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         u64 qgroup_rsv = 0;
 176
 177         if (flags &
 178             ((1 << BTRFS_ORDERED_NOCOW) | (1 << BTRFS_ORDERED_PREALLOC))) {
 179                 /* For nocow write, we can release the qgroup rsv right now */
 180                 ret = btrfs_qgroup_free_data(inode, NULL, file_offset, num_bytes, &qgroup_rsv);
 181                 if (ret < 0)
 182                         return ret;
 183                 ret = 0;
 184         } else {
 185                 /*
 186                  * The ordered extent has reserved qgroup space, release now
 187                  * and pass the reserved number for qgroup_record to free.
 188                  */
 189                 ret = btrfs_qgroup_release_data(inode, file_offset, num_bytes, &qgroup_rsv);
 190                 if (ret < 0)
 191                         return ret;
 192         }
 193         entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 194         if (!entry)
 195                 return -ENOMEM;
 196
 197         entry->file_offset = file_offset;
 198         entry->num_bytes = num_bytes;
 199         entry->ram_bytes = ram_bytes;
 200         entry->disk_bytenr = disk_bytenr;
 201         entry->disk_num_bytes = disk_num_bytes;
 202         entry->offset = offset;
 203         entry->bytes_left = num_bytes;
 204         entry->inode = igrab(&inode->vfs_inode);
 205         entry->compress_type = compress_type;
 206         entry->truncated_len = (u64)-1;
 207         entry->qgroup_rsv = qgroup_rsv;
 208         entry->physical = (u64)-1;
 209
 210         ASSERT((flags & ~BTRFS_ORDERED_TYPE_FLAGS) == 0);
 211         entry->flags = flags;
 212
 213         percpu_counter_add_batch(&fs_info->ordered_bytes, num_bytes,
 214                                  fs_info->delalloc_batch);
 215
 216         /* one ref for the tree */
 217         refcount_set(&entry->refs, 1);
 218         init_waitqueue_head(&entry->wait);
 219         INIT_LIST_HEAD(&entry->list);
 220         INIT_LIST_HEAD(&entry->log_list);
 221         INIT_LIST_HEAD(&entry->root_extent_list);
 222         INIT_LIST_HEAD(&entry->work_list);
 223         init_completion(&entry->completion);
 224
 225         trace_btrfs_ordered_extent_add(inode, entry);
 226
 227         spin_lock_irq(&tree->lock);
 228         node = tree_insert(&tree->tree, file_offset,
 229                            &entry->rb_node);
 230         if (node)
 231                 btrfs_panic(fs_info, -EEXIST,
 232                                 "inconsistency in ordered tree at offset %llu",
 233                                 file_offset);
 234         spin_unlock_irq(&tree->lock);
 235
 236         spin_lock(&root->ordered_extent_lock);
 237         list_add_tail(&entry->root_extent_list,
 238                       &root->ordered_extents);
 239         root->nr_ordered_extents++;
 240         if (root->nr_ordered_extents == 1) {
 241                 spin_lock(&fs_info->ordered_root_lock);
 242                 BUG_ON(!list_empty(&root->ordered_root));
 243                 list_add_tail(&root->ordered_root, &fs_info->ordered_roots);
 244                 spin_unlock(&fs_info->ordered_root_lock);
 245         }
 246         spin_unlock(&root->ordered_extent_lock);
 247
 248         /*
 249          * We don't need the count_max_extents here, we can assume that all of
 250          * that work has been done at higher layers, so this is truly the
 251          * smallest the extent is going to get.
 252          */
 253         spin_lock(&inode->lock);
 254         btrfs_mod_outstanding_extents(inode, 1);
 255         spin_unlock(&inode->lock);
 256
 257         return 0;
 258 }
 259
 260 /*
 261  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 262  * when an ordered extent is finished.  If the list covers more than one
 263  * ordered extent, it is split across multiples.
 264  */
 265 void btrfs_add_ordered_sum(struct btrfs_ordered_extent *entry,
 266                            struct btrfs_ordered_sum *sum)
 267 {
 268         struct btrfs_ordered_inode_tree *tree;
 269
 270         tree = &BTRFS_I(entry->inode)->ordered_tree;
 271         spin_lock_irq(&tree->lock);
 272         list_add_tail(&sum->list, &entry->list);
 273         spin_unlock_irq(&tree->lock);
 274 }
 275
 276 static void finish_ordered_fn(struct btrfs_work *work)
 277 {
 278         struct btrfs_ordered_extent *ordered_extent;
 279
 280         ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
 281         btrfs_finish_ordered_io(ordered_extent);
 282 }
 283
 284 /*
 285  * Mark all ordered extents io inside the specified range finished.
