fs/btrfs/ordered-data.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/slab.h>
   7 #include <linux/blkdev.h>
   8 #include <linux/writeback.h>
   9 #include <linux/sched/mm.h>
  10 #include "messages.h"
  11 #include "misc.h"
  12 #include "ctree.h"
  13 #include "transaction.h"
  14 #include "btrfs_inode.h"
  15 #include "extent_io.h"
  16 #include "disk-io.h"
  17 #include "compression.h"
  18 #include "delalloc-space.h"
  19 #include "qgroup.h"
  20 #include "subpage.h"
  21 #include "file.h"
  22 #include "super.h"
  23
  24 static struct kmem_cache *btrfs_ordered_extent_cache;
  25
  26 static u64 entry_end(struct btrfs_ordered_extent *entry)
  27 {
  28         if (entry->file_offset + entry->num_bytes < entry->file_offset)
  29                 return (u64)-1;
  30         return entry->file_offset + entry->num_bytes;
  31 }
  32
  33 /* returns NULL if the insertion worked, or it returns the node it did find
  34  * in the tree
  35  */
  36 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  37                                    struct rb_node *node)
  38 {
  39         struct rb_node **p = &root->rb_node;
  40         struct rb_node *parent = NULL;
  41         struct btrfs_ordered_extent *entry;
  42
  43         while (*p) {
  44                 parent = *p;
  45                 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  46
  47                 if (file_offset < entry->file_offset)
  48                         p = &(*p)->rb_left;
  49                 else if (file_offset >= entry_end(entry))
  50                         p = &(*p)->rb_right;
  51                 else
  52                         return parent;
  53         }
  54
  55         rb_link_node(node, parent, p);
  56         rb_insert_color(node, root);
  57         return NULL;
  58 }
  59
  60 /*
  61  * look for a given offset in the tree, and if it can't be found return the
  62  * first lesser offset
  63  */
  64 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
  65                                      struct rb_node **prev_ret)
  66 {
  67         struct rb_node *n = root->rb_node;
  68         struct rb_node *prev = NULL;
  69         struct rb_node *test;
  70         struct btrfs_ordered_extent *entry;
  71         struct btrfs_ordered_extent *prev_entry = NULL;
  72
  73         while (n) {
  74                 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
  75                 prev = n;
  76                 prev_entry = entry;
  77
  78                 if (file_offset < entry->file_offset)
  79                         n = n->rb_left;
  80                 else if (file_offset >= entry_end(entry))
  81                         n = n->rb_right;
  82                 else
  83                         return n;
  84         }
  85         if (!prev_ret)
  86                 return NULL;
  87
  88         while (prev && file_offset >= entry_end(prev_entry)) {
  89                 test = rb_next(prev);
  90                 if (!test)
  91                         break;
  92                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
  93                                       rb_node);
  94                 if (file_offset < entry_end(prev_entry))
  95                         break;
  96
  97                 prev = test;
  98         }
  99         if (prev)
 100                 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
 101                                       rb_node);
 102         while (prev && file_offset < entry_end(prev_entry)) {
 103                 test = rb_prev(prev);
 104                 if (!test)
 105                         break;
 106                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 107                                       rb_node);
 108                 prev = test;
 109         }
 110         *prev_ret = prev;
 111         return NULL;
 112 }
 113
 114 static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
 115                           u64 len)
 116 {
 117         if (file_offset + len <= entry->file_offset ||
 118             entry->file_offset + entry->num_bytes <= file_offset)
 119                 return 0;
 120         return 1;
 121 }
 122
 123 /*
 124  * look find the first ordered struct that has this offset, otherwise
 125  * the first one less than this offset
 126  */
 127 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 128                                           u64 file_offset)
 129 {
 130         struct rb_root *root = &tree->tree;
 131         struct rb_node *prev = NULL;
 132         struct rb_node *ret;
 133         struct btrfs_ordered_extent *entry;
 134
 135         if (tree->last) {
 136                 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
 137                                  rb_node);
 138                 if (in_range(file_offset, entry->file_offset, entry->num_bytes))
 139                         return tree->last;
 140         }
 141         ret = __tree_search(root, file_offset, &prev);
 142         if (!ret)
 143                 ret = prev;
 144         if (ret)
 145                 tree->last = ret;
 146         return ret;
 147 }
 148
 149 /*
 150  * Add an ordered extent to the per-inode tree.
 151  *
 152  * @inode:           Inode that this extent is for.
 153  * @file_offset:     Logical offset in file where the extent starts.
 154  * @num_bytes:       Logical length of extent in file.
 155  * @ram_bytes:       Full length of unencoded data.
 156  * @disk_bytenr:     Offset of extent on disk.
 157  * @disk_num_bytes:  Size of extent on disk.
 158  * @offset:          Offset into unencoded data where file data starts.
 159  * @flags:           Flags specifying type of extent (1 << BTRFS_ORDERED_*).
 160  * @compress_type:   Compression algorithm used for data.
 161  *
 162  * Most of these parameters correspond to &struct btrfs_file_extent_item. The
 163  * tree is given a single reference on the ordered extent that was inserted, and
 164  * the returned pointer is given a second reference.
