blob: 7483a177dc97b8eccb64d46a736fdb73236238f6 [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/*
Weston Andros Adamson1aba1562012-04-24 16:50:37 -040055 * return the path component of "<server>:<path>"
56 * nfspath - the "<server>:<path>" string
57 * end - one past the last char that could contain "<server>:"
58 * returns NULL on failure
59 */
60static char *nfs_path_component(const char *nfspath, const char *end)
61{
62 char *p;
63
64 if (*nfspath == '[') {
65 /* parse [] escaped IPv6 addrs */
66 p = strchr(nfspath, ']');
67 if (p != NULL && ++p < end && *p == ':')
68 return p + 1;
69 } else {
70 /* otherwise split on first colon */
71 p = strchr(nfspath, ':');
72 if (p != NULL && p < end)
73 return p + 1;
74 }
75 return NULL;
76}
77
78/*
David Howells54ceac42006-08-22 20:06:13 -040079 * Determine the mount path as a string
80 */
Al Virob514f872011-03-16 06:26:11 -040081static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
David Howells54ceac42006-08-22 20:06:13 -040082{
Al Virob514f872011-03-16 06:26:11 -040083 char *limit;
84 char *path = nfs_path(&limit, dentry, buffer, buflen);
85 if (!IS_ERR(path)) {
Weston Andros Adamson1aba1562012-04-24 16:50:37 -040086 char *path_component = nfs_path_component(path, limit);
87 if (path_component)
88 return path_component;
Al Virob514f872011-03-16 06:26:11 -040089 }
90 return path;
David Howells54ceac42006-08-22 20:06:13 -040091}
92
93/*
94 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
95 * believe to be the server path to this dentry
96 */
Al Virob514f872011-03-16 06:26:11 -040097static int nfs4_validate_fspath(struct dentry *dentry,
David Howells54ceac42006-08-22 20:06:13 -040098 const struct nfs4_fs_locations *locations,
99 char *page, char *page2)
100{
101 const char *path, *fs_path;
102
Al Virob514f872011-03-16 06:26:11 -0400103 path = nfs4_path(dentry, page, PAGE_SIZE);
David Howells54ceac42006-08-22 20:06:13 -0400104 if (IS_ERR(path))
105 return PTR_ERR(path);
106
107 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
108 if (IS_ERR(fs_path))
109 return PTR_ERR(fs_path);
110
111 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
112 dprintk("%s: path %s does not begin with fsroot %s\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700113 __func__, path, fs_path);
David Howells54ceac42006-08-22 20:06:13 -0400114 return -ENOENT;
115 }
116
117 return 0;
118}
119
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400120static size_t nfs_parse_server_name(char *string, size_t len,
Stanislav Kinsbursky1b340d02011-11-25 17:13:04 +0300121 struct sockaddr *sa, size_t salen, struct nfs_server *server)
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400122{
Trond Myklebust2446ab62012-03-01 17:00:56 -0500123 struct net *net = rpc_net_ns(server->client);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400124 ssize_t ret;
125
Stanislav Kinsbursky33faaa32012-01-26 15:12:05 +0400126 ret = rpc_pton(net, string, len, sa, salen);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400127 if (ret == 0) {
Stanislav Kinsbursky33faaa32012-01-26 15:12:05 +0400128 ret = nfs_dns_resolve_name(net, string, len, sa, salen);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400129 if (ret < 0)
130 ret = 0;
131 }
132 return ret;
133}
134
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400135static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
136 char *page, char *page2,
137 const struct nfs4_fs_location *location)
138{
Trond Myklebust364d015e52010-04-16 16:22:46 -0400139 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400140 struct vfsmount *mnt = ERR_PTR(-ENOENT);
141 char *mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400142 unsigned int maxbuflen;
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400143 unsigned int s;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400144
145 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
