From 24125c4495b6b9da2d7fe3bb816aa1a9fb297bf4 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 8 Aug 2023 15:53:53 +0800 Subject: [PATCH] dm: requeue IO if mapping table not yet available mainline inclusion from mainline-v5.18-rc1 commit fa247089de9936a46e290d4724cb5f0b845600f5 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7FI78 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.4-rc7&id=fa247089de9936a46e290d4724cb5f0b845600f5 ---------------------------------------- Update both bio-based and request-based DM to requeue IO if the mapping table not available. This race of IO being submitted before the DM device ready is so narrow, yet possible for initial table load given that the DM device's request_queue is created prior, that it best to requeue IO to handle this unlikely case. Reported-by: Zhang Yi Signed-off-by: Mike Snitzer Signed-off-by: Li Lingfeng Reviewed-by: Yu Kuai Signed-off-by: Yongqiang Liu --- drivers/md/dm-rq.c | 7 ++++++- drivers/md/dm.c | 5 +++-- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c index 46bba3de378c..288064e94e52 100644 --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -752,8 +752,13 @@ static blk_status_t dm_mq_queue_rq(struct blk_mq_hw_ctx *hctx, if (unlikely(!ti)) { int srcu_idx; - struct dm_table *map = dm_get_live_table(md, &srcu_idx); + struct dm_table *map; + map = dm_get_live_table(md, &srcu_idx); + if (unlikely(!map)) { + dm_put_live_table(md, srcu_idx); + return BLK_STS_RESOURCE; + } ti = dm_table_find_target(map, 0); dm_put_live_table(md, srcu_idx); } diff --git a/drivers/md/dm.c b/drivers/md/dm.c index ea1baea3a11d..326b3ea2a21f 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1781,8 +1781,9 @@ static blk_qc_t dm_make_request(struct request_queue *q, struct bio *bio) map = dm_get_live_table(md, &srcu_idx); - /* if we're suspended, we have to queue this io for later */ - if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags))) { + /* If suspended, or map not yet available, queue this IO for later */ + if (unlikely(test_bit(DMF_BLOCK_IO_FOR_SUSPEND, &md->flags)) || + unlikely(!map)) { dm_put_live_table(md, srcu_idx); if (!(bio->bi_opf & REQ_RAHEAD)) -- GitLab