scsi: fix random memory corruption with scsi-mq + T10 PI
scsi: fix random memory corruption with scsi-mq + T10 PI

This fixes random memory corruption triggered when all three of the
following are true:

* scsi-mq enabled
* T10 Protection Information (DIF) enabled
* SCSI host with sg_tablesize > SCSI_MAX_SG_SEGMENTS (128)

The symptoms of this bug are unpredictable memory corruption, BUG()s,
oopses, lockups, etc., any of which may appear to be completely
unrelated to the root cause.

Cc: <4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org> # 3.17.x, 3.18.x
Signed-off-by: Tony Battersby <628d250d3f69f0c4ee54390536c2ff69fa614e72@cybernetics.com>
Reviewed-by: Nicholas Bellinger <978acd1567d5598152161fdf8bf3ca568f950c9b@linux-iscsi.org>
Signed-off-by: Christoph Hellwig <923f7720577207a44b32e59bbfbea59d27f1ae8e@lst.de>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs