xref: /linux/fs/nfs/super.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/stats.h>
35 #include <linux/sunrpc/metrics.h>
36 #include <linux/sunrpc/xprtsock.h>
37 #include <linux/sunrpc/xprtrdma.h>
38 #include <linux/nfs_fs.h>
39 #include <linux/nfs_mount.h>
40 #include <linux/nfs4_mount.h>
41 #include <linux/lockd/bind.h>
42 #include <linux/seq_file.h>
43 #include <linux/mount.h>
44 #include <linux/namei.h>
45 #include <linux/nfs_idmap.h>
46 #include <linux/vfs.h>
47 #include <linux/inet.h>
48 #include <linux/in6.h>
49 #include <linux/slab.h>
50 #include <net/ipv6.h>
51 #include <linux/netdevice.h>
52 #include <linux/nfs_xdr.h>
53 #include <linux/magic.h>
54 #include <linux/parser.h>
55 #include <linux/nsproxy.h>
56 #include <linux/rcupdate.h>
57 
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 #include "pnfs.h"
67 #include "nfs.h"
68 
69 #define NFSDBG_FACILITY		NFSDBG_VFS
70 #define NFS_TEXT_DATA		1
71 
72 #if IS_ENABLED(CONFIG_NFS_V3)
73 #define NFS_DEFAULT_VERSION 3
74 #else
75 #define NFS_DEFAULT_VERSION 2
76 #endif
77 
78 enum {
79 	/* Mount options that take no arguments */
80 	Opt_soft, Opt_hard,
81 	Opt_posix, Opt_noposix,
82 	Opt_cto, Opt_nocto,
83 	Opt_ac, Opt_noac,
84 	Opt_lock, Opt_nolock,
85 	Opt_udp, Opt_tcp, Opt_rdma,
86 	Opt_acl, Opt_noacl,
87 	Opt_rdirplus, Opt_nordirplus,
88 	Opt_sharecache, Opt_nosharecache,
89 	Opt_resvport, Opt_noresvport,
90 	Opt_fscache, Opt_nofscache,
91 
92 	/* Mount options that take integer arguments */
93 	Opt_port,
94 	Opt_rsize, Opt_wsize, Opt_bsize,
95 	Opt_timeo, Opt_retrans,
96 	Opt_acregmin, Opt_acregmax,
97 	Opt_acdirmin, Opt_acdirmax,
98 	Opt_actimeo,
99 	Opt_namelen,
100 	Opt_mountport,
101 	Opt_mountvers,
102 	Opt_minorversion,
103 
104 	/* Mount options that take string arguments */
105 	Opt_nfsvers,
106 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
107 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
108 	Opt_lookupcache,
109 	Opt_fscache_uniq,
110 	Opt_local_lock,
111 
112 	/* Special mount options */
113 	Opt_userspace, Opt_deprecated, Opt_sloppy,
114 
115 	Opt_err
116 };
117 
118 static const match_table_t nfs_mount_option_tokens = {
119 	{ Opt_userspace, "bg" },
120 	{ Opt_userspace, "fg" },
121 	{ Opt_userspace, "retry=%s" },
122 
123 	{ Opt_sloppy, "sloppy" },
124 
125 	{ Opt_soft, "soft" },
126 	{ Opt_hard, "hard" },
127 	{ Opt_deprecated, "intr" },
128 	{ Opt_deprecated, "nointr" },
129 	{ Opt_posix, "posix" },
130 	{ Opt_noposix, "noposix" },
131 	{ Opt_cto, "cto" },
132 	{ Opt_nocto, "nocto" },
133 	{ Opt_ac, "ac" },
134 	{ Opt_noac, "noac" },
135 	{ Opt_lock, "lock" },
136 	{ Opt_nolock, "nolock" },
137 	{ Opt_udp, "udp" },
138 	{ Opt_tcp, "tcp" },
139 	{ Opt_rdma, "rdma" },
140 	{ Opt_acl, "acl" },
141 	{ Opt_noacl, "noacl" },
142 	{ Opt_rdirplus, "rdirplus" },
143 	{ Opt_nordirplus, "nordirplus" },
144 	{ Opt_sharecache, "sharecache" },
145 	{ Opt_nosharecache, "nosharecache" },
146 	{ Opt_resvport, "resvport" },
147 	{ Opt_noresvport, "noresvport" },
148 	{ Opt_fscache, "fsc" },
149 	{ Opt_nofscache, "nofsc" },
150 
151 	{ Opt_port, "port=%s" },
152 	{ Opt_rsize, "rsize=%s" },
153 	{ Opt_wsize, "wsize=%s" },
154 	{ Opt_bsize, "bsize=%s" },
155 	{ Opt_timeo, "timeo=%s" },
156 	{ Opt_retrans, "retrans=%s" },
157 	{ Opt_acregmin, "acregmin=%s" },
158 	{ Opt_acregmax, "acregmax=%s" },
159 	{ Opt_acdirmin, "acdirmin=%s" },
160 	{ Opt_acdirmax, "acdirmax=%s" },
161 	{ Opt_actimeo, "actimeo=%s" },
162 	{ Opt_namelen, "namlen=%s" },
163 	{ Opt_mountport, "mountport=%s" },
164 	{ Opt_mountvers, "mountvers=%s" },
165 	{ Opt_minorversion, "minorversion=%s" },
166 
167 	{ Opt_nfsvers, "nfsvers=%s" },
168 	{ Opt_nfsvers, "vers=%s" },
169 
170 	{ Opt_sec, "sec=%s" },
171 	{ Opt_proto, "proto=%s" },
172 	{ Opt_mountproto, "mountproto=%s" },
173 	{ Opt_addr, "addr=%s" },
174 	{ Opt_clientaddr, "clientaddr=%s" },
175 	{ Opt_mounthost, "mounthost=%s" },
176 	{ Opt_mountaddr, "mountaddr=%s" },
177 
178 	{ Opt_lookupcache, "lookupcache=%s" },
179 	{ Opt_fscache_uniq, "fsc=%s" },
180 	{ Opt_local_lock, "local_lock=%s" },
181 
182 	/* The following needs to be listed after all other options */
183 	{ Opt_nfsvers, "v%s" },
184 
185 	{ Opt_err, NULL }
186 };
187 
188 enum {
189 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
190 
191 	Opt_xprt_err
192 };
193 
194 static const match_table_t nfs_xprt_protocol_tokens = {
195 	{ Opt_xprt_udp, "udp" },
196 	{ Opt_xprt_udp6, "udp6" },
197 	{ Opt_xprt_tcp, "tcp" },
198 	{ Opt_xprt_tcp6, "tcp6" },
199 	{ Opt_xprt_rdma, "rdma" },
200 
201 	{ Opt_xprt_err, NULL }
202 };
203 
204 enum {
205 	Opt_sec_none, Opt_sec_sys,
206 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
207 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
208 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
209 
210 	Opt_sec_err
211 };
212 
213 static const match_table_t nfs_secflavor_tokens = {
214 	{ Opt_sec_none, "none" },
215 	{ Opt_sec_none, "null" },
216 	{ Opt_sec_sys, "sys" },
217 
218 	{ Opt_sec_krb5, "krb5" },
219 	{ Opt_sec_krb5i, "krb5i" },
220 	{ Opt_sec_krb5p, "krb5p" },
221 
222 	{ Opt_sec_lkey, "lkey" },
223 	{ Opt_sec_lkeyi, "lkeyi" },
224 	{ Opt_sec_lkeyp, "lkeyp" },
225 
226 	{ Opt_sec_spkm, "spkm3" },
227 	{ Opt_sec_spkmi, "spkm3i" },
228 	{ Opt_sec_spkmp, "spkm3p" },
229 
230 	{ Opt_sec_err, NULL }
231 };
232 
233 enum {