 165  *
 166  * Return: the new ordered extent or error pointer.
 167  */
 168 struct btrfs_ordered_extent *btrfs_alloc_ordered_extent(
 169                         struct btrfs_inode *inode, u64 file_offset,
 170                         u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
 171                         u64 disk_num_bytes, u64 offset, unsigned long flags,
 172                         int compress_type)
 173 {
 174         struct btrfs_root *root = inode->root;
 175         struct btrfs_fs_info *fs_info = root->fs_info;
 176         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 177         struct rb_node *node;
 178         struct btrfs_ordered_extent *entry;
 179         int ret;
 180
 181         if (flags &
 182             ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
 183                 /* For nocow write, we can release the qgroup rsv right now */
 184                 ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
 185                 if (ret < 0)
 186                         return ERR_PTR(ret);
 187                 ret = 0;
 188         } else {
 189                 /*
 190                  * The ordered extent has reserved qgroup space, release now
 191                  * and pass the reserved number for qgroup_record to free.
 192                  */
 193                 ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
 194                 if (ret < 0)
 195                         return ERR_PTR(ret);
 196         }
 197         entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 198         if (!entry)
 199                 return ERR_PTR(-ENOMEM);
 200
 201         entry->file_offset = file_offset;
 202         entry->num_bytes = num_bytes;
 203         entry->ram_bytes = ram_bytes;
 204         entry->disk_bytenr = disk_bytenr;
 205         entry->disk_num_bytes = disk_num_bytes;
 206         entry->offset = offset;
 207         entry->bytes_left = num_bytes;
 208         entry->inode = igrab(&inode->vfs_inode);
 209         entry->compress_type = compress_type;
 210         entry->truncated_len = (u64)-1;
 211         entry->qgroup_rsv = ret;
 212         entry->physical = (u64)-1;
 213
 214         ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
 215         entry->flags = flags;
 216
 217         percpu_counter_add_batch(&fs_info->ordered_bytes, num_bytes,
 218                                  fs_info->delalloc_batch);
 219
 220         /* one ref for the tree */
 221         refcount_set(&entry->refs, 1);
 222         init_waitqueue_head(&entry->wait);
 223         INIT_LIST_HEAD(&entry->list);
 224         INIT_LIST_HEAD(&entry->log_list);
 225         INIT_LIST_HEAD(&entry->root_extent_list);
 226         INIT_LIST_HEAD(&entry->work_list);
 227         init_completion(&entry->completion);
 228
 229         trace_btrfs_ordered_extent_add(inode, entry);
 230
 231         spin_lock_irq(&tree->lock);
 232         node = tree_insert(&tree->tree, file_offset,
 233                            &entry->rb_node);
 234         if (node)
 235                 btrfs_panic(fs_info, -EEXIST,
 236                                 "inconsistency in ordered tree at offset %llu",
 237                                 file_offset);
 238         spin_unlock_irq(&tree->lock);
 239
 240         spin_lock(&root->ordered_extent_lock);
 241         list_add_tail(&entry->root_extent_list,
 242                       &root->ordered_extents);
 243         root->nr_ordered_extents++;
 244         if (root->nr_ordered_extents == 1) {
 245                 spin_lock(&fs_info->ordered_root_lock);
 246                 BUG_ON(!list_empty(&root->ordered_root));
 247                 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 248                 spin_unlock(&fs_info->ordered_root_lock);
 249         }
 250         spin_unlock(&root->ordered_extent_lock);
 251
 252         /*
 253          * We don't need the count_max_extents here, we can assume that all of
 254          * that work has been done at higher layers, so this is truly the
 255          * smallest the extent is going to get.
 256          */
 257         spin_lock(&inode->lock);
 258         btrfs_mod_outstanding_extents(inode, 1);
 259         spin_unlock(&inode->lock);
 260
 261         /* One ref for the returned entry to match semantics of lookup. */
 262         refcount_inc(&entry->refs);
 263
 264         return entry;
 265 }
 266
 267 /*
 268  * Add a new btrfs_ordered_extent for the range, but drop the reference instead
 269  * of returning it to the caller.
 270  */
 271 int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
 272                              u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
 273                              u64 disk_num_bytes, u64 offset, unsigned long flags,
 274                              int compress_type)
 275 {
 276         struct btrfs_ordered_extent *ordered;
 277
 278         ordered = btrfs_alloc_ordered_extent(inode, file_offset, num_bytes,
 279                                              ram_bytes, disk_bytenr,
 280                                              disk_num_bytes, offset, flags,
 281                                              compress_type);
 282
 283         if (IS_ERR(ordered))
 284                 return PTR_ERR(ordered);
 285         btrfs_put_ordered_extent(ordered);
 286
 287         return 0;
 288 }
 289
 290 /*
 291  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 292  * when an ordered extent is finished.  If the list covers more than one
 293  * ordered extent, it is split across multiples.
