NFS: Clean up nfs_validate_mount_data

Move error handling code out of the main code path.  The switch statement
was also improperly indented, according to Documentation/CodingStyle.  This
prepares nfs_validate_mount_data for the addition of option string parsing.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 67 insertions, 58 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 7f5bc28ea8d1..baf75e9bd3fe 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -470,77 +470,86 @@ static int nfs_verify_server_address(struct sockaddr *addr)
 static int nfs_validate_mount_data(struct nfs_mount_data *data,
                                    struct nfs_fh *mntfh)
 {
-        if (data == NULL) {
-                dprintk("%s: missing data argument\n", __FUNCTION__);
-                return -EINVAL;
-        }
-
-        if (data->version <= 0 || data->version > NFS_MOUNT_VERSION) {
-                dprintk("%s: bad mount version\n", __FUNCTION__);
-                return -EINVAL;
-        }
+        if (data == NULL)
+                goto out_no_data;
 
         switch (data->version) {
-                case 1:
-                        data->namlen = 0;
-                case 2:
-                        data->bsize  = 0;
-                case 3:
-                        if (data->flags & NFS_MOUNT_VER3) {
-                                dprintk("%s: mount structure version %d does not support NFSv3\n",
-                                                __FUNCTION__,
-                                                data->version);
-                                return -EINVAL;
-                        }
-                        data->root.size = NFS2_FHSIZE;
-                        memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
-                case 4:
-                        if (data->flags & NFS_MOUNT_SECFLAVOUR) {
-                                dprintk("%s: mount structure version %d does not support strong security\n",
-                                                __FUNCTION__,
-                                                data->version);
-                                return -EINVAL;
-                        }
-                case 5:
-                        memset(data->context, 0, sizeof(data->context));
+        case 1:
+                data->namlen = 0;
+        case 2:
+                data->bsize = 0;
+        case 3:
+                if (data->flags & NFS_MOUNT_VER3)
+                        goto out_no_v3;
+                data->root.size = NFS2_FHSIZE;
+                memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
+        case 4:
+                if (data->flags & NFS_MOUNT_SECFLAVOUR)
+                        goto out_no_sec;
+        case 5:
+                memset(data->context, 0, sizeof(data->context));
+        case 6:
+                if (data->flags & NFS_MOUNT_VER3)
+                        mntfh->size = data->root.size;
+                else
+                        mntfh->size = NFS2_FHSIZE;
+
+                if (mntfh->size > sizeof(mntfh->data))
+                        goto out_invalid_fh;
+
+                memcpy(mntfh->data, data->root.data, mntfh->size);
+                if (mntfh->size < sizeof(mntfh->data))
+                        memset(mntfh->data + mntfh->size, 0,
+                               sizeof(mntfh->data) - mntfh->size);
+                break;
+        default:
+                goto out_bad_version;
         }
 
-        /* Set the pseudoflavor */
         if (!(data->flags & NFS_MOUNT_SECFLAVOUR))
                 data->pseudoflavor = RPC_AUTH_UNIX;
 
 #ifndef CONFIG_NFS_V3
-        /* If NFSv3 is not compiled in, return -EPROTONOSUPPORT */
-        if (data->flags & NFS_MOUNT_VER3) {
-                dprintk("%s: NFSv3 not compiled into kernel\n", __FUNCTION__);
-                return -EPROTONOSUPPORT;
-        }
-#endif /* CONFIG_NFS_V3 */
+        if (data->flags & NFS_MOUNT_VER3)
+                goto out_v3_not_compiled;
+#endif /* !CONFIG_NFS_V3 */
 
-        /* We now require that the mount process passes the remote address */
-        if (!nfs_verify_server_address((struct sockaddr *) &data->addr)) {
-                dprintk("%s: mount program didn't pass remote address!\n",
-                        __FUNCTION__);
-                return -EINVAL;
-        }
+        if (!nfs_verify_server_address((struct sockaddr *) &data->addr))
+                goto out_no_address;
 
-        /* Prepare the root filehandle */
-        if (data->flags & NFS_MOUNT_VER3)
-                mntfh->size = data->root.size;
-        else
-                mntfh->size = NFS2_FHSIZE;
+        return 0;
 
-        if (mntfh->size > sizeof(mntfh->data)) {
-                dprintk("%s: invalid root filehandle\n", __FUNCTION__);
-                return -EINVAL;
-        }
+out_no_data:
+        dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
+        return -EINVAL;
 
-        memcpy(mntfh->data, data->root.data, mntfh->size);
-        if (mntfh->size < sizeof(mntfh->data))
-                memset(mntfh->data + mntfh->size, 0,
-                       sizeof(mntfh->data) - mntfh->size);
+out_no_v3:
+        dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
+                 data->version);
+        return -EINVAL;
 
-        return 0;
+out_no_sec:
+        dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
+        return -EINVAL;
+
+out_bad_version:
+        dfprintk(MOUNT, "NFS: bad nfs_mount_data version %d\n",
+                 data->version);
+        return -EINVAL;
+
+#ifndef CONFIG_NFS_V3
+out_v3_not_compiled:
+        dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
+        return -EPROTONOSUPPORT;
+#endif /* !CONFIG_NFS_V3 */
+
+out_no_address:
+        dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
+        return -EINVAL;
+
+out_invalid_fh:
+        dfprintk(MOUNT, "NFS: invalid root filehandle\n");
+        return -EINVAL;
 }
 
 /*