 286  *
 287  * @page:        The involved page for the operation.
 288  *               For uncompressed buffered IO, the page status also needs to be
 289  *               updated to indicate whether the pending ordered io is finished.
 290  *               Can be NULL for direct IO and compressed write.
 291  *               For these cases, callers are ensured they won't execute the
 292  *               endio function twice.
 293  *
 294  * This function is called for endio, thus the range must have ordered
 295  * extent(s) covering it.
 296  */
 297 void btrfs_mark_ordered_io_finished(struct btrfs_inode *inode,
 298                                     struct page *page, u64 file_offset,
 299                                     u64 num_bytes, bool uptodate)
 300 {
 301         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 302         struct btrfs_fs_info *fs_info = inode->root->fs_info;
 303         struct btrfs_workqueue *wq;
 304         struct rb_node *node;
 305         struct btrfs_ordered_extent *entry = NULL;
 306         unsigned long flags;
 307         u64 cur = file_offset;
 308
 309         if (btrfs_is_free_space_inode(inode))
 310                 wq = fs_info->endio_freespace_worker;
 311         else
 312                 wq = fs_info->endio_write_workers;
 313
 314         if (page)
 315                 ASSERT(page->mapping && page_offset(page) <= file_offset &&
 316                        file_offset + num_bytes <= page_offset(page) + PAGE_SIZE);
 317
 318         spin_lock_irqsave(&tree->lock, flags);
 319         while (cur < file_offset + num_bytes) {
 320                 u64 entry_end;
 321                 u64 end;
 322                 u32 len;
 323
 324                 node = tree_search(tree, cur);
 325                 /* No ordered extents at all */
 326                 if (!node)
 327                         break;
 328
 329                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 330                 entry_end = entry->file_offset + entry->num_bytes;
 331                 /*
 332                  * |<-- OE --->|  |
 333                  *                cur
 334                  * Go to next OE.
 335                  */
 336                 if (cur >= entry_end) {
 337                         node = rb_next(node);
 338                         /* No more ordered extents, exit */
 339                         if (!node)
 340                                 break;
 341                         entry = rb_entry(node, struct btrfs_ordered_extent,
 342                                          rb_node);
 343
 344                         /* Go to next ordered extent and continue */
 345                         cur = entry->file_offset;
 346                         continue;
 347                 }
 348                 /*
 349                  * |    |<--- OE --->|
 350                  * cur
 351                  * Go to the start of OE.
 352                  */
 353                 if (cur < entry->file_offset) {
 354                         cur = entry->file_offset;
 355                         continue;
 356                 }
 357
 358                 /*
 359                  * Now we are definitely inside one ordered extent.
 360                  *
 361                  * |<--- OE --->|
 362                  *      |
 363                  *      cur
 364                  */
 365                 end = min(entry->file_offset + entry->num_bytes,
 366                           file_offset + num_bytes) - 1;
 367                 ASSERT(end + 1 - cur < U32_MAX);
 368                 len = end + 1 - cur;
 369
 370                 if (page) {
 371                         /*
 372                          * Ordered (Private2) bit indicates whether we still
 373                          * have pending io unfinished for the ordered extent.
 374                          *
 375                          * If there's no such bit, we need to skip to next range.
 376                          */
 377                         if (!btrfs_page_test_ordered(fs_info, page, cur, len)) {
 378                                 cur += len;
 379                                 continue;
 380                         }
 381                         btrfs_page_clear_ordered(fs_info, page, cur, len);
 382                 }
 383
 384                 /* Now we're fine to update the accounting */
 385                 if (unlikely(len > entry->bytes_left)) {
 386                         WARN_ON(1);
 387                         btrfs_crit(fs_info,
 388 "bad ordered extent accounting, root=%llu ino=%llu OE offset=%llu OE len=%llu to_dec=%u left=%llu",
 389                                    inode->root->root_key.objectid,
 390                                    btrfs_ino(inode),
 391                                    entry->file_offset,
 392                                    entry->num_bytes,
 393                                    len, entry->bytes_left);
 394                         entry->bytes_left = 0;
 395                 } else {
 396                         entry->bytes_left -= len;
 397                 }
 398
 399                 if (!uptodate)
 400                         set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 401
 402                 /*
 403                  * All the IO of the ordered extent is finished, we need to queue
 404                  * the finish_func to be executed.
