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/pagevec.h>
  10 #include "ctree.h"
  11 #include "transaction.h"
  12 #include "btrfs_inode.h"
  13 #include "extent_io.h"
  14 #include "disk-io.h"
  15 #include "compression.h"
  16
  17 static struct kmem_cache *btrfs_ordered_extent_cache;
  18
  19 static u64 entry_end(struct btrfs_ordered_extent *entry)
  20 {
  21         if (entry->file_offset + entry->len < entry->file_offset)
  22                 return (u64)-1;
  23         return entry->file_offset + entry->len;
  24 }
  25
  26 /* returns NULL if the insertion worked, or it returns the node it did find
  27  * in the tree
  28  */
  29 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  30                                    struct rb_node *node)
  31 {
  32         struct rb_node **p = &root->rb_node;
  33         struct rb_node *parent = NULL;
  34         struct btrfs_ordered_extent *entry;
  35
  36         while (*p) {
  37                 parent = *p;
  38                 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  39
  40                 if (file_offset < entry->file_offset)
  41                         p = &(*p)->rb_left;
  42                 else if (file_offset >= entry_end(entry))
  43                         p = &(*p)->rb_right;
  44                 else
  45                         return parent;
  46         }
  47
  48         rb_link_node(node, parent, p);
  49         rb_insert_color(node, root);
  50         return NULL;
  51 }
  52
  53 static void ordered_data_tree_panic(struct inode *inode, int errno,
  54                                                u64 offset)
  55 {
  56         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
  57         btrfs_panic(fs_info, errno,
  58                     "Inconsistency in ordered tree at offset %llu", offset);
  59 }
  60
  61 /*
  62  * look for a given offset in the tree, and if it can't be found return the
  63  * first lesser offset
  64  */
  65 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
  66                                      struct rb_node **prev_ret)
  67 {
  68         struct rb_node *n = root->rb_node;
  69         struct rb_node *prev = NULL;
  70         struct rb_node *test;
  71         struct btrfs_ordered_extent *entry;
  72         struct btrfs_ordered_extent *prev_entry = NULL;
  73
  74         while (n) {
  75                 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
  76                 prev = n;
  77                 prev_entry = entry;
  78
  79                 if (file_offset < entry->file_offset)
  80                         n = n->rb_left;
  81                 else if (file_offset >= entry_end(entry))
  82                         n = n->rb_right;
  83                 else
  84                         return n;
  85         }
  86         if (!prev_ret)
  87                 return NULL;
  88
  89         while (prev && file_offset >= entry_end(prev_entry)) {
  90                 test = rb_next(prev);
  91                 if (!test)
  92                         break;
  93                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
  94                                       rb_node);
  95                 if (file_offset < entry_end(prev_entry))
  96                         break;
  97
  98                 prev = test;
  99         }
 100         if (prev)
 101                 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
 102                                       rb_node);
 103         while (prev && file_offset < entry_end(prev_entry)) {
 104                 test = rb_prev(prev);
 105                 if (!test)
 106                         break;
 107                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 108                                       rb_node);
 109                 prev = test;
 110         }
 111         *prev_ret = prev;
 112         return NULL;
 113 }
 114
 115 /*
 116  * helper to check if a given offset is inside a given entry
 117  */
 118 static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
 119 {
 120         if (file_offset < entry->file_offset ||
 121             entry->file_offset + entry->len <= file_offset)
 122                 return 0;
 123         return 1;
 124 }
 125
 126 static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
 127                           u64 len)
 128 {
 129         if (file_offset + len <= entry->file_offset ||
 130             entry->file_offset + entry->len <= file_offset)
 131                 return 0;
 132         return 1;
 133 }
 134
 135 /*
 136  * look find the first ordered struct that has this offset, otherwise
 137  * the first one less than this offset
 138  */
 139 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 140                                           u64 file_offset)
 141 {
 142         struct rb_root *root = &tree->tree;
 143         struct rb_node *prev = NULL;
 144         struct rb_node *ret;
 145         struct btrfs_ordered_extent *entry;
 146
 147         if (tree->last) {
 148                 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
 149                                  rb_node);
 150                 if (offset_in_entry(entry, file_offset))
 151                         return tree->last;
 152         }
 153         ret = __tree_search(root, file_offset, &prev);
 154         if (!ret)
 155                 ret = prev;
 156         if (ret)
 157                 tree->last = ret;
 158         return ret;
 159 }
 160
 161 /* allocate and add a new ordered_extent into the per-inode tree.
 162  * file_offset is the logical offset in the file
 163  *
 164  * start is the disk block number of an extent already reserved in the
 165  * extent allocation tree
 166  *
 167  * len is the length of the extent
 168  *
 169  * The tree is given a single reference on the ordered extent that was
 170  * inserted.
