                 int err;
4814
4815                 err = btrfs_del_inode_ref(trans, root, name, name_len,
4816                                           ino, parent_ino, &local_index);
4817         }
4818         return ret;
4819 }
4820
4821 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
4822                             struct inode *dir, struct dentry *dentry,
4823                             struct inode *inode, int backref, u64 index)
4824 {
4825         int err = btrfs_add_link(trans, dir, inode,
4826                                  dentry->d_name.name, dentry->d_name.len,
4827                                  backref, index);
4828         if (err > 0)
4829                 err = -EEXIST;
4830         return err;
4831 }
4832
4833 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
4834                         umode_t mode, dev_t rdev)
4835 {
4836         struct btrfs_trans_handle *trans;
4837         struct btrfs_root *root = BTRFS_I(dir)->root;
4838         struct inode *inode = NULL;
4839         int err;
4840         int drop_inode = 0;
4841         u64 objectid;
4842         unsigned long nr = 0;
4843         u64 index = 0;
4844
4845         if (!new_valid_dev(rdev))
4846                 return -EINVAL;
4847
4848         /*
4849          * 2 for inode item and ref
4850          * 2 for dir items
4851          * 1 for xattr if selinux is on
4852          */
4853         trans = btrfs_start_transaction(root, 5);
4854         if (IS_ERR(trans))
4855                 return PTR_ERR(trans);
4856
4857         err = btrfs_find_free_ino(root, &objectid);
4858         if (err)
4859                 goto out_unlock;
4860
4861         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4862                                 dentry->d_name.len, btrfs_ino(dir), objectid,
4863                                 mode, &index);
4864         if (IS_ERR(inode)) {
4865                 err = PTR_ERR(inode);
4866                 goto out_unlock;
4867         }
4868
4869         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4870         if (err) {
4871                 drop_inode = 1;
4872                 goto out_unlock;
4873         }
4874
4875         /*
4876         * If the active LSM wants to access the inode during
4877         * d_instantiate it needs these. Smack checks to see
4878         * if the filesystem supports xattrs by looking at the
4879         * ops vector.
4880         */
4881
4882         inode->i_op = &btrfs_special_inode_operations;
4883         err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4884         if (err)
4885                 drop_inode = 1;
4886         else {
4887                 init_special_inode(inode, inode->i_mode, rdev);
4888                 btrfs_update_inode(trans, root, inode);
4889                 d_instantiate(dentry, inode);
4890         }
4891 out_unlock:
4892         nr = trans->blocks_used;
4893         btrfs_end_transaction(trans, root);
4894         btrfs_btree_balance_dirty(root, nr);
4895         if (drop_inode) {
4896                 inode_dec_link_count(inode);
4897                 iput(inode);
4898         }
4899         return err;
4900 }
4901
4902 static int btrfs_create(struct inode *dir, struct dentry *dentry,
4903                         umode_t mode, struct nameidata *nd)
4904 {
4905         struct btrfs_trans_handle *trans;
4906         struct btrfs_root *root = BTRFS_I(dir)->root;
4907         struct inode *inode = NULL;
4908         int drop_inode = 0;
4909         int err;
4910         unsigned long nr = 0;
4911         u64 objectid;
4912         u64 index = 0;
4913
4914         /*
4915          * 2 for inode item and ref
4916          * 2 for dir items
4917          * 1 for xattr if selinux is on
4918          */
4919         trans = btrfs_start_transaction(root, 5);
4920         if (IS_ERR(trans))
4921                 return PTR_ERR(trans);
4922
4923         err = btrfs_find_free_ino(root, &objectid);
4924         if (err)
4925                 goto out_unlock;
4926
4927         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4928                                 dentry->d_name.len, btrfs_ino(dir), objectid,
4929                                 mode, &index);
4930         if (IS_ERR(inode)) {
4931                 err = PTR_ERR(inode);
4932                 goto out_unlock;
4933         }
4934
4935         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
4936         if (err) {
4937                 drop_inode = 1;
4938                 goto out_unlock;
4939         }
4940
4941         /*
4942         * If the active LSM wants to access the inode during
4943         * d_instantiate it needs these. Smack checks to see
4944         * if the filesystem supports xattrs by looking at the
4945         * ops vector.
4946         */
4947         inode->i_fop = &btrfs_file_operations;
4948         inode->i_op = &btrfs_file_inode_operations;
4949
4950         err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
4951         if (err)
4952                 drop_inode = 1;
4953         else {
4954                 inode->i_mapping->a_ops = &btrfs_aops;
4955                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
4956                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
4957                 d_instantiate(dentry, inode);
4958         }
4959 out_unlock:
4960         nr = trans->blocks_used;
4961         btrfs_end_transaction(trans, root);
4962         if (drop_inode) {
4963                 inode_dec_link_count(inode);
4964                 iput(inode);
4965         }
4966         btrfs_btree_balance_dirty(root, nr);
4967         return err;
4968 }
4969
4970 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
4971                       struct dentry *dentry)
4972 {
4973         struct btrfs_trans_handle *trans;
4974         struct btrfs_root *root = BTRFS_I(dir)->root;
4975         struct inode *inode = old_dentry->d_inode;
4976         u64 index;
4977         unsigned long nr = 0;
4978         int err;
4979         int drop_inode = 0;
4980
4981         /* do not allow sys_link's with other subvols of the same device */
4982         if (root->objectid != BTRFS_I(inode)->root->objectid)
4983                 return -EXDEV;
4984
4985         if (inode->i_nlink == ~0U)
4986                 return -EMLINK;
4987
4988         err = btrfs_set_inode_index(dir, &index);
4989         if (err)
4990                 goto fail;
4991
4992         /*
4993          * 2 items for inode and inode ref
4994          * 2 items for dir items
4995          * 1 item for parent inode
4996          */
4997         trans = btrfs_start_transaction(root, 5);
4998         if (IS_ERR(trans)) {
4999                 err = PTR_ERR(trans);
5000                 goto fail;
5001         }
5002
5003         btrfs_inc_nlink(inode);
5004         inode_inc_iversion(inode);
5005         inode->i_ctime = CURRENT_TIME;
5006         ihold(inode);
5007
5008         err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
5009
5010         if (err) {
5011                 drop_inode = 1;
5012         } else {
5013                 struct dentry *parent = dentry->d_parent;
5014                 err = btrfs_update_inode(trans, root, inode);
5015                 if (err)
5016                         goto fail;
5017                 d_instantiate(dentry, inode);
5018                 btrfs_log_new_name(trans, inode, NULL, parent);
5019         }
5020
5021         nr = trans->blocks_used;
5022         btrfs_end_transaction(trans, root);
5023 fail:
5024         if (drop_inode) {
5025                 inode_dec_link_count(inode);
5026                 iput(inode);
5027         }
5028         btrfs_btree_balance_dirty(root, nr);
5029         return err;
5030 }
5031
5032 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
5033 {
5034         struct inode *inode = NULL;
5035         struct btrfs_trans_handle *trans;
5036         struct btrfs_root *root = BTRFS_I(dir)->root;
5037         int err = 0;
5038         int drop_on_err = 0;
5039         u64 objectid = 0;
5040         u64 index = 0;
5041         unsigned long nr = 1;
5042
5043         /*
5044          * 2 items for inode and ref
5045          * 2 items for dir items
5046          * 1 for xattr if selinux is on
5047          */
5048         trans = btrfs_start_transaction(root, 5);
5049         if (IS_ERR(trans))
5050                 return PTR_ERR(trans);
5051
5052         err = btrfs_find_free_ino(root, &objectid);
5053         if (err)
5054                 goto out_fail;
5055
5056         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
5057                                 dentry->d_name.len, btrfs_ino(dir), objectid,
5058                                 S_IFDIR | mode, &index);
5059         if (IS_ERR(inode)) {
5060                 err = PTR_ERR(inode);
5061                 goto out_fail;
5062         }
5063
5064         drop_on_err = 1;
5065
5066         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
5067         if (err)
5068                 goto out_fail;
5069
5070         inode->i_op = &btrfs_dir_inode_operations;
5071         inode->i_fop = &btrfs_dir_file_operations;
5072
5073         btrfs_i_size_write(inode, 0);
5074         err = btrfs_update_inode(trans, root, inode);
5075         if (err)
5076                 goto out_fail;
5077
5078         err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
5079                              dentry->d_name.len, 0, index);
5080         if (err)
5081                 goto out_fail;
5082
5083         d_instantiate(dentry, inode);
5084         drop_on_err = 0;
5085
5086 out_fail:
5087         nr = trans->blocks_used;
5088         btrfs_end_transaction(trans, root);
5089         if (drop_on_err)
5090                 iput(inode);
5091         btrfs_btree_balance_dirty(root, nr);
5092         return err;
5093 }
5094
5095 /* helper for btfs_get_extent.  Given an existing extent in the tree,
5096  * and an extent that you want to insert, deal with overlap and insert
5097  * the new extent into the tree.
5098  */
5099 static int merge_extent_mapping(struct extent_map_tree *em_tree,
5100                                 struct extent_map *existing,
5101                                 struct extent_map *em,
5102                                 u64 map_start, u64 map_len)
5103 {
5104         u64 start_diff;
5105
5106         BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
5107         start_diff = map_start - em->start;
5108         em->start = map_start;
5109         em->len = map_len;
5110         if (em->block_start < EXTENT_MAP_LAST_BYTE &&
5111             !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
5112                 em->block_start += start_diff;
5113                 em->block_len -= start_diff;
5114         }
5115         return add_extent_mapping(em_tree, em);
5116 }
5117
5118 static noinline int uncompress_inline(struct btrfs_path *path,
5119                                       struct inode *inode, struct page *page,
5120                                       size_t pg_offset, u64 extent_offset,
5121                                       struct btrfs_file_extent_item *item)
5122 {
5123         int ret;
5124         struct extent_buffer *leaf = path->nodes[0];
5125         char *tmp;
5126         size_t max_size;
5127         unsigned long inline_size;
5128         unsigned long ptr;
5129         int compress_type;
5130
5131         WARN_ON(pg_offset != 0);
5132         compress_type = btrfs_file_extent_compression(leaf, item);
5133         max_size = btrfs_file_extent_ram_bytes(leaf, item);
5134         inline_size = btrfs_file_extent_inline_item_len(leaf,
5135                                         btrfs_item_nr(leaf, path->slots[0]));
5136         tmp = kmalloc(inline_size, GFP_NOFS);
5137         if (!tmp)
5138                 return -ENOMEM;
5139         ptr = btrfs_file_extent_inline_start(item);
5140
5141         read_extent_buffer(leaf, tmp, ptr, inline_size);
5142
5143         max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
5144         ret = btrfs_decompress(compress_type, tmp, page,
5145                                extent_offset, inline_size, max_size);
5146         if (ret) {
5147                 char *kaddr = kmap_atomic(page);
5148                 unsigned long copy_size = min_t(u64,
5149                                   PAGE_CACHE_SIZE - pg_offset,
5150                                   max_size - extent_offset);
5151                 memset(kaddr + pg_offset, 0, copy_size);
5152                 kunmap_atomic(kaddr);
5153         }
5154         kfree(tmp);
5155         return 0;
5156 }
5157
5158 /*
5159  * a bit scary, this does extent mapping from logical file offset to the disk.
5160  * the ugly parts come from merging extents from the disk with the in-ram
5161  * representation.  This gets more complex because of the data=ordered code,
5162  * where the in-ram extents might be locked pending data=ordered completion.
5163  *
5164  * This also copies inline extents directly into the page.