234 	Opt_lookupcache_all, Opt_lookupcache_positive,
235 	Opt_lookupcache_none,
236 
237 	Opt_lookupcache_err
238 };
239 
240 static match_table_t nfs_lookupcache_tokens = {
241 	{ Opt_lookupcache_all, "all" },
242 	{ Opt_lookupcache_positive, "pos" },
243 	{ Opt_lookupcache_positive, "positive" },
244 	{ Opt_lookupcache_none, "none" },
245 
246 	{ Opt_lookupcache_err, NULL }
247 };
248 
249 enum {
250 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
251 	Opt_local_lock_none,
252 
253 	Opt_local_lock_err
254 };
255 
256 static match_table_t nfs_local_lock_tokens = {
257 	{ Opt_local_lock_all, "all" },
258 	{ Opt_local_lock_flock, "flock" },
259 	{ Opt_local_lock_posix, "posix" },
260 	{ Opt_local_lock_none, "none" },
261 
262 	{ Opt_local_lock_err, NULL }
263 };
264 
265 enum {
266 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
267 	Opt_vers_4_1,
268 
269 	Opt_vers_err
270 };
271 
272 static match_table_t nfs_vers_tokens = {
273 	{ Opt_vers_2, "2" },
274 	{ Opt_vers_3, "3" },
275 	{ Opt_vers_4, "4" },
276 	{ Opt_vers_4_0, "4.0" },
277 	{ Opt_vers_4_1, "4.1" },
278 
279 	{ Opt_vers_err, NULL }
280 };
281 
282 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
283 		int flags, const char *dev_name, void *raw_data);
284 
285 struct file_system_type nfs_fs_type = {
286 	.owner		= THIS_MODULE,
287 	.name		= "nfs",
288 	.mount		= nfs_fs_mount,
289 	.kill_sb	= nfs_kill_super,
290 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
291 };
292 EXPORT_SYMBOL_GPL(nfs_fs_type);
293 
294 struct file_system_type nfs_xdev_fs_type = {
295 	.owner		= THIS_MODULE,
296 	.name		= "nfs",
297 	.mount		= nfs_xdev_mount,
298 	.kill_sb	= nfs_kill_super,
299 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
300 };
301 
302 const struct super_operations nfs_sops = {
303 	.alloc_inode	= nfs_alloc_inode,
304 	.destroy_inode	= nfs_destroy_inode,
305 	.write_inode	= nfs_write_inode,
306 	.put_super	= nfs_put_super,
307 	.statfs		= nfs_statfs,
308 	.evict_inode	= nfs_evict_inode,
309 	.umount_begin	= nfs_umount_begin,
310 	.show_options	= nfs_show_options,
311 	.show_devname	= nfs_show_devname,
312 	.show_path	= nfs_show_path,
313 	.show_stats	= nfs_show_stats,
314 	.remount_fs	= nfs_remount,
315 };
316 EXPORT_SYMBOL_GPL(nfs_sops);
317 
318 #if IS_ENABLED(CONFIG_NFS_V4)
319 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
320 static int nfs4_validate_mount_data(void *options,
321 	struct nfs_parsed_mount_data *args, const char *dev_name);
322 
323 struct file_system_type nfs4_fs_type = {
324 	.owner		= THIS_MODULE,
325 	.name		= "nfs4",
326 	.mount		= nfs_fs_mount,
327 	.kill_sb	= nfs_kill_super,
328 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
329 };
330 EXPORT_SYMBOL_GPL(nfs4_fs_type);
331 
332 static int __init register_nfs4_fs(void)
333 {
334 	return register_filesystem(&nfs4_fs_type);
335 }
336 
337 static void unregister_nfs4_fs(void)
338 {
339 	unregister_filesystem(&nfs4_fs_type);
340 }
341 #else
342 static int __init register_nfs4_fs(void)
343 {
344 	return 0;
345 }
346 
347 static void unregister_nfs4_fs(void)
348 {
349 }
350 #endif
351 
352 static struct shrinker acl_shrinker = {
353 	.shrink		= nfs_access_cache_shrinker,
354 	.seeks		= DEFAULT_SEEKS,
355 };
356 
357 /*
358  * Register the NFS filesystems
359  */
360 int __init register_nfs_fs(void)
361 {
362 	int ret;
363 
364         ret = register_filesystem(&nfs_fs_type);
365 	if (ret < 0)
366 		goto error_0;
367 
368 	ret = register_nfs4_fs();
369 	if (ret < 0)
370 		goto error_1;
371 
372 	ret = nfs_register_sysctl();
373 	if (ret < 0)
374 		goto error_2;
375 	register_shrinker(&acl_shrinker);
376 	return 0;
377 
378 error_2:
379 	unregister_nfs4_fs();
380 error_1:
381 	unregister_filesystem(&nfs_fs_type);
382 error_0:
383 	return ret;
384 }
385 
386 /*
387  * Unregister the NFS filesystems
388  */
389 void __exit unregister_nfs_fs(void)
390 {
391 	unregister_shrinker(&acl_shrinker);
392 	nfs_unregister_sysctl();
393 	unregister_nfs4_fs();
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 EXPORT_SYMBOL_GPL(nfs_sb_active);
405 
406 void nfs_sb_deactive(struct super_block *sb)
407 {
408 	struct nfs_server *server = NFS_SB(sb);
409 
410 	if (atomic_dec_and_test(&server->active))
411 		deactivate_super(sb);
412 }
413 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
414 
415 /*
416  * Deliver file system statistics to userspace
417  */
418 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
419 {
420 	struct nfs_server *server = NFS_SB(dentry->d_sb);
421 	unsigned char blockbits;
422 	unsigned long blockres;
423 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
424 	struct nfs_fsstat res;
425 	int error = -ENOMEM;
426 
427 	res.fattr = nfs_alloc_fattr();
428 	if (res.fattr == NULL)
429 		goto out_err;
430 
431 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
432 	if (unlikely(error == -ESTALE)) {
433 		struct dentry *pd_dentry;
434 
435 		pd_dentry = dget_parent(dentry);
436 		if (pd_dentry != NULL) {
437 			nfs_zap_caches(pd_dentry->d_inode);
438 			dput(pd_dentry);
439 		}
440 	}
441 	nfs_free_fattr(res.fattr);
442 	if (error < 0)
443 		goto out_err;
444 
445 	buf->f_type = NFS_SUPER_MAGIC;
446 
447 	/*
448 	 * Current versions of glibc do not correctly handle the
449 	 * case where f_frsize != f_bsize.  Eventually we want to
450 	 * report the value of wtmult in this field.
