block: Introduce blk_queue_flag_{set,clear,test_and_{set,clear}}()

Introduce functions that modify the queue flags and that protect
these modifications with the request queue lock. Except for moving
one wake_up_all() call from inside to outside a critical section,
this patch does not change any functionality.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Bart Van Assche 2018-03-07 17:10:04 -08:00 committed by Jens Axboe
parent f78bac2c8e
commit 8814ce8a0f
6 changed files with 93 additions and 49 deletions

View File

@ -71,6 +71,78 @@ struct kmem_cache *blk_requestq_cachep;
*/
static struct workqueue_struct *kblockd_workqueue;
/**
* blk_queue_flag_set - atomically set a queue flag
* @flag: flag to be set
* @q: request queue
*/
void blk_queue_flag_set(unsigned int flag, struct request_queue *q)
{
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
queue_flag_set(flag, q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
EXPORT_SYMBOL(blk_queue_flag_set);
/**
* blk_queue_flag_clear - atomically clear a queue flag
* @flag: flag to be cleared
* @q: request queue
*/
void blk_queue_flag_clear(unsigned int flag, struct request_queue *q)
{
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
queue_flag_clear(flag, q);
spin_unlock_irqrestore(q->queue_lock, flags);
}
EXPORT_SYMBOL(blk_queue_flag_clear);
/**
* blk_queue_flag_test_and_set - atomically test and set a queue flag
* @flag: flag to be set
* @q: request queue
*
* Returns the previous value of @flag - 0 if the flag was not set and 1 if
* the flag was already set.
*/
bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q)
{
unsigned long flags;
bool res;
spin_lock_irqsave(q->queue_lock, flags);
res = queue_flag_test_and_set(flag, q);
spin_unlock_irqrestore(q->queue_lock, flags);
return res;
}
EXPORT_SYMBOL_GPL(blk_queue_flag_test_and_set);
/**
* blk_queue_flag_test_and_clear - atomically test and clear a queue flag
* @flag: flag to be cleared
* @q: request queue
*
* Returns the previous value of @flag - 0 if the flag was not set and 1 if
* the flag was set.
*/
bool blk_queue_flag_test_and_clear(unsigned int flag, struct request_queue *q)
{
unsigned long flags;
bool res;
spin_lock_irqsave(q->queue_lock, flags);
res = queue_flag_test_and_clear(flag, q);
spin_unlock_irqrestore(q->queue_lock, flags);
return res;
}
EXPORT_SYMBOL_GPL(blk_queue_flag_test_and_clear);
static void blk_clear_congested(struct request_list *rl, int sync)
{
#ifdef CONFIG_CGROUP_WRITEBACK
@ -361,25 +433,14 @@ EXPORT_SYMBOL(blk_sync_queue);
*/
int blk_set_preempt_only(struct request_queue *q)
{
unsigned long flags;
int res;
spin_lock_irqsave(q->queue_lock, flags);
res = queue_flag_test_and_set(QUEUE_FLAG_PREEMPT_ONLY, q);
spin_unlock_irqrestore(q->queue_lock, flags);
return res;
return blk_queue_flag_test_and_set(QUEUE_FLAG_PREEMPT_ONLY, q);
}
EXPORT_SYMBOL_GPL(blk_set_preempt_only);
void blk_clear_preempt_only(struct request_queue *q)
{
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
queue_flag_clear(QUEUE_FLAG_PREEMPT_ONLY, q);
blk_queue_flag_clear(QUEUE_FLAG_PREEMPT_ONLY, q);
wake_up_all(&q->mq_freeze_wq);
spin_unlock_irqrestore(q->queue_lock, flags);
}
EXPORT_SYMBOL_GPL(blk_clear_preempt_only);
@ -629,9 +690,7 @@ EXPORT_SYMBOL_GPL(blk_queue_bypass_end);
void blk_set_queue_dying(struct request_queue *q)
{
spin_lock_irq(q->queue_lock);
queue_flag_set(QUEUE_FLAG_DYING, q);
spin_unlock_irq(q->queue_lock);
blk_queue_flag_set(QUEUE_FLAG_DYING, q);
/*
* When queue DYING flag is set, we need to block new req

