xref: /linux/fs/nfs/super.c (revision b06ede84dd1473dec7c6af03a41c8d04d2fee437)
1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/stats.h>
35 #include <linux/sunrpc/metrics.h>
36 #include <linux/sunrpc/xprtsock.h>
37 #include <linux/sunrpc/xprtrdma.h>
38 #include <linux/nfs_fs.h>
39 #include <linux/nfs_mount.h>
40 #include <linux/nfs4_mount.h>
41 #include <linux/lockd/bind.h>
42 #include <linux/smp_lock.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/mnt_namespace.h>
46 #include <linux/namei.h>
47 #include <linux/nfs_idmap.h>
48 #include <linux/vfs.h>
49 #include <linux/inet.h>
50 #include <linux/in6.h>
51 #include <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 enum {
70 	/* Mount options that take no arguments */
71 	Opt_soft, Opt_hard,
72 	Opt_posix, Opt_noposix,
73 	Opt_cto, Opt_nocto,
74 	Opt_ac, Opt_noac,
75 	Opt_lock, Opt_nolock,
76 	Opt_v2, Opt_v3, Opt_v4,
77 	Opt_udp, Opt_tcp, Opt_rdma,
78 	Opt_acl, Opt_noacl,
79 	Opt_rdirplus, Opt_nordirplus,
80 	Opt_sharecache, Opt_nosharecache,
81 	Opt_resvport, Opt_noresvport,
82 	Opt_fscache, Opt_nofscache,
83 
84 	/* Mount options that take integer arguments */
85 	Opt_port,
86 	Opt_rsize, Opt_wsize, Opt_bsize,
87 	Opt_timeo, Opt_retrans,
88 	Opt_acregmin, Opt_acregmax,
89 	Opt_acdirmin, Opt_acdirmax,
90 	Opt_actimeo,
91 	Opt_namelen,
92 	Opt_mountport,
93 	Opt_mountvers,
94 	Opt_nfsvers,
95 	Opt_minorversion,
96 
97 	/* Mount options that take string arguments */
98 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
99 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
100 	Opt_lookupcache,
101 	Opt_fscache_uniq,
102 
103 	/* Special mount options */
104 	Opt_userspace, Opt_deprecated, Opt_sloppy,
105 
106 	Opt_err
107 };
108 
109 static const match_table_t nfs_mount_option_tokens = {
110 	{ Opt_userspace, "bg" },
111 	{ Opt_userspace, "fg" },
112 	{ Opt_userspace, "retry=%s" },
113 
114 	{ Opt_sloppy, "sloppy" },
115 
116 	{ Opt_soft, "soft" },
117 	{ Opt_hard, "hard" },
118 	{ Opt_deprecated, "intr" },
119 	{ Opt_deprecated, "nointr" },
120 	{ Opt_posix, "posix" },
121 	{ Opt_noposix, "noposix" },
122 	{ Opt_cto, "cto" },
123 	{ Opt_nocto, "nocto" },
124 	{ Opt_ac, "ac" },
125 	{ Opt_noac, "noac" },
126 	{ Opt_lock, "lock" },
127 	{ Opt_nolock, "nolock" },
128 	{ Opt_v2, "v2" },
129 	{ Opt_v3, "v3" },
130 	{ Opt_v4, "v4" },
131 	{ Opt_udp, "udp" },
132 	{ Opt_tcp, "tcp" },
133 	{ Opt_rdma, "rdma" },
134 	{ Opt_acl, "acl" },
135 	{ Opt_noacl, "noacl" },
136 	{ Opt_rdirplus, "rdirplus" },
137 	{ Opt_nordirplus, "nordirplus" },
138 	{ Opt_sharecache, "sharecache" },
139 	{ Opt_nosharecache, "nosharecache" },
140 	{ Opt_resvport, "resvport" },
141 	{ Opt_noresvport, "noresvport" },
142 	{ Opt_fscache, "fsc" },
143 	{ Opt_fscache_uniq, "fsc=%s" },
144 	{ Opt_nofscache, "nofsc" },
145 
146 	{ Opt_port, "port=%s" },
147 	{ Opt_rsize, "rsize=%s" },
148 	{ Opt_wsize, "wsize=%s" },
149 	{ Opt_bsize, "bsize=%s" },
150 	{ Opt_timeo, "timeo=%s" },
151 	{ Opt_retrans, "retrans=%s" },
152 	{ Opt_acregmin, "acregmin=%s" },
153 	{ Opt_acregmax, "acregmax=%s" },
154 	{ Opt_acdirmin, "acdirmin=%s" },
155 	{ Opt_acdirmax, "acdirmax=%s" },
156 	{ Opt_actimeo, "actimeo=%s" },
157 	{ Opt_namelen, "namlen=%s" },
158 	{ Opt_mountport, "mountport=%s" },
159 	{ Opt_mountvers, "mountvers=%s" },
160 	{ Opt_nfsvers, "nfsvers=%s" },
161 	{ Opt_nfsvers, "vers=%s" },
162 	{ Opt_minorversion, "minorversion=%s" },
163 
164 	{ Opt_sec, "sec=%s" },
165 	{ Opt_proto, "proto=%s" },
166 	{ Opt_mountproto, "mountproto=%s" },
167 	{ Opt_addr, "addr=%s" },
168 	{ Opt_clientaddr, "clientaddr=%s" },
169 	{ Opt_mounthost, "mounthost=%s" },
170 	{ Opt_mountaddr, "mountaddr=%s" },
171 
172 	{ Opt_lookupcache, "lookupcache=%s" },
173 
174 	{ Opt_err, NULL }
175 };
176 
177 enum {
178 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
179 
180 	Opt_xprt_err
181 };
182 
183 static const match_table_t nfs_xprt_protocol_tokens = {
184 	{ Opt_xprt_udp, "udp" },
185 	{ Opt_xprt_udp6, "udp6" },
186 	{ Opt_xprt_tcp, "tcp" },
187 	{ Opt_xprt_tcp6, "tcp6" },
188 	{ Opt_xprt_rdma, "rdma" },
189 
190 	{ Opt_xprt_err, NULL }
191 };
192 
193 enum {
194 	Opt_sec_none, Opt_sec_sys,
195 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
196 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
197 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
198 
199 	Opt_sec_err
200 };
201 
202 static const match_table_t nfs_secflavor_tokens = {
203 	{ Opt_sec_none, "none" },
204 	{ Opt_sec_none, "null" },
205 	{ Opt_sec_sys, "sys" },
206 
207 	{ Opt_sec_krb5, "krb5" },
208 	{ Opt_sec_krb5i, "krb5i" },
209 	{ Opt_sec_krb5p, "krb5p" },
210 
211 	{ Opt_sec_lkey, "lkey" },
212 	{ Opt_sec_lkeyi, "lkeyi" },
213 	{ Opt_sec_lkeyp, "lkeyp" },
214 
215 	{ Opt_sec_spkm, "spkm3" },
216 	{ Opt_sec_spkmi, "spkm3i" },
217 	{ Opt_sec_spkmp, "spkm3p" },
218 
219 	{ Opt_sec_err, NULL }
220 };
221 
222 enum {
223 	Opt_lookupcache_all, Opt_lookupcache_positive,
224 	Opt_lookupcache_none,
225 
226 	Opt_lookupcache_err
227 };
228 
229 static match_table_t nfs_lookupcache_tokens = {
230 	{ Opt_lookupcache_all, "all" },
231 	{ Opt_lookupcache_positive, "pos" },
232 	{ Opt_lookupcache_positive, "positive" },
233 	{ Opt_lookupcache_none, "none" },
234 
235 	{ Opt_lookupcache_err, NULL }
236 };
237 
238 
239 static void nfs_umount_begin(struct super_block *);
240 static int  nfs_statfs(struct dentry *, struct kstatfs *);
241 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
242 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
243 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
244 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
245 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
246 static void nfs_put_super(struct super_block *);
247 static void nfs_kill_super(struct super_block *);
248 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
249 
250 static struct file_system_type nfs_fs_type = {
251 	.owner		= THIS_MODULE,
252 	.name		= "nfs",
253 	.get_sb		= nfs_get_sb,
254 	.kill_sb	= nfs_kill_super,
255 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
256 };
257 
258 struct file_system_type nfs_xdev_fs_type = {
259 	.owner		= THIS_MODULE,
260 	.name		= "nfs",
261 	.get_sb		= nfs_xdev_get_sb,
262 	.kill_sb	= nfs_kill_super,
263 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
264 };
265 
266 static const struct super_operations nfs_sops = {
267 	.alloc_inode	= nfs_alloc_inode,
268 	.destroy_inode	= nfs_destroy_inode,
269 	.write_inode	= nfs_write_inode,
270 	.put_super	= nfs_put_super,
271 	.statfs		= nfs_statfs,
272 	.clear_inode	= nfs_clear_inode,
273 	.umount_begin	= nfs_umount_begin,
274 	.show_options	= nfs_show_options,
275 	.show_stats	= nfs_show_stats,
276 	.remount_fs	= nfs_remount,
277 };
278 
279 #ifdef CONFIG_NFS_V4
280 static int nfs4_validate_text_mount_data(void *options,
281 	struct nfs_parsed_mount_data *args, const char *dev_name);
282 static int nfs4_try_mount(int flags, const char *dev_name,
283 	struct nfs_parsed_mount_data *data, struct vfsmount *mnt);
284 static int nfs4_get_sb(struct file_system_type *fs_type,
285 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
286 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
287 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
288 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
289 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
290 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
291 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
292 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
293 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
294 static void nfs4_kill_super(struct super_block *sb);
295 
296 static struct file_system_type nfs4_fs_type = {
297 	.owner		= THIS_MODULE,
298 	.name		= "nfs4",
299 	.get_sb		= nfs4_get_sb,
300 	.kill_sb	= nfs4_kill_super,
301 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
302 };
303 
304 static struct file_system_type nfs4_remote_fs_type = {
305 	.owner		= THIS_MODULE,
306 	.name		= "nfs4",
307 	.get_sb		= nfs4_remote_get_sb,
308 	.kill_sb	= nfs4_kill_super,
309 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
310 };
311 
312 struct file_system_type nfs4_xdev_fs_type = {
313 	.owner		= THIS_MODULE,
314 	.name		= "nfs4",
315 	.get_sb		= nfs4_xdev_get_sb,
316 	.kill_sb	= nfs4_kill_super,
317 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
318 };
319 
320 static struct file_system_type nfs4_remote_referral_fs_type = {
321 	.owner		= THIS_MODULE,
322 	.name		= "nfs4",
323 	.get_sb		= nfs4_remote_referral_get_sb,
324 	.kill_sb	= nfs4_kill_super,
325 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
326 };
327 
328 struct file_system_type nfs4_referral_fs_type = {
329 	.owner		= THIS_MODULE,
330 	.name		= "nfs4",
331 	.get_sb		= nfs4_referral_get_sb,
332 	.kill_sb	= nfs4_kill_super,
333 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
334 };
335 
336 static const struct super_operations nfs4_sops = {
337 	.alloc_inode	= nfs_alloc_inode,
338 	.destroy_inode	= nfs_destroy_inode,
339 	.write_inode	= nfs_write_inode,
340 	.put_super	= nfs_put_super,
341 	.statfs		= nfs_statfs,
342 	.clear_inode	= nfs4_clear_inode,
343 	.umount_begin	= nfs_umount_begin,
344 	.show_options	= nfs_show_options,
345 	.show_stats	= nfs_show_stats,
346 	.remount_fs	= nfs_remount,
347 };
348 #endif
349 
350 static struct shrinker acl_shrinker = {
351 	.shrink		= nfs_access_cache_shrinker,
352 	.seeks		= DEFAULT_SEEKS,
353 };
354 
355 /*
356  * Register the NFS filesystems
357  */
358 int __init register_nfs_fs(void)
359 {
360 	int ret;
361 
362         ret = register_filesystem(&nfs_fs_type);
363 	if (ret < 0)
364 		goto error_0;
365 
366 	ret = nfs_register_sysctl();
367 	if (ret < 0)
368 		goto error_1;
369 #ifdef CONFIG_NFS_V4
370 	ret = register_filesystem(&nfs4_fs_type);
371 	if (ret < 0)
372 		goto error_2;
373 #endif
374 	register_shrinker(&acl_shrinker);
375 	return 0;
376 
377 #ifdef CONFIG_NFS_V4
378 error_2:
379 	nfs_unregister_sysctl();
380 #endif
381 error_1:
382 	unregister_filesystem(&nfs_fs_type);
383 error_0:
384 	return ret;
385 }
386 
387 /*
388  * Unregister the NFS filesystems
389  */
390 void __exit unregister_nfs_fs(void)
391 {
392 	unregister_shrinker(&acl_shrinker);
393 #ifdef CONFIG_NFS_V4
394 	unregister_filesystem(&nfs4_fs_type);
395 #endif
396 	nfs_unregister_sysctl();
397 	unregister_filesystem(&nfs_fs_type);
398 }
399 
400 void nfs_sb_active(struct super_block *sb)
401 {
402 	struct nfs_server *server = NFS_SB(sb);
403 
404 	if (atomic_inc_return(&server->active) == 1)
405 		atomic_inc(&sb->s_active);
406 }
407 
408 void nfs_sb_deactive(struct super_block *sb)
409 {
410 	struct nfs_server *server = NFS_SB(sb);
411 
412 	if (atomic_dec_and_test(&server->active))
413 		deactivate_super(sb);
414 }
415 
416 /*
417  * Deliver file system statistics to userspace
418  */
419 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
420 {
421 	struct nfs_server *server = NFS_SB(dentry->d_sb);
422 	unsigned char blockbits;
423 	unsigned long blockres;
424 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
425 	struct nfs_fattr fattr;
426 	struct nfs_fsstat res = {
427 			.fattr = &fattr,
428 	};
429 	int error;
430 
431 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
432 	if (error < 0)
433 		goto out_err;
434 	buf->f_type = NFS_SUPER_MAGIC;
435 
436 	/*
437 	 * Current versions of glibc do not correctly handle the
438 	 * case where f_frsize != f_bsize.  Eventually we want to
439 	 * report the value of wtmult in this field.
