1 files changed, 77 insertions, 45 deletions

diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index 66984a9aafaa..f13d25d95b85 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* getroot.c: get the root dentry for an NFS mount
  *
  * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
  */
 
 #include <linux/module.h>
@@ -30,7 +26,7 @@
 #include <linux/namei.h>
 #include <linux/security.h>
 
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 #include "internal.h"
 
@@ -51,82 +47,118 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i
 		/*
 		 * Ensure that this dentry is invisible to d_find_alias().
 		 * Otherwise, it may be spliced into the tree by
-		 * d_materialise_unique if a parent directory from the same
+		 * d_splice_alias if a parent directory from the same
 		 * filesystem gets mounted at a later time.
 		 * This again causes shrink_dcache_for_umount_subtree() to
 		 * Oops, since the test for IS_ROOT() will fail.
 		 */
-		spin_lock(&sb->s_root->d_inode->i_lock);
+		spin_lock(&d_inode(sb->s_root)->i_lock);
 		spin_lock(&sb->s_root->d_lock);
-		hlist_del_init(&sb->s_root->d_alias);
+		hlist_del_init(&sb->s_root->d_u.d_alias);
 		spin_unlock(&sb->s_root->d_lock);
-		spin_unlock(&sb->s_root->d_inode->i_lock);
+		spin_unlock(&d_inode(sb->s_root)->i_lock);
 	}
 	return 0;
 }
 
 /*
- * get an NFS2/NFS3 root dentry from the root filehandle
+ * get a root dentry from the root filehandle
  */
-struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh,
-			    const char *devname)
+int nfs_get_root(struct super_block *s, struct fs_context *fc)
 {
-	struct nfs_server *server = NFS_SB(sb);
+	struct nfs_fs_context *ctx = nfs_fc2context(fc);
+	struct nfs_server *server = NFS_SB(s), *clone_server;
 	struct nfs_fsinfo fsinfo;
-	struct dentry *ret;
+	struct dentry *root;
 	struct inode *inode;
-	void *name = kstrdup(devname, GFP_KERNEL);
-	int error;
+	char *name;
+	int error = -ENOMEM;
+	unsigned long kflags = 0, kflags_out = 0;
 
+	name = kstrdup(fc->source, GFP_KERNEL);
 	if (!name)
-		return ERR_PTR(-ENOMEM);
+		goto out;
 
 	/* get the actual root for this mount */
-	fsinfo.fattr = nfs_alloc_fattr();
-	if (fsinfo.fattr == NULL) {
-		kfree(name);
-		return ERR_PTR(-ENOMEM);
-	}
+	fsinfo.fattr = nfs_alloc_fattr_with_label(server);
+	if (fsinfo.fattr == NULL)
+		goto out_name;
 
-	error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
+	error = server->nfs_client->rpc_ops->getroot(server, ctx->mntfh, &fsinfo);
 	if (error < 0) {
 		dprintk("nfs_get_root: getattr error = %d\n", -error);
-		ret = ERR_PTR(error);
-		goto out;
+		nfs_errorf(fc, "NFS: Couldn't getattr on root");
+		goto out_fattr;
 	}
 
-	inode = nfs_fhget(sb, mntfh, fsinfo.fattr, NULL);
+	inode = nfs_fhget(s, ctx->mntfh, fsinfo.fattr);
 	if (IS_ERR(inode)) {
 		dprintk("nfs_get_root: get root inode failed\n");
-		ret = ERR_CAST(inode);
-		goto out;
+		error = PTR_ERR(inode);
+		nfs_errorf(fc, "NFS: Couldn't get root inode");
+		goto out_fattr;
 	}
 
-	error = nfs_superblock_set_dummy_root(sb, inode);
-	if (error != 0) {
-		ret = ERR_PTR(error);
-		goto out;
-	}
+	error = nfs_superblock_set_dummy_root(s, inode);
+	if (error != 0)
+		goto out_fattr;
 
 	/* root dentries normally start off anonymous and get spliced in later
 	 * if the dentry tree reaches them; however if the dentry already
 	 * exists, we'll pick it up at this point and use it as the root
 	 */
-	ret = d_obtain_alias(inode);
-	if (IS_ERR(ret)) {
+	root = d_obtain_root(inode);
+	if (IS_ERR(root)) {
 		dprintk("nfs_get_root: get root dentry failed\n");
-		goto out;
+		error = PTR_ERR(root);
+		nfs_errorf(fc, "NFS: Couldn't get root dentry");
+		goto out_fattr;
 	}
 
-	security_d_instantiate(ret, inode);
-	spin_lock(&ret->d_lock);
-	if (IS_ROOT(ret) && !(ret->d_flags & DCACHE_NFSFS_RENAMED)) {
-		ret->d_fsdata = name;
+	security_d_instantiate(root, inode);
+	spin_lock(&root->d_lock);
+	if (IS_ROOT(root) && !root->d_fsdata &&
+	    !(root->d_flags & DCACHE_NFSFS_RENAMED)) {
+		root->d_fsdata = name;
 		name = NULL;
 	}
-	spin_unlock(&ret->d_lock);
-out:
-	kfree(name);
+	spin_unlock(&root->d_lock);
+	fc->root = root;
+	if (server->caps & NFS_CAP_SECURITY_LABEL)
+		kflags |= SECURITY_LSM_NATIVE_LABELS;
+	if (ctx->clone_data.sb) {
+		if (d_inode(fc->root)->i_fop != &nfs_dir_operations) {
+			error = -ESTALE;
+			goto error_splat_root;
+		}
+		/* clone lsm security options from the parent to the new sb */
+		error = security_sb_clone_mnt_opts(ctx->clone_data.sb,
+						   s, kflags, &kflags_out);
+		if (error)
+			goto error_splat_root;
+		clone_server = NFS_SB(ctx->clone_data.sb);
+		server->has_sec_mnt_opts = clone_server->has_sec_mnt_opts;
+	} else {
+		error = security_sb_set_mnt_opts(s, fc->security,
+							kflags, &kflags_out);
+	}
+	if (error)
+		goto error_splat_root;
+	if (server->caps & NFS_CAP_SECURITY_LABEL &&
+		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
+		server->caps &= ~NFS_CAP_SECURITY_LABEL;
+
+	nfs_setsecurity(inode, fsinfo.fattr);
+	error = 0;
+
+out_fattr:
 	nfs_free_fattr(fsinfo.fattr);
-	return ret;
+out_name:
+	kfree(name);
+out:
+	return error;
+error_splat_root:
+	dput(fc->root);
+	fc->root = NULL;
+	goto out_fattr;
 }