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".
Cc: James Bottomley <[email protected]> Cc: Mike Christie <[email protected]> Cc: Jens Axboe <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Chanho Min <[email protected]> Signed-off-by: Bart Van Assche <[email protected]> --- block/blk-core.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index ef2e045..76aff1d 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) { unsigned drain = 0; - 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 DEAD 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); -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