451 	 */
452 	buf->f_frsize = dentry->d_sb->s_blocksize;
453 
454 	/*
455 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
456 	 * are reported in units of f_frsize.  Linux hasn't had
457 	 * an f_frsize field in its statfs struct until recently,
458 	 * thus historically Linux's sys_statfs reports these
459 	 * fields in units of f_bsize.
460 	 */
461 	buf->f_bsize = dentry->d_sb->s_blocksize;
462 	blockbits = dentry->d_sb->s_blocksize_bits;
463 	blockres = (1 << blockbits) - 1;
464 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
465 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
466 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
467 
468 	buf->f_files = res.tfiles;
469 	buf->f_ffree = res.afiles;
470 
471 	buf->f_namelen = server->namelen;
472 
473 	return 0;
474 
475  out_err:
476 	dprintk("%s: statfs error = %d\n", __func__, -error);
477 	return error;
478 }
479 EXPORT_SYMBOL_GPL(nfs_statfs);
480 
481 /*
482  * Map the security flavour number to a name
483  */
484 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
485 {
486 	static const struct {
487 		rpc_authflavor_t flavour;
488 		const char *str;
489 	} sec_flavours[] = {
490 		{ RPC_AUTH_NULL, "null" },
491 		{ RPC_AUTH_UNIX, "sys" },
492 		{ RPC_AUTH_GSS_KRB5, "krb5" },
493 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
494 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
495 		{ RPC_AUTH_GSS_LKEY, "lkey" },
496 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
497 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
498 		{ RPC_AUTH_GSS_SPKM, "spkm" },
499 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
500 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
501 		{ UINT_MAX, "unknown" }
502 	};
503 	int i;
504 
505 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
506 		if (sec_flavours[i].flavour == flavour)
507 			break;
508 	}
509 	return sec_flavours[i].str;
510 }
511 
512 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
513 				  int showdefaults)
514 {
515 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
516 
517 	seq_printf(m, ",mountproto=");
518 	switch (sap->sa_family) {
519 	case AF_INET:
520 		switch (nfss->mountd_protocol) {
521 		case IPPROTO_UDP:
522 			seq_printf(m, RPCBIND_NETID_UDP);
523 			break;
524 		case IPPROTO_TCP:
525 			seq_printf(m, RPCBIND_NETID_TCP);
526 			break;
527 		default:
528 			if (showdefaults)
529 				seq_printf(m, "auto");
530 		}
531 		break;
532 	case AF_INET6:
533 		switch (nfss->mountd_protocol) {
534 		case IPPROTO_UDP:
535 			seq_printf(m, RPCBIND_NETID_UDP6);
536 			break;
537 		case IPPROTO_TCP:
538 			seq_printf(m, RPCBIND_NETID_TCP6);
539 			break;
540 		default:
541 			if (showdefaults)
542 				seq_printf(m, "auto");
543 		}
544 		break;
545 	default:
546 		if (showdefaults)
547 			seq_printf(m, "auto");
548 	}
549 }
550 
551 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
552 				    int showdefaults)
553 {
554 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
555 
556 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
557 		return;
558 
559 	switch (sap->sa_family) {
560 	case AF_INET: {
561 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
562 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
563 		break;
564 	}
565 	case AF_INET6: {
566 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
567 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
568 		break;
569 	}
570 	default:
571 		if (showdefaults)
572 			seq_printf(m, ",mountaddr=unspecified");
573 	}
574 
575 	if (nfss->mountd_version || showdefaults)
576 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
577 	if ((nfss->mountd_port &&
578 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
579 		showdefaults)
580 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
581 
582 	nfs_show_mountd_netid(m, nfss, showdefaults);
583 }
584 
585 #if IS_ENABLED(CONFIG_NFS_V4)
586 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
587 				    int showdefaults)
588 {
589 	struct nfs_client *clp = nfss->nfs_client;
590 
591 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
592 }
593 #else
594 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
595 				    int showdefaults)
596 {
597 }
598 #endif
599 
600 static void nfs_show_nfs_version(struct seq_file *m,
601 		unsigned int version,
602 		unsigned int minorversion)
603 {
604 	seq_printf(m, ",vers=%u", version);
605 	if (version == 4)
606 		seq_printf(m, ".%u", minorversion);
607 }
608 
609 /*
610  * Describe the mount options in force on this server representation
611  */
612 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
613 				   int showdefaults)
614 {
615 	static const struct proc_nfs_info {
616 		int flag;
617 		const char *str;
618 		const char *nostr;
619 	} nfs_info[] = {
620 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
621 		{ NFS_MOUNT_POSIX, ",posix", "" },
622 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
623 		{ NFS_MOUNT_NOAC, ",noac", "" },
624 		{ NFS_MOUNT_NONLM, ",nolock", "" },
625 		{ NFS_MOUNT_NOACL, ",noacl", "" },
626 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
627 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
628 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
629 		{ 0, NULL, NULL }
630 	};
631 	const struct proc_nfs_info *nfs_infop;
632 	struct nfs_client *clp = nfss->nfs_client;
633 	u32 version = clp->rpc_ops->version;
634 	int local_flock, local_fcntl;
635 
636 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
637 	seq_printf(m, ",rsize=%u", nfss->rsize);
638 	seq_printf(m, ",wsize=%u", nfss->wsize);
639 	if (nfss->bsize != 0)
640 		seq_printf(m, ",bsize=%u", nfss->bsize);
641 	seq_printf(m, ",namlen=%u", nfss->namelen);
642 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
643 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
644 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
645 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
646 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
647 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
648 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
649 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
650 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
651 		if (nfss->flags & nfs_infop->flag)
652 			seq_puts(m, nfs_infop->str);
653 		else
654 			seq_puts(m, nfs_infop->nostr);
655 	}
656 	rcu_read_lock();
657 	seq_printf(m, ",proto=%s",
658 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
659 	rcu_read_unlock();
660 	if (version == 4) {
661 		if (nfss->port != NFS_PORT)
662 			seq_printf(m, ",port=%u", nfss->port);
663 	} else
664 		if (nfss->port)
665 			seq_printf(m, ",port=%u", nfss->port);
666 
667 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
668 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
669 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
670 
671 	if (version != 4)
672 		nfs_show_mountd_options(m, nfss, showdefaults);
673 	else
674 		nfs_show_nfsv4_options(m, nfss, showdefaults);
675 
676 	if (nfss->options & NFS_OPTION_FSCACHE)
677 		seq_printf(m, ",fsc");
678 
679 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
680 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
681 			seq_printf(m, ",lookupcache=none");
682 		else
683 			seq_printf(m, ",lookupcache=pos");
684 	}
685 
686 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
