1/*
   2 * Copyright (C) 2008 Oracle.  All rights reserved.
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public
   6 * License v2 as published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11 * General Public License for more details.
  12 *
  13 * You should have received a copy of the GNU General Public
  14 * License along with this program; if not, write to the
  15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16 * Boston, MA 021110-1307, USA.
  17 */
  18
  19#include <linux/sched.h>
  20#include <linux/slab.h>
  21#include <linux/blkdev.h>
  22#include <linux/list_sort.h>
 
 
  23#include "tree-log.h"
  24#include "disk-io.h"
  25#include "locking.h"
  26#include "print-tree.h"
  27#include "backref.h"
  28#include "hash.h"
  29#include "compression.h"
  30#include "qgroup.h"
 
  31
  32/* magic values for the inode_only field in btrfs_log_inode:
  33 *
  34 * LOG_INODE_ALL means to log everything
  35 * LOG_INODE_EXISTS means to log just enough to recreate the inode
  36 * during log replay
  37 */
  38#define LOG_INODE_ALL 0
  39#define LOG_INODE_EXISTS 1
  40#define LOG_OTHER_INODE 2
  41
  42/*
  43 * directory trouble cases
  44 *
  45 * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
  46 * log, we must force a full commit before doing an fsync of the directory
  47 * where the unlink was done.
  48 * ---> record transid of last unlink/rename per directory
  49 *
  50 * mkdir foo/some_dir
  51 * normal commit
  52 * rename foo/some_dir foo2/some_dir
  53 * mkdir foo/some_dir
  54 * fsync foo/some_dir/some_file
  55 *
  56 * The fsync above will unlink the original some_dir without recording
  57 * it in its new location (foo2).  After a crash, some_dir will be gone
  58 * unless the fsync of some_file forces a full commit
  59 *
  60 * 2) we must log any new names for any file or dir that is in the fsync
  61 * log. ---> check inode while renaming/linking.
  62 *
  63 * 2a) we must log any new names for any file or dir during rename
  64 * when the directory they are being removed from was logged.
  65 * ---> check inode and old parent dir during rename
  66 *
  67 *  2a is actually the more important variant.  With the extra logging
  68 *  a crash might unlink the old name without recreating the new one
  69 *
  70 * 3) after a crash, we must go through any directories with a link count
  71 * of zero and redo the rm -rf
  72 *
  73 * mkdir f1/foo
  74 * normal commit
  75 * rm -rf f1/foo
  76 * fsync(f1)
  77 *
  78 * The directory f1 was fully removed from the FS, but fsync was never
  79 * called on f1, only its parent dir.  After a crash the rm -rf must
  80 * be replayed.  This must be able to recurse down the entire
  81 * directory tree.  The inode link count fixup code takes care of the
  82 * ugly details.
  83 */
  84
  85/*
  86 * stages for the tree walking.  The first
  87 * stage (0) is to only pin down the blocks we find
  88 * the second stage (1) is to make sure that all the inodes
  89 * we find in the log are created in the subvolume.
  90 *
  91 * The last stage is to deal with directories and links and extents
  92 * and all the other fun semantics
  93 */
  94#define LOG_WALK_PIN_ONLY 0
  95#define LOG_WALK_REPLAY_INODES 1
  96#define LOG_WALK_REPLAY_DIR_INDEX 2
  97#define LOG_WALK_REPLAY_ALL 3
  98
  99static int btrfs_log_inode(struct btrfs_trans_handle *trans,
 100			   struct btrfs_root *root, struct inode *inode,
 101			   int inode_only,
 102			   const loff_t start,
 103			   const loff_t end,
 104			   struct btrfs_log_ctx *ctx);
 105static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
 106			     struct btrfs_root *root,
 107			     struct btrfs_path *path, u64 objectid);
 108static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
 109				       struct btrfs_root *root,
 110				       struct btrfs_root *log,
 111				       struct btrfs_path *path,
 112				       u64 dirid, int del_all);
 113
 114/*
 115 * tree logging is a special write ahead log used to make sure that
 116 * fsyncs and O_SYNCs can happen without doing full tree commits.
 117 *
 118 * Full tree commits are expensive because they require commonly
 119 * modified blocks to be recowed, creating many dirty pages in the
 120 * extent tree an 4x-6x higher write load than ext3.
 121 *
 122 * Instead of doing a tree commit on every fsync, we use the
 123 * key ranges and transaction ids to find items for a given file or directory
 124 * that have changed in this transaction.  Those items are copied into
 125 * a special tree (one per subvolume root), that tree is written to disk
 126 * and then the fsync is considered complete.
 127 *
 128 * After a crash, items are copied out of the log-tree back into the
 129 * subvolume tree.  Any file data extents found are recorded in the extent
 130 * allocation tree, and the log-tree freed.
 131 *
 132 * The log tree is read three times, once to pin down all the extents it is
 133 * using in ram and once, once to create all the inodes logged in the tree
 134 * and once to do all the other items.
 135 */
 136
 137/*
 138 * start a sub transaction and setup the log tree
 139 * this increments the log tree writer count to make the people
 140 * syncing the tree wait for us to finish
 141 */
 142static int start_log_trans(struct btrfs_trans_handle *trans,
 143			   struct btrfs_root *root,
 144			   struct btrfs_log_ctx *ctx)
 145{
 146	struct btrfs_fs_info *fs_info = root->fs_info;
 147	int ret = 0;
 148
 149	mutex_lock(&root->log_mutex);
 150
 151	if (root->log_root) {
 152		if (btrfs_need_log_full_commit(fs_info, trans)) {
 153			ret = -EAGAIN;
 154			goto out;
 155		}
 156
 157		if (!root->log_start_pid) {
 158			clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
 159			root->log_start_pid = current->pid;
 160		} else if (root->log_start_pid != current->pid) {
 161			set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
 162		}
 163	} else {
 164		mutex_lock(&fs_info->tree_log_mutex);
 165		if (!fs_info->log_root_tree)
 166			ret = btrfs_init_log_root_tree(trans, fs_info);
 167		mutex_unlock(&fs_info->tree_log_mutex);
 168		if (ret)
 169			goto out;
 170
 171		ret = btrfs_add_log_tree(trans, root);
 172		if (ret)
 173			goto out;
 174
 175		clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
 176		root->log_start_pid = current->pid;
 177	}
 178
 179	atomic_inc(&root->log_batch);
 180	atomic_inc(&root->log_writers);
 181	if (ctx) {
 182		int index = root->log_transid % 2;
 183		list_add_tail(&ctx->list, &root->log_ctxs[index]);
 184		ctx->log_transid = root->log_transid;
 185	}
 186
 187out:
 188	mutex_unlock(&root->log_mutex);
 189	return ret;
 190}
 191
 192/*
 193 * returns 0 if there was a log transaction running and we were able
 194 * to join, or returns -ENOENT if there were not transactions
 195 * in progress
 196 */
 197static int join_running_log_trans(struct btrfs_root *root)
 198{
 199	int ret = -ENOENT;
 200
 201	smp_mb();
 202	if (!root->log_root)
 203		return -ENOENT;
 204
 205	mutex_lock(&root->log_mutex);
 206	if (root->log_root) {
 207		ret = 0;
 208		atomic_inc(&root->log_writers);
 209	}
 210	mutex_unlock(&root->log_mutex);
 211	return ret;
 212}
 213
 214/*
 215 * This either makes the current running log transaction wait
 216 * until you call btrfs_end_log_trans() or it makes any future
 217 * log transactions wait until you call btrfs_end_log_trans()
 218 */
 219int btrfs_pin_log_trans(struct btrfs_root *root)
 220{
 221	int ret = -ENOENT;
 222
 223	mutex_lock(&root->log_mutex);
 224	atomic_inc(&root->log_writers);
 225	mutex_unlock(&root->log_mutex);
 226	return ret;
 227}
 228
 229/*
 230 * indicate we're done making changes to the log tree
 231 * and wake up anyone waiting to do a sync
 232 */
 233void btrfs_end_log_trans(struct btrfs_root *root)
 234{
 235	if (atomic_dec_and_test(&root->log_writers)) {
 236		/*
 237		 * Implicit memory barrier after atomic_dec_and_test
 238		 */
 239		if (waitqueue_active(&root->log_writer_wait))
 240			wake_up(&root->log_writer_wait);
 241	}
 242}
 243
 244
 245/*
 246 * the walk control struct is used to pass state down the chain when
 247 * processing the log tree.  The stage field tells us which part
 248 * of the log tree processing we are currently doing.  The others
 249 * are state fields used for that specific part
 250 */
 251struct walk_control {
 252	/* should we free the extent on disk when done?  This is used
 253	 * at transaction commit time while freeing a log tree
 254	 */
 255	int free;
 256
 257	/* should we write out the extent buffer?  This is used
 258	 * while flushing the log tree to disk during a sync
 259	 */
 260	int write;
 261
 262	/* should we wait for the extent buffer io to finish?  Also used
 263	 * while flushing the log tree to disk for a sync
 264	 */
 265	int wait;
 266
 267	/* pin only walk, we record which extents on disk belong to the
 268	 * log trees
 269	 */
 270	int pin;
 271
 272	/* what stage of the replay code we're currently in */
 273	int stage;
 274
 275	/* the root we are currently replaying */
 276	struct btrfs_root *replay_dest;
 277
 278	/* the trans handle for the current replay */
 279	struct btrfs_trans_handle *trans;
 280
 281	/* the function that gets used to process blocks we find in the
 282	 * tree.  Note the extent_buffer might not be up to date when it is
 283	 * passed in, and it must be checked or read if you need the data
 284	 * inside it
 285	 */
 286	int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
 287			    struct walk_control *wc, u64 gen);
 288};
 289
 290/*
 291 * process_func used to pin down extents, write them or wait on them
 292 */
 293static int process_one_buffer(struct btrfs_root *log,
 294			      struct extent_buffer *eb,
 295			      struct walk_control *wc, u64 gen)
 296{
 297	struct btrfs_fs_info *fs_info = log->fs_info;
 298	int ret = 0;
 299
 300	/*
 301	 * If this fs is mixed then we need to be able to process the leaves to
 302	 * pin down any logged extents, so we have to read the block.
 303	 */
 304	if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
 305		ret = btrfs_read_buffer(eb, gen);
 306		if (ret)
 307			return ret;
 308	}
 309
 310	if (wc->pin)
 311		ret = btrfs_pin_extent_for_log_replay(fs_info, eb->start,
 312						      eb->len);
 313
 314	if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) {
 315		if (wc->pin && btrfs_header_level(eb) == 0)
 316			ret = btrfs_exclude_logged_extents(fs_info, eb);
 317		if (wc->write)
 318			btrfs_write_tree_block(eb);
 319		if (wc->wait)
 320			btrfs_wait_tree_block_writeback(eb);
 321	}
 322	return ret;
 323}
 324
 325/*
 326 * Item overwrite used by replay and tree logging.  eb, slot and key all refer
 327 * to the src data we are copying out.
 328 *
 329 * root is the tree we are copying into, and path is a scratch
 330 * path for use in this function (it should be released on entry and
 331 * will be released on exit).
 332 *
 333 * If the key is already in the destination tree the existing item is
 334 * overwritten.  If the existing item isn't big enough, it is extended.
 335 * If it is too large, it is truncated.
 336 *
 337 * If the key isn't in the destination yet, a new item is inserted.
 338 */
 339static noinline int overwrite_item(struct btrfs_trans_handle *trans,
 340				   struct btrfs_root *root,
 341				   struct btrfs_path *path,
 342				   struct extent_buffer *eb, int slot,
 343				   struct btrfs_key *key)
 344{
 345	struct btrfs_fs_info *fs_info = root->fs_info;
 346	int ret;
 347	u32 item_size;
 348	u64 saved_i_size = 0;
 349	int save_old_i_size = 0;
 350	unsigned long src_ptr;
 351	unsigned long dst_ptr;
 352	int overwrite_root = 0;
 353	bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
 354
 355	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
 356		overwrite_root = 1;
 357
 358	item_size = btrfs_item_size_nr(eb, slot);
 359	src_ptr = btrfs_item_ptr_offset(eb, slot);
 360
 361	/* look for the key in the destination tree */
 362	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
 363	if (ret < 0)
 364		return ret;
 365
 366	if (ret == 0) {
 367		char *src_copy;
 368		char *dst_copy;
 369		u32 dst_size = btrfs_item_size_nr(path->nodes[0],
 370						  path->slots[0]);
 371		if (dst_size != item_size)
 372			goto insert;
 373
 374		if (item_size == 0) {
 375			btrfs_release_path(path);
 376			return 0;
 377		}
 378		dst_copy = kmalloc(item_size, GFP_NOFS);
 379		src_copy = kmalloc(item_size, GFP_NOFS);
 380		if (!dst_copy || !src_copy) {
 381			btrfs_release_path(path);
 382			kfree(dst_copy);
 383			kfree(src_copy);
 384			return -ENOMEM;
 385		}
 386
 387		read_extent_buffer(eb, src_copy, src_ptr, item_size);
 388
 389		dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
 390		read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
 391				   item_size);
 392		ret = memcmp(dst_copy, src_copy, item_size);
 393
 394		kfree(dst_copy);
 395		kfree(src_copy);
 396		/*
 397		 * they have the same contents, just return, this saves
 398		 * us from cowing blocks in the destination tree and doing
 399		 * extra writes that may not have been done by a previous
 400		 * sync
 401		 */
 402		if (ret == 0) {
 403			btrfs_release_path(path);
 404			return 0;
 405		}
 406
 407		/*
 408		 * We need to load the old nbytes into the inode so when we
 409		 * replay the extents we've logged we get the right nbytes.
 410		 */
 411		if (inode_item) {
 412			struct btrfs_inode_item *item;
 413			u64 nbytes;
 414			u32 mode;
 415
 416			item = btrfs_item_ptr(path->nodes[0], path->slots[0],
 417					      struct btrfs_inode_item);
 418			nbytes = btrfs_inode_nbytes(path->nodes[0], item);
 419			item = btrfs_item_ptr(eb, slot,
 420					      struct btrfs_inode_item);
 421			btrfs_set_inode_nbytes(eb, item, nbytes);
 422
 423			/*
 424			 * If this is a directory we need to reset the i_size to
 425			 * 0 so that we can set it up properly when replaying
 426			 * the rest of the items in this log.
 427			 */
 428			mode = btrfs_inode_mode(eb, item);
 429			if (S_ISDIR(mode))
 430				btrfs_set_inode_size(eb, item, 0);
 431		}
 432	} else if (inode_item) {
 433		struct btrfs_inode_item *item;
 434		u32 mode;
 435
 436		/*
 437		 * New inode, set nbytes to 0 so that the nbytes comes out
 438		 * properly when we replay the extents.
 439		 */
 440		item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
 441		btrfs_set_inode_nbytes(eb, item, 0);
 442
 443		/*
 444		 * If this is a directory we need to reset the i_size to 0 so
 445		 * that we can set it up properly when replaying the rest of
 446		 * the items in this log.
 447		 */
 448		mode = btrfs_inode_mode(eb, item);
 449		if (S_ISDIR(mode))
 450			btrfs_set_inode_size(eb, item, 0);
 451	}
 452insert:
 453	btrfs_release_path(path);
 454	/* try to insert the key into the destination tree */
 455	path->skip_release_on_error = 1;
 456	ret = btrfs_insert_empty_item(trans, root, path,
 457				      key, item_size);
 458	path->skip_release_on_error = 0;
 459
 460	/* make sure any existing item is the correct size */
 461	if (ret == -EEXIST || ret == -EOVERFLOW) {
 462		u32 found_size;
 463		found_size = btrfs_item_size_nr(path->nodes[0],
 464						path->slots[0]);
 465		if (found_size > item_size)
 466			btrfs_truncate_item(fs_info, path, item_size, 1);
 467		else if (found_size < item_size)
 468			btrfs_extend_item(fs_info, path,
 469					  item_size - found_size);
 470	} else if (ret) {
 471		return ret;
 472	}
 473	dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
 474					path->slots[0]);
 475
 476	/* don't overwrite an existing inode if the generation number
 477	 * was logged as zero.  This is done when the tree logging code
 478	 * is just logging an inode to make sure it exists after recovery.
 479	 *
 480	 * Also, don't overwrite i_size on directories during replay.
 481	 * log replay inserts and removes directory items based on the
 482	 * state of the tree found in the subvolume, and i_size is modified
 483	 * as it goes
 484	 */
 485	if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
 486		struct btrfs_inode_item *src_item;
 487		struct btrfs_inode_item *dst_item;
 488
 489		src_item = (struct btrfs_inode_item *)src_ptr;
 490		dst_item = (struct btrfs_inode_item *)dst_ptr;
 491
 492		if (btrfs_inode_generation(eb, src_item) == 0) {
 493			struct extent_buffer *dst_eb = path->nodes[0];
 494			const u64 ino_size = btrfs_inode_size(eb, src_item);
 495
 496			/*
 497			 * For regular files an ino_size == 0 is used only when
 498			 * logging that an inode exists, as part of a directory
 499			 * fsync, and the inode wasn't fsynced before. In this
 500			 * case don't set the size of the inode in the fs/subvol
 501			 * tree, otherwise we would be throwing valid data away.
 502			 */
 503			if (S_ISREG(btrfs_inode_mode(eb, src_item)) &&
 504			    S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) &&
 505			    ino_size != 0) {
 506				struct btrfs_map_token token;
 507
 508				btrfs_init_map_token(&token);
 509				btrfs_set_token_inode_size(dst_eb, dst_item,
 510							   ino_size, &token);
 511			}
 512			goto no_copy;
 513		}
 514
 515		if (overwrite_root &&
 516		    S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
 517		    S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
 518			save_old_i_size = 1;
 519			saved_i_size = btrfs_inode_size(path->nodes[0],
 520							dst_item);
 521		}
 522	}
 523
 524	copy_extent_buffer(path->nodes[0], eb, dst_ptr,
 525			   src_ptr, item_size);
 526
 527	if (save_old_i_size) {
 528		struct btrfs_inode_item *dst_item;
 529		dst_item = (struct btrfs_inode_item *)dst_ptr;
 530		btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
 531	}
 532
 533	/* make sure the generation is filled in */
 534	if (key->type == BTRFS_INODE_ITEM_KEY) {
 535		struct btrfs_inode_item *dst_item;
 536		dst_item = (struct btrfs_inode_item *)dst_ptr;
 537		if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
 538			btrfs_set_inode_generation(path->nodes[0], dst_item,
 539						   trans->transid);
 540		}
 541	}
 542no_copy:
 543	btrfs_mark_buffer_dirty(path->nodes[0]);
 544	btrfs_release_path(path);
 545	return 0;
 546}
 547
 548/*
 549 * simple helper to read an inode off the disk from a given root
 550 * This can only be called for subvolume roots and not for the log
 551 */
 552static noinline struct inode *read_one_inode(struct btrfs_root *root,
 553					     u64 objectid)
 554{
 555	struct btrfs_key key;
 556	struct inode *inode;
 557
 558	key.objectid = objectid;
 559	key.type = BTRFS_INODE_ITEM_KEY;
 560	key.offset = 0;
 561	inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
 562	if (IS_ERR(inode)) {
 563		inode = NULL;
 564	} else if (is_bad_inode(inode)) {
 565		iput(inode);
 566		inode = NULL;
 567	}
 568	return inode;
 569}
 570
 571/* replays a single extent in 'eb' at 'slot' with 'key' into the
 572 * subvolume 'root'.  path is released on entry and should be released
 573 * on exit.
 574 *
 575 * extents in the log tree have not been allocated out of the extent
 576 * tree yet.  So, this completes the allocation, taking a reference
 577 * as required if the extent already exists or creating a new extent
 578 * if it isn't in the extent allocation tree yet.
 579 *
 580 * The extent is inserted into the file, dropping any existing extents
 581 * from the file that overlap the new one.
 582 */
 583static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
 584				      struct btrfs_root *root,
 585				      struct btrfs_path *path,
 586				      struct extent_buffer *eb, int slot,
 587				      struct btrfs_key *key)
 588{
 589	struct btrfs_fs_info *fs_info = root->fs_info;
 590	int found_type;
 591	u64 extent_end;
 592	u64 start = key->offset;
 593	u64 nbytes = 0;
 594	struct btrfs_file_extent_item *item;
 595	struct inode *inode = NULL;
 596	unsigned long size;
 597	int ret = 0;
 598
 599	item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
 600	found_type = btrfs_file_extent_type(eb, item);
 601
 602	if (found_type == BTRFS_FILE_EXTENT_REG ||
 603	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
 604		nbytes = btrfs_file_extent_num_bytes(eb, item);
 605		extent_end = start + nbytes;
 606
 607		/*
 608		 * We don't add to the inodes nbytes if we are prealloc or a
 609		 * hole.
 610		 */
 611		if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
 612			nbytes = 0;
 613	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 614		size = btrfs_file_extent_inline_len(eb, slot, item);
 615		nbytes = btrfs_file_extent_ram_bytes(eb, item);
 616		extent_end = ALIGN(start + size,
 617				   fs_info->sectorsize);
 618	} else {
 619		ret = 0;
 620		goto out;
 621	}
 622
 623	inode = read_one_inode(root, key->objectid);
 624	if (!inode) {
 625		ret = -EIO;
 626		goto out;
 627	}
 628
 629	/*
 630	 * first check to see if we already have this extent in the
 631	 * file.  This must be done before the btrfs_drop_extents run
 632	 * so we don't try to drop this extent.
 633	 */
 634	ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
 635				       start, 0);
 636
 637	if (ret == 0 &&
 638	    (found_type == BTRFS_FILE_EXTENT_REG ||
 639	     found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
 640		struct btrfs_file_extent_item cmp1;
 641		struct btrfs_file_extent_item cmp2;
 642		struct btrfs_file_extent_item *existing;
 643		struct extent_buffer *leaf;
 644
 645		leaf = path->nodes[0];
 646		existing = btrfs_item_ptr(leaf, path->slots[0],
 647					  struct btrfs_file_extent_item);
 648
 649		read_extent_buffer(eb, &cmp1, (unsigned long)item,
 650				   sizeof(cmp1));
 651		read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
 652				   sizeof(cmp2));
 653
 654		/*
 655		 * we already have a pointer to this exact extent,
 656		 * we don't have to do anything
 657		 */
 658		if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
 659			btrfs_release_path(path);
 660			goto out;
 661		}
 662	}
 663	btrfs_release_path(path);
 664
 665	/* drop any overlapping extents */
 666	ret = btrfs_drop_extents(trans, root, inode, start, extent_end, 1);
 667	if (ret)
 668		goto out;
 669
 670	if (found_type == BTRFS_FILE_EXTENT_REG ||
 671	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
 672		u64 offset;
 673		unsigned long dest_offset;
 674		struct btrfs_key ins;
 675
 
 
 
