blob: 9c8eca315f431199aa481c0eabc6ae3e044f8267 [file] [log] [blame]
David Howellsf7b422b2006-06-09 09:34:33 -04001/*
2 * linux/fs/nfs/nfs4namespace.c
3 *
4 * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
David Howells54ceac42006-08-22 20:06:13 -04005 * - Modified by David Howells <dhowells@redhat.com>
David Howellsf7b422b2006-06-09 09:34:33 -04006 *
7 * NFSv4 namespace
8 */
9
David Howellsf7b422b2006-06-09 09:34:33 -040010#include <linux/dcache.h>
11#include <linux/mount.h>
12#include <linux/namei.h>
13#include <linux/nfs_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
David Howellsf7b422b2006-06-09 09:34:33 -040015#include <linux/string.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/vfs.h>
18#include <linux/inet.h>
19#include "internal.h"
Trond Myklebustc228fd32007-01-13 02:28:11 -050020#include "nfs4_fs.h"
Trond Myklebust7d7ea882009-08-19 18:12:34 -040021#include "dns_resolve.h"
David Howellsf7b422b2006-06-09 09:34:33 -040022
23#define NFSDBG_FACILITY NFSDBG_VFS
24
25/*
Trond Myklebustef95d312009-03-10 20:33:17 -040026 * Convert the NFSv4 pathname components into a standard posix path.
27 *
28 * Note that the resulting string will be placed at the end of the buffer
David Howellsf7b422b2006-06-09 09:34:33 -040029 */
David Howells509de812006-08-22 20:06:11 -040030static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
David Howellsf7b422b2006-06-09 09:34:33 -040031 char *buffer, ssize_t buflen)
32{
33 char *end = buffer + buflen;
34 int n;
35
36 *--end = '\0';
37 buflen--;
38
39 n = pathname->ncomponents;
40 while (--n >= 0) {
David Howells509de812006-08-22 20:06:11 -040041 const struct nfs4_string *component = &pathname->components[n];
David Howellsf7b422b2006-06-09 09:34:33 -040042 buflen -= component->len + 1;
43 if (buflen < 0)
44 goto Elong;
45 end -= component->len;
46 memcpy(end, component->data, component->len);
47 *--end = '/';
48 }
49 return end;
50Elong:
51 return ERR_PTR(-ENAMETOOLONG);
52}
53
David Howells54ceac42006-08-22 20:06:13 -040054/*
55 * Determine the mount path as a string
56 */
Al Virob514f872011-03-16 06:26:11 -040057static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
David Howells54ceac42006-08-22 20:06:13 -040058{
Al Virob514f872011-03-16 06:26:11 -040059 char *limit;
60 char *path = nfs_path(&limit, dentry, buffer, buflen);
61 if (!IS_ERR(path)) {
62 char *colon = strchr(path, ':');
63 if (colon && colon < limit)
64 path = colon + 1;
65 }
66 return path;
David Howells54ceac42006-08-22 20:06:13 -040067}
68
69/*
70 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
71 * believe to be the server path to this dentry
72 */
Al Virob514f872011-03-16 06:26:11 -040073static int nfs4_validate_fspath(struct dentry *dentry,
David Howells54ceac42006-08-22 20:06:13 -040074 const struct nfs4_fs_locations *locations,
75 char *page, char *page2)
76{
77 const char *path, *fs_path;
78
Al Virob514f872011-03-16 06:26:11 -040079 path = nfs4_path(dentry, page, PAGE_SIZE);
David Howells54ceac42006-08-22 20:06:13 -040080 if (IS_ERR(path))
81 return PTR_ERR(path);
82
83 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
84 if (IS_ERR(fs_path))
85 return PTR_ERR(fs_path);
86
87 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
88 dprintk("%s: path %s does not begin with fsroot %s\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -070089 __func__, path, fs_path);
David Howells54ceac42006-08-22 20:06:13 -040090 return -ENOENT;
91 }
92
93 return 0;
94}
95
Trond Myklebust7d7ea882009-08-19 18:12:34 -040096static size_t nfs_parse_server_name(char *string, size_t len,
Stanislav Kinsbursky1b340d02011-11-25 17:13:04 +030097 struct sockaddr *sa, size_t salen, struct nfs_server *server)
Trond Myklebust7d7ea882009-08-19 18:12:34 -040098{
Trond Myklebust2446ab62012-03-01 17:00:56 -050099 struct net *net = rpc_net_ns(server->client);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400100 ssize_t ret;
101
Stanislav Kinsbursky33faaa32012-01-26 15:12:05 +0400102 ret = rpc_pton(net, string, len, sa, salen);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400103 if (ret == 0) {
Stanislav Kinsbursky33faaa32012-01-26 15:12:05 +0400104 ret = nfs_dns_resolve_name(net, string, len, sa, salen);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400105 if (ret < 0)
