xref: /openbmc/linux/fs/nfs/super.c (revision 9d56dd3b083a3bec56e9da35ce07baca81030b03)
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_kill_super(struct super_block *);
247 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
248 
249 static struct file_system_type nfs_fs_type = {
250 	.owner		= THIS_MODULE,
251 	.name		= "nfs",
252 	.get_sb		= nfs_get_sb,
253 	.kill_sb	= nfs_kill_super,
254 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
255 };
256 
257 struct file_system_type nfs_xdev_fs_type = {
258 	.owner		= THIS_MODULE,
259 	.name		= "nfs",
260 	.get_sb		= nfs_xdev_get_sb,
261 	.kill_sb	= nfs_kill_super,
262 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
263 };
264 
265 static const struct super_operations nfs_sops = {
266 	.alloc_inode	= nfs_alloc_inode,
267 	.destroy_inode	= nfs_destroy_inode,
268 	.write_inode	= nfs_write_inode,
269 	.statfs		= nfs_statfs,
270 	.clear_inode	= nfs_clear_inode,
271 	.umount_begin	= nfs_umount_begin,
272 	.show_options	= nfs_show_options,
273 	.show_stats	= nfs_show_stats,
274 	.remount_fs	= nfs_remount,
275 };
276 
277 #ifdef CONFIG_NFS_V4
278 static int nfs4_validate_text_mount_data(void *options,
279 	struct nfs_parsed_mount_data *args, const char *dev_name);
280 static int nfs4_try_mount(int flags, const char *dev_name,
281 	struct nfs_parsed_mount_data *data, struct vfsmount *mnt);
282 static int nfs4_get_sb(struct file_system_type *fs_type,
283 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
284 static int nfs4_remote_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_xdev_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_referral_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_remote_referral_get_sb(struct file_system_type *fs_type,
291 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
292 static void nfs4_kill_super(struct super_block *sb);
293 
294 static struct file_system_type nfs4_fs_type = {
295 	.owner		= THIS_MODULE,
296 	.name		= "nfs4",
297 	.get_sb		= nfs4_get_sb,
298 	.kill_sb	= nfs4_kill_super,
299 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
300 };
301 
302 static struct file_system_type nfs4_remote_fs_type = {
303 	.owner		= THIS_MODULE,
304 	.name		= "nfs4",
305 	.get_sb		= nfs4_remote_get_sb,
306 	.kill_sb	= nfs4_kill_super,
307 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
308 };
309 
310 struct file_system_type nfs4_xdev_fs_type = {
311 	.owner		= THIS_MODULE,
312 	.name		= "nfs4",
313 	.get_sb		= nfs4_xdev_get_sb,
314 	.kill_sb	= nfs4_kill_super,
315 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
316 };
317 
318 static struct file_system_type nfs4_remote_referral_fs_type = {
319 	.owner		= THIS_MODULE,
320 	.name		= "nfs4",
321 	.get_sb		= nfs4_remote_referral_get_sb,
322 	.kill_sb	= nfs4_kill_super,
323 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
324 };
325 
326 struct file_system_type nfs4_referral_fs_type = {
327 	.owner		= THIS_MODULE,
328 	.name		= "nfs4",
329 	.get_sb		= nfs4_referral_get_sb,
330 	.kill_sb	= nfs4_kill_super,
331 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
332 };
333 
334 static const struct super_operations nfs4_sops = {
335 	.alloc_inode	= nfs_alloc_inode,
336 	.destroy_inode	= nfs_destroy_inode,
337 	.write_inode	= nfs_write_inode,
338 	.statfs		= nfs_statfs,
339 	.clear_inode	= nfs4_clear_inode,
340 	.umount_begin	= nfs_umount_begin,
341 	.show_options	= nfs_show_options,
342 	.show_stats	= nfs_show_stats,
343 	.remount_fs	= nfs_remount,
344 };
345 #endif
346 
347 static struct shrinker acl_shrinker = {
348 	.shrink		= nfs_access_cache_shrinker,
349 	.seeks		= DEFAULT_SEEKS,
350 };
351 
352 /*
353  * Register the NFS filesystems
354  */
355 int __init register_nfs_fs(void)
356 {
357 	int ret;
358 
359         ret = register_filesystem(&nfs_fs_type);
360 	if (ret < 0)
361 		goto error_0;
362 
363 	ret = nfs_register_sysctl();
364 	if (ret < 0)
365 		goto error_1;
366 #ifdef CONFIG_NFS_V4
367 	ret = register_filesystem(&nfs4_fs_type);
368 	if (ret < 0)
369 		goto error_2;
370 #endif
371 	register_shrinker(&acl_shrinker);
372 	return 0;
373 
374 #ifdef CONFIG_NFS_V4
375 error_2:
376 	nfs_unregister_sysctl();
377 #endif
378 error_1:
379 	unregister_filesystem(&nfs_fs_type);
380 error_0:
381 	return ret;
382 }
383 
384 /*
385  * Unregister the NFS filesystems
386  */
387 void __exit unregister_nfs_fs(void)
388 {
389 	unregister_shrinker(&acl_shrinker);
390 #ifdef CONFIG_NFS_V4
391 	unregister_filesystem(&nfs4_fs_type);
392 #endif
393 	nfs_unregister_sysctl();
394 	unregister_filesystem(&nfs_fs_type);
395 }
396 
397 void nfs_sb_active(struct super_block *sb)
398 {
399 	struct nfs_server *server = NFS_SB(sb);
400 
401 	if (atomic_inc_return(&server->active) == 1)
402 		atomic_inc(&sb->s_active);
403 }
404 
405 void nfs_sb_deactive(struct super_block *sb)
406 {
407 	struct nfs_server *server = NFS_SB(sb);
408 
409 	if (atomic_dec_and_test(&server->active))
410 		deactivate_super(sb);
411 }
412 
413 /*
414  * Deliver file system statistics to userspace
415  */
416 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
417 {
418 	struct nfs_server *server = NFS_SB(dentry->d_sb);
419 	unsigned char blockbits;
420 	unsigned long blockres;
421 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
422 	struct nfs_fattr fattr;
423 	struct nfs_fsstat res = {
424 			.fattr = &fattr,
425 	};
426 	int error;
427 
428 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
429 	if (error < 0)
430 		goto out_err;
431 	buf->f_type = NFS_SUPER_MAGIC;
432 
433 	/*
434 	 * Current versions of glibc do not correctly handle the
435 	 * case where f_frsize != f_bsize.  Eventually we want to
436 	 * report the value of wtmult in this field.
437 	 */
438 	buf->f_frsize = dentry->d_sb->s_blocksize;
439 
440 	/*
441 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
442 	 * are reported in units of f_frsize.  Linux hasn't had
443 	 * an f_frsize field in its statfs struct until recently,
444 	 * thus historically Linux's sys_statfs reports these
445 	 * fields in units of f_bsize.
446 	 */
447 	buf->f_bsize = dentry->d_sb->s_blocksize;
448 	blockbits = dentry->d_sb->s_blocksize_bits;
449 	blockres = (1 << blockbits) - 1;
450 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
451 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
452 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
453 
454 	buf->f_files = res.tfiles;
455 	buf->f_ffree = res.afiles;
456 
457 	buf->f_namelen = server->namelen;
458 
459 	return 0;
460 
461  out_err:
462 	dprintk("%s: statfs error = %d\n", __func__, -error);
463 	return error;
464 }
465 
466 /*
467  * Map the security flavour number to a name
468  */
469 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
470 {
471 	static const struct {
472 		rpc_authflavor_t flavour;
473 		const char *str;
474 	} sec_flavours[] = {
475 		{ RPC_AUTH_NULL, "null" },
476 		{ RPC_AUTH_UNIX, "sys" },
477 		{ RPC_AUTH_GSS_KRB5, "krb5" },
478 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
479 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
480 		{ RPC_AUTH_GSS_LKEY, "lkey" },
481 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
482 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
483 		{ RPC_AUTH_GSS_SPKM, "spkm" },
484 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
485 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
486 		{ UINT_MAX, "unknown" }
487 	};
488 	int i;
489 
490 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
491 		if (sec_flavours[i].flavour == flavour)
492 			break;
493 	}
494 	return sec_flavours[i].str;
495 }
496 
497 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
498 				  int showdefaults)
499 {
500 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
501 
502 	seq_printf(m, ",mountproto=");
503 	switch (sap->sa_family) {
504 	case AF_INET:
505 		switch (nfss->mountd_protocol) {
506 		case IPPROTO_UDP:
507 			seq_printf(m, RPCBIND_NETID_UDP);
508 			break;
509 		case IPPROTO_TCP:
510 			seq_printf(m, RPCBIND_NETID_TCP);
511 			break;
512 		default:
513 			if (showdefaults)
514 				seq_printf(m, "auto");
515 		}
516 		break;
517 	case AF_INET6:
518 		switch (nfss->mountd_protocol) {
519 		case IPPROTO_UDP:
520 			seq_printf(m, RPCBIND_NETID_UDP6);
521 			break;
522 		case IPPROTO_TCP:
523 			seq_printf(m, RPCBIND_NETID_TCP6);
524 			break;
525 		default:
526 			if (showdefaults)
527 				seq_printf(m, "auto");
528 		}
529 		break;
530 	default:
531 		if (showdefaults)
532 			seq_printf(m, "auto");
533 	}
534 }
535 
536 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
537 				    int showdefaults)
538 {
539 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
540 
541 	switch (sap->sa_family) {
542 	case AF_INET: {
543 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
544 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
545 		break;
546 	}
547 	case AF_INET6: {
548 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
549 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
550 		break;
551 	}
552 	default:
553 		if (showdefaults)
554 			seq_printf(m, ",mountaddr=unspecified");
555 	}
556 
557 	if (nfss->mountd_version || showdefaults)
558 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
559 	if (nfss->mountd_port || showdefaults)
560 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
561 
562 	nfs_show_mountd_netid(m, nfss, showdefaults);
563 }
564 
565 /*
566  * Describe the mount options in force on this server representation
567  */
568 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
569 				   int showdefaults)
570 {
571 	static const struct proc_nfs_info {
572 		int flag;
573 		const char *str;
574 		const char *nostr;
575 	} nfs_info[] = {
576 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
577 		{ NFS_MOUNT_POSIX, ",posix", "" },
578 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
579 		{ NFS_MOUNT_NOAC, ",noac", "" },
580 		{ NFS_MOUNT_NONLM, ",nolock", "" },
581 		{ NFS_MOUNT_NOACL, ",noacl", "" },
582 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
583 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
584 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
