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