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authorMing Lei <tom.leiming@gmail.com>2013-12-26 17:31:35 +0400
committerJens Axboe <axboe@kernel.dk>2013-12-31 20:53:05 +0400
commit43a5e4e21964a6efb4d14a34644ec7109d0ae891 (patch)
tree9ff635ec990583c0877d4056841d35e6018825a1 /block/blk-mq.c
parentb28bc9b38c52f63f43e3fd875af982f2240a2859 (diff)
downloadlinux-43a5e4e21964a6efb4d14a34644ec7109d0ae891.tar.xz
block: blk-mq: support draining mq queue
blk_mq_drain_queue() is introduced so that we can drain mq queue inside blk_cleanup_queue(). Also don't accept new requests any more if queue is marked as dying. Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c43
1 files changed, 27 insertions, 16 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3929f43d0b03..e2f811cba417 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -106,10 +106,13 @@ static int blk_mq_queue_enter(struct request_queue *q)
spin_lock_irq(q->queue_lock);
ret = wait_event_interruptible_lock_irq(q->mq_freeze_wq,
- !blk_queue_bypass(q), *q->queue_lock);
+ !blk_queue_bypass(q) || blk_queue_dying(q),
+ *q->queue_lock);
/* inc usage with lock hold to avoid freeze_queue runs here */
- if (!ret)
+ if (!ret && !blk_queue_dying(q))
__percpu_counter_add(&q->mq_usage_counter, 1, 1000000);
+ else if (blk_queue_dying(q))
+ ret = -ENODEV;
spin_unlock_irq(q->queue_lock);
return ret;
@@ -120,6 +123,22 @@ static void blk_mq_queue_exit(struct request_queue *q)
__percpu_counter_add(&q->mq_usage_counter, -1, 1000000);
}
+static void __blk_mq_drain_queue(struct request_queue *q)
+{
+ while (true) {
+ s64 count;
+
+ spin_lock_irq(q->queue_lock);
+ count = percpu_counter_sum(&q->mq_usage_counter);
+ spin_unlock_irq(q->queue_lock);
+
+ if (count == 0)
+ break;
+ blk_mq_run_queues(q, false);
+ msleep(10);
+ }
+}
+
/*
* Guarantee no request is in use, so we can change any data structure of
* the queue afterward.
@@ -133,21 +152,13 @@ static void blk_mq_freeze_queue(struct request_queue *q)
queue_flag_set(QUEUE_FLAG_BYPASS, q);
spin_unlock_irq(q->queue_lock);
- if (!drain)
- return;
-
- while (true) {
- s64 count;
-
- spin_lock_irq(q->queue_lock);
- count = percpu_counter_sum(&q->mq_usage_counter);
- spin_unlock_irq(q->queue_lock);
+ if (drain)
+ __blk_mq_drain_queue(q);
+}
- if (count == 0)
- break;
- blk_mq_run_queues(q, false);
- msleep(10);
- }
+void blk_mq_drain_queue(struct request_queue *q)
+{
+ __blk_mq_drain_queue(q);
}
static void blk_mq_unfreeze_queue(struct request_queue *q)