Re: [PATCH 5/5] NFSD: Create PF_INET6 listener in write_ports

J. Bruce Fields
2010-01-26T23:28:46Z

On Tue, Jan 26, 2010 at 02:04:22PM -0500, Chuck Lever wrote:
> Try to create a PF_INET6 listener for NFSD, if IPv6 is enabled in the
> kernel.
>
> Make sure nfsd_serv's reference count is decreased if
> __write_ports_addxprt() failed to create a listener. See
> __write_ports_addfd().
>
> Our current plan is to rely on rpc.nfsd to create appropriate IPv6
> listeners when server-side NFS/IPv6 support is desired. Legacy
> behavior, via the write_threads or write_svc kernel APIs, will remain
> the same -- only IPv4 listeners are created.

Looks fine, thanks, but:
>
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>
> fs/nfsd/nfsctl.c | 20 +++++++++++++++++++-
> 1 files changed, 19 insertions(+), 1 deletions(-)
>
> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> index f43ecd6..f0a614e 100644
> --- a/fs/nfsd/nfsctl.c
> +++ b/fs/nfsd/nfsctl.c
> @@ -1003,8 +1003,26 @@ static ssize_t __write_ports_addxprt(char *buf)
> err = svc_create_xprt(nfsd_serv, transport,
> PF_INET, port, SVC_SOCK_ANONYMOUS);
> if (err < 0)
> - return err;
> + goto out_err;
> +
> + err = svc_create_xprt(nfsd_serv, transport,
> + PF_INET6, port, SVC_SOCK_ANONYMOUS);
> + if (err < 0 && err != -EAFNOSUPPORT) {
> + struct svc_xprt *xprt;
> + xprt = svc_find_xprt(nfsd_serv, transport, PF_INET, port);
> + if (xprt != NULL) {
> + svc_close_xprt(xprt);
> + svc_xprt_put(xprt);
> + }
> + goto out_err;
> + }
> +
> return 0;
> +
> +out_err:
> + /* Decrease the count, but don't shut down the service */
> + nfsd_serv->sv_nrthreads--;
> + return err;
> }

Any objection to moving the extra error-handling to the end, as in the
following? If there's no objection, I'll fold it into your last patch.

--b.

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index f0a614e..f4474e5 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -988,6 +988,7 @@ static ssize_t __write_ports_delfd(char *buf)
static ssize_t __write_ports_addxprt(char *buf)
{
char transport[16];
+ struct svc_xprt *xprt;
int port, err;

if (sscanf(buf, "%15s %4u", transport, &port) != 2)
@@ -1007,18 +1008,15 @@ static ssize_t __write_ports_addxprt(char *buf)

err = svc_create_xprt(nfsd_serv, transport,
PF_INET6, port, SVC_SOCK_ANONYMOUS);
- if (err < 0 && err != -EAFNOSUPPORT) {
- struct svc_xprt *xprt;
- xprt = svc_find_xprt(nfsd_serv, transport, PF_INET, port);
- if (xprt != NULL) {
- svc_close_xprt(xprt);
- svc_xprt_put(xprt);
- }
- goto out_err;
- }
-
+ if (err < 0 && err != -EAFNOSUPPORT)
+ goto out_err_cleanup_inet;
return 0;
-
+out_err_cleanup_inet:
+ xprt = svc_find_xprt(nfsd_serv, transport, PF_INET, port);
+ if (xprt != NULL) {
+ svc_close_xprt(xprt);
+ svc_xprt_put(xprt);
+ }
out_err:
/* Decrease the count, but don't shut down the service */
nfsd_serv->sv_nrthreads--;