687 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
688 
689 	if (!local_flock && !local_fcntl)
690 		seq_printf(m, ",local_lock=none");
691 	else if (local_flock && local_fcntl)
692 		seq_printf(m, ",local_lock=all");
693 	else if (local_flock)
694 		seq_printf(m, ",local_lock=flock");
695 	else
696 		seq_printf(m, ",local_lock=posix");
697 }
698 
699 /*
700  * Describe the mount options on this VFS mountpoint
701  */
702 int nfs_show_options(struct seq_file *m, struct dentry *root)
703 {
704 	struct nfs_server *nfss = NFS_SB(root->d_sb);
705 
706 	nfs_show_mount_options(m, nfss, 0);
707 
708 	rcu_read_lock();
709 	seq_printf(m, ",addr=%s",
710 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
711 							RPC_DISPLAY_ADDR));
712 	rcu_read_unlock();
713 
714 	return 0;
715 }
716 EXPORT_SYMBOL_GPL(nfs_show_options);
717 
718 #if IS_ENABLED(CONFIG_NFS_V4)
719 #ifdef CONFIG_NFS_V4_1
720 static void show_sessions(struct seq_file *m, struct nfs_server *server)
721 {
722 	if (nfs4_has_session(server->nfs_client))
723 		seq_printf(m, ",sessions");
724 }
725 #else
726 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
727 #endif
728 #endif
729 
730 #ifdef CONFIG_NFS_V4_1
731 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
732 {
733 	seq_printf(m, ",pnfs=");
734 	if (server->pnfs_curr_ld)
735 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
736 	else
737 		seq_printf(m, "not configured");
738 }
739 
740 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
741 {
742 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
743 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
744 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
745 			   "date='%llu,%u'",
746 			   impl_id->name, impl_id->domain,
747 			   impl_id->date.seconds, impl_id->date.nseconds);
748 	}
749 }
750 #else
751 #if IS_ENABLED(CONFIG_NFS_V4)
752 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
753 {
754 }
755 #endif
756 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
757 {
758 }
759 #endif
760 
761 int nfs_show_devname(struct seq_file *m, struct dentry *root)
762 {
763 	char *page = (char *) __get_free_page(GFP_KERNEL);
764 	char *devname, *dummy;
765 	int err = 0;
766 	if (!page)
767 		return -ENOMEM;
768 	devname = nfs_path(&dummy, root, page, PAGE_SIZE);
769 	if (IS_ERR(devname))
770 		err = PTR_ERR(devname);
771 	else
772 		seq_escape(m, devname, " \t\n\\");
773 	free_page((unsigned long)page);
774 	return err;
775 }
776 EXPORT_SYMBOL_GPL(nfs_show_devname);
777 
778 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
779 {
780 	seq_puts(m, "/");
781 	return 0;
782 }
783 EXPORT_SYMBOL_GPL(nfs_show_path);
784 
785 /*
786  * Present statistical information for this VFS mountpoint
787  */
788 int nfs_show_stats(struct seq_file *m, struct dentry *root)
789 {
790 	int i, cpu;
791 	struct nfs_server *nfss = NFS_SB(root->d_sb);
792 	struct rpc_auth *auth = nfss->client->cl_auth;
793 	struct nfs_iostats totals = { };
794 
795 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
796 
797 	/*
798 	 * Display all mount option settings
799 	 */
800 	seq_printf(m, "\n\topts:\t");
801 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
802 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
803 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
804 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
805 	nfs_show_mount_options(m, nfss, 1);
806 
807 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
808 
809 	show_implementation_id(m, nfss);
810 
811 	seq_printf(m, "\n\tcaps:\t");
812 	seq_printf(m, "caps=0x%x", nfss->caps);
813 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
814 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
815 	seq_printf(m, ",bsize=%u", nfss->bsize);
816 	seq_printf(m, ",namlen=%u", nfss->namelen);
817 
818 #if IS_ENABLED(CONFIG_NFS_V4)
819 	if (nfss->nfs_client->rpc_ops->version == 4) {
820 		seq_printf(m, "\n\tnfsv4:\t");
821 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
822 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
823 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
824 		show_sessions(m, nfss);
825 		show_pnfs(m, nfss);
826 	}
827 #endif
828 
829 	/*
830 	 * Display security flavor in effect for this mount
831 	 */
832 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
833 	if (auth->au_flavor)
834 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
835 
836 	/*
837 	 * Display superblock I/O counters
838 	 */
839 	for_each_possible_cpu(cpu) {
840 		struct nfs_iostats *stats;
841 
842 		preempt_disable();
843 		stats = per_cpu_ptr(nfss->io_stats, cpu);
844 
845 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
846 			totals.events[i] += stats->events[i];
847 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
848 			totals.bytes[i] += stats->bytes[i];
849 #ifdef CONFIG_NFS_FSCACHE
850 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
851 			totals.fscache[i] += stats->fscache[i];
852 #endif
853 
854 		preempt_enable();
855 	}
856 
857 	seq_printf(m, "\n\tevents:\t");
858 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
859 		seq_printf(m, "%lu ", totals.events[i]);
860 	seq_printf(m, "\n\tbytes:\t");
861 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
862 		seq_printf(m, "%Lu ", totals.bytes[i]);
863 #ifdef CONFIG_NFS_FSCACHE
864 	if (nfss->options & NFS_OPTION_FSCACHE) {
865 		seq_printf(m, "\n\tfsc:\t");
866 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
867 			seq_printf(m, "%Lu ", totals.bytes[i]);
868 	}
869 #endif
870 	seq_printf(m, "\n");
871 
872 	rpc_print_iostats(m, nfss->client);
873 
874 	return 0;
875 }
876 EXPORT_SYMBOL_GPL(nfs_show_stats);
877 
878 /*
879  * Begin unmount by attempting to remove all automounted mountpoints we added
880  * in response to xdev traversals and referrals
881  */
882 void nfs_umount_begin(struct super_block *sb)
883 {
884 	struct nfs_server *server;
885 	struct rpc_clnt *rpc;
886 
887 	server = NFS_SB(sb);
888 	/* -EIO all pending I/O */
889 	rpc = server->client_acl;
890 	if (!IS_ERR(rpc))
891 		rpc_killall_tasks(rpc);
892 	rpc = server->client;
893 	if (!IS_ERR(rpc))
894 		rpc_killall_tasks(rpc);
895 }
896 EXPORT_SYMBOL_GPL(nfs_umount_begin);
897 
898 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
899 {
900 	struct nfs_parsed_mount_data *data;
901 
902 	data = kzalloc(sizeof(*data), GFP_KERNEL);
903 	if (data) {
904 		data->acregmin		= NFS_DEF_ACREGMIN;
905 		data->acregmax		= NFS_DEF_ACREGMAX;
906 		data->acdirmin		= NFS_DEF_ACDIRMIN;
907 		data->acdirmax		= NFS_DEF_ACDIRMAX;
908 		data->mount_server.port	= NFS_UNSPEC_PORT;
909 		data->nfs_server.port	= NFS_UNSPEC_PORT;
910 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
911 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
912 		data->auth_flavor_len	= 1;
913 		data->minorversion	= 0;
914 		data->need_mount	= true;
915 		data->net		= current->nsproxy->net_ns;
916 		security_init_mnt_opts(&data->lsm_opts);
917 	}
918 	return data;
919 }
920 
921 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
922 {
923 	if (data) {
924 		kfree(data->client_address);
925 		kfree(data->mount_server.hostname);
926 		kfree(data->nfs_server.export_path);
927 		kfree(data->nfs_server.hostname);
928 		kfree(data->fscache_uniq);
929 		security_free_mnt_opts(&data->lsm_opts);
930 		kfree(data);
931 	}
932 }
933 
934 /*
935  * Sanity-check a server address provided by the mount command.
