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 "misc.h"
  11 #include "ctree.h"
  12 #include "transaction.h"
  13 #include "btrfs_inode.h"
  14 #include "extent_io.h"
  15 #include "disk-io.h"
  16 #include "compression.h"
  17 #include "delalloc-space.h"
  18 #include "qgroup.h"
  19
  20 static struct kmem_cache *btrfs_ordered_extent_cache;
  21
  22 static u64 entry_end(struct btrfs_ordered_extent *entry)
  23 {
  24         if (entry->file_offset + entry->num_bytes < entry->file_offset)
  25                 return (u64)-1;
  26         return entry->file_offset + entry->num_bytes;
  27 }
  28
  29 /* returns NULL if the insertion worked, or it returns the node it did find
  30  * in the tree
  31  */
  32 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  33                                    struct rb_node *node)
  34 {
  35         struct rb_node **p = &root->rb_node;
  36         struct rb_node *parent = NULL;
  37         struct btrfs_ordered_extent *entry;
  38
  39         while (*p) {
  40                 parent = *p;
  41                 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  42
  43                 if (file_offset < entry->file_offset)
  44                         p = &(*p)->rb_left;
  45                 else if (file_offset >= entry_end(entry))
  46                         p = &(*p)->rb_right;
  47                 else
  48                         return parent;
  49         }
  50
  51         rb_link_node(node, parent, p);
  52         rb_insert_color(node, root);
  53         return NULL;
  54 }
  55
  56 /*
  57  * look for a given offset in the tree, and if it can't be found return the
  58  * first lesser offset
  59  */
  60 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
  61                                      struct rb_node **prev_ret)
  62 {
  63         struct rb_node *n = root->rb_node;
  64         struct rb_node *prev = NULL;
  65         struct rb_node *test;
  66         struct btrfs_ordered_extent *entry;
  67         struct btrfs_ordered_extent *prev_entry = NULL;
  68
  69         while (n) {
  70                 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
  71                 prev = n;
  72                 prev_entry = entry;
  73
  74                 if (file_offset < entry->file_offset)
  75                         n = n->rb_left;
  76                 else if (file_offset >= entry_end(entry))
  77                         n = n->rb_right;
  78                 else
  79                         return n;
  80         }
  81         if (!prev_ret)
  82                 return NULL;
  83
  84         while (prev && file_offset >= entry_end(prev_entry)) {
  85                 test = rb_next(prev);
  86                 if (!test)
  87                         break;
  88                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
  89                                       rb_node);
  90                 if (file_offset < entry_end(prev_entry))
  91                         break;
  92
  93                 prev = test;
  94         }
  95         if (prev)
  96                 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
  97                                       rb_node);
  98         while (prev && file_offset < entry_end(prev_entry)) {
  99                 test = rb_prev(prev);
 100                 if (!test)
 101                         break;
 102                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 103                                       rb_node);
 104                 prev = test;
 105         }
 106         *prev_ret = prev;
 107         return NULL;
 108 }
 109
 110 /*
 111  * helper to check if a given offset is inside a given entry
 112  */
 113 static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
 114 {
 115         if (file_offset < entry->file_offset ||
 116             entry->file_offset + entry->num_bytes <= file_offset)
 117                 return 0;
 118         return 1;
 119 }
 120
 121 static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
 122                           u64 len)
 123 {
 124         if (file_offset + len <= entry->file_offset ||
 125             entry->file_offset + entry->num_bytes <= file_offset)
 126                 return 0;
 127         return 1;
 128 }
 129
 130 /*
 131  * look find the first ordered struct that has this offset, otherwise
 132  * the first one less than this offset
 133  */
 134 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 135                                           u64 file_offset)
 136 {
 137         struct rb_root *root = &tree->tree;
 138         struct rb_node *prev = NULL;
 139         struct rb_node *ret;
 140         struct btrfs_ordered_extent *entry;
 141
 142         if (tree->last) {
 143                 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
 144                                  rb_node);
 145                 if (offset_in_entry(entry, file_offset))
 146                         return tree->last;
 147         }
 148         ret = __tree_search(root, file_offset, &prev);
 149         if (!ret)
 150                 ret = prev;
 151         if (ret)
 152                 tree->last = ret;
 153         return ret;
 154 }
 155
 156 /*
 157  * Allocate and add a new ordered_extent into the per-inode tree.
 158  *
 159  * The tree is given a single reference on the ordered extent that was
 160  * inserted.
