1 /* getroot.c: get the root dentry for an NFS mount
3 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/config.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
16 #include <linux/time.h>
17 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/stat.h>
21 #include <linux/errno.h>
22 #include <linux/unistd.h>
23 #include <linux/sunrpc/clnt.h>
24 #include <linux/sunrpc/stats.h>
25 #include <linux/nfs_fs.h>
26 #include <linux/nfs_mount.h>
27 #include <linux/nfs4_mount.h>
28 #include <linux/lockd/bind.h>
29 #include <linux/smp_lock.h>
30 #include <linux/seq_file.h>
31 #include <linux/mount.h>
32 #include <linux/nfs_idmap.h>
33 #include <linux/vfs.h>
34 #include <linux/namei.h>
35 #include <linux/namespace.h>
37 #include <asm/system.h>
38 #include <asm/uaccess.h>
41 #include "delegation.h"
44 #define NFSDBG_FACILITY NFSDBG_CLIENT
45 #define NFS_PARANOIA 1
48 * get an NFS2/NFS3 root dentry from the root filehandle
50 struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
52 struct nfs_server *server = NFS_SB(sb);
53 struct nfs_fsinfo fsinfo;
54 struct nfs_fattr fattr;
55 struct dentry *mntroot;
59 /* create a dummy root dentry with dummy inode for this superblock */
61 struct nfs_fh dummyfh;
65 memset(&dummyfh, 0, sizeof(dummyfh));
66 memset(&fattr, 0, sizeof(fattr));
67 nfs_fattr_init(&fattr);
68 fattr.valid = NFS_ATTR_FATTR;
70 fattr.mode = S_IFDIR | S_IRUSR | S_IWUSR;
73 iroot = nfs_fhget(sb, &dummyfh, &fattr);
75 return ERR_PTR(PTR_ERR(iroot));
77 root = d_alloc_root(iroot);
80 return ERR_PTR(-ENOMEM);
86 /* get the actual root for this mount */
87 fsinfo.fattr = &fattr;
89 error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
91 dprintk("nfs_get_root: getattr error = %d\n", -error);
92 return ERR_PTR(error);
95 inode = nfs_fhget(sb, mntfh, fsinfo.fattr);
97 dprintk("nfs_get_root: get root inode failed\n");
98 return ERR_PTR(PTR_ERR(inode));
101 /* root dentries normally start off anonymous and get spliced in later
102 * if the dentry tree reaches them; however if the dentry already
103 * exists, we'll pick it up at this point and use it as the root
105 mntroot = d_alloc_anon(inode);
108 dprintk("nfs_get_root: get root dentry failed\n");
109 return ERR_PTR(-ENOMEM);
113 mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops;
121 * Do a simple pathwalk from the root FH of the server to the nominated target
123 * - give error on symlinks
124 * - give error on ".." occurring in the path
125 * - follow traversals
127 int nfs4_path_walk(struct nfs_server *server,
128 struct nfs_fh *mntfh,
131 struct nfs_fsinfo fsinfo;
132 struct nfs_fattr fattr;
133 struct nfs_fh lastfh;
136 //int referral_count = 0;
138 dprintk("--> nfs4_path_walk(,,%s)\n", path);
140 fsinfo.fattr = &fattr;
141 nfs_fattr_init(&fattr);
143 if (*path++ != '/') {
144 dprintk("nfs4_get_root: Path does not begin with a slash\n");
148 /* Start by getting the root filehandle from the server */
149 ret = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
151 dprintk("nfs4_get_root: getroot error = %d\n", -ret);
155 if (fattr.type != NFDIR) {
156 printk(KERN_ERR "nfs4_get_root:"
157 " getroot encountered non-directory\n");
161 if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) {
162 printk(KERN_ERR "nfs4_get_root:"
163 " getroot obtained referral\n");
168 dprintk("Next: %s\n", path);
170 /* extract the next bit of the path */
172 goto path_walk_complete;
175 while (*path && *path != '/')
177 name.len = path - (const char *) name.name;
183 if (path[0] == '.' && (path[1] == '/' || !path[1])) {
188 if (path[0] == '.' && path[1] == '.' && (path[2] == '/' || !path[2])
190 printk(KERN_ERR "nfs4_get_root:"
191 " Mount path contains reference to \"..\"\n");
195 /* lookup the next FH in the sequence */
196 memcpy(&lastfh, mntfh, sizeof(lastfh));
198 dprintk("LookupFH: %*.*s [%s]\n", name.len, name.len, name.name, path);
200 ret = server->nfs_client->rpc_ops->lookupfh(server, &lastfh, &name,
203 dprintk("nfs4_get_root: getroot error = %d\n", -ret);
207 if (fattr.type != NFDIR) {
208 printk(KERN_ERR "nfs4_get_root:"
209 " lookupfh encountered non-directory\n");
213 if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) {
214 printk(KERN_ERR "nfs4_get_root:"
215 " lookupfh obtained referral\n");
222 memcpy(&server->fsid, &fattr.fsid, sizeof(server->fsid));
223 dprintk("<-- nfs4_path_walk() = 0\n");
228 * get an NFS4 root dentry from the root filehandle
230 struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
232 struct nfs_server *server = NFS_SB(sb);
233 struct nfs_fattr fattr;
234 struct dentry *mntroot;
238 dprintk("--> nfs4_get_root()\n");
240 /* create a dummy root dentry with dummy inode for this superblock */
242 struct nfs_fh dummyfh;
246 memset(&dummyfh, 0, sizeof(dummyfh));
247 memset(&fattr, 0, sizeof(fattr));
248 nfs_fattr_init(&fattr);
249 fattr.valid = NFS_ATTR_FATTR;
251 fattr.mode = S_IFDIR | S_IRUSR | S_IWUSR;
254 iroot = nfs_fhget(sb, &dummyfh, &fattr);
256 return ERR_PTR(PTR_ERR(iroot));
258 root = d_alloc_root(iroot);
261 return ERR_PTR(-ENOMEM);
267 /* get the info about the server and filesystem */
268 error = nfs4_server_capabilities(server, mntfh);
270 dprintk("nfs_get_root: getcaps error = %d\n",
272 return ERR_PTR(error);
275 /* get the actual root for this mount */
276 error = server->nfs_client->rpc_ops->getattr(server, mntfh, &fattr);
278 dprintk("nfs_get_root: getattr error = %d\n", -error);
279 return ERR_PTR(error);
282 inode = nfs_fhget(sb, mntfh, &fattr);
284 dprintk("nfs_get_root: get root inode failed\n");
285 return ERR_PTR(PTR_ERR(inode));
288 /* root dentries normally start off anonymous and get spliced in later
289 * if the dentry tree reaches them; however if the dentry already
290 * exists, we'll pick it up at this point and use it as the root
292 mntroot = d_alloc_anon(inode);
295 dprintk("nfs_get_root: get root dentry failed\n");
296 return ERR_PTR(-ENOMEM);
300 mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops;
302 dprintk("<-- nfs4_get_root()\n");
306 #endif /* CONFIG_NFS_V4 */