blk-mq: fix waiting for reserved tags

blk_mq_wait_for_tags() is only able to wait for "normal" tags,
not reserved tags. Pass in which one we should attempt to get
a tag for, so that waiting for reserved tags will work.

Reserved tags are used for internal commands, which are usually
serialized. Hence no waiting generally takes place, but we should
ensure that it actually works if users need that functionality.

Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 7a799c46c32d0c358fc9f912b9e0b2f0ab0fb3ee..1f43d6ee956fbdab557bb5bab70938e0155499e0 100644 (file)
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -6,9 +6,9 @@
 #include "blk-mq.h"
 #include "blk-mq-tag.h"
 
-void blk_mq_wait_for_tags(struct blk_mq_tags *tags)
+void blk_mq_wait_for_tags(struct blk_mq_tags *tags, bool reserved)
 {
-       int tag = blk_mq_get_tag(tags, __GFP_WAIT, false);
+       int tag = blk_mq_get_tag(tags, __GFP_WAIT, reserved);
        blk_mq_put_tag(tags, tag);
 }
 

diff --git a/block/blk-mq-tag.h b/block/blk-mq-tag.h
index b602e3fa66ea0ad5aad11dd99dbb53bb681ec223..c8e0645ea331c74775cb211b876188f2c808af39 100644 (file)
--- a/block/blk-mq-tag.h
+++ b/block/blk-mq-tag.h
@@ -24,7 +24,7 @@ extern struct blk_mq_tags *blk_mq_init_tags(unsigned int nr_tags, unsigned int r
 extern void blk_mq_free_tags(struct blk_mq_tags *tags);
 
 extern unsigned int blk_mq_get_tag(struct blk_mq_tags *tags, gfp_t gfp, bool reserved);
-extern void blk_mq_wait_for_tags(struct blk_mq_tags *tags);
+extern void blk_mq_wait_for_tags(struct blk_mq_tags *tags, bool reserved);
 extern void blk_mq_put_tag(struct blk_mq_tags *tags, unsigned int tag);
 extern void blk_mq_tag_busy_iter(struct blk_mq_tags *tags, void (*fn)(void *data, unsigned long *), void *data);
 extern bool blk_mq_has_free_tags(struct blk_mq_tags *tags);

diff --git a/block/blk-mq.c b/block/blk-mq.c
index f2e92eb92803b16f66e348a60d0b229205b9039c..0aee325682103a1af4f038755897abfcce96b341 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -218,7 +218,7 @@ static struct request *blk_mq_alloc_request_pinned(struct request_queue *q,
                        break;
                }
 
-               blk_mq_wait_for_tags(hctx->tags);
+               blk_mq_wait_for_tags(hctx->tags, reserved);
        } while (1);
 
        return rq;