[linux-cifs-client] Re: [PATCH 6/6] cifs: don't retry on blocking sends

[Steve French]

We probably do need to retry, but closer to the 20 second range total which
is only slightly longer than the large (non-blocking) send retry used to wait.

On Sun, Nov 30, 2008 at 7:57 AM, Jeff Layton <jlayton at redhat.com> wrote:
> smb_send2 will attempt to send a message and retry if it doesn't work.
> It's rather pointless to do this in the case of blocking sends. We can
> just set the socket sndtimeo to a reasonable value and try the send
> once.
>
> Why change the timeout to 30s? That seems like a reasonable amount of
> time to wait for the send. It's also what sunrpc uses for sndtimeo
> with TCP sockets. At some point we might consider making this
> tunable, but a generic "timeo" setting similar to what NFS has is
> probably more user friendly.
>
> Signed-off-by: Jeff Layton <jlayton at redhat.com>
> ---
>  fs/cifs/connect.c   |    4 ++--
>  fs/cifs/transport.c |   12 ++++++++++++
>  2 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index 25f7cba..16afe2d 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -1753,7 +1753,7 @@ ipv4_connect(struct TCP_Server_Info *server)
>         *  user space buffer
>         */
>        socket->sk->sk_rcvtimeo = 7 * HZ;
> -       socket->sk->sk_sndtimeo = 3 * HZ;
> +       socket->sk->sk_sndtimeo = 30 * HZ;
>
>        /* make the bufsizes depend on wsize/rsize and max requests */
>        if (server->noautotune) {
> @@ -1904,7 +1904,7 @@ ipv6_connect(struct TCP_Server_Info *server)
>         * user space buffer
>         */
>        socket->sk->sk_rcvtimeo = 7 * HZ;
> -       socket->sk->sk_sndtimeo = 3 * HZ;
> +       socket->sk->sk_sndtimeo = 30 * HZ;
>        server->ssocket = socket;
>
>        return rc;
> diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
> index 2d1bd28..e4bf0b4 100644
> --- a/fs/cifs/transport.c
> +++ b/fs/cifs/transport.c
> @@ -197,6 +197,18 @@ smb_send2(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
>        while (total_len) {
>                rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
>                                    n_vec - first_vec, total_len);
> +
> +               /*
> +                * blocking send -- just update total_len and break out of
> +                * the loop. No sense in retrying since we've already given
> +                * it a long timeout.
> +                */
> +               if (!server->noblocksnd) {
> +                       if (rc >= 0)
> +                               total_len -= rc;
> +                       break;
> +               }
> +
>                if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
>                        i++;
>                        if (i >= 14) {
> --
> 1.5.5.1
>
>



-- 
Thanks,

Steve