From: Ming Lei <ming.lei@redhat.com>
To: chengming.zhou@linux.dev
Cc: axboe@kernel.dk, hch@lst.de, bvanassche@acm.org,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
zhouchengming@bytedance.com
Subject: Re: [PATCH 1/3] blk-mq: fix tags leak when shrink nr_hw_queues
Date: Tue, 22 Aug 2023 20:45:33 +0800 [thread overview]
Message-ID: <ZOSt7XayXNGkMofU@fedora> (raw)
In-Reply-To: <20230821095602.70742-1-chengming.zhou@linux.dev>
On Mon, Aug 21, 2023 at 05:56:00PM +0800, chengming.zhou@linux.dev wrote:
> From: Chengming Zhou <zhouchengming@bytedance.com>
>
> Although we don't need to realloc set->tags[] when shrink nr_hw_queues,
> we need to free them. Or these tags will be leaked.
>
> How to reproduce:
> 1. mount -t configfs configfs /mnt
> 2. modprobe null_blk nr_devices=0 submit_queues=8
> 3. mkdir /mnt/nullb/nullb0
> 4. echo 1 > /mnt/nullb/nullb0/power
> 5. echo 4 > /mnt/nullb/nullb0/submit_queues
> 6. rmdir /mnt/nullb/nullb0
>
> In step 4, will alloc 9 tags (8 submit queues and 1 poll queue), then
> in step 5, new_nr_hw_queues = 5 (4 submit queues and 1 poll queue).
> At last in step 6, only these 5 tags are freed, the other 4 tags leaked.
>
> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
--
Ming
next prev parent reply other threads:[~2023-08-22 12:46 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-21 9:56 [PATCH 1/3] blk-mq: fix tags leak when shrink nr_hw_queues chengming.zhou
2023-08-21 9:56 ` [PATCH 2/3] blk-mq: delete redundant tagset map update when fallback chengming.zhou
2023-08-22 12:46 ` Ming Lei
2023-08-21 9:56 ` [PATCH 3/3] blk-mq: prealloc tags when increase tagset nr_hw_queues chengming.zhou
2023-08-22 12:55 ` Ming Lei
2023-08-22 12:45 ` Ming Lei [this message]
2023-08-22 14:58 ` [PATCH 1/3] blk-mq: fix tags leak when shrink nr_hw_queues Jens Axboe
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