blob: 3d83cb1fdc700ee95f120eee7286ff63f17e17e2 [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>
Trond Myklebust47040da2013-09-07 16:01:07 -040014#include <linux/nfs_mount.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090015#include <linux/slab.h>
David Howellsf7b422b2006-06-09 09:34:33 -040016#include <linux/string.h>
17#include <linux/sunrpc/clnt.h>
Jeff Layton59766872013-02-04 12:50:00 -050018#include <linux/sunrpc/addr.h>
David Howellsf7b422b2006-06-09 09:34:33 -040019#include <linux/vfs.h>
20#include <linux/inet.h>
21#include "internal.h"
Trond Myklebustc228fd32007-01-13 02:28:11 -050022#include "nfs4_fs.h"
Trond Myklebust7d7ea882009-08-19 18:12:34 -040023#include "dns_resolve.h"
David Howellsf7b422b2006-06-09 09:34:33 -040024
25#define NFSDBG_FACILITY NFSDBG_VFS
26
27/*
Trond Myklebustef95d312009-03-10 20:33:17 -040028 * Convert the NFSv4 pathname components into a standard posix path.
29 *
30 * Note that the resulting string will be placed at the end of the buffer
David Howellsf7b422b2006-06-09 09:34:33 -040031 */
David Howells509de812006-08-22 20:06:11 -040032static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
David Howellsf7b422b2006-06-09 09:34:33 -040033 char *buffer, ssize_t buflen)
34{
35 char *end = buffer + buflen;
36 int n;
37
38 *--end = '\0';
39 buflen--;
40
41 n = pathname->ncomponents;
42 while (--n >= 0) {
David Howells509de812006-08-22 20:06:11 -040043 const struct nfs4_string *component = &pathname->components[n];
David Howellsf7b422b2006-06-09 09:34:33 -040044 buflen -= component->len + 1;
45 if (buflen < 0)
46 goto Elong;
47 end -= component->len;
48 memcpy(end, component->data, component->len);
49 *--end = '/';
50 }
51 return end;
52Elong:
53 return ERR_PTR(-ENAMETOOLONG);
54}
55
David Howells54ceac42006-08-22 20:06:13 -040056/*
Weston Andros Adamson1aba1562012-04-24 16:50:37 -040057 * return the path component of "<server>:<path>"
58 * nfspath - the "<server>:<path>" string
59 * end - one past the last char that could contain "<server>:"
60 * returns NULL on failure
61 */
62static char *nfs_path_component(const char *nfspath, const char *end)
63{
64 char *p;
65
66 if (*nfspath == '[') {
67 /* parse [] escaped IPv6 addrs */
68 p = strchr(nfspath, ']');
69 if (p != NULL && ++p < end && *p == ':')
70 return p + 1;
71 } else {
72 /* otherwise split on first colon */
73 p = strchr(nfspath, ':');
74 if (p != NULL && p < end)
75 return p + 1;
76 }
77 return NULL;
78}
79
80/*
David Howells54ceac42006-08-22 20:06:13 -040081 * Determine the mount path as a string
82 */
Al Virob514f872011-03-16 06:26:11 -040083static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
David Howells54ceac42006-08-22 20:06:13 -040084{
Al Virob514f872011-03-16 06:26:11 -040085 char *limit;
Ben Hutchings97a54862012-10-21 19:23:52 +010086 char *path = nfs_path(&limit, dentry, buffer, buflen,
87 NFS_PATH_CANONICAL);
Al Virob514f872011-03-16 06:26:11 -040088 if (!IS_ERR(path)) {
Weston Andros Adamson1aba1562012-04-24 16:50:37 -040089 char *path_component = nfs_path_component(path, limit);
90 if (path_component)
91 return path_component;
Al Virob514f872011-03-16 06:26:11 -040092 }
93 return path;
David Howells54ceac42006-08-22 20:06:13 -040094}
95
96/*
97 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
98 * believe to be the server path to this dentry
99 */
Al Virob514f872011-03-16 06:26:11 -0400100static int nfs4_validate_fspath(struct dentry *dentry,
David Howells54ceac42006-08-22 20:06:13 -0400101 const struct nfs4_fs_locations *locations,
102 char *page, char *page2)
103{
104 const char *path, *fs_path;
105
Al Virob514f872011-03-16 06:26:11 -0400106 path = nfs4_path(dentry, page, PAGE_SIZE);
David Howells54ceac42006-08-22 20:06:13 -0400107 if (IS_ERR(path))
108 return PTR_ERR(path);
109
110 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
111 if (IS_ERR(fs_path))
112 return PTR_ERR(fs_path);
113
