fs/btrfs/disk-io.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/fs.h>
  20 #include <linux/blkdev.h>
  21 #include <linux/scatterlist.h>
  22 #include <linux/swap.h>
  23 #include <linux/radix-tree.h>
  24 #include <linux/writeback.h>
  25 #include <linux/buffer_head.h> // for block_sync_page
  26 #include <linux/workqueue.h>
  27 #include "crc32c.h"
  28 #include "ctree.h"
  29 #include "disk-io.h"
  30 #include "transaction.h"
  31 #include "btrfs_inode.h"
  32 #include "volumes.h"
  33 #include "print-tree.h"
  34
  35 #if 0
  36 static int check_tree_block(struct btrfs_root *root, struct extent_buffer *buf)
  37 {
  38         if (extent_buffer_blocknr(buf) != btrfs_header_blocknr(buf)) {
  39                 printk(KERN_CRIT "buf blocknr(buf) is %llu, header is %llu\n",
  40                        (unsigned long long)extent_buffer_blocknr(buf),
  41                        (unsigned long long)btrfs_header_blocknr(buf));
  42                 return 1;
  43         }
  44         return 0;
  45 }
  46 #endif
  47
  48 static struct extent_io_ops btree_extent_io_ops;
  49 static struct workqueue_struct *end_io_workqueue;
  50 static struct workqueue_struct *async_submit_workqueue;
  51
  52 struct end_io_wq {
  53         struct bio *bio;
  54         bio_end_io_t *end_io;
  55         void *private;
  56         struct btrfs_fs_info *info;
  57         int error;
  58         int metadata;
  59         struct list_head list;
  60 };
  61
  62 struct async_submit_bio {
  63         struct inode *inode;
  64         struct bio *bio;
  65         struct list_head list;
  66         extent_submit_bio_hook_t *submit_bio_hook;
  67         int rw;
  68         int mirror_num;
  69 };
  70
  71 struct extent_map *btree_get_extent(struct inode *inode, struct page *page,
  72                                     size_t page_offset, u64 start, u64 len,
  73                                     int create)
  74 {
  75         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
  76         struct extent_map *em;
  77         int ret;
  78
  79         spin_lock(&em_tree->lock);
  80         em = lookup_extent_mapping(em_tree, start, len);
  81         spin_unlock(&em_tree->lock);
  82         if (em)
  83                 goto out;
  84
  85         em = alloc_extent_map(GFP_NOFS);
  86         if (!em) {
  87                 em = ERR_PTR(-ENOMEM);
  88                 goto out;
  89         }
  90         em->start = 0;
  91         em->len = (u64)-1;
  92         em->block_start = 0;
  93         em->bdev = inode->i_sb->s_bdev;
  94
  95         spin_lock(&em_tree->lock);
  96         ret = add_extent_mapping(em_tree, em);
  97         if (ret == -EEXIST) {
  98                 u64 failed_start = em->start;
  99                 u64 failed_len = em->len;
 100
 101                 printk("failed to insert %Lu %Lu -> %Lu into tree\n",
 102                        em->start, em->len, em->block_start);
 103                 free_extent_map(em);
 104                 em = lookup_extent_mapping(em_tree, start, len);
 105                 if (em) {
 106                         printk("after failing, found %Lu %Lu %Lu\n",
 107                                em->start, em->len, em->block_start);
 108                         ret = 0;
 109                 } else {
 110                         em = lookup_extent_mapping(em_tree, failed_start,
 111                                                    failed_len);
 112                         if (em) {
 113                                 printk("double failure lookup gives us "
 114                                        "%Lu %Lu -> %Lu\n", em->start,
 115                                        em->len, em->block_start);
 116                                 free_extent_map(em);
 117                         }
 118                         ret = -EIO;
 119                 }
 120         } else if (ret) {
 121                 free_extent_map(em);
 122                 em = NULL;
 123         }
 124         spin_unlock(&em_tree->lock);
 125
 126         if (ret)
 127                 em = ERR_PTR(ret);
 128 out:
 129         return em;
 130 }
 131
 132 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
 133 {
 134         return btrfs_crc32c(seed, data, len);
 135 }
 136
 137 void btrfs_csum_final(u32 crc, char *result)
 138 {
 139         *(__le32 *)result = ~cpu_to_le32(crc);
 140 }
 141
 142 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
 143                            int verify)
 144 {
 145         char result[BTRFS_CRC32_SIZE];
 146         unsigned long len;
 147         unsigned long cur_len;
 148         unsigned long offset = BTRFS_CSUM_SIZE;
 149         char *map_token = NULL;
 150         char *kaddr;
 151         unsigned long map_start;
 152         unsigned long map_len;
 153         int err;
 154         u32 crc = ~(u32)0;
 155
 156         len = buf->len - offset;
 157         while(len > 0) {
 158                 err = map_private_extent_buffer(buf, offset, 32,
 159                                         &map_token, &kaddr,
 160                                         &map_start, &map_len, KM_USER0);
 161                 if (err) {
 162                         printk("failed to map extent buffer! %lu\n",
 163                                offset);
 164                         return 1;
 165                 }
 166                 cur_len = min(len, map_len - (offset - map_start));
 167                 crc = btrfs_csum_data(root, kaddr + offset - map_start,
 168                                       crc, cur_len);
 169                 len -= cur_len;
 170                 offset += cur_len;
 171                 unmap_extent_buffer(buf, map_token, KM_USER0);
 172         }
 173         btrfs_csum_final(crc, result);
 174
 175         if (verify) {
 176                 int from_this_trans = 0;
 177
 178                 if (root->fs_info->running_transaction &&
 179                     btrfs_header_generation(buf) ==
 180                     root->fs_info->running_transaction->transid)
 181                         from_this_trans = 1;
 182
 183                 /* FIXME, this is not good */
 184                 if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
 185                         u32 val;
 186                         u32 found = 0;
 187                         memcpy(&found, result, BTRFS_CRC32_SIZE);
 188
 189                         read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
 190                         printk("btrfs: %s checksum verify failed on %llu "
 191                                "wanted %X found %X from_this_trans %d "
 192                                "level %d\n",
 193                                root->fs_info->sb->s_id,
 194                                buf->start, val, found, from_this_trans,
 195                                btrfs_header_level(buf));
 196                         return 1;
 197                 }
 198         } else {
 199                 write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
 200         }
 201         return 0;
 202 }
 203
 204 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
 205                                           struct extent_buffer *eb,
 206                                           u64 start)
 207 {
 208         struct extent_io_tree *io_tree;
 209         int ret;
 210         int num_copies = 0;
 211         int mirror_num = 0;
 212
 213         io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
 214         while (1) {
 215                 ret = read_extent_buffer_pages(io_tree, eb, start, 1,
 216                                                btree_get_extent, mirror_num);
 217                 if (!ret) {
 218                         if (mirror_num)
 219 printk("good read %Lu mirror %d total %d\n", eb->start, mirror_num, num_copies);
 220                         return ret;
 221                 }
 222                 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
 223                                               eb->start, eb->len);
 224 printk("failed to read %Lu mirror %d total %d\n", eb->start, mirror_num, num_copies);
 225                 if (num_copies == 1) {
 226 printk("reading %Lu failed only one copy\n", eb->start);
 227                         return ret;
 228                 }
 229                 mirror_num++;
 230                 if (mirror_num > num_copies) {
 231 printk("bailing at mirror %d of %d\n", mirror_num, num_copies);
 232                         return ret;
 233                 }
 234         }
 235 printk("read extent buffer page last\n");
 236         return -EIO;
 237 }
 238
 239 int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
 240 {
 241         struct extent_io_tree *tree;
 242         u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
 243         u64 found_start;
 244         int found_level;
 245         unsigned long len;
 246         struct extent_buffer *eb;
 247         int ret;
 248
 249         tree = &BTRFS_I(page->mapping->host)->io_tree;
