ext2: Fix memory leak when truncate races ext2_get_blocks

Buffer heads referencing indirect blocks may not be released if the file
is truncated at the right time. This happens because ext2_get_branch()
returns NULL when it finds the whole chain of indirect blocks already
set, and when truncate alters the chain this value of NULL is
treated as the address of the last head to be released. Handle this in the
same way as it's done after the got_it label.

Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 2dcbd56988843ccdfb017c9b14ca8f5b05a31b62..30163d007b2f287180d9d22827e638618038de22 100644 (file)
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -659,6 +659,7 @@ static int ext2_get_blocks(struct inode *inode,
                                 */
                                err = -EAGAIN;
                                count = 0;
+                               partial = chain + depth - 1;
                                break;
                        }
                        blk = le32_to_cpu(*(chain[depth-1].p + count));