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         if (wc->pin)
 281                 btrfs_pin_extent_for_log_replay(log->fs_info->extent_root,
 282                                                 eb->start, eb->len);
 283
 284         if (btrfs_buffer_uptodate(eb, gen, 0)) {
 285                 if (wc->write)
 286                         btrfs_write_tree_block(eb);
 287                 if (wc->wait)
 288                         btrfs_wait_tree_block_writeback(eb);
 289         }
 290         return 0;
 291 }
 292
 293 /*
 294  * Item overwrite used by replay and tree logging.  eb, slot and key all refer
 295  * to the src data we are copying out.
 296  *
 297  * root is the tree we are copying into, and path is a scratch
 298  * path for use in this function (it should be released on entry and
 299  * will be released on exit).
 300  *
 301  * If the key is already in the destination tree the existing item is
 302  * overwritten.  If the existing item isn't big enough, it is extended.
 303  * If it is too large, it is truncated.
 304  *
 305  * If the key isn't in the destination yet, a new item is inserted.
 306  */
 307 static noinline int overwrite_item(struct btrfs_trans_handle *trans,
 308                                    struct btrfs_root *root,
 309                                    struct btrfs_path *path,
 310                                    struct extent_buffer *eb, int slot,
 311                                    struct btrfs_key *key)
 312 {
 313         int ret;
 314         u32 item_size;
 315         u64 saved_i_size = 0;
 316         int save_old_i_size = 0;
 317         unsigned long src_ptr;
 318         unsigned long dst_ptr;
 319         int overwrite_root = 0;
 320         bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
 321
 322         if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
 323                 overwrite_root = 1;
 324
 325         item_size = btrfs_item_size_nr(eb, slot);
 326         src_ptr = btrfs_item_ptr_offset(eb, slot);
 327
 328         /* look for the key in the destination tree */
 329         ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
 330         if (ret < 0)
 331                 return ret;
 332
 333         if (ret == 0) {
 334                 char *src_copy;
 335                 char *dst_copy;
 336                 u32 dst_size = btrfs_item_size_nr(path->nodes[0],
 337                                                   path->slots[0]);
 338                 if (dst_size != item_size)
 339                         goto insert;
 340
 341                 if (item_size == 0) {
 342                         btrfs_release_path(path);
 343                         return 0;
 344                 }
 345                 dst_copy = kmalloc(item_size, GFP_NOFS);
 346                 src_copy = kmalloc(item_size, GFP_NOFS);
 347                 if (!dst_copy || !src_copy) {
 348                         btrfs_release_path(path);
 349                         kfree(dst_copy);
 350                         kfree(src_copy);
 351                         return -ENOMEM;
 352                 }
 353
 354                 read_extent_buffer(eb, src_copy, src_ptr, item_size);
 355
 356                 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
 357                 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
 358                                    item_size);
 359                 ret = memcmp(dst_copy, src_copy, item_size);
 360
 361                 kfree(dst_copy);
 362                 kfree(src_copy);
 363                 /*
 364                  * they have the same contents, just return, this saves
 365                  * us from cowing blocks in the destination tree and doing
 366                  * extra writes that may not have been done by a previous
 367                  * sync
 368                  */
 369                 if (ret == 0) {
 370                         btrfs_release_path(path);
 371                         return 0;
 372                 }
 373
 374                 /*
 375                  * We need to load the old nbytes into the inode so when we
 376                  * replay the extents we've logged we get the right nbytes.
 377                  */
 378                 if (inode_item) {
 379                         struct btrfs_inode_item *item;
 380                         u64 nbytes;
 381
 382                         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
 383                                               struct btrfs_inode_item);
 384                         nbytes = btrfs_inode_nbytes(path->nodes[0], item);
 385                         item = btrfs_item_ptr(eb, slot,
 386                                               struct btrfs_inode_item);
 387                         btrfs_set_inode_nbytes(eb, item, nbytes);
 388                 }
 389         } else if (inode_item) {
 390                 struct btrfs_inode_item *item;
 391
 392                 /*
 393                  * New inode, set nbytes to 0 so that the nbytes comes out
 394                  * properly when we replay the extents.
 395                  */
 396                 item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
 397                 btrfs_set_inode_nbytes(eb, item, 0);
 398         }
 399 insert:
 400         btrfs_release_path(path);
 401         /* try to insert the key into the destination tree */
 402         ret = btrfs_insert_empty_item(trans, root, path,
 403                                       key, item_size);
 404
 405         /* make sure any existing item is the correct size */
 406         if (ret == -EEXIST) {
 407                 u32 found_size;
 408                 found_size = btrfs_item_size_nr(path->nodes[0],
 409                                                 path->slots[0]);
 410                 if (found_size > item_size)
 411                         btrfs_truncate_item(trans, root, path, item_size, 1);
 412                 else if (found_size < item_size)
 413                         btrfs_extend_item(trans, root, path,
 414                                           item_size - found_size);
 415         } else if (ret) {
 416                 return ret;
 417         }
 418         dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
 419                                         path->slots[0]);
 420
 421         /* don't overwrite an existing inode if the generation number
 422          * was logged as zero.  This is done when the tree logging code
 423          * is just logging an inode to make sure it exists after recovery.
 424          *
 425          * Also, don't overwrite i_size on directories during replay.
 426          * log replay inserts and removes directory items based on the
 427          * state of the tree found in the subvolume, and i_size is modified
 428          * as it goes
 429          */
 430         if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
 431                 struct btrfs_inode_item *src_item;
 432                 struct btrfs_inode_item *dst_item;
 433
 434                 src_item = (struct btrfs_inode_item *)src_ptr;
 435                 dst_item = (struct btrfs_inode_item *)dst_ptr;
 436
 437                 if (btrfs_inode_generation(eb, src_item) == 0)
 438                         goto no_copy;
 439
 440                 if (overwrite_root &&
 441                     S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
 442                     S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
 443                         save_old_i_size = 1;
 444                         saved_i_size = btrfs_inode_size(path->nodes[0],
 445                                                         dst_item);
 446                 }
 447         }
 448
 449         copy_extent_buffer(path->nodes[0], eb, dst_ptr,
 450                            src_ptr, item_size);
 451
 452         if (save_old_i_size) {
 453                 struct btrfs_inode_item *dst_item;
 454                 dst_item = (struct btrfs_inode_item *)dst_ptr;
 455                 btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
 456         }
 457
 458         /* make sure the generation is filled in */
 459         if (key->type == BTRFS_INODE_ITEM_KEY) {
 460                 struct btrfs_inode_item *dst_item;
 461                 dst_item = (struct btrfs_inode_item *)dst_ptr;
 462                 if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
 463                         btrfs_set_inode_generation(path->nodes[0], dst_item,
 464                                                    trans->transid);
 465                 }
 466         }
 467 no_copy:
 468         btrfs_mark_buffer_dirty(path->nodes[0]);
 469         btrfs_release_path(path);
 470         return 0;
 471 }
 472
 473 /*
 474  * simple helper to read an inode off the disk from a given root
 475  * This can only be called for subvolume roots and not for the log
 476  */
 477 static noinline struct inode *read_one_inode(struct btrfs_root *root,
 478                                              u64 objectid)
 479 {
 480         struct btrfs_key key;
 481         struct inode *inode;
 482
 483         key.objectid = objectid;
 484         key.type = BTRFS_INODE_ITEM_KEY;
 485         key.offset = 0;
 486         inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
 487         if (IS_ERR(inode)) {
 488                 inode = NULL;
 489         } else if (is_bad_inode(inode)) {
 490                 iput(inode);
 491                 inode = NULL;
 492         }
 493         return inode;
 494 }
 495
 496 /* replays a single extent in 'eb' at 'slot' with 'key' into the
 497  * subvolume 'root'.  path is released on entry and should be released
 498  * on exit.
 499  *
 500  * extents in the log tree have not been allocated out of the extent
 501  * tree yet.  So, this completes the allocation, taking a reference
 502  * as required if the extent already exists or creating a new extent
 503  * if it isn't in the extent allocation tree yet.
 504  *
 505  * The extent is inserted into the file, dropping any existing extents
 506  * from the file that overlap the new one.
 507  */
 508 static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
 509                                       struct btrfs_root *root,
 510                                       struct btrfs_path *path,
 511                                       struct extent_buffer *eb, int slot,
 512                                       struct btrfs_key *key)
 513 {
 514         int found_type;
 515         u64 extent_end;
 516         u64 start = key->offset;
 517         u64 nbytes = 0;
 518         struct btrfs_file_extent_item *item;
 519         struct inode *inode = NULL;
 520         unsigned long size;
 521         int ret = 0;
 522
 523         item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
 524         found_type = btrfs_file_extent_type(eb, item);
 525
 526         if (found_type == BTRFS_FILE_EXTENT_REG ||
 527             found_type == BTRFS_FILE_EXTENT_PREALLOC) {
 528                 nbytes = btrfs_file_extent_num_bytes(eb, item);
 529                 extent_end = start + nbytes;
 530
 531                 /*
 532                  * We don't add to the inodes nbytes if we are prealloc or a
 533                  * hole.
 534                  */
 535                 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
 536                         nbytes = 0;
 537         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 538                 size = btrfs_file_extent_inline_len(eb, item);
 539                 nbytes = btrfs_file_extent_ram_bytes(eb, item);
 540                 extent_end = ALIGN(start + size, root->sectorsize);
 541         } else {
 542                 ret = 0;
 543                 goto out;
 544         }
 545
 546         inode = read_one_inode(root, key->objectid);
 547         if (!inode) {
 548                 ret = -EIO;
 549                 goto out;
 550         }
 551
 552         /*
 553          * first check to see if we already have this extent in the
 554          * file.  This must be done before the btrfs_drop_extents run
 555          * so we don't try to drop this extent.
 556          */
 557         ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
 558                                        start, 0);
 559
 560         if (ret == 0 &&
 561             (found_type == BTRFS_FILE_EXTENT_REG ||
 562              found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
 563                 struct btrfs_file_extent_item cmp1;
 564                 struct btrfs_file_extent_item cmp2;
 565                 struct btrfs_file_extent_item *existing;
 566                 struct extent_buffer *leaf;
 567
 568                 leaf = path->nodes[0];
 569                 existing = btrfs_item_ptr(leaf, path->slots[0],
 570                                           struct btrfs_file_extent_item);
 571
 572                 read_extent_buffer(eb, &cmp1, (unsigned long)item,
 573                                    sizeof(cmp1));
 574                 read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
 575                                    sizeof(cmp2));
 576
 577                 /*
 578                  * we already have a pointer to this exact extent,
 579                  * we don't have to do anything
 580                  */
 581                 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
 582                         btrfs_release_path(path);
 583                         goto out;
 584                 }
 585         }
 586         btrfs_release_path(path);
 587
 588         /* drop any overlapping extents */
 589         ret = btrfs_drop_extents(trans, root, inode, start, extent_end, 1);
 590         BUG_ON(ret);
 591
 592         if (found_type == BTRFS_FILE_EXTENT_REG ||
 593             found_type == BTRFS_FILE_EXTENT_PREALLOC) {
 594                 u64 offset;
 595                 unsigned long dest_offset;
 596                 struct btrfs_key ins;
 597
 598                 ret = btrfs_insert_empty_item(trans, root, path, key,
 599                                               sizeof(*item));
 600                 BUG_ON(ret);
 601                 dest_offset = btrfs_item_ptr_offset(path->nodes[0],
 602                                                     path->slots[0]);
 603                 copy_extent_buffer(path->nodes[0], eb, dest_offset,
 604                                 (unsigned long)item,  sizeof(*item));
 605
 606                 ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
 607                 ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
 608                 ins.type = BTRFS_EXTENT_ITEM_KEY;
 609                 offset = key->offset - btrfs_file_extent_offset(eb, item);
 610
 611                 if (ins.objectid > 0) {
 612                         u64 csum_start;
 613                         u64 csum_end;
 614                         LIST_HEAD(ordered_sums);
 615                         /*
 616                          * is this extent already allocated in the extent
 617                          * allocation tree?  If so, just add a reference
 618                          */
 619                         ret = btrfs_lookup_extent(root, ins.objectid,
 620                                                 ins.offset);
 621                         if (ret == 0) {
 622                                 ret = btrfs_inc_extent_ref(trans, root,
 623                                                 ins.objectid, ins.offset,
 624                                                 0, root->root_key.objectid,
 625                                                 key->objectid, offset, 0);
 626                                 BUG_ON(ret);
 627                         } else {
 628                                 /*
 629                                  * insert the extent pointer in the extent
 630                                  * allocation tree
 631                                  */
 632                                 ret = btrfs_alloc_logged_file_extent(trans,
 633                                                 root, root->root_key.objectid,
 634                                                 key->objectid, offset, &ins);
 635                                 BUG_ON(ret);
 636                         }
 637                         btrfs_release_path(path);
 638
 639                         if (btrfs_file_extent_compression(eb, item)) {
 640                                 csum_start = ins.objectid;
 641                                 csum_end = csum_start + ins.offset;
 642                         } else {
 643                                 csum_start = ins.objectid +
 644                                         btrfs_file_extent_offset(eb, item);
 645                                 csum_end = csum_start +
 646                                         btrfs_file_extent_num_bytes(eb, item);
 647                         }
 648
 649                         ret = btrfs_lookup_csums_range(root->log_root,
 650                                                 csum_start, csum_end - 1,
 651                                                 &ordered_sums, 0);
 652                         BUG_ON(ret);
 653                         while (!list_empty(&ordered_sums)) {
 654                                 struct btrfs_ordered_sum *sums;
 655                                 sums = list_entry(ordered_sums.next,
 656                                                 struct btrfs_ordered_sum,
 657                                                 list);
 658                                 ret = btrfs_csum_file_blocks(trans,
 659                                                 root->fs_info->csum_root,
 660                                                 sums);
 661                                 BUG_ON(ret);
 662                                 list_del(&sums->list);
 663                                 kfree(sums);
 664                         }
 665                 } else {
 666                         btrfs_release_path(path);
 667                 }
 668         } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 669                 /* inline extents are easy, we just overwrite them */
 670                 ret = overwrite_item(trans, root, path, eb, slot, key);
 671                 BUG_ON(ret);
 672         }
 673
 674         inode_add_bytes(inode, nbytes);
 675         ret = btrfs_update_inode(trans, root, inode);
 676 out:
 677         if (inode)
 678                 iput(inode);
 679         return ret;
 680 }
 681
 682 /*
 683  * when cleaning up conflicts between the directory names in the
 684  * subvolume, directory names in the log and directory names in the
 685  * inode back references, we may have to unlink inodes from directories.
 686  *
 687  * This is a helper function to do the unlink of a specific directory
 688  * item
 689  */
 690 static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
 691                                       struct btrfs_root *root,
 692                                       struct btrfs_path *path,
 693                                       struct inode *dir,
 694                                       struct btrfs_dir_item *di)
 695 {
 696         struct inode *inode;
 697         char *name;
 698         int name_len;
 699         struct extent_buffer *leaf;
 700         struct btrfs_key location;
 701         int ret;
 702
 703         leaf = path->nodes[0];
 704
 705         btrfs_dir_item_key_to_cpu(leaf, di, &location);
 706         name_len = btrfs_dir_name_len(leaf, di);
 707         name = kmalloc(name_len, GFP_NOFS);
 708         if (!name)
 709                 return -ENOMEM;
 710
 711         read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
 712         btrfs_release_path(path);
 713
 714         inode = read_one_inode(root, location.objectid);
 715         if (!inode) {
 716                 kfree(name);
 717                 return -EIO;
 718         }
 719
 720         ret = link_to_fixup_dir(trans, root, path, location.objectid);
 721         BUG_ON(ret);
 722
 723         ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
 724         BUG_ON(ret);
 725         kfree(name);
 726
 727         iput(inode);
 728
 729         btrfs_run_delayed_items(trans, root);
 730         return ret;
 731 }
 732
 733 /*
 734  * helper function to see if a given name and sequence number found
 735  * in an inode back reference are already in a directory and correctly
 736  * point to this inode
 737  */
 738 static noinline int inode_in_dir(struct btrfs_root *root,
 739                                  struct btrfs_path *path,
 740                                  u64 dirid, u64 objectid, u64 index,
 741                                  const char *name, int name_len)
 742 {
 743         struct btrfs_dir_item *di;
 744         struct btrfs_key location;
 745         int match = 0;
 746
 747         di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
 748                                          index, name, name_len, 0);
 749         if (di && !IS_ERR(di)) {
 750                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 751                 if (location.objectid != objectid)
 752                         goto out;
 753         } else
 754                 goto out;
 755         btrfs_release_path(path);
 756
 757         di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
 758         if (di && !IS_ERR(di)) {
 759                 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 760                 if (location.objectid != objectid)
 761                         goto out;
 762         } else
 763                 goto out;
 764         match = 1;
 765 out:
 766         btrfs_release_path(path);
 767         return match;
 768 }
 769
 770 /*
 771  * helper function to check a log tree for a named back reference in
 772  * an inode.  This is used to decide if a back reference that is
 773  * found in the subvolume conflicts with what we find in the log.
