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 #include "subpage.h"
  20
  21 static struct kmem_cache *btrfs_ordered_extent_cache;
  22
  23 static u64 entry_end(struct btrfs_ordered_extent *entry)
  24 {
  25         if (entry->file_offset + entry->num_bytes < entry->file_offset)
  26                 return (u64)-1;
  27         return entry->file_offset + entry->num_bytes;
  28 }
  29
  30 /* returns NULL if the insertion worked, or it returns the node it did find
  31  * in the tree
  32  */
  33 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  34                                    struct rb_node *node)
  35 {
  36         struct rb_node **p = &root->rb_node;
  37         struct rb_node *parent = NULL;
  38         struct btrfs_ordered_extent *entry;
  39
  40         while (*p) {
  41                 parent = *p;
  42                 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  43
  44                 if (file_offset < entry->file_offset)
  45                         p = &(*p)->rb_left;
  46                 else if (file_offset >= entry_end(entry))
  47                         p = &(*p)->rb_right;
  48                 else
  49                         return parent;
  50         }
  51
  52         rb_link_node(node, parent, p);
  53         rb_insert_color(node, root);
  54         return NULL;
  55 }
  56
  57 /*
  58  * look for a given offset in the tree, and if it can't be found return the
  59  * first lesser offset
  60  */
  61 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
  62                                      struct rb_node **prev_ret)
  63 {
  64         struct rb_node *n = root->rb_node;
  65         struct rb_node *prev = NULL;
  66         struct rb_node *test;
  67         struct btrfs_ordered_extent *entry;
  68         struct btrfs_ordered_extent *prev_entry = NULL;
  69
  70         while (n) {
  71                 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
  72                 prev = n;
  73                 prev_entry = entry;
  74
  75                 if (file_offset < entry->file_offset)
  76                         n = n->rb_left;
  77                 else if (file_offset >= entry_end(entry))
  78                         n = n->rb_right;
  79                 else
  80                         return n;
  81         }
  82         if (!prev_ret)
  83                 return NULL;
  84
  85         while (prev && file_offset >= entry_end(prev_entry)) {
  86                 test = rb_next(prev);
  87                 if (!test)
  88                         break;
  89                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
  90                                       rb_node);
  91                 if (file_offset < entry_end(prev_entry))
  92                         break;
  93
  94                 prev = test;
  95         }
  96         if (prev)
  97                 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
  98                                       rb_node);
  99         while (prev && file_offset < entry_end(prev_entry)) {
 100                 test = rb_prev(prev);
 101                 if (!test)
 102                         break;
 103                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 104                                       rb_node);
 105                 prev = test;
 106         }
 107         *prev_ret = prev;
 108         return NULL;
 109 }
 110
 111 static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
 112                           u64 len)
 113 {
 114         if (file_offset + len <= entry->file_offset ||
 115             entry->file_offset + entry->num_bytes <= file_offset)
 116                 return 0;
 117         return 1;
 118 }
 119
 120 /*
 121  * look find the first ordered struct that has this offset, otherwise
 122  * the first one less than this offset
 123  */
 124 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 125                                           u64 file_offset)
 126 {
 127         struct rb_root *root = &tree->tree;
 128         struct rb_node *prev = NULL;
 129         struct rb_node *ret;
 130         struct btrfs_ordered_extent *entry;
 131
 132         if (tree->last) {
 133                 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
 134                                  rb_node);
 135                 if (in_range(file_offset, entry->file_offset, entry->num_bytes))
 136                         return tree->last;
 137         }
 138         ret = __tree_search(root, file_offset, &prev);
 139         if (!ret)
 140                 ret = prev;
 141         if (ret)
 142                 tree->last = ret;
 143         return ret;
 144 }
 145
 146 /**
 147  * Add an ordered extent to the per-inode tree.
 148  *
 149  * @inode:           Inode that this extent is for.
 150  * @file_offset:     Logical offset in file where the extent starts.
 151  * @num_bytes:       Logical length of extent in file.
 152  * @ram_bytes:       Full length of unencoded data.
 153  * @disk_bytenr:     Offset of extent on disk.
 154  * @disk_num_bytes:  Size of extent on disk.
 155  * @offset:          Offset into unencoded data where file data starts.
 156  * @flags:           Flags specifying type of extent (1 << BTRFS_ORDERED_*).
 157  * @compress_type:   Compression algorithm used for data.
 158  *
 159  * Most of these parameters correspond to &struct btrfs_file_extent_item. The
 160  * tree is given a single reference on the ordered extent that was inserted.
 161  *
 162  * Return: 0 or -ENOMEM.