5165  */
5166
5167 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
5168                                     size_t pg_offset, u64 start, u64 len,
5169                                     int create)
5170 {
5171         int ret;
5172         int err = 0;
5173         u64 bytenr;
5174         u64 extent_start = 0;
5175         u64 extent_end = 0;
5176         u64 objectid = btrfs_ino(inode);
5177         u32 found_type;
5178         struct btrfs_path *path = NULL;
5179         struct btrfs_root *root = BTRFS_I(inode)->root;
5180         struct btrfs_file_extent_item *item;
5181         struct extent_buffer *leaf;
5182         struct btrfs_key found_key;
5183         struct extent_map *em = NULL;
5184         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5185         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5186         struct btrfs_trans_handle *trans = NULL;
5187         int compress_type;
5188
5189 again:
5190         read_lock(&em_tree->lock);
5191         em = lookup_extent_mapping(em_tree, start, len);
5192         if (em)
5193                 em->bdev = root->fs_info->fs_devices->latest_bdev;
5194         read_unlock(&em_tree->lock);
5195
5196         if (em) {
5197                 if (em->start > start || em->start + em->len <= start)
5198                         free_extent_map(em);
5199                 else if (em->block_start == EXTENT_MAP_INLINE && page)
5200                         free_extent_map(em);
5201                 else
5202                         goto out;
5203         }
5204         em = alloc_extent_map();
5205         if (!em) {
5206                 err = -ENOMEM;
5207                 goto out;
5208         }
5209         em->bdev = root->fs_info->fs_devices->latest_bdev;
5210         em->start = EXTENT_MAP_HOLE;
5211         em->orig_start = EXTENT_MAP_HOLE;
5212         em->len = (u64)-1;
5213         em->block_len = (u64)-1;
5214
5215         if (!path) {
5216                 path = btrfs_alloc_path();
5217                 if (!path) {
5218                         err = -ENOMEM;
5219                         goto out;
5220                 }
5221                 /*
5222                  * Chances are we'll be called again, so go ahead and do
5223                  * readahead
5224                  */
5225                 path->reada = 1;
5226         }
5227
5228         ret = btrfs_lookup_file_extent(trans, root, path,
5229                                        objectid, start, trans != NULL);
5230         if (ret < 0) {
5231                 err = ret;
5232                 goto out;
5233         }
5234
5235         if (ret != 0) {
5236                 if (path->slots[0] == 0)
5237                         goto not_found;
5238                 path->slots[0]--;
5239         }
5240
5241         leaf = path->nodes[0];
5242         item = btrfs_item_ptr(leaf, path->slots[0],
5243                               struct btrfs_file_extent_item);
5244         /* are we inside the extent that was found? */
5245         btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5246         found_type = btrfs_key_type(&found_key);
5247         if (found_key.objectid != objectid ||
5248             found_type != BTRFS_EXTENT_DATA_KEY) {
5249                 goto not_found;
5250         }
5251
5252         found_type = btrfs_file_extent_type(leaf, item);
5253         extent_start = found_key.offset;
5254         compress_type = btrfs_file_extent_compression(leaf, item);
5255         if (found_type == BTRFS_FILE_EXTENT_REG ||
5256             found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5257                 extent_end = extent_start +
5258                        btrfs_file_extent_num_bytes(leaf, item);
5259         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5260                 size_t size;
5261                 size = btrfs_file_extent_inline_len(leaf, item);
5262                 extent_end = (extent_start + size + root->sectorsize - 1) &
5263                         ~((u64)root->sectorsize - 1);
5264         }
5265
5266         if (start >= extent_end) {
5267                 path->slots[0]++;
5268                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
5269                         ret = btrfs_next_leaf(root, path);
5270                         if (ret < 0) {
5271                                 err = ret;
5272                                 goto out;
5273                         }
5274                         if (ret > 0)
5275                                 goto not_found;
5276                         leaf = path->nodes[0];
5277                 }
5278                 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5279                 if (found_key.objectid != objectid ||
5280                     found_key.type != BTRFS_EXTENT_DATA_KEY)
5281                         goto not_found;
5282                 if (start + len <= found_key.offset)
5283                         goto not_found;
5284                 em->start = start;
5285                 em->len = found_key.offset - start;
5286                 goto not_found_em;
5287         }
5288
5289         if (found_type == BTRFS_FILE_EXTENT_REG ||
5290             found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5291                 em->start = extent_start;
5292                 em->len = extent_end - extent_start;
5293                 em->orig_start = extent_start -
5294                                  btrfs_file_extent_offset(leaf, item);
5295                 bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
5296                 if (bytenr == 0) {
5297                         em->block_start = EXTENT_MAP_HOLE;
5298                         goto insert;
5299                 }
5300                 if (compress_type != BTRFS_COMPRESS_NONE) {
5301                         set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5302                         em->compress_type = compress_type;
5303                         em->block_start = bytenr;
5304                         em->block_len = btrfs_file_extent_disk_num_bytes(leaf,
5305                                                                          item);
5306                 } else {
5307                         bytenr += btrfs_file_extent_offset(leaf, item);
5308                         em->block_start = bytenr;
5309                         em->block_len = em->len;
5310                         if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
5311                                 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
5312                 }
5313                 goto insert;
5314         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5315                 unsigned long ptr;
5316                 char *map;
5317                 size_t size;
5318                 size_t extent_offset;
5319                 size_t copy_size;
5320
5321                 em->block_start = EXTENT_MAP_INLINE;
5322                 if (!page || create) {
5323                         em->start = extent_start;
5324                         em->len = extent_end - extent_start;
5325                         goto out;
5326                 }
5327
5328                 size = btrfs_file_extent_inline_len(leaf, item);
5329                 extent_offset = page_offset(page) + pg_offset - extent_start;
5330                 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
5331                                 size - extent_offset);
5332                 em->start = extent_start + extent_offset;
5333                 em->len = (copy_size + root->sectorsize - 1) &
5334                         ~((u64)root->sectorsize - 1);
5335                 em->orig_start = EXTENT_MAP_INLINE;
5336                 if (compress_type) {
5337                         set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5338                         em->compress_type = compress_type;
5339                 }
5340                 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
5341                 if (create == 0 && !PageUptodate(page)) {
5342                         if (btrfs_file_extent_compression(leaf, item) !=
5343                             BTRFS_COMPRESS_NONE) {
5344                                 ret = uncompress_inline(path, inode, page,
5345                                                         pg_offset,
5346                                                         extent_offset, item);
5347                                 BUG_ON(ret); /* -ENOMEM */
5348                         } else {
5349                                 map = kmap(page);
5350                                 read_extent_buffer(leaf, map + pg_offset, ptr,
5351                                                    copy_size);
5352                                 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
5353                                         memset(map + pg_offset + copy_size, 0,
5354                                                PAGE_CACHE_SIZE - pg_offset -
5355                                                copy_size);
5356                                 }
5357                                 kunmap(page);
5358                         }
5359                         flush_dcache_page(page);
5360                 } else if (create && PageUptodate(page)) {
5361                         BUG();
5362                         if (!trans) {
5363                                 kunmap(page);
5364                                 free_extent_map(em);
5365                                 em = NULL;
5366
5367                                 btrfs_release_path(path);
5368                                 trans = btrfs_join_transaction(root);
5369
5370                                 if (IS_ERR(trans))
5371                                         return ERR_CAST(trans);
5372                                 goto again;
5373                         }
5374                         map = kmap(page);
5375                         write_extent_buffer(leaf, map + pg_offset, ptr,
5376                                             copy_size);
5377                         kunmap(page);
5378                         btrfs_mark_buffer_dirty(leaf);
5379                 }
5380                 set_extent_uptodate(io_tree, em->start,
5381                                     extent_map_end(em) - 1, NULL, GFP_NOFS);
5382                 goto insert;
5383         } else {
5384                 printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
5385                 WARN_ON(1);
5386         }
5387 not_found:
5388         em->start = start;
5389         em->len = len;
5390 not_found_em:
5391         em->block_start = EXTENT_MAP_HOLE;
5392         set_bit(EXTENT_FLAG_VACANCY, &em->flags);
5393 insert:
5394         btrfs_release_path(path);
5395         if (em->start > start || extent_map_end(em) <= start) {
5396                 printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed "
5397                        "[%llu %llu]\n", (unsigned long long)em->start,
5398                        (unsigned long long)em->len,
5399                        (unsigned long long)start,
5400                        (unsigned long long)len);
5401                 err = -EIO;
5402                 goto out;
5403         }
5404
5405         err = 0;
5406         write_lock(&em_tree->lock);
5407         ret = add_extent_mapping(em_tree, em);
5408         /* it is possible that someone inserted the extent into the tree
5409          * while we had the lock dropped.  It is also possible that
5410          * an overlapping map exists in the tree
5411          */
5412         if (ret == -EEXIST) {
5413                 struct extent_map *existing;
5414
5415                 ret = 0;
5416
5417                 existing = lookup_extent_mapping(em_tree, start, len);
5418                 if (existing && (existing->start > start ||
5419                     existing->start + existing->len <= start)) {
5420                         free_extent_map(existing);
5421                         existing = NULL;
5422                 }
5423                 if (!existing) {
5424                         existing = lookup_extent_mapping(em_tree, em->start,
5425                                                          em->len);
5426                         if (existing) {
5427                                 err = merge_extent_mapping(em_tree, existing,
5428                                                            em, start,
5429                                                            root->sectorsize);
5430                                 free_extent_map(existing);
5431                                 if (err) {
5432                                         free_extent_map(em);
5433                                         em = NULL;
5434                                 }
5435                         } else {
5436                                 err = -EIO;
5437                                 free_extent_map(em);
5438                                 em = NULL;
5439                         }
5440                 } else {
5441                         free_extent_map(em);
5442                         em = existing;
5443                         err = 0;
5444                 }
5445         }
5446         write_unlock(&em_tree->lock);
5447 out:
5448
5449         trace_btrfs_get_extent(root, em);
5450
5451         if (path)
5452                 btrfs_free_path(path);
5453         if (trans) {
5454                 ret = btrfs_end_transaction(trans, root);
5455                 if (!err)
5456                         err = ret;
5457         }
5458         if (err) {
5459                 free_extent_map(em);
5460                 return ERR_PTR(err);
5461         }
5462         BUG_ON(!em); /* Error is always set */
5463         return em;
5464 }
5465
5466 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
5467                                            size_t pg_offset, u64 start, u64 len,
5468                                            int create)
5469 {
5470         struct extent_map *em;
5471         struct extent_map *hole_em = NULL;
5472         u64 range_start = start;
5473         u64 end;
5474         u64 found;
5475         u64 found_end;
5476         int err = 0;
5477
5478         em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
5479         if (IS_ERR(em))
5480                 return em;
5481         if (em) {
5482                 /*
5483                  * if our em maps to a hole, there might
5484                  * actually be delalloc bytes behind it
5485                  */
5486                 if (em->block_start != EXTENT_MAP_HOLE)
5487                         return em;
5488                 else
5489                         hole_em = em;
5490         }
5491
5492         /* check to see if we've wrapped (len == -1 or similar) */
5493         end = start + len;
5494         if (end < start)
5495                 end = (u64)-1;
5496         else
5497                 end -= 1;
5498
5499         em = NULL;
5500
5501         /* ok, we didn't find anything, lets look for delalloc */
5502         found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
5503                                  end, len, EXTENT_DELALLOC, 1);
5504         found_end = range_start + found;
5505         if (found_end < range_start)
5506                 found_end = (u64)-1;
5507
5508         /*
5509          * we didn't find anything useful, return
5510          * the original results from get_extent()
5511          */
5512         if (range_start > end || found_end <= start) {
5513                 em = hole_em;
5514                 hole_em = NULL;
5515                 goto out;
5516         }
5517
5518         /* adjust the range_start to make sure it doesn't
5519          * go backwards from the start they passed in
5520          */
5521         range_start = max(start,range_start);
5522         found = found_end - range_start;
5523
5524         if (found > 0) {
5525                 u64 hole_start = start;
5526                 u64 hole_len = len;
5527
5528                 em = alloc_extent_map();
5529                 if (!em) {
5530                         err = -ENOMEM;
5531                         goto out;
5532                 }
5533                 /*
5534                  * when btrfs_get_extent can't find anything it
5535                  * returns one huge hole
5536                  *
5537                  * make sure what it found really fits our range, and
5538                  * adjust to make sure it is based on the start from
5539                  * the caller
5540                  */
5541                 if (hole_em) {
5542                         u64 calc_end = extent_map_end(hole_em);
5543
5544                         if (calc_end <= start || (hole_em->start > end)) {
5545                                 free_extent_map(hole_em);
5546                                 hole_em = NULL;
5547                         } else {
5548                                 hole_start = max(hole_em->start, start);
5549                                 hole_len = calc_end - hole_start;
5550                         }
5551                 }
5552                 em->bdev = NULL;
5553                 if (hole_em && range_start > hole_start) {
5554                         /* our hole starts before our delalloc, so we
5555                          * have to return just the parts of the hole
5556                          * that go until  the delalloc starts
5557                          */
5558                         em->len = min(hole_len,
5559                                       range_start - hole_start);
5560                         em->start = hole_start;
5561                         em->orig_start = hole_start;
5562                         /*
5563                          * don't adjust block start at all,
5564                          * it is fixed at EXTENT_MAP_HOLE
5565                          */
5566                         em->block_start = hole_em->block_start;
5567                         em->block_len = hole_len;
5568                 } else {
5569                         em->start = range_start;
5570                         em->len = found;
5571                         em->orig_start = range_start;
5572                         em->block_start = EXTENT_MAP_DELALLOC;
5573                         em->block_len = found;
5574                 }
5575         } else if (hole_em) {
5576                 return hole_em;
5577         }
5578 out:
5579
5580         free_extent_map(hole_em);
5581         if (err) {
5582                 free_extent_map(em);
5583                 return ERR_PTR(err);
5584         }
5585         return em;
5586 }
5587
5588 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
5589                                                   struct extent_map *em,
5590                                                   u64 start, u64 len)
5591 {
5592         struct btrfs_root *root = BTRFS_I(inode)->root;
5593         struct btrfs_trans_handle *trans;
5594         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5595         struct btrfs_key ins;
5596         u64 alloc_hint;
5597         int ret;
5598         bool insert = false;
5599
5600         /*
5601          * Ok if the extent map we looked up is a hole and is for the exact
5602          * range we want, there is no reason to allocate a new one, however if
5603          * it is not right then we need to free this one and drop the cache for
5604          * our range.
