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 "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                 percpu_counter_add_batch(&fs_info->dio_bytes, len,
 200                                          fs_info->delalloc_batch);
 201                 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
 202         }
 203
 204         /* one ref for the tree */
 205         refcount_set(&entry->refs, 1);
 206         init_waitqueue_head(&entry->wait);
 207         INIT_LIST_HEAD(&entry->list);
 208         INIT_LIST_HEAD(&entry->root_extent_list);
 209         INIT_LIST_HEAD(&entry->work_list);
 210         init_completion(&entry->completion);
 211         INIT_LIST_HEAD(&entry->log_list);
 212         INIT_LIST_HEAD(&entry->trans_list);
 213
 214         trace_btrfs_ordered_extent_add(inode, entry);
 215
 216         spin_lock_irq(&tree->lock);
 217         node = tree_insert(&tree->tree, file_offset,
 218                            &entry->rb_node);
 219         if (node)
 220                 ordered_data_tree_panic(inode, -EEXIST, file_offset);
 221         spin_unlock_irq(&tree->lock);
 222
 223         spin_lock(&root->ordered_extent_lock);
 224         list_add_tail(&entry->root_extent_list,
 225                       &root->ordered_extents);
 226         root->nr_ordered_extents++;
 227         if (root->nr_ordered_extents == 1) {
 228                 spin_lock(&fs_info->ordered_root_lock);
 229                 BUG_ON(!list_empty(&root->ordered_root));
 230                 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 231                 spin_unlock(&fs_info->ordered_root_lock);
 232         }
 233         spin_unlock(&root->ordered_extent_lock);
 234
 235         /*
 236          * We don't need the count_max_extents here, we can assume that all of
 237          * that work has been done at higher layers, so this is truly the
 238          * smallest the extent is going to get.
 239          */
 240         spin_lock(&BTRFS_I(inode)->lock);
 241         btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
 242         spin_unlock(&BTRFS_I(inode)->lock);
 243
 244         return 0;
 245 }
 246
 247 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 248                              u64 start, u64 len, u64 disk_len, int type)
 249 {
 250         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 251                                           disk_len, type, 0,
 252                                           BTRFS_COMPRESS_NONE);
 253 }
 254
 255 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 256                                  u64 start, u64 len, u64 disk_len, int type)
 257 {
 258         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 259                                           disk_len, type, 1,
 260                                           BTRFS_COMPRESS_NONE);
 261 }
 262
 263 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 264                                       u64 start, u64 len, u64 disk_len,
 265                                       int type, int compress_type)
 266 {
 267         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 268                                           disk_len, type, 0,
 269                                           compress_type);
 270 }
 271
 272 /*
 273  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 274  * when an ordered extent is finished.  If the list covers more than one
 275  * ordered extent, it is split across multiples.
 276  */
 277 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 278                            struct btrfs_ordered_sum *sum)
 279 {
 280         struct btrfs_ordered_inode_tree *tree;
 281
 282         tree = &BTRFS_I(entry->inode)->ordered_tree;
 283         spin_lock_irq(&tree->lock);
 284         list_add_tail(&sum->list, &entry->list);
 285         spin_unlock_irq(&tree->lock);
 286 }
 287
 288 /*
 289  * this is used to account for finished IO across a given range
 290  * of the file.  The IO may span ordered extents.  If
 291  * a given ordered_extent is completely done, 1 is returned, otherwise
 292  * 0.
 293  *
 294  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 295  * to make sure this function only returns 1 once for a given ordered extent.
 296  *
 297  * file_offset is updated to one byte past the range that is recorded as
 298  * complete.  This allows you to walk forward in the file.
