xref: /openbmc/linux/fs/nfs/super.c (revision 54525552)
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/seq_file.h>
43 #include <linux/mount.h>
44 #include <linux/mnt_namespace.h>
45 #include <linux/namei.h>
46 #include <linux/nfs_idmap.h>
47 #include <linux/vfs.h>
48 #include <linux/inet.h>
49 #include <linux/in6.h>
50 #include <linux/slab.h>
51 #include <net/ipv6.h>
52 #include <linux/netdevice.h>
53 #include <linux/nfs_xdr.h>
54 #include <linux/magic.h>
55 #include <linux/parser.h>
56 
57 #include <asm/system.h>
58 #include <asm/uaccess.h>
59 
60 #include "nfs4_fs.h"
61 #include "callback.h"
62 #include "delegation.h"
63 #include "iostat.h"
64 #include "internal.h"
65 #include "fscache.h"
66 
67 #define NFSDBG_FACILITY		NFSDBG_VFS
68 
69 #ifdef CONFIG_NFS_V3
70 #define NFS_DEFAULT_VERSION 3
71 #else
72 #define NFS_DEFAULT_VERSION 2
73 #endif
74 
75 enum {
76 	/* Mount options that take no arguments */
77 	Opt_soft, Opt_hard,
78 	Opt_posix, Opt_noposix,
79 	Opt_cto, Opt_nocto,
80 	Opt_ac, Opt_noac,
81 	Opt_lock, Opt_nolock,
82 	Opt_v2, Opt_v3, Opt_v4,
83 	Opt_udp, Opt_tcp, Opt_rdma,
84 	Opt_acl, Opt_noacl,
85 	Opt_rdirplus, Opt_nordirplus,
86 	Opt_sharecache, Opt_nosharecache,
87 	Opt_resvport, Opt_noresvport,
88 	Opt_fscache, Opt_nofscache,
89 
90 	/* Mount options that take integer arguments */
91 	Opt_port,
92 	Opt_rsize, Opt_wsize, Opt_bsize,
93 	Opt_timeo, Opt_retrans,
94 	Opt_acregmin, Opt_acregmax,
95 	Opt_acdirmin, Opt_acdirmax,
96 	Opt_actimeo,
97 	Opt_namelen,
98 	Opt_mountport,
99 	Opt_mountvers,
100 	Opt_nfsvers,
101 	Opt_minorversion,
102 
103 	/* Mount options that take string arguments */
104 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
105 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
106 	Opt_lookupcache,
107 	Opt_fscache_uniq,
108 	Opt_local_lock,
109 
110 	/* Special mount options */
111 	Opt_userspace, Opt_deprecated, Opt_sloppy,
112 
113 	Opt_err
114 };
115 
116 static const match_table_t nfs_mount_option_tokens = {
117 	{ Opt_userspace, "bg" },
118 	{ Opt_userspace, "fg" },
119 	{ Opt_userspace, "retry=%s" },
120 
121 	{ Opt_sloppy, "sloppy" },
122 
123 	{ Opt_soft, "soft" },
124 	{ Opt_hard, "hard" },
125 	{ Opt_deprecated, "intr" },
126 	{ Opt_deprecated, "nointr" },
127 	{ Opt_posix, "posix" },
128 	{ Opt_noposix, "noposix" },
129 	{ Opt_cto, "cto" },
130 	{ Opt_nocto, "nocto" },
131 	{ Opt_ac, "ac" },
132 	{ Opt_noac, "noac" },
133 	{ Opt_lock, "lock" },
134 	{ Opt_nolock, "nolock" },
135 	{ Opt_v2, "v2" },
136 	{ Opt_v3, "v3" },
137 	{ Opt_v4, "v4" },
138 	{ Opt_udp, "udp" },
139 	{ Opt_tcp, "tcp" },
140 	{ Opt_rdma, "rdma" },
141 	{ Opt_acl, "acl" },
142 	{ Opt_noacl, "noacl" },
143 	{ Opt_rdirplus, "rdirplus" },
144 	{ Opt_nordirplus, "nordirplus" },
145 	{ Opt_sharecache, "sharecache" },
146 	{ Opt_nosharecache, "nosharecache" },
147 	{ Opt_resvport, "resvport" },
148 	{ Opt_noresvport, "noresvport" },
149 	{ Opt_fscache, "fsc" },
150 	{ Opt_nofscache, "nofsc" },
151 
152 	{ Opt_port, "port=%s" },
153 	{ Opt_rsize, "rsize=%s" },
154 	{ Opt_wsize, "wsize=%s" },
155 	{ Opt_bsize, "bsize=%s" },
156 	{ Opt_timeo, "timeo=%s" },
157 	{ Opt_retrans, "retrans=%s" },
158 	{ Opt_acregmin, "acregmin=%s" },
159 	{ Opt_acregmax, "acregmax=%s" },
160 	{ Opt_acdirmin, "acdirmin=%s" },
161 	{ Opt_acdirmax, "acdirmax=%s" },
162 	{ Opt_actimeo, "actimeo=%s" },
163 	{ Opt_namelen, "namlen=%s" },
164 	{ Opt_mountport, "mountport=%s" },
165 	{ Opt_mountvers, "mountvers=%s" },
166 	{ Opt_nfsvers, "nfsvers=%s" },
167 	{ Opt_nfsvers, "vers=%s" },
168 	{ Opt_minorversion, "minorversion=%s" },
169 
170 	{ Opt_sec, "sec=%s" },
171 	{ Opt_proto, "proto=%s" },
172 	{ Opt_mountproto, "mountproto=%s" },
173 	{ Opt_addr, "addr=%s" },
174 	{ Opt_clientaddr, "clientaddr=%s" },
175 	{ Opt_mounthost, "mounthost=%s" },
176 	{ Opt_mountaddr, "mountaddr=%s" },
177 
178 	{ Opt_lookupcache, "lookupcache=%s" },
179 	{ Opt_fscache_uniq, "fsc=%s" },
180 	{ Opt_local_lock, "local_lock=%s" },
181 
182 	{ Opt_err, NULL }
183 };
184 
185 enum {
186 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
187 
188 	Opt_xprt_err
189 };
190 
191 static const match_table_t nfs_xprt_protocol_tokens = {
192 	{ Opt_xprt_udp, "udp" },
193 	{ Opt_xprt_udp6, "udp6" },
194 	{ Opt_xprt_tcp, "tcp" },
195 	{ Opt_xprt_tcp6, "tcp6" },
196 	{ Opt_xprt_rdma, "rdma" },
197 
198 	{ Opt_xprt_err, NULL }
199 };
200 
201 enum {
202 	Opt_sec_none, Opt_sec_sys,
203 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
204 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
205 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
206 
207 	Opt_sec_err
208 };
209 
210 static const match_table_t nfs_secflavor_tokens = {
211 	{ Opt_sec_none, "none" },
212 	{ Opt_sec_none, "null" },
213 	{ Opt_sec_sys, "sys" },
214 
215 	{ Opt_sec_krb5, "krb5" },
216 	{ Opt_sec_krb5i, "krb5i" },
217 	{ Opt_sec_krb5p, "krb5p" },
218 
219 	{ Opt_sec_lkey, "lkey" },
220 	{ Opt_sec_lkeyi, "lkeyi" },
221 	{ Opt_sec_lkeyp, "lkeyp" },
222 
223 	{ Opt_sec_spkm, "spkm3" },
224 	{ Opt_sec_spkmi, "spkm3i" },
225 	{ Opt_sec_spkmp, "spkm3p" },
226 
227 	{ Opt_sec_err, NULL }
228 };
229 
230 enum {
231 	Opt_lookupcache_all, Opt_lookupcache_positive,
232 	Opt_lookupcache_none,
233 
234 	Opt_lookupcache_err
235 };
236 
237 static match_table_t nfs_lookupcache_tokens = {
238 	{ Opt_lookupcache_all, "all" },
239 	{ Opt_lookupcache_positive, "pos" },
240 	{ Opt_lookupcache_positive, "positive" },
241 	{ Opt_lookupcache_none, "none" },
242 
243 	{ Opt_lookupcache_err, NULL }
244 };
245 
246 enum {
247 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
248 	Opt_local_lock_none,
249 
250 	Opt_local_lock_err
251 };
252 
253 static match_table_t nfs_local_lock_tokens = {
254 	{ Opt_local_lock_all, "all" },
255 	{ Opt_local_lock_flock, "flock" },
256 	{ Opt_local_lock_posix, "posix" },
257 	{ Opt_local_lock_none, "none" },
258 
259 	{ Opt_local_lock_err, NULL }
260 };
261 
262 
263 static void nfs_umount_begin(struct super_block *);
264 static int  nfs_statfs(struct dentry *, struct kstatfs *);
265 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
266 static int  nfs_show_devname(struct seq_file *, struct vfsmount *);
267 static int  nfs_show_path(struct seq_file *, struct vfsmount *);
268 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
269 static struct dentry *nfs_fs_mount(struct file_system_type *,
270 		int, const char *, void *);
271 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
272 		int flags, const char *dev_name, void *raw_data);
273 static void nfs_put_super(struct super_block *);
274 static void nfs_kill_super(struct super_block *);
275 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
276 
277 static struct file_system_type nfs_fs_type = {
278 	.owner		= THIS_MODULE,
279 	.name		= "nfs",
280 	.mount		= nfs_fs_mount,
281 	.kill_sb	= nfs_kill_super,
282 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
283 };
284 
285 struct file_system_type nfs_xdev_fs_type = {
286 	.owner		= THIS_MODULE,
287 	.name		= "nfs",
288 	.mount		= nfs_xdev_mount,
289 	.kill_sb	= nfs_kill_super,
290 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
291 };
292 
293 static const struct super_operations nfs_sops = {
294 	.alloc_inode	= nfs_alloc_inode,
295 	.destroy_inode	= nfs_destroy_inode,
296 	.write_inode	= nfs_write_inode,
297 	.put_super	= nfs_put_super,
298 	.statfs		= nfs_statfs,
299 	.evict_inode	= nfs_evict_inode,
300 	.umount_begin	= nfs_umount_begin,
301 	.show_options	= nfs_show_options,
302 	.show_devname	= nfs_show_devname,
303 	.show_path	= nfs_show_path,
304 	.show_stats	= nfs_show_stats,
305 	.remount_fs	= nfs_remount,
306 };
307 
308 #ifdef CONFIG_NFS_V4
309 static int nfs4_validate_text_mount_data(void *options,
310 	struct nfs_parsed_mount_data *args, const char *dev_name);
311 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
312 	struct nfs_parsed_mount_data *data);
313 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
314 	int flags, const char *dev_name, void *raw_data);
315 static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
316 	int flags, const char *dev_name, void *raw_data);
317 static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type,
318 	int flags, const char *dev_name, void *raw_data);
319 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
320 	int flags, const char *dev_name, void *raw_data);
321 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
322 	int flags, const char *dev_name, void *raw_data);
323 static void nfs4_kill_super(struct super_block *sb);
324 
325 static struct file_system_type nfs4_fs_type = {
326 	.owner		= THIS_MODULE,
327 	.name		= "nfs4",
328 	.mount		= nfs4_mount,
329 	.kill_sb	= nfs4_kill_super,
330 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
331 };
332 
333 static struct file_system_type nfs4_remote_fs_type = {
334 	.owner		= THIS_MODULE,
335 	.name		= "nfs4",
336 	.mount		= nfs4_remote_mount,
337 	.kill_sb	= nfs4_kill_super,
338 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
339 };
340 
341 struct file_system_type nfs4_xdev_fs_type = {
342 	.owner		= THIS_MODULE,
343 	.name		= "nfs4",
344 	.mount		= nfs4_xdev_mount,
345 	.kill_sb	= nfs4_kill_super,
346 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
347 };
348 
349 static struct file_system_type nfs4_remote_referral_fs_type = {
350 	.owner		= THIS_MODULE,
351 	.name		= "nfs4",
352 	.mount		= nfs4_remote_referral_mount,
353 	.kill_sb	= nfs4_kill_super,
354 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
355 };
356 
357 struct file_system_type nfs4_referral_fs_type = {
358 	.owner		= THIS_MODULE,
359 	.name		= "nfs4",
360 	.mount		= nfs4_referral_mount,
361 	.kill_sb	= nfs4_kill_super,
362 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
363 };
364 
365 static const struct super_operations nfs4_sops = {
366 	.alloc_inode	= nfs_alloc_inode,
367 	.destroy_inode	= nfs_destroy_inode,
368 	.write_inode	= nfs_write_inode,
369 	.put_super	= nfs_put_super,
370 	.statfs		= nfs_statfs,
371 	.evict_inode	= nfs4_evict_inode,
372 	.umount_begin	= nfs_umount_begin,
373 	.show_options	= nfs_show_options,
374 	.show_devname	= nfs_show_devname,
375 	.show_path	= nfs_show_path,
376 	.show_stats	= nfs_show_stats,
377 	.remount_fs	= nfs_remount,
378 };
379 #endif
380 
381 static struct shrinker acl_shrinker = {
382 	.shrink		= nfs_access_cache_shrinker,
383 	.seeks		= DEFAULT_SEEKS,
384 };
385 
386 /*
387  * Register the NFS filesystems
388  */
389 int __init register_nfs_fs(void)
390 {
391 	int ret;
392 
393         ret = register_filesystem(&nfs_fs_type);
394 	if (ret < 0)
395 		goto error_0;
396 
397 	ret = nfs_register_sysctl();
398 	if (ret < 0)
399 		goto error_1;
400 #ifdef CONFIG_NFS_V4
401 	ret = register_filesystem(&nfs4_fs_type);
402 	if (ret < 0)
403 		goto error_2;
404 #endif
405 	register_shrinker(&acl_shrinker);
406 	return 0;
407 
408 #ifdef CONFIG_NFS_V4
409 error_2:
410 	nfs_unregister_sysctl();
411 #endif
412 error_1:
413 	unregister_filesystem(&nfs_fs_type);
414 error_0:
415 	return ret;
416 }
417 
418 /*
419  * Unregister the NFS filesystems
420  */
421 void __exit unregister_nfs_fs(void)
422 {
423 	unregister_shrinker(&acl_shrinker);
424 #ifdef CONFIG_NFS_V4
425 	unregister_filesystem(&nfs4_fs_type);
426 #endif
427 	nfs_unregister_sysctl();
428 	unregister_filesystem(&nfs_fs_type);
429 }
430 
431 void nfs_sb_active(struct super_block *sb)
432 {
433 	struct nfs_server *server = NFS_SB(sb);
434 
435 	if (atomic_inc_return(&server->active) == 1)
436 		atomic_inc(&sb->s_active);
437 }
438 
439 void nfs_sb_deactive(struct super_block *sb)
440 {
441 	struct nfs_server *server = NFS_SB(sb);
442 
443 	if (atomic_dec_and_test(&server->active))
444 		deactivate_super(sb);
445 }
446 
447 /*
448  * Deliver file system statistics to userspace
449  */
450 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
451 {
452 	struct nfs_server *server = NFS_SB(dentry->d_sb);
453 	unsigned char blockbits;
454 	unsigned long blockres;
455 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
456 	struct nfs_fsstat res;
457 	int error = -ENOMEM;
458 
459 	res.fattr = nfs_alloc_fattr();
460 	if (res.fattr == NULL)
461 		goto out_err;
462 
463 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
464 	if (unlikely(error == -ESTALE)) {
465 		struct dentry *pd_dentry;
466 
467 		pd_dentry = dget_parent(dentry);
468 		if (pd_dentry != NULL) {
469 			nfs_zap_caches(pd_dentry->d_inode);
470 			dput(pd_dentry);
471 		}
472 	}
473 	nfs_free_fattr(res.fattr);
474 	if (error < 0)
475 		goto out_err;
476 
477 	buf->f_type = NFS_SUPER_MAGIC;
478 
479 	/*
480 	 * Current versions of glibc do not correctly handle the