5605          */
5606         if (em->block_start != EXTENT_MAP_HOLE || em->start != start ||
5607             em->len != len) {
5608                 free_extent_map(em);
5609                 em = NULL;
5610                 insert = true;
5611                 btrfs_drop_extent_cache(inode, start, start + len - 1, 0);
5612         }
5613
5614         trans = btrfs_join_transaction(root);
5615         if (IS_ERR(trans))
5616                 return ERR_CAST(trans);
5617
5618         if (start <= BTRFS_I(inode)->disk_i_size && len < 64 * 1024)
5619                 btrfs_add_inode_defrag(trans, inode);
5620
5621         trans->block_rsv = &root->fs_info->delalloc_block_rsv;
5622
5623         alloc_hint = get_extent_allocation_hint(inode, start, len);
5624         ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
5625                                    alloc_hint, &ins, 1);
5626         if (ret) {
5627                 em = ERR_PTR(ret);
5628                 goto out;
5629         }
5630
5631         if (!em) {
5632                 em = alloc_extent_map();
5633                 if (!em) {
5634                         em = ERR_PTR(-ENOMEM);
5635                         goto out;
5636                 }
5637         }
5638
5639         em->start = start;
5640         em->orig_start = em->start;
5641         em->len = ins.offset;
5642
5643         em->block_start = ins.objectid;
5644         em->block_len = ins.offset;
5645         em->bdev = root->fs_info->fs_devices->latest_bdev;
5646
5647         /*
5648          * We need to do this because if we're using the original em we searched
5649          * for, we could have EXTENT_FLAG_VACANCY set, and we don't want that.
5650          */
5651         em->flags = 0;
5652         set_bit(EXTENT_FLAG_PINNED, &em->flags);
5653
5654         while (insert) {
5655                 write_lock(&em_tree->lock);
5656                 ret = add_extent_mapping(em_tree, em);
5657                 write_unlock(&em_tree->lock);
5658                 if (ret != -EEXIST)
5659                         break;
5660                 btrfs_drop_extent_cache(inode, start, start + em->len - 1, 0);
5661         }
5662
5663         ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
5664                                            ins.offset, ins.offset, 0);
5665         if (ret) {
5666                 btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
5667                 em = ERR_PTR(ret);
5668         }
5669 out:
5670         btrfs_end_transaction(trans, root);
5671         return em;
5672 }
5673
5674 /*
5675  * returns 1 when the nocow is safe, < 1 on error, 0 if the
5676  * block must be cow'd
5677  */
5678 static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
5679                                       struct inode *inode, u64 offset, u64 len)
5680 {
5681         struct btrfs_path *path;
5682         int ret;
5683         struct extent_buffer *leaf;
5684         struct btrfs_root *root = BTRFS_I(inode)->root;
5685         struct btrfs_file_extent_item *fi;
5686         struct btrfs_key key;
5687         u64 disk_bytenr;
5688         u64 backref_offset;
5689         u64 extent_end;
5690         u64 num_bytes;
5691         int slot;
5692         int found_type;
5693
5694         path = btrfs_alloc_path();
5695         if (!path)
5696                 return -ENOMEM;
5697
5698         ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
5699                                        offset, 0);
5700         if (ret < 0)
5701                 goto out;
5702
5703         slot = path->slots[0];
5704         if (ret == 1) {
5705                 if (slot == 0) {
5706                         /* can't find the item, must cow */
5707                         ret = 0;
5708                         goto out;
5709                 }
5710                 slot--;
5711         }
5712         ret = 0;
5713         leaf = path->nodes[0];
5714         btrfs_item_key_to_cpu(leaf, &key, slot);
5715         if (key.objectid != btrfs_ino(inode) ||
5716             key.type != BTRFS_EXTENT_DATA_KEY) {
5717                 /* not our file or wrong item type, must cow */
5718                 goto out;
5719         }
5720
5721         if (key.offset > offset) {
5722                 /* Wrong offset, must cow */
5723                 goto out;
5724         }
5725
5726         fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
5727         found_type = btrfs_file_extent_type(leaf, fi);
5728         if (found_type != BTRFS_FILE_EXTENT_REG &&
5729             found_type != BTRFS_FILE_EXTENT_PREALLOC) {
5730                 /* not a regular extent, must cow */
5731                 goto out;
5732         }
5733         disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
5734         backref_offset = btrfs_file_extent_offset(leaf, fi);
5735
5736         extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
5737         if (extent_end < offset + len) {
5738                 /* extent doesn't include our full range, must cow */
5739                 goto out;
5740         }
5741
5742         if (btrfs_extent_readonly(root, disk_bytenr))
5743                 goto out;
5744
5745         /*
5746          * look for other files referencing this extent, if we
5747          * find any we must cow
5748          */
5749         if (btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
5750                                   key.offset - backref_offset, disk_bytenr))
5751                 goto out;
5752
5753         /*
5754          * adjust disk_bytenr and num_bytes to cover just the bytes
5755          * in this extent we are about to write.  If there
5756          * are any csums in that range we have to cow in order
5757          * to keep the csums correct
5758          */
5759         disk_bytenr += backref_offset;
5760         disk_bytenr += offset - key.offset;
5761         num_bytes = min(offset + len, extent_end) - offset;
5762         if (csum_exist_in_range(root, disk_bytenr, num_bytes))
5763                                 goto out;
5764         /*
5765          * all of the above have passed, it is safe to overwrite this extent
5766          * without cow
5767          */
5768         ret = 1;
5769 out:
5770         btrfs_free_path(path);
5771         return ret;
5772 }
5773
5774 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
5775                               struct extent_state **cached_state, int writing)
5776 {
5777         struct btrfs_ordered_extent *ordered;
5778         int ret = 0;
5779
5780         while (1) {
5781                 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
5782                                  0, cached_state);
5783                 /*
5784                  * We're concerned with the entire range that we're going to be
5785                  * doing DIO to, so we need to make sure theres no ordered
5786                  * extents in this range.
5787                  */
5788                 ordered = btrfs_lookup_ordered_range(inode, lockstart,
5789                                                      lockend - lockstart + 1);
5790
5791                 /*
5792                  * We need to make sure there are no buffered pages in this
5793                  * range either, we could have raced between the invalidate in
5794                  * generic_file_direct_write and locking the extent.  The
5795                  * invalidate needs to happen so that reads after a write do not
5796                  * get stale data.
5797                  */
5798                 if (!ordered && (!writing ||
5799                     !test_range_bit(&BTRFS_I(inode)->io_tree,
5800                                     lockstart, lockend, EXTENT_UPTODATE, 0,
5801                                     *cached_state)))
5802                         break;
5803
5804                 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
5805                                      cached_state, GFP_NOFS);
5806
5807                 if (ordered) {
5808                         btrfs_start_ordered_extent(inode, ordered, 1);
5809                         btrfs_put_ordered_extent(ordered);
5810                 } else {
5811                         /* Screw you mmap */
5812                         ret = filemap_write_and_wait_range(inode->i_mapping,
5813                                                            lockstart,
5814                                                            lockend);
5815                         if (ret)
5816                                 break;
5817
5818                         /*
5819                          * If we found a page that couldn't be invalidated just
5820                          * fall back to buffered.
5821                          */
5822                         ret = invalidate_inode_pages2_range(inode->i_mapping,
5823                                         lockstart >> PAGE_CACHE_SHIFT,
5824                                         lockend >> PAGE_CACHE_SHIFT);
5825                         if (ret)
5826                                 break;
5827                 }
5828
5829                 cond_resched();
5830         }
5831
5832         return ret;
5833 }
5834
5835 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
5836                                    struct buffer_head *bh_result, int create)
5837 {
5838         struct extent_map *em;
5839         struct btrfs_root *root = BTRFS_I(inode)->root;
5840         struct extent_state *cached_state = NULL;
5841         u64 start = iblock << inode->i_blkbits;
5842         u64 lockstart, lockend;
5843         u64 len = bh_result->b_size;
5844         struct btrfs_trans_handle *trans;
5845         int unlock_bits = EXTENT_LOCKED;
5846         int ret;
5847
5848         if (create) {
5849                 ret = btrfs_delalloc_reserve_space(inode, len);
5850                 if (ret)
5851                         return ret;
5852                 unlock_bits |= EXTENT_DELALLOC | EXTENT_DIRTY;
5853         } else {
5854                 len = min_t(u64, len, root->sectorsize);
5855         }
5856
5857         lockstart = start;
5858         lockend = start + len - 1;
5859
5860         /*
5861          * If this errors out it's because we couldn't invalidate pagecache for
5862          * this range and we need to fallback to buffered.
5863          */
5864         if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
5865                 return -ENOTBLK;
5866
5867         if (create) {
5868                 ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
5869                                      lockend, EXTENT_DELALLOC, NULL,
5870                                      &cached_state, GFP_NOFS);
5871                 if (ret)
5872                         goto unlock_err;
5873         }
5874
5875         em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
5876         if (IS_ERR(em)) {
5877                 ret = PTR_ERR(em);
5878                 goto unlock_err;
5879         }
5880
5881         /*
5882          * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
5883          * io.  INLINE is special, and we could probably kludge it in here, but
5884          * it's still buffered so for safety lets just fall back to the generic
5885          * buffered path.
5886          *
5887          * For COMPRESSED we _have_ to read the entire extent in so we can
5888          * decompress it, so there will be buffering required no matter what we
5889          * do, so go ahead and fallback to buffered.
5890          *
5891          * We return -ENOTBLK because thats what makes DIO go ahead and go back
5892          * to buffered IO.  Don't blame me, this is the price we pay for using
5893          * the generic code.
5894          */
5895         if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
5896             em->block_start == EXTENT_MAP_INLINE) {
5897                 free_extent_map(em);
5898                 ret = -ENOTBLK;
5899                 goto unlock_err;
5900         }
5901
5902         /* Just a good old fashioned hole, return */
5903         if (!create && (em->block_start == EXTENT_MAP_HOLE ||
5904                         test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
5905                 free_extent_map(em);
5906                 ret = 0;
5907                 goto unlock_err;
5908         }
5909
5910         /*
5911          * We don't allocate a new extent in the following cases
5912          *
5913          * 1) The inode is marked as NODATACOW.  In this case we'll just use the
5914          * existing extent.
5915          * 2) The extent is marked as PREALLOC.  We're good to go here and can
5916          * just use the extent.
5917          *
5918          */
5919         if (!create) {
5920                 len = min(len, em->len - (start - em->start));
5921                 lockstart = start + len;
5922                 goto unlock;
5923         }
5924
5925         if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
5926             ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
5927              em->block_start != EXTENT_MAP_HOLE)) {
5928                 int type;
5929                 int ret;
5930                 u64 block_start;
5931
5932                 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5933                         type = BTRFS_ORDERED_PREALLOC;
5934                 else
5935                         type = BTRFS_ORDERED_NOCOW;
5936                 len = min(len, em->len - (start - em->start));
5937                 block_start = em->block_start + (start - em->start);
5938
5939                 /*
5940                  * we're not going to log anything, but we do need
5941                  * to make sure the current transaction stays open
5942                  * while we look for nocow cross refs
5943                  */
5944                 trans = btrfs_join_transaction(root);
5945                 if (IS_ERR(trans))
5946                         goto must_cow;
5947
5948                 if (can_nocow_odirect(trans, inode, start, len) == 1) {
5949                         ret = btrfs_add_ordered_extent_dio(inode, start,
5950                                            block_start, len, len, type);
5951                         btrfs_end_transaction(trans, root);
5952                         if (ret) {
5953                                 free_extent_map(em);
5954                                 goto unlock_err;
5955                         }
5956                         goto unlock;
5957                 }
5958                 btrfs_end_transaction(trans, root);
5959         }
5960 must_cow:
5961         /*
5962          * this will cow the extent, reset the len in case we changed
5963          * it above
5964          */
5965         len = bh_result->b_size;
5966         em = btrfs_new_extent_direct(inode, em, start, len);
5967         if (IS_ERR(em)) {
5968                 ret = PTR_ERR(em);
5969                 goto unlock_err;
5970         }
5971         len = min(len, em->len - (start - em->start));
5972 unlock:
5973         bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
5974                 inode->i_blkbits;
5975         bh_result->b_size = len;
5976         bh_result->b_bdev = em->bdev;
5977         set_buffer_mapped(bh_result);
5978         if (create) {
5979                 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
5980                         set_buffer_new(bh_result);
5981
5982                 /*
5983                  * Need to update the i_size under the extent lock so buffered
5984                  * readers will get the updated i_size when we unlock.
