xref: /linux/fs/nfs/super.c (revision 092e0e7e520a1fca03e13c9f2d157432a8657ff2)
1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/stats.h>
35 #include <linux/sunrpc/metrics.h>
36 #include <linux/sunrpc/xprtsock.h>
37 #include <linux/sunrpc/xprtrdma.h>
38 #include <linux/nfs_fs.h>
39 #include <linux/nfs_mount.h>
40 #include <linux/nfs4_mount.h>
41 #include <linux/lockd/bind.h>
42 #include <linux/smp_lock.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/mnt_namespace.h>
46 #include <linux/namei.h>
47 #include <linux/nfs_idmap.h>
48 #include <linux/vfs.h>
49 #include <linux/inet.h>
50 #include <linux/in6.h>
51 #include <linux/slab.h>
52 #include <net/ipv6.h>
53 #include <linux/netdevice.h>
54 #include <linux/nfs_xdr.h>
55 #include <linux/magic.h>
56 #include <linux/parser.h>
57 
58 #include <asm/system.h>
59 #include <asm/uaccess.h>
60 
61 #include "nfs4_fs.h"
62 #include "callback.h"
63 #include "delegation.h"
64 #include "iostat.h"
65 #include "internal.h"
66 #include "fscache.h"
67 
68 #define NFSDBG_FACILITY		NFSDBG_VFS
69 
70 enum {
71 	/* Mount options that take no arguments */
72 	Opt_soft, Opt_hard,
73 	Opt_posix, Opt_noposix,
74 	Opt_cto, Opt_nocto,
75 	Opt_ac, Opt_noac,
76 	Opt_lock, Opt_nolock,
77 	Opt_v2, Opt_v3, Opt_v4,
78 	Opt_udp, Opt_tcp, Opt_rdma,
79 	Opt_acl, Opt_noacl,
80 	Opt_rdirplus, Opt_nordirplus,
81 	Opt_sharecache, Opt_nosharecache,
82 	Opt_resvport, Opt_noresvport,
83 	Opt_fscache, Opt_nofscache,
84 
85 	/* Mount options that take integer arguments */
86 	Opt_port,
87 	Opt_rsize, Opt_wsize, Opt_bsize,
88 	Opt_timeo, Opt_retrans,
89 	Opt_acregmin, Opt_acregmax,
90 	Opt_acdirmin, Opt_acdirmax,
91 	Opt_actimeo,
92 	Opt_namelen,
93 	Opt_mountport,
94 	Opt_mountvers,
95 	Opt_nfsvers,
96 	Opt_minorversion,
97 
98 	/* Mount options that take string arguments */
99 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
100 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
101 	Opt_lookupcache,
102 	Opt_fscache_uniq,
103 
104 	/* Special mount options */
105 	Opt_userspace, Opt_deprecated, Opt_sloppy,
106 
107 	Opt_err
108 };
109 
110 static const match_table_t nfs_mount_option_tokens = {
111 	{ Opt_userspace, "bg" },
112 	{ Opt_userspace, "fg" },
113 	{ Opt_userspace, "retry=%s" },
114 
115 	{ Opt_sloppy, "sloppy" },
116 
117 	{ Opt_soft, "soft" },
118 	{ Opt_hard, "hard" },
119 	{ Opt_deprecated, "intr" },
120 	{ Opt_deprecated, "nointr" },
121 	{ Opt_posix, "posix" },
122 	{ Opt_noposix, "noposix" },
123 	{ Opt_cto, "cto" },
124 	{ Opt_nocto, "nocto" },
125 	{ Opt_ac, "ac" },
126 	{ Opt_noac, "noac" },
127 	{ Opt_lock, "lock" },
128 	{ Opt_nolock, "nolock" },
129 	{ Opt_v2, "v2" },
130 	{ Opt_v3, "v3" },
131 	{ Opt_v4, "v4" },
132 	{ Opt_udp, "udp" },
133 	{ Opt_tcp, "tcp" },
134 	{ Opt_rdma, "rdma" },
135 	{ Opt_acl, "acl" },
136 	{ Opt_noacl, "noacl" },
137 	{ Opt_rdirplus, "rdirplus" },
138 	{ Opt_nordirplus, "nordirplus" },
139 	{ Opt_sharecache, "sharecache" },
140 	{ Opt_nosharecache, "nosharecache" },
141 	{ Opt_resvport, "resvport" },
142 	{ Opt_noresvport, "noresvport" },
143 	{ Opt_fscache, "fsc" },
144 	{ Opt_nofscache, "nofsc" },
145 
146 	{ Opt_port, "port=%s" },
147 	{ Opt_rsize, "rsize=%s" },
148 	{ Opt_wsize, "wsize=%s" },
149 	{ Opt_bsize, "bsize=%s" },
150 	{ Opt_timeo, "timeo=%s" },
151 	{ Opt_retrans, "retrans=%s" },
152 	{ Opt_acregmin, "acregmin=%s" },
153 	{ Opt_acregmax, "acregmax=%s" },
154 	{ Opt_acdirmin, "acdirmin=%s" },
155 	{ Opt_acdirmax, "acdirmax=%s" },
156 	{ Opt_actimeo, "actimeo=%s" },
157 	{ Opt_namelen, "namlen=%s" },
158 	{ Opt_mountport, "mountport=%s" },
159 	{ Opt_mountvers, "mountvers=%s" },
160 	{ Opt_nfsvers, "nfsvers=%s" },
161 	{ Opt_nfsvers, "vers=%s" },
162 	{ Opt_minorversion, "minorversion=%s" },
163 
164 	{ Opt_sec, "sec=%s" },
165 	{ Opt_proto, "proto=%s" },
166 	{ Opt_mountproto, "mountproto=%s" },
167 	{ Opt_addr, "addr=%s" },
168 	{ Opt_clientaddr, "clientaddr=%s" },
169 	{ Opt_mounthost, "mounthost=%s" },
170 	{ Opt_mountaddr, "mountaddr=%s" },
171 
172 	{ Opt_lookupcache, "lookupcache=%s" },
173 	{ Opt_fscache_uniq, "fsc=%s" },
174 
175 	{ Opt_err, NULL }
176 };
177 
178 enum {
179 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
180 
181 	Opt_xprt_err
182 };
183 
184 static const match_table_t nfs_xprt_protocol_tokens = {
185 	{ Opt_xprt_udp, "udp" },
186 	{ Opt_xprt_udp6, "udp6" },
187 	{ Opt_xprt_tcp, "tcp" },
188 	{ Opt_xprt_tcp6, "tcp6" },
189 	{ Opt_xprt_rdma, "rdma" },
190 
191 	{ Opt_xprt_err, NULL }
192 };
193 
194 enum {
195 	Opt_sec_none, Opt_sec_sys,
196 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
197 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
198 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
199 
200 	Opt_sec_err
201 };
202 
203 static const match_table_t nfs_secflavor_tokens = {
204 	{ Opt_sec_none, "none" },
205 	{ Opt_sec_none, "null" },
206 	{ Opt_sec_sys, "sys" },
207 
208 	{ Opt_sec_krb5, "krb5" },
209 	{ Opt_sec_krb5i, "krb5i" },
210 	{ Opt_sec_krb5p, "krb5p" },
211 
212 	{ Opt_sec_lkey, "lkey" },
213 	{ Opt_sec_lkeyi, "lkeyi" },
214 	{ Opt_sec_lkeyp, "lkeyp" },
215 
216 	{ Opt_sec_spkm, "spkm3" },
217 	{ Opt_sec_spkmi, "spkm3i" },
218 	{ Opt_sec_spkmp, "spkm3p" },
219 
220 	{ Opt_sec_err, NULL }
221 };
222 
223 enum {
224 	Opt_lookupcache_all, Opt_lookupcache_positive,
225 	Opt_lookupcache_none,
226 
227 	Opt_lookupcache_err
228 };
229 
230 static match_table_t nfs_lookupcache_tokens = {
231 	{ Opt_lookupcache_all, "all" },
232 	{ Opt_lookupcache_positive, "pos" },
233 	{ Opt_lookupcache_positive, "positive" },
234 	{ Opt_lookupcache_none, "none" },
235 
236 	{ Opt_lookupcache_err, NULL }
237 };
238 
239 
240 static void nfs_umount_begin(struct super_block *);
241 static int  nfs_statfs(struct dentry *, struct kstatfs *);
242 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
243 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
244 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
245 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
246 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
247 static void nfs_put_super(struct super_block *);
248 static void nfs_kill_super(struct super_block *);
249 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
250 
251 static struct file_system_type nfs_fs_type = {
252 	.owner		= THIS_MODULE,
253 	.name		= "nfs",
254 	.get_sb		= nfs_get_sb,
255 	.kill_sb	= nfs_kill_super,
256 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
257 };
258 
259 struct file_system_type nfs_xdev_fs_type = {
260 	.owner		= THIS_MODULE,
261 	.name		= "nfs",
262 	.get_sb		= nfs_xdev_get_sb,
263 	.kill_sb	= nfs_kill_super,
264 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
265 };
266 
267 static const struct super_operations nfs_sops = {
268 	.alloc_inode	= nfs_alloc_inode,
269 	.destroy_inode	= nfs_destroy_inode,
270 	.write_inode	= nfs_write_inode,
271 	.put_super	= nfs_put_super,
272 	.statfs		= nfs_statfs,
273 	.evict_inode	= nfs_evict_inode,
274 	.umount_begin	= nfs_umount_begin,
275 	.show_options	= nfs_show_options,
276 	.show_stats	= nfs_show_stats,
277 	.remount_fs	= nfs_remount,
278 };
279 
280 #ifdef CONFIG_NFS_V4
281 static int nfs4_validate_text_mount_data(void *options,
282 	struct nfs_parsed_mount_data *args, const char *dev_name);
283 static int nfs4_try_mount(int flags, const char *dev_name,
284 	struct nfs_parsed_mount_data *data, struct vfsmount *mnt);
285 static int nfs4_get_sb(struct file_system_type *fs_type,
286 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
287 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
288 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
289 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
290 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
291 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
292 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
293 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
294 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
295 static void nfs4_kill_super(struct super_block *sb);
296 
297 static struct file_system_type nfs4_fs_type = {
298 	.owner		= THIS_MODULE,
299 	.name		= "nfs4",
300 	.get_sb		= nfs4_get_sb,
301 	.kill_sb	= nfs4_kill_super,
302 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
303 };
304 
305 static struct file_system_type nfs4_remote_fs_type = {
306 	.owner		= THIS_MODULE,
307 	.name		= "nfs4",
308 	.get_sb		= nfs4_remote_get_sb,
309 	.kill_sb	= nfs4_kill_super,
310 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
311 };
312 
313 struct file_system_type nfs4_xdev_fs_type = {
314 	.owner		= THIS_MODULE,
315 	.name		= "nfs4",
316 	.get_sb		= nfs4_xdev_get_sb,
317 	.kill_sb	= nfs4_kill_super,
318 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
319 };
320 
321 static struct file_system_type nfs4_remote_referral_fs_type = {
322 	.owner		= THIS_MODULE,
323 	.name		= "nfs4",
324 	.get_sb		= nfs4_remote_referral_get_sb,
325 	.kill_sb	= nfs4_kill_super,
326 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
327 };
328 
329 struct file_system_type nfs4_referral_fs_type = {
330 	.owner		= THIS_MODULE,
331 	.name		= "nfs4",
332 	.get_sb		= nfs4_referral_get_sb,
333 	.kill_sb	= nfs4_kill_super,
334 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
335 };
336 
337 static const struct super_operations nfs4_sops = {
338 	.alloc_inode	= nfs_alloc_inode,
339 	.destroy_inode	= nfs_destroy_inode,
340 	.write_inode	= nfs_write_inode,
341 	.put_super	= nfs_put_super,
342 	.statfs		= nfs_statfs,
343 	.evict_inode	= nfs4_evict_inode,
344 	.umount_begin	= nfs_umount_begin,
345 	.show_options	= nfs_show_options,
346 	.show_stats	= nfs_show_stats,
347 	.remount_fs	= nfs_remount,
348 };
349 #endif
350 
351 static struct shrinker acl_shrinker = {
352 	.shrink		= nfs_access_cache_shrinker,
353 	.seeks		= DEFAULT_SEEKS,
354 };
355 
356 /*
357  * Register the NFS filesystems
358  */
359 int __init register_nfs_fs(void)
360 {
361 	int ret;
362 
363         ret = register_filesystem(&nfs_fs_type);
364 	if (ret < 0)
365 		goto error_0;
366 
367 	ret = nfs_register_sysctl();
368 	if (ret < 0)
369 		goto error_1;
370 #ifdef CONFIG_NFS_V4
371 	ret = register_filesystem(&nfs4_fs_type);
372 	if (ret < 0)
373 		goto error_2;
374 #endif
375 	register_shrinker(&acl_shrinker);
376 	return 0;
377 
378 #ifdef CONFIG_NFS_V4
379 error_2:
380 	nfs_unregister_sysctl();
381 #endif
382 error_1:
383 	unregister_filesystem(&nfs_fs_type);
384 error_0:
385 	return ret;
386 }
387 
388 /*
389  * Unregister the NFS filesystems
390  */
391 void __exit unregister_nfs_fs(void)
392 {
393 	unregister_shrinker(&acl_shrinker);
394 #ifdef CONFIG_NFS_V4
395 	unregister_filesystem(&nfs4_fs_type);
396 #endif
397 	nfs_unregister_sysctl();
398 	unregister_filesystem(&nfs_fs_type);
399 }
400 
401 void nfs_sb_active(struct super_block *sb)
402 {
403 	struct nfs_server *server = NFS_SB(sb);
404 
405 	if (atomic_inc_return(&server->active) == 1)
406 		atomic_inc(&sb->s_active);
407 }
408 
409 void nfs_sb_deactive(struct super_block *sb)
410 {
411 	struct nfs_server *server = NFS_SB(sb);
412 
413 	if (atomic_dec_and_test(&server->active))
414 		deactivate_super(sb);
415 }
416 
417 /*
418  * Deliver file system statistics to userspace
419  */
420 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
421 {
422 	struct nfs_server *server = NFS_SB(dentry->d_sb);
423 	unsigned char blockbits;
424 	unsigned long blockres;
425 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
426 	struct nfs_fsstat res;
427 	int error = -ENOMEM;
428 
429 	res.fattr = nfs_alloc_fattr();
430 	if (res.fattr == NULL)
431 		goto out_err;
432 
433 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
434 	if (unlikely(error == -ESTALE)) {
435 		struct dentry *pd_dentry;
436 
437 		pd_dentry = dget_parent(dentry);
438 		if (pd_dentry != NULL) {
439 			nfs_zap_caches(pd_dentry->d_inode);
440 			dput(pd_dentry);
441 		}
442 	}
443 	nfs_free_fattr(res.fattr);
444 	if (error < 0)
445 		goto out_err;
446 
447 	buf->f_type = NFS_SUPER_MAGIC;
448 
449 	/*
450 	 * Current versions of glibc do not correctly handle the
451 	 * case where f_frsize != f_bsize.  Eventually we want to
452 	 * report the value of wtmult in this field.