 294  */
 295 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 296                            struct btrfs_ordered_sum *sum)
 297 {
 298         struct btrfs_ordered_inode_tree *tree;
 299
 300         tree = &BTRFS_I(entry->inode)->ordered_tree;
 301         spin_lock_irq(&tree->lock);
 302         list_add_tail(&sum->list, &entry->list);
 303         spin_unlock_irq(&tree->lock);
 304 }
 305
 306 static void finish_ordered_fn(struct btrfs_work *work)
 307 {
 308         struct btrfs_ordered_extent *ordered_extent;
 309
 310         ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
 311         btrfs_finish_ordered_io(ordered_extent);
 312 }
 313
 314 /*
 315  * Mark all ordered extents io inside the specified range finished.
 316  *
 317  * @page:        The involved page for the operation.
 318  *               For uncompressed buffered IO, the page status also needs to be
 319  *               updated to indicate whether the pending ordered io is finished.
 320  *               Can be NULL for direct IO and compressed write.
 321  *               For these cases, callers are ensured they won't execute the
 322  *               endio function twice.
 323  *
 324  * This function is called for endio, thus the range must have ordered
 325  * extent(s) covering it.
 326  */
 327 void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
 328                                     struct page *page, u64 file_offset,
 329                                     u64 num_bytes, bool uptodate)
 330 {
 331         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 332         struct btrfs_fs_info *fs_info = inode->root->fs_info;
 333         struct btrfs_workqueue *wq;
 334         struct rb_node *node;
 335         struct btrfs_ordered_extent *entry = NULL;
 336         unsigned long flags;
 337         u64 cur = file_offset;
 338
 339         if (btrfs_is_free_space_inode(inode))
 340                 wq = fs_info->endio_freespace_worker;
 341         else
 342                 wq = fs_info->endio_write_workers;
 343
 344         if (page)
 345                 ASSERT(page->mapping && page_offset(page) <= file_offset &&
 346                        file_offset + num_bytes <= page_offset(page) + PAGE_SIZE);
 347
 348         spin_lock_irqsave(&tree->lock, flags);
 349         while (cur < file_offset + num_bytes) {
 350                 u64 entry_end;
 351                 u64 end;
 352                 u32 len;
 353
 354                 node = tree_search(tree, cur);
 355                 /* No ordered extents at all */
 356                 if (!node)
 357                         break;
 358
 359                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 360                 entry_end = entry->file_offset + entry->num_bytes;
 361                 /*
 362                  * |<-- OE --->|  |
 363                  *                cur
 364                  * Go to next OE.
 365                  */
 366                 if (cur >= entry_end) {
 367                         node = rb_next(node);
 368                         /* No more ordered extents, exit */
 369                         if (!node)
 370                                 break;
 371                         entry = rb_entry(node, struct btrfs_ordered_extent,
 372                                          rb_node);
 373
 374                         /* Go to next ordered extent and continue */
 375                         cur = entry->file_offset;
 376                         continue;
 377                 }
 378                 /*
 379                  * |    |<--- OE --->|
 380                  * cur
 381                  * Go to the start of OE.
 382                  */
 383                 if (cur < entry->file_offset) {
 384                         cur = entry->file_offset;
 385                         continue;
 386                 }
 387
 388                 /*
 389                  * Now we are definitely inside one ordered extent.
 390                  *
 391                  * |<--- OE --->|
 392                  *      |
 393                  *      cur
 394                  */
 395                 end = min(entry->file_offset + entry->num_bytes,
 396                           file_offset + num_bytes) - 1;
 397                 ASSERT(end + 1 - cur < U32_MAX);
 398                 len = end + 1 - cur;
 399
 400                 if (page) {
 401                         /*
 402                          * Ordered (Private2) bit indicates whether we still
 403                          * have pending io unfinished for the ordered extent.
 404                          *
 405                          * If there's no such bit, we need to skip to next range.
 406                          */
 407                         if (!btrfs_page_test_ordered(fs_info, page, cur, len)) {
 408                                 cur += len;
 409                                 continue;
 410                         }
 411                         btrfs_page_clear_ordered(fs_info, page, cur, len);
 412                 }
 413
 414                 /* Now we're fine to update the accounting */
 415                 if (unlikely(len > entry->bytes_left)) {
 416                         WARN_ON(1);
 417                         btrfs_crit(fs_info,
 418 "bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%u left=%llu",
 419                                    inode->root->root_key.objectid,
 420                                    btrfs_ino(inode),
 421                                    entry->file_offset,
 422                                    entry->num_bytes,
 423                                    len, entry->bytes_left);
 424                         entry->bytes_left = 0;
 425                 } else {
 426                         entry->bytes_left -= len;
 427                 }
 428
 429                 if (!uptodate)
 430                         set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 431
 432                 /*
 433                  * All the IO of the ordered extent is finished, we need to queue
 434                  * the finish_func to be executed.
 435                  */
 436                 if (entry->bytes_left == 0) {
 437                         set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 438                         cond_wake_up(&entry->wait);
 439                         refcount_inc(&entry->refs);
 440                         trace_btrfs_ordered_extent_mark_finished(inode, entry);
 441                         spin_unlock_irqrestore(&tree->lock, flags);
 442                         btrfs_init_work(&entry->work, finish_ordered_fn, NULL, NULL);
 443                         btrfs_queue_work(wq, &entry->work);
 444                         spin_lock_irqsave(&tree->lock, flags);
 445                 }
 446                 cur += len;
 447         }
 448         spin_unlock_irqrestore(&tree->lock, flags);
 449 }
 450
 451 /*
 452  * Finish IO for one ordered extent across a given range.  The range can only
 453  * contain one ordered extent.
