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 "ctree.h"
  10 #include "transaction.h"
  11 #include "btrfs_inode.h"
  12 #include "extent_io.h"
  13 #include "disk-io.h"
  14 #include "compression.h"
  15
  16 static struct kmem_cache *btrfs_ordered_extent_cache;
  17
  18 static u64 entry_end(struct btrfs_ordered_extent *entry)
  19 {
  20         if (entry->file_offset + entry->len < entry->file_offset)
  21                 return (u64)-1;
  22         return entry->file_offset + entry->len;
  23 }
  24
  25 /* returns NULL if the insertion worked, or it returns the node it did find
  26  * in the tree
  27  */
  28 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  29                                    struct rb_node *node)
  30 {
  31         struct rb_node **p = &root->rb_node;
  32         struct rb_node *parent = NULL;
  33         struct btrfs_ordered_extent *entry;
  34
  35         while (*p) {
  36                 parent = *p;
  37                 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  38
  39                 if (file_offset < entry->file_offset)
  40                         p = &(*p)->rb_left;
  41                 else if (file_offset >= entry_end(entry))
  42                         p = &(*p)->rb_right;
  43                 else
  44                         return parent;
  45         }
  46
  47         rb_link_node(node, parent, p);
  48         rb_insert_color(node, root);
  49         return NULL;
  50 }
  51
  52 static void ordered_data_tree_panic(struct inode *inode, int errno,
  53                                                u64 offset)
  54 {
  55         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
  56         btrfs_panic(fs_info, errno,
  57                     "Inconsistency in ordered tree at offset %llu", offset);
  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 /*
 115  * helper to check if a given offset is inside a given entry
 116  */
 117 static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
 118 {
 119         if (file_offset < entry->file_offset ||
 120             entry->file_offset + entry->len <= file_offset)
 121                 return 0;
 122         return 1;
 123 }
 124
 125 static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
 126                           u64 len)
 127 {
 128         if (file_offset + len <= entry->file_offset ||
 129             entry->file_offset + entry->len <= file_offset)
 130                 return 0;
 131         return 1;
 132 }
 133
 134 /*
 135  * look find the first ordered struct that has this offset, otherwise
 136  * the first one less than this offset
 137  */
 138 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 139                                           u64 file_offset)
 140 {
 141         struct rb_root *root = &tree->tree;
 142         struct rb_node *prev = NULL;
 143         struct rb_node *ret;
 144         struct btrfs_ordered_extent *entry;
 145
 146         if (tree->last) {
 147                 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
 148                                  rb_node);
 149                 if (offset_in_entry(entry, file_offset))
 150                         return tree->last;
 151         }
 152         ret = __tree_search(root, file_offset, &prev);
 153         if (!ret)
 154                 ret = prev;
 155         if (ret)
 156                 tree->last = ret;
 157         return ret;
 158 }
 159
 160 /* allocate and add a new ordered_extent into the per-inode tree.
 161  * file_offset is the logical offset in the file
 162  *
 163  * start is the disk block number of an extent already reserved in the
 164  * extent allocation tree
 165  *
 166  * len is the length of the extent
 167  *
 168  * The tree is given a single reference on the ordered extent that was
 169  * inserted.
