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                 if (waitqueue_active(&entry->wait))
 349                         wake_up(&entry->wait);
 350         } else {
 351                 ret = 1;
 352         }
 353 out:
 354         if (!ret && cached && entry) {
 355                 *cached = entry;
 356                 atomic_inc(&entry->refs);
 357         }
 358         spin_unlock_irqrestore(&tree->lock, flags);
 359         return ret == 0;
 360 }
 361
 362 /*
 363  * this is used to account for finished IO across a given range
 364  * of the file.  The IO should not span ordered extents.  If
 365  * a given ordered_extent is completely done, 1 is returned, otherwise
 366  * 0.
 367  *
 368  * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
 369  * to make sure this function only returns 1 once for a given ordered extent.
 370  */
 371 int btrfs_dec_test_ordered_pending(struct inode *inode,
 372                                    struct btrfs_ordered_extent **cached,
 373                                    u64 file_offset, u64 io_size, int uptodate)
 374 {
 375         struct btrfs_ordered_inode_tree *tree;
 376         struct rb_node *node;
 377         struct btrfs_ordered_extent *entry = NULL;
 378         unsigned long flags;
 379         int ret;
 380
 381         tree = &BTRFS_I(inode)->ordered_tree;
 382         spin_lock_irqsave(&tree->lock, flags);
 383         if (cached && *cached) {
 384                 entry = *cached;
 385                 goto have_entry;
 386         }
 387
 388         node = tree_search(tree, file_offset);
 389         if (!node) {
 390                 ret = 1;
 391                 goto out;
 392         }
 393
 394         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 395 have_entry:
 396         if (!offset_in_entry(entry, file_offset)) {
 397                 ret = 1;
 398                 goto out;
 399         }
 400
 401         if (io_size > entry->bytes_left) {
 402                 btrfs_crit(BTRFS_I(inode)->root->fs_info,
 403                            "bad ordered accounting left %llu size %llu",
 404                        entry->bytes_left, io_size);
 405         }
 406         entry->bytes_left -= io_size;
 407         if (!uptodate)
 408                 set_bit(BTRFS_ORDERED_IOERR, &entry->flags);
 409
 410         if (entry->bytes_left == 0) {
 411                 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
 412                 if (waitqueue_active(&entry->wait))
 413                         wake_up(&entry->wait);
 414         } else {
 415                 ret = 1;
 416         }
 417 out:
 418         if (!ret && cached && entry) {
 419                 *cached = entry;
 420                 atomic_inc(&entry->refs);
 421         }
 422         spin_unlock_irqrestore(&tree->lock, flags);
 423         return ret == 0;
 424 }
 425
 426 /* Needs to either be called under a log transaction or the log_mutex */
 427 void btrfs_get_logged_extents(struct inode *inode,
 428                               struct list_head *logged_list,
 429                               const loff_t start,
 430                               const loff_t end)
 431 {
 432         struct btrfs_ordered_inode_tree *tree;
 433         struct btrfs_ordered_extent *ordered;
 434         struct rb_node *n;
 435         struct rb_node *prev;
 436
 437         tree = &BTRFS_I(inode)->ordered_tree;
 438         spin_lock_irq(&tree->lock);
 439         n = __tree_search(&tree->tree, end, &prev);
 440         if (!n)
 441                 n = prev;
 442         for (; n; n = rb_prev(n)) {
 443                 ordered = rb_entry(n, struct btrfs_ordered_extent, rb_node);
 444                 if (ordered->file_offset > end)
 445                         continue;
 446                 if (entry_end(ordered) <= start)
 447                         break;
 448                 if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags))
 449                         continue;
 450                 list_add(&ordered->log_list, logged_list);
 451                 atomic_inc(&ordered->refs);
 452         }
 453         spin_unlock_irq(&tree->lock);
 454 }
 455
 456 void btrfs_put_logged_extents(struct list_head *logged_list)
 457 {
 458         struct btrfs_ordered_extent *ordered;