114 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
115 dprintk("%s: path %s does not begin with fsroot %s\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700116 __func__, path, fs_path);
David Howells54ceac42006-08-22 20:06:13 -0400117 return -ENOENT;
118 }
119
120 return 0;
121}
122
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400123static size_t nfs_parse_server_name(char *string, size_t len,
Trond Myklebust292f5032014-02-16 21:42:56 -0500124 struct sockaddr *sa, size_t salen, struct net *net)
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400125{
126 ssize_t ret;
127
Stanislav Kinsbursky33faaa32012-01-26 15:12:05 +0400128 ret = rpc_pton(net, string, len, sa, salen);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400129 if (ret == 0) {
Stanislav Kinsbursky33faaa32012-01-26 15:12:05 +0400130 ret = nfs_dns_resolve_name(net, string, len, sa, salen);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400131 if (ret < 0)
132 ret = 0;
133 }
134 return ret;
135}
136
Chuck Lever9568c5e2013-03-16 15:54:43 -0400137/**
138 * nfs_find_best_sec - Find a security mechanism supported locally
Weston Andros Adamson4d4b69d2013-10-18 15:15:19 -0400139 * @server: NFS server struct
Chuck Lever9568c5e2013-03-16 15:54:43 -0400140 * @flavors: List of security tuples returned by SECINFO procedure
141 *
Andy Adamson66b06862014-06-12 15:02:32 -0400142 * Return an rpc client that uses the first security mechanism in
143 * "flavors" that is locally supported. The "flavors" array
Chuck Lever9568c5e2013-03-16 15:54:43 -0400144 * is searched in the order returned from the server, per RFC 3530
Andy Adamson66b06862014-06-12 15:02:32 -0400145 * recommendation and each flavor is checked for membership in the
146 * sec= mount option list if it exists.
Andy Adamson8445cd32014-06-09 15:33:20 -0400147 *
148 * Return -EPERM if no matching flavor is found in the array.
Andy Adamson66b06862014-06-12 15:02:32 -0400149 *
150 * Please call rpc_shutdown_client() when you are done with this rpc client.
151 *
Chuck Lever9568c5e2013-03-16 15:54:43 -0400152 */
Andy Adamson66b06862014-06-12 15:02:32 -0400153static struct rpc_clnt *nfs_find_best_sec(struct rpc_clnt *clnt,
154 struct nfs_server *server,
Weston Andros Adamson4d4b69d2013-10-18 15:15:19 -0400155 struct nfs4_secinfo_flavors *flavors)
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400156{
Andy Adamson66b06862014-06-12 15:02:32 -0400157 rpc_authflavor_t pflavor;
Chuck Lever9568c5e2013-03-16 15:54:43 -0400158 struct nfs4_secinfo4 *secinfo;
Chuck Leverfb15b262013-03-16 15:54:34 -0400159 unsigned int i;
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400160
161 for (i = 0; i < flavors->num_flavors; i++) {
Chuck Lever9568c5e2013-03-16 15:54:43 -0400162 secinfo = &flavors->flavors[i];
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400163
Chuck Lever9568c5e2013-03-16 15:54:43 -0400164 switch (secinfo->flavor) {
165 case RPC_AUTH_NULL:
166 case RPC_AUTH_UNIX:
167 case RPC_AUTH_GSS:
Andy Adamson66b06862014-06-12 15:02:32 -0400168 pflavor = rpcauth_get_pseudoflavor(secinfo->flavor,
Chuck Lever9568c5e2013-03-16 15:54:43 -0400169 &secinfo->flavor_info);
Andy Adamson66b06862014-06-12 15:02:32 -0400170 /* does the pseudoflavor match a sec= mount opt? */
171 if (pflavor != RPC_AUTH_MAXFLAVOR &&
172 nfs_auth_info_match(&server->auth_info, pflavor)) {
173 struct rpc_clnt *new;
174 struct rpc_cred *cred;
175
176 /* Cloning creates an rpc_auth for the flavor */
177 new = rpc_clone_client_set_auth(clnt, pflavor);
178 if (IS_ERR(new))
179 continue;
180 /**
181 * Check that the user actually can use the
182 * flavor. This is mostly for RPC_AUTH_GSS
183 * where cr_init obtains a gss context
184 */
185 cred = rpcauth_lookupcred(new->cl_auth, 0);
186 if (IS_ERR(cred)) {
187 rpc_shutdown_client(new);
188 continue;
189 }
190 put_rpccred(cred);
191 return new;
192 }
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400193 }
194 }
