Re: [PATCH 1/5] NFS: Enable NFSv4 callback server to listen on AF_INET6 sockets

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Aug 22, 2008, at Aug 22, 2008, 10:34 PM, Chuck Lever wrote:
On Fri, Aug 22, 2008 at 7:18 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote:
On Fri, Aug 22, 2008 at 12:42:02PM -0400, Chuck Lever wrote:
Allow the NFS callback server to listen for requests via an AF_INET6
or AF_INET socket.

The NFS callback server determines the listener's address family from
the address the client uses to contact the server.  The server will
always call the client back using the same address family.

Won't the server determine that from the callback address which the
client provides in the setclientid?

A client has to have IPv6 networking to mount an IPv6 server.
Otherwise both will use IPv4.  Do you think we should worry about the
case where a client provides a callback address in a different address
family from the server's address?

But I suppose it would be more precise to call nfs_callback_up() using
the family of the passed-in clientaddr= mount option instead of the
passed-in addr= option.  That will require discovering the address
family of the clientaddr string.

We could convert the clientaddr string into a sockaddr temporarily (we
don't already do that... it's converted into a universal address
string, but not into a sockaddr).

I thought about this more over the weekend.

We've got a similar problem here that we have with starting just a TCP or UDP listener for lockd based on what transport protocols were requested on the mount command line.

The NFSv4 callback server (and lockd, and probably NFSD) should start either a single AF_INET or a single AF_INET6 listener, not both. Right now, the callback server's address family is selected based on mount options for the first mount request. But we only want one of these listeners for all mount points on a system, and it should be one that covers all the needed address families, no matter which address family was used during the first mount request.

So these services need to start a listener not based on mount options, but on what kind of networking is available on the host. If IPV6 is available in the kernel, I think, an AF_INET6 listener should be started; otherwise, start an AF_INET listener.

I think the only externally visible issue with doing this is how addresses are presented in kernel log and error messages. If the functions which generate presentation format address strings are smart enough to recognize a mapped IPv4 address and present it in dotted- quad format, that should be enough.

Thoughts/opinions?

Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---

fs/nfs/callback.c |   11 ++++++-----
fs/nfs/callback.h |    4 ++--
fs/nfs/client.c   |    2 +-
3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 6a09760..59948ef 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -97,7 +97,7 @@ nfs_callback_svc(void *vrqstp)
/*
 * Bring up the callback thread if it is not already up.
 */
-int nfs_callback_up(void)
+int nfs_callback_up(const sa_family_t family)
{
     struct svc_serv *serv = NULL;
     int ret = 0;
@@ -106,7 +106,7 @@ int nfs_callback_up(void)
if (nfs_callback_info.users++ || nfs_callback_info.task != NULL)
             goto out;
serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE,
-                             AF_INET, NULL);
+                             family, NULL);
     ret = -ENOMEM;
     if (!serv)
             goto out_err;
@@ -116,7 +116,8 @@ int nfs_callback_up(void)
     if (ret <= 0)
             goto out_err;
     nfs_callback_tcpport = ret;
-     dprintk("Callback port = 0x%x\n", nfs_callback_tcpport);
+     dprintk("NFS: Callback listener port = %u (af %u)\n",
+                     nfs_callback_tcpport, family);

nfs_callback_info.rqst = svc_prepare_thread(serv, &serv- >sv_pools[0]);
     if (IS_ERR(nfs_callback_info.rqst)) {
@@ -149,8 +150,8 @@ out:
     mutex_unlock(&nfs_callback_mutex);
     return ret;
out_err:
- dprintk("Couldn't create callback socket or server thread; err = %d\n",
-             ret);
+ dprintk("NFS: Couldn't create callback socket or server thread; "
+             "err = %d\n", ret);
     nfs_callback_info.users--;
     goto out;
}
diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index bb25d21..85d8102 100644
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -63,10 +63,10 @@ extern __be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getat extern __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy);

#ifdef CONFIG_NFS_V4
-extern int nfs_callback_up(void);
+extern int nfs_callback_up(const sa_family_t family);
extern void nfs_callback_down(void);
#else
-#define nfs_callback_up()    (0)
+#define nfs_callback_up(x)   (0)
#define nfs_callback_down()  do {} while(0)
#endif

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index fc6a95d..5f8889f 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -120,7 +120,7 @@ static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_
     clp->rpc_ops = cl_init->rpc_ops;

     if (cl_init->rpc_ops->version == 4) {
-             if (nfs_callback_up() < 0)
+             if (nfs_callback_up(cl_init->addr->sa_family) < 0)
                     goto error_2;
             __set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
     }

--
To unsubscribe from this list: send the line "unsubscribe linux- nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




--
"If you simplify your English, you are freed from the worst follies of
orthodoxy."
-- George Orwell
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
Chuck Lever
chuck[dot]lever[at]oracle[dot]com




--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Filesystem Development]     [Linux USB Development]     [Linux Media Development]     [Video for Linux]     [Linux NILFS]     [Linux Audio Users]     [Yosemite Info]     [Linux SCSI]

  Powered by Linux