481 	 * case where f_frsize != f_bsize.  Eventually we want to
482 	 * report the value of wtmult in this field.
483 	 */
484 	buf->f_frsize = dentry->d_sb->s_blocksize;
485 
486 	/*
487 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
488 	 * are reported in units of f_frsize.  Linux hasn't had
489 	 * an f_frsize field in its statfs struct until recently,
490 	 * thus historically Linux's sys_statfs reports these
491 	 * fields in units of f_bsize.
492 	 */
493 	buf->f_bsize = dentry->d_sb->s_blocksize;
494 	blockbits = dentry->d_sb->s_blocksize_bits;
495 	blockres = (1 << blockbits) - 1;
496 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
497 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
498 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
499 
500 	buf->f_files = res.tfiles;
501 	buf->f_ffree = res.afiles;
502 
503 	buf->f_namelen = server->namelen;
504 
505 	return 0;
506 
507  out_err:
508 	dprintk("%s: statfs error = %d\n", __func__, -error);
509 	return error;
510 }
511 
512 /*
513  * Map the security flavour number to a name
514  */
515 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
516 {
517 	static const struct {
518 		rpc_authflavor_t flavour;
519 		const char *str;
520 	} sec_flavours[] = {
521 		{ RPC_AUTH_NULL, "null" },
522 		{ RPC_AUTH_UNIX, "sys" },
523 		{ RPC_AUTH_GSS_KRB5, "krb5" },
524 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
525 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
526 		{ RPC_AUTH_GSS_LKEY, "lkey" },
527 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
528 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
529 		{ RPC_AUTH_GSS_SPKM, "spkm" },
530 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
531 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
532 		{ UINT_MAX, "unknown" }
533 	};
534 	int i;
535 
536 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
537 		if (sec_flavours[i].flavour == flavour)
538 			break;
539 	}
540 	return sec_flavours[i].str;
541 }
542 
543 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
544 				  int showdefaults)
545 {
546 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
547 
548 	seq_printf(m, ",mountproto=");
549 	switch (sap->sa_family) {
550 	case AF_INET:
551 		switch (nfss->mountd_protocol) {
552 		case IPPROTO_UDP:
553 			seq_printf(m, RPCBIND_NETID_UDP);
554 			break;
555 		case IPPROTO_TCP:
556 			seq_printf(m, RPCBIND_NETID_TCP);
557 			break;
558 		default:
559 			if (showdefaults)
560 				seq_printf(m, "auto");
561 		}
562 		break;
563 	case AF_INET6:
564 		switch (nfss->mountd_protocol) {
565 		case IPPROTO_UDP:
566 			seq_printf(m, RPCBIND_NETID_UDP6);
567 			break;
568 		case IPPROTO_TCP:
569 			seq_printf(m, RPCBIND_NETID_TCP6);
570 			break;
571 		default:
572 			if (showdefaults)
573 				seq_printf(m, "auto");
574 		}
575 		break;
576 	default:
577 		if (showdefaults)
578 			seq_printf(m, "auto");
579 	}
580 }
581 
582 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
583 				    int showdefaults)
584 {
585 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
586 
587 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
588 		return;
589 
590 	switch (sap->sa_family) {
591 	case AF_INET: {
592 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
593 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
594 		break;
595 	}
596 	case AF_INET6: {
597 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
598 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
599 		break;
600 	}
601 	default:
602 		if (showdefaults)
603 			seq_printf(m, ",mountaddr=unspecified");
604 	}
605 
606 	if (nfss->mountd_version || showdefaults)
607 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
608 	if ((nfss->mountd_port &&
609 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
610 		showdefaults)
611 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
612 
613 	nfs_show_mountd_netid(m, nfss, showdefaults);
614 }
615 
616 #ifdef CONFIG_NFS_V4
617 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
618 				    int showdefaults)
619 {
620 	struct nfs_client *clp = nfss->nfs_client;
621 
622 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
623 	seq_printf(m, ",minorversion=%u", clp->cl_minorversion);
624 }
625 #else
626 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
627 				    int showdefaults)
628 {
629 }
630 #endif
631 
632 /*
633  * Describe the mount options in force on this server representation
634  */
635 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
636 				   int showdefaults)
637 {
638 	static const struct proc_nfs_info {
639 		int flag;
640 		const char *str;
641 		const char *nostr;
642 	} nfs_info[] = {
643 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
644 		{ NFS_MOUNT_POSIX, ",posix", "" },
645 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
646 		{ NFS_MOUNT_NOAC, ",noac", "" },
647 		{ NFS_MOUNT_NONLM, ",nolock", "" },
648 		{ NFS_MOUNT_NOACL, ",noacl", "" },
649 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
650 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
651 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
652 		{ 0, NULL, NULL }
653 	};
654 	const struct proc_nfs_info *nfs_infop;
655 	struct nfs_client *clp = nfss->nfs_client;
656 	u32 version = clp->rpc_ops->version;
657 	int local_flock, local_fcntl;
658 
659 	seq_printf(m, ",vers=%u", version);
660 	seq_printf(m, ",rsize=%u", nfss->rsize);
661 	seq_printf(m, ",wsize=%u", nfss->wsize);
662 	if (nfss->bsize != 0)
663 		seq_printf(m, ",bsize=%u", nfss->bsize);
664 	seq_printf(m, ",namlen=%u", nfss->namelen);
665 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
666 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
667 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
668 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
669 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
670 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
671 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
672 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
673 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
674 		if (nfss->flags & nfs_infop->flag)
675 			seq_puts(m, nfs_infop->str);
676 		else
677 			seq_puts(m, nfs_infop->nostr);
678 	}
679 	seq_printf(m, ",proto=%s",
680 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
681 	if (version == 4) {
682 		if (nfss->port != NFS_PORT)
683 			seq_printf(m, ",port=%u", nfss->port);
684 	} else
685 		if (nfss->port)
686 			seq_printf(m, ",port=%u", nfss->port);
687 
688 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
689 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
690 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
691 
692 	if (version != 4)
693 		nfs_show_mountd_options(m, nfss, showdefaults);
694 	else
695 		nfs_show_nfsv4_options(m, nfss, showdefaults);
696 
697 	if (nfss->options & NFS_OPTION_FSCACHE)
698 		seq_printf(m, ",fsc");
699 
700 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
701 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
702 			seq_printf(m, ",lookupcache=none");
703 		else
704 			seq_printf(m, ",lookupcache=pos");
705 	}
706 
707 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
708 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
709 
710 	if (!local_flock && !local_fcntl)
711 		seq_printf(m, ",local_lock=none");
712 	else if (local_flock && local_fcntl)
713 		seq_printf(m, ",local_lock=all");
714 	else if (local_flock)
715 		seq_printf(m, ",local_lock=flock");
716 	else
717 		seq_printf(m, ",local_lock=posix");
718 }
719 
720 /*
721  * Describe the mount options on this VFS mountpoint
722  */
723 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
724 {
725 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
726 
727 	nfs_show_mount_options(m, nfss, 0);
728 
729 	seq_printf(m, ",addr=%s",
730 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
731 							RPC_DISPLAY_ADDR));
732 
733 	return 0;
734 }
735 
736 static int nfs_show_devname(struct seq_file *m, struct vfsmount *mnt)
737 {
738 	char *page = (char *) __get_free_page(GFP_KERNEL);
739 	char *devname, *dummy;
740 	int err = 0;
741 	if (!page)
742 		return -ENOMEM;
743 	devname = nfs_path(&dummy, mnt->mnt_root, page, PAGE_SIZE);
744 	if (IS_ERR(devname))
745 		err = PTR_ERR(devname);
746 	else
747 		seq_escape(m, devname, " \t\n\\");
748 	free_page((unsigned long)page);
749 	return err;
750 }
751 
752 static int nfs_show_path(struct seq_file *m, struct vfsmount *mnt)
753 {
754 	seq_puts(m, "/");
755 	return 0;
756 }
757 
758 /*
759  * Present statistical information for this VFS mountpoint
760  */
761 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
762 {
763 	int i, cpu;
764 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
765 	struct rpc_auth *auth = nfss->client->cl_auth;
766 	struct nfs_iostats totals = { };
767 
768 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
769 
770 	/*
771 	 * Display all mount option settings
772 	 */
773 	seq_printf(m, "\n\topts:\t");
774 	seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
775 	seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
776 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
777 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
778 	nfs_show_mount_options(m, nfss, 1);
779 
780 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
781 
782 	seq_printf(m, "\n\tcaps:\t");
783 	seq_printf(m, "caps=0x%x", nfss->caps);
784 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
785 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
786 	seq_printf(m, ",bsize=%u", nfss->bsize);
787 	seq_printf(m, ",namlen=%u", nfss->namelen);
788 
789 #ifdef CONFIG_NFS_V4
790 	if (nfss->nfs_client->rpc_ops->version == 4) {
791 		seq_printf(m, "\n\tnfsv4:\t");
792 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
793 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
794 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
795 	}
796 #endif
797 
798 	/*
799 	 * Display security flavor in effect for this mount
800 	 */
801 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
802 	if (auth->au_flavor)
803 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
804 
805 	/*
806 	 * Display superblock I/O counters
807 	 */
808 	for_each_possible_cpu(cpu) {
809 		struct nfs_iostats *stats;
810 
811 		preempt_disable();
812 		stats = per_cpu_ptr(nfss->io_stats, cpu);
813 
814 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
815 			totals.events[i] += stats->events[i];
816 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
817 			totals.bytes[i] += stats->bytes[i];
818 #ifdef CONFIG_NFS_FSCACHE
819 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
820 			totals.fscache[i] += stats->fscache[i];
821 #endif
822 
823 		preempt_enable();
824 	}
825 
826 	seq_printf(m, "\n\tevents:\t");
827 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
828 		seq_printf(m, "%lu ", totals.events[i]);
829 	seq_printf(m, "\n\tbytes:\t");
830 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
831 		seq_printf(m, "%Lu ", totals.bytes[i]);
832 #ifdef CONFIG_NFS_FSCACHE
833 	if (nfss->options & NFS_OPTION_FSCACHE) {
834 		seq_printf(m, "\n\tfsc:\t");
835 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
836 			seq_printf(m, "%Lu ", totals.bytes[i]);
837 	}
838 #endif
839 	seq_printf(m, "\n");
840 
841 	rpc_print_iostats(m, nfss->client);
842 
843 	return 0;
844 }
845 
846 /*
847  * Begin unmount by attempting to remove all automounted mountpoints we added
848  * in response to xdev traversals and referrals
849  */
850 static void nfs_umount_begin(struct super_block *sb)
851 {
852 	struct nfs_server *server;
853 	struct rpc_clnt *rpc;
854 
855 	server = NFS_SB(sb);
856 	/* -EIO all pending I/O */
857 	rpc = server->client_acl;
858 	if (!IS_ERR(rpc))
859 		rpc_killall_tasks(rpc);
860 	rpc = server->client;
861 	if (!IS_ERR(rpc))
862 		rpc_killall_tasks(rpc);
863 }
864 
865 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
866 {
867 	struct nfs_parsed_mount_data *data;
868 
869 	data = kzalloc(sizeof(*data), GFP_KERNEL);
870 	if (data) {
871 		data->acregmin		= NFS_DEF_ACREGMIN;
872 		data->acregmax		= NFS_DEF_ACREGMAX;
873 		data->acdirmin		= NFS_DEF_ACDIRMIN;
874 		data->acdirmax		= NFS_DEF_ACDIRMAX;
875 		data->mount_server.port	= NFS_UNSPEC_PORT;
876 		data->nfs_server.port	= NFS_UNSPEC_PORT;
877 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
878 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
879 		data->auth_flavor_len	= 1;
880 		data->version		= version;
881 		data->minorversion	= 0;
882 	}
883 	return data;
884 }
885 
886 /*
887  * Sanity-check a server address provided by the mount command.
