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Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
f7b422b1 DH |
2 | /* |
3 | * linux/fs/nfs/nfs4namespace.c | |
4 | * | |
5 | * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com> | |
54ceac45 | 6 | * - Modified by David Howells <dhowells@redhat.com> |
f7b422b1 DH |
7 | * |
8 | * NFSv4 namespace | |
9 | */ | |
10 | ||
f7b422b1 DH |
11 | #include <linux/dcache.h> |
12 | #include <linux/mount.h> | |
13 | #include <linux/namei.h> | |
14 | #include <linux/nfs_fs.h> | |
47040da3 | 15 | #include <linux/nfs_mount.h> |
5a0e3ad6 | 16 | #include <linux/slab.h> |
f7b422b1 DH |
17 | #include <linux/string.h> |
18 | #include <linux/sunrpc/clnt.h> | |
5976687a | 19 | #include <linux/sunrpc/addr.h> |
f7b422b1 DH |
20 | #include <linux/vfs.h> |
21 | #include <linux/inet.h> | |
22 | #include "internal.h" | |
c228fd3a | 23 | #include "nfs4_fs.h" |
7d7ea882 | 24 | #include "dns_resolve.h" |
f7b422b1 DH |
25 | |
26 | #define NFSDBG_FACILITY NFSDBG_VFS | |
27 | ||
28 | /* | |
ef95d31e TM |
29 | * Convert the NFSv4 pathname components into a standard posix path. |
30 | * | |
31 | * Note that the resulting string will be placed at the end of the buffer | |
f7b422b1 | 32 | */ |
509de811 | 33 | static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname, |
f7b422b1 DH |
34 | char *buffer, ssize_t buflen) |
35 | { | |
36 | char *end = buffer + buflen; | |
37 | int n; | |
38 | ||
39 | *--end = '\0'; | |
40 | buflen--; | |
41 | ||
42 | n = pathname->ncomponents; | |
43 | while (--n >= 0) { | |
509de811 | 44 | const struct nfs4_string *component = &pathname->components[n]; |
f7b422b1 DH |
45 | buflen -= component->len + 1; |
46 | if (buflen < 0) | |
47 | goto Elong; | |
48 | end -= component->len; | |
49 | memcpy(end, component->data, component->len); | |
50 | *--end = '/'; | |
51 | } | |
52 | return end; | |
53 | Elong: | |
54 | return ERR_PTR(-ENAMETOOLONG); | |
55 | } | |
56 | ||
1aba1567 WAA |
57 | /* |
58 | * return the path component of "<server>:<path>" | |
59 | * nfspath - the "<server>:<path>" string | |
60 | * end - one past the last char that could contain "<server>:" | |
61 | * returns NULL on failure | |
62 | */ | |
63 | static char *nfs_path_component(const char *nfspath, const char *end) | |
64 | { | |
65 | char *p; | |
66 | ||
67 | if (*nfspath == '[') { | |
68 | /* parse [] escaped IPv6 addrs */ | |
69 | p = strchr(nfspath, ']'); | |
70 | if (p != NULL && ++p < end && *p == ':') | |
71 | return p + 1; | |
72 | } else { | |
73 | /* otherwise split on first colon */ | |
74 | p = strchr(nfspath, ':'); | |
75 | if (p != NULL && p < end) | |
76 | return p + 1; | |
77 | } | |
78 | return NULL; | |
79 | } | |
80 | ||
54ceac45 DH |
81 | /* |
82 | * Determine the mount path as a string | |
83 | */ | |
b514f872 | 84 | static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen) |
54ceac45 | 85 | { |
b514f872 | 86 | char *limit; |
97a54868 BH |
87 | char *path = nfs_path(&limit, dentry, buffer, buflen, |
88 | NFS_PATH_CANONICAL); | |
b514f872 | 89 | if (!IS_ERR(path)) { |
1aba1567 WAA |
90 | char *path_component = nfs_path_component(path, limit); |
91 | if (path_component) | |
92 | return path_component; | |
