fs/btrfs/ordered-data.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/slab.h>
  20 #include <linux/blkdev.h>
  21 #include <linux/writeback.h>
  22 #include <linux/pagevec.h>
  23 #include "ctree.h"
  24 #include "transaction.h"
  25 #include "btrfs_inode.h"
  26 #include "extent_io.h"
  27 #include "disk-io.h"
  28 #include "compression.h"
  29
  30 static struct kmem_cache *btrfs_ordered_extent_cache;
  31
  32 static u64 entry_end(struct btrfs_ordered_extent *entry)
  33 {
  34         if (entry->file_offset + entry->len < entry->file_offset)
  35                 return (u64)-1;
  36         return entry->file_offset + entry->len;
  37 }
  38
  39 /* returns NULL if the insertion worked, or it returns the node it did find
  40  * in the tree
  41  */
  42 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
  43                                    struct rb_node *node)
  44 {
  45         struct rb_node **p = &root->rb_node;
  46         struct rb_node *parent = NULL;
  47         struct btrfs_ordered_extent *entry;
  48
  49         while (*p) {
  50                 parent = *p;
  51                 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
  52
  53                 if (file_offset < entry->file_offset)
  54                         p = &(*p)->rb_left;
  55                 else if (file_offset >= entry_end(entry))
  56                         p = &(*p)->rb_right;
  57                 else
  58                         return parent;
  59         }
  60
  61         rb_link_node(node, parent, p);
  62         rb_insert_color(node, root);
  63         return NULL;
  64 }
  65
  66 static void ordered_data_tree_panic(struct inode *inode, int errno,
  67                                                u64 offset)
  68 {
  69         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
  70         btrfs_panic(fs_info, errno, "Inconsistency in ordered tree at offset "
  71                     "%llu", offset);
  72 }
  73
  74 /*
  75  * look for a given offset in the tree, and if it can't be found return the
  76  * first lesser offset
  77  */
  78 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
  79                                      struct rb_node **prev_ret)
  80 {
  81         struct rb_node *n = root->rb_node;
  82         struct rb_node *prev = NULL;
  83         struct rb_node *test;
  84         struct btrfs_ordered_extent *entry;
  85         struct btrfs_ordered_extent *prev_entry = NULL;
  86
  87         while (n) {
  88                 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
  89                 prev = n;
  90                 prev_entry = entry;
  91
  92                 if (file_offset < entry->file_offset)
  93                         n = n->rb_left;
  94                 else if (file_offset >= entry_end(entry))
  95                         n = n->rb_right;
  96                 else
  97                         return n;
  98         }
  99         if (!prev_ret)
 100                 return NULL;
 101
 102         while (prev && file_offset >= entry_end(prev_entry)) {
 103                 test = rb_next(prev);
 104                 if (!test)
 105                         break;
 106                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 107                                       rb_node);
 108                 if (file_offset < entry_end(prev_entry))
 109                         break;
 110
 111                 prev = test;
 112         }
 113         if (prev)
 114                 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
 115                                       rb_node);
 116         while (prev && file_offset < entry_end(prev_entry)) {
 117                 test = rb_prev(prev);
 118                 if (!test)
 119                         break;
 120                 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
 121                                       rb_node);
 122                 prev = test;
 123         }
 124         *prev_ret = prev;
 125         return NULL;
 126 }
 127
 128 /*
 129  * helper to check if a given offset is inside a given entry
 130  */
 131 static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
 132 {
 133         if (file_offset < entry->file_offset ||
 134             entry->file_offset + entry->len <= file_offset)
 135                 return 0;
 136         return 1;
 137 }
 138
 139 static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
 140                           u64 len)
 141 {
 142         if (file_offset + len <= entry->file_offset ||
 143             entry->file_offset + entry->len <= file_offset)
 144                 return 0;
 145         return 1;
 146 }
 147
 148 /*
 149  * look find the first ordered struct that has this offset, otherwise
 150  * the first one less than this offset
 151  */
 152 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
 153                                           u64 file_offset)
 154 {
 155         struct rb_root *root = &tree->tree;
 156         struct rb_node *prev = NULL;
 157         struct rb_node *ret;
 158         struct btrfs_ordered_extent *entry;
 159
 160         if (tree->last) {
 161                 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
 162                                  rb_node);
 163                 if (offset_in_entry(entry, file_offset))
 164                         return tree->last;
 165         }
 166         ret = __tree_search(root, file_offset, &prev);
 167         if (!ret)
 168                 ret = prev;
 169         if (ret)
 170                 tree->last = ret;
 171         return ret;
 172 }
 173
 174 /* allocate and add a new ordered_extent into the per-inode tree.
 175  * file_offset is the logical offset in the file
 176  *
 177  * start is the disk block number of an extent already reserved in the
 178  * extent allocation tree
 179  *
 180  * len is the length of the extent
 181  *
 182  * The tree is given a single reference on the ordered extent that was
 183  * inserted.