888  *
889  * Address family must be initialized, and address must not be
890  * the ANY address for that family.
891  */
892 static int nfs_verify_server_address(struct sockaddr *addr)
893 {
894 	switch (addr->sa_family) {
895 	case AF_INET: {
896 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
897 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
898 	}
899 	case AF_INET6: {
900 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
901 		return !ipv6_addr_any(sa);
902 	}
903 	}
904 
905 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
906 	return 0;
907 }
908 
909 /*
910  * Select between a default port value and a user-specified port value.
911  * If a zero value is set, then autobind will be used.
912  */
913 static void nfs_set_port(struct sockaddr *sap, int *port,
914 				 const unsigned short default_port)
915 {
916 	if (*port == NFS_UNSPEC_PORT)
917 		*port = default_port;
918 
919 	rpc_set_port(sap, *port);
920 }
921 
922 /*
923  * Sanity check the NFS transport protocol.
924  *
925  */
926 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
927 {
928 	switch (mnt->nfs_server.protocol) {
929 	case XPRT_TRANSPORT_UDP:
930 	case XPRT_TRANSPORT_TCP:
931 	case XPRT_TRANSPORT_RDMA:
932 		break;
933 	default:
934 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
935 	}
936 }
937 
938 /*
939  * For text based NFSv2/v3 mounts, the mount protocol transport default
940  * settings should depend upon the specified NFS transport.
941  */
942 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
943 {
944 	nfs_validate_transport_protocol(mnt);
945 
946 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
947 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
948 			return;
949 	switch (mnt->nfs_server.protocol) {
950 	case XPRT_TRANSPORT_UDP:
951 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
952 		break;
953 	case XPRT_TRANSPORT_TCP:
954 	case XPRT_TRANSPORT_RDMA:
955 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
956 	}
957 }
958 
959 /*
960  * Parse the value of the 'sec=' option.
961  */
962 static int nfs_parse_security_flavors(char *value,
963 				      struct nfs_parsed_mount_data *mnt)
964 {
965 	substring_t args[MAX_OPT_ARGS];
966 
967 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
968 
969 	switch (match_token(value, nfs_secflavor_tokens, args)) {
970 	case Opt_sec_none:
971 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
972 		break;
973 	case Opt_sec_sys:
974 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
975 		break;
976 	case Opt_sec_krb5:
977 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
978 		break;
979 	case Opt_sec_krb5i:
980 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
981 		break;
982 	case Opt_sec_krb5p:
983 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
984 		break;
985 	case Opt_sec_lkey:
986 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
987 		break;
988 	case Opt_sec_lkeyi:
989 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
990 		break;
991 	case Opt_sec_lkeyp:
992 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
993 		break;
994 	case Opt_sec_spkm:
995 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
996 		break;
997 	case Opt_sec_spkmi:
998 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
999 		break;
1000 	case Opt_sec_spkmp:
1001 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1002 		break;
1003 	default:
1004 		return 0;
1005 	}
1006 
1007 	mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1008 	mnt->auth_flavor_len = 1;
1009 	return 1;
1010 }
1011 
1012 static int nfs_get_option_str(substring_t args[], char **option)
1013 {
1014 	kfree(*option);
1015 	*option = match_strdup(args);
1016 	return !option;
1017 }
1018 
1019 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1020 {
1021 	int rc;
1022 	char *string;
1023 
1024 	string = match_strdup(args);
1025 	if (string == NULL)
1026 		return -ENOMEM;
1027 	rc = strict_strtoul(string, 10, option);
1028 	kfree(string);
1029 
1030 	return rc;
1031 }
1032 
1033 /*
1034  * Error-check and convert a string of mount options from user space into
1035  * a data structure.  The whole mount string is processed; bad options are
1036  * skipped as they are encountered.  If there were no errors, return 1;
1037  * otherwise return 0 (zero).
1038  */
1039 static int nfs_parse_mount_options(char *raw,
1040 				   struct nfs_parsed_mount_data *mnt)
1041 {
1042 	char *p, *string, *secdata;
1043 	int rc, sloppy = 0, invalid_option = 0;
1044 	unsigned short protofamily = AF_UNSPEC;
1045 	unsigned short mountfamily = AF_UNSPEC;
1046 
1047 	if (!raw) {
1048 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1049 		return 1;
1050 	}
1051 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1052 
1053 	secdata = alloc_secdata();
1054 	if (!secdata)
1055 		goto out_nomem;
1056 
1057 	rc = security_sb_copy_data(raw, secdata);
1058 	if (rc)
1059 		goto out_security_failure;
1060 
1061 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1062 	if (rc)
1063 		goto out_security_failure;
1064 
1065 	free_secdata(secdata);
1066 
1067 	while ((p = strsep(&raw, ",")) != NULL) {
1068 		substring_t args[MAX_OPT_ARGS];
1069 		unsigned long option;
1070 		int token;
1071 
1072 		if (!*p)
1073 			continue;
1074 
1075 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1076 
1077 		token = match_token(p, nfs_mount_option_tokens, args);
1078 		switch (token) {
1079 
1080 		/*
1081 		 * boolean options:  foo/nofoo
1082 		 */
1083 		case Opt_soft:
1084 			mnt->flags |= NFS_MOUNT_SOFT;
1085 			break;
1086 		case Opt_hard:
1087 			mnt->flags &= ~NFS_MOUNT_SOFT;
1088 			break;
1089 		case Opt_posix:
1090 			mnt->flags |= NFS_MOUNT_POSIX;
1091 			break;
1092 		case Opt_noposix:
1093 			mnt->flags &= ~NFS_MOUNT_POSIX;
1094 			break;
1095 		case Opt_cto:
1096 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1097 			break;
1098 		case Opt_nocto:
1099 			mnt->flags |= NFS_MOUNT_NOCTO;
1100 			break;
1101 		case Opt_ac:
1102 			mnt->flags &= ~NFS_MOUNT_NOAC;
1103 			break;
1104 		case Opt_noac:
1105 			mnt->flags |= NFS_MOUNT_NOAC;
1106 			break;
1107 		case Opt_lock:
1108 			mnt->flags &= ~NFS_MOUNT_NONLM;
1109 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1110 					NFS_MOUNT_LOCAL_FCNTL);
1111 			break;
1112 		case Opt_nolock:
1113 			mnt->flags |= NFS_MOUNT_NONLM;
1114 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1115 				       NFS_MOUNT_LOCAL_FCNTL);
1116 			break;
1117 		case Opt_v2:
1118 			mnt->flags &= ~NFS_MOUNT_VER3;
1119 			mnt->version = 2;
1120 			break;
1121 		case Opt_v3:
1122 			mnt->flags |= NFS_MOUNT_VER3;
1123 			mnt->version = 3;
1124 			break;
1125 		case Opt_v4:
1126 			mnt->flags &= ~NFS_MOUNT_VER3;
1127 			mnt->version = 4;
1128 			break;
1129 		case Opt_udp:
1130 			mnt->flags &= ~NFS_MOUNT_TCP;
1131 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1132 			break;
1133 		case Opt_tcp:
1134 			mnt->flags |= NFS_MOUNT_TCP;
1135 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1136 			break;
1137 		case Opt_rdma:
1138 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1139 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1140 			xprt_load_transport(p);
1141 			break;
1142 		case Opt_acl:
1143 			mnt->flags &= ~NFS_MOUNT_NOACL;
1144 			break;
1145 		case Opt_noacl:
1146 			mnt->flags |= NFS_MOUNT_NOACL;
1147 			break;
1148 		case Opt_rdirplus:
1149 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1150 			break;
1151 		case Opt_nordirplus:
1152 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1153 			break;
1154 		case Opt_sharecache:
1155 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1156 			break;
1157 		case Opt_nosharecache:
1158 			mnt->flags |= NFS_MOUNT_UNSHARED;
1159 			break;
1160 		case Opt_resvport:
1161 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1162 			break;
1163 		case Opt_noresvport:
1164 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1165 			break;
1166 		case Opt_fscache:
1167 			mnt->options |= NFS_OPTION_FSCACHE;
1168 			kfree(mnt->fscache_uniq);
1169 			mnt->fscache_uniq = NULL;
1170 			break;
1171 		case Opt_nofscache:
1172 			mnt->options &= ~NFS_OPTION_FSCACHE;
1173 			kfree(mnt->fscache_uniq);
1174 			mnt->fscache_uniq = NULL;
1175 			break;
1176 
1177 		/*
1178 		 * options that take numeric values
1179 		 */
1180 		case Opt_port:
1181 			if (nfs_get_option_ul(args, &option) ||
1182 			    option > USHRT_MAX)
1183 				goto out_invalid_value;
1184 			mnt->nfs_server.port = option;
1185 			break;
1186 		case Opt_rsize:
1187 			if (nfs_get_option_ul(args, &option))
1188 				goto out_invalid_value;
1189 			mnt->rsize = option;
1190 			break;
1191 		case Opt_wsize:
1192 			if (nfs_get_option_ul(args, &option))
1193 				goto out_invalid_value;
1194 			mnt->wsize = option;
1195 			break;
1196 		case Opt_bsize:
1197 			if (nfs_get_option_ul(args, &option))
1198 				goto out_invalid_value;
1199 			mnt->bsize = option;
1200 			break;
1201 		case Opt_timeo:
1202 			if (nfs_get_option_ul(args, &option) || option == 0)
1203 				goto out_invalid_value;
1204 			mnt->timeo = option;
1205 			break;
1206 		case Opt_retrans:
1207 			if (nfs_get_option_ul(args, &option) || option == 0)
1208 				goto out_invalid_value;
1209 			mnt->retrans = option;
1210 			break;
1211 		case Opt_acregmin:
1212 			if (nfs_get_option_ul(args, &option))
1213 				goto out_invalid_value;
1214 			mnt->acregmin = option;
1215 			break;
1216 		case Opt_acregmax:
1217 			if (nfs_get_option_ul(args, &option))
1218 				goto out_invalid_value;
1219 			mnt->acregmax = option;
1220 			break;
1221 		case Opt_acdirmin:
1222 			if (nfs_get_option_ul(args, &option))
1223 				goto out_invalid_value;
1224 			mnt->acdirmin = option;
1225 			break;
1226 		case Opt_acdirmax:
1227 			if (nfs_get_option_ul(args, &option))
1228 				goto out_invalid_value;
1229 			mnt->acdirmax = option;
1230 			break;
1231 		case Opt_actimeo:
1232 			if (nfs_get_option_ul(args, &option))
1233 				goto out_invalid_value;
1234 			mnt->acregmin = mnt->acregmax =
1235 			mnt->acdirmin = mnt->acdirmax = option;
1236 			break;
1237 		case Opt_namelen:
1238 			if (nfs_get_option_ul(args, &option))
1239 				goto out_invalid_value;