 459
 460         while (!list_empty(logged_list)) {
 461                 ordered = list_first_entry(logged_list,
 462                                            struct btrfs_ordered_extent,
 463                                            log_list);
 464                 list_del_init(&ordered->log_list);
 465                 btrfs_put_ordered_extent(ordered);
 466         }
 467 }
 468
 469 void btrfs_submit_logged_extents(struct list_head *logged_list,
 470                                  struct btrfs_root *log)
 471 {
 472         int index = log->log_transid % 2;
 473
 474         spin_lock_irq(&log->log_extents_lock[index]);
 475         list_splice_tail(logged_list, &log->logged_list[index]);
 476         spin_unlock_irq(&log->log_extents_lock[index]);
 477 }
 478
 479 void btrfs_wait_logged_extents(struct btrfs_trans_handle *trans,
 480                                struct btrfs_root *log, u64 transid)
 481 {
 482         struct btrfs_ordered_extent *ordered;
 483         int index = transid % 2;
 484
 485         spin_lock_irq(&log->log_extents_lock[index]);
 486         while (!list_empty(&log->logged_list[index])) {
 487                 ordered = list_first_entry(&log->logged_list[index],
 488                                            struct btrfs_ordered_extent,
 489                                            log_list);
 490                 list_del_init(&ordered->log_list);
 491                 spin_unlock_irq(&log->log_extents_lock[index]);
 492
 493                 if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
 494                     !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
 495                         struct inode *inode = ordered->inode;
 496                         u64 start = ordered->file_offset;
 497                         u64 end = ordered->file_offset + ordered->len - 1;
 498
 499                         WARN_ON(!inode);
 500                         filemap_fdatawrite_range(inode->i_mapping, start, end);
 501                 }
 502                 wait_event(ordered->wait, test_bit(BTRFS_ORDERED_IO_DONE,
 503                                                    &ordered->flags));
 504
 505                 list_add_tail(&ordered->trans_list, &trans->ordered);
 506                 spin_lock_irq(&log->log_extents_lock[index]);
 507         }
 508         spin_unlock_irq(&log->log_extents_lock[index]);
 509 }
 510
 511 void btrfs_free_logged_extents(struct btrfs_root *log, u64 transid)
 512 {
 513         struct btrfs_ordered_extent *ordered;
 514         int index = transid % 2;
 515
 516         spin_lock_irq(&log->log_extents_lock[index]);
 517         while (!list_empty(&log->logged_list[index])) {
 518                 ordered = list_first_entry(&log->logged_list[index],
 519                                            struct btrfs_ordered_extent,
 520                                            log_list);
 521                 list_del_init(&ordered->log_list);
 522                 spin_unlock_irq(&log->log_extents_lock[index]);
 523                 btrfs_put_ordered_extent(ordered);
 524                 spin_lock_irq(&log->log_extents_lock[index]);
 525         }
 526         spin_unlock_irq(&log->log_extents_lock[index]);
 527 }
 528
 529 /*
 530  * used to drop a reference on an ordered extent.  This will free
 531  * the extent if the last reference is dropped
 532  */
 533 void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
 534 {
 535         struct list_head *cur;
 536         struct btrfs_ordered_sum *sum;
 537
 538         trace_btrfs_ordered_extent_put(entry->inode, entry);
 539
 540         if (atomic_dec_and_test(&entry->refs)) {
 541                 if (entry->inode)
 542                         btrfs_add_delayed_iput(entry->inode);
 543                 while (!list_empty(&entry->list)) {
 544                         cur = entry->list.next;
 545                         sum = list_entry(cur, struct btrfs_ordered_sum, list);
 546                         list_del(&sum->list);
 547                         kfree(sum);
 548                 }
 549                 kmem_cache_free(btrfs_ordered_extent_cache, entry);
 550         }
 551 }
 552
 553 /*
 554  * remove an ordered extent from the tree.  No references are dropped
 555  * and waiters are woken up.