View File

@ -194,11 +194,7 @@ EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
*/
void blk_mq_quiesce_queue_nowait(struct request_queue *q)
{
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
queue_flag_set(QUEUE_FLAG_QUIESCED, q);
spin_unlock_irqrestore(q->queue_lock, flags);
blk_queue_flag_set(QUEUE_FLAG_QUIESCED, q);
}
EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait);
@ -239,11 +235,7 @@ EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue);
*/
void blk_mq_unquiesce_queue(struct request_queue *q)
{
unsigned long flags;
spin_lock_irqsave(q->queue_lock, flags);
queue_flag_clear(QUEUE_FLAG_QUIESCED, q);
spin_unlock_irqrestore(q->queue_lock, flags);
blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q);
/* dispatch requests which are inserted during quiescing */
blk_mq_run_hw_queues(q, true);

View File

@ -859,12 +859,10 @@ EXPORT_SYMBOL(blk_queue_update_dma_alignment);
void blk_queue_flush_queueable(struct request_queue *q, bool queueable)
{
spin_lock_irq(q->queue_lock);
if (queueable)
queue_flag_clear(QUEUE_FLAG_FLUSH_NQ, q);
blk_queue_flag_clear(QUEUE_FLAG_FLUSH_NQ, q);
else
queue_flag_set(QUEUE_FLAG_FLUSH_NQ, q);
spin_unlock_irq(q->queue_lock);
blk_queue_flag_set(QUEUE_FLAG_FLUSH_NQ, q);
}
EXPORT_SYMBOL_GPL(blk_queue_flush_queueable);

View File

@ -276,12 +276,10 @@ queue_store_##name(struct request_queue *q, const char *page, size_t count) \
if (neg) \
val = !val; \
\
spin_lock_irq(q->queue_lock); \
if (val) \
queue_flag_set(QUEUE_FLAG_##flag, q); \
blk_queue_flag_set(QUEUE_FLAG_##flag, q); \
else \
queue_flag_clear(QUEUE_FLAG_##flag, q); \
spin_unlock_irq(q->queue_lock); \
blk_queue_flag_clear(QUEUE_FLAG_##flag, q); \
return ret; \
}
@ -414,12 +412,10 @@ static ssize_t queue_poll_store(struct request_queue *q, const char *page,
if (ret < 0)
return ret;
spin_lock_irq(q->queue_lock);
if (poll_on)
queue_flag_set(QUEUE_FLAG_POLL, q);
blk_queue_flag_set(QUEUE_FLAG_POLL, q);
else
queue_flag_clear(QUEUE_FLAG_POLL, q);
spin_unlock_irq(q->queue_lock);
blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
return ret;
}
@ -487,12 +483,10 @@ static ssize_t queue_wc_store(struct request_queue *q, const char *page,
if (set == -1)
return -EINVAL;
spin_lock_irq(q->queue_lock);
if (set)
queue_flag_set(QUEUE_FLAG_WC, q);
blk_queue_flag_set(QUEUE_FLAG_WC, q);
else
queue_flag_clear(QUEUE_FLAG_WC, q);
spin_unlock_irq(q->queue_lock);
blk_queue_flag_clear(QUEUE_FLAG_WC, q);
return count;
}
@ -946,9 +940,7 @@ void blk_unregister_queue(struct gendisk *disk)
*/
mutex_lock(&q->sysfs_lock);
spin_lock_irq(q->queue_lock);
queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
spin_unlock_irq(q->queue_lock);
blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
/*
* Remove the sysfs attributes before unregistering the queue data

View File

@ -57,12 +57,10 @@ ssize_t part_timeout_store(struct device *dev, struct device_attribute *attr,
char *p = (char *) buf;
val = simple_strtoul(p, &p, 10);
spin_lock_irq(q->queue_lock);
if (val)
queue_flag_set(QUEUE_FLAG_FAIL_IO, q);
blk_queue_flag_set(QUEUE_FLAG_FAIL_IO, q);
else
queue_flag_clear(QUEUE_FLAG_FAIL_IO, q);
spin_unlock_irq(q->queue_lock);
blk_queue_flag_clear(QUEUE_FLAG_FAIL_IO, q);
}
return count;

View File

@ -707,6 +707,11 @@ struct request_queue {
(1 << QUEUE_FLAG_SAME_COMP) | \
(1 << QUEUE_FLAG_POLL))
void blk_queue_flag_set(unsigned int flag, struct request_queue *q);
void blk_queue_flag_clear(unsigned int flag, struct request_queue *q);
bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q);
bool blk_queue_flag_test_and_clear(unsigned int flag, struct request_queue *q);
/*
* @q->queue_lock is set while a queue is being initialized. Since we know
* that no other threads access the queue object before @q->queue_lock has