1240 			mnt->namlen = option;
1241 			break;
1242 		case Opt_mountport:
1243 			if (nfs_get_option_ul(args, &option) ||
1244 			    option > USHRT_MAX)
1245 				goto out_invalid_value;
1246 			mnt->mount_server.port = option;
1247 			break;
1248 		case Opt_mountvers:
1249 			if (nfs_get_option_ul(args, &option) ||
1250 			    option < NFS_MNT_VERSION ||
1251 			    option > NFS_MNT3_VERSION)
1252 				goto out_invalid_value;
1253 			mnt->mount_server.version = option;
1254 			break;
1255 		case Opt_nfsvers:
1256 			if (nfs_get_option_ul(args, &option))
1257 				goto out_invalid_value;
1258 			switch (option) {
1259 			case NFS2_VERSION:
1260 				mnt->flags &= ~NFS_MOUNT_VER3;
1261 				mnt->version = 2;
1262 				break;
1263 			case NFS3_VERSION:
1264 				mnt->flags |= NFS_MOUNT_VER3;
1265 				mnt->version = 3;
1266 				break;
1267 			case NFS4_VERSION:
1268 				mnt->flags &= ~NFS_MOUNT_VER3;
1269 				mnt->version = 4;
1270 				break;
1271 			default:
1272 				goto out_invalid_value;
1273 			}
1274 			break;
1275 		case Opt_minorversion:
1276 			if (nfs_get_option_ul(args, &option))
1277 				goto out_invalid_value;
1278 			if (option > NFS4_MAX_MINOR_VERSION)
1279 				goto out_invalid_value;
1280 			mnt->minorversion = option;
1281 			break;
1282 
1283 		/*
1284 		 * options that take text values
1285 		 */
1286 		case Opt_sec:
1287 			string = match_strdup(args);
1288 			if (string == NULL)
1289 				goto out_nomem;
1290 			rc = nfs_parse_security_flavors(string, mnt);
1291 			kfree(string);
1292 			if (!rc) {
1293 				dfprintk(MOUNT, "NFS:   unrecognized "
1294 						"security flavor\n");
1295 				return 0;
1296 			}
1297 			break;
1298 		case Opt_proto:
1299 			string = match_strdup(args);
1300 			if (string == NULL)
1301 				goto out_nomem;
1302 			token = match_token(string,
1303 					    nfs_xprt_protocol_tokens, args);
1304 
1305 			protofamily = AF_INET;
1306 			switch (token) {
1307 			case Opt_xprt_udp6:
1308 				protofamily = AF_INET6;
1309 			case Opt_xprt_udp:
1310 				mnt->flags &= ~NFS_MOUNT_TCP;
1311 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1312 				break;
1313 			case Opt_xprt_tcp6:
1314 				protofamily = AF_INET6;
1315 			case Opt_xprt_tcp:
1316 				mnt->flags |= NFS_MOUNT_TCP;
1317 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1318 				break;
1319 			case Opt_xprt_rdma:
1320 				/* vector side protocols to TCP */
1321 				mnt->flags |= NFS_MOUNT_TCP;
1322 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1323 				xprt_load_transport(string);
1324 				break;
1325 			default:
1326 				dfprintk(MOUNT, "NFS:   unrecognized "
1327 						"transport protocol\n");
1328 				kfree(string);
1329 				return 0;
1330 			}
1331 			kfree(string);
1332 			break;
1333 		case Opt_mountproto:
1334 			string = match_strdup(args);
1335 			if (string == NULL)
1336 				goto out_nomem;
1337 			token = match_token(string,
1338 					    nfs_xprt_protocol_tokens, args);
1339 			kfree(string);
1340 
1341 			mountfamily = AF_INET;
1342 			switch (token) {
1343 			case Opt_xprt_udp6:
1344 				mountfamily = AF_INET6;
1345 			case Opt_xprt_udp:
1346 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1347 				break;
1348 			case Opt_xprt_tcp6:
1349 				mountfamily = AF_INET6;
1350 			case Opt_xprt_tcp:
1351 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1352 				break;
1353 			case Opt_xprt_rdma: /* not used for side protocols */
1354 			default:
1355 				dfprintk(MOUNT, "NFS:   unrecognized "
1356 						"transport protocol\n");
1357 				return 0;
1358 			}
1359 			break;
1360 		case Opt_addr:
1361 			string = match_strdup(args);
1362 			if (string == NULL)
1363 				goto out_nomem;
1364 			mnt->nfs_server.addrlen =
1365 				rpc_pton(string, strlen(string),
1366 					(struct sockaddr *)
1367 					&mnt->nfs_server.address,
1368 					sizeof(mnt->nfs_server.address));
1369 			kfree(string);
1370 			if (mnt->nfs_server.addrlen == 0)
1371 				goto out_invalid_address;
1372 			break;
1373 		case Opt_clientaddr:
1374 			if (nfs_get_option_str(args, &mnt->client_address))
1375 				goto out_nomem;
1376 			break;
1377 		case Opt_mounthost:
1378 			if (nfs_get_option_str(args,
1379 					       &mnt->mount_server.hostname))
1380 				goto out_nomem;
1381 			break;
1382 		case Opt_mountaddr:
1383 			string = match_strdup(args);
1384 			if (string == NULL)
1385 				goto out_nomem;
1386 			mnt->mount_server.addrlen =
1387 				rpc_pton(string, strlen(string),
1388 					(struct sockaddr *)
1389 					&mnt->mount_server.address,
1390 					sizeof(mnt->mount_server.address));
1391 			kfree(string);
1392 			if (mnt->mount_server.addrlen == 0)
1393 				goto out_invalid_address;
1394 			break;
1395 		case Opt_lookupcache:
1396 			string = match_strdup(args);
1397 			if (string == NULL)
1398 				goto out_nomem;
1399 			token = match_token(string,
1400 					nfs_lookupcache_tokens, args);
1401 			kfree(string);
1402 			switch (token) {
1403 				case Opt_lookupcache_all:
1404 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1405 					break;
1406 				case Opt_lookupcache_positive:
1407 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1408 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1409 					break;
1410 				case Opt_lookupcache_none:
1411 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1412 					break;
1413 				default:
1414 					dfprintk(MOUNT, "NFS:   invalid "
1415 							"lookupcache argument\n");
1416 					return 0;
1417 			};
1418 			break;
1419 		case Opt_fscache_uniq:
1420 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1421 				goto out_nomem;
1422 			mnt->options |= NFS_OPTION_FSCACHE;
1423 			break;
1424 		case Opt_local_lock:
1425 			string = match_strdup(args);
1426 			if (string == NULL)
1427 				goto out_nomem;
1428 			token = match_token(string, nfs_local_lock_tokens,
1429 					args);
1430 			kfree(string);
1431 			switch (token) {
1432 			case Opt_local_lock_all:
1433 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1434 					       NFS_MOUNT_LOCAL_FCNTL);
1435 				break;
1436 			case Opt_local_lock_flock:
1437 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1438 				break;
1439 			case Opt_local_lock_posix:
1440 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1441 				break;
1442 			case Opt_local_lock_none:
1443 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1444 						NFS_MOUNT_LOCAL_FCNTL);
1445 				break;
1446 			default:
1447 				dfprintk(MOUNT, "NFS:	invalid	"
1448 						"local_lock argument\n");
1449 				return 0;
1450 			};
1451 			break;
1452 
1453 		/*
1454 		 * Special options
1455 		 */
1456 		case Opt_sloppy:
1457 			sloppy = 1;
1458 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1459 			break;
1460 		case Opt_userspace:
1461 		case Opt_deprecated:
1462 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1463 					"'%s'\n", p);
1464 			break;
1465 
1466 		default:
1467 			invalid_option = 1;
1468 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1469 					"'%s'\n", p);
1470 		}
1471 	}
1472 
1473 	if (!sloppy && invalid_option)
1474 		return 0;
1475 
1476 	/*
1477 	 * verify that any proto=/mountproto= options match the address
1478 	 * familiies in the addr=/mountaddr= options.
1479 	 */
1480 	if (protofamily != AF_UNSPEC &&
1481 	    protofamily != mnt->nfs_server.address.ss_family)
1482 		goto out_proto_mismatch;
1483 
1484 	if (mountfamily != AF_UNSPEC) {
1485 		if (mnt->mount_server.addrlen) {
1486 			if (mountfamily != mnt->mount_server.address.ss_family)
1487 				goto out_mountproto_mismatch;
1488 		} else {
1489 			if (mountfamily != mnt->nfs_server.address.ss_family)
1490 				goto out_mountproto_mismatch;
1491 		}
1492 	}
1493 
1494 	return 1;
1495 
1496 out_mountproto_mismatch:
1497 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1498 			 "option\n");
1499 	return 0;
1500 out_proto_mismatch:
1501 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1502 	return 0;
1503 out_invalid_address:
1504 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1505 	return 0;
1506 out_invalid_value:
1507 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1508 	return 0;
1509 out_nomem:
1510 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1511 	return 0;
1512 out_security_failure:
1513 	free_secdata(secdata);
1514 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1515 	return 0;
1516 }
1517 
1518 /*
1519  * Match the requested auth flavors with the list returned by
1520  * the server.  Returns zero and sets the mount's authentication
1521  * flavor on success; returns -EACCES if server does not support
1522  * the requested flavor.
1523  */
1524 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1525 			     struct nfs_mount_request *request)
1526 {
1527 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1528 
1529 	/*
1530 	 * Certain releases of Linux's mountd return an empty
1531 	 * flavor list.  To prevent behavioral regression with
1532 	 * these servers (ie. rejecting mounts that used to
1533 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1534 	 * if the returned flavor list is empty.
1535 	 */
1536 	if (server_authlist_len == 0)
1537 		return 0;
1538 
1539 	/*
1540 	 * We avoid sophisticated negotiating here, as there are
1541 	 * plenty of cases where we can get it wrong, providing
1542 	 * either too little or too much security.
1543 	 *
1544 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1545 	 * flavor listed first.  However, some servers list
1546 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1547 	 * preferred default, in args->auth_flavors[0] if user
1548 	 * didn't specify sec= mount option.
1549 	 */
1550 	for (i = 0; i < args->auth_flavor_len; i++)
1551 		for (j = 0; j < server_authlist_len; j++)
1552 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1553 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1554 					request->auth_flavs[j]);
1555 				args->auth_flavors[0] = request->auth_flavs[j];
1556 				return 0;
1557 			}
1558 
1559 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1560 	nfs_umount(request);
1561 	return -EACCES;
1562 }
1563 
1564 /*
1565  * Use the remote server's MOUNT service to request the NFS file handle
1566  * corresponding to the provided path.