 171  */
 172 static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 173                                       u64 start, u64 len, u64 disk_len,
 174                                       int type, int dio, int compress_type)
 175 {
 176         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 177         struct btrfs_root *root = BTRFS_I(inode)->root;
 178         struct btrfs_ordered_inode_tree *tree;
 179         struct rb_node *node;
 180         struct btrfs_ordered_extent *entry;
 181
 182         tree = &BTRFS_I(inode)->ordered_tree;
 183         entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 184         if (!entry)
 185                 return -ENOMEM;
 186
 187         entry->file_offset = file_offset;
 188         entry->start = start;
 189         entry->len = len;
 190         entry->disk_len = disk_len;
 191         entry->bytes_left = len;
 192         entry->inode = igrab(inode);
 193         entry->compress_type = compress_type;
 194         entry->truncated_len = (u64)-1;
 195         if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
 196                 set_bit(type, &entry->flags);
 197
 198         if (dio)
 199                 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
 200
 201         /* one ref for the tree */
 202         refcount_set(&entry->refs, 1);
 203         init_waitqueue_head(&entry->wait);
 204         INIT_LIST_HEAD(&entry->list);
 205         INIT_LIST_HEAD(&entry->root_extent_list);
 206         INIT_LIST_HEAD(&entry->work_list);
 207         init_completion(&entry->completion);
 208         INIT_LIST_HEAD(&entry->log_list);
 209         INIT_LIST_HEAD(&entry->trans_list);
 210
 211         trace_btrfs_ordered_extent_add(inode, entry);
 212
 213         spin_lock_irq(&tree->lock);
 214         node = tree_insert(&tree->tree, file_offset,
 215                            &entry->rb_node);
 216         if (node)
 217                 ordered_data_tree_panic(inode, -EEXIST, file_offset);
 218         spin_unlock_irq(&tree->lock);
 219
 220         spin_lock(&root->ordered_extent_lock);
 221         list_add_tail(&entry->root_extent_list,
 222                       &root->ordered_extents);
 223         root->nr_ordered_extents++;
 224         if (root->nr_ordered_extents == 1) {
 225                 spin_lock(&fs_info->ordered_root_lock);
 226                 BUG_ON(!list_empty(&root->ordered_root));
 227                 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 228                 spin_unlock(&fs_info->ordered_root_lock);
 229         }
 230         spin_unlock(&root->ordered_extent_lock);
 231
 232         /*
 233          * We don't need the count_max_extents here, we can assume that all of
 234          * that work has been done at higher layers, so this is truly the
 235          * smallest the extent is going to get.
 236          */
 237         spin_lock(&BTRFS_I(inode)->lock);
 238         btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
 239         spin_unlock(&BTRFS_I(inode)->lock);
 240
 241         return 0;
 242 }
 243
 244 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 245                              u64 start, u64 len, u64 disk_len, int type)
 246 {
 247         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 248                                           disk_len, type, 0,
 249                                           BTRFS_COMPRESS_NONE);
 250 }
 251
 252 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 253                                  u64 start, u64 len, u64 disk_len, int type)
 254 {
 255         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 256                                           disk_len, type, 1,
 257                                           BTRFS_COMPRESS_NONE);
 258 }
 259
 260 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 261                                       u64 start, u64 len, u64 disk_len,
 262                                       int type, int compress_type)
 263 {
 264         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 265                                           disk_len, type, 0,
 266                                           compress_type);
 267 }
 268
 269 /*
 270  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 271  * when an ordered extent is finished.  If the list covers more than one
 272  * ordered extent, it is split across multiples.
 273  */
 274 void btrfs_add_ordered_sum(struct inode *inode,
 275                            struct btrfs_ordered_extent *entry,
 276                            struct btrfs_ordered_sum *sum)
 277 {
 278         struct btrfs_ordered_inode_tree *tree;
 279
 280         tree = &BTRFS_I(inode)->ordered_tree;
 281         spin_lock_irq(&tree->lock);
 282         list_add_tail(&sum->list, &entry->list);
 283         spin_unlock_irq(&tree->lock);
 284 }
 285
 286 /*
 287  * this is used to account for finished IO across a given range
 288  * of the file.  The IO may span ordered extents.  If
 289  * a given ordered_extent is completely done, 1 is returned, otherwise
 290  * 0.
 291  *
 292  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 293  * to make sure this function only returns 1 once for a given ordered extent.
 294  *
 295  * file_offset is updated to one byte past the range that is recorded as
 296  * complete.  This allows you to walk forward in the file.