440 	 */
441 	buf->f_frsize = dentry->d_sb->s_blocksize;
442 
443 	/*
444 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
445 	 * are reported in units of f_frsize.  Linux hasn't had
446 	 * an f_frsize field in its statfs struct until recently,
447 	 * thus historically Linux's sys_statfs reports these
448 	 * fields in units of f_bsize.
449 	 */
450 	buf->f_bsize = dentry->d_sb->s_blocksize;
451 	blockbits = dentry->d_sb->s_blocksize_bits;
452 	blockres = (1 << blockbits) - 1;
453 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
454 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
455 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
456 
457 	buf->f_files = res.tfiles;
458 	buf->f_ffree = res.afiles;
459 
460 	buf->f_namelen = server->namelen;
461 
462 	return 0;
463 
464  out_err:
465 	dprintk("%s: statfs error = %d\n", __func__, -error);
466 	return error;
467 }
468 
469 /*
470  * Map the security flavour number to a name
471  */
472 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
473 {
474 	static const struct {
475 		rpc_authflavor_t flavour;
476 		const char *str;
477 	} sec_flavours[] = {
478 		{ RPC_AUTH_NULL, "null" },
479 		{ RPC_AUTH_UNIX, "sys" },
480 		{ RPC_AUTH_GSS_KRB5, "krb5" },
481 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
482 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
483 		{ RPC_AUTH_GSS_LKEY, "lkey" },
484 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
485 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
486 		{ RPC_AUTH_GSS_SPKM, "spkm" },
487 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
488 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
489 		{ UINT_MAX, "unknown" }
490 	};
491 	int i;
492 
493 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
494 		if (sec_flavours[i].flavour == flavour)
495 			break;
496 	}
497 	return sec_flavours[i].str;
498 }
499 
500 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
501 				  int showdefaults)
502 {
503 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
504 
505 	seq_printf(m, ",mountproto=");
506 	switch (sap->sa_family) {
507 	case AF_INET:
508 		switch (nfss->mountd_protocol) {
509 		case IPPROTO_UDP:
510 			seq_printf(m, RPCBIND_NETID_UDP);
511 			break;
512 		case IPPROTO_TCP:
513 			seq_printf(m, RPCBIND_NETID_TCP);
514 			break;
515 		default:
516 			if (showdefaults)
517 				seq_printf(m, "auto");
518 		}
519 		break;
520 	case AF_INET6:
521 		switch (nfss->mountd_protocol) {
522 		case IPPROTO_UDP:
523 			seq_printf(m, RPCBIND_NETID_UDP6);
524 			break;
525 		case IPPROTO_TCP:
526 			seq_printf(m, RPCBIND_NETID_TCP6);
527 			break;
528 		default:
529 			if (showdefaults)
530 				seq_printf(m, "auto");
531 		}
532 		break;
533 	default:
534 		if (showdefaults)
535 			seq_printf(m, "auto");
536 	}
537 }
538 
539 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
540 				    int showdefaults)
541 {
542 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
543 
544 	switch (sap->sa_family) {
545 	case AF_INET: {
546 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
547 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
548 		break;
549 	}
550 	case AF_INET6: {
551 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
552 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
553 		break;
554 	}
555 	default:
556 		if (showdefaults)
557 			seq_printf(m, ",mountaddr=unspecified");
558 	}
559 
560 	if (nfss->mountd_version || showdefaults)
561 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
562 	if (nfss->mountd_port || showdefaults)
563 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
564 
565 	nfs_show_mountd_netid(m, nfss, showdefaults);
566 }
567 
568 /*
569  * Describe the mount options in force on this server representation
570  */
571 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
572 				   int showdefaults)
573 {
574 	static const struct proc_nfs_info {
575 		int flag;
576 		const char *str;
577 		const char *nostr;
578 	} nfs_info[] = {
579 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
580 		{ NFS_MOUNT_POSIX, ",posix", "" },
581 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
582 		{ NFS_MOUNT_NOAC, ",noac", "" },
583 		{ NFS_MOUNT_NONLM, ",nolock", "" },
584 		{ NFS_MOUNT_NOACL, ",noacl", "" },
585 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
586 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
587 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
588 		{ 0, NULL, NULL }
589 	};
590 	const struct proc_nfs_info *nfs_infop;
591 	struct nfs_client *clp = nfss->nfs_client;
592 	u32 version = clp->rpc_ops->version;
593 
594 	seq_printf(m, ",vers=%u", version);
595 	seq_printf(m, ",rsize=%u", nfss->rsize);
596 	seq_printf(m, ",wsize=%u", nfss->wsize);
597 	if (nfss->bsize != 0)
598 		seq_printf(m, ",bsize=%u", nfss->bsize);
599 	seq_printf(m, ",namlen=%u", nfss->namelen);
600 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
601 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
602 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
603 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
604 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
605 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
606 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
607 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
608 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
609 		if (nfss->flags & nfs_infop->flag)
610 			seq_puts(m, nfs_infop->str);
611 		else
612 			seq_puts(m, nfs_infop->nostr);
613 	}
614 	seq_printf(m, ",proto=%s",
615 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
616 	if (version == 4) {
617 		if (nfss->port != NFS_PORT)
618 			seq_printf(m, ",port=%u", nfss->port);
619 	} else
620 		if (nfss->port)
621 			seq_printf(m, ",port=%u", nfss->port);
622 
623 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
624 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
625 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
626 
627 	if (version != 4)
628 		nfs_show_mountd_options(m, nfss, showdefaults);
629 
630 #ifdef CONFIG_NFS_V4
631 	if (clp->rpc_ops->version == 4)
632 		seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
633 #endif
634 	if (nfss->options & NFS_OPTION_FSCACHE)
635 		seq_printf(m, ",fsc");
636 }
637 
638 /*
639  * Describe the mount options on this VFS mountpoint
640  */
641 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
642 {
643 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
644 
645 	nfs_show_mount_options(m, nfss, 0);
646 
647 	seq_printf(m, ",addr=%s",
648 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
649 							RPC_DISPLAY_ADDR));
650 
651 	return 0;
652 }
653 
654 /*
655  * Present statistical information for this VFS mountpoint
656  */
657 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
658 {
659 	int i, cpu;
660 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
661 	struct rpc_auth *auth = nfss->client->cl_auth;
662 	struct nfs_iostats totals = { };
663 
664 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
665 
666 	/*
667 	 * Display all mount option settings
668 	 */
669 	seq_printf(m, "\n\topts:\t");
670 	seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
671 	seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
672 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
673 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
674 	nfs_show_mount_options(m, nfss, 1);
675 
676 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
677 
678 	seq_printf(m, "\n\tcaps:\t");
679 	seq_printf(m, "caps=0x%x", nfss->caps);
680 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
681 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
682 	seq_printf(m, ",bsize=%u", nfss->bsize);
683 	seq_printf(m, ",namlen=%u", nfss->namelen);
684 
685 #ifdef CONFIG_NFS_V4
686 	if (nfss->nfs_client->rpc_ops->version == 4) {
687 		seq_printf(m, "\n\tnfsv4:\t");
688 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
689 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
690 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
691 	}
692 #endif
693 
694 	/*
695 	 * Display security flavor in effect for this mount
696 	 */
697 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
698 	if (auth->au_flavor)
699 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
700 
701 	/*
702 	 * Display superblock I/O counters
703 	 */
704 	for_each_possible_cpu(cpu) {
705 		struct nfs_iostats *stats;
706 
707 		preempt_disable();
708 		stats = per_cpu_ptr(nfss->io_stats, cpu);
709 
710 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
711 			totals.events[i] += stats->events[i];
712 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
713 			totals.bytes[i] += stats->bytes[i];
714 #ifdef CONFIG_NFS_FSCACHE
715 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
716 			totals.fscache[i] += stats->fscache[i];
717 #endif
718 
719 		preempt_enable();
720 	}
721 
722 	seq_printf(m, "\n\tevents:\t");
723 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
724 		seq_printf(m, "%lu ", totals.events[i]);
725 	seq_printf(m, "\n\tbytes:\t");
726 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
727 		seq_printf(m, "%Lu ", totals.bytes[i]);
728 #ifdef CONFIG_NFS_FSCACHE
729 	if (nfss->options & NFS_OPTION_FSCACHE) {
730 		seq_printf(m, "\n\tfsc:\t");
731 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
732 			seq_printf(m, "%Lu ", totals.bytes[i]);
733 	}
734 #endif
735 	seq_printf(m, "\n");
736 
737 	rpc_print_iostats(m, nfss->client);
738 
739 	return 0;
740 }
741 
742 /*
743  * Begin unmount by attempting to remove all automounted mountpoints we added
744  * in response to xdev traversals and referrals
745  */
746 static void nfs_umount_begin(struct super_block *sb)
747 {
748 	struct nfs_server *server;
749 	struct rpc_clnt *rpc;
750 
751 	server = NFS_SB(sb);
752 	/* -EIO all pending I/O */
753 	rpc = server->client_acl;
754 	if (!IS_ERR(rpc))
755 		rpc_killall_tasks(rpc);
756 	rpc = server->client;
757 	if (!IS_ERR(rpc))
758 		rpc_killall_tasks(rpc);
759 }
760 
761 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
762 {
763 	struct nfs_parsed_mount_data *data;
764 
765 	data = kzalloc(sizeof(*data), GFP_KERNEL);
766 	if (data) {
767 		data->acregmin		= NFS_DEF_ACREGMIN;
768 		data->acregmax		= NFS_DEF_ACREGMAX;
769 		data->acdirmin		= NFS_DEF_ACDIRMIN;
770 		data->acdirmax		= NFS_DEF_ACDIRMAX;
771 		data->mount_server.port	= NFS_UNSPEC_PORT;
772 		data->nfs_server.port	= NFS_UNSPEC_PORT;
773 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
774 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
775 		data->auth_flavor_len	= 1;
776 		data->version		= version;
777 		data->minorversion	= 0;
778 	}
779 	return data;
780 }
781 
782 /*
783  * Sanity-check a server address provided by the mount command.