Andy Adamson66b06862014-06-12 15:02:32 -0400195 return ERR_PTR(-EPERM);
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400196}
197
Andy Adamson66b06862014-06-12 15:02:32 -0400198/**
199 * nfs4_negotiate_security - in response to an NFS4ERR_WRONGSEC on lookup,
200 * return an rpc_clnt that uses the best available security flavor with
201 * respect to the secinfo flavor list and the sec= mount options.
202 *
203 * @clnt: RPC client to clone
204 * @inode: directory inode
205 * @name: lookup name
206 *
207 * Please call rpc_shutdown_client() when you are done with this rpc client.
208 */
209struct rpc_clnt *
210nfs4_negotiate_security(struct rpc_clnt *clnt, struct inode *inode,
211 struct qstr *name)
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400212{
213 struct page *page;
214 struct nfs4_secinfo_flavors *flavors;
Andy Adamson66b06862014-06-12 15:02:32 -0400215 struct rpc_clnt *new;
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400216 int err;
217
218 page = alloc_page(GFP_KERNEL);
219 if (!page)
Andy Adamson66b06862014-06-12 15:02:32 -0400220 return ERR_PTR(-ENOMEM);
221
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400222 flavors = page_address(page);
223
224 err = nfs4_proc_secinfo(inode, name, flavors);
225 if (err < 0) {
Andy Adamson66b06862014-06-12 15:02:32 -0400226 new = ERR_PTR(err);
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400227 goto out;
228 }
229
Andy Adamson66b06862014-06-12 15:02:32 -0400230 new = nfs_find_best_sec(clnt, NFS_SERVER(inode), flavors);
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400231
232out:
233 put_page(page);
Andy Adamson66b06862014-06-12 15:02:32 -0400234 return new;
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400235}
236
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400237static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
238 char *page, char *page2,
239 const struct nfs4_fs_location *location)
240{
Trond Myklebust364d015e52010-04-16 16:22:46 -0400241 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
Trond Myklebust292f5032014-02-16 21:42:56 -0500242 struct net *net = rpc_net_ns(NFS_SB(mountdata->sb)->client);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400243 struct vfsmount *mnt = ERR_PTR(-ENOENT);
244 char *mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400245 unsigned int maxbuflen;
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400246 unsigned int s;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400247
248 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
249 if (IS_ERR(mnt_path))
Trond Myklebust517be092009-10-06 15:42:20 -0400250 return ERR_CAST(mnt_path);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400251 mountdata->mnt_path = mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400252 maxbuflen = mnt_path - 1 - page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400253
Trond Myklebust364d015e52010-04-16 16:22:46 -0400254 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
255 if (mountdata->addr == NULL)
256 return ERR_PTR(-ENOMEM);
257
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400258 for (s = 0; s < location->nservers; s++) {
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400259 const struct nfs4_string *buf = &location->servers[s];
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400260
Trond Myklebustef95d312009-03-10 20:33:17 -0400261 if (buf->len <= 0 || buf->len >= maxbuflen)
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400262 continue;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400263
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400264 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
265 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400266
267 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
Trond Myklebust292f5032014-02-16 21:42:56 -0500268 mountdata->addr, addr_bufsize, net);
Chuck Lever53a0b9c2009-08-09 15:09:36 -0400269 if (mountdata->addrlen == 0)