 170  */
 171 static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 172                                       u64 start, u64 len, u64 disk_len,
 173                                       int type, int dio, int compress_type)
 174 {
 175         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 176         struct btrfs_root *root = BTRFS_I(inode)->root;
 177         struct btrfs_ordered_inode_tree *tree;
 178         struct rb_node *node;
 179         struct btrfs_ordered_extent *entry;
 180
 181         tree = &BTRFS_I(inode)->ordered_tree;
 182         entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 183         if (!entry)
 184                 return -ENOMEM;
 185
 186         entry->file_offset = file_offset;
 187         entry->start = start;
 188         entry->len = len;
 189         entry->disk_len = disk_len;
 190         entry->bytes_left = len;
 191         entry->inode = igrab(inode);
 192         entry->compress_type = compress_type;
 193         entry->truncated_len = (u64)-1;
 194         if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
 195                 set_bit(type, &entry->flags);
 196
 197         if (dio)
 198                 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
 199
 200         /* one ref for the tree */
 201         refcount_set(&entry->refs, 1);
 202         init_waitqueue_head(&entry->wait);
 203         INIT_LIST_HEAD(&entry->list);
 204         INIT_LIST_HEAD(&entry->root_extent_list);
 205         INIT_LIST_HEAD(&entry->work_list);
 206         init_completion(&entry->completion);
 207         INIT_LIST_HEAD(&entry->log_list);
 208         INIT_LIST_HEAD(&entry->trans_list);
 209
 210         trace_btrfs_ordered_extent_add(inode, entry);
 211
 212         spin_lock_irq(&tree->lock);
 213         node = tree_insert(&tree->tree, file_offset,
 214                            &entry->rb_node);
 215         if (node)
 216                 ordered_data_tree_panic(inode, -EEXIST, file_offset);
 217         spin_unlock_irq(&tree->lock);
 218
 219         spin_lock(&root->ordered_extent_lock);
 220         list_add_tail(&entry->root_extent_list,
 221                       &root->ordered_extents);
 222         root->nr_ordered_extents++;
 223         if (root->nr_ordered_extents == 1) {
 224                 spin_lock(&fs_info->ordered_root_lock);
 225                 BUG_ON(!list_empty(&root->ordered_root));
 226                 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 227                 spin_unlock(&fs_info->ordered_root_lock);
 228         }
 229         spin_unlock(&root->ordered_extent_lock);
 230
 231         /*
 232          * We don't need the count_max_extents here, we can assume that all of
 233          * that work has been done at higher layers, so this is truly the
 234          * smallest the extent is going to get.
 235          */
 236         spin_lock(&BTRFS_I(inode)->lock);
 237         btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
 238         spin_unlock(&BTRFS_I(inode)->lock);
 239
 240         return 0;
 241 }
 242
 243 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 244                              u64 start, u64 len, u64 disk_len, int type)
 245 {
 246         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 247                                           disk_len, type, 0,
 248                                           BTRFS_COMPRESS_NONE);
 249 }
 250
 251 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 252                                  u64 start, u64 len, u64 disk_len, int type)
 253 {
 254         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 255                                           disk_len, type, 1,
 256                                           BTRFS_COMPRESS_NONE);
 257 }
 258
 259 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 260                                       u64 start, u64 len, u64 disk_len,
 261                                       int type, int compress_type)
 262 {
 263         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 264                                           disk_len, type, 0,
 265                                           compress_type);
 266 }
 267
 268 /*
 269  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 270  * when an ordered extent is finished.  If the list covers more than one
 271  * ordered extent, it is split across multiples.
 272  */
 273 void btrfs_add_ordered_sum(struct inode *inode,
 274                            struct btrfs_ordered_extent *entry,
 275                            struct btrfs_ordered_sum *sum)
 276 {
 277         struct btrfs_ordered_inode_tree *tree;
 278
 279         tree = &BTRFS_I(inode)->ordered_tree;
 280         spin_lock_irq(&tree->lock);
 281         list_add_tail(&sum->list, &entry->list);
 282         spin_unlock_irq(&tree->lock);
 283 }
 284
 285 /*
 286  * this is used to account for finished IO across a given range
 287  * of the file.  The IO may span ordered extents.  If
 288  * a given ordered_extent is completely done, 1 is returned, otherwise
 289  * 0.
 290  *
 291  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 292  * to make sure this function only returns 1 once for a given ordered extent.
 293  *
 294  * file_offset is updated to one byte past the range that is recorded as
 295  * complete.  This allows you to walk forward in the file.