453 	 */
454 	buf->f_frsize = dentry->d_sb->s_blocksize;
455 
456 	/*
457 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
458 	 * are reported in units of f_frsize.  Linux hasn't had
459 	 * an f_frsize field in its statfs struct until recently,
460 	 * thus historically Linux's sys_statfs reports these
461 	 * fields in units of f_bsize.
462 	 */
463 	buf->f_bsize = dentry->d_sb->s_blocksize;
464 	blockbits = dentry->d_sb->s_blocksize_bits;
465 	blockres = (1 << blockbits) - 1;
466 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
467 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
468 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
469 
470 	buf->f_files = res.tfiles;
471 	buf->f_ffree = res.afiles;
472 
473 	buf->f_namelen = server->namelen;
474 
475 	return 0;
476 
477  out_err:
478 	dprintk("%s: statfs error = %d\n", __func__, -error);
479 	return error;
480 }
481 
482 /*
483  * Map the security flavour number to a name
484  */
485 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
486 {
487 	static const struct {
488 		rpc_authflavor_t flavour;
489 		const char *str;
490 	} sec_flavours[] = {
491 		{ RPC_AUTH_NULL, "null" },
492 		{ RPC_AUTH_UNIX, "sys" },
493 		{ RPC_AUTH_GSS_KRB5, "krb5" },
494 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
495 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
496 		{ RPC_AUTH_GSS_LKEY, "lkey" },
497 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
498 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
499 		{ RPC_AUTH_GSS_SPKM, "spkm" },
500 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
501 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
502 		{ UINT_MAX, "unknown" }
503 	};
504 	int i;
505 
506 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
507 		if (sec_flavours[i].flavour == flavour)
508 			break;
509 	}
510 	return sec_flavours[i].str;
511 }
512 
513 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
514 				  int showdefaults)
515 {
516 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
517 
518 	seq_printf(m, ",mountproto=");
519 	switch (sap->sa_family) {
520 	case AF_INET:
521 		switch (nfss->mountd_protocol) {
522 		case IPPROTO_UDP:
523 			seq_printf(m, RPCBIND_NETID_UDP);
524 			break;
525 		case IPPROTO_TCP:
526 			seq_printf(m, RPCBIND_NETID_TCP);
527 			break;
528 		default:
529 			if (showdefaults)
530 				seq_printf(m, "auto");
531 		}
532 		break;
533 	case AF_INET6:
534 		switch (nfss->mountd_protocol) {
535 		case IPPROTO_UDP:
536 			seq_printf(m, RPCBIND_NETID_UDP6);
537 			break;
538 		case IPPROTO_TCP:
539 			seq_printf(m, RPCBIND_NETID_TCP6);
540 			break;
541 		default:
542 			if (showdefaults)
543 				seq_printf(m, "auto");
544 		}
545 		break;
546 	default:
547 		if (showdefaults)
548 			seq_printf(m, "auto");
549 	}
550 }
551 
552 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
553 				    int showdefaults)
554 {
555 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
556 
557 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
558 		return;
559 
560 	switch (sap->sa_family) {
561 	case AF_INET: {
562 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
563 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
564 		break;
565 	}
566 	case AF_INET6: {
567 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
568 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
569 		break;
570 	}
571 	default:
572 		if (showdefaults)
573 			seq_printf(m, ",mountaddr=unspecified");
574 	}
575 
576 	if (nfss->mountd_version || showdefaults)
577 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
578 	if (nfss->mountd_port || showdefaults)
579 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
580 
581 	nfs_show_mountd_netid(m, nfss, showdefaults);
582 }
583 
584 #ifdef CONFIG_NFS_V4
585 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
586 				    int showdefaults)
587 {
588 	struct nfs_client *clp = nfss->nfs_client;
589 
590 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
591 	seq_printf(m, ",minorversion=%u", clp->cl_minorversion);
592 }
593 #else
594 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
595 				    int showdefaults)
596 {
597 }
598 #endif
599 
600 /*
601  * Describe the mount options in force on this server representation
602  */
603 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
604 				   int showdefaults)
605 {
606 	static const struct proc_nfs_info {
607 		int flag;
608 		const char *str;
609 		const char *nostr;
610 	} nfs_info[] = {
611 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
612 		{ NFS_MOUNT_POSIX, ",posix", "" },
613 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
614 		{ NFS_MOUNT_NOAC, ",noac", "" },
615 		{ NFS_MOUNT_NONLM, ",nolock", "" },
616 		{ NFS_MOUNT_NOACL, ",noacl", "" },
617 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
618 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
619 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
620 		{ 0, NULL, NULL }
621 	};
622 	const struct proc_nfs_info *nfs_infop;
623 	struct nfs_client *clp = nfss->nfs_client;
624 	u32 version = clp->rpc_ops->version;
625 
626 	seq_printf(m, ",vers=%u", version);
627 	seq_printf(m, ",rsize=%u", nfss->rsize);
628 	seq_printf(m, ",wsize=%u", nfss->wsize);
629 	if (nfss->bsize != 0)
630 		seq_printf(m, ",bsize=%u", nfss->bsize);
631 	seq_printf(m, ",namlen=%u", nfss->namelen);
632 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
633 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
634 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
635 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
636 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
637 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
638 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
639 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
640 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
641 		if (nfss->flags & nfs_infop->flag)
642 			seq_puts(m, nfs_infop->str);
643 		else
644 			seq_puts(m, nfs_infop->nostr);
645 	}
646 	seq_printf(m, ",proto=%s",
647 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
648 	if (version == 4) {
649 		if (nfss->port != NFS_PORT)
650 			seq_printf(m, ",port=%u", nfss->port);
651 	} else
652 		if (nfss->port)
653 			seq_printf(m, ",port=%u", nfss->port);
654 
655 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
656 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
657 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
658 
659 	if (version != 4)
660 		nfs_show_mountd_options(m, nfss, showdefaults);
661 	else
662 		nfs_show_nfsv4_options(m, nfss, showdefaults);
663 
664 	if (nfss->options & NFS_OPTION_FSCACHE)
665 		seq_printf(m, ",fsc");
666 
667 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
668 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
669 			seq_printf(m, ",lookupcache=none");
670 		else
671 			seq_printf(m, ",lookupcache=pos");
672 	}
673 }
674 
675 /*
676  * Describe the mount options on this VFS mountpoint
677  */
678 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
679 {
680 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
681 
682 	nfs_show_mount_options(m, nfss, 0);
683 
684 	seq_printf(m, ",addr=%s",
685 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
686 							RPC_DISPLAY_ADDR));
687 
688 	return 0;
689 }
690 
691 /*
692  * Present statistical information for this VFS mountpoint
693  */
694 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
695 {
696 	int i, cpu;
697 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
698 	struct rpc_auth *auth = nfss->client->cl_auth;
699 	struct nfs_iostats totals = { };
700 
701 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
702 
703 	/*
704 	 * Display all mount option settings
705 	 */
706 	seq_printf(m, "\n\topts:\t");
707 	seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
708 	seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
709 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
710 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
711 	nfs_show_mount_options(m, nfss, 1);
712 
713 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
714 
715 	seq_printf(m, "\n\tcaps:\t");
716 	seq_printf(m, "caps=0x%x", nfss->caps);
717 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
718 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
719 	seq_printf(m, ",bsize=%u", nfss->bsize);
720 	seq_printf(m, ",namlen=%u", nfss->namelen);
721 
722 #ifdef CONFIG_NFS_V4
723 	if (nfss->nfs_client->rpc_ops->version == 4) {
724 		seq_printf(m, "\n\tnfsv4:\t");
725 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
726 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
727 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
728 	}
729 #endif
730 
731 	/*
732 	 * Display security flavor in effect for this mount
733 	 */
734 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
735 	if (auth->au_flavor)
736 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
737 
738 	/*
739 	 * Display superblock I/O counters
740 	 */
741 	for_each_possible_cpu(cpu) {
742 		struct nfs_iostats *stats;
743 
744 		preempt_disable();
745 		stats = per_cpu_ptr(nfss->io_stats, cpu);
746 
747 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
748 			totals.events[i] += stats->events[i];
749 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
750 			totals.bytes[i] += stats->bytes[i];
751 #ifdef CONFIG_NFS_FSCACHE
752 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
753 			totals.fscache[i] += stats->fscache[i];
754 #endif
755 
756 		preempt_enable();
757 	}
758 
759 	seq_printf(m, "\n\tevents:\t");
760 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
761 		seq_printf(m, "%lu ", totals.events[i]);
762 	seq_printf(m, "\n\tbytes:\t");
763 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
764 		seq_printf(m, "%Lu ", totals.bytes[i]);
765 #ifdef CONFIG_NFS_FSCACHE
766 	if (nfss->options & NFS_OPTION_FSCACHE) {
767 		seq_printf(m, "\n\tfsc:\t");
768 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
769 			seq_printf(m, "%Lu ", totals.bytes[i]);
770 	}
771 #endif
772 	seq_printf(m, "\n");
773 
774 	rpc_print_iostats(m, nfss->client);
775 
776 	return 0;
777 }
778 
779 /*
780  * Begin unmount by attempting to remove all automounted mountpoints we added
781  * in response to xdev traversals and referrals
782  */
783 static void nfs_umount_begin(struct super_block *sb)
784 {
785 	struct nfs_server *server;
786 	struct rpc_clnt *rpc;
787 
788 	server = NFS_SB(sb);
789 	/* -EIO all pending I/O */
790 	rpc = server->client_acl;
791 	if (!IS_ERR(rpc))
792 		rpc_killall_tasks(rpc);
793 	rpc = server->client;
794 	if (!IS_ERR(rpc))
795 		rpc_killall_tasks(rpc);
796 }
797 
798 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
799 {
800 	struct nfs_parsed_mount_data *data;
801 
802 	data = kzalloc(sizeof(*data), GFP_KERNEL);
803 	if (data) {
804 		data->acregmin		= NFS_DEF_ACREGMIN;
805 		data->acregmax		= NFS_DEF_ACREGMAX;
806 		data->acdirmin		= NFS_DEF_ACDIRMIN;
807 		data->acdirmax		= NFS_DEF_ACDIRMAX;
808 		data->mount_server.port	= NFS_UNSPEC_PORT;
809 		data->nfs_server.port	= NFS_UNSPEC_PORT;
810 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
811 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
812 		data->auth_flavor_len	= 1;
813 		data->version		= version;
814 		data->minorversion	= 0;
815 	}
816 	return data;
817 }
818 
819 /*
820  * Sanity-check a server address provided by the mount command.
