tree-log.c 92.2 KB
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/*
 * Copyright (C) 2008 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/list_sort.h>
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#include "ctree.h"
#include "transaction.h"
#include "disk-io.h"
#include "locking.h"
#include "print-tree.h"
#include "compat.h"
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#include "tree-log.h"
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/* magic values for the inode_only field in btrfs_log_inode:
 *
 * LOG_INODE_ALL means to log everything
 * LOG_INODE_EXISTS means to log just enough to recreate the inode
 * during log replay
 */
#define LOG_INODE_ALL 0
#define LOG_INODE_EXISTS 1

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/*
 * directory trouble cases
 *
 * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
 * log, we must force a full commit before doing an fsync of the directory
 * where the unlink was done.
 * ---> record transid of last unlink/rename per directory
 *
 * mkdir foo/some_dir
 * normal commit
 * rename foo/some_dir foo2/some_dir
 * mkdir foo/some_dir
 * fsync foo/some_dir/some_file
 *
 * The fsync above will unlink the original some_dir without recording
 * it in its new location (foo2).  After a crash, some_dir will be gone
 * unless the fsync of some_file forces a full commit
 *
 * 2) we must log any new names for any file or dir that is in the fsync
 * log. ---> check inode while renaming/linking.
 *
 * 2a) we must log any new names for any file or dir during rename
 * when the directory they are being removed from was logged.
 * ---> check inode and old parent dir during rename
 *
 *  2a is actually the more important variant.  With the extra logging
 *  a crash might unlink the old name without recreating the new one
 *
 * 3) after a crash, we must go through any directories with a link count
 * of zero and redo the rm -rf
 *
 * mkdir f1/foo
 * normal commit
 * rm -rf f1/foo
 * fsync(f1)
 *
 * The directory f1 was fully removed from the FS, but fsync was never
 * called on f1, only its parent dir.  After a crash the rm -rf must
 * be replayed.  This must be able to recurse down the entire
 * directory tree.  The inode link count fixup code takes care of the
 * ugly details.
 */

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/*
 * stages for the tree walking.  The first
 * stage (0) is to only pin down the blocks we find
 * the second stage (1) is to make sure that all the inodes
 * we find in the log are created in the subvolume.
 *
 * The last stage is to deal with directories and links and extents
 * and all the other fun semantics
 */
#define LOG_WALK_PIN_ONLY 0
#define LOG_WALK_REPLAY_INODES 1
#define LOG_WALK_REPLAY_ALL 2

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static int btrfs_log_inode(struct btrfs_trans_handle *trans,
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			     struct btrfs_root *root, struct inode *inode,
			     int inode_only);
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static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
			     struct btrfs_root *root,
			     struct btrfs_path *path, u64 objectid);
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static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
				       struct btrfs_root *root,
				       struct btrfs_root *log,
				       struct btrfs_path *path,
				       u64 dirid, int del_all);
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/*
 * tree logging is a special write ahead log used to make sure that
 * fsyncs and O_SYNCs can happen without doing full tree commits.
 *
 * Full tree commits are expensive because they require commonly
 * modified blocks to be recowed, creating many dirty pages in the
 * extent tree an 4x-6x higher write load than ext3.
 *
 * Instead of doing a tree commit on every fsync, we use the
 * key ranges and transaction ids to find items for a given file or directory
 * that have changed in this transaction.  Those items are copied into
 * a special tree (one per subvolume root), that tree is written to disk
 * and then the fsync is considered complete.
 *
 * After a crash, items are copied out of the log-tree back into the
 * subvolume tree.  Any file data extents found are recorded in the extent
 * allocation tree, and the log-tree freed.
 *
 * The log tree is read three times, once to pin down all the extents it is
 * using in ram and once, once to create all the inodes logged in the tree
 * and once to do all the other items.
 */

/*
 * start a sub transaction and setup the log tree
 * this increments the log tree writer count to make the people
 * syncing the tree wait for us to finish
 */
static int start_log_trans(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root)
{
	int ret;
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	int err = 0;
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	mutex_lock(&root->log_mutex);
	if (root->log_root) {
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		if (!root->log_start_pid) {
			root->log_start_pid = current->pid;
			root->log_multiple_pids = false;
		} else if (root->log_start_pid != current->pid) {
			root->log_multiple_pids = true;
		}

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		root->log_batch++;
		atomic_inc(&root->log_writers);
		mutex_unlock(&root->log_mutex);
		return 0;
	}
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	root->log_multiple_pids = false;
	root->log_start_pid = current->pid;
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	mutex_lock(&root->fs_info->tree_log_mutex);
	if (!root->fs_info->log_root_tree) {
		ret = btrfs_init_log_root_tree(trans, root->fs_info);
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		if (ret)
			err = ret;
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	}
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	if (err == 0 && !root->log_root) {
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		ret = btrfs_add_log_tree(trans, root);
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		if (ret)
			err = ret;
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	}
	mutex_unlock(&root->fs_info->tree_log_mutex);
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	root->log_batch++;
	atomic_inc(&root->log_writers);
	mutex_unlock(&root->log_mutex);
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	return err;
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}

/*
 * returns 0 if there was a log transaction running and we were able
 * to join, or returns -ENOENT if there were not transactions
 * in progress
 */
static int join_running_log_trans(struct btrfs_root *root)
{
	int ret = -ENOENT;

	smp_mb();
	if (!root->log_root)
		return -ENOENT;

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	mutex_lock(&root->log_mutex);
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	if (root->log_root) {
		ret = 0;
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		atomic_inc(&root->log_writers);
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	}
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	mutex_unlock(&root->log_mutex);
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	return ret;
}

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/*
 * This either makes the current running log transaction wait
 * until you call btrfs_end_log_trans() or it makes any future
 * log transactions wait until you call btrfs_end_log_trans()
 */
int btrfs_pin_log_trans(struct btrfs_root *root)
{
	int ret = -ENOENT;

	mutex_lock(&root->log_mutex);
	atomic_inc(&root->log_writers);
	mutex_unlock(&root->log_mutex);
	return ret;
}

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/*
 * indicate we're done making changes to the log tree
 * and wake up anyone waiting to do a sync
 */
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void btrfs_end_log_trans(struct btrfs_root *root)
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{
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	if (atomic_dec_and_test(&root->log_writers)) {
		smp_mb();
		if (waitqueue_active(&root->log_writer_wait))
			wake_up(&root->log_writer_wait);
	}
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}


/*
 * the walk control struct is used to pass state down the chain when
 * processing the log tree.  The stage field tells us which part
 * of the log tree processing we are currently doing.  The others
 * are state fields used for that specific part
 */
struct walk_control {
	/* should we free the extent on disk when done?  This is used
	 * at transaction commit time while freeing a log tree
	 */
	int free;

	/* should we write out the extent buffer?  This is used
	 * while flushing the log tree to disk during a sync
	 */
	int write;

	/* should we wait for the extent buffer io to finish?  Also used
	 * while flushing the log tree to disk for a sync
	 */
	int wait;

	/* pin only walk, we record which extents on disk belong to the
	 * log trees
	 */
	int pin;

	/* what stage of the replay code we're currently in */
	int stage;

	/* the root we are currently replaying */
	struct btrfs_root *replay_dest;

	/* the trans handle for the current replay */
	struct btrfs_trans_handle *trans;

	/* the function that gets used to process blocks we find in the
	 * tree.  Note the extent_buffer might not be up to date when it is
	 * passed in, and it must be checked or read if you need the data
	 * inside it
	 */
	int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
			    struct walk_control *wc, u64 gen);
};

/*
 * process_func used to pin down extents, write them or wait on them
 */
static int process_one_buffer(struct btrfs_root *log,
			      struct extent_buffer *eb,
			      struct walk_control *wc, u64 gen)
{
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	if (wc->pin)
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		btrfs_pin_extent_for_log_replay(wc->trans,
						log->fs_info->extent_root,
						eb->start, eb->len);
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	if (btrfs_buffer_uptodate(eb, gen, 0)) {
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		if (wc->write)
			btrfs_write_tree_block(eb);
		if (wc->wait)
			btrfs_wait_tree_block_writeback(eb);
	}
	return 0;
}

/*
 * Item overwrite used by replay and tree logging.  eb, slot and key all refer
 * to the src data we are copying out.
 *
 * root is the tree we are copying into, and path is a scratch
 * path for use in this function (it should be released on entry and
 * will be released on exit).
 *
 * If the key is already in the destination tree the existing item is
 * overwritten.  If the existing item isn't big enough, it is extended.
 * If it is too large, it is truncated.
 *
 * If the key isn't in the destination yet, a new item is inserted.
 */
static noinline int overwrite_item(struct btrfs_trans_handle *trans,
				   struct btrfs_root *root,
				   struct btrfs_path *path,
				   struct extent_buffer *eb, int slot,
				   struct btrfs_key *key)
{
	int ret;
	u32 item_size;
	u64 saved_i_size = 0;
	int save_old_i_size = 0;
	unsigned long src_ptr;
	unsigned long dst_ptr;
	int overwrite_root = 0;

	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
		overwrite_root = 1;

	item_size = btrfs_item_size_nr(eb, slot);
	src_ptr = btrfs_item_ptr_offset(eb, slot);

	/* look for the key in the destination tree */
	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
	if (ret == 0) {
		char *src_copy;
		char *dst_copy;
		u32 dst_size = btrfs_item_size_nr(path->nodes[0],
						  path->slots[0]);
		if (dst_size != item_size)
			goto insert;

		if (item_size == 0) {
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			btrfs_release_path(path);
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			return 0;
		}
		dst_copy = kmalloc(item_size, GFP_NOFS);
		src_copy = kmalloc(item_size, GFP_NOFS);
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		if (!dst_copy || !src_copy) {
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			btrfs_release_path(path);
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			kfree(dst_copy);
			kfree(src_copy);
			return -ENOMEM;
		}
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		read_extent_buffer(eb, src_copy, src_ptr, item_size);

		dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
		read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
				   item_size);
		ret = memcmp(dst_copy, src_copy, item_size);

		kfree(dst_copy);
		kfree(src_copy);
		/*
		 * they have the same contents, just return, this saves
		 * us from cowing blocks in the destination tree and doing
		 * extra writes that may not have been done by a previous
		 * sync
		 */
		if (ret == 0) {
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			btrfs_release_path(path);
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			return 0;
		}

	}
insert:
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	btrfs_release_path(path);
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	/* try to insert the key into the destination tree */
	ret = btrfs_insert_empty_item(trans, root, path,
				      key, item_size);

	/* make sure any existing item is the correct size */
	if (ret == -EEXIST) {
		u32 found_size;
		found_size = btrfs_item_size_nr(path->nodes[0],
						path->slots[0]);
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		if (found_size > item_size)
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			btrfs_truncate_item(trans, root, path, item_size, 1);
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		else if (found_size < item_size)
			btrfs_extend_item(trans, root, path,
					  item_size - found_size);
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	} else if (ret) {
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		return ret;
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	}
	dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
					path->slots[0]);

	/* don't overwrite an existing inode if the generation number
	 * was logged as zero.  This is done when the tree logging code
	 * is just logging an inode to make sure it exists after recovery.
	 *
	 * Also, don't overwrite i_size on directories during replay.
	 * log replay inserts and removes directory items based on the
	 * state of the tree found in the subvolume, and i_size is modified
	 * as it goes
	 */
	if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
		struct btrfs_inode_item *src_item;
		struct btrfs_inode_item *dst_item;

		src_item = (struct btrfs_inode_item *)src_ptr;
		dst_item = (struct btrfs_inode_item *)dst_ptr;

		if (btrfs_inode_generation(eb, src_item) == 0)
			goto no_copy;

		if (overwrite_root &&
		    S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
		    S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
			save_old_i_size = 1;
			saved_i_size = btrfs_inode_size(path->nodes[0],
							dst_item);
		}
	}

	copy_extent_buffer(path->nodes[0], eb, dst_ptr,
			   src_ptr, item_size);

	if (save_old_i_size) {
		struct btrfs_inode_item *dst_item;
		dst_item = (struct btrfs_inode_item *)dst_ptr;
		btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
	}

	/* make sure the generation is filled in */
	if (key->type == BTRFS_INODE_ITEM_KEY) {
		struct btrfs_inode_item *dst_item;
		dst_item = (struct btrfs_inode_item *)dst_ptr;
		if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
			btrfs_set_inode_generation(path->nodes[0], dst_item,
						   trans->transid);
		}
	}
no_copy:
	btrfs_mark_buffer_dirty(path->nodes[0]);
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	btrfs_release_path(path);
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	return 0;
}

/*
 * simple helper to read an inode off the disk from a given root
 * This can only be called for subvolume roots and not for the log
 */
static noinline struct inode *read_one_inode(struct btrfs_root *root,
					     u64 objectid)
{
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	struct btrfs_key key;
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	struct inode *inode;

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	key.objectid = objectid;
	key.type = BTRFS_INODE_ITEM_KEY;
	key.offset = 0;
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	inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
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	if (IS_ERR(inode)) {
		inode = NULL;
	} else if (is_bad_inode(inode)) {
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		iput(inode);
		inode = NULL;
	}
	return inode;
}

/* replays a single extent in 'eb' at 'slot' with 'key' into the
 * subvolume 'root'.  path is released on entry and should be released
 * on exit.
 *
 * extents in the log tree have not been allocated out of the extent
 * tree yet.  So, this completes the allocation, taking a reference
 * as required if the extent already exists or creating a new extent
 * if it isn't in the extent allocation tree yet.
 *
 * The extent is inserted into the file, dropping any existing extents
 * from the file that overlap the new one.
 */
static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
				      struct btrfs_root *root,
				      struct btrfs_path *path,
				      struct extent_buffer *eb, int slot,
				      struct btrfs_key *key)
{
	int found_type;
	u64 mask = root->sectorsize - 1;
	u64 extent_end;
	u64 alloc_hint;
	u64 start = key->offset;
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	u64 saved_nbytes;
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	struct btrfs_file_extent_item *item;
	struct inode *inode = NULL;
	unsigned long size;
	int ret = 0;

	item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
	found_type = btrfs_file_extent_type(eb, item);