 405                  */
 406                 if (entry->bytes_left == 0) {
 407                         set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 408                         cond_wake_up(&entry->wait);
 409                         refcount_inc(&entry->refs);
 410                         trace_btrfs_ordered_extent_mark_finished(inode, entry);
 411                         spin_unlock_irqrestore(&tree->lock, flags);
 412                         btrfs_init_work(&entry->work, finish_ordered_fn, NULL, NULL);
 413                         btrfs_queue_work(wq, &entry->work);
 414                         spin_lock_irqsave(&tree->lock, flags);
 415                 }
 416                 cur += len;
 417         }
 418         spin_unlock_irqrestore(&tree->lock, flags);
 419 }
 420
 421 /*
 422  * Finish IO for one ordered extent across a given range.  The range can only
 423  * contain one ordered extent.
 424  *
 425  * @cached:      The cached ordered extent. If not NULL, we can skip the tree
 426  *               search and use the ordered extent directly.
 427  *               Will be also used to store the finished ordered extent.
 428  * @file_offset: File offset for the finished IO
 429  * @io_size:     Length of the finish IO range
 430  *
 431  * Return true if the ordered extent is finished in the range, and update
 432  * @cached.
 433  * Return false otherwise.
 434  *
 435  * NOTE: The range can NOT cross multiple ordered extents.
 436  * Thus caller should ensure the range doesn't cross ordered extents.
 437  */
 438 bool btrfs_dec_test_ordered_pending(struct btrfs_inode *inode,
 439                                     struct btrfs_ordered_extent **cached,
 440                                     u64 file_offset, u64 io_size)
 441 {
 442         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 443         struct rb_node *node;
 444         struct btrfs_ordered_extent *entry = NULL;
 445         unsigned long flags;
 446         bool finished = false;
 447
 448         spin_lock_irqsave(&tree->lock, flags);
 449         if (cached && *cached) {
 450                 entry = *cached;
 451                 goto have_entry;
 452         }
 453
 454         node = tree_search(tree, file_offset);
 455         if (!node)
 456                 goto out;
 457
 458         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 459 have_entry:
 460         if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 461                 goto out;
 462
 463         if (io_size > entry->bytes_left)
 464                 btrfs_crit(inode->root->fs_info,
 465                            "bad ordered accounting left %llu size %llu",
 466                        entry->bytes_left, io_size);
 467
 468         entry->bytes_left -= io_size;
 469
 470         if (entry->bytes_left == 0) {
 471                 /*
 472                  * Ensure only one caller can set the flag and finished_ret
 473                  * accordingly
 474                  */
 475                 finished = !test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 476                 /* test_and_set_bit implies a barrier */
 477                 cond_wake_up_nomb(&entry->wait);
 478         }
 479 out:
 480         if (finished && cached && entry) {
 481                 *cached = entry;
 482                 refcount_inc(&entry->refs);
 483                 trace_btrfs_ordered_extent_dec_test_pending(inode, entry);
 484         }
 485         spin_unlock_irqrestore(&tree->lock, flags);
 486         return finished;
 487 }
 488
 489 /*
 490  * used to drop a reference on an ordered extent.  This will free
 491  * the extent if the last reference is dropped
 492  */
 493 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 494 {
 495         struct list_head *cur;
 496         struct btrfs_ordered_sum *sum;
 497
 498         trace_btrfs_ordered_extent_put(BTRFS_I(entry->inode), entry);
 499
 500         if (refcount_dec_and_test(&entry->refs)) {
 501                 ASSERT(list_empty(&entry->root_extent_list));
 502                 ASSERT(list_empty(&entry->log_list));
 503                 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 504                 if (entry->inode)
 505                         btrfs_add_delayed_iput(entry->inode);
 506                 while (!list_empty(&entry->list)) {
 507                         cur = entry->list.next;
 508                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 509                         list_del(&sum->list);
 510                         kvfree(sum);
 511                 }
 512                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
 513         }
 514 }
 515
 516 /*
 517  * remove an ordered extent from the tree.  No references are dropped
 518  * and waiters are woken up.
 519  */
 520 void btrfs_remove_ordered_extent(struct btrfs_inode *btrfs_inode,
 521                                  struct btrfs_ordered_extent *entry)
 522 {
 523         struct btrfs_ordered_inode_tree *tree;
 524         struct btrfs_root *root = btrfs_inode->root;
 525         struct btrfs_fs_info *fs_info = root->fs_info;
 526         struct rb_node *node;
 527         bool pending;
 528         bool freespace_inode;
 529
 530         /*
 531          * If this is a free space inode the thread has not acquired the ordered
 532          * extents lockdep map.