821  *
822  * Address family must be initialized, and address must not be
823  * the ANY address for that family.
824  */
825 static int nfs_verify_server_address(struct sockaddr *addr)
826 {
827 	switch (addr->sa_family) {
828 	case AF_INET: {
829 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
830 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
831 	}
832 	case AF_INET6: {
833 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
834 		return !ipv6_addr_any(sa);
835 	}
836 	}
837 
838 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
839 	return 0;
840 }
841 
842 /*
843  * Select between a default port value and a user-specified port value.
844  * If a zero value is set, then autobind will be used.
845  */
846 static void nfs_set_port(struct sockaddr *sap, int *port,
847 				 const unsigned short default_port)
848 {
849 	if (*port == NFS_UNSPEC_PORT)
850 		*port = default_port;
851 
852 	rpc_set_port(sap, *port);
853 }
854 
855 /*
856  * Sanity check the NFS transport protocol.
857  *
858  */
859 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
860 {
861 	switch (mnt->nfs_server.protocol) {
862 	case XPRT_TRANSPORT_UDP:
863 	case XPRT_TRANSPORT_TCP:
864 	case XPRT_TRANSPORT_RDMA:
865 		break;
866 	default:
867 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
868 	}
869 }
870 
871 /*
872  * For text based NFSv2/v3 mounts, the mount protocol transport default
873  * settings should depend upon the specified NFS transport.
874  */
875 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
876 {
877 	nfs_validate_transport_protocol(mnt);
878 
879 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
880 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
881 			return;
882 	switch (mnt->nfs_server.protocol) {
883 	case XPRT_TRANSPORT_UDP:
884 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
885 		break;
886 	case XPRT_TRANSPORT_TCP:
887 	case XPRT_TRANSPORT_RDMA:
888 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
889 	}
890 }
891 
892 /*
893  * Parse the value of the 'sec=' option.
894  */
895 static int nfs_parse_security_flavors(char *value,
896 				      struct nfs_parsed_mount_data *mnt)
897 {
898 	substring_t args[MAX_OPT_ARGS];
899 
900 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
901 
902 	switch (match_token(value, nfs_secflavor_tokens, args)) {
903 	case Opt_sec_none:
904 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
905 		break;
906 	case Opt_sec_sys:
907 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
908 		break;
909 	case Opt_sec_krb5:
910 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
911 		break;
912 	case Opt_sec_krb5i:
913 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
914 		break;
915 	case Opt_sec_krb5p:
916 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
917 		break;
918 	case Opt_sec_lkey:
919 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
920 		break;
921 	case Opt_sec_lkeyi:
922 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
923 		break;
924 	case Opt_sec_lkeyp:
925 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
926 		break;
927 	case Opt_sec_spkm:
928 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
929 		break;
930 	case Opt_sec_spkmi:
931 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
932 		break;
933 	case Opt_sec_spkmp:
934 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
935 		break;
936 	default:
937 		return 0;
938 	}
939 
940 	mnt->auth_flavor_len = 1;
941 	return 1;
942 }
943 
944 /*
945  * Error-check and convert a string of mount options from user space into
946  * a data structure.  The whole mount string is processed; bad options are
947  * skipped as they are encountered.  If there were no errors, return 1;
948  * otherwise return 0 (zero).
949  */
950 static int nfs_parse_mount_options(char *raw,
951 				   struct nfs_parsed_mount_data *mnt)
952 {
953 	char *p, *string, *secdata;
954 	int rc, sloppy = 0, invalid_option = 0;
955 	unsigned short protofamily = AF_UNSPEC;
956 	unsigned short mountfamily = AF_UNSPEC;
957 
958 	if (!raw) {
959 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
960 		return 1;
961 	}
962 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
963 
964 	secdata = alloc_secdata();
965 	if (!secdata)
966 		goto out_nomem;
967 
968 	rc = security_sb_copy_data(raw, secdata);
969 	if (rc)
970 		goto out_security_failure;
971 
972 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
973 	if (rc)
974 		goto out_security_failure;
975 
976 	free_secdata(secdata);
977 
978 	while ((p = strsep(&raw, ",")) != NULL) {
979 		substring_t args[MAX_OPT_ARGS];
980 		unsigned long option;
981 		int token;
982 
983 		if (!*p)
984 			continue;
985 
986 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
987 
988 		token = match_token(p, nfs_mount_option_tokens, args);
989 		switch (token) {
990 
991 		/*
992 		 * boolean options:  foo/nofoo
993 		 */
994 		case Opt_soft:
995 			mnt->flags |= NFS_MOUNT_SOFT;
996 			break;
997 		case Opt_hard:
998 			mnt->flags &= ~NFS_MOUNT_SOFT;
999 			break;
1000 		case Opt_posix:
1001 			mnt->flags |= NFS_MOUNT_POSIX;
1002 			break;
1003 		case Opt_noposix:
1004 			mnt->flags &= ~NFS_MOUNT_POSIX;
1005 			break;
1006 		case Opt_cto:
1007 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1008 			break;
1009 		case Opt_nocto:
1010 			mnt->flags |= NFS_MOUNT_NOCTO;
1011 			break;
1012 		case Opt_ac:
1013 			mnt->flags &= ~NFS_MOUNT_NOAC;
1014 			break;
1015 		case Opt_noac:
1016 			mnt->flags |= NFS_MOUNT_NOAC;
1017 			break;
1018 		case Opt_lock:
1019 			mnt->flags &= ~NFS_MOUNT_NONLM;
1020 			break;
1021 		case Opt_nolock:
1022 			mnt->flags |= NFS_MOUNT_NONLM;
1023 			break;
1024 		case Opt_v2:
1025 			mnt->flags &= ~NFS_MOUNT_VER3;
1026 			mnt->version = 2;
1027 			break;
1028 		case Opt_v3:
1029 			mnt->flags |= NFS_MOUNT_VER3;
1030 			mnt->version = 3;
1031 			break;
1032 #ifdef CONFIG_NFS_V4
1033 		case Opt_v4:
1034 			mnt->flags &= ~NFS_MOUNT_VER3;
1035 			mnt->version = 4;
1036 			break;
1037 #endif
1038 		case Opt_udp:
1039 			mnt->flags &= ~NFS_MOUNT_TCP;
1040 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1041 			break;
1042 		case Opt_tcp:
1043 			mnt->flags |= NFS_MOUNT_TCP;
1044 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1045 			break;
1046 		case Opt_rdma:
1047 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1048 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1049 			xprt_load_transport(p);
1050 			break;
1051 		case Opt_acl:
1052 			mnt->flags &= ~NFS_MOUNT_NOACL;
1053 			break;
1054 		case Opt_noacl:
1055 			mnt->flags |= NFS_MOUNT_NOACL;
1056 			break;
1057 		case Opt_rdirplus:
1058 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1059 			break;
1060 		case Opt_nordirplus:
1061 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1062 			break;
1063 		case Opt_sharecache:
1064 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1065 			break;
1066 		case Opt_nosharecache:
1067 			mnt->flags |= NFS_MOUNT_UNSHARED;
1068 			break;
1069 		case Opt_resvport:
1070 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1071 			break;
1072 		case Opt_noresvport:
1073 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1074 			break;
1075 		case Opt_fscache:
1076 			mnt->options |= NFS_OPTION_FSCACHE;
1077 			kfree(mnt->fscache_uniq);
1078 			mnt->fscache_uniq = NULL;
1079 			break;
1080 		case Opt_nofscache:
1081 			mnt->options &= ~NFS_OPTION_FSCACHE;
1082 			kfree(mnt->fscache_uniq);
1083 			mnt->fscache_uniq = NULL;
1084 			break;
1085 
1086 		/*
1087 		 * options that take numeric values
1088 		 */
1089 		case Opt_port:
1090 			string = match_strdup(args);
1091 			if (string == NULL)
1092 				goto out_nomem;
1093 			rc = strict_strtoul(string, 10, &option);
1094 			kfree(string);
1095 			if (rc != 0 || option > USHRT_MAX)
1096 				goto out_invalid_value;
1097 			mnt->nfs_server.port = option;
1098 			break;
1099 		case Opt_rsize:
1100 			string = match_strdup(args);
1101 			if (string == NULL)
1102 				goto out_nomem;
1103 			rc = strict_strtoul(string, 10, &option);
1104 			kfree(string);
1105 			if (rc != 0)
1106 				goto out_invalid_value;
1107 			mnt->rsize = option;
1108 			break;
1109 		case Opt_wsize:
1110 			string = match_strdup(args);
1111 			if (string == NULL)
1112 				goto out_nomem;
1113 			rc = strict_strtoul(string, 10, &option);
1114 			kfree(string);
1115 			if (rc != 0)
1116 				goto out_invalid_value;
1117 			mnt->wsize = option;
1118 			break;
1119 		case Opt_bsize:
1120 			string = match_strdup(args);
1121 			if (string == NULL)
1122 				goto out_nomem;
1123 			rc = strict_strtoul(string, 10, &option);
1124 			kfree(string);
1125 			if (rc != 0)
1126 				goto out_invalid_value;
1127 			mnt->bsize = option;
1128 			break;
1129 		case Opt_timeo:
1130 			string = match_strdup(args);
1131 			if (string == NULL)
1132 				goto out_nomem;
1133 			rc = strict_strtoul(string, 10, &option);
1134 			kfree(string);
1135 			if (rc != 0 || option == 0)
1136 				goto out_invalid_value;
1137 			mnt->timeo = option;
1138 			break;
1139 		case Opt_retrans:
1140 			string = match_strdup(args);
1141 			if (string == NULL)
1142 				goto out_nomem;
1143 			rc = strict_strtoul(string, 10, &option);
1144 			kfree(string);
1145 			if (rc != 0 || option == 0)
1146 				goto out_invalid_value;
1147 			mnt->retrans = option;
1148 			break;
1149 		case Opt_acregmin:
1150 			string = match_strdup(args);
1151 			if (string == NULL)
1152 				goto out_nomem;
1153 			rc = strict_strtoul(string, 10, &option);
1154 			kfree(string);
1155 			if (rc != 0)
1156 				goto out_invalid_value;
1157 			mnt->acregmin = option;
1158 			break;
1159 		case Opt_acregmax:
1160 			string = match_strdup(args);
1161 			if (string == NULL)
1162 				goto out_nomem;
1163 			rc = strict_strtoul(string, 10, &option);
1164 			kfree(string);
1165 			if (rc != 0)
1166 				goto out_invalid_value;
1167 			mnt->acregmax = option;
1168 			break;
1169 		case Opt_acdirmin:
1170 			string = match_strdup(args);
1171 			if (string == NULL)
1172 				goto out_nomem;
1173 			rc = strict_strtoul(string, 10, &option);
1174 			kfree(string);
1175 			if (rc != 0)
1176 				goto out_invalid_value;
1177 			mnt->acdirmin = option;
1178 			break;
1179 		case Opt_acdirmax:
1180 			string = match_strdup(args);
1181 			if (string == NULL)
1182 				goto out_nomem;
1183 			rc = strict_strtoul(string, 10, &option);
1184 			kfree(string);
1185 			if (rc != 0)
1186 				goto out_invalid_value;
1187 			mnt->acdirmax = option;
1188 			break;
1189 		case Opt_actimeo:
1190 			string = match_strdup(args);
1191 			if (string == NULL)
1192 				goto out_nomem;
1193 			rc = strict_strtoul(string, 10, &option);
1194 			kfree(string);
1195 			if (rc != 0)
1196 				goto out_invalid_value;
1197 			mnt->acregmin = mnt->acregmax =
1198 			mnt->acdirmin = mnt->acdirmax = option;
1199 			break;
1200 		case Opt_namelen:
1201 			string = match_strdup(args);
1202 			if (string == NULL)
1203 				goto out_nomem;
1204 			rc = strict_strtoul(string, 10, &option);
1205 			kfree(string);
1206 			if (rc != 0)
1207 				goto out_invalid_value;
1208 			mnt->namlen = option;
1209 			break;
1210 		case Opt_mountport:
1211 			string = match_strdup(args);
