tree-log.c 85.8 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 "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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int 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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	return 0;
}


/*
 * 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(log->fs_info->extent_root,
				 eb->start, eb->len, 0);
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	if (btrfs_buffer_uptodate(eb, gen)) {
		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]);
		if (found_size > item_size) {
			btrfs_truncate_item(trans, root, path, item_size, 1);
		} else if (found_size < item_size) {
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			ret = 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, inode, start, extent_end,
				 &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,
						key->objectid, offset);
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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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			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);
641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673
	btrfs_update_inode(trans, root, inode);
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);
691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718
	kfree(name);

	iput(inode);
	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;
719
	btrfs_release_path(path);
720 721 722 723 724 725 726 727 728 729

	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:
730
	btrfs_release_path(path);
731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758
	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();
759 760 761
	if (!path)
		return -ENOMEM;

762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802
	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
803 804
	struct btrfs_dir_item *di;
	struct inode *dir;
805 806 807
	struct inode *inode;
	unsigned long ref_ptr;
	unsigned long ref_end;
L
liubo 已提交
808 809 810
	char *name;
	int namelen;
	int ret;
811
	int search_done = 0;
812 813 814 815 816 817 818 819 820 821 822 823

	/*
	 * 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);
824 825 826 827
	if (!inode) {
		iput(dir);
		return -EIO;
	}
828 829 830 831 832 833 834 835 836 837 838 839 840 841

	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
842
	if (inode_in_dir(root, path, btrfs_ino(dir), btrfs_ino(inode),
843 844 845 846 847 848 849 850 851 852 853 854
			 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.
	 */
855 856 857 858

	if (search_done)
		goto insert;

859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879
	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
880
		while (ptr < ptr_end) {
881 882 883 884 885 886 887 888 889 890 891 892 893
			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);
894
				btrfs_release_path(path);
895

896 897 898 899 900 901 902 903 904
				ret = btrfs_unlink_inode(trans, root, dir,
							 inode, victim_name,
							 victim_name_len);
			}
			kfree(victim_name);
			ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
		}
		BUG_ON(ret);

905 906 907 908 909
		/*
		 * NOTE: we have searched root tree and checked the
		 * coresponding ref, it does not need to check again.
		 */
		search_done = 1;
910
	}
911
	btrfs_release_path(path);
912

L
liubo 已提交
913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931
	/* 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);

932
insert:
933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950
	/* 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:
951
	btrfs_release_path(path);
952 953 954 955 956
	iput(dir);
	iput(inode);
	return 0;
}

957 958 959 960 961 962 963 964 965 966 967
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;
}


968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988
/*
 * 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
989
	u64 ino = btrfs_ino(inode);
990

L
Li Zefan 已提交
991
	key.objectid = ino;
992 993 994 995
	key.type = BTRFS_INODE_REF_KEY;
	key.offset = (u64)-1;

	path = btrfs_alloc_path();
996 997
	if (!path)
		return -ENOMEM;
998

C
Chris Mason 已提交
999
	while (1) {
1000 1001 1002 1003 1004 1005 1006 1007 1008 1009
		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
1010
		if (key.objectid != ino ||
1011 1012 1013 1014 1015
		    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
1016
		while (ptr < ptr_end) {
1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028
			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--;
1029
		btrfs_release_path(path);
1030
	}
1031
	btrfs_release_path(path);
1032 1033 1034 1035
	if (nlink != inode->i_nlink) {
		inode->i_nlink = nlink;
		btrfs_update_inode(trans, root, inode);
	}
1036
	BTRFS_I(inode)->index_cnt = (u64)-1;
1037

1038 1039 1040
	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
1041
						 ino, 1);
1042 1043
			BUG_ON(ret);
		}
L
Li Zefan 已提交
1044
		ret = insert_orphan_item(trans, root, ino);
1045 1046 1047 1048
		BUG_ON(ret);
	}
	btrfs_free_path(path);

1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062
	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
1063
	while (1) {
1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079
		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);
1080 1081
		if (ret)
			goto out;
1082

1083
		btrfs_release_path(path);
1084
		inode = read_one_inode(root, key.offset);
1085 1086
		if (!inode)
			return -EIO;
1087 1088 1089 1090 1091 1092

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

		iput(inode);

1093 1094 1095 1096 1097 1098
		/*
		 * fixup on a directory may create new entries,
		 * make sure we always look for the highset possible
		 * offset
		 */
		key.offset = (u64)-1;
1099
	}
1100 1101
	ret = 0;
out:
1102
	btrfs_release_path(path);
1103
	return ret;
1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121
}


/*
 * 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);
1122 1123
	if (!inode)
		return -EIO;
1124 1125 1126 1127 1128 1129 1130

	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);

1131
	btrfs_release_path(path);
1132 1133 1134 1135 1136 1137 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
	if (ret == 0) {
		btrfs_inc_nlink(inode);
		btrfs_update_inode(trans, root, inode);
	} 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
1206
	int exists;
1207 1208 1209
	int ret;

	dir = read_one_inode(root, key->objectid);
1210 1211
	if (!dir)
		return -EIO;
1212 1213 1214

	name_len = btrfs_dir_name_len(eb, di);
	name = kmalloc(name_len, GFP_NOFS);
1215 1216 1217
	if (!name)
		return -ENOMEM;