 250
 251         if (page->private == EXTENT_PAGE_PRIVATE)
 252                 goto out;
 253         if (!page->private)
 254                 goto out;
 255         len = page->private >> 2;
 256         if (len == 0) {
 257                 WARN_ON(1);
 258         }
 259         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 260         ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE);
 261         BUG_ON(ret);
 262         btrfs_clear_buffer_defrag(eb);
 263         found_start = btrfs_header_bytenr(eb);
 264         if (found_start != start) {
 265                 printk("warning: eb start incorrect %Lu buffer %Lu len %lu\n",
 266                        start, found_start, len);
 267                 WARN_ON(1);
 268                 goto err;
 269         }
 270         if (eb->first_page != page) {
 271                 printk("bad first page %lu %lu\n", eb->first_page->index,
 272                        page->index);
 273                 WARN_ON(1);
 274                 goto err;
 275         }
 276         if (!PageUptodate(page)) {
 277                 printk("csum not up to date page %lu\n", page->index);
 278                 WARN_ON(1);
 279                 goto err;
 280         }
 281         found_level = btrfs_header_level(eb);
 282         spin_lock(&root->fs_info->hash_lock);
 283         btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
 284         spin_unlock(&root->fs_info->hash_lock);
 285         csum_tree_block(root, eb, 0);
 286 err:
 287         free_extent_buffer(eb);
 288 out:
 289         return 0;
 290 }
 291
 292 static int btree_writepage_io_hook(struct page *page, u64 start, u64 end)
 293 {
 294         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 295
 296         csum_dirty_buffer(root, page);
 297         return 0;
 298 }
 299
 300 int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 301                                struct extent_state *state)
 302 {
 303         struct extent_io_tree *tree;
 304         u64 found_start;
 305         int found_level;
 306         unsigned long len;
 307         struct extent_buffer *eb;
 308         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 309         int ret = 0;
 310
 311         tree = &BTRFS_I(page->mapping->host)->io_tree;
 312         if (page->private == EXTENT_PAGE_PRIVATE)
 313                 goto out;
 314         if (!page->private)
 315                 goto out;
 316         len = page->private >> 2;
 317         if (len == 0) {
 318                 WARN_ON(1);
 319         }
 320         eb = alloc_extent_buffer(tree, start, len, page, GFP_NOFS);
 321
 322         btrfs_clear_buffer_defrag(eb);
 323         found_start = btrfs_header_bytenr(eb);
 324         if (found_start != start) {
 325 printk("bad start on %Lu found %Lu\n", eb->start, found_start);
 326                 ret = -EIO;
 327                 goto err;
 328         }
 329         if (eb->first_page != page) {
 330                 printk("bad first page %lu %lu\n", eb->first_page->index,
 331                        page->index);
 332                 WARN_ON(1);
 333                 ret = -EIO;
 334                 goto err;
 335         }
 336         found_level = btrfs_header_level(eb);
 337
 338         ret = csum_tree_block(root, eb, 1);
 339         if (ret)
 340                 ret = -EIO;
 341
 342         end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
 343         end = eb->start + end - 1;
 344         release_extent_buffer_tail_pages(eb);
 345 err:
 346         free_extent_buffer(eb);
 347 out:
 348         return ret;
 349 }
 350
 351 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 352 static void end_workqueue_bio(struct bio *bio, int err)
 353 #else
 354 static int end_workqueue_bio(struct bio *bio,
 355                                    unsigned int bytes_done, int err)
 356 #endif
 357 {
 358         struct end_io_wq *end_io_wq = bio->bi_private;
 359         struct btrfs_fs_info *fs_info;
 360         unsigned long flags;
 361
 362 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
 363         if (bio->bi_size)
 364                 return 1;
 365 #endif
 366
 367         fs_info = end_io_wq->info;
 368         spin_lock_irqsave(&fs_info->end_io_work_lock, flags);
 369         end_io_wq->error = err;
 370         list_add_tail(&end_io_wq->list, &fs_info->end_io_work_list);
 371         spin_unlock_irqrestore(&fs_info->end_io_work_lock, flags);
 372         queue_work(end_io_workqueue, &fs_info->end_io_work);
 373
 374 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
 375         return 0;
 376 #endif
 377 }
 378
 379 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
 380                         int metadata)
 381 {
 382         struct end_io_wq *end_io_wq;
 383         end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
 384         if (!end_io_wq)
 385                 return -ENOMEM;
 386
 387         end_io_wq->private = bio->bi_private;
 388         end_io_wq->end_io = bio->bi_end_io;
 389         end_io_wq->info = info;
 390         end_io_wq->error = 0;
 391         end_io_wq->bio = bio;
 392         end_io_wq->metadata = metadata;
 393
 394         bio->bi_private = end_io_wq;
 395         bio->bi_end_io = end_workqueue_bio;
 396         return 0;
 397 }
 398
 399 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
 400                         int rw, struct bio *bio, int mirror_num,
 401                         extent_submit_bio_hook_t *submit_bio_hook)
 402 {
 403         struct async_submit_bio *async;
 404
 405         /*
 406          * inline writerback should stay inline, only hop to the async
 407          * queue if we're pdflush
 408          */
 409         if (!current_is_pdflush())
 410                 return submit_bio_hook(inode, rw, bio, mirror_num);
 411
 412         async = kmalloc(sizeof(*async), GFP_NOFS);
 413         if (!async)
 414                 return -ENOMEM;
 415
 416         async->inode = inode;
 417         async->rw = rw;
 418         async->bio = bio;
 419         async->mirror_num = mirror_num;
 420         async->submit_bio_hook = submit_bio_hook;
 421
 422         spin_lock(&fs_info->async_submit_work_lock);
 423         list_add_tail(&async->list, &fs_info->async_submit_work_list);
 424         spin_unlock(&fs_info->async_submit_work_lock);
 425
 426         queue_work(async_submit_workqueue, &fs_info->async_submit_work);
 427         return 0;
 428 }
 429
 430 static int __btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 431                                  int mirror_num)
 432 {
 433         struct btrfs_root *root = BTRFS_I(inode)->root;
 434         u64 offset;
 435         int ret;
 436
 437         offset = bio->bi_sector << 9;
 438
 439         if (rw & (1 << BIO_RW)) {
 440                 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num);
 441         }
 442
 443         ret = btrfs_bio_wq_end_io(root->fs_info, bio, 1);
 444         BUG_ON(ret);
 445
 446         if (offset == BTRFS_SUPER_INFO_OFFSET) {
 447                 bio->bi_bdev = root->fs_info->fs_devices->latest_bdev;
 448                 submit_bio(rw, bio);
 449                 return 0;
 450         }
 451         return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num);
 452 }
 453
 454 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 455                                  int mirror_num)
 456 {
 457         if (!(rw & (1 << BIO_RW))) {
 458                 return __btree_submit_bio_hook(inode, rw, bio, mirror_num);
 459         }
 460         return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
 461                                    inode, rw, bio, mirror_num,
 462                                    __btree_submit_bio_hook);
 463 }
 464
 465 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 466 {
 467         struct extent_io_tree *tree;
 468         tree = &BTRFS_I(page->mapping->host)->io_tree;
 469         return extent_write_full_page(tree, page, btree_get_extent, wbc);
 470 }
 471
 472 static int btree_writepages(struct address_space *mapping,
 473                             struct writeback_control *wbc)
 474 {
 475         struct extent_io_tree *tree;
 476         tree = &BTRFS_I(mapping->host)->io_tree;
 477         if (wbc->sync_mode == WB_SYNC_NONE) {
 478                 u64 num_dirty;
 479                 u64 start = 0;
 480                 unsigned long thresh = 96 * 1024 * 1024;
 481
 482                 if (wbc->for_kupdate)
 483                         return 0;
 484
 485                 if (current_is_pdflush()) {
 486                         thresh = 96 * 1024 * 1024;
 487                 } else {
 488                         thresh = 8 * 1024 * 1024;
 489                 }
 490                 num_dirty = count_range_bits(tree, &start, (u64)-1,
 491                                              thresh, EXTENT_DIRTY);
 492                 if (num_dirty < thresh) {
 493                         return 0;
 494                 }
