[PATCH 2/4] xfs: reject completely bogus remount options

[Mark Tinguely]

On 10/11/13 14:11, Eric Sandeen wrote:
> There's a long comment about handling non-remountable
> options in xfs_fs_remount, but nothing addresses the case
> of completely bogus mount options at remount time, which
> can lead to some severe strangeness:
>
> # for I in `seq 1 10`; do mount -o remount,noacl /mnt/test2; done
> # for I in `seq 1 10`; do mount -o remount,badoption /mnt/test2; done
> # grep sdb4 /etc/mtab
> /dev/sdb4 /mnt/test2 xfs rw,noacl,noacl,noacl,noacl,noacl,noacl,noacl,noacl,noacl,noacl,noacl,badoption,badoption,badoption,badoption,badoption,badoption,badoption,badoption,badoption,badoption 0 0
>
> This is a bit of a hack, but we can re-use xfs_parseargs()
> with a dummy mount struct to just vet all of the remount
> options which were passed in.  With this, we get a saner
> result:
>
> [44898.102990] EXT4-fs (sdb4): Unrecognized mount option "badoption" or missing value
>
> if we try to remount with something ridiculous.
>
> In the long run we should probably revamp a lot of the mount option
> handling...
>
> Signed-off-by: Eric Sandeen<sandeen at redhat.com>
> ---


I don't seem to get the duplicate mtab entries on a top of tree kernel.
Is this still appropriate?

--Mark.