784  *
785  * Address family must be initialized, and address must not be
786  * the ANY address for that family.
787  */
788 static int nfs_verify_server_address(struct sockaddr *addr)
789 {
790 	switch (addr->sa_family) {
791 	case AF_INET: {
792 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
793 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
794 	}
795 	case AF_INET6: {
796 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
797 		return !ipv6_addr_any(sa);
798 	}
799 	}
800 
801 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
802 	return 0;
803 }
804 
805 /*
806  * Select between a default port value and a user-specified port value.
807  * If a zero value is set, then autobind will be used.
808  */
809 static void nfs_set_port(struct sockaddr *sap, int *port,
810 				 const unsigned short default_port)
811 {
812 	if (*port == NFS_UNSPEC_PORT)
813 		*port = default_port;
814 
815 	rpc_set_port(sap, *port);
816 }
817 
818 /*
819  * Sanity check the NFS transport protocol.
820  *
821  */
822 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
823 {
824 	switch (mnt->nfs_server.protocol) {
825 	case XPRT_TRANSPORT_UDP:
826 	case XPRT_TRANSPORT_TCP:
827 	case XPRT_TRANSPORT_RDMA:
828 		break;
829 	default:
830 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
831 	}
832 }
833 
834 /*
835  * For text based NFSv2/v3 mounts, the mount protocol transport default
836  * settings should depend upon the specified NFS transport.
837  */
838 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
839 {
840 	nfs_validate_transport_protocol(mnt);
841 
842 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
843 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
844 			return;
845 	switch (mnt->nfs_server.protocol) {
846 	case XPRT_TRANSPORT_UDP:
847 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
848 		break;
849 	case XPRT_TRANSPORT_TCP:
850 	case XPRT_TRANSPORT_RDMA:
851 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
852 	}
853 }
854 
855 /*
856  * Parse the value of the 'sec=' option.
857  */
858 static int nfs_parse_security_flavors(char *value,
859 				      struct nfs_parsed_mount_data *mnt)
860 {
861 	substring_t args[MAX_OPT_ARGS];
862 
863 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
864 
865 	switch (match_token(value, nfs_secflavor_tokens, args)) {
866 	case Opt_sec_none:
867 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
868 		break;
869 	case Opt_sec_sys:
870 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
871 		break;
872 	case Opt_sec_krb5:
873 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
874 		break;
875 	case Opt_sec_krb5i:
876 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
877 		break;
878 	case Opt_sec_krb5p:
879 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
880 		break;
881 	case Opt_sec_lkey:
882 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
883 		break;
884 	case Opt_sec_lkeyi:
885 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
886 		break;
887 	case Opt_sec_lkeyp:
888 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
889 		break;
890 	case Opt_sec_spkm:
891 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
892 		break;
893 	case Opt_sec_spkmi:
894 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
895 		break;
896 	case Opt_sec_spkmp:
897 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
898 		break;
899 	default:
900 		return 0;
901 	}
902 
903 	mnt->auth_flavor_len = 1;
904 	return 1;
905 }
906 
907 /*
908  * Error-check and convert a string of mount options from user space into
909  * a data structure.  The whole mount string is processed; bad options are
910  * skipped as they are encountered.  If there were no errors, return 1;
911  * otherwise return 0 (zero).
912  */
913 static int nfs_parse_mount_options(char *raw,
914 				   struct nfs_parsed_mount_data *mnt)
915 {
916 	char *p, *string, *secdata;
917 	int rc, sloppy = 0, invalid_option = 0;
918 	unsigned short protofamily = AF_UNSPEC;
919 	unsigned short mountfamily = AF_UNSPEC;
920 
921 	if (!raw) {
922 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
923 		return 1;
924 	}
925 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
926 
927 	secdata = alloc_secdata();
928 	if (!secdata)
929 		goto out_nomem;
930 
931 	rc = security_sb_copy_data(raw, secdata);
932 	if (rc)
933 		goto out_security_failure;
934 
935 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
936 	if (rc)
937 		goto out_security_failure;
938 
939 	free_secdata(secdata);
940 
941 	while ((p = strsep(&raw, ",")) != NULL) {
942 		substring_t args[MAX_OPT_ARGS];
943 		unsigned long option;
944 		int token;
945 
946 		if (!*p)
947 			continue;
948 
949 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
950 
951 		token = match_token(p, nfs_mount_option_tokens, args);
952 		switch (token) {
953 
954 		/*
955 		 * boolean options:  foo/nofoo
956 		 */
957 		case Opt_soft:
958 			mnt->flags |= NFS_MOUNT_SOFT;
959 			break;
960 		case Opt_hard:
961 			mnt->flags &= ~NFS_MOUNT_SOFT;
962 			break;
963 		case Opt_posix:
964 			mnt->flags |= NFS_MOUNT_POSIX;
965 			break;
966 		case Opt_noposix:
967 			mnt->flags &= ~NFS_MOUNT_POSIX;
968 			break;
969 		case Opt_cto:
970 			mnt->flags &= ~NFS_MOUNT_NOCTO;
971 			break;
972 		case Opt_nocto:
973 			mnt->flags |= NFS_MOUNT_NOCTO;
974 			break;
975 		case Opt_ac:
976 			mnt->flags &= ~NFS_MOUNT_NOAC;
977 			break;
978 		case Opt_noac:
979 			mnt->flags |= NFS_MOUNT_NOAC;
980 			break;
981 		case Opt_lock:
982 			mnt->flags &= ~NFS_MOUNT_NONLM;
983 			break;
984 		case Opt_nolock:
985 			mnt->flags |= NFS_MOUNT_NONLM;
986 			break;
987 		case Opt_v2:
988 			mnt->flags &= ~NFS_MOUNT_VER3;
989 			mnt->version = 2;
990 			break;
991 		case Opt_v3:
992 			mnt->flags |= NFS_MOUNT_VER3;
993 			mnt->version = 3;
994 			break;
995 #ifdef CONFIG_NFS_V4
996 		case Opt_v4:
997 			mnt->flags &= ~NFS_MOUNT_VER3;
998 			mnt->version = 4;
999 			break;
1000 #endif
1001 		case Opt_udp:
1002 			mnt->flags &= ~NFS_MOUNT_TCP;
1003 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1004 			break;
1005 		case Opt_tcp:
1006 			mnt->flags |= NFS_MOUNT_TCP;
1007 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1008 			break;
1009 		case Opt_rdma:
1010 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1011 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1012 			xprt_load_transport(p);
1013 			break;
1014 		case Opt_acl:
1015 			mnt->flags &= ~NFS_MOUNT_NOACL;
1016 			break;
1017 		case Opt_noacl:
1018 			mnt->flags |= NFS_MOUNT_NOACL;
1019 			break;
1020 		case Opt_rdirplus:
1021 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1022 			break;
1023 		case Opt_nordirplus:
1024 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1025 			break;
1026 		case Opt_sharecache:
1027 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1028 			break;
1029 		case Opt_nosharecache:
1030 			mnt->flags |= NFS_MOUNT_UNSHARED;
1031 			break;
1032 		case Opt_resvport:
1033 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1034 			break;
1035 		case Opt_noresvport:
1036 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1037 			break;
1038 		case Opt_fscache:
1039 			mnt->options |= NFS_OPTION_FSCACHE;
1040 			kfree(mnt->fscache_uniq);
1041 			mnt->fscache_uniq = NULL;
1042 			break;
1043 		case Opt_nofscache:
1044 			mnt->options &= ~NFS_OPTION_FSCACHE;
1045 			kfree(mnt->fscache_uniq);
1046 			mnt->fscache_uniq = NULL;
1047 			break;
1048 		case Opt_fscache_uniq:
1049 			string = match_strdup(args);
1050 			if (!string)
1051 				goto out_nomem;
1052 			kfree(mnt->fscache_uniq);
1053 			mnt->fscache_uniq = string;
1054 			mnt->options |= NFS_OPTION_FSCACHE;
1055 			break;
1056 
1057 		/*
1058 		 * options that take numeric values
1059 		 */
1060 		case Opt_port:
1061 			string = match_strdup(args);
1062 			if (string == NULL)
1063 				goto out_nomem;
1064 			rc = strict_strtoul(string, 10, &option);
1065 			kfree(string);
1066 			if (rc != 0 || option > USHORT_MAX)
1067 				goto out_invalid_value;
1068 			mnt->nfs_server.port = option;
1069 			break;
1070 		case Opt_rsize:
1071 			string = match_strdup(args);
1072 			if (string == NULL)
1073 				goto out_nomem;
1074 			rc = strict_strtoul(string, 10, &option);
1075 			kfree(string);
1076 			if (rc != 0)
1077 				goto out_invalid_value;
1078 			mnt->rsize = option;
1079 			break;
1080 		case Opt_wsize:
1081 			string = match_strdup(args);
1082 			if (string == NULL)
1083 				goto out_nomem;
1084 			rc = strict_strtoul(string, 10, &option);
1085 			kfree(string);
1086 			if (rc != 0)
1087 				goto out_invalid_value;
1088 			mnt->wsize = option;
1089 			break;
1090 		case Opt_bsize:
1091 			string = match_strdup(args);
1092 			if (string == NULL)
1093 				goto out_nomem;
1094 			rc = strict_strtoul(string, 10, &option);
1095 			kfree(string);
1096 			if (rc != 0)
1097 				goto out_invalid_value;
1098 			mnt->bsize = option;
1099 			break;
1100 		case Opt_timeo:
1101 			string = match_strdup(args);
1102 			if (string == NULL)
1103 				goto out_nomem;
1104 			rc = strict_strtoul(string, 10, &option);
1105 			kfree(string);
1106 			if (rc != 0 || option == 0)
1107 				goto out_invalid_value;
1108 			mnt->timeo = option;
1109 			break;
1110 		case Opt_retrans:
1111 			string = match_strdup(args);
1112 			if (string == NULL)
1113 				goto out_nomem;
1114 			rc = strict_strtoul(string, 10, &option);
1115 			kfree(string);
1116 			if (rc != 0 || option == 0)
1117 				goto out_invalid_value;
1118 			mnt->retrans = option;
1119 			break;
1120 		case Opt_acregmin:
1121 			string = match_strdup(args);
1122 			if (string == NULL)
1123 				goto out_nomem;
1124 			rc = strict_strtoul(string, 10, &option);
1125 			kfree(string);
1126 			if (rc != 0)
1127 				goto out_invalid_value;
1128 			mnt->acregmin = option;
1129 			break;
1130 		case Opt_acregmax:
1131 			string = match_strdup(args);
1132 			if (string == NULL)
1133 				goto out_nomem;
1134 			rc = strict_strtoul(string, 10, &option);
1135 			kfree(string);
1136 			if (rc != 0)
1137 				goto out_invalid_value;
1138 			mnt->acregmax = option;
1139 			break;
1140 		case Opt_acdirmin:
1141 			string = match_strdup(args);
1142 			if (string == NULL)
1143 				goto out_nomem;
1144 			rc = strict_strtoul(string, 10, &option);