 184  */
 185 static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 186                                       u64 start, u64 len, u64 disk_len,
 187                                       int type, int dio, int compress_type)
 188 {
 189         struct btrfs_root *root = BTRFS_I(inode)->root;
 190         struct btrfs_ordered_inode_tree *tree;
 191         struct rb_node *node;
 192         struct btrfs_ordered_extent *entry;
 193
 194         tree = &BTRFS_I(inode)->ordered_tree;
 195         entry = kmem_cache_zalloc(btrfs_ordered_extent_cache, GFP_NOFS);
 196         if (!entry)
 197                 return -ENOMEM;
 198
 199         entry->file_offset = file_offset;
 200         entry->start = start;
 201         entry->len = len;
 202         entry->disk_len = disk_len;
 203         entry->bytes_left = len;
 204         entry->inode = igrab(inode);
 205         entry->compress_type = compress_type;
 206         entry->truncated_len = (u64)-1;
 207         if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
 208                 set_bit(type, &entry->flags);
 209
 210         if (dio)
 211                 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
 212
 213         /* one ref for the tree */
 214         atomic_set(&entry->refs, 1);
 215         init_waitqueue_head(&entry->wait);
 216         INIT_LIST_HEAD(&entry->list);
 217         INIT_LIST_HEAD(&entry->root_extent_list);
 218         INIT_LIST_HEAD(&entry->work_list);
 219         init_completion(&entry->completion);
 220         INIT_LIST_HEAD(&entry->log_list);
 221         INIT_LIST_HEAD(&entry->trans_list);
 222
 223         trace_btrfs_ordered_extent_add(inode, entry);
 224
 225         spin_lock_irq(&tree->lock);
 226         node = tree_insert(&tree->tree, file_offset,
 227                            &entry->rb_node);
 228         if (node)
 229                 ordered_data_tree_panic(inode, -EEXIST, file_offset);
 230         spin_unlock_irq(&tree->lock);
 231
 232         spin_lock(&root->ordered_extent_lock);
 233         list_add_tail(&entry->root_extent_list,
 234                       &root->ordered_extents);
 235         root->nr_ordered_extents++;
 236         if (root->nr_ordered_extents == 1) {
 237                 spin_lock(&root->fs_info->ordered_root_lock);
 238                 BUG_ON(!list_empty(&root->ordered_root));
 239                 list_add_tail(&root->ordered_root,
 240                               &root->fs_info->ordered_roots);
 241                 spin_unlock(&root->fs_info->ordered_root_lock);
 242         }
 243         spin_unlock(&root->ordered_extent_lock);
 244
 245         return 0;
 246 }
 247
 248 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
 249                              u64 start, u64 len, u64 disk_len, int type)
 250 {
 251         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 252                                           disk_len, type, 0,
 253                                           BTRFS_COMPRESS_NONE);
 254 }
 255
 256 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
 257                                  u64 start, u64 len, u64 disk_len, int type)
 258 {
 259         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 260                                           disk_len, type, 1,
 261                                           BTRFS_COMPRESS_NONE);
 262 }
 263
 264 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
 265                                       u64 start, u64 len, u64 disk_len,
 266                                       int type, int compress_type)
 267 {
 268         return __btrfs_add_ordered_extent(inode, file_offset, start, len,
 269                                           disk_len, type, 0,
 270                                           compress_type);
 271 }
 272
 273 /*
 274  * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
 275  * when an ordered extent is finished.  If the list covers more than one
 276  * ordered extent, it is split across multiples.
 277  */
 278 void btrfs_add_ordered_sum(struct inode *inode,
 279                            struct btrfs_ordered_extent *entry,
 280                            struct btrfs_ordered_sum *sum)
 281 {
 282         struct btrfs_ordered_inode_tree *tree;
 283
 284         tree = &BTRFS_I(inode)->ordered_tree;
 285         spin_lock_irq(&tree->lock);
 286         list_add_tail(&sum->list, &entry->list);
 287         spin_unlock_irq(&tree->lock);
 288 }
 289
 290 /*
 291  * this is used to account for finished IO across a given range
 292  * of the file.  The IO may span ordered extents.  If
 293  * a given ordered_extent is completely done, 1 is returned, otherwise
 294  * 0.
 295  *
 296  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 297  * to make sure this function only returns 1 once for a given ordered extent.
 298  *
 299  * file_offset is updated to one byte past the range that is recorded as
 300  * complete.  This allows you to walk forward in the file.
