NFS: Adjust nfs_clone_mount structure to store "struct sockaddr *"

Change the addr field in the nfs_clone_mount structure to store a "struct
sockaddr *" to support non-IPv4 addresses in the NFS client.

Note this is mostly a cosmetic change, and does not actually allow
referrals using IPv6 addresses.  The existing referral code assumes that
the server returns a string that represents an IPv4 address.  This code
needs to support hostnames and IPv6 addresses as well as IPv4 addresses,
thus it will need to be reorganized completely (to handle DNS resolution
in user space).

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

3 files changed, 11 insertions, 8 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 11380601fc78..ba114faf195f 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1094,8 +1094,8 @@ struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
         /* Get a client representation.
          * Note: NFSv4 always uses TCP, */
         error = nfs4_set_client(server, data->hostname,
-                                (struct sockaddr *)data->addr,
-                                sizeof(*data->addr),
+                                data->addr,
+                                data->addrlen,
                                 parent_client->cl_ipaddr,
                                 data->authflavor,
                                 parent_server->client->cl_xprt->prot,
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index c8458b168018..75dd4e252cae 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -21,7 +21,8 @@ struct nfs_clone_mount {
         struct nfs_fattr *fattr;
         char *hostname;
         char *mnt_path;
-        struct sockaddr_in *addr;
+        struct sockaddr *addr;
+        size_t addrlen;
         rpc_authflavor_t authflavor;
 };
 
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index bd1b1617905d..5f9ba41ed5bf 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -172,7 +172,10 @@ static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
 
                 s = 0;
                 while (s < location->nservers) {
-                        struct sockaddr_in addr = {};
+                        struct sockaddr_in addr = {
+                                .sin_family     = AF_INET,
+                                .sin_port       = htons(NFS_PORT),
+                        };
 
                         if (location->servers[s].len <= 0 ||
                             valid_ipaddr4(location->servers[s].data) < 0) {
@@ -181,10 +184,9 @@ static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
                         }
 
                         mountdata.hostname = location->servers[s].data;
-                        addr.sin_addr.s_addr = in_aton(mountdata.hostname);
-                        addr.sin_family = AF_INET;
-                        addr.sin_port = htons(NFS_PORT);
-                        mountdata.addr = &addr;
+                        addr.sin_addr.s_addr = in_aton(mountdata.hostname),
+                        mountdata.addr = (struct sockaddr *)&addr;
+                        mountdata.addrlen = sizeof(addr);
 
                         snprintf(page, PAGE_SIZE, "%s:%s",
                                         mountdata.hostname,