 495         }
 496         return extent_writepages(tree, mapping, btree_get_extent, wbc);
 497 }
 498
 499 int btree_readpage(struct file *file, struct page *page)
 500 {
 501         struct extent_io_tree *tree;
 502         tree = &BTRFS_I(page->mapping->host)->io_tree;
 503         return extent_read_full_page(tree, page, btree_get_extent);
 504 }
 505
 506 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
 507 {
 508         struct extent_io_tree *tree;
 509         struct extent_map_tree *map;
 510         int ret;
 511
 512         if (page_count(page) > 3) {
 513                 /* once for page->private, once for the caller, once
 514                  * once for the page cache
 515                  */
 516                 return 0;
 517         }
 518         tree = &BTRFS_I(page->mapping->host)->io_tree;
 519         map = &BTRFS_I(page->mapping->host)->extent_tree;
 520         ret = try_release_extent_state(map, tree, page, gfp_flags);
 521         if (ret == 1) {
 522                 invalidate_extent_lru(tree, page_offset(page), PAGE_CACHE_SIZE);
 523                 ClearPagePrivate(page);
 524                 set_page_private(page, 0);
 525                 page_cache_release(page);
 526         }
 527         return ret;
 528 }
 529
 530 static void btree_invalidatepage(struct page *page, unsigned long offset)
 531 {
 532         struct extent_io_tree *tree;
 533         tree = &BTRFS_I(page->mapping->host)->io_tree;
 534         extent_invalidatepage(tree, page, offset);
 535         btree_releasepage(page, GFP_NOFS);
 536         if (PagePrivate(page)) {
 537                 invalidate_extent_lru(tree, page_offset(page), PAGE_CACHE_SIZE);
 538                 ClearPagePrivate(page);
 539                 set_page_private(page, 0);
 540                 page_cache_release(page);
 541         }
 542 }
 543
 544 #if 0
 545 static int btree_writepage(struct page *page, struct writeback_control *wbc)
 546 {
 547         struct buffer_head *bh;
 548         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
 549         struct buffer_head *head;
 550         if (!page_has_buffers(page)) {
 551                 create_empty_buffers(page, root->fs_info->sb->s_blocksize,
 552                                         (1 << BH_Dirty)|(1 << BH_Uptodate));
 553         }
 554         head = page_buffers(page);
 555         bh = head;
 556         do {
 557                 if (buffer_dirty(bh))
 558                         csum_tree_block(root, bh, 0);
 559                 bh = bh->b_this_page;
 560         } while (bh != head);
 561         return block_write_full_page(page, btree_get_block, wbc);
 562 }
 563 #endif
 564
 565 static struct address_space_operations btree_aops = {
 566         .readpage       = btree_readpage,
 567         .writepage      = btree_writepage,
 568         .writepages     = btree_writepages,
 569         .releasepage    = btree_releasepage,
 570         .invalidatepage = btree_invalidatepage,
 571         .sync_page      = block_sync_page,
 572 };
 573
 574 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize)
 575 {
 576         struct extent_buffer *buf = NULL;
 577         struct inode *btree_inode = root->fs_info->btree_inode;
 578         int ret = 0;
 579
 580         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 581         if (!buf)
 582                 return 0;
 583         read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
 584                                  buf, 0, 0, btree_get_extent, 0);
 585         free_extent_buffer(buf);
 586         return ret;
 587 }
 588
 589 static int close_all_devices(struct btrfs_fs_info *fs_info)
 590 {
 591         struct list_head *list;
 592         struct list_head *next;
 593         struct btrfs_device *device;
 594
 595         list = &fs_info->fs_devices->devices;
 596         list_for_each(next, list) {
 597                 device = list_entry(next, struct btrfs_device, dev_list);
 598                 if (device->bdev && device->bdev != fs_info->sb->s_bdev)
 599                         close_bdev_excl(device->bdev);
 600                 device->bdev = NULL;
 601         }
 602         return 0;
 603 }
 604
 605 int btrfs_verify_block_csum(struct btrfs_root *root,
 606                             struct extent_buffer *buf)
 607 {
 608         return btrfs_buffer_uptodate(buf);
 609 }
 610
 611 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
 612                                             u64 bytenr, u32 blocksize)
 613 {
 614         struct inode *btree_inode = root->fs_info->btree_inode;
 615         struct extent_buffer *eb;
 616         eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 617                                 bytenr, blocksize, GFP_NOFS);
 618         return eb;
 619 }
 620
 621 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
 622                                                  u64 bytenr, u32 blocksize)
 623 {
 624         struct inode *btree_inode = root->fs_info->btree_inode;
 625         struct extent_buffer *eb;
 626
 627         eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
 628                                  bytenr, blocksize, NULL, GFP_NOFS);
 629         return eb;
 630 }
 631
 632
 633 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
 634                                       u32 blocksize)
 635 {
 636         struct extent_buffer *buf = NULL;
 637         struct inode *btree_inode = root->fs_info->btree_inode;
 638         struct extent_io_tree *io_tree;
 639         int ret;
 640
 641         io_tree = &BTRFS_I(btree_inode)->io_tree;
 642
 643         buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
 644         if (!buf)
 645                 return NULL;
 646
 647         ret = btree_read_extent_buffer_pages(root, buf, 0);
 648
 649         if (ret == 0) {
 650                 buf->flags |= EXTENT_UPTODATE;
 651         }
 652         return buf;
 653
 654 }
 655
 656 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 657                      struct extent_buffer *buf)
 658 {
 659         struct inode *btree_inode = root->fs_info->btree_inode;
 660         if (btrfs_header_generation(buf) ==
 661             root->fs_info->running_transaction->transid)
 662                 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
 663                                           buf);
 664         return 0;
 665 }
 666
 667 int wait_on_tree_block_writeback(struct btrfs_root *root,
 668                                  struct extent_buffer *buf)
 669 {
 670         struct inode *btree_inode = root->fs_info->btree_inode;
 671         wait_on_extent_buffer_writeback(&BTRFS_I(btree_inode)->io_tree,
 672                                         buf);
 673         return 0;
 674 }
 675
 676 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
 677                         u32 stripesize, struct btrfs_root *root,
 678                         struct btrfs_fs_info *fs_info,
 679                         u64 objectid)
 680 {
 681         root->node = NULL;
 682         root->inode = NULL;
 683         root->commit_root = NULL;
 684         root->sectorsize = sectorsize;
 685         root->nodesize = nodesize;
 686         root->leafsize = leafsize;
 687         root->stripesize = stripesize;
 688         root->ref_cows = 0;
 689         root->track_dirty = 0;
 690
 691         root->fs_info = fs_info;
 692         root->objectid = objectid;
 693         root->last_trans = 0;
 694         root->highest_inode = 0;
 695         root->last_inode_alloc = 0;
 696         root->name = NULL;
 697         root->in_sysfs = 0;
 698
 699         INIT_LIST_HEAD(&root->dirty_list);
 700         memset(&root->root_key, 0, sizeof(root->root_key));
 701         memset(&root->root_item, 0, sizeof(root->root_item));
 702         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
 703         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
 704         init_completion(&root->kobj_unregister);
 705         root->defrag_running = 0;
 706         root->defrag_level = 0;
 707         root->root_key.objectid = objectid;
 708         return 0;
 709 }
 710
 711 static int find_and_setup_root(struct btrfs_root *tree_root,
 712                                struct btrfs_fs_info *fs_info,
 713                                u64 objectid,
 714                                struct btrfs_root *root)
 715 {
 716         int ret;
 717         u32 blocksize;
 718
 719         __setup_root(tree_root->nodesize, tree_root->leafsize,
 720                      tree_root->sectorsize, tree_root->stripesize,
 721                      root, fs_info, objectid);
 722         ret = btrfs_find_last_root(tree_root, objectid,
 723                                    &root->root_item, &root->root_key);
 724         BUG_ON(ret);
 725
 726         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 727         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 728                                      blocksize);