1145 			kfree(string);
1146 			if (rc != 0)
1147 				goto out_invalid_value;
1148 			mnt->acdirmin = option;
1149 			break;
1150 		case Opt_acdirmax:
1151 			string = match_strdup(args);
1152 			if (string == NULL)
1153 				goto out_nomem;
1154 			rc = strict_strtoul(string, 10, &option);
1155 			kfree(string);
1156 			if (rc != 0)
1157 				goto out_invalid_value;
1158 			mnt->acdirmax = option;
1159 			break;
1160 		case Opt_actimeo:
1161 			string = match_strdup(args);
1162 			if (string == NULL)
1163 				goto out_nomem;
1164 			rc = strict_strtoul(string, 10, &option);
1165 			kfree(string);
1166 			if (rc != 0)
1167 				goto out_invalid_value;
1168 			mnt->acregmin = mnt->acregmax =
1169 			mnt->acdirmin = mnt->acdirmax = option;
1170 			break;
1171 		case Opt_namelen:
1172 			string = match_strdup(args);
1173 			if (string == NULL)
1174 				goto out_nomem;
1175 			rc = strict_strtoul(string, 10, &option);
1176 			kfree(string);
1177 			if (rc != 0)
1178 				goto out_invalid_value;
1179 			mnt->namlen = option;
1180 			break;
1181 		case Opt_mountport:
1182 			string = match_strdup(args);
1183 			if (string == NULL)
1184 				goto out_nomem;
1185 			rc = strict_strtoul(string, 10, &option);
1186 			kfree(string);
1187 			if (rc != 0 || option > USHORT_MAX)
1188 				goto out_invalid_value;
1189 			mnt->mount_server.port = option;
1190 			break;
1191 		case Opt_mountvers:
1192 			string = match_strdup(args);
1193 			if (string == NULL)
1194 				goto out_nomem;
1195 			rc = strict_strtoul(string, 10, &option);
1196 			kfree(string);
1197 			if (rc != 0 ||
1198 			    option < NFS_MNT_VERSION ||
1199 			    option > NFS_MNT3_VERSION)
1200 				goto out_invalid_value;
1201 			mnt->mount_server.version = option;
1202 			break;
1203 		case Opt_nfsvers:
1204 			string = match_strdup(args);
1205 			if (string == NULL)
1206 				goto out_nomem;
1207 			rc = strict_strtoul(string, 10, &option);
1208 			kfree(string);
1209 			if (rc != 0)
1210 				goto out_invalid_value;
1211 			switch (option) {
1212 			case NFS2_VERSION:
1213 				mnt->flags &= ~NFS_MOUNT_VER3;
1214 				mnt->version = 2;
1215 				break;
1216 			case NFS3_VERSION:
1217 				mnt->flags |= NFS_MOUNT_VER3;
1218 				mnt->version = 3;
1219 				break;
1220 #ifdef CONFIG_NFS_V4
1221 			case NFS4_VERSION:
1222 				mnt->flags &= ~NFS_MOUNT_VER3;
1223 				mnt->version = 4;
1224 				break;
1225 #endif
1226 			default:
1227 				goto out_invalid_value;
1228 			}
1229 			break;
1230 		case Opt_minorversion:
1231 			string = match_strdup(args);
1232 			if (string == NULL)
1233 				goto out_nomem;
1234 			rc = strict_strtoul(string, 10, &option);
1235 			kfree(string);
1236 			if (rc != 0)
1237 				goto out_invalid_value;
1238 			if (option > NFS4_MAX_MINOR_VERSION)
1239 				goto out_invalid_value;
1240 			mnt->minorversion = option;
1241 			break;
1242 
1243 		/*
1244 		 * options that take text values
1245 		 */
1246 		case Opt_sec:
1247 			string = match_strdup(args);
1248 			if (string == NULL)
1249 				goto out_nomem;
1250 			rc = nfs_parse_security_flavors(string, mnt);
1251 			kfree(string);
1252 			if (!rc) {
1253 				dfprintk(MOUNT, "NFS:   unrecognized "
1254 						"security flavor\n");
1255 				return 0;
1256 			}
1257 			break;
1258 		case Opt_proto:
1259 			string = match_strdup(args);
1260 			if (string == NULL)
1261 				goto out_nomem;
1262 			token = match_token(string,
1263 					    nfs_xprt_protocol_tokens, args);
1264 
1265 			protofamily = AF_INET;
1266 			switch (token) {
1267 			case Opt_xprt_udp6:
1268 				protofamily = AF_INET6;
1269 			case Opt_xprt_udp:
1270 				mnt->flags &= ~NFS_MOUNT_TCP;
1271 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1272 				kfree(string);
1273 				break;
1274 			case Opt_xprt_tcp6:
1275 				protofamily = AF_INET6;
1276 			case Opt_xprt_tcp:
1277 				mnt->flags |= NFS_MOUNT_TCP;
1278 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1279 				kfree(string);
1280 				break;
1281 			case Opt_xprt_rdma:
1282 				/* vector side protocols to TCP */
1283 				mnt->flags |= NFS_MOUNT_TCP;
1284 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1285 				xprt_load_transport(string);
1286 				kfree(string);
1287 				break;
1288 			default:
1289 				dfprintk(MOUNT, "NFS:   unrecognized "
1290 						"transport protocol\n");
1291 				kfree(string);
1292 				return 0;
1293 			}
1294 			break;
1295 		case Opt_mountproto:
1296 			string = match_strdup(args);
1297 			if (string == NULL)
1298 				goto out_nomem;
1299 			token = match_token(string,
1300 					    nfs_xprt_protocol_tokens, args);
1301 			kfree(string);
1302 
1303 			mountfamily = AF_INET;
1304 			switch (token) {
1305 			case Opt_xprt_udp6:
1306 				mountfamily = AF_INET6;
1307 			case Opt_xprt_udp:
1308 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1309 				break;
1310 			case Opt_xprt_tcp6:
1311 				mountfamily = AF_INET6;
1312 			case Opt_xprt_tcp:
1313 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1314 				break;
1315 			case Opt_xprt_rdma: /* not used for side protocols */
1316 			default:
1317 				dfprintk(MOUNT, "NFS:   unrecognized "
1318 						"transport protocol\n");
1319 				return 0;
1320 			}
1321 			break;
1322 		case Opt_addr:
1323 			string = match_strdup(args);
1324 			if (string == NULL)
1325 				goto out_nomem;
1326 			mnt->nfs_server.addrlen =
1327 				rpc_pton(string, strlen(string),
1328 					(struct sockaddr *)
1329 					&mnt->nfs_server.address,
1330 					sizeof(mnt->nfs_server.address));
1331 			kfree(string);
1332 			if (mnt->nfs_server.addrlen == 0)
1333 				goto out_invalid_address;
1334 			break;
1335 		case Opt_clientaddr:
1336 			string = match_strdup(args);
1337 			if (string == NULL)
1338 				goto out_nomem;
1339 			kfree(mnt->client_address);
1340 			mnt->client_address = string;
1341 			break;
1342 		case Opt_mounthost:
1343 			string = match_strdup(args);
1344 			if (string == NULL)
1345 				goto out_nomem;
1346 			kfree(mnt->mount_server.hostname);
1347 			mnt->mount_server.hostname = string;
1348 			break;
1349 		case Opt_mountaddr:
1350 			string = match_strdup(args);
1351 			if (string == NULL)
1352 				goto out_nomem;
1353 			mnt->mount_server.addrlen =
1354 				rpc_pton(string, strlen(string),
1355 					(struct sockaddr *)
1356 					&mnt->mount_server.address,
1357 					sizeof(mnt->mount_server.address));
1358 			kfree(string);
1359 			if (mnt->mount_server.addrlen == 0)
1360 				goto out_invalid_address;
1361 			break;
1362 		case Opt_lookupcache:
1363 			string = match_strdup(args);
1364 			if (string == NULL)
1365 				goto out_nomem;
1366 			token = match_token(string,
1367 					nfs_lookupcache_tokens, args);
1368 			kfree(string);
1369 			switch (token) {
1370 				case Opt_lookupcache_all:
1371 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1372 					break;
1373 				case Opt_lookupcache_positive:
1374 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1375 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1376 					break;
1377 				case Opt_lookupcache_none:
1378 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1379 					break;
1380 				default:
1381 					dfprintk(MOUNT, "NFS:   invalid "
1382 							"lookupcache argument\n");
1383 					return 0;
1384 			};
1385 			break;
1386 
1387 		/*
1388 		 * Special options
1389 		 */
1390 		case Opt_sloppy:
1391 			sloppy = 1;
1392 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1393 			break;
1394 		case Opt_userspace:
1395 		case Opt_deprecated:
1396 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1397 					"'%s'\n", p);
1398 			break;
1399 
1400 		default:
1401 			invalid_option = 1;
1402 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1403 					"'%s'\n", p);
1404 		}
1405 	}
1406 
1407 	if (!sloppy && invalid_option)
1408 		return 0;
1409 
1410 	/*
1411 	 * verify that any proto=/mountproto= options match the address
1412 	 * familiies in the addr=/mountaddr= options.
1413 	 */
1414 	if (protofamily != AF_UNSPEC &&
1415 	    protofamily != mnt->nfs_server.address.ss_family)
1416 		goto out_proto_mismatch;
1417 
1418 	if (mountfamily != AF_UNSPEC) {
1419 		if (mnt->mount_server.addrlen) {
1420 			if (mountfamily != mnt->mount_server.address.ss_family)
1421 				goto out_mountproto_mismatch;
1422 		} else {
1423 			if (mountfamily != mnt->nfs_server.address.ss_family)
1424 				goto out_mountproto_mismatch;
1425 		}
1426 	}
1427 
1428 	return 1;
1429 
1430 out_mountproto_mismatch:
1431 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1432 			 "option\n");
1433 	return 0;
1434 out_proto_mismatch:
1435 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1436 	return 0;
1437 out_invalid_address:
1438 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1439 	return 0;
1440 out_invalid_value:
1441 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1442 	return 0;
1443 out_nomem:
1444 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1445 	return 0;
1446 out_security_failure:
1447 	free_secdata(secdata);
1448 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1449 	return 0;
1450 }
1451 
1452 /*
1453  * Match the requested auth flavors with the list returned by
1454  * the server.  Returns zero and sets the mount's authentication
1455  * flavor on success; returns -EACCES if server does not support
1456  * the requested flavor.
1457  */
1458 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1459 			     struct nfs_mount_request *request)
1460 {
1461 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1462 
1463 	/*
1464 	 * Certain releases of Linux's mountd return an empty
1465 	 * flavor list.  To prevent behavioral regression with
1466 	 * these servers (ie. rejecting mounts that used to
1467 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1468 	 * if the returned flavor list is empty.
1469 	 */
1470 	if (server_authlist_len == 0)
1471 		return 0;
1472 
1473 	/*
1474 	 * We avoid sophisticated negotiating here, as there are
1475 	 * plenty of cases where we can get it wrong, providing
1476 	 * either too little or too much security.
1477 	 *
1478 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1479 	 * flavor listed first.  However, some servers list
1480 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1481 	 * preferred default, in args->auth_flavors[0] if user
1482 	 * didn't specify sec= mount option.
