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| author | Jens Axboe <axboe@kernel.dk> | 2018-08-20 13:22:27 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-08-22 15:07:32 -0600 |
| commit | c45e6a037a536530bd25781ac7c989e52deb2a63 (patch) | |
| tree | 0d81aff4f1352d26dbb143a60291817fc154fc24 /block/blk-wbt.c | |
| parent | b78820937b4762b7d30b807d7156bec1d89e4dd3 (diff) | |
| download | lwn-c45e6a037a536530bd25781ac7c989e52deb2a63.tar.gz lwn-c45e6a037a536530bd25781ac7c989e52deb2a63.zip | |
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>
Diffstat (limited to 'block/blk-wbt.c')
| -rw-r--r-- | block/blk-wbt.c | 8 |
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); |