 774  *
 775  * inode backreferences may have multiple refs in a single item,
 776  * during replay we process one reference at a time, and we don't
 777  * want to delete valid links to a file from the subvolume if that
 778  * link is also in the log.
 779  */
 780 static noinline int backref_in_log(struct btrfs_root *log,
 781                                    struct btrfs_key *key,
 782                                    u64 ref_objectid,
 783                                    char *name, int namelen)
 784 {
 785         struct btrfs_path *path;
 786         struct btrfs_inode_ref *ref;
 787         unsigned long ptr;
 788         unsigned long ptr_end;
 789         unsigned long name_ptr;
 790         int found_name_len;
 791         int item_size;
 792         int ret;
 793         int match = 0;
 794
 795         path = btrfs_alloc_path();
 796         if (!path)
 797                 return -ENOMEM;
 798
 799         ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
 800         if (ret != 0)
 801                 goto out;
 802
 803         ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
 804
 805         if (key->type == BTRFS_INODE_EXTREF_KEY) {
 806                 if (btrfs_find_name_in_ext_backref(path, ref_objectid,
 807                                                    name, namelen, NULL))
 808                         match = 1;
 809
 810                 goto out;
 811         }
 812
 813         item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
 814         ptr_end = ptr + item_size;
 815         while (ptr < ptr_end) {
 816                 ref = (struct btrfs_inode_ref *)ptr;
 817                 found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
 818                 if (found_name_len == namelen) {
 819                         name_ptr = (unsigned long)(ref + 1);
 820                         ret = memcmp_extent_buffer(path->nodes[0], name,
 821                                                    name_ptr, namelen);
 822                         if (ret == 0) {
 823                                 match = 1;
 824                                 goto out;
 825                         }
 826                 }
 827                 ptr = (unsigned long)(ref + 1) + found_name_len;
 828         }
 829 out:
 830         btrfs_free_path(path);
 831         return match;
 832 }
 833
 834 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
 835                                   struct btrfs_root *root,
 836                                   struct btrfs_path *path,
 837                                   struct btrfs_root *log_root,
 838                                   struct inode *dir, struct inode *inode,
 839                                   struct extent_buffer *eb,
 840                                   u64 inode_objectid, u64 parent_objectid,
 841                                   u64 ref_index, char *name, int namelen,
 842                                   int *search_done)
 843 {
 844         int ret;
 845         char *victim_name;
 846         int victim_name_len;
 847         struct extent_buffer *leaf;
 848         struct btrfs_dir_item *di;
 849         struct btrfs_key search_key;
 850         struct btrfs_inode_extref *extref;
 851
 852 again:
 853         /* Search old style refs */
 854         search_key.objectid = inode_objectid;
 855         search_key.type = BTRFS_INODE_REF_KEY;
 856         search_key.offset = parent_objectid;
 857         ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
 858         if (ret == 0) {
 859                 struct btrfs_inode_ref *victim_ref;
 860                 unsigned long ptr;
 861                 unsigned long ptr_end;
 862
 863                 leaf = path->nodes[0];
 864
 865                 /* are we trying to overwrite a back ref for the root directory
 866                  * if so, just jump out, we're done
 867                  */
 868                 if (search_key.objectid == search_key.offset)
 869                         return 1;
 870
 871                 /* check all the names in this back reference to see
 872                  * if they are in the log.  if so, we allow them to stay
 873                  * otherwise they must be unlinked as a conflict
 874                  */
 875                 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
 876                 ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
 877                 while (ptr < ptr_end) {
 878                         victim_ref = (struct btrfs_inode_ref *)ptr;
 879                         victim_name_len = btrfs_inode_ref_name_len(leaf,
 880                                                                    victim_ref);
 881                         victim_name = kmalloc(victim_name_len, GFP_NOFS);
 882                         BUG_ON(!victim_name);
 883
 884                         read_extent_buffer(leaf, victim_name,
 885                                            (unsigned long)(victim_ref + 1),
 886                                            victim_name_len);
 887
 888                         if (!backref_in_log(log_root, &search_key,
 889                                             parent_objectid,
 890                                             victim_name,
 891                                             victim_name_len)) {
 892                                 btrfs_inc_nlink(inode);
 893                                 btrfs_release_path(path);
 894
 895                                 ret = btrfs_unlink_inode(trans, root, dir,
 896                                                          inode, victim_name,
 897                                                          victim_name_len);
 898                                 BUG_ON(ret);
 899                                 btrfs_run_delayed_items(trans, root);
 900                                 kfree(victim_name);
 901                                 *search_done = 1;
 902                                 goto again;
 903                         }
 904                         kfree(victim_name);
 905
 906                         ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
 907                 }
 908                 BUG_ON(ret);
 909
 910                 /*
 911                  * NOTE: we have searched root tree and checked the
 912                  * coresponding ref, it does not need to check again.
 913                  */
 914                 *search_done = 1;
 915         }
 916         btrfs_release_path(path);
 917
 918         /* Same search but for extended refs */
 919         extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
 920                                            inode_objectid, parent_objectid, 0,
 921                                            0);
 922         if (!IS_ERR_OR_NULL(extref)) {
 923                 u32 item_size;
 924                 u32 cur_offset = 0;
 925                 unsigned long base;
 926                 struct inode *victim_parent;
 927
 928                 leaf = path->nodes[0];
 929
 930                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
 931                 base = btrfs_item_ptr_offset(leaf, path->slots[0]);
 932
 933                 while (cur_offset < item_size) {
 934                         extref = (struct btrfs_inode_extref *)base + cur_offset;
 935
 936                         victim_name_len = btrfs_inode_extref_name_len(leaf, extref);
 937
 938                         if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
 939                                 goto next;
 940
 941                         victim_name = kmalloc(victim_name_len, GFP_NOFS);
 942                         read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name,
 943                                            victim_name_len);
 944
 945                         search_key.objectid = inode_objectid;
 946                         search_key.type = BTRFS_INODE_EXTREF_KEY;
 947                         search_key.offset = btrfs_extref_hash(parent_objectid,
 948                                                               victim_name,
 949                                                               victim_name_len);
 950                         ret = 0;
 951                         if (!backref_in_log(log_root, &search_key,
 952                                             parent_objectid, victim_name,
 953                                             victim_name_len)) {
 954                                 ret = -ENOENT;
 955                                 victim_parent = read_one_inode(root,
 956                                                                parent_objectid);
 957                                 if (victim_parent) {
 958                                         btrfs_inc_nlink(inode);
 959                                         btrfs_release_path(path);
 960
 961                                         ret = btrfs_unlink_inode(trans, root,
 962                                                                  victim_parent,
 963                                                                  inode,
 964                                                                  victim_name,
 965                                                                  victim_name_len);
 966                                         btrfs_run_delayed_items(trans, root);
 967                                 }
 968                                 BUG_ON(ret);
 969                                 iput(victim_parent);
 970                                 kfree(victim_name);
 971                                 *search_done = 1;
 972                                 goto again;
 973                         }
 974                         kfree(victim_name);
 975                         BUG_ON(ret);
 976 next:
 977                         cur_offset += victim_name_len + sizeof(*extref);
 978                 }
 979                 *search_done = 1;
 980         }
 981         btrfs_release_path(path);
 982
 983         /* look for a conflicting sequence number */
 984         di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
 985                                          ref_index, name, namelen, 0);
 986         if (di && !IS_ERR(di)) {
 987                 ret = drop_one_dir_item(trans, root, path, dir, di);
 988                 BUG_ON(ret);
 989         }
 990         btrfs_release_path(path);
 991
 992         /* look for a conflicing name */
 993         di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
 994                                    name, namelen, 0);
 995         if (di && !IS_ERR(di)) {
 996                 ret = drop_one_dir_item(trans, root, path, dir, di);
 997                 BUG_ON(ret);
 998         }
 999         btrfs_release_path(path);
1000
1001         return 0;
1002 }
1003
1004 static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1005                              u32 *namelen, char **name, u64 *index,
1006                              u64 *parent_objectid)
1007 {
1008         struct btrfs_inode_extref *extref;
1009
1010         extref = (struct btrfs_inode_extref *)ref_ptr;
1011
1012         *namelen = btrfs_inode_extref_name_len(eb, extref);
1013         *name = kmalloc(*namelen, GFP_NOFS);
1014         if (*name == NULL)
1015                 return -ENOMEM;
1016
1017         read_extent_buffer(eb, *name, (unsigned long)&extref->name,
1018                            *namelen);
1019
1020         *index = btrfs_inode_extref_index(eb, extref);
1021         if (parent_objectid)
1022                 *parent_objectid = btrfs_inode_extref_parent(eb, extref);
1023
1024         return 0;
1025 }
1026
1027 static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1028                           u32 *namelen, char **name, u64 *index)
1029 {
1030         struct btrfs_inode_ref *ref;
1031
1032         ref = (struct btrfs_inode_ref *)ref_ptr;
1033
1034         *namelen = btrfs_inode_ref_name_len(eb, ref);
1035         *name = kmalloc(*namelen, GFP_NOFS);
1036         if (*name == NULL)
1037                 return -ENOMEM;
1038
1039         read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
1040
1041         *index = btrfs_inode_ref_index(eb, ref);
1042
1043         return 0;
1044 }
1045
1046 /*
1047  * replay one inode back reference item found in the log tree.
1048  * eb, slot and key refer to the buffer and key found in the log tree.
1049  * root is the destination we are replaying into, and path is for temp
1050  * use by this function.  (it should be released on return).
1051  */
1052 static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
1053                                   struct btrfs_root *root,
1054                                   struct btrfs_root *log,
1055                                   struct btrfs_path *path,
1056                                   struct extent_buffer *eb, int slot,
1057                                   struct btrfs_key *key)
1058 {
1059         struct inode *dir;
1060         struct inode *inode;
1061         unsigned long ref_ptr;
1062         unsigned long ref_end;
1063         char *name;
1064         int namelen;
1065         int ret;
1066         int search_done = 0;
1067         int log_ref_ver = 0;
1068         u64 parent_objectid;
1069         u64 inode_objectid;
1070         u64 ref_index = 0;
1071         int ref_struct_size;
1072
1073         ref_ptr = btrfs_item_ptr_offset(eb, slot);
1074         ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
1075
1076         if (key->type == BTRFS_INODE_EXTREF_KEY) {
1077                 struct btrfs_inode_extref *r;
1078
1079                 ref_struct_size = sizeof(struct btrfs_inode_extref);
1080                 log_ref_ver = 1;
1081                 r = (struct btrfs_inode_extref *)ref_ptr;
1082                 parent_objectid = btrfs_inode_extref_parent(eb, r);
1083         } else {
1084                 ref_struct_size = sizeof(struct btrfs_inode_ref);
1085                 parent_objectid = key->offset;
1086         }
1087         inode_objectid = key->objectid;
1088
1089         /*
1090          * it is possible that we didn't log all the parent directories
1091          * for a given inode.  If we don't find the dir, just don't
1092          * copy the back ref in.  The link count fixup code will take
1093          * care of the rest
1094          */
1095         dir = read_one_inode(root, parent_objectid);
1096         if (!dir)
1097                 return -ENOENT;
1098
1099         inode = read_one_inode(root, inode_objectid);
1100         if (!inode) {
1101                 iput(dir);
1102                 return -EIO;
1103         }
1104
1105         while (ref_ptr < ref_end) {
1106                 if (log_ref_ver) {
1107                         ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
1108                                                 &ref_index, &parent_objectid);
1109                         /*
1110                          * parent object can change from one array
1111                          * item to another.
1112                          */
1113                         if (!dir)
1114                                 dir = read_one_inode(root, parent_objectid);
1115                         if (!dir)
1116                                 return -ENOENT;
1117                 } else {
1118                         ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
1119                                              &ref_index);
1120                 }
1121                 if (ret)
1122                         return ret;
1123
1124                 /* if we already have a perfect match, we're done */
1125                 if (!inode_in_dir(root, path, btrfs_ino(dir), btrfs_ino(inode),
1126                                   ref_index, name, namelen)) {
1127                         /*
1128                          * look for a conflicting back reference in the
1129                          * metadata. if we find one we have to unlink that name
1130                          * of the file before we add our new link.  Later on, we
1131                          * overwrite any existing back reference, and we don't
1132                          * want to create dangling pointers in the directory.
1133                          */
1134
1135                         if (!search_done) {
1136                                 ret = __add_inode_ref(trans, root, path, log,
1137                                                       dir, inode, eb,
1138                                                       inode_objectid,
1139                                                       parent_objectid,
1140                                                       ref_index, name, namelen,
1141                                                       &search_done);
1142                                 if (ret == 1)
1143                                         goto out;
1144                                 BUG_ON(ret);
1145                         }
1146
1147                         /* insert our name */
1148                         ret = btrfs_add_link(trans, dir, inode, name, namelen,
1149                                              0, ref_index);
1150                         BUG_ON(ret);
1151
1152                         btrfs_update_inode(trans, root, inode);
1153                 }
1154
1155                 ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
1156                 kfree(name);
1157                 if (log_ref_ver) {
1158                         iput(dir);
1159                         dir = NULL;
1160                 }
1161         }
1162
1163         /* finally write the back reference in the inode */
1164         ret = overwrite_item(trans, root, path, eb, slot, key);
1165         BUG_ON(ret);
1166
1167 out:
1168         btrfs_release_path(path);
1169         iput(dir);
1170         iput(inode);
1171         return 0;
1172 }
1173
1174 static int insert_orphan_item(struct btrfs_trans_handle *trans,
1175                               struct btrfs_root *root, u64 offset)
1176 {
1177         int ret;
1178         ret = btrfs_find_orphan_item(root, offset);
1179         if (ret > 0)
1180                 ret = btrfs_insert_orphan_item(trans, root, offset);
1181         return ret;
1182 }
1183
1184 static int count_inode_extrefs(struct btrfs_root *root,
1185                                struct inode *inode, struct btrfs_path *path)
1186 {
1187         int ret = 0;
1188         int name_len;
1189         unsigned int nlink = 0;
1190         u32 item_size;
1191         u32 cur_offset = 0;
1192         u64 inode_objectid = btrfs_ino(inode);
1193         u64 offset = 0;
1194         unsigned long ptr;
1195         struct btrfs_inode_extref *extref;
1196         struct extent_buffer *leaf;
1197
1198         while (1) {
1199                 ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
1200                                             &extref, &offset);
1201                 if (ret)
1202                         break;
1203
1204                 leaf = path->nodes[0];
1205                 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1206                 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1207
1208                 while (cur_offset < item_size) {
1209                         extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
1210                         name_len = btrfs_inode_extref_name_len(leaf, extref);
1211
1212                         nlink++;
1213
1214                         cur_offset += name_len + sizeof(*extref);
1215                 }
1216
1217                 offset++;
1218                 btrfs_release_path(path);
1219         }
1220         btrfs_release_path(path);
1221
1222         if (ret < 0)
1223                 return ret;
1224         return nlink;
1225 }
1226
1227 static int count_inode_refs(struct btrfs_root *root,
1228                                struct inode *inode, struct btrfs_path *path)
1229 {
1230         int ret;
1231         struct btrfs_key key;
1232         unsigned int nlink = 0;
1233         unsigned long ptr;
1234         unsigned long ptr_end;
1235         int name_len;
1236         u64 ino = btrfs_ino(inode);
1237
1238         key.objectid = ino;
1239         key.type = BTRFS_INODE_REF_KEY;
1240         key.offset = (u64)-1;
1241
1242         while (1) {
1243                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1244                 if (ret < 0)
1245                         break;
1246                 if (ret > 0) {
1247                         if (path->slots[0] == 0)
1248                                 break;
1249                         path->slots[0]--;
1250                 }
1251                 btrfs_item_key_to_cpu(path->nodes[0], &key,
1252                                       path->slots[0]);
1253                 if (key.objectid != ino ||
1254                     key.type != BTRFS_INODE_REF_KEY)
1255                         break;
1256                 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1257                 ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
1258                                                    path->slots[0]);
1259                 while (ptr < ptr_end) {
1260                         struct btrfs_inode_ref *ref;
1261
1262                         ref = (struct btrfs_inode_ref *)ptr;
1263                         name_len = btrfs_inode_ref_name_len(path->nodes[0],
1264                                                             ref);
1265                         ptr = (unsigned long)(ref + 1) + name_len;
1266                         nlink++;
1267                 }
1268
1269                 if (key.offset == 0)
1270                         break;
1271                 key.offset--;
1272                 btrfs_release_path(path);
1273         }
1274         btrfs_release_path(path);
1275
1276         return nlink;
1277 }
1278
1279 /*
1280  * There are a few corners where the link count of the file can't
1281  * be properly maintained during replay.  So, instead of adding
1282  * lots of complexity to the log code, we just scan the backrefs
1283  * for any file that has been through replay.