1212 			if (string == NULL)
1213 				goto out_nomem;
1214 			rc = strict_strtoul(string, 10, &option);
1215 			kfree(string);
1216 			if (rc != 0 || option > USHRT_MAX)
1217 				goto out_invalid_value;
1218 			mnt->mount_server.port = option;
1219 			break;
1220 		case Opt_mountvers:
1221 			string = match_strdup(args);
1222 			if (string == NULL)
1223 				goto out_nomem;
1224 			rc = strict_strtoul(string, 10, &option);
1225 			kfree(string);
1226 			if (rc != 0 ||
1227 			    option < NFS_MNT_VERSION ||
1228 			    option > NFS_MNT3_VERSION)
1229 				goto out_invalid_value;
1230 			mnt->mount_server.version = option;
1231 			break;
1232 		case Opt_nfsvers:
1233 			string = match_strdup(args);
1234 			if (string == NULL)
1235 				goto out_nomem;
1236 			rc = strict_strtoul(string, 10, &option);
1237 			kfree(string);
1238 			if (rc != 0)
1239 				goto out_invalid_value;
1240 			switch (option) {
1241 			case NFS2_VERSION:
1242 				mnt->flags &= ~NFS_MOUNT_VER3;
1243 				mnt->version = 2;
1244 				break;
1245 			case NFS3_VERSION:
1246 				mnt->flags |= NFS_MOUNT_VER3;
1247 				mnt->version = 3;
1248 				break;
1249 #ifdef CONFIG_NFS_V4
1250 			case NFS4_VERSION:
1251 				mnt->flags &= ~NFS_MOUNT_VER3;
1252 				mnt->version = 4;
1253 				break;
1254 #endif
1255 			default:
1256 				goto out_invalid_value;
1257 			}
1258 			break;
1259 		case Opt_minorversion:
1260 			string = match_strdup(args);
1261 			if (string == NULL)
1262 				goto out_nomem;
1263 			rc = strict_strtoul(string, 10, &option);
1264 			kfree(string);
1265 			if (rc != 0)
1266 				goto out_invalid_value;
1267 			if (option > NFS4_MAX_MINOR_VERSION)
1268 				goto out_invalid_value;
1269 			mnt->minorversion = option;
1270 			break;
1271 
1272 		/*
1273 		 * options that take text values
1274 		 */
1275 		case Opt_sec:
1276 			string = match_strdup(args);
1277 			if (string == NULL)
1278 				goto out_nomem;
1279 			rc = nfs_parse_security_flavors(string, mnt);
1280 			kfree(string);
1281 			if (!rc) {
1282 				dfprintk(MOUNT, "NFS:   unrecognized "
1283 						"security flavor\n");
1284 				return 0;
1285 			}
1286 			break;
1287 		case Opt_proto:
1288 			string = match_strdup(args);
1289 			if (string == NULL)
1290 				goto out_nomem;
1291 			token = match_token(string,
1292 					    nfs_xprt_protocol_tokens, args);
1293 
1294 			protofamily = AF_INET;
1295 			switch (token) {
1296 			case Opt_xprt_udp6:
1297 				protofamily = AF_INET6;
1298 			case Opt_xprt_udp:
1299 				mnt->flags &= ~NFS_MOUNT_TCP;
1300 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1301 				kfree(string);
1302 				break;
1303 			case Opt_xprt_tcp6:
1304 				protofamily = AF_INET6;
1305 			case Opt_xprt_tcp:
1306 				mnt->flags |= NFS_MOUNT_TCP;
1307 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1308 				kfree(string);
1309 				break;
1310 			case Opt_xprt_rdma:
1311 				/* vector side protocols to TCP */
1312 				mnt->flags |= NFS_MOUNT_TCP;
1313 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1314 				xprt_load_transport(string);
1315 				kfree(string);
1316 				break;
1317 			default:
1318 				dfprintk(MOUNT, "NFS:   unrecognized "
1319 						"transport protocol\n");
1320 				kfree(string);
1321 				return 0;
1322 			}
1323 			break;
1324 		case Opt_mountproto:
1325 			string = match_strdup(args);
1326 			if (string == NULL)
1327 				goto out_nomem;
1328 			token = match_token(string,
1329 					    nfs_xprt_protocol_tokens, args);
1330 			kfree(string);
1331 
1332 			mountfamily = AF_INET;
1333 			switch (token) {
1334 			case Opt_xprt_udp6:
1335 				mountfamily = AF_INET6;
1336 			case Opt_xprt_udp:
1337 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1338 				break;
1339 			case Opt_xprt_tcp6:
1340 				mountfamily = AF_INET6;
1341 			case Opt_xprt_tcp:
1342 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1343 				break;
1344 			case Opt_xprt_rdma: /* not used for side protocols */
1345 			default:
1346 				dfprintk(MOUNT, "NFS:   unrecognized "
1347 						"transport protocol\n");
1348 				return 0;
1349 			}
1350 			break;
1351 		case Opt_addr:
1352 			string = match_strdup(args);
1353 			if (string == NULL)
1354 				goto out_nomem;
1355 			mnt->nfs_server.addrlen =
1356 				rpc_pton(string, strlen(string),
1357 					(struct sockaddr *)
1358 					&mnt->nfs_server.address,
1359 					sizeof(mnt->nfs_server.address));
1360 			kfree(string);
1361 			if (mnt->nfs_server.addrlen == 0)
1362 				goto out_invalid_address;
1363 			break;
1364 		case Opt_clientaddr:
1365 			string = match_strdup(args);
1366 			if (string == NULL)
1367 				goto out_nomem;
1368 			kfree(mnt->client_address);
1369 			mnt->client_address = string;
1370 			break;
1371 		case Opt_mounthost:
1372 			string = match_strdup(args);
1373 			if (string == NULL)
1374 				goto out_nomem;
1375 			kfree(mnt->mount_server.hostname);
1376 			mnt->mount_server.hostname = string;
1377 			break;
1378 		case Opt_mountaddr:
1379 			string = match_strdup(args);
1380 			if (string == NULL)
1381 				goto out_nomem;
1382 			mnt->mount_server.addrlen =
1383 				rpc_pton(string, strlen(string),
1384 					(struct sockaddr *)
1385 					&mnt->mount_server.address,
1386 					sizeof(mnt->mount_server.address));
1387 			kfree(string);
1388 			if (mnt->mount_server.addrlen == 0)
1389 				goto out_invalid_address;
1390 			break;
1391 		case Opt_lookupcache:
1392 			string = match_strdup(args);
1393 			if (string == NULL)
1394 				goto out_nomem;
1395 			token = match_token(string,
1396 					nfs_lookupcache_tokens, args);
1397 			kfree(string);
1398 			switch (token) {
1399 				case Opt_lookupcache_all:
1400 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1401 					break;
1402 				case Opt_lookupcache_positive:
1403 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1404 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1405 					break;
1406 				case Opt_lookupcache_none:
1407 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1408 					break;
1409 				default:
1410 					dfprintk(MOUNT, "NFS:   invalid "
1411 							"lookupcache argument\n");
1412 					return 0;
1413 			};
1414 			break;
1415 		case Opt_fscache_uniq:
1416 			string = match_strdup(args);
1417 			if (string == NULL)
1418 				goto out_nomem;
1419 			kfree(mnt->fscache_uniq);
1420 			mnt->fscache_uniq = string;
1421 			mnt->options |= NFS_OPTION_FSCACHE;
1422 			break;
1423 
1424 		/*
1425 		 * Special options
1426 		 */
1427 		case Opt_sloppy:
1428 			sloppy = 1;
1429 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1430 			break;
1431 		case Opt_userspace:
1432 		case Opt_deprecated:
1433 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1434 					"'%s'\n", p);
1435 			break;
1436 
1437 		default:
1438 			invalid_option = 1;
1439 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1440 					"'%s'\n", p);
1441 		}
1442 	}
1443 
1444 	if (!sloppy && invalid_option)
1445 		return 0;
1446 
1447 	/*
1448 	 * verify that any proto=/mountproto= options match the address
1449 	 * familiies in the addr=/mountaddr= options.
1450 	 */
1451 	if (protofamily != AF_UNSPEC &&
1452 	    protofamily != mnt->nfs_server.address.ss_family)
1453 		goto out_proto_mismatch;
1454 
1455 	if (mountfamily != AF_UNSPEC) {
1456 		if (mnt->mount_server.addrlen) {
1457 			if (mountfamily != mnt->mount_server.address.ss_family)
1458 				goto out_mountproto_mismatch;
1459 		} else {
1460 			if (mountfamily != mnt->nfs_server.address.ss_family)
1461 				goto out_mountproto_mismatch;
1462 		}
1463 	}
1464 
1465 	return 1;
1466 
1467 out_mountproto_mismatch:
1468 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1469 			 "option\n");
1470 	return 0;
1471 out_proto_mismatch:
1472 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1473 	return 0;
1474 out_invalid_address:
1475 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1476 	return 0;
1477 out_invalid_value:
1478 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1479 	return 0;
1480 out_nomem:
1481 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1482 	return 0;
1483 out_security_failure:
1484 	free_secdata(secdata);
1485 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1486 	return 0;
1487 }
1488 
1489 /*
1490  * Match the requested auth flavors with the list returned by
1491  * the server.  Returns zero and sets the mount's authentication
1492  * flavor on success; returns -EACCES if server does not support
1493  * the requested flavor.
1494  */
1495 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1496 			     struct nfs_mount_request *request)
1497 {
1498 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1499 
1500 	/*
1501 	 * Certain releases of Linux's mountd return an empty
1502 	 * flavor list.  To prevent behavioral regression with
1503 	 * these servers (ie. rejecting mounts that used to
1504 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1505 	 * if the returned flavor list is empty.
1506 	 */
1507 	if (server_authlist_len == 0)
1508 		return 0;
1509 
1510 	/*
1511 	 * We avoid sophisticated negotiating here, as there are
1512 	 * plenty of cases where we can get it wrong, providing
1513 	 * either too little or too much security.
1514 	 *
1515 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1516 	 * flavor listed first.  However, some servers list
1517 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1518 	 * preferred default, in args->auth_flavors[0] if user
1519 	 * didn't specify sec= mount option.
1520 	 */
1521 	for (i = 0; i < args->auth_flavor_len; i++)
1522 		for (j = 0; j < server_authlist_len; j++)
1523 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1524 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1525 					request->auth_flavs[j]);
1526 				args->auth_flavors[0] = request->auth_flavs[j];
1527 				return 0;
1528 			}
1529 
1530 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1531 	nfs_umount(request);
1532 	return -EACCES;
1533 }
1534 
1535 /*
1536  * Use the remote server's MOUNT service to request the NFS file handle
1537  * corresponding to the provided path.
1538  */
1539 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1540 			 struct nfs_fh *root_fh)
1541 {
1542 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1543 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1544 	struct nfs_mount_request request = {
1545 		.sap		= (struct sockaddr *)
1546 						&args->mount_server.address,
1547 		.dirpath	= args->nfs_server.export_path,
1548 		.protocol	= args->mount_server.protocol,
1549 		.fh		= root_fh,
1550 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1551 		.auth_flav_len	= &server_authlist_len,
1552 		.auth_flavs	= server_authlist,
1553 	};
1554 	int status;
1555 
1556 	if (args->mount_server.version == 0) {
1557 		switch (args->version) {
1558 			default:
1559 				args->mount_server.version = NFS_MNT3_VERSION;
1560 				break;
1561 			case 2:
1562 				args->mount_server.version = NFS_MNT_VERSION;
1563 		}
1564 	}
1565 	request.version = args->mount_server.version;
1566 
1567 	if (args->mount_server.hostname)
1568 		request.hostname = args->mount_server.hostname;
1569 	else
1570 		request.hostname = args->nfs_server.hostname;
1571 
1572 	/*
1573 	 * Construct the mount server's address.