 297  */
 298 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 299                                    struct btrfs_ordered_extent **cached,
 300                                    u64 *file_offset, u64 io_size, int uptodate)
 301 {
 302         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 303         struct btrfs_ordered_inode_tree *tree;
 304         struct rb_node *node;
 305         struct btrfs_ordered_extent *entry = NULL;
 306         int ret;
 307         unsigned long flags;
 308         u64 dec_end;
 309         u64 dec_start;
 310         u64 to_dec;
 311
 312         tree = &BTRFS_I(inode)->ordered_tree;
 313         spin_lock_irqsave(&tree->lock, flags);
 314         node = tree_search(tree, *file_offset);
 315         if (!node) {
 316                 ret = 1;
 317                 goto out;
 318         }
 319
 320         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 321         if (!offset_in_entry(entry, *file_offset)) {
 322                 ret = 1;
 323                 goto out;
 324         }
 325
 326         dec_start = max(*file_offset, entry->file_offset);
 327         dec_end = min(*file_offset + io_size, entry->file_offset +
 328                       entry->len);
 329         *file_offset = dec_end;
 330         if (dec_start > dec_end) {
 331                 btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu",
 332                            dec_start, dec_end);
 333         }
 334         to_dec = dec_end - dec_start;
 335         if (to_dec > entry->bytes_left) {
 336                 btrfs_crit(fs_info,
 337                            "bad ordered accounting left %llu size %llu",
 338                            entry->bytes_left, to_dec);
 339         }
 340         entry->bytes_left -= to_dec;
 341         if (!uptodate)
 342                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 343
 344         if (entry->bytes_left == 0) {
 345                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 346                 /* test_and_set_bit implies a barrier */
 347                 cond_wake_up_nomb(&entry->wait);
 348         } else {
 349                 ret = 1;
 350         }
 351 out:
 352         if (!ret && cached && entry) {
 353                 *cached = entry;
 354                 refcount_inc(&entry->refs);
 355         }
 356         spin_unlock_irqrestore(&tree->lock, flags);
 357         return ret == 0;
 358 }
 359
 360 /*
 361  * this is used to account for finished IO across a given range
 362  * of the file.  The IO should not span ordered extents.  If
 363  * a given ordered_extent is completely done, 1 is returned, otherwise
 364  * 0.
 365  *
 366  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 367  * to make sure this function only returns 1 once for a given ordered extent.
 368  */
 369 int btrfs_dec_test_ordered_pending(struct inode *inode,
 370                                    struct btrfs_ordered_extent **cached,
 371                                    u64 file_offset, u64 io_size, int uptodate)
 372 {
 373         struct btrfs_ordered_inode_tree *tree;
 374         struct rb_node *node;
 375         struct btrfs_ordered_extent *entry = NULL;
 376         unsigned long flags;
 377         int ret;
 378
 379         tree = &BTRFS_I(inode)->ordered_tree;
 380         spin_lock_irqsave(&tree->lock, flags);
 381         if (cached && *cached) {
 382                 entry = *cached;
 383                 goto have_entry;
 384         }
 385
 386         node = tree_search(tree, file_offset);
 387         if (!node) {
 388                 ret = 1;
 389                 goto out;
 390         }
 391
 392         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 393 have_entry:
 394         if (!offset_in_entry(entry, file_offset)) {
 395                 ret = 1;
 396                 goto out;
 397         }
 398
 399         if (io_size > entry->bytes_left) {
 400                 btrfs_crit(BTRFS_I(inode)->root->fs_info,
 401                            "bad ordered accounting left %llu size %llu",
 402                        entry->bytes_left, io_size);
 403         }
 404         entry->bytes_left -= io_size;
 405         if (!uptodate)
 406                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 407
 408         if (entry->bytes_left == 0) {
 409                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 410                 /* test_and_set_bit implies a barrier */
 411                 cond_wake_up_nomb(&entry->wait);
 412         } else {
 413                 ret = 1;
 414         }
 415 out:
 416         if (!ret && cached && entry) {
 417                 *cached = entry;
 418                 refcount_inc(&entry->refs);
 419         }
 420         spin_unlock_irqrestore(&tree->lock, flags);
 421         return ret == 0;
 422 }
 423
 424 /* Needs to either be called under a log transaction or the log_mutex */
 425 void btrfs_get_logged_extents(struct btrfs_inode *inode,
 426                               struct list_head *logged_list,
 427                               const loff_t start,
 428                               const loff_t end)
 429 {
 430         struct btrfs_ordered_inode_tree *tree;
 431         struct btrfs_ordered_extent *ordered;
 432         struct rb_node *n;
 433         struct rb_node *prev;
 434
 435         tree = &inode->ordered_tree;
 436         spin_lock_irq(&tree->lock);
 437         n = __tree_search(&tree->tree, end, &prev);
 438         if (!n)
 439                 n = prev;
 440         for (; n; n = rb_prev(n)) {
 441                 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 442                 if (ordered->file_offset > end)
 443                         continue;
 444                 if (entry_end(ordered) <= start)
 445                         break;
