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 static struct btrfs_ordered_extent *alloc_ordered_extent(
 150                         struct btrfs_inode *inode, u64 file_offset, u64 num_bytes,
 151                         u64 ram_bytes, u64 disk_bytenr, u64 disk_num_bytes,
 152                         u64 offset, unsigned long flags, int compress_type)
 153 {
 154         struct btrfs_ordered_extent *entry;
 155         int ret;
 156
 157         if (flags &
 158             ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
 159                 /* For nocow write, we can release the qgroup rsv right now */
 160                 ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
 161                 if (ret < 0)
 162                         return ERR_PTR(ret);
 163         } else {
 164                 /*
 165                  * The ordered extent has reserved qgroup space, release now
 166                  * and pass the reserved number for qgroup_record to free.
 167                  */
 168                 ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
 169                 if (ret < 0)
 170                         return ERR_PTR(ret);
 171         }
 172         entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 173         if (!entry)
 174                 return ERR_PTR(-ENOMEM);
 175
 176         entry->file_offset = file_offset;
 177         entry->num_bytes = num_bytes;
 178         entry->ram_bytes = ram_bytes;
 179         entry->disk_bytenr = disk_bytenr;
 180         entry->disk_num_bytes = disk_num_bytes;
 181         entry->offset = offset;
 182         entry->bytes_left = num_bytes;
 183         entry->inode = igrab(&inode->vfs_inode);
 184         entry->compress_type = compress_type;
 185         entry->truncated_len = (u64)-1;
 186         entry->qgroup_rsv = ret;
 187         entry->flags = flags;
 188         refcount_set(&entry->refs, 1);
 189         init_waitqueue_head(&entry->wait);
 190         INIT_LIST_HEAD(&entry->list);
 191         INIT_LIST_HEAD(&entry->log_list);
 192         INIT_LIST_HEAD(&entry->root_extent_list);
 193         INIT_LIST_HEAD(&entry->work_list);
 194         init_completion(&entry->completion);
 195
 196         /*
 197          * We don't need the count_max_extents here, we can assume that all of
 198          * that work has been done at higher layers, so this is truly the
 199          * smallest the extent is going to get.
 200          */
 201         spin_lock(&inode->lock);
 202         btrfs_mod_outstanding_extents(inode, 1);
 203         spin_unlock(&inode->lock);
 204
 205         return entry;
 206 }
 207
 208 static void insert_ordered_extent(struct btrfs_ordered_extent *entry)
 209 {
 210         struct btrfs_inode *inode = BTRFS_I(entry->inode);
 211         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 212         struct btrfs_root *root = inode->root;
 213         struct btrfs_fs_info *fs_info = root->fs_info;
 214         struct rb_node *node;
 215
 216         trace_btrfs_ordered_extent_add(inode, entry);
 217
 218         percpu_counter_add_batch(&fs_info->ordered_bytes, entry->num_bytes,
 219                                  fs_info->delalloc_batch);
 220
 221         /* One ref for the tree. */
 222         refcount_inc(&entry->refs);
 223
 224         spin_lock_irq(&tree->lock);
 225         node = tree_insert(&tree->tree, entry->file_offset, &entry->rb_node);
 226         if (node)
 227                 btrfs_panic(fs_info, -EEXIST,
 228                                 "inconsistency in ordered tree at offset %llu",
 229                                 entry->file_offset);
 230         spin_unlock_irq(&tree->lock);
 231
 232         spin_lock(&root->ordered_extent_lock);
 233         list_add_tail(&entry->root_extent_list,
 234                       &root->ordered_extents);
 235         root->nr_ordered_extents++;
 236         if (root->nr_ordered_extents == 1) {
 237                 spin_lock(&fs_info->ordered_root_lock);
 238                 BUG_ON(!list_empty(&root->ordered_root));
 239                 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 240                 spin_unlock(&fs_info->ordered_root_lock);
 241         }
 242         spin_unlock(&root->ordered_extent_lock);
 243 }
 244
 245 /*
 246  * Add an ordered extent to the per-inode tree.
 247  *
 248  * @inode:           Inode that this extent is for.
 249  * @file_offset:     Logical offset in file where the extent starts.
 250  * @num_bytes:       Logical length of extent in file.
 251  * @ram_bytes:       Full length of unencoded data.
 252  * @disk_bytenr:     Offset of extent on disk.
 253  * @disk_num_bytes:  Size of extent on disk.
 254  * @offset:          Offset into unencoded data where file data starts.
 255  * @flags:           Flags specifying type of extent (1 << BTRFS_ORDERED_*).
 256  * @compress_type:   Compression algorithm used for data.
 257  *
 258  * Most of these parameters correspond to &struct btrfs_file_extent_item. The
 259  * tree is given a single reference on the ordered extent that was inserted, and
 260  * the returned pointer is given a second reference.
 261  *
 262  * Return: the new ordered extent or error pointer.
