Re: [PATCH v2 3/4] erofs: relinquish volume with mutex held

[Gao Xiang <hsiangkao@linux.alibaba.com>]

On 2023/2/9 13:18, Jingbo Xu wrote:
> Relinquish fscache volume with mutex held.  Otherwise if a new domain is
> registered when the old domain with the same name gets removed from the
> list but not relinquished yet, fscache may complain the collision.
> 
> Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
> Reviewed-by: Jia Zhu <zhujia.zj@bytedance.com>

Do we need to backport this to old kernels?
IOWs, whether "Fixes:" tag is needed?

Thanks,
Gao Xiang

> ---
>   fs/erofs/fscache.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
> index 2f5930e177cc..a6f030966147 100644
> --- a/fs/erofs/fscache.c
> +++ b/fs/erofs/fscache.c
> @@ -328,8 +328,8 @@ static void erofs_fscache_domain_put(struct erofs_domain *domain)
>   			kern_unmount(erofs_pseudo_mnt);
>   			erofs_pseudo_mnt = NULL;
>   		}
> -		mutex_unlock(&erofs_domain_list_lock);
>   		fscache_relinquish_volume(domain->volume, NULL, false);
> +		mutex_unlock(&erofs_domain_list_lock);
>   		kfree(domain->domain_id);
>   		kfree(domain);
>   		return;