block: move a few merge helpers out of <linux/blkdev.h>
These are block-layer internal helpers, so move them to block/blk.h and
block/blk-merge.c. Also update a comment a bit to use better grammar.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-16-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk.h b/block/blk.h
index f245699..fa90691c 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -96,6 +96,44 @@ static inline bool bvec_gap_to_prev(struct request_queue *q,
return __bvec_gap_to_prev(q, bprv, offset);
}
+static inline bool rq_mergeable(struct request *rq)
+{
+ if (blk_rq_is_passthrough(rq))
+ return false;
+
+ if (req_op(rq) == REQ_OP_FLUSH)
+ return false;
+
+ if (req_op(rq) == REQ_OP_WRITE_ZEROES)
+ return false;
+
+ if (req_op(rq) == REQ_OP_ZONE_APPEND)
+ return false;
+
+ if (rq->cmd_flags & REQ_NOMERGE_FLAGS)
+ return false;
+ if (rq->rq_flags & RQF_NOMERGE_FLAGS)
+ return false;
+
+ return true;
+}
+
+/*
+ * There are two different ways to handle DISCARD merges:
+ * 1) If max_discard_segments > 1, the driver treats every bio as a range and
+ * send the bios to controller together. The ranges don't need to be
+ * contiguous.
+ * 2) Otherwise, the request will be normal read/write requests. The ranges
+ * need to be contiguous.
+ */
+static inline bool blk_discard_mergable(struct request *req)
+{
+ if (req_op(req) == REQ_OP_DISCARD &&
+ queue_max_discard_segments(req->q) > 1)
+ return true;
+ return false;
+}
+
#ifdef CONFIG_BLK_DEV_INTEGRITY
void blk_flush_integrity(void);
bool __bio_integrity_endio(struct bio *);
