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