936  *
937  * Address family must be initialized, and address must not be
938  * the ANY address for that family.
939  */
940 static int nfs_verify_server_address(struct sockaddr *addr)
941 {
942 	switch (addr->sa_family) {
943 	case AF_INET: {
944 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
945 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
946 	}
947 	case AF_INET6: {
948 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
949 		return !ipv6_addr_any(sa);
950 	}
951 	}
952 
953 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
954 	return 0;
955 }
956 
957 /*
958  * Select between a default port value and a user-specified port value.
959  * If a zero value is set, then autobind will be used.
960  */
961 static void nfs_set_port(struct sockaddr *sap, int *port,
962 				 const unsigned short default_port)
963 {
964 	if (*port == NFS_UNSPEC_PORT)
965 		*port = default_port;
966 
967 	rpc_set_port(sap, *port);
968 }
969 
970 /*
971  * Sanity check the NFS transport protocol.
972  *
973  */
974 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
975 {
976 	switch (mnt->nfs_server.protocol) {
977 	case XPRT_TRANSPORT_UDP:
978 	case XPRT_TRANSPORT_TCP:
979 	case XPRT_TRANSPORT_RDMA:
980 		break;
981 	default:
982 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
983 	}
984 }
985 
986 /*
987  * For text based NFSv2/v3 mounts, the mount protocol transport default
988  * settings should depend upon the specified NFS transport.
989  */
990 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
991 {
992 	nfs_validate_transport_protocol(mnt);
993 
994 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
995 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
996 			return;
997 	switch (mnt->nfs_server.protocol) {
998 	case XPRT_TRANSPORT_UDP:
999 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1000 		break;
1001 	case XPRT_TRANSPORT_TCP:
1002 	case XPRT_TRANSPORT_RDMA:
1003 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1004 	}
1005 }
1006 
1007 /*
1008  * Parse the value of the 'sec=' option.
1009  */
1010 static int nfs_parse_security_flavors(char *value,
1011 				      struct nfs_parsed_mount_data *mnt)
1012 {
1013 	substring_t args[MAX_OPT_ARGS];
1014 
1015 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1016 
1017 	switch (match_token(value, nfs_secflavor_tokens, args)) {
1018 	case Opt_sec_none:
1019 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
1020 		break;
1021 	case Opt_sec_sys:
1022 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1023 		break;
1024 	case Opt_sec_krb5:
1025 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1026 		break;
1027 	case Opt_sec_krb5i:
1028 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1029 		break;
1030 	case Opt_sec_krb5p:
1031 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1032 		break;
1033 	case Opt_sec_lkey:
1034 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1035 		break;
1036 	case Opt_sec_lkeyi:
1037 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1038 		break;
1039 	case Opt_sec_lkeyp:
1040 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1041 		break;
1042 	case Opt_sec_spkm:
1043 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1044 		break;
1045 	case Opt_sec_spkmi:
1046 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1047 		break;
1048 	case Opt_sec_spkmp:
1049 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1050 		break;
1051 	default:
1052 		return 0;
1053 	}
1054 
1055 	mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1056 	mnt->auth_flavor_len = 1;
1057 	return 1;
1058 }
1059 
1060 static int nfs_parse_version_string(char *string,
1061 		struct nfs_parsed_mount_data *mnt,
1062 		substring_t *args)
1063 {
1064 	mnt->flags &= ~NFS_MOUNT_VER3;
1065 	switch (match_token(string, nfs_vers_tokens, args)) {
1066 	case Opt_vers_2:
1067 		mnt->version = 2;
1068 		break;
1069 	case Opt_vers_3:
1070 		mnt->flags |= NFS_MOUNT_VER3;
1071 		mnt->version = 3;
1072 		break;
1073 	case Opt_vers_4:
1074 		/* Backward compatibility option. In future,
1075 		 * the mount program should always supply
1076 		 * a NFSv4 minor version number.
1077 		 */
1078 		mnt->version = 4;
1079 		break;
1080 	case Opt_vers_4_0:
1081 		mnt->version = 4;
1082 		mnt->minorversion = 0;
1083 		break;
1084 	case Opt_vers_4_1:
1085 		mnt->version = 4;
1086 		mnt->minorversion = 1;
1087 		break;
1088 	default:
1089 		return 0;
1090 	}
1091 	return 1;
1092 }
1093 
1094 static int nfs_get_option_str(substring_t args[], char **option)
1095 {
1096 	kfree(*option);
1097 	*option = match_strdup(args);
1098 	return !option;
1099 }
1100 
1101 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1102 {
1103 	int rc;
1104 	char *string;
1105 
1106 	string = match_strdup(args);
1107 	if (string == NULL)
1108 		return -ENOMEM;
1109 	rc = strict_strtoul(string, 10, option);
1110 	kfree(string);
1111 
1112 	return rc;
1113 }
1114 
1115 /*
1116  * Error-check and convert a string of mount options from user space into
1117  * a data structure.  The whole mount string is processed; bad options are
1118  * skipped as they are encountered.  If there were no errors, return 1;
1119  * otherwise return 0 (zero).