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	if (found_type == BTRFS_FILE_EXTENT_REG ||
	    found_type == BTRFS_FILE_EXTENT_PREALLOC)
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		extent_end = start + btrfs_file_extent_num_bytes(eb, item);
	else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
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		size = btrfs_file_extent_inline_len(eb, item);
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		extent_end = (start + size + mask) & ~mask;
	} else {
		ret = 0;
		goto out;
	}

	inode = read_one_inode(root, key->objectid);
	if (!inode) {
		ret = -EIO;
		goto out;
	}

	/*
	 * first check to see if we already have this extent in the
	 * file.  This must be done before the btrfs_drop_extents run
	 * so we don't try to drop this extent.
	 */
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	ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode),
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				       start, 0);

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	if (ret == 0 &&
	    (found_type == BTRFS_FILE_EXTENT_REG ||
	     found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
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		struct btrfs_file_extent_item cmp1;
		struct btrfs_file_extent_item cmp2;
		struct btrfs_file_extent_item *existing;
		struct extent_buffer *leaf;

		leaf = path->nodes[0];
		existing = btrfs_item_ptr(leaf, path->slots[0],
					  struct btrfs_file_extent_item);

		read_extent_buffer(eb, &cmp1, (unsigned long)item,
				   sizeof(cmp1));
		read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
				   sizeof(cmp2));

		/*
		 * we already have a pointer to this exact extent,
		 * we don't have to do anything
		 */
		if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
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			btrfs_release_path(path);
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			goto out;
		}
	}
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	btrfs_release_path(path);
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	saved_nbytes = inode_get_bytes(inode);
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	/* drop any overlapping extents */
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	ret = btrfs_drop_extents(trans, root, inode, start, extent_end,
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				 &alloc_hint, 1);
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	BUG_ON(ret);

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	if (found_type == BTRFS_FILE_EXTENT_REG ||
	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
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		u64 offset;
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		unsigned long dest_offset;
		struct btrfs_key ins;

		ret = btrfs_insert_empty_item(trans, root, path, key,
					      sizeof(*item));
		BUG_ON(ret);
		dest_offset = btrfs_item_ptr_offset(path->nodes[0],
						    path->slots[0]);
		copy_extent_buffer(path->nodes[0], eb, dest_offset,
				(unsigned long)item,  sizeof(*item));

		ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
		ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
		ins.type = BTRFS_EXTENT_ITEM_KEY;
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		offset = key->offset - btrfs_file_extent_offset(eb, item);
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		if (ins.objectid > 0) {
			u64 csum_start;
			u64 csum_end;
			LIST_HEAD(ordered_sums);
			/*
			 * is this extent already allocated in the extent
			 * allocation tree?  If so, just add a reference
			 */
			ret = btrfs_lookup_extent(root, ins.objectid,
						ins.offset);
			if (ret == 0) {
				ret = btrfs_inc_extent_ref(trans, root,
						ins.objectid, ins.offset,
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						0, root->root_key.objectid,
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						key->objectid, offset, 0);
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				BUG_ON(ret);
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			} else {
				/*
				 * insert the extent pointer in the extent
				 * allocation tree
				 */
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				ret = btrfs_alloc_logged_file_extent(trans,
						root, root->root_key.objectid,
						key->objectid, offset, &ins);
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				BUG_ON(ret);
			}
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			btrfs_release_path(path);
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			if (btrfs_file_extent_compression(eb, item)) {
				csum_start = ins.objectid;
				csum_end = csum_start + ins.offset;
			} else {
				csum_start = ins.objectid +
					btrfs_file_extent_offset(eb, item);
				csum_end = csum_start +
					btrfs_file_extent_num_bytes(eb, item);
			}

			ret = btrfs_lookup_csums_range(root->log_root,
						csum_start, csum_end - 1,
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						&ordered_sums, 0);
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618 619 620 621 622 623 624 625 626 627 628 629 630 631
			BUG_ON(ret);
			while (!list_empty(&ordered_sums)) {
				struct btrfs_ordered_sum *sums;
				sums = list_entry(ordered_sums.next,
						struct btrfs_ordered_sum,
						list);
				ret = btrfs_csum_file_blocks(trans,
						root->fs_info->csum_root,
						sums);
				BUG_ON(ret);
				list_del(&sums->list);
				kfree(sums);
			}
		} else {
632
			btrfs_release_path(path);
Y
Yan Zheng 已提交
633 634 635 636 637 638
		}
	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
		/* inline extents are easy, we just overwrite them */
		ret = overwrite_item(trans, root, path, eb, slot, key);
		BUG_ON(ret);
	}
639

Y
Yan Zheng 已提交
640
	inode_set_bytes(inode, saved_nbytes);
641
	ret = btrfs_update_inode(trans, root, inode);
642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673
out:
	if (inode)
		iput(inode);
	return ret;
}

/*
 * when cleaning up conflicts between the directory names in the
 * subvolume, directory names in the log and directory names in the
 * inode back references, we may have to unlink inodes from directories.
 *
 * This is a helper function to do the unlink of a specific directory
 * item
 */
static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
				      struct btrfs_root *root,
				      struct btrfs_path *path,
				      struct inode *dir,
				      struct btrfs_dir_item *di)
{
	struct inode *inode;
	char *name;
	int name_len;
	struct extent_buffer *leaf;
	struct btrfs_key location;
	int ret;

	leaf = path->nodes[0];

	btrfs_dir_item_key_to_cpu(leaf, di, &location);
	name_len = btrfs_dir_name_len(leaf, di);
	name = kmalloc(name_len, GFP_NOFS);
674 675 676
	if (!name)
		return -ENOMEM;

677
	read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
678
	btrfs_release_path(path);
679 680

	inode = read_one_inode(root, location.objectid);
681 682 683 684
	if (!inode) {
		kfree(name);
		return -EIO;
	}
685

686 687
	ret = link_to_fixup_dir(trans, root, path, location.objectid);
	BUG_ON(ret);
688

689
	ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
690
	BUG_ON(ret);
691 692 693
	kfree(name);

	iput(inode);
694 695

	btrfs_run_delayed_items(trans, root);
696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720
	return ret;
}

/*
 * helper function to see if a given name and sequence number found
 * in an inode back reference are already in a directory and correctly
 * point to this inode
 */
static noinline int inode_in_dir(struct btrfs_root *root,
				 struct btrfs_path *path,
				 u64 dirid, u64 objectid, u64 index,
				 const char *name, int name_len)
{
	struct btrfs_dir_item *di;
	struct btrfs_key location;
	int match = 0;

	di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
					 index, name, name_len, 0);
	if (di && !IS_ERR(di)) {
		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
		if (location.objectid != objectid)
			goto out;
	} else
		goto out;
721
	btrfs_release_path(path);
722 723 724 725 726 727 728 729 730 731

	di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
	if (di && !IS_ERR(di)) {
		btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
		if (location.objectid != objectid)
			goto out;
	} else
		goto out;
	match = 1;
out:
732
	btrfs_release_path(path);
733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760
	return match;
}

/*
 * helper function to check a log tree for a named back reference in
 * an inode.  This is used to decide if a back reference that is
 * found in the subvolume conflicts with what we find in the log.
 *
 * inode backreferences may have multiple refs in a single item,
 * during replay we process one reference at a time, and we don't
 * want to delete valid links to a file from the subvolume if that
 * link is also in the log.
 */
static noinline int backref_in_log(struct btrfs_root *log,
				   struct btrfs_key *key,
				   char *name, int namelen)
{
	struct btrfs_path *path;
	struct btrfs_inode_ref *ref;
	unsigned long ptr;
	unsigned long ptr_end;
	unsigned long name_ptr;
	int found_name_len;
	int item_size;
	int ret;
	int match = 0;

	path = btrfs_alloc_path();
761 762 763
	if (!path)
		return -ENOMEM;

764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804
	ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
	if (ret != 0)
		goto out;

	item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
	ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
	ptr_end = ptr + item_size;
	while (ptr < ptr_end) {
		ref = (struct btrfs_inode_ref *)ptr;
		found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
		if (found_name_len == namelen) {
			name_ptr = (unsigned long)(ref + 1);
			ret = memcmp_extent_buffer(path->nodes[0], name,
						   name_ptr, namelen);
			if (ret == 0) {
				match = 1;
				goto out;
			}
		}
		ptr = (unsigned long)(ref + 1) + found_name_len;
	}
out:
	btrfs_free_path(path);
	return match;
}


/*
 * replay one inode back reference item found in the log tree.
 * eb, slot and key refer to the buffer and key found in the log tree.
 * root is the destination we are replaying into, and path is for temp
 * use by this function.  (it should be released on return).
 */
static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
				  struct btrfs_root *root,
				  struct btrfs_root *log,
				  struct btrfs_path *path,
				  struct extent_buffer *eb, int slot,
				  struct btrfs_key *key)
{
	struct btrfs_inode_ref *ref;
L
liubo 已提交
805 806
	struct btrfs_dir_item *di;
	struct inode *dir;
807 808 809
	struct inode *inode;
	unsigned long ref_ptr;
	unsigned long ref_end;
L
liubo 已提交
810 811 812
	char *name;
	int namelen;
	int ret;
813
	int search_done = 0;
814 815 816 817 818 819 820 821 822 823 824 825

	/*
	 * it is possible that we didn't log all the parent directories
	 * for a given inode.  If we don't find the dir, just don't
	 * copy the back ref in.  The link count fixup code will take
	 * care of the rest
	 */
	dir = read_one_inode(root, key->offset);
	if (!dir)
		return -ENOENT;

	inode = read_one_inode(root, key->objectid);
826 827 828 829
	if (!inode) {
		iput(dir);
		return -EIO;
	}
830 831 832 833 834 835 836 837 838 839 840 841 842 843

	ref_ptr = btrfs_item_ptr_offset(eb, slot);
	ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);

again:
	ref = (struct btrfs_inode_ref *)ref_ptr;

	namelen = btrfs_inode_ref_name_len(eb, ref);
	name = kmalloc(namelen, GFP_NOFS);
	BUG_ON(!name);

	read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen);

	/* if we already have a perfect match, we're done */
L
Li Zefan 已提交
844
	if (inode_in_dir(root, path, btrfs_ino(dir), btrfs_ino(inode),
845 846 847 848 849 850 851 852 853 854 855 856
			 btrfs_inode_ref_index(eb, ref),
			 name, namelen)) {
		goto out;
	}

	/*
	 * look for a conflicting back reference in the metadata.
	 * if we find one we have to unlink that name of the file
	 * before we add our new link.  Later on, we overwrite any
	 * existing back reference, and we don't want to create
	 * dangling pointers in the directory.
	 */
857 858 859 860

	if (search_done)
		goto insert;

861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881
	ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
	if (ret == 0) {
		char *victim_name;
		int victim_name_len;
		struct btrfs_inode_ref *victim_ref;
		unsigned long ptr;
		unsigned long ptr_end;
		struct extent_buffer *leaf = path->nodes[0];

		/* are we trying to overwrite a back ref for the root directory
		 * if so, just jump out, we're done
		 */
		if (key->objectid == key->offset)
			goto out_nowrite;

		/* check all the names in this back reference to see
		 * if they are in the log.  if so, we allow them to stay
		 * otherwise they must be unlinked as a conflict
		 */
		ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
		ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
C
Chris Mason 已提交
882
		while (ptr < ptr_end) {
883 884 885 886 887 888 889 890 891 892 893 894 895
			victim_ref = (struct btrfs_inode_ref *)ptr;
			victim_name_len = btrfs_inode_ref_name_len(leaf,
								   victim_ref);
			victim_name = kmalloc(victim_name_len, GFP_NOFS);
			BUG_ON(!victim_name);

			read_extent_buffer(leaf, victim_name,
					   (unsigned long)(victim_ref + 1),
					   victim_name_len);

			if (!backref_in_log(log, key, victim_name,
					    victim_name_len)) {
				btrfs_inc_nlink(inode);
896
				btrfs_release_path(path);
897

898 899 900
				ret = btrfs_unlink_inode(trans, root, dir,
							 inode, victim_name,
							 victim_name_len);
901
				btrfs_run_delayed_items(trans, root);
902 903 904 905 906 907
			}
			kfree(victim_name);
			ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
		}
		BUG_ON(ret);

908 909 910 911 912
		/*
		 * NOTE: we have searched root tree and checked the
		 * coresponding ref, it does not need to check again.
		 */
		search_done = 1;
913
	}
914
	btrfs_release_path(path);
915

L
liubo 已提交
916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934
	/* look for a conflicting sequence number */
	di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
					 btrfs_inode_ref_index(eb, ref),
					 name, namelen, 0);
	if (di && !IS_ERR(di)) {
		ret = drop_one_dir_item(trans, root, path, dir, di);
		BUG_ON(ret);
	}
	btrfs_release_path(path);

	/* look for a conflicing name */
	di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
				   name, namelen, 0);
	if (di && !IS_ERR(di)) {
		ret = drop_one_dir_item(trans, root, path, dir, di);
		BUG_ON(ret);
	}
	btrfs_release_path(path);

935
insert:
936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953
	/* insert our name */
	ret = btrfs_add_link(trans, dir, inode, name, namelen, 0,
			     btrfs_inode_ref_index(eb, ref));
	BUG_ON(ret);

	btrfs_update_inode(trans, root, inode);

out:
	ref_ptr = (unsigned long)(ref + 1) + namelen;
	kfree(name);
	if (ref_ptr < ref_end)
		goto again;

	/* finally write the back reference in the inode */
	ret = overwrite_item(trans, root, path, eb, slot, key);
	BUG_ON(ret);

out_nowrite:
954
	btrfs_release_path(path);
955 956 957 958 959
	iput(dir);
	iput(inode);
	return 0;
}

960 961 962 963 964 965 966 967 968 969 970
static int insert_orphan_item(struct btrfs_trans_handle *trans,
			      struct btrfs_root *root, u64 offset)
{
	int ret;
	ret = btrfs_find_orphan_item(root, offset);
	if (ret > 0)
		ret = btrfs_insert_orphan_item(trans, root, offset);
	return ret;
}


971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991
/*
 * There are a few corners where the link count of the file can't
 * be properly maintained during replay.  So, instead of adding
 * lots of complexity to the log code, we just scan the backrefs
 * for any file that has been through replay.
 *
 * The scan will update the link count on the inode to reflect the
 * number of back refs found.  If it goes down to zero, the iput
 * will free the inode.
 */
static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
					   struct btrfs_root *root,
					   struct inode *inode)
{
	struct btrfs_path *path;
	int ret;
	struct btrfs_key key;
	u64 nlink = 0;
	unsigned long ptr;
	unsigned long ptr_end;
	int name_len;
L
Li Zefan 已提交
992
	u64 ino = btrfs_ino(inode);
993