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400270 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400271
Chuck Leverec6ee612009-08-09 15:09:37 -0400272 rpc_set_port(mountdata->addr, NFS_PORT);
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400273
Trond Myklebustef95d312009-03-10 20:33:17 -0400274 memcpy(page2, buf->data, buf->len);
275 page2[buf->len] = '\0';
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400276 mountdata->hostname = page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400277
278 snprintf(page, PAGE_SIZE, "%s:%s",
279 mountdata->hostname,
280 mountdata->mnt_path);
281
282 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
283 if (!IS_ERR(mnt))
284 break;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400285 }
Trond Myklebust364d015e52010-04-16 16:22:46 -0400286 kfree(mountdata->addr);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400287 return mnt;
288}
289
David Howellsf7b422b2006-06-09 09:34:33 -0400290/**
291 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
David Howellsf7b422b2006-06-09 09:34:33 -0400292 * @dentry - parent directory
Chuck Lever3f43c662007-12-10 14:57:31 -0500293 * @locations - array of NFSv4 server location information
David Howellsf7b422b2006-06-09 09:34:33 -0400294 *
295 */
Al Virof8ad9c42011-03-16 06:32:07 -0400296static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
David Howells509de812006-08-22 20:06:11 -0400297 const struct nfs4_fs_locations *locations)
David Howellsf7b422b2006-06-09 09:34:33 -0400298{
299 struct vfsmount *mnt = ERR_PTR(-ENOENT);
300 struct nfs_clone_mount mountdata = {
Al Virof8ad9c42011-03-16 06:32:07 -0400301 .sb = dentry->d_sb,
David Howellsf7b422b2006-06-09 09:34:33 -0400302 .dentry = dentry,
Al Virof8ad9c42011-03-16 06:32:07 -0400303 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
David Howellsf7b422b2006-06-09 09:34:33 -0400304 };
David Howells54ceac42006-08-22 20:06:13 -0400305 char *page = NULL, *page2 = NULL;
Chuck Lever3f43c662007-12-10 14:57:31 -0500306 int loc, error;
David Howellsf7b422b2006-06-09 09:34:33 -0400307
308 if (locations == NULL || locations->nlocations <= 0)
309 goto out;
310
Al Viro6de14722013-09-16 10:53:17 -0400311 dprintk("%s: referral at %pd2\n", __func__, dentry);
David Howellsf7b422b2006-06-09 09:34:33 -0400312
David Howellsf7b422b2006-06-09 09:34:33 -0400313 page = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400314 if (!page)
David Howellsf7b422b2006-06-09 09:34:33 -0400315 goto out;
David Howells54ceac42006-08-22 20:06:13 -0400316
David Howellsf7b422b2006-06-09 09:34:33 -0400317 page2 = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400318 if (!page2)
David Howellsf7b422b2006-06-09 09:34:33 -0400319 goto out;
320
David Howells54ceac42006-08-22 20:06:13 -0400321 /* Ensure fs path is a prefix of current dentry path */
Al Virob514f872011-03-16 06:26:11 -0400322 error = nfs4_validate_fspath(dentry, locations, page, page2);
David Howells54ceac42006-08-22 20:06:13 -0400323 if (error < 0) {
324 mnt = ERR_PTR(error);
325 goto out;
David Howellsf7b422b2006-06-09 09:34:33 -0400326 }
327
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400328 for (loc = 0; loc < locations->nlocations; loc++) {
David Howells509de812006-08-22 20:06:11 -0400329 const struct nfs4_fs_location *location = &locations->locations[loc];
David Howellsf7b422b2006-06-09 09:34:33 -0400330
331 if (location == NULL || location->nservers <= 0 ||
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400332 location->rootpath.ncomponents == 0)
David Howellsf7b422b2006-06-09 09:34:33 -0400333 continue;
David Howellsf7b422b2006-06-09 09:34:33 -0400334
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400335 mnt = try_location(&mountdata, page, page2, location);
336 if (!IS_ERR(mnt))
337 break;
David Howellsf7b422b2006-06-09 09:34:33 -0400338 }
339
David Howellsf7b422b2006-06-09 09:34:33 -0400340out:
