fs/btrfs/tree-log.c

   1 /*
   2  * Copyright (C) 2008 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/sched.h>
  20 #include <linux/slab.h>
  21 #include <linux/list_sort.h>
  22 #include "ctree.h"
  23 #include "transaction.h"
  24 #include "disk-io.h"
  25 #include "locking.h"
  26 #include "print-tree.h"
  27 #include "backref.h"
  28 #include "compat.h"
  29 #include "tree-log.h"
  30 #include "hash.h"
  31
  32 /* magic values for the inode_only field in btrfs_log_inode:
  33  *
  34  * LOG_INODE_ALL means to log everything
  35  * LOG_INODE_EXISTS means to log just enough to recreate the inode
  36  * during log replay
  37  */
  38 #define LOG_INODE_ALL 0
  39 #define LOG_INODE_EXISTS 1
  40
  41 /*
  42  * directory trouble cases
  43  *
  44  * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
  45  * log, we must force a full commit before doing an fsync of the directory
  46  * where the unlink was done.
  47  * ---> record transid of last unlink/rename per directory
  48  *
  49  * mkdir foo/some_dir
  50  * normal commit
  51  * rename foo/some_dir foo2/some_dir
  52  * mkdir foo/some_dir
  53  * fsync foo/some_dir/some_file
  54  *
  55  * The fsync above will unlink the original some_dir without recording
  56  * it in its new location (foo2).  After a crash, some_dir will be gone
  57  * unless the fsync of some_file forces a full commit
  58  *
  59  * 2) we must log any new names for any file or dir that is in the fsync
  60  * log. ---> check inode while renaming/linking.
  61  *
  62  * 2a) we must log any new names for any file or dir during rename
  63  * when the directory they are being removed from was logged.
  64  * ---> check inode and old parent dir during rename
  65  *
  66  *  2a is actually the more important variant.  With the extra logging
  67  *  a crash might unlink the old name without recreating the new one
  68  *
  69  * 3) after a crash, we must go through any directories with a link count
  70  * of zero and redo the rm -rf
  71  *
  72  * mkdir f1/foo
  73  * normal commit
  74  * rm -rf f1/foo
  75  * fsync(f1)
  76  *
  77  * The directory f1 was fully removed from the FS, but fsync was never
  78  * called on f1, only its parent dir.  After a crash the rm -rf must
  79  * be replayed.  This must be able to recurse down the entire
  80  * directory tree.  The inode link count fixup code takes care of the
  81  * ugly details.
  82  */
  83
  84 /*
  85  * stages for the tree walking.  The first
  86  * stage (0) is to only pin down the blocks we find
  87  * the second stage (1) is to make sure that all the inodes
  88  * we find in the log are created in the subvolume.
  89  *
  90  * The last stage is to deal with directories and links and extents
  91  * and all the other fun semantics
  92  */
  93 #define LOG_WALK_PIN_ONLY 0
  94 #define LOG_WALK_REPLAY_INODES 1
  95 #define LOG_WALK_REPLAY_ALL 2
  96
  97 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
  98                              struct btrfs_root *root, struct inode *inode,
  99                              int inode_only);
 100 static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
 101                              struct btrfs_root *root,
 102                              struct btrfs_path *path, u64 objectid);
 103 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
 104                                        struct btrfs_root *root,
 105                                        struct btrfs_root *log,
 106                                        struct btrfs_path *path,
 107                                        u64 dirid, int del_all);
 108
 109 /*
 110  * tree logging is a special write ahead log used to make sure that
 111  * fsyncs and O_SYNCs can happen without doing full tree commits.
 112  *
 113  * Full tree commits are expensive because they require commonly
 114  * modified blocks to be recowed, creating many dirty pages in the
 115  * extent tree an 4x-6x higher write load than ext3.
 116  *
 117  * Instead of doing a tree commit on every fsync, we use the
 118  * key ranges and transaction ids to find items for a given file or directory
 119  * that have changed in this transaction.  Those items are copied into
 120  * a special tree (one per subvolume root), that tree is written to disk
 121  * and then the fsync is considered complete.
 122  *
 123  * After a crash, items are copied out of the log-tree back into the
 124  * subvolume tree.  Any file data extents found are recorded in the extent
 125  * allocation tree, and the log-tree freed.
 126  *
 127  * The log tree is read three times, once to pin down all the extents it is
 128  * using in ram and once, once to create all the inodes logged in the tree
 129  * and once to do all the other items.
 130  */
 131
 132 /*
 133  * start a sub transaction and setup the log tree
 134  * this increments the log tree writer count to make the people
 135  * syncing the tree wait for us to finish
 136  */
 137 static int start_log_trans(struct btrfs_trans_handle *trans,
 138                            struct btrfs_root *root)
 139 {
 140         int ret;
 141         int err = 0;
 142
 143         mutex_lock(&root->log_mutex);
 144         if (root->log_root) {
 145                 if (!root->log_start_pid) {
 146                         root->log_start_pid = current->pid;
 147                         root->log_multiple_pids = false;
 148                 } else if (root->log_start_pid != current->pid) {
 149                         root->log_multiple_pids = true;
 150                 }
 151
 152                 atomic_inc(&root->log_batch);
 153                 atomic_inc(&root->log_writers);
 154                 mutex_unlock(&root->log_mutex);
 155                 return 0;
 156         }
 157         root->log_multiple_pids = false;
 158         root->log_start_pid = current->pid;
 159         mutex_lock(&root->fs_info->tree_log_mutex);
 160         if (!root->fs_info->log_root_tree) {
 161                 ret = btrfs_init_log_root_tree(trans, root->fs_info);
 162                 if (ret)
 163                         err = ret;
 164         }
 165         if (err == 0 && !root->log_root) {
 166                 ret = btrfs_add_log_tree(trans, root);
 167                 if (ret)
 168                         err = ret;
 169         }
 170         mutex_unlock(&root->fs_info->tree_log_mutex);
 171         atomic_inc(&root->log_batch);
 172         atomic_inc(&root->log_writers);
 173         mutex_unlock(&root->log_mutex);
 174         return err;
 175 }
 176
 177 /*
 178  * returns 0 if there was a log transaction running and we were able
 179  * to join, or returns -ENOENT if there were not transactions
 180  * in progress
 181  */
 182 static int join_running_log_trans(struct btrfs_root *root)
 183 {
 184         int ret = -ENOENT;
 185
 186         smp_mb();
 187         if (!root->log_root)
 188                 return -ENOENT;
 189
 190         mutex_lock(&root->log_mutex);
 191         if (root->log_root) {
 192                 ret = 0;
 193                 atomic_inc(&root->log_writers);
 194         }
 195         mutex_unlock(&root->log_mutex);
 196         return ret;
 197 }
 198
 199 /*
 200  * This either makes the current running log transaction wait
 201  * until you call btrfs_end_log_trans() or it makes any future
 202  * log transactions wait until you call btrfs_end_log_trans()
 203  */
 204 int btrfs_pin_log_trans(struct btrfs_root *root)
 205 {
 206         int ret = -ENOENT;
 207
 208         mutex_lock(&root->log_mutex);
 209         atomic_inc(&root->log_writers);
 210         mutex_unlock(&root->log_mutex);
 211         return ret;
 212 }
 213
 214 /*
 215  * indicate we're done making changes to the log tree
 216  * and wake up anyone waiting to do a sync
 217  */
 218 void btrfs_end_log_trans(struct btrfs_root *root)
 219 {
 220         if (atomic_dec_and_test(&root->log_writers)) {
 221                 smp_mb();
 222                 if (waitqueue_active(&root->log_writer_wait))
 223                         wake_up(&root->log_writer_wait);
 224         }
 225 }
 226
 227
 228 /*
 229  * the walk control struct is used to pass state down the chain when
 230  * processing the log tree.  The stage field tells us which part
 231  * of the log tree processing we are currently doing.  The others
 232  * are state fields used for that specific part
 233  */
 234 struct walk_control {
 235         /* should we free the extent on disk when done?  This is used
 236          * at transaction commit time while freeing a log tree
 237          */
 238         int free;
 239
 240         /* should we write out the extent buffer?  This is used
 241          * while flushing the log tree to disk during a sync
 242          */
 243         int write;
 244
 245         /* should we wait for the extent buffer io to finish?  Also used
 246          * while flushing the log tree to disk for a sync
 247          */
 248         int wait;
 249
 250         /* pin only walk, we record which extents on disk belong to the
 251          * log trees
 252          */
 253         int pin;
 254
 255         /* what stage of the replay code we're currently in */
 256         int stage;
 257
 258         /* the root we are currently replaying */
 259         struct btrfs_root *replay_dest;
 260
 261         /* the trans handle for the current replay */
 262         struct btrfs_trans_handle *trans;
 263
 264         /* the function that gets used to process blocks we find in the
 265          * tree.  Note the extent_buffer might not be up to date when it is
 266          * passed in, and it must be checked or read if you need the data
 267          * inside it
 268          */
 269         int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
 270                             struct walk_control *wc, u64 gen);
 271 };
 272
 273 /*
 274  * process_func used to pin down extents, write them or wait on them
 275  */
 276 static int process_one_buffer(struct btrfs_root *log,
 277                               struct extent_buffer *eb,
 278                               struct walk_control *wc, u64 gen)
 279 {
 280         int ret = 0;
 281
 282         if (wc->pin)
 283                 ret = btrfs_pin_extent_for_log_replay(log->fs_info->extent_root,
 284                                                       eb->start, eb->len);
 285
 286         if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) {
 287                 if (wc->write)
 288                         btrfs_write_tree_block(eb);
 289                 if (wc->wait)
 290                         btrfs_wait_tree_block_writeback(eb);
 291         }
 292         return ret;
 293 }
 294
 295 /*
 296  * Item overwrite used by replay and tree logging.  eb, slot and key all refer
 297  * to the src data we are copying out.
 298  *
 299  * root is the tree we are copying into, and path is a scratch
 300  * path for use in this function (it should be released on entry and
 301  * will be released on exit).
 302  *
 303  * If the key is already in the destination tree the existing item is
 304  * overwritten.  If the existing item isn't big enough, it is extended.
 305  * If it is too large, it is truncated.
 306  *
 307  * If the key isn't in the destination yet, a new item is inserted.
 308  */
 309 static noinline int overwrite_item(struct btrfs_trans_handle *trans,
 310                                    struct btrfs_root *root,
 311                                    struct btrfs_path *path,
 312                                    struct extent_buffer *eb, int slot,
 313                                    struct btrfs_key *key)
 314 {
 315         int ret;
 316         u32 item_size;
 317         u64 saved_i_size = 0;
 318         int save_old_i_size = 0;
 319         unsigned long src_ptr;
 320         unsigned long dst_ptr;
 321         int overwrite_root = 0;
 322         bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
 323
 324         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
 325                 overwrite_root = 1;
 326
 327         item_size = btrfs_item_size_nr(eb, slot);
 328         src_ptr = btrfs_item_ptr_offset(eb, slot);
 329
 330         /* look for the key in the destination tree */
 331         ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
 332         if (ret < 0)
 333                 return ret;
 334
 335         if (ret == 0) {
 336                 char *src_copy;
 337                 char *dst_copy;
 338                 u32 dst_size = btrfs_item_size_nr(path->nodes[0],
 339                                                   path->slots[0]);
 340                 if (dst_size != item_size)
 341                         goto insert;
 342
 343                 if (item_size == 0) {
 344                         btrfs_release_path(path);
 345                         return 0;
 346                 }
 347                 dst_copy = kmalloc(item_size, GFP_NOFS);
 348                 src_copy = kmalloc(item_size, GFP_NOFS);
 349                 if (!dst_copy || !src_copy) {
 350                         btrfs_release_path(path);
 351                         kfree(dst_copy);
 352                         kfree(src_copy);
 353                         return -ENOMEM;
 354                 }
 355
 356                 read_extent_buffer(eb, src_copy, src_ptr, item_size);
 357
 358                 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
 359                 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
 360                                    item_size);
 361                 ret = memcmp(dst_copy, src_copy, item_size);
 362
 363                 kfree(dst_copy);
 364                 kfree(src_copy);
 365                 /*
 366                  * they have the same contents, just return, this saves
 367                  * us from cowing blocks in the destination tree and doing
 368                  * extra writes that may not have been done by a previous
 369                  * sync
 370                  */
 371                 if (ret == 0) {
 372                         btrfs_release_path(path);
 373                         return 0;
 374                 }
 375
 376                 /*
 377                  * We need to load the old nbytes into the inode so when we
 378                  * replay the extents we've logged we get the right nbytes.
 379                  */
 380                 if (inode_item) {
 381                         struct btrfs_inode_item *item;
 382                         u64 nbytes;
 383
 384                         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
 385                                               struct btrfs_inode_item);
 386                         nbytes = btrfs_inode_nbytes(path->nodes[0], item);
 387                         item = btrfs_item_ptr(eb, slot,
 388                                               struct btrfs_inode_item);
 389                         btrfs_set_inode_nbytes(eb, item, nbytes);
 390                 }
 391         } else if (inode_item) {
 392                 struct btrfs_inode_item *item;
 393
 394                 /*
 395                  * New inode, set nbytes to 0 so that the nbytes comes out
 396                  * properly when we replay the extents.
 397                  */
 398                 item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
 399                 btrfs_set_inode_nbytes(eb, item, 0);
 400         }
 401 insert:
 402         btrfs_release_path(path);
 403         /* try to insert the key into the destination tree */
 404         ret = btrfs_insert_empty_item(trans, root, path,
 405                                       key, item_size);
 406
 407         /* make sure any existing item is the correct size */
 408         if (ret == -EEXIST) {
 409                 u32 found_size;
 410                 found_size = btrfs_item_size_nr(path->nodes[0],
 411                                                 path->slots[0]);
 412                 if (found_size > item_size)
 413                         btrfs_truncate_item(root, path, item_size, 1);
 414                 else if (found_size < item_size)
 415                         btrfs_extend_item(root, path,
 416                                           item_size - found_size);
 417         } else if (ret) {
 418                 return ret;
 419         }
 420         dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
 421                                         path->slots[0]);
 422
 423         /* don't overwrite an existing inode if the generation number
 424          * was logged as zero.  This is done when the tree logging code
 425          * is just logging an inode to make sure it exists after recovery.
 426          *
 427          * Also, don't overwrite i_size on directories during replay.
 428          * log replay inserts and removes directory items based on the
 429          * state of the tree found in the subvolume, and i_size is modified
 430          * as it goes
 431          */
 432         if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
 433                 struct btrfs_inode_item *src_item;
 434                 struct btrfs_inode_item *dst_item;
 435
 436                 src_item = (struct btrfs_inode_item *)src_ptr;
 437                 dst_item = (struct btrfs_inode_item *)dst_ptr;
 438
 439                 if (btrfs_inode_generation(eb, src_item) == 0)
 440                         goto no_copy;
 441
 442                 if (overwrite_root &&
 443                     S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
 444                     S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
 445                         save_old_i_size = 1;
 446                         saved_i_size = btrfs_inode_size(path->nodes[0],
 447                                                         dst_item);
 448                 }
 449         }
 450
 451         copy_extent_buffer(path->nodes[0], eb, dst_ptr,
 452                            src_ptr, item_size);
 453
 454         if (save_old_i_size) {
 455                 struct btrfs_inode_item *dst_item;
 456                 dst_item = (struct btrfs_inode_item *)dst_ptr;
 457                 btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
 458         }
 459
 460         /* make sure the generation is filled in */
 461         if (key->type == BTRFS_INODE_ITEM_KEY) {
 462                 struct btrfs_inode_item *dst_item;
 463                 dst_item = (struct btrfs_inode_item *)dst_ptr;
 464                 if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
 465                         btrfs_set_inode_generation(path->nodes[0], dst_item,
 466                                                    trans->transid);
 467                 }
 468         }
 469 no_copy:
 470         btrfs_mark_buffer_dirty(path->nodes[0]);
 471         btrfs_release_path(path);
 472         return 0;
 473 }
 474
 475 /*
 476  * simple helper to read an inode off the disk from a given root
 477  * This can only be called for subvolume roots and not for the log
 478  */
 479 static noinline struct inode *read_one_inode(struct btrfs_root *root,
 480                                              u64 objectid)
 481 {
 482         struct btrfs_key key;
 483         struct inode *inode;
 484
 485         key.objectid = objectid;
 486         key.type = BTRFS_INODE_ITEM_KEY;
 487         key.offset = 0;
 488         inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
 489         if (IS_ERR(inode)) {
 490                 inode = NULL;
 491         } else if (is_bad_inode(inode)) {
 492                 iput(inode);
 493                 inode = NULL;
 494         }
 495         return inode;
 496 }
 497
 498 /* replays a single extent in 'eb' at 'slot' with 'key' into the
 499  * subvolume 'root'.  path is released on entry and should be released
 500  * on exit.
 501  *
 502  * extents in the log tree have not been allocated out of the extent
 503  * tree yet.  So, this completes the allocation, taking a reference
 504  * as required if the extent already exists or creating a new extent
 505  * if it isn't in the extent allocation tree yet.
 506  *
 507  * The extent is inserted into the file, dropping any existing extents
 508  * from the file that overlap the new one.