 163  */
 164 int btrfs_add_ordered_extent(struct btrfs_inode *inode, u64 file_offset,
 165                              u64 num_bytes, u64 ram_bytes, u64 disk_bytenr,
 166                              u64 disk_num_bytes, u64 offset, unsigned flags,
 167                              int compress_type)
 168 {
 169         struct btrfs_root *root = inode->root;
 170         struct btrfs_fs_info *fs_info = root->fs_info;
 171         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 172         struct rb_node *node;
 173         struct btrfs_ordered_extent *entry;
 174         int ret;
 175
 176         if (flags &
 177             ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
 178                 /* For nocow write, we can release the qgroup rsv right now */
 179                 ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes);
 180                 if (ret < 0)
 181                         return ret;
 182                 ret = 0;
 183         } else {
 184                 /*
 185                  * The ordered extent has reserved qgroup space, release now
 186                  * and pass the reserved number for qgroup_record to free.
 187                  */
 188                 ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes);
 189                 if (ret < 0)
 190                         return ret;
 191         }
 192         entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 193         if (!entry)
 194                 return -ENOMEM;
 195
 196         entry->file_offset = file_offset;
 197         entry->num_bytes = num_bytes;
 198         entry->ram_bytes = ram_bytes;
 199         entry->disk_bytenr = disk_bytenr;
 200         entry->disk_num_bytes = disk_num_bytes;
 201         entry->offset = offset;
 202         entry->bytes_left = num_bytes;
 203         entry->inode = igrab(&inode->vfs_inode);
 204         entry->compress_type = compress_type;
 205         entry->truncated_len = (u64)-1;
 206         entry->qgroup_rsv = ret;
 207         entry->physical = (u64)-1;
 208
 209         ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
 210         entry->flags = flags;
 211
 212         percpu_counter_add_batch(&fs_info->ordered_bytes, num_bytes,
 213                                  fs_info->delalloc_batch);
 214
 215         /* one ref for the tree */
 216         refcount_set(&entry->refs, 1);
 217         init_waitqueue_head(&entry->wait);
 218         INIT_LIST_HEAD(&entry->list);
 219         INIT_LIST_HEAD(&entry->log_list);
 220         INIT_LIST_HEAD(&entry->root_extent_list);
 221         INIT_LIST_HEAD(&entry->work_list);
 222         init_completion(&entry->completion);
 223
 224         trace_btrfs_ordered_extent_add(inode, entry);
 225
 226         spin_lock_irq(&tree->lock);
 227         node = tree_insert(&tree->tree, file_offset,
 228                            &entry->rb_node);
 229         if (node)
 230                 btrfs_panic(fs_info, -EEXIST,
 231                                 "inconsistency in ordered tree at offset %llu",
 232                                 file_offset);
 233         spin_unlock_irq(&tree->lock);
 234
 235         spin_lock(&root->ordered_extent_lock);
 236         list_add_tail(&entry->root_extent_list,
 237                       &root->ordered_extents);
 238         root->nr_ordered_extents++;
 239         if (root->nr_ordered_extents == 1) {
 240                 spin_lock(&fs_info->ordered_root_lock);
 241                 BUG_ON(!list_empty(&root->ordered_root));
 242                 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 243                 spin_unlock(&fs_info->ordered_root_lock);
 244         }
 245         spin_unlock(&root->ordered_extent_lock);
 246
 247         /*
 248          * We don't need the count_max_extents here, we can assume that all of
 249          * that work has been done at higher layers, so this is truly the
 250          * smallest the extent is going to get.
 251          */
 252         spin_lock(&inode->lock);
 253         btrfs_mod_outstanding_extents(inode, 1);
 254         spin_unlock(&inode->lock);
 255
 256         return 0;
 257 }
 258
 259 /*
 260  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 261  * when an ordered extent is finished.  If the list covers more than one
 262  * ordered extent, it is split across multiples.
 263  */
 264 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 265                            struct btrfs_ordered_sum *sum)
 266 {
 267         struct btrfs_ordered_inode_tree *tree;
 268
 269         tree = &BTRFS_I(entry->inode)->ordered_tree;
 270         spin_lock_irq(&tree->lock);
 271         list_add_tail(&sum->list, &entry->list);
 272         spin_unlock_irq(&tree->lock);
 273 }
 274
 275 /*
 276  * Mark all ordered extents io inside the specified range finished.
 277  *
 278  * @page:        The invovled page for the opeartion.
 279  *               For uncompressed buffered IO, the page status also needs to be
 280  *               updated to indicate whether the pending ordered io is finished.
 281  *               Can be NULL for direct IO and compressed write.
 282  *               For these cases, callers are ensured they won't execute the
 283  *               endio function twice.
 284  * @finish_func: The function to be executed when all the IO of an ordered
 285  *               extent are finished.
