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block: extend queue_flag bitops 

Add test_and_clear and test_and_set.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Jens Axboe 2008-07-03 13:18:54 +02:00
parent e180f59493
commit e48ec69005
2 changed files with 30 additions and 8 deletions
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12
block/blk-core.c
View File

@ -205,8 +205,7 @@ void blk_plug_device(struct request_queue *q)
if (blk_queue_stopped(q))
return;
if (!test_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags)) {
__set_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags);
if (!queue_flag_test_and_set(QUEUE_FLAG_PLUGGED, q)) {
mod_timer(&q->unplug_timer, jiffies + q->unplug_delay);
blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG);
}
@ -221,10 +220,9 @@ int blk_remove_plug(struct request_queue *q)
{
WARN_ON(!irqs_disabled());
if (!test_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags))
if (!queue_flag_test_and_clear(QUEUE_FLAG_PLUGGED, q))
return 0;
queue_flag_clear(QUEUE_FLAG_PLUGGED, q);
del_timer(&q->unplug_timer);
return 1;
}
@ -328,8 +326,7 @@ void blk_start_queue(struct request_queue *q)
* one level of recursion is ok and is much faster than kicking
* the unplug handling
*/
if (!test_bit(QUEUE_FLAG_REENTER, &q->queue_flags)) {
queue_flag_set(QUEUE_FLAG_REENTER, q);
if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
q->request_fn(q);
queue_flag_clear(QUEUE_FLAG_REENTER, q);
} else {
@ -394,8 +391,7 @@ void __blk_run_queue(struct request_queue *q)
* handling reinvoke the handler shortly if we already got there.
*/
if (!elv_queue_empty(q)) {
if (!test_bit(QUEUE_FLAG_REENTER, &q->queue_flags)) {
queue_flag_set(QUEUE_FLAG_REENTER, q);
if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
q->request_fn(q);
queue_flag_clear(QUEUE_FLAG_REENTER, q);
} else {

26
include/linux/blkdev.h
View File

@ -428,6 +428,32 @@ static inline void queue_flag_set_unlocked(unsigned int flag,
__set_bit(flag, &q->queue_flags);
}
static inline int queue_flag_test_and_clear(unsigned int flag,
struct request_queue *q)
{
WARN_ON_ONCE(!queue_is_locked(q));
if (test_bit(flag, &q->queue_flags)) {
__clear_bit(flag, &q->queue_flags);
return 1;
}
return 0;
}
static inline int queue_flag_test_and_set(unsigned int flag,
struct request_queue *q)
{
WARN_ON_ONCE(!queue_is_locked(q));
if (!test_bit(flag, &q->queue_flags)) {
__set_bit(flag, &q->queue_flags);
return 0;
}
return 1;
}
static inline void queue_flag_set(unsigned int flag, struct request_queue *q)
{
WARN_ON_ONCE(!queue_is_locked(q));