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