1567  */
1568 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1569 			 struct nfs_fh *root_fh)
1570 {
1571 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1572 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1573 	struct nfs_mount_request request = {
1574 		.sap		= (struct sockaddr *)
1575 						&args->mount_server.address,
1576 		.dirpath	= args->nfs_server.export_path,
1577 		.protocol	= args->mount_server.protocol,
1578 		.fh		= root_fh,
1579 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1580 		.auth_flav_len	= &server_authlist_len,
1581 		.auth_flavs	= server_authlist,
1582 	};
1583 	int status;
1584 
1585 	if (args->mount_server.version == 0) {
1586 		switch (args->version) {
1587 			default:
1588 				args->mount_server.version = NFS_MNT3_VERSION;
1589 				break;
1590 			case 2:
1591 				args->mount_server.version = NFS_MNT_VERSION;
1592 		}
1593 	}
1594 	request.version = args->mount_server.version;
1595 
1596 	if (args->mount_server.hostname)
1597 		request.hostname = args->mount_server.hostname;
1598 	else
1599 		request.hostname = args->nfs_server.hostname;
1600 
1601 	/*
1602 	 * Construct the mount server's address.
1603 	 */
1604 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1605 		memcpy(request.sap, &args->nfs_server.address,
1606 		       args->nfs_server.addrlen);
1607 		args->mount_server.addrlen = args->nfs_server.addrlen;
1608 	}
1609 	request.salen = args->mount_server.addrlen;
1610 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1611 
1612 	/*
1613 	 * Now ask the mount server to map our export path
1614 	 * to a file handle.
1615 	 */
1616 	status = nfs_mount(&request);
1617 	if (status != 0) {
1618 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1619 				request.hostname, status);
1620 		return status;
1621 	}
1622 
1623 	/*
1624 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1625 	 */
1626 	if (args->mount_server.version != NFS_MNT3_VERSION)
1627 		return 0;
1628 	return nfs_walk_authlist(args, &request);
1629 }
1630 
1631 /*
1632  * Split "dev_name" into "hostname:export_path".
1633  *
1634  * The leftmost colon demarks the split between the server's hostname
1635  * and the export path.  If the hostname starts with a left square
1636  * bracket, then it may contain colons.
1637  *
1638  * Note: caller frees hostname and export path, even on error.
1639  */
1640 static int nfs_parse_devname(const char *dev_name,
1641 			     char **hostname, size_t maxnamlen,
1642 			     char **export_path, size_t maxpathlen)
1643 {
1644 	size_t len;
1645 	char *end;
1646 
1647 	/* Is the host name protected with square brakcets? */
1648 	if (*dev_name == '[') {
1649 		end = strchr(++dev_name, ']');
1650 		if (end == NULL || end[1] != ':')
1651 			goto out_bad_devname;
1652 
1653 		len = end - dev_name;
1654 		end++;
1655 	} else {
1656 		char *comma;
1657 
1658 		end = strchr(dev_name, ':');
1659 		if (end == NULL)
1660 			goto out_bad_devname;
1661 		len = end - dev_name;
1662 
1663 		/* kill possible hostname list: not supported */
1664 		comma = strchr(dev_name, ',');
1665 		if (comma != NULL && comma < end)
1666 			*comma = 0;
1667 	}
1668 
1669 	if (len > maxnamlen)
1670 		goto out_hostname;
1671 
1672 	/* N.B. caller will free nfs_server.hostname in all cases */
1673 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1674 	if (*hostname == NULL)
1675 		goto out_nomem;
1676 	len = strlen(++end);
1677 	if (len > maxpathlen)
1678 		goto out_path;
1679 	*export_path = kstrndup(end, len, GFP_KERNEL);
1680 	if (!*export_path)
1681 		goto out_nomem;
1682 
1683 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1684 	return 0;
1685 
1686 out_bad_devname:
1687 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1688 	return -EINVAL;
1689 
1690 out_nomem:
1691 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1692 	return -ENOMEM;
1693 
1694 out_hostname:
1695 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1696 	return -ENAMETOOLONG;
1697 
1698 out_path:
1699 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1700 	return -ENAMETOOLONG;
1701 }
1702 
1703 /*
1704  * Validate the NFS2/NFS3 mount data
1705  * - fills in the mount root filehandle
1706  *
1707  * For option strings, user space handles the following behaviors:
1708  *
1709  * + DNS: mapping server host name to IP address ("addr=" option)
1710  *
1711  * + failure mode: how to behave if a mount request can't be handled
1712  *   immediately ("fg/bg" option)
1713  *
1714  * + retry: how often to retry a mount request ("retry=" option)
1715  *
1716  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1717  *   mountproto=tcp after mountproto=udp, and so on
1718  */
1719 static int nfs_validate_mount_data(void *options,
1720 				   struct nfs_parsed_mount_data *args,
1721 				   struct nfs_fh *mntfh,
1722 				   const char *dev_name)
1723 {
1724 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1725 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1726 
1727 	if (data == NULL)
1728 		goto out_no_data;
1729 
1730 	switch (data->version) {
1731 	case 1:
1732 		data->namlen = 0;
1733 	case 2:
1734 		data->bsize = 0;
1735 	case 3:
1736 		if (data->flags & NFS_MOUNT_VER3)
1737 			goto out_no_v3;
1738 		data->root.size = NFS2_FHSIZE;
1739 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1740 	case 4:
1741 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1742 			goto out_no_sec;
1743 	case 5:
1744 		memset(data->context, 0, sizeof(data->context));
1745 	case 6:
1746 		if (data->flags & NFS_MOUNT_VER3) {
1747 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1748 				goto out_invalid_fh;
1749 			mntfh->size = data->root.size;
1750 			args->version = 3;
1751 		} else {
1752 			mntfh->size = NFS2_FHSIZE;
1753 			args->version = 2;
1754 		}
1755 
1756 
1757 		memcpy(mntfh->data, data->root.data, mntfh->size);
1758 		if (mntfh->size < sizeof(mntfh->data))
1759 			memset(mntfh->data + mntfh->size, 0,
1760 			       sizeof(mntfh->data) - mntfh->size);
1761 
1762 		/*
1763 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1764 		 * can deal with.
1765 		 */
1766 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1767 		args->flags		|= NFS_MOUNT_LEGACY_INTERFACE;
1768 		args->rsize		= data->rsize;
1769 		args->wsize		= data->wsize;
1770 		args->timeo		= data->timeo;
1771 		args->retrans		= data->retrans;
1772 		args->acregmin		= data->acregmin;
1773 		args->acregmax		= data->acregmax;
1774 		args->acdirmin		= data->acdirmin;
1775 		args->acdirmax		= data->acdirmax;
1776 
1777 		memcpy(sap, &data->addr, sizeof(data->addr));
1778 		args->nfs_server.addrlen = sizeof(data->addr);
1779 		if (!nfs_verify_server_address(sap))
1780 			goto out_no_address;
1781 
1782 		if (!(data->flags & NFS_MOUNT_TCP))
1783 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1784 		/* N.B. caller will free nfs_server.hostname in all cases */
1785 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1786 		args->namlen		= data->namlen;
1787 		args->bsize		= data->bsize;
1788 
1789 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1790 			args->auth_flavors[0] = data->pseudoflavor;
1791 		if (!args->nfs_server.hostname)
1792 			goto out_nomem;
1793 
1794 		if (!(data->flags & NFS_MOUNT_NONLM))
1795 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1796 					 NFS_MOUNT_LOCAL_FCNTL);
1797 		else
1798 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1799 					NFS_MOUNT_LOCAL_FCNTL);
1800 		/*
1801 		 * The legacy version 6 binary mount data from userspace has a
1802 		 * field used only to transport selinux information into the
1803 		 * the kernel.  To continue to support that functionality we
1804 		 * have a touch of selinux knowledge here in the NFS code. The
1805 		 * userspace code converted context=blah to just blah so we are
1806 		 * converting back to the full string selinux understands.
1807 		 */
1808 		if (data->context[0]){
1809 #ifdef CONFIG_SECURITY_SELINUX
1810 			int rc;
1811 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1812 			if (!opts_str)
1813 				return -ENOMEM;
1814 			strcpy(opts_str, "context=");
1815 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1816 			strcat(opts_str, &data->context[0]);
1817 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1818 			kfree(opts_str);
1819 			if (rc)
1820 				return rc;
1821 #else
1822 			return -EINVAL;
1823 #endif
1824 		}
1825 
1826 		break;
1827 	default: {
1828 		int status;
1829 
1830 		if (nfs_parse_mount_options((char *)options, args) == 0)
1831 			return -EINVAL;
1832 
1833 		if (!nfs_verify_server_address(sap))
1834 			goto out_no_address;
1835 
1836 		if (args->version == 4)
1837 #ifdef CONFIG_NFS_V4
1838 			return nfs4_validate_text_mount_data(options,
1839 							     args, dev_name);
1840 #else
1841 			goto out_v4_not_compiled;
1842 #endif
1843 
1844 		nfs_set_port(sap, &args->nfs_server.port, 0);
1845 
1846 		nfs_set_mount_transport_protocol(args);
1847 
1848 		status = nfs_parse_devname(dev_name,
1849 					   &args->nfs_server.hostname,
1850 					   PAGE_SIZE,
1851 					   &args->nfs_server.export_path,
1852 					   NFS_MAXPATHLEN);
1853 		if (!status)
1854 			status = nfs_try_mount(args, mntfh);
1855 
1856 		kfree(args->nfs_server.export_path);
1857 		args->nfs_server.export_path = NULL;
1858 
1859 		if (status)
1860 			return status;
1861 
1862 		break;
1863 		}
1864 	}
1865 
1866 #ifndef CONFIG_NFS_V3
1867 	if (args->version == 3)
1868 		goto out_v3_not_compiled;
1869 #endif /* !CONFIG_NFS_V3 */
1870 
1871 	return 0;
1872 
1873 out_no_data:
1874 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1875 	return -EINVAL;
1876 
1877 out_no_v3:
1878 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1879 		 data->version);
1880 	return -EINVAL;
1881 
1882 out_no_sec:
1883 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1884 	return -EINVAL;
1885 
1886 #ifndef CONFIG_NFS_V3
1887 out_v3_not_compiled:
1888 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1889 	return -EPROTONOSUPPORT;
1890 #endif /* !CONFIG_NFS_V3 */
1891 
1892 #ifndef CONFIG_NFS_V4
1893 out_v4_not_compiled:
1894 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1895 	return -EPROTONOSUPPORT;
1896 #endif /* !CONFIG_NFS_V4 */
1897 
1898 out_nomem:
1899 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1900 	return -ENOMEM;
1901 
1902 out_no_address:
1903 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1904 	return -EINVAL;
1905 
1906 out_invalid_fh:
1907 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1908 	return -EINVAL;
1909 }
1910 
1911 static int
1912 nfs_compare_remount_data(struct nfs_server *nfss,
1913 			 struct nfs_parsed_mount_data *data)
1914 {
1915 	if (data->flags != nfss->flags ||
1916 	    data->rsize != nfss->rsize ||
1917 	    data->wsize != nfss->wsize ||
1918 	    data->retrans != nfss->client->cl_timeout->to_retries ||
1919 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1920 	    data->acregmin != nfss->acregmin / HZ ||
1921 	    data->acregmax != nfss->acregmax / HZ ||
1922 	    data->acdirmin != nfss->acdirmin / HZ ||
1923 	    data->acdirmax != nfss->acdirmax / HZ ||
1924 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1925 	    data->nfs_server.port != nfss->port ||
1926 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1927 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1928 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
1929 		return -EINVAL;
1930 
1931 	return 0;
1932 }
1933 
1934 static int
1935 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1936 {
1937 	int error;
1938 	struct nfs_server *nfss = sb->s_fs_info;
1939 	struct nfs_parsed_mount_data *data;
1940 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1941 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1942 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1943 
1944 	/*
1945 	 * Userspace mount programs that send binary options generally send
1946 	 * them populated with default values. We have no way to know which
1947 	 * ones were explicitly specified. Fall back to legacy behavior and
1948 	 * just return success.