5985                  */
5986                 if (start + len > i_size_read(inode))
5987                         i_size_write(inode, start + len);
5988         }
5989
5990         /*
5991          * In the case of write we need to clear and unlock the entire range,
5992          * in the case of read we need to unlock only the end area that we
5993          * aren't using if there is any left over space.
5994          */
5995         if (lockstart < lockend)
5996                 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
5997                                  unlock_bits, 1, 0, &cached_state, GFP_NOFS);
5998         else
5999                 free_extent_state(cached_state);
6000
6001         free_extent_map(em);
6002
6003         return 0;
6004
6005 unlock_err:
6006         if (create)
6007                 unlock_bits |= EXTENT_DO_ACCOUNTING;
6008
6009         clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
6010                          unlock_bits, 1, 0, &cached_state, GFP_NOFS);
6011         return ret;
6012 }
6013
6014 struct btrfs_dio_private {
6015         struct inode *inode;
6016         u64 logical_offset;
6017         u64 disk_bytenr;
6018         u64 bytes;
6019         void *private;
6020
6021         /* number of bios pending for this dio */
6022         atomic_t pending_bios;
6023
6024         /* IO errors */
6025         int errors;
6026
6027         struct bio *orig_bio;
6028 };
6029
6030 static void btrfs_endio_direct_read(struct bio *bio, int err)
6031 {
6032         struct btrfs_dio_private *dip = bio->bi_private;
6033         struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
6034         struct bio_vec *bvec = bio->bi_io_vec;
6035         struct inode *inode = dip->inode;
6036         struct btrfs_root *root = BTRFS_I(inode)->root;
6037         u64 start;
6038
6039         start = dip->logical_offset;
6040         do {
6041                 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
6042                         struct page *page = bvec->bv_page;
6043                         char *kaddr;
6044                         u32 csum = ~(u32)0;
6045                         u64 private = ~(u32)0;
6046                         unsigned long flags;
6047
6048                         if (get_state_private(&BTRFS_I(inode)->io_tree,
6049                                               start, &private))
6050                                 goto failed;
6051                         local_irq_save(flags);
6052                         kaddr = kmap_atomic(page);
6053                         csum = btrfs_csum_data(root, kaddr + bvec->bv_offset,
6054                                                csum, bvec->bv_len);
6055                         btrfs_csum_final(csum, (char *)&csum);
6056                         kunmap_atomic(kaddr);
6057                         local_irq_restore(flags);
6058
6059                         flush_dcache_page(bvec->bv_page);
6060                         if (csum != private) {
6061 failed:
6062                                 printk(KERN_ERR "btrfs csum failed ino %llu off"
6063                                       " %llu csum %u private %u\n",
6064                                       (unsigned long long)btrfs_ino(inode),
6065                                       (unsigned long long)start,
6066                                       csum, (unsigned)private);
6067                                 err = -EIO;
6068                         }
6069                 }
6070
6071                 start += bvec->bv_len;
6072                 bvec++;
6073         } while (bvec <= bvec_end);
6074
6075         unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
6076                       dip->logical_offset + dip->bytes - 1);
6077         bio->bi_private = dip->private;
6078
6079         kfree(dip);
6080
6081         /* If we had a csum failure make sure to clear the uptodate flag */
6082         if (err)
6083                 clear_bit(BIO_UPTODATE, &bio->bi_flags);
6084         dio_end_io(bio, err);
6085 }
6086
6087 static void btrfs_endio_direct_write(struct bio *bio, int err)
6088 {
6089         struct btrfs_dio_private *dip = bio->bi_private;
6090         struct inode *inode = dip->inode;
6091         struct btrfs_root *root = BTRFS_I(inode)->root;
6092         struct btrfs_ordered_extent *ordered = NULL;
6093         u64 ordered_offset = dip->logical_offset;
6094         u64 ordered_bytes = dip->bytes;
6095         int ret;
6096
6097         if (err)
6098                 goto out_done;
6099 again:
6100         ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
6101                                                    &ordered_offset,
6102                                                    ordered_bytes, !err);
6103         if (!ret)
6104                 goto out_test;
6105
6106         ordered->work.func = finish_ordered_fn;
6107         ordered->work.flags = 0;
6108         btrfs_queue_worker(&root->fs_info->endio_write_workers,
6109                            &ordered->work);
6110 out_test:
6111         /*
6112          * our bio might span multiple ordered extents.  If we haven't
6113          * completed the accounting for the whole dio, go back and try again
6114          */
6115         if (ordered_offset < dip->logical_offset + dip->bytes) {
6116                 ordered_bytes = dip->logical_offset + dip->bytes -
6117                         ordered_offset;
6118                 ordered = NULL;
6119                 goto again;
6120         }
6121 out_done:
6122         bio->bi_private = dip->private;
6123
6124         kfree(dip);
6125
6126         /* If we had an error make sure to clear the uptodate flag */
6127         if (err)
6128                 clear_bit(BIO_UPTODATE, &bio->bi_flags);
6129         dio_end_io(bio, err);
6130 }
6131
6132 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
6133                                     struct bio *bio, int mirror_num,
6134                                     unsigned long bio_flags, u64 offset)
6135 {
6136         int ret;
6137         struct btrfs_root *root = BTRFS_I(inode)->root;
6138         ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
6139         BUG_ON(ret); /* -ENOMEM */
6140         return 0;
6141 }
6142
6143 static void btrfs_end_dio_bio(struct bio *bio, int err)
6144 {
6145         struct btrfs_dio_private *dip = bio->bi_private;
6146
6147         if (err) {
6148                 printk(KERN_ERR "btrfs direct IO failed ino %llu rw %lu "
6149                       "sector %#Lx len %u err no %d\n",
6150                       (unsigned long long)btrfs_ino(dip->inode), bio->bi_rw,
6151                       (unsigned long long)bio->bi_sector, bio->bi_size, err);
6152                 dip->errors = 1;
6153
6154                 /*
6155                  * before atomic variable goto zero, we must make sure
6156                  * dip->errors is perceived to be set.
6157                  */
6158                 smp_mb__before_atomic_dec();
6159         }
6160
6161         /* if there are more bios still pending for this dio, just exit */
6162         if (!atomic_dec_and_test(&dip->pending_bios))
6163                 goto out;
6164
6165         if (dip->errors)
6166                 bio_io_error(dip->orig_bio);
6167         else {
6168                 set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
6169                 bio_endio(dip->orig_bio, 0);
6170         }
6171 out:
6172         bio_put(bio);
6173 }
6174
6175 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
6176                                        u64 first_sector, gfp_t gfp_flags)
6177 {
6178         int nr_vecs = bio_get_nr_vecs(bdev);
6179         return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
6180 }
6181
6182 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
6183                                          int rw, u64 file_offset, int skip_sum,
6184                                          int async_submit)
6185 {
6186         int write = rw & REQ_WRITE;
6187         struct btrfs_root *root = BTRFS_I(inode)->root;
6188         int ret;
6189
6190         bio_get(bio);
6191
6192         if (!write) {
6193                 ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
6194                 if (ret)
6195                         goto err;
6196         }
6197
6198         if (skip_sum)
6199                 goto map;
6200
6201         if (write && async_submit) {
6202                 ret = btrfs_wq_submit_bio(root->fs_info,
6203                                    inode, rw, bio, 0, 0,
6204                                    file_offset,
6205                                    __btrfs_submit_bio_start_direct_io,
6206                                    __btrfs_submit_bio_done);
6207                 goto err;
6208         } else if (write) {
6209                 /*
6210                  * If we aren't doing async submit, calculate the csum of the
6211                  * bio now.
6212                  */
6213                 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
6214                 if (ret)
6215                         goto err;
6216         } else if (!skip_sum) {
6217                 ret = btrfs_lookup_bio_sums_dio(root, inode, bio, file_offset);
6218                 if (ret)
6219                         goto err;
6220         }
6221
6222 map:
6223         ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
6224 err:
6225         bio_put(bio);
6226         return ret;
6227 }
6228
6229 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
6230                                     int skip_sum)
6231 {
6232         struct inode *inode = dip->inode;
6233         struct btrfs_root *root = BTRFS_I(inode)->root;
6234         struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
6235         struct bio *bio;
6236         struct bio *orig_bio = dip->orig_bio;
6237         struct bio_vec *bvec = orig_bio->bi_io_vec;
6238         u64 start_sector = orig_bio->bi_sector;
6239         u64 file_offset = dip->logical_offset;
6240         u64 submit_len = 0;
6241         u64 map_length;
6242         int nr_pages = 0;
6243         int ret = 0;
6244         int async_submit = 0;
6245
6246         map_length = orig_bio->bi_size;
6247         ret = btrfs_map_block(map_tree, READ, start_sector << 9,
6248                               &map_length, NULL, 0);
6249         if (ret) {
6250                 bio_put(orig_bio);
6251                 return -EIO;
6252         }
6253
6254         if (map_length >= orig_bio->bi_size) {
6255                 bio = orig_bio;
6256                 goto submit;
6257         }
6258
6259         async_submit = 1;
6260         bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
6261         if (!bio)
6262                 return -ENOMEM;
6263         bio->bi_private = dip;
6264         bio->bi_end_io = btrfs_end_dio_bio;
6265         atomic_inc(&dip->pending_bios);
6266
6267         while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
6268                 if (unlikely(map_length < submit_len + bvec->bv_len ||
6269                     bio_add_page(bio, bvec->bv_page, bvec->bv_len,
6270                                  bvec->bv_offset) < bvec->bv_len)) {
6271                         /*
6272                          * inc the count before we submit the bio so
6273                          * we know the end IO handler won't happen before
6274                          * we inc the count. Otherwise, the dip might get freed
6275                          * before we're done setting it up
6276                          */
6277                         atomic_inc(&dip->pending_bios);
6278                         ret = __btrfs_submit_dio_bio(bio, inode, rw,
6279                                                      file_offset, skip_sum,
6280                                                      async_submit);
6281                         if (ret) {
6282                                 bio_put(bio);
6283                                 atomic_dec(&dip->pending_bios);
6284                                 goto out_err;
6285                         }
6286
6287                         start_sector += submit_len >> 9;
6288                         file_offset += submit_len;
6289
6290                         submit_len = 0;
6291                         nr_pages = 0;
6292
6293                         bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
6294                                                   start_sector, GFP_NOFS);
6295                         if (!bio)
6296                                 goto out_err;
6297                         bio->bi_private = dip;
6298                         bio->bi_end_io = btrfs_end_dio_bio;
6299
6300                         map_length = orig_bio->bi_size;
6301                         ret = btrfs_map_block(map_tree, READ, start_sector << 9,
6302                                               &map_length, NULL, 0);
6303                         if (ret) {
6304                                 bio_put(bio);
6305                                 goto out_err;
6306                         }
6307                 } else {
6308                         submit_len += bvec->bv_len;
6309                         nr_pages ++;
6310                         bvec++;
6311                 }
6312         }
6313
6314 submit:
6315         ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
6316                                      async_submit);
6317         if (!ret)
6318                 return 0;
6319
6320         bio_put(bio);
6321 out_err:
6322         dip->errors = 1;
6323         /*
6324          * before atomic variable goto zero, we must
6325          * make sure dip->errors is perceived to be set.