 161  */
 162 static int __btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
 163                                       u64 disk_bytenr, u64 num_bytes,
 164                                       u64 disk_num_bytes, int type, int dio,
 165                                       int compress_type)
 166 {
 167         struct btrfs_root *root = inode->root;
 168         struct btrfs_fs_info *fs_info = root->fs_info;
 169         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 170         struct rb_node *node;
 171         struct btrfs_ordered_extent *entry;
 172         int ret;
 173
 174         if (type == BTRFS_ORDERED_NOCOW || type == BTRFS_ORDERED_PREALLOC) {
 175                 /* For nocow write, we can release the qgroup rsv right now */
 176                 ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
 177                 if (ret < 0)
 178                         return ret;
 179                 ret = 0;
 180         } else {
 181                 /*
 182                  * The ordered extent has reserved qgroup space, release now
 183                  * and pass the reserved number for qgroup_record to free.
 184                  */
 185                 ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
 186                 if (ret < 0)
 187                         return ret;
 188         }
 189         entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 190         if (!entry)
 191                 return -ENOMEM;
 192
 193         entry->file_offset = file_offset;
 194         entry->disk_bytenr = disk_bytenr;
 195         entry->num_bytes = num_bytes;
 196         entry->disk_num_bytes = disk_num_bytes;
 197         entry->bytes_left = num_bytes;
 198         entry->inode = igrab(&inode->vfs_inode);
 199         entry->compress_type = compress_type;
 200         entry->truncated_len = (u64)-1;
 201         entry->qgroup_rsv = ret;
 202         entry->physical = (u64)-1;
 203         entry->disk = NULL;
 204         entry->partno = (u8)-1;
 205
 206         ASSERT(type == BTRFS_ORDERED_REGULAR ||
 207                type == BTRFS_ORDERED_NOCOW ||
 208                type == BTRFS_ORDERED_PREALLOC ||
 209                type == BTRFS_ORDERED_COMPRESSED);
 210         set_bit(type, &entry->flags);
 211
 212         percpu_counter_add_batch(&fs_info->ordered_bytes, num_bytes,
 213                                  fs_info->delalloc_batch);
 214
 215         if (dio)
 216                 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
 217
 218         /* one ref for the tree */
 219         refcount_set(&entry->refs, 1);
 220         init_waitqueue_head(&entry->wait);
 221         INIT_LIST_HEAD(&entry->list);
 222         INIT_LIST_HEAD(&entry->log_list);
 223         INIT_LIST_HEAD(&entry->root_extent_list);
 224         INIT_LIST_HEAD(&entry->work_list);
 225         init_completion(&entry->completion);
 226
 227         trace_btrfs_ordered_extent_add(inode, entry);
 228
 229         spin_lock_irq(&tree->lock);
 230         node = tree_insert(&tree->tree, file_offset,
 231                            &entry->rb_node);
 232         if (node)
 233                 btrfs_panic(fs_info, -EEXIST,
 234                                 "inconsistency in ordered tree at offset %llu",
 235                                 file_offset);
 236         spin_unlock_irq(&tree->lock);
 237
 238         spin_lock(&root->ordered_extent_lock);
 239         list_add_tail(&entry->root_extent_list,
 240                       &root->ordered_extents);
 241         root->nr_ordered_extents++;
 242         if (root->nr_ordered_extents == 1) {
 243                 spin_lock(&fs_info->ordered_root_lock);
 244                 BUG_ON(!list_empty(&root->ordered_root));
 245                 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 246                 spin_unlock(&fs_info->ordered_root_lock);
 247         }
 248         spin_unlock(&root->ordered_extent_lock);
 249
 250         /*
 251          * We don't need the count_max_extents here, we can assume that all of
 252          * that work has been done at higher layers, so this is truly the
 253          * smallest the extent is going to get.