 533          */
 534         freespace_inode = btrfs_is_free_space_inode(btrfs_inode);
 535
 536         btrfs_lockdep_acquire(fs_info, btrfs_trans_pending_ordered);
 537         /* This is paired with btrfs_add_ordered_extent. */
 538         spin_lock(&btrfs_inode->lock);
 539         btrfs_mod_outstanding_extents(btrfs_inode, -1);
 540         spin_unlock(&btrfs_inode->lock);
 541         if (root != fs_info->tree_root) {
 542                 u64 release;
 543
 544                 if (test_bit(BTRFS_ORDERED_ENCODED, &entry->flags))
 545                         release = entry->disk_num_bytes;
 546                 else
 547                         release = entry->num_bytes;
 548                 btrfs_delalloc_release_metadata(btrfs_inode, release,
 549                                                 test_bit(BTRFS_ORDERED_IOERR,
 550                                                          &entry->flags));
 551         }
 552
 553         percpu_counter_add_batch(&fs_info->ordered_bytes, -entry->num_bytes,
 554                                  fs_info->delalloc_batch);
 555
 556         tree = &btrfs_inode->ordered_tree;
 557         spin_lock_irq(&tree->lock);
 558         node = &entry->rb_node;
 559         rb_erase(node, &tree->tree);
 560         RB_CLEAR_NODE(node);
 561         if (tree->last == node)
 562                 tree->last = NULL;
 563         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 564         pending = test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags);
 565         spin_unlock_irq(&tree->lock);
 566
 567         /*
 568          * The current running transaction is waiting on us, we need to let it
 569          * know that we're complete and wake it up.
 570          */
 571         if (pending) {
 572                 struct btrfs_transaction *trans;
 573
 574                 /*
 575                  * The checks for trans are just a formality, it should be set,
 576                  * but if it isn't we don't want to deref/assert under the spin
 577                  * lock, so be nice and check if trans is set, but ASSERT() so
 578                  * if it isn't set a developer will notice.
 579                  */
 580                 spin_lock(&fs_info->trans_lock);
 581                 trans = fs_info->running_transaction;
 582                 if (trans)
 583                         refcount_inc(&trans->use_count);
 584                 spin_unlock(&fs_info->trans_lock);
 585
 586                 ASSERT(trans || BTRFS_FS_ERROR(fs_info));
 587                 if (trans) {
 588                         if (atomic_dec_and_test(&trans->pending_ordered))
 589                                 wake_up(&trans->pending_wait);
 590                         btrfs_put_transaction(trans);
 591                 }
 592         }
 593
 594         btrfs_lockdep_release(fs_info, btrfs_trans_pending_ordered);
 595
 596         spin_lock(&root->ordered_extent_lock);
 597         list_del_init(&entry->root_extent_list);
 598         root->nr_ordered_extents--;
 599
 600         trace_btrfs_ordered_extent_remove(btrfs_inode, entry);
 601
 602         if (!root->nr_ordered_extents) {
 603                 spin_lock(&fs_info->ordered_root_lock);
 604                 BUG_ON(list_empty(&root->ordered_root));
 605                 list_del_init(&root->ordered_root);
 606                 spin_unlock(&fs_info->ordered_root_lock);
 607         }
 608         spin_unlock(&root->ordered_extent_lock);
 609         wake_up(&entry->wait);
 610         if (!freespace_inode)
 611                 btrfs_lockdep_release(fs_info, btrfs_ordered_extent);
 612 }
 613
 614 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 615 {
 616         struct btrfs_ordered_extent *ordered;
 617
 618         ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 619         btrfs_start_ordered_extent(ordered, 1);
 620         complete(&ordered->completion);
 621 }
 622
 623 /*
 624  * wait for all the ordered extents in a root.  This is done when balancing
 625  * space between drives.