 296  */
 297 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 298                                    struct btrfs_ordered_extent **cached,
 299                                    u64 *file_offset, u64 io_size, int uptodate)
 300 {
 301         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 302         struct btrfs_ordered_inode_tree *tree;
 303         struct rb_node *node;
 304         struct btrfs_ordered_extent *entry = NULL;
 305         int ret;
 306         unsigned long flags;
 307         u64 dec_end;
 308         u64 dec_start;
 309         u64 to_dec;
 310
 311         tree = &BTRFS_I(inode)->ordered_tree;
 312         spin_lock_irqsave(&tree->lock, flags);
 313         node = tree_search(tree, *file_offset);
 314         if (!node) {
 315                 ret = 1;
 316                 goto out;
 317         }
 318
 319         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 320         if (!offset_in_entry(entry, *file_offset)) {
 321                 ret = 1;
 322                 goto out;
 323         }
 324
 325         dec_start = max(*file_offset, entry->file_offset);
 326         dec_end = min(*file_offset + io_size, entry->file_offset +
 327                       entry->len);
 328         *file_offset = dec_end;
 329         if (dec_start > dec_end) {
 330                 btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu",
 331                            dec_start, dec_end);
 332         }
 333         to_dec = dec_end - dec_start;
 334         if (to_dec > entry->bytes_left) {
 335                 btrfs_crit(fs_info,
 336                            "bad ordered accounting left %llu size %llu",
 337                            entry->bytes_left, to_dec);
 338         }
 339         entry->bytes_left -= to_dec;
 340         if (!uptodate)
 341                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 342
 343         if (entry->bytes_left == 0) {
 344                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 345                 /* test_and_set_bit implies a barrier */
 346                 cond_wake_up_nomb(&entry->wait);
 347         } else {
 348                 ret = 1;
 349         }
 350 out:
 351         if (!ret && cached && entry) {
 352                 *cached = entry;
 353                 refcount_inc(&entry->refs);
 354         }
 355         spin_unlock_irqrestore(&tree->lock, flags);
 356         return ret == 0;
 357 }
 358
 359 /*
 360  * this is used to account for finished IO across a given range
 361  * of the file.  The IO should not span ordered extents.  If
 362  * a given ordered_extent is completely done, 1 is returned, otherwise
 363  * 0.
 364  *
 365  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 366  * to make sure this function only returns 1 once for a given ordered extent.
 367  */
 368 int btrfs_dec_test_ordered_pending(struct inode *inode,
 369                                    struct btrfs_ordered_extent **cached,
 370                                    u64 file_offset, u64 io_size, int uptodate)
 371 {
 372         struct btrfs_ordered_inode_tree *tree;
 373         struct rb_node *node;
 374         struct btrfs_ordered_extent *entry = NULL;
 375         unsigned long flags;
 376         int ret;
 377
 378         tree = &BTRFS_I(inode)->ordered_tree;
 379         spin_lock_irqsave(&tree->lock, flags);
 380         if (cached && *cached) {
 381                 entry = *cached;
 382                 goto have_entry;
 383         }
 384
 385         node = tree_search(tree, file_offset);
 386         if (!node) {
 387                 ret = 1;
 388                 goto out;
 389         }
 390
 391         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 392 have_entry:
 393         if (!offset_in_entry(entry, file_offset)) {
 394                 ret = 1;
 395                 goto out;
 396         }
 397
 398         if (io_size > entry->bytes_left) {
 399                 btrfs_crit(BTRFS_I(inode)->root->fs_info,
 400                            "bad ordered accounting left %llu size %llu",
 401                        entry->bytes_left, io_size);
 402         }
 403         entry->bytes_left -= io_size;
 404         if (!uptodate)
 405                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 406
 407         if (entry->bytes_left == 0) {
 408                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 409                 /* test_and_set_bit implies a barrier */
 410                 cond_wake_up_nomb(&entry->wait);
 411         } else {
 412                 ret = 1;
 413         }
 414 out:
 415         if (!ret && cached && entry) {
 416                 *cached = entry;
 417                 refcount_inc(&entry->refs);
 418         }
 419         spin_unlock_irqrestore(&tree->lock, flags);
 420         return ret == 0;
 421 }
 422
 423 /*
 424  * used to drop a reference on an ordered extent.  This will free
 425  * the extent if the last reference is dropped
 426  */
 427 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 428 {
 429         struct list_head *cur;
 430         struct btrfs_ordered_sum *sum;
 431
 432         trace_btrfs_ordered_extent_put(entry->inode, entry);
 433
 434         if (refcount_dec_and_test(&entry->refs)) {
 435                 ASSERT(list_empty(&entry->log_list));
 436                 ASSERT(list_empty(&entry->trans_list));
 437                 ASSERT(list_empty(&entry->root_extent_list));
 438                 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 439                 if (entry->inode)
 440                         btrfs_add_delayed_iput(entry->inode);
 441                 while (!list_empty(&entry->list)) {
 442                         cur = entry->list.next;
 443                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 444                         list_del(&sum->list);
 445                         kfree(sum);
 446                 }
 447                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
 448         }
 449 }
 450
 451 /*
 452  * remove an ordered extent from the tree.  No references are dropped
 453  * and waiters are woken up.