1120  */
1121 static int nfs_parse_mount_options(char *raw,
1122 				   struct nfs_parsed_mount_data *mnt)
1123 {
1124 	char *p, *string, *secdata;
1125 	int rc, sloppy = 0, invalid_option = 0;
1126 	unsigned short protofamily = AF_UNSPEC;
1127 	unsigned short mountfamily = AF_UNSPEC;
1128 
1129 	if (!raw) {
1130 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1131 		return 1;
1132 	}
1133 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1134 
1135 	secdata = alloc_secdata();
1136 	if (!secdata)
1137 		goto out_nomem;
1138 
1139 	rc = security_sb_copy_data(raw, secdata);
1140 	if (rc)
1141 		goto out_security_failure;
1142 
1143 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1144 	if (rc)
1145 		goto out_security_failure;
1146 
1147 	free_secdata(secdata);
1148 
1149 	while ((p = strsep(&raw, ",")) != NULL) {
1150 		substring_t args[MAX_OPT_ARGS];
1151 		unsigned long option;
1152 		int token;
1153 
1154 		if (!*p)
1155 			continue;
1156 
1157 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1158 
1159 		token = match_token(p, nfs_mount_option_tokens, args);
1160 		switch (token) {
1161 
1162 		/*
1163 		 * boolean options:  foo/nofoo
1164 		 */
1165 		case Opt_soft:
1166 			mnt->flags |= NFS_MOUNT_SOFT;
1167 			break;
1168 		case Opt_hard:
1169 			mnt->flags &= ~NFS_MOUNT_SOFT;
1170 			break;
1171 		case Opt_posix:
1172 			mnt->flags |= NFS_MOUNT_POSIX;
1173 			break;
1174 		case Opt_noposix:
1175 			mnt->flags &= ~NFS_MOUNT_POSIX;
1176 			break;
1177 		case Opt_cto:
1178 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1179 			break;
1180 		case Opt_nocto:
1181 			mnt->flags |= NFS_MOUNT_NOCTO;
1182 			break;
1183 		case Opt_ac:
1184 			mnt->flags &= ~NFS_MOUNT_NOAC;
1185 			break;
1186 		case Opt_noac:
1187 			mnt->flags |= NFS_MOUNT_NOAC;
1188 			break;
1189 		case Opt_lock:
1190 			mnt->flags &= ~NFS_MOUNT_NONLM;
1191 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1192 					NFS_MOUNT_LOCAL_FCNTL);
1193 			break;
1194 		case Opt_nolock:
1195 			mnt->flags |= NFS_MOUNT_NONLM;
1196 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1197 				       NFS_MOUNT_LOCAL_FCNTL);
1198 			break;
1199 		case Opt_udp:
1200 			mnt->flags &= ~NFS_MOUNT_TCP;
1201 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1202 			break;
1203 		case Opt_tcp:
1204 			mnt->flags |= NFS_MOUNT_TCP;
1205 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1206 			break;
1207 		case Opt_rdma:
1208 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1209 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1210 			xprt_load_transport(p);
1211 			break;
1212 		case Opt_acl:
1213 			mnt->flags &= ~NFS_MOUNT_NOACL;
1214 			break;
1215 		case Opt_noacl:
1216 			mnt->flags |= NFS_MOUNT_NOACL;
1217 			break;
1218 		case Opt_rdirplus:
1219 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1220 			break;
1221 		case Opt_nordirplus:
1222 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1223 			break;
1224 		case Opt_sharecache:
1225 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1226 			break;
1227 		case Opt_nosharecache:
1228 			mnt->flags |= NFS_MOUNT_UNSHARED;
1229 			break;
1230 		case Opt_resvport:
1231 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1232 			break;
1233 		case Opt_noresvport:
1234 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1235 			break;
1236 		case Opt_fscache:
1237 			mnt->options |= NFS_OPTION_FSCACHE;
1238 			kfree(mnt->fscache_uniq);
1239 			mnt->fscache_uniq = NULL;
1240 			break;
1241 		case Opt_nofscache:
1242 			mnt->options &= ~NFS_OPTION_FSCACHE;
1243 			kfree(mnt->fscache_uniq);
1244 			mnt->fscache_uniq = NULL;
1245 			break;
1246 
1247 		/*
1248 		 * options that take numeric values
1249 		 */
1250 		case Opt_port:
1251 			if (nfs_get_option_ul(args, &option) ||
1252 			    option > USHRT_MAX)
1253 				goto out_invalid_value;
1254 			mnt->nfs_server.port = option;
1255 			break;
1256 		case Opt_rsize:
1257 			if (nfs_get_option_ul(args, &option))
1258 				goto out_invalid_value;
1259 			mnt->rsize = option;
1260 			break;
1261 		case Opt_wsize:
1262 			if (nfs_get_option_ul(args, &option))
1263 				goto out_invalid_value;
1264 			mnt->wsize = option;
1265 			break;
1266 		case Opt_bsize:
1267 			if (nfs_get_option_ul(args, &option))
1268 				goto out_invalid_value;
1269 			mnt->bsize = option;
1270 			break;
1271 		case Opt_timeo:
1272 			if (nfs_get_option_ul(args, &option) || option == 0)
1273 				goto out_invalid_value;
1274 			mnt->timeo = option;
1275 			break;
1276 		case Opt_retrans:
1277 			if (nfs_get_option_ul(args, &option) || option == 0)
1278 				goto out_invalid_value;
1279 			mnt->retrans = option;
1280 			break;
1281 		case Opt_acregmin:
1282 			if (nfs_get_option_ul(args, &option))
1283 				goto out_invalid_value;
1284 			mnt->acregmin = option;
1285 			break;
1286 		case Opt_acregmax:
1287 			if (nfs_get_option_ul(args, &option))
1288 				goto out_invalid_value;
1289 			mnt->acregmax = option;
1290 			break;
1291 		case Opt_acdirmin:
1292 			if (nfs_get_option_ul(args, &option))
1293 				goto out_invalid_value;
1294 			mnt->acdirmin = option;
1295 			break;
1296 		case Opt_acdirmax:
1297 			if (nfs_get_option_ul(args, &option))
1298 				goto out_invalid_value;
1299 			mnt->acdirmax = option;
1300 			break;
1301 		case Opt_actimeo:
1302 			if (nfs_get_option_ul(args, &option))
1303 				goto out_invalid_value;
1304 			mnt->acregmin = mnt->acregmax =
1305 			mnt->acdirmin = mnt->acdirmax = option;
1306 			break;
1307 		case Opt_namelen:
1308 			if (nfs_get_option_ul(args, &option))
1309 				goto out_invalid_value;
1310 			mnt->namlen = option;
1311 			break;
1312 		case Opt_mountport:
1313 			if (nfs_get_option_ul(args, &option) ||
1314 			    option > USHRT_MAX)
1315 				goto out_invalid_value;
1316 			mnt->mount_server.port = option;
1317 			break;
1318 		case Opt_mountvers:
1319 			if (nfs_get_option_ul(args, &option) ||
1320 			    option < NFS_MNT_VERSION ||
1321 			    option > NFS_MNT3_VERSION)
1322 				goto out_invalid_value;
1323 			mnt->mount_server.version = option;
1324 			break;
1325 		case Opt_minorversion:
1326 			if (nfs_get_option_ul(args, &option))
1327 				goto out_invalid_value;
1328 			if (option > NFS4_MAX_MINOR_VERSION)
1329 				goto out_invalid_value;
1330 			mnt->minorversion = option;
1331 			break;
1332 
1333 		/*
1334 		 * options that take text values
1335 		 */
1336 		case Opt_nfsvers:
1337 			string = match_strdup(args);
1338 			if (string == NULL)
1339 				goto out_nomem;
1340 			rc = nfs_parse_version_string(string, mnt, args);
1341 			kfree(string);
1342 			if (!rc)
1343 				goto out_invalid_value;
1344 			break;
1345 		case Opt_sec:
1346 			string = match_strdup(args);
1347 			if (string == NULL)
1348 				goto out_nomem;
1349 			rc = nfs_parse_security_flavors(string, mnt);
1350 			kfree(string);
1351 			if (!rc) {
1352 				dfprintk(MOUNT, "NFS:   unrecognized "
1353 						"security flavor\n");
1354 				return 0;
1355 			}
1356 			break;
1357 		case Opt_proto:
1358 			string = match_strdup(args);
1359 			if (string == NULL)
1360 				goto out_nomem;
