From: Benjamin Marzinski Date: Tue, 7 May 2024 21:16:23 +0000 (-0400) Subject: dm-delay: fix workqueue delay_timer race X-Git-Tag: io_uring-6.10-20240523~87^2~4 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=8d24790ed08ab4e619ce58ed4a1b353ab77ffdc5;p=linux-block.git dm-delay: fix workqueue delay_timer race delay_timer could be pending when delay_dtr() is called. It needs to be shut down before kdelayd_wq is destroyed, so it won't try queueing more work to kdelayd_wq while that's getting destroyed. Also the del_timer_sync() call in delay_presuspend() doesn't protect against the timer getting immediately rearmed by the queued call to flush_delayed_bios(), but there's no real harm if that does happen. timer_delete() is less work, and is basically just as likely to stop a pointless call to flush_delayed_bios(). Fixes: 26b9f228703f ("dm: delay target") Signed-off-by: Benjamin Marzinski Signed-off-by: Mike Snitzer --- diff --git a/drivers/md/dm-delay.c b/drivers/md/dm-delay.c index 5eabdb06c649..eec0daa4b227 100644 --- a/drivers/md/dm-delay.c +++ b/drivers/md/dm-delay.c @@ -154,8 +154,10 @@ static void delay_dtr(struct dm_target *ti) { struct delay_c *dc = ti->private; - if (dc->kdelayd_wq) + if (dc->kdelayd_wq) { + timer_shutdown_sync(&dc->delay_timer); destroy_workqueue(dc->kdelayd_wq); + } if (dc->read.dev) dm_put_device(ti, dc->read.dev); @@ -335,7 +337,7 @@ static void delay_presuspend(struct dm_target *ti) mutex_unlock(&delayed_bios_lock); if (!delay_is_fast(dc)) - del_timer_sync(&dc->delay_timer); + timer_delete(&dc->delay_timer); flush_delayed_bios(dc, true); }