 446                 if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 447                         continue;
 448                 list_add(&ordered->log_list, logged_list);
 449                 refcount_inc(&ordered->refs);
 450         }
 451         spin_unlock_irq(&tree->lock);
 452 }
 453
 454 void btrfs_put_logged_extents(struct list_head *logged_list)
 455 {
 456         struct btrfs_ordered_extent *ordered;
 457
 458         while (!list_empty(logged_list)) {
 459                 ordered = list_first_entry(logged_list,
 460                                            struct btrfs_ordered_extent,
 461                                            log_list);
 462                 list_del_init(&ordered->log_list);
 463                 btrfs_put_ordered_extent(ordered);
 464         }
 465 }
 466
 467 void btrfs_submit_logged_extents(struct list_head *logged_list,
 468                                  struct btrfs_root *log)
 469 {
 470         int index = log->log_transid % 2;
 471
 472         spin_lock_irq(&log->log_extents_lock[index]);
 473         list_splice_tail(logged_list, &log->logged_list[index]);
 474         spin_unlock_irq(&log->log_extents_lock[index]);
 475 }
 476
 477 void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
 478                                struct btrfs_root *log, u64 transid)
 479 {
 480         struct btrfs_ordered_extent *ordered;
 481         int index = transid % 2;
 482
 483         spin_lock_irq(&log->log_extents_lock[index]);
 484         while (!list_empty(&log->logged_list[index])) {
 485                 struct inode *inode;
 486                 ordered = list_first_entry(&log->logged_list[index],
 487                                            struct btrfs_ordered_extent,
 488                                            log_list);
 489                 list_del_init(&ordered->log_list);
 490                 inode = ordered->inode;
 491                 spin_unlock_irq(&log->log_extents_lock[index]);
 492
 493                 if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
 494                     !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
 495                         u64 start = ordered->file_offset;
 496                         u64 end = ordered->file_offset + ordered->len - 1;
 497
 498                         WARN_ON(!inode);
 499                         filemap_fdatawrite_range(inode->i_mapping, start, end);
 500                 }
 501                 wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
 502                                                    &ordered->flags));
 503
 504                 /*
 505                  * In order to keep us from losing our ordered extent
 506                  * information when committing the transaction we have to make
 507                  * sure that any logged extents are completed when we go to
 508                  * commit the transaction.  To do this we simply increase the
 509                  * current transactions pending_ordered counter and decrement it
 510                  * when the ordered extent completes.
 511                  */
 512                 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
 513                         struct btrfs_ordered_inode_tree *tree;
 514
 515                         tree = &BTRFS_I(inode)->ordered_tree;
 516                         spin_lock_irq(&tree->lock);
 517                         if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
 518                                 set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
 519                                 atomic_inc(&trans->transaction->pending_ordered);
 520                         }
 521                         spin_unlock_irq(&tree->lock);
 522                 }
 523                 btrfs_put_ordered_extent(ordered);
 524                 spin_lock_irq(&log->log_extents_lock[index]);
 525         }
 526         spin_unlock_irq(&log->log_extents_lock[index]);
 527 }
 528
 529 void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
 530 {
 531         struct btrfs_ordered_extent *ordered;
 532         int index = transid % 2;
 533
 534         spin_lock_irq(&log->log_extents_lock[index]);
 535         while (!list_empty(&log->logged_list[index])) {
 536                 ordered = list_first_entry(&log->logged_list[index],
 537                                            struct btrfs_ordered_extent,
 538                                            log_list);
 539                 list_del_init(&ordered->log_list);
 540                 spin_unlock_irq(&log->log_extents_lock[index]);
 541                 btrfs_put_ordered_extent(ordered);
 542                 spin_lock_irq(&log->log_extents_lock[index]);
 543         }
 544         spin_unlock_irq(&log->log_extents_lock[index]);
 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(entry->inode, entry);
 557
 558         if (refcount_dec_and_test(&entry->refs)) {
 559                 ASSERT(list_empty(&entry->log_list));
 560                 ASSERT(list_empty(&entry->trans_list));
 561                 ASSERT(list_empty(&entry->root_extent_list));
 562                 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 563                 if (entry->inode)
 564                         btrfs_add_delayed_iput(entry->inode);
 565                 while (!list_empty(&entry->list)) {
 566                         cur = entry->list.next;
 567                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 568                         list_del(&sum->list);
 569                         kfree(sum);
 570                 }
 571                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
 572         }
 573 }
 574
 575 /*
 576  * remove an ordered extent from the tree.  No references are dropped
 577  * and waiters are woken up.
