DM uses blk-mq's quiesce/unquiesce to stop/start device mapper queue. But blk-mq's unquiesce may come from outside events, such as elevator switch, updating nr_requests or others, and request may come during suspend, so simply ask for blk-mq to requeue it.
Fixes one kernel panic issue when running updating nr_requests and dm-mpath suspend/resume stress test. Signed-off-by: Ming Lei <[email protected]> --- drivers/md/dm-rq.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c index 5b95eea517d1..a896dea9750e 100644 --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -490,6 +490,14 @@ static blk_status_t dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx, struct mapped_device *md = tio->md; struct dm_target *ti = md->immutable_target; + /* + * blk-mq's unquiesce may come from outside events, such as + * elevator switch, updating nr_requests or others, and request may + * come during suspend, so simply ask for blk-mq to requeue it. + */ + if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) + return BLK_STS_RESOURCE; + if (unlikely(!ti)) { int srcu_idx; struct dm_table *map = dm_get_live_table(md, &srcu_idx); -- 2.31.1 -- dm-devel mailing list [email protected] https://listman.redhat.com/mailman/listinfo/dm-devel