 301  */
 302 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
 303                                    struct btrfs_ordered_extent **cached,
 304                                    u64 *file_offset, u64 io_size, int uptodate)
 305 {
 306         struct btrfs_ordered_inode_tree *tree;
 307         struct rb_node *node;
 308         struct btrfs_ordered_extent *entry = NULL;
 309         int ret;
 310         unsigned long flags;
 311         u64 dec_end;
 312         u64 dec_start;
 313         u64 to_dec;
 314
 315         tree = &BTRFS_I(inode)->ordered_tree;
 316         spin_lock_irqsave(&tree->lock, flags);
 317         node = tree_search(tree, *file_offset);
 318         if (!node) {
 319                 ret = 1;
 320                 goto out;
 321         }
 322
 323         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 324         if (!offset_in_entry(entry, *file_offset)) {
 325                 ret = 1;
 326                 goto out;
 327         }
 328
 329         dec_start = max(*file_offset, entry->file_offset);
 330         dec_end = min(*file_offset + io_size, entry->file_offset +
 331                       entry->len);
 332         *file_offset = dec_end;
 333         if (dec_start > dec_end) {
 334                 btrfs_crit(BTRFS_I(inode)->root->fs_info,
 335                         "bad ordering dec_start %llu end %llu", dec_start, dec_end);
 336         }
 337         to_dec = dec_end - dec_start;
 338         if (to_dec > entry->bytes_left) {
 339                 btrfs_crit(BTRFS_I(inode)->root->fs_info,
 340                         "bad ordered accounting left %llu size %llu",
 341                         entry->bytes_left, to_dec);
 342         }
 343         entry->bytes_left -= to_dec;
 344         if (!uptodate)
 345                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 346
 347         if (entry->bytes_left == 0) {
 348                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 349                 /*
 350                  * Implicit memory barrier after test_and_set_bit
 351                  */
 352                 if (waitqueue_active(&entry->wait))
 353                         wake_up(&entry->wait);
 354         } else {
 355                 ret = 1;
 356         }
 357 out:
 358         if (!ret && cached && entry) {
 359                 *cached = entry;
 360                 atomic_inc(&entry->refs);
 361         }
 362         spin_unlock_irqrestore(&tree->lock, flags);
 363         return ret == 0;
 364 }
 365
 366 /*
 367  * this is used to account for finished IO across a given range
 368  * of the file.  The IO should not span ordered extents.  If
 369  * a given ordered_extent is completely done, 1 is returned, otherwise
 370  * 0.
 371  *
 372  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 373  * to make sure this function only returns 1 once for a given ordered extent.
 374  */
 375 int btrfs_dec_test_ordered_pending(struct inode *inode,
 376                                    struct btrfs_ordered_extent **cached,
 377                                    u64 file_offset, u64 io_size, int uptodate)
 378 {
 379         struct btrfs_ordered_inode_tree *tree;
 380         struct rb_node *node;
 381         struct btrfs_ordered_extent *entry = NULL;
 382         unsigned long flags;
 383         int ret;
 384
 385         tree = &BTRFS_I(inode)->ordered_tree;
 386         spin_lock_irqsave(&tree->lock, flags);
 387         if (cached && *cached) {
 388                 entry = *cached;
 389                 goto have_entry;
 390         }
 391
 392         node = tree_search(tree, file_offset);
 393         if (!node) {
 394                 ret = 1;
 395                 goto out;
 396         }
 397
 398         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 399 have_entry:
 400         if (!offset_in_entry(entry, file_offset)) {
 401                 ret = 1;
 402                 goto out;
 403         }
 404
 405         if (io_size > entry->bytes_left) {
 406                 btrfs_crit(BTRFS_I(inode)->root->fs_info,
 407                            "bad ordered accounting left %llu size %llu",
 408                        entry->bytes_left, io_size);
 409         }
 410         entry->bytes_left -= io_size;
 411         if (!uptodate)
 412                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 413
 414         if (entry->bytes_left == 0) {
 415                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 416                 /*
 417                  * Implicit memory barrier after test_and_set_bit
 418                  */
 419                 if (waitqueue_active(&entry->wait))
 420                         wake_up(&entry->wait);
 421         } else {
 422                 ret = 1;
 423         }
 424 out:
 425         if (!ret && cached && entry) {
 426                 *cached = entry;
 427                 atomic_inc(&entry->refs);
 428         }
 429         spin_unlock_irqrestore(&tree->lock, flags);
 430         return ret == 0;
 431 }
 432
 433 /* Needs to either be called under a log transaction or the log_mutex */
 434 void btrfs_get_logged_extents(struct inode *inode,
 435                               struct list_head *logged_list,
 436                               const loff_t start,
 437                               const loff_t end)
 438 {
 439         struct btrfs_ordered_inode_tree *tree;
 440         struct btrfs_ordered_extent *ordered;
 441         struct rb_node *n;
 442         struct rb_node *prev;
 443
 444         tree = &BTRFS_I(inode)->ordered_tree;
 445         spin_lock_irq(&tree->lock);
 446         n = __tree_search(&tree->tree, end, &prev);
 447         if (!n)
 448                 n = prev;
 449         for (; n; n = rb_prev(n)) {
 450                 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 451                 if (ordered->file_offset > end)
 452                         continue;
 453                 if (entry_end(ordered) <= start)
 454                         break;