585 		{ 0, NULL, NULL }
586 	};
587 	const struct proc_nfs_info *nfs_infop;
588 	struct nfs_client *clp = nfss->nfs_client;
589 	u32 version = clp->rpc_ops->version;
590 
591 	seq_printf(m, ",vers=%u", version);
592 	seq_printf(m, ",rsize=%u", nfss->rsize);
593 	seq_printf(m, ",wsize=%u", nfss->wsize);
594 	if (nfss->bsize != 0)
595 		seq_printf(m, ",bsize=%u", nfss->bsize);
596 	seq_printf(m, ",namlen=%u", nfss->namelen);
597 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
598 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
599 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
600 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
601 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
602 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
603 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
604 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
605 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
606 		if (nfss->flags & nfs_infop->flag)
607 			seq_puts(m, nfs_infop->str);
608 		else
609 			seq_puts(m, nfs_infop->nostr);
610 	}
611 	seq_printf(m, ",proto=%s",
612 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
613 	if (version == 4) {
614 		if (nfss->port != NFS_PORT)
615 			seq_printf(m, ",port=%u", nfss->port);
616 	} else
617 		if (nfss->port)
618 			seq_printf(m, ",port=%u", nfss->port);
619 
620 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
621 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
622 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
623 
624 	if (version != 4)
625 		nfs_show_mountd_options(m, nfss, showdefaults);
626 
627 #ifdef CONFIG_NFS_V4
628 	if (clp->rpc_ops->version == 4)
629 		seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
630 #endif
631 	if (nfss->options & NFS_OPTION_FSCACHE)
632 		seq_printf(m, ",fsc");
633 }
634 
635 /*
636  * Describe the mount options on this VFS mountpoint
637  */
638 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
639 {
640 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
641 
642 	nfs_show_mount_options(m, nfss, 0);
643 
644 	seq_printf(m, ",addr=%s",
645 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
646 							RPC_DISPLAY_ADDR));
647 
648 	return 0;
649 }
650 
651 /*
652  * Present statistical information for this VFS mountpoint
653  */
654 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
655 {
656 	int i, cpu;
657 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
658 	struct rpc_auth *auth = nfss->client->cl_auth;
659 	struct nfs_iostats totals = { };
660 
661 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
662 
663 	/*
664 	 * Display all mount option settings
665 	 */
666 	seq_printf(m, "\n\topts:\t");
667 	seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
668 	seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
669 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
670 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
671 	nfs_show_mount_options(m, nfss, 1);
672 
673 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
674 
675 	seq_printf(m, "\n\tcaps:\t");
676 	seq_printf(m, "caps=0x%x", nfss->caps);
677 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
678 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
679 	seq_printf(m, ",bsize=%u", nfss->bsize);
680 	seq_printf(m, ",namlen=%u", nfss->namelen);
681 
682 #ifdef CONFIG_NFS_V4
683 	if (nfss->nfs_client->rpc_ops->version == 4) {
684 		seq_printf(m, "\n\tnfsv4:\t");
685 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
686 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
687 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
688 	}
689 #endif
690 
691 	/*
692 	 * Display security flavor in effect for this mount
693 	 */
694 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
695 	if (auth->au_flavor)
696 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
697 
698 	/*
699 	 * Display superblock I/O counters
700 	 */
701 	for_each_possible_cpu(cpu) {
702 		struct nfs_iostats *stats;
703 
704 		preempt_disable();
705 		stats = per_cpu_ptr(nfss->io_stats, cpu);
706 
707 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
708 			totals.events[i] += stats->events[i];
709 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
710 			totals.bytes[i] += stats->bytes[i];
711 #ifdef CONFIG_NFS_FSCACHE
712 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
713 			totals.fscache[i] += stats->fscache[i];
714 #endif
715 
716 		preempt_enable();
717 	}
718 
719 	seq_printf(m, "\n\tevents:\t");
720 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
721 		seq_printf(m, "%lu ", totals.events[i]);
722 	seq_printf(m, "\n\tbytes:\t");
723 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
724 		seq_printf(m, "%Lu ", totals.bytes[i]);
725 #ifdef CONFIG_NFS_FSCACHE
726 	if (nfss->options & NFS_OPTION_FSCACHE) {
727 		seq_printf(m, "\n\tfsc:\t");
728 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
729 			seq_printf(m, "%Lu ", totals.bytes[i]);
730 	}
731 #endif
732 	seq_printf(m, "\n");
733 
734 	rpc_print_iostats(m, nfss->client);
735 
736 	return 0;
737 }
738 
739 /*
740  * Begin unmount by attempting to remove all automounted mountpoints we added
741  * in response to xdev traversals and referrals
742  */
743 static void nfs_umount_begin(struct super_block *sb)
744 {
745 	struct nfs_server *server;
746 	struct rpc_clnt *rpc;
747 
748 	server = NFS_SB(sb);
749 	/* -EIO all pending I/O */
750 	rpc = server->client_acl;
751 	if (!IS_ERR(rpc))
752 		rpc_killall_tasks(rpc);
753 	rpc = server->client;
754 	if (!IS_ERR(rpc))
755 		rpc_killall_tasks(rpc);
756 }
757 
758 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
759 {
760 	struct nfs_parsed_mount_data *data;
761 
762 	data = kzalloc(sizeof(*data), GFP_KERNEL);
763 	if (data) {
764 		data->acregmin		= NFS_DEF_ACREGMIN;
765 		data->acregmax		= NFS_DEF_ACREGMAX;
766 		data->acdirmin		= NFS_DEF_ACDIRMIN;
767 		data->acdirmax		= NFS_DEF_ACDIRMAX;
768 		data->mount_server.port	= NFS_UNSPEC_PORT;
769 		data->nfs_server.port	= NFS_UNSPEC_PORT;
770 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
771 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
772 		data->auth_flavor_len	= 1;
773 		data->version		= version;
774 		data->minorversion	= 0;
775 	}
776 	return data;
777 }
778 
779 /*
780  * Sanity-check a server address provided by the mount command.
781  *
782  * Address family must be initialized, and address must not be
783  * the ANY address for that family.
784  */
785 static int nfs_verify_server_address(struct sockaddr *addr)
786 {
787 	switch (addr->sa_family) {
788 	case AF_INET: {
789 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
790 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
791 	}
792 	case AF_INET6: {
793 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
794 		return !ipv6_addr_any(sa);
795 	}
796 	}
797 
798 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
799 	return 0;
800 }
801 
802 /*
803  * Select between a default port value and a user-specified port value.
804  * If a zero value is set, then autobind will be used.
805  */
806 static void nfs_set_port(struct sockaddr *sap, int *port,
807 				 const unsigned short default_port)
808 {
809 	if (*port == NFS_UNSPEC_PORT)
810 		*port = default_port;
811 
812 	rpc_set_port(sap, *port);
813 }
814 
815 /*
816  * Sanity check the NFS transport protocol.
817  *
818  */
819 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
820 {
821 	switch (mnt->nfs_server.protocol) {
822 	case XPRT_TRANSPORT_UDP:
823 	case XPRT_TRANSPORT_TCP:
824 	case XPRT_TRANSPORT_RDMA:
825 		break;
826 	default:
827 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
828 	}
829 }
830 
831 /*
832  * For text based NFSv2/v3 mounts, the mount protocol transport default
833  * settings should depend upon the specified NFS transport.
834  */
835 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
836 {
837 	nfs_validate_transport_protocol(mnt);
838 
839 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
840 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
841 			return;
842 	switch (mnt->nfs_server.protocol) {
843 	case XPRT_TRANSPORT_UDP:
844 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
845 		break;
846 	case XPRT_TRANSPORT_TCP:
847 	case XPRT_TRANSPORT_RDMA:
848 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
849 	}
850 }
851 
852 /*
853  * Parse the value of the 'sec=' option.
854  */
855 static int nfs_parse_security_flavors(char *value,
856 				      struct nfs_parsed_mount_data *mnt)
857 {
858 	substring_t args[MAX_OPT_ARGS];
859 
860 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
861 
862 	switch (match_token(value, nfs_secflavor_tokens, args)) {
863 	case Opt_sec_none:
864 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
865 		break;
866 	case Opt_sec_sys:
867 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
868 		break;
869 	case Opt_sec_krb5:
870 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
871 		break;
872 	case Opt_sec_krb5i:
873 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
874 		break;
875 	case Opt_sec_krb5p:
876 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
877 		break;
878 	case Opt_sec_lkey:
879 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
880 		break;
881 	case Opt_sec_lkeyi:
882 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
883 		break;
884 	case Opt_sec_lkeyp:
885 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
886 		break;
887 	case Opt_sec_spkm:
888 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
889 		break;
890 	case Opt_sec_spkmi:
891 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
892 		break;
893 	case Opt_sec_spkmp:
894 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
895 		break;
896 	default:
897 		return 0;
898 	}
899 
900 	mnt->auth_flavor_len = 1;
901 	return 1;
902 }
903 
904 /*
905  * Error-check and convert a string of mount options from user space into
906  * a data structure.  The whole mount string is processed; bad options are
907  * skipped as they are encountered.  If there were no errors, return 1;
908  * otherwise return 0 (zero).