1218 1219 1220 1221 1222
	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
1223 1224 1225 1226 1227
	exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
	if (exists == 0)
		exists = 1;
	else
		exists = 0;
1228
	btrfs_release_path(path);
C
Chris Mason 已提交
1229

1230 1231 1232
	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
1233
	} else if (key->type == BTRFS_DIR_INDEX_KEY) {
1234 1235 1236 1237 1238 1239 1240
		dst_di = btrfs_lookup_dir_index_item(trans, root, path,
						     key->objectid,
						     key->offset, name,
						     name_len, 1);
	} else {
		BUG();
	}
1241
	if (IS_ERR_OR_NULL(dst_di)) {
1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262
		/* 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
1263
	if (!exists)
1264 1265 1266 1267 1268 1269 1270 1271
		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:
1272
	btrfs_release_path(path);
1273 1274 1275 1276 1277
	kfree(name);
	iput(dir);
	return 0;

insert:
1278
	btrfs_release_path(path);
1279 1280 1281
	ret = insert_one_name(trans, root, path, key->objectid, key->offset,
			      name, name_len, log_type, &log_key);

S
Stoyan Gaydarov 已提交
1282
	BUG_ON(ret && ret != -ENOENT);
1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306
	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
1307
	while (ptr < ptr_end) {
1308
		di = (struct btrfs_dir_item *)ptr;
1309 1310
		if (verify_dir_item(root, eb, di))
			return -EIO;
1311 1312 1313 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
		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:
1399
	btrfs_release_path(path);
1400 1401 1402 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
	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
1435
	while (ptr < ptr_end) {
1436
		di = (struct btrfs_dir_item *)ptr;
1437 1438 1439 1440 1441
		if (verify_dir_item(root, eb, di)) {
			ret = -EIO;
			goto out;
		}

1442 1443 1444 1445 1446 1447 1448 1449 1450
		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;
1451
		if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
1452 1453 1454
			log_di = btrfs_lookup_dir_item(trans, log, log_path,
						       dir_key->objectid,
						       name, name_len, 0);
1455
		} else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
1456 1457 1458 1459 1460 1461
			log_di = btrfs_lookup_dir_index_item(trans, log,
						     log_path,
						     dir_key->objectid,
						     dir_key->offset,
						     name, name_len, 0);
		}
1462
		if (IS_ERR_OR_NULL(log_di)) {
1463
			btrfs_dir_item_key_to_cpu(eb, di, &location);
1464 1465
			btrfs_release_path(path);
			btrfs_release_path(log_path);
1466
			inode = read_one_inode(root, location.objectid);
1467 1468 1469 1470
			if (!inode) {
				kfree(name);
				return -EIO;
			}
1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491

			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);
			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;
		}
1492
		btrfs_release_path(log_path);
1493 1494 1495 1496 1497 1498 1499
		kfree(name);

		ptr = (unsigned long)(di + 1);
		ptr += name_len;
	}
	ret = 0;
out:
1500 1501
	btrfs_release_path(path);
	btrfs_release_path(log_path);
1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518
	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,
1519
				       u64 dirid, int del_all)
1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547
{
	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
1548
	while (1) {
1549 1550 1551 1552 1553 1554 1555 1556
		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;
		}
1557 1558

		dir_key.offset = range_start;
C
Chris Mason 已提交
1559
		while (1) {
1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581
			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,
1582 1583
						log_path, dir,
						&found_key);
1584 1585 1586 1587 1588
			BUG_ON(ret);
			if (found_key.offset == (u64)-1)
				break;
			dir_key.offset = found_key.offset + 1;
		}
1589
		btrfs_release_path(path);
1590 1591 1592 1593 1594 1595 1596 1597 1598 1599
		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;
1600
		btrfs_release_path(path);
1601 1602 1603
		goto again;
	}
out:
1604
	btrfs_release_path(path);
1605 1606 1607 1608 1609 1610 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 1638 1639
	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;

	btrfs_read_buffer(eb, gen);

	level = btrfs_header_level(eb);

	if (level != 0)
		return 0;

	path = btrfs_alloc_path();
1640 1641
	if (!path)
		return -ENOMEM;
1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657

	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,
1658
					 root, log, path, key.objectid, 0);
1659 1660 1661 1662 1663 1664
				BUG_ON(ret);
			}
			ret = overwrite_item(wc->trans, root, path,
					     eb, i, &key);
			BUG_ON(ret);

1665 1666 1667
			/* for regular files, make sure corresponding
			 * orhpan item exist. extents past the new EOF
			 * will be truncated later by orphan cleanup.
1668 1669
			 */
			if (S_ISREG(mode)) {
1670 1671
				ret = insert_orphan_item(wc->trans, root,
							 key.objectid);
1672 1673
				BUG_ON(ret);
			}
1674

1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705
			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
1706
static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722
				   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
1723
	while (*level > 0) {
1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742
		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);
1743 1744
		if (!next)
			return -ENOMEM;
1745 1746

		if (*level == 1) {
1747 1748 1749
			ret = wc->process_func(root, next, wc, ptr_gen);
			if (ret)
				return ret;
1750