 455                 if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 456                         continue;
 457                 list_add(&ordered->log_list, logged_list);
 458                 atomic_inc(&ordered->refs);
 459         }
 460         spin_unlock_irq(&tree->lock);
 461 }
 462
 463 void btrfs_put_logged_extents(struct list_head *logged_list)
 464 {
 465         struct btrfs_ordered_extent *ordered;
 466
 467         while (!list_empty(logged_list)) {
 468                 ordered = list_first_entry(logged_list,
 469                                            struct btrfs_ordered_extent,
 470                                            log_list);
 471                 list_del_init(&ordered->log_list);
 472                 btrfs_put_ordered_extent(ordered);
 473         }
 474 }
 475
 476 void btrfs_submit_logged_extents(struct list_head *logged_list,
 477                                  struct btrfs_root *log)
 478 {
 479         int index = log->log_transid % 2;
 480
 481         spin_lock_irq(&log->log_extents_lock[index]);
 482         list_splice_tail(logged_list, &log->logged_list[index]);
 483         spin_unlock_irq(&log->log_extents_lock[index]);
 484 }
 485
 486 void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
 487                                struct btrfs_root *log, u64 transid)
 488 {
 489         struct btrfs_ordered_extent *ordered;
 490         int index = transid % 2;
 491
 492         spin_lock_irq(&log->log_extents_lock[index]);
 493         while (!list_empty(&log->logged_list[index])) {
 494                 struct inode *inode;
 495                 ordered = list_first_entry(&log->logged_list[index],
 496                                            struct btrfs_ordered_extent,
 497                                            log_list);
 498                 list_del_init(&ordered->log_list);
 499                 inode = ordered->inode;
 500                 spin_unlock_irq(&log->log_extents_lock[index]);
 501
 502                 if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
 503                     !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
 504                         u64 start = ordered->file_offset;
 505                         u64 end = ordered->file_offset + ordered->len - 1;
 506
 507                         WARN_ON(!inode);
 508                         filemap_fdatawrite_range(inode->i_mapping, start, end);
 509                 }
 510                 wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
 511                                                    &ordered->flags));
 512
 513                 /*
 514                  * In order to keep us from losing our ordered extent
 515                  * information when committing the transaction we have to make
 516                  * sure that any logged extents are completed when we go to
 517                  * commit the transaction.  To do this we simply increase the
 518                  * current transactions pending_ordered counter and decrement it
 519                  * when the ordered extent completes.
 520                  */
 521                 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
 522                         struct btrfs_ordered_inode_tree *tree;
 523
 524                         tree = &BTRFS_I(inode)->ordered_tree;
 525                         spin_lock_irq(&tree->lock);
 526                         if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
 527                                 set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
 528                                 atomic_inc(&trans->transaction->pending_ordered);
 529                         }
 530                         spin_unlock_irq(&tree->lock);
 531                 }
 532                 btrfs_put_ordered_extent(ordered);
 533                 spin_lock_irq(&log->log_extents_lock[index]);
 534         }
 535         spin_unlock_irq(&log->log_extents_lock[index]);
 536 }
 537
 538 void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
 539 {
 540         struct btrfs_ordered_extent *ordered;
 541         int index = transid % 2;
 542
 543         spin_lock_irq(&log->log_extents_lock[index]);
 544         while (!list_empty(&log->logged_list[index])) {
 545                 ordered = list_first_entry(&log->logged_list[index],
 546                                            struct btrfs_ordered_extent,
 547                                            log_list);
 548                 list_del_init(&ordered->log_list);
 549                 spin_unlock_irq(&log->log_extents_lock[index]);
 550                 btrfs_put_ordered_extent(ordered);
 551                 spin_lock_irq(&log->log_extents_lock[index]);
 552         }
 553         spin_unlock_irq(&log->log_extents_lock[index]);
 554 }
 555
 556 /*
 557  * used to drop a reference on an ordered extent.  This will free
 558  * the extent if the last reference is dropped
 559  */
 560 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 561 {
 562         struct list_head *cur;
 563         struct btrfs_ordered_sum *sum;
 564
 565         trace_btrfs_ordered_extent_put(entry->inode, entry);
 566
 567         if (atomic_dec_and_test(&entry->refs)) {
 568                 ASSERT(list_empty(&entry->log_list));
 569                 ASSERT(list_empty(&entry->trans_list));
 570                 ASSERT(list_empty(&entry->root_extent_list));
 571                 ASSERT(RB_EMPTY_NODE(&entry->rb_node));
 572                 if (entry->inode)
 573                         btrfs_add_delayed_iput(entry->inode);
 574                 while (!list_empty(&entry->list)) {
 575                         cur = entry->list.next;
 576                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 577                         list_del(&sum->list);
 578                         kfree(sum);
 579                 }
 580                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
 581         }
 582 }
 583
 584 /*
 585  * remove an ordered extent from the tree.  No references are dropped
 586  * and waiters are woken up.