909  */
910 static int nfs_parse_mount_options(char *raw,
911 				   struct nfs_parsed_mount_data *mnt)
912 {
913 	char *p, *string, *secdata;
914 	int rc, sloppy = 0, invalid_option = 0;
915 	unsigned short protofamily = AF_UNSPEC;
916 	unsigned short mountfamily = AF_UNSPEC;
917 
918 	if (!raw) {
919 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
920 		return 1;
921 	}
922 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
923 
924 	secdata = alloc_secdata();
925 	if (!secdata)
926 		goto out_nomem;
927 
928 	rc = security_sb_copy_data(raw, secdata);
929 	if (rc)
930 		goto out_security_failure;
931 
932 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
933 	if (rc)
934 		goto out_security_failure;
935 
936 	free_secdata(secdata);
937 
938 	while ((p = strsep(&raw, ",")) != NULL) {
939 		substring_t args[MAX_OPT_ARGS];
940 		unsigned long option;
941 		int token;
942 
943 		if (!*p)
944 			continue;
945 
946 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
947 
948 		token = match_token(p, nfs_mount_option_tokens, args);
949 		switch (token) {
950 
951 		/*
952 		 * boolean options:  foo/nofoo
953 		 */
954 		case Opt_soft:
955 			mnt->flags |= NFS_MOUNT_SOFT;
956 			break;
957 		case Opt_hard:
958 			mnt->flags &= ~NFS_MOUNT_SOFT;
959 			break;
960 		case Opt_posix:
961 			mnt->flags |= NFS_MOUNT_POSIX;
962 			break;
963 		case Opt_noposix:
964 			mnt->flags &= ~NFS_MOUNT_POSIX;
965 			break;
966 		case Opt_cto:
967 			mnt->flags &= ~NFS_MOUNT_NOCTO;
968 			break;
969 		case Opt_nocto:
970 			mnt->flags |= NFS_MOUNT_NOCTO;
971 			break;
972 		case Opt_ac:
973 			mnt->flags &= ~NFS_MOUNT_NOAC;
974 			break;
975 		case Opt_noac:
976 			mnt->flags |= NFS_MOUNT_NOAC;
977 			break;
978 		case Opt_lock:
979 			mnt->flags &= ~NFS_MOUNT_NONLM;
980 			break;
981 		case Opt_nolock:
982 			mnt->flags |= NFS_MOUNT_NONLM;
983 			break;
984 		case Opt_v2:
985 			mnt->flags &= ~NFS_MOUNT_VER3;
986 			mnt->version = 2;
987 			break;
988 		case Opt_v3:
989 			mnt->flags |= NFS_MOUNT_VER3;
990 			mnt->version = 3;
991 			break;
992 #ifdef CONFIG_NFS_V4
993 		case Opt_v4:
994 			mnt->flags &= ~NFS_MOUNT_VER3;
995 			mnt->version = 4;
996 			break;
997 #endif
998 		case Opt_udp:
999 			mnt->flags &= ~NFS_MOUNT_TCP;
1000 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1001 			break;
1002 		case Opt_tcp:
1003 			mnt->flags |= NFS_MOUNT_TCP;
1004 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1005 			break;
1006 		case Opt_rdma:
1007 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1008 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1009 			xprt_load_transport(p);
1010 			break;
1011 		case Opt_acl:
1012 			mnt->flags &= ~NFS_MOUNT_NOACL;
1013 			break;
1014 		case Opt_noacl:
1015 			mnt->flags |= NFS_MOUNT_NOACL;
1016 			break;
1017 		case Opt_rdirplus:
1018 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1019 			break;
1020 		case Opt_nordirplus:
1021 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1022 			break;
1023 		case Opt_sharecache:
1024 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1025 			break;
1026 		case Opt_nosharecache:
1027 			mnt->flags |= NFS_MOUNT_UNSHARED;
1028 			break;
1029 		case Opt_resvport:
1030 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1031 			break;
1032 		case Opt_noresvport:
1033 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1034 			break;
1035 		case Opt_fscache:
1036 			mnt->options |= NFS_OPTION_FSCACHE;
1037 			kfree(mnt->fscache_uniq);
1038 			mnt->fscache_uniq = NULL;
1039 			break;
1040 		case Opt_nofscache:
1041 			mnt->options &= ~NFS_OPTION_FSCACHE;
1042 			kfree(mnt->fscache_uniq);
1043 			mnt->fscache_uniq = NULL;
1044 			break;
1045 		case Opt_fscache_uniq:
1046 			string = match_strdup(args);
1047 			if (!string)
1048 				goto out_nomem;
1049 			kfree(mnt->fscache_uniq);
1050 			mnt->fscache_uniq = string;
1051 			mnt->options |= NFS_OPTION_FSCACHE;
1052 			break;
1053 
1054 		/*
1055 		 * options that take numeric values
1056 		 */
1057 		case Opt_port:
1058 			string = match_strdup(args);
1059 			if (string == NULL)
1060 				goto out_nomem;
1061 			rc = strict_strtoul(string, 10, &option);
1062 			kfree(string);
1063 			if (rc != 0 || option > USHORT_MAX)
1064 				goto out_invalid_value;
1065 			mnt->nfs_server.port = option;
1066 			break;
1067 		case Opt_rsize:
1068 			string = match_strdup(args);
1069 			if (string == NULL)
1070 				goto out_nomem;
1071 			rc = strict_strtoul(string, 10, &option);
1072 			kfree(string);
1073 			if (rc != 0)
1074 				goto out_invalid_value;
1075 			mnt->rsize = option;
1076 			break;
1077 		case Opt_wsize:
1078 			string = match_strdup(args);
1079 			if (string == NULL)
1080 				goto out_nomem;
1081 			rc = strict_strtoul(string, 10, &option);
1082 			kfree(string);
1083 			if (rc != 0)
1084 				goto out_invalid_value;
1085 			mnt->wsize = option;
1086 			break;
1087 		case Opt_bsize:
1088 			string = match_strdup(args);
1089 			if (string == NULL)
1090 				goto out_nomem;
1091 			rc = strict_strtoul(string, 10, &option);
1092 			kfree(string);
1093 			if (rc != 0)
1094 				goto out_invalid_value;
1095 			mnt->bsize = option;
1096 			break;
1097 		case Opt_timeo:
1098 			string = match_strdup(args);
1099 			if (string == NULL)
1100 				goto out_nomem;
1101 			rc = strict_strtoul(string, 10, &option);
1102 			kfree(string);
1103 			if (rc != 0 || option == 0)
1104 				goto out_invalid_value;
1105 			mnt->timeo = option;
1106 			break;
1107 		case Opt_retrans:
1108 			string = match_strdup(args);
1109 			if (string == NULL)
1110 				goto out_nomem;
1111 			rc = strict_strtoul(string, 10, &option);
1112 			kfree(string);
1113 			if (rc != 0 || option == 0)
1114 				goto out_invalid_value;
1115 			mnt->retrans = option;
1116 			break;
1117 		case Opt_acregmin:
1118 			string = match_strdup(args);
1119 			if (string == NULL)
1120 				goto out_nomem;
1121 			rc = strict_strtoul(string, 10, &option);
1122 			kfree(string);
1123 			if (rc != 0)
1124 				goto out_invalid_value;
1125 			mnt->acregmin = option;
1126 			break;
1127 		case Opt_acregmax:
1128 			string = match_strdup(args);
1129 			if (string == NULL)
1130 				goto out_nomem;
1131 			rc = strict_strtoul(string, 10, &option);
1132 			kfree(string);
1133 			if (rc != 0)
1134 				goto out_invalid_value;
1135 			mnt->acregmax = option;
1136 			break;
1137 		case Opt_acdirmin:
1138 			string = match_strdup(args);
1139 			if (string == NULL)
1140 				goto out_nomem;
1141 			rc = strict_strtoul(string, 10, &option);
1142 			kfree(string);
1143 			if (rc != 0)
1144 				goto out_invalid_value;
1145 			mnt->acdirmin = option;
1146 			break;
1147 		case Opt_acdirmax:
1148 			string = match_strdup(args);
1149 			if (string == NULL)
1150 				goto out_nomem;
1151 			rc = strict_strtoul(string, 10, &option);
1152 			kfree(string);
1153 			if (rc != 0)
1154 				goto out_invalid_value;
1155 			mnt->acdirmax = option;
1156 			break;
1157 		case Opt_actimeo:
1158 			string = match_strdup(args);
1159 			if (string == NULL)
1160 				goto out_nomem;
1161 			rc = strict_strtoul(string, 10, &option);
1162 			kfree(string);
1163 			if (rc != 0)
1164 				goto out_invalid_value;
1165 			mnt->acregmin = mnt->acregmax =
1166 			mnt->acdirmin = mnt->acdirmax = option;
1167 			break;
1168 		case Opt_namelen:
1169 			string = match_strdup(args);
1170 			if (string == NULL)
1171 				goto out_nomem;
1172 			rc = strict_strtoul(string, 10, &option);
1173 			kfree(string);
1174 			if (rc != 0)
1175 				goto out_invalid_value;
1176 			mnt->namlen = option;
1177 			break;
1178 		case Opt_mountport:
1179 			string = match_strdup(args);
1180 			if (string == NULL)
1181 				goto out_nomem;
1182 			rc = strict_strtoul(string, 10, &option);
1183 			kfree(string);
1184 			if (rc != 0 || option > USHORT_MAX)
1185 				goto out_invalid_value;
1186 			mnt->mount_server.port = option;
1187 			break;
1188 		case Opt_mountvers:
1189 			string = match_strdup(args);
1190 			if (string == NULL)
1191 				goto out_nomem;
1192 			rc = strict_strtoul(string, 10, &option);
1193 			kfree(string);
1194 			if (rc != 0 ||
1195 			    option < NFS_MNT_VERSION ||
1196 			    option > NFS_MNT3_VERSION)
1197 				goto out_invalid_value;
1198 			mnt->mount_server.version = option;
1199 			break;
1200 		case Opt_nfsvers:
1201 			string = match_strdup(args);
1202 			if (string == NULL)
1203 				goto out_nomem;
1204 			rc = strict_strtoul(string, 10, &option);
1205 			kfree(string);
1206 			if (rc != 0)
1207 				goto out_invalid_value;
1208 			switch (option) {
1209 			case NFS2_VERSION:
1210 				mnt->flags &= ~NFS_MOUNT_VER3;
1211 				mnt->version = 2;
1212 				break;
1213 			case NFS3_VERSION:
1214 				mnt->flags |= NFS_MOUNT_VER3;
1215 				mnt->version = 3;
1216 				break;
1217 #ifdef CONFIG_NFS_V4
1218 			case NFS4_VERSION:
1219 				mnt->flags &= ~NFS_MOUNT_VER3;
1220 				mnt->version = 4;
1221 				break;
1222 #endif
1223 			default:
1224 				goto out_invalid_value;
1225 			}
1226 			break;
1227 		case Opt_minorversion:
1228 			string = match_strdup(args);
1229 			if (string == NULL)
1230 				goto out_nomem;
1231 			rc = strict_strtoul(string, 10, &option);
1232 			kfree(string);
1233 			if (rc != 0)
1234 				goto out_invalid_value;
1235 			if (option > NFS4_MAX_MINOR_VERSION)
1236 				goto out_invalid_value;
1237 			mnt->minorversion = option;
1238 			break;
1239 
1240 		/*
1241 		 * options that take text values
1242 		 */
1243 		case Opt_sec:
1244 			string = match_strdup(args);
1245 			if (string == NULL)
1246 				goto out_nomem;
1247 			rc = nfs_parse_security_flavors(string, mnt);
1248 			kfree(string);
1249 			if (!rc) {
1250 				dfprintk(MOUNT, "NFS:   unrecognized "
1251 						"security flavor\n");
1252 				return 0;
1253 			}
1254 			break;
1255 		case Opt_proto:
1256 			string = match_strdup(args);
1257 			if (string == NULL)
1258 				goto out_nomem;
1259 			token = match_token(string,
1260 					    nfs_xprt_protocol_tokens, args);
1261 
1262 			protofamily = AF_INET;
1263 			switch (token) {
1264 			case Opt_xprt_udp6:
1265 				protofamily = AF_INET6;
1266 			case Opt_xprt_udp:
1267 				mnt->flags &= ~NFS_MOUNT_TCP;
1268 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1269 				kfree(string);
1270 				break;
1271 			case Opt_xprt_tcp6:
1272 				protofamily = AF_INET6;
1273 			case Opt_xprt_tcp:
1274 				mnt->flags |= NFS_MOUNT_TCP;
1275 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1276 				kfree(string);
1277 				break;
1278 			case Opt_xprt_rdma:
1279 				/* vector side protocols to TCP */
1280 				mnt->flags |= NFS_MOUNT_TCP;
