linux-ext4 - [PATCH 1/2] ext4: start handle at least possible moment when renaming files

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Message-Id: <1371843030-24038-1-git-send-email-tytso@mit.edu>
Date:	Fri, 21 Jun 2013 15:30:29 -0400
From:	Theodore Ts'o <tytso@....edu>
To:	Ext4 Developers List <linux-ext4@...r.kernel.org>
Cc:	desrt@...rt.ca, Theodore Ts'o <tytso@....edu>
Subject: [PATCH 1/2] ext4: start handle at least possible moment when renaming files

In ext4_rename(), don't start the journal handle until the the
directory entries have been successfully looked up.

Signed-off-by: "Theodore Ts'o" <tytso@....edu>
---
 fs/ext4/namei.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index ab2f6dc..f57980c 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2965,7 +2965,7 @@ static struct buffer_head *ext4_get_first_dir_block(handle_t *handle,
 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 		       struct inode *new_dir, struct dentry *new_dentry)
 {
-	handle_t *handle;
+	handle_t *handle = NULL;
 	struct inode *old_inode, *new_inode;
 	struct buffer_head *old_bh, *new_bh, *dir_bh;
 	struct ext4_dir_entry_2 *old_de, *new_de;
@@ -2982,14 +2982,6 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 	 * in separate transaction */
 	if (new_dentry->d_inode)
 		dquot_initialize(new_dentry->d_inode);
-	handle = ext4_journal_start(old_dir, EXT4_HT_DIR,
-		(2 * EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
-		 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
-	if (IS_ERR(handle))
-		return PTR_ERR(handle);
-
-	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
-		ext4_handle_sync(handle);
 
 	old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de, NULL);
 	/*
@@ -3012,6 +3004,16 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 			new_bh = NULL;
 		}
 	}
+
+	handle = ext4_journal_start(old_dir, EXT4_HT_DIR,
+		(2 * EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
+		 EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2));
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
+		ext4_handle_sync(handle);
+
 	if (S_ISDIR(old_inode->i_mode)) {
 		if (new_inode) {
 			retval = -ENOTEMPTY;
@@ -3151,7 +3153,8 @@ end_rename:
 	brelse(dir_bh);
 	brelse(old_bh);
 	brelse(new_bh);
-	ext4_journal_stop(handle);
+	if (handle)
+		ext4_journal_stop(handle);
 	if (retval == 0 && force_da_alloc)
 		ext4_alloc_da_blocks(old_inode);
 	return retval;
-- 
1.7.12.rc0.22.gcdd159b

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