2 * linux/fs/nfs/nfs4namespace.c
4 * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
5 * - Modified by David Howells <dhowells@redhat.com>
10 #include <linux/dcache.h>
11 #include <linux/mount.h>
12 #include <linux/namei.h>
13 #include <linux/nfs_fs.h>
14 #include <linux/string.h>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/vfs.h>
17 #include <linux/inet.h>
20 #include "dns_resolve.h"
22 #define NFSDBG_FACILITY NFSDBG_VFS
25 * Convert the NFSv4 pathname components into a standard posix path.
27 * Note that the resulting string will be placed at the end of the buffer
29 static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
30 char *buffer, ssize_t buflen)
32 char *end = buffer + buflen;
38 n = pathname->ncomponents;
40 const struct nfs4_string *component = &pathname->components[n];
41 buflen -= component->len + 1;
44 end -= component->len;
45 memcpy(end, component->data, component->len);
50 return ERR_PTR(-ENAMETOOLONG);
54 * Determine the mount path as a string
56 static char *nfs4_path(const struct vfsmount *mnt_parent,
57 const struct dentry *dentry,
58 char *buffer, ssize_t buflen)
62 srvpath = strchr(mnt_parent->mnt_devname, ':');
66 srvpath = mnt_parent->mnt_devname;
68 return nfs_path(srvpath, mnt_parent->mnt_root, dentry, buffer, buflen);
72 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
73 * believe to be the server path to this dentry
75 static int nfs4_validate_fspath(const struct vfsmount *mnt_parent,
76 const struct dentry *dentry,
77 const struct nfs4_fs_locations *locations,
78 char *page, char *page2)
80 const char *path, *fs_path;
82 path = nfs4_path(mnt_parent, dentry, page, PAGE_SIZE);
86 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
88 return PTR_ERR(fs_path);
90 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
91 dprintk("%s: path %s does not begin with fsroot %s\n",
92 __func__, path, fs_path);
99 static size_t nfs_parse_server_name(char *string, size_t len,
100 struct sockaddr *sa, size_t salen)
104 ret = rpc_pton(string, len, sa, salen);
106 ret = nfs_dns_resolve_name(string, len, sa, salen);
113 static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
114 char *page, char *page2,
115 const struct nfs4_fs_location *location)
117 struct vfsmount *mnt = ERR_PTR(-ENOENT);
119 unsigned int maxbuflen;
122 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
123 if (IS_ERR(mnt_path))
124 return ERR_CAST(mnt_path);
125 mountdata->mnt_path = mnt_path;
126 maxbuflen = mnt_path - 1 - page2;
128 for (s = 0; s < location->nservers; s++) {
129 const struct nfs4_string *buf = &location->servers[s];
130 struct sockaddr_storage addr;
132 if (buf->len <= 0 || buf->len >= maxbuflen)
135 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
138 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
139 (struct sockaddr *)&addr, sizeof(addr));
140 if (mountdata->addrlen == 0)
143 mountdata->addr = (struct sockaddr *)&addr;
144 rpc_set_port(mountdata->addr, NFS_PORT);
146 memcpy(page2, buf->data, buf->len);
147 page2[buf->len] = '\0';
148 mountdata->hostname = page2;
150 snprintf(page, PAGE_SIZE, "%s:%s",
152 mountdata->mnt_path);
154 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
162 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
163 * @mnt_parent - mountpoint of parent directory
164 * @dentry - parent directory
165 * @locations - array of NFSv4 server location information
168 static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
169 const struct dentry *dentry,
170 const struct nfs4_fs_locations *locations)
172 struct vfsmount *mnt = ERR_PTR(-ENOENT);
173 struct nfs_clone_mount mountdata = {
174 .sb = mnt_parent->mnt_sb,
176 .authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
178 char *page = NULL, *page2 = NULL;
181 if (locations == NULL || locations->nlocations <= 0)
184 dprintk("%s: referral at %s/%s\n", __func__,
185 dentry->d_parent->d_name.name, dentry->d_name.name);
187 page = (char *) __get_free_page(GFP_USER);
191 page2 = (char *) __get_free_page(GFP_USER);
195 /* Ensure fs path is a prefix of current dentry path */
196 error = nfs4_validate_fspath(mnt_parent, dentry, locations, page, page2);
198 mnt = ERR_PTR(error);
202 for (loc = 0; loc < locations->nlocations; loc++) {
203 const struct nfs4_fs_location *location = &locations->locations[loc];
205 if (location == NULL || location->nservers <= 0 ||
206 location->rootpath.ncomponents == 0)
209 mnt = try_location(&mountdata, page, page2, location);
215 free_page((unsigned long) page);
216 free_page((unsigned long) page2);
217 dprintk("%s: done\n", __func__);
222 * nfs_do_refmount - handle crossing a referral on server
223 * @dentry - dentry of referral
224 * @nd - nameidata info
227 struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
229 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
230 struct dentry *parent;
231 struct nfs4_fs_locations *fs_locations = NULL;
235 /* BUG_ON(IS_ROOT(dentry)); */
236 dprintk("%s: enter\n", __func__);
238 page = alloc_page(GFP_KERNEL);
242 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
243 if (fs_locations == NULL)
247 mnt = ERR_PTR(-ENOENT);
249 parent = dget_parent(dentry);
250 dprintk("%s: getting locations for %s/%s\n",
251 __func__, parent->d_name.name, dentry->d_name.name);
253 err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page);
256 fs_locations->nlocations <= 0 ||
257 fs_locations->fs_path.ncomponents <= 0)
260 mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations);
265 dprintk("%s: done\n", __func__);