ext4: return ENOMEM if sb_getblk() fails

The only reason for sb_getblk() failing is if it can't allocate the
buffer_head.  So ENOMEM is more appropriate than EIO.  In addition,
make sure that the file system is marked as being inconsistent if
sb_getblk() fails.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index fe7c63f4717e..44734f1ca554 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -80,6 +80,8 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh,
          * is not blocked in the elevator. */
         if (!*bh)
                 *bh = sb_getblk(sb, mmp_block);
+        if (!*bh)
+                return -ENOMEM;
         if (*bh) {
                 get_bh(*bh);
                 lock_buffer(*bh);