 299  */
 300 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 301                                    struct btrfs_ordered_extent **cached,
 302                                    u64 *file_offset, u64 io_size, int uptodate)
 303 {
 304         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 305         struct btrfs_ordered_inode_tree *tree;
 306         struct rb_node *node;
 307         struct btrfs_ordered_extent *entry = NULL;
 308         int ret;
 309         unsigned long flags;
 310         u64 dec_end;
 311         u64 dec_start;
 312         u64 to_dec;
 313
 314         tree = &BTRFS_I(inode)->ordered_tree;
 315         spin_lock_irqsave(&tree->lock, flags);
 316         node = tree_search(tree, *file_offset);
 317         if (!node) {
 318                 ret = 1;
 319                 goto out;
 320         }
 321
 322         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 323         if (!offset_in_entry(entry, *file_offset)) {
 324                 ret = 1;
 325                 goto out;
 326         }
 327
 328         dec_start = max(*file_offset, entry->file_offset);
 329         dec_end = min(*file_offset + io_size, entry->file_offset +
 330                       entry->len);
 331         *file_offset = dec_end;
 332         if (dec_start > dec_end) {
 333                 btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu",
 334                            dec_start, dec_end);
 335         }
 336         to_dec = dec_end - dec_start;
 337         if (to_dec > entry->bytes_left) {
 338                 btrfs_crit(fs_info,
 339                            "bad ordered accounting left %llu size %llu",
 340                            entry->bytes_left, to_dec);
 341         }
 342         entry->bytes_left -= to_dec;
 343         if (!uptodate)
 344                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 345
 346         if (entry->bytes_left == 0) {
 347                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 348                 /* test_and_set_bit implies a barrier */
 349                 cond_wake_up_nomb(&entry->wait);
 350         } else {
 351                 ret = 1;
 352         }
 353 out:
 354         if (!ret && cached && entry) {
 355                 *cached = entry;
 356                 refcount_inc(&entry->refs);
 357         }
 358         spin_unlock_irqrestore(&tree->lock, flags);
 359         return ret == 0;
 360 }
 361
 362 /*
 363  * this is used to account for finished IO across a given range
 364  * of the file.  The IO should not span ordered extents.  If
 365  * a given ordered_extent is completely done, 1 is returned, otherwise
 366  * 0.
 367  *
 368  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 369  * to make sure this function only returns 1 once for a given ordered extent.
 370  */
 371 int btrfs_dec_test_ordered_pending(struct inode *inode,
 372                                    struct btrfs_ordered_extent **cached,
 373                                    u64 file_offset, u64 io_size, int uptodate)
 374 {
 375         struct btrfs_ordered_inode_tree *tree;
 376         struct rb_node *node;
 377         struct btrfs_ordered_extent *entry = NULL;
 378         unsigned long flags;
 379         int ret;
 380
 381         tree = &BTRFS_I(inode)->ordered_tree;
 382         spin_lock_irqsave(&tree->lock, flags);
 383         if (cached && *cached) {
 384                 entry = *cached;
 385                 goto have_entry;
 386         }
 387
 388         node = tree_search(tree, file_offset);
 389         if (!node) {
 390                 ret = 1;
 391                 goto out;
 392         }
 393
 394         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 395 have_entry:
 396         if (!offset_in_entry(entry, file_offset)) {
 397                 ret = 1;
 398                 goto out;
 399         }
 400
 401         if (io_size > entry->bytes_left) {
 402                 btrfs_crit(BTRFS_I(inode)->root->fs_info,
 403                            "bad ordered accounting left %llu size %llu",
 404                        entry->bytes_left, io_size);
 405         }
 406         entry->bytes_left -= io_size;
 407         if (!uptodate)
 408                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 409
 410         if (entry->bytes_left == 0) {
 411                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 412                 /* test_and_set_bit implies a barrier */
 413                 cond_wake_up_nomb(&entry->wait);
 414         } else {
 415                 ret = 1;
 416         }
 417 out:
 418         if (!ret && cached && entry) {
 419                 *cached = entry;
 420                 refcount_inc(&entry->refs);
 421         }
 422         spin_unlock_irqrestore(&tree->lock, flags);
 423         return ret == 0;
 424 }
 425
 426 /*
 427  * used to drop a reference on an ordered extent.  This will free
 428  * the extent if the last reference is dropped
 429  */
 430 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 431 {
 432         struct list_head *cur;
 433         struct btrfs_ordered_sum *sum;
 434
 435         trace_btrfs_ordered_extent_put(entry->inode, entry);
 436
 437         if (refcount_dec_and_test(&entry->refs)) {
 438                 ASSERT(list_empty(&entry->log_list));
 439                 ASSERT(list_empty(&entry->trans_list));
 440                 ASSERT(list_empty(&entry->root_extent_list));
 441                 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 442                 if (entry->inode)
 443                         btrfs_add_delayed_iput(entry->inode);
 444                 while (!list_empty(&entry->list)) {
 445                         cur = entry->list.next;
 446                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 447                         list_del(&sum->list);
 448                         kvfree(sum);
 449                 }
 450                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
 451         }
 452 }
 453
 454 /*
 455  * remove an ordered extent from the tree.  No references are dropped
 456  * and waiters are woken up.