106 ret = 0;
107 }
108 return ret;
109}
110
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400111static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
112 char *page, char *page2,
113 const struct nfs4_fs_location *location)
114{
Trond Myklebust364d015e52010-04-16 16:22:46 -0400115 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400116 struct vfsmount *mnt = ERR_PTR(-ENOENT);
117 char *mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400118 unsigned int maxbuflen;
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400119 unsigned int s;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400120
121 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
122 if (IS_ERR(mnt_path))
Trond Myklebust517be092009-10-06 15:42:20 -0400123 return ERR_CAST(mnt_path);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400124 mountdata->mnt_path = mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400125 maxbuflen = mnt_path - 1 - page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400126
Trond Myklebust364d015e52010-04-16 16:22:46 -0400127 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
128 if (mountdata->addr == NULL)
129 return ERR_PTR(-ENOMEM);
130
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400131 for (s = 0; s < location->nservers; s++) {
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400132 const struct nfs4_string *buf = &location->servers[s];
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400133
Trond Myklebustef95d312009-03-10 20:33:17 -0400134 if (buf->len <= 0 || buf->len >= maxbuflen)
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400135 continue;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400136
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400137 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
138 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400139
140 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
Stanislav Kinsbursky1b340d02011-11-25 17:13:04 +0300141 mountdata->addr, addr_bufsize,
142 NFS_SB(mountdata->sb));
Chuck Lever53a0b9c2009-08-09 15:09:36 -0400143 if (mountdata->addrlen == 0)
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400144 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400145
Chuck Leverec6ee612009-08-09 15:09:37 -0400146 rpc_set_port(mountdata->addr, NFS_PORT);
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400147
Trond Myklebustef95d312009-03-10 20:33:17 -0400148 memcpy(page2, buf->data, buf->len);
149 page2[buf->len] = '\0';
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400150 mountdata->hostname = page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400151
152 snprintf(page, PAGE_SIZE, "%s:%s",
153 mountdata->hostname,
154 mountdata->mnt_path);
155
156 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
157 if (!IS_ERR(mnt))
158 break;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400159 }
Trond Myklebust364d015e52010-04-16 16:22:46 -0400160 kfree(mountdata->addr);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400161 return mnt;
162}
163
David Howellsf7b422b2006-06-09 09:34:33 -0400164/**
165 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
David Howellsf7b422b2006-06-09 09:34:33 -0400166 * @dentry - parent directory
Chuck Lever3f43c662007-12-10 14:57:31 -0500167 * @locations - array of NFSv4 server location information
David Howellsf7b422b2006-06-09 09:34:33 -0400168 *
169 */
Al Virof8ad9c42011-03-16 06:32:07 -0400170static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
David Howells509de812006-08-22 20:06:11 -0400171 const struct nfs4_fs_locations *locations)
David Howellsf7b422b2006-06-09 09:34:33 -0400172{
173 struct vfsmount *mnt = ERR_PTR(-ENOENT);
174 struct nfs_clone_mount mountdata = {
Al Virof8ad9c42011-03-16 06:32:07 -0400175 .sb = dentry->d_sb,
David Howellsf7b422b2006-06-09 09:34:33 -0400176 .dentry = dentry,
Al Virof8ad9c42011-03-16 06:32:07 -0400177 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
David Howellsf7b422b2006-06-09 09:34:33 -0400178 };
David Howells54ceac42006-08-22 20:06:13 -0400179 char *page = NULL, *page2 = NULL;
Chuck Lever3f43c662007-12-10 14:57:31 -0500180 int loc, error;