L
Li Zefan 已提交
994
	key.objectid = ino;
995 996 997 998
	key.type = BTRFS_INODE_REF_KEY;
	key.offset = (u64)-1;

	path = btrfs_alloc_path();
999 1000
	if (!path)
		return -ENOMEM;
1001

C
Chris Mason 已提交
1002
	while (1) {
1003 1004 1005 1006 1007 1008 1009 1010 1011 1012
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret < 0)
			break;
		if (ret > 0) {
			if (path->slots[0] == 0)
				break;
			path->slots[0]--;
		}
		btrfs_item_key_to_cpu(path->nodes[0], &key,
				      path->slots[0]);
L
Li Zefan 已提交
1013
		if (key.objectid != ino ||
1014 1015 1016 1017 1018
		    key.type != BTRFS_INODE_REF_KEY)
			break;
		ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
		ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
						   path->slots[0]);
C
Chris Mason 已提交
1019
		while (ptr < ptr_end) {
1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031
			struct btrfs_inode_ref *ref;

			ref = (struct btrfs_inode_ref *)ptr;
			name_len = btrfs_inode_ref_name_len(path->nodes[0],
							    ref);
			ptr = (unsigned long)(ref + 1) + name_len;
			nlink++;
		}

		if (key.offset == 0)
			break;
		key.offset--;
1032
		btrfs_release_path(path);
1033
	}
1034
	btrfs_release_path(path);
1035
	if (nlink != inode->i_nlink) {
M
Miklos Szeredi 已提交
1036
		set_nlink(inode, nlink);
1037 1038
		btrfs_update_inode(trans, root, inode);
	}
1039
	BTRFS_I(inode)->index_cnt = (u64)-1;
1040

1041 1042 1043
	if (inode->i_nlink == 0) {
		if (S_ISDIR(inode->i_mode)) {
			ret = replay_dir_deletes(trans, root, NULL, path,
L
Li Zefan 已提交
1044
						 ino, 1);
1045 1046
			BUG_ON(ret);
		}
L
Li Zefan 已提交
1047
		ret = insert_orphan_item(trans, root, ino);
1048 1049 1050 1051
		BUG_ON(ret);
	}
	btrfs_free_path(path);

1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065
	return 0;
}

static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
					    struct btrfs_root *root,
					    struct btrfs_path *path)
{
	int ret;
	struct btrfs_key key;
	struct inode *inode;

	key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
	key.type = BTRFS_ORPHAN_ITEM_KEY;
	key.offset = (u64)-1;
C
Chris Mason 已提交
1066
	while (1) {
1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082
		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
		if (ret < 0)
			break;

		if (ret == 1) {
			if (path->slots[0] == 0)
				break;
			path->slots[0]--;
		}

		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
		if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
		    key.type != BTRFS_ORPHAN_ITEM_KEY)
			break;

		ret = btrfs_del_item(trans, root, path);
1083 1084
		if (ret)
			goto out;
1085

1086
		btrfs_release_path(path);
1087
		inode = read_one_inode(root, key.offset);
1088 1089
		if (!inode)
			return -EIO;
1090 1091 1092 1093 1094 1095

		ret = fixup_inode_link_count(trans, root, inode);
		BUG_ON(ret);

		iput(inode);

1096 1097 1098 1099 1100 1101
		/*
		 * fixup on a directory may create new entries,
		 * make sure we always look for the highset possible
		 * offset
		 */
		key.offset = (u64)-1;
1102
	}
1103 1104
	ret = 0;
out:
1105
	btrfs_release_path(path);
1106
	return ret;
1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124
}


/*
 * record a given inode in the fixup dir so we can check its link
 * count when replay is done.  The link count is incremented here
 * so the inode won't go away until we check it
 */
static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
				      struct btrfs_root *root,
				      struct btrfs_path *path,
				      u64 objectid)
{
	struct btrfs_key key;
	int ret = 0;
	struct inode *inode;

	inode = read_one_inode(root, objectid);
1125 1126
	if (!inode)
		return -EIO;
1127 1128 1129 1130 1131 1132 1133

	key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
	btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
	key.offset = objectid;

	ret = btrfs_insert_empty_item(trans, root, path, &key, 0);

1134
	btrfs_release_path(path);
1135 1136
	if (ret == 0) {
		btrfs_inc_nlink(inode);
1137
		ret = btrfs_update_inode(trans, root, inode);
1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208
	} else if (ret == -EEXIST) {
		ret = 0;
	} else {
		BUG();
	}
	iput(inode);

	return ret;
}

/*
 * when replaying the log for a directory, we only insert names
 * for inodes that actually exist.  This means an fsync on a directory
 * does not implicitly fsync all the new files in it
 */
static noinline int insert_one_name(struct btrfs_trans_handle *trans,
				    struct btrfs_root *root,
				    struct btrfs_path *path,
				    u64 dirid, u64 index,
				    char *name, int name_len, u8 type,
				    struct btrfs_key *location)
{
	struct inode *inode;
	struct inode *dir;
	int ret;

	inode = read_one_inode(root, location->objectid);
	if (!inode)
		return -ENOENT;

	dir = read_one_inode(root, dirid);
	if (!dir) {
		iput(inode);
		return -EIO;
	}
	ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);

	/* FIXME, put inode into FIXUP list */

	iput(inode);
	iput(dir);
	return ret;
}

/*
 * take a single entry in a log directory item and replay it into
 * the subvolume.
 *
 * if a conflicting item exists in the subdirectory already,
 * the inode it points to is unlinked and put into the link count
 * fix up tree.
 *
 * If a name from the log points to a file or directory that does
 * not exist in the FS, it is skipped.  fsyncs on directories
 * do not force down inodes inside that directory, just changes to the
 * names or unlinks in a directory.
 */
static noinline int replay_one_name(struct btrfs_trans_handle *trans,
				    struct btrfs_root *root,
				    struct btrfs_path *path,
				    struct extent_buffer *eb,
				    struct btrfs_dir_item *di,
				    struct btrfs_key *key)
{
	char *name;
	int name_len;
	struct btrfs_dir_item *dst_di;
	struct btrfs_key found_key;
	struct btrfs_key log_key;
	struct inode *dir;
	u8 log_type;
C
Chris Mason 已提交
1209
	int exists;
1210 1211 1212
	int ret;

	dir = read_one_inode(root, key->objectid);
1213 1214
	if (!dir)
		return -EIO;
1215 1216 1217

	name_len = btrfs_dir_name_len(eb, di);
	name = kmalloc(name_len, GFP_NOFS);
1218 1219 1220
	if (!name)
		return -ENOMEM;

1221 1222 1223 1224 1225
	log_type = btrfs_dir_type(eb, di);
	read_extent_buffer(eb, name, (unsigned long)(di + 1),
		   name_len);

	btrfs_dir_item_key_to_cpu(eb, di, &log_key);
C
Chris Mason 已提交
1226 1227 1228 1229 1230
	exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
	if (exists == 0)
		exists = 1;
	else
		exists = 0;
1231
	btrfs_release_path(path);
C
Chris Mason 已提交
1232

1233 1234 1235
	if (key->type == BTRFS_DIR_ITEM_KEY) {
		dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
				       name, name_len, 1);
C
Chris Mason 已提交
1236
	} else if (key->type == BTRFS_DIR_INDEX_KEY) {
1237 1238 1239 1240 1241 1242 1243
		dst_di = btrfs_lookup_dir_index_item(trans, root, path,
						     key->objectid,
						     key->offset, name,
						     name_len, 1);
	} else {
		BUG();
	}
1244
	if (IS_ERR_OR_NULL(dst_di)) {
1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265
		/* we need a sequence number to insert, so we only
		 * do inserts for the BTRFS_DIR_INDEX_KEY types
		 */
		if (key->type != BTRFS_DIR_INDEX_KEY)
			goto out;
		goto insert;
	}

	btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
	/* the existing item matches the logged item */
	if (found_key.objectid == log_key.objectid &&
	    found_key.type == log_key.type &&
	    found_key.offset == log_key.offset &&
	    btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
		goto out;
	}

	/*
	 * don't drop the conflicting directory entry if the inode
	 * for the new entry doesn't exist
	 */
C
Chris Mason 已提交
1266
	if (!exists)
1267 1268 1269 1270 1271 1272 1273 1274
		goto out;

	ret = drop_one_dir_item(trans, root, path, dir, dst_di);
	BUG_ON(ret);

	if (key->type == BTRFS_DIR_INDEX_KEY)
		goto insert;
out:
1275
	btrfs_release_path(path);
1276 1277 1278 1279 1280
	kfree(name);
	iput(dir);
	return 0;

insert:
1281
	btrfs_release_path(path);
1282 1283 1284
	ret = insert_one_name(trans, root, path, key->objectid, key->offset,
			      name, name_len, log_type, &log_key);

S
Stoyan Gaydarov 已提交
1285
	BUG_ON(ret && ret != -ENOENT);
1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309
	goto out;
}

/*
 * find all the names in a directory item and reconcile them into
 * the subvolume.  Only BTRFS_DIR_ITEM_KEY types will have more than
 * one name in a directory item, but the same code gets used for
 * both directory index types
 */
static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
					struct btrfs_root *root,
					struct btrfs_path *path,
					struct extent_buffer *eb, int slot,
					struct btrfs_key *key)
{
	int ret;
	u32 item_size = btrfs_item_size_nr(eb, slot);
	struct btrfs_dir_item *di;
	int name_len;
	unsigned long ptr;
	unsigned long ptr_end;

	ptr = btrfs_item_ptr_offset(eb, slot);
	ptr_end = ptr + item_size;
C
Chris Mason 已提交
1310
	while (ptr < ptr_end) {
1311
		di = (struct btrfs_dir_item *)ptr;
1312 1313
		if (verify_dir_item(root, eb, di))
			return -EIO;
1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401
		name_len = btrfs_dir_name_len(eb, di);
		ret = replay_one_name(trans, root, path, eb, di, key);
		BUG_ON(ret);
		ptr = (unsigned long)(di + 1);
		ptr += name_len;
	}
	return 0;
}

/*
 * directory replay has two parts.  There are the standard directory
 * items in the log copied from the subvolume, and range items
 * created in the log while the subvolume was logged.
 *
 * The range items tell us which parts of the key space the log
 * is authoritative for.  During replay, if a key in the subvolume
 * directory is in a logged range item, but not actually in the log
 * that means it was deleted from the directory before the fsync
 * and should be removed.
 */
static noinline int find_dir_range(struct btrfs_root *root,
				   struct btrfs_path *path,
				   u64 dirid, int key_type,
				   u64 *start_ret, u64 *end_ret)
{
	struct btrfs_key key;
	u64 found_end;
	struct btrfs_dir_log_item *item;
	int ret;
	int nritems;

	if (*start_ret == (u64)-1)
		return 1;

	key.objectid = dirid;
	key.type = key_type;
	key.offset = *start_ret;

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
	if (ret > 0) {
		if (path->slots[0] == 0)
			goto out;
		path->slots[0]--;
	}
	if (ret != 0)
		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);

	if (key.type != key_type || key.objectid != dirid) {
		ret = 1;
		goto next;
	}
	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
			      struct btrfs_dir_log_item);
	found_end = btrfs_dir_log_end(path->nodes[0], item);

	if (*start_ret >= key.offset && *start_ret <= found_end) {
		ret = 0;
		*start_ret = key.offset;
		*end_ret = found_end;
		goto out;
	}
	ret = 1;
next:
	/* check the next slot in the tree to see if it is a valid item */
	nritems = btrfs_header_nritems(path->nodes[0]);
	if (path->slots[0] >= nritems) {
		ret = btrfs_next_leaf(root, path);
		if (ret)
			goto out;
	} else {
		path->slots[0]++;
	}

	btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);

	if (key.type != key_type || key.objectid != dirid) {
		ret = 1;
		goto out;
	}
	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
			      struct btrfs_dir_log_item);
	found_end = btrfs_dir_log_end(path->nodes[0], item);
	*start_ret = key.offset;
	*end_ret = found_end;
	ret = 0;
out:
1402
	btrfs_release_path(path);
1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437
	return ret;
}

/*
 * this looks for a given directory item in the log.  If the directory
 * item is not in the log, the item is removed and the inode it points
 * to is unlinked
 */
static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
				      struct btrfs_root *root,
				      struct btrfs_root *log,
				      struct btrfs_path *path,
				      struct btrfs_path *log_path,
				      struct inode *dir,
				      struct btrfs_key *dir_key)
{
	int ret;
	struct extent_buffer *eb;
	int slot;
	u32 item_size;
	struct btrfs_dir_item *di;
	struct btrfs_dir_item *log_di;
	int name_len;
	unsigned long ptr;
	unsigned long ptr_end;
	char *name;
	struct inode *inode;
	struct btrfs_key location;

again:
	eb = path->nodes[0];
	slot = path->slots[0];
	item_size = btrfs_item_size_nr(eb, slot);
	ptr = btrfs_item_ptr_offset(eb, slot);
	ptr_end = ptr + item_size;
C
Chris Mason 已提交
1438
	while (ptr < ptr_end) {
1439
		di = (struct btrfs_dir_item *)ptr;
1440 1441 1442 1443 1444
		if (verify_dir_item(root, eb, di)) {
			ret = -EIO;
			goto out;
		}

1445 1446 1447 1448 1449 1450 1451 1452 1453
		name_len = btrfs_dir_name_len(eb, di);
		name = kmalloc(name_len, GFP_NOFS);
		if (!name) {
			ret = -ENOMEM;
			goto out;
		}
		read_extent_buffer(eb, name, (unsigned long)(di + 1),
				  name_len);
		log_di = NULL;
1454
		if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
1455 1456 1457
			log_di = btrfs_lookup_dir_item(trans, log, log_path,
						       dir_key->objectid,
						       name, name_len, 0);
1458
		} else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
1459 1460 1461 1462 1463 1464
			log_di = btrfs_lookup_dir_index_item(trans, log,
						     log_path,
						     dir_key->objectid,
						     dir_key->offset,
						     name, name_len, 0);
		}
1465
		if (IS_ERR_OR_NULL(log_di)) {
1466
			btrfs_dir_item_key_to_cpu(eb, di, &location);
1467 1468
			btrfs_release_path(path);
			btrfs_release_path(log_path);
1469
			inode = read_one_inode(root, location.objectid);
1470 1471 1472 1473
			if (!inode) {
				kfree(name);
				return -EIO;
			}
1474 1475 1476 1477 1478 1479 1480 1481

			ret = link_to_fixup_dir(trans, root,
						path, location.objectid);
			BUG_ON(ret);
			btrfs_inc_nlink(inode);
			ret = btrfs_unlink_inode(trans, root, dir, inode,
						 name, name_len);
			BUG_ON(ret);
1482 1483 1484

			btrfs_run_delayed_items(trans, root);