 
 676		ret = btrfs_insert_empty_item(trans, root, path, key,
 677					      sizeof(*item));
 678		if (ret)
 679			goto out;
 680		dest_offset = btrfs_item_ptr_offset(path->nodes[0],
 681						    path->slots[0]);
 682		copy_extent_buffer(path->nodes[0], eb, dest_offset,
 683				(unsigned long)item,  sizeof(*item));
 684
 685		ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
 686		ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
 687		ins.type = BTRFS_EXTENT_ITEM_KEY;
 688		offset = key->offset - btrfs_file_extent_offset(eb, item);
 689
 690		/*
 691		 * Manually record dirty extent, as here we did a shallow
 692		 * file extent item copy and skip normal backref update,
 693		 * but modifying extent tree all by ourselves.
 694		 * So need to manually record dirty extent for qgroup,
 695		 * as the owner of the file extent changed from log tree
 696		 * (doesn't affect qgroup) to fs/file tree(affects qgroup)
 697		 */
 698		ret = btrfs_qgroup_trace_extent(trans, fs_info,
 699				btrfs_file_extent_disk_bytenr(eb, item),
 700				btrfs_file_extent_disk_num_bytes(eb, item),
 701				GFP_NOFS);
 702		if (ret < 0)
 703			goto out;
 704
 705		if (ins.objectid > 0) {
 706			u64 csum_start;
 707			u64 csum_end;
 708			LIST_HEAD(ordered_sums);
 709			/*
 710			 * is this extent already allocated in the extent
 711			 * allocation tree?  If so, just add a reference
 712			 */
 713			ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
 714						ins.offset);
 715			if (ret == 0) {
 716				ret = btrfs_inc_extent_ref(trans, fs_info,
 717						ins.objectid, ins.offset,
 718						0, root->root_key.objectid,
 719						key->objectid, offset);
 720				if (ret)
 721					goto out;
 722			} else {
 723				/*
 724				 * insert the extent pointer in the extent
 725				 * allocation tree
 726				 */
 727				ret = btrfs_alloc_logged_file_extent(trans,
 728						fs_info,
 729						root->root_key.objectid,
 730						key->objectid, offset, &ins);
 731				if (ret)
 732					goto out;
 733			}
 734			btrfs_release_path(path);
 735
 736			if (btrfs_file_extent_compression(eb, item)) {
 737				csum_start = ins.objectid;
 738				csum_end = csum_start + ins.offset;
 739			} else {
 740				csum_start = ins.objectid +
 741					btrfs_file_extent_offset(eb, item);
 742				csum_end = csum_start +
 743					btrfs_file_extent_num_bytes(eb, item);
 744			}
 745
 746			ret = btrfs_lookup_csums_range(root->log_root,
 747						csum_start, csum_end - 1,
 748						&ordered_sums, 0);
 749			if (ret)
 750				goto out;
 751			/*
 752			 * Now delete all existing cums in the csum root that
 753			 * cover our range. We do this because we can have an
 754			 * extent that is completely referenced by one file
 755			 * extent item and partially referenced by another
 756			 * file extent item (like after using the clone or
 757			 * extent_same ioctls). In this case if we end up doing
 758			 * the replay of the one that partially references the
 759			 * extent first, and we do not do the csum deletion
 760			 * below, we can get 2 csum items in the csum tree that
 761			 * overlap each other. For example, imagine our log has
 762			 * the two following file extent items:
 763			 *
 764			 * key (257 EXTENT_DATA 409600)
 765			 *     extent data disk byte 12845056 nr 102400
 766			 *     extent data offset 20480 nr 20480 ram 102400
 767			 *
 768			 * key (257 EXTENT_DATA 819200)
 769			 *     extent data disk byte 12845056 nr 102400
 770			 *     extent data offset 0 nr 102400 ram 102400
 771			 *
 772			 * Where the second one fully references the 100K extent
 773			 * that starts at disk byte 12845056, and the log tree
 774			 * has a single csum item that covers the entire range
 775			 * of the extent:
 776			 *
 777			 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
 778			 *
 779			 * After the first file extent item is replayed, the
 780			 * csum tree gets the following csum item:
 781			 *
 782			 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
 783			 *
 784			 * Which covers the 20K sub-range starting at offset 20K
 785			 * of our extent. Now when we replay the second file
 786			 * extent item, if we do not delete existing csum items
 787			 * that cover any of its blocks, we end up getting two
 788			 * csum items in our csum tree that overlap each other:
 789			 *
 790			 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
 791			 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
 792			 *
 793			 * Which is a problem, because after this anyone trying
 794			 * to lookup up for the checksum of any block of our
 795			 * extent starting at an offset of 40K or higher, will
 796			 * end up looking at the second csum item only, which
 797			 * does not contain the checksum for any block starting
 798			 * at offset 40K or higher of our extent.
 799			 */
 800			while (!list_empty(&ordered_sums)) {
 801				struct btrfs_ordered_sum *sums;
 802				sums = list_entry(ordered_sums.next,
 803						struct btrfs_ordered_sum,
 804						list);
 805				if (!ret)
 806					ret = btrfs_del_csums(trans, fs_info,
 807							      sums->bytenr,
 808							      sums->len);
 809				if (!ret)
 810					ret = btrfs_csum_file_blocks(trans,
 811						fs_info->csum_root, sums);
 812				list_del(&sums->list);
 813				kfree(sums);
 814			}
 815			if (ret)
 816				goto out;
 817		} else {
 818			btrfs_release_path(path);
 819		}
 820	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
 821		/* inline extents are easy, we just overwrite them */
 822		ret = overwrite_item(trans, root, path, eb, slot, key);
 823		if (ret)
 824			goto out;
 825	}
 826
 827	inode_add_bytes(inode, nbytes);
 
 828	ret = btrfs_update_inode(trans, root, inode);
 829out:
 830	if (inode)
 831		iput(inode);
 832	return ret;
 833}
 834
 835/*
 836 * when cleaning up conflicts between the directory names in the
 837 * subvolume, directory names in the log and directory names in the
 838 * inode back references, we may have to unlink inodes from directories.
 839 *
 840 * This is a helper function to do the unlink of a specific directory
 841 * item
 842 */
 843static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
 844				      struct btrfs_root *root,
 845				      struct btrfs_path *path,
 846				      struct inode *dir,
 847				      struct btrfs_dir_item *di)
 848{
 849	struct btrfs_fs_info *fs_info = root->fs_info;
 850	struct inode *inode;
 851	char *name;
 852	int name_len;
 853	struct extent_buffer *leaf;
 854	struct btrfs_key location;
 855	int ret;
 856
 857	leaf = path->nodes[0];
 858
 859	btrfs_dir_item_key_to_cpu(leaf, di, &location);
 860	name_len = btrfs_dir_name_len(leaf, di);
 861	name = kmalloc(name_len, GFP_NOFS);
 862	if (!name)
 863		return -ENOMEM;
 864
 865	read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
 866	btrfs_release_path(path);
 867
 868	inode = read_one_inode(root, location.objectid);
 869	if (!inode) {
 870		ret = -EIO;
 871		goto out;
 872	}
 873
 874	ret = link_to_fixup_dir(trans, root, path, location.objectid);
 875	if (ret)
 876		goto out;
 877
 878	ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
 
 879	if (ret)
 880		goto out;
 881	else
 882		ret = btrfs_run_delayed_items(trans, fs_info);
 883out:
 884	kfree(name);
 885	iput(inode);
 886	return ret;
 887}
 888
 889/*
 890 * helper function to see if a given name and sequence number found
 891 * in an inode back reference are already in a directory and correctly
 892 * point to this inode
 893 */
 894static noinline int inode_in_dir(struct btrfs_root *root,
 895				 struct btrfs_path *path,
 896				 u64 dirid, u64 objectid, u64 index,
 897				 const char *name, int name_len)
 898{
 899	struct btrfs_dir_item *di;
 900	struct btrfs_key location;
 901	int match = 0;
 902
 903	di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
 904					 index, name, name_len, 0);
 905	if (di && !IS_ERR(di)) {
 906		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 907		if (location.objectid != objectid)
 908			goto out;
 909	} else
 910		goto out;
 911	btrfs_release_path(path);
 912
 913	di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
 914	if (di && !IS_ERR(di)) {
 915		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 916		if (location.objectid != objectid)
 917			goto out;
 918	} else
 919		goto out;
 920	match = 1;
 921out:
 922	btrfs_release_path(path);
 923	return match;
 924}
 925
 926/*
 927 * helper function to check a log tree for a named back reference in
 928 * an inode.  This is used to decide if a back reference that is
 929 * found in the subvolume conflicts with what we find in the log.
 930 *
 931 * inode backreferences may have multiple refs in a single item,
 932 * during replay we process one reference at a time, and we don't
 933 * want to delete valid links to a file from the subvolume if that
 934 * link is also in the log.
 935 */
 936static noinline int backref_in_log(struct btrfs_root *log,
 937				   struct btrfs_key *key,
 938				   u64 ref_objectid,
 939				   const char *name, int namelen)
 940{
 941	struct btrfs_path *path;
 942	struct btrfs_inode_ref *ref;
 943	unsigned long ptr;
 944	unsigned long ptr_end;
 945	unsigned long name_ptr;
 946	int found_name_len;
 947	int item_size;
 948	int ret;
 949	int match = 0;
 950
 951	path = btrfs_alloc_path();
 952	if (!path)
 953		return -ENOMEM;
 954
 955	ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
 956	if (ret != 0)
 957		goto out;
 958
 959	ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
 960
 961	if (key->type == BTRFS_INODE_EXTREF_KEY) {
 962		if (btrfs_find_name_in_ext_backref(path, ref_objectid,
 
 
 963						   name, namelen, NULL))
 964			match = 1;
 965
 966		goto out;
 967	}
 968
 969	item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
 970	ptr_end = ptr + item_size;
 971	while (ptr < ptr_end) {
 972		ref = (struct btrfs_inode_ref *)ptr;
 973		found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
 974		if (found_name_len == namelen) {
 975			name_ptr = (unsigned long)(ref + 1);
 976			ret = memcmp_extent_buffer(path->nodes[0], name,
 977						   name_ptr, namelen);
 978			if (ret == 0) {
 979				match = 1;
 980				goto out;
 981			}
 982		}
 983		ptr = (unsigned long)(ref + 1) + found_name_len;
 984	}
 985out:
 986	btrfs_free_path(path);
 987	return match;
 988}
 989
 990static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
 991				  struct btrfs_root *root,
 992				  struct btrfs_path *path,
 993				  struct btrfs_root *log_root,
 994				  struct inode *dir, struct inode *inode,
 995				  struct extent_buffer *eb,
 996				  u64 inode_objectid, u64 parent_objectid,
 997				  u64 ref_index, char *name, int namelen,
 998				  int *search_done)
 999{
1000	struct btrfs_fs_info *fs_info = root->fs_info;
1001	int ret;
1002	char *victim_name;
1003	int victim_name_len;
1004	struct extent_buffer *leaf;
1005	struct btrfs_dir_item *di;
1006	struct btrfs_key search_key;
1007	struct btrfs_inode_extref *extref;
1008
1009again:
1010	/* Search old style refs */
1011	search_key.objectid = inode_objectid;
1012	search_key.type = BTRFS_INODE_REF_KEY;
1013	search_key.offset = parent_objectid;
1014	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
1015	if (ret == 0) {
1016		struct btrfs_inode_ref *victim_ref;
1017		unsigned long ptr;
1018		unsigned long ptr_end;
1019
1020		leaf = path->nodes[0];
1021
1022		/* are we trying to overwrite a back ref for the root directory
1023		 * if so, just jump out, we're done
1024		 */
1025		if (search_key.objectid == search_key.offset)
1026			return 1;
1027
1028		/* check all the names in this back reference to see
1029		 * if they are in the log.  if so, we allow them to stay
1030		 * otherwise they must be unlinked as a conflict
1031		 */
1032		ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1033		ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
1034		while (ptr < ptr_end) {
1035			victim_ref = (struct btrfs_inode_ref *)ptr;
1036			victim_name_len = btrfs_inode_ref_name_len(leaf,
1037								   victim_ref);
1038			victim_name = kmalloc(victim_name_len, GFP_NOFS);
1039			if (!victim_name)
1040				return -ENOMEM;
1041
1042			read_extent_buffer(leaf, victim_name,
1043					   (unsigned long)(victim_ref + 1),
1044					   victim_name_len);
1045
1046			if (!backref_in_log(log_root, &search_key,
1047					    parent_objectid,
1048					    victim_name,
1049					    victim_name_len)) {
1050				inc_nlink(inode);
1051				btrfs_release_path(path);
1052
1053				ret = btrfs_unlink_inode(trans, root, dir,
1054							 inode, victim_name,
1055							 victim_name_len);
1056				kfree(victim_name);
1057				if (ret)
1058					return ret;
1059				ret = btrfs_run_delayed_items(trans, fs_info);
1060				if (ret)
1061					return ret;
1062				*search_done = 1;
1063				goto again;
1064			}
1065			kfree(victim_name);
1066
1067			ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
1068		}
1069
1070		/*
1071		 * NOTE: we have searched root tree and checked the
1072		 * corresponding ref, it does not need to check again.
1073		 */
1074		*search_done = 1;
1075	}
1076	btrfs_release_path(path);
1077
1078	/* Same search but for extended refs */
1079	extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
1080					   inode_objectid, parent_objectid, 0,
1081					   0);
1082	if (!IS_ERR_OR_NULL(extref)) {
1083		u32 item_size;
1084		u32 cur_offset = 0;
1085		unsigned long base;
1086		struct inode *victim_parent;
1087
1088		leaf = path->nodes[0];
1089
1090		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1091		base = btrfs_item_ptr_offset(leaf, path->slots[0]);
1092
1093		while (cur_offset < item_size) {
1094			extref = (struct btrfs_inode_extref *)(base + cur_offset);
1095
1096			victim_name_len = btrfs_inode_extref_name_len(leaf, extref);
1097
1098			if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
1099				goto next;
1100
1101			victim_name = kmalloc(victim_name_len, GFP_NOFS);
1102			if (!victim_name)
1103				return -ENOMEM;
1104			read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name,
1105					   victim_name_len);
1106
1107			search_key.objectid = inode_objectid;
1108			search_key.type = BTRFS_INODE_EXTREF_KEY;
1109			search_key.offset = btrfs_extref_hash(parent_objectid,
1110							      victim_name,
1111							      victim_name_len);
1112			ret = 0;
1113			if (!backref_in_log(log_root, &search_key,
1114					    parent_objectid, victim_name,
1115					    victim_name_len)) {
1116				ret = -ENOENT;
1117				victim_parent = read_one_inode(root,
1118							       parent_objectid);
1119				if (victim_parent) {
1120					inc_nlink(inode);
1121					btrfs_release_path(path);
1122
1123					ret = btrfs_unlink_inode(trans, root,
1124								 victim_parent,
1125								 inode,
1126								 victim_name,
1127								 victim_name_len);
1128					if (!ret)
1129						ret = btrfs_run_delayed_items(
1130								  trans,
1131								  fs_info);
1132				}
1133				iput(victim_parent);
1134				kfree(victim_name);
1135				if (ret)
1136					return ret;
1137				*search_done = 1;
1138				goto again;
1139			}
1140			kfree(victim_name);
1141			if (ret)
1142				return ret;
1143next:
1144			cur_offset += victim_name_len + sizeof(*extref);
1145		}
1146		*search_done = 1;
1147	}
1148	btrfs_release_path(path);
1149
1150	/* look for a conflicting sequence number */
1151	di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
1152					 ref_index, name, namelen, 0);
1153	if (di && !IS_ERR(di)) {
1154		ret = drop_one_dir_item(trans, root, path, dir, di);
1155		if (ret)
1156			return ret;
1157	}
1158	btrfs_release_path(path);
1159
1160	/* look for a conflicing name */
1161	di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
1162				   name, namelen, 0);
1163	if (di && !IS_ERR(di)) {
1164		ret = drop_one_dir_item(trans, root, path, dir, di);
1165		if (ret)
1166			return ret;
1167	}
1168	btrfs_release_path(path);
1169
1170	return 0;
1171}
1172
1173static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1174			     u32 *namelen, char **name, u64 *index,
1175			     u64 *parent_objectid)
1176{
1177	struct btrfs_inode_extref *extref;
1178
1179	extref = (struct btrfs_inode_extref *)ref_ptr;
1180
1181	*namelen = btrfs_inode_extref_name_len(eb, extref);
1182	*name = kmalloc(*namelen, GFP_NOFS);
1183	if (*name == NULL)
1184		return -ENOMEM;
1185
1186	read_extent_buffer(eb, *name, (unsigned long)&extref->name,
1187			   *namelen);
1188
1189	*index = btrfs_inode_extref_index(eb, extref);
 
1190	if (parent_objectid)
1191		*parent_objectid = btrfs_inode_extref_parent(eb, extref);
1192
1193	return 0;
1194}
1195
1196static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1197			  u32 *namelen, char **name, u64 *index)
1198{
1199	struct btrfs_inode_ref *ref;
1200
1201	ref = (struct btrfs_inode_ref *)ref_ptr;
1202
1203	*namelen = btrfs_inode_ref_name_len(eb, ref);
1204	*name = kmalloc(*namelen, GFP_NOFS);
1205	if (*name == NULL)
1206		return -ENOMEM;
1207
1208	read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
1209
1210	*index = btrfs_inode_ref_index(eb, ref);
 
1211
1212	return 0;
1213}
1214
1215/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1216 * replay one inode back reference item found in the log tree.
1217 * eb, slot and key refer to the buffer and key found in the log tree.
1218 * root is the destination we are replaying into, and path is for temp
1219 * use by this function.  (it should be released on return).
1220 */
1221static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
1222				  struct btrfs_root *root,
1223				  struct btrfs_root *log,
1224				  struct btrfs_path *path,
1225				  struct extent_buffer *eb, int slot,
1226				  struct btrfs_key *key)
1227{
1228	struct inode *dir = NULL;
1229	struct inode *inode = NULL;
1230	unsigned long ref_ptr;
1231	unsigned long ref_end;
1232	char *name = NULL;
1233	int namelen;
1234	int ret;
1235	int search_done = 0;
1236	int log_ref_ver = 0;
1237	u64 parent_objectid;
1238	u64 inode_objectid;
1239	u64 ref_index = 0;
1240	int ref_struct_size;
1241
1242	ref_ptr = btrfs_item_ptr_offset(eb, slot);
1243	ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
1244
1245	if (key->type == BTRFS_INODE_EXTREF_KEY) {
1246		struct btrfs_inode_extref *r;
1247
1248		ref_struct_size = sizeof(struct btrfs_inode_extref);
1249		log_ref_ver = 1;
1250		r = (struct btrfs_inode_extref *)ref_ptr;
1251		parent_objectid = btrfs_inode_extref_parent(eb, r);
1252	} else {
1253		ref_struct_size = sizeof(struct btrfs_inode_ref);
1254		parent_objectid = key->offset;
1255	}
1256	inode_objectid = key->objectid;
1257
1258	/*
1259	 * it is possible that we didn't log all the parent directories
1260	 * for a given inode.  If we don't find the dir, just don't
1261	 * copy the back ref in.  The link count fixup code will take
1262	 * care of the rest
1263	 */
1264	dir = read_one_inode(root, parent_objectid);
1265	if (!dir) {
1266		ret = -ENOENT;
1267		goto out;
1268	}
1269
1270	inode = read_one_inode(root, inode_objectid);
1271	if (!inode) {
1272		ret = -EIO;
1273		goto out;
1274	}
1275
1276	while (ref_ptr < ref_end) {
1277		if (log_ref_ver) {
1278			ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
1279						&ref_index, &parent_objectid);
1280			/*
1281			 * parent object can change from one array
1282			 * item to another.
1283			 */
1284			if (!dir)
1285				dir = read_one_inode(root, parent_objectid);
1286			if (!dir) {
1287				ret = -ENOENT;
1288				goto out;
1289			}
1290		} else {
1291			ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
1292					     &ref_index);
1293		}
1294		if (ret)
1295			goto out;
1296
1297		/* if we already have a perfect match, we're done */
1298		if (!inode_in_dir(root, path, btrfs_ino(dir), btrfs_ino(inode),
1299				  ref_index, name, namelen)) {
 
1300			/*
1301			 * look for a conflicting back reference in the
1302			 * metadata. if we find one we have to unlink that name
1303			 * of the file before we add our new link.  Later on, we
1304			 * overwrite any existing back reference, and we don't
1305			 * want to create dangling pointers in the directory.
1306			 */
1307
1308			if (!search_done) {
1309				ret = __add_inode_ref(trans, root, path, log,
1310						      dir, inode, eb,
 
1311						      inode_objectid,
1312						      parent_objectid,
1313						      ref_index, name, namelen,
1314						      &search_done);
1315				if (ret) {
1316					if (ret == 1)
1317						ret = 0;
1318					goto out;
1319				}
1320			}
1321
1322			/* insert our name */
1323			ret = btrfs_add_link(trans, dir, inode, name, namelen,
1324					     0, ref_index);
 
1325			if (ret)
1326				goto out;
1327
1328			btrfs_update_inode(trans, root, inode);
1329		}
1330
1331		ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
1332		kfree(name);
1333		name = NULL;
1334		if (log_ref_ver) {
1335			iput(dir);
1336			dir = NULL;
1337		}
1338	}
1339
 
 
 
 
 
 
 
 
 
 
 
 
 
1340	/* finally write the back reference in the inode */
1341	ret = overwrite_item(trans, root, path, eb, slot, key);
1342out:
1343	btrfs_release_path(path);
1344	kfree(name);
1345	iput(dir);
1346	iput(inode);
1347	return ret;
1348}
1349
1350static int insert_orphan_item(struct btrfs_trans_handle *trans,
1351			      struct btrfs_root *root, u64 ino)
1352{
1353	int ret;
1354
1355	ret = btrfs_insert_orphan_item(trans, root, ino);
1356	if (ret == -EEXIST)
1357		ret = 0;
1358
1359	return ret;
1360}
1361
1362static int count_inode_extrefs(struct btrfs_root *root,
1363			       struct inode *inode, struct btrfs_path *path)
1364{
1365	int ret = 0;
1366	int name_len;
1367	unsigned int nlink = 0;
1368	u32 item_size;
1369	u32 cur_offset = 0;
1370	u64 inode_objectid = btrfs_ino(inode);
1371	u64 offset = 0;
1372	unsigned long ptr;
1373	struct btrfs_inode_extref *extref;
1374	struct extent_buffer *leaf;
1375
1376	while (1) {
1377		ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
1378					    &extref, &offset);
1379		if (ret)
1380			break;
1381
1382		leaf = path->nodes[0];
1383		item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1384		ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1385		cur_offset = 0;
1386
1387		while (cur_offset < item_size) {
1388			extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
1389			name_len = btrfs_inode_extref_name_len(leaf, extref);
1390
1391			nlink++;
1392
1393			cur_offset += name_len + sizeof(*extref);
1394		}
1395
1396		offset++;
1397		btrfs_release_path(path);
1398	}
1399	btrfs_release_path(path);
1400
1401	if (ret < 0 && ret != -ENOENT)
1402		return ret;
1403	return nlink;
1404}
1405
1406static int count_inode_refs(struct btrfs_root *root,
1407			       struct inode *inode, struct btrfs_path *path)
1408{
1409	int ret;
1410	struct btrfs_key key;
1411	unsigned int nlink = 0;
1412	unsigned long ptr;
1413	unsigned long ptr_end;
1414	int name_len;
1415	u64 ino = btrfs_ino(inode);
1416
1417	key.objectid = ino;
1418	key.type = BTRFS_INODE_REF_KEY;
1419	key.offset = (u64)-1;
1420
1421	while (1) {
1422		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1423		if (ret < 0)
1424			break;
1425		if (ret > 0) {
1426			if (path->slots[0] == 0)
1427				break;
1428			path->slots[0]--;
1429		}
1430process_slot:
1431		btrfs_item_key_to_cpu(path->nodes[0], &key,
1432				      path->slots[0]);
1433		if (key.objectid != ino ||
1434		    key.type != BTRFS_INODE_REF_KEY)
1435			break;
1436		ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1437		ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
1438						   path->slots[0]);
1439		while (ptr < ptr_end) {
1440			struct btrfs_inode_ref *ref;
1441
1442			ref = (struct btrfs_inode_ref *)ptr;
1443			name_len = btrfs_inode_ref_name_len(path->nodes[0],
1444							    ref);
1445			ptr = (unsigned long)(ref + 1) + name_len;
1446			nlink++;
1447		}
1448
1449		if (key.offset == 0)
1450			break;
1451		if (path->slots[0] > 0) {
1452			path->slots[0]--;
1453			goto process_slot;
1454		}
1455		key.offset--;
1456		btrfs_release_path(path);
1457	}
1458	btrfs_release_path(path);
1459
1460	return nlink;
1461}
1462
1463/*
1464 * There are a few corners where the link count of the file can't
1465 * be properly maintained during replay.  So, instead of adding
1466 * lots of complexity to the log code, we just scan the backrefs
1467 * for any file that has been through replay.
1468 *
1469 * The scan will update the link count on the inode to reflect the
1470 * number of back refs found.  If it goes down to zero, the iput
1471 * will free the inode.
1472 */
1473static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
1474					   struct btrfs_root *root,
1475					   struct inode *inode)
1476{
1477	struct btrfs_path *path;
1478	int ret;
1479	u64 nlink = 0;
1480	u64 ino = btrfs_ino(inode);
1481
1482	path = btrfs_alloc_path();
1483	if (!path)
1484		return -ENOMEM;
1485
1486	ret = count_inode_refs(root, inode, path);
1487	if (ret < 0)
1488		goto out;
1489
1490	nlink = ret;
1491
1492	ret = count_inode_extrefs(root, inode, path);
1493	if (ret < 0)
1494		goto out;
1495
1496	nlink += ret;
1497
1498	ret = 0;
1499
1500	if (nlink != inode->i_nlink) {
1501		set_nlink(inode, nlink);
1502		btrfs_update_inode(trans, root, inode);
1503	}
1504	BTRFS_I(inode)->index_cnt = (u64)-1;
1505
1506	if (inode->i_nlink == 0) {
1507		if (S_ISDIR(inode->i_mode)) {
1508			ret = replay_dir_deletes(trans, root, NULL, path,
1509						 ino, 1);
1510			if (ret)
1511				goto out;
1512		}
1513		ret = insert_orphan_item(trans, root, ino);
1514	}
1515
1516out:
1517	btrfs_free_path(path);
1518	return ret;
1519}
1520
1521static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1522					    struct btrfs_root *root,
1523					    struct btrfs_path *path)
1524{
1525	int ret;
1526	struct btrfs_key key;
1527	struct inode *inode;
1528
1529	key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1530	key.type = BTRFS_ORPHAN_ITEM_KEY;
1531	key.offset = (u64)-1;
1532	while (1) {
1533		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1534		if (ret < 0)
1535			break;
1536
1537		if (ret == 1) {
1538			if (path->slots[0] == 0)
1539				break;
1540			path->slots[0]--;
1541		}
1542
1543		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1544		if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1545		    key.type != BTRFS_ORPHAN_ITEM_KEY)
1546			break;
1547
1548		ret = btrfs_del_item(trans, root, path);
1549		if (ret)
1550			goto out;
1551
1552		btrfs_release_path(path);
1553		inode = read_one_inode(root, key.offset);
1554		if (!inode)
1555			return -EIO;
1556
1557		ret = fixup_inode_link_count(trans, root, inode);
1558		iput(inode);
1559		if (ret)
1560			goto out;
1561
1562		/*
1563		 * fixup on a directory may create new entries,
1564		 * make sure we always look for the highset possible
1565		 * offset
1566		 */
1567		key.offset = (u64)-1;
1568	}
1569	ret = 0;
1570out:
1571	btrfs_release_path(path);
1572	return ret;
1573}
1574
1575
1576/*
1577 * record a given inode in the fixup dir so we can check its link
1578 * count when replay is done.  The link count is incremented here
1579 * so the inode won't go away until we check it
1580 */
1581static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1582				      struct btrfs_root *root,
1583				      struct btrfs_path *path,
1584				      u64 objectid)
1585{
1586	struct btrfs_key key;
1587	int ret = 0;
1588	struct inode *inode;
1589
1590	inode = read_one_inode(root, objectid);
1591	if (!inode)
1592		return -EIO;
1593
1594	key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1595	key.type = BTRFS_ORPHAN_ITEM_KEY;
1596	key.offset = objectid;
1597
1598	ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1599
1600	btrfs_release_path(path);
1601	if (ret == 0) {
1602		if (!inode->i_nlink)
1603			set_nlink(inode, 1);
1604		else
1605			inc_nlink(inode);
1606		ret = btrfs_update_inode(trans, root, inode);
1607	} else if (ret == -EEXIST) {
1608		ret = 0;
1609	} else {
1610		BUG(); /* Logic Error */
1611	}
1612	iput(inode);
1613
1614	return ret;
1615}
1616
1617/*
1618 * when replaying the log for a directory, we only insert names
1619 * for inodes that actually exist.  This means an fsync on a directory
1620 * does not implicitly fsync all the new files in it
1621 */
1622static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1623				    struct btrfs_root *root,
1624				    u64 dirid, u64 index,
1625				    char *name, int name_len,
1626				    struct btrfs_key *location)
1627{
1628	struct inode *inode;
1629	struct inode *dir;
1630	int ret;
1631
1632	inode = read_one_inode(root, location->objectid);
1633	if (!inode)
1634		return -ENOENT;
1635
1636	dir = read_one_inode(root, dirid);
1637	if (!dir) {
1638		iput(inode);
1639		return -EIO;
1640	}
1641
1642	ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
 