 578  */
 579 void btrfs_remove_ordered_extent(struct inode *inode,
 580                                  struct btrfs_ordered_extent *entry)
 581 {
 582         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 583         struct btrfs_ordered_inode_tree *tree;
 584         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 585         struct btrfs_root *root = btrfs_inode->root;
 586         struct rb_node *node;
 587         bool dec_pending_ordered = false;
 588
 589         /* This is paired with btrfs_add_ordered_extent. */
 590         spin_lock(&btrfs_inode->lock);
 591         btrfs_mod_outstanding_extents(btrfs_inode, -1);
 592         spin_unlock(&btrfs_inode->lock);
 593         if (root != fs_info->tree_root)
 594                 btrfs_delalloc_release_metadata(btrfs_inode, entry->len, false);
 595
 596         tree = &btrfs_inode->ordered_tree;
 597         spin_lock_irq(&tree->lock);
 598         node = &entry->rb_node;
 599         rb_erase(node, &tree->tree);
 600         RB_CLEAR_NODE(node);
 601         if (tree->last == node)
 602                 tree->last = NULL;
 603         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 604         if (test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags))
 605                 dec_pending_ordered = true;
 606         spin_unlock_irq(&tree->lock);
 607
 608         /*
 609          * The current running transaction is waiting on us, we need to let it
 610          * know that we're complete and wake it up.
 611          */
 612         if (dec_pending_ordered) {
 613                 struct btrfs_transaction *trans;
 614
 615                 /*
 616                  * The checks for trans are just a formality, it should be set,
 617                  * but if it isn't we don't want to deref/assert under the spin
 618                  * lock, so be nice and check if trans is set, but ASSERT() so
 619                  * if it isn't set a developer will notice.
 620                  */
 621                 spin_lock(&fs_info->trans_lock);
 622                 trans = fs_info->running_transaction;
 623                 if (trans)
 624                         refcount_inc(&trans->use_count);
 625                 spin_unlock(&fs_info->trans_lock);
 626
 627                 ASSERT(trans);
 628                 if (trans) {
 629                         if (atomic_dec_and_test(&trans->pending_ordered))
 630                                 wake_up(&trans->pending_wait);
 631                         btrfs_put_transaction(trans);
 632                 }
 633         }
 634
 635         spin_lock(&root->ordered_extent_lock);
 636         list_del_init(&entry->root_extent_list);
 637         root->nr_ordered_extents--;
 638
 639         trace_btrfs_ordered_extent_remove(inode, entry);
 640
 641         if (!root->nr_ordered_extents) {
 642                 spin_lock(&fs_info->ordered_root_lock);
 643                 BUG_ON(list_empty(&root->ordered_root));
 644                 list_del_init(&root->ordered_root);
 645                 spin_unlock(&fs_info->ordered_root_lock);
 646         }
 647         spin_unlock(&root->ordered_extent_lock);
 648         wake_up(&entry->wait);
 649 }
 650
 651 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 652 {
 653         struct btrfs_ordered_extent *ordered;
 654
 655         ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 656         btrfs_start_ordered_extent(ordered->inode, ordered, 1);
 657         complete(&ordered->completion);
 658 }
 659
 660 /*
 661  * wait for all the ordered extents in a root.  This is done when balancing
 662  * space between drives.
 663  */
 664 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 665                                const u64 range_start, const u64 range_len)
 666 {
 667         struct btrfs_fs_info *fs_info = root->fs_info;
 668         LIST_HEAD(splice);
 669         LIST_HEAD(skipped);
 670         LIST_HEAD(works);
 671         struct btrfs_ordered_extent *ordered, *next;
 672         u64 count = 0;
 673         const u64 range_end = range_start + range_len;
 674
 675         mutex_lock(&root->ordered_extent_mutex);
 676         spin_lock(&root->ordered_extent_lock);
 677         list_splice_init(&root->ordered_extents, &splice);
 678         while (!list_empty(&splice) && nr) {
 679                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 680                                            root_extent_list);
 681
 682                 if (range_end <= ordered->start ||
 683                     ordered->start + ordered->disk_len <= range_start) {
 684                         list_move_tail(&ordered->root_extent_list, &skipped);
 685                         cond_resched_lock(&root->ordered_extent_lock);
 686                         continue;
 687                 }
 688
 689                 list_move_tail(&ordered->root_extent_list,
 690                                &root->ordered_extents);
 691                 refcount_inc(&ordered->refs);
 692                 spin_unlock(&root->ordered_extent_lock);
 693
 694                 btrfs_init_work(&ordered->flush_work,
 695                                 btrfs_flush_delalloc_helper,
 696                                 btrfs_run_ordered_extent_work, NULL, NULL);
 697                 list_add_tail(&ordered->work_list, &works);
 698                 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 699
 700                 cond_resched();
 701                 spin_lock(&root->ordered_extent_lock);
 702                 if (nr != U64_MAX)
 703                         nr--;
 704                 count++;
 705         }
 706         list_splice_tail(&skipped, &root->ordered_extents);
 707         list_splice_tail(&splice, &root->ordered_extents);
 708         spin_unlock(&root->ordered_extent_lock);
 709
 710         list_for_each_entry_safe(ordered, next, &works, work_list) {
 711                 list_del_init(&ordered->work_list);
 712                 wait_for_completion(&ordered->completion);
 713                 btrfs_put_ordered_extent(ordered);
 714                 cond_resched();
 715         }
 716         mutex_unlock(&root->ordered_extent_mutex);
 717
 718         return count;
 719 }
 720
 721 u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 722                              const u64 range_start, const u64 range_len)