1284  *
1285  * The scan will update the link count on the inode to reflect the
1286  * number of back refs found.  If it goes down to zero, the iput
1287  * will free the inode.
1288  */
1289 static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
1290                                            struct btrfs_root *root,
1291                                            struct inode *inode)
1292 {
1293         struct btrfs_path *path;
1294         int ret;
1295         u64 nlink = 0;
1296         u64 ino = btrfs_ino(inode);
1297
1298         path = btrfs_alloc_path();
1299         if (!path)
1300                 return -ENOMEM;
1301
1302         ret = count_inode_refs(root, inode, path);
1303         if (ret < 0)
1304                 goto out;
1305
1306         nlink = ret;
1307
1308         ret = count_inode_extrefs(root, inode, path);
1309         if (ret == -ENOENT)
1310                 ret = 0;
1311
1312         if (ret < 0)
1313                 goto out;
1314
1315         nlink += ret;
1316
1317         ret = 0;
1318
1319         if (nlink != inode->i_nlink) {
1320                 set_nlink(inode, nlink);
1321                 btrfs_update_inode(trans, root, inode);
1322         }
1323         BTRFS_I(inode)->index_cnt = (u64)-1;
1324
1325         if (inode->i_nlink == 0) {
1326                 if (S_ISDIR(inode->i_mode)) {
1327                         ret = replay_dir_deletes(trans, root, NULL, path,
1328                                                  ino, 1);
1329                         BUG_ON(ret);
1330                 }
1331                 ret = insert_orphan_item(trans, root, ino);
1332                 BUG_ON(ret);
1333         }
1334
1335 out:
1336         btrfs_free_path(path);
1337         return ret;
1338 }
1339
1340 static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1341                                             struct btrfs_root *root,
1342                                             struct btrfs_path *path)
1343 {
1344         int ret;
1345         struct btrfs_key key;
1346         struct inode *inode;
1347
1348         key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1349         key.type = BTRFS_ORPHAN_ITEM_KEY;
1350         key.offset = (u64)-1;
1351         while (1) {
1352                 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1353                 if (ret < 0)
1354                         break;
1355
1356                 if (ret == 1) {
1357                         if (path->slots[0] == 0)
1358                                 break;
1359                         path->slots[0]--;
1360                 }
1361
1362                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1363                 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1364                     key.type != BTRFS_ORPHAN_ITEM_KEY)
1365                         break;
1366
1367                 ret = btrfs_del_item(trans, root, path);
1368                 if (ret)
1369                         goto out;
1370
1371                 btrfs_release_path(path);
1372                 inode = read_one_inode(root, key.offset);
1373                 if (!inode)
1374                         return -EIO;
1375
1376                 ret = fixup_inode_link_count(trans, root, inode);
1377                 BUG_ON(ret);
1378
1379                 iput(inode);
1380
1381                 /*
1382                  * fixup on a directory may create new entries,
1383                  * make sure we always look for the highset possible
1384                  * offset
1385                  */
1386                 key.offset = (u64)-1;
1387         }
1388         ret = 0;
1389 out:
1390         btrfs_release_path(path);
1391         return ret;
1392 }
1393
1394
1395 /*
1396  * record a given inode in the fixup dir so we can check its link
1397  * count when replay is done.  The link count is incremented here
1398  * so the inode won't go away until we check it
1399  */
1400 static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1401                                       struct btrfs_root *root,
1402                                       struct btrfs_path *path,
1403                                       u64 objectid)
1404 {
1405         struct btrfs_key key;
1406         int ret = 0;
1407         struct inode *inode;
1408
1409         inode = read_one_inode(root, objectid);
1410         if (!inode)
1411                 return -EIO;
1412
1413         key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1414         btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
1415         key.offset = objectid;
1416
1417         ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1418
1419         btrfs_release_path(path);
1420         if (ret == 0) {
1421                 if (!inode->i_nlink)
1422                         set_nlink(inode, 1);
1423                 else
1424                         btrfs_inc_nlink(inode);
1425                 ret = btrfs_update_inode(trans, root, inode);
1426         } else if (ret == -EEXIST) {
1427                 ret = 0;
1428         } else {
1429                 BUG();
1430         }
1431         iput(inode);
1432
1433         return ret;
1434 }
1435
1436 /*
1437  * when replaying the log for a directory, we only insert names
1438  * for inodes that actually exist.  This means an fsync on a directory
1439  * does not implicitly fsync all the new files in it
1440  */
1441 static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1442                                     struct btrfs_root *root,
1443                                     struct btrfs_path *path,
1444                                     u64 dirid, u64 index,
1445                                     char *name, int name_len, u8 type,
1446                                     struct btrfs_key *location)
1447 {
1448         struct inode *inode;
1449         struct inode *dir;
1450         int ret;
1451
1452         inode = read_one_inode(root, location->objectid);
1453         if (!inode)
1454                 return -ENOENT;
1455
1456         dir = read_one_inode(root, dirid);
1457         if (!dir) {
1458                 iput(inode);
1459                 return -EIO;
1460         }
1461         ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
1462
1463         /* FIXME, put inode into FIXUP list */
1464
1465         iput(inode);
1466         iput(dir);
1467         return ret;
1468 }
1469
1470 /*
1471  * take a single entry in a log directory item and replay it into
1472  * the subvolume.
1473  *
1474  * if a conflicting item exists in the subdirectory already,
1475  * the inode it points to is unlinked and put into the link count
1476  * fix up tree.
1477  *
1478  * If a name from the log points to a file or directory that does
1479  * not exist in the FS, it is skipped.  fsyncs on directories
1480  * do not force down inodes inside that directory, just changes to the
1481  * names or unlinks in a directory.
1482  */
1483 static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1484                                     struct btrfs_root *root,
1485                                     struct btrfs_path *path,
1486                                     struct extent_buffer *eb,
1487                                     struct btrfs_dir_item *di,
1488                                     struct btrfs_key *key)
1489 {
1490         char *name;
1491         int name_len;
1492         struct btrfs_dir_item *dst_di;
1493         struct btrfs_key found_key;
1494         struct btrfs_key log_key;
1495         struct inode *dir;
1496         u8 log_type;
1497         int exists;
1498         int ret;
1499
1500         dir = read_one_inode(root, key->objectid);
1501         if (!dir)
1502                 return -EIO;
1503
1504         name_len = btrfs_dir_name_len(eb, di);
1505         name = kmalloc(name_len, GFP_NOFS);
1506         if (!name)
1507                 return -ENOMEM;
1508
1509         log_type = btrfs_dir_type(eb, di);
1510         read_extent_buffer(eb, name, (unsigned long)(di + 1),
1511                    name_len);
1512
1513         btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1514         exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1515         if (exists == 0)
1516                 exists = 1;
1517         else
1518                 exists = 0;
1519         btrfs_release_path(path);
1520
1521         if (key->type == BTRFS_DIR_ITEM_KEY) {
1522                 dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1523                                        name, name_len, 1);
1524         } else if (key->type == BTRFS_DIR_INDEX_KEY) {
1525                 dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1526                                                      key->objectid,
1527                                                      key->offset, name,
1528                                                      name_len, 1);
1529         } else {
1530                 BUG();
1531         }
1532         if (IS_ERR_OR_NULL(dst_di)) {
1533                 /* we need a sequence number to insert, so we only
1534                  * do inserts for the BTRFS_DIR_INDEX_KEY types
1535                  */
1536                 if (key->type != BTRFS_DIR_INDEX_KEY)
1537                         goto out;
1538                 goto insert;
1539         }
1540
1541         btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1542         /* the existing item matches the logged item */
1543         if (found_key.objectid == log_key.objectid &&
1544             found_key.type == log_key.type &&
1545             found_key.offset == log_key.offset &&
1546             btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
1547                 goto out;
1548         }
1549
1550         /*
1551          * don't drop the conflicting directory entry if the inode
1552          * for the new entry doesn't exist
1553          */
1554         if (!exists)
1555                 goto out;
1556
1557         ret = drop_one_dir_item(trans, root, path, dir, dst_di);
1558         BUG_ON(ret);
1559
1560         if (key->type == BTRFS_DIR_INDEX_KEY)
1561                 goto insert;
1562 out:
1563         btrfs_release_path(path);
1564         kfree(name);
1565         iput(dir);
1566         return 0;
1567
1568 insert:
1569         btrfs_release_path(path);
1570         ret = insert_one_name(trans, root, path, key->objectid, key->offset,
1571                               name, name_len, log_type, &log_key);
1572
1573         BUG_ON(ret && ret != -ENOENT);
1574         goto out;
1575 }
1576
1577 /*
1578  * find all the names in a directory item and reconcile them into
1579  * the subvolume.  Only BTRFS_DIR_ITEM_KEY types will have more than
1580  * one name in a directory item, but the same code gets used for
1581  * both directory index types
1582  */
1583 static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
1584                                         struct btrfs_root *root,
1585                                         struct btrfs_path *path,
1586                                         struct extent_buffer *eb, int slot,
1587                                         struct btrfs_key *key)
1588 {
1589         int ret;
1590         u32 item_size = btrfs_item_size_nr(eb, slot);
1591         struct btrfs_dir_item *di;
1592         int name_len;
1593         unsigned long ptr;
1594         unsigned long ptr_end;
1595
1596         ptr = btrfs_item_ptr_offset(eb, slot);
1597         ptr_end = ptr + item_size;
1598         while (ptr < ptr_end) {
1599                 di = (struct btrfs_dir_item *)ptr;
1600                 if (verify_dir_item(root, eb, di))
1601                         return -EIO;
1602                 name_len = btrfs_dir_name_len(eb, di);
1603                 ret = replay_one_name(trans, root, path, eb, di, key);
1604                 BUG_ON(ret);
1605                 ptr = (unsigned long)(di + 1);
1606                 ptr += name_len;
1607         }
1608         return 0;
1609 }
1610
1611 /*
1612  * directory replay has two parts.  There are the standard directory
1613  * items in the log copied from the subvolume, and range items
1614  * created in the log while the subvolume was logged.
1615  *
1616  * The range items tell us which parts of the key space the log
1617  * is authoritative for.  During replay, if a key in the subvolume
1618  * directory is in a logged range item, but not actually in the log
1619  * that means it was deleted from the directory before the fsync
1620  * and should be removed.
1621  */
1622 static noinline int find_dir_range(struct btrfs_root *root,
1623                                    struct btrfs_path *path,
1624                                    u64 dirid, int key_type,
1625                                    u64 *start_ret, u64 *end_ret)
1626 {
1627         struct btrfs_key key;
1628         u64 found_end;
1629         struct btrfs_dir_log_item *item;
1630         int ret;
1631         int nritems;
1632
1633         if (*start_ret == (u64)-1)
1634                 return 1;
1635
1636         key.objectid = dirid;
1637         key.type = key_type;
1638         key.offset = *start_ret;
1639
1640         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1641         if (ret < 0)
1642                 goto out;
1643         if (ret > 0) {
1644                 if (path->slots[0] == 0)
1645                         goto out;
1646                 path->slots[0]--;
1647         }
1648         if (ret != 0)
1649                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1650
1651         if (key.type != key_type || key.objectid != dirid) {
1652                 ret = 1;
1653                 goto next;
1654         }
1655         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1656                               struct btrfs_dir_log_item);
1657         found_end = btrfs_dir_log_end(path->nodes[0], item);
1658
1659         if (*start_ret >= key.offset && *start_ret <= found_end) {
1660                 ret = 0;
1661                 *start_ret = key.offset;
1662                 *end_ret = found_end;
1663                 goto out;
1664         }
1665         ret = 1;
1666 next:
1667         /* check the next slot in the tree to see if it is a valid item */
1668         nritems = btrfs_header_nritems(path->nodes[0]);
1669         if (path->slots[0] >= nritems) {
1670                 ret = btrfs_next_leaf(root, path);
1671                 if (ret)
1672                         goto out;
1673         } else {
1674                 path->slots[0]++;
1675         }
1676
1677         btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1678
1679         if (key.type != key_type || key.objectid != dirid) {
1680                 ret = 1;
1681                 goto out;
1682         }
1683         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1684                               struct btrfs_dir_log_item);
1685         found_end = btrfs_dir_log_end(path->nodes[0], item);
1686         *start_ret = key.offset;
1687         *end_ret = found_end;
1688         ret = 0;
1689 out:
1690         btrfs_release_path(path);
1691         return ret;
1692 }
1693
1694 /*
1695  * this looks for a given directory item in the log.  If the directory
1696  * item is not in the log, the item is removed and the inode it points
1697  * to is unlinked
1698  */
1699 static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
1700                                       struct btrfs_root *root,
1701                                       struct btrfs_root *log,
1702                                       struct btrfs_path *path,
1703                                       struct btrfs_path *log_path,
1704                                       struct inode *dir,
1705                                       struct btrfs_key *dir_key)
1706 {
1707         int ret;
1708         struct extent_buffer *eb;
1709         int slot;
1710         u32 item_size;
1711         struct btrfs_dir_item *di;
1712         struct btrfs_dir_item *log_di;
1713         int name_len;
1714         unsigned long ptr;
1715         unsigned long ptr_end;
1716         char *name;
1717         struct inode *inode;
1718         struct btrfs_key location;
1719
1720 again:
1721         eb = path->nodes[0];
1722         slot = path->slots[0];
1723         item_size = btrfs_item_size_nr(eb, slot);
1724         ptr = btrfs_item_ptr_offset(eb, slot);
1725         ptr_end = ptr + item_size;
1726         while (ptr < ptr_end) {
1727                 di = (struct btrfs_dir_item *)ptr;
1728                 if (verify_dir_item(root, eb, di)) {
1729                         ret = -EIO;
1730                         goto out;
1731                 }
1732
1733                 name_len = btrfs_dir_name_len(eb, di);
1734                 name = kmalloc(name_len, GFP_NOFS);
1735                 if (!name) {
1736                         ret = -ENOMEM;
1737                         goto out;
1738                 }
1739                 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1740                                   name_len);
1741                 log_di = NULL;
1742                 if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
1743                         log_di = btrfs_lookup_dir_item(trans, log, log_path,
1744                                                        dir_key->objectid,
1745                                                        name, name_len, 0);
1746                 } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
1747                         log_di = btrfs_lookup_dir_index_item(trans, log,
1748                                                      log_path,
1749                                                      dir_key->objectid,
1750                                                      dir_key->offset,
1751                                                      name, name_len, 0);
1752                 }
1753                 if (IS_ERR_OR_NULL(log_di)) {
1754                         btrfs_dir_item_key_to_cpu(eb, di, &location);
1755                         btrfs_release_path(path);
1756                         btrfs_release_path(log_path);
1757                         inode = read_one_inode(root, location.objectid);
1758                         if (!inode) {
1759                                 kfree(name);
1760                                 return -EIO;
1761                         }
1762
1763                         ret = link_to_fixup_dir(trans, root,
1764                                                 path, location.objectid);
1765                         BUG_ON(ret);
1766                         btrfs_inc_nlink(inode);
1767                         ret = btrfs_unlink_inode(trans, root, dir, inode,
1768                                                  name, name_len);
1769                         BUG_ON(ret);
1770
1771                         btrfs_run_delayed_items(trans, root);
1772
1773                         kfree(name);
1774                         iput(inode);
1775
1776                         /* there might still be more names under this key
1777                          * check and repeat if required
1778                          */
1779                         ret = btrfs_search_slot(NULL, root, dir_key, path,
1780                                                 0, 0);
1781                         if (ret == 0)
1782                                 goto again;
1783                         ret = 0;
1784                         goto out;
1785                 }
1786                 btrfs_release_path(log_path);
1787                 kfree(name);
1788
1789                 ptr = (unsigned long)(di + 1);
1790                 ptr += name_len;
1791         }
1792         ret = 0;
1793 out:
1794         btrfs_release_path(path);
1795         btrfs_release_path(log_path);
1796         return ret;
1797 }
1798
1799 /*
1800  * deletion replay happens before we copy any new directory items
1801  * out of the log or out of backreferences from inodes.  It
1802  * scans the log to find ranges of keys that log is authoritative for,
1803  * and then scans the directory to find items in those ranges that are
1804  * not present in the log.
1805  *
1806  * Anything we don't find in the log is unlinked and removed from the
1807  * directory.