1949 	 */
1950 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1951 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
1952 					   options->version <= 6))))
1953 		return 0;
1954 
1955 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1956 	if (data == NULL)
1957 		return -ENOMEM;
1958 
1959 	/* fill out struct with values from existing mount */
1960 	data->flags = nfss->flags;
1961 	data->rsize = nfss->rsize;
1962 	data->wsize = nfss->wsize;
1963 	data->retrans = nfss->client->cl_timeout->to_retries;
1964 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1965 	data->acregmin = nfss->acregmin / HZ;
1966 	data->acregmax = nfss->acregmax / HZ;
1967 	data->acdirmin = nfss->acdirmin / HZ;
1968 	data->acdirmax = nfss->acdirmax / HZ;
1969 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1970 	data->nfs_server.port = nfss->port;
1971 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1972 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1973 		data->nfs_server.addrlen);
1974 
1975 	/* overwrite those values with any that were specified */
1976 	error = nfs_parse_mount_options((char *)options, data);
1977 	if (error < 0)
1978 		goto out;
1979 
1980 	/*
1981 	 * noac is a special case. It implies -o sync, but that's not
1982 	 * necessarily reflected in the mtab options. do_remount_sb
1983 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
1984 	 * remount options, so we have to explicitly reset it.
1985 	 */
1986 	if (data->flags & NFS_MOUNT_NOAC)
1987 		*flags |= MS_SYNCHRONOUS;
1988 
1989 	/* compare new mount options with old ones */
1990 	error = nfs_compare_remount_data(nfss, data);
1991 out:
1992 	kfree(data);
1993 	return error;
1994 }
1995 
1996 /*
1997  * Initialise the common bits of the superblock
1998  */
1999 static inline void nfs_initialise_sb(struct super_block *sb)
2000 {
2001 	struct nfs_server *server = NFS_SB(sb);
2002 
2003 	sb->s_magic = NFS_SUPER_MAGIC;
2004 
2005 	/* We probably want something more informative here */
2006 	snprintf(sb->s_id, sizeof(sb->s_id),
2007 		 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2008 
2009 	if (sb->s_blocksize == 0)
2010 		sb->s_blocksize = nfs_block_bits(server->wsize,
2011 						 &sb->s_blocksize_bits);
2012 
2013 	if (server->flags & NFS_MOUNT_NOAC)
2014 		sb->s_flags |= MS_SYNCHRONOUS;
2015 
2016 	sb->s_bdi = &server->backing_dev_info;
2017 
2018 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2019 }
2020 
2021 /*
2022  * Finish setting up an NFS2/3 superblock
2023  */
2024 static void nfs_fill_super(struct super_block *sb,
2025 			   struct nfs_parsed_mount_data *data)
2026 {
2027 	struct nfs_server *server = NFS_SB(sb);
2028 
2029 	sb->s_blocksize_bits = 0;
2030 	sb->s_blocksize = 0;
2031 	if (data->bsize)
2032 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2033 
2034 	if (server->nfs_client->rpc_ops->version == 3) {
2035 		/* The VFS shouldn't apply the umask to mode bits. We will do
2036 		 * so ourselves when necessary.
2037 		 */
2038 		sb->s_flags |= MS_POSIXACL;
2039 		sb->s_time_gran = 1;
2040 	}
2041 
2042 	sb->s_op = &nfs_sops;
2043  	nfs_initialise_sb(sb);
2044 }
2045 
2046 /*
2047  * Finish setting up a cloned NFS2/3 superblock
2048  */
2049 static void nfs_clone_super(struct super_block *sb,
2050 			    const struct super_block *old_sb)
2051 {
2052 	struct nfs_server *server = NFS_SB(sb);
2053 
2054 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2055 	sb->s_blocksize = old_sb->s_blocksize;
2056 	sb->s_maxbytes = old_sb->s_maxbytes;
2057 
2058 	if (server->nfs_client->rpc_ops->version == 3) {
2059 		/* The VFS shouldn't apply the umask to mode bits. We will do
2060 		 * so ourselves when necessary.
2061 		 */
2062 		sb->s_flags |= MS_POSIXACL;
2063 		sb->s_time_gran = 1;
2064 	}
2065 
2066 	sb->s_op = old_sb->s_op;
2067  	nfs_initialise_sb(sb);
2068 }
2069 
2070 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2071 {
2072 	const struct nfs_server *a = s->s_fs_info;
2073 	const struct rpc_clnt *clnt_a = a->client;
2074 	const struct rpc_clnt *clnt_b = b->client;
2075 
2076 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2077 		goto Ebusy;
2078 	if (a->nfs_client != b->nfs_client)
2079 		goto Ebusy;
2080 	if (a->flags != b->flags)
2081 		goto Ebusy;
2082 	if (a->wsize != b->wsize)
2083 		goto Ebusy;
2084 	if (a->rsize != b->rsize)
2085 		goto Ebusy;
2086 	if (a->acregmin != b->acregmin)
2087 		goto Ebusy;
2088 	if (a->acregmax != b->acregmax)
2089 		goto Ebusy;
2090 	if (a->acdirmin != b->acdirmin)
2091 		goto Ebusy;
2092 	if (a->acdirmax != b->acdirmax)
2093 		goto Ebusy;
2094 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2095 		goto Ebusy;
2096 	return 1;
2097 Ebusy:
2098 	return 0;
2099 }
2100 
2101 struct nfs_sb_mountdata {
2102 	struct nfs_server *server;
2103 	int mntflags;
2104 };
2105 
2106 static int nfs_set_super(struct super_block *s, void *data)
2107 {
2108 	struct nfs_sb_mountdata *sb_mntdata = data;
2109 	struct nfs_server *server = sb_mntdata->server;
2110 	int ret;
2111 
2112 	s->s_flags = sb_mntdata->mntflags;
2113 	s->s_fs_info = server;
2114 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2115 	ret = set_anon_super(s, server);
2116 	if (ret == 0)
2117 		server->s_dev = s->s_dev;
2118 	return ret;
2119 }
2120 
2121 static int nfs_compare_super_address(struct nfs_server *server1,
2122 				     struct nfs_server *server2)
2123 {
2124 	struct sockaddr *sap1, *sap2;
2125 
2126 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2127 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2128 
2129 	if (sap1->sa_family != sap2->sa_family)
2130 		return 0;
2131 
2132 	switch (sap1->sa_family) {
2133 	case AF_INET: {
2134 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2135 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2136 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2137 			return 0;
2138 		if (sin1->sin_port != sin2->sin_port)
2139 			return 0;
2140 		break;
2141 	}
2142 	case AF_INET6: {
2143 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2144 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2145 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2146 			return 0;
2147 		if (sin1->sin6_port != sin2->sin6_port)
2148 			return 0;
2149 		break;
2150 	}
2151 	default:
2152 		return 0;
2153 	}
2154 
2155 	return 1;
2156 }
2157 
2158 static int nfs_compare_super(struct super_block *sb, void *data)
2159 {
2160 	struct nfs_sb_mountdata *sb_mntdata = data;
2161 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2162 	int mntflags = sb_mntdata->mntflags;
2163 
2164 	if (!nfs_compare_super_address(old, server))
2165 		return 0;
2166 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2167 	if (old->flags & NFS_MOUNT_UNSHARED)
2168 		return 0;
2169 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2170 		return 0;
2171 	return nfs_compare_mount_options(sb, server, mntflags);
2172 }
2173 
2174 static int nfs_bdi_register(struct nfs_server *server)
2175 {
2176 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2177 }
2178 
2179 static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2180 	int flags, const char *dev_name, void *raw_data)
2181 {
2182 	struct nfs_server *server = NULL;
2183 	struct super_block *s;
2184 	struct nfs_parsed_mount_data *data;
2185 	struct nfs_fh *mntfh;
2186 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2187 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2188 	struct nfs_sb_mountdata sb_mntdata = {
2189 		.mntflags = flags,
2190 	};
2191 	int error;
2192 
2193 	data = nfs_alloc_parsed_mount_data(NFS_DEFAULT_VERSION);
2194 	mntfh = nfs_alloc_fhandle();
2195 	if (data == NULL || mntfh == NULL)
2196 		goto out_free_fh;
2197 
2198 	security_init_mnt_opts(&data->lsm_opts);
2199 
2200 	/* Validate the mount data */
2201 	error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2202 	if (error < 0) {
2203 		mntroot = ERR_PTR(error);
2204 		goto out;
2205 	}
2206 
2207 #ifdef CONFIG_NFS_V4
2208 	if (data->version == 4) {
2209 		mntroot = nfs4_try_mount(flags, dev_name, data);
2210 		kfree(data->client_address);
2211 		kfree(data->nfs_server.export_path);
2212 		goto out;
2213 	}
2214 #endif	/* CONFIG_NFS_V4 */
2215 
2216 	/* Get a volume representation */
2217 	server = nfs_create_server(data, mntfh);
2218 	if (IS_ERR(server)) {
2219 		mntroot = ERR_CAST(server);
2220 		goto out;
2221 	}
2222 	sb_mntdata.server = server;
2223 
2224 	if (server->flags & NFS_MOUNT_UNSHARED)
2225 		compare_super = NULL;
2226 
2227 	/* Get a superblock - note that we may end up sharing one that already exists */
2228 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2229 	if (IS_ERR(s)) {
2230 		mntroot = ERR_CAST(s);
2231 		goto out_err_nosb;
2232 	}
2233 
2234 	if (s->s_fs_info != server) {
2235 		nfs_free_server(server);
2236 		server = NULL;
2237 	} else {
2238 		error = nfs_bdi_register(server);
2239 		if (error) {
2240 			mntroot = ERR_PTR(error);
2241 			goto error_splat_bdi;
2242 		}
2243 	}
2244 
2245 	if (!s->s_root) {
2246 		/* initial superblock/root creation */
2247 		nfs_fill_super(s, data);
2248 		nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL);
2249 	}
2250 
2251 	mntroot = nfs_get_root(s, mntfh, dev_name);
2252 	if (IS_ERR(mntroot))
2253 		goto error_splat_super;
2254 
2255 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2256 	if (error)
2257 		goto error_splat_root;
2258 
2259 	s->s_flags |= MS_ACTIVE;
2260 
2261 out:
2262 	kfree(data->nfs_server.hostname);
2263 	kfree(data->mount_server.hostname);
2264 	kfree(data->fscache_uniq);
2265 	security_free_mnt_opts(&data->lsm_opts);
2266 out_free_fh:
2267 	nfs_free_fhandle(mntfh);
2268 	kfree(data);
2269 	return mntroot;
2270 
2271 out_err_nosb:
2272 	nfs_free_server(server);
2273 	goto out;
2274 
2275 error_splat_root:
2276 	dput(mntroot);
2277 	mntroot = ERR_PTR(error);
2278 error_splat_super:
2279 	if (server && !s->s_root)
2280 		bdi_unregister(&server->backing_dev_info);
2281 error_splat_bdi:
2282 	deactivate_locked_super(s);
2283 	goto out;
2284 }
2285 
2286 /*
2287  * Ensure that we unregister the bdi before kill_anon_super
2288  * releases the device name
2289  */
2290 static void nfs_put_super(struct super_block *s)
2291 {
2292 	struct nfs_server *server = NFS_SB(s);
2293 
2294 	bdi_unregister(&server->backing_dev_info);
2295 }
2296 
2297 /*
2298  * Destroy an NFS2/3 superblock
2299  */
2300 static void nfs_kill_super(struct super_block *s)
2301 {
2302 	struct nfs_server *server = NFS_SB(s);
2303 
2304 	kill_anon_super(s);
2305 	nfs_fscache_release_super_cookie(s);
2306 	nfs_free_server(server);
2307 }
2308 
2309 /*
2310  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2311  */
2312 static struct dentry *
2313 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2314 		const char *dev_name, void *raw_data)
2315 {
2316 	struct nfs_clone_mount *data = raw_data;
2317 	struct super_block *s;
2318 	struct nfs_server *server;
2319 	struct dentry *mntroot;
2320 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2321 	struct nfs_sb_mountdata sb_mntdata = {
2322 		.mntflags = flags,
2323 	};
2324 	int error;
2325 
2326 	dprintk("--> nfs_xdev_mount()\n");
2327 
2328 	/* create a new volume representation */
2329 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2330 	if (IS_ERR(server)) {
2331 		error = PTR_ERR(server);
2332 		goto out_err_noserver;
2333 	}
2334 	sb_mntdata.server = server;
2335 
2336 	if (server->flags & NFS_MOUNT_UNSHARED)
2337 		compare_super = NULL;
2338 
2339 	/* Get a superblock - note that we may end up sharing one that already exists */
2340 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2341 	if (IS_ERR(s)) {
2342 		error = PTR_ERR(s);
2343 		goto out_err_nosb;
2344 	}
2345 
2346 	if (s->s_fs_info != server) {
2347 		nfs_free_server(server);
2348 		server = NULL;
2349 	} else {
2350 		error = nfs_bdi_register(server);
2351 		if (error)
2352 			goto error_splat_bdi;
2353 	}
2354 
2355 	if (!s->s_root) {
2356 		/* initial superblock/root creation */
2357 		nfs_clone_super(s, data->sb);
2358 		nfs_fscache_get_super_cookie(s, NULL, data);
2359 	}
2360 
2361 	mntroot = nfs_get_root(s, data->fh, dev_name);
2362 	if (IS_ERR(mntroot)) {
2363 		error = PTR_ERR(mntroot);
2364 		goto error_splat_super;
2365 	}
2366 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2367 		dput(mntroot);
2368 		error = -ESTALE;
2369 		goto error_splat_super;
2370 	}
2371 
2372 	s->s_flags |= MS_ACTIVE;
2373 
2374 	/* clone any lsm security options from the parent to the new sb */
2375 	security_sb_clone_mnt_opts(data->sb, s);
2376 
2377 	dprintk("<-- nfs_xdev_mount() = 0\n");
2378 	return mntroot;
2379 
2380 out_err_nosb:
2381 	nfs_free_server(server);
2382 out_err_noserver:
2383 	dprintk("<-- nfs_xdev_mount() = %d [error]\n", error);
2384 	return ERR_PTR(error);
2385 
2386 error_splat_super:
2387 	if (server && !s->s_root)
2388 		bdi_unregister(&server->backing_dev_info);
2389 error_splat_bdi:
2390 	deactivate_locked_super(s);
2391 	dprintk("<-- nfs_xdev_mount() = %d [splat]\n", error);
2392 	return ERR_PTR(error);
2393 }
2394 
2395 #ifdef CONFIG_NFS_V4
2396 
2397 /*
2398  * Finish setting up a cloned NFS4 superblock
2399  */
2400 static void nfs4_clone_super(struct super_block *sb,
2401 			    const struct super_block *old_sb)
2402 {
2403 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2404 	sb->s_blocksize = old_sb->s_blocksize;
2405 	sb->s_maxbytes = old_sb->s_maxbytes;
2406 	sb->s_time_gran = 1;
2407 	sb->s_op = old_sb->s_op;
2408 	/*
2409 	 * The VFS shouldn't apply the umask to mode bits. We will do
2410 	 * so ourselves when necessary.