 454  *
 455  * @cached:      The cached ordered extent. If not NULL, we can skip the tree
 456  *               search and use the ordered extent directly.
 457  *               Will be also used to store the finished ordered extent.
 458  * @file_offset: File offset for the finished IO
 459  * @io_size:     Length of the finish IO range
 460  *
 461  * Return true if the ordered extent is finished in the range, and update
 462  * @cached.
 463  * Return false otherwise.
 464  *
 465  * NOTE: The range can NOT cross multiple ordered extents.
 466  * Thus caller should ensure the range doesn't cross ordered extents.
 467  */
 468 bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 469                                     struct btrfs_ordered_extent **cached,
 470                                     u64 file_offset, u64 io_size)
 471 {
 472         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 473         struct rb_node *node;
 474         struct btrfs_ordered_extent *entry = NULL;
 475         unsigned long flags;
 476         bool finished = false;
 477
 478         spin_lock_irqsave(&tree->lock, flags);
 479         if (cached && *cached) {
 480                 entry = *cached;
 481                 goto have_entry;
 482         }
 483
 484         node = tree_search(tree, file_offset);
 485         if (!node)
 486                 goto out;
 487
 488         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 489 have_entry:
 490         if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 491                 goto out;
 492
 493         if (io_size > entry->bytes_left)
 494                 btrfs_crit(inode->root->fs_info,
 495                            "bad ordered accounting left %llu size %llu",
 496                        entry->bytes_left, io_size);
 497
 498         entry->bytes_left -= io_size;
 499
 500         if (entry->bytes_left == 0) {
 501                 /*
 502                  * Ensure only one caller can set the flag and finished_ret
 503                  * accordingly
 504                  */
 505                 finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 506                 /* test_and_set_bit implies a barrier */
 507                 cond_wake_up_nomb(&entry->wait);
 508         }
 509 out:
 510         if (finished && cached && entry) {
 511                 *cached = entry;
 512                 refcount_inc(&entry->refs);
 513                 trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
 514         }
 515         spin_unlock_irqrestore(&tree->lock, flags);
 516         return finished;
 517 }
 518
 519 /*
 520  * used to drop a reference on an ordered extent.  This will free
 521  * the extent if the last reference is dropped
 522  */
 523 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 524 {
 525         struct list_head *cur;
 526         struct btrfs_ordered_sum *sum;
 527
 528         trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
 529
 530         if (refcount_dec_and_test(&entry->refs)) {
 531                 ASSERT(list_empty(&entry->root_extent_list));
 532                 ASSERT(list_empty(&entry->log_list));
 533                 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 534                 if (entry->inode)
 535                         btrfs_add_delayed_iput(BTRFS_I(entry->inode));
 536                 while (!list_empty(&entry->list)) {
 537                         cur = entry->list.next;
 538                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 539                         list_del(&sum->list);
 540                         kvfree(sum);
 541                 }
 542                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
 543         }
 544 }
 545
 546 /*
 547  * remove an ordered extent from the tree.  No references are dropped
 548  * and waiters are woken up.
 549  */
 550 void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 551                                  struct btrfs_ordered_extent *entry)
 552 {
 553         struct btrfs_ordered_inode_tree *tree;
 554         struct btrfs_root *root = btrfs_inode->root;
 555         struct btrfs_fs_info *fs_info = root->fs_info;
 556         struct rb_node *node;
 557         bool pending;
 558         bool freespace_inode;
 559
 560         /*
 561          * If this is a free space inode the thread has not acquired the ordered
 562          * extents lockdep map.
 563          */
 564         freespace_inode = btrfs_is_free_space_inode(btrfs_inode);
 565
 566         btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);
 567         /* This is paired with btrfs_add_ordered_extent. */
 568         spin_lock(&btrfs_inode->lock);
 569         btrfs_mod_outstanding_extents(btrfs_inode, -1);
 570         spin_unlock(&btrfs_inode->lock);
 571         if (root != fs_info->tree_root) {
 572                 u64 release;
 573
 574                 if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
 575                         release = entry->disk_num_bytes;
 576                 else
 577                         release = entry->num_bytes;
 578                 btrfs_delalloc_release_metadata(btrfs_inode, release, false);
 579         }
 580
 581         percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 582                                  fs_info->delalloc_batch);
 583
 584         tree = &btrfs_inode->ordered_tree;
 585         spin_lock_irq(&tree->lock);
 586         node = &entry->rb_node;
 587         rb_erase(node, &tree->tree);
 588         RB_CLEAR_NODE(node);
 589         if (tree->last == node)
 590                 tree->last = NULL;
 591         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 592         pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
 593         spin_unlock_irq(&tree->lock);
 594
 595         /*
 596          * The current running transaction is waiting on us, we need to let it
 597          * know that we're complete and wake it up.