 457  */
 458 void btrfs_remove_ordered_extent(struct inode *inode,
 459                                  struct btrfs_ordered_extent *entry)
 460 {
 461         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 462         struct btrfs_ordered_inode_tree *tree;
 463         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 464         struct btrfs_root *root = btrfs_inode->root;
 465         struct rb_node *node;
 466
 467         /* This is paired with btrfs_add_ordered_extent. */
 468         spin_lock(&btrfs_inode->lock);
 469         btrfs_mod_outstanding_extents(btrfs_inode, -1);
 470         spin_unlock(&btrfs_inode->lock);
 471         if (root != fs_info->tree_root)
 472                 btrfs_delalloc_release_metadata(btrfs_inode, entry->len, false);
 473
 474         if (test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 475                 percpu_counter_add_batch(&fs_info->dio_bytes, -entry->len,
 476                                          fs_info->delalloc_batch);
 477
 478         tree = &btrfs_inode->ordered_tree;
 479         spin_lock_irq(&tree->lock);
 480         node = &entry->rb_node;
 481         rb_erase(node, &tree->tree);
 482         RB_CLEAR_NODE(node);
 483         if (tree->last == node)
 484                 tree->last = NULL;
 485         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 486         spin_unlock_irq(&tree->lock);
 487
 488         spin_lock(&root->ordered_extent_lock);
 489         list_del_init(&entry->root_extent_list);
 490         root->nr_ordered_extents--;
 491
 492         trace_btrfs_ordered_extent_remove(inode, entry);
 493
 494         if (!root->nr_ordered_extents) {
 495                 spin_lock(&fs_info->ordered_root_lock);
 496                 BUG_ON(list_empty(&root->ordered_root));
 497                 list_del_init(&root->ordered_root);
 498                 spin_unlock(&fs_info->ordered_root_lock);
 499         }
 500         spin_unlock(&root->ordered_extent_lock);
 501         wake_up(&entry->wait);
 502 }
 503
 504 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 505 {
 506         struct btrfs_ordered_extent *ordered;
 507
 508         ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 509         btrfs_start_ordered_extent(ordered->inode, ordered, 1);
 510         complete(&ordered->completion);
 511 }
 512
 513 /*
 514  * wait for all the ordered extents in a root.  This is done when balancing
 515  * space between drives.