1574 	 */
1575 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1576 		memcpy(request.sap, &args->nfs_server.address,
1577 		       args->nfs_server.addrlen);
1578 		args->mount_server.addrlen = args->nfs_server.addrlen;
1579 	}
1580 	request.salen = args->mount_server.addrlen;
1581 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1582 
1583 	/*
1584 	 * Now ask the mount server to map our export path
1585 	 * to a file handle.
1586 	 */
1587 	status = nfs_mount(&request);
1588 	if (status != 0) {
1589 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1590 				request.hostname, status);
1591 		return status;
1592 	}
1593 
1594 	/*
1595 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1596 	 */
1597 	if (args->mount_server.version != NFS_MNT3_VERSION)
1598 		return 0;
1599 	return nfs_walk_authlist(args, &request);
1600 }
1601 
1602 static int nfs_parse_simple_hostname(const char *dev_name,
1603 				     char **hostname, size_t maxnamlen,
1604 				     char **export_path, size_t maxpathlen)
1605 {
1606 	size_t len;
1607 	char *colon, *comma;
1608 
1609 	colon = strchr(dev_name, ':');
1610 	if (colon == NULL)
1611 		goto out_bad_devname;
1612 
1613 	len = colon - dev_name;
1614 	if (len > maxnamlen)
1615 		goto out_hostname;
1616 
1617 	/* N.B. caller will free nfs_server.hostname in all cases */
1618 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1619 	if (!*hostname)
1620 		goto out_nomem;
1621 
1622 	/* kill possible hostname list: not supported */
1623 	comma = strchr(*hostname, ',');
1624 	if (comma != NULL) {
1625 		if (comma == *hostname)
1626 			goto out_bad_devname;
1627 		*comma = '\0';
1628 	}
1629 
1630 	colon++;
1631 	len = strlen(colon);
1632 	if (len > maxpathlen)
1633 		goto out_path;
1634 	*export_path = kstrndup(colon, len, GFP_KERNEL);
1635 	if (!*export_path)
1636 		goto out_nomem;
1637 
1638 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1639 	return 0;
1640 
1641 out_bad_devname:
1642 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1643 	return -EINVAL;
1644 
1645 out_nomem:
1646 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1647 	return -ENOMEM;
1648 
1649 out_hostname:
1650 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1651 	return -ENAMETOOLONG;
1652 
1653 out_path:
1654 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1655 	return -ENAMETOOLONG;
1656 }
1657 
1658 /*
1659  * Hostname has square brackets around it because it contains one or
1660  * more colons.  We look for the first closing square bracket, and a
1661  * colon must follow it.
1662  */
1663 static int nfs_parse_protected_hostname(const char *dev_name,
1664 					char **hostname, size_t maxnamlen,
1665 					char **export_path, size_t maxpathlen)
1666 {
1667 	size_t len;
1668 	char *start, *end;
1669 
1670 	start = (char *)(dev_name + 1);
1671 
1672 	end = strchr(start, ']');
1673 	if (end == NULL)
1674 		goto out_bad_devname;
1675 	if (*(end + 1) != ':')
1676 		goto out_bad_devname;
1677 
1678 	len = end - start;
1679 	if (len > maxnamlen)
1680 		goto out_hostname;
1681 
1682 	/* N.B. caller will free nfs_server.hostname in all cases */
1683 	*hostname = kstrndup(start, len, GFP_KERNEL);
1684 	if (*hostname == NULL)
1685 		goto out_nomem;
1686 
1687 	end += 2;
1688 	len = strlen(end);
1689 	if (len > maxpathlen)
1690 		goto out_path;
1691 	*export_path = kstrndup(end, len, GFP_KERNEL);
1692 	if (!*export_path)
1693 		goto out_nomem;
1694 
1695 	return 0;
1696 
1697 out_bad_devname:
1698 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1699 	return -EINVAL;
1700 
1701 out_nomem:
1702 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1703 	return -ENOMEM;
1704 
1705 out_hostname:
1706 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1707 	return -ENAMETOOLONG;
1708 
1709 out_path:
1710 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1711 	return -ENAMETOOLONG;
1712 }
1713 
1714 /*
1715  * Split "dev_name" into "hostname:export_path".
1716  *
1717  * The leftmost colon demarks the split between the server's hostname
1718  * and the export path.  If the hostname starts with a left square
1719  * bracket, then it may contain colons.
1720  *
1721  * Note: caller frees hostname and export path, even on error.
1722  */
1723 static int nfs_parse_devname(const char *dev_name,
1724 			     char **hostname, size_t maxnamlen,
1725 			     char **export_path, size_t maxpathlen)
1726 {
1727 	if (*dev_name == '[')
1728 		return nfs_parse_protected_hostname(dev_name,
1729 						    hostname, maxnamlen,
1730 						    export_path, maxpathlen);
1731 
1732 	return nfs_parse_simple_hostname(dev_name,
1733 					 hostname, maxnamlen,
1734 					 export_path, maxpathlen);
1735 }
1736 
1737 /*
1738  * Validate the NFS2/NFS3 mount data
1739  * - fills in the mount root filehandle
1740  *
1741  * For option strings, user space handles the following behaviors:
1742  *
1743  * + DNS: mapping server host name to IP address ("addr=" option)
1744  *
1745  * + failure mode: how to behave if a mount request can't be handled
1746  *   immediately ("fg/bg" option)
1747  *
1748  * + retry: how often to retry a mount request ("retry=" option)
1749  *
1750  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1751  *   mountproto=tcp after mountproto=udp, and so on
1752  */
1753 static int nfs_validate_mount_data(void *options,
1754 				   struct nfs_parsed_mount_data *args,
1755 				   struct nfs_fh *mntfh,
1756 				   const char *dev_name)
1757 {
1758 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1759 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1760 
1761 	if (data == NULL)
1762 		goto out_no_data;
1763 
1764 	switch (data->version) {
1765 	case 1:
1766 		data->namlen = 0;
1767 	case 2:
1768 		data->bsize = 0;
1769 	case 3:
1770 		if (data->flags & NFS_MOUNT_VER3)
1771 			goto out_no_v3;
1772 		data->root.size = NFS2_FHSIZE;
1773 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1774 	case 4:
1775 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1776 			goto out_no_sec;
1777 	case 5:
1778 		memset(data->context, 0, sizeof(data->context));
1779 	case 6:
1780 		if (data->flags & NFS_MOUNT_VER3) {
1781 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1782 				goto out_invalid_fh;
1783 			mntfh->size = data->root.size;
1784 			args->version = 3;
1785 		} else {
1786 			mntfh->size = NFS2_FHSIZE;
1787 			args->version = 2;
1788 		}
1789 
1790 
1791 		memcpy(mntfh->data, data->root.data, mntfh->size);
1792 		if (mntfh->size < sizeof(mntfh->data))
1793 			memset(mntfh->data + mntfh->size, 0,
1794 			       sizeof(mntfh->data) - mntfh->size);
1795 
1796 		/*
1797 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1798 		 * can deal with.
1799 		 */
1800 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1801 		args->flags		|= NFS_MOUNT_LEGACY_INTERFACE;
1802 		args->rsize		= data->rsize;
1803 		args->wsize		= data->wsize;
1804 		args->timeo		= data->timeo;
1805 		args->retrans		= data->retrans;
1806 		args->acregmin		= data->acregmin;
1807 		args->acregmax		= data->acregmax;
1808 		args->acdirmin		= data->acdirmin;
1809 		args->acdirmax		= data->acdirmax;
1810 
1811 		memcpy(sap, &data->addr, sizeof(data->addr));
1812 		args->nfs_server.addrlen = sizeof(data->addr);
1813 		if (!nfs_verify_server_address(sap))
1814 			goto out_no_address;
1815 
1816 		if (!(data->flags & NFS_MOUNT_TCP))
1817 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1818 		/* N.B. caller will free nfs_server.hostname in all cases */
1819 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1820 		args->namlen		= data->namlen;
1821 		args->bsize		= data->bsize;
1822 
1823 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1824 			args->auth_flavors[0] = data->pseudoflavor;
1825 		if (!args->nfs_server.hostname)
1826 			goto out_nomem;
1827 
1828 		/*
1829 		 * The legacy version 6 binary mount data from userspace has a
1830 		 * field used only to transport selinux information into the
1831 		 * the kernel.  To continue to support that functionality we
1832 		 * have a touch of selinux knowledge here in the NFS code. The
1833 		 * userspace code converted context=blah to just blah so we are
1834 		 * converting back to the full string selinux understands.
1835 		 */
1836 		if (data->context[0]){
1837 #ifdef CONFIG_SECURITY_SELINUX
1838 			int rc;
1839 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1840 			if (!opts_str)
1841 				return -ENOMEM;
1842 			strcpy(opts_str, "context=");
1843 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1844 			strcat(opts_str, &data->context[0]);
1845 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1846 			kfree(opts_str);
1847 			if (rc)
1848 				return rc;
1849 #else
1850 			return -EINVAL;
1851 #endif
1852 		}
1853 
1854 		break;
1855 	default: {
1856 		int status;
1857 
1858 		if (nfs_parse_mount_options((char *)options, args) == 0)
1859 			return -EINVAL;
1860 
1861 		if (!nfs_verify_server_address(sap))
1862 			goto out_no_address;
1863 
1864 		if (args->version == 4)
1865 #ifdef CONFIG_NFS_V4
1866 			return nfs4_validate_text_mount_data(options,
1867 							     args, dev_name);
1868 #else
1869 			goto out_v4_not_compiled;
1870 #endif
1871 
1872 		nfs_set_port(sap, &args->nfs_server.port, 0);
1873 
1874 		nfs_set_mount_transport_protocol(args);
1875 
1876 		status = nfs_parse_devname(dev_name,
1877 					   &args->nfs_server.hostname,
1878 					   PAGE_SIZE,
1879 					   &args->nfs_server.export_path,
1880 					   NFS_MAXPATHLEN);
1881 		if (!status)
1882 			status = nfs_try_mount(args, mntfh);
1883 
1884 		kfree(args->nfs_server.export_path);
1885 		args->nfs_server.export_path = NULL;
1886 
1887 		if (status)
1888 			return status;
1889 
1890 		break;
1891 		}
1892 	}
1893 
1894 #ifndef CONFIG_NFS_V3
1895 	if (args->version == 3)
1896 		goto out_v3_not_compiled;
1897 #endif /* !CONFIG_NFS_V3 */
1898 
1899 	return 0;
1900 
1901 out_no_data:
1902 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1903 	return -EINVAL;
1904 
1905 out_no_v3:
1906 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1907 		 data->version);
1908 	return -EINVAL;
1909 
1910 out_no_sec:
1911 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1912 	return -EINVAL;
1913 
1914 #ifndef CONFIG_NFS_V3
1915 out_v3_not_compiled:
1916 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1917 	return -EPROTONOSUPPORT;
1918 #endif /* !CONFIG_NFS_V3 */
1919 
1920 #ifndef CONFIG_NFS_V4
1921 out_v4_not_compiled:
1922 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1923 	return -EPROTONOSUPPORT;
1924 #endif /* !CONFIG_NFS_V4 */
1925 
1926 out_nomem:
1927 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1928 	return -ENOMEM;
1929 
1930 out_no_address:
1931 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1932 	return -EINVAL;
1933 
1934 out_invalid_fh:
1935 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1936 	return -EINVAL;
1937 }
1938 
1939 static int
1940 nfs_compare_remount_data(struct nfs_server *nfss,
1941 			 struct nfs_parsed_mount_data *data)
1942 {
1943 	if (data->flags != nfss->flags ||
1944 	    data->rsize != nfss->rsize ||
1945 	    data->wsize != nfss->wsize ||
1946 	    data->retrans != nfss->client->cl_timeout->to_retries ||
1947 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1948 	    data->acregmin != nfss->acregmin / HZ ||
1949 	    data->acregmax != nfss->acregmax / HZ ||
1950 	    data->acdirmin != nfss->acdirmin / HZ ||
1951 	    data->acdirmax != nfss->acdirmax / HZ ||
1952 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1953 	    data->nfs_server.port != nfss->port ||
1954 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1955 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1956 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
1957 		return -EINVAL;
1958 
1959 	return 0;
1960 }
1961 
1962 static int
1963 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1964 {
1965 	int error;
1966 	struct nfs_server *nfss = sb->s_fs_info;
1967 	struct nfs_parsed_mount_data *data;
1968 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1969 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1970 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1971 
1972 	/*
1973 	 * Userspace mount programs that send binary options generally send
1974 	 * them populated with default values. We have no way to know which
1975 	 * ones were explicitly specified. Fall back to legacy behavior and
1976 	 * just return success.