1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497
			kfree(name);
			iput(inode);

			/* there might still be more names under this key
			 * check and repeat if required
			 */
			ret = btrfs_search_slot(NULL, root, dir_key, path,
						0, 0);
			if (ret == 0)
				goto again;
			ret = 0;
			goto out;
		}
1498
		btrfs_release_path(log_path);
1499 1500 1501 1502 1503 1504 1505
		kfree(name);

		ptr = (unsigned long)(di + 1);
		ptr += name_len;
	}
	ret = 0;
out:
1506 1507
	btrfs_release_path(path);
	btrfs_release_path(log_path);
1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524
	return ret;
}

/*
 * deletion replay happens before we copy any new directory items
 * out of the log or out of backreferences from inodes.  It
 * scans the log to find ranges of keys that log is authoritative for,
 * and then scans the directory to find items in those ranges that are
 * not present in the log.
 *
 * Anything we don't find in the log is unlinked and removed from the
 * directory.
 */
static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
				       struct btrfs_root *root,
				       struct btrfs_root *log,
				       struct btrfs_path *path,
1525
				       u64 dirid, int del_all)
1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553
{
	u64 range_start;
	u64 range_end;
	int key_type = BTRFS_DIR_LOG_ITEM_KEY;
	int ret = 0;
	struct btrfs_key dir_key;
	struct btrfs_key found_key;
	struct btrfs_path *log_path;
	struct inode *dir;

	dir_key.objectid = dirid;
	dir_key.type = BTRFS_DIR_ITEM_KEY;
	log_path = btrfs_alloc_path();
	if (!log_path)
		return -ENOMEM;

	dir = read_one_inode(root, dirid);
	/* it isn't an error if the inode isn't there, that can happen
	 * because we replay the deletes before we copy in the inode item
	 * from the log
	 */
	if (!dir) {
		btrfs_free_path(log_path);
		return 0;
	}
again:
	range_start = 0;
	range_end = 0;
C
Chris Mason 已提交
1554
	while (1) {
1555 1556 1557 1558 1559 1560 1561 1562
		if (del_all)
			range_end = (u64)-1;
		else {
			ret = find_dir_range(log, path, dirid, key_type,
					     &range_start, &range_end);
			if (ret != 0)
				break;
		}
1563 1564

		dir_key.offset = range_start;
C
Chris Mason 已提交
1565
		while (1) {
1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587
			int nritems;
			ret = btrfs_search_slot(NULL, root, &dir_key, path,
						0, 0);
			if (ret < 0)
				goto out;

			nritems = btrfs_header_nritems(path->nodes[0]);
			if (path->slots[0] >= nritems) {
				ret = btrfs_next_leaf(root, path);
				if (ret)
					break;
			}
			btrfs_item_key_to_cpu(path->nodes[0], &found_key,
					      path->slots[0]);
			if (found_key.objectid != dirid ||
			    found_key.type != dir_key.type)
				goto next_type;

			if (found_key.offset > range_end)
				break;

			ret = check_item_in_log(trans, root, log, path,
1588 1589
						log_path, dir,
						&found_key);
1590 1591 1592 1593 1594
			BUG_ON(ret);
			if (found_key.offset == (u64)-1)
				break;
			dir_key.offset = found_key.offset + 1;
		}
1595
		btrfs_release_path(path);
1596 1597 1598 1599 1600 1601 1602 1603 1604 1605
		if (range_end == (u64)-1)
			break;
		range_start = range_end + 1;
	}

next_type:
	ret = 0;
	if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
		key_type = BTRFS_DIR_LOG_INDEX_KEY;
		dir_key.type = BTRFS_DIR_INDEX_KEY;
1606
		btrfs_release_path(path);
1607 1608 1609
		goto again;
	}
out:
1610
	btrfs_release_path(path);
1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637
	btrfs_free_path(log_path);
	iput(dir);
	return ret;
}

/*
 * the process_func used to replay items from the log tree.  This
 * gets called in two different stages.  The first stage just looks
 * for inodes and makes sure they are all copied into the subvolume.
 *
 * The second stage copies all the other item types from the log into
 * the subvolume.  The two stage approach is slower, but gets rid of
 * lots of complexity around inodes referencing other inodes that exist
 * only in the log (references come from either directory items or inode
 * back refs).
 */
static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
			     struct walk_control *wc, u64 gen)
{
	int nritems;
	struct btrfs_path *path;
	struct btrfs_root *root = wc->replay_dest;
	struct btrfs_key key;
	int level;
	int i;
	int ret;

1638 1639 1640
	ret = btrfs_read_buffer(eb, gen);
	if (ret)
		return ret;
1641 1642 1643 1644 1645 1646 1647

	level = btrfs_header_level(eb);

	if (level != 0)
		return 0;

	path = btrfs_alloc_path();
1648 1649
	if (!path)
		return -ENOMEM;
1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665

	nritems = btrfs_header_nritems(eb);
	for (i = 0; i < nritems; i++) {
		btrfs_item_key_to_cpu(eb, &key, i);

		/* inode keys are done during the first stage */
		if (key.type == BTRFS_INODE_ITEM_KEY &&
		    wc->stage == LOG_WALK_REPLAY_INODES) {
			struct btrfs_inode_item *inode_item;
			u32 mode;

			inode_item = btrfs_item_ptr(eb, i,
					    struct btrfs_inode_item);
			mode = btrfs_inode_mode(eb, inode_item);
			if (S_ISDIR(mode)) {
				ret = replay_dir_deletes(wc->trans,
1666
					 root, log, path, key.objectid, 0);
1667 1668 1669 1670 1671 1672
				BUG_ON(ret);
			}
			ret = overwrite_item(wc->trans, root, path,
					     eb, i, &key);
			BUG_ON(ret);

1673 1674 1675
			/* for regular files, make sure corresponding
			 * orhpan item exist. extents past the new EOF
			 * will be truncated later by orphan cleanup.
1676 1677
			 */
			if (S_ISREG(mode)) {
1678 1679
				ret = insert_orphan_item(wc->trans, root,
							 key.objectid);
1680 1681
				BUG_ON(ret);
			}
1682

1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713
			ret = link_to_fixup_dir(wc->trans, root,
						path, key.objectid);
			BUG_ON(ret);
		}
		if (wc->stage < LOG_WALK_REPLAY_ALL)
			continue;

		/* these keys are simply copied */
		if (key.type == BTRFS_XATTR_ITEM_KEY) {
			ret = overwrite_item(wc->trans, root, path,
					     eb, i, &key);
			BUG_ON(ret);
		} else if (key.type == BTRFS_INODE_REF_KEY) {
			ret = add_inode_ref(wc->trans, root, log, path,
					    eb, i, &key);
			BUG_ON(ret && ret != -ENOENT);
		} else if (key.type == BTRFS_EXTENT_DATA_KEY) {
			ret = replay_one_extent(wc->trans, root, path,
						eb, i, &key);
			BUG_ON(ret);
		} else if (key.type == BTRFS_DIR_ITEM_KEY ||
			   key.type == BTRFS_DIR_INDEX_KEY) {
			ret = replay_one_dir_item(wc->trans, root, path,
						  eb, i, &key);
			BUG_ON(ret);
		}
	}
	btrfs_free_path(path);
	return 0;
}

C
Chris Mason 已提交
1714
static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730
				   struct btrfs_root *root,
				   struct btrfs_path *path, int *level,
				   struct walk_control *wc)
{
	u64 root_owner;
	u64 bytenr;
	u64 ptr_gen;
	struct extent_buffer *next;
	struct extent_buffer *cur;
	struct extent_buffer *parent;
	u32 blocksize;
	int ret = 0;

	WARN_ON(*level < 0);
	WARN_ON(*level >= BTRFS_MAX_LEVEL);

C
Chris Mason 已提交
1731
	while (*level > 0) {
1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750
		WARN_ON(*level < 0);
		WARN_ON(*level >= BTRFS_MAX_LEVEL);
		cur = path->nodes[*level];

		if (btrfs_header_level(cur) != *level)
			WARN_ON(1);

		if (path->slots[*level] >=
		    btrfs_header_nritems(cur))
			break;

		bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
		ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
		blocksize = btrfs_level_size(root, *level - 1);

		parent = path->nodes[*level];
		root_owner = btrfs_header_owner(parent);

		next = btrfs_find_create_tree_block(root, bytenr, blocksize);
1751 1752
		if (!next)
			return -ENOMEM;
1753 1754

		if (*level == 1) {
1755 1756 1757
			ret = wc->process_func(root, next, wc, ptr_gen);
			if (ret)
				return ret;
1758

1759 1760
			path->slots[*level]++;
			if (wc->free) {
1761 1762 1763 1764 1765
				ret = btrfs_read_buffer(next, ptr_gen);
				if (ret) {
					free_extent_buffer(next);
					return ret;
				}
1766 1767

				btrfs_tree_lock(next);
1768
				btrfs_set_lock_blocking(next);
1769
				clean_tree_block(trans, root, next);
1770 1771 1772 1773 1774
				btrfs_wait_tree_block_writeback(next);
				btrfs_tree_unlock(next);

				WARN_ON(root_owner !=
					BTRFS_TREE_LOG_OBJECTID);
1775
				ret = btrfs_free_and_pin_reserved_extent(root,
1776
							 bytenr, blocksize);
1777
				BUG_ON(ret); /* -ENOMEM or logic errors */
1778 1779 1780 1781
			}
			free_extent_buffer(next);
			continue;
		}
1782 1783 1784 1785 1786
		ret = btrfs_read_buffer(next, ptr_gen);
		if (ret) {
			free_extent_buffer(next);
			return ret;
		}
1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798

		WARN_ON(*level <= 0);
		if (path->nodes[*level-1])
			free_extent_buffer(path->nodes[*level-1]);
		path->nodes[*level-1] = next;
		*level = btrfs_header_level(next);
		path->slots[*level] = 0;
		cond_resched();
	}
	WARN_ON(*level < 0);
	WARN_ON(*level >= BTRFS_MAX_LEVEL);

1799
	path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
1800 1801 1802 1803 1804

	cond_resched();
	return 0;
}

C
Chris Mason 已提交
1805
static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
1806 1807 1808 1809 1810 1811 1812 1813 1814
				 struct btrfs_root *root,
				 struct btrfs_path *path, int *level,
				 struct walk_control *wc)
{
	u64 root_owner;
	int i;
	int slot;
	int ret;

C
Chris Mason 已提交
1815
	for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1816
		slot = path->slots[i];
1817
		if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
1818 1819 1820 1821 1822
			path->slots[i]++;
			*level = i;
			WARN_ON(*level == 0);
			return 0;
		} else {
Z
Zheng Yan 已提交
1823 1824 1825 1826 1827 1828 1829
			struct extent_buffer *parent;
			if (path->nodes[*level] == root->node)
				parent = path->nodes[*level];
			else
				parent = path->nodes[*level + 1];

			root_owner = btrfs_header_owner(parent);
1830
			ret = wc->process_func(root, path->nodes[*level], wc,
1831
				 btrfs_header_generation(path->nodes[*level]));
1832 1833 1834
			if (ret)
				return ret;

1835 1836 1837 1838 1839 1840
			if (wc->free) {
				struct extent_buffer *next;

				next = path->nodes[*level];

				btrfs_tree_lock(next);
1841
				btrfs_set_lock_blocking(next);
1842
				clean_tree_block(trans, root, next);
1843 1844 1845 1846
				btrfs_wait_tree_block_writeback(next);
				btrfs_tree_unlock(next);

				WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1847
				ret = btrfs_free_and_pin_reserved_extent(root,
1848
						path->nodes[*level]->start,
1849
						path->nodes[*level]->len);
1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875
				BUG_ON(ret);
			}
			free_extent_buffer(path->nodes[*level]);
			path->nodes[*level] = NULL;
			*level = i + 1;
		}
	}
	return 1;
}

/*
 * drop the reference count on the tree rooted at 'snap'.  This traverses
 * the tree freeing any blocks that have a ref count of zero after being
 * decremented.
 */
static int walk_log_tree(struct btrfs_trans_handle *trans,
			 struct btrfs_root *log, struct walk_control *wc)
{
	int ret = 0;
	int wret;
	int level;
	struct btrfs_path *path;
	int i;
	int orig_level;

	path = btrfs_alloc_path();
T
Tsutomu Itoh 已提交
1876 1877
	if (!path)
		return -ENOMEM;
1878 1879 1880 1881 1882 1883 1884

	level = btrfs_header_level(log->node);
	orig_level = level;
	path->nodes[level] = log->node;
	extent_buffer_get(log->node);
	path->slots[level] = 0;

C
Chris Mason 已提交
1885
	while (1) {
1886 1887 1888
		wret = walk_down_log_tree(trans, log, path, &level, wc);
		if (wret > 0)
			break;
1889
		if (wret < 0) {
1890
			ret = wret;
1891 1892
			goto out;
		}
1893 1894 1895 1896

		wret = walk_up_log_tree(trans, log, path, &level, wc);
		if (wret > 0)
			break;
1897
		if (wret < 0) {
1898
			ret = wret;
1899 1900
			goto out;
		}
1901 1902 1903 1904
	}

	/* was the root node processed? if not, catch it here */
	if (path->nodes[orig_level]) {
1905
		ret = wc->process_func(log, path->nodes[orig_level], wc,
1906
			 btrfs_header_generation(path->nodes[orig_level]));
1907 1908
		if (ret)
			goto out;
1909 1910 1911 1912 1913 1914
		if (wc->free) {
			struct extent_buffer *next;

			next = path->nodes[orig_level];

			btrfs_tree_lock(next);
1915
			btrfs_set_lock_blocking(next);
1916
			clean_tree_block(trans, log, next);
1917 1918 1919 1920 1921
			btrfs_wait_tree_block_writeback(next);
			btrfs_tree_unlock(next);