2411 	 */
2412 	sb->s_flags  |= MS_POSIXACL;
2413 	sb->s_xattr  = old_sb->s_xattr;
2414 	nfs_initialise_sb(sb);
2415 }
2416 
2417 /*
2418  * Set up an NFS4 superblock
2419  */
2420 static void nfs4_fill_super(struct super_block *sb)
2421 {
2422 	sb->s_time_gran = 1;
2423 	sb->s_op = &nfs4_sops;
2424 	/*
2425 	 * The VFS shouldn't apply the umask to mode bits. We will do
2426 	 * so ourselves when necessary.
2427 	 */
2428 	sb->s_flags  |= MS_POSIXACL;
2429 	sb->s_xattr = nfs4_xattr_handlers;
2430 	nfs_initialise_sb(sb);
2431 }
2432 
2433 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2434 {
2435 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2436 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2437 }
2438 
2439 static int nfs4_validate_text_mount_data(void *options,
2440 					 struct nfs_parsed_mount_data *args,
2441 					 const char *dev_name)
2442 {
2443 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2444 
2445 	nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2446 
2447 	nfs_validate_transport_protocol(args);
2448 
2449 	nfs4_validate_mount_flags(args);
2450 
2451 	if (args->version != 4) {
2452 		dfprintk(MOUNT,
2453 			 "NFS4: Illegal mount version\n");
2454 		return -EINVAL;
2455 	}
2456 
2457 	if (args->auth_flavor_len > 1) {
2458 		dfprintk(MOUNT,
2459 			 "NFS4: Too many RPC auth flavours specified\n");
2460 		return -EINVAL;
2461 	}
2462 
2463 	if (args->client_address == NULL) {
2464 		dfprintk(MOUNT,
2465 			 "NFS4: mount program didn't pass callback address\n");
2466 		return -EINVAL;
2467 	}
2468 
2469 	return nfs_parse_devname(dev_name,
2470 				   &args->nfs_server.hostname,
2471 				   NFS4_MAXNAMLEN,
2472 				   &args->nfs_server.export_path,
2473 				   NFS4_MAXPATHLEN);
2474 }
2475 
2476 /*
2477  * Validate NFSv4 mount options
2478  */
2479 static int nfs4_validate_mount_data(void *options,
2480 				    struct nfs_parsed_mount_data *args,
2481 				    const char *dev_name)
2482 {
2483 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2484 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2485 	char *c;
2486 
2487 	if (data == NULL)
2488 		goto out_no_data;
2489 
2490 	switch (data->version) {
2491 	case 1:
2492 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2493 			goto out_no_address;
2494 		if (data->host_addrlen == 0)
2495 			goto out_no_address;
2496 		args->nfs_server.addrlen = data->host_addrlen;
2497 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2498 			return -EFAULT;
2499 		if (!nfs_verify_server_address(sap))
2500 			goto out_no_address;
2501 
2502 		if (data->auth_flavourlen) {
2503 			if (data->auth_flavourlen > 1)
2504 				goto out_inval_auth;
2505 			if (copy_from_user(&args->auth_flavors[0],
2506 					   data->auth_flavours,
2507 					   sizeof(args->auth_flavors[0])))
2508 				return -EFAULT;
2509 		}
2510 
2511 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2512 		if (IS_ERR(c))
2513 			return PTR_ERR(c);
2514 		args->nfs_server.hostname = c;
2515 
2516 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2517 		if (IS_ERR(c))
2518 			return PTR_ERR(c);
2519 		args->nfs_server.export_path = c;
2520 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2521 
2522 		c = strndup_user(data->client_addr.data, 16);
2523 		if (IS_ERR(c))
2524 			return PTR_ERR(c);
2525 		args->client_address = c;
2526 
2527 		/*
2528 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2529 		 * can deal with.
2530 		 */
2531 
2532 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2533 		args->rsize	= data->rsize;
2534 		args->wsize	= data->wsize;
2535 		args->timeo	= data->timeo;
2536 		args->retrans	= data->retrans;
2537 		args->acregmin	= data->acregmin;
2538 		args->acregmax	= data->acregmax;
2539 		args->acdirmin	= data->acdirmin;
2540 		args->acdirmax	= data->acdirmax;
2541 		args->nfs_server.protocol = data->proto;
2542 		nfs_validate_transport_protocol(args);
2543 
2544 		break;
2545 	default:
2546 		if (nfs_parse_mount_options((char *)options, args) == 0)
2547 			return -EINVAL;
2548 
2549 		if (!nfs_verify_server_address(sap))
2550 			return -EINVAL;
2551 
2552 		return nfs4_validate_text_mount_data(options, args, dev_name);
2553 	}
2554 
2555 	return 0;
2556 
2557 out_no_data:
2558 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2559 	return -EINVAL;
2560 
2561 out_inval_auth:
2562 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2563 		 data->auth_flavourlen);
2564 	return -EINVAL;
2565 
2566 out_no_address:
2567 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2568 	return -EINVAL;
2569 }
2570 
2571 /*
2572  * Get the superblock for the NFS4 root partition
2573  */
2574 static struct dentry *
2575 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
2576 		  const char *dev_name, void *raw_data)
2577 {
2578 	struct nfs_parsed_mount_data *data = raw_data;
2579 	struct super_block *s;
2580 	struct nfs_server *server;
2581 	struct nfs_fh *mntfh;
2582 	struct dentry *mntroot;
2583 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2584 	struct nfs_sb_mountdata sb_mntdata = {
2585 		.mntflags = flags,
2586 	};
2587 	int error = -ENOMEM;
2588 
2589 	mntfh = nfs_alloc_fhandle();
2590 	if (data == NULL || mntfh == NULL)
2591 		goto out_free_fh;
2592 
2593 	security_init_mnt_opts(&data->lsm_opts);
2594 
2595 	/* Get a volume representation */
2596 	server = nfs4_create_server(data, mntfh);
2597 	if (IS_ERR(server)) {
2598 		error = PTR_ERR(server);
2599 		goto out;
2600 	}
2601 	sb_mntdata.server = server;
2602 
2603 	if (server->flags & NFS4_MOUNT_UNSHARED)
2604 		compare_super = NULL;
2605 
2606 	/* Get a superblock - note that we may end up sharing one that already exists */
2607 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2608 	if (IS_ERR(s)) {
2609 		error = PTR_ERR(s);
2610 		goto out_free;
2611 	}
2612 
2613 	if (s->s_fs_info != server) {
2614 		nfs_free_server(server);
2615 		server = NULL;
2616 	} else {
2617 		error = nfs_bdi_register(server);
2618 		if (error)
2619 			goto error_splat_bdi;
2620 	}
2621 
2622 	if (!s->s_root) {
2623 		/* initial superblock/root creation */
2624 		nfs4_fill_super(s);
2625 		nfs_fscache_get_super_cookie(
2626 			s, data ? data->fscache_uniq : NULL, NULL);
2627 	}
2628 
2629 	mntroot = nfs4_get_root(s, mntfh, dev_name);
2630 	if (IS_ERR(mntroot)) {
2631 		error = PTR_ERR(mntroot);
2632 		goto error_splat_super;
2633 	}
2634 
2635 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2636 	if (error)
2637 		goto error_splat_root;
2638 
2639 	s->s_flags |= MS_ACTIVE;
2640 
2641 	security_free_mnt_opts(&data->lsm_opts);
2642 	nfs_free_fhandle(mntfh);
2643 	return mntroot;
2644 
2645 out:
2646 	security_free_mnt_opts(&data->lsm_opts);
2647 out_free_fh:
2648 	nfs_free_fhandle(mntfh);
2649 	return ERR_PTR(error);
2650 
2651 out_free:
2652 	nfs_free_server(server);
2653 	goto out;
2654 
2655 error_splat_root:
2656 	dput(mntroot);
2657 error_splat_super:
2658 	if (server && !s->s_root)
2659 		bdi_unregister(&server->backing_dev_info);
2660 error_splat_bdi:
2661 	deactivate_locked_super(s);
2662 	goto out;
2663 }
2664 
2665 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2666 		int flags, void *data, const char *hostname)
2667 {
2668 	struct vfsmount *root_mnt;
2669 	char *root_devname;
2670 	size_t len;
2671 
2672 	len = strlen(hostname) + 3;
2673 	root_devname = kmalloc(len, GFP_KERNEL);
2674 	if (root_devname == NULL)
2675 		return ERR_PTR(-ENOMEM);
2676 	snprintf(root_devname, len, "%s:/", hostname);
2677 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2678 	kfree(root_devname);
2679 	return root_mnt;
2680 }
2681 
2682 struct nfs_referral_count {
2683 	struct list_head list;
2684 	const struct task_struct *task;
2685 	unsigned int referral_count;
2686 };
2687 
2688 static LIST_HEAD(nfs_referral_count_list);
2689 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2690 
2691 static struct nfs_referral_count *nfs_find_referral_count(void)
2692 {
2693 	struct nfs_referral_count *p;
2694 
2695 	list_for_each_entry(p, &nfs_referral_count_list, list) {
2696 		if (p->task == current)
2697 			return p;
2698 	}
2699 	return NULL;
2700 }
2701 
2702 #define NFS_MAX_NESTED_REFERRALS 2
2703 
2704 static int nfs_referral_loop_protect(void)
2705 {
2706 	struct nfs_referral_count *p, *new;
2707 	int ret = -ENOMEM;
2708 
2709 	new = kmalloc(sizeof(*new), GFP_KERNEL);
2710 	if (!new)
2711 		goto out;
2712 	new->task = current;
2713 	new->referral_count = 1;
2714 
2715 	ret = 0;
2716 	spin_lock(&nfs_referral_count_list_lock);
2717 	p = nfs_find_referral_count();
2718 	if (p != NULL) {
2719 		if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2720 			ret = -ELOOP;
2721 		else
2722 			p->referral_count++;
2723 	} else {
2724 		list_add(&new->list, &nfs_referral_count_list);
2725 		new = NULL;
2726 	}
2727 	spin_unlock(&nfs_referral_count_list_lock);
2728 	kfree(new);
2729 out:
2730 	return ret;
2731 }
2732 
2733 static void nfs_referral_loop_unprotect(void)
2734 {
2735 	struct nfs_referral_count *p;
2736 
2737 	spin_lock(&nfs_referral_count_list_lock);
2738 	p = nfs_find_referral_count();
2739 	p->referral_count--;
2740 	if (p->referral_count == 0)
2741 		list_del(&p->list);
2742 	else
2743 		p = NULL;
2744 	spin_unlock(&nfs_referral_count_list_lock);
2745 	kfree(p);
2746 }