1751 1752 1753 1754 1755
			path->slots[*level]++;
			if (wc->free) {
				btrfs_read_buffer(next, ptr_gen);

				btrfs_tree_lock(next);
1756
				btrfs_set_lock_blocking(next);
1757
				clean_tree_block(trans, root, next);
1758 1759 1760 1761 1762
				btrfs_wait_tree_block_writeback(next);
				btrfs_tree_unlock(next);

				WARN_ON(root_owner !=
					BTRFS_TREE_LOG_OBJECTID);
1763 1764
				ret = btrfs_free_reserved_extent(root,
							 bytenr, blocksize);
1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782
				BUG_ON(ret);
			}
			free_extent_buffer(next);
			continue;
		}
		btrfs_read_buffer(next, ptr_gen);

		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);

1783
	path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
1784 1785 1786 1787 1788

	cond_resched();
	return 0;
}

C
Chris Mason 已提交
1789
static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
1790 1791 1792 1793 1794 1795 1796 1797 1798
				 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
1799
	for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1800
		slot = path->slots[i];
1801
		if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
1802 1803 1804 1805 1806
			path->slots[i]++;
			*level = i;
			WARN_ON(*level == 0);
			return 0;
		} else {
Z
Zheng Yan 已提交
1807 1808 1809 1810 1811 1812 1813
			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);
1814
			ret = wc->process_func(root, path->nodes[*level], wc,
1815
				 btrfs_header_generation(path->nodes[*level]));
1816 1817 1818
			if (ret)
				return ret;

1819 1820 1821 1822 1823 1824
			if (wc->free) {
				struct extent_buffer *next;

				next = path->nodes[*level];

				btrfs_tree_lock(next);
1825
				btrfs_set_lock_blocking(next);
1826
				clean_tree_block(trans, root, next);
1827 1828 1829 1830
				btrfs_wait_tree_block_writeback(next);
				btrfs_tree_unlock(next);

				WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1831
				ret = btrfs_free_reserved_extent(root,
1832
						path->nodes[*level]->start,
1833
						path->nodes[*level]->len);
1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859
				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
1860 1861
	if (!path)
		return -ENOMEM;
1862 1863 1864 1865 1866 1867 1868

	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
1869
	while (1) {
1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892
		wret = walk_down_log_tree(trans, log, path, &level, wc);
		if (wret > 0)
			break;
		if (wret < 0)
			ret = wret;

		wret = walk_up_log_tree(trans, log, path, &level, wc);
		if (wret > 0)
			break;
		if (wret < 0)
			ret = wret;
	}

	/* was the root node processed? if not, catch it here */
	if (path->nodes[orig_level]) {
		wc->process_func(log, path->nodes[orig_level], wc,
			 btrfs_header_generation(path->nodes[orig_level]));
		if (wc->free) {
			struct extent_buffer *next;

			next = path->nodes[orig_level];

			btrfs_tree_lock(next);
1893
			btrfs_set_lock_blocking(next);
1894
			clean_tree_block(trans, log, next);
1895 1896 1897 1898 1899
			btrfs_wait_tree_block_writeback(next);
			btrfs_tree_unlock(next);

			WARN_ON(log->root_key.objectid !=
				BTRFS_TREE_LOG_OBJECTID);
1900 1901
			ret = btrfs_free_reserved_extent(log, next->start,
							 next->len);
1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915
			BUG_ON(ret);
		}
	}

	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
1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
/*
 * 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;
}

1936 1937
static int wait_log_commit(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root, unsigned long transid)
1938 1939
{
	DEFINE_WAIT(wait);
Y
Yan Zheng 已提交
1940
	int index = transid % 2;
1941

Y
Yan Zheng 已提交
1942 1943 1944 1945 1946
	/*
	 * 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
	 */
1947
	do {
Y
Yan Zheng 已提交
1948 1949 1950
		prepare_to_wait(&root->log_commit_wait[index],
				&wait, TASK_UNINTERRUPTIBLE);
		mutex_unlock(&root->log_mutex);
1951 1952 1953

		if (root->fs_info->last_trans_log_full_commit !=
		    trans->transid && root->log_transid < transid + 2 &&
Y
Yan Zheng 已提交
1954 1955
		    atomic_read(&root->log_commit[index]))
			schedule();
1956

Y
Yan Zheng 已提交
1957 1958 1959 1960 1961 1962 1963
		finish_wait(&root->log_commit_wait[index], &wait);
		mutex_lock(&root->log_mutex);
	} while (root->log_transid < transid + 2 &&
		 atomic_read(&root->log_commit[index]));
	return 0;
}