1483 	 */
1484 	for (i = 0; i < args->auth_flavor_len; i++)
1485 		for (j = 0; j < server_authlist_len; j++)
1486 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1487 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1488 					request->auth_flavs[j]);
1489 				args->auth_flavors[0] = request->auth_flavs[j];
1490 				return 0;
1491 			}
1492 
1493 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1494 	nfs_umount(request);
1495 	return -EACCES;
1496 }
1497 
1498 /*
1499  * Use the remote server's MOUNT service to request the NFS file handle
1500  * corresponding to the provided path.
1501  */
1502 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1503 			 struct nfs_fh *root_fh)
1504 {
1505 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1506 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1507 	struct nfs_mount_request request = {
1508 		.sap		= (struct sockaddr *)
1509 						&args->mount_server.address,
1510 		.dirpath	= args->nfs_server.export_path,
1511 		.protocol	= args->mount_server.protocol,
1512 		.fh		= root_fh,
1513 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1514 		.auth_flav_len	= &server_authlist_len,
1515 		.auth_flavs	= server_authlist,
1516 	};
1517 	int status;
1518 
1519 	if (args->mount_server.version == 0) {
1520 		switch (args->version) {
1521 			default:
1522 				args->mount_server.version = NFS_MNT3_VERSION;
1523 				break;
1524 			case 2:
1525 				args->mount_server.version = NFS_MNT_VERSION;
1526 		}
1527 	}
1528 	request.version = args->mount_server.version;
1529 
1530 	if (args->mount_server.hostname)
1531 		request.hostname = args->mount_server.hostname;
1532 	else
1533 		request.hostname = args->nfs_server.hostname;
1534 
1535 	/*
1536 	 * Construct the mount server's address.
1537 	 */
1538 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1539 		memcpy(request.sap, &args->nfs_server.address,
1540 		       args->nfs_server.addrlen);
1541 		args->mount_server.addrlen = args->nfs_server.addrlen;
1542 	}
1543 	request.salen = args->mount_server.addrlen;
1544 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1545 
1546 	/*
1547 	 * Now ask the mount server to map our export path
1548 	 * to a file handle.
1549 	 */
1550 	status = nfs_mount(&request);
1551 	if (status != 0) {
1552 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1553 				request.hostname, status);
1554 		return status;
1555 	}
1556 
1557 	/*
1558 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1559 	 */
1560 	if (args->mount_server.version != NFS_MNT3_VERSION)
1561 		return 0;
1562 	return nfs_walk_authlist(args, &request);
1563 }
1564 
1565 static int nfs_parse_simple_hostname(const char *dev_name,
1566 				     char **hostname, size_t maxnamlen,
1567 				     char **export_path, size_t maxpathlen)
1568 {
1569 	size_t len;
1570 	char *colon, *comma;
1571 
1572 	colon = strchr(dev_name, ':');
1573 	if (colon == NULL)
1574 		goto out_bad_devname;
1575 
1576 	len = colon - dev_name;
1577 	if (len > maxnamlen)
1578 		goto out_hostname;
1579 
1580 	/* N.B. caller will free nfs_server.hostname in all cases */
1581 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1582 	if (!*hostname)
1583 		goto out_nomem;
1584 
1585 	/* kill possible hostname list: not supported */
1586 	comma = strchr(*hostname, ',');
1587 	if (comma != NULL) {
1588 		if (comma == *hostname)
1589 			goto out_bad_devname;
1590 		*comma = '\0';
1591 	}
1592 
1593 	colon++;
1594 	len = strlen(colon);
1595 	if (len > maxpathlen)
1596 		goto out_path;
1597 	*export_path = kstrndup(colon, len, GFP_KERNEL);
1598 	if (!*export_path)
1599 		goto out_nomem;
1600 
1601 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1602 	return 0;
1603 
1604 out_bad_devname:
1605 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1606 	return -EINVAL;
1607 
1608 out_nomem:
1609 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1610 	return -ENOMEM;
1611 
1612 out_hostname:
1613 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1614 	return -ENAMETOOLONG;
1615 
1616 out_path:
1617 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1618 	return -ENAMETOOLONG;
1619 }
1620 
1621 /*
1622  * Hostname has square brackets around it because it contains one or
1623  * more colons.  We look for the first closing square bracket, and a
1624  * colon must follow it.
1625  */
1626 static int nfs_parse_protected_hostname(const char *dev_name,
1627 					char **hostname, size_t maxnamlen,
1628 					char **export_path, size_t maxpathlen)
1629 {
1630 	size_t len;
1631 	char *start, *end;
1632 
1633 	start = (char *)(dev_name + 1);
1634 
1635 	end = strchr(start, ']');
1636 	if (end == NULL)
1637 		goto out_bad_devname;
1638 	if (*(end + 1) != ':')
1639 		goto out_bad_devname;
1640 
1641 	len = end - start;
1642 	if (len > maxnamlen)
1643 		goto out_hostname;
1644 
1645 	/* N.B. caller will free nfs_server.hostname in all cases */
1646 	*hostname = kstrndup(start, len, GFP_KERNEL);
1647 	if (*hostname == NULL)
1648 		goto out_nomem;
1649 
1650 	end += 2;
1651 	len = strlen(end);
1652 	if (len > maxpathlen)
1653 		goto out_path;
1654 	*export_path = kstrndup(end, len, GFP_KERNEL);
1655 	if (!*export_path)
1656 		goto out_nomem;
1657 
1658 	return 0;
1659 
1660 out_bad_devname:
1661 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1662 	return -EINVAL;
1663 
1664 out_nomem:
1665 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1666 	return -ENOMEM;
1667 
1668 out_hostname:
1669 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1670 	return -ENAMETOOLONG;
1671 
1672 out_path:
1673 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1674 	return -ENAMETOOLONG;
1675 }
1676 
1677 /*
1678  * Split "dev_name" into "hostname:export_path".
1679  *
1680  * The leftmost colon demarks the split between the server's hostname
1681  * and the export path.  If the hostname starts with a left square
1682  * bracket, then it may contain colons.
1683  *
1684  * Note: caller frees hostname and export path, even on error.
1685  */
1686 static int nfs_parse_devname(const char *dev_name,
1687 			     char **hostname, size_t maxnamlen,
1688 			     char **export_path, size_t maxpathlen)
1689 {
1690 	if (*dev_name == '[')
1691 		return nfs_parse_protected_hostname(dev_name,
1692 						    hostname, maxnamlen,
1693 						    export_path, maxpathlen);
1694 
1695 	return nfs_parse_simple_hostname(dev_name,
1696 					 hostname, maxnamlen,
1697 					 export_path, maxpathlen);
1698 }
1699 
1700 /*
1701  * Validate the NFS2/NFS3 mount data
1702  * - fills in the mount root filehandle
1703  *
1704  * For option strings, user space handles the following behaviors:
1705  *
1706  * + DNS: mapping server host name to IP address ("addr=" option)
1707  *
1708  * + failure mode: how to behave if a mount request can't be handled
1709  *   immediately ("fg/bg" option)
1710  *
1711  * + retry: how often to retry a mount request ("retry=" option)
1712  *
1713  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1714  *   mountproto=tcp after mountproto=udp, and so on
1715  */
1716 static int nfs_validate_mount_data(void *options,
1717 				   struct nfs_parsed_mount_data *args,
1718 				   struct nfs_fh *mntfh,
1719 				   const char *dev_name)
1720 {
1721 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1722 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1723 
1724 	if (data == NULL)
1725 		goto out_no_data;
1726 
1727 	switch (data->version) {
1728 	case 1:
1729 		data->namlen = 0;
1730 	case 2:
1731 		data->bsize = 0;
1732 	case 3:
1733 		if (data->flags & NFS_MOUNT_VER3)
1734 			goto out_no_v3;
1735 		data->root.size = NFS2_FHSIZE;
1736 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1737 	case 4:
1738 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1739 			goto out_no_sec;
1740 	case 5:
1741 		memset(data->context, 0, sizeof(data->context));
1742 	case 6:
1743 		if (data->flags & NFS_MOUNT_VER3) {
1744 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1745 				goto out_invalid_fh;
1746 			mntfh->size = data->root.size;
1747 			args->version = 3;
1748 		} else {
1749 			mntfh->size = NFS2_FHSIZE;
1750 			args->version = 2;
1751 		}
1752 
1753 
1754 		memcpy(mntfh->data, data->root.data, mntfh->size);
1755 		if (mntfh->size < sizeof(mntfh->data))
1756 			memset(mntfh->data + mntfh->size, 0,
1757 			       sizeof(mntfh->data) - mntfh->size);
1758 
1759 		/*
1760 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1761 		 * can deal with.
1762 		 */
1763 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1764 		args->rsize		= data->rsize;
1765 		args->wsize		= data->wsize;
1766 		args->timeo		= data->timeo;
1767 		args->retrans		= data->retrans;
1768 		args->acregmin		= data->acregmin;
1769 		args->acregmax		= data->acregmax;
1770 		args->acdirmin		= data->acdirmin;
1771 		args->acdirmax		= data->acdirmax;
1772 
1773 		memcpy(sap, &data->addr, sizeof(data->addr));
1774 		args->nfs_server.addrlen = sizeof(data->addr);
1775 		if (!nfs_verify_server_address(sap))
1776 			goto out_no_address;
1777 
1778 		if (!(data->flags & NFS_MOUNT_TCP))
1779 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1780 		/* N.B. caller will free nfs_server.hostname in all cases */
1781 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1782 		args->namlen		= data->namlen;
1783 		args->bsize		= data->bsize;
1784 
1785 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1786 			args->auth_flavors[0] = data->pseudoflavor;
1787 		if (!args->nfs_server.hostname)
1788 			goto out_nomem;
1789 
1790 		/*
1791 		 * The legacy version 6 binary mount data from userspace has a
1792 		 * field used only to transport selinux information into the
1793 		 * the kernel.  To continue to support that functionality we
1794 		 * have a touch of selinux knowledge here in the NFS code. The
1795 		 * userspace code converted context=blah to just blah so we are
1796 		 * converting back to the full string selinux understands.
