tree e8e1d3d0b6a33859392bcba516933aff256dc4b4
parent c98b2cc29af8e84e7364b53e9bb4cc7cfaf62555
author Martin K. Petersen <martin.petersen@oracle.com> 1326295631 +0100
committer Jens Axboe <axboe@kernel.dk> 1326295631 +0100

block: Introduce blk_set_stacking_limits function

Stacking driver queue limits are typically bounded exclusively by the
capabilities of the low level devices, not by the stacking driver
itself.

This patch introduces blk_set_stacking_limits() which has more liberal
metrics than the default queue limits function. This allows us to
inherit topology parameters from bottom devices without manually
tweaking the default limits in each driver prior to calling the stacking
function.

Since there is now a clear distinction between stacking and low-level
devices, blk_set_default_limits() has been modified to carry the more
conservative values that we used to manually set in
blk_queue_make_request().

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>