 598          */
 599         if (pending) {
 600                 struct btrfs_transaction *trans;
 601
 602                 /*
 603                  * The checks for trans are just a formality, it should be set,
 604                  * but if it isn't we don't want to deref/assert under the spin
 605                  * lock, so be nice and check if trans is set, but ASSERT() so
 606                  * if it isn't set a developer will notice.
 607                  */
 608                 spin_lock(&fs_info->trans_lock);
 609                 trans = fs_info->running_transaction;
 610                 if (trans)
 611                         refcount_inc(&trans->use_count);
 612                 spin_unlock(&fs_info->trans_lock);
 613
 614                 ASSERT(trans);
 615                 if (trans) {
 616                         if (atomic_dec_and_test(&trans->pending_ordered))
 617                                 wake_up(&trans->pending_wait);
 618                         btrfs_put_transaction(trans);
 619                 }
 620         }
 621
 622         btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);
 623
 624         spin_lock(&root->ordered_extent_lock);
 625         list_del_init(&entry->root_extent_list);
 626         root->nr_ordered_extents--;
 627
 628         trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
 629
 630         if (!root->nr_ordered_extents) {
 631                 spin_lock(&fs_info->ordered_root_lock);
 632                 BUG_ON(list_empty(&root->ordered_root));
 633                 list_del_init(&root->ordered_root);
 634                 spin_unlock(&fs_info->ordered_root_lock);
 635         }
 636         spin_unlock(&root->ordered_extent_lock);
 637         wake_up(&entry->wait);
 638         if (!freespace_inode)
 639                 btrfs_lockdep_release(fs_info, btrfs_ordered_extent);
 640 }
 641
 642 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 643 {
 644         struct btrfs_ordered_extent *ordered;
 645
 646         ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 647         btrfs_start_ordered_extent(ordered);
 648         complete(&ordered->completion);
 649 }
 650
 651 /*
 652  * wait for all the ordered extents in a root.  This is done when balancing
 653  * space between drives.
 654  */
 655 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 656                                const u64 range_start, const u64 range_len)
 657 {
 658         struct btrfs_fs_info *fs_info = root->fs_info;
 659         LIST_HEAD(splice);
 660         LIST_HEAD(skipped);
 661         LIST_HEAD(works);
 662         struct btrfs_ordered_extent *ordered, *next;
 663         u64 count = 0;
 664         const u64 range_end = range_start + range_len;
 665
 666         mutex_lock(&root->ordered_extent_mutex);
 667         spin_lock(&root->ordered_extent_lock);
 668         list_splice_init(&root->ordered_extents, &splice);
 669         while (!list_empty(&splice) && nr) {
 670                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 671                                            root_extent_list);
 672
 673                 if (range_end <= ordered->disk_bytenr ||
 674                     ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
 675                         list_move_tail(&ordered->root_extent_list, &skipped);
 676                         cond_resched_lock(&root->ordered_extent_lock);
 677                         continue;
 678                 }
 679
 680                 list_move_tail(&ordered->root_extent_list,
 681                                &root->ordered_extents);
 682                 refcount_inc(&ordered->refs);
 683                 spin_unlock(&root->ordered_extent_lock);
 684
 685                 btrfs_init_work(&ordered->flush_work,
 686                                 btrfs_run_ordered_extent_work, NULL, NULL);
 687                 list_add_tail(&ordered->work_list, &works);
 688                 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 689
 690                 cond_resched();
 691                 spin_lock(&root->ordered_extent_lock);
 692                 if (nr != U64_MAX)
 693                         nr--;
 694                 count++;
 695         }
 696         list_splice_tail(&skipped, &root->ordered_extents);
 697         list_splice_tail(&splice, &root->ordered_extents);
 698         spin_unlock(&root->ordered_extent_lock);
 699
 700         list_for_each_entry_safe(ordered, next, &works, work_list) {
 701                 list_del_init(&ordered->work_list);
 702                 wait_for_completion(&ordered->completion);
 703                 btrfs_put_ordered_extent(ordered);
 704                 cond_resched();
 705         }
 706         mutex_unlock(&root->ordered_extent_mutex);
 707
 708         return count;
 709 }
 710
 711 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 712                              const u64 range_start, const u64 range_len)
 713 {
 714         struct btrfs_root *root;
 715         struct list_head splice;
 716         u64 done;
 717
 718         INIT_LIST_HEAD(&splice);
 719
 720         mutex_lock(&fs_info->ordered_operations_mutex);
 721         spin_lock(&fs_info->ordered_root_lock);
 722         list_splice_init(&fs_info->ordered_roots, &splice);
 723         while (!list_empty(&splice) && nr) {
 724                 root = list_first_entry(&splice, struct btrfs_root,
 725                                         ordered_root);
 726                 root = btrfs_grab_root(root);
 727                 BUG_ON(!root);
 728                 list_move_tail(&root->ordered_root,
 729                                &fs_info->ordered_roots);
 730                 spin_unlock(&fs_info->ordered_root_lock);
 731
 732                 done = btrfs_wait_ordered_extents(root, nr,
 733                                                   range_start, range_len);
 734                 btrfs_put_root(root);
 735
 736                 spin_lock(&fs_info->ordered_root_lock);
 737                 if (nr != U64_MAX) {
 738                         nr -= done;
 739                 }
 740         }
 741         list_splice_tail(&splice, &fs_info->ordered_roots);
 742         spin_unlock(&fs_info->ordered_root_lock);
 743         mutex_unlock(&fs_info->ordered_operations_mutex);
 744 }
 745
 746 /*
 747  * Start IO and wait for a given ordered extent to finish.
