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authorJens Axboe <axboe@kernel.dk>2018-08-20 13:24:25 -0600
committerJens Axboe <axboe@kernel.dk>2018-08-22 15:07:31 -0600
commitffa358dcaae1f2f00926484e712e06daa8953cb4 (patch)
tree9b1050c8182c0f032ff5a1b0b706968ac4535708 /block/blk-wbt.c
parent3943b040f11ed0cc6d4585fd286a623ca8634547 (diff)
downloadlinux-ffa358dcaae1f2f00926484e712e06daa8953cb4.tar.gz
blk-wbt: move disable check into get_limit()
Check it in one place, instead of in multiple places.

Tested-by: Anchal Agarwal <anchalag@amazon.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-wbt.c')
-rw-r--r--block/blk-wbt.c22
1 files changed, 7 insertions, 15 deletions
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index bb93c7c2b182..1dd7edce7a99 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -449,6 +449,13 @@ static inline unsigned int get_limit(struct rq_wb *rwb, unsigned long rw)
 {
 	unsigned int limit;
 
+	/*
+	 * If we got disabled, just return UINT_MAX. This ensures that
+	 * we'll properly inc a new IO, and dec+wakeup at the end.
+	 */
+	if (!rwb_enabled(rwb))
+		return UINT_MAX;
+
 	if ((rw & REQ_OP_MASK) == REQ_OP_DISCARD)
 		return rwb->wb_background;
 
@@ -486,16 +493,6 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct,
 	struct rq_wait *rqw = get_rq_wait(rwb, wb_acct);
 	DECLARE_WAITQUEUE(wait, current);
 
-	/*
-	* inc it here even if disabled, since we'll dec it at completion.
-	* this only happens if the task was sleeping in __wbt_wait(),
-	* and someone turned it off at the same time.
-	*/
-	if (!rwb_enabled(rwb)) {
-		atomic_inc(&rqw->inflight);
-		return;
-	}
-
 	if (!waitqueue_active(&rqw->wait)
 		&& rq_wait_inc_below(rqw, get_limit(rwb, rw)))
 		return;
@@ -504,11 +501,6 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct,
 	do {
 		set_current_state(TASK_UNINTERRUPTIBLE);
 
-		if (!rwb_enabled(rwb)) {
-			atomic_inc(&rqw->inflight);
-			break;
-		}
-
 		if (rq_wait_inc_below(rqw, get_limit(rwb, rw)))
 			break;