From e48ec69005f02b70b7ecfde1bc39a599086d16ef Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 3 Jul 2008 13:18:54 +0200 Subject: [PATCH] block: extend queue_flag bitops Add test_and_clear and test_and_set. Signed-off-by: Jens Axboe --- block/blk-core.c | 12 ++++-------- include/linux/blkdev.h | 26 ++++++++++++++++++++++++++ 2 files changed, 30 insertions(+), 8 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index e0fb0bcc0c..dbc7f42b5d 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -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 { diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ff9d0bdf2a..e04c4ac8a7 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -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)); -- 2.39.5