 263  */
 264 struct btrfs_ordered_extent *btrfs_alloc_ordered_extent(
 265                         struct btrfs_inode *inode, u64 file_offset,
 266                         u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
 267                         u64 disk_num_bytes, u64 offset, unsigned long flags,
 268                         int compress_type)
 269 {
 270         struct btrfs_ordered_extent *entry;
 271
 272         ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
 273
 274         entry = alloc_ordered_extent(inode, file_offset, num_bytes, ram_bytes,
 275                                      disk_bytenr, disk_num_bytes, offset, flags,
 276                                      compress_type);
 277         if (!IS_ERR(entry))
 278                 insert_ordered_extent(entry);
 279         return entry;
 280 }
 281
 282 /*
 283  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 284  * when an ordered extent is finished.  If the list covers more than one
 285  * ordered extent, it is split across multiples.
 286  */
 287 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 288                            struct btrfs_ordered_sum *sum)
 289 {
 290         struct btrfs_ordered_inode_tree *tree;
 291
 292         tree = &BTRFS_I(entry->inode)->ordered_tree;
 293         spin_lock_irq(&tree->lock);
 294         list_add_tail(&sum->list, &entry->list);
 295         spin_unlock_irq(&tree->lock);
 296 }
 297
 298 static void finish_ordered_fn(struct btrfs_work *work)
 299 {
 300         struct btrfs_ordered_extent *ordered_extent;
 301
 302         ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
 303         btrfs_finish_ordered_io(ordered_extent);
 304 }
 305
 306 static bool can_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
 307                                       struct page *page, u64 file_offset,
 308                                       u64 len, bool uptodate)
 309 {
 310         struct btrfs_inode *inode = BTRFS_I(ordered->inode);
 311         struct btrfs_fs_info *fs_info = inode->root->fs_info;
 312
 313         lockdep_assert_held(&inode->ordered_tree.lock);
 314
 315         if (page) {
 316                 ASSERT(page->mapping);
 317                 ASSERT(page_offset(page) <= file_offset);
 318                 ASSERT(file_offset + len <= page_offset(page) + PAGE_SIZE);
 319
 320                 /*
 321                  * Ordered (Private2) bit indicates whether we still have
 322                  * pending io unfinished for the ordered extent.
 323                  *
 324                  * If there's no such bit, we need to skip to next range.
 325                  */
 326                 if (!btrfs_page_test_ordered(fs_info, page, file_offset, len))
 327                         return false;
 328                 btrfs_page_clear_ordered(fs_info, page, file_offset, len);
 329         }
 330
 331         /* Now we're fine to update the accounting. */
 332         if (WARN_ON_ONCE(len > ordered->bytes_left)) {
 333                 btrfs_crit(fs_info,
 334 "bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%llu left=%llu",
 335                            inode->root->root_key.objectid, btrfs_ino(inode),
 336                            ordered->file_offset, ordered->num_bytes,
 337                            len, ordered->bytes_left);
 338                 ordered->bytes_left = 0;
 339         } else {
 340                 ordered->bytes_left -= len;
 341         }
 342
 343         if (!uptodate)
 344                 set_bit(BTRFS_ORDERED_IOERR, &ordered->flags);
 345
 346         if (ordered->bytes_left)
 347                 return false;
 348
 349         /*
 350          * All the IO of the ordered extent is finished, we need to queue
 351          * the finish_func to be executed.
 352          */
 353         set_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags);
 354         cond_wake_up(&ordered->wait);
 355         refcount_inc(&ordered->refs);
 356         trace_btrfs_ordered_extent_mark_finished(inode, ordered);
 357         return true;
 358 }
 359
 360 static void btrfs_queue_ordered_fn(struct btrfs_ordered_extent *ordered)
 361 {
 362         struct btrfs_inode *inode = BTRFS_I(ordered->inode);
 363         struct btrfs_fs_info *fs_info = inode->root->fs_info;
 364         struct btrfs_workqueue *wq = btrfs_is_free_space_inode(inode) ?
 365                 fs_info->endio_freespace_worker : fs_info->endio_write_workers;
 366
 367         btrfs_init_work(&ordered->work, finish_ordered_fn, NULL, NULL);
 368         btrfs_queue_work(wq, &ordered->work);
 369 }
 370
 371 bool btrfs_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
 372                                  struct page *page, u64 file_offset, u64 len,
 373                                  bool uptodate)
 374 {
 375         struct btrfs_inode *inode = BTRFS_I(ordered->inode);
 376         unsigned long flags;
 377         bool ret;
 378
 379         trace_btrfs_finish_ordered_extent(inode, file_offset, len, uptodate);
 380
 381         spin_lock_irqsave(&inode->ordered_tree.lock, flags);
 382         ret = can_finish_ordered_extent(ordered, page, file_offset, len, uptodate);
 383         spin_unlock_irqrestore(&inode->ordered_tree.lock, flags);
 384
 385         if (ret)
 386                 btrfs_queue_ordered_fn(ordered);
 387         return ret;
 388 }
 389
 390 /*
 391  * Mark all ordered extents io inside the specified range finished.
 392  *
 393  * @page:        The involved page for the operation.