1964 1965
static int wait_for_writer(struct btrfs_trans_handle *trans,
			   struct btrfs_root *root)
Y
Yan Zheng 已提交
1966 1967 1968 1969 1970 1971
{
	DEFINE_WAIT(wait);
	while (atomic_read(&root->log_writers)) {
		prepare_to_wait(&root->log_writer_wait,
				&wait, TASK_UNINTERRUPTIBLE);
		mutex_unlock(&root->log_mutex);
1972 1973
		if (root->fs_info->last_trans_log_full_commit !=
		    trans->transid && atomic_read(&root->log_writers))
1974
			schedule();
Y
Yan Zheng 已提交
1975 1976 1977
		mutex_lock(&root->log_mutex);
		finish_wait(&root->log_writer_wait, &wait);
	}
1978 1979 1980 1981 1982 1983
	return 0;
}

/*
 * 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,
1984 1985 1986 1987 1988 1989 1990 1991
 * 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.
1992 1993 1994 1995
 */
int btrfs_sync_log(struct btrfs_trans_handle *trans,
		   struct btrfs_root *root)
{
Y
Yan Zheng 已提交
1996 1997
	int index1;
	int index2;
1998
	int mark;
1999 2000
	int ret;
	struct btrfs_root *log = root->log_root;
Y
Yan Zheng 已提交
2001
	struct btrfs_root *log_root_tree = root->fs_info->log_root_tree;
2002
	unsigned long log_transid = 0;
2003

Y
Yan Zheng 已提交
2004 2005 2006
	mutex_lock(&root->log_mutex);
	index1 = root->log_transid % 2;
	if (atomic_read(&root->log_commit[index1])) {
2007
		wait_log_commit(trans, root, root->log_transid);
Y
Yan Zheng 已提交
2008 2009
		mutex_unlock(&root->log_mutex);
		return 0;
2010
	}
Y
Yan Zheng 已提交
2011 2012 2013 2014
	atomic_set(&root->log_commit[index1], 1);

	/* wait for previous tree log sync to complete */
	if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
2015
		wait_log_commit(trans, root, root->log_transid - 1);
2016
	while (1) {
Y
Yan Zheng 已提交
2017
		unsigned long batch = root->log_batch;
2018 2019
		/* when we're on an ssd, just kick the log commit out */
		if (!btrfs_test_opt(root, SSD) && root->log_multiple_pids) {
2020 2021 2022 2023
			mutex_unlock(&root->log_mutex);
			schedule_timeout_uninterruptible(1);
			mutex_lock(&root->log_mutex);
		}
2024
		wait_for_writer(trans, root);
Y
Yan Zheng 已提交
2025
		if (batch == root->log_batch)
2026 2027 2028
			break;
	}

2029 2030 2031 2032 2033 2034 2035
	/* 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;
	}

2036 2037 2038 2039 2040 2041
	log_transid = root->log_transid;
	if (log_transid % 2 == 0)
		mark = EXTENT_DIRTY;
	else
		mark = EXTENT_NEW;

2042 2043 2044
	/* we start IO on  all the marked extents here, but we don't actually
	 * wait for them until later.
	 */
2045
	ret = btrfs_write_marked_extents(log, &log->dirty_log_pages, mark);
2046
	BUG_ON(ret);
Y
Yan Zheng 已提交
2047

2048
	btrfs_set_root_node(&log->root_item, log->node);
Y
Yan Zheng 已提交
2049 2050 2051 2052

	root->log_batch = 0;
	root->log_transid++;
	log->log_transid = root->log_transid;
2053
	root->log_start_pid = 0;
Y
Yan Zheng 已提交
2054 2055
	smp_mb();
	/*
2056 2057 2058
	 * 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
2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075
	 */
	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);
	}

2076 2077 2078 2079 2080 2081 2082 2083 2084
	if (ret) {
		BUG_ON(ret != -ENOSPC);
		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
2085 2086
	index2 = log_root_tree->log_transid % 2;
	if (atomic_read(&log_root_tree->log_commit[index2])) {
2087
		btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2088 2089
		wait_log_commit(trans, log_root_tree,
				log_root_tree->log_transid);
Y
Yan Zheng 已提交
2090
		mutex_unlock(&log_root_tree->log_mutex);
2091
		ret = 0;
Y
Yan Zheng 已提交
2092 2093 2094 2095
		goto out;
	}
	atomic_set(&log_root_tree->log_commit[index2], 1);

2096 2097 2098 2099 2100 2101
	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
2102

2103 2104 2105 2106 2107
	/*
	 * 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) {
2108
		btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2109 2110 2111 2112
		mutex_unlock(&log_root_tree->log_mutex);
		ret = -EAGAIN;
		goto out_wake_log_root;
	}
Y
Yan Zheng 已提交
2113 2114

	ret = btrfs_write_and_wait_marked_extents(log_root_tree,
2115 2116
				&log_root_tree->dirty_log_pages,
				EXTENT_DIRTY | EXTENT_NEW);
2117
	BUG_ON(ret);
2118
	btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2119 2120

	btrfs_set_super_log_root(&root->fs_info->super_for_commit,
Y
Yan Zheng 已提交
2121
				log_root_tree->node->start);
2122
	btrfs_set_super_log_root_level(&root->fs_info->super_for_commit,
Y
Yan Zheng 已提交
2123
				btrfs_header_level(log_root_tree->node));
2124

Y
Yan Zheng 已提交
2125 2126
	log_root_tree->log_batch = 0;
	log_root_tree->log_transid++;
2127
	smp_mb();
Y
Yan Zheng 已提交
2128 2129 2130 2131 2132 2133 2134 2135 2136 2137