1281 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1282 				xprt_load_transport(string);
1283 				kfree(string);
1284 				break;
1285 			default:
1286 				dfprintk(MOUNT, "NFS:   unrecognized "
1287 						"transport protocol\n");
1288 				kfree(string);
1289 				return 0;
1290 			}
1291 			break;
1292 		case Opt_mountproto:
1293 			string = match_strdup(args);
1294 			if (string == NULL)
1295 				goto out_nomem;
1296 			token = match_token(string,
1297 					    nfs_xprt_protocol_tokens, args);
1298 			kfree(string);
1299 
1300 			mountfamily = AF_INET;
1301 			switch (token) {
1302 			case Opt_xprt_udp6:
1303 				mountfamily = AF_INET6;
1304 			case Opt_xprt_udp:
1305 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1306 				break;
1307 			case Opt_xprt_tcp6:
1308 				mountfamily = AF_INET6;
1309 			case Opt_xprt_tcp:
1310 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1311 				break;
1312 			case Opt_xprt_rdma: /* not used for side protocols */
1313 			default:
1314 				dfprintk(MOUNT, "NFS:   unrecognized "
1315 						"transport protocol\n");
1316 				return 0;
1317 			}
1318 			break;
1319 		case Opt_addr:
1320 			string = match_strdup(args);
1321 			if (string == NULL)
1322 				goto out_nomem;
1323 			mnt->nfs_server.addrlen =
1324 				rpc_pton(string, strlen(string),
1325 					(struct sockaddr *)
1326 					&mnt->nfs_server.address,
1327 					sizeof(mnt->nfs_server.address));
1328 			kfree(string);
1329 			if (mnt->nfs_server.addrlen == 0)
1330 				goto out_invalid_address;
1331 			break;
1332 		case Opt_clientaddr:
1333 			string = match_strdup(args);
1334 			if (string == NULL)
1335 				goto out_nomem;
1336 			kfree(mnt->client_address);
1337 			mnt->client_address = string;
1338 			break;
1339 		case Opt_mounthost:
1340 			string = match_strdup(args);
1341 			if (string == NULL)
1342 				goto out_nomem;
1343 			kfree(mnt->mount_server.hostname);
1344 			mnt->mount_server.hostname = string;
1345 			break;
1346 		case Opt_mountaddr:
1347 			string = match_strdup(args);
1348 			if (string == NULL)
1349 				goto out_nomem;
1350 			mnt->mount_server.addrlen =
1351 				rpc_pton(string, strlen(string),
1352 					(struct sockaddr *)
1353 					&mnt->mount_server.address,
1354 					sizeof(mnt->mount_server.address));
1355 			kfree(string);
1356 			if (mnt->mount_server.addrlen == 0)
1357 				goto out_invalid_address;
1358 			break;
1359 		case Opt_lookupcache:
1360 			string = match_strdup(args);
1361 			if (string == NULL)
1362 				goto out_nomem;
1363 			token = match_token(string,
1364 					nfs_lookupcache_tokens, args);
1365 			kfree(string);
1366 			switch (token) {
1367 				case Opt_lookupcache_all:
1368 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1369 					break;
1370 				case Opt_lookupcache_positive:
1371 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1372 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1373 					break;
1374 				case Opt_lookupcache_none:
1375 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1376 					break;
1377 				default:
1378 					dfprintk(MOUNT, "NFS:   invalid "
1379 							"lookupcache argument\n");
1380 					return 0;
1381 			};
1382 			break;
1383 
1384 		/*
1385 		 * Special options
1386 		 */
1387 		case Opt_sloppy:
1388 			sloppy = 1;
1389 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1390 			break;
1391 		case Opt_userspace:
1392 		case Opt_deprecated:
1393 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1394 					"'%s'\n", p);
1395 			break;
1396 
1397 		default:
1398 			invalid_option = 1;
1399 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1400 					"'%s'\n", p);
1401 		}
1402 	}
1403 
1404 	if (!sloppy && invalid_option)
1405 		return 0;
1406 
1407 	/*
1408 	 * verify that any proto=/mountproto= options match the address
1409 	 * familiies in the addr=/mountaddr= options.
1410 	 */
1411 	if (protofamily != AF_UNSPEC &&
1412 	    protofamily != mnt->nfs_server.address.ss_family)
1413 		goto out_proto_mismatch;
1414 
1415 	if (mountfamily != AF_UNSPEC) {
1416 		if (mnt->mount_server.addrlen) {
1417 			if (mountfamily != mnt->mount_server.address.ss_family)
1418 				goto out_mountproto_mismatch;
1419 		} else {
1420 			if (mountfamily != mnt->nfs_server.address.ss_family)
1421 				goto out_mountproto_mismatch;
1422 		}
1423 	}
1424 
1425 	return 1;
1426 
1427 out_mountproto_mismatch:
1428 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1429 			 "option\n");
1430 	return 0;
1431 out_proto_mismatch:
1432 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1433 	return 0;
1434 out_invalid_address:
1435 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1436 	return 0;
1437 out_invalid_value:
1438 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1439 	return 0;
1440 out_nomem:
1441 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1442 	return 0;
1443 out_security_failure:
1444 	free_secdata(secdata);
1445 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1446 	return 0;
1447 }
1448 
1449 /*
1450  * Match the requested auth flavors with the list returned by
1451  * the server.  Returns zero and sets the mount's authentication
1452  * flavor on success; returns -EACCES if server does not support
1453  * the requested flavor.
1454  */
1455 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1456 			     struct nfs_mount_request *request)
1457 {
1458 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1459 
1460 	/*
1461 	 * Certain releases of Linux's mountd return an empty
1462 	 * flavor list.  To prevent behavioral regression with
1463 	 * these servers (ie. rejecting mounts that used to
1464 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1465 	 * if the returned flavor list is empty.
1466 	 */
1467 	if (server_authlist_len == 0)
1468 		return 0;
1469 
1470 	/*
1471 	 * We avoid sophisticated negotiating here, as there are
1472 	 * plenty of cases where we can get it wrong, providing
1473 	 * either too little or too much security.
1474 	 *
1475 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1476 	 * flavor listed first.  However, some servers list
1477 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1478 	 * preferred default, in args->auth_flavors[0] if user
1479 	 * didn't specify sec= mount option.
1480 	 */
1481 	for (i = 0; i < args->auth_flavor_len; i++)
1482 		for (j = 0; j < server_authlist_len; j++)
1483 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1484 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1485 					request->auth_flavs[j]);
1486 				args->auth_flavors[0] = request->auth_flavs[j];
1487 				return 0;
1488 			}
1489 
1490 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1491 	nfs_umount(request);
1492 	return -EACCES;
1493 }
1494 
1495 /*
1496  * Use the remote server's MOUNT service to request the NFS file handle
1497  * corresponding to the provided path.
1498  */
1499 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1500 			 struct nfs_fh *root_fh)
1501 {
1502 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1503 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1504 	struct nfs_mount_request request = {
1505 		.sap		= (struct sockaddr *)
1506 						&args->mount_server.address,
1507 		.dirpath	= args->nfs_server.export_path,
1508 		.protocol	= args->mount_server.protocol,
1509 		.fh		= root_fh,
1510 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1511 		.auth_flav_len	= &server_authlist_len,
1512 		.auth_flavs	= server_authlist,
1513 	};
1514 	int status;
1515 
1516 	if (args->mount_server.version == 0) {
1517 		switch (args->version) {
1518 			default:
1519 				args->mount_server.version = NFS_MNT3_VERSION;
1520 				break;
1521 			case 2:
1522 				args->mount_server.version = NFS_MNT_VERSION;
1523 		}
1524 	}
1525 	request.version = args->mount_server.version;
1526 
1527 	if (args->mount_server.hostname)
1528 		request.hostname = args->mount_server.hostname;
1529 	else
1530 		request.hostname = args->nfs_server.hostname;
1531 
1532 	/*
1533 	 * Construct the mount server's address.
1534 	 */
1535 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1536 		memcpy(request.sap, &args->nfs_server.address,
1537 		       args->nfs_server.addrlen);
1538 		args->mount_server.addrlen = args->nfs_server.addrlen;
1539 	}
1540 	request.salen = args->mount_server.addrlen;
1541 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1542 
1543 	/*
1544 	 * Now ask the mount server to map our export path
1545 	 * to a file handle.
1546 	 */
1547 	status = nfs_mount(&request);
1548 	if (status != 0) {
1549 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1550 				request.hostname, status);
1551 		return status;
1552 	}
1553 
1554 	/*
1555 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1556 	 */
1557 	if (args->mount_server.version != NFS_MNT3_VERSION)
1558 		return 0;
1559 	return nfs_walk_authlist(args, &request);
1560 }
1561 
1562 static int nfs_parse_simple_hostname(const char *dev_name,
1563 				     char **hostname, size_t maxnamlen,
1564 				     char **export_path, size_t maxpathlen)
1565 {
1566 	size_t len;
1567 	char *colon, *comma;
1568 
1569 	colon = strchr(dev_name, ':');
1570 	if (colon == NULL)
1571 		goto out_bad_devname;
1572 
1573 	len = colon - dev_name;
1574 	if (len > maxnamlen)
1575 		goto out_hostname;
1576 
1577 	/* N.B. caller will free nfs_server.hostname in all cases */
1578 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1579 	if (!*hostname)
1580 		goto out_nomem;
1581 
1582 	/* kill possible hostname list: not supported */
1583 	comma = strchr(*hostname, ',');
1584 	if (comma != NULL) {
1585 		if (comma == *hostname)
1586 			goto out_bad_devname;
1587 		*comma = '\0';
1588 	}
1589 
1590 	colon++;
1591 	len = strlen(colon);
1592 	if (len > maxpathlen)
1593 		goto out_path;
1594 	*export_path = kstrndup(colon, len, GFP_KERNEL);
1595 	if (!*export_path)
1596 		goto out_nomem;
1597 
1598 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1599 	return 0;
1600 
1601 out_bad_devname:
1602 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1603 	return -EINVAL;
1604 
1605 out_nomem:
1606 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1607 	return -ENOMEM;
1608 
1609 out_hostname:
1610 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1611 	return -ENAMETOOLONG;
1612 
1613 out_path:
1614 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1615 	return -ENAMETOOLONG;
1616 }
1617 
1618 /*
1619  * Hostname has square brackets around it because it contains one or
1620  * more colons.  We look for the first closing square bracket, and a
1621  * colon must follow it.