 254          */
 255         spin_lock(&inode->lock);
 256         btrfs_mod_outstanding_extents(inode, 1);
 257         spin_unlock(&inode->lock);
 258
 259         return 0;
 260 }
 261
 262 int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
 263                              u64 disk_bytenr, u64 num_bytes, u64 disk_num_bytes,
 264                              int type)
 265 {
 266         ASSERT(type == BTRFS_ORDERED_REGULAR ||
 267                type == BTRFS_ORDERED_NOCOW ||
 268                type == BTRFS_ORDERED_PREALLOC);
 269         return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
 270                                           num_bytes, disk_num_bytes, type, 0,
 271                                           BTRFS_COMPRESS_NONE);
 272 }
 273
 274 int btrfs_add_ordered_extent_dio(struct btrfs_inode *inode, u64 file_offset,
 275                                  u64 disk_bytenr, u64 num_bytes,
 276                                  u64 disk_num_bytes, int type)
 277 {
 278         ASSERT(type == BTRFS_ORDERED_REGULAR ||
 279                type == BTRFS_ORDERED_NOCOW ||
 280                type == BTRFS_ORDERED_PREALLOC);
 281         return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
 282                                           num_bytes, disk_num_bytes, type, 1,
 283                                           BTRFS_COMPRESS_NONE);
 284 }
 285
 286 int btrfs_add_ordered_extent_compress(struct btrfs_inode *inode, u64 file_offset,
 287                                       u64 disk_bytenr, u64 num_bytes,
 288                                       u64 disk_num_bytes, int compress_type)
 289 {
 290         ASSERT(compress_type != BTRFS_COMPRESS_NONE);
 291         return __btrfs_add_ordered_extent(inode, file_offset, disk_bytenr,
 292                                           num_bytes, disk_num_bytes,
 293                                           BTRFS_ORDERED_COMPRESSED, 0,
 294                                           compress_type);
 295 }
 296
 297 /*
 298  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 299  * when an ordered extent is finished.  If the list covers more than one
 300  * ordered extent, it is split across multiples.
 301  */
 302 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 303                            struct btrfs_ordered_sum *sum)
 304 {
 305         struct btrfs_ordered_inode_tree *tree;
 306
 307         tree = &BTRFS_I(entry->inode)->ordered_tree;
 308         spin_lock_irq(&tree->lock);
 309         list_add_tail(&sum->list, &entry->list);
 310         spin_unlock_irq(&tree->lock);
 311 }
 312
 313 /*
 314  * Finish IO for one ordered extent across a given range.  The range can
 315  * contain several ordered extents.
 316  *
 317  * @found_ret:   Return the finished ordered extent
 318  * @file_offset: File offset for the finished IO
 319  *               Will also be updated to one byte past the range that is
 320  *               recordered as finished. This allows caller to walk forward.
 321  * @io_size:     Length of the finish IO range
 322  * @uptodate:    If the IO finished without problem
 323  *
 324  * Return true if any ordered extent is finished in the range, and update
 325  * @found_ret and @file_offset.
 326  * Return false otherwise.
 327  *
 328  * NOTE: Although The range can cross multiple ordered extents, only one
 329  * ordered extent will be updated during one call. The caller is responsible to
 330  * iterate all ordered extents in the range.
 331  */
 332 bool btrfs_dec_test_first_ordered_pending(struct btrfs_inode *inode,
 333                                    struct btrfs_ordered_extent **finished_ret,
 334                                    u64 *file_offset, u64 io_size, int uptodate)
 335 {
 336         struct btrfs_fs_info *fs_info = inode->root->fs_info;
 337         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 338         struct rb_node *node;
 339         struct btrfs_ordered_extent *entry = NULL;
 340         bool finished = false;
 341         unsigned long flags;
 342         u64 dec_end;
 343         u64 dec_start;
 344         u64 to_dec;
 345
 346         spin_lock_irqsave(&tree->lock, flags);
 347         node = tree_search(tree, *file_offset);
 348         if (!node)
 349                 goto out;
 350
 351         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 352         if (!offset_in_entry(entry, *file_offset))
 353                 goto out;
 354
 355         dec_start = max(*file_offset, entry->file_offset);
 356         dec_end = min(*file_offset + io_size,
 357                       entry->file_offset + entry->num_bytes);
 358         *file_offset = dec_end;
 359         if (dec_start > dec_end) {
 360                 btrfs_crit(fs_info, "bad ordering dec_start %llu end %llu",
 361                            dec_start, dec_end);
 362         }
 363         to_dec = dec_end - dec_start;
 364         if (to_dec > entry->bytes_left) {
 365                 btrfs_crit(fs_info,
 366                            "bad ordered accounting left %llu size %llu",
 367                            entry->bytes_left, to_dec);
 368         }
 369         entry->bytes_left -= to_dec;
 370         if (!uptodate)
 371                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 372
 373         if (entry->bytes_left == 0) {
 374                 /*
 375                  * Ensure only one caller can set the flag and finished_ret
 376                  * accordingly
 377                  */
 378                 finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 379                 /* test_and_set_bit implies a barrier */
 380                 cond_wake_up_nomb(&entry->wait);
 381         }
 382 out:
 383         if (finished && finished_ret && entry) {
 384                 *finished_ret = entry;
 385                 refcount_inc(&entry->refs);
 386         }
 387         spin_unlock_irqrestore(&tree->lock, flags);
 388         return finished;
 389 }
 390
 391 /*
 392  * Finish IO for one ordered extent across a given range.  The range can only
 393  * contain one ordered extent.