 394  *               For uncompressed buffered IO, the page status also needs to be
 395  *               updated to indicate whether the pending ordered io is finished.
 396  *               Can be NULL for direct IO and compressed write.
 397  *               For these cases, callers are ensured they won't execute the
 398  *               endio function twice.
 399  *
 400  * This function is called for endio, thus the range must have ordered
 401  * extent(s) covering it.
 402  */
 403 void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
 404                                     struct page *page, u64 file_offset,
 405                                     u64 num_bytes, bool uptodate)
 406 {
 407         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 408         struct rb_node *node;
 409         struct btrfs_ordered_extent *entry = NULL;
 410         unsigned long flags;
 411         u64 cur = file_offset;
 412
 413         trace_btrfs_writepage_end_io_hook(inode, file_offset,
 414                                           file_offset + num_bytes - 1,
 415                                           uptodate);
 416
 417         spin_lock_irqsave(&tree->lock, flags);
 418         while (cur < file_offset + num_bytes) {
 419                 u64 entry_end;
 420                 u64 end;
 421                 u32 len;
 422
 423                 node = tree_search(tree, cur);
 424                 /* No ordered extents at all */
 425                 if (!node)
 426                         break;
 427
 428                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 429                 entry_end = entry->file_offset + entry->num_bytes;
 430                 /*
 431                  * |<-- OE --->|  |
 432                  *                cur
 433                  * Go to next OE.
 434                  */
 435                 if (cur >= entry_end) {
 436                         node = rb_next(node);
 437                         /* No more ordered extents, exit */
 438                         if (!node)
 439                                 break;
 440                         entry = rb_entry(node, struct btrfs_ordered_extent,
 441                                          rb_node);
 442
 443                         /* Go to next ordered extent and continue */
 444                         cur = entry->file_offset;
 445                         continue;
 446                 }
 447                 /*
 448                  * |    |<--- OE --->|
 449                  * cur
 450                  * Go to the start of OE.
 451                  */
 452                 if (cur < entry->file_offset) {
 453                         cur = entry->file_offset;
 454                         continue;
 455                 }
 456
 457                 /*
 458                  * Now we are definitely inside one ordered extent.
 459                  *
 460                  * |<--- OE --->|
 461                  *      |
 462                  *      cur
 463                  */
 464                 end = min(entry->file_offset + entry->num_bytes,
 465                           file_offset + num_bytes) - 1;
 466                 ASSERT(end + 1 - cur < U32_MAX);
 467                 len = end + 1 - cur;
 468
 469                 if (can_finish_ordered_extent(entry, page, cur, len, uptodate)) {
 470                         spin_unlock_irqrestore(&tree->lock, flags);
 471                         btrfs_queue_ordered_fn(entry);
 472                         spin_lock_irqsave(&tree->lock, flags);
 473                 }
 474                 cur += len;
 475         }
 476         spin_unlock_irqrestore(&tree->lock, flags);
 477 }
 478
 479 /*
 480  * Finish IO for one ordered extent across a given range.  The range can only
 481  * contain one ordered extent.
 482  *
 483  * @cached:      The cached ordered extent. If not NULL, we can skip the tree
 484  *               search and use the ordered extent directly.
 485  *               Will be also used to store the finished ordered extent.
 486  * @file_offset: File offset for the finished IO
 487  * @io_size:     Length of the finish IO range
 488  *
 489  * Return true if the ordered extent is finished in the range, and update
 490  * @cached.
 491  * Return false otherwise.
 492  *
 493  * NOTE: The range can NOT cross multiple ordered extents.
 494  * Thus caller should ensure the range doesn't cross ordered extents.
 495  */
 496 bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 497                                     struct btrfs_ordered_extent **cached,
 498                                     u64 file_offset, u64 io_size)
 499 {
 500         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 501         struct rb_node *node;
 502         struct btrfs_ordered_extent *entry = NULL;
 503         unsigned long flags;
 504         bool finished = false;
 505
 506         spin_lock_irqsave(&tree->lock, flags);
 507         if (cached && *cached) {
 508                 entry = *cached;
 509                 goto have_entry;
 510         }
 511
 512         node = tree_search(tree, file_offset);
 513         if (!node)
 514                 goto out;
 515
 516         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 517 have_entry:
 518         if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 519                 goto out;
 520
 521         if (io_size > entry->bytes_left)
 522                 btrfs_crit(inode->root->fs_info,
 523                            "bad ordered accounting left %llu size %llu",
 524                        entry->bytes_left, io_size);
 525
 526         entry->bytes_left -= io_size;
 527
 528         if (entry->bytes_left == 0) {
 529                 /*
 530                  * Ensure only one caller can set the flag and finished_ret
 531                  * accordingly
 532                  */
 533                 finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 534                 /* test_and_set_bit implies a barrier */
 535                 cond_wake_up_nomb(&entry->wait);
 536         }
 537 out:
 538         if (finished && cached && entry) {
 539                 *cached = entry;
 540                 refcount_inc(&entry->refs);
 541                 trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
 542         }
 543         spin_unlock_irqrestore(&tree->lock, flags);
 544         return finished;
 545 }
 546
 547 /*
 548  * used to drop a reference on an ordered extent.  This will free
 549  * the extent if the last reference is dropped
 550  */
 551 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 552 {
 553         struct list_head *cur;
 554         struct btrfs_ordered_sum *sum;
 555
 556         trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
 557
 558         if (refcount_dec_and_test(&entry->refs)) {
 559                 ASSERT(list_empty(&entry->root_extent_list));
 560                 ASSERT(list_empty(&entry->log_list));
 561                 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 562                 if (entry->inode)
 563                         btrfs_add_delayed_iput(BTRFS_I(entry->inode));
 564                 while (!list_empty(&entry->list)) {
 565                         cur = entry->list.next;
 566                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 567                         list_del(&sum->list);
 568                         kvfree(sum);
 569                 }
 570                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
 571         }
 572 }
 573
 574 /*
 575  * remove an ordered extent from the tree.  No references are dropped
 576  * and waiters are woken up.