1808  */
1809 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
1810                                        struct btrfs_root *root,
1811                                        struct btrfs_root *log,
1812                                        struct btrfs_path *path,
1813                                        u64 dirid, int del_all)
1814 {
1815         u64 range_start;
1816         u64 range_end;
1817         int key_type = BTRFS_DIR_LOG_ITEM_KEY;
1818         int ret = 0;
1819         struct btrfs_key dir_key;
1820         struct btrfs_key found_key;
1821         struct btrfs_path *log_path;
1822         struct inode *dir;
1823
1824         dir_key.objectid = dirid;
1825         dir_key.type = BTRFS_DIR_ITEM_KEY;
1826         log_path = btrfs_alloc_path();
1827         if (!log_path)
1828                 return -ENOMEM;
1829
1830         dir = read_one_inode(root, dirid);
1831         /* it isn't an error if the inode isn't there, that can happen
1832          * because we replay the deletes before we copy in the inode item
1833          * from the log
1834          */
1835         if (!dir) {
1836                 btrfs_free_path(log_path);
1837                 return 0;
1838         }
1839 again:
1840         range_start = 0;
1841         range_end = 0;
1842         while (1) {
1843                 if (del_all)
1844                         range_end = (u64)-1;
1845                 else {
1846                         ret = find_dir_range(log, path, dirid, key_type,
1847                                              &range_start, &range_end);
1848                         if (ret != 0)
1849                                 break;
1850                 }
1851
1852                 dir_key.offset = range_start;
1853                 while (1) {
1854                         int nritems;
1855                         ret = btrfs_search_slot(NULL, root, &dir_key, path,
1856                                                 0, 0);
1857                         if (ret < 0)
1858                                 goto out;
1859
1860                         nritems = btrfs_header_nritems(path->nodes[0]);
1861                         if (path->slots[0] >= nritems) {
1862                                 ret = btrfs_next_leaf(root, path);
1863                                 if (ret)
1864                                         break;
1865                         }
1866                         btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1867                                               path->slots[0]);
1868                         if (found_key.objectid != dirid ||
1869                             found_key.type != dir_key.type)
1870                                 goto next_type;
1871
1872                         if (found_key.offset > range_end)
1873                                 break;
1874
1875                         ret = check_item_in_log(trans, root, log, path,
1876                                                 log_path, dir,
1877                                                 &found_key);
1878                         BUG_ON(ret);
1879                         if (found_key.offset == (u64)-1)
1880                                 break;
1881                         dir_key.offset = found_key.offset + 1;
1882                 }
1883                 btrfs_release_path(path);
1884                 if (range_end == (u64)-1)
1885                         break;
1886                 range_start = range_end + 1;
1887         }
1888
1889 next_type:
1890         ret = 0;
1891         if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
1892                 key_type = BTRFS_DIR_LOG_INDEX_KEY;
1893                 dir_key.type = BTRFS_DIR_INDEX_KEY;
1894                 btrfs_release_path(path);
1895                 goto again;
1896         }
1897 out:
1898         btrfs_release_path(path);
1899         btrfs_free_path(log_path);
1900         iput(dir);
1901         return ret;
1902 }
1903
1904 /*
1905  * the process_func used to replay items from the log tree.  This
1906  * gets called in two different stages.  The first stage just looks
1907  * for inodes and makes sure they are all copied into the subvolume.
1908  *
1909  * The second stage copies all the other item types from the log into
1910  * the subvolume.  The two stage approach is slower, but gets rid of
1911  * lots of complexity around inodes referencing other inodes that exist
1912  * only in the log (references come from either directory items or inode
1913  * back refs).
1914  */
1915 static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
1916                              struct walk_control *wc, u64 gen)
1917 {
1918         int nritems;
1919         struct btrfs_path *path;
1920         struct btrfs_root *root = wc->replay_dest;
1921         struct btrfs_key key;
1922         int level;
1923         int i;
1924         int ret;
1925
1926         ret = btrfs_read_buffer(eb, gen);
1927         if (ret)
1928                 return ret;
1929
1930         level = btrfs_header_level(eb);
1931
1932         if (level != 0)
1933                 return 0;
1934
1935         path = btrfs_alloc_path();
1936         if (!path)
1937                 return -ENOMEM;
1938
1939         nritems = btrfs_header_nritems(eb);
1940         for (i = 0; i < nritems; i++) {
1941                 btrfs_item_key_to_cpu(eb, &key, i);
1942
1943                 /* inode keys are done during the first stage */
1944                 if (key.type == BTRFS_INODE_ITEM_KEY &&
1945                     wc->stage == LOG_WALK_REPLAY_INODES) {
1946                         struct btrfs_inode_item *inode_item;
1947                         u32 mode;
1948
1949                         inode_item = btrfs_item_ptr(eb, i,
1950                                             struct btrfs_inode_item);
1951                         mode = btrfs_inode_mode(eb, inode_item);
1952                         if (S_ISDIR(mode)) {
1953                                 ret = replay_dir_deletes(wc->trans,
1954                                          root, log, path, key.objectid, 0);
1955                                 BUG_ON(ret);
1956                         }
1957                         ret = overwrite_item(wc->trans, root, path,
1958                                              eb, i, &key);
1959                         BUG_ON(ret);
1960
1961                         /* for regular files, make sure corresponding
1962                          * orhpan item exist. extents past the new EOF
1963                          * will be truncated later by orphan cleanup.
1964                          */
1965                         if (S_ISREG(mode)) {
1966                                 ret = insert_orphan_item(wc->trans, root,
1967                                                          key.objectid);
1968                                 BUG_ON(ret);
1969                         }
1970
1971                         ret = link_to_fixup_dir(wc->trans, root,
1972                                                 path, key.objectid);
1973                         BUG_ON(ret);
1974                 }
1975                 if (wc->stage < LOG_WALK_REPLAY_ALL)
1976                         continue;
1977
1978                 /* these keys are simply copied */
1979                 if (key.type == BTRFS_XATTR_ITEM_KEY) {
1980                         ret = overwrite_item(wc->trans, root, path,
1981                                              eb, i, &key);
1982                         BUG_ON(ret);
1983                 } else if (key.type == BTRFS_INODE_REF_KEY) {
1984                         ret = add_inode_ref(wc->trans, root, log, path,
1985                                             eb, i, &key);
1986                         BUG_ON(ret && ret != -ENOENT);
1987                 } else if (key.type == BTRFS_INODE_EXTREF_KEY) {
1988                         ret = add_inode_ref(wc->trans, root, log, path,
1989                                             eb, i, &key);
1990                         BUG_ON(ret && ret != -ENOENT);
1991                 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
1992                         ret = replay_one_extent(wc->trans, root, path,
1993                                                 eb, i, &key);
1994                         BUG_ON(ret);
1995                 } else if (key.type == BTRFS_DIR_ITEM_KEY ||
1996                            key.type == BTRFS_DIR_INDEX_KEY) {
1997                         ret = replay_one_dir_item(wc->trans, root, path,
1998                                                   eb, i, &key);
1999                         BUG_ON(ret);
2000                 }
2001         }
2002         btrfs_free_path(path);
2003         return 0;
2004 }
2005
2006 static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
2007                                    struct btrfs_root *root,
2008                                    struct btrfs_path *path, int *level,
2009                                    struct walk_control *wc)
2010 {
2011         u64 root_owner;
2012         u64 bytenr;
2013         u64 ptr_gen;
2014         struct extent_buffer *next;
2015         struct extent_buffer *cur;
2016         struct extent_buffer *parent;
2017         u32 blocksize;
2018         int ret = 0;
2019
2020         WARN_ON(*level < 0);
2021         WARN_ON(*level >= BTRFS_MAX_LEVEL);
2022
2023         while (*level > 0) {
2024                 WARN_ON(*level < 0);
2025                 WARN_ON(*level >= BTRFS_MAX_LEVEL);
2026                 cur = path->nodes[*level];
2027
2028                 if (btrfs_header_level(cur) != *level)
2029                         WARN_ON(1);
2030
2031                 if (path->slots[*level] >=
2032                     btrfs_header_nritems(cur))
2033                         break;
2034
2035                 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2036                 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2037                 blocksize = btrfs_level_size(root, *level - 1);
2038
2039                 parent = path->nodes[*level];
2040                 root_owner = btrfs_header_owner(parent);
2041
2042                 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
2043                 if (!next)
2044                         return -ENOMEM;
2045
2046                 if (*level == 1) {
2047                         ret = wc->process_func(root, next, wc, ptr_gen);
2048                         if (ret)
2049                                 return ret;
2050
2051                         path->slots[*level]++;
2052                         if (wc->free) {
2053                                 ret = btrfs_read_buffer(next, ptr_gen);
2054                                 if (ret) {
2055                                         free_extent_buffer(next);
2056                                         return ret;
2057                                 }
2058
2059                                 btrfs_tree_lock(next);
2060                                 btrfs_set_lock_blocking(next);
2061                                 clean_tree_block(trans, root, next);
2062                                 btrfs_wait_tree_block_writeback(next);
2063                                 btrfs_tree_unlock(next);
2064
2065                                 WARN_ON(root_owner !=
2066                                         BTRFS_TREE_LOG_OBJECTID);
2067                                 ret = btrfs_free_and_pin_reserved_extent(root,
2068                                                          bytenr, blocksize);
2069                                 BUG_ON(ret); /* -ENOMEM or logic errors */
2070                         }
2071                         free_extent_buffer(next);
2072                         continue;
2073                 }
2074                 ret = btrfs_read_buffer(next, ptr_gen);
2075                 if (ret) {
2076                         free_extent_buffer(next);
2077                         return ret;
2078                 }
2079
2080                 WARN_ON(*level <= 0);
2081                 if (path->nodes[*level-1])
2082                         free_extent_buffer(path->nodes[*level-1]);
2083                 path->nodes[*level-1] = next;
2084                 *level = btrfs_header_level(next);
2085                 path->slots[*level] = 0;
2086                 cond_resched();
2087         }
2088         WARN_ON(*level < 0);
2089         WARN_ON(*level >= BTRFS_MAX_LEVEL);
2090
2091         path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
2092
2093         cond_resched();
2094         return 0;
2095 }
2096
2097 static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
2098                                  struct btrfs_root *root,
2099                                  struct btrfs_path *path, int *level,
2100                                  struct walk_control *wc)
2101 {
2102         u64 root_owner;
2103         int i;
2104         int slot;
2105         int ret;
2106
2107         for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2108                 slot = path->slots[i];
2109                 if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
2110                         path->slots[i]++;
2111                         *level = i;
2112                         WARN_ON(*level == 0);
2113                         return 0;
2114                 } else {
2115                         struct extent_buffer *parent;
2116                         if (path->nodes[*level] == root->node)
2117                                 parent = path->nodes[*level];
2118                         else
2119                                 parent = path->nodes[*level + 1];
2120
2121                         root_owner = btrfs_header_owner(parent);
2122                         ret = wc->process_func(root, path->nodes[*level], wc,
2123                                  btrfs_header_generation(path->nodes[*level]));
2124                         if (ret)
2125                                 return ret;
2126
2127                         if (wc->free) {
2128                                 struct extent_buffer *next;
2129
2130                                 next = path->nodes[*level];
2131
2132                                 btrfs_tree_lock(next);
2133                                 btrfs_set_lock_blocking(next);
2134                                 clean_tree_block(trans, root, next);
2135                                 btrfs_wait_tree_block_writeback(next);
2136                                 btrfs_tree_unlock(next);
2137
2138                                 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
2139                                 ret = btrfs_free_and_pin_reserved_extent(root,
2140                                                 path->nodes[*level]->start,
2141                                                 path->nodes[*level]->len);
2142                                 BUG_ON(ret);
2143                         }
2144                         free_extent_buffer(path->nodes[*level]);
2145                         path->nodes[*level] = NULL;
2146                         *level = i + 1;
2147                 }
2148         }
2149         return 1;
2150 }
2151
2152 /*
2153  * drop the reference count on the tree rooted at 'snap'.  This traverses
2154  * the tree freeing any blocks that have a ref count of zero after being
2155  * decremented.
2156  */
2157 static int walk_log_tree(struct btrfs_trans_handle *trans,
2158                          struct btrfs_root *log, struct walk_control *wc)
2159 {
2160         int ret = 0;
2161         int wret;
2162         int level;
2163         struct btrfs_path *path;
2164         int i;
2165         int orig_level;
2166
2167         path = btrfs_alloc_path();
2168         if (!path)
2169                 return -ENOMEM;
2170
2171         level = btrfs_header_level(log->node);
2172         orig_level = level;
2173         path->nodes[level] = log->node;
2174         extent_buffer_get(log->node);
2175         path->slots[level] = 0;
2176
2177         while (1) {
2178                 wret = walk_down_log_tree(trans, log, path, &level, wc);
2179                 if (wret > 0)
2180                         break;
2181                 if (wret < 0) {
2182                         ret = wret;
2183                         goto out;
2184                 }
2185
2186                 wret = walk_up_log_tree(trans, log, path, &level, wc);
2187                 if (wret > 0)
2188                         break;
2189                 if (wret < 0) {
2190                         ret = wret;
2191                         goto out;
2192                 }
2193         }
2194
2195         /* was the root node processed? if not, catch it here */
2196         if (path->nodes[orig_level]) {
2197                 ret = wc->process_func(log, path->nodes[orig_level], wc,
2198                          btrfs_header_generation(path->nodes[orig_level]));
2199                 if (ret)
2200                         goto out;
2201                 if (wc->free) {
2202                         struct extent_buffer *next;
2203
2204                         next = path->nodes[orig_level];
2205
2206                         btrfs_tree_lock(next);
2207                         btrfs_set_lock_blocking(next);
2208                         clean_tree_block(trans, log, next);
2209                         btrfs_wait_tree_block_writeback(next);
2210                         btrfs_tree_unlock(next);
2211
2212                         WARN_ON(log->root_key.objectid !=
2213                                 BTRFS_TREE_LOG_OBJECTID);
2214                         ret = btrfs_free_and_pin_reserved_extent(log, next->start,
2215                                                          next->len);
2216                         BUG_ON(ret); /* -ENOMEM or logic errors */
2217                 }
2218         }
2219
2220 out:
2221         for (i = 0; i <= orig_level; i++) {
2222                 if (path->nodes[i]) {
2223                         free_extent_buffer(path->nodes[i]);
2224                         path->nodes[i] = NULL;
2225                 }
2226         }
2227         btrfs_free_path(path);
2228         return ret;
2229 }
2230
2231 /*
2232  * helper function to update the item for a given subvolumes log root
2233  * in the tree of log roots
2234  */
2235 static int update_log_root(struct btrfs_trans_handle *trans,
2236                            struct btrfs_root *log)
2237 {
2238         int ret;
2239
2240         if (log->log_transid == 1) {
2241                 /* insert root item on the first sync */
2242                 ret = btrfs_insert_root(trans, log->fs_info->log_root_tree,
2243                                 &log->root_key, &log->root_item);
2244         } else {
2245                 ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
2246                                 &log->root_key, &log->root_item);
2247         }
2248         return ret;
2249 }
2250
2251 static int wait_log_commit(struct btrfs_trans_handle *trans,
2252                            struct btrfs_root *root, unsigned long transid)
2253 {
2254         DEFINE_WAIT(wait);
2255         int index = transid % 2;
2256
2257         /*
2258          * we only allow two pending log transactions at a time,
2259          * so we know that if ours is more than 2 older than the
2260          * current transaction, we're done
2261          */
2262         do {
2263                 prepare_to_wait(&root->log_commit_wait[index],
2264                                 &wait, TASK_UNINTERRUPTIBLE);
2265                 mutex_unlock(&root->log_mutex);
2266
2267                 if (root->fs_info->last_trans_log_full_commit !=
2268                     trans->transid && root->log_transid < transid + 2 &&
2269                     atomic_read(&root->log_commit[index]))
2270                         schedule();
2271
2272                 finish_wait(&root->log_commit_wait[index], &wait);
2273                 mutex_lock(&root->log_mutex);
2274         } while (root->fs_info->last_trans_log_full_commit !=
2275                  trans->transid && root->log_transid < transid + 2 &&
2276                  atomic_read(&root->log_commit[index]));
2277         return 0;
2278 }
2279
2280 static void wait_for_writer(struct btrfs_trans_handle *trans,
2281                             struct btrfs_root *root)
2282 {
2283         DEFINE_WAIT(wait);
2284         while (root->fs_info->last_trans_log_full_commit !=
2285                trans->transid && atomic_read(&root->log_writers)) {
2286                 prepare_to_wait(&root->log_writer_wait,
2287                                 &wait, TASK_UNINTERRUPTIBLE);
2288                 mutex_unlock(&root->log_mutex);
2289                 if (root->fs_info->last_trans_log_full_commit !=
2290                     trans->transid && atomic_read(&root->log_writers))
2291                         schedule();
2292                 mutex_lock(&root->log_mutex);
2293                 finish_wait(&root->log_writer_wait, &wait);
2294         }
2295 }
2296
2297 /*
2298  * btrfs_sync_log does sends a given tree log down to the disk and
2299  * updates the super blocks to record it.  When this call is done,
2300  * you know that any inodes previously logged are safely on disk only
2301  * if it returns 0.