 587  */
 588 void btrfs_remove_ordered_extent(struct inode *inode,
 589                                  struct btrfs_ordered_extent *entry)
 590 {
 591         struct btrfs_ordered_inode_tree *tree;
 592         struct btrfs_root *root = BTRFS_I(inode)->root;
 593         struct rb_node *node;
 594         bool dec_pending_ordered = false;
 595
 596         tree = &BTRFS_I(inode)->ordered_tree;
 597         spin_lock_irq(&tree->lock);
 598         node = &entry->rb_node;
 599         rb_erase(node, &tree->tree);
 600         RB_CLEAR_NODE(node);
 601         if (tree->last == node)
 602                 tree->last = NULL;
 603         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 604         if (test_and_clear_bit(BTRFS_ORDERED_PENDING, &entry->flags))
 605                 dec_pending_ordered = true;
 606         spin_unlock_irq(&tree->lock);
 607
 608         /*
 609          * The current running transaction is waiting on us, we need to let it
 610          * know that we're complete and wake it up.
 611          */
 612         if (dec_pending_ordered) {
 613                 struct btrfs_transaction *trans;
 614
 615                 /*
 616                  * The checks for trans are just a formality, it should be set,
 617                  * but if it isn't we don't want to deref/assert under the spin
 618                  * lock, so be nice and check if trans is set, but ASSERT() so
 619                  * if it isn't set a developer will notice.
 620                  */
 621                 spin_lock(&root->fs_info->trans_lock);
 622                 trans = root->fs_info->running_transaction;
 623                 if (trans)
 624                         atomic_inc(&trans->use_count);
 625                 spin_unlock(&root->fs_info->trans_lock);
 626
 627                 ASSERT(trans);
 628                 if (trans) {
 629                         if (atomic_dec_and_test(&trans->pending_ordered))
 630                                 wake_up(&trans->pending_wait);
 631                         btrfs_put_transaction(trans);
 632                 }
 633         }
 634
 635         spin_lock(&root->ordered_extent_lock);
 636         list_del_init(&entry->root_extent_list);
 637         root->nr_ordered_extents--;
 638
 639         trace_btrfs_ordered_extent_remove(inode, entry);
 640
 641         if (!root->nr_ordered_extents) {
 642                 spin_lock(&root->fs_info->ordered_root_lock);
 643                 BUG_ON(list_empty(&root->ordered_root));
 644                 list_del_init(&root->ordered_root);
 645                 spin_unlock(&root->fs_info->ordered_root_lock);
 646         }
 647         spin_unlock(&root->ordered_extent_lock);
 648         wake_up(&entry->wait);
 649 }
 650
 651 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 652 {
 653         struct btrfs_ordered_extent *ordered;
 654
 655         ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 656         btrfs_start_ordered_extent(ordered->inode, ordered, 1);
 657         complete(&ordered->completion);
 658 }
 659
 660 /*
 661  * wait for all the ordered extents in a root.  This is done when balancing
 662  * space between drives.
 663  */
 664 int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr,
 665                                const u64 range_start, const u64 range_len)
 666 {
 667         LIST_HEAD(splice);
 668         LIST_HEAD(skipped);
 669         LIST_HEAD(works);
 670         struct btrfs_ordered_extent *ordered, *next;
 671         int count = 0;
 672         const u64 range_end = range_start + range_len;
 673
 674         mutex_lock(&root->ordered_extent_mutex);
 675         spin_lock(&root->ordered_extent_lock);
 676         list_splice_init(&root->ordered_extents, &splice);
 677         while (!list_empty(&splice) && nr) {
 678                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 679                                            root_extent_list);
 680
 681                 if (range_end <= ordered->start ||
 682                     ordered->start + ordered->disk_len <= range_start) {
 683                         list_move_tail(&ordered->root_extent_list, &skipped);
 684                         cond_resched_lock(&root->ordered_extent_lock);
 685                         continue;
 686                 }
 687
 688                 list_move_tail(&ordered->root_extent_list,
 689                                &root->ordered_extents);
 690                 atomic_inc(&ordered->refs);
 691                 spin_unlock(&root->ordered_extent_lock);
 692
 693                 btrfs_init_work(&ordered->flush_work,
 694                                 btrfs_flush_delalloc_helper,
 695                                 btrfs_run_ordered_extent_work, NULL, NULL);
 696                 list_add_tail(&ordered->work_list, &works);
 697                 btrfs_queue_work(root->fs_info->flush_workers,
 698                                  &ordered->flush_work);
 699
