dm rq: don't queue request to blk-mq during DM suspend

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.

Cc: stable@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Ming Lei 2021-09-23 17:11:31 +08:00 committed by Mike Snitzer
parent ec132ef2d1
commit b4459b11e8
1 changed files with 8 additions and 0 deletions

View File

@ -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);