 748  *
 749  * Wait on page writeback for all the pages in the extent and the IO completion
 750  * code to insert metadata into the btree corresponding to the extent.
 751  */
 752 void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry)
 753 {
 754         u64 start = entry->file_offset;
 755         u64 end = start + entry->num_bytes - 1;
 756         struct btrfs_inode *inode = BTRFS_I(entry->inode);
 757         bool freespace_inode;
 758
 759         trace_btrfs_ordered_extent_start(inode, entry);
 760
 761         /*
 762          * If this is a free space inode do not take the ordered extents lockdep
 763          * map.
 764          */
 765         freespace_inode = btrfs_is_free_space_inode(inode);
 766
 767         /*
 768          * pages in the range can be dirty, clean or writeback.  We
 769          * start IO on any dirty ones so the wait doesn't stall waiting
 770          * for the flusher thread to find them
 771          */
 772         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 773                 filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
 774
 775         if (!freespace_inode)
 776                 btrfs_might_wait_for_event(inode->root->fs_info, btrfs_ordered_extent);
 777         wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE, &entry->flags));
 778 }
 779
 780 /*
 781  * Used to wait on ordered extents across a large range of bytes.
 782  */
 783 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 784 {
 785         int ret = 0;
 786         int ret_wb = 0;
 787         u64 end;
 788         u64 orig_end;
 789         struct btrfs_ordered_extent *ordered;
 790
 791         if (start + len < start) {
 792                 orig_end = OFFSET_MAX;
 793         } else {
 794                 orig_end = start + len - 1;
 795                 if (orig_end > OFFSET_MAX)
 796                         orig_end = OFFSET_MAX;
 797         }
 798
 799         /* start IO across the range first to instantiate any delalloc
 800          * extents
 801          */
 802         ret = btrfs_fdatawrite_range(inode, start, orig_end);
 803         if (ret)
 804                 return ret;
 805
 806         /*
 807          * If we have a writeback error don't return immediately. Wait first
 808          * for any ordered extents that haven't completed yet. This is to make
 809          * sure no one can dirty the same page ranges and call writepages()
 810          * before the ordered extents complete - to avoid failures (-EEXIST)
 811          * when adding the new ordered extents to the ordered tree.
 812          */
 813         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 814
 815         end = orig_end;
 816         while (1) {
 817                 ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
 818                 if (!ordered)
 819                         break;
 820                 if (ordered->file_offset > orig_end) {
 821                         btrfs_put_ordered_extent(ordered);
 822                         break;
 823                 }
 824                 if (ordered->file_offset + ordered->num_bytes <= start) {
 825                         btrfs_put_ordered_extent(ordered);
 826                         break;
 827                 }
 828                 btrfs_start_ordered_extent(ordered);
 829                 end = ordered->file_offset;
 830                 /*
 831                  * If the ordered extent had an error save the error but don't
 832                  * exit without waiting first for all other ordered extents in
 833                  * the range to complete.
 834                  */
 835                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 836                         ret = -EIO;
 837                 btrfs_put_ordered_extent(ordered);
 838                 if (end == 0 || end == start)
 839                         break;
 840                 end--;
 841         }
 842         return ret_wb ? ret_wb : ret;
 843 }
 844
 845 /*
 846  * find an ordered extent corresponding to file_offset.  return NULL if
 847  * nothing is found, otherwise take a reference on the extent and return it
 848  */
 849 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
 850                                                          u64 file_offset)
 851 {
 852         struct btrfs_ordered_inode_tree *tree;
 853         struct rb_node *node;
 854         struct btrfs_ordered_extent *entry = NULL;
 855         unsigned long flags;
 856
 857         tree = &inode->ordered_tree;
 858         spin_lock_irqsave(&tree->lock, flags);
 859         node = tree_search(tree, file_offset);
 860         if (!node)
 861                 goto out;
 862
 863         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 864         if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 865                 entry = NULL;
 866         if (entry) {
 867                 refcount_inc(&entry->refs);
 868                 trace_btrfs_ordered_extent_lookup(inode, entry);
 869         }
 870 out:
 871         spin_unlock_irqrestore(&tree->lock, flags);
 872         return entry;
 873 }
 874
 875 /* Since the DIO code tries to lock a wide area we need to look for any ordered
 876  * extents that exist in the range, rather than just the start of the range.