6326          */
6327         smp_mb__before_atomic_dec();
6328         if (atomic_dec_and_test(&dip->pending_bios))
6329                 bio_io_error(dip->orig_bio);
6330
6331         /* bio_end_io() will handle error, so we needn't return it */
6332         return 0;
6333 }
6334
6335 static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
6336                                 loff_t file_offset)
6337 {
6338         struct btrfs_root *root = BTRFS_I(inode)->root;
6339         struct btrfs_dio_private *dip;
6340         struct bio_vec *bvec = bio->bi_io_vec;
6341         int skip_sum;
6342         int write = rw & REQ_WRITE;
6343         int ret = 0;
6344
6345         skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
6346
6347         dip = kmalloc(sizeof(*dip), GFP_NOFS);
6348         if (!dip) {
6349                 ret = -ENOMEM;
6350                 goto free_ordered;
6351         }
6352
6353         dip->private = bio->bi_private;
6354         dip->inode = inode;
6355         dip->logical_offset = file_offset;
6356
6357         dip->bytes = 0;
6358         do {
6359                 dip->bytes += bvec->bv_len;
6360                 bvec++;
6361         } while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));
6362
6363         dip->disk_bytenr = (u64)bio->bi_sector << 9;
6364         bio->bi_private = dip;
6365         dip->errors = 0;
6366         dip->orig_bio = bio;
6367         atomic_set(&dip->pending_bios, 0);
6368
6369         if (write)
6370                 bio->bi_end_io = btrfs_endio_direct_write;
6371         else
6372                 bio->bi_end_io = btrfs_endio_direct_read;
6373
6374         ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
6375         if (!ret)
6376                 return;
6377 free_ordered:
6378         /*
6379          * If this is a write, we need to clean up the reserved space and kill
6380          * the ordered extent.
6381          */
6382         if (write) {
6383                 struct btrfs_ordered_extent *ordered;
6384                 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
6385                 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
6386                     !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
6387                         btrfs_free_reserved_extent(root, ordered->start,
6388                                                    ordered->disk_len);
6389                 btrfs_put_ordered_extent(ordered);
6390                 btrfs_put_ordered_extent(ordered);
6391         }
6392         bio_endio(bio, ret);
6393 }
6394
6395 static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
6396                         const struct iovec *iov, loff_t offset,
6397                         unsigned long nr_segs)
6398 {
6399         int seg;
6400         int i;
6401         size_t size;
6402         unsigned long addr;
6403         unsigned blocksize_mask = root->sectorsize - 1;
6404         ssize_t retval = -EINVAL;
6405         loff_t end = offset;
6406
6407         if (offset & blocksize_mask)
6408                 goto out;
6409
6410         /* Check the memory alignment.  Blocks cannot straddle pages */
6411         for (seg = 0; seg < nr_segs; seg++) {
6412                 addr = (unsigned long)iov[seg].iov_base;
6413                 size = iov[seg].iov_len;
6414                 end += size;
6415                 if ((addr & blocksize_mask) || (size & blocksize_mask))
6416                         goto out;
6417
6418                 /* If this is a write we don't need to check anymore */
6419                 if (rw & WRITE)
6420                         continue;
6421
6422                 /*
6423                  * Check to make sure we don't have duplicate iov_base's in this
6424                  * iovec, if so return EINVAL, otherwise we'll get csum errors
6425                  * when reading back.
6426                  */
6427                 for (i = seg + 1; i < nr_segs; i++) {
6428                         if (iov[seg].iov_base == iov[i].iov_base)
6429                                 goto out;
6430                 }
6431         }
6432         retval = 0;
6433 out:
6434         return retval;
6435 }
6436
6437 static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
6438                         const struct iovec *iov, loff_t offset,
6439                         unsigned long nr_segs)
6440 {
6441         struct file *file = iocb->ki_filp;
6442         struct inode *inode = file->f_mapping->host;
6443
6444         if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
6445                             offset, nr_segs))
6446                 return 0;
6447
6448         return __blockdev_direct_IO(rw, iocb, inode,
6449                    BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
6450                    iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
6451                    btrfs_submit_direct, 0);
6452 }
6453
6454 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
6455                 __u64 start, __u64 len)
6456 {
6457         return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
6458 }
6459
6460 int btrfs_readpage(struct file *file, struct page *page)
6461 {
6462         struct extent_io_tree *tree;
6463         tree = &BTRFS_I(page->mapping->host)->io_tree;
6464         return extent_read_full_page(tree, page, btrfs_get_extent, 0);
6465 }
6466
6467 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
6468 {
6469         struct extent_io_tree *tree;
6470
6471
6472         if (current->flags & PF_MEMALLOC) {
6473                 redirty_page_for_writepage(wbc, page);
6474                 unlock_page(page);
6475                 return 0;
6476         }
6477         tree = &BTRFS_I(page->mapping->host)->io_tree;
6478         return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
6479 }
6480
6481 int btrfs_writepages(struct address_space *mapping,
6482                      struct writeback_control *wbc)
6483 {
6484         struct extent_io_tree *tree;
6485
6486         tree = &BTRFS_I(mapping->host)->io_tree;
6487         return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
6488 }
6489
6490 static int
6491 btrfs_readpages(struct file *file, struct address_space *mapping,
6492                 struct list_head *pages, unsigned nr_pages)
6493 {
6494         struct extent_io_tree *tree;
6495         tree = &BTRFS_I(mapping->host)->io_tree;
6496         return extent_readpages(tree, mapping, pages, nr_pages,
6497                                 btrfs_get_extent);
6498 }
6499 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6500 {
6501         struct extent_io_tree *tree;
6502         struct extent_map_tree *map;
6503         int ret;
6504
6505         tree = &BTRFS_I(page->mapping->host)->io_tree;
6506         map = &BTRFS_I(page->mapping->host)->extent_tree;
6507         ret = try_release_extent_mapping(map, tree, page, gfp_flags);
6508         if (ret == 1) {
6509                 ClearPagePrivate(page);
6510                 set_page_private(page, 0);
6511                 page_cache_release(page);
6512         }
6513         return ret;
6514 }
6515
6516 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
6517 {
6518         if (PageWriteback(page) || PageDirty(page))
6519                 return 0;
6520         return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
6521 }
6522
6523 static void btrfs_invalidatepage(struct page *page, unsigned long offset)
6524 {
6525         struct inode *inode = page->mapping->host;
6526         struct extent_io_tree *tree;
6527         struct btrfs_ordered_extent *ordered;
6528         struct extent_state *cached_state = NULL;
6529         u64 page_start = page_offset(page);
6530         u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
6531
6532         /*
6533          * we have the page locked, so new writeback can't start,
6534          * and the dirty bit won't be cleared while we are here.
6535          *
6536          * Wait for IO on this page so that we can safely clear
6537          * the PagePrivate2 bit and do ordered accounting
6538          */
6539         wait_on_page_writeback(page);
6540
6541         tree = &BTRFS_I(inode)->io_tree;
6542         if (offset) {
6543                 btrfs_releasepage(page, GFP_NOFS);
6544                 return;
6545         }
6546         lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
6547         ordered = btrfs_lookup_ordered_extent(inode,
6548                                            page_offset(page));
6549         if (ordered) {
6550                 /*
6551                  * IO on this page will never be started, so we need
6552                  * to account for any ordered extents now
6553                  */
6554                 clear_extent_bit(tree, page_start, page_end,
6555                                  EXTENT_DIRTY | EXTENT_DELALLOC |
6556                                  EXTENT_LOCKED | EXTENT_DO_ACCOUNTING, 1, 0,
6557                                  &cached_state, GFP_NOFS);
6558                 /*
6559                  * whoever cleared the private bit is responsible
6560                  * for the finish_ordered_io
6561                  */
6562                 if (TestClearPagePrivate2(page) &&
6563                     btrfs_dec_test_ordered_pending(inode, &ordered, page_start,
6564                                                    PAGE_CACHE_SIZE, 1)) {
6565                         btrfs_finish_ordered_io(ordered);
6566                 }
6567                 btrfs_put_ordered_extent(ordered);
6568                 cached_state = NULL;
6569                 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
6570         }
6571         clear_extent_bit(tree, page_start, page_end,
6572                  EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
6573                  EXTENT_DO_ACCOUNTING, 1, 1, &cached_state, GFP_NOFS);
6574         __btrfs_releasepage(page, GFP_NOFS);
6575
6576         ClearPageChecked(page);
6577         if (PagePrivate(page)) {
6578                 ClearPagePrivate(page);
6579                 set_page_private(page, 0);
6580                 page_cache_release(page);
6581         }
6582 }
6583
6584 /*
6585  * btrfs_page_mkwrite() is not allowed to change the file size as it gets
6586  * called from a page fault handler when a page is first dirtied. Hence we must
6587  * be careful to check for EOF conditions here. We set the page up correctly
6588  * for a written page which means we get ENOSPC checking when writing into
6589  * holes and correct delalloc and unwritten extent mapping on filesystems that
6590  * support these features.
6591  *
6592  * We are not allowed to take the i_mutex here so we have to play games to
6593  * protect against truncate races as the page could now be beyond EOF.  Because
6594  * vmtruncate() writes the inode size before removing pages, once we have the
6595  * page lock we can determine safely if the page is beyond EOF. If it is not
6596  * beyond EOF, then the page is guaranteed safe against truncation until we
6597  * unlock the page.
6598  */
6599 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
6600 {
6601         struct page *page = vmf->page;
6602         struct inode *inode = fdentry(vma->vm_file)->d_inode;
6603         struct btrfs_root *root = BTRFS_I(inode)->root;
6604         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6605         struct btrfs_ordered_extent *ordered;
6606         struct extent_state *cached_state = NULL;
6607         char *kaddr;
6608         unsigned long zero_start;
6609         loff_t size;
6610         int ret;
6611         int reserved = 0;
6612         u64 page_start;
6613         u64 page_end;
6614
6615         ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
6616         if (!ret) {
6617                 ret = file_update_time(vma->vm_file);
6618                 reserved = 1;
6619         }
6620         if (ret) {
6621                 if (ret == -ENOMEM)
6622                         ret = VM_FAULT_OOM;
6623                 else /* -ENOSPC, -EIO, etc */
6624                         ret = VM_FAULT_SIGBUS;
6625                 if (reserved)
6626                         goto out;
6627                 goto out_noreserve;
6628         }
6629
6630         ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
6631 again:
6632         lock_page(page);
6633         size = i_size_read(inode);
6634         page_start = page_offset(page);
6635         page_end = page_start + PAGE_CACHE_SIZE - 1;
6636
6637         if ((page->mapping != inode->i_mapping) ||
6638             (page_start >= size)) {
6639                 /* page got truncated out from underneath us */
6640                 goto out_unlock;
6641         }
6642         wait_on_page_writeback(page);
6643
6644         lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
6645         set_page_extent_mapped(page);
6646
6647         /*
6648          * we can't set the delalloc bits if there are pending ordered
6649          * extents.  Drop our locks and wait for them to finish
6650          */
6651         ordered = btrfs_lookup_ordered_extent(inode, page_start);
6652         if (ordered) {
6653                 unlock_extent_cached(io_tree, page_start, page_end,
6654                                      &cached_state, GFP_NOFS);
6655                 unlock_page(page);
6656                 btrfs_start_ordered_extent(inode, ordered, 1);
6657                 btrfs_put_ordered_extent(ordered);
6658                 goto again;
6659         }
6660
6661         /*
6662          * XXX - page_mkwrite gets called every time the page is dirtied, even
6663          * if it was already dirty, so for space accounting reasons we need to
6664          * clear any delalloc bits for the range we are fixing to save.  There
6665          * is probably a better way to do this, but for now keep consistent with
6666          * prepare_pages in the normal write path.
6667          */
6668         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
6669                           EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
6670                           0, 0, &cached_state, GFP_NOFS);
6671
6672         ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
6673                                         &cached_state);
6674         if (ret) {
6675                 unlock_extent_cached(io_tree, page_start, page_end,
6676                                      &cached_state, GFP_NOFS);
6677                 ret = VM_FAULT_SIGBUS;
6678                 goto out_unlock;
6679         }
6680         ret = 0;
6681
6682         /* page is wholly or partially inside EOF */
6683         if (page_start + PAGE_CACHE_SIZE > size)
6684                 zero_start = size & ~PAGE_CACHE_MASK;
6685         else
6686                 zero_start = PAGE_CACHE_SIZE;
6687
6688         if (zero_start != PAGE_CACHE_SIZE) {
6689                 kaddr = kmap(page);
6690                 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
6691                 flush_dcache_page(page);
6692                 kunmap(page);
6693         }
6694         ClearPageChecked(page);
6695         set_page_dirty(page);
6696         SetPageUptodate(page);
6697
6698         BTRFS_I(inode)->last_trans = root->fs_info->generation;
6699         BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
6700
6701         unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
6702
6703 out_unlock:
6704         if (!ret)
6705                 return VM_FAULT_LOCKED;
6706         unlock_page(page);
6707 out:
6708         btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
6709 out_noreserve:
6710         return ret;
6711 }
6712
6713 static int btrfs_truncate(struct inode *inode)
6714 {
6715         struct btrfs_root *root = BTRFS_I(inode)->root;
6716         struct btrfs_block_rsv *rsv;
6717         int ret;
6718         int err = 0;
6719         struct btrfs_trans_handle *trans;
6720         unsigned long nr;
6721         u64 mask = root->sectorsize - 1;
6722         u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
6723
6724         ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
6725         if (ret)
6726                 return ret;
6727
6728         btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
6729         btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
6730
6731         /*
6732          * Yes ladies and gentelment, this is indeed ugly.  The fact is we have
6733          * 3 things going on here
6734          *
6735          * 1) We need to reserve space for our orphan item and the space to
6736          * delete our orphan item.  Lord knows we don't want to have a dangling
6737          * orphan item because we didn't reserve space to remove it.