 700                 cond_resched();
 701                 spin_lock(&root->ordered_extent_lock);
 702                 if (nr != -1)
 703                         nr--;
 704                 count++;
 705         }
 706         list_splice_tail(&skipped, &root->ordered_extents);
 707         list_splice_tail(&splice, &root->ordered_extents);
 708         spin_unlock(&root->ordered_extent_lock);
 709
 710         list_for_each_entry_safe(ordered, next, &works, work_list) {
 711                 list_del_init(&ordered->work_list);
 712                 wait_for_completion(&ordered->completion);
 713                 btrfs_put_ordered_extent(ordered);
 714                 cond_resched();
 715         }
 716         mutex_unlock(&root->ordered_extent_mutex);
 717
 718         return count;
 719 }
 720
 721 int btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr,
 722                               const u64 range_start, const u64 range_len)
 723 {
 724         struct btrfs_root *root;
 725         struct list_head splice;
 726         int done;
 727         int total_done = 0;
 728
 729         INIT_LIST_HEAD(&splice);
 730
 731         mutex_lock(&fs_info->ordered_operations_mutex);
 732         spin_lock(&fs_info->ordered_root_lock);
 733         list_splice_init(&fs_info->ordered_roots, &splice);
 734         while (!list_empty(&splice) && nr) {
 735                 root = list_first_entry(&splice, struct btrfs_root,
 736                                         ordered_root);
 737                 root = btrfs_grab_fs_root(root);
 738                 BUG_ON(!root);
 739                 list_move_tail(&root->ordered_root,
 740                                &fs_info->ordered_roots);
 741                 spin_unlock(&fs_info->ordered_root_lock);
 742
 743                 done = btrfs_wait_ordered_extents(root, nr,
 744                                                   range_start, range_len);
 745                 btrfs_put_fs_root(root);
 746                 total_done += done;
 747
 748                 spin_lock(&fs_info->ordered_root_lock);
 749                 if (nr != -1) {
 750                         nr -= done;
 751                         WARN_ON(nr < 0);
 752                 }
 753         }
 754         list_splice_tail(&splice, &fs_info->ordered_roots);
 755         spin_unlock(&fs_info->ordered_root_lock);
 756         mutex_unlock(&fs_info->ordered_operations_mutex);
 757
 758         return total_done;
 759 }
 760
 761 /*
 762  * Used to start IO or wait for a given ordered extent to finish.
 763  *
 764  * If wait is one, this effectively waits on page writeback for all the pages
 765  * in the extent, and it waits on the io completion code to insert
 766  * metadata into the btree corresponding to the extent
 767  */
 768 void btrfs_start_ordered_extent(struct inode *inode,
 769                                        struct btrfs_ordered_extent *entry,
 770                                        int wait)
 771 {
 772         u64 start = entry->file_offset;
 773         u64 end = start + entry->len - 1;
 774
 775         trace_btrfs_ordered_extent_start(inode, entry);
 776
 777         /*
 778          * pages in the range can be dirty, clean or writeback.  We
 779          * start IO on any dirty ones so the wait doesn't stall waiting
 780          * for the flusher thread to find them
 781          */
 782         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 783                 filemap_fdatawrite_range(inode->i_mapping, start, end);
 784         if (wait) {
 785                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 786                                                  &entry->flags));
 787         }
 788 }
 789
 790 /*
 791  * Used to wait on ordered extents across a large range of bytes.
 792  */
 793 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 794 {
 795         int ret = 0;
 796         int ret_wb = 0;
 797         u64 end;
 798         u64 orig_end;
 799         struct btrfs_ordered_extent *ordered;
 800
 801         if (start + len < start) {
 802                 orig_end = INT_LIMIT(loff_t);
 803         } else {
 804                 orig_end = start + len - 1;
 805                 if (orig_end > INT_LIMIT(loff_t))
 806                         orig_end = INT_LIMIT(loff_t);
 807         }
 808
 809         /* start IO across the range first to instantiate any delalloc
 810          * extents
 811          */
 812         ret = btrfs_fdatawrite_range(inode, start, orig_end);
 813         if (ret)
 814                 return ret;
 815
 816         /*
 817          * If we have a writeback error don't return immediately. Wait first
 818          * for any ordered extents that haven't completed yet. This is to make
 819          * sure no one can dirty the same page ranges and call writepages()
 820          * before the ordered extents complete - to avoid failures (-EEXIST)
 821          * when adding the new ordered extents to the ordered tree.