1977 	 */
1978 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1979 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
1980 					   options->version <= 6))))
1981 		return 0;
1982 
1983 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1984 	if (data == NULL)
1985 		return -ENOMEM;
1986 
1987 	/* fill out struct with values from existing mount */
1988 	data->flags = nfss->flags;
1989 	data->rsize = nfss->rsize;
1990 	data->wsize = nfss->wsize;
1991 	data->retrans = nfss->client->cl_timeout->to_retries;
1992 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1993 	data->acregmin = nfss->acregmin / HZ;
1994 	data->acregmax = nfss->acregmax / HZ;
1995 	data->acdirmin = nfss->acdirmin / HZ;
1996 	data->acdirmax = nfss->acdirmax / HZ;
1997 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1998 	data->nfs_server.port = nfss->port;
1999 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2000 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2001 		data->nfs_server.addrlen);
2002 
2003 	/* overwrite those values with any that were specified */
2004 	error = nfs_parse_mount_options((char *)options, data);
2005 	if (error < 0)
2006 		goto out;
2007 
2008 	/* compare new mount options with old ones */
2009 	error = nfs_compare_remount_data(nfss, data);
2010 out:
2011 	kfree(data);
2012 	return error;
2013 }
2014 
2015 /*
2016  * Initialise the common bits of the superblock
2017  */
2018 static inline void nfs_initialise_sb(struct super_block *sb)
2019 {
2020 	struct nfs_server *server = NFS_SB(sb);
2021 
2022 	sb->s_magic = NFS_SUPER_MAGIC;
2023 
2024 	/* We probably want something more informative here */
2025 	snprintf(sb->s_id, sizeof(sb->s_id),
2026 		 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2027 
2028 	if (sb->s_blocksize == 0)
2029 		sb->s_blocksize = nfs_block_bits(server->wsize,
2030 						 &sb->s_blocksize_bits);
2031 
2032 	if (server->flags & NFS_MOUNT_NOAC)
2033 		sb->s_flags |= MS_SYNCHRONOUS;
2034 
2035 	sb->s_bdi = &server->backing_dev_info;
2036 
2037 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2038 }
2039 
2040 /*
2041  * Finish setting up an NFS2/3 superblock
2042  */
2043 static void nfs_fill_super(struct super_block *sb,
2044 			   struct nfs_parsed_mount_data *data)
2045 {
2046 	struct nfs_server *server = NFS_SB(sb);
2047 
2048 	sb->s_blocksize_bits = 0;
2049 	sb->s_blocksize = 0;
2050 	if (data->bsize)
2051 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2052 
2053 	if (server->nfs_client->rpc_ops->version == 3) {
2054 		/* The VFS shouldn't apply the umask to mode bits. We will do
2055 		 * so ourselves when necessary.
2056 		 */
2057 		sb->s_flags |= MS_POSIXACL;
2058 		sb->s_time_gran = 1;
2059 	}
2060 
2061 	sb->s_op = &nfs_sops;
2062  	nfs_initialise_sb(sb);
2063 }
2064 
2065 /*
2066  * Finish setting up a cloned NFS2/3 superblock
2067  */
2068 static void nfs_clone_super(struct super_block *sb,
2069 			    const struct super_block *old_sb)
2070 {
2071 	struct nfs_server *server = NFS_SB(sb);
2072 
2073 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2074 	sb->s_blocksize = old_sb->s_blocksize;
2075 	sb->s_maxbytes = old_sb->s_maxbytes;
2076 
2077 	if (server->nfs_client->rpc_ops->version == 3) {
2078 		/* The VFS shouldn't apply the umask to mode bits. We will do
2079 		 * so ourselves when necessary.
2080 		 */
2081 		sb->s_flags |= MS_POSIXACL;
2082 		sb->s_time_gran = 1;
2083 	}
2084 
2085 	sb->s_op = old_sb->s_op;
2086  	nfs_initialise_sb(sb);
2087 }
2088 
2089 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2090 {
2091 	const struct nfs_server *a = s->s_fs_info;
2092 	const struct rpc_clnt *clnt_a = a->client;
2093 	const struct rpc_clnt *clnt_b = b->client;
2094 
2095 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2096 		goto Ebusy;
2097 	if (a->nfs_client != b->nfs_client)
2098 		goto Ebusy;
2099 	if (a->flags != b->flags)
2100 		goto Ebusy;
2101 	if (a->wsize != b->wsize)
2102 		goto Ebusy;
2103 	if (a->rsize != b->rsize)
2104 		goto Ebusy;
2105 	if (a->acregmin != b->acregmin)
2106 		goto Ebusy;
2107 	if (a->acregmax != b->acregmax)
2108 		goto Ebusy;
2109 	if (a->acdirmin != b->acdirmin)
2110 		goto Ebusy;
2111 	if (a->acdirmax != b->acdirmax)
2112 		goto Ebusy;
2113 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2114 		goto Ebusy;
2115 	return 1;
2116 Ebusy:
2117 	return 0;
2118 }
2119 
2120 struct nfs_sb_mountdata {
2121 	struct nfs_server *server;
2122 	int mntflags;
2123 };
2124 
2125 static int nfs_set_super(struct super_block *s, void *data)
2126 {
2127 	struct nfs_sb_mountdata *sb_mntdata = data;
2128 	struct nfs_server *server = sb_mntdata->server;
2129 	int ret;
2130 
2131 	s->s_flags = sb_mntdata->mntflags;
2132 	s->s_fs_info = server;
2133 	ret = set_anon_super(s, server);
2134 	if (ret == 0)
2135 		server->s_dev = s->s_dev;
2136 	return ret;
2137 }
2138 
2139 static int nfs_compare_super_address(struct nfs_server *server1,
2140 				     struct nfs_server *server2)
2141 {
2142 	struct sockaddr *sap1, *sap2;
2143 
2144 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2145 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2146 
2147 	if (sap1->sa_family != sap2->sa_family)
2148 		return 0;
2149 
2150 	switch (sap1->sa_family) {
2151 	case AF_INET: {
2152 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2153 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2154 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2155 			return 0;
2156 		if (sin1->sin_port != sin2->sin_port)
2157 			return 0;
2158 		break;
2159 	}
2160 	case AF_INET6: {
2161 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2162 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2163 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2164 			return 0;
2165 		if (sin1->sin6_port != sin2->sin6_port)
2166 			return 0;
2167 		break;
2168 	}
2169 	default:
2170 		return 0;
2171 	}
2172 
2173 	return 1;
2174 }
2175 
2176 static int nfs_compare_super(struct super_block *sb, void *data)
2177 {
2178 	struct nfs_sb_mountdata *sb_mntdata = data;
2179 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2180 	int mntflags = sb_mntdata->mntflags;
2181 
2182 	if (!nfs_compare_super_address(old, server))
2183 		return 0;
2184 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2185 	if (old->flags & NFS_MOUNT_UNSHARED)
2186 		return 0;
2187 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2188 		return 0;
2189 	return nfs_compare_mount_options(sb, server, mntflags);
2190 }
2191 
2192 static int nfs_bdi_register(struct nfs_server *server)
2193 {
2194 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2195 }
2196 
2197 static int nfs_get_sb(struct file_system_type *fs_type,
2198 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2199 {
2200 	struct nfs_server *server = NULL;
2201 	struct super_block *s;
2202 	struct nfs_parsed_mount_data *data;
2203 	struct nfs_fh *mntfh;
2204 	struct dentry *mntroot;
2205 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2206 	struct nfs_sb_mountdata sb_mntdata = {
2207 		.mntflags = flags,
2208 	};
2209 	int error = -ENOMEM;
2210 
2211 	data = nfs_alloc_parsed_mount_data(3);
2212 	mntfh = nfs_alloc_fhandle();
2213 	if (data == NULL || mntfh == NULL)
2214 		goto out_free_fh;
2215 
2216 	security_init_mnt_opts(&data->lsm_opts);
2217 
2218 	/* Validate the mount data */
2219 	error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2220 	if (error < 0)
2221 		goto out;
2222 
2223 #ifdef CONFIG_NFS_V4
2224 	if (data->version == 4) {
2225 		error = nfs4_try_mount(flags, dev_name, data, mnt);
2226 		kfree(data->client_address);
2227 		kfree(data->nfs_server.export_path);
2228 		goto out;
2229 	}
2230 #endif	/* CONFIG_NFS_V4 */
2231 
2232 	/* Get a volume representation */
2233 	server = nfs_create_server(data, mntfh);
2234 	if (IS_ERR(server)) {
2235 		error = PTR_ERR(server);
2236 		goto out;
2237 	}
2238 	sb_mntdata.server = server;
2239 
2240 	if (server->flags & NFS_MOUNT_UNSHARED)
2241 		compare_super = NULL;
2242 
2243 	/* Get a superblock - note that we may end up sharing one that already exists */
2244 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2245 	if (IS_ERR(s)) {
2246 		error = PTR_ERR(s);
2247 		goto out_err_nosb;
2248 	}
2249 
2250 	if (s->s_fs_info != server) {
2251 		nfs_free_server(server);
2252 		server = NULL;
2253 	} else {
2254 		error = nfs_bdi_register(server);
2255 		if (error)
2256 			goto error_splat_bdi;
2257 	}
2258 
2259 	if (!s->s_root) {
2260 		/* initial superblock/root creation */
2261 		nfs_fill_super(s, data);
2262 		nfs_fscache_get_super_cookie(
2263 			s, data ? data->fscache_uniq : NULL, NULL);
2264 	}
2265 
2266 	mntroot = nfs_get_root(s, mntfh);
2267 	if (IS_ERR(mntroot)) {
2268 		error = PTR_ERR(mntroot);
2269 		goto error_splat_super;
2270 	}
2271 
2272 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2273 	if (error)
2274 		goto error_splat_root;
2275 
2276 	s->s_flags |= MS_ACTIVE;
2277 	mnt->mnt_sb = s;
2278 	mnt->mnt_root = mntroot;
2279 	error = 0;
2280 
2281 out:
2282 	kfree(data->nfs_server.hostname);
2283 	kfree(data->mount_server.hostname);
2284 	kfree(data->fscache_uniq);
2285 	security_free_mnt_opts(&data->lsm_opts);
2286 out_free_fh:
2287 	nfs_free_fhandle(mntfh);
2288 	kfree(data);
2289 	return error;
2290 
2291 out_err_nosb:
2292 	nfs_free_server(server);
2293 	goto out;
2294 
2295 error_splat_root:
2296 	dput(mntroot);
2297 error_splat_super:
2298 	if (server && !s->s_root)
2299 		bdi_unregister(&server->backing_dev_info);
2300 error_splat_bdi:
2301 	deactivate_locked_super(s);
2302 	goto out;
2303 }
2304 
2305 /*
2306  * Ensure that we unregister the bdi before kill_anon_super
2307  * releases the device name
2308  */
2309 static void nfs_put_super(struct super_block *s)
2310 {
2311 	struct nfs_server *server = NFS_SB(s);
2312 
2313 	bdi_unregister(&server->backing_dev_info);
2314 }
2315 
2316 /*
2317  * Destroy an NFS2/3 superblock
2318  */
2319 static void nfs_kill_super(struct super_block *s)
2320 {
2321 	struct nfs_server *server = NFS_SB(s);
2322 
2323 	kill_anon_super(s);
2324 	nfs_fscache_release_super_cookie(s);
2325 	nfs_free_server(server);
2326 }
2327 
2328 /*
2329  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2330  */
2331 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2332 			   const char *dev_name, void *raw_data,
2333 			   struct vfsmount *mnt)
2334 {
2335 	struct nfs_clone_mount *data = raw_data;
2336 	struct super_block *s;
2337 	struct nfs_server *server;
2338 	struct dentry *mntroot;
2339 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2340 	struct nfs_sb_mountdata sb_mntdata = {
2341 		.mntflags = flags,