2302  *
2303  * Any other return value means you need to call btrfs_commit_transaction.
2304  * Some of the edge cases for fsyncing directories that have had unlinks
2305  * or renames done in the past mean that sometimes the only safe
2306  * fsync is to commit the whole FS.  When btrfs_sync_log returns -EAGAIN,
2307  * that has happened.
2308  */
2309 int btrfs_sync_log(struct btrfs_trans_handle *trans,
2310                    struct btrfs_root *root)
2311 {
2312         int index1;
2313         int index2;
2314         int mark;
2315         int ret;
2316         struct btrfs_root *log = root->log_root;
2317         struct btrfs_root *log_root_tree = root->fs_info->log_root_tree;
2318         unsigned long log_transid = 0;
2319
2320         mutex_lock(&root->log_mutex);
2321         log_transid = root->log_transid;
2322         index1 = root->log_transid % 2;
2323         if (atomic_read(&root->log_commit[index1])) {
2324                 wait_log_commit(trans, root, root->log_transid);
2325                 mutex_unlock(&root->log_mutex);
2326                 return 0;
2327         }
2328         atomic_set(&root->log_commit[index1], 1);
2329
2330         /* wait for previous tree log sync to complete */
2331         if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
2332                 wait_log_commit(trans, root, root->log_transid - 1);
2333         while (1) {
2334                 int batch = atomic_read(&root->log_batch);
2335                 /* when we're on an ssd, just kick the log commit out */
2336                 if (!btrfs_test_opt(root, SSD) && root->log_multiple_pids) {
2337                         mutex_unlock(&root->log_mutex);
2338                         schedule_timeout_uninterruptible(1);
2339                         mutex_lock(&root->log_mutex);
2340                 }
2341                 wait_for_writer(trans, root);
2342                 if (batch == atomic_read(&root->log_batch))
2343                         break;
2344         }
2345
2346         /* bail out if we need to do a full commit */
2347         if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2348                 ret = -EAGAIN;
2349                 btrfs_free_logged_extents(log, log_transid);
2350                 mutex_unlock(&root->log_mutex);
2351                 goto out;
2352         }
2353
2354         if (log_transid % 2 == 0)
2355                 mark = EXTENT_DIRTY;
2356         else
2357                 mark = EXTENT_NEW;
2358
2359         /* we start IO on  all the marked extents here, but we don't actually
2360          * wait for them until later.
2361          */
2362         ret = btrfs_write_marked_extents(log, &log->dirty_log_pages, mark);
2363         if (ret) {
2364                 btrfs_abort_transaction(trans, root, ret);
2365                 btrfs_free_logged_extents(log, log_transid);
2366                 mutex_unlock(&root->log_mutex);
2367                 goto out;
2368         }
2369
2370         btrfs_set_root_node(&log->root_item, log->node);
2371
2372         root->log_transid++;
2373         log->log_transid = root->log_transid;
2374         root->log_start_pid = 0;
2375         smp_mb();
2376         /*
2377          * IO has been started, blocks of the log tree have WRITTEN flag set
2378          * in their headers. new modifications of the log will be written to
2379          * new positions. so it's safe to allow log writers to go in.
2380          */
2381         mutex_unlock(&root->log_mutex);
2382
2383         mutex_lock(&log_root_tree->log_mutex);
2384         atomic_inc(&log_root_tree->log_batch);
2385         atomic_inc(&log_root_tree->log_writers);
2386         mutex_unlock(&log_root_tree->log_mutex);
2387
2388         ret = update_log_root(trans, log);
2389
2390         mutex_lock(&log_root_tree->log_mutex);
2391         if (atomic_dec_and_test(&log_root_tree->log_writers)) {
2392                 smp_mb();
2393                 if (waitqueue_active(&log_root_tree->log_writer_wait))
2394                         wake_up(&log_root_tree->log_writer_wait);
2395         }
2396
2397         if (ret) {
2398                 if (ret != -ENOSPC) {
2399                         btrfs_abort_transaction(trans, root, ret);
2400                         mutex_unlock(&log_root_tree->log_mutex);
2401                         goto out;
2402                 }
2403                 root->fs_info->last_trans_log_full_commit = trans->transid;
2404                 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2405                 btrfs_free_logged_extents(log, log_transid);
2406                 mutex_unlock(&log_root_tree->log_mutex);
2407                 ret = -EAGAIN;
2408                 goto out;
2409         }
2410
2411         index2 = log_root_tree->log_transid % 2;
2412         if (atomic_read(&log_root_tree->log_commit[index2])) {
2413                 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2414                 wait_log_commit(trans, log_root_tree,
2415                                 log_root_tree->log_transid);
2416                 btrfs_free_logged_extents(log, log_transid);
2417                 mutex_unlock(&log_root_tree->log_mutex);
2418                 ret = 0;
2419                 goto out;
2420         }
2421         atomic_set(&log_root_tree->log_commit[index2], 1);
2422
2423         if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
2424                 wait_log_commit(trans, log_root_tree,
2425                                 log_root_tree->log_transid - 1);
2426         }
2427
2428         wait_for_writer(trans, log_root_tree);
2429
2430         /*
2431          * now that we've moved on to the tree of log tree roots,
2432          * check the full commit flag again
2433          */
2434         if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2435                 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2436                 btrfs_free_logged_extents(log, log_transid);
2437                 mutex_unlock(&log_root_tree->log_mutex);
2438                 ret = -EAGAIN;
2439                 goto out_wake_log_root;
2440         }
2441
2442         ret = btrfs_write_and_wait_marked_extents(log_root_tree,
2443                                 &log_root_tree->dirty_log_pages,
2444                                 EXTENT_DIRTY | EXTENT_NEW);
2445         if (ret) {
2446                 btrfs_abort_transaction(trans, root, ret);
2447                 btrfs_free_logged_extents(log, log_transid);
2448                 mutex_unlock(&log_root_tree->log_mutex);
2449                 goto out_wake_log_root;
2450         }
2451         btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2452         btrfs_wait_logged_extents(log, log_transid);
2453
2454         btrfs_set_super_log_root(root->fs_info->super_for_commit,
2455                                 log_root_tree->node->start);
2456         btrfs_set_super_log_root_level(root->fs_info->super_for_commit,
2457                                 btrfs_header_level(log_root_tree->node));
2458
2459         log_root_tree->log_transid++;
2460         smp_mb();
2461
2462         mutex_unlock(&log_root_tree->log_mutex);
2463
2464         /*
2465          * nobody else is going to jump in and write the the ctree
2466          * super here because the log_commit atomic below is protecting
2467          * us.  We must be called with a transaction handle pinning
2468          * the running transaction open, so a full commit can't hop
2469          * in and cause problems either.
2470          */
2471         btrfs_scrub_pause_super(root);
2472         ret = write_ctree_super(trans, root->fs_info->tree_root, 1);
2473         btrfs_scrub_continue_super(root);
2474         if (ret) {
2475                 btrfs_abort_transaction(trans, root, ret);
2476                 goto out_wake_log_root;
2477         }
2478
2479         mutex_lock(&root->log_mutex);
2480         if (root->last_log_commit < log_transid)
2481                 root->last_log_commit = log_transid;
2482         mutex_unlock(&root->log_mutex);
2483
2484 out_wake_log_root:
2485         atomic_set(&log_root_tree->log_commit[index2], 0);
2486         smp_mb();
2487         if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
2488                 wake_up(&log_root_tree->log_commit_wait[index2]);
2489 out:
2490         atomic_set(&root->log_commit[index1], 0);
2491         smp_mb();
2492         if (waitqueue_active(&root->log_commit_wait[index1]))
2493                 wake_up(&root->log_commit_wait[index1]);
2494         return ret;
2495 }
2496
2497 static void free_log_tree(struct btrfs_trans_handle *trans,
2498                           struct btrfs_root *log)
2499 {
2500         int ret;
2501         u64 start;
2502         u64 end;
2503         struct walk_control wc = {
2504                 .free = 1,
2505                 .process_func = process_one_buffer
2506         };
2507
2508         if (trans) {
2509                 ret = walk_log_tree(trans, log, &wc);
2510                 BUG_ON(ret);
2511         }
2512
2513         while (1) {
2514                 ret = find_first_extent_bit(&log->dirty_log_pages,
2515                                 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW,
2516                                 NULL);
2517                 if (ret)
2518                         break;
2519
2520                 clear_extent_bits(&log->dirty_log_pages, start, end,
2521                                   EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
2522         }
2523
2524         /*
2525          * We may have short-circuited the log tree with the full commit logic
2526          * and left ordered extents on our list, so clear these out to keep us
2527          * from leaking inodes and memory.
2528          */
2529         btrfs_free_logged_extents(log, 0);
2530         btrfs_free_logged_extents(log, 1);
2531
2532         free_extent_buffer(log->node);
2533         kfree(log);
2534 }
2535
2536 /*
2537  * free all the extents used by the tree log.  This should be called
2538  * at commit time of the full transaction
2539  */
2540 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
2541 {
2542         if (root->log_root) {
2543                 free_log_tree(trans, root->log_root);
2544                 root->log_root = NULL;
2545         }
2546         return 0;
2547 }
2548
2549 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
2550                              struct btrfs_fs_info *fs_info)
2551 {
2552         if (fs_info->log_root_tree) {
2553                 free_log_tree(trans, fs_info->log_root_tree);
2554                 fs_info->log_root_tree = NULL;
2555         }
2556         return 0;
2557 }
2558
2559 /*
2560  * If both a file and directory are logged, and unlinks or renames are
2561  * mixed in, we have a few interesting corners:
2562  *
2563  * create file X in dir Y
2564  * link file X to X.link in dir Y
2565  * fsync file X
2566  * unlink file X but leave X.link
2567  * fsync dir Y
2568  *
2569  * After a crash we would expect only X.link to exist.  But file X
2570  * didn't get fsync'd again so the log has back refs for X and X.link.
2571  *
2572  * We solve this by removing directory entries and inode backrefs from the
2573  * log when a file that was logged in the current transaction is
2574  * unlinked.  Any later fsync will include the updated log entries, and
2575  * we'll be able to reconstruct the proper directory items from backrefs.
2576  *
2577  * This optimizations allows us to avoid relogging the entire inode
2578  * or the entire directory.
2579  */
2580 int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
2581                                  struct btrfs_root *root,
2582                                  const char *name, int name_len,
2583                                  struct inode *dir, u64 index)
2584 {
2585         struct btrfs_root *log;
2586         struct btrfs_dir_item *di;
2587         struct btrfs_path *path;
2588         int ret;
2589         int err = 0;
2590         int bytes_del = 0;
2591         u64 dir_ino = btrfs_ino(dir);
2592
2593         if (BTRFS_I(dir)->logged_trans < trans->transid)
2594                 return 0;
2595
2596         ret = join_running_log_trans(root);
2597         if (ret)
2598                 return 0;
2599
2600         mutex_lock(&BTRFS_I(dir)->log_mutex);
2601
2602         log = root->log_root;
2603         path = btrfs_alloc_path();
2604         if (!path) {
2605                 err = -ENOMEM;
2606                 goto out_unlock;
2607         }
2608
2609         di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
2610                                    name, name_len, -1);
2611         if (IS_ERR(di)) {
2612                 err = PTR_ERR(di);
2613                 goto fail;
2614         }
2615         if (di) {
2616                 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2617                 bytes_del += name_len;
2618                 BUG_ON(ret);
2619         }
2620         btrfs_release_path(path);
2621         di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
2622                                          index, name, name_len, -1);
2623         if (IS_ERR(di)) {
2624                 err = PTR_ERR(di);
2625                 goto fail;
2626         }
2627         if (di) {
2628                 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2629                 bytes_del += name_len;
2630                 BUG_ON(ret);
2631         }
2632
2633         /* update the directory size in the log to reflect the names
2634          * we have removed
2635          */
2636         if (bytes_del) {
2637                 struct btrfs_key key;
2638
2639                 key.objectid = dir_ino;
2640                 key.offset = 0;
2641                 key.type = BTRFS_INODE_ITEM_KEY;
2642                 btrfs_release_path(path);
2643
2644                 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
2645                 if (ret < 0) {
2646                         err = ret;
2647                         goto fail;
2648                 }
2649                 if (ret == 0) {
2650                         struct btrfs_inode_item *item;
2651                         u64 i_size;
2652
2653                         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2654                                               struct btrfs_inode_item);
2655                         i_size = btrfs_inode_size(path->nodes[0], item);
2656                         if (i_size > bytes_del)
2657                                 i_size -= bytes_del;
2658                         else
2659                                 i_size = 0;
2660                         btrfs_set_inode_size(path->nodes[0], item, i_size);
2661                         btrfs_mark_buffer_dirty(path->nodes[0]);
2662                 } else
2663                         ret = 0;
2664                 btrfs_release_path(path);
2665         }
2666 fail:
2667         btrfs_free_path(path);
2668 out_unlock:
2669         mutex_unlock(&BTRFS_I(dir)->log_mutex);
2670         if (ret == -ENOSPC) {
2671                 root->fs_info->last_trans_log_full_commit = trans->transid;
2672                 ret = 0;
2673         } else if (ret < 0)
2674                 btrfs_abort_transaction(trans, root, ret);
2675
2676         btrfs_end_log_trans(root);
2677
2678         return err;
2679 }
2680
2681 /* see comments for btrfs_del_dir_entries_in_log */
2682 int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
2683                                struct btrfs_root *root,
2684                                const char *name, int name_len,
2685                                struct inode *inode, u64 dirid)
2686 {
2687         struct btrfs_root *log;
2688         u64 index;
2689         int ret;
2690
2691         if (BTRFS_I(inode)->logged_trans < trans->transid)
2692                 return 0;
2693
2694         ret = join_running_log_trans(root);
2695         if (ret)
2696                 return 0;
2697         log = root->log_root;
2698         mutex_lock(&BTRFS_I(inode)->log_mutex);
2699
2700         ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
2701                                   dirid, &index);
2702         mutex_unlock(&BTRFS_I(inode)->log_mutex);
2703         if (ret == -ENOSPC) {
2704                 root->fs_info->last_trans_log_full_commit = trans->transid;
2705                 ret = 0;
2706         } else if (ret < 0 && ret != -ENOENT)
2707                 btrfs_abort_transaction(trans, root, ret);
2708         btrfs_end_log_trans(root);
2709
2710         return ret;
2711 }
2712
2713 /*
2714  * creates a range item in the log for 'dirid'.  first_offset and
2715  * last_offset tell us which parts of the key space the log should
2716  * be considered authoritative for.
2717  */
2718 static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
2719                                        struct btrfs_root *log,
2720                                        struct btrfs_path *path,
2721                                        int key_type, u64 dirid,
2722                                        u64 first_offset, u64 last_offset)
2723 {
2724         int ret;
2725         struct btrfs_key key;
2726         struct btrfs_dir_log_item *item;
2727
2728         key.objectid = dirid;
2729         key.offset = first_offset;
2730         if (key_type == BTRFS_DIR_ITEM_KEY)
2731                 key.type = BTRFS_DIR_LOG_ITEM_KEY;
2732         else
2733                 key.type = BTRFS_DIR_LOG_INDEX_KEY;
2734         ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
2735         if (ret)
2736                 return ret;
2737
2738         item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2739                               struct btrfs_dir_log_item);
2740         btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
2741         btrfs_mark_buffer_dirty(path->nodes[0]);
2742         btrfs_release_path(path);
2743         return 0;
2744 }
2745
2746 /*
2747  * log all the items included in the current transaction for a given
2748  * directory.  This also creates the range items in the log tree required
2749  * to replay anything deleted before the fsync
2750  */
2751 static noinline int log_dir_items(struct btrfs_trans_handle *trans,
2752                           struct btrfs_root *root, struct inode *inode,
2753                           struct btrfs_path *path,
2754                           struct btrfs_path *dst_path, int key_type,
2755                           u64 min_offset, u64 *last_offset_ret)
2756 {
2757         struct btrfs_key min_key;
2758         struct btrfs_key max_key;
2759         struct btrfs_root *log = root->log_root;
2760         struct extent_buffer *src;
2761         int err = 0;
2762         int ret;
2763         int i;
2764         int nritems;
2765         u64 first_offset = min_offset;
2766         u64 last_offset = (u64)-1;
2767         u64 ino = btrfs_ino(inode);
2768
2769         log = root->log_root;
2770         max_key.objectid = ino;
2771         max_key.offset = (u64)-1;
2772         max_key.type = key_type;
2773
2774         min_key.objectid = ino;
2775         min_key.type = key_type;
2776         min_key.offset = min_offset;
2777
2778         path->keep_locks = 1;
2779
2780         ret = btrfs_search_forward(root, &min_key, &max_key,
2781                                    path, trans->transid);
2782
2783         /*
2784          * we didn't find anything from this transaction, see if there
2785          * is anything at all
2786          */
2787         if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
2788                 min_key.objectid = ino;
2789                 min_key.type = key_type;
2790                 min_key.offset = (u64)-1;
2791                 btrfs_release_path(path);
2792                 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2793                 if (ret < 0) {
2794                         btrfs_release_path(path);
2795                         return ret;
2796                 }
2797                 ret = btrfs_previous_item(root, path, ino, key_type);
2798
2799                 /* if ret == 0 there are items for this type,
2800                  * create a range to tell us the last key of this type.