 509  */
 510 static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
 511                                       struct btrfs_root *root,
 512                                       struct btrfs_path *path,
 513                                       struct extent_buffer *eb, int slot,
 514                                       struct btrfs_key *key)
 515 {
 516         int found_type;
 517         u64 extent_end;
 518         u64 start = key->offset;
 519         u64 nbytes = 0;
 520         struct btrfs_file_extent_item *item;
 521         struct inode *inode = NULL;
 522         unsigned long size;
 523         int ret = 0;
 524
 525         item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
 526         found_type = btrfs_file_extent_type(eb, item);
 527
 528         if (found_type == BTRFS_FILE_EXTENT_REG ||
 529             found_type == BTRFS_FILE_EXTENT_PREALLOC) {
 530                 nbytes = btrfs_file_extent_num_bytes(eb, item);
 531                 extent_end = start + nbytes;
 532
 533                 /*
 534                  * We don't add to the inodes nbytes if we are prealloc or a
 535                  * hole.
 536                  */
 537                 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
 538                         nbytes = 0;
 539         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 540                 size = btrfs_file_extent_inline_len(eb, item);
 541                 nbytes = btrfs_file_extent_ram_bytes(eb, item);
 542                 extent_end = ALIGN(start + size, root->sectorsize);
 543         } else {
 544                 ret = 0;
 545                 goto out;
 546         }
 547
 548         inode = read_one_inode(root, key->objectid);
 549         if (!inode) {
 550                 ret = -EIO;
 551                 goto out;
 552         }
 553
 554         /*
 555          * first check to see if we already have this extent in the
 556          * file.  This must be done before the btrfs_drop_extents run
 557          * so we don't try to drop this extent.
 558          */
 559         ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
 560                                        start, 0);
 561
 562         if (ret == 0 &&
 563             (found_type == BTRFS_FILE_EXTENT_REG ||
 564              found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
 565                 struct btrfs_file_extent_item cmp1;
 566                 struct btrfs_file_extent_item cmp2;
 567                 struct btrfs_file_extent_item *existing;
 568                 struct extent_buffer *leaf;
 569
 570                 leaf = path->nodes[0];
 571                 existing = btrfs_item_ptr(leaf, path->slots[0],
 572                                           struct btrfs_file_extent_item);
 573
 574                 read_extent_buffer(eb, &cmp1, (unsigned long)item,
 575                                    sizeof(cmp1));
 576                 read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
 577                                    sizeof(cmp2));
 578
 579                 /*
 580                  * we already have a pointer to this exact extent,
 581                  * we don't have to do anything
 582                  */
 583                 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
 584                         btrfs_release_path(path);
 585                         goto out;
 586                 }
 587         }
 588         btrfs_release_path(path);
 589
 590         /* drop any overlapping extents */
 591         ret = btrfs_drop_extents(trans, root, inode, start, extent_end, 1);
 592         if (ret)
 593                 goto out;
 594
 595         if (found_type == BTRFS_FILE_EXTENT_REG ||
 596             found_type == BTRFS_FILE_EXTENT_PREALLOC) {
 597                 u64 offset;
 598                 unsigned long dest_offset;
 599                 struct btrfs_key ins;
 600
 601                 ret = btrfs_insert_empty_item(trans, root, path, key,
 602                                               sizeof(*item));
 603                 if (ret)
 604                         goto out;
 605                 dest_offset = btrfs_item_ptr_offset(path->nodes[0],
 606                                                     path->slots[0]);
 607                 copy_extent_buffer(path->nodes[0], eb, dest_offset,
 608                                 (unsigned long)item,  sizeof(*item));
 609
 610                 ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
 611                 ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
 612                 ins.type = BTRFS_EXTENT_ITEM_KEY;
 613                 offset = key->offset - btrfs_file_extent_offset(eb, item);
 614
 615                 if (ins.objectid > 0) {
 616                         u64 csum_start;
 617                         u64 csum_end;
 618                         LIST_HEAD(ordered_sums);
 619                         /*
 620                          * is this extent already allocated in the extent
 621                          * allocation tree?  If so, just add a reference
 622                          */
 623                         ret = btrfs_lookup_extent(root, ins.objectid,
 624                                                 ins.offset);
 625                         if (ret == 0) {
 626                                 ret = btrfs_inc_extent_ref(trans, root,
 627                                                 ins.objectid, ins.offset,
 628                                                 0, root->root_key.objectid,
 629                                                 key->objectid, offset, 0);
 630                                 if (ret)
 631                                         goto out;
 632                         } else {
 633                                 /*
 634                                  * insert the extent pointer in the extent
 635                                  * allocation tree
 636                                  */
 637                                 ret = btrfs_alloc_logged_file_extent(trans,
 638                                                 root, root->root_key.objectid,
 639                                                 key->objectid, offset, &ins);
 640                                 if (ret)
 641                                         goto out;
 642                         }
 643                         btrfs_release_path(path);
 644
 645                         if (btrfs_file_extent_compression(eb, item)) {
 646                                 csum_start = ins.objectid;
 647                                 csum_end = csum_start + ins.offset;
 648                         } else {
 649                                 csum_start = ins.objectid +
 650                                         btrfs_file_extent_offset(eb, item);
 651                                 csum_end = csum_start +
 652                                         btrfs_file_extent_num_bytes(eb, item);
 653                         }
 654
 655                         ret = btrfs_lookup_csums_range(root->log_root,
 656                                                 csum_start, csum_end - 1,
 657                                                 &ordered_sums, 0);
 658                         if (ret)
 659                                 goto out;
 660                         while (!list_empty(&ordered_sums)) {
 661                                 struct btrfs_ordered_sum *sums;
 662                                 sums = list_entry(ordered_sums.next,
 663                                                 struct btrfs_ordered_sum,
 664                                                 list);
 665                                 if (!ret)
 666                                         ret = btrfs_csum_file_blocks(trans,
 667                                                 root->fs_info->csum_root,
 668                                                 sums);
 669                                 list_del(&sums->list);
 670                                 kfree(sums);
 671                         }
 672                         if (ret)
 673                                 goto out;
 674                 } else {
 675                         btrfs_release_path(path);
 676                 }
 677         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 678                 /* inline extents are easy, we just overwrite them */
 679                 ret = overwrite_item(trans, root, path, eb, slot, key);
 680                 if (ret)
 681                         goto out;
 682         }
 683
 684         inode_add_bytes(inode, nbytes);
 685         ret = btrfs_update_inode(trans, root, inode);
 686 out:
 687         if (inode)
 688                 iput(inode);
 689         return ret;
 690 }
 691
 692 /*
 693  * when cleaning up conflicts between the directory names in the
 694  * subvolume, directory names in the log and directory names in the
 695  * inode back references, we may have to unlink inodes from directories.
 696  *
 697  * This is a helper function to do the unlink of a specific directory
 698  * item
 699  */
 700 static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
 701                                       struct btrfs_root *root,
 702                                       struct btrfs_path *path,
 703                                       struct inode *dir,
 704                                       struct btrfs_dir_item *di)
 705 {
 706         struct inode *inode;
 707         char *name;
 708         int name_len;
 709         struct extent_buffer *leaf;
 710         struct btrfs_key location;
 711         int ret;
 712
 713         leaf = path->nodes[0];
 714
 715         btrfs_dir_item_key_to_cpu(leaf, di, &location);
 716         name_len = btrfs_dir_name_len(leaf, di);
 717         name = kmalloc(name_len, GFP_NOFS);
 718         if (!name)
 719                 return -ENOMEM;
 720
 721         read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
 722         btrfs_release_path(path);
 723
 724         inode = read_one_inode(root, location.objectid);
 725         if (!inode) {
 726                 ret = -EIO;
 727                 goto out;
 728         }
 729
 730         ret = link_to_fixup_dir(trans, root, path, location.objectid);
 731         if (ret)
 732                 goto out;
 733
 734         ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
 735         if (ret)
 736                 goto out;
 737         btrfs_run_delayed_items(trans, root);
 738 out:
 739         kfree(name);
 740         iput(inode);
 741         return ret;
 742 }
 743
 744 /*
 745  * helper function to see if a given name and sequence number found
 746  * in an inode back reference are already in a directory and correctly
 747  * point to this inode
 748  */
 749 static noinline int inode_in_dir(struct btrfs_root *root,
 750                                  struct btrfs_path *path,
 751                                  u64 dirid, u64 objectid, u64 index,
 752                                  const char *name, int name_len)
 753 {
 754         struct btrfs_dir_item *di;
 755         struct btrfs_key location;
 756         int match = 0;
 757
 758         di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
 759                                          index, name, name_len, 0);
 760         if (di && !IS_ERR(di)) {
 761                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 762                 if (location.objectid != objectid)
 763                         goto out;
 764         } else
 765                 goto out;
 766         btrfs_release_path(path);
 767
 768         di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
 769         if (di && !IS_ERR(di)) {
 770                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 771                 if (location.objectid != objectid)
 772                         goto out;
 773         } else
 774                 goto out;
 775         match = 1;
 776 out:
 777         btrfs_release_path(path);
 778         return match;
 779 }
 780
 781 /*
 782  * helper function to check a log tree for a named back reference in
 783  * an inode.  This is used to decide if a back reference that is
 784  * found in the subvolume conflicts with what we find in the log.
 785  *
 786  * inode backreferences may have multiple refs in a single item,
 787  * during replay we process one reference at a time, and we don't
 788  * want to delete valid links to a file from the subvolume if that
 789  * link is also in the log.
 790  */
 791 static noinline int backref_in_log(struct btrfs_root *log,
 792                                    struct btrfs_key *key,
 793                                    u64 ref_objectid,
 794                                    char *name, int namelen)
 795 {
 796         struct btrfs_path *path;
 797         struct btrfs_inode_ref *ref;
 798         unsigned long ptr;
 799         unsigned long ptr_end;
 800         unsigned long name_ptr;
 801         int found_name_len;
 802         int item_size;
 803         int ret;
 804         int match = 0;
 805
 806         path = btrfs_alloc_path();
 807         if (!path)
 808                 return -ENOMEM;
 809
 810         ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
 811         if (ret != 0)
 812                 goto out;
 813
 814         ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
 815
 816         if (key->type == BTRFS_INODE_EXTREF_KEY) {
 817                 if (btrfs_find_name_in_ext_backref(path, ref_objectid,
 818                                                    name, namelen, NULL))
 819                         match = 1;
 820
 821                 goto out;
 822         }
 823
 824         item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
 825         ptr_end = ptr + item_size;
 826         while (ptr < ptr_end) {
 827                 ref = (struct btrfs_inode_ref *)ptr;
 828                 found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
 829                 if (found_name_len == namelen) {
 830                         name_ptr = (unsigned long)(ref + 1);
 831                         ret = memcmp_extent_buffer(path->nodes[0], name,
 832                                                    name_ptr, namelen);
 833                         if (ret == 0) {
 834                                 match = 1;
 835                                 goto out;
 836                         }
 837                 }
 838                 ptr = (unsigned long)(ref + 1) + found_name_len;
 839         }
 840 out:
 841         btrfs_free_path(path);
 842         return match;
 843 }
 844
 845 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
 846                                   struct btrfs_root *root,
 847                                   struct btrfs_path *path,
 848                                   struct btrfs_root *log_root,
 849                                   struct inode *dir, struct inode *inode,
 850                                   struct extent_buffer *eb,
 851                                   u64 inode_objectid, u64 parent_objectid,
 852                                   u64 ref_index, char *name, int namelen,
 853                                   int *search_done)
 854 {
 855         int ret;
 856         char *victim_name;
 857         int victim_name_len;
 858         struct extent_buffer *leaf;
 859         struct btrfs_dir_item *di;
 860         struct btrfs_key search_key;
 861         struct btrfs_inode_extref *extref;
 862
 863 again:
 864         /* Search old style refs */
 865         search_key.objectid = inode_objectid;
 866         search_key.type = BTRFS_INODE_REF_KEY;
 867         search_key.offset = parent_objectid;
 868         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
 869         if (ret == 0) {
 870                 struct btrfs_inode_ref *victim_ref;
 871                 unsigned long ptr;
 872                 unsigned long ptr_end;
 873
 874                 leaf = path->nodes[0];
 875
 876                 /* are we trying to overwrite a back ref for the root directory
 877                  * if so, just jump out, we're done
 878                  */
 879                 if (search_key.objectid == search_key.offset)
 880                         return 1;
 881
 882                 /* check all the names in this back reference to see
 883                  * if they are in the log.  if so, we allow them to stay
 884                  * otherwise they must be unlinked as a conflict
 885                  */
 886                 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
 887                 ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
 888                 while (ptr < ptr_end) {
 889                         victim_ref = (struct btrfs_inode_ref *)ptr;
 890                         victim_name_len = btrfs_inode_ref_name_len(leaf,
 891                                                                    victim_ref);
 892                         victim_name = kmalloc(victim_name_len, GFP_NOFS);
 893                         if (!victim_name)
 894                                 return -ENOMEM;
 895
 896                         read_extent_buffer(leaf, victim_name,
 897                                            (unsigned long)(victim_ref + 1),
 898                                            victim_name_len);
 899
 900                         if (!backref_in_log(log_root, &search_key,
 901                                             parent_objectid,
 902                                             victim_name,
 903                                             victim_name_len)) {
 904                                 btrfs_inc_nlink(inode);
 905                                 btrfs_release_path(path);
 906
 907                                 ret = btrfs_unlink_inode(trans, root, dir,
 908                                                          inode, victim_name,
 909                                                          victim_name_len);
 910                                 kfree(victim_name);
 911                                 if (ret)
 912                                         return ret;
 913                                 btrfs_run_delayed_items(trans, root);
 914                                 *search_done = 1;
 915                                 goto again;
 916                         }
 917                         kfree(victim_name);
 918
 919                         ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
 920                 }
 921
 922                 /*
 923                  * NOTE: we have searched root tree and checked the
 924                  * coresponding ref, it does not need to check again.
 925                  */
 926                 *search_done = 1;
 927         }
 928         btrfs_release_path(path);
 929
 930         /* Same search but for extended refs */
 931         extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
 932                                            inode_objectid, parent_objectid, 0,
 933                                            0);
 934         if (!IS_ERR_OR_NULL(extref)) {
 935                 u32 item_size;
 936                 u32 cur_offset = 0;
 937                 unsigned long base;
 938                 struct inode *victim_parent;
 939
 940                 leaf = path->nodes[0];
 941
 942                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
 943                 base = btrfs_item_ptr_offset(leaf, path->slots[0]);
 944
 945                 while (cur_offset < item_size) {
 946                         extref = (struct btrfs_inode_extref *)base + cur_offset;
 947
 948                         victim_name_len = btrfs_inode_extref_name_len(leaf, extref);
 949
 950                         if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
 951                                 goto next;
 952
 953                         victim_name = kmalloc(victim_name_len, GFP_NOFS);
 954                         if (!victim_name)
 955                                 return -ENOMEM;
 956                         read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name,
 957                                            victim_name_len);
 958
 959                         search_key.objectid = inode_objectid;
 960                         search_key.type = BTRFS_INODE_EXTREF_KEY;
 961                         search_key.offset = btrfs_extref_hash(parent_objectid,
 962                                                               victim_name,
 963                                                               victim_name_len);
 964                         ret = 0;
 965                         if (!backref_in_log(log_root, &search_key,
 966                                             parent_objectid, victim_name,
 967                                             victim_name_len)) {
 968                                 ret = -ENOENT;
 969                                 victim_parent = read_one_inode(root,
 970                                                                parent_objectid);
 971                                 if (victim_parent) {
 972                                         btrfs_inc_nlink(inode);
 973                                         btrfs_release_path(path);
 974
 975                                         ret = btrfs_unlink_inode(trans, root,
 976                                                                  victim_parent,
 977                                                                  inode,
 978                                                                  victim_name,
 979                                                                  victim_name_len);
 980                                         btrfs_run_delayed_items(trans, root);
 981                                 }
 982                                 iput(victim_parent);
 983                                 kfree(victim_name);
 984                                 if (ret)
 985                                         return ret;
 986                                 *search_done = 1;
 987                                 goto again;
 988                         }
 989                         kfree(victim_name);
 990                         if (ret)
 991                                 return ret;
 992 next:
 993                         cur_offset += victim_name_len + sizeof(*extref);
 994                 }
 995                 *search_done = 1;
 996         }
 997         btrfs_release_path(path);
 998
 999         /* look for a conflicting sequence number */
1000         di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
1001                                          ref_index, name, namelen, 0);
1002         if (di && !IS_ERR(di)) {
1003                 ret = drop_one_dir_item(trans, root, path, dir, di);
1004                 if (ret)
1005                         return ret;
1006         }
1007         btrfs_release_path(path);
1008
1009         /* look for a conflicing name */
1010         di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
1011                                    name, namelen, 0);
1012         if (di && !IS_ERR(di)) {
1013                 ret = drop_one_dir_item(trans, root, path, dir, di);
1014                 if (ret)
1015                         return ret;
1016         }
1017         btrfs_release_path(path);
1018
1019         return 0;
1020 }
1021
1022 static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1023                              u32 *namelen, char **name, u64 *index,
1024                              u64 *parent_objectid)
1025 {
1026         struct btrfs_inode_extref *extref;
1027
1028         extref = (struct btrfs_inode_extref *)ref_ptr;
1029
1030         *namelen = btrfs_inode_extref_name_len(eb, extref);
1031         *name = kmalloc(*namelen, GFP_NOFS);
1032         if (*name == NULL)
1033                 return -ENOMEM;
1034
1035         read_extent_buffer(eb, *name, (unsigned long)&extref->name,
1036                            *namelen);
1037
1038         *index = btrfs_inode_extref_index(eb, extref);
1039         if (parent_objectid)
1040                 *parent_objectid = btrfs_inode_extref_parent(eb, extref);
1041
1042         return 0;
1043 }
1044
1045 static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1046                           u32 *namelen, char **name, u64 *index)
1047 {
1048         struct btrfs_inode_ref *ref;
1049
1050         ref = (struct btrfs_inode_ref *)ref_ptr;
1051
1052         *namelen = btrfs_inode_ref_name_len(eb, ref);
1053         *name = kmalloc(*namelen, GFP_NOFS);
1054         if (*name == NULL)
1055                 return -ENOMEM;
1056
1057         read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
1058
1059         *index = btrfs_inode_ref_index(eb, ref);
1060
1061         return 0;
1062 }
1063
1064 /*
1065  * replay one inode back reference item found in the log tree.
