From: Ming Lei <ming.lei@redhat.com> stable inclusion from stable-v5.10.137 commit ed6ae2381150bd8235e5f8460913ea6152bde2e1 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit f3ec5d11554778c24ac8915e847223ed71d104fc ] blk_mq_debugfs_register_hctx() can be called by blk_mq_update_nr_hw_queues when gendisk isn't added yet, such as nvme tcp. Fixes the warning of 'debugfs: Directory 'hctx0' with parent '/' already present!' which can be observed reliably when running blktests nvme/005. Fixes: 6cfc0081b046 ("blk-mq: no need to check return value of debugfs_create functions") Reported-by: Yi Zhang <yi.zhang@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Tested-by: Yi Zhang <yi.zhang@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220711090808.259682-1-ming.lei@redhat.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> --- block/blk-mq-debugfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index ab8040485442..8a86fa590db1 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -915,6 +915,9 @@ void blk_mq_debugfs_register_hctx(struct request_queue *q, char name[20]; int i; + if (!q->debugfs_dir) + return; + snprintf(name, sizeof(name), "hctx%u", hctx->queue_num); hctx->debugfs_dir = debugfs_create_dir(name, q->debugfs_dir); -- 2.20.1