b514f872 AV |
93 | } |
94 | return path; | |
54ceac45 DH |
95 | } |
96 | ||
97 | /* | |
98 | * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we | |
99 | * believe to be the server path to this dentry | |
100 | */ | |
b514f872 | 101 | static int nfs4_validate_fspath(struct dentry *dentry, |
54ceac45 DH |
102 | const struct nfs4_fs_locations *locations, |
103 | char *page, char *page2) | |
104 | { | |
105 | const char *path, *fs_path; | |
106 | ||
b514f872 | 107 | path = nfs4_path(dentry, page, PAGE_SIZE); |
54ceac45 DH |
108 | if (IS_ERR(path)) |
109 | return PTR_ERR(path); | |
110 | ||
111 | fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE); | |
112 | if (IS_ERR(fs_path)) | |
113 | return PTR_ERR(fs_path); | |
114 | ||
115 | if (strncmp(path, fs_path, strlen(fs_path)) != 0) { | |
116 | dprintk("%s: path %s does not begin with fsroot %s\n", | |
3110ff80 | 117 | __func__, path, fs_path); |
54ceac45 DH |
118 | return -ENOENT; |
119 | } | |
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
7d7ea882 | 124 | static size_t nfs_parse_server_name(char *string, size_t len, |
292f503c | 125 | struct sockaddr *sa, size_t salen, struct net *net) |
7d7ea882 TM |
126 | { |
127 | ssize_t ret; | |
128 | ||
33faaa38 | 129 | ret = rpc_pton(net, string, len, sa, salen); |
7d7ea882 | 130 | if (ret == 0) { |
33faaa38 | 131 | ret = nfs_dns_resolve_name(net, string, len, sa, salen); |
7d7ea882 TM |
132 | if (ret < 0) |
133 | ret = 0; | |
134 | } | |
135 | return ret; | |
136 | } | |
137 | ||
9568c5e9 CL |
138 | /** |
139 | * nfs_find_best_sec - Find a security mechanism supported locally | |
302fad7b | 140 | * @clnt: pointer to rpc_clnt |
4d4b69dd | 141 | * @server: NFS server struct |
9568c5e9 CL |
142 | * @flavors: List of security tuples returned by SECINFO procedure |
143 | * | |
66b06860 AA |
144 | * Return an rpc client that uses the first security mechanism in |
145 | * "flavors" that is locally supported. The "flavors" array | |
9568c5e9 | 146 | * is searched in the order returned from the server, per RFC 3530 |
66b06860 AA |
147 | * recommendation and each flavor is checked for membership in the |
148 | * sec= mount option list if it exists. | |
8445cd35 AA |
149 | * |
150 | * Return -EPERM if no matching flavor is found in the array. | |
66b06860 AA |
151 | * |
152 | * Please call rpc_shutdown_client() when you are done with this rpc client. | |
153 | * | |
9568c5e9 | 154 | */ |
66b06860 AA |
155 | static struct rpc_clnt *nfs_find_best_sec(struct rpc_clnt *clnt, |
156 | struct nfs_server *server, | |
4d4b69dd | 157 | struct nfs4_secinfo_flavors *flavors) |
2671bfc3 | 158 | { |
66b06860 | 159 | rpc_authflavor_t pflavor; |
9568c5e9 | 160 | struct nfs4_secinfo4 *secinfo; |
fb15b26f | 161 | unsigned int i; |
2671bfc3 BS |
162 | |
163 | for (i = 0; i < flavors->num_flavors; i++) { | |
9568c5e9 CL |
164 | secinfo = &flavors->flavors[i]; |
165 | ||
166 | switch (secinfo->flavor) { | |
167 | case RPC_AUTH_NULL: | |
168 | case RPC_AUTH_UNIX: | |
169 | case RPC_AUTH_GSS: | |
66b06860 | 170 | pflavor = rpcauth_get_pseudoflavor(secinfo->flavor, |
9568c5e9 | 171 | &secinfo->flavor_info); |
66b06860 AA |
172 | /* does the pseudoflavor match a sec= mount opt? */ |
