ublk: refactor ublk_queue_rq() and add ublk_batch_queue_rq()

Extract common request preparation and cancellation logic into
__ublk_queue_rq_common() helper function. Add dedicated
ublk_batch_queue_rq() for batch mode operations to eliminate runtime check
in ublk_queue_rq().

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 0a0210f9d41744b588cc2d09399568a6ba645c82..90a6d6a123030fbbb82b0bce7e30432d1006f80d 100644 (file)
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1975,16 +1975,22 @@ static blk_status_t ublk_prep_req(struct ublk_queue *ubq, struct request *rq,
        return BLK_STS_OK;
 }
 
-static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx,
-               const struct blk_mq_queue_data *bd)
+/*
+ * Common helper for queue_rq that handles request preparation and
+ * cancellation checks. Returns status and sets should_queue to indicate
+ * whether the caller should proceed with queuing the request.
+ */
+static inline blk_status_t __ublk_queue_rq_common(struct ublk_queue *ubq,
+                                                  struct request *rq,
+                                                  bool *should_queue)
 {
-       struct ublk_queue *ubq = hctx->driver_data;
-       struct request *rq = bd->rq;
        blk_status_t res;
 
        res = ublk_prep_req(ubq, rq, false);
-       if (res != BLK_STS_OK)
+       if (res != BLK_STS_OK) {
+               *should_queue = false;
                return res;
+       }
 
        /*
         * ->canceling has to be handled after ->force_abort and ->fail_io
@@ -1992,14 +1998,44 @@ static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx,
         * of recovery, and cause hang when deleting disk
         */
        if (unlikely(ubq->canceling)) {
+               *should_queue = false;
                __ublk_abort_rq(ubq, rq);
                return BLK_STS_OK;
        }
 
-       if (ublk_support_batch_io(ubq))
-               ublk_batch_queue_cmd(ubq, rq, bd->last);
-       else
-               ublk_queue_cmd(ubq, rq);
+       *should_queue = true;
+       return BLK_STS_OK;
+}
+
+static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx,
+               const struct blk_mq_queue_data *bd)
+{
+       struct ublk_queue *ubq = hctx->driver_data;
+       struct request *rq = bd->rq;
+       bool should_queue;
+       blk_status_t res;
+
+       res = __ublk_queue_rq_common(ubq, rq, &should_queue);
+       if (!should_queue)
+               return res;
+
+       ublk_queue_cmd(ubq, rq);
+       return BLK_STS_OK;
+}
+
+static blk_status_t ublk_batch_queue_rq(struct blk_mq_hw_ctx *hctx,
+               const struct blk_mq_queue_data *bd)
+{
+       struct ublk_queue *ubq = hctx->driver_data;
+       struct request *rq = bd->rq;
+       bool should_queue;
+       blk_status_t res;
+
+       res = __ublk_queue_rq_common(ubq, rq, &should_queue);
+       if (!should_queue)
+               return res;
+
+       ublk_batch_queue_cmd(ubq, rq, bd->last);
        return BLK_STS_OK;
 }
 
@@ -2122,7 +2158,7 @@ static const struct blk_mq_ops ublk_mq_ops = {
 
 static const struct blk_mq_ops ublk_batch_mq_ops = {
        .commit_rqs     = ublk_commit_rqs,
-       .queue_rq       = ublk_queue_rq,
+       .queue_rq       = ublk_batch_queue_rq,
        .queue_rqs      = ublk_batch_queue_rqs,
        .init_hctx      = ublk_init_hctx,
        .timeout        = ublk_timeout,