 286  *
 287  * This function is called for endio, thus the range must have ordered
 288  * extent(s) coveri it.
 289  */
 290 void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
 291                                 struct page *page, u64 file_offset,
 292                                 u64 num_bytes, btrfs_func_t finish_func,
 293                                 bool uptodate)
 294 {
 295         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 296         struct btrfs_fs_info *fs_info = inode->root->fs_info;
 297         struct btrfs_workqueue *wq;
 298         struct rb_node *node;
 299         struct btrfs_ordered_extent *entry = NULL;
 300         unsigned long flags;
 301         u64 cur = file_offset;
 302
 303         if (btrfs_is_free_space_inode(inode))
 304                 wq = fs_info->endio_freespace_worker;
 305         else
 306                 wq = fs_info->endio_write_workers;
 307
 308         if (page)
 309                 ASSERT(page->mapping && page_offset(page) <= file_offset &&
 310                        file_offset + num_bytes <= page_offset(page) + PAGE_SIZE);
 311
 312         spin_lock_irqsave(&tree->lock, flags);
 313         while (cur < file_offset + num_bytes) {
 314                 u64 entry_end;
 315                 u64 end;
 316                 u32 len;
 317
 318                 node = tree_search(tree, cur);
 319                 /* No ordered extents at all */
 320                 if (!node)
 321                         break;
 322
 323                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 324                 entry_end = entry->file_offset + entry->num_bytes;
 325                 /*
 326                  * |<-- OE --->|  |
 327                  *                cur
 328                  * Go to next OE.
 329                  */
 330                 if (cur >= entry_end) {
 331                         node = rb_next(node);
 332                         /* No more ordered extents, exit */
 333                         if (!node)
 334                                 break;
 335                         entry = rb_entry(node, struct btrfs_ordered_extent,
 336                                          rb_node);
 337
 338                         /* Go to next ordered extent and continue */
 339                         cur = entry->file_offset;
 340                         continue;
 341                 }
 342                 /*
 343                  * |    |<--- OE --->|
 344                  * cur
 345                  * Go to the start of OE.
 346                  */
 347                 if (cur < entry->file_offset) {
 348                         cur = entry->file_offset;
 349                         continue;
 350                 }
 351
 352                 /*
 353                  * Now we are definitely inside one ordered extent.
 354                  *
 355                  * |<--- OE --->|
 356                  *      |
 357                  *      cur
 358                  */
 359                 end = min(entry->file_offset + entry->num_bytes,
 360                           file_offset + num_bytes) - 1;
 361                 ASSERT(end + 1 - cur < U32_MAX);
 362                 len = end + 1 - cur;
 363
 364                 if (page) {
 365                         /*
 366                          * Ordered (Private2) bit indicates whether we still
 367                          * have pending io unfinished for the ordered extent.
 368                          *
 369                          * If there's no such bit, we need to skip to next range.
 370                          */
 371                         if (!btrfs_page_test_ordered(fs_info, page, cur, len)) {
 372                                 cur += len;
 373                                 continue;
 374                         }
 375                         btrfs_page_clear_ordered(fs_info, page, cur, len);
 376                 }
 377
 378                 /* Now we're fine to update the accounting */
 379                 if (unlikely(len > entry->bytes_left)) {
 380                         WARN_ON(1);
 381                         btrfs_crit(fs_info,
 382 "bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%u left=%llu",
 383                                    inode->root->root_key.objectid,
 384                                    btrfs_ino(inode),
 385                                    entry->file_offset,
 386                                    entry->num_bytes,
 387                                    len, entry->bytes_left);
 388                         entry->bytes_left = 0;
 389                 } else {
 390                         entry->bytes_left -= len;
 391                 }
 392
 393                 if (!uptodate)
 394                         set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 395
 396                 /*
 397                  * All the IO of the ordered extent is finished, we need to queue
 398                  * the finish_func to be executed.
 399                  */
 400                 if (entry->bytes_left == 0) {
 401                         set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 402                         cond_wake_up(&entry->wait);
 403                         refcount_inc(&entry->refs);
 404                         spin_unlock_irqrestore(&tree->lock, flags);
 405                         btrfs_init_work(&entry->work, finish_func, NULL, NULL);
 406                         btrfs_queue_work(wq, &entry->work);
 407                         spin_lock_irqsave(&tree->lock, flags);
 408                 }
 409                 cur += len;
 410         }
 411         spin_unlock_irqrestore(&tree->lock, flags);
 412 }
 413
 414 /*
 415  * Finish IO for one ordered extent across a given range.  The range can only
 416  * contain one ordered extent.
 417  *
 418  * @cached:      The cached ordered extent. If not NULL, we can skip the tree
 419  *               search and use the ordered extent directly.
