ext4: don't try to modify s_flags if the the file system is read-only
authorTheodore Ts'o <tytso@mit.edu>
Wed, 12 Feb 2014 17:16:04 +0000 (12:16 -0500)
committerTheodore Ts'o <tytso@mit.edu>
Wed, 12 Feb 2014 17:16:04 +0000 (12:16 -0500)
commit23301410972330c0ae9a8afc379ba2005e249cc6
tree5931e3ca6be2f6d7b98525ce204f908c30a30936
parent30d29b119ef01776e0a301444ab24defe8d8bef3
ext4: don't try to modify s_flags if the the file system is read-only

If an ext4 file system is created by some tool other than mke2fs
(perhaps by someone who has a pathalogical fear of the GPL) that
doesn't set one or the other of the EXT2_FLAGS_{UN}SIGNED_HASH flags,
and that file system is then mounted read-only, don't try to modify
the s_flags field.  Otherwise, if dm_verity is in use, the superblock
will change, causing an dm_verity failure.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
fs/ext4/super.c