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