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authorBart Van Assche <bvanassche@acm.org>2012-11-28 13:43:38 +0100
committerJens Axboe <axboe@kernel.dk>2012-12-06 14:30:59 +0100
commit807592a4fafba1fea6e98b9cf1fb02b7c38fb24c (patch)
tree663e227bd15b6abacd2439c1c4cdfd42ec95e493 /block/blk-core.c
parent3f3299d5c0268d6cc3f47b446e8aca436e4a5651 (diff)
downloadlinux-linaro-stable-807592a4fafba1fea6e98b9cf1fb02b7c38fb24c.tar.gz
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/blk-core.c')
-rw-r--r--block/blk-core.c30
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);