	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
2138
	btrfs_scrub_pause_super(root);
2139
	write_ctree_super(trans, root->fs_info->tree_root, 1);
A
Arne Jansen 已提交
2140
	btrfs_scrub_continue_super(root);
2141
	ret = 0;
Y
Yan Zheng 已提交
2142

2143 2144 2145 2146 2147
	mutex_lock(&root->log_mutex);
	if (root->last_log_commit < log_transid)
		root->last_log_commit = log_transid;
	mutex_unlock(&root->log_mutex);

2148
out_wake_log_root:
Y
Yan Zheng 已提交
2149 2150 2151 2152
	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]);
2153
out:
Y
Yan Zheng 已提交
2154 2155 2156 2157
	atomic_set(&root->log_commit[index1], 0);
	smp_mb();
	if (waitqueue_active(&root->log_commit_wait[index1]))
		wake_up(&root->log_commit_wait[index1]);
2158
	return ret;
2159 2160
}

2161 2162
static void free_log_tree(struct btrfs_trans_handle *trans,
			  struct btrfs_root *log)
2163 2164
{
	int ret;
2165 2166
	u64 start;
	u64 end;
2167 2168 2169 2170 2171 2172 2173 2174
	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
2175
	while (1) {
2176
		ret = find_first_extent_bit(&log->dirty_log_pages,
2177
				0, &start, &end, EXTENT_DIRTY | EXTENT_NEW);
2178 2179 2180
		if (ret)
			break;

2181 2182
		clear_extent_bits(&log->dirty_log_pages, start, end,
				  EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
2183 2184
	}

Y
Yan Zheng 已提交
2185 2186
	free_extent_buffer(log->node);
	kfree(log);
2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208
}

/*
 * 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;
	}
2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241
	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;
2242
	int err = 0;
2243
	int bytes_del = 0;
L
Li Zefan 已提交
2244
	u64 dir_ino = btrfs_ino(dir);
2245

2246 2247 2248
	if (BTRFS_I(dir)->logged_trans < trans->transid)
		return 0;

2249 2250 2251 2252 2253 2254 2255 2256
	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();
2257 2258 2259 2260
	if (!path) {
		err = -ENOMEM;
		goto out_unlock;
	}
2261

L
Li Zefan 已提交
2262
	di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
2263
				   name, name_len, -1);
2264 2265 2266 2267 2268
	if (IS_ERR(di)) {
		err = PTR_ERR(di);
		goto fail;
	}
	if (di) {
2269 2270 2271 2272
		ret = btrfs_delete_one_dir_name(trans, log, path, di);
		bytes_del += name_len;
		BUG_ON(ret);
	}
2273
	btrfs_release_path(path);
L
Li Zefan 已提交
2274
	di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
2275
					 index, name, name_len, -1);
2276 2277 2278 2279 2280
	if (IS_ERR(di)) {
		err = PTR_ERR(di);
		goto fail;
	}
	if (di) {
2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291
		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
2292
		key.objectid = dir_ino;
2293 2294
		key.offset = 0;
		key.type = BTRFS_INODE_ITEM_KEY;
2295
		btrfs_release_path(path);
2296 2297

		ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
2298 2299 2300 2301
		if (ret < 0) {
			err = ret;
			goto fail;
		}
2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316
		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;
2317
		btrfs_release_path(path);
2318
	}
2319
fail:
2320
	btrfs_free_path(path);
2321
out_unlock:
2322
	mutex_unlock(&BTRFS_I(dir)->log_mutex);
2323 2324 2325 2326
	if (ret == -ENOSPC) {
		root->fs_info->last_trans_log_full_commit = trans->transid;
		ret = 0;
	}
2327
	btrfs_end_log_trans(root);
2328

2329
	return err;
2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341
}

/* 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;

2342 2343 2344
	if (BTRFS_I(inode)->logged_trans < trans->transid)
		return 0;

2345 2346 2347 2348 2349 2350
	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
2351
	ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
2352 2353
				  dirid, &index);
	mutex_unlock(&BTRFS_I(inode)->log_mutex);
2354 2355 2356 2357
	if (ret == -ENOSPC) {
		root->fs_info->last_trans_log_full_commit = trans->transid;
		ret = 0;
	}
2358
	btrfs_end_log_trans(root);
2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384

	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));
2385 2386
	if (ret)
		return ret;
2387 2388 2389 2390 2391

	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]);
2392
	btrfs_release_path(path);
2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410
	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;
2411
	int err = 0;
2412 2413 2414 2415 2416
	int ret;
	int i;
	int nritems;
	u64 first_offset = min_offset;
	u64 last_offset = (u64)-1;
L
Li Zefan 已提交
2417
	u64 ino = btrfs_ino(inode);
2418 2419

	log = root->log_root;
L
Li Zefan 已提交
2420
	max_key.objectid = ino;
2421 2422 2423
	max_key.offset = (u64)-1;
	max_key.type = key_type;