1066  * eb, slot and key refer to the buffer and key found in the log tree.
1067  * root is the destination we are replaying into, and path is for temp
1068  * use by this function.  (it should be released on return).
1069  */
1070 static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
1071                                   struct btrfs_root *root,
1072                                   struct btrfs_root *log,
1073                                   struct btrfs_path *path,
1074                                   struct extent_buffer *eb, int slot,
1075                                   struct btrfs_key *key)
1076 {
1077         struct inode *dir;
1078         struct inode *inode;
1079         unsigned long ref_ptr;
1080         unsigned long ref_end;
1081         char *name;
1082         int namelen;
1083         int ret;
1084         int search_done = 0;
1085         int log_ref_ver = 0;
1086         u64 parent_objectid;
1087         u64 inode_objectid;
1088         u64 ref_index = 0;
1089         int ref_struct_size;
1090
1091         ref_ptr = btrfs_item_ptr_offset(eb, slot);
1092         ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
1093
1094         if (key->type == BTRFS_INODE_EXTREF_KEY) {
1095                 struct btrfs_inode_extref *r;
1096
1097                 ref_struct_size = sizeof(struct btrfs_inode_extref);
1098                 log_ref_ver = 1;
1099                 r = (struct btrfs_inode_extref *)ref_ptr;
1100                 parent_objectid = btrfs_inode_extref_parent(eb, r);
1101         } else {
1102                 ref_struct_size = sizeof(struct btrfs_inode_ref);
1103                 parent_objectid = key->offset;
1104         }
1105         inode_objectid = key->objectid;
1106
1107         /*
1108          * it is possible that we didn't log all the parent directories
1109          * for a given inode.  If we don't find the dir, just don't
1110          * copy the back ref in.  The link count fixup code will take
1111          * care of the rest
1112          */
1113         dir = read_one_inode(root, parent_objectid);
1114         if (!dir)
1115                 return -ENOENT;
1116
1117         inode = read_one_inode(root, inode_objectid);
1118         if (!inode) {
1119                 iput(dir);
1120                 return -EIO;
1121         }
1122
1123         while (ref_ptr < ref_end) {
1124                 if (log_ref_ver) {
1125                         ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
1126                                                 &ref_index, &parent_objectid);
1127                         /*
1128                          * parent object can change from one array
1129                          * item to another.
1130                          */
1131                         if (!dir)
1132                                 dir = read_one_inode(root, parent_objectid);
1133                         if (!dir)
1134                                 return -ENOENT;
1135                 } else {
1136                         ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
1137                                              &ref_index);
1138                 }
1139                 if (ret)
1140                         return ret;
1141
1142                 /* if we already have a perfect match, we're done */
1143                 if (!inode_in_dir(root, path, btrfs_ino(dir), btrfs_ino(inode),
1144                                   ref_index, name, namelen)) {
1145                         /*
1146                          * look for a conflicting back reference in the
1147                          * metadata. if we find one we have to unlink that name
1148                          * of the file before we add our new link.  Later on, we
1149                          * overwrite any existing back reference, and we don't
1150                          * want to create dangling pointers in the directory.
1151                          */
1152
1153                         if (!search_done) {
1154                                 ret = __add_inode_ref(trans, root, path, log,
1155                                                       dir, inode, eb,
1156                                                       inode_objectid,
1157                                                       parent_objectid,
1158                                                       ref_index, name, namelen,
1159                                                       &search_done);
1160                                 if (ret == 1) {
1161                                         ret = 0;
1162                                         goto out;
1163                                 }
1164                                 if (ret)
1165                                         goto out;
1166                         }
1167
1168                         /* insert our name */
1169                         ret = btrfs_add_link(trans, dir, inode, name, namelen,
1170                                              0, ref_index);
1171                         if (ret)
1172                                 goto out;
1173
1174                         btrfs_update_inode(trans, root, inode);
1175                 }
1176
1177                 ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
1178                 kfree(name);
1179                 if (log_ref_ver) {
1180                         iput(dir);
1181                         dir = NULL;
1182                 }
1183         }
1184
1185         /* finally write the back reference in the inode */
1186         ret = overwrite_item(trans, root, path, eb, slot, key);
1187 out:
1188         btrfs_release_path(path);
1189         iput(dir);
1190         iput(inode);
1191         return ret;
1192 }
1193
1194 static int insert_orphan_item(struct btrfs_trans_handle *trans,
1195                               struct btrfs_root *root, u64 offset)
1196 {
1197         int ret;
1198         ret = btrfs_find_orphan_item(root, offset);
1199         if (ret > 0)
1200                 ret = btrfs_insert_orphan_item(trans, root, offset);
1201         return ret;
1202 }
1203
1204 static int count_inode_extrefs(struct btrfs_root *root,
1205                                struct inode *inode, struct btrfs_path *path)
1206 {
1207         int ret = 0;
1208         int name_len;
1209         unsigned int nlink = 0;
1210         u32 item_size;
1211         u32 cur_offset = 0;
1212         u64 inode_objectid = btrfs_ino(inode);
1213         u64 offset = 0;
1214         unsigned long ptr;
1215         struct btrfs_inode_extref *extref;
1216         struct extent_buffer *leaf;
1217
1218         while (1) {
1219                 ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
1220                                             &extref, &offset);
1221                 if (ret)
1222                         break;
1223
1224                 leaf = path->nodes[0];
1225                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1226                 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1227
1228                 while (cur_offset < item_size) {
1229                         extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
1230                         name_len = btrfs_inode_extref_name_len(leaf, extref);
1231
1232                         nlink++;
1233
1234                         cur_offset += name_len + sizeof(*extref);
1235                 }
1236
1237                 offset++;
1238                 btrfs_release_path(path);
1239         }
1240         btrfs_release_path(path);
1241
1242         if (ret < 0)
1243                 return ret;
1244         return nlink;
1245 }
1246
1247 static int count_inode_refs(struct btrfs_root *root,
1248                                struct inode *inode, struct btrfs_path *path)
1249 {
1250         int ret;
1251         struct btrfs_key key;
1252         unsigned int nlink = 0;
1253         unsigned long ptr;
1254         unsigned long ptr_end;
1255         int name_len;
1256         u64 ino = btrfs_ino(inode);
1257
1258         key.objectid = ino;
1259         key.type = BTRFS_INODE_REF_KEY;
1260         key.offset = (u64)-1;
1261
1262         while (1) {
1263                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1264                 if (ret < 0)
1265                         break;
1266                 if (ret > 0) {
1267                         if (path->slots[0] == 0)
1268                                 break;
1269                         path->slots[0]--;
1270                 }
1271                 btrfs_item_key_to_cpu(path->nodes[0], &key,
1272                                       path->slots[0]);
1273                 if (key.objectid != ino ||
1274                     key.type != BTRFS_INODE_REF_KEY)
1275                         break;
1276                 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1277                 ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
1278                                                    path->slots[0]);
1279                 while (ptr < ptr_end) {
1280                         struct btrfs_inode_ref *ref;
1281
1282                         ref = (struct btrfs_inode_ref *)ptr;
1283                         name_len = btrfs_inode_ref_name_len(path->nodes[0],
1284                                                             ref);
1285                         ptr = (unsigned long)(ref + 1) + name_len;
1286                         nlink++;
1287                 }
1288
1289                 if (key.offset == 0)
1290                         break;
1291                 key.offset--;
1292                 btrfs_release_path(path);
1293         }
1294         btrfs_release_path(path);
1295
1296         return nlink;
1297 }
1298
1299 /*
1300  * There are a few corners where the link count of the file can't
1301  * be properly maintained during replay.  So, instead of adding
1302  * lots of complexity to the log code, we just scan the backrefs
1303  * for any file that has been through replay.
1304  *
1305  * The scan will update the link count on the inode to reflect the
1306  * number of back refs found.  If it goes down to zero, the iput
1307  * will free the inode.
1308  */
1309 static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
1310                                            struct btrfs_root *root,
1311                                            struct inode *inode)
1312 {
1313         struct btrfs_path *path;
1314         int ret;
1315         u64 nlink = 0;
1316         u64 ino = btrfs_ino(inode);
1317
1318         path = btrfs_alloc_path();
1319         if (!path)
1320                 return -ENOMEM;
1321
1322         ret = count_inode_refs(root, inode, path);
1323         if (ret < 0)
1324                 goto out;
1325
1326         nlink = ret;
1327
1328         ret = count_inode_extrefs(root, inode, path);
1329         if (ret == -ENOENT)
1330                 ret = 0;
1331
1332         if (ret < 0)
1333                 goto out;
1334
1335         nlink += ret;
1336
1337         ret = 0;
1338
1339         if (nlink != inode->i_nlink) {
1340                 set_nlink(inode, nlink);
1341                 btrfs_update_inode(trans, root, inode);
1342         }
1343         BTRFS_I(inode)->index_cnt = (u64)-1;
1344
1345         if (inode->i_nlink == 0) {
1346                 if (S_ISDIR(inode->i_mode)) {
1347                         ret = replay_dir_deletes(trans, root, NULL, path,
1348                                                  ino, 1);
1349                         if (ret)
1350                                 goto out;
1351                 }
1352                 ret = insert_orphan_item(trans, root, ino);
1353         }
1354
1355 out:
1356         btrfs_free_path(path);
1357         return ret;
1358 }
1359
1360 static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1361                                             struct btrfs_root *root,
1362                                             struct btrfs_path *path)
1363 {
1364         int ret;
1365         struct btrfs_key key;
1366         struct inode *inode;
1367
1368         key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1369         key.type = BTRFS_ORPHAN_ITEM_KEY;
1370         key.offset = (u64)-1;
1371         while (1) {
1372                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1373                 if (ret < 0)
1374                         break;
1375
1376                 if (ret == 1) {
1377                         if (path->slots[0] == 0)
1378                                 break;
1379                         path->slots[0]--;
1380                 }
1381
1382                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1383                 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1384                     key.type != BTRFS_ORPHAN_ITEM_KEY)
1385                         break;
1386
1387                 ret = btrfs_del_item(trans, root, path);
1388                 if (ret)
1389                         goto out;
1390
1391                 btrfs_release_path(path);
1392                 inode = read_one_inode(root, key.offset);
1393                 if (!inode)
1394                         return -EIO;
1395
1396                 ret = fixup_inode_link_count(trans, root, inode);
1397                 iput(inode);
1398                 if (ret)
1399                         goto out;
1400
1401                 /*
1402                  * fixup on a directory may create new entries,
1403                  * make sure we always look for the highset possible
1404                  * offset
1405                  */
1406                 key.offset = (u64)-1;
1407         }
1408         ret = 0;
1409 out:
1410         btrfs_release_path(path);
1411         return ret;
1412 }
1413
1414
1415 /*
1416  * record a given inode in the fixup dir so we can check its link
1417  * count when replay is done.  The link count is incremented here
1418  * so the inode won't go away until we check it
1419  */
1420 static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1421                                       struct btrfs_root *root,
1422                                       struct btrfs_path *path,
1423                                       u64 objectid)
1424 {
1425         struct btrfs_key key;
1426         int ret = 0;
1427         struct inode *inode;
1428
1429         inode = read_one_inode(root, objectid);
1430         if (!inode)
1431                 return -EIO;
1432
1433         key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1434         btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
1435         key.offset = objectid;
1436
1437         ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1438
1439         btrfs_release_path(path);
1440         if (ret == 0) {
1441                 if (!inode->i_nlink)
1442                         set_nlink(inode, 1);
1443                 else
1444                         btrfs_inc_nlink(inode);
1445                 ret = btrfs_update_inode(trans, root, inode);
1446         } else if (ret == -EEXIST) {
1447                 ret = 0;
1448         } else {
1449                 BUG(); /* Logic Error */
1450         }
1451         iput(inode);
1452
1453         return ret;
1454 }
1455
1456 /*
1457  * when replaying the log for a directory, we only insert names
1458  * for inodes that actually exist.  This means an fsync on a directory
1459  * does not implicitly fsync all the new files in it
1460  */
1461 static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1462                                     struct btrfs_root *root,
1463                                     struct btrfs_path *path,
1464                                     u64 dirid, u64 index,
1465                                     char *name, int name_len, u8 type,
1466                                     struct btrfs_key *location)
1467 {
1468         struct inode *inode;
1469         struct inode *dir;
1470         int ret;
1471
1472         inode = read_one_inode(root, location->objectid);
1473         if (!inode)
1474                 return -ENOENT;
1475
1476         dir = read_one_inode(root, dirid);
1477         if (!dir) {
1478                 iput(inode);
1479                 return -EIO;
1480         }
1481         ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
1482
1483         /* FIXME, put inode into FIXUP list */
1484
1485         iput(inode);
1486         iput(dir);
1487         return ret;
1488 }
1489
1490 /*
1491  * take a single entry in a log directory item and replay it into
1492  * the subvolume.
1493  *
1494  * if a conflicting item exists in the subdirectory already,
1495  * the inode it points to is unlinked and put into the link count
1496  * fix up tree.
1497  *
1498  * If a name from the log points to a file or directory that does
1499  * not exist in the FS, it is skipped.  fsyncs on directories
1500  * do not force down inodes inside that directory, just changes to the
1501  * names or unlinks in a directory.
1502  */
1503 static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1504                                     struct btrfs_root *root,
1505                                     struct btrfs_path *path,
1506                                     struct extent_buffer *eb,
1507                                     struct btrfs_dir_item *di,
1508                                     struct btrfs_key *key)
1509 {
1510         char *name;
1511         int name_len;
1512         struct btrfs_dir_item *dst_di;
1513         struct btrfs_key found_key;
1514         struct btrfs_key log_key;
1515         struct inode *dir;
1516         u8 log_type;
1517         int exists;
1518         int ret = 0;
1519
1520         dir = read_one_inode(root, key->objectid);
1521         if (!dir)
1522                 return -EIO;
1523
1524         name_len = btrfs_dir_name_len(eb, di);
1525         name = kmalloc(name_len, GFP_NOFS);
1526         if (!name)
1527                 return -ENOMEM;
1528
1529         log_type = btrfs_dir_type(eb, di);
1530         read_extent_buffer(eb, name, (unsigned long)(di + 1),
1531                    name_len);
1532
1533         btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1534         exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1535         if (exists == 0)
1536                 exists = 1;
1537         else
1538                 exists = 0;
1539         btrfs_release_path(path);
1540
1541         if (key->type == BTRFS_DIR_ITEM_KEY) {
1542                 dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1543                                        name, name_len, 1);
1544         } else if (key->type == BTRFS_DIR_INDEX_KEY) {
1545                 dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1546                                                      key->objectid,
1547                                                      key->offset, name,
1548                                                      name_len, 1);
1549         } else {
1550                 /* Corruption */
1551                 ret = -EINVAL;
1552                 goto out;
1553         }
1554         if (IS_ERR_OR_NULL(dst_di)) {
1555                 /* we need a sequence number to insert, so we only
1556                  * do inserts for the BTRFS_DIR_INDEX_KEY types
1557                  */
1558                 if (key->type != BTRFS_DIR_INDEX_KEY)
1559                         goto out;
1560                 goto insert;
1561         }
1562
1563         btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1564         /* the existing item matches the logged item */
1565         if (found_key.objectid == log_key.objectid &&
1566             found_key.type == log_key.type &&
1567             found_key.offset == log_key.offset &&
1568             btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
1569                 goto out;
1570         }
1571
1572         /*
1573          * don't drop the conflicting directory entry if the inode
1574          * for the new entry doesn't exist
1575          */
1576         if (!exists)
1577                 goto out;
1578
1579         ret = drop_one_dir_item(trans, root, path, dir, dst_di);
1580         if (ret)
1581                 goto out;
1582
1583         if (key->type == BTRFS_DIR_INDEX_KEY)
1584                 goto insert;
1585 out:
1586         btrfs_release_path(path);
1587         kfree(name);
1588         iput(dir);
1589         return ret;
1590
1591 insert:
1592         btrfs_release_path(path);
1593         ret = insert_one_name(trans, root, path, key->objectid, key->offset,
1594                               name, name_len, log_type, &log_key);
1595         if (ret && ret != -ENOENT)
1596                 goto out;
1597         ret = 0;
1598         goto out;
1599 }
1600
1601 /*
1602  * find all the names in a directory item and reconcile them into
1603  * the subvolume.  Only BTRFS_DIR_ITEM_KEY types will have more than
1604  * one name in a directory item, but the same code gets used for
1605  * both directory index types
1606  */
1607 static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
1608                                         struct btrfs_root *root,
1609                                         struct btrfs_path *path,
1610                                         struct extent_buffer *eb, int slot,
1611                                         struct btrfs_key *key)
1612 {
1613         int ret;
1614         u32 item_size = btrfs_item_size_nr(eb, slot);
1615         struct btrfs_dir_item *di;
1616         int name_len;
1617         unsigned long ptr;
1618         unsigned long ptr_end;
1619
1620         ptr = btrfs_item_ptr_offset(eb, slot);
1621         ptr_end = ptr + item_size;
1622         while (ptr < ptr_end) {
1623                 di = (struct btrfs_dir_item *)ptr;
1624                 if (verify_dir_item(root, eb, di))
1625                         return -EIO;
1626                 name_len = btrfs_dir_name_len(eb, di);
1627                 ret = replay_one_name(trans, root, path, eb, di, key);
1628                 if (ret)
1629                         return ret;
1630                 ptr = (unsigned long)(di + 1);
1631                 ptr += name_len;
1632         }
1633         return 0;
1634 }
1635
1636 /*
1637  * directory replay has two parts.  There are the standard directory
1638  * items in the log copied from the subvolume, and range items
1639  * created in the log while the subvolume was logged.