2801                  * otherwise, there are no items in this directory after
2802                  * *min_offset, and we create a range to indicate that.
2803                  */
2804                 if (ret == 0) {
2805                         struct btrfs_key tmp;
2806                         btrfs_item_key_to_cpu(path->nodes[0], &tmp,
2807                                               path->slots[0]);
2808                         if (key_type == tmp.type)
2809                                 first_offset = max(min_offset, tmp.offset) + 1;
2810                 }
2811                 goto done;
2812         }
2813
2814         /* go backward to find any previous key */
2815         ret = btrfs_previous_item(root, path, ino, key_type);
2816         if (ret == 0) {
2817                 struct btrfs_key tmp;
2818                 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2819                 if (key_type == tmp.type) {
2820                         first_offset = tmp.offset;
2821                         ret = overwrite_item(trans, log, dst_path,
2822                                              path->nodes[0], path->slots[0],
2823                                              &tmp);
2824                         if (ret) {
2825                                 err = ret;
2826                                 goto done;
2827                         }
2828                 }
2829         }
2830         btrfs_release_path(path);
2831
2832         /* find the first key from this transaction again */
2833         ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2834         if (ret != 0) {
2835                 WARN_ON(1);
2836                 goto done;
2837         }
2838
2839         /*
2840          * we have a block from this transaction, log every item in it
2841          * from our directory
2842          */
2843         while (1) {
2844                 struct btrfs_key tmp;
2845                 src = path->nodes[0];
2846                 nritems = btrfs_header_nritems(src);
2847                 for (i = path->slots[0]; i < nritems; i++) {
2848                         btrfs_item_key_to_cpu(src, &min_key, i);
2849
2850                         if (min_key.objectid != ino || min_key.type != key_type)
2851                                 goto done;
2852                         ret = overwrite_item(trans, log, dst_path, src, i,
2853                                              &min_key);
2854                         if (ret) {
2855                                 err = ret;
2856                                 goto done;
2857                         }
2858                 }
2859                 path->slots[0] = nritems;
2860
2861                 /*
2862                  * look ahead to the next item and see if it is also
2863                  * from this directory and from this transaction
2864                  */
2865                 ret = btrfs_next_leaf(root, path);
2866                 if (ret == 1) {
2867                         last_offset = (u64)-1;
2868                         goto done;
2869                 }
2870                 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2871                 if (tmp.objectid != ino || tmp.type != key_type) {
2872                         last_offset = (u64)-1;
2873                         goto done;
2874                 }
2875                 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
2876                         ret = overwrite_item(trans, log, dst_path,
2877                                              path->nodes[0], path->slots[0],
2878                                              &tmp);
2879                         if (ret)
2880                                 err = ret;
2881                         else
2882                                 last_offset = tmp.offset;
2883                         goto done;
2884                 }
2885         }
2886 done:
2887         btrfs_release_path(path);
2888         btrfs_release_path(dst_path);
2889
2890         if (err == 0) {
2891                 *last_offset_ret = last_offset;
2892                 /*
2893                  * insert the log range keys to indicate where the log
2894                  * is valid
2895                  */
2896                 ret = insert_dir_log_key(trans, log, path, key_type,
2897                                          ino, first_offset, last_offset);
2898                 if (ret)
2899                         err = ret;
2900         }
2901         return err;
2902 }
2903
2904 /*
2905  * logging directories is very similar to logging inodes, We find all the items
2906  * from the current transaction and write them to the log.
2907  *
2908  * The recovery code scans the directory in the subvolume, and if it finds a
2909  * key in the range logged that is not present in the log tree, then it means
2910  * that dir entry was unlinked during the transaction.
2911  *
2912  * In order for that scan to work, we must include one key smaller than
2913  * the smallest logged by this transaction and one key larger than the largest
2914  * key logged by this transaction.
2915  */
2916 static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
2917                           struct btrfs_root *root, struct inode *inode,
2918                           struct btrfs_path *path,
2919                           struct btrfs_path *dst_path)
2920 {
2921         u64 min_key;
2922         u64 max_key;
2923         int ret;
2924         int key_type = BTRFS_DIR_ITEM_KEY;
2925
2926 again:
2927         min_key = 0;
2928         max_key = 0;
2929         while (1) {
2930                 ret = log_dir_items(trans, root, inode, path,
2931                                     dst_path, key_type, min_key,
2932                                     &max_key);
2933                 if (ret)
2934                         return ret;
2935                 if (max_key == (u64)-1)
2936                         break;
2937                 min_key = max_key + 1;
2938         }
2939
2940         if (key_type == BTRFS_DIR_ITEM_KEY) {
2941                 key_type = BTRFS_DIR_INDEX_KEY;
2942                 goto again;
2943         }
2944         return 0;
2945 }
2946
2947 /*
2948  * a helper function to drop items from the log before we relog an
2949  * inode.  max_key_type indicates the highest item type to remove.
2950  * This cannot be run for file data extents because it does not
2951  * free the extents they point to.
2952  */
2953 static int drop_objectid_items(struct btrfs_trans_handle *trans,
2954                                   struct btrfs_root *log,
2955                                   struct btrfs_path *path,
2956                                   u64 objectid, int max_key_type)
2957 {
2958         int ret;
2959         struct btrfs_key key;
2960         struct btrfs_key found_key;
2961         int start_slot;
2962
2963         key.objectid = objectid;
2964         key.type = max_key_type;
2965         key.offset = (u64)-1;
2966
2967         while (1) {
2968                 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
2969                 BUG_ON(ret == 0);
2970                 if (ret < 0)
2971                         break;
2972
2973                 if (path->slots[0] == 0)
2974                         break;
2975
2976                 path->slots[0]--;
2977                 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2978                                       path->slots[0]);
2979
2980                 if (found_key.objectid != objectid)
2981                         break;
2982
2983                 found_key.offset = 0;
2984                 found_key.type = 0;
2985                 ret = btrfs_bin_search(path->nodes[0], &found_key, 0,
2986                                        &start_slot);
2987
2988                 ret = btrfs_del_items(trans, log, path, start_slot,
2989                                       path->slots[0] - start_slot + 1);
2990                 /*
2991                  * If start slot isn't 0 then we don't need to re-search, we've
2992                  * found the last guy with the objectid in this tree.
2993                  */
2994                 if (ret || start_slot != 0)
2995                         break;
2996                 btrfs_release_path(path);
2997         }
2998         btrfs_release_path(path);
2999         if (ret > 0)
3000                 ret = 0;
3001         return ret;
3002 }
3003
3004 static void fill_inode_item(struct btrfs_trans_handle *trans,
3005                             struct extent_buffer *leaf,
3006                             struct btrfs_inode_item *item,
3007                             struct inode *inode, int log_inode_only)
3008 {
3009         struct btrfs_map_token token;
3010
3011         btrfs_init_map_token(&token);
3012
3013         if (log_inode_only) {
3014                 /* set the generation to zero so the recover code
3015                  * can tell the difference between an logging
3016                  * just to say 'this inode exists' and a logging
3017                  * to say 'update this inode with these values'
3018                  */
3019                 btrfs_set_token_inode_generation(leaf, item, 0, &token);
3020                 btrfs_set_token_inode_size(leaf, item, 0, &token);
3021         } else {
3022                 btrfs_set_token_inode_generation(leaf, item,
3023                                                  BTRFS_I(inode)->generation,
3024                                                  &token);
3025                 btrfs_set_token_inode_size(leaf, item, inode->i_size, &token);
3026         }
3027
3028         btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3029         btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3030         btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3031         btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3032
3033         btrfs_set_token_timespec_sec(leaf, btrfs_inode_atime(item),
3034                                      inode->i_atime.tv_sec, &token);
3035         btrfs_set_token_timespec_nsec(leaf, btrfs_inode_atime(item),
3036                                       inode->i_atime.tv_nsec, &token);
3037
3038         btrfs_set_token_timespec_sec(leaf, btrfs_inode_mtime(item),
3039                                      inode->i_mtime.tv_sec, &token);
3040         btrfs_set_token_timespec_nsec(leaf, btrfs_inode_mtime(item),
3041                                       inode->i_mtime.tv_nsec, &token);
3042
3043         btrfs_set_token_timespec_sec(leaf, btrfs_inode_ctime(item),
3044                                      inode->i_ctime.tv_sec, &token);
3045         btrfs_set_token_timespec_nsec(leaf, btrfs_inode_ctime(item),
3046                                       inode->i_ctime.tv_nsec, &token);
3047
3048         btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3049                                      &token);
3050
3051         btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3052         btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3053         btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3054         btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3055         btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3056 }
3057
3058 static int log_inode_item(struct btrfs_trans_handle *trans,
3059                           struct btrfs_root *log, struct btrfs_path *path,
3060                           struct inode *inode)
3061 {
3062         struct btrfs_inode_item *inode_item;
3063         struct btrfs_key key;
3064         int ret;
3065
3066         memcpy(&key, &BTRFS_I(inode)->location, sizeof(key));
3067         ret = btrfs_insert_empty_item(trans, log, path, &key,
3068                                       sizeof(*inode_item));
3069         if (ret && ret != -EEXIST)
3070                 return ret;
3071         inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3072                                     struct btrfs_inode_item);
3073         fill_inode_item(trans, path->nodes[0], inode_item, inode, 0);
3074         btrfs_release_path(path);
3075         return 0;
3076 }
3077
3078 static noinline int copy_items(struct btrfs_trans_handle *trans,
3079                                struct inode *inode,
3080                                struct btrfs_path *dst_path,
3081                                struct extent_buffer *src,
3082                                int start_slot, int nr, int inode_only)
3083 {
3084         unsigned long src_offset;
3085         unsigned long dst_offset;
3086         struct btrfs_root *log = BTRFS_I(inode)->root->log_root;
3087         struct btrfs_file_extent_item *extent;
3088         struct btrfs_inode_item *inode_item;
3089         int ret;
3090         struct btrfs_key *ins_keys;
3091         u32 *ins_sizes;
3092         char *ins_data;
3093         int i;
3094         struct list_head ordered_sums;
3095         int skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
3096
3097         INIT_LIST_HEAD(&ordered_sums);
3098
3099         ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
3100                            nr * sizeof(u32), GFP_NOFS);
3101         if (!ins_data)
3102                 return -ENOMEM;
3103
3104         ins_sizes = (u32 *)ins_data;
3105         ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
3106
3107         for (i = 0; i < nr; i++) {
3108                 ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
3109                 btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
3110         }
3111         ret = btrfs_insert_empty_items(trans, log, dst_path,
3112                                        ins_keys, ins_sizes, nr);
3113         if (ret) {
3114                 kfree(ins_data);
3115                 return ret;
3116         }
3117
3118         for (i = 0; i < nr; i++, dst_path->slots[0]++) {
3119                 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
3120                                                    dst_path->slots[0]);
3121
3122                 src_offset = btrfs_item_ptr_offset(src, start_slot + i);
3123
3124                 if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
3125                         inode_item = btrfs_item_ptr(dst_path->nodes[0],
3126                                                     dst_path->slots[0],
3127                                                     struct btrfs_inode_item);
3128                         fill_inode_item(trans, dst_path->nodes[0], inode_item,
3129                                         inode, inode_only == LOG_INODE_EXISTS);
3130                 } else {
3131                         copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
3132                                            src_offset, ins_sizes[i]);
3133                 }
3134
3135                 /* take a reference on file data extents so that truncates
3136                  * or deletes of this inode don't have to relog the inode
3137                  * again
3138                  */
3139                 if (btrfs_key_type(ins_keys + i) == BTRFS_EXTENT_DATA_KEY &&
3140                     !skip_csum) {
3141                         int found_type;
3142                         extent = btrfs_item_ptr(src, start_slot + i,
3143                                                 struct btrfs_file_extent_item);
3144
3145                         if (btrfs_file_extent_generation(src, extent) < trans->transid)
3146                                 continue;
3147
3148                         found_type = btrfs_file_extent_type(src, extent);
3149                         if (found_type == BTRFS_FILE_EXTENT_REG) {
3150                                 u64 ds, dl, cs, cl;
3151                                 ds = btrfs_file_extent_disk_bytenr(src,
3152                                                                 extent);
3153                                 /* ds == 0 is a hole */
3154                                 if (ds == 0)
3155                                         continue;
3156
3157                                 dl = btrfs_file_extent_disk_num_bytes(src,
3158                                                                 extent);
3159                                 cs = btrfs_file_extent_offset(src, extent);
3160                                 cl = btrfs_file_extent_num_bytes(src,
3161                                                                 extent);
3162                                 if (btrfs_file_extent_compression(src,
3163                                                                   extent)) {
3164                                         cs = 0;
3165                                         cl = dl;
3166                                 }
3167
3168                                 ret = btrfs_lookup_csums_range(
3169                                                 log->fs_info->csum_root,
3170                                                 ds + cs, ds + cs + cl - 1,
3171                                                 &ordered_sums, 0);
3172                                 BUG_ON(ret);
3173                         }
3174                 }
3175         }
3176
3177         btrfs_mark_buffer_dirty(dst_path->nodes[0]);
3178         btrfs_release_path(dst_path);
3179         kfree(ins_data);
3180
3181         /*
3182          * we have to do this after the loop above to avoid changing the
3183          * log tree while trying to change the log tree.
3184          */
3185         ret = 0;
3186         while (!list_empty(&ordered_sums)) {
3187                 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
3188                                                    struct btrfs_ordered_sum,
3189                                                    list);
3190                 if (!ret)
3191                         ret = btrfs_csum_file_blocks(trans, log, sums);
3192                 list_del(&sums->list);
3193                 kfree(sums);
3194         }
3195         return ret;
3196 }
3197
3198 static int extent_cmp(void *priv, struct list_head *a, struct list_head *b)
3199 {
3200         struct extent_map *em1, *em2;
3201
3202         em1 = list_entry(a, struct extent_map, list);
3203         em2 = list_entry(b, struct extent_map, list);
3204
3205         if (em1->start < em2->start)
3206                 return -1;
3207         else if (em1->start > em2->start)
3208                 return 1;
3209         return 0;
3210 }
3211
3212 static int drop_adjacent_extents(struct btrfs_trans_handle *trans,
3213                                  struct btrfs_root *root, struct inode *inode,
3214                                  struct extent_map *em,
3215                                  struct btrfs_path *path)
3216 {
3217         struct btrfs_file_extent_item *fi;
3218         struct extent_buffer *leaf;
3219         struct btrfs_key key, new_key;
3220         struct btrfs_map_token token;
3221         u64 extent_end;
3222         u64 extent_offset = 0;
3223         int extent_type;
3224         int del_slot = 0;
3225         int del_nr = 0;
3226         int ret = 0;
3227
3228         while (1) {
3229                 btrfs_init_map_token(&token);
3230                 leaf = path->nodes[0];
3231                 path->slots[0]++;
3232                 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3233                         if (del_nr) {
3234                                 ret = btrfs_del_items(trans, root, path,
3235                                                       del_slot, del_nr);
3236                                 if (ret)
3237                                         return ret;
3238                                 del_nr = 0;
3239                         }
3240
3241                         ret = btrfs_next_leaf_write(trans, root, path, 1);
3242                         if (ret < 0)
3243                                 return ret;
3244                         if (ret > 0)
3245                                 return 0;
3246                         leaf = path->nodes[0];
3247                 }
3248
3249                 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3250                 if (key.objectid != btrfs_ino(inode) ||
3251                     key.type != BTRFS_EXTENT_DATA_KEY ||
3252                     key.offset >= em->start + em->len)
3253                         break;
3254
3255                 fi = btrfs_item_ptr(leaf, path->slots[0],
3256                                     struct btrfs_file_extent_item);
3257                 extent_type = btrfs_token_file_extent_type(leaf, fi, &token);
3258                 if (extent_type == BTRFS_FILE_EXTENT_REG ||
3259                     extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
3260                         extent_offset = btrfs_token_file_extent_offset(leaf,
3261                                                                 fi, &token);
3262                         extent_end = key.offset +
3263                                 btrfs_token_file_extent_num_bytes(leaf, fi,
3264                                                                   &token);
3265                 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
3266                         extent_end = key.offset +
3267                                 btrfs_file_extent_inline_len(leaf, fi);
3268                 } else {
3269                         BUG();
3270                 }
3271
3272                 if (extent_end <= em->len + em->start) {
3273                         if (!del_nr) {
3274                                 del_slot = path->slots[0];
3275                         }
3276                         del_nr++;
3277                         continue;
3278                 }
3279
3280                 /*
3281                  * Ok so we'll ignore previous items if we log a new extent,
3282                  * which can lead to overlapping extents, so if we have an
3283                  * existing extent we want to adjust we _have_ to check the next
3284                  * guy to make sure we even need this extent anymore, this keeps
3285                  * us from panicing in set_item_key_safe.