 454  */
 455 void btrfs_remove_ordered_extent(struct inode *inode,
 456                                  struct btrfs_ordered_extent *entry)
 457 {
 458         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 459         struct btrfs_ordered_inode_tree *tree;
 460         struct btrfs_inode *btrfs_inode = BTRFS_I(inode);
 461         struct btrfs_root *root = btrfs_inode->root;
 462         struct rb_node *node;
 463
 464         /* This is paired with btrfs_add_ordered_extent. */
 465         spin_lock(&btrfs_inode->lock);
 466         btrfs_mod_outstanding_extents(btrfs_inode, -1);
 467         spin_unlock(&btrfs_inode->lock);
 468         if (root != fs_info->tree_root)
 469                 btrfs_delalloc_release_metadata(btrfs_inode, entry->len, false);
 470
 471         tree = &btrfs_inode->ordered_tree;
 472         spin_lock_irq(&tree->lock);
 473         node = &entry->rb_node;
 474         rb_erase(node, &tree->tree);
 475         RB_CLEAR_NODE(node);
 476         if (tree->last == node)
 477                 tree->last = NULL;
 478         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 479         spin_unlock_irq(&tree->lock);
 480
 481         spin_lock(&root->ordered_extent_lock);
 482         list_del_init(&entry->root_extent_list);
 483         root->nr_ordered_extents--;
 484
 485         trace_btrfs_ordered_extent_remove(inode, entry);
 486
 487         if (!root->nr_ordered_extents) {
 488                 spin_lock(&fs_info->ordered_root_lock);
 489                 BUG_ON(list_empty(&root->ordered_root));
 490                 list_del_init(&root->ordered_root);
 491                 spin_unlock(&fs_info->ordered_root_lock);
 492         }
 493         spin_unlock(&root->ordered_extent_lock);
 494         wake_up(&entry->wait);
 495 }
 496
 497 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 498 {
 499         struct btrfs_ordered_extent *ordered;
 500
 501         ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 502         btrfs_start_ordered_extent(ordered->inode, ordered, 1);
 503         complete(&ordered->completion);
 504 }
 505
 506 /*
 507  * wait for all the ordered extents in a root.  This is done when balancing
 508  * space between drives.