 556  */
 557 void btrfs_remove_ordered_extent(struct inode *inode,
 558                                  struct btrfs_ordered_extent *entry)
 559 {
 560         struct btrfs_ordered_inode_tree *tree;
 561         struct btrfs_root *root = BTRFS_I(inode)->root;
 562         struct rb_node *node;
 563
 564         tree = &BTRFS_I(inode)->ordered_tree;
 565         spin_lock_irq(&tree->lock);
 566         node = &entry->rb_node;
 567         rb_erase(node, &tree->tree);
 568         if (tree->last == node)
 569                 tree->last = NULL;
 570         set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
 571         spin_unlock_irq(&tree->lock);
 572
 573         spin_lock(&root->ordered_extent_lock);
 574         list_del_init(&entry->root_extent_list);
 575         root->nr_ordered_extents--;
 576
 577         trace_btrfs_ordered_extent_remove(inode, entry);
 578
 579         if (!root->nr_ordered_extents) {
 580                 spin_lock(&root->fs_info->ordered_root_lock);
 581                 BUG_ON(list_empty(&root->ordered_root));
 582                 list_del_init(&root->ordered_root);
 583                 spin_unlock(&root->fs_info->ordered_root_lock);
 584         }
 585         spin_unlock(&root->ordered_extent_lock);
 586         wake_up(&entry->wait);
 587 }
 588
 589 static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
 590 {
 591         struct btrfs_ordered_extent *ordered;
 592
 593         ordered = container_of(work, struct btrfs_ordered_extent, flush_work);
 594         btrfs_start_ordered_extent(ordered->inode, ordered, 1);
 595         complete(&ordered->completion);
 596 }
 597
 598 /*
 599  * wait for all the ordered extents in a root.  This is done when balancing
 600  * space between drives.
 601  */
 602 int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr)
 603 {
 604         struct list_head splice, works;
 605         struct btrfs_ordered_extent *ordered, *next;
 606         int count = 0;
 607
 608         INIT_LIST_HEAD(&splice);
 609         INIT_LIST_HEAD(&works);
 610
 611         mutex_lock(&root->ordered_extent_mutex);
 612         spin_lock(&root->ordered_extent_lock);
 613         list_splice_init(&root->ordered_extents, &splice);
 614         while (!list_empty(&splice) && nr) {
 615                 ordered = list_first_entry(&splice, struct btrfs_ordered_extent,
 616                                            root_extent_list);
 617                 list_move_tail(&ordered->root_extent_list,
 618                                &root->ordered_extents);
 619                 atomic_inc(&ordered->refs);
 620                 spin_unlock(&root->ordered_extent_lock);
 621
 622                 btrfs_init_work(&ordered->flush_work,
 623                                 btrfs_flush_delalloc_helper,
 624                                 btrfs_run_ordered_extent_work, NULL, NULL);
 625                 list_add_tail(&ordered->work_list, &works);
 626                 btrfs_queue_work(root->fs_info->flush_workers,
 627                                  &ordered->flush_work);
 628
 629                 cond_resched();
 630                 spin_lock(&root->ordered_extent_lock);
 631                 if (nr != -1)
 632                         nr--;
 633                 count++;
 634         }
 635         list_splice_tail(&splice, &root->ordered_extents);
 636         spin_unlock(&root->ordered_extent_lock);
 637
 638         list_for_each_entry_safe(ordered, next, &works, work_list) {
 639                 list_del_init(&ordered->work_list);
 640                 wait_for_completion(&ordered->completion);
 641                 btrfs_put_ordered_extent(ordered);
 642                 cond_resched();
 643         }
 644         mutex_unlock(&root->ordered_extent_mutex);
 645
 646         return count;
 647 }
 648
 649 void btrfs_wait_ordered_roots(struct btrfs_fs_info *fs_info, int nr)
 650 {
 651         struct btrfs_root *root;
 652         struct list_head splice;
 653         int done;
 654
 655         INIT_LIST_HEAD(&splice);
 656
 657         mutex_lock(&fs_info->ordered_operations_mutex);
 658         spin_lock(&fs_info->ordered_root_lock);
 659         list_splice_init(&fs_info->ordered_roots, &splice);
 660         while (!list_empty(&splice) && nr) {
 661                 root = list_first_entry(&splice, struct btrfs_root,
 662                                         ordered_root);
 663                 root = btrfs_grab_fs_root(root);
 664                 BUG_ON(!root);
 665                 list_move_tail(&root->ordered_root,
 666                                &fs_info->ordered_roots);
 667                 spin_unlock(&fs_info->ordered_root_lock);
 668
 669                 done = btrfs_wait_ordered_extents(root, nr);
 670                 btrfs_put_fs_root(root);
 671
 672                 spin_lock(&fs_info->ordered_root_lock);
 673                 if (nr != -1) {
 674                         nr -= done;
 675                         WARN_ON(nr < 0);
 676                 }
 677         }
 678         list_splice_tail(&splice, &fs_info->ordered_roots);
 679         spin_unlock(&fs_info->ordered_root_lock);
 680         mutex_unlock(&fs_info->ordered_operations_mutex);
 681 }
 682
 683 /*
 684  * Used to start IO or wait for a given ordered extent to finish.
 685  *
 686  * If wait is one, this effectively waits on page writeback for all the pages
 687  * in the extent, and it waits on the io completion code to insert
 688  * metadata into the btree corresponding to the extent
 689  */
 690 void btrfs_start_ordered_extent(struct inode *inode,
 691                                        struct btrfs_ordered_extent *entry,
 692                                        int wait)
 693 {
 694         u64 start = entry->file_offset;
 695         u64 end = start + entry->len - 1;
 696
 697         trace_btrfs_ordered_extent_start(inode, entry);
 698
 699         /*
 700          * pages in the range can be dirty, clean or writeback.  We
 701          * start IO on any dirty ones so the wait doesn't stall waiting
 702          * for the flusher thread to find them
 703          */
 704         if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
 705                 filemap_fdatawrite_range(inode->i_mapping, start, end);
 706         if (wait) {
 707                 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
 708                                                  &entry->flags));
 709         }
 710 }
 711
 712 /*
 713  * Used to wait on ordered extents across a large range of bytes.
 714  */
 715 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
 716 {
 717         int ret = 0;
 718         int ret_wb = 0;
 719         u64 end;
 720         u64 orig_end;
 721         struct btrfs_ordered_extent *ordered;
 722
 723         if (start + len < start) {
 724                 orig_end = INT_LIMIT(loff_t);
 725         } else {
 726                 orig_end = start + len - 1;
 727                 if (orig_end > INT_LIMIT(loff_t))
 728                         orig_end = INT_LIMIT(loff_t);
 729         }
 730
 731         /* start IO across the range first to instantiate any delalloc
 732          * extents
 733          */
 734         ret = btrfs_fdatawrite_range(inode, start, orig_end);
 735         if (ret)
 736                 return ret;
 737
 738         /*
 739          * If we have a writeback error don't return immediately. Wait first
 740          * for any ordered extents that haven't completed yet. This is to make
 741          * sure no one can dirty the same page ranges and call writepages()
 742          * before the ordered extents complete - to avoid failures (-EEXIST)
 743          * when adding the new ordered extents to the ordered tree.
 744          */
 745         ret_wb = filemap_fdatawait_range(inode->i_mapping, start, orig_end);
 746
 747         end = orig_end;
 748         while (1) {
 749                 ordered = btrfs_lookup_first_ordered_extent(inode, end);
 750                 if (!ordered)
 751                         break;
 752                 if (ordered->file_offset > orig_end) {
 753                         btrfs_put_ordered_extent(ordered);
 754                         break;
 755                 }
 756                 if (ordered->file_offset + ordered->len <= start) {
 757                         btrfs_put_ordered_extent(ordered);
 758                         break;
 759                 }
 760                 btrfs_start_ordered_extent(inode, ordered, 1);
 761                 end = ordered->file_offset;
 762                 if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags))
 763                         ret = -EIO;
 764                 btrfs_put_ordered_extent(ordered);
 765                 if (ret || end == 0 || end == start)
 766                         break;
 767                 end--;
 768         }
 769         return ret_wb ? ret_wb : ret;
 770 }
 771
 772 /*
 773  * find an ordered extent corresponding to file_offset.  return NULL if
 774  * nothing is found, otherwise take a reference on the extent and return it
 775  */
 776 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
 777                                                          u64 file_offset)
 778 {
 779         struct btrfs_ordered_inode_tree *tree;
 780         struct rb_node *node;
 781         struct btrfs_ordered_extent *entry = NULL;
 782
 783         tree = &BTRFS_I(inode)->ordered_tree;
 784         spin_lock_irq(&tree->lock);
 785         node = tree_search(tree, file_offset);
 786         if (!node)
 787                 goto out;
 788
 789         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 790         if (!offset_in_entry(entry, file_offset))
 791                 entry = NULL;
 792         if (entry)
 793                 atomic_inc(&entry->refs);
 794 out:
 795         spin_unlock_irq(&tree->lock);
 796         return entry;
 797 }
 798
 799 /* Since the DIO code tries to lock a wide area we need to look for any ordered
 800  * extents that exist in the range, rather than just the start of the range.