 420  *               Will be also used to store the finished ordered extent.
 421  * @file_offset: File offset for the finished IO
 422  * @io_size:     Length of the finish IO range
 423  *
 424  * Return true if the ordered extent is finished in the range, and update
 425  * @cached.
 426  * Return false otherwise.
 427  *
 428  * NOTE: The range can NOT cross multiple ordered extents.
 429  * Thus caller should ensure the range doesn't cross ordered extents.
 430  */
 431 bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 432                                     struct btrfs_ordered_extent **cached,
 433                                     u64 file_offset, u64 io_size)
 434 {
 435         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 436         struct rb_node *node;
 437         struct btrfs_ordered_extent *entry = NULL;
 438         unsigned long flags;
 439         bool finished = false;
 440
 441         spin_lock_irqsave(&tree->lock, flags);
 442         if (cached && *cached) {
 443                 entry = *cached;
 444                 goto have_entry;
 445         }
 446
 447         node = tree_search(tree, file_offset);
 448         if (!node)
 449                 goto out;
 450
 451         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 452 have_entry:
 453         if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 454                 goto out;
 455
 456         if (io_size > entry->bytes_left)
 457                 btrfs_crit(inode->root->fs_info,
 458                            "bad ordered accounting left %llu size %llu",
 459                        entry->bytes_left, io_size);
 460
 461         entry->bytes_left -= io_size;
 462
 463         if (entry->bytes_left == 0) {
 464                 /*
 465                  * Ensure only one caller can set the flag and finished_ret
 466                  * accordingly
 467                  */
 468                 finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 469                 /* test_and_set_bit implies a barrier */
 470                 cond_wake_up_nomb(&entry->wait);
 471         }
 472 out:
 473         if (finished && cached && entry) {
 474                 *cached = entry;
 475                 refcount_inc(&entry->refs);
 476         }
 477         spin_unlock_irqrestore(&tree->lock, flags);
 478         return finished;
 479 }
 480
 481 /*
 482  * used to drop a reference on an ordered extent.  This will free
 483  * the extent if the last reference is dropped
 484  */
 485 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 486 {
 487         struct list_head *cur;
 488         struct btrfs_ordered_sum *sum;
 489
 490         trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
 491
 492         if (refcount_dec_and_test(&entry->refs)) {
 493                 ASSERT(list_empty(&entry->root_extent_list));
 494                 ASSERT(list_empty(&entry->log_list));
 495                 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 496                 if (entry->inode)
 497                         btrfs_add_delayed_iput(entry->inode);
 498                 while (!list_empty(&entry->list)) {
 499                         cur = entry->list.next;
 500                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 501                         list_del(&sum->list);
 502                         kvfree(sum);
 503                 }
 504                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
 505         }
 506 }
 507
 508 /*
 509  * remove an ordered extent from the tree.  No references are dropped
 510  * and waiters are woken up.
 511  */
 512 void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 513                                  struct btrfs_ordered_extent *entry)
 514 {
 515         struct btrfs_ordered_inode_tree *tree;
 516         struct btrfs_root *root = btrfs_inode->root;
 517         struct btrfs_fs_info *fs_info = root->fs_info;
 518         struct rb_node *node;
 519         bool pending;
 520
 521         /* This is paired with btrfs_add_ordered_extent. */
 522         spin_lock(&btrfs_inode->lock);
 523         btrfs_mod_outstanding_extents(btrfs_inode, -1);
 524         spin_unlock(&btrfs_inode->lock);
 525         if (root != fs_info->tree_root) {
 526                 u64 release;
 527
 528                 if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
 529                         release = entry->disk_num_bytes;
 530                 else
 531                         release = entry->num_bytes;
 532                 btrfs_delalloc_release_metadata(btrfs_inode, release, false);
 533         }
 534
 535         percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 536                                  fs_info->delalloc_batch);
 537
 538         tree = &btrfs_inode->ordered_tree;
 539         spin_lock_irq(&tree->lock);
 540         node = &entry->rb_node;
 541         rb_erase(node, &tree->tree);
 542         RB_CLEAR_NODE(node);
 543         if (tree->last == node)
 544                 tree->last = NULL;
 545         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 546         pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
 547         spin_unlock_irq(&tree->lock);
 548
 549         /*
 550          * The current running transaction is waiting on us, we need to let it
 551          * know that we're complete and wake it up.
 552          */
 553         if (pending) {
 554                 struct btrfs_transaction *trans;
 555
 556                 /*
 557                  * The checks for trans are just a formality, it should be set,
 558                  * but if it isn't we don't want to deref/assert under the spin
 559                  * lock, so be nice and check if trans is set, but ASSERT() so
 560                  * if it isn't set a developer will notice.