 394  *
 395  * @cached:      The cached ordered extent. If not NULL, we can skip the tree
 396  *               search and use the ordered extent directly.
 397  *               Will be also used to store the finished ordered extent.
 398  * @file_offset: File offset for the finished IO
 399  * @io_size:     Length of the finish IO range
 400  * @uptodate:    If the IO finishes without problem
 401  *
 402  * Return true if the ordered extent is finished in the range, and update
 403  * @cached.
 404  * Return false otherwise.
 405  *
 406  * NOTE: The range can NOT cross multiple ordered extents.
 407  * Thus caller should ensure the range doesn't cross ordered extents.
 408  */
 409 bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 410                                     struct btrfs_ordered_extent **cached,
 411                                     u64 file_offset, u64 io_size, int uptodate)
 412 {
 413         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 414         struct rb_node *node;
 415         struct btrfs_ordered_extent *entry = NULL;
 416         unsigned long flags;
 417         bool finished = false;
 418
 419         spin_lock_irqsave(&tree->lock, flags);
 420         if (cached && *cached) {
 421                 entry = *cached;
 422                 goto have_entry;
 423         }
 424
 425         node = tree_search(tree, file_offset);
 426         if (!node)
 427                 goto out;
 428
 429         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 430 have_entry:
 431         if (!offset_in_entry(entry, file_offset))
 432                 goto out;
 433
 434         if (io_size > entry->bytes_left)
 435                 btrfs_crit(inode->root->fs_info,
 436                            "bad ordered accounting left %llu size %llu",
 437                        entry->bytes_left, io_size);
 438
 439         entry->bytes_left -= io_size;
 440         if (!uptodate)
 441                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 442
 443         if (entry->bytes_left == 0) {
 444                 /*
 445                  * Ensure only one caller can set the flag and finished_ret
 446                  * accordingly
 447                  */
 448                 finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 449                 /* test_and_set_bit implies a barrier */
 450                 cond_wake_up_nomb(&entry->wait);
 451         }
 452 out:
 453         if (finished && cached && entry) {
 454                 *cached = entry;
 455                 refcount_inc(&entry->refs);
 456         }
 457         spin_unlock_irqrestore(&tree->lock, flags);
 458         return finished;
 459 }
 460
 461 /*
 462  * used to drop a reference on an ordered extent.  This will free
 463  * the extent if the last reference is dropped
 464  */
 465 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 466 {
 467         struct list_head *cur;
 468         struct btrfs_ordered_sum *sum;
 469
 470         trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
 471
 472         if (refcount_dec_and_test(&entry->refs)) {
 473                 ASSERT(list_empty(&entry->root_extent_list));
 474                 ASSERT(list_empty(&entry->log_list));
 475                 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 476                 if (entry->inode)
 477                         btrfs_add_delayed_iput(entry->inode);
 478                 while (!list_empty(&entry->list)) {
 479                         cur = entry->list.next;
 480                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 481                         list_del(&sum->list);
 482                         kvfree(sum);
 483                 }
 484                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
 485         }
 486 }
 487
 488 /*
 489  * remove an ordered extent from the tree.  No references are dropped
 490  * and waiters are woken up.
 491  */
 492 void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 493                                  struct btrfs_ordered_extent *entry)
 494 {
 495         struct btrfs_ordered_inode_tree *tree;
 496         struct btrfs_root *root = btrfs_inode->root;
 497         struct btrfs_fs_info *fs_info = root->fs_info;
 498         struct rb_node *node;
 499         bool pending;
 500
 501         /* This is paired with btrfs_add_ordered_extent. */
 502         spin_lock(&btrfs_inode->lock);
 503         btrfs_mod_outstanding_extents(btrfs_inode, -1);
 504         spin_unlock(&btrfs_inode->lock);
 505         if (root != fs_info->tree_root)
 506                 btrfs_delalloc_release_metadata(btrfs_inode, entry->num_bytes,
 507                                                 false);
 508
 509         percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 510                                  fs_info->delalloc_batch);
 511
 512         tree = &btrfs_inode->ordered_tree;
 513         spin_lock_irq(&tree->lock);
 514         node = &entry->rb_node;
 515         rb_erase(node, &tree->tree);
 516         RB_CLEAR_NODE(node);
 517         if (tree->last == node)
 518                 tree->last = NULL;
 519         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 520         pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
 521         spin_unlock_irq(&tree->lock);
 522
 523         /*
 524          * The current running transaction is waiting on us, we need to let it
 525          * know that we're complete and wake it up.
 526          */
 527         if (pending) {
 528                 struct btrfs_transaction *trans;
 529
 530                 /*
 531                  * The checks for trans are just a formality, it should be set,
 532                  * but if it isn't we don't want to deref/assert under the spin
 533                  * lock, so be nice and check if trans is set, but ASSERT() so
 534                  * if it isn't set a developer will notice.
 535                  */
 536                 spin_lock(&fs_info->trans_lock);
 537                 trans = fs_info->running_transaction;
 538                 if (trans)
 539                         refcount_inc(&trans->use_count);
 540                 spin_unlock(&fs_info->trans_lock);
 541
 542                 ASSERT(trans);
 543                 if (trans) {
 544                         if (atomic_dec_and_test(&trans->pending_ordered))
 545                                 wake_up(&trans->pending_wait);
 546                         btrfs_put_transaction(trans);
 547                 }
 548         }
 549
 550         spin_lock(&root->ordered_extent_lock);
 551         list_del_init(&entry->root_extent_list);
 552         root->nr_ordered_extents--;
 553
 554         trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
 555
 556         if (!root->nr_ordered_extents) {
 557                 spin_lock(&fs_info->ordered_root_lock);
 558                 BUG_ON(list_empty(&root->ordered_root));
 559                 list_del_init(&root->ordered_root);
 560                 spin_unlock(&fs_info->ordered_root_lock);
 561         }
 562         spin_unlock(&root->ordered_extent_lock);
 563         wake_up(&entry->wait);
 564 }
 565
 566 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 567 {
 568         struct btrfs_ordered_extent *ordered;
 569
 570         ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 571         btrfs_start_ordered_extent(ordered, 1);
 572         complete(&ordered->completion);
 573 }
 574
 575 /*
 576  * wait for all the ordered extents in a root.  This is done when balancing
 577  * space between drives.
 578  */
 579 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 580                                const u64 range_start, const u64 range_len)
 581 {
 582         struct btrfs_fs_info *fs_info = root->fs_info;
 583         LIST_HEAD(splice);
 584         LIST_HEAD(skipped);
 585         LIST_HEAD(works);
 586         struct btrfs_ordered_extent *ordered, *next;
 587         u64 count = 0;
 588         const u64 range_end = range_start + range_len;
 589
 590         mutex_lock(&root->ordered_extent_mutex);
 591         spin_lock(&root->ordered_extent_lock);
 592         list_splice_init(&root->ordered_extents, &splice);
 593         while (!list_empty(&splice) && nr) {
 594                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 595                                            root_extent_list);
 596
 597                 if (range_end <= ordered->disk_bytenr ||
 598                     ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
 599                         list_move_tail(&ordered->root_extent_list, &skipped);
 600                         cond_resched_lock(&root->ordered_extent_lock);
 601                         continue;
 602                 }
 603
 604                 list_move_tail(&ordered->root_extent_list,
 605                                &root->ordered_extents);
 606                 refcount_inc(&ordered->refs);
 607                 spin_unlock(&root->ordered_extent_lock);
 608
 609                 btrfs_init_work(&ordered->flush_work,
 610                                 btrfs_run_ordered_extent_work, NULL, NULL);
 611                 list_add_tail(&ordered->work_list, &works);
 612                 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 613
 614                 cond_resched();
 615                 spin_lock(&root->ordered_extent_lock);
 616                 if (nr != U64_MAX)
 617                         nr--;
 618                 count++;
 619         }
 620         list_splice_tail(&skipped, &root->ordered_extents);
 621         list_splice_tail(&splice, &root->ordered_extents);
 622         spin_unlock(&root->ordered_extent_lock);
 623
 624         list_for_each_entry_safe(ordered, next, &works, work_list) {
 625                 list_del_init(&ordered->work_list);
 626                 wait_for_completion(&ordered->completion);
 627                 btrfs_put_ordered_extent(ordered);
 628                 cond_resched();
 629         }
 630         mutex_unlock(&root->ordered_extent_mutex);
 631
 632         return count;
 633 }
 634
 635 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 636                              const u64 range_start, const u64 range_len)
 637 {
 638         struct btrfs_root *root;
