ext4: ext4_fill_super shouldn't return 0 on corruption
At the start of ext4_fill_super, ret is set to -EINVAL, and any failure path
out of that function returns ret. However, the generic_check_addressable
clause sets ret = 0 (if it passes), which means that a subsequent failure (e.g.
a group checksum error) returns 0 even though the mount should fail. This
causes vfs_kern_mount in turn to think that the mount succeeded, leading to an
oops.
A simple fix is to avoid using ret for the generic_check_addressable check,
which was last changed in commit
30ca22c70e3ef0a96ff84de69cd7e8561b416cb2.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>