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authorChristoph Hellwig <hch@infradead.org>2014-02-07 22:22:36 +0400
committerJens Axboe <axboe@fb.com>2014-02-07 22:58:54 +0400
commit72a0a36e2854a6eadb4cf2561858f613f9cd4639 (patch)
tree26679a518f6e06640fd34a04fcff733450ef15e3
parent96d2e8b5e288e9d2a40b95161b855944846526a5 (diff)
downloadlinux-72a0a36e2854a6eadb4cf2561858f613f9cd4639.tar.xz
blk-mq: support at_head inserations for blk_execute_rq
This is neede for proper SG_IO operation as well as various uses of blk_execute_rq from the SCSI midlayer. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
-rw-r--r--block/blk-exec.c2
-rw-r--r--block/blk-mq.c17
-rw-r--r--include/linux/blk-mq.h3
3 files changed, 13 insertions, 9 deletions
diff --git a/block/blk-exec.c b/block/blk-exec.c
index bbfc072a79c2..c68613bb4c79 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -65,7 +65,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
* be resued after dying flag is set
*/
if (q->mq_ops) {
- blk_mq_insert_request(q, rq, true);
+ blk_mq_insert_request(q, rq, at_head, true);
return;
}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 9072d0ab184f..c9306e3403fe 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -714,13 +714,16 @@ static void blk_mq_work_fn(struct work_struct *work)
}
static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
- struct request *rq)
+ struct request *rq, bool at_head)
{
struct blk_mq_ctx *ctx = rq->mq_ctx;
trace_block_rq_insert(hctx->queue, rq);
- list_add_tail(&rq->queuelist, &ctx->rq_list);
+ if (at_head)
+ list_add(&rq->queuelist, &ctx->rq_list);
+ else
+ list_add_tail(&rq->queuelist, &ctx->rq_list);
blk_mq_hctx_mark_pending(hctx, ctx);
/*
@@ -730,7 +733,7 @@ static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
}
void blk_mq_insert_request(struct request_queue *q, struct request *rq,
- bool run_queue)
+ bool at_head, bool run_queue)
{
struct blk_mq_hw_ctx *hctx;
struct blk_mq_ctx *ctx, *current_ctx;
@@ -749,7 +752,7 @@ void blk_mq_insert_request(struct request_queue *q, struct request *rq,
rq->mq_ctx = ctx;
}
spin_lock(&ctx->lock);
- __blk_mq_insert_request(hctx, rq);
+ __blk_mq_insert_request(hctx, rq, at_head);
spin_unlock(&ctx->lock);
blk_mq_put_ctx(current_ctx);
@@ -781,7 +784,7 @@ void blk_mq_run_request(struct request *rq, bool run_queue, bool async)
/* ctx->cpu might be offline */
spin_lock(&ctx->lock);
- __blk_mq_insert_request(hctx, rq);
+ __blk_mq_insert_request(hctx, rq, false);
spin_unlock(&ctx->lock);
blk_mq_put_ctx(current_ctx);
@@ -819,7 +822,7 @@ static void blk_mq_insert_requests(struct request_queue *q,
rq = list_first_entry(list, struct request, queuelist);
list_del_init(&rq->queuelist);
rq->mq_ctx = ctx;
- __blk_mq_insert_request(hctx, rq);
+ __blk_mq_insert_request(hctx, rq, false);
}
spin_unlock(&ctx->lock);
@@ -971,7 +974,7 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
__blk_mq_free_request(hctx, ctx, rq);
else {
blk_mq_bio_to_request(rq, bio);
- __blk_mq_insert_request(hctx, rq);
+ __blk_mq_insert_request(hctx, rq, false);
}
spin_unlock(&ctx->lock);
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 1e8f16f65af4..b7638be58599 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -122,7 +122,8 @@ void blk_mq_init_commands(struct request_queue *, void (*init)(void *data, struc
void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule);
-void blk_mq_insert_request(struct request_queue *, struct request *, bool);
+void blk_mq_insert_request(struct request_queue *, struct request *,
+ bool, bool);
void blk_mq_run_queues(struct request_queue *q, bool async);
void blk_mq_free_request(struct request *rq);
bool blk_mq_can_queue(struct blk_mq_hw_ctx *);