			WARN_ON(log->root_key.objectid !=
				BTRFS_TREE_LOG_OBJECTID);
1922
			ret = btrfs_free_and_pin_reserved_extent(log, next->start,
1923
							 next->len);
1924
			BUG_ON(ret); /* -ENOMEM or logic errors */
1925 1926 1927
		}
	}

1928
out:
1929 1930 1931 1932 1933 1934 1935 1936 1937 1938
	for (i = 0; i <= orig_level; i++) {
		if (path->nodes[i]) {
			free_extent_buffer(path->nodes[i]);
			path->nodes[i] = NULL;
		}
	}
	btrfs_free_path(path);
	return ret;
}

Y
Yan Zheng 已提交
1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958
/*
 * helper function to update the item for a given subvolumes log root
 * in the tree of log roots
 */
static int update_log_root(struct btrfs_trans_handle *trans,
			   struct btrfs_root *log)
{
	int ret;

	if (log->log_transid == 1) {
		/* insert root item on the first sync */
		ret = btrfs_insert_root(trans, log->fs_info->log_root_tree,
				&log->root_key, &log->root_item);
	} else {
		ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
				&log->root_key, &log->root_item);
	}
	return ret;
}

1959 1960
static int wait_log_commit(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root, unsigned long transid)
1961 1962
{
	DEFINE_WAIT(wait);
Y
Yan Zheng 已提交
1963
	int index = transid % 2;
1964

Y
Yan Zheng 已提交
1965 1966 1967 1968 1969
	/*
	 * we only allow two pending log transactions at a time,
	 * so we know that if ours is more than 2 older than the
	 * current transaction, we're done
	 */
1970
	do {
Y
Yan Zheng 已提交
1971 1972 1973
		prepare_to_wait(&root->log_commit_wait[index],
				&wait, TASK_UNINTERRUPTIBLE);
		mutex_unlock(&root->log_mutex);
1974 1975 1976

		if (root->fs_info->last_trans_log_full_commit !=
		    trans->transid && root->log_transid < transid + 2 &&
Y
Yan Zheng 已提交
1977 1978
		    atomic_read(&root->log_commit[index]))
			schedule();
1979

Y
Yan Zheng 已提交
1980 1981
		finish_wait(&root->log_commit_wait[index], &wait);
		mutex_lock(&root->log_mutex);
1982 1983
	} while (root->fs_info->last_trans_log_full_commit !=
		 trans->transid && root->log_transid < transid + 2 &&
Y
Yan Zheng 已提交
1984 1985 1986 1987
		 atomic_read(&root->log_commit[index]));
	return 0;
}

1988 1989
static void wait_for_writer(struct btrfs_trans_handle *trans,
			    struct btrfs_root *root)
Y
Yan Zheng 已提交
1990 1991
{
	DEFINE_WAIT(wait);
1992 1993
	while (root->fs_info->last_trans_log_full_commit !=
	       trans->transid && atomic_read(&root->log_writers)) {
Y
Yan Zheng 已提交
1994 1995 1996
		prepare_to_wait(&root->log_writer_wait,
				&wait, TASK_UNINTERRUPTIBLE);
		mutex_unlock(&root->log_mutex);
1997 1998
		if (root->fs_info->last_trans_log_full_commit !=
		    trans->transid && atomic_read(&root->log_writers))
1999
			schedule();
Y
Yan Zheng 已提交
2000 2001 2002
		mutex_lock(&root->log_mutex);
		finish_wait(&root->log_writer_wait, &wait);
	}
2003 2004 2005 2006 2007
}

/*
 * btrfs_sync_log does sends a given tree log down to the disk and
 * updates the super blocks to record it.  When this call is done,
2008 2009 2010 2011 2012 2013 2014 2015
 * you know that any inodes previously logged are safely on disk only
 * if it returns 0.
 *
 * Any other return value means you need to call btrfs_commit_transaction.
 * Some of the edge cases for fsyncing directories that have had unlinks
 * or renames done in the past mean that sometimes the only safe
 * fsync is to commit the whole FS.  When btrfs_sync_log returns -EAGAIN,
 * that has happened.
2016 2017 2018 2019
 */
int btrfs_sync_log(struct btrfs_trans_handle *trans,
		   struct btrfs_root *root)
{
Y
Yan Zheng 已提交
2020 2021
	int index1;
	int index2;
2022
	int mark;
2023 2024
	int ret;
	struct btrfs_root *log = root->log_root;
Y
Yan Zheng 已提交
2025
	struct btrfs_root *log_root_tree = root->fs_info->log_root_tree;
2026
	unsigned long log_transid = 0;
2027

Y
Yan Zheng 已提交
2028 2029 2030
	mutex_lock(&root->log_mutex);
	index1 = root->log_transid % 2;
	if (atomic_read(&root->log_commit[index1])) {
2031
		wait_log_commit(trans, root, root->log_transid);
Y
Yan Zheng 已提交
2032 2033
		mutex_unlock(&root->log_mutex);
		return 0;
2034
	}
Y
Yan Zheng 已提交
2035 2036 2037 2038
	atomic_set(&root->log_commit[index1], 1);

	/* wait for previous tree log sync to complete */
	if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
2039
		wait_log_commit(trans, root, root->log_transid - 1);
2040
	while (1) {
Y
Yan Zheng 已提交
2041
		unsigned long batch = root->log_batch;
2042 2043
		/* when we're on an ssd, just kick the log commit out */
		if (!btrfs_test_opt(root, SSD) && root->log_multiple_pids) {
2044 2045 2046 2047
			mutex_unlock(&root->log_mutex);
			schedule_timeout_uninterruptible(1);
			mutex_lock(&root->log_mutex);
		}
2048
		wait_for_writer(trans, root);
Y
Yan Zheng 已提交
2049
		if (batch == root->log_batch)
2050 2051 2052
			break;
	}

2053 2054 2055 2056 2057 2058 2059
	/* bail out if we need to do a full commit */
	if (root->fs_info->last_trans_log_full_commit == trans->transid) {
		ret = -EAGAIN;
		mutex_unlock(&root->log_mutex);
		goto out;
	}

2060 2061 2062 2063 2064 2065
	log_transid = root->log_transid;
	if (log_transid % 2 == 0)
		mark = EXTENT_DIRTY;
	else
		mark = EXTENT_NEW;

2066 2067 2068
	/* we start IO on  all the marked extents here, but we don't actually
	 * wait for them until later.
	 */
2069
	ret = btrfs_write_marked_extents(log, &log->dirty_log_pages, mark);
2070 2071 2072 2073 2074
	if (ret) {
		btrfs_abort_transaction(trans, root, ret);
		mutex_unlock(&root->log_mutex);
		goto out;
	}
Y
Yan Zheng 已提交
2075

2076
	btrfs_set_root_node(&log->root_item, log->node);
Y
Yan Zheng 已提交
2077 2078 2079 2080

	root->log_batch = 0;
	root->log_transid++;
	log->log_transid = root->log_transid;
2081
	root->log_start_pid = 0;
Y
Yan Zheng 已提交
2082 2083
	smp_mb();
	/*
2084 2085 2086
	 * IO has been started, blocks of the log tree have WRITTEN flag set
	 * in their headers. new modifications of the log will be written to
	 * new positions. so it's safe to allow log writers to go in.
Y
Yan Zheng 已提交
2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103
	 */
	mutex_unlock(&root->log_mutex);

	mutex_lock(&log_root_tree->log_mutex);
	log_root_tree->log_batch++;
	atomic_inc(&log_root_tree->log_writers);
	mutex_unlock(&log_root_tree->log_mutex);

	ret = update_log_root(trans, log);

	mutex_lock(&log_root_tree->log_mutex);
	if (atomic_dec_and_test(&log_root_tree->log_writers)) {
		smp_mb();
		if (waitqueue_active(&log_root_tree->log_writer_wait))
			wake_up(&log_root_tree->log_writer_wait);
	}

2104
	if (ret) {
2105 2106 2107 2108 2109
		if (ret != -ENOSPC) {
			btrfs_abort_transaction(trans, root, ret);
			mutex_unlock(&log_root_tree->log_mutex);
			goto out;
		}
2110 2111 2112 2113 2114 2115 2116
		root->fs_info->last_trans_log_full_commit = trans->transid;
		btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
		mutex_unlock(&log_root_tree->log_mutex);
		ret = -EAGAIN;
		goto out;
	}

Y
Yan Zheng 已提交
2117 2118
	index2 = log_root_tree->log_transid % 2;
	if (atomic_read(&log_root_tree->log_commit[index2])) {
2119
		btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2120 2121
		wait_log_commit(trans, log_root_tree,
				log_root_tree->log_transid);
Y
Yan Zheng 已提交
2122
		mutex_unlock(&log_root_tree->log_mutex);
2123
		ret = 0;
Y
Yan Zheng 已提交
2124 2125 2126 2127
		goto out;
	}
	atomic_set(&log_root_tree->log_commit[index2], 1);

2128 2129 2130 2131 2132 2133
	if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
		wait_log_commit(trans, log_root_tree,
				log_root_tree->log_transid - 1);
	}

	wait_for_writer(trans, log_root_tree);
Y
Yan Zheng 已提交
2134

2135 2136 2137 2138 2139
	/*
	 * now that we've moved on to the tree of log tree roots,
	 * check the full commit flag again
	 */
	if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2140
		btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2141 2142 2143 2144
		mutex_unlock(&log_root_tree->log_mutex);
		ret = -EAGAIN;
		goto out_wake_log_root;
	}
Y
Yan Zheng 已提交
2145 2146

	ret = btrfs_write_and_wait_marked_extents(log_root_tree,
2147 2148
				&log_root_tree->dirty_log_pages,
				EXTENT_DIRTY | EXTENT_NEW);
2149 2150 2151 2152 2153
	if (ret) {
		btrfs_abort_transaction(trans, root, ret);
		mutex_unlock(&log_root_tree->log_mutex);
		goto out_wake_log_root;
	}
2154
	btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2155

2156
	btrfs_set_super_log_root(root->fs_info->super_for_commit,
Y
Yan Zheng 已提交
2157
				log_root_tree->node->start);
2158
	btrfs_set_super_log_root_level(root->fs_info->super_for_commit,
Y
Yan Zheng 已提交
2159
				btrfs_header_level(log_root_tree->node));
2160

Y
Yan Zheng 已提交
2161 2162
	log_root_tree->log_batch = 0;
	log_root_tree->log_transid++;
2163
	smp_mb();
Y
Yan Zheng 已提交
2164 2165 2166 2167 2168 2169 2170 2171 2172 2173

	mutex_unlock(&log_root_tree->log_mutex);

	/*
	 * nobody else is going to jump in and write the the ctree
	 * super here because the log_commit atomic below is protecting
	 * us.  We must be called with a transaction handle pinning
	 * the running transaction open, so a full commit can't hop
	 * in and cause problems either.
	 */
A
Arne Jansen 已提交
2174
	btrfs_scrub_pause_super(root);
2175
	write_ctree_super(trans, root->fs_info->tree_root, 1);
A
Arne Jansen 已提交
2176
	btrfs_scrub_continue_super(root);
2177
	ret = 0;
Y
Yan Zheng 已提交
2178

2179 2180 2181 2182 2183
	mutex_lock(&root->log_mutex);
	if (root->last_log_commit < log_transid)
		root->last_log_commit = log_transid;
	mutex_unlock(&root->log_mutex);

2184
out_wake_log_root:
Y
Yan Zheng 已提交
2185 2186 2187 2188
	atomic_set(&log_root_tree->log_commit[index2], 0);
	smp_mb();
	if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
		wake_up(&log_root_tree->log_commit_wait[index2]);
2189
out:
Y
Yan Zheng 已提交
2190 2191 2192 2193
	atomic_set(&root->log_commit[index1], 0);
	smp_mb();
	if (waitqueue_active(&root->log_commit_wait[index1]))
		wake_up(&root->log_commit_wait[index1]);
2194
	return ret;
2195 2196
}

2197 2198
static void free_log_tree(struct btrfs_trans_handle *trans,
			  struct btrfs_root *log)
2199 2200
{
	int ret;
2201 2202
	u64 start;
	u64 end;
2203 2204 2205 2206 2207 2208 2209 2210
	struct walk_control wc = {
		.free = 1,
		.process_func = process_one_buffer
	};

	ret = walk_log_tree(trans, log, &wc);
	BUG_ON(ret);

C
Chris Mason 已提交
2211
	while (1) {
2212
		ret = find_first_extent_bit(&log->dirty_log_pages,
2213
				0, &start, &end, EXTENT_DIRTY | EXTENT_NEW);
2214 2215 2216
		if (ret)
			break;

2217 2218
		clear_extent_bits(&log->dirty_log_pages, start, end,
				  EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
2219 2220
	}

Y
Yan Zheng 已提交
2221 2222
	free_extent_buffer(log->node);
	kfree(log);
2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244
}

/*
 * free all the extents used by the tree log.  This should be called
 * at commit time of the full transaction
 */
int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
{
	if (root->log_root) {
		free_log_tree(trans, root->log_root);
		root->log_root = NULL;
	}
	return 0;
}

int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
			     struct btrfs_fs_info *fs_info)
{
	if (fs_info->log_root_tree) {
		free_log_tree(trans, fs_info->log_root_tree);
		fs_info->log_root_tree = NULL;
	}
2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277
	return 0;
}

/*
 * If both a file and directory are logged, and unlinks or renames are
 * mixed in, we have a few interesting corners:
 *
 * create file X in dir Y
 * link file X to X.link in dir Y
 * fsync file X
 * unlink file X but leave X.link
 * fsync dir Y
 *
 * After a crash we would expect only X.link to exist.  But file X
 * didn't get fsync'd again so the log has back refs for X and X.link.
 *
 * We solve this by removing directory entries and inode backrefs from the
 * log when a file that was logged in the current transaction is
 * unlinked.  Any later fsync will include the updated log entries, and
 * we'll be able to reconstruct the proper directory items from backrefs.
 *
 * This optimizations allows us to avoid relogging the entire inode
 * or the entire directory.
 */
int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
				 struct btrfs_root *root,
				 const char *name, int name_len,
				 struct inode *dir, u64 index)
{
	struct btrfs_root *log;
	struct btrfs_dir_item *di;
	struct btrfs_path *path;
	int ret;
2278
	int err = 0;
2279
	int bytes_del = 0;
L
Li Zefan 已提交
2280
	u64 dir_ino = btrfs_ino(dir);
2281