 639         struct list_head splice;
 640         u64 done;
 641
 642         INIT_LIST_HEAD(&splice);
 643
 644         mutex_lock(&fs_info->ordered_operations_mutex);
 645         spin_lock(&fs_info->ordered_root_lock);
 646         list_splice_init(&fs_info->ordered_roots, &splice);
 647         while (!list_empty(&splice) && nr) {
 648                 root = list_first_entry(&splice, struct btrfs_root,
 649                                         ordered_root);
 650                 root = btrfs_grab_root(root);
 651                 BUG_ON(!root);
 652                 list_move_tail(&root->ordered_root,
 653                                &fs_info->ordered_roots);
 654                 spin_unlock(&fs_info->ordered_root_lock);
 655
 656                 done = btrfs_wait_ordered_extents(root, nr,
 657                                                   range_start, range_len);
 658                 btrfs_put_root(root);
 659
 660                 spin_lock(&fs_info->ordered_root_lock);
 661                 if (nr != U64_MAX) {
 662                         nr -= done;
 663                 }
 664         }
 665         list_splice_tail(&splice, &fs_info->ordered_roots);
 666         spin_unlock(&fs_info->ordered_root_lock);
 667         mutex_unlock(&fs_info->ordered_operations_mutex);
 668 }
 669
 670 /*
 671  * Used to start IO or wait for a given ordered extent to finish.
 672  *
 673  * If wait is one, this effectively waits on page writeback for all the pages
 674  * in the extent, and it waits on the io completion code to insert
 675  * metadata into the btree corresponding to the extent
 676  */
 677 void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry, int wait)
 678 {
 679         u64 start = entry->file_offset;
 680         u64 end = start + entry->num_bytes - 1;
 681         struct btrfs_inode *inode = BTRFS_I(entry->inode);
 682
 683         trace_btrfs_ordered_extent_start(inode, entry);
 684
 685         /*
 686          * pages in the range can be dirty, clean or writeback.  We
 687          * start IO on any dirty ones so the wait doesn't stall waiting
 688          * for the flusher thread to find them
 689          */
 690         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 691                 filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
 692         if (wait) {
 693                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 694                                                  &entry->flags));
 695         }
 696 }
 697
 698 /*
 699  * Used to wait on ordered extents across a large range of bytes.
 700  */
 701 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 702 {
 703         int ret = 0;
 704         int ret_wb = 0;
 705         u64 end;
 706         u64 orig_end;
 707         struct btrfs_ordered_extent *ordered;
 708
 709         if (start + len < start) {
 710                 orig_end = INT_LIMIT(loff_t);
 711         } else {
 712                 orig_end = start + len - 1;
 713                 if (orig_end > INT_LIMIT(loff_t))
 714                         orig_end = INT_LIMIT(loff_t);
 715         }
 716
 717         /* start IO across the range first to instantiate any delalloc
 718          * extents
 719          */
 720         ret = btrfs_fdatawrite_range(inode, start, orig_end);
 721         if (ret)
 722                 return ret;
 723
 724         /*
 725          * If we have a writeback error don't return immediately. Wait first
 726          * for any ordered extents that haven't completed yet. This is to make
 727          * sure no one can dirty the same page ranges and call writepages()
 728          * before the ordered extents complete - to avoid failures (-EEXIST)
 729          * when adding the new ordered extents to the ordered tree.
 730          */
 731         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 732
 733         end = orig_end;
 734         while (1) {
 735                 ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
 736                 if (!ordered)
 737                         break;
 738                 if (ordered->file_offset > orig_end) {
 739                         btrfs_put_ordered_extent(ordered);
 740                         break;
 741                 }
 742                 if (ordered->file_offset + ordered->num_bytes <= start) {
 743                         btrfs_put_ordered_extent(ordered);
 744                         break;
 745                 }
 746                 btrfs_start_ordered_extent(ordered, 1);
 747                 end = ordered->file_offset;
 748                 /*
 749                  * If the ordered extent had an error save the error but don't
 750                  * exit without waiting first for all other ordered extents in
 751                  * the range to complete.