6738          *
6739          * 2) We need to reserve space to update our inode.
6740          *
6741          * 3) We need to have something to cache all the space that is going to
6742          * be free'd up by the truncate operation, but also have some slack
6743          * space reserved in case it uses space during the truncate (thank you
6744          * very much snapshotting).
6745          *
6746          * And we need these to all be seperate.  The fact is we can use alot of
6747          * space doing the truncate, and we have no earthly idea how much space
6748          * we will use, so we need the truncate reservation to be seperate so it
6749          * doesn't end up using space reserved for updating the inode or
6750          * removing the orphan item.  We also need to be able to stop the
6751          * transaction and start a new one, which means we need to be able to
6752          * update the inode several times, and we have no idea of knowing how
6753          * many times that will be, so we can't just reserve 1 item for the
6754          * entirety of the opration, so that has to be done seperately as well.
6755          * Then there is the orphan item, which does indeed need to be held on
6756          * to for the whole operation, and we need nobody to touch this reserved
6757          * space except the orphan code.
6758          *
6759          * So that leaves us with
6760          *
6761          * 1) root->orphan_block_rsv - for the orphan deletion.
6762          * 2) rsv - for the truncate reservation, which we will steal from the
6763          * transaction reservation.
6764          * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
6765          * updating the inode.
6766          */
6767         rsv = btrfs_alloc_block_rsv(root);
6768         if (!rsv)
6769                 return -ENOMEM;
6770         rsv->size = min_size;
6771
6772         /*
6773          * 1 for the truncate slack space
6774          * 1 for the orphan item we're going to add
6775          * 1 for the orphan item deletion
6776          * 1 for updating the inode.
6777          */
6778         trans = btrfs_start_transaction(root, 4);
6779         if (IS_ERR(trans)) {
6780                 err = PTR_ERR(trans);
6781                 goto out;
6782         }
6783
6784         /* Migrate the slack space for the truncate to our reserve */
6785         ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
6786                                       min_size);
6787         BUG_ON(ret);
6788
6789         ret = btrfs_orphan_add(trans, inode);
6790         if (ret) {
6791                 btrfs_end_transaction(trans, root);
6792                 goto out;
6793         }
6794
6795         /*
6796          * setattr is responsible for setting the ordered_data_close flag,
6797          * but that is only tested during the last file release.  That
6798          * could happen well after the next commit, leaving a great big
6799          * window where new writes may get lost if someone chooses to write
6800          * to this file after truncating to zero
6801          *
6802          * The inode doesn't have any dirty data here, and so if we commit
6803          * this is a noop.  If someone immediately starts writing to the inode
6804          * it is very likely we'll catch some of their writes in this
6805          * transaction, and the commit will find this file on the ordered
6806          * data list with good things to send down.
6807          *
6808          * This is a best effort solution, there is still a window where
6809          * using truncate to replace the contents of the file will
6810          * end up with a zero length file after a crash.
6811          */
6812         if (inode->i_size == 0 && test_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
6813                                            &BTRFS_I(inode)->runtime_flags))
6814                 btrfs_add_ordered_operation(trans, root, inode);
6815
6816         while (1) {
6817                 ret = btrfs_block_rsv_refill(root, rsv, min_size);
6818                 if (ret) {
6819                         /*
6820                          * This can only happen with the original transaction we
6821                          * started above, every other time we shouldn't have a
6822                          * transaction started yet.
6823                          */
6824                         if (ret == -EAGAIN)
6825                                 goto end_trans;
6826                         err = ret;
6827                         break;
6828                 }
6829
6830                 if (!trans) {
6831                         /* Just need the 1 for updating the inode */
6832                         trans = btrfs_start_transaction(root, 1);
6833                         if (IS_ERR(trans)) {
6834                                 ret = err = PTR_ERR(trans);
6835                                 trans = NULL;
6836                                 break;
6837                         }
6838                 }
6839
6840                 trans->block_rsv = rsv;
6841
6842                 ret = btrfs_truncate_inode_items(trans, root, inode,
6843                                                  inode->i_size,
6844                                                  BTRFS_EXTENT_DATA_KEY);
6845                 if (ret != -EAGAIN) {
6846                         err = ret;
6847                         break;
6848                 }
6849
6850                 trans->block_rsv = &root->fs_info->trans_block_rsv;
6851                 ret = btrfs_update_inode(trans, root, inode);
6852                 if (ret) {
6853                         err = ret;
6854                         break;
6855                 }
6856 end_trans:
6857                 nr = trans->blocks_used;
6858                 btrfs_end_transaction(trans, root);
6859                 trans = NULL;
6860                 btrfs_btree_balance_dirty(root, nr);
6861         }
6862
6863         if (ret == 0 && inode->i_nlink > 0) {
6864                 trans->block_rsv = root->orphan_block_rsv;
6865                 ret = btrfs_orphan_del(trans, inode);
6866                 if (ret)
6867                         err = ret;
6868         } else if (ret && inode->i_nlink > 0) {
6869                 /*
6870                  * Failed to do the truncate, remove us from the in memory
6871                  * orphan list.
6872                  */
6873                 ret = btrfs_orphan_del(NULL, inode);
6874         }
6875
6876         if (trans) {
6877                 trans->block_rsv = &root->fs_info->trans_block_rsv;
6878                 ret = btrfs_update_inode(trans, root, inode);
6879                 if (ret && !err)
6880                         err = ret;
6881
6882                 nr = trans->blocks_used;
6883                 ret = btrfs_end_transaction(trans, root);
6884                 btrfs_btree_balance_dirty(root, nr);
6885         }
6886
6887 out:
6888         btrfs_free_block_rsv(root, rsv);
6889
6890         if (ret && !err)
6891                 err = ret;
6892
6893         return err;
6894 }
6895
6896 /*
6897  * create a new subvolume directory/inode (helper for the ioctl).
6898  */
6899 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
6900                              struct btrfs_root *new_root, u64 new_dirid)
6901 {
6902         struct inode *inode;
6903         int err;
6904         u64 index = 0;
6905
6906         inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
6907                                 new_dirid, new_dirid,
6908                                 S_IFDIR | (~current_umask() & S_IRWXUGO),
6909                                 &index);
6910         if (IS_ERR(inode))
6911                 return PTR_ERR(inode);
6912         inode->i_op = &btrfs_dir_inode_operations;
6913         inode->i_fop = &btrfs_dir_file_operations;
6914
6915         set_nlink(inode, 1);
6916         btrfs_i_size_write(inode, 0);
6917
6918         err = btrfs_update_inode(trans, new_root, inode);
6919
6920         iput(inode);
6921         return err;
6922 }
6923
6924 struct inode *btrfs_alloc_inode(struct super_block *sb)
6925 {
6926         struct btrfs_inode *ei;
6927         struct inode *inode;
6928
6929         ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
6930         if (!ei)
6931                 return NULL;
6932
6933         ei->root = NULL;
6934         ei->generation = 0;
6935         ei->last_trans = 0;
6936         ei->last_sub_trans = 0;
6937         ei->logged_trans = 0;
6938         ei->delalloc_bytes = 0;
6939         ei->disk_i_size = 0;
6940         ei->flags = 0;
6941         ei->csum_bytes = 0;
6942         ei->index_cnt = (u64)-1;
6943         ei->last_unlink_trans = 0;
6944
6945         spin_lock_init(&ei->lock);
6946         ei->outstanding_extents = 0;
6947         ei->reserved_extents = 0;
6948
6949         ei->runtime_flags = 0;
6950         ei->force_compress = BTRFS_COMPRESS_NONE;
6951
6952         ei->delayed_node = NULL;
6953
6954         inode = &ei->vfs_inode;
6955         extent_map_tree_init(&ei->extent_tree);
6956         extent_io_tree_init(&ei->io_tree, &inode->i_data);
6957         extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
6958         ei->io_tree.track_uptodate = 1;
6959         ei->io_failure_tree.track_uptodate = 1;
6960         mutex_init(&ei->log_mutex);
6961         mutex_init(&ei->delalloc_mutex);
6962         btrfs_ordered_inode_tree_init(&ei->ordered_tree);
6963         INIT_LIST_HEAD(&ei->delalloc_inodes);
6964         INIT_LIST_HEAD(&ei->ordered_operations);
6965         RB_CLEAR_NODE(&ei->rb_node);
6966
6967         return inode;
6968 }
6969
6970 static void btrfs_i_callback(struct rcu_head *head)
6971 {
6972         struct inode *inode = container_of(head, struct inode, i_rcu);
6973         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
6974 }
6975
6976 void btrfs_destroy_inode(struct inode *inode)
6977 {
6978         struct btrfs_ordered_extent *ordered;
6979         struct btrfs_root *root = BTRFS_I(inode)->root;
6980
6981         WARN_ON(!list_empty(&inode->i_dentry));
6982         WARN_ON(inode->i_data.nrpages);
6983         WARN_ON(BTRFS_I(inode)->outstanding_extents);
6984         WARN_ON(BTRFS_I(inode)->reserved_extents);
6985         WARN_ON(BTRFS_I(inode)->delalloc_bytes);
6986         WARN_ON(BTRFS_I(inode)->csum_bytes);
6987
6988         /*
6989          * This can happen where we create an inode, but somebody else also
6990          * created the same inode and we need to destroy the one we already
6991          * created.
6992          */
6993         if (!root)
6994                 goto free;
6995
6996         /*
6997          * Make sure we're properly removed from the ordered operation
6998          * lists.
6999          */
7000         smp_mb();
7001         if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
7002                 spin_lock(&root->fs_info->ordered_extent_lock);
7003                 list_del_init(&BTRFS_I(inode)->ordered_operations);
7004                 spin_unlock(&root->fs_info->ordered_extent_lock);
7005         }
7006
7007         if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
7008                      &BTRFS_I(inode)->runtime_flags)) {
7009                 printk(KERN_INFO "BTRFS: inode %llu still on the orphan list\n",
7010                        (unsigned long long)btrfs_ino(inode));
7011                 atomic_dec(&root->orphan_inodes);
7012         }
7013
7014         while (1) {
7015                 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
7016                 if (!ordered)
7017                         break;
7018                 else {
7019                         printk(KERN_ERR "btrfs found ordered "
7020                                "extent %llu %llu on inode cleanup\n",
7021                                (unsigned long long)ordered->file_offset,
7022                                (unsigned long long)ordered->len);
7023                         btrfs_remove_ordered_extent(inode, ordered);
7024                         btrfs_put_ordered_extent(ordered);
7025                         btrfs_put_ordered_extent(ordered);
7026                 }
7027         }
7028         inode_tree_del(inode);
7029         btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
7030 free:
7031         btrfs_remove_delayed_node(inode);
7032         call_rcu(&inode->i_rcu, btrfs_i_callback);
7033 }
7034
7035 int btrfs_drop_inode(struct inode *inode)
7036 {
7037         struct btrfs_root *root = BTRFS_I(inode)->root;
7038
7039         if (btrfs_root_refs(&root->root_item) == 0 &&
7040             !btrfs_is_free_space_inode(inode))
7041                 return 1;
7042         else
7043                 return generic_drop_inode(inode);
7044 }
7045
7046 static void init_once(void *foo)
7047 {
7048         struct btrfs_inode *ei = (struct btrfs_inode *) foo;
7049
7050         inode_init_once(&ei->vfs_inode);
7051 }
7052
7053 void btrfs_destroy_cachep(void)
7054 {
7055         if (btrfs_inode_cachep)
7056                 kmem_cache_destroy(btrfs_inode_cachep);
7057         if (btrfs_trans_handle_cachep)
7058                 kmem_cache_destroy(btrfs_trans_handle_cachep);
7059         if (btrfs_transaction_cachep)
7060                 kmem_cache_destroy(btrfs_transaction_cachep);
7061         if (btrfs_path_cachep)
7062                 kmem_cache_destroy(btrfs_path_cachep);
7063         if (btrfs_free_space_cachep)
7064                 kmem_cache_destroy(btrfs_free_space_cachep);
7065 }
7066
7067 int btrfs_init_cachep(void)
7068 {
7069         btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
7070                         sizeof(struct btrfs_inode), 0,
7071                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
7072         if (!btrfs_inode_cachep)
7073                 goto fail;
7074
7075         btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
7076                         sizeof(struct btrfs_trans_handle), 0,
7077                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7078         if (!btrfs_trans_handle_cachep)
7079                 goto fail;
7080
7081         btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
7082                         sizeof(struct btrfs_transaction), 0,
7083                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7084         if (!btrfs_transaction_cachep)
7085                 goto fail;
7086
7087         btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
7088                         sizeof(struct btrfs_path), 0,
7089                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7090         if (!btrfs_path_cachep)
7091                 goto fail;
7092
7093         btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space_cache",
7094                         sizeof(struct btrfs_free_space), 0,
7095                         SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
7096         if (!btrfs_free_space_cachep)
7097                 goto fail;
7098
7099         return 0;
7100 fail:
7101         btrfs_destroy_cachep();
7102         return -ENOMEM;
7103 }
7104
7105 static int btrfs_getattr(struct vfsmount *mnt,
7106                          struct dentry *dentry, struct kstat *stat)
7107 {
7108         struct inode *inode = dentry->d_inode;
7109         u32 blocksize = inode->i_sb->s_blocksize;
7110
7111         generic_fillattr(inode, stat);
7112         stat->dev = BTRFS_I(inode)->root->anon_dev;
7113         stat->blksize = PAGE_CACHE_SIZE;
7114         stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
7115                 ALIGN(BTRFS_I(inode)->delalloc_bytes, blocksize)) >> 9;
7116         return 0;
7117 }
7118
7119 /*
7120  * If a file is moved, it will inherit the cow and compression flags of the new
7121  * directory.
