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authorJohannes Thumshirn <johannes.thumshirn@wdc.com>2020-03-24 18:24:44 +0300
committerJens Axboe <axboe@kernel.dk>2020-03-25 18:40:24 +0300
commitc92a41031a6d57395889b5c87cea359220a24d2a (patch)
tree6ac0dd78c2f11befd3a402628e98cb3a0af0162a /block/blk-mq.c
parent8cd5b8fc00716fb71f6b32d594b38a8f286d6c20 (diff)
downloadlinux-c92a41031a6d57395889b5c87cea359220a24d2a.tar.xz
block: factor out requeue handling from dispatch code
Factor out the requeue handling from the dispatch code, this will make subsequent addition of different requeueing schemes easier. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c29
1 files changed, 18 insertions, 11 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5b2e6550e0b6..745ec592a513 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1178,6 +1178,23 @@ static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy)
#define BLK_MQ_RESOURCE_DELAY 3 /* ms units */
+static void blk_mq_handle_dev_resource(struct request *rq,
+ struct list_head *list)
+{
+ struct request *next =
+ list_first_entry_or_null(list, struct request, queuelist);
+
+ /*
+ * If an I/O scheduler has been configured and we got a driver tag for
+ * the next request already, free it.
+ */
+ if (next)
+ blk_mq_put_driver_tag(next);
+
+ list_add(&rq->queuelist, list);
+ __blk_mq_requeue_request(rq);
+}
+
/*
* Returns true if we did some work AND can potentially do more.
*/
@@ -1245,17 +1262,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
ret = q->mq_ops->queue_rq(hctx, &bd);
if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) {
- /*
- * If an I/O scheduler has been configured and we got a
- * driver tag for the next request already, free it
- * again.
- */
- if (!list_empty(list)) {
- nxt = list_first_entry(list, struct request, queuelist);
- blk_mq_put_driver_tag(nxt);
- }
- list_add(&rq->queuelist, list);
- __blk_mq_requeue_request(rq);
+ blk_mq_handle_dev_resource(rq, list);
break;
}