blk-mq: Shared tag enhancements
Storage controllers may expose multiple block devices that share hardware
resources managed by blk-mq. This patch enhances the shared tags so a
low-level driver can access the shared resources not tied to the unshared
h/w contexts. This way the LLD can dynamically add and delete disks and
request queues without having to track all the request_queue hctx's to
iterate outstanding tags.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 2056a99..37d1602 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -96,6 +96,7 @@
typedef void (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
bool);
+typedef void (busy_tag_iter_fn)(struct request *, void *, bool);
struct blk_mq_ops {
/*
@@ -182,6 +183,7 @@
struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
gfp_t gfp, bool reserved);
struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag);
+struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags);
enum {
BLK_MQ_UNIQUE_TAG_BITS = 16,
@@ -224,6 +226,8 @@
void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
void blk_mq_tag_busy_iter(struct blk_mq_hw_ctx *hctx, busy_iter_fn *fn,
void *priv);
+void blk_mq_all_tag_busy_iter(struct blk_mq_tags *tags, busy_tag_iter_fn *fn,
+ void *priv);
void blk_mq_freeze_queue(struct request_queue *q);
void blk_mq_unfreeze_queue(struct request_queue *q);
void blk_mq_freeze_queue_start(struct request_queue *q);