1643
1644	/* FIXME, put inode into FIXUP list */
1645
1646	iput(inode);
1647	iput(dir);
1648	return ret;
1649}
1650
1651/*
1652 * Return true if an inode reference exists in the log for the given name,
1653 * inode and parent inode.
1654 */
1655static bool name_in_log_ref(struct btrfs_root *log_root,
1656			    const char *name, const int name_len,
1657			    const u64 dirid, const u64 ino)
1658{
1659	struct btrfs_key search_key;
1660
1661	search_key.objectid = ino;
1662	search_key.type = BTRFS_INODE_REF_KEY;
1663	search_key.offset = dirid;
1664	if (backref_in_log(log_root, &search_key, dirid, name, name_len))
1665		return true;
1666
1667	search_key.type = BTRFS_INODE_EXTREF_KEY;
1668	search_key.offset = btrfs_extref_hash(dirid, name, name_len);
1669	if (backref_in_log(log_root, &search_key, dirid, name, name_len))
1670		return true;
1671
1672	return false;
1673}
1674
1675/*
1676 * take a single entry in a log directory item and replay it into
1677 * the subvolume.
1678 *
1679 * if a conflicting item exists in the subdirectory already,
1680 * the inode it points to is unlinked and put into the link count
1681 * fix up tree.
1682 *
1683 * If a name from the log points to a file or directory that does
1684 * not exist in the FS, it is skipped.  fsyncs on directories
1685 * do not force down inodes inside that directory, just changes to the
1686 * names or unlinks in a directory.
1687 *
1688 * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
1689 * non-existing inode) and 1 if the name was replayed.
1690 */
1691static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1692				    struct btrfs_root *root,
1693				    struct btrfs_path *path,
1694				    struct extent_buffer *eb,
1695				    struct btrfs_dir_item *di,
1696				    struct btrfs_key *key)
1697{
1698	char *name;
1699	int name_len;
1700	struct btrfs_dir_item *dst_di;
1701	struct btrfs_key found_key;
1702	struct btrfs_key log_key;
1703	struct inode *dir;
1704	u8 log_type;
1705	int exists;
1706	int ret = 0;
1707	bool update_size = (key->type == BTRFS_DIR_INDEX_KEY);
1708	bool name_added = false;
1709
1710	dir = read_one_inode(root, key->objectid);
1711	if (!dir)
1712		return -EIO;
1713
1714	name_len = btrfs_dir_name_len(eb, di);
1715	name = kmalloc(name_len, GFP_NOFS);
1716	if (!name) {
1717		ret = -ENOMEM;
1718		goto out;
1719	}
1720
1721	log_type = btrfs_dir_type(eb, di);
1722	read_extent_buffer(eb, name, (unsigned long)(di + 1),
1723		   name_len);
1724
1725	btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1726	exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1727	if (exists == 0)
1728		exists = 1;
1729	else
1730		exists = 0;
1731	btrfs_release_path(path);
1732
1733	if (key->type == BTRFS_DIR_ITEM_KEY) {
1734		dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1735				       name, name_len, 1);
1736	} else if (key->type == BTRFS_DIR_INDEX_KEY) {
1737		dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1738						     key->objectid,
1739						     key->offset, name,
1740						     name_len, 1);
1741	} else {
1742		/* Corruption */
1743		ret = -EINVAL;
1744		goto out;
1745	}
1746	if (IS_ERR_OR_NULL(dst_di)) {
1747		/* we need a sequence number to insert, so we only
1748		 * do inserts for the BTRFS_DIR_INDEX_KEY types
1749		 */
1750		if (key->type != BTRFS_DIR_INDEX_KEY)
1751			goto out;
1752		goto insert;
1753	}
1754
1755	btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1756	/* the existing item matches the logged item */
1757	if (found_key.objectid == log_key.objectid &&
1758	    found_key.type == log_key.type &&
1759	    found_key.offset == log_key.offset &&
1760	    btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
1761		update_size = false;
1762		goto out;
1763	}
1764
1765	/*
1766	 * don't drop the conflicting directory entry if the inode
1767	 * for the new entry doesn't exist
1768	 */
1769	if (!exists)
1770		goto out;
1771
1772	ret = drop_one_dir_item(trans, root, path, dir, dst_di);
1773	if (ret)
1774		goto out;
1775
1776	if (key->type == BTRFS_DIR_INDEX_KEY)
1777		goto insert;
1778out:
1779	btrfs_release_path(path);
1780	if (!ret && update_size) {
1781		btrfs_i_size_write(dir, dir->i_size + name_len * 2);
1782		ret = btrfs_update_inode(trans, root, dir);
1783	}
1784	kfree(name);
1785	iput(dir);
1786	if (!ret && name_added)
1787		ret = 1;
1788	return ret;
1789
1790insert:
1791	if (name_in_log_ref(root->log_root, name, name_len,
1792			    key->objectid, log_key.objectid)) {
1793		/* The dentry will be added later. */
1794		ret = 0;
1795		update_size = false;
1796		goto out;
1797	}
1798	btrfs_release_path(path);
1799	ret = insert_one_name(trans, root, key->objectid, key->offset,
1800			      name, name_len, &log_key);
1801	if (ret && ret != -ENOENT && ret != -EEXIST)
1802		goto out;
1803	if (!ret)
1804		name_added = true;
1805	update_size = false;
1806	ret = 0;
1807	goto out;
1808}
1809
1810/*
1811 * find all the names in a directory item and reconcile them into
1812 * the subvolume.  Only BTRFS_DIR_ITEM_KEY types will have more than
1813 * one name in a directory item, but the same code gets used for
1814 * both directory index types
1815 */
1816static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
1817					struct btrfs_root *root,
1818					struct btrfs_path *path,
1819					struct extent_buffer *eb, int slot,
1820					struct btrfs_key *key)
1821{
1822	struct btrfs_fs_info *fs_info = root->fs_info;
1823	int ret = 0;
1824	u32 item_size = btrfs_item_size_nr(eb, slot);
1825	struct btrfs_dir_item *di;
1826	int name_len;
1827	unsigned long ptr;
1828	unsigned long ptr_end;
1829	struct btrfs_path *fixup_path = NULL;
1830
1831	ptr = btrfs_item_ptr_offset(eb, slot);
1832	ptr_end = ptr + item_size;
1833	while (ptr < ptr_end) {
1834		di = (struct btrfs_dir_item *)ptr;
1835		if (verify_dir_item(fs_info, eb, di))
1836			return -EIO;
1837		name_len = btrfs_dir_name_len(eb, di);
1838		ret = replay_one_name(trans, root, path, eb, di, key);
1839		if (ret < 0)
1840			break;
1841		ptr = (unsigned long)(di + 1);
1842		ptr += name_len;
1843
1844		/*
1845		 * If this entry refers to a non-directory (directories can not
1846		 * have a link count > 1) and it was added in the transaction
1847		 * that was not committed, make sure we fixup the link count of
1848		 * the inode it the entry points to. Otherwise something like
1849		 * the following would result in a directory pointing to an
1850		 * inode with a wrong link that does not account for this dir
1851		 * entry:
1852		 *
1853		 * mkdir testdir
1854		 * touch testdir/foo
1855		 * touch testdir/bar
1856		 * sync
1857		 *
1858		 * ln testdir/bar testdir/bar_link
1859		 * ln testdir/foo testdir/foo_link
1860		 * xfs_io -c "fsync" testdir/bar
1861		 *
1862		 * <power failure>
1863		 *
1864		 * mount fs, log replay happens
1865		 *
1866		 * File foo would remain with a link count of 1 when it has two
1867		 * entries pointing to it in the directory testdir. This would
1868		 * make it impossible to ever delete the parent directory has
1869		 * it would result in stale dentries that can never be deleted.
1870		 */
1871		if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) {
1872			struct btrfs_key di_key;
1873
1874			if (!fixup_path) {
1875				fixup_path = btrfs_alloc_path();
1876				if (!fixup_path) {
1877					ret = -ENOMEM;
1878					break;
1879				}
1880			}
1881
1882			btrfs_dir_item_key_to_cpu(eb, di, &di_key);
1883			ret = link_to_fixup_dir(trans, root, fixup_path,
1884						di_key.objectid);
1885			if (ret)
1886				break;
1887		}
1888		ret = 0;
1889	}
1890	btrfs_free_path(fixup_path);
1891	return ret;
1892}
1893
1894/*
1895 * directory replay has two parts.  There are the standard directory
1896 * items in the log copied from the subvolume, and range items
1897 * created in the log while the subvolume was logged.
1898 *
1899 * The range items tell us which parts of the key space the log
1900 * is authoritative for.  During replay, if a key in the subvolume
1901 * directory is in a logged range item, but not actually in the log
1902 * that means it was deleted from the directory before the fsync
1903 * and should be removed.
1904 */
1905static noinline int find_dir_range(struct btrfs_root *root,
1906				   struct btrfs_path *path,
1907				   u64 dirid, int key_type,
1908				   u64 *start_ret, u64 *end_ret)
1909{
1910	struct btrfs_key key;
1911	u64 found_end;
1912	struct btrfs_dir_log_item *item;
1913	int ret;
1914	int nritems;
1915
1916	if (*start_ret == (u64)-1)
1917		return 1;
1918
1919	key.objectid = dirid;
1920	key.type = key_type;
1921	key.offset = *start_ret;
1922
1923	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1924	if (ret < 0)
1925		goto out;
1926	if (ret > 0) {
1927		if (path->slots[0] == 0)
1928			goto out;
1929		path->slots[0]--;
1930	}
1931	if (ret != 0)
1932		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1933
1934	if (key.type != key_type || key.objectid != dirid) {
1935		ret = 1;
1936		goto next;
1937	}
1938	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1939			      struct btrfs_dir_log_item);
1940	found_end = btrfs_dir_log_end(path->nodes[0], item);
1941
1942	if (*start_ret >= key.offset && *start_ret <= found_end) {
1943		ret = 0;
1944		*start_ret = key.offset;
1945		*end_ret = found_end;
1946		goto out;
1947	}
1948	ret = 1;
1949next:
1950	/* check the next slot in the tree to see if it is a valid item */
1951	nritems = btrfs_header_nritems(path->nodes[0]);
1952	path->slots[0]++;
1953	if (path->slots[0] >= nritems) {
1954		ret = btrfs_next_leaf(root, path);
1955		if (ret)
1956			goto out;
1957	}
1958
1959	btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1960
1961	if (key.type != key_type || key.objectid != dirid) {
1962		ret = 1;
1963		goto out;
1964	}
1965	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1966			      struct btrfs_dir_log_item);
1967	found_end = btrfs_dir_log_end(path->nodes[0], item);
1968	*start_ret = key.offset;
1969	*end_ret = found_end;
1970	ret = 0;
1971out:
1972	btrfs_release_path(path);
1973	return ret;
1974}
1975
1976/*
1977 * this looks for a given directory item in the log.  If the directory
1978 * item is not in the log, the item is removed and the inode it points
1979 * to is unlinked
1980 */
1981static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
1982				      struct btrfs_root *root,
1983				      struct btrfs_root *log,
1984				      struct btrfs_path *path,
1985				      struct btrfs_path *log_path,
1986				      struct inode *dir,
1987				      struct btrfs_key *dir_key)
1988{
1989	struct btrfs_fs_info *fs_info = root->fs_info;
1990	int ret;
1991	struct extent_buffer *eb;
1992	int slot;
1993	u32 item_size;
1994	struct btrfs_dir_item *di;
1995	struct btrfs_dir_item *log_di;
1996	int name_len;
1997	unsigned long ptr;
1998	unsigned long ptr_end;
1999	char *name;
2000	struct inode *inode;
2001	struct btrfs_key location;
2002
2003again:
2004	eb = path->nodes[0];
2005	slot = path->slots[0];
2006	item_size = btrfs_item_size_nr(eb, slot);
2007	ptr = btrfs_item_ptr_offset(eb, slot);
2008	ptr_end = ptr + item_size;
2009	while (ptr < ptr_end) {
2010		di = (struct btrfs_dir_item *)ptr;
2011		if (verify_dir_item(fs_info, eb, di)) {
2012			ret = -EIO;
2013			goto out;
2014		}
2015
2016		name_len = btrfs_dir_name_len(eb, di);
2017		name = kmalloc(name_len, GFP_NOFS);
2018		if (!name) {
2019			ret = -ENOMEM;
2020			goto out;
2021		}
2022		read_extent_buffer(eb, name, (unsigned long)(di + 1),
2023				  name_len);
2024		log_di = NULL;
2025		if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
2026			log_di = btrfs_lookup_dir_item(trans, log, log_path,
2027						       dir_key->objectid,
2028						       name, name_len, 0);
2029		} else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
2030			log_di = btrfs_lookup_dir_index_item(trans, log,
2031						     log_path,
2032						     dir_key->objectid,
2033						     dir_key->offset,
2034						     name, name_len, 0);
2035		}
2036		if (!log_di || (IS_ERR(log_di) && PTR_ERR(log_di) == -ENOENT)) {
2037			btrfs_dir_item_key_to_cpu(eb, di, &location);
2038			btrfs_release_path(path);
2039			btrfs_release_path(log_path);
2040			inode = read_one_inode(root, location.objectid);
2041			if (!inode) {
2042				kfree(name);
2043				return -EIO;
2044			}
2045
2046			ret = link_to_fixup_dir(trans, root,
2047						path, location.objectid);
2048			if (ret) {
2049				kfree(name);
2050				iput(inode);
2051				goto out;
2052			}
2053
2054			inc_nlink(inode);
2055			ret = btrfs_unlink_inode(trans, root, dir, inode,
2056						 name, name_len);
2057			if (!ret)
2058				ret = btrfs_run_delayed_items(trans, fs_info);
2059			kfree(name);
2060			iput(inode);
2061			if (ret)
2062				goto out;
2063
2064			/* there might still be more names under this key
2065			 * check and repeat if required
2066			 */
2067			ret = btrfs_search_slot(NULL, root, dir_key, path,
2068						0, 0);
2069			if (ret == 0)
2070				goto again;
2071			ret = 0;
2072			goto out;
2073		} else if (IS_ERR(log_di)) {
2074			kfree(name);
2075			return PTR_ERR(log_di);
2076		}
2077		btrfs_release_path(log_path);
2078		kfree(name);
2079
2080		ptr = (unsigned long)(di + 1);
2081		ptr += name_len;
2082	}
2083	ret = 0;
2084out:
2085	btrfs_release_path(path);
2086	btrfs_release_path(log_path);
2087	return ret;
2088}
2089
2090static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
2091			      struct btrfs_root *root,
2092			      struct btrfs_root *log,
2093			      struct btrfs_path *path,
2094			      const u64 ino)
2095{
2096	struct btrfs_key search_key;
2097	struct btrfs_path *log_path;
2098	int i;
2099	int nritems;
2100	int ret;
2101
2102	log_path = btrfs_alloc_path();
2103	if (!log_path)
2104		return -ENOMEM;
2105
2106	search_key.objectid = ino;
2107	search_key.type = BTRFS_XATTR_ITEM_KEY;
2108	search_key.offset = 0;
2109again:
2110	ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
2111	if (ret < 0)
2112		goto out;
2113process_leaf:
2114	nritems = btrfs_header_nritems(path->nodes[0]);
2115	for (i = path->slots[0]; i < nritems; i++) {
2116		struct btrfs_key key;
2117		struct btrfs_dir_item *di;
2118		struct btrfs_dir_item *log_di;
2119		u32 total_size;
2120		u32 cur;
2121
2122		btrfs_item_key_to_cpu(path->nodes[0], &key, i);
2123		if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) {
2124			ret = 0;
2125			goto out;
2126		}
2127
2128		di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item);
2129		total_size = btrfs_item_size_nr(path->nodes[0], i);
2130		cur = 0;
2131		while (cur < total_size) {
2132			u16 name_len = btrfs_dir_name_len(path->nodes[0], di);
2133			u16 data_len = btrfs_dir_data_len(path->nodes[0], di);
2134			u32 this_len = sizeof(*di) + name_len + data_len;
2135			char *name;
2136
2137			name = kmalloc(name_len, GFP_NOFS);
2138			if (!name) {
2139				ret = -ENOMEM;
2140				goto out;
2141			}
2142			read_extent_buffer(path->nodes[0], name,
2143					   (unsigned long)(di + 1), name_len);
2144
2145			log_di = btrfs_lookup_xattr(NULL, log, log_path, ino,
2146						    name, name_len, 0);
2147			btrfs_release_path(log_path);
2148			if (!log_di) {
2149				/* Doesn't exist in log tree, so delete it. */
2150				btrfs_release_path(path);
2151				di = btrfs_lookup_xattr(trans, root, path, ino,
2152							name, name_len, -1);
2153				kfree(name);
2154				if (IS_ERR(di)) {
2155					ret = PTR_ERR(di);
2156					goto out;
2157				}
2158				ASSERT(di);
2159				ret = btrfs_delete_one_dir_name(trans, root,
2160								path, di);
2161				if (ret)
2162					goto out;
2163				btrfs_release_path(path);
2164				search_key = key;
2165				goto again;
2166			}
2167			kfree(name);
2168			if (IS_ERR(log_di)) {
2169				ret = PTR_ERR(log_di);
2170				goto out;
2171			}
2172			cur += this_len;
2173			di = (struct btrfs_dir_item *)((char *)di + this_len);
2174		}
2175	}
2176	ret = btrfs_next_leaf(root, path);
2177	if (ret > 0)
2178		ret = 0;
2179	else if (ret == 0)
2180		goto process_leaf;
2181out:
2182	btrfs_free_path(log_path);
2183	btrfs_release_path(path);
2184	return ret;
2185}
2186
2187
2188/*
2189 * deletion replay happens before we copy any new directory items
2190 * out of the log or out of backreferences from inodes.  It
2191 * scans the log to find ranges of keys that log is authoritative for,
2192 * and then scans the directory to find items in those ranges that are
2193 * not present in the log.
2194 *
2195 * Anything we don't find in the log is unlinked and removed from the
2196 * directory.
2197 */
2198static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
2199				       struct btrfs_root *root,
2200				       struct btrfs_root *log,
2201				       struct btrfs_path *path,
2202				       u64 dirid, int del_all)
2203{
2204	u64 range_start;
2205	u64 range_end;
2206	int key_type = BTRFS_DIR_LOG_ITEM_KEY;
2207	int ret = 0;
2208	struct btrfs_key dir_key;
2209	struct btrfs_key found_key;
2210	struct btrfs_path *log_path;
2211	struct inode *dir;
2212
2213	dir_key.objectid = dirid;
2214	dir_key.type = BTRFS_DIR_ITEM_KEY;
2215	log_path = btrfs_alloc_path();
2216	if (!log_path)
2217		return -ENOMEM;
2218
2219	dir = read_one_inode(root, dirid);
2220	/* it isn't an error if the inode isn't there, that can happen
2221	 * because we replay the deletes before we copy in the inode item
2222	 * from the log
2223	 */
2224	if (!dir) {
2225		btrfs_free_path(log_path);
2226		return 0;
2227	}
2228again:
2229	range_start = 0;
2230	range_end = 0;
2231	while (1) {
2232		if (del_all)
2233			range_end = (u64)-1;
2234		else {
2235			ret = find_dir_range(log, path, dirid, key_type,
2236					     &range_start, &range_end);
2237			if (ret != 0)
2238				break;
2239		}
2240
2241		dir_key.offset = range_start;
2242		while (1) {
2243			int nritems;
2244			ret = btrfs_search_slot(NULL, root, &dir_key, path,
2245						0, 0);
2246			if (ret < 0)
2247				goto out;
2248
2249			nritems = btrfs_header_nritems(path->nodes[0]);
2250			if (path->slots[0] >= nritems) {
2251				ret = btrfs_next_leaf(root, path);
2252				if (ret)
2253					break;
 
 
2254			}
2255			btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2256					      path->slots[0]);
2257			if (found_key.objectid != dirid ||
2258			    found_key.type != dir_key.type)
2259				goto next_type;
2260
2261			if (found_key.offset > range_end)
2262				break;
2263
2264			ret = check_item_in_log(trans, root, log, path,
2265						log_path, dir,
2266						&found_key);
2267			if (ret)
2268				goto out;
2269			if (found_key.offset == (u64)-1)
2270				break;
2271			dir_key.offset = found_key.offset + 1;
2272		}
2273		btrfs_release_path(path);
2274		if (range_end == (u64)-1)
2275			break;
2276		range_start = range_end + 1;
2277	}
2278
2279next_type:
2280	ret = 0;
2281	if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
2282		key_type = BTRFS_DIR_LOG_INDEX_KEY;
2283		dir_key.type = BTRFS_DIR_INDEX_KEY;
2284		btrfs_release_path(path);
2285		goto again;
2286	}
2287out:
2288	btrfs_release_path(path);
2289	btrfs_free_path(log_path);
2290	iput(dir);
2291	return ret;
2292}
2293
2294/*
2295 * the process_func used to replay items from the log tree.  This
2296 * gets called in two different stages.  The first stage just looks
2297 * for inodes and makes sure they are all copied into the subvolume.
2298 *
2299 * The second stage copies all the other item types from the log into
2300 * the subvolume.  The two stage approach is slower, but gets rid of
2301 * lots of complexity around inodes referencing other inodes that exist
2302 * only in the log (references come from either directory items or inode
2303 * back refs).
2304 */
2305static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
2306			     struct walk_control *wc, u64 gen)
2307{
2308	int nritems;
2309	struct btrfs_path *path;
2310	struct btrfs_root *root = wc->replay_dest;
2311	struct btrfs_key key;
2312	int level;
2313	int i;
2314	int ret;
2315
2316	ret = btrfs_read_buffer(eb, gen);
2317	if (ret)
2318		return ret;
2319
2320	level = btrfs_header_level(eb);
2321
2322	if (level != 0)
2323		return 0;
2324
2325	path = btrfs_alloc_path();
2326	if (!path)
2327		return -ENOMEM;
2328
2329	nritems = btrfs_header_nritems(eb);
2330	for (i = 0; i < nritems; i++) {
2331		btrfs_item_key_to_cpu(eb, &key, i);
2332
2333		/* inode keys are done during the first stage */
2334		if (key.type == BTRFS_INODE_ITEM_KEY &&
2335		    wc->stage == LOG_WALK_REPLAY_INODES) {
2336			struct btrfs_inode_item *inode_item;
2337			u32 mode;
2338
2339			inode_item = btrfs_item_ptr(eb, i,
2340					    struct btrfs_inode_item);
2341			ret = replay_xattr_deletes(wc->trans, root, log,
2342						   path, key.objectid);
2343			if (ret)
2344				break;
2345			mode = btrfs_inode_mode(eb, inode_item);
2346			if (S_ISDIR(mode)) {
2347				ret = replay_dir_deletes(wc->trans,
2348					 root, log, path, key.objectid, 0);
2349				if (ret)
2350					break;
2351			}
2352			ret = overwrite_item(wc->trans, root, path,
2353					     eb, i, &key);
2354			if (ret)
2355				break;
2356
2357			/* for regular files, make sure corresponding
2358			 * orphan item exist. extents past the new EOF
2359			 * will be truncated later by orphan cleanup.
 