173 | if (pflavor != RPC_AUTH_MAXFLAVOR && | |
174 | nfs_auth_info_match(&server->auth_info, pflavor)) { | |
175 | struct rpc_clnt *new; | |
176 | struct rpc_cred *cred; | |
177 | ||
178 | /* Cloning creates an rpc_auth for the flavor */ | |
179 | new = rpc_clone_client_set_auth(clnt, pflavor); | |
180 | if (IS_ERR(new)) | |
181 | continue; | |
182 | /** | |
183 | * Check that the user actually can use the | |
184 | * flavor. This is mostly for RPC_AUTH_GSS | |
185 | * where cr_init obtains a gss context | |
186 | */ | |
187 | cred = rpcauth_lookupcred(new->cl_auth, 0); | |
188 | if (IS_ERR(cred)) { | |
189 | rpc_shutdown_client(new); | |
190 | continue; | |
191 | } | |
192 | put_rpccred(cred); | |
193 | return new; | |
194 | } | |
2671bfc3 BS |
195 | } |
196 | } | |
66b06860 | 197 | return ERR_PTR(-EPERM); |
2671bfc3 BS |
198 | } |
199 | ||
66b06860 AA |
200 | /** |
201 | * nfs4_negotiate_security - in response to an NFS4ERR_WRONGSEC on lookup, | |
202 | * return an rpc_clnt that uses the best available security flavor with | |
203 | * respect to the secinfo flavor list and the sec= mount options. | |
204 | * | |
205 | * @clnt: RPC client to clone | |
206 | * @inode: directory inode | |
207 | * @name: lookup name | |
208 | * | |
209 | * Please call rpc_shutdown_client() when you are done with this rpc client. | |
210 | */ | |
211 | struct rpc_clnt * | |
212 | nfs4_negotiate_security(struct rpc_clnt *clnt, struct inode *inode, | |
beffb8fe | 213 | const struct qstr *name) |
72de53ec BS |
214 | { |
215 | struct page *page; | |
216 | struct nfs4_secinfo_flavors *flavors; | |
66b06860 | 217 | struct rpc_clnt *new; |
72de53ec BS |
218 | int err; |
219 | ||
220 | page = alloc_page(GFP_KERNEL); | |
221 | if (!page) | |
66b06860 AA |
222 | return ERR_PTR(-ENOMEM); |
223 | ||
72de53ec BS |
224 | flavors = page_address(page); |
225 | ||
226 | err = nfs4_proc_secinfo(inode, name, flavors); | |
227 | if (err < 0) { | |
66b06860 | 228 | new = ERR_PTR(err); |
72de53ec BS |
229 | goto out; |
230 | } | |
231 | ||
66b06860 | 232 | new = nfs_find_best_sec(clnt, NFS_SERVER(inode), flavors); |
72de53ec BS |
233 | |
234 | out: | |
235 | put_page(page); | |
66b06860 | 236 | return new; |
72de53ec BS |
237 | } |
238 | ||
4ada29d5 BF |
239 | static struct vfsmount *try_location(struct nfs_clone_mount *mountdata, |
240 | char *page, char *page2, | |
241 | const struct nfs4_fs_location *location) | |
242 | { | |
364d015e | 243 | const size_t addr_bufsize = sizeof(struct sockaddr_storage); |
292f503c | 244 | struct net *net = rpc_net_ns(NFS_SB(mountdata->sb)->client); |
4ada29d5 BF |
245 | struct vfsmount *mnt = ERR_PTR(-ENOENT); |
246 | char *mnt_path; | |
ef95d31e | 247 | unsigned int maxbuflen; |
460cdbc8 | 248 | unsigned int s; |
4ada29d5 BF |
249 | |
250 | mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE); | |
251 | if (IS_ERR(mnt_path)) | |
517be09d | 252 | return ERR_CAST(mnt_path); |
4ada29d5 | 253 | mountdata->mnt_path = mnt_path; |
ef95d31e | 254 | maxbuflen = mnt_path - 1 - page2; |
4ada29d5 | 255 | |
364d015e TM |
256 | mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL); |
257 | if (mountdata->addr == NULL) | |
