[PATCH 2/2] xfs: xfs_readsb needs to check for magic numbers

[Christoph Hellwig]

On Tue, May 27, 2014 at 08:26:54AM +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner at redhat.com>
> 
> Commit daba542 ("xfs: skip verification on initial "guess"
> superblock read") dropped the use of a verifier for the initial
> superblock read so we can probe the sector size of the filesystem
> stored in the superblock. It, however, now fails to validate that
> what was read initially is actually an XFS superblock and hence will
> fail the sector size check and return ENOSYS.
> 
> This causes probe-based mounts to fail because it expects XFS to
> return EINVAL when it doesn't recognise the superblock format.

Looks good,

Reviewed-by: Christoph Hellwig <hch at lst.de>