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authorZheng Qixing <zhengqixing@huawei.com>2025-08-26 15:42:03 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-10-15 11:58:08 +0200
commited6877417298327aa11cc82100f611dc0d8ab6a5 (patch)
tree947d9371425fd69e6b8ccf9eb4b60774db7c7fc9
parent2647603d42d99b16d6d0ed973d7dcc7b70354656 (diff)
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dm: fix queue start/stop imbalance under suspend/load/resume races
commit 7f597c2cdb9d3263a6fce07c4fc0a9eaa8e8fc43 upstream. When suspend and load run concurrently, before q->mq_ops is set in blk_mq_init_allocated_queue(), __dm_suspend() skip dm_stop_queue(). As a result, the queue's quiesce depth is not incremented. Later, once table load has finished and __dm_resume() runs, which triggers q->quiesce_depth ==0 warning in blk_mq_unquiesce_queue(): Call Trace: <TASK> dm_start_queue+0x16/0x20 [dm_mod] __dm_resume+0xac/0xb0 [dm_mod] dm_resume+0x12d/0x150 [dm_mod] do_resume+0x2c2/0x420 [dm_mod] dev_suspend+0x30/0x130 [dm_mod] ctl_ioctl+0x402/0x570 [dm_mod] dm_ctl_ioctl+0x23/0x30 [dm_mod] Fix this by explicitly tracking whether the request queue was stopped in __dm_suspend() via a new DMF_QUEUE_STOPPED flag. Only call dm_start_queue() in __dm_resume() if the queue was actually stopped. Fixes: e70feb8b3e68 ("blk-mq: support concurrent queue quiesce/unquiesce") Cc: stable@vger.kernel.org Signed-off-by: Zheng Qixing <zhengqixing@huawei.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/md/dm-core.h1
-rw-r--r--drivers/md/dm.c8
2 files changed, 6 insertions, 3 deletions
diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h
index e6757a30dcca..8a42c1590ece 100644
--- a/drivers/md/dm-core.h
+++ b/drivers/md/dm-core.h
@@ -161,6 +161,7 @@ struct mapped_device {
#define DMF_SUSPENDED_INTERNALLY 7
#define DMF_POST_SUSPENDING 8
#define DMF_EMULATE_ZONE_APPEND 9
+#define DMF_QUEUE_STOPPED 10
void disable_discard(struct mapped_device *md);
void disable_write_zeroes(struct mapped_device *md);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 44424554e6b5..34307876a521 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2740,8 +2740,10 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
* Stop md->queue before flushing md->wq in case request-based
* dm defers requests to md->wq from md->queue.
*/
- if (dm_request_based(md))
+ if (dm_request_based(md)) {
dm_stop_queue(md->queue);
+ set_bit(DMF_QUEUE_STOPPED, &md->flags);
+ }
flush_workqueue(md->wq);
@@ -2763,7 +2765,7 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map,
if (r < 0) {
dm_queue_flush(md);
- if (dm_request_based(md))
+ if (test_and_clear_bit(DMF_QUEUE_STOPPED, &md->flags))
dm_start_queue(md->queue);
unlock_fs(md);
@@ -2847,7 +2849,7 @@ static int __dm_resume(struct mapped_device *md, struct dm_table *map)
* so that mapping of targets can work correctly.
* Request-based dm is queueing the deferred I/Os in its request_queue.
*/
- if (dm_request_based(md))
+ if (test_and_clear_bit(DMF_QUEUE_STOPPED, &md->flags))
dm_start_queue(md->queue);
unlock_fs(md);