block: mark blk-mq devices as stackable
authorMike Snitzer <snitzer@redhat.com>
Tue, 16 Dec 2014 17:54:25 +0000 (12:54 -0500)
committerJens Axboe <axboe@fb.com>
Wed, 28 Jan 2015 16:44:33 +0000 (09:44 -0700)
commitad9cf3bbd18a94806314741ac8092c3422f5aebe
tree85b1b24402535ca8322495915b9e50fe3be7494d
parent77a086890173c0958515f7322880e4680cf12f8e
block: mark blk-mq devices as stackable

Commit 4ee5eaf4 ("block: add a queue flag for request stacking support")
introduced the concept of "STACKABLE" and blk-mq devices fit the
definition in that they establish q->request_fn.  So establish
QUEUE_FLAG_STACKABLE in QUEUE_FLAG_MQ_DEFAULT.

While not strictly needed (DM _could_ just check for q->mq_ops to assume
the device is request-based), request-based DM support for blk-mq devices
benefits from the ability to consistently check for QUEUE_FLAG_STACKABLE
before allowing a device to be stacked into a request-based DM table.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
include/linux/blkdev.h