1640  *
1641  * The range items tell us which parts of the key space the log
1642  * is authoritative for.  During replay, if a key in the subvolume
1643  * directory is in a logged range item, but not actually in the log
1644  * that means it was deleted from the directory before the fsync
1645  * and should be removed.
1646  */
1647 static noinline int find_dir_range(struct btrfs_root *root,
1648                                    struct btrfs_path *path,
1649                                    u64 dirid, int key_type,
1650                                    u64 *start_ret, u64 *end_ret)
1651 {
1652         struct btrfs_key key;
1653         u64 found_end;
1654         struct btrfs_dir_log_item *item;
1655         int ret;
1656         int nritems;
1657
1658         if (*start_ret == (u64)-1)
1659                 return 1;
1660
1661         key.objectid = dirid;
1662         key.type = key_type;
1663         key.offset = *start_ret;
1664
1665         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1666         if (ret < 0)
1667                 goto out;
1668         if (ret > 0) {
1669                 if (path->slots[0] == 0)
1670                         goto out;
1671                 path->slots[0]--;
1672         }
1673         if (ret != 0)
1674                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1675
1676         if (key.type != key_type || key.objectid != dirid) {
1677                 ret = 1;
1678                 goto next;
1679         }
1680         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1681                               struct btrfs_dir_log_item);
1682         found_end = btrfs_dir_log_end(path->nodes[0], item);
1683
1684         if (*start_ret >= key.offset && *start_ret <= found_end) {
1685                 ret = 0;
1686                 *start_ret = key.offset;
1687                 *end_ret = found_end;
1688                 goto out;
1689         }
1690         ret = 1;
1691 next:
1692         /* check the next slot in the tree to see if it is a valid item */
1693         nritems = btrfs_header_nritems(path->nodes[0]);
1694         if (path->slots[0] >= nritems) {
1695                 ret = btrfs_next_leaf(root, path);
1696                 if (ret)
1697                         goto out;
1698         } else {
1699                 path->slots[0]++;
1700         }
1701
1702         btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1703
1704         if (key.type != key_type || key.objectid != dirid) {
1705                 ret = 1;
1706                 goto out;
1707         }
1708         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1709                               struct btrfs_dir_log_item);
1710         found_end = btrfs_dir_log_end(path->nodes[0], item);
1711         *start_ret = key.offset;
1712         *end_ret = found_end;
1713         ret = 0;
1714 out:
1715         btrfs_release_path(path);
1716         return ret;
1717 }
1718
1719 /*
1720  * this looks for a given directory item in the log.  If the directory
1721  * item is not in the log, the item is removed and the inode it points
1722  * to is unlinked
1723  */
1724 static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
1725                                       struct btrfs_root *root,
1726                                       struct btrfs_root *log,
1727                                       struct btrfs_path *path,
1728                                       struct btrfs_path *log_path,
1729                                       struct inode *dir,
1730                                       struct btrfs_key *dir_key)
1731 {
1732         int ret;
1733         struct extent_buffer *eb;
1734         int slot;
1735         u32 item_size;
1736         struct btrfs_dir_item *di;
1737         struct btrfs_dir_item *log_di;
1738         int name_len;
1739         unsigned long ptr;
1740         unsigned long ptr_end;
1741         char *name;
1742         struct inode *inode;
1743         struct btrfs_key location;
1744
1745 again:
1746         eb = path->nodes[0];
1747         slot = path->slots[0];
1748         item_size = btrfs_item_size_nr(eb, slot);
1749         ptr = btrfs_item_ptr_offset(eb, slot);
1750         ptr_end = ptr + item_size;
1751         while (ptr < ptr_end) {
1752                 di = (struct btrfs_dir_item *)ptr;
1753                 if (verify_dir_item(root, eb, di)) {
1754                         ret = -EIO;
1755                         goto out;
1756                 }
1757
1758                 name_len = btrfs_dir_name_len(eb, di);
1759                 name = kmalloc(name_len, GFP_NOFS);
1760                 if (!name) {
1761                         ret = -ENOMEM;
1762                         goto out;
1763                 }
1764                 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1765                                   name_len);
1766                 log_di = NULL;
1767                 if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
1768                         log_di = btrfs_lookup_dir_item(trans, log, log_path,
1769                                                        dir_key->objectid,
1770                                                        name, name_len, 0);
1771                 } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
1772                         log_di = btrfs_lookup_dir_index_item(trans, log,
1773                                                      log_path,
1774                                                      dir_key->objectid,
1775                                                      dir_key->offset,
1776                                                      name, name_len, 0);
1777                 }
1778                 if (IS_ERR_OR_NULL(log_di)) {
1779                         btrfs_dir_item_key_to_cpu(eb, di, &location);
1780                         btrfs_release_path(path);
1781                         btrfs_release_path(log_path);
1782                         inode = read_one_inode(root, location.objectid);
1783                         if (!inode) {
1784                                 kfree(name);
1785                                 return -EIO;
1786                         }
1787
1788                         ret = link_to_fixup_dir(trans, root,
1789                                                 path, location.objectid);
1790                         if (ret) {
1791                                 kfree(name);
1792                                 iput(inode);
1793                                 goto out;
1794                         }
1795
1796                         btrfs_inc_nlink(inode);
1797                         ret = btrfs_unlink_inode(trans, root, dir, inode,
1798                                                  name, name_len);
1799                         if (!ret)
1800                                 btrfs_run_delayed_items(trans, root);
1801                         kfree(name);
1802                         iput(inode);
1803                         if (ret)
1804                                 goto out;
1805
1806                         /* there might still be more names under this key
1807                          * check and repeat if required
1808                          */
1809                         ret = btrfs_search_slot(NULL, root, dir_key, path,
1810                                                 0, 0);
1811                         if (ret == 0)
1812                                 goto again;
1813                         ret = 0;
1814                         goto out;
1815                 }
1816                 btrfs_release_path(log_path);
1817                 kfree(name);
1818
1819                 ptr = (unsigned long)(di + 1);
1820                 ptr += name_len;
1821         }
1822         ret = 0;
1823 out:
1824         btrfs_release_path(path);
1825         btrfs_release_path(log_path);
1826         return ret;
1827 }
1828
1829 /*
1830  * deletion replay happens before we copy any new directory items
1831  * out of the log or out of backreferences from inodes.  It
1832  * scans the log to find ranges of keys that log is authoritative for,
1833  * and then scans the directory to find items in those ranges that are
1834  * not present in the log.
1835  *
1836  * Anything we don't find in the log is unlinked and removed from the
1837  * directory.
1838  */
1839 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
1840                                        struct btrfs_root *root,
1841                                        struct btrfs_root *log,
1842                                        struct btrfs_path *path,
1843                                        u64 dirid, int del_all)
1844 {
1845         u64 range_start;
1846         u64 range_end;
1847         int key_type = BTRFS_DIR_LOG_ITEM_KEY;
1848         int ret = 0;
1849         struct btrfs_key dir_key;
1850         struct btrfs_key found_key;
1851         struct btrfs_path *log_path;
1852         struct inode *dir;
1853
1854         dir_key.objectid = dirid;
1855         dir_key.type = BTRFS_DIR_ITEM_KEY;
1856         log_path = btrfs_alloc_path();
1857         if (!log_path)
1858                 return -ENOMEM;
1859
1860         dir = read_one_inode(root, dirid);
1861         /* it isn't an error if the inode isn't there, that can happen
1862          * because we replay the deletes before we copy in the inode item
1863          * from the log
1864          */
1865         if (!dir) {
1866                 btrfs_free_path(log_path);
1867                 return 0;
1868         }
1869 again:
1870         range_start = 0;
1871         range_end = 0;
1872         while (1) {
1873                 if (del_all)
1874                         range_end = (u64)-1;
1875                 else {
1876                         ret = find_dir_range(log, path, dirid, key_type,
1877                                              &range_start, &range_end);
1878                         if (ret != 0)
1879                                 break;
1880                 }
1881
1882                 dir_key.offset = range_start;
1883                 while (1) {
1884                         int nritems;
1885                         ret = btrfs_search_slot(NULL, root, &dir_key, path,
1886                                                 0, 0);
1887                         if (ret < 0)
1888                                 goto out;
1889
1890                         nritems = btrfs_header_nritems(path->nodes[0]);
1891                         if (path->slots[0] >= nritems) {
1892                                 ret = btrfs_next_leaf(root, path);
1893                                 if (ret)
1894                                         break;
1895                         }
1896                         btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1897                                               path->slots[0]);
1898                         if (found_key.objectid != dirid ||
1899                             found_key.type != dir_key.type)
1900                                 goto next_type;
1901
1902                         if (found_key.offset > range_end)
1903                                 break;
1904
1905                         ret = check_item_in_log(trans, root, log, path,
1906                                                 log_path, dir,
1907                                                 &found_key);
1908                         if (ret)
1909                                 goto out;
1910                         if (found_key.offset == (u64)-1)
1911                                 break;
1912                         dir_key.offset = found_key.offset + 1;
1913                 }
1914                 btrfs_release_path(path);
1915                 if (range_end == (u64)-1)
1916                         break;
1917                 range_start = range_end + 1;
1918         }
1919
1920 next_type:
1921         ret = 0;
1922         if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
1923                 key_type = BTRFS_DIR_LOG_INDEX_KEY;
1924                 dir_key.type = BTRFS_DIR_INDEX_KEY;
1925                 btrfs_release_path(path);
1926                 goto again;
1927         }
1928 out:
1929         btrfs_release_path(path);
1930         btrfs_free_path(log_path);
1931         iput(dir);
1932         return ret;
1933 }
1934
1935 /*
1936  * the process_func used to replay items from the log tree.  This
1937  * gets called in two different stages.  The first stage just looks
1938  * for inodes and makes sure they are all copied into the subvolume.
1939  *
1940  * The second stage copies all the other item types from the log into
1941  * the subvolume.  The two stage approach is slower, but gets rid of
1942  * lots of complexity around inodes referencing other inodes that exist
1943  * only in the log (references come from either directory items or inode
1944  * back refs).
1945  */
1946 static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
1947                              struct walk_control *wc, u64 gen)
1948 {
1949         int nritems;
1950         struct btrfs_path *path;
1951         struct btrfs_root *root = wc->replay_dest;
1952         struct btrfs_key key;
1953         int level;
1954         int i;
1955         int ret;
1956
1957         ret = btrfs_read_buffer(eb, gen);
1958         if (ret)
1959                 return ret;
1960
1961         level = btrfs_header_level(eb);
1962
1963         if (level != 0)
1964                 return 0;
1965
1966         path = btrfs_alloc_path();
1967         if (!path)
1968                 return -ENOMEM;
1969
1970         nritems = btrfs_header_nritems(eb);
1971         for (i = 0; i < nritems; i++) {
1972                 btrfs_item_key_to_cpu(eb, &key, i);
1973
1974                 /* inode keys are done during the first stage */
1975                 if (key.type == BTRFS_INODE_ITEM_KEY &&
1976                     wc->stage == LOG_WALK_REPLAY_INODES) {
1977                         struct btrfs_inode_item *inode_item;
1978                         u32 mode;
1979
1980                         inode_item = btrfs_item_ptr(eb, i,
1981                                             struct btrfs_inode_item);
1982                         mode = btrfs_inode_mode(eb, inode_item);
1983                         if (S_ISDIR(mode)) {
1984                                 ret = replay_dir_deletes(wc->trans,
1985                                          root, log, path, key.objectid, 0);
1986                                 if (ret)
1987                                         break;
1988                         }
1989                         ret = overwrite_item(wc->trans, root, path,
1990                                              eb, i, &key);
1991                         if (ret)
1992                                 break;
1993
1994                         /* for regular files, make sure corresponding
1995                          * orhpan item exist. extents past the new EOF
1996                          * will be truncated later by orphan cleanup.
1997                          */
1998                         if (S_ISREG(mode)) {
1999                                 ret = insert_orphan_item(wc->trans, root,
2000                                                          key.objectid);
2001                                 if (ret)
2002                                         break;
2003                         }
2004
2005                         ret = link_to_fixup_dir(wc->trans, root,
2006                                                 path, key.objectid);
2007                         if (ret)
2008                                 break;
2009                 }
2010                 if (wc->stage < LOG_WALK_REPLAY_ALL)
2011                         continue;
2012
2013                 /* these keys are simply copied */
2014                 if (key.type == BTRFS_XATTR_ITEM_KEY) {
2015                         ret = overwrite_item(wc->trans, root, path,
2016                                              eb, i, &key);
2017                         if (ret)
2018                                 break;
2019                 } else if (key.type == BTRFS_INODE_REF_KEY ||
2020                            key.type == BTRFS_INODE_EXTREF_KEY) {
2021                         ret = add_inode_ref(wc->trans, root, log, path,
2022                                             eb, i, &key);
2023                         if (ret && ret != -ENOENT)
2024                                 break;
2025                         ret = 0;
2026                 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
2027                         ret = replay_one_extent(wc->trans, root, path,
2028                                                 eb, i, &key);
2029                         if (ret)
2030                                 break;
2031                 } else if (key.type == BTRFS_DIR_ITEM_KEY ||
2032                            key.type == BTRFS_DIR_INDEX_KEY) {
2033                         ret = replay_one_dir_item(wc->trans, root, path,
2034                                                   eb, i, &key);
2035                         if (ret)
2036                                 break;
2037                 }
2038         }
2039         btrfs_free_path(path);
2040         return ret;
2041 }
2042
2043 static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
2044                                    struct btrfs_root *root,
2045                                    struct btrfs_path *path, int *level,
2046                                    struct walk_control *wc)
2047 {
2048         u64 root_owner;
2049         u64 bytenr;
2050         u64 ptr_gen;
2051         struct extent_buffer *next;
2052         struct extent_buffer *cur;
2053         struct extent_buffer *parent;
2054         u32 blocksize;
2055         int ret = 0;
2056
2057         WARN_ON(*level < 0);
2058         WARN_ON(*level >= BTRFS_MAX_LEVEL);
2059
2060         while (*level > 0) {
2061                 WARN_ON(*level < 0);
2062                 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2063                 cur = path->nodes[*level];
2064
2065                 if (btrfs_header_level(cur) != *level)
2066                         WARN_ON(1);
2067
2068                 if (path->slots[*level] >=
2069                     btrfs_header_nritems(cur))
2070                         break;
2071
2072                 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2073                 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2074                 blocksize = btrfs_level_size(root, *level - 1);
2075
2076                 parent = path->nodes[*level];
2077                 root_owner = btrfs_header_owner(parent);
2078
2079                 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
2080                 if (!next)
2081                         return -ENOMEM;
2082
2083                 if (*level == 1) {
2084                         ret = wc->process_func(root, next, wc, ptr_gen);
2085                         if (ret) {
2086                                 free_extent_buffer(next);
2087                                 return ret;
2088                         }
2089
2090                         path->slots[*level]++;
2091                         if (wc->free) {
2092                                 ret = btrfs_read_buffer(next, ptr_gen);
2093                                 if (ret) {
2094                                         free_extent_buffer(next);
2095                                         return ret;
2096                                 }
2097
2098                                 btrfs_tree_lock(next);
2099                                 btrfs_set_lock_blocking(next);
2100                                 clean_tree_block(trans, root, next);
2101                                 btrfs_wait_tree_block_writeback(next);
2102                                 btrfs_tree_unlock(next);
2103
2104                                 WARN_ON(root_owner !=
2105                                         BTRFS_TREE_LOG_OBJECTID);
2106                                 ret = btrfs_free_and_pin_reserved_extent(root,
2107                                                          bytenr, blocksize);
2108                                 if (ret) {
2109                                         free_extent_buffer(next);
2110                                         return ret;
2111                                 }
2112                         }
2113                         free_extent_buffer(next);
2114                         continue;
2115                 }
2116                 ret = btrfs_read_buffer(next, ptr_gen);
2117                 if (ret) {
2118                         free_extent_buffer(next);
2119                         return ret;
2120                 }
2121
2122                 WARN_ON(*level <= 0);
2123                 if (path->nodes[*level-1])
2124                         free_extent_buffer(path->nodes[*level-1]);
2125                 path->nodes[*level-1] = next;
2126                 *level = btrfs_header_level(next);
2127                 path->slots[*level] = 0;
2128                 cond_resched();
2129         }
2130         WARN_ON(*level < 0);
2131         WARN_ON(*level >= BTRFS_MAX_LEVEL);
2132
2133         path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
2134
2135         cond_resched();
2136         return 0;
2137 }
2138
2139 static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
2140                                  struct btrfs_root *root,
2141                                  struct btrfs_path *path, int *level,
2142                                  struct walk_control *wc)
2143 {
2144         u64 root_owner;
2145         int i;
2146         int slot;
2147         int ret;
2148
2149         for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2150                 slot = path->slots[i];
2151                 if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
2152                         path->slots[i]++;
2153                         *level = i;
2154                         WARN_ON(*level == 0);
2155                         return 0;
2156                 } else {
2157                         struct extent_buffer *parent;
2158                         if (path->nodes[*level] == root->node)
2159                                 parent = path->nodes[*level];
2160                         else
2161                                 parent = path->nodes[*level + 1];
2162
2163                         root_owner = btrfs_header_owner(parent);
2164                         ret = wc->process_func(root, path->nodes[*level], wc,
2165                                  btrfs_header_generation(path->nodes[*level]));
2166                         if (ret)
2167                                 return ret;
2168
2169                         if (wc->free) {
2170                                 struct extent_buffer *next;
2171
2172                                 next = path->nodes[*level];
2173
2174                                 btrfs_tree_lock(next);
2175                                 btrfs_set_lock_blocking(next);
2176                                 clean_tree_block(trans, root, next);
2177                                 btrfs_wait_tree_block_writeback(next);
2178                                 btrfs_tree_unlock(next);
2179
2180                                 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
2181                                 ret = btrfs_free_and_pin_reserved_extent(root,
2182                                                 path->nodes[*level]->start,
2183                                                 path->nodes[*level]->len);
2184                                 if (ret)
2185                                         return ret;
2186                         }
2187                         free_extent_buffer(path->nodes[*level]);
2188                         path->nodes[*level] = NULL;
2189                         *level = i + 1;
2190                 }
2191         }
2192         return 1;
2193 }
2194
2195 /*
2196  * drop the reference count on the tree rooted at 'snap'.  This traverses
2197  * the tree freeing any blocks that have a ref count of zero after being
2198  * decremented.