 577  */
 578 void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 579                                  struct btrfs_ordered_extent *entry)
 580 {
 581         struct btrfs_ordered_inode_tree *tree;
 582         struct btrfs_root *root = btrfs_inode->root;
 583         struct btrfs_fs_info *fs_info = root->fs_info;
 584         struct rb_node *node;
 585         bool pending;
 586         bool freespace_inode;
 587
 588         /*
 589          * If this is a free space inode the thread has not acquired the ordered
 590          * extents lockdep map.
 591          */
 592         freespace_inode = btrfs_is_free_space_inode(btrfs_inode);
 593
 594         btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);
 595         /* This is paired with btrfs_alloc_ordered_extent. */
 596         spin_lock(&btrfs_inode->lock);
 597         btrfs_mod_outstanding_extents(btrfs_inode, -1);
 598         spin_unlock(&btrfs_inode->lock);
 599         if (root != fs_info->tree_root) {
 600                 u64 release;
 601
 602                 if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
 603                         release = entry->disk_num_bytes;
 604                 else
 605                         release = entry->num_bytes;
 606                 btrfs_delalloc_release_metadata(btrfs_inode, release, false);
 607         }
 608
 609         percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 610                                  fs_info->delalloc_batch);
 611
 612         tree = &btrfs_inode->ordered_tree;
 613         spin_lock_irq(&tree->lock);
 614         node = &entry->rb_node;
 615         rb_erase(node, &tree->tree);
 616         RB_CLEAR_NODE(node);
 617         if (tree->last == node)
 618                 tree->last = NULL;
 619         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 620         pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
 621         spin_unlock_irq(&tree->lock);
 622
 623         /*
 624          * The current running transaction is waiting on us, we need to let it
 625          * know that we're complete and wake it up.
 626          */
 627         if (pending) {
 628                 struct btrfs_transaction *trans;
 629
 630                 /*
 631                  * The checks for trans are just a formality, it should be set,
 632                  * but if it isn't we don't want to deref/assert under the spin
 633                  * lock, so be nice and check if trans is set, but ASSERT() so
 634                  * if it isn't set a developer will notice.
 635                  */
 636                 spin_lock(&fs_info->trans_lock);
 637                 trans = fs_info->running_transaction;
 638                 if (trans)
 639                         refcount_inc(&trans->use_count);
 640                 spin_unlock(&fs_info->trans_lock);
 641
 642                 ASSERT(trans || BTRFS_FS_ERROR(fs_info));
 643                 if (trans) {
 644                         if (atomic_dec_and_test(&trans->pending_ordered))
 645                                 wake_up(&trans->pending_wait);
 646                         btrfs_put_transaction(trans);
 647                 }
 648         }
 649
 650         btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);
 651
 652         spin_lock(&root->ordered_extent_lock);
 653         list_del_init(&entry->root_extent_list);
 654         root->nr_ordered_extents--;
 655
 656         trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
 657
 658         if (!root->nr_ordered_extents) {
 659                 spin_lock(&fs_info->ordered_root_lock);
 660                 BUG_ON(list_empty(&root->ordered_root));
 661                 list_del_init(&root->ordered_root);
 662                 spin_unlock(&fs_info->ordered_root_lock);
 663         }
 664         spin_unlock(&root->ordered_extent_lock);
 665         wake_up(&entry->wait);
 666         if (!freespace_inode)
 667                 btrfs_lockdep_release(fs_info, btrfs_ordered_extent);
 668 }
 669
 670 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 671 {
 672         struct btrfs_ordered_extent *ordered;
 673
 674         ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 675         btrfs_start_ordered_extent(ordered);
 676         complete(&ordered->completion);
 677 }
 678
 679 /*
 680  * wait for all the ordered extents in a root.  This is done when balancing
 681  * space between drives.