258 | return ERR_PTR(-ENOMEM); | |
259 | ||
460cdbc8 | 260 | for (s = 0; s < location->nservers; s++) { |
ea31a443 | 261 | const struct nfs4_string *buf = &location->servers[s]; |
4ada29d5 | 262 | |
ef95d31e | 263 | if (buf->len <= 0 || buf->len >= maxbuflen) |
4ada29d5 | 264 | continue; |
4ada29d5 | 265 | |
ea31a443 BF |
266 | if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len)) |
267 | continue; | |
517be09d TM |
268 | |
269 | mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len, | |
292f503c | 270 | mountdata->addr, addr_bufsize, net); |
53a0b9c4 | 271 | if (mountdata->addrlen == 0) |
ea31a443 | 272 | continue; |
517be09d | 273 | |
ef95d31e TM |
274 | memcpy(page2, buf->data, buf->len); |
275 | page2[buf->len] = '\0'; | |
ea31a443 | 276 | mountdata->hostname = page2; |
4ada29d5 BF |
277 | |
278 | snprintf(page, PAGE_SIZE, "%s:%s", | |
279 | mountdata->hostname, | |
280 | mountdata->mnt_path); | |
281 | ||
93faccbb | 282 | mnt = vfs_submount(mountdata->dentry, &nfs4_referral_fs_type, page, mountdata); |
4ada29d5 BF |
283 | if (!IS_ERR(mnt)) |
284 | break; | |
4ada29d5 | 285 | } |
364d015e | 286 | kfree(mountdata->addr); |
4ada29d5 BF |
287 | return mnt; |
288 | } | |
289 | ||
f7b422b1 DH |
290 | /** |
291 | * nfs_follow_referral - set up mountpoint when hitting a referral on moved error | |
302fad7b TM |
292 | * @dentry: parent directory |
293 | * @locations: array of NFSv4 server location information | |
f7b422b1 DH |
294 | * |
295 | */ | |
f8ad9c4b | 296 | static struct vfsmount *nfs_follow_referral(struct dentry *dentry, |
509de811 | 297 | const struct nfs4_fs_locations *locations) |
f7b422b1 DH |
298 | { |
299 | struct vfsmount *mnt = ERR_PTR(-ENOENT); | |
300 | struct nfs_clone_mount mountdata = { | |
f8ad9c4b | 301 | .sb = dentry->d_sb, |
f7b422b1 | 302 | .dentry = dentry, |
f8ad9c4b | 303 | .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor, |
f7b422b1 | 304 | }; |
54ceac45 | 305 | char *page = NULL, *page2 = NULL; |
3f43c666 | 306 | int loc, error; |
f7b422b1 DH |
307 | |
308 | if (locations == NULL || locations->nlocations <= 0) | |
309 | goto out; | |
310 | ||
6de1472f | 311 | dprintk("%s: referral at %pd2\n", __func__, dentry); |
f7b422b1 | 312 | |
f7b422b1 | 313 | page = (char *) __get_free_page(GFP_USER); |
54ceac45 | 314 | if (!page) |
f7b422b1 | 315 | goto out; |
54ceac45 | 316 | |
f7b422b1 | 317 | page2 = (char *) __get_free_page(GFP_USER); |
54ceac45 | 318 | if (!page2) |
f7b422b1 DH |
319 | goto out; |
320 | ||
54ceac45 | 321 | /* Ensure fs path is a prefix of current dentry path */ |
b514f872 | 322 | error = nfs4_validate_fspath(dentry, locations, page, page2); |
54ceac45 DH |
323 | if (error < 0) { |
324 | mnt = ERR_PTR(error); | |
325 | goto out; | |
f7b422b1 DH |
326 | } |
327 | ||
460cdbc8 | 328 | for (loc = 0; loc < locations->nlocations; loc++) { |
509de811 | 329 | const struct nfs4_fs_location *location = &locations->locations[loc]; |
f7b422b1 DH |
330 | |
331 | if (location == NULL || location->nservers <= 0 || | |
460cdbc8 | 332 | location->rootpath.ncomponents == 0) |
f7b422b1 | 333 | continue; |
f7b422b1 | 334 | |
4ada29d5 BF |
335 | mnt = try_location(&mountdata, page, page2, location); |