 801  */
 802 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
 803                                                         u64 file_offset,
 804                                                         u64 len)
 805 {
 806         struct btrfs_ordered_inode_tree *tree;
 807         struct rb_node *node;
 808         struct btrfs_ordered_extent *entry = NULL;
 809
 810         tree = &BTRFS_I(inode)->ordered_tree;
 811         spin_lock_irq(&tree->lock);
 812         node = tree_search(tree, file_offset);
 813         if (!node) {
 814                 node = tree_search(tree, file_offset + len);
 815                 if (!node)
 816                         goto out;
 817         }
 818
 819         while (1) {
 820                 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 821                 if (range_overlaps(entry, file_offset, len))
 822                         break;
 823
 824                 if (entry->file_offset >= file_offset + len) {
 825                         entry = NULL;
 826                         break;
 827                 }
 828                 entry = NULL;
 829                 node = rb_next(node);
 830                 if (!node)
 831                         break;
 832         }
 833 out:
 834         if (entry)
 835                 atomic_inc(&entry->refs);
 836         spin_unlock_irq(&tree->lock);
 837         return entry;
 838 }
 839
 840 /*
 841  * lookup and return any extent before 'file_offset'.  NULL is returned
 842  * if none is found
 843  */
 844 struct btrfs_ordered_extent *
 845 btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
 846 {
 847         struct btrfs_ordered_inode_tree *tree;
 848         struct rb_node *node;
 849         struct btrfs_ordered_extent *entry = NULL;
 850
 851         tree = &BTRFS_I(inode)->ordered_tree;
 852         spin_lock_irq(&tree->lock);
 853         node = tree_search(tree, file_offset);
 854         if (!node)
 855                 goto out;
 856
 857         entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 858         atomic_inc(&entry->refs);
 859 out:
 860         spin_unlock_irq(&tree->lock);
 861         return entry;
 862 }
 863
 864 /*
 865  * After an extent is done, call this to conditionally update the on disk
 866  * i_size.  i_size is updated to cover any fully written part of the file.
 867  */
 868 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
 869                                 struct btrfs_ordered_extent *ordered)
 870 {
 871         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 872         u64 disk_i_size;
 873         u64 new_i_size;
 874         u64 i_size = i_size_read(inode);
 875         struct rb_node *node;
 876         struct rb_node *prev = NULL;
 877         struct btrfs_ordered_extent *test;
 878         int ret = 1;
 879
 880         spin_lock_irq(&tree->lock);
 881         if (ordered) {
 882                 offset = entry_end(ordered);
 883                 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags))
 884                         offset = min(offset,
 885                                      ordered->file_offset +
 886                                      ordered->truncated_len);
 887         } else {
 888                 offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
 889         }
 890         disk_i_size = BTRFS_I(inode)->disk_i_size;
 891
 892         /* truncate file */
 893         if (disk_i_size > i_size) {
 894                 BTRFS_I(inode)->disk_i_size = i_size;
 895                 ret = 0;
 896                 goto out;
 897         }
 898
 899         /*
 900          * if the disk i_size is already at the inode->i_size, or
 901          * this ordered extent is inside the disk i_size, we're done
 902          */
 903         if (disk_i_size == i_size)
 904                 goto out;
 905
 906         /*
 907          * We still need to update disk_i_size if outstanding_isize is greater
 908          * than disk_i_size.
 909          */
 910         if (offset <= disk_i_size &&
 911             (!ordered || ordered->outstanding_isize <= disk_i_size))
 912                 goto out;
 913
 914         /*
 915          * walk backward from this ordered extent to disk_i_size.