146 if (IS_ERR(mnt_path))
Trond Myklebust517be092009-10-06 15:42:20 -0400147 return ERR_CAST(mnt_path);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400148 mountdata->mnt_path = mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400149 maxbuflen = mnt_path - 1 - page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400150
Trond Myklebust364d015e52010-04-16 16:22:46 -0400151 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
152 if (mountdata->addr == NULL)
153 return ERR_PTR(-ENOMEM);
154
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400155 for (s = 0; s < location->nservers; s++) {
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400156 const struct nfs4_string *buf = &location->servers[s];
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400157
Trond Myklebustef95d312009-03-10 20:33:17 -0400158 if (buf->len <= 0 || buf->len >= maxbuflen)
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400159 continue;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400160
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400161 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
162 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400163
164 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
Stanislav Kinsbursky1b340d02011-11-25 17:13:04 +0300165 mountdata->addr, addr_bufsize,
166 NFS_SB(mountdata->sb));
Chuck Lever53a0b9c2009-08-09 15:09:36 -0400167 if (mountdata->addrlen == 0)
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400168 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400169
Chuck Leverec6ee612009-08-09 15:09:37 -0400170 rpc_set_port(mountdata->addr, NFS_PORT);
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400171
Trond Myklebustef95d312009-03-10 20:33:17 -0400172 memcpy(page2, buf->data, buf->len);
173 page2[buf->len] = '\0';
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400174 mountdata->hostname = page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400175
176 snprintf(page, PAGE_SIZE, "%s:%s",
177 mountdata->hostname,
178 mountdata->mnt_path);
179
180 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
181 if (!IS_ERR(mnt))
182 break;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400183 }
Trond Myklebust364d015e52010-04-16 16:22:46 -0400184 kfree(mountdata->addr);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400185 return mnt;
186}
187
David Howellsf7b422b2006-06-09 09:34:33 -0400188/**
189 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
David Howellsf7b422b2006-06-09 09:34:33 -0400190 * @dentry - parent directory
Chuck Lever3f43c662007-12-10 14:57:31 -0500191 * @locations - array of NFSv4 server location information
David Howellsf7b422b2006-06-09 09:34:33 -0400192 *
193 */
Al Virof8ad9c42011-03-16 06:32:07 -0400194static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
David Howells509de812006-08-22 20:06:11 -0400195 const struct nfs4_fs_locations *locations)
David Howellsf7b422b2006-06-09 09:34:33 -0400196{
197 struct vfsmount *mnt = ERR_PTR(-ENOENT);
198 struct nfs_clone_mount mountdata = {
Al Virof8ad9c42011-03-16 06:32:07 -0400199 .sb = dentry->d_sb,
David Howellsf7b422b2006-06-09 09:34:33 -0400200 .dentry = dentry,
Al Virof8ad9c42011-03-16 06:32:07 -0400201 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
David Howellsf7b422b2006-06-09 09:34:33 -0400202 };
David Howells54ceac42006-08-22 20:06:13 -0400203 char *page = NULL, *page2 = NULL;
Chuck Lever3f43c662007-12-10 14:57:31 -0500204 int loc, error;
David Howellsf7b422b2006-06-09 09:34:33 -0400205
206 if (locations == NULL || locations->nlocations <= 0)
207 goto out;
208
Harvey Harrison3110ff82008-05-02 13:42:44 -0700209 dprintk("%s: referral at %s/%s\n", __func__,
David Howellsf7b422b2006-06-09 09:34:33 -0400210 dentry->d_parent->d_name.name, dentry->d_name.name);
211