 561                  */
 562                 spin_lock(&fs_info->trans_lock);
 563                 trans = fs_info->running_transaction;
 564                 if (trans)
 565                         refcount_inc(&trans->use_count);
 566                 spin_unlock(&fs_info->trans_lock);
 567
 568                 ASSERT(trans);
 569                 if (trans) {
 570                         if (atomic_dec_and_test(&trans->pending_ordered))
 571                                 wake_up(&trans->pending_wait);
 572                         btrfs_put_transaction(trans);
 573                 }
 574         }
 575
 576         spin_lock(&root->ordered_extent_lock);
 577         list_del_init(&entry->root_extent_list);
 578         root->nr_ordered_extents--;
 579
 580         trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
 581
 582         if (!root->nr_ordered_extents) {
 583                 spin_lock(&fs_info->ordered_root_lock);
 584                 BUG_ON(list_empty(&root->ordered_root));
 585                 list_del_init(&root->ordered_root);
 586                 spin_unlock(&fs_info->ordered_root_lock);
 587         }
 588         spin_unlock(&root->ordered_extent_lock);
 589         wake_up(&entry->wait);
 590 }
 591
 592 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 593 {
 594         struct btrfs_ordered_extent *ordered;
 595
 596         ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 597         btrfs_start_ordered_extent(ordered, 1);
 598         complete(&ordered->completion);
 599 }
 600
 601 /*
 602  * wait for all the ordered extents in a root.  This is done when balancing
 603  * space between drives.
 604  */
 605 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 606                                const u64 range_start, const u64 range_len)
 607 {
 608         struct btrfs_fs_info *fs_info = root->fs_info;
 609         LIST_HEAD(splice);
 610         LIST_HEAD(skipped);
 611         LIST_HEAD(works);
 612         struct btrfs_ordered_extent *ordered, *next;
 613         u64 count = 0;
 614         const u64 range_end = range_start + range_len;
 615
 616         mutex_lock(&root->ordered_extent_mutex);
 617         spin_lock(&root->ordered_extent_lock);
 618         list_splice_init(&root->ordered_extents, &splice);
 619         while (!list_empty(&splice) && nr) {
 620                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 621                                            root_extent_list);
 622
 623                 if (range_end <= ordered->disk_bytenr ||
 624                     ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
 625                         list_move_tail(&ordered->root_extent_list, &skipped);
 626                         cond_resched_lock(&root->ordered_extent_lock);
 627                         continue;
 628                 }
 629
 630                 list_move_tail(&ordered->root_extent_list,
 631                                &root->ordered_extents);
 632                 refcount_inc(&ordered->refs);
 633                 spin_unlock(&root->ordered_extent_lock);
 634
 635                 btrfs_init_work(&ordered->flush_work,
 636                                 btrfs_run_ordered_extent_work, NULL, NULL);
 637                 list_add_tail(&ordered->work_list, &works);
 638                 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 639
 640                 cond_resched();
 641                 spin_lock(&root->ordered_extent_lock);
 642                 if (nr != U64_MAX)
 643                         nr--;
 644                 count++;
 645         }
 646         list_splice_tail(&skipped, &root->ordered_extents);
 647         list_splice_tail(&splice, &root->ordered_extents);
 648         spin_unlock(&root->ordered_extent_lock);
 649
 650         list_for_each_entry_safe(ordered, next, &works, work_list) {
 651                 list_del_init(&ordered->work_list);
 652                 wait_for_completion(&ordered->completion);
 653                 btrfs_put_ordered_extent(ordered);
 654                 cond_resched();
 655         }
 656         mutex_unlock(&root->ordered_extent_mutex);
 657
 658         return count;
 659 }
 660
 661 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 662                              const u64 range_start, const u64 range_len)
 663 {
 664         struct btrfs_root *root;
 665         struct list_head splice;
 666         u64 done;
 667
 668         INIT_LIST_HEAD(&splice);
 669
 670         mutex_lock(&fs_info->ordered_operations_mutex);
 671         spin_lock(&fs_info->ordered_root_lock);
 672         list_splice_init(&fs_info->ordered_roots, &splice);
 673         while (!list_empty(&splice) && nr) {
 674                 root = list_first_entry(&splice, struct btrfs_root,
 675                                         ordered_root);
 676                 root = btrfs_grab_root(root);
 677                 BUG_ON(!root);
 678                 list_move_tail(&root->ordered_root,
 679                                &fs_info->ordered_roots);
 680                 spin_unlock(&fs_info->ordered_root_lock);
 681
 682                 done = btrfs_wait_ordered_extents(root, nr,
 683                                                   range_start, range_len);
 684                 btrfs_put_root(root);
 685
 686                 spin_lock(&fs_info->ordered_root_lock);
 687                 if (nr != U64_MAX) {
 688                         nr -= done;
 689                 }
 690         }
 691         list_splice_tail(&splice, &fs_info->ordered_roots);
 692         spin_unlock(&fs_info->ordered_root_lock);
 693         mutex_unlock(&fs_info->ordered_operations_mutex);
 694 }
 695
 696 /*
 697  * Used to start IO or wait for a given ordered extent to finish.
