block: extend queue_flag bitops

Add test_and_clear and test_and_set.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 30 insertions, 8 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index e0fb0bcc0c17..dbc7f42b5d2b 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 ff9d0bdf2a16..e04c4ac8a7cf 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));