 729         BUG_ON(!root->node);
 730         return 0;
 731 }
 732
 733 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_fs_info *fs_info,
 734                                                struct btrfs_key *location)
 735 {
 736         struct btrfs_root *root;
 737         struct btrfs_root *tree_root = fs_info->tree_root;
 738         struct btrfs_path *path;
 739         struct extent_buffer *l;
 740         u64 highest_inode;
 741         u32 blocksize;
 742         int ret = 0;
 743
 744         root = kzalloc(sizeof(*root), GFP_NOFS);
 745         if (!root)
 746                 return ERR_PTR(-ENOMEM);
 747         if (location->offset == (u64)-1) {
 748                 ret = find_and_setup_root(tree_root, fs_info,
 749                                           location->objectid, root);
 750                 if (ret) {
 751                         kfree(root);
 752                         return ERR_PTR(ret);
 753                 }
 754                 goto insert;
 755         }
 756
 757         __setup_root(tree_root->nodesize, tree_root->leafsize,
 758                      tree_root->sectorsize, tree_root->stripesize,
 759                      root, fs_info, location->objectid);
 760
 761         path = btrfs_alloc_path();
 762         BUG_ON(!path);
 763         ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
 764         if (ret != 0) {
 765                 if (ret > 0)
 766                         ret = -ENOENT;
 767                 goto out;
 768         }
 769         l = path->nodes[0];
 770         read_extent_buffer(l, &root->root_item,
 771                btrfs_item_ptr_offset(l, path->slots[0]),
 772                sizeof(root->root_item));
 773         memcpy(&root->root_key, location, sizeof(*location));
 774         ret = 0;
 775 out:
 776         btrfs_release_path(root, path);
 777         btrfs_free_path(path);
 778         if (ret) {
 779                 kfree(root);
 780                 return ERR_PTR(ret);
 781         }
 782         blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
 783         root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
 784                                      blocksize);
 785         BUG_ON(!root->node);
 786 insert:
 787         root->ref_cows = 1;
 788         ret = btrfs_find_highest_inode(root, &highest_inode);
 789         if (ret == 0) {
 790                 root->highest_inode = highest_inode;
 791                 root->last_inode_alloc = highest_inode;
 792         }
 793         return root;
 794 }
 795
 796 struct btrfs_root *btrfs_lookup_fs_root(struct btrfs_fs_info *fs_info,
 797                                         u64 root_objectid)
 798 {
 799         struct btrfs_root *root;
 800
 801         if (root_objectid == BTRFS_ROOT_TREE_OBJECTID)
 802                 return fs_info->tree_root;
 803         if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID)
 804                 return fs_info->extent_root;
 805
 806         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 807                                  (unsigned long)root_objectid);
 808         return root;
 809 }
 810
 811 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
 812                                               struct btrfs_key *location)
 813 {
 814         struct btrfs_root *root;
 815         int ret;
 816
 817         if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
 818                 return fs_info->tree_root;
 819         if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
 820                 return fs_info->extent_root;
 821         if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
 822                 return fs_info->chunk_root;
 823         if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
 824                 return fs_info->dev_root;
 825
 826         root = radix_tree_lookup(&fs_info->fs_roots_radix,
 827                                  (unsigned long)location->objectid);
 828         if (root)
 829                 return root;
 830
 831         root = btrfs_read_fs_root_no_radix(fs_info, location);
 832         if (IS_ERR(root))
 833                 return root;
 834         ret = radix_tree_insert(&fs_info->fs_roots_radix,
 835                                 (unsigned long)root->root_key.objectid,
 836                                 root);
 837         if (ret) {
 838                 free_extent_buffer(root->node);
 839                 kfree(root);
 840                 return ERR_PTR(ret);
 841         }
 842         ret = btrfs_find_dead_roots(fs_info->tree_root,
 843                                     root->root_key.objectid, root);
 844         BUG_ON(ret);
 845
 846         return root;
 847 }
 848
 849 struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info,
 850                                       struct btrfs_key *location,
 851                                       const char *name, int namelen)
 852 {
 853         struct btrfs_root *root;
 854         int ret;
 855
 856         root = btrfs_read_fs_root_no_name(fs_info, location);
 857         if (!root)
 858                 return NULL;
 859
 860         if (root->in_sysfs)
 861                 return root;
 862
 863         ret = btrfs_set_root_name(root, name, namelen);
 864         if (ret) {
 865                 free_extent_buffer(root->node);
 866                 kfree(root);
 867                 return ERR_PTR(ret);
 868         }
 869
 870         ret = btrfs_sysfs_add_root(root);
 871         if (ret) {
 872                 free_extent_buffer(root->node);
 873                 kfree(root->name);
 874                 kfree(root);
 875                 return ERR_PTR(ret);
 876         }
 877         root->in_sysfs = 1;
 878         return root;
 879 }
 880 #if 0
 881 static int add_hasher(struct btrfs_fs_info *info, char *type) {
 882         struct btrfs_hasher *hasher;
 883
 884         hasher = kmalloc(sizeof(*hasher), GFP_NOFS);
 885         if (!hasher)
 886                 return -ENOMEM;
 887         hasher->hash_tfm = crypto_alloc_hash(type, 0, CRYPTO_ALG_ASYNC);
 888         if (!hasher->hash_tfm) {
 889                 kfree(hasher);
 890                 return -EINVAL;
 891         }
 892         spin_lock(&info->hash_lock);
 893         list_add(&hasher->list, &info->hashers);
 894         spin_unlock(&info->hash_lock);
 895         return 0;
 896 }
 897 #endif
 898
 899 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
 900 {
 901         struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
 902         int ret = 0;
 903         struct list_head *cur;
 904         struct btrfs_device *device;
 905         struct backing_dev_info *bdi;
 906
 907         list_for_each(cur, &info->fs_devices->devices) {
 908                 device = list_entry(cur, struct btrfs_device, dev_list);
 909                 bdi = blk_get_backing_dev_info(device->bdev);
 910                 if (bdi && bdi_congested(bdi, bdi_bits)) {
 911                         ret = 1;
 912                         break;
 913                 }
 914         }
 915         return ret;
 916 }
 917
 918 /*
 919  * this unplugs every device on the box, and it is only used when page
 920  * is null
 921  */
 922 static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 923 {
 924         struct list_head *cur;
 925         struct btrfs_device *device;
 926         struct btrfs_fs_info *info;
 927
 928         info = (struct btrfs_fs_info *)bdi->unplug_io_data;
 929         list_for_each(cur, &info->fs_devices->devices) {
 930                 device = list_entry(cur, struct btrfs_device, dev_list);
 931                 bdi = blk_get_backing_dev_info(device->bdev);
 932                 if (bdi->unplug_io_fn) {
 933                         bdi->unplug_io_fn(bdi, page);
 934                 }
 935         }
 936 }
 937
 938 void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 939 {
 940         struct inode *inode;
 941         struct extent_map_tree *em_tree;
 942         struct extent_map *em;
 943         struct address_space *mapping;
 944         u64 offset;
 945
 946         /* the generic O_DIRECT read code does this */
 947         if (!page) {
 948                 __unplug_io_fn(bdi, page);
 949                 return;
 950         }
 951
 952         /*
 953          * page->mapping may change at any time.  Get a consistent copy
 954          * and use that for everything below
 955          */
 956         smp_mb();
 957         mapping = page->mapping;
 958         if (!mapping)
 959                 return;
 960
 961         inode = mapping->host;
 962         offset = page_offset(page);
 963
 964         em_tree = &BTRFS_I(inode)->extent_tree;
 965         spin_lock(&em_tree->lock);
 966         em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
 967         spin_unlock(&em_tree->lock);
 968         if (!em)
 969                 return;
 970
 971         offset = offset - em->start;
 972         btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