 682  */
 683 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 684                                const u64 range_start, const u64 range_len)
 685 {
 686         struct btrfs_fs_info *fs_info = root->fs_info;
 687         LIST_HEAD(splice);
 688         LIST_HEAD(skipped);
 689         LIST_HEAD(works);
 690         struct btrfs_ordered_extent *ordered, *next;
 691         u64 count = 0;
 692         const u64 range_end = range_start + range_len;
 693
 694         mutex_lock(&root->ordered_extent_mutex);
 695         spin_lock(&root->ordered_extent_lock);
 696         list_splice_init(&root->ordered_extents, &splice);
 697         while (!list_empty(&splice) && nr) {
 698                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 699                                            root_extent_list);
 700
 701                 if (range_end <= ordered->disk_bytenr ||
 702                     ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
 703                         list_move_tail(&ordered->root_extent_list, &skipped);
 704                         cond_resched_lock(&root->ordered_extent_lock);
 705                         continue;
 706                 }
 707
 708                 list_move_tail(&ordered->root_extent_list,
 709                                &root->ordered_extents);
 710                 refcount_inc(&ordered->refs);
 711                 spin_unlock(&root->ordered_extent_lock);
 712
 713                 btrfs_init_work(&ordered->flush_work,
 714                                 btrfs_run_ordered_extent_work, NULL, NULL);
 715                 list_add_tail(&ordered->work_list, &works);
 716                 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 717
 718                 cond_resched();
 719                 spin_lock(&root->ordered_extent_lock);
 720                 if (nr != U64_MAX)
 721                         nr--;
 722                 count++;
 723         }
 724         list_splice_tail(&skipped, &root->ordered_extents);
 725         list_splice_tail(&splice, &root->ordered_extents);
 726         spin_unlock(&root->ordered_extent_lock);
 727
 728         list_for_each_entry_safe(ordered, next, &works, work_list) {
 729                 list_del_init(&ordered->work_list);
 730                 wait_for_completion(&ordered->completion);
 731                 btrfs_put_ordered_extent(ordered);
 732                 cond_resched();
 733         }
 734         mutex_unlock(&root->ordered_extent_mutex);
 735
 736         return count;
 737 }
 738
 739 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 740                              const u64 range_start, const u64 range_len)
 741 {
 742         struct btrfs_root *root;
 743         LIST_HEAD(splice);
 744         u64 done;
 745
 746         mutex_lock(&fs_info->ordered_operations_mutex);
 747         spin_lock(&fs_info->ordered_root_lock);
 748         list_splice_init(&fs_info->ordered_roots, &splice);
 749         while (!list_empty(&splice) && nr) {
 750                 root = list_first_entry(&splice, struct btrfs_root,
 751                                         ordered_root);
 752                 root = btrfs_grab_root(root);
 753                 BUG_ON(!root);
 754                 list_move_tail(&root->ordered_root,
 755                                &fs_info->ordered_roots);
 756                 spin_unlock(&fs_info->ordered_root_lock);
 757
 758                 done = btrfs_wait_ordered_extents(root, nr,
 759                                                   range_start, range_len);
 760                 btrfs_put_root(root);
 761
 762                 spin_lock(&fs_info->ordered_root_lock);
 763                 if (nr != U64_MAX) {
 764                         nr -= done;
 765                 }
 766         }
 767         list_splice_tail(&splice, &fs_info->ordered_roots);
 768         spin_unlock(&fs_info->ordered_root_lock);
 769         mutex_unlock(&fs_info->ordered_operations_mutex);
 770 }
 771
 772 /*
 773  * Start IO and wait for a given ordered extent to finish.
 774  *
 775  * Wait on page writeback for all the pages in the extent and the IO completion
 776  * code to insert metadata into the btree corresponding to the extent.
 777  */
 778 void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry)
 779 {
 780         u64 start = entry->file_offset;
 781         u64 end = start + entry->num_bytes - 1;
 782         struct btrfs_inode *inode = BTRFS_I(entry->inode);
 783         bool freespace_inode;
 784
 785         trace_btrfs_ordered_extent_start(inode, entry);
 786
 787         /*
 788          * If this is a free space inode do not take the ordered extents lockdep
 789          * map.
 790          */
 791         freespace_inode = btrfs_is_free_space_inode(inode);
 792
 793         /*
 794          * pages in the range can be dirty, clean or writeback.  We
 795          * start IO on any dirty ones so the wait doesn't stall waiting
 796          * for the flusher thread to find them
 797          */
 798         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 799                 filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
 800
 801         if (!freespace_inode)
 802                 btrfs_might_wait_for_event(inode->root->fs_info, btrfs_ordered_extent);
 803         wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE, &entry->flags));
 804 }
 805
 806 /*
 807  * Used to wait on ordered extents across a large range of bytes.
