Re: [PATCH v5 5/8] md: Don't clear MD_CLOSING when the raid is about to stop

[Yu Kuai]

在 2024/02/01 14:34, linan666@xxxxxxxxxxxxxxx 写道:
> From: Li Nan <linan122@xxxxxxxxxx>
>
> The raid should not be opened anymore when it is about to be stopped.
> However, other processes can open it again if the flag MD_CLOSING is
> cleared before exiting. From now on, this flag will not be cleared when
> the raid will be stopped.
>
> Fixes: 065e519e71b2 ("md: MD_CLOSING needs to be cleared after called md_set_readonly or do_md_stop")
> Signed-off-by: Li Nan <linan122@xxxxxxxxxx>

LGTM
Reviewed-by: Yu Kuai <yukuai3@xxxxxxxxxx>

> ---
>   drivers/md/md.c | 14 ++++++++++----
>   1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 5442e8e3c161..deee004b8f22 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -6247,7 +6247,15 @@ static void md_clean(struct mddev *mddev)
>   	mddev->persistent = 0;
>   	mddev->level = LEVEL_NONE;
>   	mddev->clevel[0] = 0;
> -	mddev->flags = 0;
> +	/*
> +	 * Don't clear MD_CLOSING, or mddev can be opened again.
> +	 * 'hold_active != 0' means mddev is still in the creation
> +	 * process and will be used later.
> +	 */
> +	if (mddev->hold_active)
> +		mddev->flags = 0;
> +	else
> +		mddev->flags &= BIT_ULL_MASK(MD_CLOSING);
>   	mddev->sb_flags = 0;
>   	mddev->ro = MD_RDWR;
>   	mddev->metadata_type[0] = 0;
> @@ -7626,7 +7634,6 @@ static int md_ioctl(struct block_device *bdev, blk_mode_t mode,
>   	int err = 0;
>   	void __user *argp = (void __user *)arg;
>   	struct mddev *mddev = NULL;
> -	bool did_set_md_closing = false;
>   
>   	err = md_ioctl_valid(cmd);
>   	if (err)
> @@ -7687,7 +7694,6 @@ static int md_ioctl(struct block_device *bdev, blk_mode_t mode,
>   			mutex_unlock(&mddev->open_mutex);
>   			return -EBUSY;
>   		}
> -		did_set_md_closing = true;
>   		mutex_unlock(&mddev->open_mutex);
>   		sync_blockdev(bdev);
>   	}
> @@ -7829,7 +7835,7 @@ static int md_ioctl(struct block_device *bdev, blk_mode_t mode,
>   				     mddev_unlock(mddev);
>   
>   out:
> -	if(did_set_md_closing)
> +	if (cmd == STOP_ARRAY_RO || (err && cmd == STOP_ARRAY))
>   		clear_bit(MD_CLOSING, &mddev->flags);
>   	return err;
>   }