 698  *
 699  * If wait is one, this effectively waits on page writeback for all the pages
 700  * in the extent, and it waits on the io completion code to insert
 701  * metadata into the btree corresponding to the extent
 702  */
 703 void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry, int wait)
 704 {
 705         u64 start = entry->file_offset;
 706         u64 end = start + entry->num_bytes - 1;
 707         struct btrfs_inode *inode = BTRFS_I(entry->inode);
 708
 709         trace_btrfs_ordered_extent_start(inode, entry);
 710
 711         /*
 712          * pages in the range can be dirty, clean or writeback.  We
 713          * start IO on any dirty ones so the wait doesn't stall waiting
 714          * for the flusher thread to find them
 715          */
 716         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 717                 filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
 718         if (wait) {
 719                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 720                                                  &entry->flags));
 721         }
 722 }
 723
 724 /*
 725  * Used to wait on ordered extents across a large range of bytes.
 726  */
 727 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 728 {
 729         int ret = 0;
 730         int ret_wb = 0;
 731         u64 end;
 732         u64 orig_end;
 733         struct btrfs_ordered_extent *ordered;
 734
 735         if (start + len < start) {
 736                 orig_end = INT_LIMIT(loff_t);
 737         } else {
 738                 orig_end = start + len - 1;
 739                 if (orig_end > INT_LIMIT(loff_t))
 740                         orig_end = INT_LIMIT(loff_t);
 741         }
 742
 743         /* start IO across the range first to instantiate any delalloc
 744          * extents
 745          */
 746         ret = btrfs_fdatawrite_range(inode, start, orig_end);
 747         if (ret)
 748                 return ret;
 749
 750         /*
 751          * If we have a writeback error don't return immediately. Wait first
 752          * for any ordered extents that haven't completed yet. This is to make
 753          * sure no one can dirty the same page ranges and call writepages()
 754          * before the ordered extents complete - to avoid failures (-EEXIST)
 755          * when adding the new ordered extents to the ordered tree.
 756          */
 757         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 758
 759         end = orig_end;
 760         while (1) {
 761                 ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
 762                 if (!ordered)
 763                         break;
 764                 if (ordered->file_offset > orig_end) {
 765                         btrfs_put_ordered_extent(ordered);
 766                         break;
 767                 }
 768                 if (ordered->file_offset + ordered->num_bytes <= start) {
 769                         btrfs_put_ordered_extent(ordered);
 770                         break;
 771                 }
 772                 btrfs_start_ordered_extent(ordered, 1);
 773                 end = ordered->file_offset;
 774                 /*
 775                  * If the ordered extent had an error save the error but don't
 776                  * exit without waiting first for all other ordered extents in
 777                  * the range to complete.
 778                  */
 779                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 780                         ret = -EIO;
 781                 btrfs_put_ordered_extent(ordered);
 782                 if (end == 0 || end == start)
 783                         break;
 784                 end--;
 785         }
 786         return ret_wb ? ret_wb : ret;
 787 }
 788
 789 /*
 790  * find an ordered extent corresponding to file_offset.  return NULL if
 791  * nothing is found, otherwise take a reference on the extent and return it
 792  */
 793 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
 794                                                          u64 file_offset)
 795 {
 796         struct btrfs_ordered_inode_tree *tree;
 797         struct rb_node *node;
 798         struct btrfs_ordered_extent *entry = NULL;
 799         unsigned long flags;
 800
 801         tree = &inode->ordered_tree;
 802         spin_lock_irqsave(&tree->lock, flags);
 803         node = tree_search(tree, file_offset);
 804         if (!node)
 805                 goto out;
 806
 807         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 808         if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 809                 entry = NULL;
 810         if (entry)
 811                 refcount_inc(&entry->refs);
 812 out:
 813         spin_unlock_irqrestore(&tree->lock, flags);
 814         return entry;
 815 }
 816
 817 /* Since the DIO code tries to lock a wide area we need to look for any ordered
 818  * extents that exist in the range, rather than just the start of the range.