 877  */
 878 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 879                 struct btrfs_inode *inode, u64 file_offset, u64 len)
 880 {
 881         struct btrfs_ordered_inode_tree *tree;
 882         struct rb_node *node;
 883         struct btrfs_ordered_extent *entry = NULL;
 884
 885         tree = &inode->ordered_tree;
 886         spin_lock_irq(&tree->lock);
 887         node = tree_search(tree, file_offset);
 888         if (!node) {
 889                 node = tree_search(tree, file_offset + len);
 890                 if (!node)
 891                         goto out;
 892         }
 893
 894         while (1) {
 895                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 896                 if (range_overlaps(entry, file_offset, len))
 897                         break;
 898
 899                 if (entry->file_offset >= file_offset + len) {
 900                         entry = NULL;
 901                         break;
 902                 }
 903                 entry = NULL;
 904                 node = rb_next(node);
 905                 if (!node)
 906                         break;
 907         }
 908 out:
 909         if (entry) {
 910                 refcount_inc(&entry->refs);
 911                 trace_btrfs_ordered_extent_lookup_range(inode, entry);
 912         }
 913         spin_unlock_irq(&tree->lock);
 914         return entry;
 915 }
 916
 917 /*
 918  * Adds all ordered extents to the given list. The list ends up sorted by the
 919  * file_offset of the ordered extents.
 920  */
 921 void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
 922                                            struct list_head *list)
 923 {
 924         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 925         struct rb_node *n;
 926
 927         ASSERT(inode_is_locked(&inode->vfs_inode));
 928
 929         spin_lock_irq(&tree->lock);
 930         for (n = rb_first(&tree->tree); n; n = rb_next(n)) {
 931                 struct btrfs_ordered_extent *ordered;
 932
 933                 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 934
 935                 if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 936                         continue;
 937
 938                 ASSERT(list_empty(&ordered->log_list));
 939                 list_add_tail(&ordered->log_list, list);
 940                 refcount_inc(&ordered->refs);
 941                 trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
 942         }
 943         spin_unlock_irq(&tree->lock);
 944 }
 945
 946 /*
 947  * lookup and return any extent before 'file_offset'.  NULL is returned
 948  * if none is found
 949  */
 950 struct btrfs_ordered_extent *
 951 btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
 952 {
 953         struct btrfs_ordered_inode_tree *tree;
 954         struct rb_node *node;
 955         struct btrfs_ordered_extent *entry = NULL;
 956
 957         tree = &inode->ordered_tree;
 958         spin_lock_irq(&tree->lock);
 959         node = tree_search(tree, file_offset);
 960         if (!node)
 961                 goto out;
 962
 963         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 964         refcount_inc(&entry->refs);
 965         trace_btrfs_ordered_extent_lookup_first(inode, entry);
 966 out:
 967         spin_unlock_irq(&tree->lock);
 968         return entry;
 969 }
 970
 971 /*
 972  * Lookup the first ordered extent that overlaps the range
 973  * [@file_offset, @file_offset + @len).
 974  *
 975  * The difference between this and btrfs_lookup_first_ordered_extent() is
 976  * that this one won't return any ordered extent that does not overlap the range.
 977  * And the difference against btrfs_lookup_ordered_extent() is, this function
 978  * ensures the first ordered extent gets returned.
 979  */
 980 struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
 981                         struct btrfs_inode *inode, u64 file_offset, u64 len)
 982 {
 983         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 984         struct rb_node *node;
 985         struct rb_node *cur;
 986         struct rb_node *prev;
 987         struct rb_node *next;
 988         struct btrfs_ordered_extent *entry = NULL;
 989
 990         spin_lock_irq(&tree->lock);
 991         node = tree->tree.rb_node;
 992         /*
 993          * Here we don't want to use tree_search() which will use tree->last
 994          * and screw up the search order.
 995          * And __tree_search() can't return the adjacent ordered extents
 996          * either, thus here we do our own search.
 997          */
 998         while (node) {
 999                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1000
1001                 if (file_offset < entry->file_offset) {
1002                         node = node->rb_left;
1003                 } else if (file_offset >= entry_end(entry)) {
1004                         node = node->rb_right;
1005                 } else {
1006                         /*
1007                          * Direct hit, got an ordered extent that starts at
1008                          * @file_offset
1009                          */
1010                         goto out;
1011                 }
1012         }
1013         if (!entry) {
1014                 /* Empty tree */
1015                 goto out;
1016         }
1017
1018         cur = &entry->rb_node;
1019         /* We got an entry around @file_offset, check adjacent entries */
1020         if (entry->file_offset < file_offset) {
1021                 prev = cur;
1022                 next = rb_next(cur);
1023         } else {
1024                 prev = rb_prev(cur);
1025                 next = cur;
1026         }
1027         if (prev) {
1028                 entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
1029                 if (range_overlaps(entry, file_offset, len))
1030                         goto out;
1031         }
1032         if (next) {
1033                 entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
1034                 if (range_overlaps(entry, file_offset, len))
1035                         goto out;
1036         }
1037         /* No ordered extent in the range */
1038         entry = NULL;
1039 out:
1040         if (entry) {
1041                 refcount_inc(&entry->refs);
1042                 trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
1043         }
1044
1045         spin_unlock_irq(&tree->lock);
1046         return entry;
1047 }
1048
1049 /*
1050  * Lock the passed range and ensures all pending ordered extents in it are run
1051  * to completion.
1052  *
1053  * @inode:        Inode whose ordered tree is to be searched
1054  * @start:        Beginning of range to flush
1055  * @end:          Last byte of range to lock
1056  * @cached_state: If passed, will return the extent state responsible for the
1057  *                locked range. It's the caller's responsibility to free the
1058  *                cached state.