 509  */
 510 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 511                                const u64 range_start, const u64 range_len)
 512 {
 513         struct btrfs_fs_info *fs_info = root->fs_info;
 514         LIST_HEAD(splice);
 515         LIST_HEAD(skipped);
 516         LIST_HEAD(works);
 517         struct btrfs_ordered_extent *ordered, *next;
 518         u64 count = 0;
 519         const u64 range_end = range_start + range_len;
 520
 521         mutex_lock(&root->ordered_extent_mutex);
 522         spin_lock(&root->ordered_extent_lock);
 523         list_splice_init(&root->ordered_extents, &splice);
 524         while (!list_empty(&splice) && nr) {
 525                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 526                                            root_extent_list);
 527
 528                 if (range_end <= ordered->start ||
 529                     ordered->start + ordered->disk_len <= range_start) {
 530                         list_move_tail(&ordered->root_extent_list, &skipped);
 531                         cond_resched_lock(&root->ordered_extent_lock);
 532                         continue;
 533                 }
 534
 535                 list_move_tail(&ordered->root_extent_list,
 536                                &root->ordered_extents);
 537                 refcount_inc(&ordered->refs);
 538                 spin_unlock(&root->ordered_extent_lock);
 539
 540                 btrfs_init_work(&ordered->flush_work,
 541                                 btrfs_flush_delalloc_helper,
 542                                 btrfs_run_ordered_extent_work, NULL, NULL);
 543                 list_add_tail(&ordered->work_list, &works);
 544                 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 545
 546                 cond_resched();
 547                 spin_lock(&root->ordered_extent_lock);
 548                 if (nr != U64_MAX)
 549                         nr--;
 550                 count++;
 551         }
 552         list_splice_tail(&skipped, &root->ordered_extents);
 553         list_splice_tail(&splice, &root->ordered_extents);
 554         spin_unlock(&root->ordered_extent_lock);
 555
 556         list_for_each_entry_safe(ordered, next, &works, work_list) {
 557                 list_del_init(&ordered->work_list);
 558                 wait_for_completion(&ordered->completion);
 559                 btrfs_put_ordered_extent(ordered);
 560                 cond_resched();
 561         }
 562         mutex_unlock(&root->ordered_extent_mutex);
 563
 564         return count;
 565 }
 566
 567 u64 btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 568                              const u64 range_start, const u64 range_len)
 569 {
 570         struct btrfs_root *root;
 571         struct list_head splice;
 572         u64 total_done = 0;
 573         u64 done;
 574
 575         INIT_LIST_HEAD(&splice);
 576
 577         mutex_lock(&fs_info->ordered_operations_mutex);
 578         spin_lock(&fs_info->ordered_root_lock);
 579         list_splice_init(&fs_info->ordered_roots, &splice);
 580         while (!list_empty(&splice) && nr) {
 581                 root = list_first_entry(&splice, struct btrfs_root,
 582                                         ordered_root);
 583                 root = btrfs_grab_fs_root(root);
 584                 BUG_ON(!root);
 585                 list_move_tail(&root->ordered_root,
 586                                &fs_info->ordered_roots);
 587                 spin_unlock(&fs_info->ordered_root_lock);
 588
 589                 done = btrfs_wait_ordered_extents(root, nr,
 590                                                   range_start, range_len);
 591                 btrfs_put_fs_root(root);
 592                 total_done += done;
 593
 594                 spin_lock(&fs_info->ordered_root_lock);
 595                 if (nr != U64_MAX) {
 596                         nr -= done;
 597                 }
 598         }
 599         list_splice_tail(&splice, &fs_info->ordered_roots);
 600         spin_unlock(&fs_info->ordered_root_lock);
 601         mutex_unlock(&fs_info->ordered_operations_mutex);
 602
 603         return total_done;
 604 }
 605
 606 /*
 607  * Used to start IO or wait for a given ordered extent to finish.
 608  *
 609  * If wait is one, this effectively waits on page writeback for all the pages
 610  * in the extent, and it waits on the io completion code to insert
 611  * metadata into the btree corresponding to the extent
 612  */
 613 void btrfs_start_ordered_extent(struct inode *inode,
 614                                        struct btrfs_ordered_extent *entry,
 615                                        int wait)
 616 {
 617         u64 start = entry->file_offset;
 618         u64 end = start + entry->len - 1;
 619
 620         trace_btrfs_ordered_extent_start(inode, entry);
 621
 622         /*
 623          * pages in the range can be dirty, clean or writeback.  We
 624          * start IO on any dirty ones so the wait doesn't stall waiting
 625          * for the flusher thread to find them
 626          */
 627         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 628                 filemap_fdatawrite_range(inode->i_mapping, start, end);
 629         if (wait) {
 630                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 631                                                  &entry->flags));
 632         }
 633 }
 634
 635 /*
 636  * Used to wait on ordered extents across a large range of bytes.
