NFS: Use the DNS resolver in the mount code.

In the referral code, use it to look up the new server's ip address if the
fs_locations attribute contains a hostname.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 17 insertions, 1 deletions

diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index ef22ee89aa77..2636c26d56fa 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -17,6 +17,7 @@
 #include <linux/inet.h>
 #include "internal.h"
 #include "nfs4_fs.h"
+#include "dns_resolve.h"
 
 #define NFSDBG_FACILITY         NFSDBG_VFS
 
@@ -95,6 +96,20 @@ static int nfs4_validate_fspath(const struct vfsmount *mnt_parent,
         return 0;
 }
 
+static size_t nfs_parse_server_name(char *string, size_t len,
+                struct sockaddr *sa, size_t salen)
+{
+        ssize_t ret;
+
+        ret = rpc_pton(string, len, sa, salen);
+        if (ret == 0) {
+                ret = nfs_dns_resolve_name(string, len, sa, salen);
+                if (ret < 0)
+                        ret = 0;
+        }
+        return ret;
+}
+
 static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
                                      char *page, char *page2,
                                      const struct nfs4_fs_location *location)
@@ -121,7 +136,8 @@ static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
 
                 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
                         continue;
-                mountdata->addrlen = rpc_pton(buf->data, buf->len,
+                mountdata->addrlen = nfs_parse_server_name(buf->data,
+                                buf->len,
                                 mountdata->addr, mountdata->addrlen);
                 if (mountdata->addrlen == 0)
                         continue;