Linux 2.6.31.8
[linux/fpc-iii.git] / fs / nfs / nfs4namespace.c
blob2a2a0a7143ad3fe05a1c8239bdde0c9f31360d92
1 /*
2 * linux/fs/nfs/nfs4namespace.c
4 * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
5 * - Modified by David Howells <dhowells@redhat.com>
7 * NFSv4 namespace
8 */
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>
18 #include "internal.h"
19 #include "nfs4_fs.h"
21 #define NFSDBG_FACILITY NFSDBG_VFS
24 * Convert the NFSv4 pathname components into a standard posix path.
26 * Note that the resulting string will be placed at the end of the buffer
28 static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
29 char *buffer, ssize_t buflen)
31 char *end = buffer + buflen;
32 int n;
34 *--end = '\0';
35 buflen--;
37 n = pathname->ncomponents;
38 while (--n >= 0) {
39 const struct nfs4_string *component = &pathname->components[n];
40 buflen -= component->len + 1;
41 if (buflen < 0)
42 goto Elong;
43 end -= component->len;
44 memcpy(end, component->data, component->len);
45 *--end = '/';
47 return end;
48 Elong:
49 return ERR_PTR(-ENAMETOOLONG);
53 * Determine the mount path as a string
55 static char *nfs4_path(const struct vfsmount *mnt_parent,
56 const struct dentry *dentry,
57 char *buffer, ssize_t buflen)
59 const char *srvpath;
61 srvpath = strchr(mnt_parent->mnt_devname, ':');
62 if (srvpath)
63 srvpath++;
64 else
65 srvpath = mnt_parent->mnt_devname;
67 return nfs_path(srvpath, mnt_parent->mnt_root, dentry, buffer, buflen);
71 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
72 * believe to be the server path to this dentry
74 static int nfs4_validate_fspath(const struct vfsmount *mnt_parent,
75 const struct dentry *dentry,
76 const struct nfs4_fs_locations *locations,
77 char *page, char *page2)
79 const char *path, *fs_path;
81 path = nfs4_path(mnt_parent, dentry, page, PAGE_SIZE);
82 if (IS_ERR(path))
83 return PTR_ERR(path);
85 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
86 if (IS_ERR(fs_path))
87 return PTR_ERR(fs_path);
89 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
90 dprintk("%s: path %s does not begin with fsroot %s\n",
91 __func__, path, fs_path);
92 return -ENOENT;
95 return 0;
98 static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
99 char *page, char *page2,
100 const struct nfs4_fs_location *location)
102 struct vfsmount *mnt = ERR_PTR(-ENOENT);
103 char *mnt_path;
104 unsigned int maxbuflen;
105 unsigned int s;
107 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
108 if (IS_ERR(mnt_path))
109 return mnt;
110 mountdata->mnt_path = mnt_path;
111 maxbuflen = mnt_path - 1 - page2;
113 for (s = 0; s < location->nservers; s++) {
114 const struct nfs4_string *buf = &location->servers[s];
115 struct sockaddr_storage addr;
117 if (buf->len <= 0 || buf->len >= maxbuflen)
118 continue;
120 mountdata->addr = (struct sockaddr *)&addr;
122 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
123 continue;
124 nfs_parse_ip_address(buf->data, buf->len,
125 mountdata->addr, &mountdata->addrlen);
126 if (mountdata->addr->sa_family == AF_UNSPEC)
127 continue;
128 nfs_set_port(mountdata->addr, NFS_PORT);
130 memcpy(page2, buf->data, buf->len);
131 page2[buf->len] = '\0';
132 mountdata->hostname = page2;
134 snprintf(page, PAGE_SIZE, "%s:%s",
135 mountdata->hostname,
136 mountdata->mnt_path);
138 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
139 if (!IS_ERR(mnt))
140 break;
142 return mnt;
146 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
147 * @mnt_parent - mountpoint of parent directory
148 * @dentry - parent directory
149 * @locations - array of NFSv4 server location information
152 static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
153 const struct dentry *dentry,
154 const struct nfs4_fs_locations *locations)
156 struct vfsmount *mnt = ERR_PTR(-ENOENT);
157 struct nfs_clone_mount mountdata = {
158 .sb = mnt_parent->mnt_sb,
159 .dentry = dentry,
160 .authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
162 char *page = NULL, *page2 = NULL;
163 int loc, error;
165 if (locations == NULL || locations->nlocations <= 0)
166 goto out;
168 dprintk("%s: referral at %s/%s\n", __func__,
169 dentry->d_parent->d_name.name, dentry->d_name.name);
171 page = (char *) __get_free_page(GFP_USER);
172 if (!page)
173 goto out;
175 page2 = (char *) __get_free_page(GFP_USER);
176 if (!page2)
177 goto out;
179 /* Ensure fs path is a prefix of current dentry path */
180 error = nfs4_validate_fspath(mnt_parent, dentry, locations, page, page2);
181 if (error < 0) {
182 mnt = ERR_PTR(error);
183 goto out;
186 for (loc = 0; loc < locations->nlocations; loc++) {
187 const struct nfs4_fs_location *location = &locations->locations[loc];
189 if (location == NULL || location->nservers <= 0 ||
190 location->rootpath.ncomponents == 0)
191 continue;
193 mnt = try_location(&mountdata, page, page2, location);
194 if (!IS_ERR(mnt))
195 break;
198 out:
199 free_page((unsigned long) page);
200 free_page((unsigned long) page2);
201 dprintk("%s: done\n", __func__);
202 return mnt;
206 * nfs_do_refmount - handle crossing a referral on server
207 * @dentry - dentry of referral
208 * @nd - nameidata info
211 struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
213 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
214 struct dentry *parent;
215 struct nfs4_fs_locations *fs_locations = NULL;
216 struct page *page;
217 int err;
219 /* BUG_ON(IS_ROOT(dentry)); */
220 dprintk("%s: enter\n", __func__);
222 page = alloc_page(GFP_KERNEL);
223 if (page == NULL)
224 goto out;
226 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
227 if (fs_locations == NULL)
228 goto out_free;
230 /* Get locations */
231 mnt = ERR_PTR(-ENOENT);
233 parent = dget_parent(dentry);
234 dprintk("%s: getting locations for %s/%s\n",
235 __func__, parent->d_name.name, dentry->d_name.name);
237 err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page);
238 dput(parent);
239 if (err != 0 ||
240 fs_locations->nlocations <= 0 ||
241 fs_locations->fs_path.ncomponents <= 0)
242 goto out_free;
244 mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations);
245 out_free:
246 __free_page(page);
247 kfree(fs_locations);
248 out:
249 dprintk("%s: done\n", __func__);
250 return mnt;