6.6-stable review patch. If anyone has any objections, please let me know.
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From: Zheng Qixing zhengqixing@huawei.com
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 --- drivers/md/dm-core.h | 1 + drivers/md/dm.c | 8 +++++--- 2 files changed, 6 insertions(+), 3 deletions(-)
--- 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); --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -2740,8 +2740,10 @@ static int __dm_suspend(struct mapped_de * 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_de 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_dev * 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);