1797 		 */
1798 		if (data->context[0]){
1799 #ifdef CONFIG_SECURITY_SELINUX
1800 			int rc;
1801 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1802 			if (!opts_str)
1803 				return -ENOMEM;
1804 			strcpy(opts_str, "context=");
1805 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1806 			strcat(opts_str, &data->context[0]);
1807 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1808 			kfree(opts_str);
1809 			if (rc)
1810 				return rc;
1811 #else
1812 			return -EINVAL;
1813 #endif
1814 		}
1815 
1816 		break;
1817 	default: {
1818 		int status;
1819 
1820 		if (nfs_parse_mount_options((char *)options, args) == 0)
1821 			return -EINVAL;
1822 
1823 		if (!nfs_verify_server_address(sap))
1824 			goto out_no_address;
1825 
1826 		if (args->version == 4)
1827 #ifdef CONFIG_NFS_V4
1828 			return nfs4_validate_text_mount_data(options,
1829 							     args, dev_name);
1830 #else
1831 			goto out_v4_not_compiled;
1832 #endif
1833 
1834 		nfs_set_port(sap, &args->nfs_server.port, 0);
1835 
1836 		nfs_set_mount_transport_protocol(args);
1837 
1838 		status = nfs_parse_devname(dev_name,
1839 					   &args->nfs_server.hostname,
1840 					   PAGE_SIZE,
1841 					   &args->nfs_server.export_path,
1842 					   NFS_MAXPATHLEN);
1843 		if (!status)
1844 			status = nfs_try_mount(args, mntfh);
1845 
1846 		kfree(args->nfs_server.export_path);
1847 		args->nfs_server.export_path = NULL;
1848 
1849 		if (status)
1850 			return status;
1851 
1852 		break;
1853 		}
1854 	}
1855 
1856 #ifndef CONFIG_NFS_V3
1857 	if (args->version == 3)
1858 		goto out_v3_not_compiled;
1859 #endif /* !CONFIG_NFS_V3 */
1860 
1861 	return 0;
1862 
1863 out_no_data:
1864 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1865 	return -EINVAL;
1866 
1867 out_no_v3:
1868 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1869 		 data->version);
1870 	return -EINVAL;
1871 
1872 out_no_sec:
1873 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1874 	return -EINVAL;
1875 
1876 #ifndef CONFIG_NFS_V3
1877 out_v3_not_compiled:
1878 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1879 	return -EPROTONOSUPPORT;
1880 #endif /* !CONFIG_NFS_V3 */
1881 
1882 #ifndef CONFIG_NFS_V4
1883 out_v4_not_compiled:
1884 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1885 	return -EPROTONOSUPPORT;
1886 #endif /* !CONFIG_NFS_V4 */
1887 
1888 out_nomem:
1889 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1890 	return -ENOMEM;
1891 
1892 out_no_address:
1893 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1894 	return -EINVAL;
1895 
1896 out_invalid_fh:
1897 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1898 	return -EINVAL;
1899 }
1900 
1901 static int
1902 nfs_compare_remount_data(struct nfs_server *nfss,
1903 			 struct nfs_parsed_mount_data *data)
1904 {
1905 	if (data->flags != nfss->flags ||
1906 	    data->rsize != nfss->rsize ||
1907 	    data->wsize != nfss->wsize ||
1908 	    data->retrans != nfss->client->cl_timeout->to_retries ||
1909 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1910 	    data->acregmin != nfss->acregmin / HZ ||
1911 	    data->acregmax != nfss->acregmax / HZ ||
1912 	    data->acdirmin != nfss->acdirmin / HZ ||
1913 	    data->acdirmax != nfss->acdirmax / HZ ||
1914 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1915 	    data->nfs_server.port != nfss->port ||
1916 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1917 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1918 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
1919 		return -EINVAL;
1920 
1921 	return 0;
1922 }
1923 
1924 static int
1925 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1926 {
1927 	int error;
1928 	struct nfs_server *nfss = sb->s_fs_info;
1929 	struct nfs_parsed_mount_data *data;
1930 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1931 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1932 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1933 
1934 	/*
1935 	 * Userspace mount programs that send binary options generally send
1936 	 * them populated with default values. We have no way to know which
1937 	 * ones were explicitly specified. Fall back to legacy behavior and
1938 	 * just return success.
1939 	 */
1940 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1941 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
1942 					   options->version <= 6))))
1943 		return 0;
1944 
1945 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1946 	if (data == NULL)
1947 		return -ENOMEM;
1948 
1949 	/* fill out struct with values from existing mount */
1950 	data->flags = nfss->flags;
1951 	data->rsize = nfss->rsize;
1952 	data->wsize = nfss->wsize;
1953 	data->retrans = nfss->client->cl_timeout->to_retries;
1954 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1955 	data->acregmin = nfss->acregmin / HZ;
1956 	data->acregmax = nfss->acregmax / HZ;
1957 	data->acdirmin = nfss->acdirmin / HZ;
1958 	data->acdirmax = nfss->acdirmax / HZ;
1959 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1960 	data->nfs_server.port = nfss->port;
1961 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1962 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1963 		data->nfs_server.addrlen);
1964 
1965 	/* overwrite those values with any that were specified */
1966 	error = nfs_parse_mount_options((char *)options, data);
1967 	if (error < 0)
1968 		goto out;
1969 
1970 	/* compare new mount options with old ones */
1971 	error = nfs_compare_remount_data(nfss, data);
1972 out:
1973 	kfree(data);
1974 	return error;
1975 }
1976 
1977 /*
1978  * Initialise the common bits of the superblock
1979  */
1980 static inline void nfs_initialise_sb(struct super_block *sb)
1981 {
1982 	struct nfs_server *server = NFS_SB(sb);
1983 
1984 	sb->s_magic = NFS_SUPER_MAGIC;
1985 
1986 	/* We probably want something more informative here */
1987 	snprintf(sb->s_id, sizeof(sb->s_id),
1988 		 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1989 
1990 	if (sb->s_blocksize == 0)
1991 		sb->s_blocksize = nfs_block_bits(server->wsize,
1992 						 &sb->s_blocksize_bits);
1993 
1994 	if (server->flags & NFS_MOUNT_NOAC)
1995 		sb->s_flags |= MS_SYNCHRONOUS;
1996 
1997 	sb->s_bdi = &server->backing_dev_info;
1998 
1999 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2000 }
2001 
2002 /*
2003  * Finish setting up an NFS2/3 superblock
2004  */
2005 static void nfs_fill_super(struct super_block *sb,
2006 			   struct nfs_parsed_mount_data *data)
2007 {
2008 	struct nfs_server *server = NFS_SB(sb);
2009 
2010 	sb->s_blocksize_bits = 0;
2011 	sb->s_blocksize = 0;
2012 	if (data->bsize)
2013 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2014 
2015 	if (server->nfs_client->rpc_ops->version == 3) {
2016 		/* The VFS shouldn't apply the umask to mode bits. We will do
2017 		 * so ourselves when necessary.
2018 		 */
2019 		sb->s_flags |= MS_POSIXACL;
2020 		sb->s_time_gran = 1;
2021 	}
2022 
2023 	sb->s_op = &nfs_sops;
2024  	nfs_initialise_sb(sb);
2025 }
2026 
2027 /*
2028  * Finish setting up a cloned NFS2/3 superblock
2029  */
2030 static void nfs_clone_super(struct super_block *sb,
2031 			    const struct super_block *old_sb)
2032 {
2033 	struct nfs_server *server = NFS_SB(sb);
2034 
2035 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2036 	sb->s_blocksize = old_sb->s_blocksize;
2037 	sb->s_maxbytes = old_sb->s_maxbytes;
2038 
2039 	if (server->nfs_client->rpc_ops->version == 3) {
2040 		/* The VFS shouldn't apply the umask to mode bits. We will do
2041 		 * so ourselves when necessary.
2042 		 */
2043 		sb->s_flags |= MS_POSIXACL;
2044 		sb->s_time_gran = 1;
2045 	}
2046 
2047 	sb->s_op = old_sb->s_op;
2048  	nfs_initialise_sb(sb);
2049 }
2050 
2051 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2052 {
2053 	const struct nfs_server *a = s->s_fs_info;
2054 	const struct rpc_clnt *clnt_a = a->client;
2055 	const struct rpc_clnt *clnt_b = b->client;
2056 
2057 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2058 		goto Ebusy;
2059 	if (a->nfs_client != b->nfs_client)
2060 		goto Ebusy;
2061 	if (a->flags != b->flags)
2062 		goto Ebusy;
2063 	if (a->wsize != b->wsize)
2064 		goto Ebusy;
2065 	if (a->rsize != b->rsize)
2066 		goto Ebusy;
2067 	if (a->acregmin != b->acregmin)
2068 		goto Ebusy;
2069 	if (a->acregmax != b->acregmax)
2070 		goto Ebusy;
2071 	if (a->acdirmin != b->acdirmin)
2072 		goto Ebusy;
2073 	if (a->acdirmax != b->acdirmax)
2074 		goto Ebusy;
2075 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2076 		goto Ebusy;
2077 	return 1;
2078 Ebusy:
2079 	return 0;
2080 }
2081 
2082 struct nfs_sb_mountdata {
2083 	struct nfs_server *server;
2084 	int mntflags;
2085 };
2086 
2087 static int nfs_set_super(struct super_block *s, void *data)
2088 {
2089 	struct nfs_sb_mountdata *sb_mntdata = data;
2090 	struct nfs_server *server = sb_mntdata->server;
2091 	int ret;
2092 
2093 	s->s_flags = sb_mntdata->mntflags;
2094 	s->s_fs_info = server;
2095 	ret = set_anon_super(s, server);
2096 	if (ret == 0)
2097 		server->s_dev = s->s_dev;
2098 	return ret;
2099 }
2100 
2101 static int nfs_compare_super_address(struct nfs_server *server1,
2102 				     struct nfs_server *server2)
2103 {
2104 	struct sockaddr *sap1, *sap2;
2105 
2106 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2107 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2108 
2109 	if (sap1->sa_family != sap2->sa_family)
2110 		return 0;
2111 
2112 	switch (sap1->sa_family) {
2113 	case AF_INET: {
2114 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2115 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2116 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2117 			return 0;
2118 		if (sin1->sin_port != sin2->sin_port)
2119 			return 0;
2120 		break;
2121 	}
2122 	case AF_INET6: {
2123 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2124 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2125 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2126 			return 0;
2127 		if (sin1->sin6_port != sin2->sin6_port)
2128 			return 0;
2129 		break;
2130 	}
2131 	default:
