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authorKemeng Shi <shikemeng@huaweicloud.com>2023-01-18 10:37:24 +0100
committerJens Axboe <axboe@kernel.dk>2023-02-06 17:22:29 +0100
commitf1ce99f7098d9e7a322caf48eb8af05be7999827 (patch)
tree5667778fce8610397787fcefbf937fce24976d22 /block/blk-mq.c
parentblk-mq: remove unnecessary error count and check in blk_mq_dispatch_rq_list (diff)
downloadlinux-f1ce99f7098d9e7a322caf48eb8af05be7999827.tar.xz
linux-f1ce99f7098d9e7a322caf48eb8af05be7999827.zip
blk-mq: remove set of bd->last when get driver tag for next request fails
Commit 113285b473824 ("blk-mq: ensure that bd->last is always set correctly") will set last if we failed to get driver tag for next request to avoid flush miss as we break the list walk and will not send the last request in the list which will be sent with last set normally. This code seems stale now becase the flush introduced is always redundant as: For case tag is really out, we will send a extra flush if we find list is not empty after list walk. For case some tag is freed before retry in blk_mq_prep_dispatch_rq for next, then we can get a tag for next request in retry and flush notified already is not necessary. Just remove these stale codes. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to '')
-rw-r--r--block/blk-mq.c24
1 files changed, 2 insertions, 22 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 6f29e6ceecd1..002ed5547bd7 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1923,16 +1923,6 @@ static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy)
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);
}
@@ -2032,7 +2022,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list,
{
enum prep_dispatch prep;
struct request_queue *q = hctx->queue;
- struct request *rq, *nxt;
+ struct request *rq;
int queued;
blk_status_t ret = BLK_STS_OK;
LIST_HEAD(zone_list);
@@ -2058,17 +2048,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list,
list_del_init(&rq->queuelist);
bd.rq = rq;
-
- /*
- * Flag last if we have no more requests, or if we have more
- * but can't assign a driver tag to it.
- */
- if (list_empty(list))
- bd.last = true;
- else {
- nxt = list_first_entry(list, struct request, queuelist);
- bd.last = !blk_mq_get_driver_tag(nxt);
- }
+ bd.last = list_empty(list);
/*
* once the request is queued to lld, no need to cover the