 516  */
 517 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 518                                const u64 range_start, const u64 range_len)
 519 {
 520         struct btrfs_fs_info *fs_info = root->fs_info;
 521         LIST_HEAD(splice);
 522         LIST_HEAD(skipped);
 523         LIST_HEAD(works);
 524         struct btrfs_ordered_extent *ordered, *next;
 525         u64 count = 0;
 526         const u64 range_end = range_start + range_len;
 527
 528         mutex_lock(&root->ordered_extent_mutex);
 529         spin_lock(&root->ordered_extent_lock);
 530         list_splice_init(&root->ordered_extents, &splice);
 531         while (!list_empty(&splice) && nr) {
 532                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 533                                            root_extent_list);
 534
 535                 if (range_end <= ordered->start ||
 536                     ordered->start + ordered->disk_len <= range_start) {
 537                         list_move_tail(&ordered->root_extent_list, &skipped);
 538                         cond_resched_lock(&root->ordered_extent_lock);
 539                         continue;
 540                 }
 541
 542                 list_move_tail(&ordered->root_extent_list,
 543                                &root->ordered_extents);
 544                 refcount_inc(&ordered->refs);
 545                 spin_unlock(&root->ordered_extent_lock);
 546
 547                 btrfs_init_work(&ordered->flush_work,
 548                                 btrfs_flush_delalloc_helper,
 549                                 btrfs_run_ordered_extent_work, NULL, NULL);
 550                 list_add_tail(&ordered->work_list, &works);
 551                 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 552
 553                 cond_resched();
 554                 spin_lock(&root->ordered_extent_lock);
 555                 if (nr != U64_MAX)
 556                         nr--;
 557                 count++;
 558         }
 559         list_splice_tail(&skipped, &root->ordered_extents);
 560         list_splice_tail(&splice, &root->ordered_extents);
 561         spin_unlock(&root->ordered_extent_lock);
 562
 563         list_for_each_entry_safe(ordered, next, &works, work_list) {
 564                 list_del_init(&ordered->work_list);
 565                 wait_for_completion(&ordered->completion);
 566                 btrfs_put_ordered_extent(ordered);
 567                 cond_resched();
 568         }
 569         mutex_unlock(&root->ordered_extent_mutex);
 570
 571         return count;
 572 }
 573
 574 u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 575                              const u64 range_start, const u64 range_len)
 576 {
 577         struct btrfs_root *root;
 578         struct list_head splice;
 579         u64 total_done = 0;
 580         u64 done;
 581
 582         INIT_LIST_HEAD(&splice);
 583
 584         mutex_lock(&fs_info->ordered_operations_mutex);
 585         spin_lock(&fs_info->ordered_root_lock);
 586         list_splice_init(&fs_info->ordered_roots, &splice);
 587         while (!list_empty(&splice) && nr) {
 588                 root = list_first_entry(&splice, struct btrfs_root,
 589                                         ordered_root);
 590                 root = btrfs_grab_fs_root(root);
 591                 BUG_ON(!root);
 592                 list_move_tail(&root->ordered_root,
 593                                &fs_info->ordered_roots);
 594                 spin_unlock(&fs_info->ordered_root_lock);
 595
 596                 done = btrfs_wait_ordered_extents(root, nr,
 597                                                   range_start, range_len);
 598                 btrfs_put_fs_root(root);
 599                 total_done += done;
 600
 601                 spin_lock(&fs_info->ordered_root_lock);
 602                 if (nr != U64_MAX) {
 603                         nr -= done;
 604                 }
 605         }
 606         list_splice_tail(&splice, &fs_info->ordered_roots);
 607         spin_unlock(&fs_info->ordered_root_lock);
 608         mutex_unlock(&fs_info->ordered_operations_mutex);
 609
 610         return total_done;
 611 }
 612
 613 /*
 614  * Used to start IO or wait for a given ordered extent to finish.
 615  *
 616  * If wait is one, this effectively waits on page writeback for all the pages
 617  * in the extent, and it waits on the io completion code to insert
 618  * metadata into the btree corresponding to the extent
 619  */
 620 void btrfs_start_ordered_extent(struct inode *inode,
 621                                        struct btrfs_ordered_extent *entry,
 622                                        int wait)
 623 {
 624         u64 start = entry->file_offset;
 625         u64 end = start + entry->len - 1;
 626
 627         trace_btrfs_ordered_extent_start(inode, entry);
 628
 629         /*
 630          * pages in the range can be dirty, clean or writeback.  We
 631          * start IO on any dirty ones so the wait doesn't stall waiting
 632          * for the flusher thread to find them
 633          */
 634         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 635                 filemap_fdatawrite_range(inode->i_mapping, start, end);
 636         if (wait) {
 637                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 638                                                  &entry->flags));
 639         }
 640 }
 641
 642 /*
 643  * Used to wait on ordered extents across a large range of bytes.