1622  */
1623 static int nfs_parse_protected_hostname(const char *dev_name,
1624 					char **hostname, size_t maxnamlen,
1625 					char **export_path, size_t maxpathlen)
1626 {
1627 	size_t len;
1628 	char *start, *end;
1629 
1630 	start = (char *)(dev_name + 1);
1631 
1632 	end = strchr(start, ']');
1633 	if (end == NULL)
1634 		goto out_bad_devname;
1635 	if (*(end + 1) != ':')
1636 		goto out_bad_devname;
1637 
1638 	len = end - start;
1639 	if (len > maxnamlen)
1640 		goto out_hostname;
1641 
1642 	/* N.B. caller will free nfs_server.hostname in all cases */
1643 	*hostname = kstrndup(start, len, GFP_KERNEL);
1644 	if (*hostname == NULL)
1645 		goto out_nomem;
1646 
1647 	end += 2;
1648 	len = strlen(end);
1649 	if (len > maxpathlen)
1650 		goto out_path;
1651 	*export_path = kstrndup(end, len, GFP_KERNEL);
1652 	if (!*export_path)
1653 		goto out_nomem;
1654 
1655 	return 0;
1656 
1657 out_bad_devname:
1658 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1659 	return -EINVAL;
1660 
1661 out_nomem:
1662 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1663 	return -ENOMEM;
1664 
1665 out_hostname:
1666 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1667 	return -ENAMETOOLONG;
1668 
1669 out_path:
1670 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1671 	return -ENAMETOOLONG;
1672 }
1673 
1674 /*
1675  * Split "dev_name" into "hostname:export_path".
1676  *
1677  * The leftmost colon demarks the split between the server's hostname
1678  * and the export path.  If the hostname starts with a left square
1679  * bracket, then it may contain colons.
1680  *
1681  * Note: caller frees hostname and export path, even on error.
1682  */
1683 static int nfs_parse_devname(const char *dev_name,
1684 			     char **hostname, size_t maxnamlen,
1685 			     char **export_path, size_t maxpathlen)
1686 {
1687 	if (*dev_name == '[')
1688 		return nfs_parse_protected_hostname(dev_name,
1689 						    hostname, maxnamlen,
1690 						    export_path, maxpathlen);
1691 
1692 	return nfs_parse_simple_hostname(dev_name,
1693 					 hostname, maxnamlen,
1694 					 export_path, maxpathlen);
1695 }
1696 
1697 /*
1698  * Validate the NFS2/NFS3 mount data
1699  * - fills in the mount root filehandle
1700  *
1701  * For option strings, user space handles the following behaviors:
1702  *
1703  * + DNS: mapping server host name to IP address ("addr=" option)
1704  *
1705  * + failure mode: how to behave if a mount request can't be handled
1706  *   immediately ("fg/bg" option)
1707  *
1708  * + retry: how often to retry a mount request ("retry=" option)
1709  *
1710  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1711  *   mountproto=tcp after mountproto=udp, and so on
1712  */
1713 static int nfs_validate_mount_data(void *options,
1714 				   struct nfs_parsed_mount_data *args,
1715 				   struct nfs_fh *mntfh,
1716 				   const char *dev_name)
1717 {
1718 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1719 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1720 
1721 	if (data == NULL)
1722 		goto out_no_data;
1723 
1724 	switch (data->version) {
1725 	case 1:
1726 		data->namlen = 0;
1727 	case 2:
1728 		data->bsize = 0;
1729 	case 3:
1730 		if (data->flags & NFS_MOUNT_VER3)
1731 			goto out_no_v3;
1732 		data->root.size = NFS2_FHSIZE;
1733 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1734 	case 4:
1735 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1736 			goto out_no_sec;
1737 	case 5:
1738 		memset(data->context, 0, sizeof(data->context));
1739 	case 6:
1740 		if (data->flags & NFS_MOUNT_VER3) {
1741 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1742 				goto out_invalid_fh;
1743 			mntfh->size = data->root.size;
1744 			args->version = 3;
1745 		} else {
1746 			mntfh->size = NFS2_FHSIZE;
1747 			args->version = 2;
1748 		}
1749 
1750 
1751 		memcpy(mntfh->data, data->root.data, mntfh->size);
1752 		if (mntfh->size < sizeof(mntfh->data))
1753 			memset(mntfh->data + mntfh->size, 0,
1754 			       sizeof(mntfh->data) - mntfh->size);
1755 
1756 		/*
1757 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1758 		 * can deal with.
1759 		 */
1760 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1761 		args->rsize		= data->rsize;
1762 		args->wsize		= data->wsize;
1763 		args->timeo		= data->timeo;
1764 		args->retrans		= data->retrans;
1765 		args->acregmin		= data->acregmin;
1766 		args->acregmax		= data->acregmax;
1767 		args->acdirmin		= data->acdirmin;
1768 		args->acdirmax		= data->acdirmax;
1769 
1770 		memcpy(sap, &data->addr, sizeof(data->addr));
1771 		args->nfs_server.addrlen = sizeof(data->addr);
1772 		if (!nfs_verify_server_address(sap))
1773 			goto out_no_address;
1774 
1775 		if (!(data->flags & NFS_MOUNT_TCP))
1776 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1777 		/* N.B. caller will free nfs_server.hostname in all cases */
1778 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1779 		args->namlen		= data->namlen;
1780 		args->bsize		= data->bsize;
1781 
1782 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1783 			args->auth_flavors[0] = data->pseudoflavor;
1784 		if (!args->nfs_server.hostname)
1785 			goto out_nomem;
1786 
1787 		/*
1788 		 * The legacy version 6 binary mount data from userspace has a
1789 		 * field used only to transport selinux information into the
1790 		 * the kernel.  To continue to support that functionality we
1791 		 * have a touch of selinux knowledge here in the NFS code. The
1792 		 * userspace code converted context=blah to just blah so we are
1793 		 * converting back to the full string selinux understands.
1794 		 */
1795 		if (data->context[0]){
1796 #ifdef CONFIG_SECURITY_SELINUX
1797 			int rc;
1798 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1799 			if (!opts_str)
1800 				return -ENOMEM;
1801 			strcpy(opts_str, "context=");
1802 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1803 			strcat(opts_str, &data->context[0]);
1804 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1805 			kfree(opts_str);
1806 			if (rc)
1807 				return rc;
1808 #else
1809 			return -EINVAL;
1810 #endif
1811 		}
1812 
1813 		break;
1814 	default: {
1815 		int status;
1816 
1817 		if (nfs_parse_mount_options((char *)options, args) == 0)
1818 			return -EINVAL;
1819 
1820 		if (!nfs_verify_server_address(sap))
1821 			goto out_no_address;
1822 
1823 		if (args->version == 4)
1824 #ifdef CONFIG_NFS_V4
1825 			return nfs4_validate_text_mount_data(options,
1826 							     args, dev_name);
1827 #else
1828 			goto out_v4_not_compiled;
1829 #endif
1830 
1831 		nfs_set_port(sap, &args->nfs_server.port, 0);
1832 
1833 		nfs_set_mount_transport_protocol(args);
1834 
1835 		status = nfs_parse_devname(dev_name,
1836 					   &args->nfs_server.hostname,
1837 					   PAGE_SIZE,
1838 					   &args->nfs_server.export_path,
1839 					   NFS_MAXPATHLEN);
1840 		if (!status)
1841 			status = nfs_try_mount(args, mntfh);
1842 
1843 		kfree(args->nfs_server.export_path);
1844 		args->nfs_server.export_path = NULL;
1845 
1846 		if (status)
1847 			return status;
1848 
1849 		break;
1850 		}
1851 	}
1852 
1853 #ifndef CONFIG_NFS_V3
1854 	if (args->version == 3)
1855 		goto out_v3_not_compiled;
1856 #endif /* !CONFIG_NFS_V3 */
1857 
1858 	return 0;
1859 
1860 out_no_data:
1861 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1862 	return -EINVAL;
1863 
1864 out_no_v3:
1865 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1866 		 data->version);
1867 	return -EINVAL;
1868 
1869 out_no_sec:
1870 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1871 	return -EINVAL;
1872 
1873 #ifndef CONFIG_NFS_V3
1874 out_v3_not_compiled:
1875 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1876 	return -EPROTONOSUPPORT;
1877 #endif /* !CONFIG_NFS_V3 */
1878 
1879 #ifndef CONFIG_NFS_V4
1880 out_v4_not_compiled:
1881 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1882 	return -EPROTONOSUPPORT;
1883 #endif /* !CONFIG_NFS_V4 */
1884 
1885 out_nomem:
1886 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1887 	return -ENOMEM;
1888 
1889 out_no_address:
1890 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1891 	return -EINVAL;
1892 
1893 out_invalid_fh:
1894 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1895 	return -EINVAL;
1896 }
1897 
1898 static int
1899 nfs_compare_remount_data(struct nfs_server *nfss,
1900 			 struct nfs_parsed_mount_data *data)
1901 {
1902 	if (data->flags != nfss->flags ||
1903 	    data->rsize != nfss->rsize ||
1904 	    data->wsize != nfss->wsize ||
1905 	    data->retrans != nfss->client->cl_timeout->to_retries ||
1906 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1907 	    data->acregmin != nfss->acregmin / HZ ||
1908 	    data->acregmax != nfss->acregmax / HZ ||
1909 	    data->acdirmin != nfss->acdirmin / HZ ||
1910 	    data->acdirmax != nfss->acdirmax / HZ ||
1911 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1912 	    data->nfs_server.port != nfss->port ||
1913 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1914 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1915 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
1916 		return -EINVAL;
1917 
1918 	return 0;
1919 }
1920 
1921 static int
1922 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1923 {
1924 	int error;
1925 	struct nfs_server *nfss = sb->s_fs_info;
1926 	struct nfs_parsed_mount_data *data;
1927 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1928 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1929 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1930 
1931 	/*
1932 	 * Userspace mount programs that send binary options generally send
1933 	 * them populated with default values. We have no way to know which
1934 	 * ones were explicitly specified. Fall back to legacy behavior and
1935 	 * just return success.