 626  */
 627 u64 btrfs_wait_ordered_extents(struct btrfs_root *root, u64 nr,
 628                                const u64 range_start, const u64 range_len)
 629 {
 630         struct btrfs_fs_info *fs_info = root->fs_info;
 631         LIST_HEAD(splice);
 632         LIST_HEAD(skipped);
 633         LIST_HEAD(works);
 634         struct btrfs_ordered_extent *ordered, *next;
 635         u64 count = 0;
 636         const u64 range_end = range_start + range_len;
 637
 638         mutex_lock(&root->ordered_extent_mutex);
 639         spin_lock(&root->ordered_extent_lock);
 640         list_splice_init(&root->ordered_extents, &splice);
 641         while (!list_empty(&splice) && nr) {
 642                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 643                                            root_extent_list);
 644
 645                 if (range_end <= ordered->disk_bytenr ||
 646                     ordered->disk_bytenr + ordered->disk_num_bytes <= range_start) {
 647                         list_move_tail(&ordered->root_extent_list, &skipped);
 648                         cond_resched_lock(&root->ordered_extent_lock);
 649                         continue;
 650                 }
 651
 652                 list_move_tail(&ordered->root_extent_list,
 653                                &root->ordered_extents);
 654                 refcount_inc(&ordered->refs);
 655                 spin_unlock(&root->ordered_extent_lock);
 656
 657                 btrfs_init_work(&ordered->flush_work,
 658                                 btrfs_run_ordered_extent_work, NULL, NULL);
 659                 list_add_tail(&ordered->work_list, &works);
 660                 btrfs_queue_work(fs_info->flush_workers, &ordered->flush_work);
 661
 662                 cond_resched();
 663                 spin_lock(&root->ordered_extent_lock);
 664                 if (nr != U64_MAX)
 665                         nr--;
 666                 count++;
 667         }
 668         list_splice_tail(&skipped, &root->ordered_extents);
 669         list_splice_tail(&splice, &root->ordered_extents);
 670         spin_unlock(&root->ordered_extent_lock);
 671
 672         list_for_each_entry_safe(ordered, next, &works, work_list) {
 673                 list_del_init(&ordered->work_list);
 674                 wait_for_completion(&ordered->completion);
 675                 btrfs_put_ordered_extent(ordered);
 676                 cond_resched();
 677         }
 678         mutex_unlock(&root->ordered_extent_mutex);
 679
 680         return count;
 681 }
 682
 683 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, u64 nr,
 684                              const u64 range_start, const u64 range_len)
 685 {
 686         struct btrfs_root *root;
 687         struct list_head splice;
 688         u64 done;
 689
 690         INIT_LIST_HEAD(&splice);
 691
 692         mutex_lock(&fs_info->ordered_operations_mutex);
 693         spin_lock(&fs_info->ordered_root_lock);
 694         list_splice_init(&fs_info->ordered_roots, &splice);
 695         while (!list_empty(&splice) && nr) {
 696                 root = list_first_entry(&splice, struct btrfs_root,
 697                                         ordered_root);
 698                 root = btrfs_grab_root(root);
 699                 BUG_ON(!root);
 700                 list_move_tail(&root->ordered_root,
 701                                &fs_info->ordered_roots);
 702                 spin_unlock(&fs_info->ordered_root_lock);
 703
 704                 done = btrfs_wait_ordered_extents(root, nr,
 705                                                   range_start, range_len);
 706                 btrfs_put_root(root);
 707
 708                 spin_lock(&fs_info->ordered_root_lock);
 709                 if (nr != U64_MAX) {
 710                         nr -= done;
 711                 }
 712         }
 713         list_splice_tail(&splice, &fs_info->ordered_roots);
 714         spin_unlock(&fs_info->ordered_root_lock);
 715         mutex_unlock(&fs_info->ordered_operations_mutex);
 716 }
 717
 718 /*
 719  * Used to start IO or wait for a given ordered extent to finish.
 720  *
 721  * If wait is one, this effectively waits on page writeback for all the pages
 722  * in the extent, and it waits on the io completion code to insert
 723  * metadata into the btree corresponding to the extent
 724  */
 725 void btrfs_start_ordered_extent(struct btrfs_ordered_extent *entry, int wait)
 726 {
 727         u64 start = entry->file_offset;
 728         u64 end = start + entry->num_bytes - 1;
 729         struct btrfs_inode *inode = BTRFS_I(entry->inode);
 730         bool freespace_inode;
 731
 732         trace_btrfs_ordered_extent_start(inode, entry);
 733
 734         /*
 735          * If this is a free space inode do not take the ordered extents lockdep
 736          * map.
 737          */
 738         freespace_inode = btrfs_is_free_space_inode(inode);
 739
 740         /*
 741          * pages in the range can be dirty, clean or writeback.  We
 742          * start IO on any dirty ones so the wait doesn't stall waiting
 743          * for the flusher thread to find them
 744          */
 745         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 746                 filemap_fdatawrite_range(inode->vfs_inode.i_mapping, start, end);
 747         if (wait) {
 748                 if (!freespace_inode)
 749                         btrfs_might_wait_for_event(inode->root->fs_info, btrfs_ordered_extent);
 750                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 751                                                  &entry->flags));
 752         }
 753 }
 754
 755 /*
 756  * Used to wait on ordered extents across a large range of bytes.
 757  */
 758 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 759 {
 760         int ret = 0;
 761         int ret_wb = 0;
 762         u64 end;
 763         u64 orig_end;
 764         struct btrfs_ordered_extent *ordered;
 765
 766         if (start + len < start) {
 767                 orig_end = INT_LIMIT(loff_t);
 768         } else {
 769                 orig_end = start + len - 1;
 770                 if (orig_end > INT_LIMIT(loff_t))
 771                         orig_end = INT_LIMIT(loff_t);
 772         }
 773
 774         /* start IO across the range first to instantiate any delalloc
 775          * extents
 776          */
 777         ret = btrfs_fdatawrite_range(inode, start, orig_end);
 778         if (ret)
 779                 return ret;
 780
 781         /*
 782          * If we have a writeback error don't return immediately. Wait first
 783          * for any ordered extents that haven't completed yet. This is to make
 784          * sure no one can dirty the same page ranges and call writepages()
 785          * before the ordered extents complete - to avoid failures (-EEXIST)
 786          * when adding the new ordered extents to the ordered tree.