3286                  */
3287                 if (path->slots[0] < btrfs_header_nritems(leaf) - 1) {
3288                         struct btrfs_key tmp_key;
3289
3290                         btrfs_item_key_to_cpu(leaf, &tmp_key,
3291                                               path->slots[0] + 1);
3292                         if (tmp_key.objectid == btrfs_ino(inode) &&
3293                             tmp_key.type == BTRFS_EXTENT_DATA_KEY &&
3294                             tmp_key.offset <= em->start + em->len) {
3295                                 if (!del_nr)
3296                                         del_slot = path->slots[0];
3297                                 del_nr++;
3298                                 continue;
3299                         }
3300                 }
3301
3302                 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
3303                 memcpy(&new_key, &key, sizeof(new_key));
3304                 new_key.offset = em->start + em->len;
3305                 btrfs_set_item_key_safe(trans, root, path, &new_key);
3306                 extent_offset += em->start + em->len - key.offset;
3307                 btrfs_set_token_file_extent_offset(leaf, fi, extent_offset,
3308                                                    &token);
3309                 btrfs_set_token_file_extent_num_bytes(leaf, fi, extent_end -
3310                                                       (em->start + em->len),
3311                                                       &token);
3312                 btrfs_mark_buffer_dirty(leaf);
3313         }
3314
3315         if (del_nr)
3316                 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
3317
3318         return ret;
3319 }
3320
3321 static int log_one_extent(struct btrfs_trans_handle *trans,
3322                           struct inode *inode, struct btrfs_root *root,
3323                           struct extent_map *em, struct btrfs_path *path)
3324 {
3325         struct btrfs_root *log = root->log_root;
3326         struct btrfs_file_extent_item *fi;
3327         struct extent_buffer *leaf;
3328         struct btrfs_ordered_extent *ordered;
3329         struct list_head ordered_sums;
3330         struct btrfs_map_token token;
3331         struct btrfs_key key;
3332         u64 mod_start = em->mod_start;
3333         u64 mod_len = em->mod_len;
3334         u64 csum_offset;
3335         u64 csum_len;
3336         u64 extent_offset = em->start - em->orig_start;
3337         u64 block_len;
3338         int ret;
3339         int index = log->log_transid % 2;
3340         bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
3341
3342 insert:
3343         INIT_LIST_HEAD(&ordered_sums);
3344         btrfs_init_map_token(&token);
3345         key.objectid = btrfs_ino(inode);
3346         key.type = BTRFS_EXTENT_DATA_KEY;
3347         key.offset = em->start;
3348         path->really_keep_locks = 1;
3349
3350         ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*fi));
3351         if (ret && ret != -EEXIST) {
3352                 path->really_keep_locks = 0;
3353                 return ret;
3354         }
3355         leaf = path->nodes[0];
3356         fi = btrfs_item_ptr(leaf, path->slots[0],
3357                             struct btrfs_file_extent_item);
3358
3359         /*
3360          * If we are overwriting an inline extent with a real one then we need
3361          * to just delete the inline extent as it may not be large enough to
3362          * have the entire file_extent_item.
3363          */
3364         if (ret && btrfs_token_file_extent_type(leaf, fi, &token) ==
3365             BTRFS_FILE_EXTENT_INLINE) {
3366                 ret = btrfs_del_item(trans, log, path);
3367                 btrfs_release_path(path);
3368                 if (ret) {
3369                         path->really_keep_locks = 0;
3370                         return ret;
3371                 }
3372                 goto insert;
3373         }
3374
3375         btrfs_set_token_file_extent_generation(leaf, fi, em->generation,
3376                                                &token);
3377         if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3378                 skip_csum = true;
3379                 btrfs_set_token_file_extent_type(leaf, fi,
3380                                                  BTRFS_FILE_EXTENT_PREALLOC,
3381                                                  &token);
3382         } else {
3383                 btrfs_set_token_file_extent_type(leaf, fi,
3384                                                  BTRFS_FILE_EXTENT_REG,
3385                                                  &token);
3386                 if (em->block_start == 0)
3387                         skip_csum = true;
3388         }
3389
3390         block_len = max(em->block_len, em->orig_block_len);
3391         if (em->compress_type != BTRFS_COMPRESS_NONE) {
3392                 btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
3393                                                         em->block_start,
3394                                                         &token);
3395                 btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
3396                                                            &token);
3397         } else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
3398                 btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
3399                                                         em->block_start -
3400                                                         extent_offset, &token);
3401                 btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
3402                                                            &token);
3403         } else {
3404                 btrfs_set_token_file_extent_disk_bytenr(leaf, fi, 0, &token);
3405                 btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, 0,
3406                                                            &token);
3407         }
3408
3409         btrfs_set_token_file_extent_offset(leaf, fi,
3410                                            em->start - em->orig_start,
3411                                            &token);
3412         btrfs_set_token_file_extent_num_bytes(leaf, fi, em->len, &token);
3413         btrfs_set_token_file_extent_ram_bytes(leaf, fi, em->ram_bytes, &token);
3414         btrfs_set_token_file_extent_compression(leaf, fi, em->compress_type,
3415                                                 &token);
3416         btrfs_set_token_file_extent_encryption(leaf, fi, 0, &token);
3417         btrfs_set_token_file_extent_other_encoding(leaf, fi, 0, &token);
3418         btrfs_mark_buffer_dirty(leaf);
3419
3420         /*
3421          * Have to check the extent to the right of us to make sure it doesn't
3422          * fall in our current range.  We're ok if the previous extent is in our
3423          * range since the recovery stuff will run us in key order and thus just
3424          * drop the part we overwrote.
3425          */
3426         ret = drop_adjacent_extents(trans, log, inode, em, path);
3427         btrfs_release_path(path);
3428         path->really_keep_locks = 0;
3429         if (ret) {
3430                 return ret;
3431         }
3432
3433         if (skip_csum)
3434                 return 0;
3435
3436         if (em->compress_type) {
3437                 csum_offset = 0;
3438                 csum_len = block_len;
3439         }
3440
3441         /*
3442          * First check and see if our csums are on our outstanding ordered
3443          * extents.
3444          */
3445 again:
3446         spin_lock_irq(&log->log_extents_lock[index]);
3447         list_for_each_entry(ordered, &log->logged_list[index], log_list) {
3448                 struct btrfs_ordered_sum *sum;
3449
3450                 if (!mod_len)
3451                         break;
3452
3453                 if (ordered->inode != inode)
3454                         continue;
3455
3456                 if (ordered->file_offset + ordered->len <= mod_start ||
3457                     mod_start + mod_len <= ordered->file_offset)
3458                         continue;
3459
3460                 /*
3461                  * We are going to copy all the csums on this ordered extent, so
3462                  * go ahead and adjust mod_start and mod_len in case this
3463                  * ordered extent has already been logged.
3464                  */
3465                 if (ordered->file_offset > mod_start) {
3466                         if (ordered->file_offset + ordered->len >=
3467                             mod_start + mod_len)
3468                                 mod_len = ordered->file_offset - mod_start;
3469                         /*
3470                          * If we have this case
3471                          *
3472                          * |--------- logged extent ---------|
3473                          *       |----- ordered extent ----|
3474                          *
3475                          * Just don't mess with mod_start and mod_len, we'll
3476                          * just end up logging more csums than we need and it
3477                          * will be ok.
3478                          */
3479                 } else {
3480                         if (ordered->file_offset + ordered->len <
3481                             mod_start + mod_len) {
3482                                 mod_len = (mod_start + mod_len) -
3483                                         (ordered->file_offset + ordered->len);
3484                                 mod_start = ordered->file_offset +
3485                                         ordered->len;
3486                         } else {
3487                                 mod_len = 0;
3488                         }
3489                 }
3490
3491                 /*
3492                  * To keep us from looping for the above case of an ordered
3493                  * extent that falls inside of the logged extent.
3494                  */
3495                 if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM,
3496                                      &ordered->flags))
3497                         continue;
3498                 atomic_inc(&ordered->refs);
3499                 spin_unlock_irq(&log->log_extents_lock[index]);
3500                 /*
3501                  * we've dropped the lock, we must either break or
3502                  * start over after this.
3503                  */
3504
3505                 wait_event(ordered->wait, ordered->csum_bytes_left == 0);
3506
3507                 list_for_each_entry(sum, &ordered->list, list) {
3508                         ret = btrfs_csum_file_blocks(trans, log, sum);
3509                         if (ret) {
3510                                 btrfs_put_ordered_extent(ordered);
3511                                 goto unlocked;
3512                         }
3513                 }
3514                 btrfs_put_ordered_extent(ordered);
3515                 goto again;
3516
3517         }
3518         spin_unlock_irq(&log->log_extents_lock[index]);
3519 unlocked:
3520
3521         if (!mod_len || ret)
3522                 return ret;
3523
3524         csum_offset = mod_start - em->start;
3525         csum_len = mod_len;
3526
3527         /* block start is already adjusted for the file extent offset. */
3528         ret = btrfs_lookup_csums_range(log->fs_info->csum_root,
3529                                        em->block_start + csum_offset,
3530                                        em->block_start + csum_offset +
3531                                        csum_len - 1, &ordered_sums, 0);
3532         if (ret)
3533                 return ret;
3534
3535         while (!list_empty(&ordered_sums)) {
3536                 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
3537                                                    struct btrfs_ordered_sum,
3538                                                    list);
3539                 if (!ret)
3540                         ret = btrfs_csum_file_blocks(trans, log, sums);
3541                 list_del(&sums->list);
3542                 kfree(sums);
3543         }
3544
3545         return ret;
3546 }
3547
3548 static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
3549                                      struct btrfs_root *root,
3550                                      struct inode *inode,
3551                                      struct btrfs_path *path)
3552 {
3553         struct extent_map *em, *n;
3554         struct list_head extents;
3555         struct extent_map_tree *tree = &BTRFS_I(inode)->extent_tree;
3556         u64 test_gen;
3557         int ret = 0;
3558         int num = 0;
3559
3560         INIT_LIST_HEAD(&extents);
3561
3562         write_lock(&tree->lock);
3563         test_gen = root->fs_info->last_trans_committed;
3564
3565         list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
3566                 list_del_init(&em->list);
3567
3568                 /*
3569                  * Just an arbitrary number, this can be really CPU intensive
3570                  * once we start getting a lot of extents, and really once we
3571                  * have a bunch of extents we just want to commit since it will
3572                  * be faster.
3573                  */
3574                 if (++num > 32768) {
3575                         list_del_init(&tree->modified_extents);
3576                         ret = -EFBIG;
3577                         goto process;
3578                 }
3579
3580                 if (em->generation <= test_gen)
3581                         continue;
3582                 /* Need a ref to keep it from getting evicted from cache */
3583                 atomic_inc(&em->refs);
3584                 set_bit(EXTENT_FLAG_LOGGING, &em->flags);
3585                 list_add_tail(&em->list, &extents);
3586                 num++;
3587         }
3588
3589         list_sort(NULL, &extents, extent_cmp);
3590
3591 process:
3592         while (!list_empty(&extents)) {
3593                 em = list_entry(extents.next, struct extent_map, list);
3594
3595                 list_del_init(&em->list);
3596
3597                 /*
3598                  * If we had an error we just need to delete everybody from our
3599                  * private list.
3600                  */
3601                 if (ret) {
3602                         clear_em_logging(tree, em);
3603                         free_extent_map(em);
3604                         continue;
3605                 }
3606
3607                 write_unlock(&tree->lock);
3608
3609                 ret = log_one_extent(trans, inode, root, em, path);
3610                 write_lock(&tree->lock);
3611                 clear_em_logging(tree, em);
3612                 free_extent_map(em);
3613         }
3614         WARN_ON(!list_empty(&extents));
3615         write_unlock(&tree->lock);
3616
3617         btrfs_release_path(path);
3618         return ret;
3619 }
3620
3621 /* log a single inode in the tree log.
3622  * At least one parent directory for this inode must exist in the tree
3623  * or be logged already.
3624  *
3625  * Any items from this inode changed by the current transaction are copied
3626  * to the log tree.  An extra reference is taken on any extents in this
3627  * file, allowing us to avoid a whole pile of corner cases around logging
3628  * blocks that have been removed from the tree.
3629  *
3630  * See LOG_INODE_ALL and related defines for a description of what inode_only
3631  * does.
3632  *
3633  * This handles both files and directories.
3634  */
3635 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
3636                              struct btrfs_root *root, struct inode *inode,
3637                              int inode_only)
3638 {
3639         struct btrfs_path *path;
3640         struct btrfs_path *dst_path;
3641         struct btrfs_key min_key;
3642         struct btrfs_key max_key;
3643         struct btrfs_root *log = root->log_root;
3644         struct extent_buffer *src = NULL;
3645         int err = 0;
3646         int ret;
3647         int nritems;
3648         int ins_start_slot = 0;
3649         int ins_nr;
3650         bool fast_search = false;
3651         u64 ino = btrfs_ino(inode);
3652
3653         path = btrfs_alloc_path();
3654         if (!path)
3655                 return -ENOMEM;
3656         dst_path = btrfs_alloc_path();
3657         if (!dst_path) {
3658                 btrfs_free_path(path);
3659                 return -ENOMEM;
3660         }
3661
3662         min_key.objectid = ino;
3663         min_key.type = BTRFS_INODE_ITEM_KEY;
3664         min_key.offset = 0;
3665
3666         max_key.objectid = ino;
3667
3668
3669         /* today the code can only do partial logging of directories */
3670         if (S_ISDIR(inode->i_mode) ||
3671             (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3672                        &BTRFS_I(inode)->runtime_flags) &&
3673              inode_only == LOG_INODE_EXISTS))
3674                 max_key.type = BTRFS_XATTR_ITEM_KEY;
3675         else
3676                 max_key.type = (u8)-1;
3677         max_key.offset = (u64)-1;
3678
3679         /* Only run delayed items if we are a dir or a new file */
3680         if (S_ISDIR(inode->i_mode) ||
3681             BTRFS_I(inode)->generation > root->fs_info->last_trans_committed) {
3682                 ret = btrfs_commit_inode_delayed_items(trans, inode);
3683                 if (ret) {
3684                         btrfs_free_path(path);
3685                         btrfs_free_path(dst_path);
3686                         return ret;
3687                 }
3688         }
3689
3690         mutex_lock(&BTRFS_I(inode)->log_mutex);
3691
3692         btrfs_get_logged_extents(log, inode);
3693
3694         /*
3695          * a brute force approach to making sure we get the most uptodate
3696          * copies of everything.
