enable or disable wbt is always called with queue freezed, so that wbt
can never be enabled or disabled while io is still inflight, and this
behaviour should always hold to avoid io hang(There have been reported
several times).
Therefor, the code to handle wbt enable/diskble with io inflight is not
and never will be used, hence remove such dead code.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230527010644.647900-3-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
inflight = atomic_dec_return(&rqw->inflight);
/*
- * wbt got disabled with IO in flight. Wake up any potential
- * waiters, we don't have to do more than that.
- */
- if (unlikely(!rwb_enabled(rwb))) {
- rwb_wake_all(rwb);
- return;
- }
-
- /*
* For discards, our limit is always the background. For writes, if
* the device does write back caching, drop further down before we
* wake people up.
{
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 ((opf & REQ_OP_MASK) == REQ_OP_DISCARD)
return rwb->wb_background;