 808  */
 809 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 810 {
 811         int ret = 0;
 812         int ret_wb = 0;
 813         u64 end;
 814         u64 orig_end;
 815         struct btrfs_ordered_extent *ordered;
 816
 817         if (start + len < start) {
 818                 orig_end = OFFSET_MAX;
 819         } else {
 820                 orig_end = start + len - 1;
 821                 if (orig_end > OFFSET_MAX)
 822                         orig_end = OFFSET_MAX;
 823         }
 824
 825         /* start IO across the range first to instantiate any delalloc
 826          * extents
 827          */
 828         ret = btrfs_fdatawrite_range(inode, start, orig_end);
 829         if (ret)
 830                 return ret;
 831
 832         /*
 833          * If we have a writeback error don't return immediately. Wait first
 834          * for any ordered extents that haven't completed yet. This is to make
 835          * sure no one can dirty the same page ranges and call writepages()
 836          * before the ordered extents complete - to avoid failures (-EEXIST)
 837          * when adding the new ordered extents to the ordered tree.
 838          */
 839         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 840
 841         end = orig_end;
 842         while (1) {
 843                 ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
 844                 if (!ordered)
 845                         break;
 846                 if (ordered->file_offset > orig_end) {
 847                         btrfs_put_ordered_extent(ordered);
 848                         break;
 849                 }
 850                 if (ordered->file_offset + ordered->num_bytes <= start) {
 851                         btrfs_put_ordered_extent(ordered);
 852                         break;
 853                 }
 854                 btrfs_start_ordered_extent(ordered);
 855                 end = ordered->file_offset;
 856                 /*
 857                  * If the ordered extent had an error save the error but don't
 858                  * exit without waiting first for all other ordered extents in
 859                  * the range to complete.
 860                  */
 861                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 862                         ret = -EIO;
 863                 btrfs_put_ordered_extent(ordered);
 864                 if (end == 0 || end == start)
 865                         break;
 866                 end--;
 867         }
 868         return ret_wb ? ret_wb : ret;
 869 }
 870
 871 /*
 872  * find an ordered extent corresponding to file_offset.  return NULL if
 873  * nothing is found, otherwise take a reference on the extent and return it
 874  */
 875 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
 876                                                          u64 file_offset)
 877 {
 878         struct btrfs_ordered_inode_tree *tree;
 879         struct rb_node *node;
 880         struct btrfs_ordered_extent *entry = NULL;
 881         unsigned long flags;
 882
 883         tree = &inode->ordered_tree;
 884         spin_lock_irqsave(&tree->lock, flags);
 885         node = tree_search(tree, file_offset);
 886         if (!node)
 887                 goto out;
 888
 889         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 890         if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 891                 entry = NULL;
 892         if (entry) {
 893                 refcount_inc(&entry->refs);
 894                 trace_btrfs_ordered_extent_lookup(inode, entry);
 895         }
 896 out:
 897         spin_unlock_irqrestore(&tree->lock, flags);
 898         return entry;
 899 }
 900
 901 /* Since the DIO code tries to lock a wide area we need to look for any ordered
 902  * extents that exist in the range, rather than just the start of the range.
 903  */
 904 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 905                 struct btrfs_inode *inode, u64 file_offset, u64 len)
 906 {
 907         struct btrfs_ordered_inode_tree *tree;
 908         struct rb_node *node;
 909         struct btrfs_ordered_extent *entry = NULL;
 910
 911         tree = &inode->ordered_tree;
 912         spin_lock_irq(&tree->lock);
 913         node = tree_search(tree, file_offset);
 914         if (!node) {
 915                 node = tree_search(tree, file_offset + len);
 916                 if (!node)
 917                         goto out;
 918         }
 919
 920         while (1) {
 921                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 922                 if (range_overlaps(entry, file_offset, len))
 923                         break;
 924
 925                 if (entry->file_offset >= file_offset + len) {
 926                         entry = NULL;
 927                         break;
 928                 }
 929                 entry = NULL;
 930                 node = rb_next(node);
 931                 if (!node)
 932                         break;
 933         }
 934 out:
 935         if (entry) {
 936                 refcount_inc(&entry->refs);
 937                 trace_btrfs_ordered_extent_lookup_range(inode, entry);
 938         }
 939         spin_unlock_irq(&tree->lock);
 940         return entry;
 941 }
 942
 943 /*
 944  * Adds all ordered extents to the given list. The list ends up sorted by the
 945  * file_offset of the ordered extents.
 946  */
 947 void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
 948                                            struct list_head *list)
 949 {
 950         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 951         struct rb_node *n;
 952
 953         ASSERT(inode_is_locked(&inode->vfs_inode));
 954
 955         spin_lock_irq(&tree->lock);
 956         for (n = rb_first(&tree->tree); n; n = rb_next(n)) {
 957                 struct btrfs_ordered_extent *ordered;
 958
 959                 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 960
 961                 if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 962                         continue;
 963
 964                 ASSERT(list_empty(&ordered->log_list));
 965                 list_add_tail(&ordered->log_list, list);
 966                 refcount_inc(&ordered->refs);
 967                 trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
 968         }
 969         spin_unlock_irq(&tree->lock);
 970 }
 971
 972 /*
 973  * lookup and return any extent before 'file_offset'.  NULL is returned
 974  * if none is found
 975  */
 976 struct btrfs_ordered_extent *
 977 btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
 978 {
 979         struct btrfs_ordered_inode_tree *tree;
 980         struct rb_node *node;
 981         struct btrfs_ordered_extent *entry = NULL;
 982
 983         tree = &inode->ordered_tree;
 984         spin_lock_irq(&tree->lock);
 985         node = tree_search(tree, file_offset);
 986         if (!node)
 987                 goto out;
 988
 989         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 990         refcount_inc(&entry->refs);
 991         trace_btrfs_ordered_extent_lookup_first(inode, entry);
 992 out:
 993         spin_unlock_irq(&tree->lock);
 994         return entry;
 995 }
 996
 997 /*
 998  * Lookup the first ordered extent that overlaps the range
 999  * [@file_offset, @file_offset + @len).