 787          */
 788         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 789
 790         end = orig_end;
 791         while (1) {
 792                 ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode), end);
 793                 if (!ordered)
 794                         break;
 795                 if (ordered->file_offset > orig_end) {
 796                         btrfs_put_ordered_extent(ordered);
 797                         break;
 798                 }
 799                 if (ordered->file_offset + ordered->num_bytes <= start) {
 800                         btrfs_put_ordered_extent(ordered);
 801                         break;
 802                 }
 803                 btrfs_start_ordered_extent(ordered, 1);
 804                 end = ordered->file_offset;
 805                 /*
 806                  * If the ordered extent had an error save the error but don't
 807                  * exit without waiting first for all other ordered extents in
 808                  * the range to complete.
 809                  */
 810                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 811                         ret = -EIO;
 812                 btrfs_put_ordered_extent(ordered);
 813                 if (end == 0 || end == start)
 814                         break;
 815                 end--;
 816         }
 817         return ret_wb ? ret_wb : ret;
 818 }
 819
 820 /*
 821  * find an ordered extent corresponding to file_offset.  return NULL if
 822  * nothing is found, otherwise take a reference on the extent and return it
 823  */
 824 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct btrfs_inode *inode,
 825                                                          u64 file_offset)
 826 {
 827         struct btrfs_ordered_inode_tree *tree;
 828         struct rb_node *node;
 829         struct btrfs_ordered_extent *entry = NULL;
 830         unsigned long flags;
 831
 832         tree = &inode->ordered_tree;
 833         spin_lock_irqsave(&tree->lock, flags);
 834         node = tree_search(tree, file_offset);
 835         if (!node)
 836                 goto out;
 837
 838         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 839         if (!in_range(file_offset, entry->file_offset, entry->num_bytes))
 840                 entry = NULL;
 841         if (entry) {
 842                 refcount_inc(&entry->refs);
 843                 trace_btrfs_ordered_extent_lookup(inode, entry);
 844         }
 845 out:
 846         spin_unlock_irqrestore(&tree->lock, flags);
 847         return entry;
 848 }
 849
 850 /* Since the DIO code tries to lock a wide area we need to look for any ordered
 851  * extents that exist in the range, rather than just the start of the range.
 852  */
 853 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(
 854                 struct btrfs_inode *inode, u64 file_offset, u64 len)
 855 {
 856         struct btrfs_ordered_inode_tree *tree;
 857         struct rb_node *node;
 858         struct btrfs_ordered_extent *entry = NULL;
 859
 860         tree = &inode->ordered_tree;
 861         spin_lock_irq(&tree->lock);
 862         node = tree_search(tree, file_offset);
 863         if (!node) {
 864                 node = tree_search(tree, file_offset + len);
 865                 if (!node)
 866                         goto out;
 867         }
 868
 869         while (1) {
 870                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 871                 if (range_overlaps(entry, file_offset, len))
 872                         break;
 873
 874                 if (entry->file_offset >= file_offset + len) {
 875                         entry = NULL;
 876                         break;
 877                 }
 878                 entry = NULL;
 879                 node = rb_next(node);
 880                 if (!node)
 881                         break;
 882         }
 883 out:
 884         if (entry) {
 885                 refcount_inc(&entry->refs);
 886                 trace_btrfs_ordered_extent_lookup_range(inode, entry);
 887         }
 888         spin_unlock_irq(&tree->lock);
 889         return entry;
 890 }
 891
 892 /*
 893  * Adds all ordered extents to the given list. The list ends up sorted by the
 894  * file_offset of the ordered extents.
