Re: [PATCH] ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release()

[Heming Zhao]

On Mon, Jun 01, 2026 at 08:16:18PM +0800, Joseph Qi wrote:
> Move atomic_inc(&ocfs2_control_opened) and the handshake state update
> inside ocfs2_control_lock to close a race window where
> ocfs2_control_release() can observe ocfs2_control_opened dropping to
> zero (resetting ocfs2_control_this_node and running_proto) while
> ocfs2_control_install_private() is about to bump the counter and mark
> the connection valid.
> 
> Fixes: 3cfd4ab6b6b4 ("ocfs2: Add the local node id to the handshake.")
> Reported-by: Ginger <ginger@xxxxxxxxx>

The code looks good to me, but above email address is not valid.
The correct should be: <ginger.jzllee@xxxxxxxxx>

- Heming

> Signed-off-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
> ---
>  fs/ocfs2/stack_user.c | 10 +++-------
>  1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
> index 5803f1dee679..91e19d33847c 100644
> --- a/fs/ocfs2/stack_user.c
> +++ b/fs/ocfs2/stack_user.c
> @@ -327,18 +327,14 @@ static int ocfs2_control_install_private(struct file *file)
>  		ocfs2_control_this_node = p->op_this_node;
>  		running_proto.pv_major = p->op_proto.pv_major;
>  		running_proto.pv_minor = p->op_proto.pv_minor;
> -	}
> -
> -out_unlock:
> -	mutex_unlock(&ocfs2_control_lock);
> -
> -	if (!rc && set_p) {
> -		/* We set the global values successfully */
>  		atomic_inc(&ocfs2_control_opened);
>  		ocfs2_control_set_handshake_state(file,
>  					OCFS2_CONTROL_HANDSHAKE_VALID);
>  	}
>  
> +out_unlock:
> +	mutex_unlock(&ocfs2_control_lock);
> +
>  	return rc;
>  }
>  
> -- 
> 2.39.3
>