 
 
 
2360			 */
2361			if (S_ISREG(mode)) {
2362				ret = insert_orphan_item(wc->trans, root,
2363							 key.objectid);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2364				if (ret)
2365					break;
2366			}
2367
2368			ret = link_to_fixup_dir(wc->trans, root,
2369						path, key.objectid);
2370			if (ret)
2371				break;
2372		}
2373
2374		if (key.type == BTRFS_DIR_INDEX_KEY &&
2375		    wc->stage == LOG_WALK_REPLAY_DIR_INDEX) {
2376			ret = replay_one_dir_item(wc->trans, root, path,
2377						  eb, i, &key);
2378			if (ret)
2379				break;
2380		}
2381
2382		if (wc->stage < LOG_WALK_REPLAY_ALL)
2383			continue;
2384
2385		/* these keys are simply copied */
2386		if (key.type == BTRFS_XATTR_ITEM_KEY) {
2387			ret = overwrite_item(wc->trans, root, path,
2388					     eb, i, &key);
2389			if (ret)
2390				break;
2391		} else if (key.type == BTRFS_INODE_REF_KEY ||
2392			   key.type == BTRFS_INODE_EXTREF_KEY) {
2393			ret = add_inode_ref(wc->trans, root, log, path,
2394					    eb, i, &key);
2395			if (ret && ret != -ENOENT)
2396				break;
2397			ret = 0;
2398		} else if (key.type == BTRFS_EXTENT_DATA_KEY) {
2399			ret = replay_one_extent(wc->trans, root, path,
2400						eb, i, &key);
2401			if (ret)
2402				break;
2403		} else if (key.type == BTRFS_DIR_ITEM_KEY) {
2404			ret = replay_one_dir_item(wc->trans, root, path,
2405						  eb, i, &key);
2406			if (ret)
2407				break;
2408		}
2409	}
2410	btrfs_free_path(path);
2411	return ret;
2412}
2413
2414static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
2415				   struct btrfs_root *root,
2416				   struct btrfs_path *path, int *level,
2417				   struct walk_control *wc)
2418{
2419	struct btrfs_fs_info *fs_info = root->fs_info;
2420	u64 root_owner;
2421	u64 bytenr;
2422	u64 ptr_gen;
2423	struct extent_buffer *next;
2424	struct extent_buffer *cur;
2425	struct extent_buffer *parent;
2426	u32 blocksize;
2427	int ret = 0;
2428
2429	WARN_ON(*level < 0);
2430	WARN_ON(*level >= BTRFS_MAX_LEVEL);
2431
2432	while (*level > 0) {
 
 
2433		WARN_ON(*level < 0);
2434		WARN_ON(*level >= BTRFS_MAX_LEVEL);
2435		cur = path->nodes[*level];
2436
2437		WARN_ON(btrfs_header_level(cur) != *level);
2438
2439		if (path->slots[*level] >=
2440		    btrfs_header_nritems(cur))
2441			break;
2442
2443		bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2444		ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
 
2445		blocksize = fs_info->nodesize;
2446
2447		parent = path->nodes[*level];
2448		root_owner = btrfs_header_owner(parent);
2449
2450		next = btrfs_find_create_tree_block(fs_info, bytenr);
2451		if (IS_ERR(next))
2452			return PTR_ERR(next);
2453
2454		if (*level == 1) {
2455			ret = wc->process_func(root, next, wc, ptr_gen);
 
2456			if (ret) {
2457				free_extent_buffer(next);
2458				return ret;
2459			}
2460
2461			path->slots[*level]++;
2462			if (wc->free) {
2463				ret = btrfs_read_buffer(next, ptr_gen);
 
2464				if (ret) {
2465					free_extent_buffer(next);
2466					return ret;
2467				}
2468
2469				if (trans) {
2470					btrfs_tree_lock(next);
2471					btrfs_set_lock_blocking(next);
2472					clean_tree_block(trans, fs_info, next);
2473					btrfs_wait_tree_block_writeback(next);
2474					btrfs_tree_unlock(next);
 
 
 
2475				}
2476
2477				WARN_ON(root_owner !=
2478					BTRFS_TREE_LOG_OBJECTID);
2479				ret = btrfs_free_and_pin_reserved_extent(
2480							fs_info, bytenr,
2481							blocksize);
2482				if (ret) {
2483					free_extent_buffer(next);
2484					return ret;
2485				}
2486			}
2487			free_extent_buffer(next);
2488			continue;
2489		}
2490		ret = btrfs_read_buffer(next, ptr_gen);
2491		if (ret) {
2492			free_extent_buffer(next);
2493			return ret;
2494		}
2495
2496		WARN_ON(*level <= 0);
2497		if (path->nodes[*level-1])
2498			free_extent_buffer(path->nodes[*level-1]);
2499		path->nodes[*level-1] = next;
2500		*level = btrfs_header_level(next);
2501		path->slots[*level] = 0;
2502		cond_resched();
2503	}
2504	WARN_ON(*level < 0);
2505	WARN_ON(*level >= BTRFS_MAX_LEVEL);
2506
2507	path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
2508
2509	cond_resched();
2510	return 0;
2511}
2512
2513static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
2514				 struct btrfs_root *root,
2515				 struct btrfs_path *path, int *level,
2516				 struct walk_control *wc)
2517{
2518	struct btrfs_fs_info *fs_info = root->fs_info;
2519	u64 root_owner;
2520	int i;
2521	int slot;
2522	int ret;
2523
2524	for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2525		slot = path->slots[i];
2526		if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
2527			path->slots[i]++;
2528			*level = i;
2529			WARN_ON(*level == 0);
2530			return 0;
2531		} else {
2532			struct extent_buffer *parent;
2533			if (path->nodes[*level] == root->node)
2534				parent = path->nodes[*level];
2535			else
2536				parent = path->nodes[*level + 1];
2537
2538			root_owner = btrfs_header_owner(parent);
2539			ret = wc->process_func(root, path->nodes[*level], wc,
2540				 btrfs_header_generation(path->nodes[*level]));
 
2541			if (ret)
2542				return ret;
2543
2544			if (wc->free) {
2545				struct extent_buffer *next;
2546
2547				next = path->nodes[*level];
2548
2549				if (trans) {
2550					btrfs_tree_lock(next);
2551					btrfs_set_lock_blocking(next);
2552					clean_tree_block(trans, fs_info, next);
2553					btrfs_wait_tree_block_writeback(next);
2554					btrfs_tree_unlock(next);
 
 
 
2555				}
2556
2557				WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
2558				ret = btrfs_free_and_pin_reserved_extent(
2559						fs_info,
2560						path->nodes[*level]->start,
2561						path->nodes[*level]->len);
2562				if (ret)
2563					return ret;
2564			}
2565			free_extent_buffer(path->nodes[*level]);
2566			path->nodes[*level] = NULL;
2567			*level = i + 1;
2568		}
2569	}
2570	return 1;
2571}
2572
2573/*
2574 * drop the reference count on the tree rooted at 'snap'.  This traverses
2575 * the tree freeing any blocks that have a ref count of zero after being
2576 * decremented.
2577 */
2578static int walk_log_tree(struct btrfs_trans_handle *trans,
2579			 struct btrfs_root *log, struct walk_control *wc)
2580{
2581	struct btrfs_fs_info *fs_info = log->fs_info;
2582	int ret = 0;
2583	int wret;
2584	int level;
2585	struct btrfs_path *path;
2586	int orig_level;
2587
2588	path = btrfs_alloc_path();
2589	if (!path)
2590		return -ENOMEM;
2591
2592	level = btrfs_header_level(log->node);
2593	orig_level = level;
2594	path->nodes[level] = log->node;
2595	extent_buffer_get(log->node);
2596	path->slots[level] = 0;
2597
2598	while (1) {
2599		wret = walk_down_log_tree(trans, log, path, &level, wc);
2600		if (wret > 0)
2601			break;
2602		if (wret < 0) {
2603			ret = wret;
2604			goto out;
2605		}
2606
2607		wret = walk_up_log_tree(trans, log, path, &level, wc);
2608		if (wret > 0)
2609			break;
2610		if (wret < 0) {
2611			ret = wret;
2612			goto out;
2613		}
2614	}
2615
2616	/* was the root node processed? if not, catch it here */
2617	if (path->nodes[orig_level]) {
2618		ret = wc->process_func(log, path->nodes[orig_level], wc,
2619			 btrfs_header_generation(path->nodes[orig_level]));
 
2620		if (ret)
2621			goto out;
2622		if (wc->free) {
2623			struct extent_buffer *next;
2624
2625			next = path->nodes[orig_level];
2626
2627			if (trans) {
2628				btrfs_tree_lock(next);
2629				btrfs_set_lock_blocking(next);
2630				clean_tree_block(trans, fs_info, next);
2631				btrfs_wait_tree_block_writeback(next);
2632				btrfs_tree_unlock(next);
 
 
 
2633			}
2634
2635			WARN_ON(log->root_key.objectid !=
2636				BTRFS_TREE_LOG_OBJECTID);
2637			ret = btrfs_free_and_pin_reserved_extent(fs_info,
2638							next->start, next->len);
2639			if (ret)
2640				goto out;
2641		}
2642	}
2643
2644out:
2645	btrfs_free_path(path);
2646	return ret;
2647}
2648
2649/*
2650 * helper function to update the item for a given subvolumes log root
2651 * in the tree of log roots
2652 */
2653static int update_log_root(struct btrfs_trans_handle *trans,
2654			   struct btrfs_root *log)
2655{
2656	struct btrfs_fs_info *fs_info = log->fs_info;
2657	int ret;
2658
2659	if (log->log_transid == 1) {
2660		/* insert root item on the first sync */
2661		ret = btrfs_insert_root(trans, fs_info->log_root_tree,
2662				&log->root_key, &log->root_item);
2663	} else {
2664		ret = btrfs_update_root(trans, fs_info->log_root_tree,
2665				&log->root_key, &log->root_item);
2666	}
2667	return ret;
2668}
2669
2670static void wait_log_commit(struct btrfs_root *root, int transid)
2671{
2672	DEFINE_WAIT(wait);
2673	int index = transid % 2;
2674
2675	/*
2676	 * we only allow two pending log transactions at a time,
2677	 * so we know that if ours is more than 2 older than the
2678	 * current transaction, we're done
2679	 */
2680	do {
2681		prepare_to_wait(&root->log_commit_wait[index],
2682				&wait, TASK_UNINTERRUPTIBLE);
2683		mutex_unlock(&root->log_mutex);
2684
2685		if (root->log_transid_committed < transid &&
2686		    atomic_read(&root->log_commit[index]))
2687			schedule();
2688
2689		finish_wait(&root->log_commit_wait[index], &wait);
 
2690		mutex_lock(&root->log_mutex);
2691	} while (root->log_transid_committed < transid &&
2692		 atomic_read(&root->log_commit[index]));
2693}
2694
2695static void wait_for_writer(struct btrfs_root *root)
2696{
2697	DEFINE_WAIT(wait);
2698
2699	while (atomic_read(&root->log_writers)) {
2700		prepare_to_wait(&root->log_writer_wait,
2701				&wait, TASK_UNINTERRUPTIBLE);
 
 
 
2702		mutex_unlock(&root->log_mutex);
2703		if (atomic_read(&root->log_writers))
2704			schedule();
2705		finish_wait(&root->log_writer_wait, &wait);
2706		mutex_lock(&root->log_mutex);
2707	}
 
2708}
2709
2710static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
2711					struct btrfs_log_ctx *ctx)
2712{
2713	if (!ctx)
2714		return;
2715
2716	mutex_lock(&root->log_mutex);
2717	list_del_init(&ctx->list);
2718	mutex_unlock(&root->log_mutex);
2719}
2720
2721/* 
2722 * Invoked in log mutex context, or be sure there is no other task which
2723 * can access the list.
2724 */
2725static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
2726					     int index, int error)
2727{
2728	struct btrfs_log_ctx *ctx;
2729	struct btrfs_log_ctx *safe;
2730
2731	list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
2732		list_del_init(&ctx->list);
2733		ctx->log_ret = error;
2734	}
2735
2736	INIT_LIST_HEAD(&root->log_ctxs[index]);
2737}
2738
2739/*
2740 * btrfs_sync_log does sends a given tree log down to the disk and
2741 * updates the super blocks to record it.  When this call is done,
2742 * you know that any inodes previously logged are safely on disk only
2743 * if it returns 0.
2744 *
2745 * Any other return value means you need to call btrfs_commit_transaction.
2746 * Some of the edge cases for fsyncing directories that have had unlinks
2747 * or renames done in the past mean that sometimes the only safe
2748 * fsync is to commit the whole FS.  When btrfs_sync_log returns -EAGAIN,
2749 * that has happened.
2750 */
2751int btrfs_sync_log(struct btrfs_trans_handle *trans,
2752		   struct btrfs_root *root, struct btrfs_log_ctx *ctx)
2753{
2754	int index1;
2755	int index2;
2756	int mark;
2757	int ret;
2758	struct btrfs_fs_info *fs_info = root->fs_info;
2759	struct btrfs_root *log = root->log_root;
2760	struct btrfs_root *log_root_tree = fs_info->log_root_tree;
2761	int log_transid = 0;
2762	struct btrfs_log_ctx root_log_ctx;
2763	struct blk_plug plug;
2764
2765	mutex_lock(&root->log_mutex);
2766	log_transid = ctx->log_transid;
2767	if (root->log_transid_committed >= log_transid) {
2768		mutex_unlock(&root->log_mutex);
2769		return ctx->log_ret;
2770	}
2771
2772	index1 = log_transid % 2;
2773	if (atomic_read(&root->log_commit[index1])) {
2774		wait_log_commit(root, log_transid);
2775		mutex_unlock(&root->log_mutex);
2776		return ctx->log_ret;
2777	}
2778	ASSERT(log_transid == root->log_transid);
2779	atomic_set(&root->log_commit[index1], 1);
2780
2781	/* wait for previous tree log sync to complete */
2782	if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
2783		wait_log_commit(root, log_transid - 1);
2784
2785	while (1) {
2786		int batch = atomic_read(&root->log_batch);
2787		/* when we're on an ssd, just kick the log commit out */
2788		if (!btrfs_test_opt(fs_info, SSD) &&
2789		    test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) {
2790			mutex_unlock(&root->log_mutex);
2791			schedule_timeout_uninterruptible(1);
2792			mutex_lock(&root->log_mutex);
2793		}
2794		wait_for_writer(root);
2795		if (batch == atomic_read(&root->log_batch))
2796			break;
2797	}
2798
2799	/* bail out if we need to do a full commit */
2800	if (btrfs_need_log_full_commit(fs_info, trans)) {
2801		ret = -EAGAIN;
2802		btrfs_free_logged_extents(log, log_transid);
2803		mutex_unlock(&root->log_mutex);
2804		goto out;
2805	}
2806
2807	if (log_transid % 2 == 0)
2808		mark = EXTENT_DIRTY;
2809	else
2810		mark = EXTENT_NEW;
2811
2812	/* we start IO on  all the marked extents here, but we don't actually
2813	 * wait for them until later.
2814	 */
2815	blk_start_plug(&plug);
2816	ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark);
2817	if (ret) {
2818		blk_finish_plug(&plug);
2819		btrfs_abort_transaction(trans, ret);
2820		btrfs_free_logged_extents(log, log_transid);
2821		btrfs_set_log_full_commit(fs_info, trans);
2822		mutex_unlock(&root->log_mutex);
2823		goto out;
2824	}
2825
2826	btrfs_set_root_node(&log->root_item, log->node);
2827
2828	root->log_transid++;
2829	log->log_transid = root->log_transid;
2830	root->log_start_pid = 0;
2831	/*
2832	 * IO has been started, blocks of the log tree have WRITTEN flag set
2833	 * in their headers. new modifications of the log will be written to
2834	 * new positions. so it's safe to allow log writers to go in.
2835	 */
2836	mutex_unlock(&root->log_mutex);
2837
2838	btrfs_init_log_ctx(&root_log_ctx, NULL);
2839
2840	mutex_lock(&log_root_tree->log_mutex);
2841	atomic_inc(&log_root_tree->log_batch);
2842	atomic_inc(&log_root_tree->log_writers);
2843
2844	index2 = log_root_tree->log_transid % 2;
2845	list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
2846	root_log_ctx.log_transid = log_root_tree->log_transid;
2847
2848	mutex_unlock(&log_root_tree->log_mutex);
2849
2850	ret = update_log_root(trans, log);
2851
2852	mutex_lock(&log_root_tree->log_mutex);
2853	if (atomic_dec_and_test(&log_root_tree->log_writers)) {
2854		/*
2855		 * Implicit memory barrier after atomic_dec_and_test
2856		 */
2857		if (waitqueue_active(&log_root_tree->log_writer_wait))
2858			wake_up(&log_root_tree->log_writer_wait);
2859	}
2860
2861	if (ret) {
2862		if (!list_empty(&root_log_ctx.list))
2863			list_del_init(&root_log_ctx.list);
2864
2865		blk_finish_plug(&plug);
2866		btrfs_set_log_full_commit(fs_info, trans);
2867
2868		if (ret != -ENOSPC) {
2869			btrfs_abort_transaction(trans, ret);
2870			mutex_unlock(&log_root_tree->log_mutex);
2871			goto out;
2872		}
2873		btrfs_wait_tree_log_extents(log, mark);
2874		btrfs_free_logged_extents(log, log_transid);
2875		mutex_unlock(&log_root_tree->log_mutex);
2876		ret = -EAGAIN;
2877		goto out;
2878	}
2879
2880	if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
2881		blk_finish_plug(&plug);
2882		list_del_init(&root_log_ctx.list);
2883		mutex_unlock(&log_root_tree->log_mutex);
2884		ret = root_log_ctx.log_ret;
2885		goto out;
2886	}
2887
2888	index2 = root_log_ctx.log_transid % 2;
2889	if (atomic_read(&log_root_tree->log_commit[index2])) {
2890		blk_finish_plug(&plug);
2891		ret = btrfs_wait_tree_log_extents(log, mark);
2892		btrfs_wait_logged_extents(trans, log, log_transid);
2893		wait_log_commit(log_root_tree,
2894				root_log_ctx.log_transid);
2895		mutex_unlock(&log_root_tree->log_mutex);
2896		if (!ret)
2897			ret = root_log_ctx.log_ret;
2898		goto out;
2899	}
2900	ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid);
2901	atomic_set(&log_root_tree->log_commit[index2], 1);
2902
2903	if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
2904		wait_log_commit(log_root_tree,
2905				root_log_ctx.log_transid - 1);
2906	}
2907
2908	wait_for_writer(log_root_tree);
2909
2910	/*
2911	 * now that we've moved on to the tree of log tree roots,
2912	 * check the full commit flag again
2913	 */
2914	if (btrfs_need_log_full_commit(fs_info, trans)) {
2915		blk_finish_plug(&plug);
2916		btrfs_wait_tree_log_extents(log, mark);
2917		btrfs_free_logged_extents(log, log_transid);
2918		mutex_unlock(&log_root_tree->log_mutex);
2919		ret = -EAGAIN;
2920		goto out_wake_log_root;
2921	}
2922
2923	ret = btrfs_write_marked_extents(fs_info,
2924					 &log_root_tree->dirty_log_pages,
2925					 EXTENT_DIRTY | EXTENT_NEW);
2926	blk_finish_plug(&plug);
2927	if (ret) {
2928		btrfs_set_log_full_commit(fs_info, trans);
2929		btrfs_abort_transaction(trans, ret);
2930		btrfs_free_logged_extents(log, log_transid);
2931		mutex_unlock(&log_root_tree->log_mutex);
2932		goto out_wake_log_root;
2933	}
2934	ret = btrfs_wait_tree_log_extents(log, mark);
2935	if (!ret)
2936		ret = btrfs_wait_tree_log_extents(log_root_tree,
2937						  EXTENT_NEW | EXTENT_DIRTY);
2938	if (ret) {
2939		btrfs_set_log_full_commit(fs_info, trans);
2940		btrfs_free_logged_extents(log, log_transid);
2941		mutex_unlock(&log_root_tree->log_mutex);
2942		goto out_wake_log_root;
2943	}
2944	btrfs_wait_logged_extents(trans, log, log_transid);
2945
2946	btrfs_set_super_log_root(fs_info->super_for_commit,
2947				 log_root_tree->node->start);
2948	btrfs_set_super_log_root_level(fs_info->super_for_commit,
2949				       btrfs_header_level(log_root_tree->node));
2950
2951	log_root_tree->log_transid++;
2952	mutex_unlock(&log_root_tree->log_mutex);
2953
2954	/*
2955	 * nobody else is going to jump in and write the the ctree
2956	 * super here because the log_commit atomic below is protecting
2957	 * us.  We must be called with a transaction handle pinning
2958	 * the running transaction open, so a full commit can't hop
2959	 * in and cause problems either.
2960	 */
2961	ret = write_ctree_super(trans, fs_info, 1);
2962	if (ret) {
2963		btrfs_set_log_full_commit(fs_info, trans);
2964		btrfs_abort_transaction(trans, ret);
2965		goto out_wake_log_root;
2966	}
2967
2968	mutex_lock(&root->log_mutex);
2969	if (root->last_log_commit < log_transid)
2970		root->last_log_commit = log_transid;
2971	mutex_unlock(&root->log_mutex);
2972
2973out_wake_log_root:
2974	mutex_lock(&log_root_tree->log_mutex);
2975	btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
2976
2977	log_root_tree->log_transid_committed++;
2978	atomic_set(&log_root_tree->log_commit[index2], 0);
2979	mutex_unlock(&log_root_tree->log_mutex);
2980
2981	/*
2982	 * The barrier before waitqueue_active is implied by mutex_unlock
2983	 */
2984	if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
2985		wake_up(&log_root_tree->log_commit_wait[index2]);
2986out:
2987	mutex_lock(&root->log_mutex);
2988	btrfs_remove_all_log_ctxs(root, index1, ret);
2989	root->log_transid_committed++;
2990	atomic_set(&root->log_commit[index1], 0);
2991	mutex_unlock(&root->log_mutex);
2992
2993	/*
2994	 * The barrier before waitqueue_active is implied by mutex_unlock
2995	 */
2996	if (waitqueue_active(&root->log_commit_wait[index1]))
2997		wake_up(&root->log_commit_wait[index1]);
2998	return ret;
2999}
3000
3001static void free_log_tree(struct btrfs_trans_handle *trans,
3002			  struct btrfs_root *log)
3003{
3004	int ret;
3005	u64 start;
3006	u64 end;
3007	struct walk_control wc = {
3008		.free = 1,
3009		.process_func = process_one_buffer
3010	};
3011
3012	ret = walk_log_tree(trans, log, &wc);
3013	/* I don't think this can happen but just in case */
3014	if (ret)
3015		btrfs_abort_transaction(trans, ret);
3016
3017	while (1) {
3018		ret = find_first_extent_bit(&log->dirty_log_pages,
3019				0, &start, &end, EXTENT_DIRTY | EXTENT_NEW,
 