 637  */
 638 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 639 {
 640         int ret = 0;
 641         int ret_wb = 0;
 642         u64 end;
 643         u64 orig_end;
 644         struct btrfs_ordered_extent *ordered;
 645
 646         if (start + len < start) {
 647                 orig_end = INT_LIMIT(loff_t);
 648         } else {
 649                 orig_end = start + len - 1;
 650                 if (orig_end > INT_LIMIT(loff_t))
 651                         orig_end = INT_LIMIT(loff_t);
 652         }
 653
 654         /* start IO across the range first to instantiate any delalloc
 655          * extents
 656          */
 657         ret = btrfs_fdatawrite_range(inode, start, orig_end);
 658         if (ret)
 659                 return ret;
 660
 661         /*
 662          * If we have a writeback error don't return immediately. Wait first
 663          * for any ordered extents that haven't completed yet. This is to make
 664          * sure no one can dirty the same page ranges and call writepages()
 665          * before the ordered extents complete - to avoid failures (-EEXIST)
 666          * when adding the new ordered extents to the ordered tree.
 667          */
 668         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 669
 670         end = orig_end;
 671         while (1) {
 672                 ordered = btrfs_lookup_first_ordered_extent(inode, end);
 673                 if (!ordered)
 674                         break;
 675                 if (ordered->file_offset > orig_end) {
 676                         btrfs_put_ordered_extent(ordered);
 677                         break;
 678                 }
 679                 if (ordered->file_offset + ordered->len <= start) {
 680                         btrfs_put_ordered_extent(ordered);
 681                         break;
 682                 }
 683                 btrfs_start_ordered_extent(inode, ordered, 1);
 684                 end = ordered->file_offset;
 685                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 686                         ret = -EIO;
 687                 btrfs_put_ordered_extent(ordered);
 688                 if (ret || end == 0 || end == start)
 689                         break;
 690                 end--;
 691         }
 692         return ret_wb ? ret_wb : ret;
 693 }
 694
 695 /*
 696  * find an ordered extent corresponding to file_offset.  return NULL if
 697  * nothing is found, otherwise take a reference on the extent and return it
 698  */
 699 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 700                                                          u64 file_offset)
 701 {
 702         struct btrfs_ordered_inode_tree *tree;
 703         struct rb_node *node;
 704         struct btrfs_ordered_extent *entry = NULL;
 705
 706         tree = &BTRFS_I(inode)->ordered_tree;
 707         spin_lock_irq(&tree->lock);
 708         node = tree_search(tree, file_offset);
 709         if (!node)
 710                 goto out;
 711
 712         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 713         if (!offset_in_entry(entry, file_offset))
 714                 entry = NULL;
 715         if (entry)
 716                 refcount_inc(&entry->refs);
 717 out:
 718         spin_unlock_irq(&tree->lock);
 719         return entry;
 720 }
 721
 722 /* Since the DIO code tries to lock a wide area we need to look for any ordered
 723  * extents that exist in the range, rather than just the start of the range.
