Re: [PATCH 3/7] cifs: No need to send SIGKILL to demux_thread during umount

[Jeff Layton <jlayton-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>]

On Wed, 20 Aug 2014 19:39:17 +0900
Namjae Jeon <namjae.jeon-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> wrote:

> There is no need to explicitly send SIGKILL to cifs_demultiplex_thread
> as it is calling module_put_and_exit to exit cleanly.
> 
> socket sk_rcvtimeo is set to 7 HZ so the thread will wake up in 7 seconds and
> clean itself.
> 
> Signed-off-by: Namjae Jeon <namjae.jeon-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> Signed-off-by: Ashish Sangwan <a.sangwan-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> ---
>  fs/cifs/connect.c |   19 -------------------
>  1 files changed, 0 insertions(+), 19 deletions(-)
> 
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index 03ed8a0..b4b6d10 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -837,7 +837,6 @@ cifs_demultiplex_thread(void *p)
>  	struct TCP_Server_Info *server = p;
>  	unsigned int pdu_length;
>  	char *buf = NULL;
> -	struct task_struct *task_to_wake = NULL;
>  	struct mid_q_entry *mid_entry;
>  
>  	current->flags |= PF_MEMALLOC;
> @@ -928,19 +927,7 @@ cifs_demultiplex_thread(void *p)
>  	if (server->smallbuf) /* no sense logging a debug message if NULL */
>  		cifs_small_buf_release(server->smallbuf);
>  
> -	task_to_wake = xchg(&server->tsk, NULL);
>  	clean_demultiplex_info(server);
> -
> -	/* if server->tsk was NULL then wait for a signal before exiting */
> -	if (!task_to_wake) {
> -		set_current_state(TASK_INTERRUPTIBLE);
> -		while (!signal_pending(current)) {
> -			schedule();
> -			set_current_state(TASK_INTERRUPTIBLE);
> -		}
> -		set_current_state(TASK_RUNNING);
> -	}
> -
>  	module_put_and_exit(0);
>  }
>  
> @@ -2061,8 +2048,6 @@ cifs_find_tcp_session(struct smb_vol *vol)
>  static void
>  cifs_put_tcp_session(struct TCP_Server_Info *server)
>  {
> -	struct task_struct *task;
> -
>  	spin_lock(&cifs_tcp_ses_lock);
>  	if (--server->srv_count > 0) {
>  		spin_unlock(&cifs_tcp_ses_lock);
> @@ -2086,10 +2071,6 @@ cifs_put_tcp_session(struct TCP_Server_Info *server)
>  	kfree(server->session_key.response);
>  	server->session_key.response = NULL;
>  	server->session_key.len = 0;
> -
> -	task = xchg(&server->tsk, NULL);
> -	if (task)
> -		force_sig(SIGKILL, task);
>  }
>  
>  static struct TCP_Server_Info *

Looks fine, I think. That code is a leftover from when we used a
different scheme to take down the kthread and I don't think it's
necessary any longer.

Acked-by: Jeff Layton <jlayton-eUNUBHrolfbYtjvyW6yDsg@public.gmane.org>