1936 	 */
1937 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1938 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
1939 					   options->version <= 6))))
1940 		return 0;
1941 
1942 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1943 	if (data == NULL)
1944 		return -ENOMEM;
1945 
1946 	/* fill out struct with values from existing mount */
1947 	data->flags = nfss->flags;
1948 	data->rsize = nfss->rsize;
1949 	data->wsize = nfss->wsize;
1950 	data->retrans = nfss->client->cl_timeout->to_retries;
1951 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1952 	data->acregmin = nfss->acregmin / HZ;
1953 	data->acregmax = nfss->acregmax / HZ;
1954 	data->acdirmin = nfss->acdirmin / HZ;
1955 	data->acdirmax = nfss->acdirmax / HZ;
1956 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1957 	data->nfs_server.port = nfss->port;
1958 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1959 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1960 		data->nfs_server.addrlen);
1961 
1962 	/* overwrite those values with any that were specified */
1963 	error = nfs_parse_mount_options((char *)options, data);
1964 	if (error < 0)
1965 		goto out;
1966 
1967 	/* compare new mount options with old ones */
1968 	error = nfs_compare_remount_data(nfss, data);
1969 out:
1970 	kfree(data);
1971 	return error;
1972 }
1973 
1974 /*
1975  * Initialise the common bits of the superblock
1976  */
1977 static inline void nfs_initialise_sb(struct super_block *sb)
1978 {
1979 	struct nfs_server *server = NFS_SB(sb);
1980 
1981 	sb->s_magic = NFS_SUPER_MAGIC;
1982 
1983 	/* We probably want something more informative here */
1984 	snprintf(sb->s_id, sizeof(sb->s_id),
1985 		 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1986 
1987 	if (sb->s_blocksize == 0)
1988 		sb->s_blocksize = nfs_block_bits(server->wsize,
1989 						 &sb->s_blocksize_bits);
1990 
1991 	if (server->flags & NFS_MOUNT_NOAC)
1992 		sb->s_flags |= MS_SYNCHRONOUS;
1993 
1994 	sb->s_bdi = &server->backing_dev_info;
1995 
1996 	nfs_super_set_maxbytes(sb, server->maxfilesize);
1997 }
1998 
1999 /*
2000  * Finish setting up an NFS2/3 superblock
2001  */
2002 static void nfs_fill_super(struct super_block *sb,
2003 			   struct nfs_parsed_mount_data *data)
2004 {
2005 	struct nfs_server *server = NFS_SB(sb);
2006 
2007 	sb->s_blocksize_bits = 0;
2008 	sb->s_blocksize = 0;
2009 	if (data->bsize)
2010 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2011 
2012 	if (server->nfs_client->rpc_ops->version == 3) {
2013 		/* The VFS shouldn't apply the umask to mode bits. We will do
2014 		 * so ourselves when necessary.
2015 		 */
2016 		sb->s_flags |= MS_POSIXACL;
2017 		sb->s_time_gran = 1;
2018 	}
2019 
2020 	sb->s_op = &nfs_sops;
2021  	nfs_initialise_sb(sb);
2022 }
2023 
2024 /*
2025  * Finish setting up a cloned NFS2/3 superblock
2026  */
2027 static void nfs_clone_super(struct super_block *sb,
2028 			    const struct super_block *old_sb)
2029 {
2030 	struct nfs_server *server = NFS_SB(sb);
2031 
2032 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2033 	sb->s_blocksize = old_sb->s_blocksize;
2034 	sb->s_maxbytes = old_sb->s_maxbytes;
2035 
2036 	if (server->nfs_client->rpc_ops->version == 3) {
2037 		/* The VFS shouldn't apply the umask to mode bits. We will do
2038 		 * so ourselves when necessary.
2039 		 */
2040 		sb->s_flags |= MS_POSIXACL;
2041 		sb->s_time_gran = 1;
2042 	}
2043 
2044 	sb->s_op = old_sb->s_op;
2045  	nfs_initialise_sb(sb);
2046 }
2047 
2048 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2049 {
2050 	const struct nfs_server *a = s->s_fs_info;
2051 	const struct rpc_clnt *clnt_a = a->client;
2052 	const struct rpc_clnt *clnt_b = b->client;
2053 
2054 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2055 		goto Ebusy;
2056 	if (a->nfs_client != b->nfs_client)
2057 		goto Ebusy;
2058 	if (a->flags != b->flags)
2059 		goto Ebusy;
2060 	if (a->wsize != b->wsize)
2061 		goto Ebusy;
2062 	if (a->rsize != b->rsize)
2063 		goto Ebusy;
2064 	if (a->acregmin != b->acregmin)
2065 		goto Ebusy;
2066 	if (a->acregmax != b->acregmax)
2067 		goto Ebusy;
2068 	if (a->acdirmin != b->acdirmin)
2069 		goto Ebusy;
2070 	if (a->acdirmax != b->acdirmax)
2071 		goto Ebusy;
2072 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2073 		goto Ebusy;
2074 	return 1;
2075 Ebusy:
2076 	return 0;
2077 }
2078 
2079 struct nfs_sb_mountdata {
2080 	struct nfs_server *server;
2081 	int mntflags;
2082 };
2083 
2084 static int nfs_set_super(struct super_block *s, void *data)
2085 {
2086 	struct nfs_sb_mountdata *sb_mntdata = data;
2087 	struct nfs_server *server = sb_mntdata->server;
2088 	int ret;
2089 
2090 	s->s_flags = sb_mntdata->mntflags;
2091 	s->s_fs_info = server;
2092 	ret = set_anon_super(s, server);
2093 	if (ret == 0)
2094 		server->s_dev = s->s_dev;
2095 	return ret;
2096 }
2097 
2098 static int nfs_compare_super_address(struct nfs_server *server1,
2099 				     struct nfs_server *server2)
2100 {
2101 	struct sockaddr *sap1, *sap2;
2102 
2103 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2104 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2105 
2106 	if (sap1->sa_family != sap2->sa_family)
2107 		return 0;
2108 
2109 	switch (sap1->sa_family) {
2110 	case AF_INET: {
2111 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2112 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2113 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2114 			return 0;
2115 		if (sin1->sin_port != sin2->sin_port)
2116 			return 0;
2117 		break;
2118 	}
2119 	case AF_INET6: {
2120 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2121 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2122 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2123 			return 0;
2124 		if (sin1->sin6_port != sin2->sin6_port)
2125 			return 0;
2126 		break;
2127 	}
2128 	default:
2129 		return 0;
2130 	}
2131 
2132 	return 1;
2133 }
2134 
2135 static int nfs_compare_super(struct super_block *sb, void *data)
2136 {
2137 	struct nfs_sb_mountdata *sb_mntdata = data;
2138 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2139 	int mntflags = sb_mntdata->mntflags;
2140 
2141 	if (!nfs_compare_super_address(old, server))
2142 		return 0;
2143 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2144 	if (old->flags & NFS_MOUNT_UNSHARED)
2145 		return 0;
2146 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2147 		return 0;
2148 	return nfs_compare_mount_options(sb, server, mntflags);
2149 }
2150 
2151 static int nfs_bdi_register(struct nfs_server *server)
2152 {
2153 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2154 }
2155 
2156 static int nfs_get_sb(struct file_system_type *fs_type,
2157 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2158 {
2159 	struct nfs_server *server = NULL;
2160 	struct super_block *s;
2161 	struct nfs_parsed_mount_data *data;
2162 	struct nfs_fh *mntfh;
2163 	struct dentry *mntroot;
2164 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2165 	struct nfs_sb_mountdata sb_mntdata = {
2166 		.mntflags = flags,
2167 	};
2168 	int error = -ENOMEM;
2169 
2170 	data = nfs_alloc_parsed_mount_data(3);
2171 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2172 	if (data == NULL || mntfh == NULL)
2173 		goto out_free_fh;
2174 
2175 	security_init_mnt_opts(&data->lsm_opts);
2176 
2177 	/* Validate the mount data */
2178 	error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2179 	if (error < 0)
2180 		goto out;
2181 
2182 #ifdef CONFIG_NFS_V4
2183 	if (data->version == 4) {
2184 		error = nfs4_try_mount(flags, dev_name, data, mnt);
2185 		kfree(data->client_address);
2186 		goto out;
2187 	}
2188 #endif	/* CONFIG_NFS_V4 */
2189 
2190 	/* Get a volume representation */
2191 	server = nfs_create_server(data, mntfh);
2192 	if (IS_ERR(server)) {
2193 		error = PTR_ERR(server);
2194 		goto out;
2195 	}
2196 	sb_mntdata.server = server;
2197 
2198 	if (server->flags & NFS_MOUNT_UNSHARED)
2199 		compare_super = NULL;
2200 
2201 	/* Get a superblock - note that we may end up sharing one that already exists */
2202 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2203 	if (IS_ERR(s)) {
2204 		error = PTR_ERR(s);
2205 		goto out_err_nosb;
2206 	}
2207 
2208 	if (s->s_fs_info != server) {
2209 		nfs_free_server(server);
2210 		server = NULL;
2211 	} else {
2212 		error = nfs_bdi_register(server);
2213 		if (error)
2214 			goto error_splat_super;
2215 	}
2216 
2217 	if (!s->s_root) {
2218 		/* initial superblock/root creation */
2219 		nfs_fill_super(s, data);
2220 		nfs_fscache_get_super_cookie(
2221 			s, data ? data->fscache_uniq : NULL, NULL);
2222 	}
2223 
2224 	mntroot = nfs_get_root(s, mntfh);
2225 	if (IS_ERR(mntroot)) {
2226 		error = PTR_ERR(mntroot);
2227 		goto error_splat_super;
2228 	}
2229 
2230 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2231 	if (error)
2232 		goto error_splat_root;
2233 
2234 	s->s_flags |= MS_ACTIVE;
2235 	mnt->mnt_sb = s;
2236 	mnt->mnt_root = mntroot;
2237 	error = 0;
2238 
2239 out:
2240 	kfree(data->nfs_server.hostname);
2241 	kfree(data->mount_server.hostname);
2242 	kfree(data->fscache_uniq);
2243 	security_free_mnt_opts(&data->lsm_opts);
2244 out_free_fh:
2245 	kfree(mntfh);
2246 	kfree(data);
2247 	return error;
2248 
2249 out_err_nosb:
2250 	nfs_free_server(server);
2251 	goto out;
2252 
2253 error_splat_root:
2254 	dput(mntroot);
2255 error_splat_super:
2256 	deactivate_locked_super(s);
2257 	goto out;
2258 }
2259 
2260 /*
2261  * Destroy an NFS2/3 superblock
2262  */
2263 static void nfs_kill_super(struct super_block *s)
2264 {
2265 	struct nfs_server *server = NFS_SB(s);
2266 
2267 	kill_anon_super(s);