 895  */
 896 void btrfs_get_ordered_extents_for_logging(struct btrfs_inode *inode,
 897                                            struct list_head *list)
 898 {
 899         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 900         struct rb_node *n;
 901
 902         ASSERT(inode_is_locked(&inode->vfs_inode));
 903
 904         spin_lock_irq(&tree->lock);
 905         for (n = rb_first(&tree->tree); n; n = rb_next(n)) {
 906                 struct btrfs_ordered_extent *ordered;
 907
 908                 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 909
 910                 if (test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 911                         continue;
 912
 913                 ASSERT(list_empty(&ordered->log_list));
 914                 list_add_tail(&ordered->log_list, list);
 915                 refcount_inc(&ordered->refs);
 916                 trace_btrfs_ordered_extent_lookup_for_logging(inode, ordered);
 917         }
 918         spin_unlock_irq(&tree->lock);
 919 }
 920
 921 /*
 922  * lookup and return any extent before 'file_offset'.  NULL is returned
 923  * if none is found
 924  */
 925 struct btrfs_ordered_extent *
 926 btrfs_lookup_first_ordered_extent(struct btrfs_inode *inode, u64 file_offset)
 927 {
 928         struct btrfs_ordered_inode_tree *tree;
 929         struct rb_node *node;
 930         struct btrfs_ordered_extent *entry = NULL;
 931
 932         tree = &inode->ordered_tree;
 933         spin_lock_irq(&tree->lock);
 934         node = tree_search(tree, file_offset);
 935         if (!node)
 936                 goto out;
 937
 938         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 939         refcount_inc(&entry->refs);
 940         trace_btrfs_ordered_extent_lookup_first(inode, entry);
 941 out:
 942         spin_unlock_irq(&tree->lock);
 943         return entry;
 944 }
 945
 946 /*
 947  * Lookup the first ordered extent that overlaps the range
 948  * [@file_offset, @file_offset + @len).
 949  *
 950  * The difference between this and btrfs_lookup_first_ordered_extent() is
 951  * that this one won't return any ordered extent that does not overlap the range.
 952  * And the difference against btrfs_lookup_ordered_extent() is, this function
 953  * ensures the first ordered extent gets returned.
 954  */
 955 struct btrfs_ordered_extent *btrfs_lookup_first_ordered_range(
 956                         struct btrfs_inode *inode, u64 file_offset, u64 len)
 957 {
 958         struct btrfs_ordered_inode_tree *tree = &inode->ordered_tree;
 959         struct rb_node *node;
 960         struct rb_node *cur;
 961         struct rb_node *prev;
 962         struct rb_node *next;
 963         struct btrfs_ordered_extent *entry = NULL;
 964
 965         spin_lock_irq(&tree->lock);
 966         node = tree->tree.rb_node;
 967         /*
 968          * Here we don't want to use tree_search() which will use tree->last
 969          * and screw up the search order.
 970          * And __tree_search() can't return the adjacent ordered extents
 971          * either, thus here we do our own search.
 972          */
 973         while (node) {
 974                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 975
 976                 if (file_offset < entry->file_offset) {
 977                         node = node->rb_left;
 978                 } else if (file_offset >= entry_end(entry)) {
 979                         node = node->rb_right;
 980                 } else {
 981                         /*
 982                          * Direct hit, got an ordered extent that starts at
 983                          * @file_offset
 984                          */
 985                         goto out;
 986                 }
 987         }
 988         if (!entry) {
 989                 /* Empty tree */
 990                 goto out;
 991         }
 992
 993         cur = &entry->rb_node;
 994         /* We got an entry around @file_offset, check adjacent entries */
 995         if (entry->file_offset < file_offset) {
 996                 prev = cur;
 997                 next = rb_next(cur);
 998         } else {
 999                 prev = rb_prev(cur);
1000                 next = cur;
1001         }
1002         if (prev) {
1003                 entry = rb_entry(prev, struct btrfs_ordered_extent, rb_node);
1004                 if (range_overlaps(entry, file_offset, len))
1005                         goto out;
1006         }
1007         if (next) {
1008                 entry = rb_entry(next, struct btrfs_ordered_extent, rb_node);
1009                 if (range_overlaps(entry, file_offset, len))
1010                         goto out;
1011         }
1012         /* No ordered extent in the range */
1013         entry = NULL;
1014 out:
1015         if (entry) {
1016                 refcount_inc(&entry->refs);
1017                 trace_btrfs_ordered_extent_lookup_first_range(inode, entry);
1018         }
1019
1020         spin_unlock_irq(&tree->lock);
1021         return entry;
1022 }
1023
1024 /*
1025  * btrfs_flush_ordered_range - Lock the passed range and ensures all pending
1026  * ordered extents in it are run to completion.
1027  *
1028  * @inode:        Inode whose ordered tree is to be searched
1029  * @start:        Beginning of range to flush
1030  * @end:          Last byte of range to lock
1031  * @cached_state: If passed, will return the extent state responsible for the
1032  * locked range. It's the caller's responsibility to free the cached state.
1033  *
1034  * This function always returns with the given range locked, ensuring after it's
1035  * called no order extent can be pending.