1059  *
1060  * Always return with the given range locked, ensuring after it's called no
1061  * order extent can be pending.
1062  */
1063 void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
1064                                         u64 end,
1065                                         struct extent_state **cached_state)
1066 {
1067         struct btrfs_ordered_extent *ordered;
1068         struct extent_state *cache = NULL;
1069         struct extent_state **cachedp = &cache;
1070
1071         if (cached_state)
1072                 cachedp = cached_state;
1073
1074         while (1) {
1075                 lock_extent(&inode->io_tree, start, end, cachedp);
1076                 ordered = btrfs_lookup_ordered_range(inode, start,
1077                                                      end - start + 1);
1078                 if (!ordered) {
1079                         /*
1080                          * If no external cached_state has been passed then
1081                          * decrement the extra ref taken for cachedp since we
1082                          * aren't exposing it outside of this function
1083                          */
1084                         if (!cached_state)
1085                                 refcount_dec(&cache->refs);
1086                         break;
1087                 }
1088                 unlock_extent(&inode->io_tree, start, end, cachedp);
1089                 btrfs_start_ordered_extent(ordered);
1090                 btrfs_put_ordered_extent(ordered);
1091         }
1092 }
1093
1094 /*
1095  * Lock the passed range and ensure all pending ordered extents in it are run
1096  * to completion in nowait mode.
1097  *
1098  * Return true if btrfs_lock_ordered_range does not return any extents,
1099  * otherwise false.
1100  */
1101 bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
1102                                   struct extent_state **cached_state)
1103 {
1104         struct btrfs_ordered_extent *ordered;
1105
1106         if (!try_lock_extent(&inode->io_tree, start, end, cached_state))
1107                 return false;
1108
1109         ordered = btrfs_lookup_ordered_range(inode, start, end - start + 1);
1110         if (!ordered)
1111                 return true;
1112
1113         btrfs_put_ordered_extent(ordered);
1114         unlock_extent(&inode->io_tree, start, end, cached_state);
1115
1116         return false;
1117 }
1118
1119 /* Split out a new ordered extent for this first @len bytes of @ordered. */
1120 int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 len)
1121 {
1122         struct inode *inode = ordered->inode;
1123         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1124         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1125         u64 file_offset = ordered->file_offset;
1126         u64 disk_bytenr = ordered->disk_bytenr;
1127         unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;
1128         struct rb_node *node;
1129
1130         trace_btrfs_ordered_extent_split(BTRFS_I(inode), ordered);
1131
1132         ASSERT(!(flags & (1U << BTRFS_ORDERED_COMPRESSED)));
1133
1134         /*
1135          * The entire bio must be covered by the ordered extent, but we can't
1136          * reduce the original extent to a zero length either.
1137          */
1138         if (WARN_ON_ONCE(len >= ordered->num_bytes))
1139                 return -EINVAL;
1140         /* We cannot split once ordered extent is past end_bio. */
1141         if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes))
1142                 return -EINVAL;
1143         /* We cannot split a compressed ordered extent. */
1144         if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes))
1145                 return -EINVAL;
1146         /* Checksum list should be empty. */
1147         if (WARN_ON_ONCE(!list_empty(&ordered->list)))
1148                 return -EINVAL;
1149
1150         spin_lock_irq(&tree->lock);
1151         /* Remove from tree once */
1152         node = &ordered->rb_node;
1153         rb_erase(node, &tree->tree);
1154         RB_CLEAR_NODE(node);
1155         if (tree->last == node)
1156                 tree->last = NULL;
1157
1158         ordered->file_offset += len;
1159         ordered->disk_bytenr += len;
1160         ordered->num_bytes -= len;
1161         ordered->disk_num_bytes -= len;
1162         ordered->bytes_left -= len;
1163
1164         /* Re-insert the node */
1165         node = tree_insert(&tree->tree, ordered->file_offset, &ordered->rb_node);
1166         if (node)
1167                 btrfs_panic(fs_info, -EEXIST,
1168                         "zoned: inconsistency in ordered tree at offset %llu",
1169                             ordered->file_offset);
1170
1171         spin_unlock_irq(&tree->lock);
1172
1173         /*
1174          * The splitting extent is already counted and will be added again in
1175          * btrfs_add_ordered_extent(). Subtract len to avoid double counting.
1176          */
1177         percpu_counter_add_batch(&fs_info->ordered_bytes, -len, fs_info->delalloc_batch);
1178
1179         return btrfs_add_ordered_extent(BTRFS_I(inode), file_offset, len, len,
1180                                         disk_bytenr, len, 0, flags,
1181                                         ordered->compress_type);
1182 }
1183
1184 int __init ordered_data_init(void)
1185 {
1186         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1187                                      sizeof(struct btrfs_ordered_extent), 0,
1188                                      SLAB_MEM_SPREAD,
1189                                      NULL);
1190         if (!btrfs_ordered_extent_cache)
1191                 return -ENOMEM;
1192
1193         return 0;
1194 }
1195
1196 void __cold ordered_data_exit(void)
1197 {
1198         kmem_cache_destroy(btrfs_ordered_extent_cache);
1199 }