blk-mq: remove blk_mq_wait_for_tags
The current logic for blocking tag allocation is rather confusing, as we
first allocated and then free again a tag in blk_mq_wait_for_tags, just
to attempt a non-blocking allocation and then repeat if someone else
managed to grab the tag before us.
Instead change blk_mq_alloc_request_pinned to simply do a blocking tag
allocation itself and use the request we get back from it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 04ef7ec..3224888 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -264,31 +264,30 @@
return NULL;
}
-
static struct request *blk_mq_alloc_request_pinned(struct request_queue *q,
int rw, gfp_t gfp,
bool reserved)
{
+ bool gfp_mask = gfp & ~__GFP_WAIT;
struct request *rq;
do {
struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);
struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q, ctx->cpu);
- rq = __blk_mq_alloc_request(q, hctx, ctx, rw, gfp & ~__GFP_WAIT,
+ rq = __blk_mq_alloc_request(q, hctx, ctx, rw, gfp_mask,
reserved);
if (rq)
break;
- if (gfp & __GFP_WAIT) {
- __blk_mq_run_hw_queue(hctx);
- blk_mq_put_ctx(ctx);
- } else {
+ if (!(gfp & __GFP_WAIT)) {
blk_mq_put_ctx(ctx);
break;
}
- blk_mq_wait_for_tags(hctx, reserved);
+ __blk_mq_run_hw_queue(hctx);
+ blk_mq_put_ctx(ctx);
+ gfp_mask = gfp;
} while (1);
return rq;