 723 {
 724         struct btrfs_root *root;
 725         struct list_head splice;
 726         u64 total_done = 0;
 727         u64 done;
 728
 729         INIT_LIST_HEAD(&splice);
 730
 731         mutex_lock(&fs_info->ordered_operations_mutex);
 732         spin_lock(&fs_info->ordered_root_lock);
 733         list_splice_init(&fs_info->ordered_roots, &splice);
 734         while (!list_empty(&splice) && nr) {
 735                 root = list_first_entry(&splice, struct btrfs_root,
 736                                         ordered_root);
 737                 root = btrfs_grab_fs_root(root);
 738                 BUG_ON(!root);
 739                 list_move_tail(&root->ordered_root,
 740                                &fs_info->ordered_roots);
 741                 spin_unlock(&fs_info->ordered_root_lock);
 742
 743                 done = btrfs_wait_ordered_extents(root, nr,
 744                                                   range_start, range_len);
 745                 btrfs_put_fs_root(root);
 746                 total_done += done;
 747
 748                 spin_lock(&fs_info->ordered_root_lock);
 749                 if (nr != U64_MAX) {
 750                         nr -= done;
 751                 }
 752         }
 753         list_splice_tail(&splice, &fs_info->ordered_roots);
 754         spin_unlock(&fs_info->ordered_root_lock);
 755         mutex_unlock(&fs_info->ordered_operations_mutex);
 756
 757         return total_done;
 758 }
 759
 760 /*
 761  * Used to start IO or wait for a given ordered extent to finish.
 762  *
 763  * If wait is one, this effectively waits on page writeback for all the pages
 764  * in the extent, and it waits on the io completion code to insert
 765  * metadata into the btree corresponding to the extent
 766  */
 767 void btrfs_start_ordered_extent(struct inode *inode,
 768                                        struct btrfs_ordered_extent *entry,
 769                                        int wait)
 770 {
 771         u64 start = entry->file_offset;
 772         u64 end = start + entry->len - 1;
 773
 774         trace_btrfs_ordered_extent_start(inode, entry);
 775
 776         /*
 777          * pages in the range can be dirty, clean or writeback.  We
 778          * start IO on any dirty ones so the wait doesn't stall waiting
 779          * for the flusher thread to find them
 780          */
 781         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 782                 filemap_fdatawrite_range(inode->i_mapping, start, end);
 783         if (wait) {
 784                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 785                                                  &entry->flags));
 786         }
 787 }
 788
 789 /*
 790  * Used to wait on ordered extents across a large range of bytes.
 791  */
 792 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 793 {
 794         int ret = 0;
 795         int ret_wb = 0;
 796         u64 end;
 797         u64 orig_end;
 798         struct btrfs_ordered_extent *ordered;
 799
 800         if (start + len < start) {
 801                 orig_end = INT_LIMIT(loff_t);
 802         } else {
 803                 orig_end = start + len - 1;
 804                 if (orig_end > INT_LIMIT(loff_t))
 805                         orig_end = INT_LIMIT(loff_t);
 806         }
 807
 808         /* start IO across the range first to instantiate any delalloc
 809          * extents
 810          */
 811         ret = btrfs_fdatawrite_range(inode, start, orig_end);
 812         if (ret)
 813                 return ret;
 814
 815         /*
 816          * If we have a writeback error don't return immediately. Wait first
 817          * for any ordered extents that haven't completed yet. This is to make
 818          * sure no one can dirty the same page ranges and call writepages()
 819          * before the ordered extents complete - to avoid failures (-EEXIST)
 820          * when adding the new ordered extents to the ordered tree.
 821          */
 822         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 823
 824         end = orig_end;
 825         while (1) {
 826                 ordered = btrfs_lookup_first_ordered_extent(inode, end);
 827                 if (!ordered)
 828                         break;
 829                 if (ordered->file_offset > orig_end) {
 830                         btrfs_put_ordered_extent(ordered);
 831                         break;
 832                 }
 833                 if (ordered->file_offset + ordered->len <= start) {
 834                         btrfs_put_ordered_extent(ordered);
 835                         break;
 836                 }
 837                 btrfs_start_ordered_extent(inode, ordered, 1);
 838                 end = ordered->file_offset;
 839                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 840                         ret = -EIO;
 841                 btrfs_put_ordered_extent(ordered);
 842                 if (ret || end == 0 || end == start)
 843                         break;
 844                 end--;
 845         }
 846         return ret_wb ? ret_wb : ret;
 847 }
 848
 849 /*
 850  * find an ordered extent corresponding to file_offset.  return NULL if
 851  * nothing is found, otherwise take a reference on the extent and return it
 852  */
 853 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 854                                                          u64 file_offset)
 855 {
 856         struct btrfs_ordered_inode_tree *tree;
 857         struct rb_node *node;
 858         struct btrfs_ordered_extent *entry = NULL;
 859
 860         tree = &BTRFS_I(inode)->ordered_tree;
 861         spin_lock_irq(&tree->lock);
 862         node = tree_search(tree, file_offset);
 863         if (!node)
 864                 goto out;
 865
 866         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 867         if (!offset_in_entry(entry, file_offset))
 868                 entry = NULL;
 869         if (entry)
 870                 refcount_inc(&entry->refs);
 871 out:
 872         spin_unlock_irq(&tree->lock);
 873         return entry;
 874 }
 875
 876 /* Since the DIO code tries to lock a wide area we need to look for any ordered
 877  * extents that exist in the range, rather than just the start of the range.
