dm: distinquish old .request_fn (dm-old) vs dm-mq request-based DM

Rename various methods to have either a "dm_old" or "dm_mq" prefix.
Improve code comments to assist with understanding the duality of code
that handles both "dm_old" and "dm_mq" cases.

It is no much easier to quickly look at the code and _know_ that a given
method is either 1) "dm_old" only 2) "dm_mq" only 3) common to both.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Mike Snitzer 2016-02-20 13:45:38 -05:00
parent c5248f79f3
commit eca7ee6dc0
2 changed files with 58 additions and 50 deletions

View file

@ -426,7 +426,11 @@ static int __multipath_map(struct dm_target *ti, struct request *clone,
clone->rq_disk = bdev->bd_disk;
clone->cmd_flags |= REQ_FAILFAST_TRANSPORT;
} else {
/* blk-mq request-based interface */
/*
* blk-mq request-based interface; used by both:
* .request_fn stacked on blk-mq path(s) and
* blk-mq stacked on blk-mq path(s).
*/
*__clone = blk_get_request(bdev_get_queue(bdev),
rq_data_dir(rq), GFP_ATOMIC);
if (IS_ERR(*__clone)) {