 973                           em->block_start + offset, page);
 974         free_extent_map(em);
 975 }
 976
 977 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 978 {
 979 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
 980         bdi_init(bdi);
 981 #endif
 982         bdi->ra_pages   = default_backing_dev_info.ra_pages;
 983         bdi->state              = 0;
 984         bdi->capabilities       = default_backing_dev_info.capabilities;
 985         bdi->unplug_io_fn       = btrfs_unplug_io_fn;
 986         bdi->unplug_io_data     = info;
 987         bdi->congested_fn       = btrfs_congested_fn;
 988         bdi->congested_data     = info;
 989         return 0;
 990 }
 991
 992 static int bio_ready_for_csum(struct bio *bio)
 993 {
 994         u64 length = 0;
 995         u64 buf_len = 0;
 996         u64 start = 0;
 997         struct page *page;
 998         struct extent_io_tree *io_tree = NULL;
 999         struct btrfs_fs_info *info = NULL;
1000         struct bio_vec *bvec;
1001         int i;
1002         int ret;
1003
1004         bio_for_each_segment(bvec, bio, i) {
1005                 page = bvec->bv_page;
1006                 if (page->private == EXTENT_PAGE_PRIVATE) {
1007                         length += bvec->bv_len;
1008                         continue;
1009                 }
1010                 if (!page->private) {
1011                         length += bvec->bv_len;
1012                         continue;
1013                 }
1014                 length = bvec->bv_len;
1015                 buf_len = page->private >> 2;
1016                 start = page_offset(page) + bvec->bv_offset;
1017                 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1018                 info = BTRFS_I(page->mapping->host)->root->fs_info;
1019         }
1020         /* are we fully contained in this bio? */
1021         if (buf_len <= length)
1022                 return 1;
1023
1024         ret = extent_range_uptodate(io_tree, start + length,
1025                                     start + buf_len - 1);
1026         if (ret == 1)
1027                 return ret;
1028         return ret;
1029 }
1030
1031 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1032 static void btrfs_end_io_csum(void *p)
1033 #else
1034 static void btrfs_end_io_csum(struct work_struct *work)
1035 #endif
1036 {
1037 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1038         struct btrfs_fs_info *fs_info = p;
1039 #else
1040         struct btrfs_fs_info *fs_info = container_of(work,
1041                                                      struct btrfs_fs_info,
1042                                                      end_io_work);
1043 #endif
1044         unsigned long flags;
1045         struct end_io_wq *end_io_wq;
1046         struct bio *bio;
1047         struct list_head *next;
1048         int error;
1049         int was_empty;
1050
1051         while(1) {
1052                 spin_lock_irqsave(&fs_info->end_io_work_lock, flags);
1053                 if (list_empty(&fs_info->end_io_work_list)) {
1054                         spin_unlock_irqrestore(&fs_info->end_io_work_lock,
1055                                                flags);
1056                         return;
1057                 }
1058                 next = fs_info->end_io_work_list.next;
1059                 list_del(next);
1060                 spin_unlock_irqrestore(&fs_info->end_io_work_lock, flags);
1061
1062                 end_io_wq = list_entry(next, struct end_io_wq, list);
1063
1064                 bio = end_io_wq->bio;
1065                 if (end_io_wq->metadata && !bio_ready_for_csum(bio)) {
1066                         spin_lock_irqsave(&fs_info->end_io_work_lock, flags);
1067                         was_empty = list_empty(&fs_info->end_io_work_list);
1068                         list_add_tail(&end_io_wq->list,
1069                                       &fs_info->end_io_work_list);
1070                         spin_unlock_irqrestore(&fs_info->end_io_work_lock,
1071                                                flags);
1072                         if (was_empty)
1073                                 return;
1074                         continue;
1075                 }
1076                 error = end_io_wq->error;
1077                 bio->bi_private = end_io_wq->private;
1078                 bio->bi_end_io = end_io_wq->end_io;
1079                 kfree(end_io_wq);
1080 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
1081                 bio_endio(bio, bio->bi_size, error);
1082 #else
1083                 bio_endio(bio, error);
1084 #endif
1085         }
1086 }
1087
1088 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1089 static void btrfs_async_submit_work(void *p)
1090 #else
1091 static void btrfs_async_submit_work(struct work_struct *work)
1092 #endif
1093 {
1094 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1095         struct btrfs_fs_info *fs_info = p;
1096 #else
1097         struct btrfs_fs_info *fs_info = container_of(work,
1098                                                      struct btrfs_fs_info,
1099                                                      async_submit_work);
1100 #endif
1101         struct async_submit_bio *async;
1102         struct list_head *next;
1103
1104         while(1) {
1105                 spin_lock(&fs_info->async_submit_work_lock);
1106                 if (list_empty(&fs_info->async_submit_work_list)) {
1107                         spin_unlock(&fs_info->async_submit_work_lock);
1108                         return;
1109                 }
1110                 next = fs_info->async_submit_work_list.next;
1111                 list_del(next);
1112                 spin_unlock(&fs_info->async_submit_work_lock);
1113
1114                 async = list_entry(next, struct async_submit_bio, list);
1115                 async->submit_bio_hook(async->inode, async->rw, async->bio,
1116                                        async->mirror_num);
1117                 kfree(async);
1118         }
1119 }
1120
1121 struct btrfs_root *open_ctree(struct super_block *sb,
1122                               struct btrfs_fs_devices *fs_devices)
1123 {
1124         u32 sectorsize;
1125         u32 nodesize;
1126         u32 leafsize;
1127         u32 blocksize;
1128         u32 stripesize;
1129         struct btrfs_root *extent_root = kmalloc(sizeof(struct btrfs_root),
1130                                                  GFP_NOFS);
1131         struct btrfs_root *tree_root = kmalloc(sizeof(struct btrfs_root),
1132                                                GFP_NOFS);
1133         struct btrfs_fs_info *fs_info = kzalloc(sizeof(*fs_info),
1134                                                 GFP_NOFS);
1135         struct btrfs_root *chunk_root = kmalloc(sizeof(struct btrfs_root),
1136                                                 GFP_NOFS);
1137         struct btrfs_root *dev_root = kmalloc(sizeof(struct btrfs_root),
1138                                               GFP_NOFS);
1139         int ret;
1140         int err = -EINVAL;
1141         struct btrfs_super_block *disk_super;
1142
1143         if (!extent_root || !tree_root || !fs_info) {
1144                 err = -ENOMEM;
1145                 goto fail;
1146         }
1147         end_io_workqueue = create_workqueue("btrfs-end-io");
1148         BUG_ON(!end_io_workqueue);
1149         async_submit_workqueue = create_workqueue("btrfs-async-submit");
1150
1151         INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_NOFS);
1152         INIT_LIST_HEAD(&fs_info->trans_list);
1153         INIT_LIST_HEAD(&fs_info->dead_roots);
1154         INIT_LIST_HEAD(&fs_info->hashers);
1155         INIT_LIST_HEAD(&fs_info->end_io_work_list);
1156         INIT_LIST_HEAD(&fs_info->async_submit_work_list);
1157         spin_lock_init(&fs_info->hash_lock);
1158         spin_lock_init(&fs_info->end_io_work_lock);
1159         spin_lock_init(&fs_info->async_submit_work_lock);
1160         spin_lock_init(&fs_info->delalloc_lock);
1161         spin_lock_init(&fs_info->new_trans_lock);
1162
1163         init_completion(&fs_info->kobj_unregister);
1164         sb_set_blocksize(sb, BTRFS_SUPER_INFO_SIZE);
1165         fs_info->tree_root = tree_root;
1166         fs_info->extent_root = extent_root;
1167         fs_info->chunk_root = chunk_root;
1168         fs_info->dev_root = dev_root;
1169         fs_info->fs_devices = fs_devices;
1170         INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1171         INIT_LIST_HEAD(&fs_info->space_info);
1172         btrfs_mapping_init(&fs_info->mapping_tree);
1173         fs_info->sb = sb;
1174         fs_info->max_extent = (u64)-1;
1175         fs_info->max_inline = 8192 * 1024;
1176         setup_bdi(fs_info, &fs_info->bdi);
1177         fs_info->btree_inode = new_inode(sb);
1178         fs_info->btree_inode->i_ino = 1;
1179         fs_info->btree_inode->i_nlink = 1;
1180
1181         /*
1182          * we set the i_size on the btree inode to the max possible int.
1183          * the real end of the address space is determined by all of
1184          * the devices in the system
1185          */
1186         fs_info->btree_inode->i_size = OFFSET_MAX;
1187         fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
1188         fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
1189
1190         extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
1191                              fs_info->btree_inode->i_mapping,
1192                              GFP_NOFS);
1193         extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree,
1194                              GFP_NOFS);
1195
1196         BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
1197
1198         extent_io_tree_init(&fs_info->free_space_cache,
1199                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1200         extent_io_tree_init(&fs_info->block_group_cache,
1201                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1202         extent_io_tree_init(&fs_info->pinned_extents,
1203                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1204         extent_io_tree_init(&fs_info->pending_del,
1205                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1206         extent_io_tree_init(&fs_info->extent_ins,
1207                              fs_info->btree_inode->i_mapping, GFP_NOFS);
1208         fs_info->do_barriers = 1;
1209
1210 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
1211         INIT_WORK(&fs_info->end_io_work, btrfs_end_io_csum, fs_info);
1212         INIT_WORK(&fs_info->async_submit_work, btrfs_async_submit_work,
1213                   fs_info);
1214         INIT_WORK(&fs_info->trans_work, btrfs_transaction_cleaner, fs_info);
1215 #else
1216         INIT_WORK(&fs_info->end_io_work, btrfs_end_io_csum);
1217         INIT_WORK(&fs_info->async_submit_work, btrfs_async_submit_work);
1218         INIT_DELAYED_WORK(&fs_info->trans_work, btrfs_transaction_cleaner);
1219 #endif
1220         BTRFS_I(fs_info->btree_inode)->root = tree_root;
1221         memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
1222                sizeof(struct btrfs_key));
1223         insert_inode_hash(fs_info->btree_inode);
1224         mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1225
1226         mutex_init(&fs_info->trans_mutex);
1227         mutex_init(&fs_info->fs_mutex);
1228
1229 #if 0
1230         ret = add_hasher(fs_info, "crc32c");
1231         if (ret) {
1232                 printk("btrfs: failed hash setup, modprobe cryptomgr?\n");
1233                 err = -ENOMEM;
1234                 goto fail_iput;
1235         }
1236 #endif
1237         __setup_root(4096, 4096, 4096, 4096, tree_root,
1238                      fs_info, BTRFS_ROOT_TREE_OBJECTID);
1239
1240         fs_info->sb_buffer = read_tree_block(tree_root,
1241                                              BTRFS_SUPER_INFO_OFFSET,
1242                                              4096);
1243
1244         if (!fs_info->sb_buffer)
1245                 goto fail_iput;
1246
1247         read_extent_buffer(fs_info->sb_buffer, &fs_info->super_copy, 0,
1248                            sizeof(fs_info->super_copy));
1249
1250         read_extent_buffer(fs_info->sb_buffer, fs_info->fsid,
1251                            (unsigned long)btrfs_super_fsid(fs_info->sb_buffer),
1252                            BTRFS_FSID_SIZE);
1253
1254         disk_super = &fs_info->super_copy;
1255         if (!btrfs_super_root(disk_super))
1256                 goto fail_sb_buffer;
1257
1258         if (btrfs_super_num_devices(disk_super) != fs_devices->num_devices) {
1259                 printk("Btrfs: wanted %llu devices, but found %llu\n",
1260                        (unsigned long long)btrfs_super_num_devices(disk_super),
1261                        (unsigned long long)fs_devices->num_devices);
1262                 goto fail_sb_buffer;
1263         }
1264         fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
1265
1266         nodesize = btrfs_super_nodesize(disk_super);
1267         leafsize = btrfs_super_leafsize(disk_super);
1268         sectorsize = btrfs_super_sectorsize(disk_super);
1269         stripesize = btrfs_super_stripesize(disk_super);
1270         tree_root->nodesize = nodesize;
1271         tree_root->leafsize = leafsize;
1272         tree_root->sectorsize = sectorsize;
1273         tree_root->stripesize = stripesize;
1274         sb_set_blocksize(sb, sectorsize);
1275
1276         if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
1277                     sizeof(disk_super->magic))) {
1278                 printk("btrfs: valid FS not found on %s\n", sb->s_id);
1279                 goto fail_sb_buffer;
1280         }
1281
1282         mutex_lock(&fs_info->fs_mutex);
1283
1284         ret = btrfs_read_sys_array(tree_root);
1285         if (ret) {
1286                 printk("btrfs: failed to read the system array on %s\n",
1287                        sb->s_id);
1288                 goto fail_sys_array;
1289         }
1290
1291         blocksize = btrfs_level_size(tree_root,
1292                                      btrfs_super_chunk_root_level(disk_super));
1293
1294         __setup_root(nodesize, leafsize, sectorsize, stripesize,
1295                      chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
1296
1297         chunk_root->node = read_tree_block(chunk_root,
1298                                            btrfs_super_chunk_root(disk_super),
1299                                            blocksize);
1300         BUG_ON(!chunk_root->node);
1301
1302         read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
1303                  (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
1304                  BTRFS_UUID_SIZE);
1305
1306         ret = btrfs_read_chunk_tree(chunk_root);
1307         BUG_ON(ret);
1308
1309         blocksize = btrfs_level_size(tree_root,
1310                                      btrfs_super_root_level(disk_super));
1311
1312
1313         tree_root->node = read_tree_block(tree_root,
1314                                           btrfs_super_root(disk_super),
1315                                           blocksize);
1316         if (!tree_root->node)
1317                 goto fail_sb_buffer;
1318
1319
1320         ret = find_and_setup_root(tree_root, fs_info,
1321                                   BTRFS_EXTENT_TREE_OBJECTID, extent_root);
1322         if (ret)
1323                 goto fail_tree_root;
1324         extent_root->track_dirty = 1;
1325
1326         ret = find_and_setup_root(tree_root, fs_info,
1327                                   BTRFS_DEV_TREE_OBJECTID, dev_root);
1328         dev_root->track_dirty = 1;
1329
1330         if (ret)
1331                 goto fail_extent_root;
1332
1333         btrfs_read_block_groups(extent_root);
1334
1335         fs_info->generation = btrfs_super_generation(disk_super) + 1;
1336         fs_info->data_alloc_profile = (u64)-1;
1337         fs_info->metadata_alloc_profile = (u64)-1;
1338         fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
1339
1340         mutex_unlock(&fs_info->fs_mutex);
1341         return tree_root;
1342
1343 fail_extent_root:
1344         free_extent_buffer(extent_root->node);
1345 fail_tree_root:
1346         free_extent_buffer(tree_root->node);
1347 fail_sys_array:
1348         mutex_unlock(&fs_info->fs_mutex);
1349 fail_sb_buffer:
1350         free_extent_buffer(fs_info->sb_buffer);
1351         extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
1352 fail_iput:
1353         iput(fs_info->btree_inode);
1354 fail:
1355         close_all_devices(fs_info);
1356         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1357
1358         kfree(extent_root);