2282 2283 2284
	if (BTRFS_I(dir)->logged_trans < trans->transid)
		return 0;

2285 2286 2287 2288 2289 2290 2291 2292
	ret = join_running_log_trans(root);
	if (ret)
		return 0;

	mutex_lock(&BTRFS_I(dir)->log_mutex);

	log = root->log_root;
	path = btrfs_alloc_path();
2293 2294 2295 2296
	if (!path) {
		err = -ENOMEM;
		goto out_unlock;
	}
2297

L
Li Zefan 已提交
2298
	di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
2299
				   name, name_len, -1);
2300 2301 2302 2303 2304
	if (IS_ERR(di)) {
		err = PTR_ERR(di);
		goto fail;
	}
	if (di) {
2305 2306 2307 2308
		ret = btrfs_delete_one_dir_name(trans, log, path, di);
		bytes_del += name_len;
		BUG_ON(ret);
	}
2309
	btrfs_release_path(path);
L
Li Zefan 已提交
2310
	di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
2311
					 index, name, name_len, -1);
2312 2313 2314 2315 2316
	if (IS_ERR(di)) {
		err = PTR_ERR(di);
		goto fail;
	}
	if (di) {
2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327
		ret = btrfs_delete_one_dir_name(trans, log, path, di);
		bytes_del += name_len;
		BUG_ON(ret);
	}

	/* update the directory size in the log to reflect the names
	 * we have removed
	 */
	if (bytes_del) {
		struct btrfs_key key;

L
Li Zefan 已提交
2328
		key.objectid = dir_ino;
2329 2330
		key.offset = 0;
		key.type = BTRFS_INODE_ITEM_KEY;
2331
		btrfs_release_path(path);
2332 2333

		ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
2334 2335 2336 2337
		if (ret < 0) {
			err = ret;
			goto fail;
		}
2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352
		if (ret == 0) {
			struct btrfs_inode_item *item;
			u64 i_size;

			item = btrfs_item_ptr(path->nodes[0], path->slots[0],
					      struct btrfs_inode_item);
			i_size = btrfs_inode_size(path->nodes[0], item);
			if (i_size > bytes_del)
				i_size -= bytes_del;
			else
				i_size = 0;
			btrfs_set_inode_size(path->nodes[0], item, i_size);
			btrfs_mark_buffer_dirty(path->nodes[0]);
		} else
			ret = 0;
2353
		btrfs_release_path(path);
2354
	}
2355
fail:
2356
	btrfs_free_path(path);
2357
out_unlock:
2358
	mutex_unlock(&BTRFS_I(dir)->log_mutex);
2359 2360 2361
	if (ret == -ENOSPC) {
		root->fs_info->last_trans_log_full_commit = trans->transid;
		ret = 0;
2362 2363 2364
	} else if (ret < 0)
		btrfs_abort_transaction(trans, root, ret);

2365
	btrfs_end_log_trans(root);
2366

2367
	return err;
2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379
}

/* see comments for btrfs_del_dir_entries_in_log */
int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
			       struct btrfs_root *root,
			       const char *name, int name_len,
			       struct inode *inode, u64 dirid)
{
	struct btrfs_root *log;
	u64 index;
	int ret;

2380 2381 2382
	if (BTRFS_I(inode)->logged_trans < trans->transid)
		return 0;

2383 2384 2385 2386 2387 2388
	ret = join_running_log_trans(root);
	if (ret)
		return 0;
	log = root->log_root;
	mutex_lock(&BTRFS_I(inode)->log_mutex);

L
Li Zefan 已提交
2389
	ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
2390 2391
				  dirid, &index);
	mutex_unlock(&BTRFS_I(inode)->log_mutex);
2392 2393 2394
	if (ret == -ENOSPC) {
		root->fs_info->last_trans_log_full_commit = trans->transid;
		ret = 0;
2395 2396
	} else if (ret < 0 && ret != -ENOENT)
		btrfs_abort_transaction(trans, root, ret);
2397
	btrfs_end_log_trans(root);
2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423

	return ret;
}

/*
 * creates a range item in the log for 'dirid'.  first_offset and
 * last_offset tell us which parts of the key space the log should
 * be considered authoritative for.
 */
static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
				       struct btrfs_root *log,
				       struct btrfs_path *path,
				       int key_type, u64 dirid,
				       u64 first_offset, u64 last_offset)
{
	int ret;
	struct btrfs_key key;
	struct btrfs_dir_log_item *item;

	key.objectid = dirid;
	key.offset = first_offset;
	if (key_type == BTRFS_DIR_ITEM_KEY)
		key.type = BTRFS_DIR_LOG_ITEM_KEY;
	else
		key.type = BTRFS_DIR_LOG_INDEX_KEY;
	ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
2424 2425
	if (ret)
		return ret;
2426 2427 2428 2429 2430

	item = btrfs_item_ptr(path->nodes[0], path->slots[0],
			      struct btrfs_dir_log_item);
	btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
	btrfs_mark_buffer_dirty(path->nodes[0]);
2431
	btrfs_release_path(path);
2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449
	return 0;
}

/*
 * log all the items included in the current transaction for a given
 * directory.  This also creates the range items in the log tree required
 * to replay anything deleted before the fsync
 */
static noinline int log_dir_items(struct btrfs_trans_handle *trans,
			  struct btrfs_root *root, struct inode *inode,
			  struct btrfs_path *path,
			  struct btrfs_path *dst_path, int key_type,
			  u64 min_offset, u64 *last_offset_ret)
{
	struct btrfs_key min_key;
	struct btrfs_key max_key;
	struct btrfs_root *log = root->log_root;
	struct extent_buffer *src;
2450
	int err = 0;
2451 2452 2453 2454 2455
	int ret;
	int i;
	int nritems;
	u64 first_offset = min_offset;
	u64 last_offset = (u64)-1;
L
Li Zefan 已提交
2456
	u64 ino = btrfs_ino(inode);
2457 2458

	log = root->log_root;
L
Li Zefan 已提交
2459
	max_key.objectid = ino;
2460 2461 2462
	max_key.offset = (u64)-1;
	max_key.type = key_type;

L
Li Zefan 已提交
2463
	min_key.objectid = ino;
2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475
	min_key.type = key_type;
	min_key.offset = min_offset;

	path->keep_locks = 1;

	ret = btrfs_search_forward(root, &min_key, &max_key,
				   path, 0, trans->transid);

	/*
	 * we didn't find anything from this transaction, see if there
	 * is anything at all
	 */
L
Li Zefan 已提交
2476 2477
	if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
		min_key.objectid = ino;
2478 2479
		min_key.type = key_type;
		min_key.offset = (u64)-1;
2480
		btrfs_release_path(path);
2481 2482
		ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
		if (ret < 0) {
2483
			btrfs_release_path(path);
2484 2485
			return ret;
		}
L
Li Zefan 已提交
2486
		ret = btrfs_previous_item(root, path, ino, key_type);
2487 2488 2489 2490 2491 2492 2493 2494 2495 2496

		/* if ret == 0 there are items for this type,
		 * create a range to tell us the last key of this type.
		 * otherwise, there are no items in this directory after
		 * *min_offset, and we create a range to indicate that.
		 */
		if (ret == 0) {
			struct btrfs_key tmp;
			btrfs_item_key_to_cpu(path->nodes[0], &tmp,
					      path->slots[0]);
C
Chris Mason 已提交
2497
			if (key_type == tmp.type)
2498 2499 2500 2501 2502 2503
				first_offset = max(min_offset, tmp.offset) + 1;
		}
		goto done;
	}

	/* go backward to find any previous key */
L
Li Zefan 已提交
2504
	ret = btrfs_previous_item(root, path, ino, key_type);
2505 2506 2507 2508 2509 2510 2511 2512
	if (ret == 0) {
		struct btrfs_key tmp;
		btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
		if (key_type == tmp.type) {
			first_offset = tmp.offset;
			ret = overwrite_item(trans, log, dst_path,
					     path->nodes[0], path->slots[0],
					     &tmp);
2513 2514 2515 2516
			if (ret) {
				err = ret;
				goto done;
			}
2517 2518
		}
	}
2519
	btrfs_release_path(path);
2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531

	/* find the first key from this transaction again */
	ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
	if (ret != 0) {
		WARN_ON(1);
		goto done;
	}

	/*
	 * we have a block from this transaction, log every item in it
	 * from our directory
	 */
C
Chris Mason 已提交
2532
	while (1) {
2533 2534 2535 2536 2537 2538
		struct btrfs_key tmp;
		src = path->nodes[0];
		nritems = btrfs_header_nritems(src);
		for (i = path->slots[0]; i < nritems; i++) {
			btrfs_item_key_to_cpu(src, &min_key, i);

L
Li Zefan 已提交
2539
			if (min_key.objectid != ino || min_key.type != key_type)
2540 2541 2542
				goto done;
			ret = overwrite_item(trans, log, dst_path, src, i,
					     &min_key);
2543 2544 2545 2546
			if (ret) {
				err = ret;
				goto done;
			}
2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559
		}
		path->slots[0] = nritems;

		/*
		 * look ahead to the next item and see if it is also
		 * from this directory and from this transaction
		 */
		ret = btrfs_next_leaf(root, path);
		if (ret == 1) {
			last_offset = (u64)-1;
			goto done;
		}
		btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
L
Li Zefan 已提交
2560
		if (tmp.objectid != ino || tmp.type != key_type) {
2561 2562 2563 2564 2565 2566 2567
			last_offset = (u64)-1;
			goto done;
		}
		if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
			ret = overwrite_item(trans, log, dst_path,
					     path->nodes[0], path->slots[0],
					     &tmp);
2568 2569 2570 2571
			if (ret)
				err = ret;
			else
				last_offset = tmp.offset;
2572 2573 2574 2575
			goto done;
		}
	}
done:
2576 2577
	btrfs_release_path(path);
	btrfs_release_path(dst_path);
2578

2579 2580 2581 2582 2583 2584 2585
	if (err == 0) {
		*last_offset_ret = last_offset;
		/*
		 * insert the log range keys to indicate where the log
		 * is valid
		 */
		ret = insert_dir_log_key(trans, log, path, key_type,
L
Li Zefan 已提交
2586
					 ino, first_offset, last_offset);
2587 2588 2589 2590
		if (ret)
			err = ret;
	}
	return err;
2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617
}

/*
 * logging directories is very similar to logging inodes, We find all the items
 * from the current transaction and write them to the log.
 *
 * The recovery code scans the directory in the subvolume, and if it finds a
 * key in the range logged that is not present in the log tree, then it means
 * that dir entry was unlinked during the transaction.
 *
 * In order for that scan to work, we must include one key smaller than
 * the smallest logged by this transaction and one key larger than the largest
 * key logged by this transaction.
 */
static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
			  struct btrfs_root *root, struct inode *inode,
			  struct btrfs_path *path,
			  struct btrfs_path *dst_path)
{
	u64 min_key;
	u64 max_key;
	int ret;
	int key_type = BTRFS_DIR_ITEM_KEY;

again:
	min_key = 0;
	max_key = 0;
C
Chris Mason 已提交
2618
	while (1) {
2619 2620 2621
		ret = log_dir_items(trans, root, inode, path,
				    dst_path, key_type, min_key,
				    &max_key);
2622 2623
		if (ret)
			return ret;
2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654
		if (max_key == (u64)-1)
			break;
		min_key = max_key + 1;
	}

	if (key_type == BTRFS_DIR_ITEM_KEY) {
		key_type = BTRFS_DIR_INDEX_KEY;
		goto again;
	}
	return 0;
}

/*
 * a helper function to drop items from the log before we relog an
 * inode.  max_key_type indicates the highest item type to remove.
 * This cannot be run for file data extents because it does not
 * free the extents they point to.
 */
static int drop_objectid_items(struct btrfs_trans_handle *trans,
				  struct btrfs_root *log,
				  struct btrfs_path *path,
				  u64 objectid, int max_key_type)
{
	int ret;
	struct btrfs_key key;
	struct btrfs_key found_key;

	key.objectid = objectid;
	key.type = max_key_type;
	key.offset = (u64)-1;

C
Chris Mason 已提交
2655
	while (1) {
2656
		ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
2657 2658
		BUG_ON(ret == 0);
		if (ret < 0)
2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671
			break;

		if (path->slots[0] == 0)
			break;

		path->slots[0]--;
		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
				      path->slots[0]);

		if (found_key.objectid != objectid)
			break;

		ret = btrfs_del_item(trans, log, path);
2672 2673
		if (ret)
			break;
2674
		btrfs_release_path(path);
2675
	}
2676
	btrfs_release_path(path);
2677 2678
	if (ret > 0)
		ret = 0;
2679
	return ret;
2680 2681
}

2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696
static noinline int copy_items(struct btrfs_trans_handle *trans,
			       struct btrfs_root *log,
			       struct btrfs_path *dst_path,
			       struct extent_buffer *src,
			       int start_slot, int nr, int inode_only)
{
	unsigned long src_offset;
	unsigned long dst_offset;
	struct btrfs_file_extent_item *extent;
	struct btrfs_inode_item *inode_item;
	int ret;
	struct btrfs_key *ins_keys;
	u32 *ins_sizes;
	char *ins_data;
	int i;
2697 2698 2699
	struct list_head ordered_sums;

	INIT_LIST_HEAD(&ordered_sums);
2700 2701 2702

	ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
			   nr * sizeof(u32), GFP_NOFS);
2703 2704 2705
	if (!ins_data)
		return -ENOMEM;

2706 2707 2708 2709 2710 2711 2712 2713 2714
	ins_sizes = (u32 *)ins_data;
	ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));

	for (i = 0; i < nr; i++) {
		ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
		btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
	}
	ret = btrfs_insert_empty_items(trans, log, dst_path,
				       ins_keys, ins_sizes, nr);
2715 2716 2717 2718
	if (ret) {
		kfree(ins_data);
		return ret;
	}
2719

