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>

diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index bb93c7c..1dd7edc 100644 (file)
--- 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;