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authorJens Axboe <axboe@kernel.dk>2018-08-20 13:22:27 -0600
committerJens Axboe <axboe@kernel.dk>2018-08-22 15:07:32 -0600
commitc45e6a037a536530bd25781ac7c989e52deb2a63 (patch)
tree0d81aff4f1352d26dbb143a60291817fc154fc24
parentb78820937b4762b7d30b807d7156bec1d89e4dd3 (diff)
blk-wbt: fix has-sleeper queueing check
We need to do this inside the loop as well, or we can allow new IO to supersede previous IO. Tested-by: Anchal Agarwal <anchalag@amazon.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--block/blk-wbt.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 853e22492f4e..c9358f1981fb 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -492,16 +492,17 @@ 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);
+ bool has_sleeper;
- if (!wq_has_sleeper(&rqw->wait) &&
- rq_wait_inc_below(rqw, get_limit(rwb, rw)))
+ has_sleeper = wq_has_sleeper(&rqw->wait);
+ if (!has_sleeper && rq_wait_inc_below(rqw, get_limit(rwb, rw)))
return;
add_wait_queue_exclusive(&rqw->wait, &wait);
do {
set_current_state(TASK_UNINTERRUPTIBLE);
- if (rq_wait_inc_below(rqw, get_limit(rwb, rw)))
+ if (!has_sleeper && rq_wait_inc_below(rqw, get_limit(rwb, rw)))
break;
if (lock) {
@@ -510,6 +511,7 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct,
spin_lock_irq(lock);
} else
io_schedule();
+ has_sleeper = false;
} while (1);
__set_current_state(TASK_RUNNING);