1359         kfree(tree_root);
1360 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
1361         bdi_destroy(&fs_info->bdi);
1362 #endif
1363         kfree(fs_info);
1364         return ERR_PTR(err);
1365 }
1366
1367 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
1368 {
1369         char b[BDEVNAME_SIZE];
1370
1371         if (uptodate) {
1372                 set_buffer_uptodate(bh);
1373         } else {
1374                 if (!buffer_eopnotsupp(bh) && printk_ratelimit()) {
1375                         printk(KERN_WARNING "lost page write due to "
1376                                         "I/O error on %s\n",
1377                                        bdevname(bh->b_bdev, b));
1378                 }
1379                 set_buffer_write_io_error(bh);
1380                 clear_buffer_uptodate(bh);
1381         }
1382         unlock_buffer(bh);
1383         put_bh(bh);
1384 }
1385
1386 int write_all_supers(struct btrfs_root *root)
1387 {
1388         struct list_head *cur;
1389         struct list_head *head = &root->fs_info->fs_devices->devices;
1390         struct btrfs_device *dev;
1391         struct extent_buffer *sb;
1392         struct btrfs_dev_item *dev_item;
1393         struct buffer_head *bh;
1394         int ret;
1395         int do_barriers;
1396
1397         do_barriers = !btrfs_test_opt(root, NOBARRIER);
1398
1399         sb = root->fs_info->sb_buffer;
1400         dev_item = (struct btrfs_dev_item *)offsetof(struct btrfs_super_block,
1401                                                       dev_item);
1402         list_for_each(cur, head) {
1403                 dev = list_entry(cur, struct btrfs_device, dev_list);
1404                 btrfs_set_device_type(sb, dev_item, dev->type);
1405                 btrfs_set_device_id(sb, dev_item, dev->devid);
1406                 btrfs_set_device_total_bytes(sb, dev_item, dev->total_bytes);
1407                 btrfs_set_device_bytes_used(sb, dev_item, dev->bytes_used);
1408                 btrfs_set_device_io_align(sb, dev_item, dev->io_align);
1409                 btrfs_set_device_io_width(sb, dev_item, dev->io_width);
1410                 btrfs_set_device_sector_size(sb, dev_item, dev->sector_size);
1411                 write_extent_buffer(sb, dev->uuid,
1412                                     (unsigned long)btrfs_device_uuid(dev_item),
1413                                     BTRFS_UUID_SIZE);
1414
1415                 btrfs_set_header_flag(sb, BTRFS_HEADER_FLAG_WRITTEN);
1416                 csum_tree_block(root, sb, 0);
1417
1418                 bh = __getblk(dev->bdev, BTRFS_SUPER_INFO_OFFSET /
1419                               root->fs_info->sb->s_blocksize,
1420                               BTRFS_SUPER_INFO_SIZE);
1421
1422                 read_extent_buffer(sb, bh->b_data, 0, BTRFS_SUPER_INFO_SIZE);
1423                 dev->pending_io = bh;
1424
1425                 get_bh(bh);
1426                 set_buffer_uptodate(bh);
1427                 lock_buffer(bh);
1428                 bh->b_end_io = btrfs_end_buffer_write_sync;
1429
1430                 if (do_barriers && dev->barriers) {
1431                         ret = submit_bh(WRITE_BARRIER, bh);
1432                         if (ret == -EOPNOTSUPP) {
1433                                 printk("btrfs: disabling barriers on dev %s\n",
1434                                        dev->name);
1435                                 set_buffer_uptodate(bh);
1436                                 dev->barriers = 0;
1437                                 get_bh(bh);
1438                                 lock_buffer(bh);
1439                                 ret = submit_bh(WRITE, bh);
1440                         }
1441                 } else {
1442                         ret = submit_bh(WRITE, bh);
1443                 }
1444                 BUG_ON(ret);
1445         }
1446
1447         list_for_each(cur, head) {
1448                 dev = list_entry(cur, struct btrfs_device, dev_list);
1449                 BUG_ON(!dev->pending_io);
1450                 bh = dev->pending_io;
1451                 wait_on_buffer(bh);
1452                 if (!buffer_uptodate(dev->pending_io)) {
1453                         if (do_barriers && dev->barriers) {
1454                                 printk("btrfs: disabling barriers on dev %s\n",
1455                                        dev->name);
1456                                 set_buffer_uptodate(bh);
1457                                 get_bh(bh);
1458                                 lock_buffer(bh);
1459                                 dev->barriers = 0;
1460                                 ret = submit_bh(WRITE, bh);
1461                                 BUG_ON(ret);
1462                                 wait_on_buffer(bh);
1463                                 BUG_ON(!buffer_uptodate(bh));
1464                         } else {
1465                                 BUG();
1466                         }
1467
1468                 }
1469                 dev->pending_io = NULL;
1470                 brelse(bh);
1471         }
1472         return 0;
1473 }
1474
1475 int write_ctree_super(struct btrfs_trans_handle *trans, struct btrfs_root
1476                       *root)
1477 {
1478         int ret;
1479
1480         ret = write_all_supers(root);
1481 #if 0
1482         if (!btrfs_test_opt(root, NOBARRIER))
1483                 blkdev_issue_flush(sb->s_bdev, NULL);
1484         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, super);
1485         ret = sync_page_range_nolock(btree_inode, btree_inode->i_mapping,
1486                                      super->start, super->len);
1487         if (!btrfs_test_opt(root, NOBARRIER))
1488                 blkdev_issue_flush(sb->s_bdev, NULL);
1489 #endif
1490         return ret;
1491 }
1492
1493 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
1494 {
1495         radix_tree_delete(&fs_info->fs_roots_radix,
1496                           (unsigned long)root->root_key.objectid);
1497         if (root->in_sysfs)
1498                 btrfs_sysfs_del_root(root);
1499         if (root->inode)
1500                 iput(root->inode);
1501         if (root->node)
1502                 free_extent_buffer(root->node);
1503         if (root->commit_root)
1504                 free_extent_buffer(root->commit_root);
1505         if (root->name)
1506                 kfree(root->name);
1507         kfree(root);
1508         return 0;
1509 }
1510
1511 static int del_fs_roots(struct btrfs_fs_info *fs_info)
1512 {
1513         int ret;
1514         struct btrfs_root *gang[8];
1515         int i;
1516
1517         while(1) {
1518                 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
1519                                              (void **)gang, 0,
1520                                              ARRAY_SIZE(gang));
1521                 if (!ret)
1522                         break;
1523                 for (i = 0; i < ret; i++)
1524                         btrfs_free_fs_root(fs_info, gang[i]);
1525         }
1526         return 0;
1527 }
1528
1529 int close_ctree(struct btrfs_root *root)
1530 {
1531         int ret;
1532         struct btrfs_trans_handle *trans;
1533         struct btrfs_fs_info *fs_info = root->fs_info;
1534
1535         fs_info->closing = 1;
1536         btrfs_transaction_flush_work(root);
1537         mutex_lock(&fs_info->fs_mutex);
1538         btrfs_defrag_dirty_roots(root->fs_info);
1539         trans = btrfs_start_transaction(root, 1);
1540         ret = btrfs_commit_transaction(trans, root);
1541         /* run commit again to  drop the original snapshot */
1542         trans = btrfs_start_transaction(root, 1);
1543         btrfs_commit_transaction(trans, root);
