From: Luis Chamberlain <mcgrof@kernel.org>
To: Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>,
linux-block@vger.kernel.org, Minchan Kim <minchan@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH V2 3/4] zram: avoid race between zram_remove and disksize_store
Date: Fri, 22 Oct 2021 12:02:42 -0700 [thread overview]
Message-ID: <YXMK0l5lDeIH8qMQ@bombadil.infradead.org> (raw)
In-Reply-To: <20211020015548.2374568-4-ming.lei@redhat.com>
On Wed, Oct 20, 2021 at 09:55:47AM +0800, Ming Lei wrote:
> After resetting device in zram_remove(), disksize_store still may come and
> allocate resources again before deleting gendisk, fix the race by resetting
> zram after del_gendisk() returns. At that time, disksize_store can't come
> any more.
>
> Reported-by: Luis Chamberlain <mcgrof@kernel.org>
> Signed-off-by: Ming Lei <ming.lei@redhat.com>
> ---
> drivers/block/zram/zram_drv.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index 8883de7aa3d7..6078d1dae44a 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -2002,6 +2002,13 @@ static int zram_remove(struct zram *zram)
> /* del_gendisk drains pending reset_store */
> WARN_ON_ONCE(claimed && zram->claim);
>
> + /*
> + * disksize store may come between zram_reset_device and del_gendisk, so
> + * run the last reset for avoiding leak anything allocated in
> + * disksize_store().
The above is not clear English, how about:
disksize_store() may be called in between zram_reset_device() and
del_gendisk(), so run the last reset to avoid leaking anything allocated
with disksize_store()
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Luis
next prev parent reply other threads:[~2021-10-22 19:02 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-20 1:55 [PATCH V2 0/4] zram: fix two races and one zram leak Ming Lei
2021-10-20 1:55 ` [PATCH V2 1/4] zram: fix race between zram_reset_device() and disksize_store() Ming Lei
2021-10-21 23:03 ` Luis Chamberlain
2021-10-20 1:55 ` [PATCH V2 2/4] zram: don't fail to remove zram during unloading module Ming Lei
2021-10-21 23:50 ` Luis Chamberlain
2021-10-22 0:38 ` Ming Lei
2021-10-20 1:55 ` [PATCH V2 3/4] zram: avoid race between zram_remove and disksize_store Ming Lei
2021-10-22 19:02 ` Luis Chamberlain [this message]
2021-10-20 1:55 ` [PATCH V2 4/4] zram: replace fsync_bdev with sync_blockdev Ming Lei
2021-10-22 19:06 ` Luis Chamberlain
2021-10-20 21:40 ` [PATCH V2 0/4] zram: fix two races and one zram leak Minchan Kim
2021-10-21 17:39 ` Luis Chamberlain
2021-10-21 17:46 ` Luis Chamberlain
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