block: Clean up special command handling logic

Remove special-casing of non-rw fs style requests (discard). The nomerge
flags are consolidated in blk_types.h, and rq_mergeable() and
bio_mergeable() have been modified to use them.

bio_is_rw() is used in place of bio_has_data() a few places. This is
done to to distinguish true reads and writes from other fs type requests
that carry a payload (e.g. write same).

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>

1 files changed, 1 insertions, 21 deletions

diff --git a/block/blk-merge.c b/block/blk-merge.c
index e76279e41162..86710ca408b8 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -418,18 +418,6 @@ static int attempt_merge(struct request_queue *q, struct request *req,
                 return 0;
 
         /*
-         * Don't merge file system requests and discard requests
-         */
-        if ((req->cmd_flags & REQ_DISCARD) != (next->cmd_flags & REQ_DISCARD))
-                return 0;
-
-        /*
-         * Don't merge discard requests and secure discard requests
-         */
-        if ((req->cmd_flags & REQ_SECURE) != (next->cmd_flags & REQ_SECURE))
-                return 0;
-
-        /*
          * not contiguous
          */
         if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))
@@ -521,15 +509,7 @@ int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
 
 bool blk_rq_merge_ok(struct request *rq, struct bio *bio)
 {
-        if (!rq_mergeable(rq))
-                return false;
-
-        /* don't merge file system requests and discard requests */
-        if ((bio->bi_rw & REQ_DISCARD) != (rq->bio->bi_rw & REQ_DISCARD))
-                return false;
-
-        /* don't merge discard requests and secure discard requests */
-        if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE))
+        if (!rq_mergeable(rq) || !bio_mergeable(bio))
                 return false;
 
         /* different data direction or already started, don't merge */