2268 	bdi_unregister(&server->backing_dev_info);
2269 	nfs_fscache_release_super_cookie(s);
2270 	nfs_free_server(server);
2271 }
2272 
2273 /*
2274  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2275  */
2276 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2277 			   const char *dev_name, void *raw_data,
2278 			   struct vfsmount *mnt)
2279 {
2280 	struct nfs_clone_mount *data = raw_data;
2281 	struct super_block *s;
2282 	struct nfs_server *server;
2283 	struct dentry *mntroot;
2284 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2285 	struct nfs_sb_mountdata sb_mntdata = {
2286 		.mntflags = flags,
2287 	};
2288 	int error;
2289 
2290 	dprintk("--> nfs_xdev_get_sb()\n");
2291 
2292 	/* create a new volume representation */
2293 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2294 	if (IS_ERR(server)) {
2295 		error = PTR_ERR(server);
2296 		goto out_err_noserver;
2297 	}
2298 	sb_mntdata.server = server;
2299 
2300 	if (server->flags & NFS_MOUNT_UNSHARED)
2301 		compare_super = NULL;
2302 
2303 	/* Get a superblock - note that we may end up sharing one that already exists */
2304 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2305 	if (IS_ERR(s)) {
2306 		error = PTR_ERR(s);
2307 		goto out_err_nosb;
2308 	}
2309 
2310 	if (s->s_fs_info != server) {
2311 		nfs_free_server(server);
2312 		server = NULL;
2313 	} else {
2314 		error = nfs_bdi_register(server);
2315 		if (error)
2316 			goto error_splat_super;
2317 	}
2318 
2319 	if (!s->s_root) {
2320 		/* initial superblock/root creation */
2321 		nfs_clone_super(s, data->sb);
2322 		nfs_fscache_get_super_cookie(s, NULL, data);
2323 	}
2324 
2325 	mntroot = nfs_get_root(s, data->fh);
2326 	if (IS_ERR(mntroot)) {
2327 		error = PTR_ERR(mntroot);
2328 		goto error_splat_super;
2329 	}
2330 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2331 		dput(mntroot);
2332 		error = -ESTALE;
2333 		goto error_splat_super;
2334 	}
2335 
2336 	s->s_flags |= MS_ACTIVE;
2337 	mnt->mnt_sb = s;
2338 	mnt->mnt_root = mntroot;
2339 
2340 	/* clone any lsm security options from the parent to the new sb */
2341 	security_sb_clone_mnt_opts(data->sb, s);
2342 
2343 	dprintk("<-- nfs_xdev_get_sb() = 0\n");
2344 	return 0;
2345 
2346 out_err_nosb:
2347 	nfs_free_server(server);
2348 out_err_noserver:
2349 	dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2350 	return error;
2351 
2352 error_splat_super:
2353 	deactivate_locked_super(s);
2354 	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2355 	return error;
2356 }
2357 
2358 #ifdef CONFIG_NFS_V4
2359 
2360 /*
2361  * Finish setting up a cloned NFS4 superblock
2362  */
2363 static void nfs4_clone_super(struct super_block *sb,
2364 			    const struct super_block *old_sb)
2365 {
2366 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2367 	sb->s_blocksize = old_sb->s_blocksize;
2368 	sb->s_maxbytes = old_sb->s_maxbytes;
2369 	sb->s_time_gran = 1;
2370 	sb->s_op = old_sb->s_op;
2371  	nfs_initialise_sb(sb);
2372 }
2373 
2374 /*
2375  * Set up an NFS4 superblock
2376  */
2377 static void nfs4_fill_super(struct super_block *sb)
2378 {
2379 	sb->s_time_gran = 1;
2380 	sb->s_op = &nfs4_sops;
2381 	nfs_initialise_sb(sb);
2382 }
2383 
2384 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2385 {
2386 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2387 }
2388 
2389 static int nfs4_validate_text_mount_data(void *options,
2390 					 struct nfs_parsed_mount_data *args,
2391 					 const char *dev_name)
2392 {
2393 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2394 
2395 	nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2396 
2397 	nfs_validate_transport_protocol(args);
2398 
2399 	nfs4_validate_mount_flags(args);
2400 
2401 	if (args->version != 4) {
2402 		dfprintk(MOUNT,
2403 			 "NFS4: Illegal mount version\n");
2404 		return -EINVAL;
2405 	}
2406 
2407 	if (args->auth_flavor_len > 1) {
2408 		dfprintk(MOUNT,
2409 			 "NFS4: Too many RPC auth flavours specified\n");
2410 		return -EINVAL;
2411 	}
2412 
2413 	if (args->client_address == NULL) {
2414 		dfprintk(MOUNT,
2415 			 "NFS4: mount program didn't pass callback address\n");
2416 		return -EINVAL;
2417 	}
2418 
2419 	return nfs_parse_devname(dev_name,
2420 				   &args->nfs_server.hostname,
2421 				   NFS4_MAXNAMLEN,
2422 				   &args->nfs_server.export_path,
2423 				   NFS4_MAXPATHLEN);
2424 }
2425 
2426 /*
2427  * Validate NFSv4 mount options
2428  */
2429 static int nfs4_validate_mount_data(void *options,
2430 				    struct nfs_parsed_mount_data *args,
2431 				    const char *dev_name)
2432 {
2433 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2434 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2435 	char *c;
2436 
2437 	if (data == NULL)
2438 		goto out_no_data;
2439 
2440 	switch (data->version) {
2441 	case 1:
2442 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2443 			goto out_no_address;
2444 		if (data->host_addrlen == 0)
2445 			goto out_no_address;
2446 		args->nfs_server.addrlen = data->host_addrlen;
2447 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2448 			return -EFAULT;
2449 		if (!nfs_verify_server_address(sap))
2450 			goto out_no_address;
2451 
2452 		if (data->auth_flavourlen) {
2453 			if (data->auth_flavourlen > 1)
2454 				goto out_inval_auth;
2455 			if (copy_from_user(&args->auth_flavors[0],
2456 					   data->auth_flavours,
2457 					   sizeof(args->auth_flavors[0])))
2458 				return -EFAULT;
2459 		}
2460 
2461 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2462 		if (IS_ERR(c))
2463 			return PTR_ERR(c);
2464 		args->nfs_server.hostname = c;
2465 
2466 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2467 		if (IS_ERR(c))
2468 			return PTR_ERR(c);
2469 		args->nfs_server.export_path = c;
2470 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2471 
2472 		c = strndup_user(data->client_addr.data, 16);
2473 		if (IS_ERR(c))
2474 			return PTR_ERR(c);
2475 		args->client_address = c;
2476 
2477 		/*
2478 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2479 		 * can deal with.
2480 		 */
2481 
2482 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2483 		args->rsize	= data->rsize;
2484 		args->wsize	= data->wsize;
2485 		args->timeo	= data->timeo;
2486 		args->retrans	= data->retrans;
2487 		args->acregmin	= data->acregmin;
2488 		args->acregmax	= data->acregmax;
2489 		args->acdirmin	= data->acdirmin;
2490 		args->acdirmax	= data->acdirmax;
2491 		args->nfs_server.protocol = data->proto;
2492 		nfs_validate_transport_protocol(args);
2493 
2494 		break;
2495 	default:
2496 		if (nfs_parse_mount_options((char *)options, args) == 0)
2497 			return -EINVAL;
2498 
2499 		if (!nfs_verify_server_address(sap))
2500 			return -EINVAL;
2501 
2502 		return nfs4_validate_text_mount_data(options, args, dev_name);
2503 	}
2504 
2505 	return 0;
2506 
2507 out_no_data:
2508 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2509 	return -EINVAL;
2510 
2511 out_inval_auth:
2512 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2513 		 data->auth_flavourlen);
2514 	return -EINVAL;
2515 
2516 out_no_address:
2517 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2518 	return -EINVAL;
2519 }
2520 
2521 /*
2522  * Get the superblock for the NFS4 root partition
2523  */
2524 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2525 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2526 {
2527 	struct nfs_parsed_mount_data *data = raw_data;
2528 	struct super_block *s;
2529 	struct nfs_server *server;
2530 	struct nfs_fh *mntfh;
2531 	struct dentry *mntroot;
2532 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2533 	struct nfs_sb_mountdata sb_mntdata = {
2534 		.mntflags = flags,
2535 	};
2536 	int error = -ENOMEM;
2537 
2538 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2539 	if (data == NULL || mntfh == NULL)
2540 		goto out_free_fh;
2541 
2542 	security_init_mnt_opts(&data->lsm_opts);
2543 
2544 	/* Get a volume representation */
2545 	server = nfs4_create_server(data, mntfh);
2546 	if (IS_ERR(server)) {
2547 		error = PTR_ERR(server);
2548 		goto out;
2549 	}
2550 	sb_mntdata.server = server;
2551 
2552 	if (server->flags & NFS4_MOUNT_UNSHARED)
2553 		compare_super = NULL;
2554 
2555 	/* Get a superblock - note that we may end up sharing one that already exists */
2556 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2557 	if (IS_ERR(s)) {
2558 		error = PTR_ERR(s);
2559 		goto out_free;
2560 	}
2561 
2562 	if (s->s_fs_info != server) {
2563 		nfs_free_server(server);
2564 		server = NULL;
2565 	} else {
2566 		error = nfs_bdi_register(server);
2567 		if (error)
2568 			goto error_splat_super;
2569 	}
2570 
2571 	if (!s->s_root) {
2572 		/* initial superblock/root creation */
2573 		nfs4_fill_super(s);
2574 		nfs_fscache_get_super_cookie(
2575 			s, data ? data->fscache_uniq : NULL, NULL);
2576 	}
2577 
2578 	mntroot = nfs4_get_root(s, mntfh);
2579 	if (IS_ERR(mntroot)) {
2580 		error = PTR_ERR(mntroot);
2581 		goto error_splat_super;
2582 	}
2583 
2584 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2585 	if (error)
2586 		goto error_splat_root;
2587 
2588 	s->s_flags |= MS_ACTIVE;
2589 	mnt->mnt_sb = s;
2590 	mnt->mnt_root = mntroot;
2591 	error = 0;
2592 
2593 out:
2594 	security_free_mnt_opts(&data->lsm_opts);
2595 out_free_fh:
2596 	kfree(mntfh);
2597 	return error;
2598 
2599 out_free:
2600 	nfs_free_server(server);
2601 	goto out;
2602 
2603 error_splat_root:
2604 	dput(mntroot);
2605 error_splat_super:
2606 	deactivate_locked_super(s);
2607 	goto out;
2608 }
2609 
2610 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2611 		int flags, void *data, const char *hostname)