3020				NULL);
3021		if (ret)
3022			break;
3023
3024		clear_extent_bits(&log->dirty_log_pages, start, end,
3025				  EXTENT_DIRTY | EXTENT_NEW);
3026	}
3027
3028	/*
3029	 * We may have short-circuited the log tree with the full commit logic
3030	 * and left ordered extents on our list, so clear these out to keep us
3031	 * from leaking inodes and memory.
3032	 */
3033	btrfs_free_logged_extents(log, 0);
3034	btrfs_free_logged_extents(log, 1);
3035
3036	free_extent_buffer(log->node);
3037	kfree(log);
3038}
3039
3040/*
3041 * free all the extents used by the tree log.  This should be called
3042 * at commit time of the full transaction
3043 */
3044int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
3045{
3046	if (root->log_root) {
3047		free_log_tree(trans, root->log_root);
3048		root->log_root = NULL;
3049	}
3050	return 0;
3051}
3052
3053int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
3054			     struct btrfs_fs_info *fs_info)
3055{
3056	if (fs_info->log_root_tree) {
3057		free_log_tree(trans, fs_info->log_root_tree);
3058		fs_info->log_root_tree = NULL;
3059	}
3060	return 0;
3061}
3062
3063/*
3064 * If both a file and directory are logged, and unlinks or renames are
3065 * mixed in, we have a few interesting corners:
3066 *
3067 * create file X in dir Y
3068 * link file X to X.link in dir Y
3069 * fsync file X
3070 * unlink file X but leave X.link
3071 * fsync dir Y
3072 *
3073 * After a crash we would expect only X.link to exist.  But file X
3074 * didn't get fsync'd again so the log has back refs for X and X.link.
3075 *
3076 * We solve this by removing directory entries and inode backrefs from the
3077 * log when a file that was logged in the current transaction is
3078 * unlinked.  Any later fsync will include the updated log entries, and
3079 * we'll be able to reconstruct the proper directory items from backrefs.
3080 *
3081 * This optimizations allows us to avoid relogging the entire inode
3082 * or the entire directory.
3083 */
3084int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
3085				 struct btrfs_root *root,
3086				 const char *name, int name_len,
3087				 struct inode *dir, u64 index)
3088{
3089	struct btrfs_root *log;
3090	struct btrfs_dir_item *di;
3091	struct btrfs_path *path;
3092	int ret;
3093	int err = 0;
3094	int bytes_del = 0;
3095	u64 dir_ino = btrfs_ino(dir);
3096
3097	if (BTRFS_I(dir)->logged_trans < trans->transid)
3098		return 0;
3099
3100	ret = join_running_log_trans(root);
3101	if (ret)
3102		return 0;
3103
3104	mutex_lock(&BTRFS_I(dir)->log_mutex);
3105
3106	log = root->log_root;
3107	path = btrfs_alloc_path();
3108	if (!path) {
3109		err = -ENOMEM;
3110		goto out_unlock;
3111	}
3112
3113	di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
3114				   name, name_len, -1);
3115	if (IS_ERR(di)) {
3116		err = PTR_ERR(di);
3117		goto fail;
3118	}
3119	if (di) {
3120		ret = btrfs_delete_one_dir_name(trans, log, path, di);
3121		bytes_del += name_len;
3122		if (ret) {
3123			err = ret;
3124			goto fail;
3125		}
3126	}
3127	btrfs_release_path(path);
3128	di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
3129					 index, name, name_len, -1);
3130	if (IS_ERR(di)) {
3131		err = PTR_ERR(di);
3132		goto fail;
3133	}
3134	if (di) {
3135		ret = btrfs_delete_one_dir_name(trans, log, path, di);
3136		bytes_del += name_len;
3137		if (ret) {
3138			err = ret;
3139			goto fail;
3140		}
3141	}
3142
3143	/* update the directory size in the log to reflect the names
3144	 * we have removed
3145	 */
3146	if (bytes_del) {
3147		struct btrfs_key key;
3148
3149		key.objectid = dir_ino;
3150		key.offset = 0;
3151		key.type = BTRFS_INODE_ITEM_KEY;
3152		btrfs_release_path(path);
3153
3154		ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
3155		if (ret < 0) {
3156			err = ret;
3157			goto fail;
3158		}
3159		if (ret == 0) {
3160			struct btrfs_inode_item *item;
3161			u64 i_size;
3162
3163			item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3164					      struct btrfs_inode_item);
3165			i_size = btrfs_inode_size(path->nodes[0], item);
3166			if (i_size > bytes_del)
3167				i_size -= bytes_del;
3168			else
3169				i_size = 0;
3170			btrfs_set_inode_size(path->nodes[0], item, i_size);
3171			btrfs_mark_buffer_dirty(path->nodes[0]);
3172		} else
3173			ret = 0;
3174		btrfs_release_path(path);
3175	}
3176fail:
3177	btrfs_free_path(path);
3178out_unlock:
3179	mutex_unlock(&BTRFS_I(dir)->log_mutex);
3180	if (ret == -ENOSPC) {
3181		btrfs_set_log_full_commit(root->fs_info, trans);
3182		ret = 0;
3183	} else if (ret < 0)
3184		btrfs_abort_transaction(trans, ret);
3185
3186	btrfs_end_log_trans(root);
3187
3188	return err;
3189}
3190
3191/* see comments for btrfs_del_dir_entries_in_log */
3192int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
3193			       struct btrfs_root *root,
3194			       const char *name, int name_len,
3195			       struct inode *inode, u64 dirid)
3196{
3197	struct btrfs_fs_info *fs_info = root->fs_info;
3198	struct btrfs_root *log;
3199	u64 index;
3200	int ret;
3201
3202	if (BTRFS_I(inode)->logged_trans < trans->transid)
3203		return 0;
3204
3205	ret = join_running_log_trans(root);
3206	if (ret)
3207		return 0;
3208	log = root->log_root;
3209	mutex_lock(&BTRFS_I(inode)->log_mutex);
3210
3211	ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
3212				  dirid, &index);
3213	mutex_unlock(&BTRFS_I(inode)->log_mutex);
3214	if (ret == -ENOSPC) {
3215		btrfs_set_log_full_commit(fs_info, trans);
3216		ret = 0;
3217	} else if (ret < 0 && ret != -ENOENT)
3218		btrfs_abort_transaction(trans, ret);
3219	btrfs_end_log_trans(root);
3220
3221	return ret;
3222}
3223
3224/*
3225 * creates a range item in the log for 'dirid'.  first_offset and
3226 * last_offset tell us which parts of the key space the log should
3227 * be considered authoritative for.
3228 */
3229static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
3230				       struct btrfs_root *log,
3231				       struct btrfs_path *path,
3232				       int key_type, u64 dirid,
3233				       u64 first_offset, u64 last_offset)
3234{
3235	int ret;
3236	struct btrfs_key key;
3237	struct btrfs_dir_log_item *item;
3238
3239	key.objectid = dirid;
3240	key.offset = first_offset;
3241	if (key_type == BTRFS_DIR_ITEM_KEY)
3242		key.type = BTRFS_DIR_LOG_ITEM_KEY;
3243	else
3244		key.type = BTRFS_DIR_LOG_INDEX_KEY;
3245	ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
3246	if (ret)
3247		return ret;
3248
3249	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3250			      struct btrfs_dir_log_item);
3251	btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
3252	btrfs_mark_buffer_dirty(path->nodes[0]);
3253	btrfs_release_path(path);
3254	return 0;
3255}
3256
3257/*
3258 * log all the items included in the current transaction for a given
3259 * directory.  This also creates the range items in the log tree required
3260 * to replay anything deleted before the fsync
3261 */
3262static noinline int log_dir_items(struct btrfs_trans_handle *trans,
3263			  struct btrfs_root *root, struct inode *inode,
3264			  struct btrfs_path *path,
3265			  struct btrfs_path *dst_path, int key_type,
3266			  struct btrfs_log_ctx *ctx,
3267			  u64 min_offset, u64 *last_offset_ret)
3268{
3269	struct btrfs_key min_key;
3270	struct btrfs_root *log = root->log_root;
3271	struct extent_buffer *src;
3272	int err = 0;
3273	int ret;
3274	int i;
3275	int nritems;
3276	u64 first_offset = min_offset;
3277	u64 last_offset = (u64)-1;
3278	u64 ino = btrfs_ino(inode);
3279
3280	log = root->log_root;
3281
3282	min_key.objectid = ino;
3283	min_key.type = key_type;
3284	min_key.offset = min_offset;
3285
3286	ret = btrfs_search_forward(root, &min_key, path, trans->transid);
3287
3288	/*
3289	 * we didn't find anything from this transaction, see if there
3290	 * is anything at all
3291	 */
3292	if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
3293		min_key.objectid = ino;
3294		min_key.type = key_type;
3295		min_key.offset = (u64)-1;
3296		btrfs_release_path(path);
3297		ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
3298		if (ret < 0) {
3299			btrfs_release_path(path);
3300			return ret;
3301		}
3302		ret = btrfs_previous_item(root, path, ino, key_type);
3303
3304		/* if ret == 0 there are items for this type,
3305		 * create a range to tell us the last key of this type.
3306		 * otherwise, there are no items in this directory after
3307		 * *min_offset, and we create a range to indicate that.
3308		 */
3309		if (ret == 0) {
3310			struct btrfs_key tmp;
3311			btrfs_item_key_to_cpu(path->nodes[0], &tmp,
3312					      path->slots[0]);
3313			if (key_type == tmp.type)
3314				first_offset = max(min_offset, tmp.offset) + 1;
3315		}
3316		goto done;
3317	}
3318
3319	/* go backward to find any previous key */
3320	ret = btrfs_previous_item(root, path, ino, key_type);
3321	if (ret == 0) {
3322		struct btrfs_key tmp;
3323		btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
3324		if (key_type == tmp.type) {
3325			first_offset = tmp.offset;
3326			ret = overwrite_item(trans, log, dst_path,
3327					     path->nodes[0], path->slots[0],
3328					     &tmp);
3329			if (ret) {
3330				err = ret;
3331				goto done;
3332			}
3333		}
3334	}
3335	btrfs_release_path(path);
3336
3337	/* find the first key from this transaction again */
3338	ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
3339	if (WARN_ON(ret != 0))
3340		goto done;
3341
3342	/*
3343	 * we have a block from this transaction, log every item in it
3344	 * from our directory
3345	 */
3346	while (1) {
3347		struct btrfs_key tmp;
3348		src = path->nodes[0];
3349		nritems = btrfs_header_nritems(src);
3350		for (i = path->slots[0]; i < nritems; i++) {
3351			struct btrfs_dir_item *di;
3352
3353			btrfs_item_key_to_cpu(src, &min_key, i);
3354
3355			if (min_key.objectid != ino || min_key.type != key_type)
3356				goto done;
3357			ret = overwrite_item(trans, log, dst_path, src, i,
3358					     &min_key);
3359			if (ret) {
3360				err = ret;
3361				goto done;
3362			}
3363
3364			/*
3365			 * We must make sure that when we log a directory entry,
3366			 * the corresponding inode, after log replay, has a
3367			 * matching link count. For example:
3368			 *
3369			 * touch foo
3370			 * mkdir mydir
3371			 * sync
3372			 * ln foo mydir/bar
3373			 * xfs_io -c "fsync" mydir
3374			 * <crash>
3375			 * <mount fs and log replay>
3376			 *
3377			 * Would result in a fsync log that when replayed, our
3378			 * file inode would have a link count of 1, but we get
3379			 * two directory entries pointing to the same inode.
3380			 * After removing one of the names, it would not be
3381			 * possible to remove the other name, which resulted
3382			 * always in stale file handle errors, and would not
3383			 * be possible to rmdir the parent directory, since
3384			 * its i_size could never decrement to the value
3385			 * BTRFS_EMPTY_DIR_SIZE, resulting in -ENOTEMPTY errors.
3386			 */
3387			di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
3388			btrfs_dir_item_key_to_cpu(src, di, &tmp);
3389			if (ctx &&
3390			    (btrfs_dir_transid(src, di) == trans->transid ||
3391			     btrfs_dir_type(src, di) == BTRFS_FT_DIR) &&
3392			    tmp.type != BTRFS_ROOT_ITEM_KEY)
3393				ctx->log_new_dentries = true;
3394		}
3395		path->slots[0] = nritems;
3396
3397		/*
3398		 * look ahead to the next item and see if it is also
3399		 * from this directory and from this transaction
3400		 */
3401		ret = btrfs_next_leaf(root, path);
3402		if (ret == 1) {
3403			last_offset = (u64)-1;
 
 
 
3404			goto done;
3405		}
3406		btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
3407		if (tmp.objectid != ino || tmp.type != key_type) {
3408			last_offset = (u64)-1;
3409			goto done;
3410		}
3411		if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
3412			ret = overwrite_item(trans, log, dst_path,
3413					     path->nodes[0], path->slots[0],
3414					     &tmp);
3415			if (ret)
3416				err = ret;
3417			else
3418				last_offset = tmp.offset;
3419			goto done;
3420		}
3421	}
3422done:
3423	btrfs_release_path(path);
3424	btrfs_release_path(dst_path);
3425
3426	if (err == 0) {
3427		*last_offset_ret = last_offset;
3428		/*
3429		 * insert the log range keys to indicate where the log
3430		 * is valid
3431		 */
3432		ret = insert_dir_log_key(trans, log, path, key_type,
3433					 ino, first_offset, last_offset);
3434		if (ret)
3435			err = ret;
3436	}
3437	return err;
3438}
3439
3440/*
3441 * logging directories is very similar to logging inodes, We find all the items
3442 * from the current transaction and write them to the log.
3443 *
3444 * The recovery code scans the directory in the subvolume, and if it finds a
3445 * key in the range logged that is not present in the log tree, then it means
3446 * that dir entry was unlinked during the transaction.
3447 *
3448 * In order for that scan to work, we must include one key smaller than
3449 * the smallest logged by this transaction and one key larger than the largest
3450 * key logged by this transaction.
3451 */
3452static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
3453			  struct btrfs_root *root, struct inode *inode,
3454			  struct btrfs_path *path,
3455			  struct btrfs_path *dst_path,
3456			  struct btrfs_log_ctx *ctx)
3457{
3458	u64 min_key;
3459	u64 max_key;
3460	int ret;
3461	int key_type = BTRFS_DIR_ITEM_KEY;
3462
3463again:
3464	min_key = 0;
3465	max_key = 0;
3466	while (1) {
3467		ret = log_dir_items(trans, root, inode, path,
3468				    dst_path, key_type, ctx, min_key,
3469				    &max_key);
3470		if (ret)
3471			return ret;
3472		if (max_key == (u64)-1)
3473			break;
3474		min_key = max_key + 1;
3475	}
3476
3477	if (key_type == BTRFS_DIR_ITEM_KEY) {
3478		key_type = BTRFS_DIR_INDEX_KEY;
3479		goto again;
3480	}
3481	return 0;
3482}
3483
3484/*
3485 * a helper function to drop items from the log before we relog an
3486 * inode.  max_key_type indicates the highest item type to remove.
3487 * This cannot be run for file data extents because it does not
3488 * free the extents they point to.
3489 */
3490static int drop_objectid_items(struct btrfs_trans_handle *trans,
3491				  struct btrfs_root *log,
3492				  struct btrfs_path *path,
3493				  u64 objectid, int max_key_type)
3494{
3495	int ret;
3496	struct btrfs_key key;
3497	struct btrfs_key found_key;
3498	int start_slot;
3499
3500	key.objectid = objectid;
3501	key.type = max_key_type;
3502	key.offset = (u64)-1;
3503
3504	while (1) {
3505		ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
3506		BUG_ON(ret == 0); /* Logic error */
3507		if (ret < 0)
3508			break;
3509
3510		if (path->slots[0] == 0)
3511			break;
3512
3513		path->slots[0]--;
3514		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
3515				      path->slots[0]);
3516
3517		if (found_key.objectid != objectid)
3518			break;
3519
3520		found_key.offset = 0;
3521		found_key.type = 0;
3522		ret = btrfs_bin_search(path->nodes[0], &found_key, 0,
3523				       &start_slot);
3524
3525		ret = btrfs_del_items(trans, log, path, start_slot,
3526				      path->slots[0] - start_slot + 1);
3527		/*
3528		 * If start slot isn't 0 then we don't need to re-search, we've
3529		 * found the last guy with the objectid in this tree.
3530		 */
3531		if (ret || start_slot != 0)
3532			break;
3533		btrfs_release_path(path);
3534	}
3535	btrfs_release_path(path);
3536	if (ret > 0)
3537		ret = 0;
3538	return ret;
3539}
3540
3541static void fill_inode_item(struct btrfs_trans_handle *trans,
3542			    struct extent_buffer *leaf,
3543			    struct btrfs_inode_item *item,
3544			    struct inode *inode, int log_inode_only,
3545			    u64 logged_isize)
3546{
3547	struct btrfs_map_token token;
3548
3549	btrfs_init_map_token(&token);
3550
3551	if (log_inode_only) {
3552		/* set the generation to zero so the recover code
3553		 * can tell the difference between an logging
3554		 * just to say 'this inode exists' and a logging
3555		 * to say 'update this inode with these values'
3556		 */
3557		btrfs_set_token_inode_generation(leaf, item, 0, &token);
3558		btrfs_set_token_inode_size(leaf, item, logged_isize, &token);
3559	} else {
3560		btrfs_set_token_inode_generation(leaf, item,
3561						 BTRFS_I(inode)->generation,
3562						 &token);
3563		btrfs_set_token_inode_size(leaf, item, inode->i_size, &token);
3564	}
3565
3566	btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3567	btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3568	btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3569	btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3570
3571	btrfs_set_token_timespec_sec(leaf, &item->atime,
3572				     inode->i_atime.tv_sec, &token);
3573	btrfs_set_token_timespec_nsec(leaf, &item->atime,
3574				      inode->i_atime.tv_nsec, &token);
3575
3576	btrfs_set_token_timespec_sec(leaf, &item->mtime,
3577				     inode->i_mtime.tv_sec, &token);
3578	btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3579				      inode->i_mtime.tv_nsec, &token);
3580
3581	btrfs_set_token_timespec_sec(leaf, &item->ctime,
3582				     inode->i_ctime.tv_sec, &token);
3583	btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3584				      inode->i_ctime.tv_nsec, &token);
3585
3586	btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3587				     &token);
3588
3589	btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
 
3590	btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3591	btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3592	btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3593	btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3594}
3595
3596static int log_inode_item(struct btrfs_trans_handle *trans,
3597			  struct btrfs_root *log, struct btrfs_path *path,
3598			  struct inode *inode)
3599{
3600	struct btrfs_inode_item *inode_item;
3601	int ret;
3602
3603	ret = btrfs_insert_empty_item(trans, log, path,
3604				      &BTRFS_I(inode)->location,
3605				      sizeof(*inode_item));
3606	if (ret && ret != -EEXIST)
3607		return ret;
3608	inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3609				    struct btrfs_inode_item);
3610	fill_inode_item(trans, path->nodes[0], inode_item, inode, 0, 0);
 
3611	btrfs_release_path(path);
3612	return 0;
3613}
3614
3615static noinline int copy_items(struct btrfs_trans_handle *trans,
3616			       struct inode *inode,
3617			       struct btrfs_path *dst_path,
3618			       struct btrfs_path *src_path, u64 *last_extent,
3619			       int start_slot, int nr, int inode_only,
3620			       u64 logged_isize)
3621{
3622	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3623	unsigned long src_offset;
3624	unsigned long dst_offset;
3625	struct btrfs_root *log = BTRFS_I(inode)->root->log_root;
3626	struct btrfs_file_extent_item *extent;
3627	struct btrfs_inode_item *inode_item;
3628	struct extent_buffer *src = src_path->nodes[0];
3629	struct btrfs_key first_key, last_key, key;
3630	int ret;
3631	struct btrfs_key *ins_keys;
3632	u32 *ins_sizes;
3633	char *ins_data;
3634	int i;
3635	struct list_head ordered_sums;
3636	int skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
3637	bool has_extents = false;
3638	bool need_find_last_extent = true;
3639	bool done = false;
3640
3641	INIT_LIST_HEAD(&ordered_sums);
3642
3643	ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
3644			   nr * sizeof(u32), GFP_NOFS);
3645	if (!ins_data)
3646		return -ENOMEM;
3647
3648	first_key.objectid = (u64)-1;
3649
3650	ins_sizes = (u32 *)ins_data;
3651	ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
3652
3653	for (i = 0; i < nr; i++) {
3654		ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
3655		btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
3656	}
3657	ret = btrfs_insert_empty_items(trans, log, dst_path,
3658				       ins_keys, ins_sizes, nr);
3659	if (ret) {
3660		kfree(ins_data);
3661		return ret;
3662	}
3663
3664	for (i = 0; i < nr; i++, dst_path->slots[0]++) {
3665		dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
3666						   dst_path->slots[0]);
3667
3668		src_offset = btrfs_item_ptr_offset(src, start_slot + i);
3669
3670		if ((i == (nr - 1)))
3671			last_key = ins_keys[i];
3672
3673		if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
3674			inode_item = btrfs_item_ptr(dst_path->nodes[0],
3675						    dst_path->slots[0],
3676						    struct btrfs_inode_item);
3677			fill_inode_item(trans, dst_path->nodes[0], inode_item,
3678					inode, inode_only == LOG_INODE_EXISTS,
 