 752                  */
 753                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 754                         ret = -EIO;
 755                 btrfs_put_ordered_extent(ordered);
 756                 if (end == 0 || end == start)
 757                         break;
 758                 end--;
 759         }
 760         return ret_wb ? ret_wb : ret;
 761 }
 762
 763 /*
 764  * find an ordered extent corresponding to file_offset.  return NULL if
 765  * nothing is found, otherwise take a reference on the extent and return it
 766  */
 767 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
 768                                                          u64 file_offset)
 769 {
 770         struct btrfs_ordered_inode_tree *tree;
 771         struct rb_node *node;
 772         struct btrfs_ordered_extent *entry = NULL;
 773         unsigned long flags;
 774
 775         tree = &inode->ordered_tree;
 776         spin_lock_irqsave(&tree->lock, flags);
 777         node = tree_search(tree, file_offset);
 778         if (!node)
 779                 goto out;
 780
 781         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 782         if (!offset_in_entry(entry, file_offset))
 783                 entry = NULL;
 784         if (entry)
 785                 refcount_inc(&entry->refs);
 786 out:
 787         spin_unlock_irqrestore(&tree->lock, flags);
 788         return entry;
 789 }
 790
 791 /* Since the DIO code tries to lock a wide area we need to look for any ordered
 792  * extents that exist in the range, rather than just the start of the range.
 793  */
 794 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 795                 struct btrfs_inode *inode, u64 file_offset, u64 len)
 796 {
 797         struct btrfs_ordered_inode_tree *tree;
 798         struct rb_node *node;
 799         struct btrfs_ordered_extent *entry = NULL;
 800
 801         tree = &inode->ordered_tree;
 802         spin_lock_irq(&tree->lock);
 803         node = tree_search(tree, file_offset);
 804         if (!node) {
 805                 node = tree_search(tree, file_offset + len);
 806                 if (!node)
 807                         goto out;
 808         }
 809
 810         while (1) {
 811                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 812                 if (range_overlaps(entry, file_offset, len))
 813                         break;
 814
 815                 if (entry->file_offset >= file_offset + len) {
 816                         entry = NULL;
 817                         break;
 818                 }
 819                 entry = NULL;
 820                 node = rb_next(node);
 821                 if (!node)
 822                         break;
 823         }
 824 out:
 825         if (entry)
 826                 refcount_inc(&entry->refs);
 827         spin_unlock_irq(&tree->lock);
 828         return entry;
 829 }
 830
 831 /*
 832  * Adds all ordered extents to the given list. The list ends up sorted by the
 833  * file_offset of the ordered extents.
 834  */
 835 void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
 836                                            struct list_head *list)
 837 {
 838         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 839         struct rb_node *n;
 840
 841         ASSERT(inode_is_locked(&inode->vfs_inode));
 842
 843         spin_lock_irq(&tree->lock);
 844         for (n = rb_first(&tree->tree); n; n = rb_next(n)) {
 845                 struct btrfs_ordered_extent *ordered;
 846
 847                 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 848
 849                 if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 850                         continue;
 851
 852                 ASSERT(list_empty(&ordered->log_list));
 853                 list_add_tail(&ordered->log_list, list);
 854                 refcount_inc(&ordered->refs);
 855         }
 856         spin_unlock_irq(&tree->lock);
 857 }
 858
 859 /*
 860  * lookup and return any extent before 'file_offset'.  NULL is returned
 861  * if none is found
 862  */
 863 struct btrfs_ordered_extent *
 864 btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
 865 {
 866         struct btrfs_ordered_inode_tree *tree;
 867         struct rb_node *node;
 868         struct btrfs_ordered_extent *entry = NULL;
 869
 870         tree = &inode->ordered_tree;
 871         spin_lock_irq(&tree->lock);
 872         node = tree_search(tree, file_offset);
 873         if (!node)
 874                 goto out;
 875
 876         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 877         refcount_inc(&entry->refs);
 878 out:
 879         spin_unlock_irq(&tree->lock);
 880         return entry;
 881 }
 882
 883 /*
 884  * btrfs_flush_ordered_range - Lock the passed range and ensures all pending
 885  * ordered extents in it are run to completion.
 886  *
 887  * @inode:        Inode whose ordered tree is to be searched
 888  * @start:        Beginning of range to flush
 889  * @end:          Last byte of range to lock
 890  * @cached_state: If passed, will return the extent state responsible for the
 891  * locked range. It's the caller's responsibility to free the cached state.
 892  *
 893  * This function always returns with the given range locked, ensuring after it's
 894  * called no order extent can be pending.