2199  */
2200 static int walk_log_tree(struct btrfs_trans_handle *trans,
2201                          struct btrfs_root *log, struct walk_control *wc)
2202 {
2203         int ret = 0;
2204         int wret;
2205         int level;
2206         struct btrfs_path *path;
2207         int orig_level;
2208
2209         path = btrfs_alloc_path();
2210         if (!path)
2211                 return -ENOMEM;
2212
2213         level = btrfs_header_level(log->node);
2214         orig_level = level;
2215         path->nodes[level] = log->node;
2216         extent_buffer_get(log->node);
2217         path->slots[level] = 0;
2218
2219         while (1) {
2220                 wret = walk_down_log_tree(trans, log, path, &level, wc);
2221                 if (wret > 0)
2222                         break;
2223                 if (wret < 0) {
2224                         ret = wret;
2225                         goto out;
2226                 }
2227
2228                 wret = walk_up_log_tree(trans, log, path, &level, wc);
2229                 if (wret > 0)
2230                         break;
2231                 if (wret < 0) {
2232                         ret = wret;
2233                         goto out;
2234                 }
2235         }
2236
2237         /* was the root node processed? if not, catch it here */
2238         if (path->nodes[orig_level]) {
2239                 ret = wc->process_func(log, path->nodes[orig_level], wc,
2240                          btrfs_header_generation(path->nodes[orig_level]));
2241                 if (ret)
2242                         goto out;
2243                 if (wc->free) {
2244                         struct extent_buffer *next;
2245
2246                         next = path->nodes[orig_level];
2247
2248                         btrfs_tree_lock(next);
2249                         btrfs_set_lock_blocking(next);
2250                         clean_tree_block(trans, log, next);
2251                         btrfs_wait_tree_block_writeback(next);
2252                         btrfs_tree_unlock(next);
2253
2254                         WARN_ON(log->root_key.objectid !=
2255                                 BTRFS_TREE_LOG_OBJECTID);
2256                         ret = btrfs_free_and_pin_reserved_extent(log, next->start,
2257                                                          next->len);
2258                         if (ret)
2259                                 goto out;
2260                 }
2261         }
2262
2263 out:
2264         btrfs_free_path(path);
2265         return ret;
2266 }
2267
2268 /*
2269  * helper function to update the item for a given subvolumes log root
2270  * in the tree of log roots
2271  */
2272 static int update_log_root(struct btrfs_trans_handle *trans,
2273                            struct btrfs_root *log)
2274 {
2275         int ret;
2276
2277         if (log->log_transid == 1) {
2278                 /* insert root item on the first sync */
2279                 ret = btrfs_insert_root(trans, log->fs_info->log_root_tree,
2280                                 &log->root_key, &log->root_item);
2281         } else {
2282                 ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
2283                                 &log->root_key, &log->root_item);
2284         }
2285         return ret;
2286 }
2287
2288 static int wait_log_commit(struct btrfs_trans_handle *trans,
2289                            struct btrfs_root *root, unsigned long transid)
2290 {
2291         DEFINE_WAIT(wait);
2292         int index = transid % 2;
2293
2294         /*
2295          * we only allow two pending log transactions at a time,
2296          * so we know that if ours is more than 2 older than the
2297          * current transaction, we're done
2298          */
2299         do {
2300                 prepare_to_wait(&root->log_commit_wait[index],
2301                                 &wait, TASK_UNINTERRUPTIBLE);
2302                 mutex_unlock(&root->log_mutex);
2303
2304                 if (root->fs_info->last_trans_log_full_commit !=
2305                     trans->transid && root->log_transid < transid + 2 &&
2306                     atomic_read(&root->log_commit[index]))
2307                         schedule();
2308
2309                 finish_wait(&root->log_commit_wait[index], &wait);
2310                 mutex_lock(&root->log_mutex);
2311         } while (root->fs_info->last_trans_log_full_commit !=
2312                  trans->transid && root->log_transid < transid + 2 &&
2313                  atomic_read(&root->log_commit[index]));
2314         return 0;
2315 }
2316
2317 static void wait_for_writer(struct btrfs_trans_handle *trans,
2318                             struct btrfs_root *root)
2319 {
2320         DEFINE_WAIT(wait);
2321         while (root->fs_info->last_trans_log_full_commit !=
2322                trans->transid && atomic_read(&root->log_writers)) {
2323                 prepare_to_wait(&root->log_writer_wait,
2324                                 &wait, TASK_UNINTERRUPTIBLE);
2325                 mutex_unlock(&root->log_mutex);
2326                 if (root->fs_info->last_trans_log_full_commit !=
2327                     trans->transid && atomic_read(&root->log_writers))
2328                         schedule();
2329                 mutex_lock(&root->log_mutex);
2330                 finish_wait(&root->log_writer_wait, &wait);
2331         }
2332 }
2333
2334 /*
2335  * btrfs_sync_log does sends a given tree log down to the disk and
2336  * updates the super blocks to record it.  When this call is done,
2337  * you know that any inodes previously logged are safely on disk only
2338  * if it returns 0.
2339  *
2340  * Any other return value means you need to call btrfs_commit_transaction.
2341  * Some of the edge cases for fsyncing directories that have had unlinks
2342  * or renames done in the past mean that sometimes the only safe
2343  * fsync is to commit the whole FS.  When btrfs_sync_log returns -EAGAIN,
2344  * that has happened.
2345  */
2346 int btrfs_sync_log(struct btrfs_trans_handle *trans,
2347                    struct btrfs_root *root)
2348 {
2349         int index1;
2350         int index2;
2351         int mark;
2352         int ret;
2353         struct btrfs_root *log = root->log_root;
2354         struct btrfs_root *log_root_tree = root->fs_info->log_root_tree;
2355         unsigned long log_transid = 0;
2356
2357         mutex_lock(&root->log_mutex);
2358         log_transid = root->log_transid;
2359         index1 = root->log_transid % 2;
2360         if (atomic_read(&root->log_commit[index1])) {
2361                 wait_log_commit(trans, root, root->log_transid);
2362                 mutex_unlock(&root->log_mutex);
2363                 return 0;
2364         }
2365         atomic_set(&root->log_commit[index1], 1);
2366
2367         /* wait for previous tree log sync to complete */
2368         if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
2369                 wait_log_commit(trans, root, root->log_transid - 1);
2370         while (1) {
2371                 int batch = atomic_read(&root->log_batch);
2372                 /* when we're on an ssd, just kick the log commit out */
2373                 if (!btrfs_test_opt(root, SSD) && root->log_multiple_pids) {
2374                         mutex_unlock(&root->log_mutex);
2375                         schedule_timeout_uninterruptible(1);
2376                         mutex_lock(&root->log_mutex);
2377                 }
2378                 wait_for_writer(trans, root);
2379                 if (batch == atomic_read(&root->log_batch))
2380                         break;
2381         }
2382
2383         /* bail out if we need to do a full commit */
2384         if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2385                 ret = -EAGAIN;
2386                 btrfs_free_logged_extents(log, log_transid);
2387                 mutex_unlock(&root->log_mutex);
2388                 goto out;
2389         }
2390
2391         if (log_transid % 2 == 0)
2392                 mark = EXTENT_DIRTY;
2393         else
2394                 mark = EXTENT_NEW;
2395
2396         /* we start IO on  all the marked extents here, but we don't actually
2397          * wait for them until later.
2398          */
2399         ret = btrfs_write_marked_extents(log, &log->dirty_log_pages, mark);
2400         if (ret) {
2401                 btrfs_abort_transaction(trans, root, ret);
2402                 btrfs_free_logged_extents(log, log_transid);
2403                 mutex_unlock(&root->log_mutex);
2404                 goto out;
2405         }
2406
2407         btrfs_set_root_node(&log->root_item, log->node);
2408
2409         root->log_transid++;
2410         log->log_transid = root->log_transid;
2411         root->log_start_pid = 0;
2412         smp_mb();
2413         /*
2414          * IO has been started, blocks of the log tree have WRITTEN flag set
2415          * in their headers. new modifications of the log will be written to
2416          * new positions. so it's safe to allow log writers to go in.
2417          */
2418         mutex_unlock(&root->log_mutex);
2419
2420         mutex_lock(&log_root_tree->log_mutex);
2421         atomic_inc(&log_root_tree->log_batch);
2422         atomic_inc(&log_root_tree->log_writers);
2423         mutex_unlock(&log_root_tree->log_mutex);
2424
2425         ret = update_log_root(trans, log);
2426
2427         mutex_lock(&log_root_tree->log_mutex);
2428         if (atomic_dec_and_test(&log_root_tree->log_writers)) {
2429                 smp_mb();
2430                 if (waitqueue_active(&log_root_tree->log_writer_wait))
2431                         wake_up(&log_root_tree->log_writer_wait);
2432         }
2433
2434         if (ret) {
2435                 if (ret != -ENOSPC) {
2436                         btrfs_abort_transaction(trans, root, ret);
2437                         mutex_unlock(&log_root_tree->log_mutex);
2438                         goto out;
2439                 }
2440                 root->fs_info->last_trans_log_full_commit = trans->transid;
2441                 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2442                 btrfs_free_logged_extents(log, log_transid);
2443                 mutex_unlock(&log_root_tree->log_mutex);
2444                 ret = -EAGAIN;
2445                 goto out;
2446         }
2447
2448         index2 = log_root_tree->log_transid % 2;
2449         if (atomic_read(&log_root_tree->log_commit[index2])) {
2450                 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2451                 wait_log_commit(trans, log_root_tree,
2452                                 log_root_tree->log_transid);
2453                 btrfs_free_logged_extents(log, log_transid);
2454                 mutex_unlock(&log_root_tree->log_mutex);
2455                 ret = 0;
2456                 goto out;
2457         }
2458         atomic_set(&log_root_tree->log_commit[index2], 1);
2459
2460         if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
2461                 wait_log_commit(trans, log_root_tree,
2462                                 log_root_tree->log_transid - 1);
2463         }
2464
2465         wait_for_writer(trans, log_root_tree);
2466
2467         /*
2468          * now that we've moved on to the tree of log tree roots,
2469          * check the full commit flag again
2470          */
2471         if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2472                 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2473                 btrfs_free_logged_extents(log, log_transid);
2474                 mutex_unlock(&log_root_tree->log_mutex);
2475                 ret = -EAGAIN;
2476                 goto out_wake_log_root;
2477         }
2478
2479         ret = btrfs_write_and_wait_marked_extents(log_root_tree,
2480                                 &log_root_tree->dirty_log_pages,
2481                                 EXTENT_DIRTY | EXTENT_NEW);
2482         if (ret) {
2483                 btrfs_abort_transaction(trans, root, ret);
2484                 btrfs_free_logged_extents(log, log_transid);
2485                 mutex_unlock(&log_root_tree->log_mutex);
2486                 goto out_wake_log_root;
2487         }
2488         btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2489         btrfs_wait_logged_extents(log, log_transid);
2490
2491         btrfs_set_super_log_root(root->fs_info->super_for_commit,
2492                                 log_root_tree->node->start);
2493         btrfs_set_super_log_root_level(root->fs_info->super_for_commit,
2494                                 btrfs_header_level(log_root_tree->node));
2495
2496         log_root_tree->log_transid++;
2497         smp_mb();
2498
2499         mutex_unlock(&log_root_tree->log_mutex);
2500
2501         /*
2502          * nobody else is going to jump in and write the the ctree
2503          * super here because the log_commit atomic below is protecting
2504          * us.  We must be called with a transaction handle pinning
2505          * the running transaction open, so a full commit can't hop
2506          * in and cause problems either.
2507          */
2508         btrfs_scrub_pause_super(root);
2509         ret = write_ctree_super(trans, root->fs_info->tree_root, 1);
2510         btrfs_scrub_continue_super(root);
2511         if (ret) {
2512                 btrfs_abort_transaction(trans, root, ret);
2513                 goto out_wake_log_root;
2514         }
2515
2516         mutex_lock(&root->log_mutex);
2517         if (root->last_log_commit < log_transid)
2518                 root->last_log_commit = log_transid;
2519         mutex_unlock(&root->log_mutex);
2520
2521 out_wake_log_root:
2522         atomic_set(&log_root_tree->log_commit[index2], 0);
2523         smp_mb();
2524         if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
2525                 wake_up(&log_root_tree->log_commit_wait[index2]);
2526 out:
2527         atomic_set(&root->log_commit[index1], 0);
2528         smp_mb();
2529         if (waitqueue_active(&root->log_commit_wait[index1]))
2530                 wake_up(&root->log_commit_wait[index1]);
2531         return ret;
2532 }
2533
2534 static void free_log_tree(struct btrfs_trans_handle *trans,
2535                           struct btrfs_root *log)
2536 {
2537         int ret;
2538         u64 start;
2539         u64 end;
2540         struct walk_control wc = {
2541                 .free = 1,
2542                 .process_func = process_one_buffer
2543         };
2544
2545         if (trans) {
2546                 ret = walk_log_tree(trans, log, &wc);
2547
2548                 /* I don't think this can happen but just in case */
2549                 if (ret)
2550                         btrfs_abort_transaction(trans, log, ret);
2551         }
2552
2553         while (1) {
2554                 ret = find_first_extent_bit(&log->dirty_log_pages,
2555                                 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW,
2556                                 NULL);
2557                 if (ret)
2558                         break;
2559
2560                 clear_extent_bits(&log->dirty_log_pages, start, end,
2561                                   EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
2562         }
2563
2564         /*
2565          * We may have short-circuited the log tree with the full commit logic
2566          * and left ordered extents on our list, so clear these out to keep us
2567          * from leaking inodes and memory.
2568          */
2569         btrfs_free_logged_extents(log, 0);
2570         btrfs_free_logged_extents(log, 1);
2571
2572         free_extent_buffer(log->node);
2573         kfree(log);
2574 }
2575
2576 /*
2577  * free all the extents used by the tree log.  This should be called
2578  * at commit time of the full transaction
2579  */
2580 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
2581 {
2582         if (root->log_root) {
2583                 free_log_tree(trans, root->log_root);
2584                 root->log_root = NULL;
2585         }
2586         return 0;
2587 }
2588
2589 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
2590                              struct btrfs_fs_info *fs_info)
2591 {
2592         if (fs_info->log_root_tree) {
2593                 free_log_tree(trans, fs_info->log_root_tree);
2594                 fs_info->log_root_tree = NULL;
2595         }
2596         return 0;
2597 }
2598
2599 /*
2600  * If both a file and directory are logged, and unlinks or renames are
2601  * mixed in, we have a few interesting corners:
2602  *
2603  * create file X in dir Y
2604  * link file X to X.link in dir Y
2605  * fsync file X
2606  * unlink file X but leave X.link
2607  * fsync dir Y
2608  *
2609  * After a crash we would expect only X.link to exist.  But file X
2610  * didn't get fsync'd again so the log has back refs for X and X.link.
2611  *
2612  * We solve this by removing directory entries and inode backrefs from the
2613  * log when a file that was logged in the current transaction is
2614  * unlinked.  Any later fsync will include the updated log entries, and
2615  * we'll be able to reconstruct the proper directory items from backrefs.