3679					logged_isize);
3680		} else {
3681			copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
3682					   src_offset, ins_sizes[i]);
3683		}
3684
3685		/*
3686		 * We set need_find_last_extent here in case we know we were
3687		 * processing other items and then walk into the first extent in
3688		 * the inode.  If we don't hit an extent then nothing changes,
3689		 * we'll do the last search the next time around.
3690		 */
3691		if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY) {
3692			has_extents = true;
3693			if (first_key.objectid == (u64)-1)
3694				first_key = ins_keys[i];
3695		} else {
3696			need_find_last_extent = false;
3697		}
3698
3699		/* take a reference on file data extents so that truncates
3700		 * or deletes of this inode don't have to relog the inode
3701		 * again
3702		 */
3703		if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY &&
3704		    !skip_csum) {
3705			int found_type;
3706			extent = btrfs_item_ptr(src, start_slot + i,
3707						struct btrfs_file_extent_item);
3708
3709			if (btrfs_file_extent_generation(src, extent) < trans->transid)
3710				continue;
3711
3712			found_type = btrfs_file_extent_type(src, extent);
3713			if (found_type == BTRFS_FILE_EXTENT_REG) {
3714				u64 ds, dl, cs, cl;
3715				ds = btrfs_file_extent_disk_bytenr(src,
3716								extent);
3717				/* ds == 0 is a hole */
3718				if (ds == 0)
3719					continue;
3720
3721				dl = btrfs_file_extent_disk_num_bytes(src,
3722								extent);
3723				cs = btrfs_file_extent_offset(src, extent);
3724				cl = btrfs_file_extent_num_bytes(src,
3725								extent);
3726				if (btrfs_file_extent_compression(src,
3727								  extent)) {
3728					cs = 0;
3729					cl = dl;
3730				}
3731
3732				ret = btrfs_lookup_csums_range(
3733						fs_info->csum_root,
3734						ds + cs, ds + cs + cl - 1,
3735						&ordered_sums, 0);
3736				if (ret) {
3737					btrfs_release_path(dst_path);
3738					kfree(ins_data);
3739					return ret;
3740				}
3741			}
3742		}
3743	}
3744
3745	btrfs_mark_buffer_dirty(dst_path->nodes[0]);
3746	btrfs_release_path(dst_path);
3747	kfree(ins_data);
3748
3749	/*
3750	 * we have to do this after the loop above to avoid changing the
3751	 * log tree while trying to change the log tree.
3752	 */
3753	ret = 0;
3754	while (!list_empty(&ordered_sums)) {
3755		struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
3756						   struct btrfs_ordered_sum,
3757						   list);
3758		if (!ret)
3759			ret = btrfs_csum_file_blocks(trans, log, sums);
3760		list_del(&sums->list);
3761		kfree(sums);
3762	}
3763
3764	if (!has_extents)
3765		return ret;
3766
3767	if (need_find_last_extent && *last_extent == first_key.offset) {
3768		/*
3769		 * We don't have any leafs between our current one and the one
3770		 * we processed before that can have file extent items for our
3771		 * inode (and have a generation number smaller than our current
3772		 * transaction id).
3773		 */
3774		need_find_last_extent = false;
3775	}
3776
3777	/*
3778	 * Because we use btrfs_search_forward we could skip leaves that were
3779	 * not modified and then assume *last_extent is valid when it really
3780	 * isn't.  So back up to the previous leaf and read the end of the last
3781	 * extent before we go and fill in holes.
3782	 */
3783	if (need_find_last_extent) {
3784		u64 len;
3785
3786		ret = btrfs_prev_leaf(BTRFS_I(inode)->root, src_path);
3787		if (ret < 0)
3788			return ret;
3789		if (ret)
3790			goto fill_holes;
3791		if (src_path->slots[0])
3792			src_path->slots[0]--;
3793		src = src_path->nodes[0];
3794		btrfs_item_key_to_cpu(src, &key, src_path->slots[0]);
3795		if (key.objectid != btrfs_ino(inode) ||
3796		    key.type != BTRFS_EXTENT_DATA_KEY)
3797			goto fill_holes;
3798		extent = btrfs_item_ptr(src, src_path->slots[0],
3799					struct btrfs_file_extent_item);
3800		if (btrfs_file_extent_type(src, extent) ==
3801		    BTRFS_FILE_EXTENT_INLINE) {
3802			len = btrfs_file_extent_inline_len(src,
3803							   src_path->slots[0],
3804							   extent);
3805			*last_extent = ALIGN(key.offset + len,
3806					     fs_info->sectorsize);
3807		} else {
3808			len = btrfs_file_extent_num_bytes(src, extent);
3809			*last_extent = key.offset + len;
3810		}
3811	}
3812fill_holes:
3813	/* So we did prev_leaf, now we need to move to the next leaf, but a few
3814	 * things could have happened
3815	 *
3816	 * 1) A merge could have happened, so we could currently be on a leaf
3817	 * that holds what we were copying in the first place.
3818	 * 2) A split could have happened, and now not all of the items we want
3819	 * are on the same leaf.
3820	 *
3821	 * So we need to adjust how we search for holes, we need to drop the
3822	 * path and re-search for the first extent key we found, and then walk
3823	 * forward until we hit the last one we copied.
3824	 */
3825	if (need_find_last_extent) {
3826		/* btrfs_prev_leaf could return 1 without releasing the path */
3827		btrfs_release_path(src_path);
3828		ret = btrfs_search_slot(NULL, BTRFS_I(inode)->root, &first_key,
3829					src_path, 0, 0);
3830		if (ret < 0)
3831			return ret;
3832		ASSERT(ret == 0);
3833		src = src_path->nodes[0];
3834		i = src_path->slots[0];
3835	} else {
3836		i = start_slot;
3837	}
3838
3839	/*
3840	 * Ok so here we need to go through and fill in any holes we may have
3841	 * to make sure that holes are punched for those areas in case they had
3842	 * extents previously.
3843	 */
3844	while (!done) {
3845		u64 offset, len;
3846		u64 extent_end;
3847
3848		if (i >= btrfs_header_nritems(src_path->nodes[0])) {
3849			ret = btrfs_next_leaf(BTRFS_I(inode)->root, src_path);
3850			if (ret < 0)
3851				return ret;
3852			ASSERT(ret == 0);
3853			src = src_path->nodes[0];
3854			i = 0;
 
3855		}
3856
3857		btrfs_item_key_to_cpu(src, &key, i);
3858		if (!btrfs_comp_cpu_keys(&key, &last_key))
3859			done = true;
3860		if (key.objectid != btrfs_ino(inode) ||
3861		    key.type != BTRFS_EXTENT_DATA_KEY) {
3862			i++;
3863			continue;
3864		}
3865		extent = btrfs_item_ptr(src, i, struct btrfs_file_extent_item);
3866		if (btrfs_file_extent_type(src, extent) ==
3867		    BTRFS_FILE_EXTENT_INLINE) {
3868			len = btrfs_file_extent_inline_len(src, i, extent);
3869			extent_end = ALIGN(key.offset + len,
3870					   fs_info->sectorsize);
3871		} else {
3872			len = btrfs_file_extent_num_bytes(src, extent);
3873			extent_end = key.offset + len;
3874		}
3875		i++;
3876
3877		if (*last_extent == key.offset) {
3878			*last_extent = extent_end;
3879			continue;
3880		}
3881		offset = *last_extent;
3882		len = key.offset - *last_extent;
3883		ret = btrfs_insert_file_extent(trans, log, btrfs_ino(inode),
3884					       offset, 0, 0, len, 0, len, 0,
3885					       0, 0);
3886		if (ret)
3887			break;
3888		*last_extent = extent_end;
3889	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3890	/*
3891	 * Need to let the callers know we dropped the path so they should
3892	 * re-search.
3893	 */
3894	if (!ret && need_find_last_extent)
3895		ret = 1;
3896	return ret;
3897}
3898
3899static int extent_cmp(void *priv, struct list_head *a, struct list_head *b)
3900{
3901	struct extent_map *em1, *em2;
3902
3903	em1 = list_entry(a, struct extent_map, list);
3904	em2 = list_entry(b, struct extent_map, list);
3905
3906	if (em1->start < em2->start)
3907		return -1;
3908	else if (em1->start > em2->start)
3909		return 1;
3910	return 0;
3911}
3912
3913static int wait_ordered_extents(struct btrfs_trans_handle *trans,
3914				struct inode *inode,
3915				struct btrfs_root *root,
3916				const struct extent_map *em,
3917				const struct list_head *logged_list,
3918				bool *ordered_io_error)
3919{
3920	struct btrfs_fs_info *fs_info = root->fs_info;
3921	struct btrfs_ordered_extent *ordered;
3922	struct btrfs_root *log = root->log_root;
3923	u64 mod_start = em->mod_start;
3924	u64 mod_len = em->mod_len;
3925	const bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
3926	u64 csum_offset;
3927	u64 csum_len;
3928	LIST_HEAD(ordered_sums);
3929	int ret = 0;
3930
3931	*ordered_io_error = false;
3932
3933	if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
3934	    em->block_start == EXTENT_MAP_HOLE)
3935		return 0;
3936
3937	/*
3938	 * Wait far any ordered extent that covers our extent map. If it
3939	 * finishes without an error, first check and see if our csums are on
3940	 * our outstanding ordered extents.
3941	 */
3942	list_for_each_entry(ordered, logged_list, log_list) {
3943		struct btrfs_ordered_sum *sum;
3944
3945		if (!mod_len)
3946			break;
3947
3948		if (ordered->file_offset + ordered->len <= mod_start ||
3949		    mod_start + mod_len <= ordered->file_offset)
3950			continue;
3951
3952		if (!test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) &&
3953		    !test_bit(BTRFS_ORDERED_IOERR, &ordered->flags) &&
3954		    !test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) {
3955			const u64 start = ordered->file_offset;
3956			const u64 end = ordered->file_offset + ordered->len - 1;
3957
3958			WARN_ON(ordered->inode != inode);
3959			filemap_fdatawrite_range(inode->i_mapping, start, end);
3960		}
3961
3962		wait_event(ordered->wait,
3963			   (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags) ||
3964			    test_bit(BTRFS_ORDERED_IOERR, &ordered->flags)));
3965
3966		if (test_bit(BTRFS_ORDERED_IOERR, &ordered->flags)) {
3967			/*
3968			 * Clear the AS_EIO/AS_ENOSPC flags from the inode's
3969			 * i_mapping flags, so that the next fsync won't get
3970			 * an outdated io error too.
3971			 */
3972			filemap_check_errors(inode->i_mapping);
3973			*ordered_io_error = true;
3974			break;
3975		}
3976		/*
3977		 * We are going to copy all the csums on this ordered extent, so
3978		 * go ahead and adjust mod_start and mod_len in case this
3979		 * ordered extent has already been logged.
3980		 */
3981		if (ordered->file_offset > mod_start) {
3982			if (ordered->file_offset + ordered->len >=
3983			    mod_start + mod_len)
3984				mod_len = ordered->file_offset - mod_start;
3985			/*
3986			 * If we have this case
3987			 *
3988			 * |--------- logged extent ---------|
3989			 *       |----- ordered extent ----|
3990			 *
3991			 * Just don't mess with mod_start and mod_len, we'll
3992			 * just end up logging more csums than we need and it
3993			 * will be ok.
3994			 */
3995		} else {
3996			if (ordered->file_offset + ordered->len <
3997			    mod_start + mod_len) {
3998				mod_len = (mod_start + mod_len) -
3999					(ordered->file_offset + ordered->len);
4000				mod_start = ordered->file_offset +
4001					ordered->len;
4002			} else {
4003				mod_len = 0;
4004			}
4005		}
4006
4007		if (skip_csum)
4008			continue;
4009
4010		/*
4011		 * To keep us from looping for the above case of an ordered
4012		 * extent that falls inside of the logged extent.
4013		 */
4014		if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM,
4015				     &ordered->flags))
4016			continue;
4017
4018		list_for_each_entry(sum, &ordered->list, list) {
4019			ret = btrfs_csum_file_blocks(trans, log, sum);
4020			if (ret)
4021				break;
4022		}
4023	}
4024
4025	if (*ordered_io_error || !mod_len || ret || skip_csum)
4026		return ret;
4027
4028	if (em->compress_type) {
4029		csum_offset = 0;
4030		csum_len = max(em->block_len, em->orig_block_len);
4031	} else {
4032		csum_offset = mod_start - em->start;
4033		csum_len = mod_len;
4034	}
4035
4036	/* block start is already adjusted for the file extent offset. */
4037	ret = btrfs_lookup_csums_range(fs_info->csum_root,
4038				       em->block_start + csum_offset,
4039				       em->block_start + csum_offset +
4040				       csum_len - 1, &ordered_sums, 0);
4041	if (ret)
4042		return ret;
4043
4044	while (!list_empty(&ordered_sums)) {
4045		struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
4046						   struct btrfs_ordered_sum,
4047						   list);
4048		if (!ret)
4049			ret = btrfs_csum_file_blocks(trans, log, sums);
4050		list_del(&sums->list);
4051		kfree(sums);
4052	}
4053
4054	return ret;
4055}
4056
4057static int log_one_extent(struct btrfs_trans_handle *trans,
4058			  struct inode *inode, struct btrfs_root *root,
4059			  const struct extent_map *em,
4060			  struct btrfs_path *path,
4061			  const struct list_head *logged_list,
4062			  struct btrfs_log_ctx *ctx)
4063{
4064	struct btrfs_root *log = root->log_root;
4065	struct btrfs_file_extent_item *fi;
4066	struct extent_buffer *leaf;
4067	struct btrfs_map_token token;
4068	struct btrfs_key key;
4069	u64 extent_offset = em->start - em->orig_start;
4070	u64 block_len;
4071	int ret;
4072	int extent_inserted = 0;
4073	bool ordered_io_err = false;
4074
4075	ret = wait_ordered_extents(trans, inode, root, em, logged_list,
4076				   &ordered_io_err);
4077	if (ret)
4078		return ret;
4079
4080	if (ordered_io_err) {
4081		ctx->io_err = -EIO;
4082		return 0;
4083	}
4084
4085	btrfs_init_map_token(&token);
4086
4087	ret = __btrfs_drop_extents(trans, log, inode, path, em->start,
4088				   em->start + em->len, NULL, 0, 1,
4089				   sizeof(*fi), &extent_inserted);
4090	if (ret)
4091		return ret;
4092
4093	if (!extent_inserted) {
4094		key.objectid = btrfs_ino(inode);
4095		key.type = BTRFS_EXTENT_DATA_KEY;
4096		key.offset = em->start;
4097
4098		ret = btrfs_insert_empty_item(trans, log, path, &key,
4099					      sizeof(*fi));
4100		if (ret)
4101			return ret;
4102	}
4103	leaf = path->nodes[0];
4104	fi = btrfs_item_ptr(leaf, path->slots[0],
4105			    struct btrfs_file_extent_item);
4106
4107	btrfs_set_token_file_extent_generation(leaf, fi, trans->transid,
4108					       &token);
4109	if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4110		btrfs_set_token_file_extent_type(leaf, fi,
4111						 BTRFS_FILE_EXTENT_PREALLOC,
4112						 &token);
4113	else
4114		btrfs_set_token_file_extent_type(leaf, fi,
4115						 BTRFS_FILE_EXTENT_REG,
4116						 &token);
4117
4118	block_len = max(em->block_len, em->orig_block_len);
4119	if (em->compress_type != BTRFS_COMPRESS_NONE) {
4120		btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
4121							em->block_start,
4122							&token);
4123		btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
4124							   &token);
4125	} else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
4126		btrfs_set_token_file_extent_disk_bytenr(leaf, fi,
4127							em->block_start -
4128							extent_offset, &token);
4129		btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, block_len,
4130							   &token);
4131	} else {
4132		btrfs_set_token_file_extent_disk_bytenr(leaf, fi, 0, &token);
4133		btrfs_set_token_file_extent_disk_num_bytes(leaf, fi, 0,
4134							   &token);
4135	}
4136
4137	btrfs_set_token_file_extent_offset(leaf, fi, extent_offset, &token);
4138	btrfs_set_token_file_extent_num_bytes(leaf, fi, em->len, &token);
4139	btrfs_set_token_file_extent_ram_bytes(leaf, fi, em->ram_bytes, &token);
4140	btrfs_set_token_file_extent_compression(leaf, fi, em->compress_type,
4141						&token);
4142	btrfs_set_token_file_extent_encryption(leaf, fi, 0, &token);
4143	btrfs_set_token_file_extent_other_encoding(leaf, fi, 0, &token);
4144	btrfs_mark_buffer_dirty(leaf);
4145
4146	btrfs_release_path(path);
4147
4148	return ret;
4149}
4150
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4151static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
4152				     struct btrfs_root *root,
4153				     struct inode *inode,
4154				     struct btrfs_path *path,
4155				     struct list_head *logged_list,
4156				     struct btrfs_log_ctx *ctx,
4157				     const u64 start,
4158				     const u64 end)
4159{
4160	struct extent_map *em, *n;
4161	struct list_head extents;
4162	struct extent_map_tree *tree = &BTRFS_I(inode)->extent_tree;
 
4163	u64 test_gen;
4164	int ret = 0;
4165	int num = 0;
4166
4167	INIT_LIST_HEAD(&extents);
4168
4169	down_write(&BTRFS_I(inode)->dio_sem);
4170	write_lock(&tree->lock);
4171	test_gen = root->fs_info->last_trans_committed;
 
 
4172
4173	list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
4174		list_del_init(&em->list);
4175
4176		/*
4177		 * Just an arbitrary number, this can be really CPU intensive
4178		 * once we start getting a lot of extents, and really once we
4179		 * have a bunch of extents we just want to commit since it will
4180		 * be faster.
4181		 */
4182		if (++num > 32768) {
4183			list_del_init(&tree->modified_extents);
4184			ret = -EFBIG;
4185			goto process;
4186		}
4187
4188		if (em->generation <= test_gen)
4189			continue;
 
 
 
 
 
 
 
 
 
 
 
4190		/* Need a ref to keep it from getting evicted from cache */
4191		atomic_inc(&em->refs);
4192		set_bit(EXTENT_FLAG_LOGGING, &em->flags);
4193		list_add_tail(&em->list, &extents);
4194		num++;
4195	}
4196
4197	list_sort(NULL, &extents, extent_cmp);
4198	btrfs_get_logged_extents(inode, logged_list, start, end);
4199	/*
4200	 * Some ordered extents started by fsync might have completed
4201	 * before we could collect them into the list logged_list, which
4202	 * means they're gone, not in our logged_list nor in the inode's
4203	 * ordered tree. We want the application/user space to know an
4204	 * error happened while attempting to persist file data so that
4205	 * it can take proper action. If such error happened, we leave
4206	 * without writing to the log tree and the fsync must report the
4207	 * file data write error and not commit the current transaction.
4208	 */
4209	ret = filemap_check_errors(inode->i_mapping);
4210	if (ret)
4211		ctx->io_err = ret;
4212process:
4213	while (!list_empty(&extents)) {
4214		em = list_entry(extents.next, struct extent_map, list);
4215
4216		list_del_init(&em->list);
4217
4218		/*
4219		 * If we had an error we just need to delete everybody from our
4220		 * private list.
4221		 */
4222		if (ret) {
4223			clear_em_logging(tree, em);
4224			free_extent_map(em);
4225			continue;
4226		}
4227
4228		write_unlock(&tree->lock);
4229
4230		ret = log_one_extent(trans, inode, root, em, path, logged_list,
4231				     ctx);
4232		write_lock(&tree->lock);
4233		clear_em_logging(tree, em);
4234		free_extent_map(em);
4235	}
4236	WARN_ON(!list_empty(&extents));
4237	write_unlock(&tree->lock);
4238	up_write(&BTRFS_I(inode)->dio_sem);
4239
4240	btrfs_release_path(path);
 
 
 
4241	return ret;
4242}
4243
4244static int logged_inode_size(struct btrfs_root *log, struct inode *inode,
4245			     struct btrfs_path *path, u64 *size_ret)
4246{
4247	struct btrfs_key key;
4248	int ret;
4249
4250	key.objectid = btrfs_ino(inode);
4251	key.type = BTRFS_INODE_ITEM_KEY;
4252	key.offset = 0;
4253
4254	ret = btrfs_search_slot(NULL, log, &key, path, 0, 0);
4255	if (ret < 0) {
4256		return ret;
4257	} else if (ret > 0) {
4258		*size_ret = 0;
4259	} else {
4260		struct btrfs_inode_item *item;
4261
4262		item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4263				      struct btrfs_inode_item);
4264		*size_ret = btrfs_inode_size(path->nodes[0], item);
4265	}
4266
4267	btrfs_release_path(path);
4268	return 0;
4269}
4270
4271/*
4272 * At the moment we always log all xattrs. This is to figure out at log replay
4273 * time which xattrs must have their deletion replayed. If a xattr is missing
4274 * in the log tree and exists in the fs/subvol tree, we delete it. This is
4275 * because if a xattr is deleted, the inode is fsynced and a power failure
4276 * happens, causing the log to be replayed the next time the fs is mounted,
4277 * we want the xattr to not exist anymore (same behaviour as other filesystems
4278 * with a journal, ext3/4, xfs, f2fs, etc).
4279 */
4280static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
4281				struct btrfs_root *root,
4282				struct inode *inode,
4283				struct btrfs_path *path,
4284				struct btrfs_path *dst_path)
4285{
4286	int ret;
4287	struct btrfs_key key;
4288	const u64 ino = btrfs_ino(inode);
4289	int ins_nr = 0;
4290	int start_slot = 0;
4291
4292	key.objectid = ino;
4293	key.type = BTRFS_XATTR_ITEM_KEY;
4294	key.offset = 0;
4295
4296	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4297	if (ret < 0)
4298		return ret;
4299
4300	while (true) {
4301		int slot = path->slots[0];
4302		struct extent_buffer *leaf = path->nodes[0];
4303		int nritems = btrfs_header_nritems(leaf);
4304
4305		if (slot >= nritems) {
4306			if (ins_nr > 0) {
4307				u64 last_extent = 0;
4308
4309				ret = copy_items(trans, inode, dst_path, path,
4310						 &last_extent, start_slot,
4311						 ins_nr, 1, 0);
4312				/* can't be 1, extent items aren't processed */
4313				ASSERT(ret <= 0);
4314				if (ret < 0)
4315					return ret;
4316				ins_nr = 0;
4317			}
4318			ret = btrfs_next_leaf(root, path);
4319			if (ret < 0)
4320				return ret;
4321			else if (ret > 0)
4322				break;
4323			continue;
4324		}
4325
4326		btrfs_item_key_to_cpu(leaf, &key, slot);
4327		if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
4328			break;
4329
4330		if (ins_nr == 0)
4331			start_slot = slot;
4332		ins_nr++;
4333		path->slots[0]++;
4334		cond_resched();
4335	}
4336	if (ins_nr > 0) {
4337		u64 last_extent = 0;
4338
4339		ret = copy_items(trans, inode, dst_path, path,
4340				 &last_extent, start_slot,
4341				 ins_nr, 1, 0);
4342		/* can't be 1, extent items aren't processed */
4343		ASSERT(ret <= 0);
4344		if (ret < 0)
4345			return ret;
4346	}
4347
4348	return 0;
4349}
4350
4351/*
4352 * If the no holes feature is enabled we need to make sure any hole between the
4353 * last extent and the i_size of our inode is explicitly marked in the log. This
4354 * is to make sure that doing something like:
4355 *
4356 *      1) create file with 128Kb of data
4357 *      2) truncate file to 64Kb
4358 *      3) truncate file to 256Kb
4359 *      4) fsync file
4360 *      5) <crash/power failure>
4361 *      6) mount fs and trigger log replay
4362 *
4363 * Will give us a file with a size of 256Kb, the first 64Kb of data match what
4364 * the file had in its first 64Kb of data at step 1 and the last 192Kb of the
4365 * file correspond to a hole. The presence of explicit holes in a log tree is
4366 * what guarantees that log replay will remove/adjust file extent items in the
4367 * fs/subvol tree.
4368 *
4369 * Here we do not need to care about holes between extents, that is already done
4370 * by copy_items(). We also only need to do this in the full sync path, where we
4371 * lookup for extents from the fs/subvol tree only. In the fast path case, we
4372 * lookup the list of modified extent maps and if any represents a hole, we
4373 * insert a corresponding extent representing a hole in the log tree.
4374 */
4375static int btrfs_log_trailing_hole(struct btrfs_trans_handle *trans,
4376				   struct btrfs_root *root,
4377				   struct inode *inode,
4378				   struct btrfs_path *path)
4379{
4380	struct btrfs_fs_info *fs_info = root->fs_info;
4381	int ret;
4382	struct btrfs_key key;
4383	u64 hole_start;
4384	u64 hole_size;
4385	struct extent_buffer *leaf;
4386	struct btrfs_root *log = root->log_root;
4387	const u64 ino = btrfs_ino(inode);
4388	const u64 i_size = i_size_read(inode);
4389
4390	if (!btrfs_fs_incompat(fs_info, NO_HOLES))
4391		return 0;
4392
4393	key.objectid = ino;
4394	key.type = BTRFS_EXTENT_DATA_KEY;
4395	key.offset = (u64)-1;
4396
4397	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4398	ASSERT(ret != 0);
4399	if (ret < 0)
4400		return ret;
4401
4402	ASSERT(path->slots[0] > 0);
4403	path->slots[0]--;
4404	leaf = path->nodes[0];
4405	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4406
4407	if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY) {
4408		/* inode does not have any extents */
4409		hole_start = 0;
4410		hole_size = i_size;
4411	} else {
4412		struct btrfs_file_extent_item *extent;
4413		u64 len;
4414
4415		/*
4416		 * If there's an extent beyond i_size, an explicit hole was
4417		 * already inserted by copy_items().
4418		 */
4419		if (key.offset >= i_size)
4420			return 0;
4421
4422		extent = btrfs_item_ptr(leaf, path->slots[0],
4423					struct btrfs_file_extent_item);
4424
4425		if (btrfs_file_extent_type(leaf, extent) ==
4426		    BTRFS_FILE_EXTENT_INLINE) {
4427			len = btrfs_file_extent_inline_len(leaf,
4428							   path->slots[0],
4429							   extent);
4430			ASSERT(len == i_size);
 
 
 
