3.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Michael Tokarev <m...@tls.msk.ru>

commit d096ad0f79a782935d2e06ae8fb235e8c5397775 upstream.

When a journal-less ext4 filesystem is mounted on a read-only block
device (blockdev --setro will do), each remount (for other, unrelated,
flags, like suid=>nosuid etc) results in a series of scary messages
from kernel telling about I/O errors on the device.

This is becauese of the following code ext4_remount():

       if (sbi->s_journal == NULL)
                ext4_commit_super(sb, 1);

at the end of remount procedure, which forces writing (flushing) of
a superblock regardless whenever it is dirty or not, if the filesystem
is readonly or not, and whenever the device itself is readonly or not.

We only need call ext4_commit_super when the file system had been
previously mounted read/write.

Thanks to Eric Sandeen for help in diagnosing this issue.

Signed-off-By: Michael Tokarev <m...@tls.msk.ru>
Signed-off-by: "Theodore Ts'o" <ty...@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 fs/ext4/super.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4438,7 +4438,7 @@ static int ext4_remount(struct super_blo
        }
 
        ext4_setup_system_zone(sb);
-       if (sbi->s_journal == NULL)
+       if (sbi->s_journal == NULL && !(old_sb_flags & MS_RDONLY))
                ext4_commit_super(sb, 1);
 
 #ifdef CONFIG_QUOTA


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to