2720
	for (i = 0; i < nr; i++, dst_path->slots[0]++) {
2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752
		dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
						   dst_path->slots[0]);

		src_offset = btrfs_item_ptr_offset(src, start_slot + i);

		copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
				   src_offset, ins_sizes[i]);

		if (inode_only == LOG_INODE_EXISTS &&
		    ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
			inode_item = btrfs_item_ptr(dst_path->nodes[0],
						    dst_path->slots[0],
						    struct btrfs_inode_item);
			btrfs_set_inode_size(dst_path->nodes[0], inode_item, 0);

			/* set the generation to zero so the recover code
			 * can tell the difference between an logging
			 * just to say 'this inode exists' and a logging
			 * to say 'update this inode with these values'
			 */
			btrfs_set_inode_generation(dst_path->nodes[0],
						   inode_item, 0);
		}
		/* take a reference on file data extents so that truncates
		 * or deletes of this inode don't have to relog the inode
		 * again
		 */
		if (btrfs_key_type(ins_keys + i) == BTRFS_EXTENT_DATA_KEY) {
			int found_type;
			extent = btrfs_item_ptr(src, start_slot + i,
						struct btrfs_file_extent_item);

2753 2754 2755
			if (btrfs_file_extent_generation(src, extent) < trans->transid)
				continue;

2756
			found_type = btrfs_file_extent_type(src, extent);
Y
Yan Zheng 已提交
2757 2758
			if (found_type == BTRFS_FILE_EXTENT_REG ||
			    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769
				u64 ds, dl, cs, cl;
				ds = btrfs_file_extent_disk_bytenr(src,
								extent);
				/* ds == 0 is a hole */
				if (ds == 0)
					continue;

				dl = btrfs_file_extent_disk_num_bytes(src,
								extent);
				cs = btrfs_file_extent_offset(src, extent);
				cl = btrfs_file_extent_num_bytes(src,
2770
								extent);
2771 2772 2773 2774 2775
				if (btrfs_file_extent_compression(src,
								  extent)) {
					cs = 0;
					cl = dl;
				}
2776 2777 2778 2779

				ret = btrfs_lookup_csums_range(
						log->fs_info->csum_root,
						ds + cs, ds + cs + cl - 1,
A
Arne Jansen 已提交
2780
						&ordered_sums, 0);
2781
				BUG_ON(ret);
2782 2783 2784 2785 2786
			}
		}
	}

	btrfs_mark_buffer_dirty(dst_path->nodes[0]);
2787
	btrfs_release_path(dst_path);
2788
	kfree(ins_data);
2789 2790 2791 2792 2793

	/*
	 * we have to do this after the loop above to avoid changing the
	 * log tree while trying to change the log tree.
	 */
2794
	ret = 0;
C
Chris Mason 已提交
2795
	while (!list_empty(&ordered_sums)) {
2796 2797 2798
		struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
						   struct btrfs_ordered_sum,
						   list);
2799 2800
		if (!ret)
			ret = btrfs_csum_file_blocks(trans, log, sums);
2801 2802 2803
		list_del(&sums->list);
		kfree(sums);
	}
2804
	return ret;
2805 2806
}

J
Josef Bacik 已提交
2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835
static int extent_cmp(void *priv, struct list_head *a, struct list_head *b)
{
	struct extent_map *em1, *em2;

	em1 = list_entry(a, struct extent_map, list);
	em2 = list_entry(b, struct extent_map, list);

	if (em1->start < em2->start)
		return -1;
	else if (em1->start > em2->start)
		return 1;
	return 0;
}

struct log_args {
	struct extent_buffer *src;
	u64 next_offset;
	int start_slot;
	int nr;
};

static int log_one_extent(struct btrfs_trans_handle *trans,
			  struct inode *inode, struct btrfs_root *root,
			  struct extent_map *em, struct btrfs_path *path,
			  struct btrfs_path *dst_path, struct log_args *args)
{
	struct btrfs_root *log = root->log_root;
	struct btrfs_file_extent_item *fi;
	struct btrfs_key key;
2836 2837
	u64 start = em->mod_start;
	u64 len = em->mod_len;
J
Josef Bacik 已提交
2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972
	u64 num_bytes;
	int nritems;
	int ret;

	if (BTRFS_I(inode)->logged_trans == trans->transid) {
		u64 tmp;
		ret = __btrfs_drop_extents(trans, log, inode, dst_path, start,
					   start + len, &tmp, 0);
		if (ret)
			return ret;
	}

	while (len) {
		if (args->nr)
			goto next_slot;
		key.objectid = btrfs_ino(inode);
		key.type = BTRFS_EXTENT_DATA_KEY;
		key.offset = start;

		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret < 0)
			return ret;
		if (ret) {
			/*
			 * This shouldn't happen, but it might so warn and
			 * return an error.
			 */
			WARN_ON(1);
			return -ENOENT;
		}
		args->src = path->nodes[0];
next_slot:
		fi = btrfs_item_ptr(args->src, path->slots[0],
				    struct btrfs_file_extent_item);
		if (args->nr &&
		    args->start_slot + args->nr == path->slots[0]) {
			args->nr++;
		} else if (args->nr) {
			ret = copy_items(trans, log, dst_path, args->src,
					 args->start_slot, args->nr,
					 LOG_INODE_ALL);
			if (ret)
				return ret;
			args->nr = 1;
			args->start_slot = path->slots[0];
		} else if (!args->nr) {
			args->nr = 1;
			args->start_slot = path->slots[0];
		}
		nritems = btrfs_header_nritems(path->nodes[0]);
		path->slots[0]++;
		num_bytes = btrfs_file_extent_num_bytes(args->src, fi);
		if (len < num_bytes) {
			/* I _think_ this is ok, envision we write to a
			 * preallocated space that is adjacent to a previously
			 * written preallocated space that gets merged when we
			 * mark this preallocated space written.  If we do not
			 * have the adjacent extent in cache then when we copy
			 * this extent it could end up being larger than our EM
			 * thinks it is, which is a-ok, so just set len to 0.
			 */
			len = 0;
		} else {
			len -= num_bytes;
		}
		start += btrfs_file_extent_num_bytes(args->src, fi);
		args->next_offset = start;

		if (path->slots[0] < nritems) {
			if (len)
				goto next_slot;
			break;
		}

		if (args->nr) {
			ret = copy_items(trans, log, dst_path, args->src,
					 args->start_slot, args->nr,
					 LOG_INODE_ALL);
			if (ret)
				return ret;
			args->nr = 0;
			btrfs_release_path(path);
		}
	}

	return 0;
}

static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
				     struct btrfs_root *root,
				     struct inode *inode,
				     struct btrfs_path *path,
				     struct btrfs_path *dst_path)
{
	struct log_args args;
	struct btrfs_root *log = root->log_root;
	struct extent_map *em, *n;
	struct list_head extents;
	struct extent_map_tree *tree = &BTRFS_I(inode)->extent_tree;
	u64 test_gen;
	int ret = 0;

	INIT_LIST_HEAD(&extents);

	memset(&args, 0, sizeof(args));

	write_lock(&tree->lock);
	test_gen = root->fs_info->last_trans_committed;

	list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
		list_del_init(&em->list);
		if (em->generation <= test_gen)
			continue;
		list_add_tail(&em->list, &extents);
	}

	list_sort(NULL, &extents, extent_cmp);

	while (!list_empty(&extents)) {
		em = list_entry(extents.next, struct extent_map, list);

		list_del_init(&em->list);

		/*
		 * If we had an error we just need to delete everybody from our
		 * private list.
		 */
		if (ret)
			continue;

		/*
		 * If the previous EM and the last extent we left off on aren't
		 * sequential then we need to copy the items we have and redo
		 * our search
		 */
2973
		if (args.nr && em->mod_start != args.next_offset) {
J
Josef Bacik 已提交
2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994
			ret = copy_items(trans, log, dst_path, args.src,
					 args.start_slot, args.nr,
					 LOG_INODE_ALL);
			if (ret)
				continue;
			btrfs_release_path(path);
			args.nr = 0;
		}

		ret = log_one_extent(trans, inode, root, em, path, dst_path, &args);
	}

	if (!ret && args.nr)
		ret = copy_items(trans, log, dst_path, args.src,
				 args.start_slot, args.nr, LOG_INODE_ALL);
	btrfs_release_path(path);
	WARN_ON(!list_empty(&extents));
	write_unlock(&tree->lock);
	return ret;
}

2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008
/* log a single inode in the tree log.
 * At least one parent directory for this inode must exist in the tree
 * or be logged already.
 *
 * Any items from this inode changed by the current transaction are copied
 * to the log tree.  An extra reference is taken on any extents in this
 * file, allowing us to avoid a whole pile of corner cases around logging
 * blocks that have been removed from the tree.
 *
 * See LOG_INODE_ALL and related defines for a description of what inode_only
 * does.
 *
 * This handles both files and directories.
 */
3009
static int btrfs_log_inode(struct btrfs_trans_handle *trans,
3010 3011 3012 3013 3014 3015 3016 3017
			     struct btrfs_root *root, struct inode *inode,
			     int inode_only)
{
	struct btrfs_path *path;
	struct btrfs_path *dst_path;
	struct btrfs_key min_key;
	struct btrfs_key max_key;
	struct btrfs_root *log = root->log_root;
3018
	struct extent_buffer *src = NULL;
3019
	int err = 0;
3020
	int ret;
3021
	int nritems;
3022 3023
	int ins_start_slot = 0;
	int ins_nr;
J
Josef Bacik 已提交
3024
	bool fast_search = false;
L
Li Zefan 已提交
3025
	u64 ino = btrfs_ino(inode);
3026 3027 3028 3029

	log = root->log_root;

	path = btrfs_alloc_path();
3030 3031
	if (!path)
		return -ENOMEM;
3032
	dst_path = btrfs_alloc_path();
3033 3034 3035 3036
	if (!dst_path) {
		btrfs_free_path(path);
		return -ENOMEM;
	}
3037

L
Li Zefan 已提交
3038
	min_key.objectid = ino;
3039 3040 3041
	min_key.type = BTRFS_INODE_ITEM_KEY;
	min_key.offset = 0;

L
Li Zefan 已提交
3042
	max_key.objectid = ino;
3043 3044


J
Josef Bacik 已提交
3045
	/* today the code can only do partial logging of directories */
3046 3047 3048 3049 3050 3051
	if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
		max_key.type = BTRFS_XATTR_ITEM_KEY;
	else
		max_key.type = (u8)-1;
	max_key.offset = (u64)-1;

3052 3053 3054 3055 3056 3057 3058
	ret = btrfs_commit_inode_delayed_items(trans, inode);
	if (ret) {
		btrfs_free_path(path);
		btrfs_free_path(dst_path);
		return ret;
	}

3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069
	mutex_lock(&BTRFS_I(inode)->log_mutex);

	/*
	 * a brute force approach to making sure we get the most uptodate
	 * copies of everything.
	 */
	if (S_ISDIR(inode->i_mode)) {
		int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;

		if (inode_only == LOG_INODE_EXISTS)
			max_key_type = BTRFS_XATTR_ITEM_KEY;
L
Li Zefan 已提交
3070
		ret = drop_objectid_items(trans, log, path, ino, max_key_type);
3071
	} else {
J
Josef Bacik 已提交
3072 3073 3074 3075 3076 3077 3078 3079 3080 3081
		if (test_and_clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
				       &BTRFS_I(inode)->runtime_flags)) {
			ret = btrfs_truncate_inode_items(trans, log,
							 inode, 0, 0);
		} else {
			fast_search = true;
			max_key.type = BTRFS_XATTR_ITEM_KEY;
			ret = drop_objectid_items(trans, log, path, ino,
						  BTRFS_XATTR_ITEM_KEY);
		}
3082
	}
3083 3084 3085 3086
	if (ret) {
		err = ret;
		goto out_unlock;
	}
3087 3088
	path->keep_locks = 1;

C
Chris Mason 已提交
3089
	while (1) {
3090
		ins_nr = 0;
3091 3092 3093 3094
		ret = btrfs_search_forward(root, &min_key, &max_key,
					   path, 0, trans->transid);
		if (ret != 0)
			break;
3095
again:
3096
		/* note, ins_nr might be > 0 here, cleanup outside the loop */
L
Li Zefan 已提交
3097
		if (min_key.objectid != ino)
3098 3099 3100
			break;
		if (min_key.type > max_key.type)
			break;
3101

3102
		src = path->nodes[0];
3103 3104 3105 3106 3107 3108 3109
		if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
			ins_nr++;
			goto next_slot;
		} else if (!ins_nr) {
			ins_start_slot = path->slots[0];
			ins_nr = 1;
			goto next_slot;
3110 3111
		}

3112 3113
		ret = copy_items(trans, log, dst_path, src, ins_start_slot,
				 ins_nr, inode_only);
3114 3115 3116 3117
		if (ret) {
			err = ret;
			goto out_unlock;
		}
3118 3119 3120
		ins_nr = 1;
		ins_start_slot = path->slots[0];
next_slot:
3121

3122 3123 3124 3125 3126 3127 3128
		nritems = btrfs_header_nritems(path->nodes[0]);
		path->slots[0]++;
		if (path->slots[0] < nritems) {
			btrfs_item_key_to_cpu(path->nodes[0], &min_key,
					      path->slots[0]);
			goto again;
		}
3129 3130 3131 3132
		if (ins_nr) {
			ret = copy_items(trans, log, dst_path, src,
					 ins_start_slot,
					 ins_nr, inode_only);
3133 3134 3135 3136
			if (ret) {
				err = ret;
				goto out_unlock;
			}
3137 3138
			ins_nr = 0;
		}
3139
		btrfs_release_path(path);
3140

