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@mit.edu>

1 files changed, 13 insertions, 10 deletions

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 35f55a0dbc4b..d9b721c172a6 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3009,7 +3009,7 @@ 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;
@@ -3026,14 +3026,6 @@ 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);
         /*
@@ -3056,6 +3048,16 @@ 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;
@@ -3195,7 +3197,8 @@ 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;