 644  */
 645 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 646 {
 647         int ret = 0;
 648         int ret_wb = 0;
 649         u64 end;
 650         u64 orig_end;
 651         struct btrfs_ordered_extent *ordered;
 652
 653         if (start + len < start) {
 654                 orig_end = INT_LIMIT(loff_t);
 655         } else {
 656                 orig_end = start + len - 1;
 657                 if (orig_end > INT_LIMIT(loff_t))
 658                         orig_end = INT_LIMIT(loff_t);
 659         }
 660
 661         /* start IO across the range first to instantiate any delalloc
 662          * extents
 663          */
 664         ret = btrfs_fdatawrite_range(inode, start, orig_end);
 665         if (ret)
 666                 return ret;
 667
 668         /*
 669          * If we have a writeback error don't return immediately. Wait first
 670          * for any ordered extents that haven't completed yet. This is to make
 671          * sure no one can dirty the same page ranges and call writepages()
 672          * before the ordered extents complete - to avoid failures (-EEXIST)
 673          * when adding the new ordered extents to the ordered tree.
 674          */
 675         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 676
 677         end = orig_end;
 678         while (1) {
 679                 ordered = btrfs_lookup_first_ordered_extent(inode, end);
 680                 if (!ordered)
 681                         break;
 682                 if (ordered->file_offset > orig_end) {
 683                         btrfs_put_ordered_extent(ordered);
 684                         break;
 685                 }
 686                 if (ordered->file_offset + ordered->len <= start) {
 687                         btrfs_put_ordered_extent(ordered);
 688                         break;
 689                 }
 690                 btrfs_start_ordered_extent(inode, ordered, 1);
 691                 end = ordered->file_offset;
 692                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 693                         ret = -EIO;
 694                 btrfs_put_ordered_extent(ordered);
 695                 if (ret || end == 0 || end == start)
 696                         break;
 697                 end--;
 698         }
 699         return ret_wb ? ret_wb : ret;
 700 }
 701
 702 /*
 703  * find an ordered extent corresponding to file_offset.  return NULL if
 704  * nothing is found, otherwise take a reference on the extent and return it
 705  */
 706 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 707                                                          u64 file_offset)
 708 {
 709         struct btrfs_ordered_inode_tree *tree;
 710         struct rb_node *node;
 711         struct btrfs_ordered_extent *entry = NULL;
 712
 713         tree = &BTRFS_I(inode)->ordered_tree;
 714         spin_lock_irq(&tree->lock);
 715         node = tree_search(tree, file_offset);
 716         if (!node)
 717                 goto out;
 718
 719         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 720         if (!offset_in_entry(entry, file_offset))
 721                 entry = NULL;
 722         if (entry)
 723                 refcount_inc(&entry->refs);
 724 out:
 725         spin_unlock_irq(&tree->lock);
 726         return entry;
 727 }
 728
 729 /* Since the DIO code tries to lock a wide area we need to look for any ordered
 730  * extents that exist in the range, rather than just the start of the range.