 822          */
 823         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 824
 825         end = orig_end;
 826         while (1) {
 827                 ordered = btrfs_lookup_first_ordered_extent(inode, end);
 828                 if (!ordered)
 829                         break;
 830                 if (ordered->file_offset > orig_end) {
 831                         btrfs_put_ordered_extent(ordered);
 832                         break;
 833                 }
 834                 if (ordered->file_offset + ordered->len <= start) {
 835                         btrfs_put_ordered_extent(ordered);
 836                         break;
 837                 }
 838                 btrfs_start_ordered_extent(inode, ordered, 1);
 839                 end = ordered->file_offset;
 840                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 841                         ret = -EIO;
 842                 btrfs_put_ordered_extent(ordered);
 843                 if (ret || end == 0 || end == start)
 844                         break;
 845                 end--;
 846         }
 847         return ret_wb ? ret_wb : ret;
 848 }
 849
 850 /*
 851  * find an ordered extent corresponding to file_offset.  return NULL if
 852  * nothing is found, otherwise take a reference on the extent and return it
 853  */
 854 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 855                                                          u64 file_offset)
 856 {
 857         struct btrfs_ordered_inode_tree *tree;
 858         struct rb_node *node;
 859         struct btrfs_ordered_extent *entry = NULL;
 860
 861         tree = &BTRFS_I(inode)->ordered_tree;
 862         spin_lock_irq(&tree->lock);
 863         node = tree_search(tree, file_offset);
 864         if (!node)
 865                 goto out;
 866
 867         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 868         if (!offset_in_entry(entry, file_offset))
 869                 entry = NULL;
 870         if (entry)
 871                 atomic_inc(&entry->refs);
 872 out:
 873         spin_unlock_irq(&tree->lock);
 874         return entry;
 875 }
 876
 877 /* Since the DIO code tries to lock a wide area we need to look for any ordered
 878  * extents that exist in the range, rather than just the start of the range.
 879  */
 880 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
 881                                                         u64 file_offset,
 882                                                         u64 len)
 883 {
 884         struct btrfs_ordered_inode_tree *tree;
 885         struct rb_node *node;
 886         struct btrfs_ordered_extent *entry = NULL;
 887
 888         tree = &BTRFS_I(inode)->ordered_tree;
 889         spin_lock_irq(&tree->lock);
 890         node = tree_search(tree, file_offset);
 891         if (!node) {
 892                 node = tree_search(tree, file_offset + len);
 893                 if (!node)
 894                         goto out;
 895         }
 896
 897         while (1) {
 898                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 899                 if (range_overlaps(entry, file_offset, len))
 900                         break;
 901
 902                 if (entry->file_offset >= file_offset + len) {
 903                         entry = NULL;
 904                         break;
 905                 }
 906                 entry = NULL;
 907                 node = rb_next(node);
 908                 if (!node)
 909                         break;
 910         }
 911 out:
 912         if (entry)
 913                 atomic_inc(&entry->refs);
 914         spin_unlock_irq(&tree->lock);
 915         return entry;
 916 }
 917
 918 bool btrfs_have_ordered_extents_in_range(struct inode *inode,
 919                                          u64 file_offset,
 920                                          u64 len)
 921 {
 922         struct btrfs_ordered_extent *oe;
 923
 924         oe = btrfs_lookup_ordered_range(inode, file_offset, len);
 925         if (oe) {
 926                 btrfs_put_ordered_extent(oe);
 927                 return true;
 928         }
 929         return false;
 930 }
 931
 932 /*
 933  * lookup and return any extent before 'file_offset'.  NULL is returned
 934  * if none is found
 935  */
 936 struct btrfs_ordered_extent *
 937 btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
 938 {
 939         struct btrfs_ordered_inode_tree *tree;
 940         struct rb_node *node;
 941         struct btrfs_ordered_extent *entry = NULL;
 942
 943         tree = &BTRFS_I(inode)->ordered_tree;
 944         spin_lock_irq(&tree->lock);
 945         node = tree_search(tree, file_offset);
 946         if (!node)
 947                 goto out;
 948
 949         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 950         atomic_inc(&entry->refs);
 951 out:
 952         spin_unlock_irq(&tree->lock);
 953         return entry;
 954 }
 955
 956 /*
 957  * After an extent is done, call this to conditionally update the on disk
 958  * i_size.  i_size is updated to cover any fully written part of the file.
 959  */
 960 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 961                                 struct btrfs_ordered_extent *ordered)
 962 {
 963         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 964         u64 disk_i_size;
 965         u64 new_i_size;
 966         u64 i_size = i_size_read(inode);
 967         struct rb_node *node;
 968         struct rb_node *prev = NULL;
 969         struct btrfs_ordered_extent *test;
 970         int ret = 1;
 971         u64 orig_offset = offset;
 972
 973         spin_lock_irq(&tree->lock);
 974         if (ordered) {
 975                 offset = entry_end(ordered);
 976                 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
 977                         offset = min(offset,
 978                                      ordered->file_offset +
 979                                      ordered->truncated_len);
 980         } else {
 981                 offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
 982         }
 983         disk_i_size = BTRFS_I(inode)->disk_i_size;
 984
 985         /* truncate file */
 986         if (disk_i_size > i_size) {
 987                 BTRFS_I(inode)->disk_i_size = orig_offset;
 988                 ret = 0;
 989                 goto out;
 990         }
 991
 992         /*
 993          * if the disk i_size is already at the inode->i_size, or
 994          * this ordered extent is inside the disk i_size, we're done
 995          */
 996         if (disk_i_size == i_size)
 997                 goto out;
 998
 999         /*
1000          * We still need to update disk_i_size if outstanding_isize is greater
1001          * than disk_i_size.