2132 		return 0;
2133 	}
2134 
2135 	return 1;
2136 }
2137 
2138 static int nfs_compare_super(struct super_block *sb, void *data)
2139 {
2140 	struct nfs_sb_mountdata *sb_mntdata = data;
2141 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2142 	int mntflags = sb_mntdata->mntflags;
2143 
2144 	if (!nfs_compare_super_address(old, server))
2145 		return 0;
2146 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2147 	if (old->flags & NFS_MOUNT_UNSHARED)
2148 		return 0;
2149 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2150 		return 0;
2151 	return nfs_compare_mount_options(sb, server, mntflags);
2152 }
2153 
2154 static int nfs_bdi_register(struct nfs_server *server)
2155 {
2156 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2157 }
2158 
2159 static int nfs_get_sb(struct file_system_type *fs_type,
2160 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2161 {
2162 	struct nfs_server *server = NULL;
2163 	struct super_block *s;
2164 	struct nfs_parsed_mount_data *data;
2165 	struct nfs_fh *mntfh;
2166 	struct dentry *mntroot;
2167 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2168 	struct nfs_sb_mountdata sb_mntdata = {
2169 		.mntflags = flags,
2170 	};
2171 	int error = -ENOMEM;
2172 
2173 	data = nfs_alloc_parsed_mount_data(3);
2174 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2175 	if (data == NULL || mntfh == NULL)
2176 		goto out_free_fh;
2177 
2178 	security_init_mnt_opts(&data->lsm_opts);
2179 
2180 	/* Validate the mount data */
2181 	error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2182 	if (error < 0)
2183 		goto out;
2184 
2185 #ifdef CONFIG_NFS_V4
2186 	if (data->version == 4) {
2187 		error = nfs4_try_mount(flags, dev_name, data, mnt);
2188 		kfree(data->client_address);
2189 		goto out;
2190 	}
2191 #endif	/* CONFIG_NFS_V4 */
2192 
2193 	/* Get a volume representation */
2194 	server = nfs_create_server(data, mntfh);
2195 	if (IS_ERR(server)) {
2196 		error = PTR_ERR(server);
2197 		goto out;
2198 	}
2199 	sb_mntdata.server = server;
2200 
2201 	if (server->flags & NFS_MOUNT_UNSHARED)
2202 		compare_super = NULL;
2203 
2204 	/* Get a superblock - note that we may end up sharing one that already exists */
2205 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2206 	if (IS_ERR(s)) {
2207 		error = PTR_ERR(s);
2208 		goto out_err_nosb;
2209 	}
2210 
2211 	if (s->s_fs_info != server) {
2212 		nfs_free_server(server);
2213 		server = NULL;
2214 	} else {
2215 		error = nfs_bdi_register(server);
2216 		if (error)
2217 			goto error_splat_super;
2218 	}
2219 
2220 	if (!s->s_root) {
2221 		/* initial superblock/root creation */
2222 		nfs_fill_super(s, data);
2223 		nfs_fscache_get_super_cookie(
2224 			s, data ? data->fscache_uniq : NULL, NULL);
2225 	}
2226 
2227 	mntroot = nfs_get_root(s, mntfh);
2228 	if (IS_ERR(mntroot)) {
2229 		error = PTR_ERR(mntroot);
2230 		goto error_splat_super;
2231 	}
2232 
2233 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2234 	if (error)
2235 		goto error_splat_root;
2236 
2237 	s->s_flags |= MS_ACTIVE;
2238 	mnt->mnt_sb = s;
2239 	mnt->mnt_root = mntroot;
2240 	error = 0;
2241 
2242 out:
2243 	kfree(data->nfs_server.hostname);
2244 	kfree(data->mount_server.hostname);
2245 	kfree(data->fscache_uniq);
2246 	security_free_mnt_opts(&data->lsm_opts);
2247 out_free_fh:
2248 	kfree(mntfh);
2249 	kfree(data);
2250 	return error;
2251 
2252 out_err_nosb:
2253 	nfs_free_server(server);
2254 	goto out;
2255 
2256 error_splat_root:
2257 	dput(mntroot);
2258 error_splat_super:
2259 	deactivate_locked_super(s);
2260 	goto out;
2261 }
2262 
2263 /*
2264  * Ensure that we unregister the bdi before kill_anon_super
2265  * releases the device name
2266  */
2267 static void nfs_put_super(struct super_block *s)
2268 {
2269 	struct nfs_server *server = NFS_SB(s);
2270 
2271 	bdi_unregister(&server->backing_dev_info);
2272 }
2273 
2274 /*
2275  * Destroy an NFS2/3 superblock
2276  */
2277 static void nfs_kill_super(struct super_block *s)
2278 {
2279 	struct nfs_server *server = NFS_SB(s);
2280 
2281 	kill_anon_super(s);
2282 	nfs_fscache_release_super_cookie(s);
2283 	nfs_free_server(server);
2284 }
2285 
2286 /*
2287  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2288  */
2289 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2290 			   const char *dev_name, void *raw_data,
2291 			   struct vfsmount *mnt)
2292 {
2293 	struct nfs_clone_mount *data = raw_data;
2294 	struct super_block *s;
2295 	struct nfs_server *server;
2296 	struct dentry *mntroot;
2297 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2298 	struct nfs_sb_mountdata sb_mntdata = {
2299 		.mntflags = flags,
2300 	};
2301 	int error;
2302 
2303 	dprintk("--> nfs_xdev_get_sb()\n");
2304 
2305 	/* create a new volume representation */
2306 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2307 	if (IS_ERR(server)) {
2308 		error = PTR_ERR(server);
2309 		goto out_err_noserver;
2310 	}
2311 	sb_mntdata.server = server;
2312 
2313 	if (server->flags & NFS_MOUNT_UNSHARED)
2314 		compare_super = NULL;
2315 
2316 	/* Get a superblock - note that we may end up sharing one that already exists */
2317 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2318 	if (IS_ERR(s)) {
2319 		error = PTR_ERR(s);
2320 		goto out_err_nosb;
2321 	}
2322 
2323 	if (s->s_fs_info != server) {
2324 		nfs_free_server(server);
2325 		server = NULL;
2326 	} else {
2327 		error = nfs_bdi_register(server);
2328 		if (error)
2329 			goto error_splat_super;
2330 	}
2331 
2332 	if (!s->s_root) {
2333 		/* initial superblock/root creation */
2334 		nfs_clone_super(s, data->sb);
2335 		nfs_fscache_get_super_cookie(s, NULL, data);
2336 	}
2337 
2338 	mntroot = nfs_get_root(s, data->fh);
2339 	if (IS_ERR(mntroot)) {
2340 		error = PTR_ERR(mntroot);
2341 		goto error_splat_super;
2342 	}
2343 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2344 		dput(mntroot);
2345 		error = -ESTALE;
2346 		goto error_splat_super;
2347 	}
2348 
2349 	s->s_flags |= MS_ACTIVE;
2350 	mnt->mnt_sb = s;
2351 	mnt->mnt_root = mntroot;
2352 
2353 	/* clone any lsm security options from the parent to the new sb */
2354 	security_sb_clone_mnt_opts(data->sb, s);
2355 
2356 	dprintk("<-- nfs_xdev_get_sb() = 0\n");
2357 	return 0;
2358 
2359 out_err_nosb:
2360 	nfs_free_server(server);
2361 out_err_noserver:
2362 	dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2363 	return error;
2364 
2365 error_splat_super:
2366 	deactivate_locked_super(s);
2367 	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2368 	return error;
2369 }
2370 
2371 #ifdef CONFIG_NFS_V4
2372 
2373 /*
2374  * Finish setting up a cloned NFS4 superblock
2375  */
2376 static void nfs4_clone_super(struct super_block *sb,
2377 			    const struct super_block *old_sb)
2378 {
2379 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2380 	sb->s_blocksize = old_sb->s_blocksize;
2381 	sb->s_maxbytes = old_sb->s_maxbytes;
2382 	sb->s_time_gran = 1;
2383 	sb->s_op = old_sb->s_op;
2384  	nfs_initialise_sb(sb);
2385 }
2386 
2387 /*
2388  * Set up an NFS4 superblock
2389  */
2390 static void nfs4_fill_super(struct super_block *sb)
2391 {
2392 	sb->s_time_gran = 1;
2393 	sb->s_op = &nfs4_sops;
2394 	nfs_initialise_sb(sb);
2395 }
2396 
2397 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2398 {
2399 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2400 }
2401 
2402 static int nfs4_validate_text_mount_data(void *options,
2403 					 struct nfs_parsed_mount_data *args,
2404 					 const char *dev_name)
2405 {
2406 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2407 
2408 	nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2409 
2410 	nfs_validate_transport_protocol(args);
2411 
2412 	nfs4_validate_mount_flags(args);
2413 
2414 	if (args->version != 4) {
2415 		dfprintk(MOUNT,
2416 			 "NFS4: Illegal mount version\n");
2417 		return -EINVAL;
2418 	}
2419 
2420 	if (args->auth_flavor_len > 1) {
2421 		dfprintk(MOUNT,
2422 			 "NFS4: Too many RPC auth flavours specified\n");
2423 		return -EINVAL;
2424 	}
2425 
2426 	if (args->client_address == NULL) {
2427 		dfprintk(MOUNT,
2428 			 "NFS4: mount program didn't pass callback address\n");
2429 		return -EINVAL;
2430 	}
2431 
2432 	return nfs_parse_devname(dev_name,
2433 				   &args->nfs_server.hostname,
2434 				   NFS4_MAXNAMLEN,
2435 				   &args->nfs_server.export_path,
2436 				   NFS4_MAXPATHLEN);
2437 }
2438 
2439 /*
2440  * Validate NFSv4 mount options
2441  */
2442 static int nfs4_validate_mount_data(void *options,
2443 				    struct nfs_parsed_mount_data *args,
2444 				    const char *dev_name)
2445 {
2446 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2447 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2448 	char *c;
2449 
2450 	if (data == NULL)
2451 		goto out_no_data;
2452 
2453 	switch (data->version) {
2454 	case 1:
2455 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2456 			goto out_no_address;
2457 		if (data->host_addrlen == 0)
2458 			goto out_no_address;
2459 		args->nfs_server.addrlen = data->host_addrlen;
2460 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2461 			return -EFAULT;
2462 		if (!nfs_verify_server_address(sap))
2463 			goto out_no_address;
2464 
2465 		if (data->auth_flavourlen) {
2466 			if (data->auth_flavourlen > 1)
2467 				goto out_inval_auth;
2468 			if (copy_from_user(&args->auth_flavors[0],
2469 					   data->auth_flavours,
2470 					   sizeof(args->auth_flavors[0])))
2471 				return -EFAULT;
2472 		}
2473 
2474 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2475 		if (IS_ERR(c))
2476 			return PTR_ERR(c);
2477 		args->nfs_server.hostname = c;
2478 
2479 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2480 		if (IS_ERR(c))
2481 			return PTR_ERR(c);
2482 		args->nfs_server.export_path = c;
2483 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2484 
2485 		c = strndup_user(data->client_addr.data, 16);
2486 		if (IS_ERR(c))
2487 			return PTR_ERR(c);
2488 		args->client_address = c;
2489 
2490 		/*
2491 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2492 		 * can deal with.