2616  *
2617  * This optimizations allows us to avoid relogging the entire inode
2618  * or the entire directory.
2619  */
2620 int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
2621                                  struct btrfs_root *root,
2622                                  const char *name, int name_len,
2623                                  struct inode *dir, u64 index)
2624 {
2625         struct btrfs_root *log;
2626         struct btrfs_dir_item *di;
2627         struct btrfs_path *path;
2628         int ret;
2629         int err = 0;
2630         int bytes_del = 0;
2631         u64 dir_ino = btrfs_ino(dir);
2632
2633         if (BTRFS_I(dir)->logged_trans < trans->transid)
2634                 return 0;
2635
2636         ret = join_running_log_trans(root);
2637         if (ret)
2638                 return 0;
2639
2640         mutex_lock(&BTRFS_I(dir)->log_mutex);
2641
2642         log = root->log_root;
2643         path = btrfs_alloc_path();
2644         if (!path) {
2645                 err = -ENOMEM;
2646                 goto out_unlock;
2647         }
2648
2649         di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
2650                                    name, name_len, -1);
2651         if (IS_ERR(di)) {
2652                 err = PTR_ERR(di);
2653                 goto fail;
2654         }
2655         if (di) {
2656                 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2657                 bytes_del += name_len;
2658                 if (ret) {
2659                         err = ret;
2660                         goto fail;
2661                 }
2662         }
2663         btrfs_release_path(path);
2664         di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
2665                                          index, name, name_len, -1);
2666         if (IS_ERR(di)) {
2667                 err = PTR_ERR(di);
2668                 goto fail;
2669         }
2670         if (di) {
2671                 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2672                 bytes_del += name_len;
2673                 if (ret) {
2674                         err = ret;
2675                         goto fail;
2676                 }
2677         }
2678
2679         /* update the directory size in the log to reflect the names
2680          * we have removed
2681          */
2682         if (bytes_del) {
2683                 struct btrfs_key key;
2684
2685                 key.objectid = dir_ino;
2686                 key.offset = 0;
2687                 key.type = BTRFS_INODE_ITEM_KEY;
2688                 btrfs_release_path(path);
2689
2690                 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
2691                 if (ret < 0) {
2692                         err = ret;
2693                         goto fail;
2694                 }
2695                 if (ret == 0) {
2696                         struct btrfs_inode_item *item;
2697                         u64 i_size;
2698
2699                         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2700                                               struct btrfs_inode_item);
2701                         i_size = btrfs_inode_size(path->nodes[0], item);
2702                         if (i_size > bytes_del)
2703                                 i_size -= bytes_del;
2704                         else
2705                                 i_size = 0;
2706                         btrfs_set_inode_size(path->nodes[0], item, i_size);
2707                         btrfs_mark_buffer_dirty(path->nodes[0]);
2708                 } else
2709                         ret = 0;
2710                 btrfs_release_path(path);
2711         }
2712 fail:
2713         btrfs_free_path(path);
2714 out_unlock:
2715         mutex_unlock(&BTRFS_I(dir)->log_mutex);
2716         if (ret == -ENOSPC) {
2717                 root->fs_info->last_trans_log_full_commit = trans->transid;
2718                 ret = 0;
2719         } else if (ret < 0)
2720                 btrfs_abort_transaction(trans, root, ret);
2721
2722         btrfs_end_log_trans(root);
2723
2724         return err;
2725 }
2726
2727 /* see comments for btrfs_del_dir_entries_in_log */
2728 int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
2729                                struct btrfs_root *root,
2730                                const char *name, int name_len,
2731                                struct inode *inode, u64 dirid)
2732 {
2733         struct btrfs_root *log;
2734         u64 index;
2735         int ret;
2736
2737         if (BTRFS_I(inode)->logged_trans < trans->transid)
2738                 return 0;
2739
2740         ret = join_running_log_trans(root);
2741         if (ret)
2742                 return 0;
2743         log = root->log_root;
2744         mutex_lock(&BTRFS_I(inode)->log_mutex);
2745
2746         ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
2747                                   dirid, &index);
2748         mutex_unlock(&BTRFS_I(inode)->log_mutex);
2749         if (ret == -ENOSPC) {
2750                 root->fs_info->last_trans_log_full_commit = trans->transid;
2751                 ret = 0;
2752         } else if (ret < 0 && ret != -ENOENT)
2753                 btrfs_abort_transaction(trans, root, ret);
2754         btrfs_end_log_trans(root);
2755
2756         return ret;
2757 }
2758
2759 /*
2760  * creates a range item in the log for 'dirid'.  first_offset and
2761  * last_offset tell us which parts of the key space the log should
2762  * be considered authoritative for.
2763  */
2764 static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
2765                                        struct btrfs_root *log,
2766                                        struct btrfs_path *path,
2767                                        int key_type, u64 dirid,
2768                                        u64 first_offset, u64 last_offset)
2769 {
2770         int ret;
2771         struct btrfs_key key;
2772         struct btrfs_dir_log_item *item;
2773
2774         key.objectid = dirid;
2775         key.offset = first_offset;
2776         if (key_type == BTRFS_DIR_ITEM_KEY)
2777                 key.type = BTRFS_DIR_LOG_ITEM_KEY;
2778         else
2779                 key.type = BTRFS_DIR_LOG_INDEX_KEY;
2780         ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
2781         if (ret)
2782                 return ret;
2783
2784         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2785                               struct btrfs_dir_log_item);
2786         btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
2787         btrfs_mark_buffer_dirty(path->nodes[0]);
2788         btrfs_release_path(path);
2789         return 0;
2790 }
2791
2792 /*
2793  * log all the items included in the current transaction for a given
2794  * directory.  This also creates the range items in the log tree required
2795  * to replay anything deleted before the fsync
2796  */
2797 static noinline int log_dir_items(struct btrfs_trans_handle *trans,
2798                           struct btrfs_root *root, struct inode *inode,
2799                           struct btrfs_path *path,
2800                           struct btrfs_path *dst_path, int key_type,
2801                           u64 min_offset, u64 *last_offset_ret)
2802 {
2803         struct btrfs_key min_key;
2804         struct btrfs_key max_key;
2805         struct btrfs_root *log = root->log_root;
2806         struct extent_buffer *src;
2807         int err = 0;
2808         int ret;
2809         int i;
2810         int nritems;
2811         u64 first_offset = min_offset;
2812         u64 last_offset = (u64)-1;
2813         u64 ino = btrfs_ino(inode);
2814
2815         log = root->log_root;
2816         max_key.objectid = ino;
2817         max_key.offset = (u64)-1;
2818         max_key.type = key_type;
2819
2820         min_key.objectid = ino;
2821         min_key.type = key_type;
2822         min_key.offset = min_offset;
2823
2824         path->keep_locks = 1;
2825
2826         ret = btrfs_search_forward(root, &min_key, &max_key,
2827                                    path, trans->transid);
2828
2829         /*
2830          * we didn't find anything from this transaction, see if there
2831          * is anything at all
2832          */
2833         if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
2834                 min_key.objectid = ino;
2835                 min_key.type = key_type;
2836                 min_key.offset = (u64)-1;
2837                 btrfs_release_path(path);
2838                 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2839                 if (ret < 0) {
2840                         btrfs_release_path(path);
2841                         return ret;
2842                 }
2843                 ret = btrfs_previous_item(root, path, ino, key_type);
2844
2845                 /* if ret == 0 there are items for this type,
2846                  * create a range to tell us the last key of this type.
2847                  * otherwise, there are no items in this directory after
2848                  * *min_offset, and we create a range to indicate that.
2849                  */
2850                 if (ret == 0) {
2851                         struct btrfs_key tmp;
2852                         btrfs_item_key_to_cpu(path->nodes[0], &tmp,
2853                                               path->slots[0]);
2854                         if (key_type == tmp.type)
2855                                 first_offset = max(min_offset, tmp.offset) + 1;
2856                 }
2857                 goto done;
2858         }
2859
2860         /* go backward to find any previous key */
2861         ret = btrfs_previous_item(root, path, ino, key_type);
2862         if (ret == 0) {
2863                 struct btrfs_key tmp;
2864                 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2865                 if (key_type == tmp.type) {
2866                         first_offset = tmp.offset;
2867                         ret = overwrite_item(trans, log, dst_path,
2868                                              path->nodes[0], path->slots[0],
2869                                              &tmp);
2870                         if (ret) {
2871                                 err = ret;
2872                                 goto done;
2873                         }
2874                 }
2875         }
2876         btrfs_release_path(path);
2877
2878         /* find the first key from this transaction again */
2879         ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2880         if (ret != 0) {
2881                 WARN_ON(1);
2882                 goto done;
2883         }
2884
2885         /*
2886          * we have a block from this transaction, log every item in it
2887          * from our directory
2888          */
2889         while (1) {
2890                 struct btrfs_key tmp;
2891                 src = path->nodes[0];
2892                 nritems = btrfs_header_nritems(src);
2893                 for (i = path->slots[0]; i < nritems; i++) {
2894                         btrfs_item_key_to_cpu(src, &min_key, i);
2895
2896                         if (min_key.objectid != ino || min_key.type != key_type)
2897                                 goto done;
2898                         ret = overwrite_item(trans, log, dst_path, src, i,
2899                                              &min_key);
2900                         if (ret) {
2901                                 err = ret;
2902                                 goto done;
2903                         }
2904                 }
2905                 path->slots[0] = nritems;
2906
2907                 /*
2908                  * look ahead to the next item and see if it is also
2909                  * from this directory and from this transaction
2910                  */
2911                 ret = btrfs_next_leaf(root, path);
2912                 if (ret == 1) {
2913                         last_offset = (u64)-1;
2914                         goto done;
2915                 }
2916                 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2917                 if (tmp.objectid != ino || tmp.type != key_type) {
2918                         last_offset = (u64)-1;
2919                         goto done;
2920                 }
2921                 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
2922                         ret = overwrite_item(trans, log, dst_path,
2923                                              path->nodes[0], path->slots[0],
2924                                              &tmp);
2925                         if (ret)
2926                                 err = ret;
2927                         else
2928                                 last_offset = tmp.offset;
2929                         goto done;
2930                 }
2931         }
2932 done:
2933         btrfs_release_path(path);
2934         btrfs_release_path(dst_path);
2935
2936         if (err == 0) {
2937                 *last_offset_ret = last_offset;
2938                 /*
2939                  * insert the log range keys to indicate where the log
2940                  * is valid
2941                  */
2942                 ret = insert_dir_log_key(trans, log, path, key_type,
2943                                          ino, first_offset, last_offset);
2944                 if (ret)
2945                         err = ret;
2946         }
2947         return err;
2948 }
2949
2950 /*
2951  * logging directories is very similar to logging inodes, We find all the items
2952  * from the current transaction and write them to the log.
2953  *
2954  * The recovery code scans the directory in the subvolume, and if it finds a
2955  * key in the range logged that is not present in the log tree, then it means
2956  * that dir entry was unlinked during the transaction.
2957  *
2958  * In order for that scan to work, we must include one key smaller than
2959  * the smallest logged by this transaction and one key larger than the largest
2960  * key logged by this transaction.
2961  */
2962 static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
2963                           struct btrfs_root *root, struct inode *inode,
2964                           struct btrfs_path *path,
2965                           struct btrfs_path *dst_path)
2966 {
2967         u64 min_key;
2968         u64 max_key;
2969         int ret;
2970         int key_type = BTRFS_DIR_ITEM_KEY;
2971
2972 again:
2973         min_key = 0;
2974         max_key = 0;
2975         while (1) {
2976                 ret = log_dir_items(trans, root, inode, path,
2977                                     dst_path, key_type, min_key,
2978                                     &max_key);
2979                 if (ret)
2980                         return ret;
2981                 if (max_key == (u64)-1)
2982                         break;
2983                 min_key = max_key + 1;
2984         }
2985
2986         if (key_type == BTRFS_DIR_ITEM_KEY) {
2987                 key_type = BTRFS_DIR_INDEX_KEY;
2988                 goto again;
2989         }
2990         return 0;
2991 }
2992
2993 /*
2994  * a helper function to drop items from the log before we relog an
2995  * inode.  max_key_type indicates the highest item type to remove.
2996  * This cannot be run for file data extents because it does not
2997  * free the extents they point to.
2998  */
2999 static int drop_objectid_items(struct btrfs_trans_handle *trans,
3000                                   struct btrfs_root *log,
3001                                   struct btrfs_path *path,
3002                                   u64 objectid, int max_key_type)
3003 {
3004         int ret;
3005         struct btrfs_key key;
3006         struct btrfs_key found_key;
3007         int start_slot;
3008
3009         key.objectid = objectid;
3010         key.type = max_key_type;
3011         key.offset = (u64)-1;
3012
3013         while (1) {
3014                 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
3015                 BUG_ON(ret == 0); /* Logic error */
3016                 if (ret < 0)
3017                         break;
3018
3019                 if (path->slots[0] == 0)
3020                         break;
3021
3022                 path->slots[0]--;
3023                 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
3024                                       path->slots[0]);
3025
3026                 if (found_key.objectid != objectid)
3027                         break;
3028
3029                 found_key.offset = 0;
3030                 found_key.type = 0;
3031                 ret = btrfs_bin_search(path->nodes[0], &found_key, 0,
3032                                        &start_slot);
3033
3034                 ret = btrfs_del_items(trans, log, path, start_slot,
3035                                       path->slots[0] - start_slot + 1);
3036                 /*
3037                  * If start slot isn't 0 then we don't need to re-search, we've
3038                  * found the last guy with the objectid in this tree.
3039                  */
3040                 if (ret || start_slot != 0)
3041                         break;
3042                 btrfs_release_path(path);
3043         }
3044         btrfs_release_path(path);
3045         if (ret > 0)
3046                 ret = 0;
3047         return ret;
3048 }
3049
3050 static void fill_inode_item(struct btrfs_trans_handle *trans,
3051                             struct extent_buffer *leaf,
3052                             struct btrfs_inode_item *item,
3053                             struct inode *inode, int log_inode_only)
3054 {
3055         struct btrfs_map_token token;
3056
3057         btrfs_init_map_token(&token);
3058
3059         if (log_inode_only) {
3060                 /* set the generation to zero so the recover code
3061                  * can tell the difference between an logging
3062                  * just to say 'this inode exists' and a logging
3063                  * to say 'update this inode with these values'
3064                  */
3065                 btrfs_set_token_inode_generation(leaf, item, 0, &token);
3066                 btrfs_set_token_inode_size(leaf, item, 0, &token);
3067         } else {
3068                 btrfs_set_token_inode_generation(leaf, item,
3069                                                  BTRFS_I(inode)->generation,
3070                                                  &token);
3071                 btrfs_set_token_inode_size(leaf, item, inode->i_size, &token);
3072         }
3073
3074         btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3075         btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3076         btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3077         btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3078
3079         btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3080                                      inode->i_atime.tv_sec, &token);
3081         btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3082                                       inode->i_atime.tv_nsec, &token);
3083
3084         btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3085                                      inode->i_mtime.tv_sec, &token);
3086         btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3087                                       inode->i_mtime.tv_nsec, &token);
3088
3089         btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3090                                      inode->i_ctime.tv_sec, &token);
3091         btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3092                                       inode->i_ctime.tv_nsec, &token);
3093
3094         btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3095                                      &token);
3096
3097         btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3098         btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3099         btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3100         btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3101         btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3102 }
3103
3104 static int log_inode_item(struct btrfs_trans_handle *trans,
3105                           struct btrfs_root *log, struct btrfs_path *path,
3106                           struct inode *inode)
3107 {
3108         struct btrfs_inode_item *inode_item;
3109         struct btrfs_key key;
3110         int ret;
3111
3112         memcpy(&key, &BTRFS_I(inode)->location, sizeof(key));
3113         ret = btrfs_insert_empty_item(trans, log, path, &key,
3114                                       sizeof(*inode_item));
3115         if (ret && ret != -EEXIST)
3116                 return ret;
3117         inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3118                                     struct btrfs_inode_item);
3119         fill_inode_item(trans, path->nodes[0], inode_item, inode, 0);
3120         btrfs_release_path(path);
3121         return 0;
3122 }
3123
3124 static noinline int copy_items(struct btrfs_trans_handle *trans,
3125                                struct inode *inode,
3126                                struct btrfs_path *dst_path,
3127                                struct extent_buffer *src,
3128                                int start_slot, int nr, int inode_only)
3129 {
3130         unsigned long src_offset;
3131         unsigned long dst_offset;
3132         struct btrfs_root *log = BTRFS_I(inode)->root->log_root;
3133         struct btrfs_file_extent_item *extent;
3134         struct btrfs_inode_item *inode_item;
3135         int ret;
3136         struct btrfs_key *ins_keys;
3137         u32 *ins_sizes;
3138         char *ins_data;
3139         int i;
3140         struct list_head ordered_sums;
3141         int skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
3142
3143         INIT_LIST_HEAD(&ordered_sums);
3144
3145         ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
3146                            nr * sizeof(u32), GFP_NOFS);
3147         if (!ins_data)
3148                 return -ENOMEM;
3149
3150         ins_sizes = (u32 *)ins_data;
3151         ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
3152
3153         for (i = 0; i < nr; i++) {
3154                 ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
3155                 btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
3156         }
3157         ret = btrfs_insert_empty_items(trans, log, dst_path,
3158                                        ins_keys, ins_sizes, nr);
3159         if (ret) {
3160                 kfree(ins_data);
3161                 return ret;
3162         }
3163
3164         for (i = 0; i < nr; i++, dst_path->slots[0]++) {
3165                 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
3166                                                    dst_path->slots[0]);
3167
3168                 src_offset = btrfs_item_ptr_offset(src, start_slot + i);
3169
3170                 if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
3171                         inode_item = btrfs_item_ptr(dst_path->nodes[0],
3172                                                     dst_path->slots[0],
3173                                                     struct btrfs_inode_item);
3174                         fill_inode_item(trans, dst_path->nodes[0], inode_item,
3175                                         inode, inode_only == LOG_INODE_EXISTS);
3176                 } else {
3177                         copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
3178                                            src_offset, ins_sizes[i]);
3179                 }
3180
3181                 /* take a reference on file data extents so that truncates
3182                  * or deletes of this inode don't have to relog the inode
3183                  * again
3184                  */
3185                 if (btrfs_key_type(ins_keys + i) == BTRFS_EXTENT_DATA_KEY &&
3186                     !skip_csum) {
3187                         int found_type;
3188                         extent = btrfs_item_ptr(src, start_slot + i,
3189                                                 struct btrfs_file_extent_item);
3190
3191                         if (btrfs_file_extent_generation(src, extent) < trans->transid)
3192                                 continue;
3193
3194                         found_type = btrfs_file_extent_type(src, extent);
3195                         if (found_type == BTRFS_FILE_EXTENT_REG) {
3196                                 u64 ds, dl, cs, cl;
3197                                 ds = btrfs_file_extent_disk_bytenr(src,
3198                                                                 extent);
3199                                 /* ds == 0 is a hole */
3200                                 if (ds == 0)
3201                                         continue;
3202
3203                                 dl = btrfs_file_extent_disk_num_bytes(src,
3204                                                                 extent);
3205                                 cs = btrfs_file_extent_offset(src, extent);
3206                                 cl = btrfs_file_extent_num_bytes(src,
3207                                                                 extent);
3208                                 if (btrfs_file_extent_compression(src,
3209                                                                   extent)) {
3210                                         cs = 0;
3211                                         cl = dl;
3212                                 }
3213
3214                                 ret = btrfs_lookup_csums_range(
3215                                                 log->fs_info->csum_root,
3216                                                 ds + cs, ds + cs + cl - 1,
3217                                                 &ordered_sums, 0);
3218                                 if (ret) {
3219                                         btrfs_release_path(dst_path);
3220                                         kfree(ins_data);
3221                                         return ret;
3222                                 }
3223                         }
3224                 }
3225         }
3226
3227         btrfs_mark_buffer_dirty(dst_path->nodes[0]);
3228         btrfs_release_path(dst_path);
3229         kfree(ins_data);
3230
3231         /*
3232          * we have to do this after the loop above to avoid changing the
3233          * log tree while trying to change the log tree.
