nfs: lift setting mount_info from nfs_xdev_mount()

Do it in nfs_do_submount() instead.  As a side benefit, nfs_clone_data
doesn't need ->fh and ->fattr anymore.
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

fs/nfs/internal.h

@@ -34,8 +34,6 @@ static inline int nfs_attr_use_mounted_on_fileid(struct nfs_fattr *fattr)
 struct nfs_clone_mount {
 	const struct super_block *sb;
 	const struct dentry *dentry;
-	struct nfs_fh *fh;
-	struct nfs_fattr *fattr;
 	char *hostname;
 	char *mnt_path;
 	struct sockaddr *addr;
@@ -405,6 +403,7 @@ struct dentry * nfs_xdev_mount_common(struct file_system_type *, int,
 		const char *, struct nfs_mount_info *);
 void nfs_kill_super(struct super_block *);
 void nfs_fill_super(struct super_block *, struct nfs_mount_info *);
+void nfs_clone_super(struct super_block *, struct nfs_mount_info *);
 
 extern struct rpc_stat nfs_rpcstat;
 

fs/nfs/namespace.c

@@ -19,6 +19,7 @@
 #include <linux/vfs.h>
 #include <linux/sunrpc/gss_api.h>
 #include "internal.h"
+#include "nfs.h"
 
 #define NFSDBG_FACILITY		NFSDBG_VFS
 
@@ -213,16 +214,6 @@ void nfs_release_automount_timer(void)
 		cancel_delayed_work(&nfs_automount_task);
 }
 
-/*
- * Clone a mountpoint of the appropriate type
- */
-static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server,
-					   const char *devname,
-					   struct nfs_clone_mount *mountdata)
-{
-	return vfs_submount(mountdata->dentry, &nfs_xdev_fs_type, devname, mountdata);
-}
-
 /**
  * nfs_do_submount - set up mountpoint when crossing a filesystem boundary
  * @dentry: parent directory
@@ -234,13 +225,20 @@ static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server,
 struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh,
 				 struct nfs_fattr *fattr, rpc_authflavor_t authflavor)
 {
+	struct super_block *sb = dentry->d_sb;
 	struct nfs_clone_mount mountdata = {
-		.sb = dentry->d_sb,
+		.sb = sb,
 		.dentry = dentry,
-		.fh = fh,
-		.fattr = fattr,
 		.authflavor = authflavor,
 	};
+	struct nfs_mount_info mount_info = {
+		.fill_super = nfs_clone_super,
+		.set_security = nfs_clone_sb_security,
+		.cloned = &mountdata,
+		.mntfh = fh,
+	};
+	struct nfs_subversion *nfs_mod = NFS_SB(sb)->nfs_client->cl_nfs_mod;
+	struct nfs_server *server;
 	struct vfsmount *mnt;
 	char *page = (char *) __get_free_page(GFP_USER);
 	char *devname;
@@ -248,12 +246,21 @@ struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh,
 	if (page == NULL)
 		return ERR_PTR(-ENOMEM);
 
+	server = nfs_mod->rpc_ops->clone_server(NFS_SB(sb), fh,
+						fattr, authflavor);
+	if (IS_ERR(server))
+		return ERR_CAST(server);
+
+	mount_info.server = server;
+
 	devname = nfs_devname(dentry, page, PAGE_SIZE);
 	if (IS_ERR(devname))
 		mnt = ERR_CAST(devname);
 	else
-		mnt = nfs_do_clone_mount(NFS_SB(dentry->d_sb), devname, &mountdata);
+		mnt = vfs_submount(dentry, &nfs_xdev_fs_type, devname, &mount_info);
 
+	if (mount_info.server)
+		nfs_free_server(mount_info.server);
 	free_page((unsigned long)page);
 	return mnt;
 }

fs/nfs/super.c

@@ -2395,7 +2395,7 @@ EXPORT_SYMBOL_GPL(nfs_fill_super);
 /*
  * Finish setting up a cloned NFS2/3/4 superblock
  */
-static void nfs_clone_super(struct super_block *sb,
+void nfs_clone_super(struct super_block *sb,
 			    struct nfs_mount_info *mount_info)
 {
 	const struct super_block *old_sb = mount_info->cloned->sb;
@@ -2796,27 +2796,10 @@ static struct dentry *
 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
 		const char *dev_name, void *raw_data)
 {
-	struct nfs_clone_mount *data = raw_data;
-	struct nfs_mount_info mount_info = {
-		.fill_super = nfs_clone_super,
-		.set_security = nfs_clone_sb_security,
-		.cloned = data,
-	};
-	struct dentry *mntroot = ERR_PTR(-ENOMEM);
-	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
-
-	dprintk("--> nfs_xdev_mount()\n");
+	struct nfs_mount_info *info = raw_data;
+	struct nfs_subversion *nfs_mod = NFS_SB(info->cloned->sb)->nfs_client->cl_nfs_mod;
 
-	mount_info.mntfh = mount_info.cloned->fh;
-
-	/* create a new volume representation */
-	mount_info.server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
-
-	mntroot = nfs_fs_mount_common(flags, dev_name, &mount_info, nfs_mod);
-
-	dprintk("<-- nfs_xdev_mount() = %ld\n",
-			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
-	return mntroot;
+	return nfs_fs_mount_common(flags, dev_name, info, nfs_mod);
 }
 
 #if IS_ENABLED(CONFIG_NFS_V4)