 878  */
 879 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 880                 struct btrfs_inode *inode, u64 file_offset, u64 len)
 881 {
 882         struct btrfs_ordered_inode_tree *tree;
 883         struct rb_node *node;
 884         struct btrfs_ordered_extent *entry = NULL;
 885
 886         tree = &inode->ordered_tree;
 887         spin_lock_irq(&tree->lock);
 888         node = tree_search(tree, file_offset);
 889         if (!node) {
 890                 node = tree_search(tree, file_offset + len);
 891                 if (!node)
 892                         goto out;
 893         }
 894
 895         while (1) {
 896                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 897                 if (range_overlaps(entry, file_offset, len))
 898                         break;
 899
 900                 if (entry->file_offset >= file_offset + len) {
 901                         entry = NULL;
 902                         break;
 903                 }
 904                 entry = NULL;
 905                 node = rb_next(node);
 906                 if (!node)
 907                         break;
 908         }
 909 out:
 910         if (entry)
 911                 refcount_inc(&entry->refs);
 912         spin_unlock_irq(&tree->lock);
 913         return entry;
 914 }
 915
 916 bool btrfs_have_ordered_extents_in_range(struct inode *inode,
 917                                          u64 file_offset,
 918                                          u64 len)
 919 {
 920         struct btrfs_ordered_extent *oe;
 921
 922         oe = btrfs_lookup_ordered_range(BTRFS_I(inode), file_offset, len);
 923         if (oe) {
 924                 btrfs_put_ordered_extent(oe);
 925                 return true;
 926         }
 927         return false;
 928 }
 929
 930 /*
 931  * lookup and return any extent before 'file_offset'.  NULL is returned
 932  * if none is found
 933  */
 934 struct btrfs_ordered_extent *
 935 btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
 936 {
 937         struct btrfs_ordered_inode_tree *tree;
 938         struct rb_node *node;
 939         struct btrfs_ordered_extent *entry = NULL;
 940
 941         tree = &BTRFS_I(inode)->ordered_tree;
 942         spin_lock_irq(&tree->lock);
 943         node = tree_search(tree, file_offset);
 944         if (!node)
 945                 goto out;
 946
 947         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 948         refcount_inc(&entry->refs);
 949 out:
 950         spin_unlock_irq(&tree->lock);
 951         return entry;
 952 }
 953
 954 /*
 955  * After an extent is done, call this to conditionally update the on disk
 956  * i_size.  i_size is updated to cover any fully written part of the file.
 957  */
 958 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 959                                 struct btrfs_ordered_extent *ordered)
 960 {
 961         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 962         u64 disk_i_size;
 963         u64 new_i_size;
 964         u64 i_size = i_size_read(inode);
 965         struct rb_node *node;
 966         struct rb_node *prev = NULL;
 967         struct btrfs_ordered_extent *test;
 968         int ret = 1;
 969         u64 orig_offset = offset;
 970
 971         spin_lock_irq(&tree->lock);
 972         if (ordered) {
 973                 offset = entry_end(ordered);
 974                 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
 975                         offset = min(offset,
 976                                      ordered->file_offset +
 977                                      ordered->truncated_len);
 978         } else {
 979                 offset = ALIGN(offset, btrfs_inode_sectorsize(inode));
 980         }
 981         disk_i_size = BTRFS_I(inode)->disk_i_size;
 982
 983         /*
 984          * truncate file.
 985          * If ordered is not NULL, then this is called from endio and
 986          * disk_i_size will be updated by either truncate itself or any
 987          * in-flight IOs which are inside the disk_i_size.
 988          *
 989          * Because btrfs_setsize() may set i_size with disk_i_size if truncate
 990          * fails somehow, we need to make sure we have a precise disk_i_size by
 991          * updating it as usual.
 992          *
 993          */
 994         if (!ordered && disk_i_size > i_size) {
 995                 BTRFS_I(inode)->disk_i_size = orig_offset;
 996                 ret = 0;
 997                 goto out;
 998         }
 999
1000         /*
1001          * if the disk i_size is already at the inode->i_size, or
1002          * this ordered extent is inside the disk i_size, we're done
1003          */
1004         if (disk_i_size == i_size)
1005                 goto out;
1006
1007         /*
1008          * We still need to update disk_i_size if outstanding_isize is greater
1009          * than disk_i_size.