1000  *
1001  * The difference between this and btrfs_lookup_first_ordered_extent() is
1002  * that this one won't return any ordered extent that does not overlap the range.
1003  * And the difference against btrfs_lookup_ordered_extent() is, this function
1004  * ensures the first ordered extent gets returned.
1005  */
1006 struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
1007                         struct btrfs_inode *inode, u64 file_offset, u64 len)
1008 {
1009         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
1010         struct rb_node *node;
1011         struct rb_node *cur;
1012         struct rb_node *prev;
1013         struct rb_node *next;
1014         struct btrfs_ordered_extent *entry = NULL;
1015
1016         spin_lock_irq(&tree->lock);
1017         node = tree->tree.rb_node;
1018         /*
1019          * Here we don't want to use tree_search() which will use tree->last
1020          * and screw up the search order.
1021          * And __tree_search() can't return the adjacent ordered extents
1022          * either, thus here we do our own search.
1023          */
1024         while (node) {
1025                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1026
1027                 if (file_offset < entry->file_offset) {
1028                         node = node->rb_left;
1029                 } else if (file_offset >= entry_end(entry)) {
1030                         node = node->rb_right;
1031                 } else {
1032                         /*
1033                          * Direct hit, got an ordered extent that starts at
1034                          * @file_offset
1035                          */
1036                         goto out;
1037                 }
1038         }
1039         if (!entry) {
1040                 /* Empty tree */
1041                 goto out;
1042         }
1043
1044         cur = &entry->rb_node;
1045         /* We got an entry around @file_offset, check adjacent entries */
1046         if (entry->file_offset < file_offset) {
1047                 prev = cur;
1048                 next = rb_next(cur);
1049         } else {
1050                 prev = rb_prev(cur);
1051                 next = cur;
1052         }
1053         if (prev) {
1054                 entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
1055                 if (range_overlaps(entry, file_offset, len))
1056                         goto out;
1057         }
1058         if (next) {
1059                 entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
1060                 if (range_overlaps(entry, file_offset, len))
1061                         goto out;
1062         }
1063         /* No ordered extent in the range */
1064         entry = NULL;
1065 out:
1066         if (entry) {
1067                 refcount_inc(&entry->refs);
1068                 trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
1069         }
1070
1071         spin_unlock_irq(&tree->lock);
1072         return entry;
1073 }
1074
1075 /*
1076  * Lock the passed range and ensures all pending ordered extents in it are run
1077  * to completion.
1078  *
1079  * @inode:        Inode whose ordered tree is to be searched
1080  * @start:        Beginning of range to flush
1081  * @end:          Last byte of range to lock
1082  * @cached_state: If passed, will return the extent state responsible for the
1083  *                locked range. It's the caller's responsibility to free the
1084  *                cached state.
1085  *
1086  * Always return with the given range locked, ensuring after it's called no
1087  * order extent can be pending.
1088  */
1089 void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
1090                                         u64 end,
1091                                         struct extent_state **cached_state)
1092 {
1093         struct btrfs_ordered_extent *ordered;
1094         struct extent_state *cache = NULL;
1095         struct extent_state **cachedp = &cache;
1096
1097         if (cached_state)
1098                 cachedp = cached_state;
1099
1100         while (1) {
1101                 lock_extent(&inode->io_tree, start, end, cachedp);
1102                 ordered = btrfs_lookup_ordered_range(inode, start,
1103                                                      end - start + 1);
1104                 if (!ordered) {
1105                         /*
1106                          * If no external cached_state has been passed then
1107                          * decrement the extra ref taken for cachedp since we
1108                          * aren't exposing it outside of this function
1109                          */
1110                         if (!cached_state)
1111                                 refcount_dec(&cache->refs);
1112                         break;
1113                 }
1114                 unlock_extent(&inode->io_tree, start, end, cachedp);
1115                 btrfs_start_ordered_extent(ordered);
1116                 btrfs_put_ordered_extent(ordered);
1117         }
1118 }
1119
1120 /*
1121  * Lock the passed range and ensure all pending ordered extents in it are run
1122  * to completion in nowait mode.
1123  *
1124  * Return true if btrfs_lock_ordered_range does not return any extents,
1125  * otherwise false.