7122  */
7123 static void fixup_inode_flags(struct inode *dir, struct inode *inode)
7124 {
7125         struct btrfs_inode *b_dir = BTRFS_I(dir);
7126         struct btrfs_inode *b_inode = BTRFS_I(inode);
7127
7128         if (b_dir->flags & BTRFS_INODE_NODATACOW)
7129                 b_inode->flags |= BTRFS_INODE_NODATACOW;
7130         else
7131                 b_inode->flags &= ~BTRFS_INODE_NODATACOW;
7132
7133         if (b_dir->flags & BTRFS_INODE_COMPRESS) {
7134                 b_inode->flags |= BTRFS_INODE_COMPRESS;
7135                 b_inode->flags &= ~BTRFS_INODE_NOCOMPRESS;
7136         } else {
7137                 b_inode->flags &= ~(BTRFS_INODE_COMPRESS |
7138                                     BTRFS_INODE_NOCOMPRESS);
7139         }
7140 }
7141
7142 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
7143                            struct inode *new_dir, struct dentry *new_dentry)
7144 {
7145         struct btrfs_trans_handle *trans;
7146         struct btrfs_root *root = BTRFS_I(old_dir)->root;
7147         struct btrfs_root *dest = BTRFS_I(new_dir)->root;
7148         struct inode *new_inode = new_dentry->d_inode;
7149         struct inode *old_inode = old_dentry->d_inode;
7150         struct timespec ctime = CURRENT_TIME;
7151         u64 index = 0;
7152         u64 root_objectid;
7153         int ret;
7154         u64 old_ino = btrfs_ino(old_inode);
7155
7156         if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
7157                 return -EPERM;
7158
7159         /* we only allow rename subvolume link between subvolumes */
7160         if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
7161                 return -EXDEV;
7162
7163         if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
7164             (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
7165                 return -ENOTEMPTY;
7166
7167         if (S_ISDIR(old_inode->i_mode) && new_inode &&
7168             new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
7169                 return -ENOTEMPTY;
7170         /*
7171          * we're using rename to replace one file with another.
7172          * and the replacement file is large.  Start IO on it now so
7173          * we don't add too much work to the end of the transaction
7174          */
7175         if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
7176             old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
7177                 filemap_flush(old_inode->i_mapping);
7178
7179         /* close the racy window with snapshot create/destroy ioctl */
7180         if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
7181                 down_read(&root->fs_info->subvol_sem);
7182         /*
7183          * We want to reserve the absolute worst case amount of items.  So if
7184          * both inodes are subvols and we need to unlink them then that would
7185          * require 4 item modifications, but if they are both normal inodes it
7186          * would require 5 item modifications, so we'll assume their normal
7187          * inodes.  So 5 * 2 is 10, plus 1 for the new link, so 11 total items
7188          * should cover the worst case number of items we'll modify.
7189          */
7190         trans = btrfs_start_transaction(root, 20);
7191         if (IS_ERR(trans)) {
7192                 ret = PTR_ERR(trans);
7193                 goto out_notrans;
7194         }
7195
7196         if (dest != root)
7197                 btrfs_record_root_in_trans(trans, dest);
7198
7199         ret = btrfs_set_inode_index(new_dir, &index);
7200         if (ret)
7201                 goto out_fail;
7202
7203         if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7204                 /* force full log commit if subvolume involved. */
7205                 root->fs_info->last_trans_log_full_commit = trans->transid;
7206         } else {
7207                 ret = btrfs_insert_inode_ref(trans, dest,
7208                                              new_dentry->d_name.name,
7209                                              new_dentry->d_name.len,
7210                                              old_ino,
7211                                              btrfs_ino(new_dir), index);
7212                 if (ret)
7213                         goto out_fail;
7214                 /*
7215                  * this is an ugly little race, but the rename is required
7216                  * to make sure that if we crash, the inode is either at the
7217                  * old name or the new one.  pinning the log transaction lets
7218                  * us make sure we don't allow a log commit to come in after
7219                  * we unlink the name but before we add the new name back in.
7220                  */
7221                 btrfs_pin_log_trans(root);
7222         }
7223         /*
7224          * make sure the inode gets flushed if it is replacing
7225          * something.
7226          */
7227         if (new_inode && new_inode->i_size && S_ISREG(old_inode->i_mode))
7228                 btrfs_add_ordered_operation(trans, root, old_inode);
7229
7230         inode_inc_iversion(old_dir);
7231         inode_inc_iversion(new_dir);
7232         inode_inc_iversion(old_inode);
7233         old_dir->i_ctime = old_dir->i_mtime = ctime;
7234         new_dir->i_ctime = new_dir->i_mtime = ctime;
7235         old_inode->i_ctime = ctime;
7236
7237         if (old_dentry->d_parent != new_dentry->d_parent)
7238                 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
7239
7240         if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
7241                 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
7242                 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
7243                                         old_dentry->d_name.name,
7244                                         old_dentry->d_name.len);
7245         } else {
7246                 ret = __btrfs_unlink_inode(trans, root, old_dir,
7247                                         old_dentry->d_inode,
7248                                         old_dentry->d_name.name,
7249                                         old_dentry->d_name.len);
7250                 if (!ret)
7251                         ret = btrfs_update_inode(trans, root, old_inode);
7252         }
7253         if (ret) {
7254                 btrfs_abort_transaction(trans, root, ret);
7255                 goto out_fail;
7256         }
7257
7258         if (new_inode) {
7259                 inode_inc_iversion(new_inode);
7260                 new_inode->i_ctime = CURRENT_TIME;
7261                 if (unlikely(btrfs_ino(new_inode) ==
7262                              BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
7263                         root_objectid = BTRFS_I(new_inode)->location.objectid;
7264                         ret = btrfs_unlink_subvol(trans, dest, new_dir,
7265                                                 root_objectid,
7266                                                 new_dentry->d_name.name,
7267                                                 new_dentry->d_name.len);
7268                         BUG_ON(new_inode->i_nlink == 0);
7269                 } else {
7270                         ret = btrfs_unlink_inode(trans, dest, new_dir,
7271                                                  new_dentry->d_inode,
7272                                                  new_dentry->d_name.name,
7273                                                  new_dentry->d_name.len);
7274                 }
7275                 if (!ret && new_inode->i_nlink == 0) {
7276                         ret = btrfs_orphan_add(trans, new_dentry->d_inode);
7277                         BUG_ON(ret);
7278                 }
7279                 if (ret) {
7280                         btrfs_abort_transaction(trans, root, ret);
7281                         goto out_fail;
7282                 }
7283         }
7284
7285         fixup_inode_flags(new_dir, old_inode);
7286
7287         ret = btrfs_add_link(trans, new_dir, old_inode,
7288                              new_dentry->d_name.name,
7289                              new_dentry->d_name.len, 0, index);
7290         if (ret) {
7291                 btrfs_abort_transaction(trans, root, ret);
7292                 goto out_fail;
7293         }
7294
7295         if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
7296                 struct dentry *parent = new_dentry->d_parent;
7297                 btrfs_log_new_name(trans, old_inode, old_dir, parent);
7298                 btrfs_end_log_trans(root);
7299         }
7300 out_fail:
7301         btrfs_end_transaction(trans, root);
7302 out_notrans:
7303         if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
7304                 up_read(&root->fs_info->subvol_sem);
7305
7306         return ret;
7307 }
7308
7309 /*
7310  * some fairly slow code that needs optimization. This walks the list
7311  * of all the inodes with pending delalloc and forces them to disk.
7312  */
7313 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
7314 {
7315         struct list_head *head = &root->fs_info->delalloc_inodes;
7316         struct btrfs_inode *binode;
7317         struct inode *inode;
7318
7319         if (root->fs_info->sb->s_flags & MS_RDONLY)
7320                 return -EROFS;
7321
7322         spin_lock(&root->fs_info->delalloc_lock);
7323         while (!list_empty(head)) {
7324                 binode = list_entry(head->next, struct btrfs_inode,
7325                                     delalloc_inodes);
7326                 inode = igrab(&binode->vfs_inode);
7327                 if (!inode)
7328                         list_del_init(&binode->delalloc_inodes);
7329                 spin_unlock(&root->fs_info->delalloc_lock);
7330                 if (inode) {
7331                         filemap_flush(inode->i_mapping);
7332                         if (delay_iput)
7333                                 btrfs_add_delayed_iput(inode);
7334                         else
7335                                 iput(inode);
7336                 }
7337                 cond_resched();
7338                 spin_lock(&root->fs_info->delalloc_lock);
7339         }
7340         spin_unlock(&root->fs_info->delalloc_lock);
7341
7342         /* the filemap_flush will queue IO into the worker threads, but
7343          * we have to make sure the IO is actually started and that
7344          * ordered extents get created before we return
7345          */
7346         atomic_inc(&root->fs_info->async_submit_draining);
7347         while (atomic_read(&root->fs_info->nr_async_submits) ||
7348               atomic_read(&root->fs_info->async_delalloc_pages)) {
7349                 wait_event(root->fs_info->async_submit_wait,
7350                    (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
7351                     atomic_read(&root->fs_info->async_delalloc_pages) == 0));
7352         }
7353         atomic_dec(&root->fs_info->async_submit_draining);
7354         return 0;
7355 }
7356
7357 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
7358                          const char *symname)
7359 {
7360         struct btrfs_trans_handle *trans;
7361         struct btrfs_root *root = BTRFS_I(dir)->root;
7362         struct btrfs_path *path;
7363         struct btrfs_key key;
7364         struct inode *inode = NULL;
7365         int err;
7366         int drop_inode = 0;
7367         u64 objectid;
7368         u64 index = 0 ;
7369         int name_len;
7370         int datasize;
7371         unsigned long ptr;
7372         struct btrfs_file_extent_item *ei;
7373         struct extent_buffer *leaf;
7374         unsigned long nr = 0;
7375
7376         name_len = strlen(symname) + 1;
7377         if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
7378                 return -ENAMETOOLONG;
7379
7380         /*
7381          * 2 items for inode item and ref
7382          * 2 items for dir items
7383          * 1 item for xattr if selinux is on
7384          */
7385         trans = btrfs_start_transaction(root, 5);
7386         if (IS_ERR(trans))
7387                 return PTR_ERR(trans);
7388
7389         err = btrfs_find_free_ino(root, &objectid);
7390         if (err)
7391                 goto out_unlock;
7392
7393         inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
7394                                 dentry->d_name.len, btrfs_ino(dir), objectid,
7395                                 S_IFLNK|S_IRWXUGO, &index);
7396         if (IS_ERR(inode)) {
7397                 err = PTR_ERR(inode);
7398                 goto out_unlock;
7399         }
7400
7401         err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
7402         if (err) {
7403                 drop_inode = 1;
7404                 goto out_unlock;
7405         }
7406
7407         /*
7408         * If the active LSM wants to access the inode during
7409         * d_instantiate it needs these. Smack checks to see
7410         * if the filesystem supports xattrs by looking at the
7411         * ops vector.