David Howells54ceac42006-08-22 20:06:13 -0400341 free_page((unsigned long) page);
342 free_page((unsigned long) page2);
Harvey Harrison3110ff82008-05-02 13:42:44 -0700343 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400344 return mnt;
345}
346
347/*
348 * nfs_do_refmount - handle crossing a referral on server
349 * @dentry - dentry of referral
David Howellsf7b422b2006-06-09 09:34:33 -0400350 *
351 */
Bryan Schumaker281cad42012-04-27 13:27:45 -0400352static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
David Howellsf7b422b2006-06-09 09:34:33 -0400353{
David Howells54ceac42006-08-22 20:06:13 -0400354 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
David Howellsf7b422b2006-06-09 09:34:33 -0400355 struct dentry *parent;
356 struct nfs4_fs_locations *fs_locations = NULL;
357 struct page *page;
358 int err;
359
360 /* BUG_ON(IS_ROOT(dentry)); */
Harvey Harrison3110ff82008-05-02 13:42:44 -0700361 dprintk("%s: enter\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400362
363 page = alloc_page(GFP_KERNEL);
364 if (page == NULL)
365 goto out;
366
367 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
368 if (fs_locations == NULL)
369 goto out_free;
370
371 /* Get locations */
David Howells54ceac42006-08-22 20:06:13 -0400372 mnt = ERR_PTR(-ENOENT);
373
David Howellsf7b422b2006-06-09 09:34:33 -0400374 parent = dget_parent(dentry);
Al Viro6de14722013-09-16 10:53:17 -0400375 dprintk("%s: getting locations for %pd2\n",
376 __func__, dentry);
David Howells54ceac42006-08-22 20:06:13 -0400377
Bryan Schumakerf05d1472012-04-27 13:27:41 -0400378 err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page);
David Howellsf7b422b2006-06-09 09:34:33 -0400379 dput(parent);
David Howells54ceac42006-08-22 20:06:13 -0400380 if (err != 0 ||
381 fs_locations->nlocations <= 0 ||
David Howellsf7b422b2006-06-09 09:34:33 -0400382 fs_locations->fs_path.ncomponents <= 0)
383 goto out_free;
384
Al Virof8ad9c42011-03-16 06:32:07 -0400385 mnt = nfs_follow_referral(dentry, fs_locations);
David Howellsf7b422b2006-06-09 09:34:33 -0400386out_free:
387 __free_page(page);
388 kfree(fs_locations);
389out:
Harvey Harrison3110ff82008-05-02 13:42:44 -0700390 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400391 return mnt;
392}
Bryan Schumaker281cad42012-04-27 13:27:45 -0400393
394struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
395 struct nfs_fh *fh, struct nfs_fattr *fattr)
396{
Trond Myklebust47040da2013-09-07 16:01:07 -0400397 rpc_authflavor_t flavor = server->client->cl_auth->au_flavor;
Bryan Schumaker281cad42012-04-27 13:27:45 -0400398 struct dentry *parent = dget_parent(dentry);
Trond Myklebust47040da2013-09-07 16:01:07 -0400399 struct inode *dir = parent->d_inode;
400 struct qstr *name = &dentry->d_name;
Bryan Schumaker281cad42012-04-27 13:27:45 -0400401 struct rpc_clnt *client;
402 struct vfsmount *mnt;
403
404 /* Look it up again to get its attributes and sec flavor */
Trond Myklebust47040da2013-09-07 16:01:07 -0400405 client = nfs4_proc_lookup_mountpoint(dir, name, fh, fattr);
Bryan Schumaker281cad42012-04-27 13:27:45 -0400406 dput(parent);
407 if (IS_ERR(client))
408 return ERR_CAST(client);
409
Trond Myklebust47040da2013-09-07 16:01:07 -0400410 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
Bryan Schumaker281cad42012-04-27 13:27:45 -0400411 mnt = nfs_do_refmount(client, dentry);
Trond Myklebust47040da2013-09-07 16:01:07 -0400412 goto out;
413 }
Bryan Schumaker281cad42012-04-27 13:27:45 -0400414
Trond Myklebust47040da2013-09-07 16:01:07 -0400415 if (client->cl_auth->au_flavor != flavor)
416 flavor = client->cl_auth->au_flavor;
Trond Myklebust47040da2013-09-07 16:01:07 -0400417 mnt = nfs_do_submount(dentry, fh, fattr, flavor);
418out:
Bryan Schumaker281cad42012-04-27 13:27:45 -0400419 rpc_shutdown_client(client);
420 return mnt;
421}
Chuck Lever800c06a2013-10-17 14:12:34 -0400422
423/*
424 * Try one location from the fs_locations array.