3234          */
3235         ret = 0;
3236         while (!list_empty(&ordered_sums)) {
3237                 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
3238                                                    struct btrfs_ordered_sum,
3239                                                    list);
3240                 if (!ret)
3241                         ret = btrfs_csum_file_blocks(trans, log, sums);
3242                 list_del(&sums->list);
3243                 kfree(sums);
3244         }
3245         return ret;
3246 }
3247
3248 static int extent_cmp(void *priv, struct list_head *a, struct list_head *b)
3249 {
3250         struct extent_map *em1, *em2;
3251
3252         em1 = list_entry(a, struct extent_map, list);
3253         em2 = list_entry(b, struct extent_map, list);
3254
3255         if (em1->start < em2->start)
3256                 return -1;
3257         else if (em1->start > em2->start)
3258                 return 1;
3259         return 0;
3260 }
3261
3262 static int log_one_extent(struct btrfs_trans_handle *trans,
3263                           struct inode *inode, struct btrfs_root *root,
3264                           struct extent_map *em, struct btrfs_path *path)
3265 {
3266         struct btrfs_root *log = root->log_root;
3267         struct btrfs_file_extent_item *fi;
3268         struct extent_buffer *leaf;
3269         struct btrfs_ordered_extent *ordered;
3270         struct list_head ordered_sums;
3271         struct btrfs_map_token token;
3272         struct btrfs_key key;
3273         u64 mod_start = em->mod_start;
3274         u64 mod_len = em->mod_len;
3275         u64 csum_offset;
3276         u64 csum_len;
3277         u64 extent_offset = em->start - em->orig_start;
3278         u64 block_len;
3279         int ret;
3280         int index = log->log_transid % 2;
3281         bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
3282
3283         ret = __btrfs_drop_extents(trans, log, inode, path, em->start,
3284                                    em->start + em->len, NULL, 0);
3285         if (ret)
3286                 return ret;
3287
3288         INIT_LIST_HEAD(&ordered_sums);
3289         btrfs_init_map_token(&token);
3290         key.objectid = btrfs_ino(inode);
3291         key.type = BTRFS_EXTENT_DATA_KEY;
3292         key.offset = em->start;
3293
3294         ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*fi));
3295         if (ret)
3296                 return ret;
3297         leaf = path->nodes[0];
3298         fi = btrfs_item_ptr(leaf, path->slots[0],
3299                             struct btrfs_file_extent_item);
3300
3301         btrfs_set_token_file_extent_generation(leaf, fi, em->generation,
3302                                                &token);
3303         if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3304                 skip_csum = true;
3305                 btrfs_set_token_file_extent_type(leaf, fi,
3306                                                  BTRFS_FILE_EXTENT_PREALLOC,
3307                                                  &token);
3308         } else {
3309                 btrfs_set_token_file_extent_type(leaf, fi,
3310                                                  BTRFS_FILE_EXTENT_REG,
3311                                                  &token);
3312                 if (em->block_start == 0)
3313                         skip_csum = true;
3314         }
3315
3316         block_len = max(em->block_len, em->orig_block_len);
3317         if (em->compress_type != BTRFS_COMPRESS_NONE) {
3318                 btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
3319                                                         em->block_start,
3320                                                         &token);
3321                 btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
3322                                                            &token);
3323         } else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
3324                 btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
3325                                                         em->block_start -
3326                                                         extent_offset, &token);
3327                 btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
3328                                                            &token);
3329         } else {
3330                 btrfs_set_token_file_extent_disk_bytenr(leaf, fi, 0, &token);
3331                 btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, 0,
3332                                                            &token);
3333         }
3334
3335         btrfs_set_token_file_extent_offset(leaf, fi,
3336                                            em->start - em->orig_start,
3337                                            &token);
3338         btrfs_set_token_file_extent_num_bytes(leaf, fi, em->len, &token);
3339         btrfs_set_token_file_extent_ram_bytes(leaf, fi, em->ram_bytes, &token);
3340         btrfs_set_token_file_extent_compression(leaf, fi, em->compress_type,
3341                                                 &token);
3342         btrfs_set_token_file_extent_encryption(leaf, fi, 0, &token);
3343         btrfs_set_token_file_extent_other_encoding(leaf, fi, 0, &token);
3344         btrfs_mark_buffer_dirty(leaf);
3345
3346         btrfs_release_path(path);
3347         if (ret) {
3348                 return ret;
3349         }
3350
3351         if (skip_csum)
3352                 return 0;
3353
3354         if (em->compress_type) {
3355                 csum_offset = 0;
3356                 csum_len = block_len;
3357         }
3358
3359         /*
3360          * First check and see if our csums are on our outstanding ordered
3361          * extents.
3362          */
3363 again:
3364         spin_lock_irq(&log->log_extents_lock[index]);
3365         list_for_each_entry(ordered, &log->logged_list[index], log_list) {
3366                 struct btrfs_ordered_sum *sum;
3367
3368                 if (!mod_len)
3369                         break;
3370
3371                 if (ordered->inode != inode)
3372                         continue;
3373
3374                 if (ordered->file_offset + ordered->len <= mod_start ||
3375                     mod_start + mod_len <= ordered->file_offset)
3376                         continue;
3377
3378                 /*
3379                  * We are going to copy all the csums on this ordered extent, so
3380                  * go ahead and adjust mod_start and mod_len in case this
3381                  * ordered extent has already been logged.
3382                  */
3383                 if (ordered->file_offset > mod_start) {
3384                         if (ordered->file_offset + ordered->len >=
3385                             mod_start + mod_len)
3386                                 mod_len = ordered->file_offset - mod_start;
3387                         /*
3388                          * If we have this case
3389                          *
3390                          * |--------- logged extent ---------|
3391                          *       |----- ordered extent ----|
3392                          *
3393                          * Just don't mess with mod_start and mod_len, we'll
3394                          * just end up logging more csums than we need and it
3395                          * will be ok.
3396                          */
3397                 } else {
3398                         if (ordered->file_offset + ordered->len <
3399                             mod_start + mod_len) {
3400                                 mod_len = (mod_start + mod_len) -
3401                                         (ordered->file_offset + ordered->len);
3402                                 mod_start = ordered->file_offset +
3403                                         ordered->len;
3404                         } else {
3405                                 mod_len = 0;
3406                         }
3407                 }
3408
3409                 /*
3410                  * To keep us from looping for the above case of an ordered
3411                  * extent that falls inside of the logged extent.
3412                  */
3413                 if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM,
3414                                      &ordered->flags))
3415                         continue;
3416                 atomic_inc(&ordered->refs);
3417                 spin_unlock_irq(&log->log_extents_lock[index]);
3418                 /*
3419                  * we've dropped the lock, we must either break or
3420                  * start over after this.
3421                  */
3422
3423                 wait_event(ordered->wait, ordered->csum_bytes_left == 0);
3424
3425                 list_for_each_entry(sum, &ordered->list, list) {
3426                         ret = btrfs_csum_file_blocks(trans, log, sum);
3427                         if (ret) {
3428                                 btrfs_put_ordered_extent(ordered);
3429                                 goto unlocked;
3430                         }
3431                 }
3432                 btrfs_put_ordered_extent(ordered);
3433                 goto again;
3434
3435         }
3436         spin_unlock_irq(&log->log_extents_lock[index]);
3437 unlocked:
3438
3439         if (!mod_len || ret)
3440                 return ret;
3441
3442         csum_offset = mod_start - em->start;
3443         csum_len = mod_len;
3444
3445         /* block start is already adjusted for the file extent offset. */
3446         ret = btrfs_lookup_csums_range(log->fs_info->csum_root,
3447                                        em->block_start + csum_offset,
3448                                        em->block_start + csum_offset +
3449                                        csum_len - 1, &ordered_sums, 0);
3450         if (ret)
3451                 return ret;
3452
3453         while (!list_empty(&ordered_sums)) {
3454                 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
3455                                                    struct btrfs_ordered_sum,
3456                                                    list);
3457                 if (!ret)
3458                         ret = btrfs_csum_file_blocks(trans, log, sums);
3459                 list_del(&sums->list);
3460                 kfree(sums);
3461         }
3462
3463         return ret;
3464 }
3465
3466 static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
3467                                      struct btrfs_root *root,
3468                                      struct inode *inode,
3469                                      struct btrfs_path *path)
3470 {
3471         struct extent_map *em, *n;
3472         struct list_head extents;
3473         struct extent_map_tree *tree = &BTRFS_I(inode)->extent_tree;
3474         u64 test_gen;
3475         int ret = 0;
3476         int num = 0;
3477
3478         INIT_LIST_HEAD(&extents);
3479
3480         write_lock(&tree->lock);
3481         test_gen = root->fs_info->last_trans_committed;
3482
3483         list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
3484                 list_del_init(&em->list);
3485
3486                 /*
3487                  * Just an arbitrary number, this can be really CPU intensive
3488                  * once we start getting a lot of extents, and really once we
3489                  * have a bunch of extents we just want to commit since it will
3490                  * be faster.
3491                  */
3492                 if (++num > 32768) {
3493                         list_del_init(&tree->modified_extents);
3494                         ret = -EFBIG;
3495                         goto process;
3496                 }
3497
3498                 if (em->generation <= test_gen)
3499                         continue;
3500                 /* Need a ref to keep it from getting evicted from cache */
3501                 atomic_inc(&em->refs);
3502                 set_bit(EXTENT_FLAG_LOGGING, &em->flags);
3503                 list_add_tail(&em->list, &extents);
3504                 num++;
3505         }
3506
3507         list_sort(NULL, &extents, extent_cmp);
3508
3509 process:
3510         while (!list_empty(&extents)) {
3511                 em = list_entry(extents.next, struct extent_map, list);
3512
3513                 list_del_init(&em->list);
3514
3515                 /*
3516                  * If we had an error we just need to delete everybody from our
3517                  * private list.
3518                  */
3519                 if (ret) {
3520                         clear_em_logging(tree, em);
3521                         free_extent_map(em);
3522                         continue;
3523                 }
3524
3525                 write_unlock(&tree->lock);
3526
3527                 ret = log_one_extent(trans, inode, root, em, path);
3528                 write_lock(&tree->lock);
3529                 clear_em_logging(tree, em);
3530                 free_extent_map(em);
3531         }
3532         WARN_ON(!list_empty(&extents));
3533         write_unlock(&tree->lock);
3534
3535         btrfs_release_path(path);
3536         return ret;
3537 }
3538
3539 /* log a single inode in the tree log.
3540  * At least one parent directory for this inode must exist in the tree
3541  * or be logged already.
3542  *
3543  * Any items from this inode changed by the current transaction are copied
3544  * to the log tree.  An extra reference is taken on any extents in this
3545  * file, allowing us to avoid a whole pile of corner cases around logging
3546  * blocks that have been removed from the tree.
3547  *
3548  * See LOG_INODE_ALL and related defines for a description of what inode_only
3549  * does.
3550  *
3551  * This handles both files and directories.
3552  */
3553 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
3554                              struct btrfs_root *root, struct inode *inode,
3555                              int inode_only)
3556 {
3557         struct btrfs_path *path;
3558         struct btrfs_path *dst_path;
3559         struct btrfs_key min_key;
3560         struct btrfs_key max_key;
3561         struct btrfs_root *log = root->log_root;
3562         struct extent_buffer *src = NULL;
3563         int err = 0;
3564         int ret;
3565         int nritems;
3566         int ins_start_slot = 0;
3567         int ins_nr;
3568         bool fast_search = false;
3569         u64 ino = btrfs_ino(inode);
3570
3571         path = btrfs_alloc_path();
3572         if (!path)
3573                 return -ENOMEM;
3574         dst_path = btrfs_alloc_path();
3575         if (!dst_path) {
3576                 btrfs_free_path(path);
3577                 return -ENOMEM;
3578         }
3579
3580         min_key.objectid = ino;
3581         min_key.type = BTRFS_INODE_ITEM_KEY;
3582         min_key.offset = 0;
3583
3584         max_key.objectid = ino;
3585
3586
3587         /* today the code can only do partial logging of directories */
3588         if (S_ISDIR(inode->i_mode) ||
3589             (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3590                        &BTRFS_I(inode)->runtime_flags) &&
3591              inode_only == LOG_INODE_EXISTS))
3592                 max_key.type = BTRFS_XATTR_ITEM_KEY;
3593         else
3594                 max_key.type = (u8)-1;
3595         max_key.offset = (u64)-1;
3596
3597         /* Only run delayed items if we are a dir or a new file */
3598         if (S_ISDIR(inode->i_mode) ||
3599             BTRFS_I(inode)->generation > root->fs_info->last_trans_committed) {
3600                 ret = btrfs_commit_inode_delayed_items(trans, inode);
3601                 if (ret) {
3602                         btrfs_free_path(path);
3603                         btrfs_free_path(dst_path);
3604                         return ret;
3605                 }
3606         }
3607
3608         mutex_lock(&BTRFS_I(inode)->log_mutex);
3609
3610         btrfs_get_logged_extents(log, inode);
3611
3612         /*
3613          * a brute force approach to making sure we get the most uptodate
3614          * copies of everything.