 895  */
 896 void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
 897                                         u64 end,
 898                                         struct extent_state **cached_state)
 899 {
 900         struct btrfs_ordered_extent *ordered;
 901         struct extent_state *cache = NULL;
 902         struct extent_state **cachedp = &cache;
 903
 904         if (cached_state)
 905                 cachedp = cached_state;
 906
 907         while (1) {
 908                 lock_extent_bits(&inode->io_tree, start, end, cachedp);
 909                 ordered = btrfs_lookup_ordered_range(inode, start,
 910                                                      end - start + 1);
 911                 if (!ordered) {
 912                         /*
 913                          * If no external cached_state has been passed then
 914                          * decrement the extra ref taken for cachedp since we
 915                          * aren't exposing it outside of this function
 916                          */
 917                         if (!cached_state)
 918                                 refcount_dec(&cache->refs);
 919                         break;
 920                 }
 921                 unlock_extent_cached(&inode->io_tree, start, end, cachedp);
 922                 btrfs_start_ordered_extent(ordered, 1);
 923                 btrfs_put_ordered_extent(ordered);
 924         }
 925 }
 926
 927 static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
 928                                 u64 len)
 929 {
 930         struct inode *inode = ordered->inode;
 931         u64 file_offset = ordered->file_offset + pos;
 932         u64 disk_bytenr = ordered->disk_bytenr + pos;
 933         u64 num_bytes = len;
 934         u64 disk_num_bytes = len;
 935         int type;
 936         unsigned long flags_masked = ordered->flags & ~(1 << BTRFS_ORDERED_DIRECT);
 937         int compress_type = ordered->compress_type;
 938         unsigned long weight;
 939         int ret;
 940
 941         weight = hweight_long(flags_masked);
 942         WARN_ON_ONCE(weight > 1);
 943         if (!weight)
 944                 type = 0;
 945         else
 946                 type = __ffs(flags_masked);
 947
 948         if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered->flags)) {
 949                 WARN_ON_ONCE(1);
 950                 ret = btrfs_add_ordered_extent_compress(BTRFS_I(inode),
 951                                 file_offset, disk_bytenr, num_bytes,
 952                                 disk_num_bytes, compress_type);
 953         } else if (test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
 954                 ret = btrfs_add_ordered_extent_dio(BTRFS_I(inode), file_offset,
 955                                 disk_bytenr, num_bytes, disk_num_bytes, type);
 956         } else {
 957                 ret = btrfs_add_ordered_extent(BTRFS_I(inode), file_offset,
 958                                 disk_bytenr, num_bytes, disk_num_bytes, type);
 959         }
 960
 961         return ret;
 962 }
 963
 964 int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
 965                                 u64 post)
 966 {
 967         struct inode *inode = ordered->inode;
 968         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 969         struct rb_node *node;
 970         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 971         int ret = 0;
 972
 973         spin_lock_irq(&tree->lock);
 974         /* Remove from tree once */
 975         node = &ordered->rb_node;
 976         rb_erase(node, &tree->tree);
 977         RB_CLEAR_NODE(node);
 978         if (tree->last == node)
 979                 tree->last = NULL;
 980
 981         ordered->file_offset += pre;
 982         ordered->disk_bytenr += pre;
 983         ordered->num_bytes -= (pre + post);
 984         ordered->disk_num_bytes -= (pre + post);
 985         ordered->bytes_left -= (pre + post);
 986
 987         /* Re-insert the node */
 988         node = tree_insert(&tree->tree, ordered->file_offset, &ordered->rb_node);
 989         if (node)
 990                 btrfs_panic(fs_info, -EEXIST,
 991                         "zoned: inconsistency in ordered tree at offset %llu",
 992                             ordered->file_offset);
 993
 994         spin_unlock_irq(&tree->lock);
 995
 996         if (pre)
 997                 ret = clone_ordered_extent(ordered, 0, pre);
 998         if (post)
 999                 ret = clone_ordered_extent(ordered, pre + ordered->disk_num_bytes,
1000                                            post);
1001
1002         return ret;
1003 }
1004
1005 int __init ordered_data_init(void)
1006 {
1007         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1008                                      sizeof(struct btrfs_ordered_extent), 0,
1009                                      SLAB_MEM_SPREAD,
1010                                      NULL);
1011         if (!btrfs_ordered_extent_cache)
1012                 return -ENOMEM;
1013
1014         return 0;
1015 }
1016
1017 void __cold ordered_data_exit(void)
1018 {
1019         kmem_cache_destroy(btrfs_ordered_extent_cache);
1020 }