David Howellsf7b422b2006-06-09 09:34:33 -0400181
182 if (locations == NULL || locations->nlocations <= 0)
183 goto out;
184
Harvey Harrison3110ff82008-05-02 13:42:44 -0700185 dprintk("%s: referral at %s/%s\n", __func__,
David Howellsf7b422b2006-06-09 09:34:33 -0400186 dentry->d_parent->d_name.name, dentry->d_name.name);
187
David Howellsf7b422b2006-06-09 09:34:33 -0400188 page = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400189 if (!page)
David Howellsf7b422b2006-06-09 09:34:33 -0400190 goto out;
David Howells54ceac42006-08-22 20:06:13 -0400191
David Howellsf7b422b2006-06-09 09:34:33 -0400192 page2 = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400193 if (!page2)
David Howellsf7b422b2006-06-09 09:34:33 -0400194 goto out;
195
David Howells54ceac42006-08-22 20:06:13 -0400196 /* Ensure fs path is a prefix of current dentry path */
Al Virob514f872011-03-16 06:26:11 -0400197 error = nfs4_validate_fspath(dentry, locations, page, page2);
David Howells54ceac42006-08-22 20:06:13 -0400198 if (error < 0) {
199 mnt = ERR_PTR(error);
200 goto out;
David Howellsf7b422b2006-06-09 09:34:33 -0400201 }
202
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400203 for (loc = 0; loc < locations->nlocations; loc++) {
David Howells509de812006-08-22 20:06:11 -0400204 const struct nfs4_fs_location *location = &locations->locations[loc];
David Howellsf7b422b2006-06-09 09:34:33 -0400205
206 if (location == NULL || location->nservers <= 0 ||
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400207 location->rootpath.ncomponents == 0)
David Howellsf7b422b2006-06-09 09:34:33 -0400208 continue;
David Howellsf7b422b2006-06-09 09:34:33 -0400209
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400210 mnt = try_location(&mountdata, page, page2, location);
211 if (!IS_ERR(mnt))
212 break;
David Howellsf7b422b2006-06-09 09:34:33 -0400213 }
214
David Howellsf7b422b2006-06-09 09:34:33 -0400215out:
David Howells54ceac42006-08-22 20:06:13 -0400216 free_page((unsigned long) page);
217 free_page((unsigned long) page2);
Harvey Harrison3110ff82008-05-02 13:42:44 -0700218 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400219 return mnt;
220}
221
222/*
223 * nfs_do_refmount - handle crossing a referral on server
224 * @dentry - dentry of referral
David Howellsf7b422b2006-06-09 09:34:33 -0400225 *
226 */
Al Virof8ad9c42011-03-16 06:32:07 -0400227struct vfsmount *nfs_do_refmount(struct dentry *dentry)
David Howellsf7b422b2006-06-09 09:34:33 -0400228{
David Howells54ceac42006-08-22 20:06:13 -0400229 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
David Howellsf7b422b2006-06-09 09:34:33 -0400230 struct dentry *parent;
231 struct nfs4_fs_locations *fs_locations = NULL;
232 struct page *page;
233 int err;
234
235 /* BUG_ON(IS_ROOT(dentry)); */
Harvey Harrison3110ff82008-05-02 13:42:44 -0700236 dprintk("%s: enter\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400237
238 page = alloc_page(GFP_KERNEL);
239 if (page == NULL)
240 goto out;
241
242 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
243 if (fs_locations == NULL)
244 goto out_free;
245
246 /* Get locations */
David Howells54ceac42006-08-22 20:06:13 -0400247 mnt = ERR_PTR(-ENOENT);
248
David Howellsf7b422b2006-06-09 09:34:33 -0400249 parent = dget_parent(dentry);
David Howells54ceac42006-08-22 20:06:13 -0400250 dprintk("%s: getting locations for %s/%s\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700251 __func__, parent->d_name.name, dentry->d_name.name);
David Howells54ceac42006-08-22 20:06:13 -0400252
Trond Myklebustc228fd32007-01-13 02:28:11 -0500253 err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page);
David Howellsf7b422b2006-06-09 09:34:33 -0400254 dput(parent);
David Howells54ceac42006-08-22 20:06:13 -0400255 if (err != 0 ||
256 fs_locations->nlocations <= 0 ||
David Howellsf7b422b2006-06-09 09:34:33 -0400257 fs_locations->fs_path.ncomponents <= 0)
258 goto out_free;
259
Al Virof8ad9c42011-03-16 06:32:07 -0400260 mnt = nfs_follow_referral(dentry, fs_locations);
David Howellsf7b422b2006-06-09 09:34:33 -0400261out_free:
262 __free_page(page);
263 kfree(fs_locations);
264out:
Harvey Harrison3110ff82008-05-02 13:42:44 -0700265 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400266 return mnt;
267}