1010          */
1011         if (offset <= disk_i_size &&
1012             (!ordered || ordered->outstanding_isize <= disk_i_size))
1013                 goto out;
1014
1015         /*
1016          * walk backward from this ordered extent to disk_i_size.
1017          * if we find an ordered extent then we can't update disk i_size
1018          * yet
1019          */
1020         if (ordered) {
1021                 node = rb_prev(&ordered->rb_node);
1022         } else {
1023                 prev = tree_search(tree, offset);
1024                 /*
1025                  * we insert file extents without involving ordered struct,
1026                  * so there should be no ordered struct cover this offset
1027                  */
1028                 if (prev) {
1029                         test = rb_entry(prev, struct btrfs_ordered_extent,
1030                                         rb_node);
1031                         BUG_ON(offset_in_entry(test, offset));
1032                 }
1033                 node = prev;
1034         }
1035         for (; node; node = rb_prev(node)) {
1036                 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1037
1038                 /* We treat this entry as if it doesn't exist */
1039                 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
1040                         continue;
1041
1042                 if (entry_end(test) <= disk_i_size)
1043                         break;
1044                 if (test->file_offset >= i_size)
1045                         break;
1046
1047                 /*
1048                  * We don't update disk_i_size now, so record this undealt
1049                  * i_size. Or we will not know the real i_size.
1050                  */
1051                 if (test->outstanding_isize < offset)
1052                         test->outstanding_isize = offset;
1053                 if (ordered &&
1054                     ordered->outstanding_isize > test->outstanding_isize)
1055                         test->outstanding_isize = ordered->outstanding_isize;
1056                 goto out;
1057         }
1058         new_i_size = min_t(u64, offset, i_size);
1059
1060         /*
1061          * Some ordered extents may completed before the current one, and
1062          * we hold the real i_size in ->outstanding_isize.
1063          */
1064         if (ordered && ordered->outstanding_isize > new_i_size)
1065                 new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
1066         BTRFS_I(inode)->disk_i_size = new_i_size;
1067         ret = 0;
1068 out:
1069         /*
1070          * We need to do this because we can't remove ordered extents until
1071          * after the i_disk_size has been updated and then the inode has been
1072          * updated to reflect the change, so we need to tell anybody who finds
1073          * this ordered extent that we've already done all the real work, we
1074          * just haven't completed all the other work.
1075          */
1076         if (ordered)
1077                 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
1078         spin_unlock_irq(&tree->lock);
1079         return ret;
1080 }
1081
1082 /*
1083  * search the ordered extents for one corresponding to 'offset' and
1084  * try to find a checksum.  This is used because we allow pages to
1085  * be reclaimed before their checksum is actually put into the btree
1086  */
1087 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
1088                            u32 *sum, int len)
1089 {
1090         struct btrfs_ordered_sum *ordered_sum;
1091         struct btrfs_ordered_extent *ordered;
1092         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1093         unsigned long num_sectors;
1094         unsigned long i;
1095         u32 sectorsize = btrfs_inode_sectorsize(inode);
1096         int index = 0;
1097
1098         ordered = btrfs_lookup_ordered_extent(inode, offset);
1099         if (!ordered)
1100                 return 0;
1101
1102         spin_lock_irq(&tree->lock);
1103         list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
1104                 if (disk_bytenr >= ordered_sum->bytenr &&
1105                     disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
1106                         i = (disk_bytenr - ordered_sum->bytenr) >>
1107                             inode->i_sb->s_blocksize_bits;
1108                         num_sectors = ordered_sum->len >>
1109                                       inode->i_sb->s_blocksize_bits;
1110                         num_sectors = min_t(int, len - index, num_sectors - i);
1111                         memcpy(sum + index, ordered_sum->sums + i,
1112                                num_sectors);
1113
1114                         index += (int)num_sectors;
1115                         if (index == len)
1116                                 goto out;
1117                         disk_bytenr += num_sectors * sectorsize;
1118                 }
1119         }
1120 out:
1121         spin_unlock_irq(&tree->lock);
1122         btrfs_put_ordered_extent(ordered);
1123         return index;
1124 }
1125
1126 int __init ordered_data_init(void)
1127 {
1128         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1129                                      sizeof(struct btrfs_ordered_extent), 0,
1130                                      SLAB_MEM_SPREAD,
1131                                      NULL);
1132         if (!btrfs_ordered_extent_cache)
1133                 return -ENOMEM;
1134
1135         return 0;
1136 }
1137
1138 void __cold ordered_data_exit(void)
1139 {
1140         kmem_cache_destroy(btrfs_ordered_extent_cache);
1141 }