1361 			token = match_token(string,
1362 					    nfs_xprt_protocol_tokens, args);
1363 
1364 			protofamily = AF_INET;
1365 			switch (token) {
1366 			case Opt_xprt_udp6:
1367 				protofamily = AF_INET6;
1368 			case Opt_xprt_udp:
1369 				mnt->flags &= ~NFS_MOUNT_TCP;
1370 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1371 				break;
1372 			case Opt_xprt_tcp6:
1373 				protofamily = AF_INET6;
1374 			case Opt_xprt_tcp:
1375 				mnt->flags |= NFS_MOUNT_TCP;
1376 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1377 				break;
1378 			case Opt_xprt_rdma:
1379 				/* vector side protocols to TCP */
1380 				mnt->flags |= NFS_MOUNT_TCP;
1381 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1382 				xprt_load_transport(string);
1383 				break;
1384 			default:
1385 				dfprintk(MOUNT, "NFS:   unrecognized "
1386 						"transport protocol\n");
1387 				kfree(string);
1388 				return 0;
1389 			}
1390 			kfree(string);
1391 			break;
1392 		case Opt_mountproto:
1393 			string = match_strdup(args);
1394 			if (string == NULL)
1395 				goto out_nomem;
1396 			token = match_token(string,
1397 					    nfs_xprt_protocol_tokens, args);
1398 			kfree(string);
1399 
1400 			mountfamily = AF_INET;
1401 			switch (token) {
1402 			case Opt_xprt_udp6:
1403 				mountfamily = AF_INET6;
1404 			case Opt_xprt_udp:
1405 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1406 				break;
1407 			case Opt_xprt_tcp6:
1408 				mountfamily = AF_INET6;
1409 			case Opt_xprt_tcp:
1410 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1411 				break;
1412 			case Opt_xprt_rdma: /* not used for side protocols */
1413 			default:
1414 				dfprintk(MOUNT, "NFS:   unrecognized "
1415 						"transport protocol\n");
1416 				return 0;
1417 			}
1418 			break;
1419 		case Opt_addr:
1420 			string = match_strdup(args);
1421 			if (string == NULL)
1422 				goto out_nomem;
1423 			mnt->nfs_server.addrlen =
1424 				rpc_pton(mnt->net, string, strlen(string),
1425 					(struct sockaddr *)
1426 					&mnt->nfs_server.address,
1427 					sizeof(mnt->nfs_server.address));
1428 			kfree(string);
1429 			if (mnt->nfs_server.addrlen == 0)
1430 				goto out_invalid_address;
1431 			break;
1432 		case Opt_clientaddr:
1433 			if (nfs_get_option_str(args, &mnt->client_address))
1434 				goto out_nomem;
1435 			break;
1436 		case Opt_mounthost:
1437 			if (nfs_get_option_str(args,
1438 					       &mnt->mount_server.hostname))
1439 				goto out_nomem;
1440 			break;
1441 		case Opt_mountaddr:
1442 			string = match_strdup(args);
1443 			if (string == NULL)
1444 				goto out_nomem;
1445 			mnt->mount_server.addrlen =
1446 				rpc_pton(mnt->net, string, strlen(string),
1447 					(struct sockaddr *)
1448 					&mnt->mount_server.address,
1449 					sizeof(mnt->mount_server.address));
1450 			kfree(string);
1451 			if (mnt->mount_server.addrlen == 0)
1452 				goto out_invalid_address;
1453 			break;
1454 		case Opt_lookupcache:
1455 			string = match_strdup(args);
1456 			if (string == NULL)
1457 				goto out_nomem;
1458 			token = match_token(string,
1459 					nfs_lookupcache_tokens, args);
1460 			kfree(string);
1461 			switch (token) {
1462 				case Opt_lookupcache_all:
1463 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1464 					break;
1465 				case Opt_lookupcache_positive:
1466 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1467 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1468 					break;
1469 				case Opt_lookupcache_none:
1470 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1471 					break;
1472 				default:
1473 					dfprintk(MOUNT, "NFS:   invalid "
1474 							"lookupcache argument\n");
1475 					return 0;
1476 			};
1477 			break;
1478 		case Opt_fscache_uniq:
1479 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1480 				goto out_nomem;
1481 			mnt->options |= NFS_OPTION_FSCACHE;
1482 			break;
1483 		case Opt_local_lock:
1484 			string = match_strdup(args);
1485 			if (string == NULL)
1486 				goto out_nomem;
1487 			token = match_token(string, nfs_local_lock_tokens,
1488 					args);
1489 			kfree(string);
1490 			switch (token) {
1491 			case Opt_local_lock_all:
1492 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1493 					       NFS_MOUNT_LOCAL_FCNTL);
1494 				break;
1495 			case Opt_local_lock_flock:
1496 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1497 				break;
1498 			case Opt_local_lock_posix:
1499 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1500 				break;
1501 			case Opt_local_lock_none:
1502 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1503 						NFS_MOUNT_LOCAL_FCNTL);
1504 				break;
1505 			default:
1506 				dfprintk(MOUNT, "NFS:	invalid	"
1507 						"local_lock argument\n");
1508 				return 0;
1509 			};
1510 			break;
1511 
1512 		/*
1513 		 * Special options
1514 		 */
1515 		case Opt_sloppy:
1516 			sloppy = 1;
1517 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1518 			break;
1519 		case Opt_userspace:
1520 		case Opt_deprecated:
1521 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1522 					"'%s'\n", p);
1523 			break;
1524 
1525 		default:
1526 			invalid_option = 1;
1527 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1528 					"'%s'\n", p);
1529 		}
1530 	}
1531 
1532 	if (!sloppy && invalid_option)
1533 		return 0;
1534 
1535 	if (mnt->minorversion && mnt->version != 4)
1536 		goto out_minorversion_mismatch;
1537 
1538 	/*
1539 	 * verify that any proto=/mountproto= options match the address
1540 	 * familiies in the addr=/mountaddr= options.
1541 	 */
1542 	if (protofamily != AF_UNSPEC &&
1543 	    protofamily != mnt->nfs_server.address.ss_family)
1544 		goto out_proto_mismatch;
1545 
1546 	if (mountfamily != AF_UNSPEC) {
1547 		if (mnt->mount_server.addrlen) {
1548 			if (mountfamily != mnt->mount_server.address.ss_family)
1549 				goto out_mountproto_mismatch;
1550 		} else {
1551 			if (mountfamily != mnt->nfs_server.address.ss_family)
1552 				goto out_mountproto_mismatch;
1553 		}
1554 	}
1555 
1556 	return 1;
1557 
1558 out_mountproto_mismatch:
1559 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1560 			 "option\n");
1561 	return 0;
1562 out_proto_mismatch:
1563 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1564 	return 0;
1565 out_invalid_address:
1566 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1567 	return 0;
1568 out_invalid_value:
1569 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1570 	return 0;
1571 out_minorversion_mismatch:
1572 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1573 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1574 	return 0;
1575 out_nomem:
1576 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1577 	return 0;
1578 out_security_failure:
1579 	free_secdata(secdata);
1580 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1581 	return 0;
1582 }
1583 
1584 /*
1585  * Match the requested auth flavors with the list returned by
1586  * the server.  Returns zero and sets the mount's authentication
1587  * flavor on success; returns -EACCES if server does not support
1588  * the requested flavor.
