From: Keith Busch <keith.busch@xxxxxxxxx>
Return -EBUSY if we're unable to enter a queue immediately when
allocating a blk-mq request without __GFP_WAIT.
Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
---
block/blk-mq.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 5706dd9..01b2912 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -77,7 +77,7 @@ static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
}
-static int blk_mq_queue_enter(struct request_queue *q)
+static int blk_mq_queue_enter(struct request_queue *q, gfp_t gfp)
{
while (true) {
int ret;
@@ -85,6 +85,9 @@ static int blk_mq_queue_enter(struct request_queue *q)
if (percpu_ref_tryget_live(&q->mq_usage_counter))
return 0;
+ if (!(gfp & __GFP_WAIT))
+ return -EBUSY;
+
ret = wait_event_interruptible(q->mq_freeze_wq,
!q->mq_freeze_depth || blk_queue_dying(q));
if (blk_queue_dying(q))
@@ -256,7 +259,7 @@ struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,
struct blk_mq_alloc_data alloc_data;
int ret;
- ret = blk_mq_queue_enter(q);
+ ret = blk_mq_queue_enter(q, gfp);
if (ret)
return ERR_PTR(ret);
@@ -1186,7 +1189,7 @@ static struct request *blk_mq_map_request(struct request_queue *q,
int rw = bio_data_dir(bio);
struct blk_mq_alloc_data alloc_data;
- if (unlikely(blk_mq_queue_enter(q))) {
+ if (unlikely(blk_mq_queue_enter(q, GFP_KERNEL))) {
bio_endio(bio, -EIO);
return NULL;
}
--
1.9.5 (Apple Git-50.3)
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