2342 	};
2343 	int error;
2344 
2345 	dprintk("--> nfs_xdev_get_sb()\n");
2346 
2347 	/* create a new volume representation */
2348 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2349 	if (IS_ERR(server)) {
2350 		error = PTR_ERR(server);
2351 		goto out_err_noserver;
2352 	}
2353 	sb_mntdata.server = server;
2354 
2355 	if (server->flags & NFS_MOUNT_UNSHARED)
2356 		compare_super = NULL;
2357 
2358 	/* Get a superblock - note that we may end up sharing one that already exists */
2359 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2360 	if (IS_ERR(s)) {
2361 		error = PTR_ERR(s);
2362 		goto out_err_nosb;
2363 	}
2364 
2365 	if (s->s_fs_info != server) {
2366 		nfs_free_server(server);
2367 		server = NULL;
2368 	} else {
2369 		error = nfs_bdi_register(server);
2370 		if (error)
2371 			goto error_splat_bdi;
2372 	}
2373 
2374 	if (!s->s_root) {
2375 		/* initial superblock/root creation */
2376 		nfs_clone_super(s, data->sb);
2377 		nfs_fscache_get_super_cookie(s, NULL, data);
2378 	}
2379 
2380 	mntroot = nfs_get_root(s, data->fh);
2381 	if (IS_ERR(mntroot)) {
2382 		error = PTR_ERR(mntroot);
2383 		goto error_splat_super;
2384 	}
2385 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2386 		dput(mntroot);
2387 		error = -ESTALE;
2388 		goto error_splat_super;
2389 	}
2390 
2391 	s->s_flags |= MS_ACTIVE;
2392 	mnt->mnt_sb = s;
2393 	mnt->mnt_root = mntroot;
2394 
2395 	/* clone any lsm security options from the parent to the new sb */
2396 	security_sb_clone_mnt_opts(data->sb, s);
2397 
2398 	dprintk("<-- nfs_xdev_get_sb() = 0\n");
2399 	return 0;
2400 
2401 out_err_nosb:
2402 	nfs_free_server(server);
2403 out_err_noserver:
2404 	dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2405 	return error;
2406 
2407 error_splat_super:
2408 	if (server && !s->s_root)
2409 		bdi_unregister(&server->backing_dev_info);
2410 error_splat_bdi:
2411 	deactivate_locked_super(s);
2412 	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2413 	return error;
2414 }
2415 
2416 #ifdef CONFIG_NFS_V4
2417 
2418 /*
2419  * Finish setting up a cloned NFS4 superblock
2420  */
2421 static void nfs4_clone_super(struct super_block *sb,
2422 			    const struct super_block *old_sb)
2423 {
2424 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2425 	sb->s_blocksize = old_sb->s_blocksize;
2426 	sb->s_maxbytes = old_sb->s_maxbytes;
2427 	sb->s_time_gran = 1;
2428 	sb->s_op = old_sb->s_op;
2429  	nfs_initialise_sb(sb);
2430 }
2431 
2432 /*
2433  * Set up an NFS4 superblock
2434  */
2435 static void nfs4_fill_super(struct super_block *sb)
2436 {
2437 	sb->s_time_gran = 1;
2438 	sb->s_op = &nfs4_sops;
2439 	nfs_initialise_sb(sb);
2440 }
2441 
2442 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2443 {
2444 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2445 }
2446 
2447 static int nfs4_validate_text_mount_data(void *options,
2448 					 struct nfs_parsed_mount_data *args,
2449 					 const char *dev_name)
2450 {
2451 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2452 
2453 	nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2454 
2455 	nfs_validate_transport_protocol(args);
2456 
2457 	nfs4_validate_mount_flags(args);
2458 
2459 	if (args->version != 4) {
2460 		dfprintk(MOUNT,
2461 			 "NFS4: Illegal mount version\n");
2462 		return -EINVAL;
2463 	}
2464 
2465 	if (args->auth_flavor_len > 1) {
2466 		dfprintk(MOUNT,
2467 			 "NFS4: Too many RPC auth flavours specified\n");
2468 		return -EINVAL;
2469 	}
2470 
2471 	if (args->client_address == NULL) {
2472 		dfprintk(MOUNT,
2473 			 "NFS4: mount program didn't pass callback address\n");
2474 		return -EINVAL;
2475 	}
2476 
2477 	return nfs_parse_devname(dev_name,
2478 				   &args->nfs_server.hostname,
2479 				   NFS4_MAXNAMLEN,
2480 				   &args->nfs_server.export_path,
2481 				   NFS4_MAXPATHLEN);
2482 }
2483 
2484 /*
2485  * Validate NFSv4 mount options
2486  */
2487 static int nfs4_validate_mount_data(void *options,
2488 				    struct nfs_parsed_mount_data *args,
2489 				    const char *dev_name)
2490 {
2491 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2492 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2493 	char *c;
2494 
2495 	if (data == NULL)
2496 		goto out_no_data;
2497 
2498 	switch (data->version) {
2499 	case 1:
2500 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2501 			goto out_no_address;
2502 		if (data->host_addrlen == 0)
2503 			goto out_no_address;
2504 		args->nfs_server.addrlen = data->host_addrlen;
2505 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2506 			return -EFAULT;
2507 		if (!nfs_verify_server_address(sap))
2508 			goto out_no_address;
2509 
2510 		if (data->auth_flavourlen) {
2511 			if (data->auth_flavourlen > 1)
2512 				goto out_inval_auth;
2513 			if (copy_from_user(&args->auth_flavors[0],
2514 					   data->auth_flavours,
2515 					   sizeof(args->auth_flavors[0])))
2516 				return -EFAULT;
2517 		}
2518 
2519 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2520 		if (IS_ERR(c))
2521 			return PTR_ERR(c);
2522 		args->nfs_server.hostname = c;
2523 
2524 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2525 		if (IS_ERR(c))
2526 			return PTR_ERR(c);
2527 		args->nfs_server.export_path = c;
2528 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2529 
2530 		c = strndup_user(data->client_addr.data, 16);
2531 		if (IS_ERR(c))
2532 			return PTR_ERR(c);
2533 		args->client_address = c;
2534 
2535 		/*
2536 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2537 		 * can deal with.
2538 		 */
2539 
2540 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2541 		args->rsize	= data->rsize;
2542 		args->wsize	= data->wsize;
2543 		args->timeo	= data->timeo;
2544 		args->retrans	= data->retrans;
2545 		args->acregmin	= data->acregmin;
2546 		args->acregmax	= data->acregmax;
2547 		args->acdirmin	= data->acdirmin;
2548 		args->acdirmax	= data->acdirmax;
2549 		args->nfs_server.protocol = data->proto;
2550 		nfs_validate_transport_protocol(args);
2551 
2552 		break;
2553 	default:
2554 		if (nfs_parse_mount_options((char *)options, args) == 0)
2555 			return -EINVAL;
2556 
2557 		if (!nfs_verify_server_address(sap))
2558 			return -EINVAL;
2559 
2560 		return nfs4_validate_text_mount_data(options, args, dev_name);
2561 	}
2562 
2563 	return 0;
2564 
2565 out_no_data:
2566 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2567 	return -EINVAL;
2568 
2569 out_inval_auth:
2570 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2571 		 data->auth_flavourlen);
2572 	return -EINVAL;
2573 
2574 out_no_address:
2575 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2576 	return -EINVAL;
2577 }
2578 
2579 /*
2580  * Get the superblock for the NFS4 root partition
2581  */
2582 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2583 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2584 {
2585 	struct nfs_parsed_mount_data *data = raw_data;
2586 	struct super_block *s;
2587 	struct nfs_server *server;
2588 	struct nfs_fh *mntfh;
2589 	struct dentry *mntroot;
2590 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2591 	struct nfs_sb_mountdata sb_mntdata = {
2592 		.mntflags = flags,
2593 	};
2594 	int error = -ENOMEM;
2595 
2596 	mntfh = nfs_alloc_fhandle();
2597 	if (data == NULL || mntfh == NULL)
2598 		goto out_free_fh;
2599 
2600 	security_init_mnt_opts(&data->lsm_opts);
2601 
2602 	/* Get a volume representation */
2603 	server = nfs4_create_server(data, mntfh);
2604 	if (IS_ERR(server)) {
2605 		error = PTR_ERR(server);
2606 		goto out;
2607 	}
2608 	sb_mntdata.server = server;
2609 
2610 	if (server->flags & NFS4_MOUNT_UNSHARED)
2611 		compare_super = NULL;
2612 
2613 	/* Get a superblock - note that we may end up sharing one that already exists */
2614 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2615 	if (IS_ERR(s)) {
2616 		error = PTR_ERR(s);
2617 		goto out_free;
2618 	}
2619 
2620 	if (s->s_fs_info != server) {
2621 		nfs_free_server(server);
2622 		server = NULL;
2623 	} else {
2624 		error = nfs_bdi_register(server);
2625 		if (error)
2626 			goto error_splat_bdi;
2627 	}
2628 
2629 	if (!s->s_root) {
2630 		/* initial superblock/root creation */
2631 		nfs4_fill_super(s);
2632 		nfs_fscache_get_super_cookie(
2633 			s, data ? data->fscache_uniq : NULL, NULL);
2634 	}
2635 
2636 	mntroot = nfs4_get_root(s, mntfh);
2637 	if (IS_ERR(mntroot)) {
2638 		error = PTR_ERR(mntroot);
2639 		goto error_splat_super;
2640 	}
2641 
2642 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2643 	if (error)
2644 		goto error_splat_root;
2645 
2646 	s->s_flags |= MS_ACTIVE;
2647 	mnt->mnt_sb = s;
2648 	mnt->mnt_root = mntroot;
2649 	error = 0;
2650 
2651 out:
2652 	security_free_mnt_opts(&data->lsm_opts);
2653 out_free_fh:
2654 	nfs_free_fhandle(mntfh);
2655 	return error;
2656 
2657 out_free:
2658 	nfs_free_server(server);
2659 	goto out;
2660 
2661 error_splat_root:
2662 	dput(mntroot);
2663 error_splat_super:
2664 	if (server && !s->s_root)
2665 		bdi_unregister(&server->backing_dev_info);
2666 error_splat_bdi:
2667 	deactivate_locked_super(s);
2668 	goto out;
2669 }
2670 
2671 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2672 		int flags, void *data, const char *hostname)
2673 {
2674 	struct vfsmount *root_mnt;
2675 	char *root_devname;
2676 	size_t len;
2677 
2678 	len = strlen(hostname) + 3;
2679 	root_devname = kmalloc(len, GFP_KERNEL);
2680 	if (root_devname == NULL)
2681 		return ERR_PTR(-ENOMEM);
2682 	snprintf(root_devname, len, "%s:/", hostname);
2683 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2684 	kfree(root_devname);
2685 	return root_mnt;
2686 }
2687 
2688 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2689 {
2690 	char *page = (char *) __get_free_page(GFP_KERNEL);
2691 	char *devname, *tmp;
2692 
2693 	if (page == NULL)
2694 		return;
2695 	devname = nfs_path(path->mnt->mnt_devname,
2696 			path->mnt->mnt_root, path->dentry,
2697 			page, PAGE_SIZE);
2698 	if (IS_ERR(devname))
2699 		goto out_freepage;
2700 	tmp = kstrdup(devname, GFP_KERNEL);
2701 	if (tmp == NULL)
2702 		goto out_freepage;
2703 	kfree(mnt->mnt_devname);
2704 	mnt->mnt_devname = tmp;
2705 out_freepage:
2706 	free_page((unsigned long)page);
2707 }
2708 
2709 struct nfs_referral_count {
2710 	struct list_head list;
2711 	const struct task_struct *task;
2712 	unsigned int referral_count;
2713 };
2714 
2715 static LIST_HEAD(nfs_referral_count_list);
2716 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2717 
2718 static struct nfs_referral_count *nfs_find_referral_count(void)
2719 {
2720 	struct nfs_referral_count *p;
2721 
2722 	list_for_each_entry(p, &nfs_referral_count_list, list) {