L
Li Zefan 已提交
2424
	min_key.objectid = ino;
2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436
	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
2437 2438
	if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
		min_key.objectid = ino;
2439 2440
		min_key.type = key_type;
		min_key.offset = (u64)-1;
2441
		btrfs_release_path(path);
2442 2443
		ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
		if (ret < 0) {
2444
			btrfs_release_path(path);
2445 2446
			return ret;
		}
L
Li Zefan 已提交
2447
		ret = btrfs_previous_item(root, path, ino, key_type);
2448 2449 2450 2451 2452 2453 2454 2455 2456 2457

		/* 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
2458
			if (key_type == tmp.type)
2459 2460 2461 2462 2463 2464
				first_offset = max(min_offset, tmp.offset) + 1;
		}
		goto done;
	}

	/* go backward to find any previous key */
L
Li Zefan 已提交
2465
	ret = btrfs_previous_item(root, path, ino, key_type);
2466 2467 2468 2469 2470 2471 2472 2473
	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);
2474 2475 2476 2477
			if (ret) {
				err = ret;
				goto done;
			}
2478 2479
		}
	}
2480
	btrfs_release_path(path);
2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492

	/* 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
2493
	while (1) {
2494 2495 2496 2497 2498 2499
		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
2500
			if (min_key.objectid != ino || min_key.type != key_type)
2501 2502 2503
				goto done;
			ret = overwrite_item(trans, log, dst_path, src, i,
					     &min_key);
2504 2505 2506 2507
			if (ret) {
				err = ret;
				goto done;
			}
2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520
		}
		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
2521
		if (tmp.objectid != ino || tmp.type != key_type) {
2522 2523 2524 2525 2526 2527 2528
			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);
2529 2530 2531 2532
			if (ret)
				err = ret;
			else
				last_offset = tmp.offset;
2533 2534 2535 2536
			goto done;
		}
	}
done:
2537 2538
	btrfs_release_path(path);
	btrfs_release_path(dst_path);
2539

2540 2541 2542 2543 2544 2545 2546
	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
2547
					 ino, first_offset, last_offset);
2548 2549 2550 2551
		if (ret)
			err = ret;
	}
	return err;
2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578
}

/*
 * 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
2579
	while (1) {
2580 2581 2582
		ret = log_dir_items(trans, root, inode, path,
				    dst_path, key_type, min_key,
				    &max_key);
2583 2584
		if (ret)
			return ret;
2585 2586 2587 2588 2589 2590 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
		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
2616
	while (1) {
2617
		ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
2618 2619
		BUG_ON(ret == 0);
		if (ret < 0)
2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
			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);
2633 2634
		if (ret)
			break;
2635
		btrfs_release_path(path);
2636
	}
2637
	btrfs_release_path(path);
2638
	return ret;
2639 2640
}

2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655
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;
2656 2657 2658
	struct list_head ordered_sums;

	INIT_LIST_HEAD(&ordered_sums);
2659 2660 2661

	ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
			   nr * sizeof(u32), GFP_NOFS);
2662 2663 2664
	if (!ins_data)
		return -ENOMEM;

2665 2666 2667 2668 2669 2670 2671 2672 2673
	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);
2674 2675 2676 2677
	if (ret) {
		kfree(ins_data);
		return ret;
	}
2678

2679
	for (i = 0; i < nr; i++, dst_path->slots[0]++) {
2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711
		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);

2712 2713 2714
			if (btrfs_file_extent_generation(src, extent) < trans->transid)
				continue;

2715
			found_type = btrfs_file_extent_type(src, extent);
Y
Yan Zheng 已提交
2716 2717
			if (found_type == BTRFS_FILE_EXTENT_REG ||
			    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728
				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,
2729
								extent);
2730 2731 2732 2733 2734
				if (btrfs_file_extent_compression(src,
								  extent)) {
					cs = 0;
					cl = dl;
				}
2735 2736 2737 2738

				ret = btrfs_lookup_csums_range(
						log->fs_info->csum_root,
						ds + cs, ds + cs + cl - 1,
A
Arne Jansen 已提交
2739
						&ordered_sums, 0);
2740
				BUG_ON(ret);
2741 2742 2743 2744 2745
			}
		}
	}

	btrfs_mark_buffer_dirty(dst_path->nodes[0]);
2746
	btrfs_release_path(dst_path);
2747
	kfree(ins_data);
2748 2749 2750 2751 2752

	/*
	 * we have to do this after the loop above to avoid changing the
	 * log tree while trying to change the log tree.
	 */
2753
	ret = 0;
C
Chris Mason 已提交
2754
	while (!list_empty(&ordered_sums)) {
2755 2756 2757
		struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
						   struct btrfs_ordered_sum,
						   list);
2758 2759
		if (!ret)
			ret = btrfs_csum_file_blocks(trans, log, sums);
2760 2761 2762
		list_del(&sums->list);
		kfree(sums);
	}
2763
	return ret;
2764 2765
}

