diff options
author | Bart Van Assche <bvanassche@acm.org> | 2012-11-28 13:43:38 +0100 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2012-12-06 14:30:59 +0100 |
commit | 807592a4fafba1fea6e98b9cf1fb02b7c38fb24c (patch) | |
tree | 663e227bd15b6abacd2439c1c4cdfd42ec95e493 /block | |
parent | block: Rename queue dead flag (diff) | |
download | linux-807592a4fafba1fea6e98b9cf1fb02b7c38fb24c.tar.xz linux-807592a4fafba1fea6e98b9cf1fb02b7c38fb24c.zip |
block: Let blk_drain_queue() caller obtain the queue lock
Let the caller of blk_drain_queue() obtain the queue lock to improve
readability of the patch called "Avoid that request_fn is invoked on
a dead queue".
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Chanho Min <chanho.min@lge.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r-- | block/blk-core.c | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index 1a95272cca50..a182b586b06a 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -349,7 +349,7 @@ void blk_put_queue(struct request_queue *q) EXPORT_SYMBOL(blk_put_queue); /** - * blk_drain_queue - drain requests from request_queue + * __blk_drain_queue - drain requests from request_queue * @q: queue to drain * @drain_all: whether to drain all requests or only the ones w/ ELVPRIV * @@ -357,15 +357,17 @@ EXPORT_SYMBOL(blk_put_queue); * If not, only ELVPRIV requests are drained. The caller is responsible * for ensuring that no new requests which need to be drained are queued. */ -void blk_drain_queue(struct request_queue *q, bool drain_all) +static void __blk_drain_queue(struct request_queue *q, bool drain_all) + __releases(q->queue_lock) + __acquires(q->queue_lock) { int i; + lockdep_assert_held(q->queue_lock); + while (true) { bool drain = false; - spin_lock_irq(q->queue_lock); - /* * The caller might be trying to drain @q before its * elevator is initialized. @@ -401,11 +403,14 @@ void blk_drain_queue(struct request_queue *q, bool drain_all) } } - spin_unlock_irq(q->queue_lock); - if (!drain) break; + + spin_unlock_irq(q->queue_lock); + msleep(10); + + spin_lock_irq(q->queue_lock); } /* @@ -416,13 +421,9 @@ void blk_drain_queue(struct request_queue *q, bool drain_all) if (q->request_fn) { struct request_list *rl; - spin_lock_irq(q->queue_lock); - blk_queue_for_each_rl(rl, q) for (i = 0; i < ARRAY_SIZE(rl->wait); i++) wake_up_all(&rl->wait[i]); - - spin_unlock_irq(q->queue_lock); } } @@ -446,7 +447,10 @@ void blk_queue_bypass_start(struct request_queue *q) spin_unlock_irq(q->queue_lock); if (drain) { - blk_drain_queue(q, false); + spin_lock_irq(q->queue_lock); + __blk_drain_queue(q, false); + spin_unlock_irq(q->queue_lock); + /* ensure blk_queue_bypass() is %true inside RCU read lock */ synchronize_rcu(); } @@ -504,7 +508,9 @@ void blk_cleanup_queue(struct request_queue *q) mutex_unlock(&q->sysfs_lock); /* drain all requests queued before DYING marking */ - blk_drain_queue(q, true); + spin_lock_irq(lock); + __blk_drain_queue(q, true); + spin_unlock_irq(lock); /* @q won't process any more request, flush async actions */ del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer); |