336 | if (!IS_ERR(mnt)) | |
337 | break; | |
f7b422b1 DH |
338 | } |
339 | ||
f7b422b1 | 340 | out: |
54ceac45 DH |
341 | free_page((unsigned long) page); |
342 | free_page((unsigned long) page2); | |
f7b422b1 DH |
343 | return mnt; |
344 | } | |
345 | ||
346 | /* | |
347 | * nfs_do_refmount - handle crossing a referral on server | |
348 | * @dentry - dentry of referral | |
f7b422b1 DH |
349 | * |
350 | */ | |
281cad46 | 351 | static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry) |
f7b422b1 | 352 | { |
54ceac45 | 353 | struct vfsmount *mnt = ERR_PTR(-ENOMEM); |
f7b422b1 DH |
354 | struct dentry *parent; |
355 | struct nfs4_fs_locations *fs_locations = NULL; | |
356 | struct page *page; | |
357 | int err; | |
358 | ||
359 | /* BUG_ON(IS_ROOT(dentry)); */ | |
f7b422b1 DH |
360 | page = alloc_page(GFP_KERNEL); |
361 | if (page == NULL) | |
3183783b | 362 | return mnt; |
f7b422b1 DH |
363 | |
364 | fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); | |
365 | if (fs_locations == NULL) | |
366 | goto out_free; | |
367 | ||
368 | /* Get locations */ | |
54ceac45 DH |
369 | mnt = ERR_PTR(-ENOENT); |
370 | ||
f7b422b1 | 371 | parent = dget_parent(dentry); |
6de1472f AV |
372 | dprintk("%s: getting locations for %pd2\n", |
373 | __func__, dentry); | |
54ceac45 | 374 | |
2b0143b5 | 375 | err = nfs4_proc_fs_locations(client, d_inode(parent), &dentry->d_name, fs_locations, page); |
f7b422b1 | 376 | dput(parent); |
54ceac45 DH |
377 | if (err != 0 || |
378 | fs_locations->nlocations <= 0 || | |
f7b422b1 DH |
379 | fs_locations->fs_path.ncomponents <= 0) |
380 | goto out_free; | |
381 | ||
f8ad9c4b | 382 | mnt = nfs_follow_referral(dentry, fs_locations); |
f7b422b1 DH |
383 | out_free: |
384 | __free_page(page); | |
385 | kfree(fs_locations); | |
f7b422b1 DH |
386 | return mnt; |
387 | } | |
281cad46 BS |
388 | |
389 | struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry, | |
390 | struct nfs_fh *fh, struct nfs_fattr *fattr) | |
391 | { | |
47040da3 | 392 | rpc_authflavor_t flavor = server->client->cl_auth->au_flavor; |
281cad46 | 393 | struct dentry *parent = dget_parent(dentry); |
2b0143b5 | 394 | struct inode *dir = d_inode(parent); |
beffb8fe | 395 | const struct qstr *name = &dentry->d_name; |
281cad46 BS |
396 | struct rpc_clnt *client; |
397 | struct vfsmount *mnt; | |
398 | ||
399 | /* Look it up again to get its attributes and sec flavor */ | |
47040da3 | 400 | client = nfs4_proc_lookup_mountpoint(dir, name, fh, fattr); |
281cad46 BS |
401 | dput(parent); |
402 | if (IS_ERR(client)) | |
403 | return ERR_CAST(client); | |
404 | ||
47040da3 | 405 | if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) { |
281cad46 | 406 | mnt = nfs_do_refmount(client, dentry); |
47040da3 TM |
407 | goto out; |
408 | } | |
281cad46 | 409 | |
47040da3 TM |
410 | if (client->cl_auth->au_flavor != flavor) |
411 | flavor = client->cl_auth->au_flavor; | |
47040da3 TM |
412 | mnt = nfs_do_submount(dentry, fh, fattr, flavor); |
413 | out: | |
281cad46 BS |
414 | rpc_shutdown_client(client); |
415 | return mnt; | |
416 | } | |
800c06a5 CL |
417 | |
418 | /* | |
419 | * Try one location from the fs_locations array. | |
420 | * | |