 819  */
 820 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 821                 struct btrfs_inode *inode, u64 file_offset, u64 len)
 822 {
 823         struct btrfs_ordered_inode_tree *tree;
 824         struct rb_node *node;
 825         struct btrfs_ordered_extent *entry = NULL;
 826
 827         tree = &inode->ordered_tree;
 828         spin_lock_irq(&tree->lock);
 829         node = tree_search(tree, file_offset);
 830         if (!node) {
 831                 node = tree_search(tree, file_offset + len);
 832                 if (!node)
 833                         goto out;
 834         }
 835
 836         while (1) {
 837                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 838                 if (range_overlaps(entry, file_offset, len))
 839                         break;
 840
 841                 if (entry->file_offset >= file_offset + len) {
 842                         entry = NULL;
 843                         break;
 844                 }
 845                 entry = NULL;
 846                 node = rb_next(node);
 847                 if (!node)
 848                         break;
 849         }
 850 out:
 851         if (entry)
 852                 refcount_inc(&entry->refs);
 853         spin_unlock_irq(&tree->lock);
 854         return entry;
 855 }
 856
 857 /*
 858  * Adds all ordered extents to the given list. The list ends up sorted by the
 859  * file_offset of the ordered extents.
 860  */
 861 void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
 862                                            struct list_head *list)
 863 {
 864         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 865         struct rb_node *n;
 866
 867         ASSERT(inode_is_locked(&inode->vfs_inode));
 868
 869         spin_lock_irq(&tree->lock);
 870         for (n = rb_first(&tree->tree); n; n = rb_next(n)) {
 871                 struct btrfs_ordered_extent *ordered;
 872
 873                 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 874
 875                 if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 876                         continue;
 877
 878                 ASSERT(list_empty(&ordered->log_list));
 879                 list_add_tail(&ordered->log_list, list);
 880                 refcount_inc(&ordered->refs);
 881         }
 882         spin_unlock_irq(&tree->lock);
 883 }
 884
 885 /*
 886  * lookup and return any extent before 'file_offset'.  NULL is returned
 887  * if none is found
 888  */
 889 struct btrfs_ordered_extent *
 890 btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
 891 {
 892         struct btrfs_ordered_inode_tree *tree;
 893         struct rb_node *node;
 894         struct btrfs_ordered_extent *entry = NULL;
 895
 896         tree = &inode->ordered_tree;
 897         spin_lock_irq(&tree->lock);
 898         node = tree_search(tree, file_offset);
 899         if (!node)
 900                 goto out;
 901
 902         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 903         refcount_inc(&entry->refs);
 904 out:
 905         spin_unlock_irq(&tree->lock);
 906         return entry;
 907 }
 908
 909 /*
 910  * Lookup the first ordered extent that overlaps the range
 911  * [@file_offset, @file_offset + @len).
 912  *
 913  * The difference between this and btrfs_lookup_first_ordered_extent() is
 914  * that this one won't return any ordered extent that does not overlap the range.
 915  * And the difference against btrfs_lookup_ordered_extent() is, this function
 916  * ensures the first ordered extent gets returned.
 917  */
 918 struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
 919                         struct btrfs_inode *inode, u64 file_offset, u64 len)
 920 {
 921         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 922         struct rb_node *node;
 923         struct rb_node *cur;
 924         struct rb_node *prev;
 925         struct rb_node *next;
 926         struct btrfs_ordered_extent *entry = NULL;
 927
 928         spin_lock_irq(&tree->lock);
 929         node = tree->tree.rb_node;
 930         /*
 931          * Here we don't want to use tree_search() which will use tree->last
 932          * and screw up the search order.
 933          * And __tree_search() can't return the adjacent ordered extents
 934          * either, thus here we do our own search.
 935          */
 936         while (node) {
 937                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 938
 939                 if (file_offset < entry->file_offset) {
 940                         node = node->rb_left;
 941                 } else if (file_offset >= entry_end(entry)) {
 942                         node = node->rb_right;
 943                 } else {
 944                         /*
 945                          * Direct hit, got an ordered extent that starts at
 946                          * @file_offset
 947                          */
 948                         goto out;
 949                 }
 950         }
 951         if (!entry) {
 952                 /* Empty tree */
 953                 goto out;
 954         }
 955
 956         cur = &entry->rb_node;
 957         /* We got an entry around @file_offset, check adjacent entries */
 958         if (entry->file_offset < file_offset) {
 959                 prev = cur;
 960                 next = rb_next(cur);
 961         } else {
 962                 prev = rb_prev(cur);
 963                 next = cur;
 964         }
 965         if (prev) {
 966                 entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
 967                 if (range_overlaps(entry, file_offset, len))
 968                         goto out;
 969         }
 970         if (next) {
 971                 entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
 972                 if (range_overlaps(entry, file_offset, len))
 973                         goto out;
 974         }
 975         /* No ordered extent in the range */
 976         entry = NULL;
 977 out:
 978         if (entry)
 979                 refcount_inc(&entry->refs);
 980         spin_unlock_irq(&tree->lock);
 981         return entry;
 982 }
 983
 984 /*
 985  * btrfs_flush_ordered_range - Lock the passed range and ensures all pending
 986  * ordered extents in it are run to completion.