1036  */
1037 void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
1038                                         u64 end,
1039                                         struct extent_state **cached_state)
1040 {
1041         struct btrfs_ordered_extent *ordered;
1042         struct extent_state *cache = NULL;
1043         struct extent_state **cachedp = &cache;
1044
1045         if (cached_state)
1046                 cachedp = cached_state;
1047
1048         while (1) {
1049                 lock_extent(&inode->io_tree, start, end, cachedp);
1050                 ordered = btrfs_lookup_ordered_range(inode, start,
1051                                                      end - start + 1);
1052                 if (!ordered) {
1053                         /*
1054                          * If no external cached_state has been passed then
1055                          * decrement the extra ref taken for cachedp since we
1056                          * aren't exposing it outside of this function
1057                          */
1058                         if (!cached_state)
1059                                 refcount_dec(&cache->refs);
1060                         break;
1061                 }
1062                 unlock_extent(&inode->io_tree, start, end, cachedp);
1063                 btrfs_start_ordered_extent(ordered, 1);
1064                 btrfs_put_ordered_extent(ordered);
1065         }
1066 }
1067
1068 /*
1069  * Lock the passed range and ensure all pending ordered extents in it are run
1070  * to completion in nowait mode.
1071  *
1072  * Return true if btrfs_lock_ordered_range does not return any extents,
1073  * otherwise false.
1074  */
1075 bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end)
1076 {
1077         struct btrfs_ordered_extent *ordered;
1078
1079         if (!try_lock_extent(&inode->io_tree, start, end))
1080                 return false;
1081
1082         ordered = btrfs_lookup_ordered_range(inode, start, end - start + 1);
1083         if (!ordered)
1084                 return true;
1085
1086         btrfs_put_ordered_extent(ordered);
1087         unlock_extent(&inode->io_tree, start, end, NULL);
1088
1089         return false;
1090 }
1091
1092
1093 static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
1094                                 u64 len)
1095 {
1096         struct inode *inode = ordered->inode;
1097         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
1098         u64 file_offset = ordered->file_offset + pos;
1099         u64 disk_bytenr = ordered->disk_bytenr + pos;
1100         unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;
1101
1102         /*
1103          * The splitting extent is already counted and will be added again in
1104          * btrfs_add_ordered_extent_*(). Subtract len to avoid double counting.
1105          */
1106         percpu_counter_add_batch(&fs_info->ordered_bytes, -len,
1107                                  fs_info->delalloc_batch);
1108         WARN_ON_ONCE(flags & (1 << BTRFS_ORDERED_COMPRESSED));
1109         return btrfs_add_ordered_extent(BTRFS_I(inode), file_offset, len, len,
1110                                         disk_bytenr, len, 0, flags,
1111                                         ordered->compress_type);
1112 }
1113
1114 int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pre,
1115                                 u64 post)
1116 {
1117         struct inode *inode = ordered->inode;
1118         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1119         struct rb_node *node;
1120         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1121         int ret = 0;
1122
1123         trace_btrfs_ordered_extent_split(BTRFS_I(inode), ordered);
1124
1125         spin_lock_irq(&tree->lock);
1126         /* Remove from tree once */
1127         node = &ordered->rb_node;
1128         rb_erase(node, &tree->tree);
1129         RB_CLEAR_NODE(node);
1130         if (tree->last == node)
1131                 tree->last = NULL;
1132
1133         ordered->file_offset += pre;
1134         ordered->disk_bytenr += pre;
1135         ordered->num_bytes -= (pre + post);
1136         ordered->disk_num_bytes -= (pre + post);
1137         ordered->bytes_left -= (pre + post);
1138
1139         /* Re-insert the node */
1140         node = tree_insert(&tree->tree, ordered->file_offset, &ordered->rb_node);
1141         if (node)
1142                 btrfs_panic(fs_info, -EEXIST,
1143                         "zoned: inconsistency in ordered tree at offset %llu",
1144                             ordered->file_offset);
1145
1146         spin_unlock_irq(&tree->lock);
1147
1148         if (pre)
1149                 ret = clone_ordered_extent(ordered, 0, pre);
1150         if (ret == 0 && post)
1151                 ret = clone_ordered_extent(ordered, pre + ordered->disk_num_bytes,
1152                                            post);
1153
1154         return ret;
1155 }
1156
1157 int __init ordered_data_init(void)
1158 {
1159         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1160                                      sizeof(struct btrfs_ordered_extent), 0,
1161                                      SLAB_MEM_SPREAD,
1162                                      NULL);
1163         if (!btrfs_ordered_extent_cache)
1164                 return -ENOMEM;
1165
1166         return 0;
1167 }
1168
1169 void __cold ordered_data_exit(void)
1170 {
1171         kmem_cache_destroy(btrfs_ordered_extent_cache);
1172 }