3141 3142 3143 3144 3145 3146 3147 3148 3149
		if (min_key.offset < (u64)-1)
			min_key.offset++;
		else if (min_key.type < (u8)-1)
			min_key.type++;
		else if (min_key.objectid < (u64)-1)
			min_key.objectid++;
		else
			break;
	}
3150 3151 3152 3153
	if (ins_nr) {
		ret = copy_items(trans, log, dst_path, src,
				 ins_start_slot,
				 ins_nr, inode_only);
3154 3155 3156 3157
		if (ret) {
			err = ret;
			goto out_unlock;
		}
3158 3159
		ins_nr = 0;
	}
J
Josef Bacik 已提交
3160 3161 3162 3163 3164 3165 3166 3167 3168 3169

	if (fast_search) {
		btrfs_release_path(path);
		btrfs_release_path(dst_path);
		ret = btrfs_log_changed_extents(trans, root, inode, path,
						dst_path);
		if (ret) {
			err = ret;
			goto out_unlock;
		}
3170 3171 3172 3173 3174 3175
	} else {
		struct extent_map_tree *tree = &BTRFS_I(inode)->extent_tree;
		struct extent_map *em, *n;

		list_for_each_entry_safe(em, n, &tree->modified_extents, list)
			list_del_init(&em->list);
J
Josef Bacik 已提交
3176 3177
	}

3178
	if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
3179 3180
		btrfs_release_path(path);
		btrfs_release_path(dst_path);
3181
		ret = log_directory_changes(trans, root, inode, path, dst_path);
3182 3183 3184 3185
		if (ret) {
			err = ret;
			goto out_unlock;
		}
3186
	}
3187
	BTRFS_I(inode)->logged_trans = trans->transid;
3188
out_unlock:
3189 3190 3191 3192
	mutex_unlock(&BTRFS_I(inode)->log_mutex);

	btrfs_free_path(path);
	btrfs_free_path(dst_path);
3193
	return err;
3194 3195
}

3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206
/*
 * follow the dentry parent pointers up the chain and see if any
 * of the directories in it require a full commit before they can
 * be logged.  Returns zero if nothing special needs to be done or 1 if
 * a full commit is required.
 */
static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
					       struct inode *inode,
					       struct dentry *parent,
					       struct super_block *sb,
					       u64 last_committed)
3207
{
3208 3209
	int ret = 0;
	struct btrfs_root *root;
3210
	struct dentry *old_parent = NULL;
3211

3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222
	/*
	 * for regular files, if its inode is already on disk, we don't
	 * have to worry about the parents at all.  This is because
	 * we can use the last_unlink_trans field to record renames
	 * and other fun in this file.
	 */
	if (S_ISREG(inode->i_mode) &&
	    BTRFS_I(inode)->generation <= last_committed &&
	    BTRFS_I(inode)->last_unlink_trans <= last_committed)
			goto out;

3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248
	if (!S_ISDIR(inode->i_mode)) {
		if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
			goto out;
		inode = parent->d_inode;
	}

	while (1) {
		BTRFS_I(inode)->logged_trans = trans->transid;
		smp_mb();

		if (BTRFS_I(inode)->last_unlink_trans > last_committed) {
			root = BTRFS_I(inode)->root;

			/*
			 * make sure any commits to the log are forced
			 * to be full commits
			 */
			root->fs_info->last_trans_log_full_commit =
				trans->transid;
			ret = 1;
			break;
		}

		if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
			break;

3249
		if (IS_ROOT(parent))
3250 3251
			break;

3252 3253 3254
		parent = dget_parent(parent);
		dput(old_parent);
		old_parent = parent;
3255 3256 3257
		inode = parent->d_inode;

	}
3258
	dput(old_parent);
3259
out:
3260 3261 3262 3263 3264 3265 3266 3267 3268
	return ret;
}

/*
 * helper function around btrfs_log_inode to make sure newly created
 * parent directories also end up in the log.  A minimal inode and backref
 * only logging is done of any parent directories that are older than
 * the last committed transaction
 */
3269 3270 3271
int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
		    struct btrfs_root *root, struct inode *inode,
		    struct dentry *parent, int exists_only)
3272
{
3273
	int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
3274
	struct super_block *sb;
3275
	struct dentry *old_parent = NULL;
3276 3277 3278 3279 3280
	int ret = 0;
	u64 last_committed = root->fs_info->last_trans_committed;

	sb = inode->i_sb;

S
Sage Weil 已提交
3281 3282 3283 3284 3285
	if (btrfs_test_opt(root, NOTREELOG)) {
		ret = 1;
		goto end_no_trans;
	}

3286 3287 3288 3289 3290 3291
	if (root->fs_info->last_trans_log_full_commit >
	    root->fs_info->last_trans_committed) {
		ret = 1;
		goto end_no_trans;
	}

3292 3293 3294 3295 3296 3297
	if (root != BTRFS_I(inode)->root ||
	    btrfs_root_refs(&root->root_item) == 0) {
		ret = 1;
		goto end_no_trans;
	}

3298 3299 3300 3301
	ret = check_parent_dirs_for_sync(trans, inode, parent,
					 sb, last_committed);
	if (ret)
		goto end_no_trans;
3302

3303
	if (btrfs_inode_in_log(inode, trans->transid)) {
3304 3305 3306 3307
		ret = BTRFS_NO_LOG_SYNC;
		goto end_no_trans;
	}

3308 3309 3310
	ret = start_log_trans(trans, root);
	if (ret)
		goto end_trans;
3311

3312
	ret = btrfs_log_inode(trans, root, inode, inode_only);
3313 3314
	if (ret)
		goto end_trans;
3315

3316 3317 3318 3319 3320 3321 3322 3323
	/*
	 * for regular files, if its inode is already on disk, we don't
	 * have to worry about the parents at all.  This is because
	 * we can use the last_unlink_trans field to record renames
	 * and other fun in this file.
	 */
	if (S_ISREG(inode->i_mode) &&
	    BTRFS_I(inode)->generation <= last_committed &&
3324 3325 3326 3327
	    BTRFS_I(inode)->last_unlink_trans <= last_committed) {
		ret = 0;
		goto end_trans;
	}
3328 3329

	inode_only = LOG_INODE_EXISTS;
3330 3331
	while (1) {
		if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3332 3333
			break;

3334
		inode = parent->d_inode;
3335 3336 3337
		if (root != BTRFS_I(inode)->root)
			break;

3338 3339 3340
		if (BTRFS_I(inode)->generation >
		    root->fs_info->last_trans_committed) {
			ret = btrfs_log_inode(trans, root, inode, inode_only);
3341 3342
			if (ret)
				goto end_trans;
3343
		}
3344
		if (IS_ROOT(parent))
3345
			break;
3346

3347 3348 3349
		parent = dget_parent(parent);
		dput(old_parent);
		old_parent = parent;
3350
	}
3351
	ret = 0;
3352
end_trans:
3353
	dput(old_parent);
3354
	if (ret < 0) {
3355
		WARN_ON(ret != -ENOSPC);
3356 3357 3358
		root->fs_info->last_trans_log_full_commit = trans->transid;
		ret = 1;
	}
3359 3360 3361
	btrfs_end_log_trans(root);
end_no_trans:
	return ret;
3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372
}

/*
 * it is not safe to log dentry if the chunk root has added new
 * chunks.  This returns 0 if the dentry was logged, and 1 otherwise.
 * If this returns 1, you must commit the transaction to safely get your
 * data on disk.
 */
int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
			  struct btrfs_root *root, struct dentry *dentry)
{
3373 3374 3375 3376 3377 3378 3379
	struct dentry *parent = dget_parent(dentry);
	int ret;

	ret = btrfs_log_inode_parent(trans, root, dentry->d_inode, parent, 0);
	dput(parent);

	return ret;
3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401
}

/*
 * should be called during mount to recover any replay any log trees
 * from the FS
 */
int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
{
	int ret;
	struct btrfs_path *path;
	struct btrfs_trans_handle *trans;
	struct btrfs_key key;
	struct btrfs_key found_key;
	struct btrfs_key tmp_key;
	struct btrfs_root *log;
	struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
	struct walk_control wc = {
		.process_func = process_one_buffer,
		.stage = 0,
	};

	path = btrfs_alloc_path();
T
Tsutomu Itoh 已提交
3402 3403 3404 3405
	if (!path)
		return -ENOMEM;

	fs_info->log_root_recovering = 1;
3406

3407
	trans = btrfs_start_transaction(fs_info->tree_root, 0);
3408 3409 3410 3411
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		goto error;
	}
3412 3413 3414 3415

	wc.trans = trans;
	wc.pin = 1;

T
Tsutomu Itoh 已提交
3416
	ret = walk_log_tree(trans, log_root_tree, &wc);
3417 3418 3419 3420 3421
	if (ret) {
		btrfs_error(fs_info, ret, "Failed to pin buffers while "
			    "recovering log root tree.");
		goto error;
	}
3422 3423 3424 3425 3426 3427

again:
	key.objectid = BTRFS_TREE_LOG_OBJECTID;
	key.offset = (u64)-1;
	btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);

C
Chris Mason 已提交
3428
	while (1) {
3429
		ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
3430 3431 3432 3433 3434 3435

		if (ret < 0) {
			btrfs_error(fs_info, ret,
				    "Couldn't find tree log root.");
			goto error;
		}
3436 3437 3438 3439 3440 3441 3442
		if (ret > 0) {
			if (path->slots[0] == 0)
				break;
			path->slots[0]--;
		}
		btrfs_item_key_to_cpu(path->nodes[0], &found_key,
				      path->slots[0]);
3443
		btrfs_release_path(path);
3444 3445 3446 3447 3448
		if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
			break;

		log = btrfs_read_fs_root_no_radix(log_root_tree,
						  &found_key);
3449 3450 3451 3452 3453 3454
		if (IS_ERR(log)) {
			ret = PTR_ERR(log);
			btrfs_error(fs_info, ret,
				    "Couldn't read tree log root.");
			goto error;
		}
3455 3456 3457 3458 3459 3460

		tmp_key.objectid = found_key.offset;
		tmp_key.type = BTRFS_ROOT_ITEM_KEY;
		tmp_key.offset = (u64)-1;

		wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
3461 3462 3463 3464 3465 3466
		if (IS_ERR(wc.replay_dest)) {
			ret = PTR_ERR(wc.replay_dest);
			btrfs_error(fs_info, ret, "Couldn't read target root "
				    "for tree log recovery.");
			goto error;
		}
3467

Y
Yan Zheng 已提交
3468
		wc.replay_dest->log_root = log;
3469
		btrfs_record_root_in_trans(trans, wc.replay_dest);
3470 3471 3472 3473 3474 3475 3476 3477 3478 3479
		ret = walk_log_tree(trans, log, &wc);
		BUG_ON(ret);

		if (wc.stage == LOG_WALK_REPLAY_ALL) {
			ret = fixup_inode_link_counts(trans, wc.replay_dest,
						      path);
			BUG_ON(ret);
		}

		key.offset = found_key.offset - 1;
Y
Yan Zheng 已提交
3480
		wc.replay_dest->log_root = NULL;
3481
		free_extent_buffer(log->node);
3482
		free_extent_buffer(log->commit_root);
3483 3484 3485 3486 3487
		kfree(log);

		if (found_key.offset == 0)
			break;
	}
3488
	btrfs_release_path(path);
3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513

	/* step one is to pin it all, step two is to replay just inodes */
	if (wc.pin) {
		wc.pin = 0;
		wc.process_func = replay_one_buffer;
		wc.stage = LOG_WALK_REPLAY_INODES;
		goto again;
	}
	/* step three is to replay everything */
	if (wc.stage < LOG_WALK_REPLAY_ALL) {
		wc.stage++;
		goto again;
	}

	btrfs_free_path(path);

	free_extent_buffer(log_root_tree->node);
	log_root_tree->log_root = NULL;
	fs_info->log_root_recovering = 0;

	/* step 4: commit the transaction, which also unpins the blocks */
	btrfs_commit_transaction(trans, fs_info->tree_root);

	kfree(log_root_tree);
	return 0;
3514 3515 3516 3517

error:
	btrfs_free_path(path);
	return ret;
3518
}
3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531

/*
 * there are some corner cases where we want to force a full
 * commit instead of allowing a directory to be logged.
 *
 * They revolve around files there were unlinked from the directory, and
 * this function updates the parent directory so that a full commit is
 * properly done if it is fsync'd later after the unlinks are done.
 */
void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
			     struct inode *dir, struct inode *inode,
			     int for_rename)
{
3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544
	/*
	 * when we're logging a file, if it hasn't been renamed
	 * or unlinked, and its inode is fully committed on disk,
	 * we don't have to worry about walking up the directory chain
	 * to log its parents.
	 *
	 * So, we use the last_unlink_trans field to put this transid
	 * into the file.  When the file is logged we check it and
	 * don't log the parents if the file is fully on disk.
	 */
	if (S_ISREG(inode->i_mode))
		BTRFS_I(inode)->last_unlink_trans = trans->transid;

3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589
	/*
	 * if this directory was already logged any new
	 * names for this file/dir will get recorded
	 */
	smp_mb();
	if (BTRFS_I(dir)->logged_trans == trans->transid)
		return;

	/*
	 * if the inode we're about to unlink was logged,
	 * the log will be properly updated for any new names
	 */
	if (BTRFS_I(inode)->logged_trans == trans->transid)
		return;

	/*
	 * when renaming files across directories, if the directory
	 * there we're unlinking from gets fsync'd later on, there's
	 * no way to find the destination directory later and fsync it
	 * properly.  So, we have to be conservative and force commits
	 * so the new name gets discovered.
	 */
	if (for_rename)
		goto record;

	/* we can safely do the unlink without any special recording */
	return;

record:
	BTRFS_I(dir)->last_unlink_trans = trans->transid;
}

/*
 * Call this after adding a new name for a file and it will properly
 * update the log to reflect the new name.
 *
 * It will return zero if all goes well, and it will return 1 if a
 * full transaction commit is required.
 */
int btrfs_log_new_name(struct btrfs_trans_handle *trans,
			struct inode *inode, struct inode *old_dir,
			struct dentry *parent)
{
	struct btrfs_root * root = BTRFS_I(inode)->root;

3590 3591 3592 3593 3594 3595 3596
	/*
	 * this will force the logging code to walk the dentry chain
	 * up for the file
	 */
	if (S_ISREG(inode->i_mode))
		BTRFS_I(inode)->last_unlink_trans = trans->transid;

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	/*
	 * if this inode hasn't been logged and directory we're renaming it
	 * from hasn't been logged, we don't need to log it
	 */
	if (BTRFS_I(inode)->logged_trans <=
	    root->fs_info->last_trans_committed &&
	    (!old_dir || BTRFS_I(old_dir)->logged_trans <=
		    root->fs_info->last_trans_committed))
		return 0;

	return btrfs_log_inode_parent(trans, root, inode, parent, 1);
}