 987  *
 988  * @inode:        Inode whose ordered tree is to be searched
 989  * @start:        Beginning of range to flush
 990  * @end:          Last byte of range to lock
 991  * @cached_state: If passed, will return the extent state responsible for the
 992  * locked range. It's the caller's responsibility to free the cached state.
 993  *
 994  * This function always returns with the given range locked, ensuring after it's
 995  * called no order extent can be pending.
 996  */
 997 void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
 998                                         u64 end,
 999                                         struct extent_state **cached_state)
1000 {
1001         struct btrfs_ordered_extent *ordered;
1002         struct extent_state *cache = NULL;
1003         struct extent_state **cachedp = &cache;
1004
1005         if (cached_state)
1006                 cachedp = cached_state;
1007
1008         while (1) {
1009                 lock_extent_bits(&inode->io_tree, start, end, cachedp);
1010                 ordered = btrfs_lookup_ordered_range(inode, start,
1011                                                      end - start + 1);
1012                 if (!ordered) {
1013                         /*
1014                          * If no external cached_state has been passed then
1015                          * decrement the extra ref taken for cachedp since we
1016                          * aren't exposing it outside of this function
1017                          */
1018                         if (!cached_state)
1019                                 refcount_dec(&cache->refs);
1020                         break;
1021                 }
1022                 unlock_extent_cached(&inode->io_tree, start, end, cachedp);
1023                 btrfs_start_ordered_extent(ordered, 1);
1024                 btrfs_put_ordered_extent(ordered);
1025         }
1026 }
1027
1028 static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
1029                                 u64 len)
1030 {
1031         struct inode *inode = ordered->inode;
1032         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1033         u64 file_offset = ordered->file_offset + pos;
1034         u64 disk_bytenr = ordered->disk_bytenr + pos;
1035         unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;
1036
1037         /*
1038          * The splitting extent is already counted and will be added again in
1039          * btrfs_add_ordered_extent_*(). Subtract len to avoid double counting.
1040          */
1041         percpu_counter_add_batch(&fs_info->ordered_bytes, -len,
1042                                  fs_info->delalloc_batch);
1043         WARN_ON_ONCE(flags & (1 << BTRFS_ORDERED_COMPRESSED));
1044         return btrfs_add_ordered_extent(BTRFS_I(inode), file_offset, len, len,
1045                                         disk_bytenr, len, 0, flags,
1046                                         ordered->compress_type);
1047 }
1048
1049 int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
1050                                 u64 post)
1051 {
1052         struct inode *inode = ordered->inode;
1053         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1054         struct rb_node *node;
1055         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1056         int ret = 0;
1057
1058         spin_lock_irq(&tree->lock);
1059         /* Remove from tree once */
1060         node = &ordered->rb_node;
1061         rb_erase(node, &tree->tree);
1062         RB_CLEAR_NODE(node);
1063         if (tree->last == node)
1064                 tree->last = NULL;
1065
1066         ordered->file_offset += pre;
1067         ordered->disk_bytenr += pre;
1068         ordered->num_bytes -= (pre + post);
1069         ordered->disk_num_bytes -= (pre + post);
1070         ordered->bytes_left -= (pre + post);
1071
1072         /* Re-insert the node */
1073         node = tree_insert(&tree->tree, ordered->file_offset, &ordered->rb_node);
1074         if (node)
1075                 btrfs_panic(fs_info, -EEXIST,
1076                         "zoned: inconsistency in ordered tree at offset %llu",
1077                             ordered->file_offset);
1078
1079         spin_unlock_irq(&tree->lock);
1080
1081         if (pre)
1082                 ret = clone_ordered_extent(ordered, 0, pre);
1083         if (ret == 0 && post)
1084                 ret = clone_ordered_extent(ordered, pre + ordered->disk_num_bytes,
1085                                            post);
1086
1087         return ret;
1088 }
1089
1090 int __init ordered_data_init(void)
1091 {
1092         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1093                                      sizeof(struct btrfs_ordered_extent), 0,
1094                                      SLAB_MEM_SPREAD,
1095                                      NULL);
1096         if (!btrfs_ordered_extent_cache)
1097                 return -ENOMEM;
1098
1099         return 0;
1100 }
1101
1102 void __cold ordered_data_exit(void)
1103 {
1104         kmem_cache_destroy(btrfs_ordered_extent_cache);
1105 }