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>

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 35f55a0dbc4b0bb044571a647a8d1982e9533c4b..d9b721c172a60c0bfa92b3a59f4f93101a56b4de 100644 (file)
--- 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;