[Cluster-devel] [PATCH] dlm: use sock_create_lite inside tcp_accept_from_sock

[Guoqing Jiang <gqjiang@suse.com>]

On 08/08/2017 03:10 AM, Bob Peterson wrote:
> | | Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
> | | ---
> | |  fs/dlm/lowcomms.c | 2 +-
> | |  1 file changed, 1 insertion(+), 1 deletion(-)
> | |
> | | diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
> | | index 9382db9..4813d0e 100644
> | | --- a/fs/dlm/lowcomms.c
> | | +++ b/fs/dlm/lowcomms.c
> | | @@ -729,7 +729,7 @@ static int tcp_accept_from_sock(struct connection *con)
> | |  	mutex_unlock(&connections_lock);
> | |
> | |  	memset(&peeraddr, 0, sizeof(peeraddr));
> | | -	result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
> | | +	result = sock_create_lite(dlm_local_addr[0]->ss_family,
> | |  				  SOCK_STREAM, IPPROTO_TCP, &newsock);
> | |  	if (result < 0)
> | |  		return -ENOMEM;
> |
> | Isn't this also a problem for the sctp equivalent, sctp_connect_to_sock?
> |
> | Regards,
> |
> | Bob Peterson
> | Red Hat File Systems
> |
>
> In fact, I see 5 different calls to sock_create_kern in DLM.
> Shouldn't it be done to all of them?

Only this one called accept immediately after the socket is created, so 
others
probably are safe. Plus, the sock is used after sock_create_kern, so I 
am not
sure it can be replaced with sock_create_lite.

         result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
                                   SOCK_STREAM, IPPROTO_SCTP, &sock);
         ...
         sock->sk->sk_user_data = con;

> One could also argue that sock_create_kern should itself be fixed,
> not its callers.

Pls see https://patchwork.ozlabs.org/patch/780356/ for more infos.

Thanks,
GUoqing