1126  */
1127 bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
1128                                   struct extent_state **cached_state)
1129 {
1130         struct btrfs_ordered_extent *ordered;
1131
1132         if (!try_lock_extent(&inode->io_tree, start, end, cached_state))
1133                 return false;
1134
1135         ordered = btrfs_lookup_ordered_range(inode, start, end - start + 1);
1136         if (!ordered)
1137                 return true;
1138
1139         btrfs_put_ordered_extent(ordered);
1140         unlock_extent(&inode->io_tree, start, end, cached_state);
1141
1142         return false;
1143 }
1144
1145 /* Split out a new ordered extent for this first @len bytes of @ordered. */
1146 struct btrfs_ordered_extent *btrfs_split_ordered_extent(
1147                         struct btrfs_ordered_extent *ordered, u64 len)
1148 {
1149         struct btrfs_inode *inode = BTRFS_I(ordered->inode);
1150         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
1151         struct btrfs_root *root = inode->root;
1152         struct btrfs_fs_info *fs_info = root->fs_info;
1153         u64 file_offset = ordered->file_offset;
1154         u64 disk_bytenr = ordered->disk_bytenr;
1155         unsigned long flags = ordered->flags;
1156         struct btrfs_ordered_sum *sum, *tmpsum;
1157         struct btrfs_ordered_extent *new;
1158         struct rb_node *node;
1159         u64 offset = 0;
1160
1161         trace_btrfs_ordered_extent_split(inode, ordered);
1162
1163         ASSERT(!(flags & (1U << BTRFS_ORDERED_COMPRESSED)));
1164
1165         /*
1166          * The entire bio must be covered by the ordered extent, but we can't
1167          * reduce the original extent to a zero length either.
1168          */
1169         if (WARN_ON_ONCE(len >= ordered->num_bytes))
1170                 return ERR_PTR(-EINVAL);
1171         /* We cannot split partially completed ordered extents. */
1172         if (ordered->bytes_left) {
1173                 ASSERT(!(flags & ~BTRFS_ORDERED_TYPE_FLAGS));
1174                 if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes))
1175                         return ERR_PTR(-EINVAL);
1176         }
1177         /* We cannot split a compressed ordered extent. */
1178         if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes))
1179                 return ERR_PTR(-EINVAL);
1180
1181         new = alloc_ordered_extent(inode, file_offset, len, len, disk_bytenr,
1182                                    len, 0, flags, ordered->compress_type);
1183         if (IS_ERR(new))
1184                 return new;
1185
1186         /* One ref for the tree. */
1187         refcount_inc(&new->refs);
1188
1189         spin_lock_irq(&root->ordered_extent_lock);
1190         spin_lock(&tree->lock);
1191         /* Remove from tree once */
1192         node = &ordered->rb_node;
1193         rb_erase(node, &tree->tree);
1194         RB_CLEAR_NODE(node);
1195         if (tree->last == node)
1196                 tree->last = NULL;
1197
1198         ordered->file_offset += len;
1199         ordered->disk_bytenr += len;
1200         ordered->num_bytes -= len;
1201         ordered->disk_num_bytes -= len;
1202
1203         if (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)) {
1204                 ASSERT(ordered->bytes_left == 0);
1205                 new->bytes_left = 0;
1206         } else {
1207                 ordered->bytes_left -= len;
1208         }
1209
1210         if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags)) {
1211                 if (ordered->truncated_len > len) {
1212                         ordered->truncated_len -= len;
1213                 } else {
1214                         new->truncated_len = ordered->truncated_len;
1215                         ordered->truncated_len = 0;
1216                 }
1217         }
1218
1219         list_for_each_entry_safe(sum, tmpsum, &ordered->list, list) {
1220                 if (offset == len)
1221                         break;
1222                 list_move_tail(&sum->list, &new->list);
1223                 offset += sum->len;
1224         }
1225
1226         /* Re-insert the node */
1227         node = tree_insert(&tree->tree, ordered->file_offset, &ordered->rb_node);
1228         if (node)
1229                 btrfs_panic(fs_info, -EEXIST,
1230                         "zoned: inconsistency in ordered tree at offset %llu",
1231                         ordered->file_offset);
1232
1233         node = tree_insert(&tree->tree, new->file_offset, &new->rb_node);
1234         if (node)
1235                 btrfs_panic(fs_info, -EEXIST,
1236                         "zoned: inconsistency in ordered tree at offset %llu",
1237                         new->file_offset);
1238         spin_unlock(&tree->lock);
1239
1240         list_add_tail(&new->root_extent_list, &root->ordered_extents);
1241         root->nr_ordered_extents++;
1242         spin_unlock_irq(&root->ordered_extent_lock);
1243         return new;
1244 }
1245
1246 int __init ordered_data_init(void)
1247 {
1248         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1249                                      sizeof(struct btrfs_ordered_extent), 0,
1250                                      SLAB_MEM_SPREAD,
1251                                      NULL);
1252         if (!btrfs_ordered_extent_cache)
1253                 return -ENOMEM;
1254
1255         return 0;
1256 }
1257
1258 void __cold ordered_data_exit(void)
1259 {
1260         kmem_cache_destroy(btrfs_ordered_extent_cache);
1261 }