 916          * if we find an ordered extent then we can't update disk i_size
 917          * yet
 918          */
 919         if (ordered) {
 920                 node = rb_prev(&ordered->rb_node);
 921         } else {
 922                 prev = tree_search(tree, offset);
 923                 /*
 924                  * we insert file extents without involving ordered struct,
 925                  * so there should be no ordered struct cover this offset
 926                  */
 927                 if (prev) {
 928                         test = rb_entry(prev, struct btrfs_ordered_extent,
 929                                         rb_node);
 930                         BUG_ON(offset_in_entry(test, offset));
 931                 }
 932                 node = prev;
 933         }
 934         for (; node; node = rb_prev(node)) {
 935                 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
 936
 937                 /* We treat this entry as if it doesnt exist */
 938                 if (test_bit(BTRFS_ORDERED_UPDATED_ISIZE, &test->flags))
 939                         continue;
 940                 if (test->file_offset + test->len <= disk_i_size)
 941                         break;
 942                 if (test->file_offset >= i_size)
 943                         break;
 944                 if (entry_end(test) > disk_i_size) {
 945                         /*
 946                          * we don't update disk_i_size now, so record this
 947                          * undealt i_size. Or we will not know the real
 948                          * i_size.
 949                          */
 950                         if (test->outstanding_isize < offset)
 951                                 test->outstanding_isize = offset;
 952                         if (ordered &&
 953                             ordered->outstanding_isize >
 954                             test->outstanding_isize)
 955                                 test->outstanding_isize =
 956                                                 ordered->outstanding_isize;
 957                         goto out;
 958                 }
 959         }
 960         new_i_size = min_t(u64, offset, i_size);
 961
 962         /*
 963          * Some ordered extents may completed before the current one, and
 964          * we hold the real i_size in ->outstanding_isize.
 965          */
 966         if (ordered && ordered->outstanding_isize > new_i_size)
 967                 new_i_size = min_t(u64, ordered->outstanding_isize, i_size);
 968         BTRFS_I(inode)->disk_i_size = new_i_size;
 969         ret = 0;
 970 out:
 971         /*
 972          * We need to do this because we can't remove ordered extents until
 973          * after the i_disk_size has been updated and then the inode has been
 974          * updated to reflect the change, so we need to tell anybody who finds
 975          * this ordered extent that we've already done all the real work, we
 976          * just haven't completed all the other work.
 977          */
 978         if (ordered)
 979                 set_bit(BTRFS_ORDERED_UPDATED_ISIZE, &ordered->flags);
 980         spin_unlock_irq(&tree->lock);
 981         return ret;
 982 }
 983
 984 /*
 985  * search the ordered extents for one corresponding to 'offset' and
 986  * try to find a checksum.  This is used because we allow pages to
 987  * be reclaimed before their checksum is actually put into the btree
 988  */
 989 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
 990                            u32 *sum, int len)
 991 {
 992         struct btrfs_ordered_sum *ordered_sum;
 993         struct btrfs_ordered_extent *ordered;
 994         struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 995         unsigned long num_sectors;
 996         unsigned long i;
 997         u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
 998         int index = 0;
 999
1000         ordered = btrfs_lookup_ordered_extent(inode, offset);
1001         if (!ordered)
1002                 return 0;
1003
1004         spin_lock_irq(&tree->lock);
1005         list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
1006                 if (disk_bytenr >= ordered_sum->bytenr &&
1007                     disk_bytenr < ordered_sum->bytenr + ordered_sum->len) {
1008                         i = (disk_bytenr - ordered_sum->bytenr) >>
1009                             inode->i_sb->s_blocksize_bits;
1010                         num_sectors = ordered_sum->len >>
1011                                       inode->i_sb->s_blocksize_bits;
1012                         num_sectors = min_t(int, len - index, num_sectors - i);
1013                         memcpy(sum + index, ordered_sum->sums + i,
1014                                num_sectors);
1015
1016                         index += (int)num_sectors;
1017                         if (index == len)
1018                                 goto out;
1019                         disk_bytenr += num_sectors * sectorsize;
1020                 }
1021         }
1022 out:
1023         spin_unlock_irq(&tree->lock);
1024         btrfs_put_ordered_extent(ordered);
1025         return index;
1026 }
1027
1028 int __init ordered_data_init(void)
1029 {
1030         btrfs_ordered_extent_cache = kmem_cache_create("btrfs_ordered_extent",
1031                                      sizeof(struct btrfs_ordered_extent), 0,
1032                                      SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
1033                                      NULL);
1034         if (!btrfs_ordered_extent_cache)
1035                 return -ENOMEM;
1036
1037         return 0;
1038 }
1039
1040 void ordered_data_exit(void)
1041 {
1042         if (btrfs_ordered_extent_cache)
1043                 kmem_cache_destroy(btrfs_ordered_extent_cache);
1044 }