4431			return 0;
4432		}
4433
4434		len = btrfs_file_extent_num_bytes(leaf, extent);
4435		/* Last extent goes beyond i_size, no need to log a hole. */
4436		if (key.offset + len > i_size)
4437			return 0;
4438		hole_start = key.offset + len;
4439		hole_size = i_size - hole_start;
4440	}
4441	btrfs_release_path(path);
4442
4443	/* Last extent ends at i_size. */
4444	if (hole_size == 0)
4445		return 0;
4446
4447	hole_size = ALIGN(hole_size, fs_info->sectorsize);
4448	ret = btrfs_insert_file_extent(trans, log, ino, hole_start, 0, 0,
4449				       hole_size, 0, hole_size, 0, 0, 0);
4450	return ret;
4451}
4452
4453/*
4454 * When we are logging a new inode X, check if it doesn't have a reference that
4455 * matches the reference from some other inode Y created in a past transaction
4456 * and that was renamed in the current transaction. If we don't do this, then at
4457 * log replay time we can lose inode Y (and all its files if it's a directory):
4458 *
4459 * mkdir /mnt/x
4460 * echo "hello world" > /mnt/x/foobar
4461 * sync
4462 * mv /mnt/x /mnt/y
4463 * mkdir /mnt/x                 # or touch /mnt/x
4464 * xfs_io -c fsync /mnt/x
4465 * <power fail>
4466 * mount fs, trigger log replay
4467 *
4468 * After the log replay procedure, we would lose the first directory and all its
4469 * files (file foobar).
4470 * For the case where inode Y is not a directory we simply end up losing it:
4471 *
4472 * echo "123" > /mnt/foo
4473 * sync
4474 * mv /mnt/foo /mnt/bar
4475 * echo "abc" > /mnt/foo
4476 * xfs_io -c fsync /mnt/foo
4477 * <power fail>
4478 *
4479 * We also need this for cases where a snapshot entry is replaced by some other
4480 * entry (file or directory) otherwise we end up with an unreplayable log due to
4481 * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
4482 * if it were a regular entry:
4483 *
4484 * mkdir /mnt/x
4485 * btrfs subvolume snapshot /mnt /mnt/x/snap
4486 * btrfs subvolume delete /mnt/x/snap
4487 * rmdir /mnt/x
4488 * mkdir /mnt/x
4489 * fsync /mnt/x or fsync some new file inside it
4490 * <power fail>
4491 *
4492 * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
4493 * the same transaction.
4494 */
4495static int btrfs_check_ref_name_override(struct extent_buffer *eb,
4496					 const int slot,
4497					 const struct btrfs_key *key,
4498					 struct inode *inode,
4499					 u64 *other_ino)
4500{
4501	int ret;
4502	struct btrfs_path *search_path;
4503	char *name = NULL;
4504	u32 name_len = 0;
4505	u32 item_size = btrfs_item_size_nr(eb, slot);
4506	u32 cur_offset = 0;
4507	unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
4508
4509	search_path = btrfs_alloc_path();
4510	if (!search_path)
4511		return -ENOMEM;
4512	search_path->search_commit_root = 1;
4513	search_path->skip_locking = 1;
4514
4515	while (cur_offset < item_size) {
4516		u64 parent;
4517		u32 this_name_len;
4518		u32 this_len;
4519		unsigned long name_ptr;
4520		struct btrfs_dir_item *di;
4521
4522		if (key->type == BTRFS_INODE_REF_KEY) {
4523			struct btrfs_inode_ref *iref;
4524
4525			iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
4526			parent = key->offset;
4527			this_name_len = btrfs_inode_ref_name_len(eb, iref);
4528			name_ptr = (unsigned long)(iref + 1);
4529			this_len = sizeof(*iref) + this_name_len;
4530		} else {
4531			struct btrfs_inode_extref *extref;
4532
4533			extref = (struct btrfs_inode_extref *)(ptr +
4534							       cur_offset);
4535			parent = btrfs_inode_extref_parent(eb, extref);
4536			this_name_len = btrfs_inode_extref_name_len(eb, extref);
4537			name_ptr = (unsigned long)&extref->name;
4538			this_len = sizeof(*extref) + this_name_len;
4539		}
4540
4541		if (this_name_len > name_len) {
4542			char *new_name;
4543
4544			new_name = krealloc(name, this_name_len, GFP_NOFS);
4545			if (!new_name) {
4546				ret = -ENOMEM;
4547				goto out;
4548			}
4549			name_len = this_name_len;
4550			name = new_name;
4551		}
4552
4553		read_extent_buffer(eb, name, name_ptr, this_name_len);
4554		di = btrfs_lookup_dir_item(NULL, BTRFS_I(inode)->root,
4555					   search_path, parent,
4556					   name, this_name_len, 0);
4557		if (di && !IS_ERR(di)) {
4558			struct btrfs_key di_key;
4559
4560			btrfs_dir_item_key_to_cpu(search_path->nodes[0],
4561						  di, &di_key);
4562			if (di_key.type == BTRFS_INODE_ITEM_KEY) {
4563				ret = 1;
4564				*other_ino = di_key.objectid;
4565			} else {
4566				ret = -EAGAIN;
4567			}
4568			goto out;
4569		} else if (IS_ERR(di)) {
4570			ret = PTR_ERR(di);
4571			goto out;
4572		}
4573		btrfs_release_path(search_path);
4574
4575		cur_offset += this_len;
4576	}
4577	ret = 0;
4578out:
4579	btrfs_free_path(search_path);
4580	kfree(name);
4581	return ret;
4582}
4583
4584/* log a single inode in the tree log.
4585 * At least one parent directory for this inode must exist in the tree
4586 * or be logged already.
4587 *
4588 * Any items from this inode changed by the current transaction are copied
4589 * to the log tree.  An extra reference is taken on any extents in this
4590 * file, allowing us to avoid a whole pile of corner cases around logging
4591 * blocks that have been removed from the tree.
4592 *
4593 * See LOG_INODE_ALL and related defines for a description of what inode_only
4594 * does.
4595 *
4596 * This handles both files and directories.
4597 */
4598static int btrfs_log_inode(struct btrfs_trans_handle *trans,
4599			   struct btrfs_root *root, struct inode *inode,
4600			   int inode_only,
4601			   const loff_t start,
4602			   const loff_t end,
4603			   struct btrfs_log_ctx *ctx)
4604{
4605	struct btrfs_fs_info *fs_info = root->fs_info;
4606	struct btrfs_path *path;
4607	struct btrfs_path *dst_path;
4608	struct btrfs_key min_key;
4609	struct btrfs_key max_key;
4610	struct btrfs_root *log = root->log_root;
4611	struct extent_buffer *src = NULL;
4612	LIST_HEAD(logged_list);
4613	u64 last_extent = 0;
4614	int err = 0;
4615	int ret;
4616	int nritems;
4617	int ins_start_slot = 0;
4618	int ins_nr;
4619	bool fast_search = false;
4620	u64 ino = btrfs_ino(inode);
4621	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4622	u64 logged_isize = 0;
4623	bool need_log_inode_item = true;
 
4624
4625	path = btrfs_alloc_path();
4626	if (!path)
4627		return -ENOMEM;
4628	dst_path = btrfs_alloc_path();
4629	if (!dst_path) {
4630		btrfs_free_path(path);
4631		return -ENOMEM;
4632	}
4633
4634	min_key.objectid = ino;
4635	min_key.type = BTRFS_INODE_ITEM_KEY;
4636	min_key.offset = 0;
4637
4638	max_key.objectid = ino;
4639
4640
4641	/* today the code can only do partial logging of directories */
4642	if (S_ISDIR(inode->i_mode) ||
4643	    (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4644		       &BTRFS_I(inode)->runtime_flags) &&
4645	     inode_only >= LOG_INODE_EXISTS))
4646		max_key.type = BTRFS_XATTR_ITEM_KEY;
4647	else
4648		max_key.type = (u8)-1;
4649	max_key.offset = (u64)-1;
4650
4651	/*
4652	 * Only run delayed items if we are a dir or a new file.
4653	 * Otherwise commit the delayed inode only, which is needed in
4654	 * order for the log replay code to mark inodes for link count
4655	 * fixup (create temporary BTRFS_TREE_LOG_FIXUP_OBJECTID items).
4656	 */
4657	if (S_ISDIR(inode->i_mode) ||
4658	    BTRFS_I(inode)->generation > fs_info->last_trans_committed)
4659		ret = btrfs_commit_inode_delayed_items(trans, inode);
4660	else
4661		ret = btrfs_commit_inode_delayed_inode(inode);
4662
4663	if (ret) {
4664		btrfs_free_path(path);
4665		btrfs_free_path(dst_path);
4666		return ret;
4667	}
4668
4669	if (inode_only == LOG_OTHER_INODE) {
4670		inode_only = LOG_INODE_EXISTS;
4671		mutex_lock_nested(&BTRFS_I(inode)->log_mutex,
4672				  SINGLE_DEPTH_NESTING);
4673	} else {
4674		mutex_lock(&BTRFS_I(inode)->log_mutex);
4675	}
4676
4677	/*
4678	 * a brute force approach to making sure we get the most uptodate
4679	 * copies of everything.
4680	 */
4681	if (S_ISDIR(inode->i_mode)) {
4682		int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
4683
4684		if (inode_only == LOG_INODE_EXISTS)
4685			max_key_type = BTRFS_XATTR_ITEM_KEY;
4686		ret = drop_objectid_items(trans, log, path, ino, max_key_type);
4687	} else {
4688		if (inode_only == LOG_INODE_EXISTS) {
4689			/*
4690			 * Make sure the new inode item we write to the log has
4691			 * the same isize as the current one (if it exists).
4692			 * This is necessary to prevent data loss after log
4693			 * replay, and also to prevent doing a wrong expanding
4694			 * truncate - for e.g. create file, write 4K into offset
4695			 * 0, fsync, write 4K into offset 4096, add hard link,
4696			 * fsync some other file (to sync log), power fail - if
4697			 * we use the inode's current i_size, after log replay
4698			 * we get a 8Kb file, with the last 4Kb extent as a hole
4699			 * (zeroes), as if an expanding truncate happened,
4700			 * instead of getting a file of 4Kb only.
4701			 */
4702			err = logged_inode_size(log, inode, path,
4703						&logged_isize);
4704			if (err)
4705				goto out_unlock;
4706		}
4707		if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4708			     &BTRFS_I(inode)->runtime_flags)) {
4709			if (inode_only == LOG_INODE_EXISTS) {
4710				max_key.type = BTRFS_XATTR_ITEM_KEY;
4711				ret = drop_objectid_items(trans, log, path, ino,
4712							  max_key.type);
4713			} else {
4714				clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4715					  &BTRFS_I(inode)->runtime_flags);
4716				clear_bit(BTRFS_INODE_COPY_EVERYTHING,
4717					  &BTRFS_I(inode)->runtime_flags);
4718				while(1) {
4719					ret = btrfs_truncate_inode_items(trans,
4720							 log, inode, 0, 0);
4721					if (ret != -EAGAIN)
4722						break;
4723				}
4724			}
4725		} else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
4726					      &BTRFS_I(inode)->runtime_flags) ||
4727			   inode_only == LOG_INODE_EXISTS) {
4728			if (inode_only == LOG_INODE_ALL)
4729				fast_search = true;
4730			max_key.type = BTRFS_XATTR_ITEM_KEY;
4731			ret = drop_objectid_items(trans, log, path, ino,
4732						  max_key.type);
4733		} else {
4734			if (inode_only == LOG_INODE_ALL)
4735				fast_search = true;
4736			goto log_extents;
4737		}
4738
4739	}
4740	if (ret) {
4741		err = ret;
4742		goto out_unlock;
4743	}
4744
4745	while (1) {
4746		ins_nr = 0;
4747		ret = btrfs_search_forward(root, &min_key,
4748					   path, trans->transid);
4749		if (ret < 0) {
4750			err = ret;
4751			goto out_unlock;
4752		}
4753		if (ret != 0)
4754			break;
4755again:
4756		/* note, ins_nr might be > 0 here, cleanup outside the loop */
4757		if (min_key.objectid != ino)
4758			break;
4759		if (min_key.type > max_key.type)
4760			break;
4761
4762		if (min_key.type == BTRFS_INODE_ITEM_KEY)
4763			need_log_inode_item = false;
4764
4765		if ((min_key.type == BTRFS_INODE_REF_KEY ||
4766		     min_key.type == BTRFS_INODE_EXTREF_KEY) &&
4767		    BTRFS_I(inode)->generation == trans->transid) {
4768			u64 other_ino = 0;
4769
4770			ret = btrfs_check_ref_name_override(path->nodes[0],
4771							    path->slots[0],
4772							    &min_key, inode,
4773							    &other_ino);
4774			if (ret < 0) {
4775				err = ret;
4776				goto out_unlock;
4777			} else if (ret > 0 && ctx &&
4778				   other_ino != btrfs_ino(ctx->inode)) {
4779				struct btrfs_key inode_key;
4780				struct inode *other_inode;
4781
4782				if (ins_nr > 0) {
4783					ins_nr++;
4784				} else {
4785					ins_nr = 1;
4786					ins_start_slot = path->slots[0];
4787				}
4788				ret = copy_items(trans, inode, dst_path, path,
4789						 &last_extent, ins_start_slot,
4790						 ins_nr, inode_only,
4791						 logged_isize);
4792				if (ret < 0) {
4793					err = ret;
4794					goto out_unlock;
4795				}
4796				ins_nr = 0;
4797				btrfs_release_path(path);
4798				inode_key.objectid = other_ino;
4799				inode_key.type = BTRFS_INODE_ITEM_KEY;
4800				inode_key.offset = 0;
4801				other_inode = btrfs_iget(fs_info->sb,
4802							 &inode_key, root,
4803							 NULL);
4804				/*
4805				 * If the other inode that had a conflicting dir
4806				 * entry was deleted in the current transaction,
4807				 * we don't need to do more work nor fallback to
4808				 * a transaction commit.
4809				 */
4810				if (IS_ERR(other_inode) &&
4811				    PTR_ERR(other_inode) == -ENOENT) {
4812					goto next_key;
4813				} else if (IS_ERR(other_inode)) {
4814					err = PTR_ERR(other_inode);
4815					goto out_unlock;
4816				}
4817				/*
4818				 * We are safe logging the other inode without
4819				 * acquiring its i_mutex as long as we log with
4820				 * the LOG_INODE_EXISTS mode. We're safe against
4821				 * concurrent renames of the other inode as well
4822				 * because during a rename we pin the log and
4823				 * update the log with the new name before we
4824				 * unpin it.
4825				 */
4826				err = btrfs_log_inode(trans, root, other_inode,
4827						      LOG_OTHER_INODE,
4828						      0, LLONG_MAX, ctx);
 
4829				iput(other_inode);
4830				if (err)
4831					goto out_unlock;
4832				else
4833					goto next_key;
4834			}
4835		}
4836
4837		/* Skip xattrs, we log them later with btrfs_log_all_xattrs() */
4838		if (min_key.type == BTRFS_XATTR_ITEM_KEY) {
4839			if (ins_nr == 0)
4840				goto next_slot;
4841			ret = copy_items(trans, inode, dst_path, path,
4842					 &last_extent, ins_start_slot,
4843					 ins_nr, inode_only, logged_isize);
4844			if (ret < 0) {
4845				err = ret;
4846				goto out_unlock;
4847			}
4848			ins_nr = 0;
4849			if (ret) {
4850				btrfs_release_path(path);
4851				continue;
4852			}
4853			goto next_slot;
4854		}
4855
4856		src = path->nodes[0];
4857		if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
4858			ins_nr++;
4859			goto next_slot;
4860		} else if (!ins_nr) {
4861			ins_start_slot = path->slots[0];
4862			ins_nr = 1;
4863			goto next_slot;
4864		}
4865
4866		ret = copy_items(trans, inode, dst_path, path, &last_extent,
4867				 ins_start_slot, ins_nr, inode_only,
4868				 logged_isize);
4869		if (ret < 0) {
4870			err = ret;
4871			goto out_unlock;
4872		}
4873		if (ret) {
4874			ins_nr = 0;
4875			btrfs_release_path(path);
4876			continue;
4877		}
4878		ins_nr = 1;
4879		ins_start_slot = path->slots[0];
4880next_slot:
4881
4882		nritems = btrfs_header_nritems(path->nodes[0]);
4883		path->slots[0]++;
4884		if (path->slots[0] < nritems) {
4885			btrfs_item_key_to_cpu(path->nodes[0], &min_key,
4886					      path->slots[0]);
4887			goto again;
4888		}
4889		if (ins_nr) {
4890			ret = copy_items(trans, inode, dst_path, path,
4891					 &last_extent, ins_start_slot,
4892					 ins_nr, inode_only, logged_isize);
4893			if (ret < 0) {
4894				err = ret;
4895				goto out_unlock;
4896			}
4897			ret = 0;
4898			ins_nr = 0;
4899		}
4900		btrfs_release_path(path);
4901next_key:
4902		if (min_key.offset < (u64)-1) {
4903			min_key.offset++;
4904		} else if (min_key.type < max_key.type) {
4905			min_key.type++;
4906			min_key.offset = 0;
4907		} else {
4908			break;
4909		}
4910	}
4911	if (ins_nr) {
4912		ret = copy_items(trans, inode, dst_path, path, &last_extent,
4913				 ins_start_slot, ins_nr, inode_only,
4914				 logged_isize);
4915		if (ret < 0) {
4916			err = ret;
4917			goto out_unlock;
4918		}
4919		ret = 0;
4920		ins_nr = 0;
4921	}
4922
4923	btrfs_release_path(path);
4924	btrfs_release_path(dst_path);
4925	err = btrfs_log_all_xattrs(trans, root, inode, path, dst_path);
4926	if (err)
4927		goto out_unlock;
 
4928	if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
4929		btrfs_release_path(path);
4930		btrfs_release_path(dst_path);
4931		err = btrfs_log_trailing_hole(trans, root, inode, path);
4932		if (err)
4933			goto out_unlock;
4934	}
4935log_extents:
4936	btrfs_release_path(path);
4937	btrfs_release_path(dst_path);
4938	if (need_log_inode_item) {
4939		err = log_inode_item(trans, log, dst_path, inode);
 
 
 
 
 