1544         ret = btrfs_write_and_wait_transaction(NULL, root);
1545         BUG_ON(ret);
1546         write_ctree_super(NULL, root);
1547         mutex_unlock(&fs_info->fs_mutex);
1548
1549         btrfs_transaction_flush_work(root);
1550
1551         if (fs_info->delalloc_bytes) {
1552                 printk("btrfs: at unmount delalloc count %Lu\n",
1553                        fs_info->delalloc_bytes);
1554         }
1555         if (fs_info->extent_root->node)
1556                 free_extent_buffer(fs_info->extent_root->node);
1557
1558         if (fs_info->tree_root->node)
1559                 free_extent_buffer(fs_info->tree_root->node);
1560
1561         if (root->fs_info->chunk_root->node);
1562                 free_extent_buffer(root->fs_info->chunk_root->node);
1563
1564         if (root->fs_info->dev_root->node);
1565                 free_extent_buffer(root->fs_info->dev_root->node);
1566
1567         free_extent_buffer(fs_info->sb_buffer);
1568
1569         btrfs_free_block_groups(root->fs_info);
1570         del_fs_roots(fs_info);
1571
1572         filemap_write_and_wait(fs_info->btree_inode->i_mapping);
1573
1574         extent_io_tree_empty_lru(&fs_info->free_space_cache);
1575         extent_io_tree_empty_lru(&fs_info->block_group_cache);
1576         extent_io_tree_empty_lru(&fs_info->pinned_extents);
1577         extent_io_tree_empty_lru(&fs_info->pending_del);
1578         extent_io_tree_empty_lru(&fs_info->extent_ins);
1579         extent_io_tree_empty_lru(&BTRFS_I(fs_info->btree_inode)->io_tree);
1580
1581         flush_workqueue(end_io_workqueue);
1582         flush_workqueue(async_submit_workqueue);
1583
1584         truncate_inode_pages(fs_info->btree_inode->i_mapping, 0);
1585
1586         flush_workqueue(end_io_workqueue);
1587         destroy_workqueue(end_io_workqueue);
1588
1589         flush_workqueue(async_submit_workqueue);
1590         destroy_workqueue(async_submit_workqueue);
1591
1592         iput(fs_info->btree_inode);
1593 #if 0
1594         while(!list_empty(&fs_info->hashers)) {
1595                 struct btrfs_hasher *hasher;
1596                 hasher = list_entry(fs_info->hashers.next, struct btrfs_hasher,
1597                                     hashers);
1598                 list_del(&hasher->hashers);
1599                 crypto_free_hash(&fs_info->hash_tfm);
1600                 kfree(hasher);
1601         }
1602 #endif
1603         close_all_devices(fs_info);
1604         btrfs_mapping_tree_free(&fs_info->mapping_tree);
1605
1606 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
1607         bdi_destroy(&fs_info->bdi);
1608 #endif
1609
1610         kfree(fs_info->extent_root);
1611         kfree(fs_info->tree_root);
1612         kfree(fs_info->chunk_root);
1613         kfree(fs_info->dev_root);
1614         return 0;
1615 }
1616
1617 int btrfs_buffer_uptodate(struct extent_buffer *buf)
1618 {
1619         struct inode *btree_inode = buf->first_page->mapping->host;
1620         return extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf);
1621 }
1622
1623 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
1624 {
1625         struct inode *btree_inode = buf->first_page->mapping->host;
1626         return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
1627                                           buf);
1628 }
1629
1630 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
1631 {
1632         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1633         u64 transid = btrfs_header_generation(buf);
1634         struct inode *btree_inode = root->fs_info->btree_inode;
1635
1636         if (transid != root->fs_info->generation) {
1637                 printk(KERN_CRIT "transid mismatch buffer %llu, found %Lu running %Lu\n",
1638                         (unsigned long long)buf->start,
1639                         transid, root->fs_info->generation);
1640                 WARN_ON(1);
1641         }
1642         set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree, buf);
1643 }
1644
1645 void btrfs_throttle(struct btrfs_root *root)
1646 {
1647         struct backing_dev_info *bdi;
1648
1649         bdi = root->fs_info->sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
1650         if (root->fs_info->throttles && bdi_write_congested(bdi)) {
1651 #if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18)
1652                 congestion_wait(WRITE, HZ/20);
1653 #else
1654                 blk_congestion_wait(WRITE, HZ/20);
1655 #endif
1656         }
1657 }
1658
1659 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
1660 {
1661         balance_dirty_pages_ratelimited_nr(
1662                                    root->fs_info->btree_inode->i_mapping, 1);
1663 }
1664
1665 void btrfs_set_buffer_defrag(struct extent_buffer *buf)
1666 {
1667         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1668         struct inode *btree_inode = root->fs_info->btree_inode;
1669         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
1670                         buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
1671 }
1672
1673 void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
1674 {
1675         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1676         struct inode *btree_inode = root->fs_info->btree_inode;
1677         set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
1678                         buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
1679                         GFP_NOFS);
1680 }
1681
1682 int btrfs_buffer_defrag(struct extent_buffer *buf)
1683 {
1684         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1685         struct inode *btree_inode = root->fs_info->btree_inode;
1686         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
1687                      buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
1688 }
1689
1690 int btrfs_buffer_defrag_done(struct extent_buffer *buf)
1691 {
1692         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1693         struct inode *btree_inode = root->fs_info->btree_inode;
1694         return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
1695                      buf->start, buf->start + buf->len - 1,
1696                      EXTENT_DEFRAG_DONE, 0);
1697 }
1698
1699 int btrfs_clear_buffer_defrag_done(struct extent_buffer *buf)
1700 {
1701         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1702         struct inode *btree_inode = root->fs_info->btree_inode;
1703         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
1704                      buf->start, buf->start + buf->len - 1,
1705                      EXTENT_DEFRAG_DONE, GFP_NOFS);
1706 }
1707
1708 int btrfs_clear_buffer_defrag(struct extent_buffer *buf)
1709 {
1710         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1711         struct inode *btree_inode = root->fs_info->btree_inode;
1712         return clear_extent_bits(&BTRFS_I(btree_inode)->io_tree,
1713                      buf->start, buf->start + buf->len - 1,
1714                      EXTENT_DEFRAG, GFP_NOFS);
1715 }
1716
1717 int btrfs_read_buffer(struct extent_buffer *buf)
1718 {
1719         struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
1720         int ret;
1721         ret = btree_read_extent_buffer_pages(root, buf, 0);
1722         if (ret == 0) {
1723                 buf->flags |= EXTENT_UPTODATE;
1724         }
1725         return ret;
1726 }
1727
1728 static struct extent_io_ops btree_extent_io_ops = {
1729         .writepage_io_hook = btree_writepage_io_hook,
1730         .readpage_end_io_hook = btree_readpage_end_io_hook,
1731         .submit_bio_hook = btree_submit_bio_hook,
1732         /* note we're sharing with inode.c for the merge bio hook */
1733         .merge_bio_hook = btrfs_merge_bio_hook,
1734 };