block: Consolidate command flag and queue limit checks for merges
- blk_check_merge_flags() verifies that cmd_flags / bi_rw are
compatible. This function is called for both req-req and req-bio
merging.
- blk_rq_get_max_sectors() and blk_queue_get_max_sectors() can be used
to query the maximum sector count for a given request or queue. The
calls will return the right value from the queue limits given the
type of command (RW, discard, write same, etc.)
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>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 3a6fea7..90f7abe 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -605,6 +605,18 @@
return true;
}
+static inline bool blk_check_merge_flags(unsigned int flags1,
+ unsigned int flags2)
+{
+ if ((flags1 & REQ_DISCARD) != (flags2 & REQ_DISCARD))
+ return false;
+
+ if ((flags1 & REQ_SECURE) != (flags2 & REQ_SECURE))
+ return false;
+
+ return true;
+}
+
/*
* q->prep_rq_fn return values
*/
@@ -800,6 +812,25 @@
return blk_rq_cur_bytes(rq) >> 9;
}
+static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q,
+ unsigned int cmd_flags)
+{
+ if (unlikely(cmd_flags & REQ_DISCARD))
+ return q->limits.max_discard_sectors;
+
+ return q->limits.max_sectors;
+}
+
+static inline unsigned int blk_rq_get_max_sectors(struct request *rq)
+{
+ struct request_queue *q = rq->q;
+
+ if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
+ return q->limits.max_hw_sectors;
+
+ return blk_queue_get_max_sectors(q, rq->cmd_flags);
+}
+
/*
* Request issue related functions.
*/