 731  */
 732 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 733                 struct btrfs_inode *inode, u64 file_offset, u64 len)
 734 {
 735         struct btrfs_ordered_inode_tree *tree;
 736         struct rb_node *node;
 737         struct btrfs_ordered_extent *entry = NULL;
 738
 739         tree = &inode->ordered_tree;
 740         spin_lock_irq(&tree->lock);
 741         node = tree_search(tree, file_offset);
 742         if (!node) {
 743                 node = tree_search(tree, file_offset + len);
 744                 if (!node)
 745                         goto out;
 746         }
 747
 748         while (1) {
 749                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 750                 if (range_overlaps(entry, file_offset, len))
 751                         break;
 752
 753                 if (entry->file_offset >= file_offset + len) {
 754                         entry = NULL;
 755                         break;
 756                 }
 757                 entry = NULL;
 758                 node = rb_next(node);
 759                 if (!node)
 760                         break;
 761         }
 762 out:
 763         if (entry)
 764                 refcount_inc(&entry->refs);
 765         spin_unlock_irq(&tree->lock);
 766         return entry;
 767 }
 768
 769 /*
 770  * lookup and return any extent before 'file_offset'.  NULL is returned
 771  * if none is found
 772  */
 773 struct btrfs_ordered_extent *
 774 btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
 775 {
 776         struct btrfs_ordered_inode_tree *tree;
 777         struct rb_node *node;
 778         struct btrfs_ordered_extent *entry = NULL;
 779
 780         tree = &BTRFS_I(inode)->ordered_tree;
 781         spin_lock_irq(&tree->lock);
 782         node = tree_search(tree, file_offset);
 783         if (!node)
 784                 goto out;
 785
 786         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 787         refcount_inc(&entry->refs);
 788 out:
 789         spin_unlock_irq(&tree->lock);
 790         return entry;
 791 }
 792
 793 /*
 794  * After an extent is done, call this to conditionally update the on disk
 795  * i_size.  i_size is updated to cover any fully written part of the file.
 796  */
 797 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 798                                 struct btrfs_ordered_extent *ordered)
 799 {
 800         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 801         u64 disk_i_size;
 802         u64 new_i_size;
 803         u64 i_size = i_size_read(inode);
 804         struct rb_node *node;
 805         struct rb_node *prev = NULL;
 806         struct btrfs_ordered_extent *test;
 807         int ret = 1;
 808         u64 orig_offset = offset;
 809
 810         spin_lock_irq(&tree->lock);
 811         if (ordered) {
 812                 offset = entry_end(ordered);
 813                 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
 814                         offset = min(offset,
 815                                      ordered->file_offset +
 816                                      ordered->truncated_len);
 817         } else {
 818                 offset = ALIGN(offset, btrfs_inode_sectorsize(inode));
 819         }
 820         disk_i_size = BTRFS_I(inode)->disk_i_size;
 821
 822         /*
 823          * truncate file.
 824          * If ordered is not NULL, then this is called from endio and
 825          * disk_i_size will be updated by either truncate itself or any
 826          * in-flight IOs which are inside the disk_i_size.
 827          *
 828          * Because btrfs_setsize() may set i_size with disk_i_size if truncate
 829          * fails somehow, we need to make sure we have a precise disk_i_size by
 830          * updating it as usual.
 831          *
 832          */
 833         if (!ordered && disk_i_size > i_size) {
 834                 BTRFS_I(inode)->disk_i_size = orig_offset;
 835                 ret = 0;
 836                 goto out;
 837         }
 838
 839         /*
 840          * if the disk i_size is already at the inode->i_size, or
 841          * this ordered extent is inside the disk i_size, we're done
 842          */
 843         if (disk_i_size == i_size)
 844                 goto out;
 845
 846         /*
 847          * We still need to update disk_i_size if outstanding_isize is greater
 848          * than disk_i_size.
 849          */
 850         if (offset <= disk_i_size &&
 851             (!ordered || ordered->outstanding_isize <= disk_i_size))
 852                 goto out;
 853
 854         /*
 855          * walk backward from this ordered extent to disk_i_size.