7412         */
7413         inode->i_fop = &btrfs_file_operations;
7414         inode->i_op = &btrfs_file_inode_operations;
7415
7416         err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
7417         if (err)
7418                 drop_inode = 1;
7419         else {
7420                 inode->i_mapping->a_ops = &btrfs_aops;
7421                 inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7422                 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
7423         }
7424         if (drop_inode)
7425                 goto out_unlock;
7426
7427         path = btrfs_alloc_path();
7428         if (!path) {
7429                 err = -ENOMEM;
7430                 drop_inode = 1;
7431                 goto out_unlock;
7432         }
7433         key.objectid = btrfs_ino(inode);
7434         key.offset = 0;
7435         btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
7436         datasize = btrfs_file_extent_calc_inline_size(name_len);
7437         err = btrfs_insert_empty_item(trans, root, path, &key,
7438                                       datasize);
7439         if (err) {
7440                 drop_inode = 1;
7441                 btrfs_free_path(path);
7442                 goto out_unlock;
7443         }
7444         leaf = path->nodes[0];
7445         ei = btrfs_item_ptr(leaf, path->slots[0],
7446                             struct btrfs_file_extent_item);
7447         btrfs_set_file_extent_generation(leaf, ei, trans->transid);
7448         btrfs_set_file_extent_type(leaf, ei,
7449                                    BTRFS_FILE_EXTENT_INLINE);
7450         btrfs_set_file_extent_encryption(leaf, ei, 0);
7451         btrfs_set_file_extent_compression(leaf, ei, 0);
7452         btrfs_set_file_extent_other_encoding(leaf, ei, 0);
7453         btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
7454
7455         ptr = btrfs_file_extent_inline_start(ei);
7456         write_extent_buffer(leaf, symname, ptr, name_len);
7457         btrfs_mark_buffer_dirty(leaf);
7458         btrfs_free_path(path);
7459
7460         inode->i_op = &btrfs_symlink_inode_operations;
7461         inode->i_mapping->a_ops = &btrfs_symlink_aops;
7462         inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
7463         inode_set_bytes(inode, name_len);
7464         btrfs_i_size_write(inode, name_len - 1);
7465         err = btrfs_update_inode(trans, root, inode);
7466         if (err)
7467                 drop_inode = 1;
7468
7469 out_unlock:
7470         if (!err)
7471                 d_instantiate(dentry, inode);
7472         nr = trans->blocks_used;
7473         btrfs_end_transaction(trans, root);
7474         if (drop_inode) {
7475                 inode_dec_link_count(inode);
7476                 iput(inode);
7477         }
7478         btrfs_btree_balance_dirty(root, nr);
7479         return err;
7480 }
7481
7482 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
7483                                        u64 start, u64 num_bytes, u64 min_size,
7484                                        loff_t actual_len, u64 *alloc_hint,
7485                                        struct btrfs_trans_handle *trans)
7486 {
7487         struct btrfs_root *root = BTRFS_I(inode)->root;
7488         struct btrfs_key ins;
7489         u64 cur_offset = start;
7490         u64 i_size;
7491         int ret = 0;
7492         bool own_trans = true;
7493
7494         if (trans)
7495                 own_trans = false;
7496         while (num_bytes > 0) {
7497                 if (own_trans) {
7498                         trans = btrfs_start_transaction(root, 3);
7499                         if (IS_ERR(trans)) {
7500                                 ret = PTR_ERR(trans);
7501                                 break;
7502                         }
7503                 }
7504
7505                 ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
7506                                            0, *alloc_hint, &ins, 1);
7507                 if (ret) {
7508                         if (own_trans)
7509                                 btrfs_end_transaction(trans, root);
7510                         break;
7511                 }
7512
7513                 ret = insert_reserved_file_extent(trans, inode,
7514                                                   cur_offset, ins.objectid,
7515                                                   ins.offset, ins.offset,
7516                                                   ins.offset, 0, 0, 0,
7517                                                   BTRFS_FILE_EXTENT_PREALLOC);
7518                 if (ret) {
7519                         btrfs_abort_transaction(trans, root, ret);
7520                         if (own_trans)
7521                                 btrfs_end_transaction(trans, root);
7522                         break;
7523                 }
7524                 btrfs_drop_extent_cache(inode, cur_offset,
7525                                         cur_offset + ins.offset -1, 0);
7526
7527                 num_bytes -= ins.offset;
7528                 cur_offset += ins.offset;
7529                 *alloc_hint = ins.objectid + ins.offset;
7530
7531                 inode_inc_iversion(inode);
7532                 inode->i_ctime = CURRENT_TIME;
7533                 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
7534                 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
7535                     (actual_len > inode->i_size) &&
7536                     (cur_offset > inode->i_size)) {
7537                         if (cur_offset > actual_len)
7538                                 i_size = actual_len;
7539                         else
7540                                 i_size = cur_offset;
7541                         i_size_write(inode, i_size);
7542                         btrfs_ordered_update_i_size(inode, i_size, NULL);
7543                 }
7544
7545                 ret = btrfs_update_inode(trans, root, inode);
7546
7547                 if (ret) {
7548                         btrfs_abort_transaction(trans, root, ret);
7549                         if (own_trans)
7550                                 btrfs_end_transaction(trans, root);
7551                         break;
7552                 }
7553
7554                 if (own_trans)
7555                         btrfs_end_transaction(trans, root);
7556         }
7557         return ret;
7558 }
7559
7560 int btrfs_prealloc_file_range(struct inode *inode, int mode,
7561                               u64 start, u64 num_bytes, u64 min_size,
7562                               loff_t actual_len, u64 *alloc_hint)
7563 {
7564         return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7565                                            min_size, actual_len, alloc_hint,
7566                                            NULL);
7567 }
7568
7569 int btrfs_prealloc_file_range_trans(struct inode *inode,
7570                                     struct btrfs_trans_handle *trans, int mode,
7571                                     u64 start, u64 num_bytes, u64 min_size,
7572                                     loff_t actual_len, u64 *alloc_hint)
7573 {
7574         return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
7575                                            min_size, actual_len, alloc_hint, trans);
7576 }
7577
7578 static int btrfs_set_page_dirty(struct page *page)
7579 {
7580         return __set_page_dirty_nobuffers(page);
7581 }
7582
7583 static int btrfs_permission(struct inode *inode, int mask)
7584 {
7585         struct btrfs_root *root = BTRFS_I(inode)->root;
7586         umode_t mode = inode->i_mode;
7587
7588         if (mask & MAY_WRITE &&
7589             (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
7590                 if (btrfs_root_readonly(root))
7591                         return -EROFS;
7592                 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
7593                         return -EACCES;
7594         }
7595         return generic_permission(inode, mask);
7596 }
7597
7598 static const struct inode_operations btrfs_dir_inode_operations = {
7599         .getattr        = btrfs_getattr,
7600         .lookup         = btrfs_lookup,
7601         .create         = btrfs_create,
7602         .unlink         = btrfs_unlink,
7603         .link           = btrfs_link,
7604         .mkdir          = btrfs_mkdir,
7605         .rmdir          = btrfs_rmdir,
7606         .rename         = btrfs_rename,
7607         .symlink        = btrfs_symlink,
7608         .setattr        = btrfs_setattr,
7609         .mknod          = btrfs_mknod,
7610         .setxattr       = btrfs_setxattr,
7611         .getxattr       = btrfs_getxattr,
7612         .listxattr      = btrfs_listxattr,
7613         .removexattr    = btrfs_removexattr,
7614         .permission     = btrfs_permission,
7615         .get_acl        = btrfs_get_acl,
7616 };
7617 static const struct inode_operations btrfs_dir_ro_inode_operations = {
7618         .lookup         = btrfs_lookup,
7619         .permission     = btrfs_permission,
7620         .get_acl        = btrfs_get_acl,
7621 };
7622
7623 static const struct file_operations btrfs_dir_file_operations = {
7624         .llseek         = generic_file_llseek,
7625         .read           = generic_read_dir,
7626         .readdir        = btrfs_real_readdir,
7627         .unlocked_ioctl = btrfs_ioctl,
7628 #ifdef CONFIG_COMPAT
7629         .compat_ioctl   = btrfs_ioctl,
7630 #endif
7631         .release        = btrfs_release_file,
7632         .fsync          = btrfs_sync_file,
7633 };
7634
7635 static struct extent_io_ops btrfs_extent_io_ops = {
7636         .fill_delalloc = run_delalloc_range,
7637         .submit_bio_hook = btrfs_submit_bio_hook,
7638         .merge_bio_hook = btrfs_merge_bio_hook,
7639         .readpage_end_io_hook = btrfs_readpage_end_io_hook,
7640         .writepage_end_io_hook = btrfs_writepage_end_io_hook,
7641         .writepage_start_hook = btrfs_writepage_start_hook,
7642         .set_bit_hook = btrfs_set_bit_hook,
7643         .clear_bit_hook = btrfs_clear_bit_hook,
7644         .merge_extent_hook = btrfs_merge_extent_hook,
7645         .split_extent_hook = btrfs_split_extent_hook,
7646 };
7647
7648 /*
7649  * btrfs doesn't support the bmap operation because swapfiles
7650  * use bmap to make a mapping of extents in the file.  They assume
7651  * these extents won't change over the life of the file and they
7652  * use the bmap result to do IO directly to the drive.
7653  *
7654  * the btrfs bmap call would return logical addresses that aren't
7655  * suitable for IO and they also will change frequently as COW
7656  * operations happen.  So, swapfile + btrfs == corruption.
7657  *
7658  * For now we're avoiding this by dropping bmap.
7659  */
7660 static const struct address_space_operations btrfs_aops = {
7661         .readpage       = btrfs_readpage,
7662         .writepage      = btrfs_writepage,
7663         .writepages     = btrfs_writepages,
7664         .readpages      = btrfs_readpages,
7665         .direct_IO      = btrfs_direct_IO,
7666         .invalidatepage = btrfs_invalidatepage,
7667         .releasepage    = btrfs_releasepage,
7668         .set_page_dirty = btrfs_set_page_dirty,
7669         .error_remove_page = generic_error_remove_page,
7670 };
7671
7672 static const struct address_space_operations btrfs_symlink_aops = {
7673         .readpage       = btrfs_readpage,
7674         .writepage      = btrfs_writepage,
7675         .invalidatepage = btrfs_invalidatepage,
7676         .releasepage    = btrfs_releasepage,
7677 };
7678
7679 static const struct inode_operations btrfs_file_inode_operations = {
7680         .getattr        = btrfs_getattr,
7681         .setattr        = btrfs_setattr,
7682         .setxattr       = btrfs_setxattr,
7683         .getxattr       = btrfs_getxattr,
7684         .listxattr      = btrfs_listxattr,
7685         .removexattr    = btrfs_removexattr,
7686         .permission     = btrfs_permission,
7687         .fiemap         = btrfs_fiemap,
7688         .get_acl        = btrfs_get_acl,
7689         .update_time    = btrfs_update_time,
7690 };
7691 static const struct inode_operations btrfs_special_inode_operations = {
7692         .getattr        = btrfs_getattr,
7693         .setattr        = btrfs_setattr,
7694         .permission     = btrfs_permission,
7695         .setxattr       = btrfs_setxattr,
7696         .getxattr       = btrfs_getxattr,
7697         .listxattr      = btrfs_listxattr,
7698         .removexattr    = btrfs_removexattr,
7699         .get_acl        = btrfs_get_acl,
7700         .update_time    = btrfs_update_time,
7701 };
7702 static const struct inode_operations btrfs_symlink_inode_operations = {
7703         .readlink       = generic_readlink,
7704         .follow_link    = page_follow_link_light,
7705         .put_link       = page_put_link,
7706         .getattr        = btrfs_getattr,
7707         .setattr        = btrfs_setattr,
7708         .permission     = btrfs_permission,
7709         .setxattr       = btrfs_setxattr,
7710         .getxattr       = btrfs_getxattr,
7711         .listxattr      = btrfs_listxattr,
7712         .removexattr    = btrfs_removexattr,
7713         .get_acl        = btrfs_get_acl,
7714         .update_time    = btrfs_update_time,
7715 };
7716
7717 const struct dentry_operations btrfs_dentry_operations = {
7718         .d_delete       = btrfs_dentry_delete,
7719         .d_release      = btrfs_dentry_release,
7720 };