1002          */
1003         if (offset <= disk_i_size &&
1004             (!ordered || ordered->outstanding_isize <= disk_i_size))
1005                 goto out;
1006
1007         /*
1008          * walk backward from this ordered extent to disk_i_size.
1009          * if we find an ordered extent then we can't update disk i_size
1010          * yet
1011          */
1012         if (ordered) {
1013                 node = rb_prev(&ordered->rb_node);
1014         } else {
1015                 prev = tree_search(tree, offset);
1016                 /*
1017                  * we insert file extents without involving ordered struct,
1018                  * so there should be no ordered struct cover this offset
1019                  */
1020                 if (prev) {
1021                         test = rb_entry(prev, struct btrfs_ordered_extent,
1022                                         rb_node);
1023                         BUG_ON(offset_in_entry(test, offset));
1024                 }
1025                 node = prev;
1026         }
1027         for (; node; node = rb_prev(node)) {
1028                 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
1029
1030                 /* We treat this entry as if it doesn't exist */
1031                 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
1032                         continue;
1033                 if (test->file_offset + test->len <= disk_i_size)
1034                         break;
1035                 if (test->file_offset >= i_size)
1036                         break;
1037                 if (entry_end(test) > disk_i_size) {
1038                         /*
1039                          * we don't update disk_i_size now, so record this
1040                          * undealt i_size. Or we will not know the real
1041                          * i_size.
1042                          */
1043                         if (test->outstanding_isize < offset)
1044                                 test->outstanding_isize = offset;
1045                         if (ordered &&
1046                             ordered->outstanding_isize >
1047                             test->outstanding_isize)
1048                                 test->outstanding_isize =
1049                                                 ordered->outstanding_isize;
1050                         goto out;
1051                 }
1052         }
1053         new_i_size = min_t(u64, offset, i_size);
1054
1055         /*
1056          * Some ordered extents may completed before the current one, and
1057          * we hold the real i_size in ->outstanding_isize.
1058          */
1059         if (ordered && ordered->outstanding_isize > new_i_size)
1060                 new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
1061         BTRFS_I(inode)->disk_i_size = new_i_size;
1062         ret = 0;
1063 out:
1064         /*
1065          * We need to do this because we can't remove ordered extents until
1066          * after the i_disk_size has been updated and then the inode has been
1067          * updated to reflect the change, so we need to tell anybody who finds
1068          * this ordered extent that we've already done all the real work, we
1069          * just haven't completed all the other work.
1070          */
1071         if (ordered)
1072                 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
1073         spin_unlock_irq(&tree->lock);
1074         return ret;
1075 }
1076
1077 /*
1078  * search the ordered extents for one corresponding to 'offset' and
1079  * try to find a checksum.  This is used because we allow pages to
1080  * be reclaimed before their checksum is actually put into the btree
1081  */
1082 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
1083                            u32 *sum, int len)
1084 {
1085         struct btrfs_ordered_sum *ordered_sum;
1086         struct btrfs_ordered_extent *ordered;
1087         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
1088         unsigned long num_sectors;
1089         unsigned long i;
1090         u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
1091         int index = 0;
1092
1093         ordered = btrfs_lookup_ordered_extent(inode, offset);
1094         if (!ordered)
1095                 return 0;
1096
1097         spin_lock_irq(&tree->lock);
1098         list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
1099                 if (disk_bytenr >= ordered_sum->bytenr &&
1100                     disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
1101                         i = (disk_bytenr - ordered_sum->bytenr) >>
1102                             inode->i_sb->s_blocksize_bits;
1103                         num_sectors = ordered_sum->len >>
1104                                       inode->i_sb->s_blocksize_bits;
1105                         num_sectors = min_t(int, len - index, num_sectors - i);
1106                         memcpy(sum + index, ordered_sum->sums + i,
1107                                num_sectors);
1108
1109                         index += (int)num_sectors;
1110                         if (index == len)
1111                                 goto out;
1112                         disk_bytenr += num_sectors * sectorsize;
1113                 }
1114         }
1115 out:
1116         spin_unlock_irq(&tree->lock);
1117         btrfs_put_ordered_extent(ordered);
1118         return index;
1119 }
1120
1121 int __init ordered_data_init(void)
1122 {
1123         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1124                                      sizeof(struct btrfs_ordered_extent), 0,
1125                                      SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
1126                                      NULL);
1127         if (!btrfs_ordered_extent_cache)
1128                 return -ENOMEM;
1129
1130         return 0;
1131 }
1132
1133 void ordered_data_exit(void)
1134 {
1135         kmem_cache_destroy(btrfs_ordered_extent_cache);
1136 }