 856          * if we find an ordered extent then we can't update disk i_size
 857          * yet
 858          */
 859         if (ordered) {
 860                 node = rb_prev(&ordered->rb_node);
 861         } else {
 862                 prev = tree_search(tree, offset);
 863                 /*
 864                  * we insert file extents without involving ordered struct,
 865                  * so there should be no ordered struct cover this offset
 866                  */
 867                 if (prev) {
 868                         test = rb_entry(prev, struct btrfs_ordered_extent,
 869                                         rb_node);
 870                         BUG_ON(offset_in_entry(test, offset));
 871                 }
 872                 node = prev;
 873         }
 874         for (; node; node = rb_prev(node)) {
 875                 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 876
 877                 /* We treat this entry as if it doesn't exist */
 878                 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
 879                         continue;
 880
 881                 if (entry_end(test) <= disk_i_size)
 882                         break;
 883                 if (test->file_offset >= i_size)
 884                         break;
 885
 886                 /*
 887                  * We don't update disk_i_size now, so record this undealt
 888                  * i_size. Or we will not know the real i_size.
 889                  */
 890                 if (test->outstanding_isize < offset)
 891                         test->outstanding_isize = offset;
 892                 if (ordered &&
 893                     ordered->outstanding_isize > test->outstanding_isize)
 894                         test->outstanding_isize = ordered->outstanding_isize;
 895                 goto out;
 896         }
 897         new_i_size = min_t(u64, offset, i_size);
 898
 899         /*
 900          * Some ordered extents may completed before the current one, and
 901          * we hold the real i_size in ->outstanding_isize.
 902          */
 903         if (ordered && ordered->outstanding_isize > new_i_size)
 904                 new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
 905         BTRFS_I(inode)->disk_i_size = new_i_size;
 906         ret = 0;
 907 out:
 908         /*
 909          * We need to do this because we can't remove ordered extents until
 910          * after the i_disk_size has been updated and then the inode has been
 911          * updated to reflect the change, so we need to tell anybody who finds
 912          * this ordered extent that we've already done all the real work, we
 913          * just haven't completed all the other work.
 914          */
 915         if (ordered)
 916                 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
 917         spin_unlock_irq(&tree->lock);
 918         return ret;
 919 }
 920
 921 /*
 922  * search the ordered extents for one corresponding to 'offset' and
 923  * try to find a checksum.  This is used because we allow pages to
 924  * be reclaimed before their checksum is actually put into the btree
 925  */
 926 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
 927                            u32 *sum, int len)
 928 {
 929         struct btrfs_ordered_sum *ordered_sum;
 930         struct btrfs_ordered_extent *ordered;
 931         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 932         unsigned long num_sectors;
 933         unsigned long i;
 934         u32 sectorsize = btrfs_inode_sectorsize(inode);
 935         int index = 0;
 936
 937         ordered = btrfs_lookup_ordered_extent(inode, offset);
 938         if (!ordered)
 939                 return 0;
 940
 941         spin_lock_irq(&tree->lock);
 942         list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
 943                 if (disk_bytenr >= ordered_sum->bytenr &&
 944                     disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
 945                         i = (disk_bytenr - ordered_sum->bytenr) >>
 946                             inode->i_sb->s_blocksize_bits;
 947                         num_sectors = ordered_sum->len >>
 948                                       inode->i_sb->s_blocksize_bits;
 949                         num_sectors = min_t(int, len - index, num_sectors - i);
 950                         memcpy(sum + index, ordered_sum->sums + i,
 951                                num_sectors);
 952
 953                         index += (int)num_sectors;
 954                         if (index == len)
 955                                 goto out;
 956                         disk_bytenr += num_sectors * sectorsize;
 957                 }
 958         }
 959 out:
 960         spin_unlock_irq(&tree->lock);
 961         btrfs_put_ordered_extent(ordered);
 962         return index;
 963 }
 964
 965 int __init ordered_data_init(void)
 966 {
 967         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
 968                                      sizeof(struct btrfs_ordered_extent), 0,
 969                                      SLAB_MEM_SPREAD,
 970                                      NULL);
 971         if (!btrfs_ordered_extent_cache)
 972                 return -ENOMEM;
 973
 974         return 0;
 975 }
 976
 977 void __cold ordered_data_exit(void)
 978 {
 979         kmem_cache_destroy(btrfs_ordered_extent_cache);
 980 }