4940		if (err)
4941			goto out_unlock;
4942	}
4943	if (fast_search) {
4944		ret = btrfs_log_changed_extents(trans, root, inode, dst_path,
4945						&logged_list, ctx, start, end);
4946		if (ret) {
4947			err = ret;
4948			goto out_unlock;
4949		}
4950	} else if (inode_only == LOG_INODE_ALL) {
4951		struct extent_map *em, *n;
4952
4953		write_lock(&em_tree->lock);
4954		/*
4955		 * We can't just remove every em if we're called for a ranged
4956		 * fsync - that is, one that doesn't cover the whole possible
4957		 * file range (0 to LLONG_MAX). This is because we can have
4958		 * em's that fall outside the range we're logging and therefore
4959		 * their ordered operations haven't completed yet
4960		 * (btrfs_finish_ordered_io() not invoked yet). This means we
4961		 * didn't get their respective file extent item in the fs/subvol
4962		 * tree yet, and need to let the next fast fsync (one which
4963		 * consults the list of modified extent maps) find the em so
4964		 * that it logs a matching file extent item and waits for the
4965		 * respective ordered operation to complete (if it's still
4966		 * running).
4967		 *
4968		 * Removing every em outside the range we're logging would make
4969		 * the next fast fsync not log their matching file extent items,
4970		 * therefore making us lose data after a log replay.
4971		 */
4972		list_for_each_entry_safe(em, n, &em_tree->modified_extents,
4973					 list) {
4974			const u64 mod_end = em->mod_start + em->mod_len - 1;
4975
4976			if (em->mod_start >= start && mod_end <= end)
4977				list_del_init(&em->list);
4978		}
4979		write_unlock(&em_tree->lock);
4980	}
4981
4982	if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
4983		ret = log_directory_changes(trans, root, inode, path, dst_path,
4984					    ctx);
4985		if (ret) {
4986			err = ret;
4987			goto out_unlock;
4988		}
4989	}
4990
4991	spin_lock(&BTRFS_I(inode)->lock);
4992	BTRFS_I(inode)->logged_trans = trans->transid;
4993	BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->last_sub_trans;
4994	spin_unlock(&BTRFS_I(inode)->lock);
4995out_unlock:
4996	if (unlikely(err))
4997		btrfs_put_logged_extents(&logged_list);
4998	else
4999		btrfs_submit_logged_extents(&logged_list, log);
5000	mutex_unlock(&BTRFS_I(inode)->log_mutex);
5001
5002	btrfs_free_path(path);
5003	btrfs_free_path(dst_path);
5004	return err;
5005}
5006
5007/*
5008 * Check if we must fallback to a transaction commit when logging an inode.
5009 * This must be called after logging the inode and is used only in the context
5010 * when fsyncing an inode requires the need to log some other inode - in which
5011 * case we can't lock the i_mutex of each other inode we need to log as that
5012 * can lead to deadlocks with concurrent fsync against other inodes (as we can
5013 * log inodes up or down in the hierarchy) or rename operations for example. So
5014 * we take the log_mutex of the inode after we have logged it and then check for
5015 * its last_unlink_trans value - this is safe because any task setting
5016 * last_unlink_trans must take the log_mutex and it must do this before it does
5017 * the actual unlink operation, so if we do this check before a concurrent task
5018 * sets last_unlink_trans it means we've logged a consistent version/state of
5019 * all the inode items, otherwise we are not sure and must do a transaction
5020 * commit (the concurrent task might have only updated last_unlink_trans before
5021 * we logged the inode or it might have also done the unlink).
5022 */
5023static bool btrfs_must_commit_transaction(struct btrfs_trans_handle *trans,
5024					  struct inode *inode)
5025{
5026	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
5027	bool ret = false;
5028
5029	mutex_lock(&BTRFS_I(inode)->log_mutex);
5030	if (BTRFS_I(inode)->last_unlink_trans > fs_info->last_trans_committed) {
5031		/*
5032		 * Make sure any commits to the log are forced to be full
5033		 * commits.
5034		 */
5035		btrfs_set_log_full_commit(fs_info, trans);
5036		ret = true;
5037	}
5038	mutex_unlock(&BTRFS_I(inode)->log_mutex);
5039
5040	return ret;
5041}
5042
5043/*
5044 * follow the dentry parent pointers up the chain and see if any
5045 * of the directories in it require a full commit before they can
5046 * be logged.  Returns zero if nothing special needs to be done or 1 if
5047 * a full commit is required.
5048 */
5049static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
5050					       struct inode *inode,
5051					       struct dentry *parent,
5052					       struct super_block *sb,
5053					       u64 last_committed)
5054{
5055	int ret = 0;
5056	struct dentry *old_parent = NULL;
5057	struct inode *orig_inode = inode;
5058
5059	/*
5060	 * for regular files, if its inode is already on disk, we don't
5061	 * have to worry about the parents at all.  This is because
5062	 * we can use the last_unlink_trans field to record renames
5063	 * and other fun in this file.
5064	 */
5065	if (S_ISREG(inode->i_mode) &&
5066	    BTRFS_I(inode)->generation <= last_committed &&
5067	    BTRFS_I(inode)->last_unlink_trans <= last_committed)
5068			goto out;
5069
5070	if (!S_ISDIR(inode->i_mode)) {
5071		if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
5072			goto out;
5073		inode = d_inode(parent);
5074	}
5075
5076	while (1) {
5077		/*
5078		 * If we are logging a directory then we start with our inode,
5079		 * not our parent's inode, so we need to skip setting the
5080		 * logged_trans so that further down in the log code we don't
5081		 * think this inode has already been logged.
5082		 */
5083		if (inode != orig_inode)
5084			BTRFS_I(inode)->logged_trans = trans->transid;
5085		smp_mb();
5086
5087		if (btrfs_must_commit_transaction(trans, inode)) {
5088			ret = 1;
5089			break;
5090		}
5091
5092		if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
5093			break;
5094
5095		if (IS_ROOT(parent)) {
5096			inode = d_inode(parent);
5097			if (btrfs_must_commit_transaction(trans, inode))
5098				ret = 1;
5099			break;
5100		}
5101
5102		parent = dget_parent(parent);
5103		dput(old_parent);
5104		old_parent = parent;
5105		inode = d_inode(parent);
5106
5107	}
5108	dput(old_parent);
5109out:
5110	return ret;
5111}
5112
5113struct btrfs_dir_list {
5114	u64 ino;
5115	struct list_head list;
5116};
5117
5118/*
5119 * Log the inodes of the new dentries of a directory. See log_dir_items() for
5120 * details about the why it is needed.
5121 * This is a recursive operation - if an existing dentry corresponds to a
5122 * directory, that directory's new entries are logged too (same behaviour as
5123 * ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes
5124 * the dentries point to we do not lock their i_mutex, otherwise lockdep
5125 * complains about the following circular lock dependency / possible deadlock:
5126 *
5127 *        CPU0                                        CPU1
5128 *        ----                                        ----
5129 * lock(&type->i_mutex_dir_key#3/2);
5130 *                                            lock(sb_internal#2);
5131 *                                            lock(&type->i_mutex_dir_key#3/2);
5132 * lock(&sb->s_type->i_mutex_key#14);
5133 *
5134 * Where sb_internal is the lock (a counter that works as a lock) acquired by
5135 * sb_start_intwrite() in btrfs_start_transaction().
5136 * Not locking i_mutex of the inodes is still safe because:
5137 *
5138 * 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible
5139 *    that while logging the inode new references (names) are added or removed
5140 *    from the inode, leaving the logged inode item with a link count that does
5141 *    not match the number of logged inode reference items. This is fine because
5142 *    at log replay time we compute the real number of links and correct the
5143 *    link count in the inode item (see replay_one_buffer() and
5144 *    link_to_fixup_dir());
5145 *
5146 * 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that
5147 *    while logging the inode's items new items with keys BTRFS_DIR_ITEM_KEY and
5148 *    BTRFS_DIR_INDEX_KEY are added to fs/subvol tree and the logged inode item
5149 *    has a size that doesn't match the sum of the lengths of all the logged
5150 *    names. This does not result in a problem because if a dir_item key is
5151 *    logged but its matching dir_index key is not logged, at log replay time we
5152 *    don't use it to replay the respective name (see replay_one_name()). On the
5153 *    other hand if only the dir_index key ends up being logged, the respective
5154 *    name is added to the fs/subvol tree with both the dir_item and dir_index
5155 *    keys created (see replay_one_name()).
5156 *    The directory's inode item with a wrong i_size is not a problem as well,
5157 *    since we don't use it at log replay time to set the i_size in the inode
5158 *    item of the fs/subvol tree (see overwrite_item()).
5159 */
5160static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
5161				struct btrfs_root *root,
5162				struct inode *start_inode,
5163				struct btrfs_log_ctx *ctx)
5164{
5165	struct btrfs_fs_info *fs_info = root->fs_info;
5166	struct btrfs_root *log = root->log_root;
5167	struct btrfs_path *path;
5168	LIST_HEAD(dir_list);
5169	struct btrfs_dir_list *dir_elem;
5170	int ret = 0;
5171
5172	path = btrfs_alloc_path();
5173	if (!path)
5174		return -ENOMEM;
5175
5176	dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS);
5177	if (!dir_elem) {
5178		btrfs_free_path(path);
5179		return -ENOMEM;
5180	}
5181	dir_elem->ino = btrfs_ino(start_inode);
5182	list_add_tail(&dir_elem->list, &dir_list);
5183
5184	while (!list_empty(&dir_list)) {
5185		struct extent_buffer *leaf;
5186		struct btrfs_key min_key;
5187		int nritems;
5188		int i;
5189
5190		dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list,
5191					    list);
5192		if (ret)
5193			goto next_dir_inode;
5194
5195		min_key.objectid = dir_elem->ino;
5196		min_key.type = BTRFS_DIR_ITEM_KEY;
5197		min_key.offset = 0;
5198again:
5199		btrfs_release_path(path);
5200		ret = btrfs_search_forward(log, &min_key, path, trans->transid);
5201		if (ret < 0) {
5202			goto next_dir_inode;
5203		} else if (ret > 0) {
5204			ret = 0;
5205			goto next_dir_inode;
5206		}
5207
5208process_leaf:
5209		leaf = path->nodes[0];
5210		nritems = btrfs_header_nritems(leaf);
5211		for (i = path->slots[0]; i < nritems; i++) {
5212			struct btrfs_dir_item *di;
5213			struct btrfs_key di_key;
5214			struct inode *di_inode;
5215			struct btrfs_dir_list *new_dir_elem;
5216			int log_mode = LOG_INODE_EXISTS;
5217			int type;
5218
5219			btrfs_item_key_to_cpu(leaf, &min_key, i);
5220			if (min_key.objectid != dir_elem->ino ||
5221			    min_key.type != BTRFS_DIR_ITEM_KEY)
5222				goto next_dir_inode;
5223
5224			di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item);
5225			type = btrfs_dir_type(leaf, di);
5226			if (btrfs_dir_transid(leaf, di) < trans->transid &&
5227			    type != BTRFS_FT_DIR)
5228				continue;
5229			btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
5230			if (di_key.type == BTRFS_ROOT_ITEM_KEY)
5231				continue;
5232
5233			btrfs_release_path(path);
5234			di_inode = btrfs_iget(fs_info->sb, &di_key, root, NULL);
5235			if (IS_ERR(di_inode)) {
5236				ret = PTR_ERR(di_inode);
5237				goto next_dir_inode;
5238			}
5239
5240			if (btrfs_inode_in_log(di_inode, trans->transid)) {
5241				iput(di_inode);
5242				break;
5243			}
5244
5245			ctx->log_new_dentries = false;
5246			if (type == BTRFS_FT_DIR || type == BTRFS_FT_SYMLINK)
5247				log_mode = LOG_INODE_ALL;
5248			ret = btrfs_log_inode(trans, root, di_inode,
5249					      log_mode, 0, LLONG_MAX, ctx);
5250			if (!ret &&
5251			    btrfs_must_commit_transaction(trans, di_inode))
5252				ret = 1;
5253			iput(di_inode);
5254			if (ret)
5255				goto next_dir_inode;
5256			if (ctx->log_new_dentries) {
5257				new_dir_elem = kmalloc(sizeof(*new_dir_elem),
5258						       GFP_NOFS);
5259				if (!new_dir_elem) {
5260					ret = -ENOMEM;
5261					goto next_dir_inode;
5262				}
5263				new_dir_elem->ino = di_key.objectid;
5264				list_add_tail(&new_dir_elem->list, &dir_list);
5265			}
5266			break;
5267		}
5268		if (i == nritems) {
5269			ret = btrfs_next_leaf(log, path);
5270			if (ret < 0) {
5271				goto next_dir_inode;
5272			} else if (ret > 0) {
5273				ret = 0;
5274				goto next_dir_inode;
5275			}
5276			goto process_leaf;
5277		}
5278		if (min_key.offset < (u64)-1) {
5279			min_key.offset++;
5280			goto again;
5281		}
5282next_dir_inode:
5283		list_del(&dir_elem->list);
5284		kfree(dir_elem);
5285	}
5286
5287	btrfs_free_path(path);
5288	return ret;
5289}
5290
5291static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
5292				 struct inode *inode,
5293				 struct btrfs_log_ctx *ctx)
5294{
5295	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5296	int ret;
5297	struct btrfs_path *path;
5298	struct btrfs_key key;
5299	struct btrfs_root *root = BTRFS_I(inode)->root;
5300	const u64 ino = btrfs_ino(inode);
5301
5302	path = btrfs_alloc_path();
5303	if (!path)
5304		return -ENOMEM;
5305	path->skip_locking = 1;
5306	path->search_commit_root = 1;
5307
5308	key.objectid = ino;
5309	key.type = BTRFS_INODE_REF_KEY;
5310	key.offset = 0;
5311	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5312	if (ret < 0)
5313		goto out;
5314
5315	while (true) {
5316		struct extent_buffer *leaf = path->nodes[0];
5317		int slot = path->slots[0];
5318		u32 cur_offset = 0;
5319		u32 item_size;
5320		unsigned long ptr;
5321
5322		if (slot >= btrfs_header_nritems(leaf)) {
5323			ret = btrfs_next_leaf(root, path);
5324			if (ret < 0)
5325				goto out;
5326			else if (ret > 0)
5327				break;
5328			continue;
5329		}
5330
5331		btrfs_item_key_to_cpu(leaf, &key, slot);
5332		/* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
5333		if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
5334			break;
5335
5336		item_size = btrfs_item_size_nr(leaf, slot);
5337		ptr = btrfs_item_ptr_offset(leaf, slot);
5338		while (cur_offset < item_size) {
5339			struct btrfs_key inode_key;
5340			struct inode *dir_inode;
5341
5342			inode_key.type = BTRFS_INODE_ITEM_KEY;
5343			inode_key.offset = 0;
5344
5345			if (key.type == BTRFS_INODE_EXTREF_KEY) {
5346				struct btrfs_inode_extref *extref;
5347
5348				extref = (struct btrfs_inode_extref *)
5349					(ptr + cur_offset);
5350				inode_key.objectid = btrfs_inode_extref_parent(
5351					leaf, extref);
5352				cur_offset += sizeof(*extref);
5353				cur_offset += btrfs_inode_extref_name_len(leaf,
5354					extref);
5355			} else {
5356				inode_key.objectid = key.offset;
5357				cur_offset = item_size;
5358			}
5359
5360			dir_inode = btrfs_iget(fs_info->sb, &inode_key,
5361					       root, NULL);
5362			/* If parent inode was deleted, skip it. */
5363			if (IS_ERR(dir_inode))
5364				continue;
5365
5366			if (ctx)
5367				ctx->log_new_dentries = false;
5368			ret = btrfs_log_inode(trans, root, dir_inode,
5369					      LOG_INODE_ALL, 0, LLONG_MAX, ctx);
5370			if (!ret &&
5371			    btrfs_must_commit_transaction(trans, dir_inode))
5372				ret = 1;
5373			if (!ret && ctx && ctx->log_new_dentries)
5374				ret = log_new_dir_dentries(trans, root,
5375							   dir_inode, ctx);
5376			iput(dir_inode);
5377			if (ret)
5378				goto out;
5379		}
5380		path->slots[0]++;
5381	}
5382	ret = 0;
5383out:
5384	btrfs_free_path(path);
5385	return ret;
5386}
5387
5388/*
5389 * helper function around btrfs_log_inode to make sure newly created
5390 * parent directories also end up in the log.  A minimal inode and backref
5391 * only logging is done of any parent directories that are older than
5392 * the last committed transaction
5393 */
5394static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
5395			    	  struct btrfs_root *root, struct inode *inode,
5396				  struct dentry *parent,
5397				  const loff_t start,
5398				  const loff_t end,
5399				  int exists_only,
5400				  struct btrfs_log_ctx *ctx)
5401{
 
5402	struct btrfs_fs_info *fs_info = root->fs_info;
5403	int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
5404	struct super_block *sb;
5405	struct dentry *old_parent = NULL;
5406	int ret = 0;
5407	u64 last_committed = fs_info->last_trans_committed;
5408	bool log_dentries = false;
5409	struct inode *orig_inode = inode;
5410
5411	sb = inode->i_sb;
5412
5413	if (btrfs_test_opt(fs_info, NOTREELOG)) {
5414		ret = 1;
5415		goto end_no_trans;
5416	}
5417
5418	/*
5419	 * The prev transaction commit doesn't complete, we need do
5420	 * full commit by ourselves.
5421	 */
5422	if (fs_info->last_trans_log_full_commit >
5423	    fs_info->last_trans_committed) {
5424		ret = 1;
5425		goto end_no_trans;
5426	}
5427
5428	if (root != BTRFS_I(inode)->root ||
5429	    btrfs_root_refs(&root->root_item) == 0) {
5430		ret = 1;
5431		goto end_no_trans;
5432	}
5433
5434	ret = check_parent_dirs_for_sync(trans, inode, parent,
5435					 sb, last_committed);
5436	if (ret)
5437		goto end_no_trans;
5438
5439	if (btrfs_inode_in_log(inode, trans->transid)) {
5440		ret = BTRFS_NO_LOG_SYNC;
5441		goto end_no_trans;
5442	}
5443
5444	ret = start_log_trans(trans, root, ctx);
5445	if (ret)
5446		goto end_no_trans;
5447
5448	ret = btrfs_log_inode(trans, root, inode, inode_only, start, end, ctx);
5449	if (ret)
5450		goto end_trans;
5451
5452	/*
5453	 * for regular files, if its inode is already on disk, we don't
5454	 * have to worry about the parents at all.  This is because
5455	 * we can use the last_unlink_trans field to record renames
5456	 * and other fun in this file.
5457	 */
5458	if (S_ISREG(inode->i_mode) &&
5459	    BTRFS_I(inode)->generation <= last_committed &&
5460	    BTRFS_I(inode)->last_unlink_trans <= last_committed) {
5461		ret = 0;
5462		goto end_trans;
5463	}
5464
5465	if (S_ISDIR(inode->i_mode) && ctx && ctx->log_new_dentries)
5466		log_dentries = true;
5467
5468	/*
5469	 * On unlink we must make sure all our current and old parent directory
5470	 * inodes are fully logged. This is to prevent leaving dangling
5471	 * directory index entries in directories that were our parents but are
5472	 * not anymore. Not doing this results in old parent directory being
5473	 * impossible to delete after log replay (rmdir will always fail with
5474	 * error -ENOTEMPTY).
5475	 *
5476	 * Example 1:
5477	 *
5478	 * mkdir testdir
5479	 * touch testdir/foo
5480	 * ln testdir/foo testdir/bar
5481	 * sync
5482	 * unlink testdir/bar
5483	 * xfs_io -c fsync testdir/foo
5484	 * <power failure>
5485	 * mount fs, triggers log replay
5486	 *
5487	 * If we don't log the parent directory (testdir), after log replay the
5488	 * directory still has an entry pointing to the file inode using the bar
5489	 * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
5490	 * the file inode has a link count of 1.
5491	 *
5492	 * Example 2:
5493	 *
5494	 * mkdir testdir
5495	 * touch foo
5496	 * ln foo testdir/foo2
5497	 * ln foo testdir/foo3
5498	 * sync
5499	 * unlink testdir/foo3
5500	 * xfs_io -c fsync foo
5501	 * <power failure>
5502	 * mount fs, triggers log replay
5503	 *
5504	 * Similar as the first example, after log replay the parent directory
5505	 * testdir still has an entry pointing to the inode file with name foo3
5506	 * but the file inode does not have a matching BTRFS_INODE_REF_KEY item
5507	 * and has a link count of 2.
5508	 */
5509	if (BTRFS_I(inode)->last_unlink_trans > last_committed) {
5510		ret = btrfs_log_all_parents(trans, orig_inode, ctx);
5511		if (ret)
5512			goto end_trans;
5513	}
5514
5515	while (1) {
5516		if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
5517			break;
5518
5519		inode = d_inode(parent);
5520		if (root != BTRFS_I(inode)->root)
5521			break;
5522
5523		if (BTRFS_I(inode)->generation > last_committed) {
5524			ret = btrfs_log_inode(trans, root, inode,
5525					      LOG_INODE_EXISTS,
5526					      0, LLONG_MAX, ctx);
5527			if (ret)
5528				goto end_trans;
5529		}
5530		if (IS_ROOT(parent))
5531			break;
5532
5533		parent = dget_parent(parent);
5534		dput(old_parent);
5535		old_parent = parent;
5536	}
5537	if (log_dentries)
5538		ret = log_new_dir_dentries(trans, root, orig_inode, ctx);
5539	else
5540		ret = 0;
5541end_trans:
5542	dput(old_parent);
5543	if (ret < 0) {
5544		btrfs_set_log_full_commit(fs_info, trans);
5545		ret = 1;
5546	}
5547
5548	if (ret)
5549		btrfs_remove_log_ctx(root, ctx);
5550	btrfs_end_log_trans(root);
5551end_no_trans:
5552	return ret;
5553}
5554
5555/*
5556 * it is not safe to log dentry if the chunk root has added new
5557 * chunks.  This returns 0 if the dentry was logged, and 1 otherwise.
5558 * If this returns 1, you must commit the transaction to safely get your
5559 * data on disk.
5560 */
5561int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
5562			  struct btrfs_root *root, struct dentry *dentry,
5563			  const loff_t start,
5564			  const loff_t end,
5565			  struct btrfs_log_ctx *ctx)
5566{
5567	struct dentry *parent = dget_parent(dentry);
5568	int ret;
5569
5570	ret = btrfs_log_inode_parent(trans, root, d_inode(dentry), parent,
5571				     start, end, 0, ctx);
5572	dput(parent);
5573
5574	return ret;
5575}
5576
5577/*
5578 * should be called during mount to recover any replay any log trees
5579 * from the FS
5580 */
5581int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
5582{
5583	int ret;
5584	struct btrfs_path *path;
5585	struct btrfs_trans_handle *trans;
5586	struct btrfs_key key;
5587	struct btrfs_key found_key;
5588	struct btrfs_key tmp_key;
5589	struct btrfs_root *log;
5590	struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
5591	struct walk_control wc = {
5592		.process_func = process_one_buffer,
5593		.stage = 0,
5594	};
5595
5596	path = btrfs_alloc_path();
5597	if (!path)
5598		return -ENOMEM;
5599
5600	set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
5601
5602	trans = btrfs_start_transaction(fs_info->tree_root, 0);
5603	if (IS_ERR(trans)) {
5604		ret = PTR_ERR(trans);
5605		goto error;
5606	}
5607
5608	wc.trans = trans;
5609	wc.pin = 1;
5610
5611	ret = walk_log_tree(trans, log_root_tree, &wc);
5612	if (ret) {
5613		btrfs_handle_fs_error(fs_info, ret,
5614			"Failed to pin buffers while recovering log root tree.");
5615		goto error;
5616	}
5617
5618again:
5619	key.objectid = BTRFS_TREE_LOG_OBJECTID;
5620	key.offset = (u64)-1;
5621	key.type = BTRFS_ROOT_ITEM_KEY;
5622
5623	while (1) {
5624		ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
5625
5626		if (ret < 0) {
5627			btrfs_handle_fs_error(fs_info, ret,
5628				    "Couldn't find tree log root.");
5629			goto error;
5630		}
5631		if (ret > 0) {
5632			if (path->slots[0] == 0)
5633				break;
5634			path->slots[0]--;
5635		}
5636		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
5637				      path->slots[0]);
5638		btrfs_release_path(path);
5639		if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
5640			break;
5641
5642		log = btrfs_read_fs_root(log_root_tree, &found_key);
5643		if (IS_ERR(log)) {
5644			ret = PTR_ERR(log);
5645			btrfs_handle_fs_error(fs_info, ret,
5646				    "Couldn't read tree log root.");
5647			goto error;
5648		}
5649
5650		tmp_key.objectid = found_key.offset;
5651		tmp_key.type = BTRFS_ROOT_ITEM_KEY;
5652		tmp_key.offset = (u64)-1;
5653
5654		wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
5655		if (IS_ERR(wc.replay_dest)) {
5656			ret = PTR_ERR(wc.replay_dest);
5657			free_extent_buffer(log->node);
5658			free_extent_buffer(log->commit_root);
5659			kfree(log);
5660			btrfs_handle_fs_error(fs_info, ret,
5661				"Couldn't read target root for tree log recovery.");
5662			goto error;
5663		}
5664
5665		wc.replay_dest->log_root = log;
5666		btrfs_record_root_in_trans(trans, wc.replay_dest);
5667		ret = walk_log_tree(trans, log, &wc);
5668
5669		if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
5670			ret = fixup_inode_link_counts(trans, wc.replay_dest,
5671						      path);
5672		}
5673
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
5674		key.offset = found_key.offset - 1;
5675		wc.replay_dest->log_root = NULL;
5676		free_extent_buffer(log->node);
5677		free_extent_buffer(log->commit_root);
5678		kfree(log);
5679
5680		if (ret)
5681			goto error;
5682
5683		if (found_key.offset == 0)
5684			break;
5685	}
5686	btrfs_release_path(path);
5687
5688	/* step one is to pin it all, step two is to replay just inodes */
5689	if (wc.pin) {
5690		wc.pin = 0;
5691		wc.process_func = replay_one_buffer;
5692		wc.stage = LOG_WALK_REPLAY_INODES;
5693		goto again;
5694	}
5695	/* step three is to replay everything */
5696	if (wc.stage < LOG_WALK_REPLAY_ALL) {
5697		wc.stage++;
5698		goto again;
5699	}
5700
5701	btrfs_free_path(path);
5702
5703	/* step 4: commit the transaction, which also unpins the blocks */
5704	ret = btrfs_commit_transaction(trans);
5705	if (ret)
5706		return ret;
5707
5708	free_extent_buffer(log_root_tree->node);
5709	log_root_tree->log_root = NULL;
5710	clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
5711	kfree(log_root_tree);
5712
5713	return 0;
5714error:
5715	if (wc.trans)
5716		btrfs_end_transaction(wc.trans);
5717	btrfs_free_path(path);
5718	return ret;
5719}
5720
5721/*
5722 * there are some corner cases where we want to force a full
5723 * commit instead of allowing a directory to be logged.
5724 *
5725 * They revolve around files there were unlinked from the directory, and
5726 * this function updates the parent directory so that a full commit is
5727 * properly done if it is fsync'd later after the unlinks are done.
5728 *
5729 * Must be called before the unlink operations (updates to the subvolume tree,
5730 * inodes, etc) are done.
5731 */
5732void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
5733			     struct inode *dir, struct inode *inode,
5734			     int for_rename)
5735{
5736	/*
5737	 * when we're logging a file, if it hasn't been renamed
5738	 * or unlinked, and its inode is fully committed on disk,
5739	 * we don't have to worry about walking up the directory chain
5740	 * to log its parents.
5741	 *
5742	 * So, we use the last_unlink_trans field to put this transid
5743	 * into the file.  When the file is logged we check it and
5744	 * don't log the parents if the file is fully on disk.
5745	 */
5746	mutex_lock(&BTRFS_I(inode)->log_mutex);
5747	BTRFS_I(inode)->last_unlink_trans = trans->transid;
5748	mutex_unlock(&BTRFS_I(inode)->log_mutex);
5749
5750	/*
5751	 * if this directory was already logged any new
5752	 * names for this file/dir will get recorded
5753	 */
5754	smp_mb();
5755	if (BTRFS_I(dir)->logged_trans == trans->transid)
5756		return;
5757
5758	/*
5759	 * if the inode we're about to unlink was logged,
5760	 * the log will be properly updated for any new names
5761	 */
5762	if (BTRFS_I(inode)->logged_trans == trans->transid)
5763		return;
5764
5765	/*
5766	 * when renaming files across directories, if the directory
5767	 * there we're unlinking from gets fsync'd later on, there's
5768	 * no way to find the destination directory later and fsync it
5769	 * properly.  So, we have to be conservative and force commits
5770	 * so the new name gets discovered.
5771	 */
5772	if (for_rename)
5773		goto record;
5774
5775	/* we can safely do the unlink without any special recording */
5776	return;
5777
5778record:
5779	mutex_lock(&BTRFS_I(dir)->log_mutex);
5780	BTRFS_I(dir)->last_unlink_trans = trans->transid;
5781	mutex_unlock(&BTRFS_I(dir)->log_mutex);
5782}
5783
5784/*
5785 * Make sure that if someone attempts to fsync the parent directory of a deleted
5786 * snapshot, it ends up triggering a transaction commit. This is to guarantee
5787 * that after replaying the log tree of the parent directory's root we will not
5788 * see the snapshot anymore and at log replay time we will not see any log tree
5789 * corresponding to the deleted snapshot's root, which could lead to replaying
5790 * it after replaying the log tree of the parent directory (which would replay
5791 * the snapshot delete operation).
5792 *
5793 * Must be called before the actual snapshot destroy operation (updates to the
5794 * parent root and tree of tree roots trees, etc) are done.
5795 */
5796void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
5797				   struct inode *dir)
5798{
5799	mutex_lock(&BTRFS_I(dir)->log_mutex);
5800	BTRFS_I(dir)->last_unlink_trans = trans->transid;
5801	mutex_unlock(&BTRFS_I(dir)->log_mutex);
5802}
5803
5804/*
5805 * Call this after adding a new name for a file and it will properly
5806 * update the log to reflect the new name.
5807 *
5808 * It will return zero if all goes well, and it will return 1 if a
5809 * full transaction commit is required.
5810 */
5811int btrfs_log_new_name(struct btrfs_trans_handle *trans,
5812			struct inode *inode, struct inode *old_dir,
5813			struct dentry *parent)
5814{
5815	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5816	struct btrfs_root * root = BTRFS_I(inode)->root;
5817
5818	/*
5819	 * this will force the logging code to walk the dentry chain
5820	 * up for the file
5821	 */
5822	if (S_ISREG(inode->i_mode))
5823		BTRFS_I(inode)->last_unlink_trans = trans->transid;
5824
5825	/*
5826	 * if this inode hasn't been logged and directory we're renaming it
5827	 * from hasn't been logged, we don't need to log it
5828	 */
5829	if (BTRFS_I(inode)->logged_trans <=
5830	    fs_info->last_trans_committed &&
5831	    (!old_dir || BTRFS_I(old_dir)->logged_trans <=
5832		    fs_info->last_trans_committed))
5833		return 0;
5834
5835	return btrfs_log_inode_parent(trans, root, inode, parent, 0,
5836				      LLONG_MAX, 1, NULL);
5837}
5838