3615          */
3616         if (S_ISDIR(inode->i_mode)) {
3617                 int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
3618
3619                 if (inode_only == LOG_INODE_EXISTS)
3620                         max_key_type = BTRFS_XATTR_ITEM_KEY;
3621                 ret = drop_objectid_items(trans, log, path, ino, max_key_type);
3622         } else {
3623                 if (test_and_clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3624                                        &BTRFS_I(inode)->runtime_flags)) {
3625                         clear_bit(BTRFS_INODE_COPY_EVERYTHING,
3626                                   &BTRFS_I(inode)->runtime_flags);
3627                         ret = btrfs_truncate_inode_items(trans, log,
3628                                                          inode, 0, 0);
3629                 } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
3630                                               &BTRFS_I(inode)->runtime_flags)) {
3631                         if (inode_only == LOG_INODE_ALL)
3632                                 fast_search = true;
3633                         max_key.type = BTRFS_XATTR_ITEM_KEY;
3634                         ret = drop_objectid_items(trans, log, path, ino,
3635                                                   max_key.type);
3636                 } else {
3637                         if (inode_only == LOG_INODE_ALL)
3638                                 fast_search = true;
3639                         ret = log_inode_item(trans, log, dst_path, inode);
3640                         if (ret) {
3641                                 err = ret;
3642                                 goto out_unlock;
3643                         }
3644                         goto log_extents;
3645                 }
3646
3647         }
3648         if (ret) {
3649                 err = ret;
3650                 goto out_unlock;
3651         }
3652         path->keep_locks = 1;
3653
3654         while (1) {
3655                 ins_nr = 0;
3656                 ret = btrfs_search_forward(root, &min_key, &max_key,
3657                                            path, trans->transid);
3658                 if (ret != 0)
3659                         break;
3660 again:
3661                 /* note, ins_nr might be > 0 here, cleanup outside the loop */
3662                 if (min_key.objectid != ino)
3663                         break;
3664                 if (min_key.type > max_key.type)
3665                         break;
3666
3667                 src = path->nodes[0];
3668                 if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
3669                         ins_nr++;
3670                         goto next_slot;
3671                 } else if (!ins_nr) {
3672                         ins_start_slot = path->slots[0];
3673                         ins_nr = 1;
3674                         goto next_slot;
3675                 }
3676
3677                 ret = copy_items(trans, inode, dst_path, src, ins_start_slot,
3678                                  ins_nr, inode_only);
3679                 if (ret) {
3680                         err = ret;
3681                         goto out_unlock;
3682                 }
3683                 ins_nr = 1;
3684                 ins_start_slot = path->slots[0];
3685 next_slot:
3686
3687                 nritems = btrfs_header_nritems(path->nodes[0]);
3688                 path->slots[0]++;
3689                 if (path->slots[0] < nritems) {
3690                         btrfs_item_key_to_cpu(path->nodes[0], &min_key,
3691                                               path->slots[0]);
3692                         goto again;
3693                 }
3694                 if (ins_nr) {
3695                         ret = copy_items(trans, inode, dst_path, src,
3696                                          ins_start_slot,
3697                                          ins_nr, inode_only);
3698                         if (ret) {
3699                                 err = ret;
3700                                 goto out_unlock;
3701                         }
3702                         ins_nr = 0;
3703                 }
3704                 btrfs_release_path(path);
3705
3706                 if (min_key.offset < (u64)-1)
3707                         min_key.offset++;
3708                 else if (min_key.type < (u8)-1)
3709                         min_key.type++;
3710                 else if (min_key.objectid < (u64)-1)
3711                         min_key.objectid++;
3712                 else
3713                         break;
3714         }
3715         if (ins_nr) {
3716                 ret = copy_items(trans, inode, dst_path, src, ins_start_slot,
3717                                  ins_nr, inode_only);
3718                 if (ret) {
3719                         err = ret;
3720                         goto out_unlock;
3721                 }
3722                 ins_nr = 0;
3723         }
3724
3725 log_extents:
3726         if (fast_search) {
3727                 btrfs_release_path(dst_path);
3728                 ret = btrfs_log_changed_extents(trans, root, inode, dst_path);
3729                 if (ret) {
3730                         err = ret;
3731                         goto out_unlock;
3732                 }
3733         } else {
3734                 struct extent_map_tree *tree = &BTRFS_I(inode)->extent_tree;
3735                 struct extent_map *em, *n;
3736
3737                 write_lock(&tree->lock);
3738                 list_for_each_entry_safe(em, n, &tree->modified_extents, list)
3739                         list_del_init(&em->list);
3740                 write_unlock(&tree->lock);
3741         }
3742
3743         if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
3744                 btrfs_release_path(path);
3745                 btrfs_release_path(dst_path);
3746                 ret = log_directory_changes(trans, root, inode, path, dst_path);
3747                 if (ret) {
3748                         err = ret;
3749                         goto out_unlock;
3750                 }
3751         }
3752         BTRFS_I(inode)->logged_trans = trans->transid;
3753         BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->last_sub_trans;
3754 out_unlock:
3755         if (err)
3756                 btrfs_free_logged_extents(log, log->log_transid);
3757         mutex_unlock(&BTRFS_I(inode)->log_mutex);
3758
3759         btrfs_free_path(path);
3760         btrfs_free_path(dst_path);
3761         return err;
3762 }
3763
3764 /*
3765  * follow the dentry parent pointers up the chain and see if any
3766  * of the directories in it require a full commit before they can
3767  * be logged.  Returns zero if nothing special needs to be done or 1 if
3768  * a full commit is required.
3769  */
3770 static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
3771                                                struct inode *inode,
3772                                                struct dentry *parent,
3773                                                struct super_block *sb,
3774                                                u64 last_committed)
3775 {
3776         int ret = 0;
3777         struct btrfs_root *root;
3778         struct dentry *old_parent = NULL;
3779
3780         /*
3781          * for regular files, if its inode is already on disk, we don't
3782          * have to worry about the parents at all.  This is because
3783          * we can use the last_unlink_trans field to record renames
3784          * and other fun in this file.
3785          */
3786         if (S_ISREG(inode->i_mode) &&
3787             BTRFS_I(inode)->generation <= last_committed &&
3788             BTRFS_I(inode)->last_unlink_trans <= last_committed)
3789                         goto out;
3790
3791         if (!S_ISDIR(inode->i_mode)) {
3792                 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3793                         goto out;
3794                 inode = parent->d_inode;
3795         }
3796
3797         while (1) {
3798                 BTRFS_I(inode)->logged_trans = trans->transid;
3799                 smp_mb();
3800
3801                 if (BTRFS_I(inode)->last_unlink_trans > last_committed) {
3802                         root = BTRFS_I(inode)->root;
3803
3804                         /*
3805                          * make sure any commits to the log are forced
3806                          * to be full commits
3807                          */
3808                         root->fs_info->last_trans_log_full_commit =
3809                                 trans->transid;
3810                         ret = 1;
3811                         break;
3812                 }
3813
3814                 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3815                         break;
3816
3817                 if (IS_ROOT(parent))
3818                         break;
3819
3820                 parent = dget_parent(parent);
3821                 dput(old_parent);
3822                 old_parent = parent;
3823                 inode = parent->d_inode;
3824
3825         }
3826         dput(old_parent);
3827 out:
3828         return ret;
3829 }
3830
3831 /*
3832  * helper function around btrfs_log_inode to make sure newly created
3833  * parent directories also end up in the log.  A minimal inode and backref
3834  * only logging is done of any parent directories that are older than
3835  * the last committed transaction
3836  */
3837 static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
3838                                   struct btrfs_root *root, struct inode *inode,
3839                                   struct dentry *parent, int exists_only)
3840 {
3841         int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
3842         struct super_block *sb;
3843         struct dentry *old_parent = NULL;
3844         int ret = 0;
3845         u64 last_committed = root->fs_info->last_trans_committed;
3846
3847         sb = inode->i_sb;
3848
3849         if (btrfs_test_opt(root, NOTREELOG)) {
3850                 ret = 1;
3851                 goto end_no_trans;
3852         }
3853
3854         if (root->fs_info->last_trans_log_full_commit >
3855             root->fs_info->last_trans_committed) {
3856                 ret = 1;
3857                 goto end_no_trans;
3858         }
3859
3860         if (root != BTRFS_I(inode)->root ||
3861             btrfs_root_refs(&root->root_item) == 0) {
3862                 ret = 1;
3863                 goto end_no_trans;
3864         }
3865
3866         ret = check_parent_dirs_for_sync(trans, inode, parent,
3867                                          sb, last_committed);
3868         if (ret)
3869                 goto end_no_trans;
3870
3871         if (btrfs_inode_in_log(inode, trans->transid)) {
3872                 ret = BTRFS_NO_LOG_SYNC;
3873                 goto end_no_trans;
3874         }
3875
3876         ret = start_log_trans(trans, root);
3877         if (ret)
3878                 goto end_trans;
3879
3880         ret = btrfs_log_inode(trans, root, inode, inode_only);
3881         if (ret)
3882                 goto end_trans;
3883
3884         /*
3885          * for regular files, if its inode is already on disk, we don't
3886          * have to worry about the parents at all.  This is because
3887          * we can use the last_unlink_trans field to record renames
3888          * and other fun in this file.
3889          */
3890         if (S_ISREG(inode->i_mode) &&
3891             BTRFS_I(inode)->generation <= last_committed &&
3892             BTRFS_I(inode)->last_unlink_trans <= last_committed) {
3893                 ret = 0;
3894                 goto end_trans;
3895         }
3896
3897         inode_only = LOG_INODE_EXISTS;
3898         while (1) {
3899                 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3900                         break;
3901
3902                 inode = parent->d_inode;
3903                 if (root != BTRFS_I(inode)->root)
3904                         break;
3905
3906                 if (BTRFS_I(inode)->generation >
3907                     root->fs_info->last_trans_committed) {
3908                         ret = btrfs_log_inode(trans, root, inode, inode_only);
3909                         if (ret)
3910                                 goto end_trans;
3911                 }
3912                 if (IS_ROOT(parent))
3913                         break;
3914
3915                 parent = dget_parent(parent);
3916                 dput(old_parent);
3917                 old_parent = parent;
3918         }
3919         ret = 0;
3920 end_trans:
3921         dput(old_parent);
3922         if (ret < 0) {
3923                 root->fs_info->last_trans_log_full_commit = trans->transid;
3924                 ret = 1;
3925         }
3926         btrfs_end_log_trans(root);
3927 end_no_trans:
3928         return ret;
3929 }
3930
3931 /*
3932  * it is not safe to log dentry if the chunk root has added new
3933  * chunks.  This returns 0 if the dentry was logged, and 1 otherwise.
3934  * If this returns 1, you must commit the transaction to safely get your
3935  * data on disk.
3936  */
3937 int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
3938                           struct btrfs_root *root, struct dentry *dentry)
3939 {
3940         struct dentry *parent = dget_parent(dentry);
3941         int ret;
3942
3943         ret = btrfs_log_inode_parent(trans, root, dentry->d_inode, parent, 0);
3944         dput(parent);
3945
3946         return ret;
3947 }
3948
3949 /*
3950  * should be called during mount to recover any replay any log trees
3951  * from the FS
3952  */
3953 int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
3954 {
3955         int ret;
3956         struct btrfs_path *path;
3957         struct btrfs_trans_handle *trans;
3958         struct btrfs_key key;
3959         struct btrfs_key found_key;
3960         struct btrfs_key tmp_key;
3961         struct btrfs_root *log;
3962         struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
3963         struct walk_control wc = {
3964                 .process_func = process_one_buffer,
3965                 .stage = 0,
3966         };
3967
3968         path = btrfs_alloc_path();
3969         if (!path)
3970                 return -ENOMEM;
3971
3972         fs_info->log_root_recovering = 1;
3973
3974         trans = btrfs_start_transaction(fs_info->tree_root, 0);
3975         if (IS_ERR(trans)) {
3976                 ret = PTR_ERR(trans);
3977                 goto error;
3978         }
3979
3980         wc.trans = trans;
3981         wc.pin = 1;
3982
3983         ret = walk_log_tree(trans, log_root_tree, &wc);
3984         if (ret) {
3985                 btrfs_error(fs_info, ret, "Failed to pin buffers while "
3986                             "recovering log root tree.");
3987                 goto error;
3988         }
3989
3990 again:
3991         key.objectid = BTRFS_TREE_LOG_OBJECTID;
3992         key.offset = (u64)-1;
3993         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
3994
3995         while (1) {
3996                 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
3997
3998                 if (ret < 0) {
3999                         btrfs_error(fs_info, ret,
4000                                     "Couldn't find tree log root.");
4001                         goto error;
4002                 }
4003                 if (ret > 0) {
4004                         if (path->slots[0] == 0)
4005                                 break;
4006                         path->slots[0]--;
4007                 }
4008                 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
4009                                       path->slots[0]);
4010                 btrfs_release_path(path);
4011                 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4012                         break;
4013
4014                 log = btrfs_read_fs_root(log_root_tree, &found_key);
4015                 if (IS_ERR(log)) {
4016                         ret = PTR_ERR(log);
4017                         btrfs_error(fs_info, ret,
4018                                     "Couldn't read tree log root.");
4019                         goto error;
4020                 }
4021
4022                 tmp_key.objectid = found_key.offset;
4023                 tmp_key.type = BTRFS_ROOT_ITEM_KEY;
4024                 tmp_key.offset = (u64)-1;
4025
4026                 wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
4027                 if (IS_ERR(wc.replay_dest)) {
4028                         ret = PTR_ERR(wc.replay_dest);
4029                         free_extent_buffer(log->node);
4030                         free_extent_buffer(log->commit_root);
4031                         kfree(log);
4032                         btrfs_error(fs_info, ret, "Couldn't read target root "
4033                                     "for tree log recovery.");
4034                         goto error;
4035                 }
4036
4037                 wc.replay_dest->log_root = log;
4038                 btrfs_record_root_in_trans(trans, wc.replay_dest);
4039                 ret = walk_log_tree(trans, log, &wc);
4040
4041                 if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
4042                         ret = fixup_inode_link_counts(trans, wc.replay_dest,
4043                                                       path);
4044                 }
4045
4046                 key.offset = found_key.offset - 1;
4047                 wc.replay_dest->log_root = NULL;
4048                 free_extent_buffer(log->node);
4049                 free_extent_buffer(log->commit_root);
4050                 kfree(log);
4051
4052                 if (ret)
4053                         goto error;
4054
4055                 if (found_key.offset == 0)
4056                         break;
4057         }
4058         btrfs_release_path(path);
4059
4060         /* step one is to pin it all, step two is to replay just inodes */
4061         if (wc.pin) {
4062                 wc.pin = 0;
4063                 wc.process_func = replay_one_buffer;
4064                 wc.stage = LOG_WALK_REPLAY_INODES;
4065                 goto again;
4066         }
4067         /* step three is to replay everything */
4068         if (wc.stage < LOG_WALK_REPLAY_ALL) {
4069                 wc.stage++;
4070                 goto again;
4071         }
4072
4073         btrfs_free_path(path);
4074
4075         /* step 4: commit the transaction, which also unpins the blocks */
4076         ret = btrfs_commit_transaction(trans, fs_info->tree_root);
4077         if (ret)
4078                 return ret;
4079
4080         free_extent_buffer(log_root_tree->node);
4081         log_root_tree->log_root = NULL;
4082         fs_info->log_root_recovering = 0;
4083         kfree(log_root_tree);
4084
4085         return 0;
4086 error:
4087         if (wc.trans)
4088                 btrfs_end_transaction(wc.trans, fs_info->tree_root);
4089         btrfs_free_path(path);
4090         return ret;
4091 }
4092
4093 /*
4094  * there are some corner cases where we want to force a full
4095  * commit instead of allowing a directory to be logged.
4096  *
4097  * They revolve around files there were unlinked from the directory, and
4098  * this function updates the parent directory so that a full commit is
4099  * properly done if it is fsync'd later after the unlinks are done.
4100  */
4101 void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
4102                              struct inode *dir, struct inode *inode,
4103                              int for_rename)
4104 {
4105         /*
4106          * when we're logging a file, if it hasn't been renamed
4107          * or unlinked, and its inode is fully committed on disk,
4108          * we don't have to worry about walking up the directory chain
4109          * to log its parents.
4110          *
4111          * So, we use the last_unlink_trans field to put this transid
4112          * into the file.  When the file is logged we check it and
4113          * don't log the parents if the file is fully on disk.
4114          */
4115         if (S_ISREG(inode->i_mode))
4116                 BTRFS_I(inode)->last_unlink_trans = trans->transid;
4117
4118         /*
4119          * if this directory was already logged any new
4120          * names for this file/dir will get recorded
4121          */
4122         smp_mb();
4123         if (BTRFS_I(dir)->logged_trans == trans->transid)
4124                 return;
4125
4126         /*
4127          * if the inode we're about to unlink was logged,
4128          * the log will be properly updated for any new names
4129          */
4130         if (BTRFS_I(inode)->logged_trans == trans->transid)
4131                 return;
4132
4133         /*
4134          * when renaming files across directories, if the directory
4135          * there we're unlinking from gets fsync'd later on, there's
4136          * no way to find the destination directory later and fsync it
4137          * properly.  So, we have to be conservative and force commits
4138          * so the new name gets discovered.
4139          */
4140         if (for_rename)
4141                 goto record;
4142
4143         /* we can safely do the unlink without any special recording */
4144         return;
4145
4146 record:
4147         BTRFS_I(dir)->last_unlink_trans = trans->transid;
4148 }
4149
4150 /*
4151  * Call this after adding a new name for a file and it will properly
4152  * update the log to reflect the new name.
4153  *
4154  * It will return zero if all goes well, and it will return 1 if a
4155  * full transaction commit is required.
4156  */
4157 int btrfs_log_new_name(struct btrfs_trans_handle *trans,
4158                         struct inode *inode, struct inode *old_dir,
4159                         struct dentry *parent)
4160 {
4161         struct btrfs_root * root = BTRFS_I(inode)->root;
4162
4163         /*
4164          * this will force the logging code to walk the dentry chain
4165          * up for the file
4166          */
4167         if (S_ISREG(inode->i_mode))
4168                 BTRFS_I(inode)->last_unlink_trans = trans->transid;
4169
4170         /*
4171          * if this inode hasn't been logged and directory we're renaming it
4172          * from hasn't been logged, we don't need to log it
4173          */
4174         if (BTRFS_I(inode)->logged_trans <=
4175             root->fs_info->last_trans_committed &&
4176             (!old_dir || BTRFS_I(old_dir)->logged_trans <=
4177                     root->fs_info->last_trans_committed))
4178                 return 0;
4179
4180         return btrfs_log_inode_parent(trans, root, inode, parent, 1);
4181 }
4182