421 | * Returns zero on success, or a negative errno value. | |
422 | */ | |
423 | static int nfs4_try_replacing_one_location(struct nfs_server *server, | |
424 | char *page, char *page2, | |
425 | const struct nfs4_fs_location *location) | |
426 | { | |
427 | const size_t addr_bufsize = sizeof(struct sockaddr_storage); | |
292f503c | 428 | struct net *net = rpc_net_ns(server->client); |
800c06a5 CL |
429 | struct sockaddr *sap; |
430 | unsigned int s; | |
431 | size_t salen; | |
432 | int error; | |
433 | ||
434 | sap = kmalloc(addr_bufsize, GFP_KERNEL); | |
435 | if (sap == NULL) | |
436 | return -ENOMEM; | |
437 | ||
438 | error = -ENOENT; | |
439 | for (s = 0; s < location->nservers; s++) { | |
440 | const struct nfs4_string *buf = &location->servers[s]; | |
441 | char *hostname; | |
442 | ||
443 | if (buf->len <= 0 || buf->len > PAGE_SIZE) | |
444 | continue; | |
445 | ||
446 | if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len) != NULL) | |
447 | continue; | |
448 | ||
449 | salen = nfs_parse_server_name(buf->data, buf->len, | |
292f503c | 450 | sap, addr_bufsize, net); |
800c06a5 CL |
451 | if (salen == 0) |
452 | continue; | |
453 | rpc_set_port(sap, NFS_PORT); | |
454 | ||
455 | error = -ENOMEM; | |
456 | hostname = kstrndup(buf->data, buf->len, GFP_KERNEL); | |
457 | if (hostname == NULL) | |
458 | break; | |
459 | ||
292f503c | 460 | error = nfs4_update_server(server, hostname, sap, salen, net); |
800c06a5 CL |
461 | kfree(hostname); |
462 | if (error == 0) | |
463 | break; | |
464 | } | |
465 | ||
466 | kfree(sap); | |
467 | return error; | |
468 | } | |
469 | ||
470 | /** | |
471 | * nfs4_replace_transport - set up transport to destination server | |
472 | * | |
473 | * @server: export being migrated | |
474 | * @locations: fs_locations array | |
475 | * | |
476 | * Returns zero on success, or a negative errno value. | |
477 | * | |
478 | * The client tries all the entries in the "locations" array, in the | |
479 | * order returned by the server, until one works or the end of the | |
480 | * array is reached. | |
481 | */ | |
482 | int nfs4_replace_transport(struct nfs_server *server, | |
483 | const struct nfs4_fs_locations *locations) | |
484 | { | |
485 | char *page = NULL, *page2 = NULL; | |
486 | int loc, error; | |
487 | ||
488 | error = -ENOENT; | |
489 | if (locations == NULL || locations->nlocations <= 0) | |
490 | goto out; | |
491 | ||
492 | error = -ENOMEM; | |
493 | page = (char *) __get_free_page(GFP_USER); | |
494 | if (!page) | |
495 | goto out; | |
496 | page2 = (char *) __get_free_page(GFP_USER); | |
497 | if (!page2) | |
498 | goto out; | |
499 | ||
500 | for (loc = 0; loc < locations->nlocations; loc++) { | |
501 | const struct nfs4_fs_location *location = | |
502 | &locations->locations[loc]; | |
503 | ||
504 | if (location == NULL || location->nservers <= 0 || | |
505 | location->rootpath.ncomponents == 0) | |
506 | continue; | |
507 | ||
508 | error = nfs4_try_replacing_one_location(server, page, | |
509 | page2, location); | |
510 | if (error == 0) | |
511 | break; | |
512 | } | |
513 | ||
514 | out: | |
515 | free_page((unsigned long)page); | |
516 | free_page((unsigned long)page2); | |
517 | return error; | |
518 | } |