David Howellsf7b422b2006-06-09 09:34:33 -0400212 page = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400213 if (!page)
David Howellsf7b422b2006-06-09 09:34:33 -0400214 goto out;
David Howells54ceac42006-08-22 20:06:13 -0400215
David Howellsf7b422b2006-06-09 09:34:33 -0400216 page2 = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400217 if (!page2)
David Howellsf7b422b2006-06-09 09:34:33 -0400218 goto out;
219
David Howells54ceac42006-08-22 20:06:13 -0400220 /* Ensure fs path is a prefix of current dentry path */
Al Virob514f872011-03-16 06:26:11 -0400221 error = nfs4_validate_fspath(dentry, locations, page, page2);
David Howells54ceac42006-08-22 20:06:13 -0400222 if (error < 0) {
223 mnt = ERR_PTR(error);
224 goto out;
David Howellsf7b422b2006-06-09 09:34:33 -0400225 }
226
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400227 for (loc = 0; loc < locations->nlocations; loc++) {
David Howells509de812006-08-22 20:06:11 -0400228 const struct nfs4_fs_location *location = &locations->locations[loc];
David Howellsf7b422b2006-06-09 09:34:33 -0400229
230 if (location == NULL || location->nservers <= 0 ||
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400231 location->rootpath.ncomponents == 0)
David Howellsf7b422b2006-06-09 09:34:33 -0400232 continue;
David Howellsf7b422b2006-06-09 09:34:33 -0400233
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400234 mnt = try_location(&mountdata, page, page2, location);
235 if (!IS_ERR(mnt))
236 break;
David Howellsf7b422b2006-06-09 09:34:33 -0400237 }
238
David Howellsf7b422b2006-06-09 09:34:33 -0400239out:
David Howells54ceac42006-08-22 20:06:13 -0400240 free_page((unsigned long) page);
241 free_page((unsigned long) page2);
Harvey Harrison3110ff82008-05-02 13:42:44 -0700242 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400243 return mnt;
244}
245
246/*
247 * nfs_do_refmount - handle crossing a referral on server
248 * @dentry - dentry of referral
David Howellsf7b422b2006-06-09 09:34:33 -0400249 *
250 */
Al Virof8ad9c42011-03-16 06:32:07 -0400251struct vfsmount *nfs_do_refmount(struct dentry *dentry)
David Howellsf7b422b2006-06-09 09:34:33 -0400252{
David Howells54ceac42006-08-22 20:06:13 -0400253 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
David Howellsf7b422b2006-06-09 09:34:33 -0400254 struct dentry *parent;
255 struct nfs4_fs_locations *fs_locations = NULL;
256 struct page *page;
257 int err;
258
259 /* BUG_ON(IS_ROOT(dentry)); */
Harvey Harrison3110ff82008-05-02 13:42:44 -0700260 dprintk("%s: enter\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400261
262 page = alloc_page(GFP_KERNEL);
263 if (page == NULL)
264 goto out;
265
266 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
267 if (fs_locations == NULL)
268 goto out_free;
269
270 /* Get locations */
David Howells54ceac42006-08-22 20:06:13 -0400271 mnt = ERR_PTR(-ENOENT);
272
David Howellsf7b422b2006-06-09 09:34:33 -0400273 parent = dget_parent(dentry);
David Howells54ceac42006-08-22 20:06:13 -0400274 dprintk("%s: getting locations for %s/%s\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700275 __func__, parent->d_name.name, dentry->d_name.name);
David Howells54ceac42006-08-22 20:06:13 -0400276
Trond Myklebustc228fd32007-01-13 02:28:11 -0500277 err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page);
David Howellsf7b422b2006-06-09 09:34:33 -0400278 dput(parent);
David Howells54ceac42006-08-22 20:06:13 -0400279 if (err != 0 ||
280 fs_locations->nlocations <= 0 ||
David Howellsf7b422b2006-06-09 09:34:33 -0400281 fs_locations->fs_path.ncomponents <= 0)
282 goto out_free;
283
Al Virof8ad9c42011-03-16 06:32:07 -0400284 mnt = nfs_follow_referral(dentry, fs_locations);
David Howellsf7b422b2006-06-09 09:34:33 -0400285out_free:
286 __free_page(page);
287 kfree(fs_locations);
288out:
Harvey Harrison3110ff82008-05-02 13:42:44 -0700289 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400290 return mnt;
291}