2747 
2748 static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
2749 		const char *export_path)
2750 {
2751 	struct nameidata *nd = NULL;
2752 	struct mnt_namespace *ns_private;
2753 	struct super_block *s;
2754 	struct dentry *dentry;
2755 	int ret;
2756 
2757 	nd = kmalloc(sizeof(*nd), GFP_KERNEL);
2758 	if (nd == NULL)
2759 		return ERR_PTR(-ENOMEM);
2760 
2761 	ns_private = create_mnt_ns(root_mnt);
2762 	ret = PTR_ERR(ns_private);
2763 	if (IS_ERR(ns_private))
2764 		goto out_mntput;
2765 
2766 	ret = nfs_referral_loop_protect();
2767 	if (ret != 0)
2768 		goto out_put_mnt_ns;
2769 
2770 	ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2771 			export_path, LOOKUP_FOLLOW, nd);
2772 
2773 	nfs_referral_loop_unprotect();
2774 	put_mnt_ns(ns_private);
2775 
2776 	if (ret != 0)
2777 		goto out_err;
2778 
2779 	s = nd->path.mnt->mnt_sb;
2780 	atomic_inc(&s->s_active);
2781 	dentry = dget(nd->path.dentry);
2782 
2783 	path_put(&nd->path);
2784 	kfree(nd);
2785 	down_write(&s->s_umount);
2786 	return dentry;
2787 out_put_mnt_ns:
2788 	put_mnt_ns(ns_private);
2789 out_mntput:
2790 	mntput(root_mnt);
2791 out_err:
2792 	kfree(nd);
2793 	return ERR_PTR(ret);
2794 }
2795 
2796 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
2797 			 struct nfs_parsed_mount_data *data)
2798 {
2799 	char *export_path;
2800 	struct vfsmount *root_mnt;
2801 	struct dentry *res;
2802 
2803 	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2804 
2805 	export_path = data->nfs_server.export_path;
2806 	data->nfs_server.export_path = "/";
2807 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2808 			data->nfs_server.hostname);
2809 	data->nfs_server.export_path = export_path;
2810 
2811 	res = ERR_CAST(root_mnt);
2812 	if (!IS_ERR(root_mnt))
2813 		res = nfs_follow_remote_path(root_mnt, export_path);
2814 
2815 	dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
2816 			IS_ERR(res) ? PTR_ERR(res) : 0,
2817 			IS_ERR(res) ? " [error]" : "");
2818 	return res;
2819 }
2820 
2821 /*
2822  * Get the superblock for an NFS4 mountpoint
2823  */
2824 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
2825 	int flags, const char *dev_name, void *raw_data)
2826 {
2827 	struct nfs_parsed_mount_data *data;
2828 	int error = -ENOMEM;
2829 	struct dentry *res = ERR_PTR(-ENOMEM);
2830 
2831 	data = nfs_alloc_parsed_mount_data(4);
2832 	if (data == NULL)
2833 		goto out_free_data;
2834 
2835 	/* Validate the mount data */
2836 	error = nfs4_validate_mount_data(raw_data, data, dev_name);
2837 	if (error < 0) {
2838 		res = ERR_PTR(error);
2839 		goto out;
2840 	}
2841 
2842 	res = nfs4_try_mount(flags, dev_name, data);
2843 	if (IS_ERR(res))
2844 		error = PTR_ERR(res);
2845 
2846 out:
2847 	kfree(data->client_address);
2848 	kfree(data->nfs_server.export_path);
2849 	kfree(data->nfs_server.hostname);
2850 	kfree(data->fscache_uniq);
2851 out_free_data:
2852 	kfree(data);
2853 	dprintk("<-- nfs4_mount() = %d%s\n", error,
2854 			error != 0 ? " [error]" : "");
2855 	return res;
2856 }
2857 
2858 static void nfs4_kill_super(struct super_block *sb)
2859 {
2860 	struct nfs_server *server = NFS_SB(sb);
2861 
2862 	dprintk("--> %s\n", __func__);
2863 	nfs_super_return_all_delegations(sb);
2864 	kill_anon_super(sb);
2865 	nfs_fscache_release_super_cookie(sb);
2866 	nfs_free_server(server);
2867 	dprintk("<-- %s\n", __func__);
2868 }
2869 
2870 /*
2871  * Clone an NFS4 server record on xdev traversal (FSID-change)
2872  */
2873 static struct dentry *
2874 nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
2875 		 const char *dev_name, void *raw_data)
2876 {
2877 	struct nfs_clone_mount *data = raw_data;
2878 	struct super_block *s;
2879 	struct nfs_server *server;
2880 	struct dentry *mntroot;
2881 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2882 	struct nfs_sb_mountdata sb_mntdata = {
2883 		.mntflags = flags,
2884 	};
2885 	int error;
2886 
2887 	dprintk("--> nfs4_xdev_mount()\n");
2888 
2889 	/* create a new volume representation */
2890 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2891 	if (IS_ERR(server)) {
2892 		error = PTR_ERR(server);
2893 		goto out_err_noserver;
2894 	}
2895 	sb_mntdata.server = server;
2896 
2897 	if (server->flags & NFS4_MOUNT_UNSHARED)
2898 		compare_super = NULL;
2899 
2900 	/* Get a superblock - note that we may end up sharing one that already exists */
2901 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2902 	if (IS_ERR(s)) {
2903 		error = PTR_ERR(s);
2904 		goto out_err_nosb;
2905 	}
2906 
2907 	if (s->s_fs_info != server) {
2908 		nfs_free_server(server);
2909 		server = NULL;
2910 	} else {
2911 		error = nfs_bdi_register(server);
2912 		if (error)
2913 			goto error_splat_bdi;
2914 	}
2915 
2916 	if (!s->s_root) {
2917 		/* initial superblock/root creation */
2918 		nfs4_clone_super(s, data->sb);
2919 		nfs_fscache_get_super_cookie(s, NULL, data);
2920 	}
2921 
2922 	mntroot = nfs4_get_root(s, data->fh, dev_name);
2923 	if (IS_ERR(mntroot)) {
2924 		error = PTR_ERR(mntroot);
2925 		goto error_splat_super;
2926 	}
2927 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2928 		dput(mntroot);
2929 		error = -ESTALE;
2930 		goto error_splat_super;
2931 	}
2932 
2933 	s->s_flags |= MS_ACTIVE;
2934 
2935 	security_sb_clone_mnt_opts(data->sb, s);
2936 
2937 	dprintk("<-- nfs4_xdev_mount() = 0\n");
2938 	return mntroot;
2939 
2940 out_err_nosb:
2941 	nfs_free_server(server);
2942 out_err_noserver:
2943 	dprintk("<-- nfs4_xdev_mount() = %d [error]\n", error);
2944 	return ERR_PTR(error);
2945 
2946 error_splat_super:
2947 	if (server && !s->s_root)
2948 		bdi_unregister(&server->backing_dev_info);
2949 error_splat_bdi:
2950 	deactivate_locked_super(s);
2951 	dprintk("<-- nfs4_xdev_mount() = %d [splat]\n", error);
2952 	return ERR_PTR(error);
2953 }
2954 
2955 static struct dentry *
2956 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
2957 			   const char *dev_name, void *raw_data)
2958 {
2959 	struct nfs_clone_mount *data = raw_data;
2960 	struct super_block *s;
2961 	struct nfs_server *server;
2962 	struct dentry *mntroot;
2963 	struct nfs_fh *mntfh;
2964 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2965 	struct nfs_sb_mountdata sb_mntdata = {
2966 		.mntflags = flags,
2967 	};
2968 	int error = -ENOMEM;
2969 
2970 	dprintk("--> nfs4_referral_get_sb()\n");
2971 
2972 	mntfh = nfs_alloc_fhandle();
2973 	if (mntfh == NULL)
2974 		goto out_err_nofh;
2975 
2976 	/* create a new volume representation */
2977 	server = nfs4_create_referral_server(data, mntfh);
2978 	if (IS_ERR(server)) {
2979 		error = PTR_ERR(server);
2980 		goto out_err_noserver;
2981 	}
2982 	sb_mntdata.server = server;
2983 
2984 	if (server->flags & NFS4_MOUNT_UNSHARED)
2985 		compare_super = NULL;
2986 
2987 	/* Get a superblock - note that we may end up sharing one that already exists */
2988 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2989 	if (IS_ERR(s)) {
2990 		error = PTR_ERR(s);
2991 		goto out_err_nosb;
2992 	}
2993 
2994 	if (s->s_fs_info != server) {
2995 		nfs_free_server(server);
2996 		server = NULL;
2997 	} else {
2998 		error = nfs_bdi_register(server);
2999 		if (error)
3000 			goto error_splat_bdi;
3001 	}
3002 
3003 	if (!s->s_root) {
3004 		/* initial superblock/root creation */
3005 		nfs4_fill_super(s);
3006 		nfs_fscache_get_super_cookie(s, NULL, data);
3007 	}
3008 
3009 	mntroot = nfs4_get_root(s, mntfh, dev_name);
3010 	if (IS_ERR(mntroot)) {
3011 		error = PTR_ERR(mntroot);
3012 		goto error_splat_super;
3013 	}
3014 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3015 		dput(mntroot);
3016 		error = -ESTALE;
3017 		goto error_splat_super;
3018 	}
3019 
3020 	s->s_flags |= MS_ACTIVE;
3021 
3022 	security_sb_clone_mnt_opts(data->sb, s);
3023 
3024 	nfs_free_fhandle(mntfh);
3025 	dprintk("<-- nfs4_referral_get_sb() = 0\n");
3026 	return mntroot;
3027 
3028 out_err_nosb:
3029 	nfs_free_server(server);
3030 out_err_noserver:
3031 	nfs_free_fhandle(mntfh);
3032 out_err_nofh:
3033 	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3034 	return ERR_PTR(error);
3035 
3036 error_splat_super:
3037 	if (server && !s->s_root)
3038 		bdi_unregister(&server->backing_dev_info);
3039 error_splat_bdi:
3040 	deactivate_locked_super(s);
3041 	nfs_free_fhandle(mntfh);
3042 	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3043 	return ERR_PTR(error);
3044 }
3045 
3046 /*
3047  * Create an NFS4 server record on referral traversal
3048  */
3049 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
3050 		int flags, const char *dev_name, void *raw_data)
3051 {
3052 	struct nfs_clone_mount *data = raw_data;
3053 	char *export_path;
3054 	struct vfsmount *root_mnt;
3055 	struct dentry *res;
3056 
3057 	dprintk("--> nfs4_referral_mount()\n");
3058 
3059 	export_path = data->mnt_path;
3060 	data->mnt_path = "/";
3061 
3062 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3063 			flags, data, data->hostname);
3064 	data->mnt_path = export_path;
3065 
3066 	res = ERR_CAST(root_mnt);
3067 	if (!IS_ERR(root_mnt))
3068 		res = nfs_follow_remote_path(root_mnt, export_path);
3069 	dprintk("<-- nfs4_referral_mount() = %ld%s\n",
3070 			IS_ERR(res) ? PTR_ERR(res) : 0,
3071 			IS_ERR(res) ? " [error]" : "");
3072 	return res;
3073 }
3074 
3075 #endif /* CONFIG_NFS_V4 */
3076