[linux-cifs-client] [PATCH] Cannot allocate memory

[Jeff Layton]

On Fri, 13 Mar 2009 15:06:30 +0300
Pavel Shilovsky <piastry at etersoft.ru> wrote:

> Jeff Layton wrote:
> 
> >> >> @@ -1418,6 +1420,11 @@ cifs_put_tcp_session(struct TCP_Server_Info *server)
> >> >>      task = xchg(&server->tsk, NULL);
> >> >>      if (task)
> >> >>          force_sig(SIGKILL, task);
> >> >> +
> >> >> +    while(server->running == 1)
> >> >> +        msleep(10);
> >>     
> > >
> > >^^^ this is pretty yucky though. Polling and sleeping isn't the way to do 
> > >this. A completion variable + wait_for_completion() might be a better fit.
> >   
> 
> Ok, thanks a lot for advices.
> 
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index 9fbf4df..a5989aa 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -182,6 +182,7 @@ struct TCP_Server_Info {
>         struct mac_key mac_signing_key;
>         char ntlmv2_hash[16];
>         unsigned long lstrp; /* when we got last response from this server */
> +       struct completion done;
>  };
> 
>  /*
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index cd4ccc8..480c48e 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -337,6 +337,7 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
>         bool isMultiRsp;
>         int reconnect;
> 
> +       init_completion(&server->done);
>         current->flags |= PF_MEMALLOC;
>         cFYI(1, ("Demultiplex PID: %d", task_pid_nr(current)));
> 
> @@ -747,7 +748,6 @@ multi_t2_fnd:
> 
>         kfree(server->hostname);
>         task_to_wake = xchg(&server->tsk, NULL);
> -       kfree(server);
> 
>         length = atomic_dec_return(&tcpSesAllocCount);
>         if (length  > 0)
> @@ -764,6 +764,8 @@ multi_t2_fnd:
>                 set_current_state(TASK_RUNNING);
>         }
> 
> +       complete_all(&server->done);
> +
>         module_put_and_exit(0);
>  }
> 
> @@ -1418,6 +1420,10 @@ cifs_put_tcp_session(struct TCP_Server_Info *server)
>         task = xchg(&server->tsk, NULL);
>         if (task)
>                 force_sig(SIGKILL, task);
> +
> +       wait_for_completion_interruptible(&server->done);
> +
> +       kfree(server);
>  }
> 
>  static struct TCP_Server_Info *
> 

Looks good to me. It might be nice to see this in conjunction with some
patches that make cifs_demultiplex_thread shut down more quickly, but I
don't guess we need to wait for that to take this one. You can add my
ack...

Acked-by: Jeff Layton <jlayton at redhat.com>