blk-mq: don't create hctx debugfs dir until q->debugfs_dir is created

[ Upstream commit f3ec5d1155 ]

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: 6cfc0081b0 ("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>
This commit is contained in:
Ming Lei 2022-07-11 17:08:08 +08:00 committed by Greg Kroah-Hartman
parent 1c350a597c
commit 6d8e185bf9
1 changed files with 3 additions and 0 deletions

View File

@ -879,6 +879,9 @@ 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);