 724  */
 725 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 726                 struct btrfs_inode *inode, u64 file_offset, u64 len)
 727 {
 728         struct btrfs_ordered_inode_tree *tree;
 729         struct rb_node *node;
 730         struct btrfs_ordered_extent *entry = NULL;
 731
 732         tree = &inode->ordered_tree;
 733         spin_lock_irq(&tree->lock);
 734         node = tree_search(tree, file_offset);
 735         if (!node) {
 736                 node = tree_search(tree, file_offset + len);
 737                 if (!node)
 738                         goto out;
 739         }
 740
 741         while (1) {
 742                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 743                 if (range_overlaps(entry, file_offset, len))
 744                         break;
 745
 746                 if (entry->file_offset >= file_offset + len) {
 747                         entry = NULL;
 748                         break;
 749                 }
 750                 entry = NULL;
 751                 node = rb_next(node);
 752                 if (!node)
 753                         break;
 754         }
 755 out:
 756         if (entry)
 757                 refcount_inc(&entry->refs);
 758         spin_unlock_irq(&tree->lock);
 759         return entry;
 760 }
 761
 762 /*
 763  * lookup and return any extent before 'file_offset'.  NULL is returned
 764  * if none is found
 765  */
 766 struct btrfs_ordered_extent *
 767 btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
 768 {
 769         struct btrfs_ordered_inode_tree *tree;
 770         struct rb_node *node;
 771         struct btrfs_ordered_extent *entry = NULL;
 772
 773         tree = &BTRFS_I(inode)->ordered_tree;
 774         spin_lock_irq(&tree->lock);
 775         node = tree_search(tree, file_offset);
 776         if (!node)
 777                 goto out;
 778
 779         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 780         refcount_inc(&entry->refs);
 781 out:
 782         spin_unlock_irq(&tree->lock);
 783         return entry;
 784 }
 785
 786 /*
 787  * After an extent is done, call this to conditionally update the on disk
 788  * i_size.  i_size is updated to cover any fully written part of the file.
 789  */
 790 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 791                                 struct btrfs_ordered_extent *ordered)
 792 {
 793         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 794         u64 disk_i_size;
 795         u64 new_i_size;
 796         u64 i_size = i_size_read(inode);
 797         struct rb_node *node;
 798         struct rb_node *prev = NULL;
 799         struct btrfs_ordered_extent *test;
 800         int ret = 1;
 801         u64 orig_offset = offset;
 802
 803         spin_lock_irq(&tree->lock);
 804         if (ordered) {
 805                 offset = entry_end(ordered);
 806                 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
 807                         offset = min(offset,
 808                                      ordered->file_offset +
 809                                      ordered->truncated_len);
 810         } else {
 811                 offset = ALIGN(offset, btrfs_inode_sectorsize(inode));
 812         }
 813         disk_i_size = BTRFS_I(inode)->disk_i_size;
 814
 815         /*
 816          * truncate file.
 817          * If ordered is not NULL, then this is called from endio and
 818          * disk_i_size will be updated by either truncate itself or any
 819          * in-flight IOs which are inside the disk_i_size.
 820          *
 821          * Because btrfs_setsize() may set i_size with disk_i_size if truncate
 822          * fails somehow, we need to make sure we have a precise disk_i_size by
 823          * updating it as usual.
 824          *
 825          */
 826         if (!ordered && disk_i_size > i_size) {
 827                 BTRFS_I(inode)->disk_i_size = orig_offset;
 828                 ret = 0;
 829                 goto out;
 830         }
 831
 832         /*
 833          * if the disk i_size is already at the inode->i_size, or
 834          * this ordered extent is inside the disk i_size, we're done
 835          */
 836         if (disk_i_size == i_size)
 837                 goto out;
 838
 839         /*
 840          * We still need to update disk_i_size if outstanding_isize is greater
 841          * than disk_i_size.
 842          */
 843         if (offset <= disk_i_size &&
 844             (!ordered || ordered->outstanding_isize <= disk_i_size))
 845                 goto out;
 846
 847         /*
 848          * walk backward from this ordered extent to disk_i_size.