2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779
/* 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.
 */
2780
static int btrfs_log_inode(struct btrfs_trans_handle *trans,
2781 2782 2783 2784 2785 2786 2787 2788
			     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;
2789
	struct extent_buffer *src = NULL;
2790
	int err = 0;
2791
	int ret;
2792
	int nritems;
2793 2794
	int ins_start_slot = 0;
	int ins_nr;
L
Li Zefan 已提交
2795
	u64 ino = btrfs_ino(inode);
2796 2797 2798 2799

	log = root->log_root;

	path = btrfs_alloc_path();
2800 2801
	if (!path)
		return -ENOMEM;
2802
	dst_path = btrfs_alloc_path();
2803 2804 2805 2806
	if (!dst_path) {
		btrfs_free_path(path);
		return -ENOMEM;
	}
2807

L
Li Zefan 已提交
2808
	min_key.objectid = ino;
2809 2810 2811
	min_key.type = BTRFS_INODE_ITEM_KEY;
	min_key.offset = 0;

L
Li Zefan 已提交
2812
	max_key.objectid = ino;
2813 2814 2815 2816 2817

	/* today the code can only do partial logging of directories */
	if (!S_ISDIR(inode->i_mode))
	    inode_only = LOG_INODE_ALL;

2818 2819 2820 2821 2822 2823
	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;

2824 2825 2826 2827 2828 2829 2830
	ret = btrfs_commit_inode_delayed_items(trans, inode);
	if (ret) {
		btrfs_free_path(path);
		btrfs_free_path(dst_path);
		return ret;
	}

2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841
	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
2842
		ret = drop_objectid_items(trans, log, path, ino, max_key_type);
2843 2844 2845
	} else {
		ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0);
	}
2846 2847 2848 2849
	if (ret) {
		err = ret;
		goto out_unlock;
	}
2850 2851
	path->keep_locks = 1;

C
Chris Mason 已提交
2852
	while (1) {
2853
		ins_nr = 0;
2854 2855 2856 2857
		ret = btrfs_search_forward(root, &min_key, &max_key,
					   path, 0, trans->transid);
		if (ret != 0)
			break;
2858
again:
2859
		/* note, ins_nr might be > 0 here, cleanup outside the loop */
L
Li Zefan 已提交
2860
		if (min_key.objectid != ino)
2861 2862 2863
			break;
		if (min_key.type > max_key.type)
			break;
2864

2865
		src = path->nodes[0];
2866 2867 2868 2869 2870 2871 2872
		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;
2873 2874
		}

2875 2876
		ret = copy_items(trans, log, dst_path, src, ins_start_slot,
				 ins_nr, inode_only);
2877 2878 2879 2880
		if (ret) {
			err = ret;
			goto out_unlock;
		}
2881 2882 2883
		ins_nr = 1;
		ins_start_slot = path->slots[0];
next_slot:
2884

2885 2886 2887 2888 2889 2890 2891
		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;
		}
2892 2893 2894 2895
		if (ins_nr) {
			ret = copy_items(trans, log, dst_path, src,
					 ins_start_slot,
					 ins_nr, inode_only);
2896 2897 2898 2899
			if (ret) {
				err = ret;
				goto out_unlock;
			}
2900 2901
			ins_nr = 0;
		}
2902
		btrfs_release_path(path);
2903

2904 2905 2906 2907 2908 2909 2910 2911 2912
		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;
	}
2913 2914 2915 2916
	if (ins_nr) {
		ret = copy_items(trans, log, dst_path, src,
				 ins_start_slot,
				 ins_nr, inode_only);
2917 2918 2919 2920
		if (ret) {
			err = ret;
			goto out_unlock;
		}
2921 2922 2923
		ins_nr = 0;
	}
	WARN_ON(ins_nr);
2924
	if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
2925 2926
		btrfs_release_path(path);
		btrfs_release_path(dst_path);
2927
		ret = log_directory_changes(trans, root, inode, path, dst_path);
2928 2929 2930 2931
		if (ret) {
			err = ret;
			goto out_unlock;
		}
2932
	}
2933
	BTRFS_I(inode)->logged_trans = trans->transid;
2934
out_unlock:
2935 2936 2937 2938
	mutex_unlock(&BTRFS_I(inode)->log_mutex);

	btrfs_free_path(path);
	btrfs_free_path(dst_path);
2939
	return err;
2940 2941
}

2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952
/*
 * 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)
2953
{
2954 2955
	int ret = 0;
	struct btrfs_root *root;
2956
	struct dentry *old_parent = NULL;
2957

2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968
	/*
	 * 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;

2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994
	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;

2995
		if (IS_ROOT(parent))
2996 2997
			break;

2998 2999 3000
		parent = dget_parent(parent);
		dput(old_parent);
		old_parent = parent;
3001 3002 3003
		inode = parent->d_inode;

	}
3004
	dput(old_parent);
3005
out:
3006 3007 3008
	return ret;
}

3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023
static int inode_in_log(struct btrfs_trans_handle *trans,
		 struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret = 0;

	mutex_lock(&root->log_mutex);
	if (BTRFS_I(inode)->logged_trans == trans->transid &&
	    BTRFS_I(inode)->last_sub_trans <= root->last_log_commit)
		ret = 1;
	mutex_unlock(&root->log_mutex);
	return ret;
}