2612 {
2613 	struct vfsmount *root_mnt;
2614 	char *root_devname;
2615 	size_t len;
2616 
2617 	len = strlen(hostname) + 3;
2618 	root_devname = kmalloc(len, GFP_KERNEL);
2619 	if (root_devname == NULL)
2620 		return ERR_PTR(-ENOMEM);
2621 	snprintf(root_devname, len, "%s:/", hostname);
2622 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2623 	kfree(root_devname);
2624 	return root_mnt;
2625 }
2626 
2627 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2628 {
2629 	char *page = (char *) __get_free_page(GFP_KERNEL);
2630 	char *devname, *tmp;
2631 
2632 	if (page == NULL)
2633 		return;
2634 	devname = nfs_path(path->mnt->mnt_devname,
2635 			path->mnt->mnt_root, path->dentry,
2636 			page, PAGE_SIZE);
2637 	if (devname == NULL)
2638 		goto out_freepage;
2639 	tmp = kstrdup(devname, GFP_KERNEL);
2640 	if (tmp == NULL)
2641 		goto out_freepage;
2642 	kfree(mnt->mnt_devname);
2643 	mnt->mnt_devname = tmp;
2644 out_freepage:
2645 	free_page((unsigned long)page);
2646 }
2647 
2648 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2649 		const char *export_path, struct vfsmount *mnt_target)
2650 {
2651 	struct mnt_namespace *ns_private;
2652 	struct nameidata nd;
2653 	struct super_block *s;
2654 	int ret;
2655 
2656 	ns_private = create_mnt_ns(root_mnt);
2657 	ret = PTR_ERR(ns_private);
2658 	if (IS_ERR(ns_private))
2659 		goto out_mntput;
2660 
2661 	ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2662 			export_path, LOOKUP_FOLLOW, &nd);
2663 
2664 	put_mnt_ns(ns_private);
2665 
2666 	if (ret != 0)
2667 		goto out_err;
2668 
2669 	s = nd.path.mnt->mnt_sb;
2670 	atomic_inc(&s->s_active);
2671 	mnt_target->mnt_sb = s;
2672 	mnt_target->mnt_root = dget(nd.path.dentry);
2673 
2674 	/* Correct the device pathname */
2675 	nfs_fix_devname(&nd.path, mnt_target);
2676 
2677 	path_put(&nd.path);
2678 	down_write(&s->s_umount);
2679 	return 0;
2680 out_mntput:
2681 	mntput(root_mnt);
2682 out_err:
2683 	return ret;
2684 }
2685 
2686 static int nfs4_try_mount(int flags, const char *dev_name,
2687 			 struct nfs_parsed_mount_data *data,
2688 			 struct vfsmount *mnt)
2689 {
2690 	char *export_path;
2691 	struct vfsmount *root_mnt;
2692 	int error;
2693 
2694 	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2695 
2696 	export_path = data->nfs_server.export_path;
2697 	data->nfs_server.export_path = "/";
2698 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2699 			data->nfs_server.hostname);
2700 	data->nfs_server.export_path = export_path;
2701 
2702 	error = PTR_ERR(root_mnt);
2703 	if (IS_ERR(root_mnt))
2704 		goto out;
2705 
2706 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2707 
2708 out:
2709 	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2710 			error != 0 ? " [error]" : "");
2711 	return error;
2712 }
2713 
2714 /*
2715  * Get the superblock for an NFS4 mountpoint
2716  */
2717 static int nfs4_get_sb(struct file_system_type *fs_type,
2718 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2719 {
2720 	struct nfs_parsed_mount_data *data;
2721 	int error = -ENOMEM;
2722 
2723 	data = nfs_alloc_parsed_mount_data(4);
2724 	if (data == NULL)
2725 		goto out_free_data;
2726 
2727 	/* Validate the mount data */
2728 	error = nfs4_validate_mount_data(raw_data, data, dev_name);
2729 	if (error < 0)
2730 		goto out;
2731 
2732 	error = nfs4_try_mount(flags, dev_name, data, mnt);
2733 
2734 out:
2735 	kfree(data->client_address);
2736 	kfree(data->nfs_server.export_path);
2737 	kfree(data->nfs_server.hostname);
2738 	kfree(data->fscache_uniq);
2739 out_free_data:
2740 	kfree(data);
2741 	dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2742 			error != 0 ? " [error]" : "");
2743 	return error;
2744 }
2745 
2746 static void nfs4_kill_super(struct super_block *sb)
2747 {
2748 	struct nfs_server *server = NFS_SB(sb);
2749 
2750 	dprintk("--> %s\n", __func__);
2751 	nfs_super_return_all_delegations(sb);
2752 	kill_anon_super(sb);
2753 	nfs_fscache_release_super_cookie(sb);
2754 	nfs_free_server(server);
2755 	dprintk("<-- %s\n", __func__);
2756 }
2757 
2758 /*
2759  * Clone an NFS4 server record on xdev traversal (FSID-change)
2760  */
2761 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2762 			    const char *dev_name, void *raw_data,
2763 			    struct vfsmount *mnt)
2764 {
2765 	struct nfs_clone_mount *data = raw_data;
2766 	struct super_block *s;
2767 	struct nfs_server *server;
2768 	struct dentry *mntroot;
2769 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2770 	struct nfs_sb_mountdata sb_mntdata = {
2771 		.mntflags = flags,
2772 	};
2773 	int error;
2774 
2775 	dprintk("--> nfs4_xdev_get_sb()\n");
2776 
2777 	/* create a new volume representation */
2778 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2779 	if (IS_ERR(server)) {
2780 		error = PTR_ERR(server);
2781 		goto out_err_noserver;
2782 	}
2783 	sb_mntdata.server = server;
2784 
2785 	if (server->flags & NFS4_MOUNT_UNSHARED)
2786 		compare_super = NULL;
2787 
2788 	/* Get a superblock - note that we may end up sharing one that already exists */
2789 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2790 	if (IS_ERR(s)) {
2791 		error = PTR_ERR(s);
2792 		goto out_err_nosb;
2793 	}
2794 
2795 	if (s->s_fs_info != server) {
2796 		nfs_free_server(server);
2797 		server = NULL;
2798 	} else {
2799 		error = nfs_bdi_register(server);
2800 		if (error)
2801 			goto error_splat_super;
2802 	}
2803 
2804 	if (!s->s_root) {
2805 		/* initial superblock/root creation */
2806 		nfs4_clone_super(s, data->sb);
2807 		nfs_fscache_get_super_cookie(s, NULL, data);
2808 	}
2809 
2810 	mntroot = nfs4_get_root(s, data->fh);
2811 	if (IS_ERR(mntroot)) {
2812 		error = PTR_ERR(mntroot);
2813 		goto error_splat_super;
2814 	}
2815 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2816 		dput(mntroot);
2817 		error = -ESTALE;
2818 		goto error_splat_super;
2819 	}
2820 
2821 	s->s_flags |= MS_ACTIVE;
2822 	mnt->mnt_sb = s;
2823 	mnt->mnt_root = mntroot;
2824 
2825 	security_sb_clone_mnt_opts(data->sb, s);
2826 
2827 	dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2828 	return 0;
2829 
2830 out_err_nosb:
2831 	nfs_free_server(server);
2832 out_err_noserver:
2833 	dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2834 	return error;
2835 
2836 error_splat_super:
2837 	deactivate_locked_super(s);
2838 	dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2839 	return error;
2840 }
2841 
2842 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2843 		int flags, const char *dev_name, void *raw_data,
2844 		struct vfsmount *mnt)
2845 {
2846 	struct nfs_clone_mount *data = raw_data;
2847 	struct super_block *s;
2848 	struct nfs_server *server;
2849 	struct dentry *mntroot;
2850 	struct nfs_fh mntfh;
2851 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2852 	struct nfs_sb_mountdata sb_mntdata = {
2853 		.mntflags = flags,
2854 	};
2855 	int error;
2856 
2857 	dprintk("--> nfs4_referral_get_sb()\n");
2858 
2859 	/* create a new volume representation */
2860 	server = nfs4_create_referral_server(data, &mntfh);
2861 	if (IS_ERR(server)) {
2862 		error = PTR_ERR(server);
2863 		goto out_err_noserver;
2864 	}
2865 	sb_mntdata.server = server;
2866 
2867 	if (server->flags & NFS4_MOUNT_UNSHARED)
2868 		compare_super = NULL;
2869 
2870 	/* Get a superblock - note that we may end up sharing one that already exists */
2871 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2872 	if (IS_ERR(s)) {
2873 		error = PTR_ERR(s);
2874 		goto out_err_nosb;
2875 	}
2876 
2877 	if (s->s_fs_info != server) {
2878 		nfs_free_server(server);
2879 		server = NULL;
2880 	} else {
2881 		error = nfs_bdi_register(server);
2882 		if (error)
2883 			goto error_splat_super;
2884 	}
2885 
2886 	if (!s->s_root) {
2887 		/* initial superblock/root creation */
2888 		nfs4_fill_super(s);
2889 		nfs_fscache_get_super_cookie(s, NULL, data);
2890 	}
2891 
2892 	mntroot = nfs4_get_root(s, &mntfh);
2893 	if (IS_ERR(mntroot)) {
2894 		error = PTR_ERR(mntroot);
2895 		goto error_splat_super;
2896 	}
2897 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2898 		dput(mntroot);
2899 		error = -ESTALE;
2900 		goto error_splat_super;
2901 	}
2902 
2903 	s->s_flags |= MS_ACTIVE;
2904 	mnt->mnt_sb = s;
2905 	mnt->mnt_root = mntroot;
2906 
2907 	security_sb_clone_mnt_opts(data->sb, s);
2908 
2909 	dprintk("<-- nfs4_referral_get_sb() = 0\n");
2910 	return 0;
2911 
2912 out_err_nosb:
2913 	nfs_free_server(server);
2914 out_err_noserver:
2915 	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2916 	return error;
2917 
2918 error_splat_super:
2919 	deactivate_locked_super(s);
2920 	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2921 	return error;
2922 }
2923 
2924 /*
2925  * Create an NFS4 server record on referral traversal
2926  */
2927 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2928 		int flags, const char *dev_name, void *raw_data,
2929 		struct vfsmount *mnt)
2930 {
2931 	struct nfs_clone_mount *data = raw_data;
2932 	char *export_path;
2933 	struct vfsmount *root_mnt;
2934 	int error;
2935 
2936 	dprintk("--> nfs4_referral_get_sb()\n");
2937 
2938 	export_path = data->mnt_path;
2939 	data->mnt_path = "/";
2940 
2941 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2942 			flags, data, data->hostname);
2943 	data->mnt_path = export_path;
2944 
2945 	error = PTR_ERR(root_mnt);
2946 	if (IS_ERR(root_mnt))
2947 		goto out;
2948 
2949 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2950 out:
2951 	dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2952 			error != 0 ? " [error]" : "");
2953 	return error;
2954 }
2955 
2956 #endif /* CONFIG_NFS_V4 */
2957