2723 		if (p->task == current)
2724 			return p;
2725 	}
2726 	return NULL;
2727 }
2728 
2729 #define NFS_MAX_NESTED_REFERRALS 2
2730 
2731 static int nfs_referral_loop_protect(void)
2732 {
2733 	struct nfs_referral_count *p, *new;
2734 	int ret = -ENOMEM;
2735 
2736 	new = kmalloc(sizeof(*new), GFP_KERNEL);
2737 	if (!new)
2738 		goto out;
2739 	new->task = current;
2740 	new->referral_count = 1;
2741 
2742 	ret = 0;
2743 	spin_lock(&nfs_referral_count_list_lock);
2744 	p = nfs_find_referral_count();
2745 	if (p != NULL) {
2746 		if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2747 			ret = -ELOOP;
2748 		else
2749 			p->referral_count++;
2750 	} else {
2751 		list_add(&new->list, &nfs_referral_count_list);
2752 		new = NULL;
2753 	}
2754 	spin_unlock(&nfs_referral_count_list_lock);
2755 	kfree(new);
2756 out:
2757 	return ret;
2758 }
2759 
2760 static void nfs_referral_loop_unprotect(void)
2761 {
2762 	struct nfs_referral_count *p;
2763 
2764 	spin_lock(&nfs_referral_count_list_lock);
2765 	p = nfs_find_referral_count();
2766 	p->referral_count--;
2767 	if (p->referral_count == 0)
2768 		list_del(&p->list);
2769 	else
2770 		p = NULL;
2771 	spin_unlock(&nfs_referral_count_list_lock);
2772 	kfree(p);
2773 }
2774 
2775 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2776 		const char *export_path, struct vfsmount *mnt_target)
2777 {
2778 	struct nameidata *nd = NULL;
2779 	struct mnt_namespace *ns_private;
2780 	struct super_block *s;
2781 	int ret;
2782 
2783 	nd = kmalloc(sizeof(*nd), GFP_KERNEL);
2784 	if (nd == NULL)
2785 		return -ENOMEM;
2786 
2787 	ns_private = create_mnt_ns(root_mnt);
2788 	ret = PTR_ERR(ns_private);
2789 	if (IS_ERR(ns_private))
2790 		goto out_mntput;
2791 
2792 	ret = nfs_referral_loop_protect();
2793 	if (ret != 0)
2794 		goto out_put_mnt_ns;
2795 
2796 	ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2797 			export_path, LOOKUP_FOLLOW, nd);
2798 
2799 	nfs_referral_loop_unprotect();
2800 	put_mnt_ns(ns_private);
2801 
2802 	if (ret != 0)
2803 		goto out_err;
2804 
2805 	s = nd->path.mnt->mnt_sb;
2806 	atomic_inc(&s->s_active);
2807 	mnt_target->mnt_sb = s;
2808 	mnt_target->mnt_root = dget(nd->path.dentry);
2809 
2810 	/* Correct the device pathname */
2811 	nfs_fix_devname(&nd->path, mnt_target);
2812 
2813 	path_put(&nd->path);
2814 	kfree(nd);
2815 	down_write(&s->s_umount);
2816 	return 0;
2817 out_put_mnt_ns:
2818 	put_mnt_ns(ns_private);
2819 out_mntput:
2820 	mntput(root_mnt);
2821 out_err:
2822 	kfree(nd);
2823 	return ret;
2824 }
2825 
2826 static int nfs4_try_mount(int flags, const char *dev_name,
2827 			 struct nfs_parsed_mount_data *data,
2828 			 struct vfsmount *mnt)
2829 {
2830 	char *export_path;
2831 	struct vfsmount *root_mnt;
2832 	int error;
2833 
2834 	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2835 
2836 	export_path = data->nfs_server.export_path;
2837 	data->nfs_server.export_path = "/";
2838 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2839 			data->nfs_server.hostname);
2840 	data->nfs_server.export_path = export_path;
2841 
2842 	error = PTR_ERR(root_mnt);
2843 	if (IS_ERR(root_mnt))
2844 		goto out;
2845 
2846 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2847 
2848 out:
2849 	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2850 			error != 0 ? " [error]" : "");
2851 	return error;
2852 }
2853 
2854 /*
2855  * Get the superblock for an NFS4 mountpoint
2856  */
2857 static int nfs4_get_sb(struct file_system_type *fs_type,
2858 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2859 {
2860 	struct nfs_parsed_mount_data *data;
2861 	int error = -ENOMEM;
2862 
2863 	data = nfs_alloc_parsed_mount_data(4);
2864 	if (data == NULL)
2865 		goto out_free_data;
2866 
2867 	/* Validate the mount data */
2868 	error = nfs4_validate_mount_data(raw_data, data, dev_name);
2869 	if (error < 0)
2870 		goto out;
2871 
2872 	error = nfs4_try_mount(flags, dev_name, data, mnt);
2873 
2874 out:
2875 	kfree(data->client_address);
2876 	kfree(data->nfs_server.export_path);
2877 	kfree(data->nfs_server.hostname);
2878 	kfree(data->fscache_uniq);
2879 out_free_data:
2880 	kfree(data);
2881 	dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2882 			error != 0 ? " [error]" : "");
2883 	return error;
2884 }
2885 
2886 static void nfs4_kill_super(struct super_block *sb)
2887 {
2888 	struct nfs_server *server = NFS_SB(sb);
2889 
2890 	dprintk("--> %s\n", __func__);
2891 	nfs_super_return_all_delegations(sb);
2892 	kill_anon_super(sb);
2893 	nfs_fscache_release_super_cookie(sb);
2894 	nfs_free_server(server);
2895 	dprintk("<-- %s\n", __func__);
2896 }
2897 
2898 /*
2899  * Clone an NFS4 server record on xdev traversal (FSID-change)
2900  */
2901 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2902 			    const char *dev_name, void *raw_data,
2903 			    struct vfsmount *mnt)
2904 {
2905 	struct nfs_clone_mount *data = raw_data;
2906 	struct super_block *s;
2907 	struct nfs_server *server;
2908 	struct dentry *mntroot;
2909 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2910 	struct nfs_sb_mountdata sb_mntdata = {
2911 		.mntflags = flags,
2912 	};
2913 	int error;
2914 
2915 	dprintk("--> nfs4_xdev_get_sb()\n");
2916 
2917 	/* create a new volume representation */
2918 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2919 	if (IS_ERR(server)) {
2920 		error = PTR_ERR(server);
2921 		goto out_err_noserver;
2922 	}
2923 	sb_mntdata.server = server;
2924 
2925 	if (server->flags & NFS4_MOUNT_UNSHARED)
2926 		compare_super = NULL;
2927 
2928 	/* Get a superblock - note that we may end up sharing one that already exists */
2929 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2930 	if (IS_ERR(s)) {
2931 		error = PTR_ERR(s);
2932 		goto out_err_nosb;
2933 	}
2934 
2935 	if (s->s_fs_info != server) {
2936 		nfs_free_server(server);
2937 		server = NULL;
2938 	} else {
2939 		error = nfs_bdi_register(server);
2940 		if (error)
2941 			goto error_splat_bdi;
2942 	}
2943 
2944 	if (!s->s_root) {
2945 		/* initial superblock/root creation */
2946 		nfs4_clone_super(s, data->sb);
2947 		nfs_fscache_get_super_cookie(s, NULL, data);
2948 	}
2949 
2950 	mntroot = nfs4_get_root(s, data->fh);
2951 	if (IS_ERR(mntroot)) {
2952 		error = PTR_ERR(mntroot);
2953 		goto error_splat_super;
2954 	}
2955 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2956 		dput(mntroot);
2957 		error = -ESTALE;
2958 		goto error_splat_super;
2959 	}
2960 
2961 	s->s_flags |= MS_ACTIVE;
2962 	mnt->mnt_sb = s;
2963 	mnt->mnt_root = mntroot;
2964 
2965 	security_sb_clone_mnt_opts(data->sb, s);
2966 
2967 	dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2968 	return 0;
2969 
2970 out_err_nosb:
2971 	nfs_free_server(server);
2972 out_err_noserver:
2973 	dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2974 	return error;
2975 
2976 error_splat_super:
2977 	if (server && !s->s_root)
2978 		bdi_unregister(&server->backing_dev_info);
2979 error_splat_bdi:
2980 	deactivate_locked_super(s);
2981 	dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2982 	return error;
2983 }
2984 
2985 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2986 		int flags, const char *dev_name, void *raw_data,
2987 		struct vfsmount *mnt)
2988 {
2989 	struct nfs_clone_mount *data = raw_data;
2990 	struct super_block *s;
2991 	struct nfs_server *server;
2992 	struct dentry *mntroot;
2993 	struct nfs_fh *mntfh;
2994 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2995 	struct nfs_sb_mountdata sb_mntdata = {
2996 		.mntflags = flags,
2997 	};
2998 	int error = -ENOMEM;
2999 
3000 	dprintk("--> nfs4_referral_get_sb()\n");
3001 
3002 	mntfh = nfs_alloc_fhandle();
3003 	if (mntfh == NULL)
3004 		goto out_err_nofh;
3005 
3006 	/* create a new volume representation */
3007 	server = nfs4_create_referral_server(data, mntfh);
3008 	if (IS_ERR(server)) {
3009 		error = PTR_ERR(server);
3010 		goto out_err_noserver;
3011 	}
3012 	sb_mntdata.server = server;
3013 
3014 	if (server->flags & NFS4_MOUNT_UNSHARED)
3015 		compare_super = NULL;
3016 
3017 	/* Get a superblock - note that we may end up sharing one that already exists */
3018 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
3019 	if (IS_ERR(s)) {
3020 		error = PTR_ERR(s);
3021 		goto out_err_nosb;
3022 	}
3023 
3024 	if (s->s_fs_info != server) {
3025 		nfs_free_server(server);
3026 		server = NULL;
3027 	} else {
3028 		error = nfs_bdi_register(server);
3029 		if (error)
3030 			goto error_splat_bdi;
3031 	}
3032 
3033 	if (!s->s_root) {
3034 		/* initial superblock/root creation */
3035 		nfs4_fill_super(s);
3036 		nfs_fscache_get_super_cookie(s, NULL, data);
3037 	}
3038 
3039 	mntroot = nfs4_get_root(s, mntfh);
3040 	if (IS_ERR(mntroot)) {
3041 		error = PTR_ERR(mntroot);
3042 		goto error_splat_super;
3043 	}
3044 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3045 		dput(mntroot);
3046 		error = -ESTALE;
3047 		goto error_splat_super;
3048 	}
3049 
3050 	s->s_flags |= MS_ACTIVE;
3051 	mnt->mnt_sb = s;
3052 	mnt->mnt_root = mntroot;
3053 
3054 	security_sb_clone_mnt_opts(data->sb, s);
3055 
3056 	nfs_free_fhandle(mntfh);
3057 	dprintk("<-- nfs4_referral_get_sb() = 0\n");
3058 	return 0;
3059 
3060 out_err_nosb:
3061 	nfs_free_server(server);
3062 out_err_noserver:
3063 	nfs_free_fhandle(mntfh);
3064 out_err_nofh:
3065 	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3066 	return error;
3067 
3068 error_splat_super:
3069 	if (server && !s->s_root)
3070 		bdi_unregister(&server->backing_dev_info);
3071 error_splat_bdi:
3072 	deactivate_locked_super(s);
3073 	nfs_free_fhandle(mntfh);
3074 	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3075 	return error;
3076 }
3077 
3078 /*
3079  * Create an NFS4 server record on referral traversal
3080  */
3081 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
3082 		int flags, const char *dev_name, void *raw_data,
3083 		struct vfsmount *mnt)
3084 {
3085 	struct nfs_clone_mount *data = raw_data;
3086 	char *export_path;
3087 	struct vfsmount *root_mnt;
3088 	int error;
3089 
3090 	dprintk("--> nfs4_referral_get_sb()\n");
3091 
3092 	export_path = data->mnt_path;
3093 	data->mnt_path = "/";
3094 
3095 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3096 			flags, data, data->hostname);
3097 	data->mnt_path = export_path;
3098 
3099 	error = PTR_ERR(root_mnt);
3100 	if (IS_ERR(root_mnt))
3101 		goto out;
3102 
3103 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
3104 out:
3105 	dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
3106 			error != 0 ? " [error]" : "");
3107 	return error;
3108 }
3109 
3110 #endif /* CONFIG_NFS_V4 */
3111