3024 3025 3026 3027 3028 3029
/*
 * 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
 */
3030 3031 3032
int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
		    struct btrfs_root *root, struct inode *inode,
		    struct dentry *parent, int exists_only)
3033
{
3034
	int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
3035
	struct super_block *sb;
3036
	struct dentry *old_parent = NULL;
3037 3038 3039 3040 3041
	int ret = 0;
	u64 last_committed = root->fs_info->last_trans_committed;

	sb = inode->i_sb;

S
Sage Weil 已提交
3042 3043 3044 3045 3046
	if (btrfs_test_opt(root, NOTREELOG)) {
		ret = 1;
		goto end_no_trans;
	}

3047 3048 3049 3050 3051 3052
	if (root->fs_info->last_trans_log_full_commit >
	    root->fs_info->last_trans_committed) {
		ret = 1;
		goto end_no_trans;
	}

3053 3054 3055 3056 3057 3058
	if (root != BTRFS_I(inode)->root ||
	    btrfs_root_refs(&root->root_item) == 0) {
		ret = 1;
		goto end_no_trans;
	}

3059 3060 3061 3062
	ret = check_parent_dirs_for_sync(trans, inode, parent,
					 sb, last_committed);
	if (ret)
		goto end_no_trans;
3063

3064 3065 3066 3067 3068
	if (inode_in_log(trans, inode)) {
		ret = BTRFS_NO_LOG_SYNC;
		goto end_no_trans;
	}

3069 3070 3071
	ret = start_log_trans(trans, root);
	if (ret)
		goto end_trans;
3072

3073
	ret = btrfs_log_inode(trans, root, inode, inode_only);
3074 3075
	if (ret)
		goto end_trans;
3076

3077 3078 3079 3080 3081 3082 3083 3084
	/*
	 * 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 &&
3085 3086 3087 3088
	    BTRFS_I(inode)->last_unlink_trans <= last_committed) {
		ret = 0;
		goto end_trans;
	}
3089 3090

	inode_only = LOG_INODE_EXISTS;
3091 3092
	while (1) {
		if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
3093 3094
			break;

3095
		inode = parent->d_inode;
3096 3097 3098
		if (root != BTRFS_I(inode)->root)
			break;

3099 3100 3101
		if (BTRFS_I(inode)->generation >
		    root->fs_info->last_trans_committed) {
			ret = btrfs_log_inode(trans, root, inode, inode_only);
3102 3103
			if (ret)
				goto end_trans;
3104
		}
3105
		if (IS_ROOT(parent))
3106
			break;
3107

3108 3109 3110
		parent = dget_parent(parent);
		dput(old_parent);
		old_parent = parent;
3111
	}
3112
	ret = 0;
3113
end_trans:
3114
	dput(old_parent);
3115 3116 3117 3118 3119
	if (ret < 0) {
		BUG_ON(ret != -ENOSPC);
		root->fs_info->last_trans_log_full_commit = trans->transid;
		ret = 1;
	}
3120 3121 3122
	btrfs_end_log_trans(root);
end_no_trans:
	return ret;
3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133
}

/*
 * 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)
{
3134 3135 3136 3137 3138 3139 3140
	struct dentry *parent = dget_parent(dentry);
	int ret;

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

	return ret;
3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162
}

/*
 * 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
3163 3164 3165 3166
	if (!path)
		return -ENOMEM;

	fs_info->log_root_recovering = 1;
3167

3168
	trans = btrfs_start_transaction(fs_info->tree_root, 0);
3169
	BUG_ON(IS_ERR(trans));
3170 3171 3172 3173

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

T
Tsutomu Itoh 已提交
3174 3175
	ret = walk_log_tree(trans, log_root_tree, &wc);
	BUG_ON(ret);
3176 3177 3178 3179 3180 3181

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
3182
	while (1) {
3183 3184 3185 3186 3187 3188 3189 3190 3191 3192
		ret = btrfs_search_slot(NULL, log_root_tree, &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], &found_key,
				      path->slots[0]);
3193
		btrfs_release_path(path);
3194 3195 3196 3197 3198
		if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
			break;

		log = btrfs_read_fs_root_no_radix(log_root_tree,
						  &found_key);
T
Tsutomu Itoh 已提交
3199
		BUG_ON(IS_ERR(log));
3200 3201 3202 3203 3204 3205

		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);
3206
		BUG_ON(IS_ERR_OR_NULL(wc.replay_dest));
3207

Y
Yan Zheng 已提交
3208
		wc.replay_dest->log_root = log;
3209
		btrfs_record_root_in_trans(trans, wc.replay_dest);
3210 3211 3212 3213 3214 3215 3216 3217 3218 3219
		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
3220
		wc.replay_dest->log_root = NULL;
3221
		free_extent_buffer(log->node);
3222
		free_extent_buffer(log->commit_root);
3223 3224 3225 3226 3227
		kfree(log);

		if (found_key.offset == 0)
			break;
	}
3228
	btrfs_release_path(path);
3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254

	/* 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;
}
3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267

/*
 * 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)
{
3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280
	/*
	 * 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;

3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325
	/*
	 * 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;

3326 3327 3328 3329 3330 3331 3332
	/*
	 * 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;

3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345
	/*
	 * 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);
}