1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* getroot.c: get the root dentry for an NFS mount
36  * Set the superblock root dentry.
41 	/* The mntroot acts as the dummy root dentry for this superblock */  in nfs_superblock_set_dummy_root()
42 	if (sb->s_root == NULL) {  in nfs_superblock_set_dummy_root()
43 		sb->s_root = d_make_root(inode);  in nfs_superblock_set_dummy_root()
44 		if (sb->s_root == NULL)  in nfs_superblock_set_dummy_root()
45 			return -ENOMEM;  in nfs_superblock_set_dummy_root()
55 		spin_lock(&d_inode(sb->s_root)->i_lock);  in nfs_superblock_set_dummy_root()
56 		spin_lock(&sb->s_root->d_lock);  in nfs_superblock_set_dummy_root()
57 		hlist_del_init(&sb->s_root->d_u.d_alias);  in nfs_superblock_set_dummy_root()
58 		spin_unlock(&sb->s_root->d_lock);  in nfs_superblock_set_dummy_root()
59 		spin_unlock(&d_inode(sb->s_root)->i_lock);  in nfs_superblock_set_dummy_root()
65  * get an NFS2/NFS3 root dentry from the root filehandle
72 	struct dentry *root;  in nfs_get_root()  local
75 	int error = -ENOMEM;  in nfs_get_root()
78 	name = kstrdup(fc->source, GFP_KERNEL);  in nfs_get_root()
82 	/* get the actual root for this mount */  in nfs_get_root()
87 	error = server->nfs_client->rpc_ops->getroot(server, ctx->mntfh, &fsinfo);  in nfs_get_root()
89 		dprintk("nfs_get_root: getattr error = %d\n", -error);  in nfs_get_root()
90 		nfs_errorf(fc, "NFS: Couldn't getattr on root");  in nfs_get_root()
94 	inode = nfs_fhget(s, ctx->mntfh, fsinfo.fattr);  in nfs_get_root()
96 		dprintk("nfs_get_root: get root inode failed\n");  in nfs_get_root()
98 		nfs_errorf(fc, "NFS: Couldn't get root inode");  in nfs_get_root()
106 	/* root dentries normally start off anonymous and get spliced in later  in nfs_get_root()
108 	 * exists, we'll pick it up at this point and use it as the root  in nfs_get_root()
110 	root = d_obtain_root(inode);  in nfs_get_root()
111 	if (IS_ERR(root)) {  in nfs_get_root()
112 		dprintk("nfs_get_root: get root dentry failed\n");  in nfs_get_root()
113 		error = PTR_ERR(root);  in nfs_get_root()
114 		nfs_errorf(fc, "NFS: Couldn't get root dentry");  in nfs_get_root()
118 	security_d_instantiate(root, inode);  in nfs_get_root()
119 	spin_lock(&root->d_lock);  in nfs_get_root()
120 	if (IS_ROOT(root) && !root->d_fsdata &&  in nfs_get_root()
121 	    !(root->d_flags & DCACHE_NFSFS_RENAMED)) {  in nfs_get_root()
122 		root->d_fsdata = name;  in nfs_get_root()
125 	spin_unlock(&root->d_lock);  in nfs_get_root()
126 	fc->root = root;  in nfs_get_root()
127 	if (server->caps & NFS_CAP_SECURITY_LABEL)  in nfs_get_root()
129 	if (ctx->clone_data.sb) {  in nfs_get_root()
130 		if (d_inode(fc->root)->i_fop != &nfs_dir_operations) {  in nfs_get_root()
131 			error = -ESTALE;  in nfs_get_root()
135 		error = security_sb_clone_mnt_opts(ctx->clone_data.sb,  in nfs_get_root()
139 		clone_server = NFS_SB(ctx->clone_data.sb);  in nfs_get_root()
140 		server->has_sec_mnt_opts = clone_server->has_sec_mnt_opts;  in nfs_get_root()
142 		error = security_sb_set_mnt_opts(s, fc->security,  in nfs_get_root()
147 	if (server->caps & NFS_CAP_SECURITY_LABEL &&  in nfs_get_root()
149 		server->caps &= ~NFS_CAP_SECURITY_LABEL;  in nfs_get_root()
161 	dput(fc->root);  in nfs_get_root()
162 	fc->root = NULL;  in nfs_get_root()