From 1d0903d61e9645c6330b94247b96dd873dfc11c8 Mon Sep 17 00:00:00 2001 From: Zhang Yi Date: Sat, 19 Jun 2021 17:36:59 +0800 Subject: blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled() Now that we disable wbt by simply zero out rwb->wb_normal in wbt_disable_default() when switch elevator to bfq, but it's not safe because it will become false positive if we change queue depth. If it become false positive between wbt_wait() and wbt_track() when submit write request, it will lead to drop rqw->inflight to -1 in wbt_done(), which will end up trigger IO hung. Fix this issue by introduce a new state which mean the wbt was disabled. Fixes: a79050434b45 ("blk-rq-qos: refactor out common elements of blk-wbt") Signed-off-by: Zhang Yi Link: https://lore.kernel.org/r/20210619093700.920393-2-yi.zhang@huawei.com Signed-off-by: Jens Axboe --- block/blk-wbt.h | 1 + 1 file changed, 1 insertion(+) (limited to 'block/blk-wbt.h') diff --git a/block/blk-wbt.h b/block/blk-wbt.h index 16bdc85b8df9..2eb01becde8c 100644 --- a/block/blk-wbt.h +++ b/block/blk-wbt.h @@ -34,6 +34,7 @@ enum { enum { WBT_STATE_ON_DEFAULT = 1, WBT_STATE_ON_MANUAL = 2, + WBT_STATE_OFF_DEFAULT }; struct rq_wb { -- cgit