2493 		 */
2494 
2495 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2496 		args->rsize	= data->rsize;
2497 		args->wsize	= data->wsize;
2498 		args->timeo	= data->timeo;
2499 		args->retrans	= data->retrans;
2500 		args->acregmin	= data->acregmin;
2501 		args->acregmax	= data->acregmax;
2502 		args->acdirmin	= data->acdirmin;
2503 		args->acdirmax	= data->acdirmax;
2504 		args->nfs_server.protocol = data->proto;
2505 		nfs_validate_transport_protocol(args);
2506 
2507 		break;
2508 	default:
2509 		if (nfs_parse_mount_options((char *)options, args) == 0)
2510 			return -EINVAL;
2511 
2512 		if (!nfs_verify_server_address(sap))
2513 			return -EINVAL;
2514 
2515 		return nfs4_validate_text_mount_data(options, args, dev_name);
2516 	}
2517 
2518 	return 0;
2519 
2520 out_no_data:
2521 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2522 	return -EINVAL;
2523 
2524 out_inval_auth:
2525 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2526 		 data->auth_flavourlen);
2527 	return -EINVAL;
2528 
2529 out_no_address:
2530 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2531 	return -EINVAL;
2532 }
2533 
2534 /*
2535  * Get the superblock for the NFS4 root partition
2536  */
2537 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2538 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2539 {
2540 	struct nfs_parsed_mount_data *data = raw_data;
2541 	struct super_block *s;
2542 	struct nfs_server *server;
2543 	struct nfs_fh *mntfh;
2544 	struct dentry *mntroot;
2545 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2546 	struct nfs_sb_mountdata sb_mntdata = {
2547 		.mntflags = flags,
2548 	};
2549 	int error = -ENOMEM;
2550 
2551 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2552 	if (data == NULL || mntfh == NULL)
2553 		goto out_free_fh;
2554 
2555 	security_init_mnt_opts(&data->lsm_opts);
2556 
2557 	/* Get a volume representation */
2558 	server = nfs4_create_server(data, mntfh);
2559 	if (IS_ERR(server)) {
2560 		error = PTR_ERR(server);
2561 		goto out;
2562 	}
2563 	sb_mntdata.server = server;
2564 
2565 	if (server->flags & NFS4_MOUNT_UNSHARED)
2566 		compare_super = NULL;
2567 
2568 	/* Get a superblock - note that we may end up sharing one that already exists */
2569 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2570 	if (IS_ERR(s)) {
2571 		error = PTR_ERR(s);
2572 		goto out_free;
2573 	}
2574 
2575 	if (s->s_fs_info != server) {
2576 		nfs_free_server(server);
2577 		server = NULL;
2578 	} else {
2579 		error = nfs_bdi_register(server);
2580 		if (error)
2581 			goto error_splat_super;
2582 	}
2583 
2584 	if (!s->s_root) {
2585 		/* initial superblock/root creation */
2586 		nfs4_fill_super(s);
2587 		nfs_fscache_get_super_cookie(
2588 			s, data ? data->fscache_uniq : NULL, NULL);
2589 	}
2590 
2591 	mntroot = nfs4_get_root(s, mntfh);
2592 	if (IS_ERR(mntroot)) {
2593 		error = PTR_ERR(mntroot);
2594 		goto error_splat_super;
2595 	}
2596 
2597 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2598 	if (error)
2599 		goto error_splat_root;
2600 
2601 	s->s_flags |= MS_ACTIVE;
2602 	mnt->mnt_sb = s;
2603 	mnt->mnt_root = mntroot;
2604 	error = 0;
2605 
2606 out:
2607 	security_free_mnt_opts(&data->lsm_opts);
2608 out_free_fh:
2609 	kfree(mntfh);
2610 	return error;
2611 
2612 out_free:
2613 	nfs_free_server(server);
2614 	goto out;
2615 
2616 error_splat_root:
2617 	dput(mntroot);
2618 error_splat_super:
2619 	deactivate_locked_super(s);
2620 	goto out;
2621 }
2622 
2623 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2624 		int flags, void *data, const char *hostname)
2625 {
2626 	struct vfsmount *root_mnt;
2627 	char *root_devname;
2628 	size_t len;
2629 
2630 	len = strlen(hostname) + 3;
2631 	root_devname = kmalloc(len, GFP_KERNEL);
2632 	if (root_devname == NULL)
2633 		return ERR_PTR(-ENOMEM);
2634 	snprintf(root_devname, len, "%s:/", hostname);
2635 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2636 	kfree(root_devname);
2637 	return root_mnt;
2638 }
2639 
2640 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2641 {
2642 	char *page = (char *) __get_free_page(GFP_KERNEL);
2643 	char *devname, *tmp;
2644 
2645 	if (page == NULL)
2646 		return;
2647 	devname = nfs_path(path->mnt->mnt_devname,
2648 			path->mnt->mnt_root, path->dentry,
2649 			page, PAGE_SIZE);
2650 	if (devname == NULL)
2651 		goto out_freepage;
2652 	tmp = kstrdup(devname, GFP_KERNEL);
2653 	if (tmp == NULL)
2654 		goto out_freepage;
2655 	kfree(mnt->mnt_devname);
2656 	mnt->mnt_devname = tmp;
2657 out_freepage:
2658 	free_page((unsigned long)page);
2659 }
2660 
2661 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2662 		const char *export_path, struct vfsmount *mnt_target)
2663 {
2664 	struct mnt_namespace *ns_private;
2665 	struct nameidata nd;
2666 	struct super_block *s;
2667 	int ret;
2668 
2669 	ns_private = create_mnt_ns(root_mnt);
2670 	ret = PTR_ERR(ns_private);
2671 	if (IS_ERR(ns_private))
2672 		goto out_mntput;
2673 
2674 	ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2675 			export_path, LOOKUP_FOLLOW, &nd);
2676 
2677 	put_mnt_ns(ns_private);
2678 
2679 	if (ret != 0)
2680 		goto out_err;
2681 
2682 	s = nd.path.mnt->mnt_sb;
2683 	atomic_inc(&s->s_active);
2684 	mnt_target->mnt_sb = s;
2685 	mnt_target->mnt_root = dget(nd.path.dentry);
2686 
2687 	/* Correct the device pathname */
2688 	nfs_fix_devname(&nd.path, mnt_target);
2689 
2690 	path_put(&nd.path);
2691 	down_write(&s->s_umount);
2692 	return 0;
2693 out_mntput:
2694 	mntput(root_mnt);
2695 out_err:
2696 	return ret;
2697 }
2698 
2699 static int nfs4_try_mount(int flags, const char *dev_name,
2700 			 struct nfs_parsed_mount_data *data,
2701 			 struct vfsmount *mnt)
2702 {
2703 	char *export_path;
2704 	struct vfsmount *root_mnt;
2705 	int error;
2706 
2707 	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2708 
2709 	export_path = data->nfs_server.export_path;
2710 	data->nfs_server.export_path = "/";
2711 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2712 			data->nfs_server.hostname);
2713 	data->nfs_server.export_path = export_path;
2714 
2715 	error = PTR_ERR(root_mnt);
2716 	if (IS_ERR(root_mnt))
2717 		goto out;
2718 
2719 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2720 
2721 out:
2722 	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2723 			error != 0 ? " [error]" : "");
2724 	return error;
2725 }
2726 
2727 /*
2728  * Get the superblock for an NFS4 mountpoint
2729  */
2730 static int nfs4_get_sb(struct file_system_type *fs_type,
2731 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2732 {
2733 	struct nfs_parsed_mount_data *data;
2734 	int error = -ENOMEM;
2735 
2736 	data = nfs_alloc_parsed_mount_data(4);
2737 	if (data == NULL)
2738 		goto out_free_data;
2739 
2740 	/* Validate the mount data */
2741 	error = nfs4_validate_mount_data(raw_data, data, dev_name);
2742 	if (error < 0)
2743 		goto out;
2744 
2745 	error = nfs4_try_mount(flags, dev_name, data, mnt);
2746 
2747 out:
2748 	kfree(data->client_address);
2749 	kfree(data->nfs_server.export_path);
2750 	kfree(data->nfs_server.hostname);
2751 	kfree(data->fscache_uniq);
2752 out_free_data:
2753 	kfree(data);
2754 	dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2755 			error != 0 ? " [error]" : "");
2756 	return error;
2757 }
2758 
2759 static void nfs4_kill_super(struct super_block *sb)
2760 {
2761 	struct nfs_server *server = NFS_SB(sb);
2762 
2763 	dprintk("--> %s\n", __func__);
2764 	nfs_super_return_all_delegations(sb);
2765 	kill_anon_super(sb);
2766 	nfs_fscache_release_super_cookie(sb);
2767 	nfs_free_server(server);
2768 	dprintk("<-- %s\n", __func__);
2769 }
2770 
2771 /*
2772  * Clone an NFS4 server record on xdev traversal (FSID-change)
2773  */
2774 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2775 			    const char *dev_name, void *raw_data,
2776 			    struct vfsmount *mnt)
2777 {
2778 	struct nfs_clone_mount *data = raw_data;
2779 	struct super_block *s;
2780 	struct nfs_server *server;
2781 	struct dentry *mntroot;
2782 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2783 	struct nfs_sb_mountdata sb_mntdata = {
2784 		.mntflags = flags,
2785 	};
2786 	int error;
2787 
2788 	dprintk("--> nfs4_xdev_get_sb()\n");
2789 
2790 	/* create a new volume representation */
2791 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2792 	if (IS_ERR(server)) {
2793 		error = PTR_ERR(server);
2794 		goto out_err_noserver;
2795 	}
2796 	sb_mntdata.server = server;
2797 
2798 	if (server->flags & NFS4_MOUNT_UNSHARED)
2799 		compare_super = NULL;
2800 
2801 	/* Get a superblock - note that we may end up sharing one that already exists */
2802 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2803 	if (IS_ERR(s)) {
2804 		error = PTR_ERR(s);
2805 		goto out_err_nosb;
2806 	}
2807 
2808 	if (s->s_fs_info != server) {
2809 		nfs_free_server(server);
2810 		server = NULL;
2811 	} else {
2812 		error = nfs_bdi_register(server);
2813 		if (error)
2814 			goto error_splat_super;
2815 	}
2816 
2817 	if (!s->s_root) {
2818 		/* initial superblock/root creation */
2819 		nfs4_clone_super(s, data->sb);
2820 		nfs_fscache_get_super_cookie(s, NULL, data);
2821 	}
2822 
2823 	mntroot = nfs4_get_root(s, data->fh);
2824 	if (IS_ERR(mntroot)) {
2825 		error = PTR_ERR(mntroot);
2826 		goto error_splat_super;
2827 	}
2828 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2829 		dput(mntroot);
2830 		error = -ESTALE;
2831 		goto error_splat_super;
2832 	}
2833 
2834 	s->s_flags |= MS_ACTIVE;
2835 	mnt->mnt_sb = s;
2836 	mnt->mnt_root = mntroot;
2837 
2838 	security_sb_clone_mnt_opts(data->sb, s);
2839 
2840 	dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2841 	return 0;
2842 
2843 out_err_nosb:
2844 	nfs_free_server(server);
2845 out_err_noserver:
2846 	dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2847 	return error;
2848 
2849 error_splat_super:
2850 	deactivate_locked_super(s);
2851 	dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2852 	return error;
2853 }
2854 
2855 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2856 		int flags, const char *dev_name, void *raw_data,
2857 		struct vfsmount *mnt)
2858 {
2859 	struct nfs_clone_mount *data = raw_data;
2860 	struct super_block *s;
2861 	struct nfs_server *server;
2862 	struct dentry *mntroot;
2863 	struct nfs_fh mntfh;
2864 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2865 	struct nfs_sb_mountdata sb_mntdata = {
2866 		.mntflags = flags,
2867 	};
2868 	int error;
2869 
2870 	dprintk("--> nfs4_referral_get_sb()\n");
2871 
2872 	/* create a new volume representation */
2873 	server = nfs4_create_referral_server(data, &mntfh);
2874 	if (IS_ERR(server)) {
2875 		error = PTR_ERR(server);
2876 		goto out_err_noserver;
2877 	}
2878 	sb_mntdata.server = server;
2879 
2880 	if (server->flags & NFS4_MOUNT_UNSHARED)
2881 		compare_super = NULL;
2882 
2883 	/* Get a superblock - note that we may end up sharing one that already exists */
2884 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2885 	if (IS_ERR(s)) {
2886 		error = PTR_ERR(s);
2887 		goto out_err_nosb;
2888 	}
2889 
2890 	if (s->s_fs_info != server) {
2891 		nfs_free_server(server);
2892 		server = NULL;
2893 	} else {
2894 		error = nfs_bdi_register(server);
2895 		if (error)
2896 			goto error_splat_super;
2897 	}
2898 
2899 	if (!s->s_root) {
2900 		/* initial superblock/root creation */
2901 		nfs4_fill_super(s);
2902 		nfs_fscache_get_super_cookie(s, NULL, data);
2903 	}
2904 
2905 	mntroot = nfs4_get_root(s, &mntfh);
2906 	if (IS_ERR(mntroot)) {
2907 		error = PTR_ERR(mntroot);
2908 		goto error_splat_super;
2909 	}
2910 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2911 		dput(mntroot);
2912 		error = -ESTALE;
2913 		goto error_splat_super;
2914 	}
2915 
2916 	s->s_flags |= MS_ACTIVE;
2917 	mnt->mnt_sb = s;
2918 	mnt->mnt_root = mntroot;
2919 
2920 	security_sb_clone_mnt_opts(data->sb, s);
2921 
2922 	dprintk("<-- nfs4_referral_get_sb() = 0\n");
2923 	return 0;
2924 
2925 out_err_nosb:
2926 	nfs_free_server(server);
2927 out_err_noserver:
2928 	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2929 	return error;
2930 
2931 error_splat_super:
2932 	deactivate_locked_super(s);
2933 	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2934 	return error;
2935 }
2936 
2937 /*
2938  * Create an NFS4 server record on referral traversal
2939  */
2940 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2941 		int flags, const char *dev_name, void *raw_data,
2942 		struct vfsmount *mnt)
2943 {
2944 	struct nfs_clone_mount *data = raw_data;
2945 	char *export_path;
2946 	struct vfsmount *root_mnt;
2947 	int error;
2948 
2949 	dprintk("--> nfs4_referral_get_sb()\n");
2950 
2951 	export_path = data->mnt_path;
2952 	data->mnt_path = "/";
2953 
2954 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2955 			flags, data, data->hostname);
2956 	data->mnt_path = export_path;
2957 
2958 	error = PTR_ERR(root_mnt);
2959 	if (IS_ERR(root_mnt))
2960 		goto out;
2961 
2962 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2963 out:
2964 	dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2965 			error != 0 ? " [error]" : "");
2966 	return error;
2967 }
2968 
2969 #endif /* CONFIG_NFS_V4 */
2970