 849          * if we find an ordered extent then we can't update disk i_size
 850          * yet
 851          */
 852         if (ordered) {
 853                 node = rb_prev(&ordered->rb_node);
 854         } else {
 855                 prev = tree_search(tree, offset);
 856                 /*
 857                  * we insert file extents without involving ordered struct,
 858                  * so there should be no ordered struct cover this offset
 859                  */
 860                 if (prev) {
 861                         test = rb_entry(prev, struct btrfs_ordered_extent,
 862                                         rb_node);
 863                         BUG_ON(offset_in_entry(test, offset));
 864                 }
 865                 node = prev;
 866         }
 867         for (; node; node = rb_prev(node)) {
 868                 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 869
 870                 /* We treat this entry as if it doesn't exist */
 871                 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
 872                         continue;
 873
 874                 if (entry_end(test) <= disk_i_size)
 875                         break;
 876                 if (test->file_offset >= i_size)
 877                         break;
 878
 879                 /*
 880                  * We don't update disk_i_size now, so record this undealt
 881                  * i_size. Or we will not know the real i_size.
 882                  */
 883                 if (test->outstanding_isize < offset)
 884                         test->outstanding_isize = offset;
 885                 if (ordered &&
 886                     ordered->outstanding_isize > test->outstanding_isize)
 887                         test->outstanding_isize = ordered->outstanding_isize;
 888                 goto out;
 889         }
 890         new_i_size = min_t(u64, offset, i_size);
 891
 892         /*
 893          * Some ordered extents may completed before the current one, and
 894          * we hold the real i_size in ->outstanding_isize.
 895          */
 896         if (ordered && ordered->outstanding_isize > new_i_size)
 897                 new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
 898         BTRFS_I(inode)->disk_i_size = new_i_size;
 899         ret = 0;
 900 out:
 901         /*
 902          * We need to do this because we can't remove ordered extents until
 903          * after the i_disk_size has been updated and then the inode has been
 904          * updated to reflect the change, so we need to tell anybody who finds
 905          * this ordered extent that we've already done all the real work, we
 906          * just haven't completed all the other work.
 907          */
 908         if (ordered)
 909                 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
 910         spin_unlock_irq(&tree->lock);
 911         return ret;
 912 }
 913
 914 /*
 915  * search the ordered extents for one corresponding to 'offset' and
 916  * try to find a checksum.  This is used because we allow pages to
 917  * be reclaimed before their checksum is actually put into the btree
 918  */
 919 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
 920                            u32 *sum, int len)
 921 {
 922         struct btrfs_ordered_sum *ordered_sum;
 923         struct btrfs_ordered_extent *ordered;
 924         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 925         unsigned long num_sectors;
 926         unsigned long i;
 927         u32 sectorsize = btrfs_inode_sectorsize(inode);
 928         int index = 0;
 929
 930         ordered = btrfs_lookup_ordered_extent(inode, offset);
 931         if (!ordered)
 932                 return 0;
 933
 934         spin_lock_irq(&tree->lock);
 935         list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
 936                 if (disk_bytenr >= ordered_sum->bytenr &&
 937                     disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
 938                         i = (disk_bytenr - ordered_sum->bytenr) >>
 939                             inode->i_sb->s_blocksize_bits;
 940                         num_sectors = ordered_sum->len >>
 941                                       inode->i_sb->s_blocksize_bits;
 942                         num_sectors = min_t(int, len - index, num_sectors - i);
 943                         memcpy(sum + index, ordered_sum->sums + i,
 944                                num_sectors);
 945
 946                         index += (int)num_sectors;
 947                         if (index == len)
 948                                 goto out;
 949                         disk_bytenr += num_sectors * sectorsize;
 950                 }
 951         }
 952 out:
 953         spin_unlock_irq(&tree->lock);
 954         btrfs_put_ordered_extent(ordered);
 955         return index;
 956 }
 957
 958 int __init ordered_data_init(void)
 959 {
 960         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
 961                                      sizeof(struct btrfs_ordered_extent), 0,
 962                                      SLAB_MEM_SPREAD,
 963                                      NULL);
 964         if (!btrfs_ordered_extent_cache)
 965                 return -ENOMEM;
 966
 967         return 0;
 968 }
 969
 970 void __cold ordered_data_exit(void)
 971 {
 972         kmem_cache_destroy(btrfs_ordered_extent_cache);
 973 }