425 *
426 * Returns zero on success, or a negative errno value.
427 */
428static int nfs4_try_replacing_one_location(struct nfs_server *server,
429 char *page, char *page2,
430 const struct nfs4_fs_location *location)
431{
432 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
Trond Myklebust292f5032014-02-16 21:42:56 -0500433 struct net *net = rpc_net_ns(server->client);
Chuck Lever800c06a2013-10-17 14:12:34 -0400434 struct sockaddr *sap;
435 unsigned int s;
436 size_t salen;
437 int error;
438
439 sap = kmalloc(addr_bufsize, GFP_KERNEL);
440 if (sap == NULL)
441 return -ENOMEM;
442
443 error = -ENOENT;
444 for (s = 0; s < location->nservers; s++) {
445 const struct nfs4_string *buf = &location->servers[s];
446 char *hostname;
447
448 if (buf->len <= 0 || buf->len > PAGE_SIZE)
449 continue;
450
451 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len) != NULL)
452 continue;
453
454 salen = nfs_parse_server_name(buf->data, buf->len,
Trond Myklebust292f5032014-02-16 21:42:56 -0500455 sap, addr_bufsize, net);
Chuck Lever800c06a2013-10-17 14:12:34 -0400456 if (salen == 0)
457 continue;
458 rpc_set_port(sap, NFS_PORT);
459
460 error = -ENOMEM;
461 hostname = kstrndup(buf->data, buf->len, GFP_KERNEL);
462 if (hostname == NULL)
463 break;
464
Trond Myklebust292f5032014-02-16 21:42:56 -0500465 error = nfs4_update_server(server, hostname, sap, salen, net);
Chuck Lever800c06a2013-10-17 14:12:34 -0400466 kfree(hostname);
467 if (error == 0)
468 break;
469 }
470
471 kfree(sap);
472 return error;
473}
474
475/**
476 * nfs4_replace_transport - set up transport to destination server
477 *
478 * @server: export being migrated
479 * @locations: fs_locations array
480 *
481 * Returns zero on success, or a negative errno value.
482 *
483 * The client tries all the entries in the "locations" array, in the
484 * order returned by the server, until one works or the end of the
485 * array is reached.
486 */
487int nfs4_replace_transport(struct nfs_server *server,
488 const struct nfs4_fs_locations *locations)
489{
490 char *page = NULL, *page2 = NULL;
491 int loc, error;
492
493 error = -ENOENT;
494 if (locations == NULL || locations->nlocations <= 0)
495 goto out;
496
497 error = -ENOMEM;
498 page = (char *) __get_free_page(GFP_USER);
499 if (!page)
500 goto out;
501 page2 = (char *) __get_free_page(GFP_USER);
502 if (!page2)
503 goto out;
504
505 for (loc = 0; loc < locations->nlocations; loc++) {
506 const struct nfs4_fs_location *location =
507 &locations->locations[loc];
508
509 if (location == NULL || location->nservers <= 0 ||
510 location->rootpath.ncomponents == 0)
511 continue;
512
513 error = nfs4_try_replacing_one_location(server, page,
514 page2, location);
515 if (error == 0)
516 break;
517 }
518
519out:
520 free_page((unsigned long)page);
521 free_page((unsigned long)page2);
522 return error;
523}