3697          */
3698         if (S_ISDIR(inode->i_mode)) {
3699                 int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
3700
3701                 if (inode_only == LOG_INODE_EXISTS)
3702                         max_key_type = BTRFS_XATTR_ITEM_KEY;
3703                 ret = drop_objectid_items(trans, log, path, ino, max_key_type);
3704         } else {
3705                 if (test_and_clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3706                                        &BTRFS_I(inode)->runtime_flags)) {
3707                         clear_bit(BTRFS_INODE_COPY_EVERYTHING,
3708                                   &BTRFS_I(inode)->runtime_flags);
3709                         ret = btrfs_truncate_inode_items(trans, log,
3710                                                          inode, 0, 0);
3711                 } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
3712                                               &BTRFS_I(inode)->runtime_flags)) {
3713                         if (inode_only == LOG_INODE_ALL)
3714                                 fast_search = true;
3715                         max_key.type = BTRFS_XATTR_ITEM_KEY;
3716                         ret = drop_objectid_items(trans, log, path, ino,
3717                                                   max_key.type);
3718                 } else {
3719                         if (inode_only == LOG_INODE_ALL)
3720                                 fast_search = true;
3721                         ret = log_inode_item(trans, log, dst_path, inode);
3722                         if (ret) {
3723                                 err = ret;
3724                                 goto out_unlock;
3725                         }
3726                         goto log_extents;
3727                 }
3728
3729         }
3730         if (ret) {
3731                 err = ret;
3732                 goto out_unlock;
3733         }
3734         path->keep_locks = 1;
3735
3736         while (1) {
3737                 ins_nr = 0;
3738                 ret = btrfs_search_forward(root, &min_key, &max_key,
3739                                            path, trans->transid);
3740                 if (ret != 0)
3741                         break;
3742 again:
3743                 /* note, ins_nr might be > 0 here, cleanup outside the loop */
3744                 if (min_key.objectid != ino)
3745                         break;
3746                 if (min_key.type > max_key.type)
3747                         break;
3748
3749                 src = path->nodes[0];
3750                 if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
3751                         ins_nr++;
3752                         goto next_slot;
3753                 } else if (!ins_nr) {
3754                         ins_start_slot = path->slots[0];
3755                         ins_nr = 1;
3756                         goto next_slot;
3757                 }
3758
3759                 ret = copy_items(trans, inode, dst_path, src, ins_start_slot,
3760                                  ins_nr, inode_only);
3761                 if (ret) {
3762                         err = ret;
3763                         goto out_unlock;
3764                 }
3765                 ins_nr = 1;
3766                 ins_start_slot = path->slots[0];
3767 next_slot:
3768
3769                 nritems = btrfs_header_nritems(path->nodes[0]);
3770                 path->slots[0]++;
3771                 if (path->slots[0] < nritems) {
3772                         btrfs_item_key_to_cpu(path->nodes[0], &min_key,
3773                                               path->slots[0]);
3774                         goto again;
3775                 }
3776                 if (ins_nr) {
3777                         ret = copy_items(trans, inode, dst_path, src,
3778                                          ins_start_slot,
3779                                          ins_nr, inode_only);
3780                         if (ret) {
3781                                 err = ret;
3782                                 goto out_unlock;
3783                         }
3784                         ins_nr = 0;
3785                 }
3786                 btrfs_release_path(path);
3787
3788                 if (min_key.offset < (u64)-1)
3789                         min_key.offset++;
3790                 else if (min_key.type < (u8)-1)
3791                         min_key.type++;
3792                 else if (min_key.objectid < (u64)-1)
3793                         min_key.objectid++;
3794                 else
3795                         break;
3796         }
3797         if (ins_nr) {
3798                 ret = copy_items(trans, inode, dst_path, src, ins_start_slot,
3799                                  ins_nr, inode_only);
3800                 if (ret) {
3801                         err = ret;
3802                         goto out_unlock;
3803                 }
3804                 ins_nr = 0;
3805         }
3806
3807 log_extents:
3808         if (fast_search) {
3809                 btrfs_release_path(dst_path);
3810                 ret = btrfs_log_changed_extents(trans, root, inode, dst_path);
3811                 if (ret) {
3812                         err = ret;
3813                         goto out_unlock;
3814                 }
3815         } else {
3816                 struct extent_map_tree *tree = &BTRFS_I(inode)->extent_tree;
3817                 struct extent_map *em, *n;
3818
3819                 write_lock(&tree->lock);
3820                 list_for_each_entry_safe(em, n, &tree->modified_extents, list)
3821                         list_del_init(&em->list);
3822                 write_unlock(&tree->lock);
3823         }
3824
3825         if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
3826                 btrfs_release_path(path);
3827                 btrfs_release_path(dst_path);
3828                 ret = log_directory_changes(trans, root, inode, path, dst_path);
3829                 if (ret) {
3830                         err = ret;
3831                         goto out_unlock;
3832                 }
3833         }
3834         BTRFS_I(inode)->logged_trans = trans->transid;
3835         BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->last_sub_trans;
3836 out_unlock:
3837         if (err)
3838                 btrfs_free_logged_extents(log, log->log_transid);
3839         mutex_unlock(&BTRFS_I(inode)->log_mutex);
3840
3841         btrfs_free_path(path);
3842         btrfs_free_path(dst_path);
3843         return err;
3844 }
3845
3846 /*
3847  * follow the dentry parent pointers up the chain and see if any
3848  * of the directories in it require a full commit before they can
3849  * be logged.  Returns zero if nothing special needs to be done or 1 if
3850  * a full commit is required.
3851  */
3852 static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
3853                                                struct inode *inode,
3854                                                struct dentry *parent,
3855                                                struct super_block *sb,
3856                                                u64 last_committed)
3857 {
3858         int ret = 0;
3859         struct btrfs_root *root;
3860         struct dentry *old_parent = NULL;
3861
3862         /*
3863          * for regular files, if its inode is already on disk, we don't
3864          * have to worry about the parents at all.  This is because
3865          * we can use the last_unlink_trans field to record renames
3866          * and other fun in this file.
3867          */
3868         if (S_ISREG(inode->i_mode) &&
3869             BTRFS_I(inode)->generation <= last_committed &&
3870             BTRFS_I(inode)->last_unlink_trans <= last_committed)
3871                         goto out;
3872
3873         if (!S_ISDIR(inode->i_mode)) {
3874                 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3875                         goto out;
3876                 inode = parent->d_inode;
3877         }
3878
3879         while (1) {
3880                 BTRFS_I(inode)->logged_trans = trans->transid;
3881                 smp_mb();
3882
3883                 if (BTRFS_I(inode)->last_unlink_trans > last_committed) {
3884                         root = BTRFS_I(inode)->root;
3885
3886                         /*
3887                          * make sure any commits to the log are forced
3888                          * to be full commits
3889                          */
3890                         root->fs_info->last_trans_log_full_commit =
3891                                 trans->transid;
3892                         ret = 1;
3893                         break;
3894                 }
3895
3896                 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3897                         break;
3898
3899                 if (IS_ROOT(parent))
3900                         break;
3901
3902                 parent = dget_parent(parent);
3903                 dput(old_parent);
3904                 old_parent = parent;
3905                 inode = parent->d_inode;
3906
3907         }
3908         dput(old_parent);
3909 out:
3910         return ret;
3911 }
3912
3913 /*
3914  * helper function around btrfs_log_inode to make sure newly created
3915  * parent directories also end up in the log.  A minimal inode and backref
3916  * only logging is done of any parent directories that are older than
3917  * the last committed transaction
3918  */
3919 int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
3920                     struct btrfs_root *root, struct inode *inode,
3921                     struct dentry *parent, int exists_only)
3922 {
3923         int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
3924         struct super_block *sb;
3925         struct dentry *old_parent = NULL;
3926         int ret = 0;
3927         u64 last_committed = root->fs_info->last_trans_committed;
3928
3929         sb = inode->i_sb;
3930
3931         if (btrfs_test_opt(root, NOTREELOG)) {
3932                 ret = 1;
3933                 goto end_no_trans;
3934         }
3935
3936         if (root->fs_info->last_trans_log_full_commit >
3937             root->fs_info->last_trans_committed) {
3938                 ret = 1;
3939                 goto end_no_trans;
3940         }
3941
3942         if (root != BTRFS_I(inode)->root ||
3943             btrfs_root_refs(&root->root_item) == 0) {
3944                 ret = 1;
3945                 goto end_no_trans;
3946         }
3947
3948         ret = check_parent_dirs_for_sync(trans, inode, parent,
3949                                          sb, last_committed);
3950         if (ret)
3951                 goto end_no_trans;
3952
3953         if (btrfs_inode_in_log(inode, trans->transid)) {
3954                 ret = BTRFS_NO_LOG_SYNC;
3955                 goto end_no_trans;
3956         }
3957
3958         ret = start_log_trans(trans, root);
3959         if (ret)
3960                 goto end_trans;
3961
3962         ret = btrfs_log_inode(trans, root, inode, inode_only);
3963         if (ret)
3964                 goto end_trans;
3965
3966         /*
3967          * for regular files, if its inode is already on disk, we don't
3968          * have to worry about the parents at all.  This is because
3969          * we can use the last_unlink_trans field to record renames
3970          * and other fun in this file.
3971          */
3972         if (S_ISREG(inode->i_mode) &&
3973             BTRFS_I(inode)->generation <= last_committed &&
3974             BTRFS_I(inode)->last_unlink_trans <= last_committed) {
3975                 ret = 0;
3976                 goto end_trans;
3977         }
3978
3979         inode_only = LOG_INODE_EXISTS;
3980         while (1) {
3981                 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3982                         break;
3983
3984                 inode = parent->d_inode;
3985                 if (root != BTRFS_I(inode)->root)
3986                         break;
3987
3988                 if (BTRFS_I(inode)->generation >
3989                     root->fs_info->last_trans_committed) {
3990                         ret = btrfs_log_inode(trans, root, inode, inode_only);
3991                         if (ret)
3992                                 goto end_trans;
3993                 }
3994                 if (IS_ROOT(parent))
3995                         break;
3996
3997                 parent = dget_parent(parent);
3998                 dput(old_parent);
3999                 old_parent = parent;
4000         }
4001         ret = 0;
4002 end_trans:
4003         dput(old_parent);
4004         if (ret < 0) {
4005                 root->fs_info->last_trans_log_full_commit = trans->transid;
4006                 ret = 1;
4007         }
4008         btrfs_end_log_trans(root);
4009 end_no_trans:
4010         return ret;
4011 }
4012
4013 /*
4014  * it is not safe to log dentry if the chunk root has added new
4015  * chunks.  This returns 0 if the dentry was logged, and 1 otherwise.
4016  * If this returns 1, you must commit the transaction to safely get your
4017  * data on disk.
4018  */
4019 int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
4020                           struct btrfs_root *root, struct dentry *dentry)
4021 {
4022         struct dentry *parent = dget_parent(dentry);
4023         int ret;
4024
4025         ret = btrfs_log_inode_parent(trans, root, dentry->d_inode, parent, 0);
4026         dput(parent);
4027
4028         return ret;
4029 }
4030
4031 /*
4032  * should be called during mount to recover any replay any log trees
4033  * from the FS
4034  */
4035 int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
4036 {
4037         int ret;
4038         struct btrfs_path *path;
4039         struct btrfs_trans_handle *trans;
4040         struct btrfs_key key;
4041         struct btrfs_key found_key;
4042         struct btrfs_key tmp_key;
4043         struct btrfs_root *log;
4044         struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
4045         struct walk_control wc = {
4046                 .process_func = process_one_buffer,
4047                 .stage = 0,
4048         };
4049
4050         path = btrfs_alloc_path();
4051         if (!path)
4052                 return -ENOMEM;
4053
4054         fs_info->log_root_recovering = 1;
4055
4056         trans = btrfs_start_transaction(fs_info->tree_root, 0);
4057         if (IS_ERR(trans)) {
4058                 ret = PTR_ERR(trans);
4059                 goto error;
4060         }
4061
4062         wc.trans = trans;
4063         wc.pin = 1;
4064
4065         ret = walk_log_tree(trans, log_root_tree, &wc);
4066         if (ret) {
4067                 btrfs_error(fs_info, ret, "Failed to pin buffers while "
4068                             "recovering log root tree.");
4069                 goto error;
4070         }
4071
4072 again:
4073         key.objectid = BTRFS_TREE_LOG_OBJECTID;
4074         key.offset = (u64)-1;
4075         btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
4076
4077         while (1) {
4078                 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
4079
4080                 if (ret < 0) {
4081                         btrfs_error(fs_info, ret,
4082                                     "Couldn't find tree log root.");
4083                         goto error;
4084                 }
4085                 if (ret > 0) {
4086                         if (path->slots[0] == 0)
4087                                 break;
4088                         path->slots[0]--;
4089                 }
4090                 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
4091                                       path->slots[0]);
4092                 btrfs_release_path(path);
4093                 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4094                         break;
4095
4096                 log = btrfs_read_fs_root_no_radix(log_root_tree,
4097                                                   &found_key);
4098                 if (IS_ERR(log)) {
4099                         ret = PTR_ERR(log);
4100                         btrfs_error(fs_info, ret,
4101                                     "Couldn't read tree log root.");
4102                         goto error;
4103                 }
4104
4105                 tmp_key.objectid = found_key.offset;
4106                 tmp_key.type = BTRFS_ROOT_ITEM_KEY;
4107                 tmp_key.offset = (u64)-1;
4108
4109                 wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
4110                 if (IS_ERR(wc.replay_dest)) {
4111                         ret = PTR_ERR(wc.replay_dest);
4112                         btrfs_error(fs_info, ret, "Couldn't read target root "
4113                                     "for tree log recovery.");
4114                         goto error;
4115                 }
4116
4117                 wc.replay_dest->log_root = log;
4118                 btrfs_record_root_in_trans(trans, wc.replay_dest);
4119                 ret = walk_log_tree(trans, log, &wc);
4120                 BUG_ON(ret);
4121
4122                 if (wc.stage == LOG_WALK_REPLAY_ALL) {
4123                         ret = fixup_inode_link_counts(trans, wc.replay_dest,
4124                                                       path);
4125                         BUG_ON(ret);
4126                 }
4127
4128                 key.offset = found_key.offset - 1;
4129                 wc.replay_dest->log_root = NULL;
4130                 free_extent_buffer(log->node);
4131                 free_extent_buffer(log->commit_root);
4132                 kfree(log);
4133
4134                 if (found_key.offset == 0)
4135                         break;
4136         }
4137         btrfs_release_path(path);
4138
4139         /* step one is to pin it all, step two is to replay just inodes */
4140         if (wc.pin) {
4141                 wc.pin = 0;
4142                 wc.process_func = replay_one_buffer;
4143                 wc.stage = LOG_WALK_REPLAY_INODES;
4144                 goto again;
4145         }
4146         /* step three is to replay everything */
4147         if (wc.stage < LOG_WALK_REPLAY_ALL) {
4148                 wc.stage++;
4149                 goto again;
4150         }
4151
4152         btrfs_free_path(path);
4153
4154         free_extent_buffer(log_root_tree->node);
4155         log_root_tree->log_root = NULL;
4156         fs_info->log_root_recovering = 0;
4157
4158         /* step 4: commit the transaction, which also unpins the blocks */
4159         btrfs_commit_transaction(trans, fs_info->tree_root);
4160
4161         kfree(log_root_tree);
4162         return 0;
4163
4164 error:
4165         btrfs_free_path(path);
4166         return ret;
4167 }
4168
4169 /*
4170  * there are some corner cases where we want to force a full
4171  * commit instead of allowing a directory to be logged.
4172  *
4173  * They revolve around files there were unlinked from the directory, and
4174  * this function updates the parent directory so that a full commit is
4175  * properly done if it is fsync'd later after the unlinks are done.
4176  */
4177 void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
4178                              struct inode *dir, struct inode *inode,
4179                              int for_rename)
4180 {
4181         /*
4182          * when we're logging a file, if it hasn't been renamed
4183          * or unlinked, and its inode is fully committed on disk,
4184          * we don't have to worry about walking up the directory chain
4185          * to log its parents.
4186          *
4187          * So, we use the last_unlink_trans field to put this transid
4188          * into the file.  When the file is logged we check it and
4189          * don't log the parents if the file is fully on disk.
4190          */
4191         if (S_ISREG(inode->i_mode))
4192                 BTRFS_I(inode)->last_unlink_trans = trans->transid;
4193
4194         /*
4195          * if this directory was already logged any new
4196          * names for this file/dir will get recorded
4197          */
4198         smp_mb();
4199         if (BTRFS_I(dir)->logged_trans == trans->transid)
4200                 return;
4201
4202         /*
4203          * if the inode we're about to unlink was logged,
4204          * the log will be properly updated for any new names
4205          */
4206         if (BTRFS_I(inode)->logged_trans == trans->transid)
4207                 return;
4208
4209         /*
4210          * when renaming files across directories, if the directory
4211          * there we're unlinking from gets fsync'd later on, there's
4212          * no way to find the destination directory later and fsync it
4213          * properly.  So, we have to be conservative and force commits
4214          * so the new name gets discovered.
4215          */
4216         if (for_rename)
4217                 goto record;
4218
4219         /* we can safely do the unlink without any special recording */
4220         return;
4221
4222 record:
4223         BTRFS_I(dir)->last_unlink_trans = trans->transid;
4224 }
4225
4226 /*
4227  * Call this after adding a new name for a file and it will properly
4228  * update the log to reflect the new name.
4229  *
4230  * It will return zero if all goes well, and it will return 1 if a
4231  * full transaction commit is required.
4232  */
4233 int btrfs_log_new_name(struct btrfs_trans_handle *trans,
4234                         struct inode *inode, struct inode *old_dir,
4235                         struct dentry *parent)
4236 {
4237         struct btrfs_root * root = BTRFS_I(inode)->root;
4238
4239         /*
4240          * this will force the logging code to walk the dentry chain
4241          * up for the file
4242          */
4243         if (S_ISREG(inode->i_mode))
4244                 BTRFS_I(inode)->last_unlink_trans = trans->transid;
4245
4246         /*
4247          * if this inode hasn't been logged and directory we're renaming it
4248          * from hasn't been logged, we don't need to log it
4249          */
4250         if (BTRFS_I(inode)->logged_trans <=
4251             root->fs_info->last_trans_committed &&
4252             (!old_dir || BTRFS_I(old_dir)->logged_trans <=
4253                     root->fs_info->last_trans_committed))
4254                 return 0;
4255
4256         return btrfs_log_inode_parent(trans, root, inode, parent, 1);
4257 }
4258