On Thu, Feb 13, 2014 at 05:32:12PM -0600, Eric Sandeen wrote:
> When xfs_readsb() does the very first read of the superblock,
> it makes a guess at the length of the buffer, based on the
> sector size of the underlying storage. This may or may
> not match the filesystem sector size in sb_sectsize, so
> we can't i.e. do a CRC check on it; it might be too short.
> In fact, mounting a filesystem with sb_sectsize larger
> than the device sector size will cause a mount failure
> if CRCs are enabled, because we are checksumming a length
> which exceeds the buffer passed to it.
> So always read twice; the first time we read with NULL
> buffer ops to skip verification; then set the proper
> read length, hook up the proper verifier, and give it
> another go.
> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
Looks fine. I'll run it through some testing and we can go from
there. FWIW, does this make your "check the sector size in the sb
verifier" patch redundant?