1589  */
1590 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1591 			     struct nfs_mount_request *request)
1592 {
1593 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1594 
1595 	/*
1596 	 * Certain releases of Linux's mountd return an empty
1597 	 * flavor list.  To prevent behavioral regression with
1598 	 * these servers (ie. rejecting mounts that used to
1599 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1600 	 * if the returned flavor list is empty.
1601 	 */
1602 	if (server_authlist_len == 0)
1603 		return 0;
1604 
1605 	/*
1606 	 * We avoid sophisticated negotiating here, as there are
1607 	 * plenty of cases where we can get it wrong, providing
1608 	 * either too little or too much security.
1609 	 *
1610 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1611 	 * flavor listed first.  However, some servers list
1612 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1613 	 * preferred default, in args->auth_flavors[0] if user
1614 	 * didn't specify sec= mount option.
1615 	 */
1616 	for (i = 0; i < args->auth_flavor_len; i++)
1617 		for (j = 0; j < server_authlist_len; j++)
1618 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1619 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1620 					request->auth_flavs[j]);
1621 				args->auth_flavors[0] = request->auth_flavs[j];
1622 				return 0;
1623 			}
1624 
1625 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1626 	nfs_umount(request);
1627 	return -EACCES;
1628 }
1629 
1630 /*
1631  * Use the remote server's MOUNT service to request the NFS file handle
1632  * corresponding to the provided path.
1633  */
1634 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1635 			     struct nfs_fh *root_fh)
1636 {
1637 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1638 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1639 	struct nfs_mount_request request = {
1640 		.sap		= (struct sockaddr *)
1641 						&args->mount_server.address,
1642 		.dirpath	= args->nfs_server.export_path,
1643 		.protocol	= args->mount_server.protocol,
1644 		.fh		= root_fh,
1645 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1646 		.auth_flav_len	= &server_authlist_len,
1647 		.auth_flavs	= server_authlist,
1648 		.net		= args->net,
1649 	};
1650 	int status;
1651 
1652 	if (args->mount_server.version == 0) {
1653 		switch (args->version) {
1654 			default:
1655 				args->mount_server.version = NFS_MNT3_VERSION;
1656 				break;
1657 			case 2:
1658 				args->mount_server.version = NFS_MNT_VERSION;
1659 		}
1660 	}
1661 	request.version = args->mount_server.version;
1662 
1663 	if (args->mount_server.hostname)
1664 		request.hostname = args->mount_server.hostname;
1665 	else
1666 		request.hostname = args->nfs_server.hostname;
1667 
1668 	/*
1669 	 * Construct the mount server's address.
1670 	 */
1671 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1672 		memcpy(request.sap, &args->nfs_server.address,
1673 		       args->nfs_server.addrlen);
1674 		args->mount_server.addrlen = args->nfs_server.addrlen;
1675 	}
1676 	request.salen = args->mount_server.addrlen;
1677 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1678 
1679 	/*
1680 	 * Now ask the mount server to map our export path
1681 	 * to a file handle.
1682 	 */
1683 	status = nfs_mount(&request);
1684 	if (status != 0) {
1685 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1686 				request.hostname, status);
1687 		return status;
1688 	}
1689 
1690 	/*
1691 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1692 	 */
1693 	if (args->mount_server.version != NFS_MNT3_VERSION)
1694 		return 0;
1695 	return nfs_walk_authlist(args, &request);
1696 }
1697 
1698 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1699 			     struct nfs_mount_info *mount_info,
1700 			     struct nfs_subversion *nfs_mod)
1701 {
1702 	int status;
1703 	struct nfs_server *server;
1704 
1705 	if (mount_info->parsed->need_mount) {
1706 		status = nfs_request_mount(mount_info->parsed, mount_info->mntfh);
1707 		if (status)
1708 			return ERR_PTR(status);
1709 	}
1710 
1711 	/* Get a volume representation */
1712 	server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1713 	if (IS_ERR(server))
1714 		return ERR_CAST(server);
1715 
1716 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1717 }
1718 EXPORT_SYMBOL_GPL(nfs_try_mount);
1719 
1720 /*
1721  * Split "dev_name" into "hostname:export_path".
1722  *
1723  * The leftmost colon demarks the split between the server's hostname
1724  * and the export path.  If the hostname starts with a left square
1725  * bracket, then it may contain colons.
1726  *
1727  * Note: caller frees hostname and export path, even on error.
1728  */
1729 static int nfs_parse_devname(const char *dev_name,
1730 			     char **hostname, size_t maxnamlen,
1731 			     char **export_path, size_t maxpathlen)
1732 {
1733 	size_t len;
1734 	char *end;
1735 
1736 	/* Is the host name protected with square brakcets? */
1737 	if (*dev_name == '[') {
1738 		end = strchr(++dev_name, ']');
1739 		if (end == NULL || end[1] != ':')
1740 			goto out_bad_devname;
1741 
1742 		len = end - dev_name;
1743 		end++;
1744 	} else {
1745 		char *comma;
1746 
1747 		end = strchr(dev_name, ':');
1748 		if (end == NULL)
1749 			goto out_bad_devname;
1750 		len = end - dev_name;
1751 
1752 		/* kill possible hostname list: not supported */
1753 		comma = strchr(dev_name, ',');
1754 		if (comma != NULL && comma < end)
1755 			*comma = 0;
1756 	}
1757 
1758 	if (len > maxnamlen)
1759 		goto out_hostname;
1760 
1761 	/* N.B. caller will free nfs_server.hostname in all cases */
1762 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1763 	if (*hostname == NULL)
1764 		goto out_nomem;
1765 	len = strlen(++end);
1766 	if (len > maxpathlen)
1767 		goto out_path;
1768 	*export_path = kstrndup(end, len, GFP_KERNEL);
1769 	if (!*export_path)
1770 		goto out_nomem;
1771 
1772 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1773 	return 0;
1774 
1775 out_bad_devname:
1776 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1777 	return -EINVAL;
1778 
1779 out_nomem:
1780 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1781 	return -ENOMEM;
1782 
1783 out_hostname:
1784 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1785 	return -ENAMETOOLONG;
1786 
1787 out_path:
1788 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1789 	return -ENAMETOOLONG;
1790 }
1791 
1792 /*
1793  * Validate the NFS2/NFS3 mount data
1794  * - fills in the mount root filehandle
1795  *
1796  * For option strings, user space handles the following behaviors:
1797  *
1798  * + DNS: mapping server host name to IP address ("addr=" option)
1799  *
1800  * + failure mode: how to behave if a mount request can't be handled
1801  *   immediately ("fg/bg" option)
1802  *
1803  * + retry: how often to retry a mount request ("retry=" option)
1804  *
1805  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1806  *   mountproto=tcp after mountproto=udp, and so on
1807  */
1808 static int nfs23_validate_mount_data(void *options,
1809 				     struct nfs_parsed_mount_data *args,
1810 				     struct nfs_fh *mntfh,
1811 				     const char *dev_name)
1812 {
1813 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1814 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1815 
1816 	if (data == NULL)
1817 		goto out_no_data;
1818 
1819 	args->version = NFS_DEFAULT_VERSION;
1820 	switch (data->version) {
1821 	case 1:
1822 		data->namlen = 0;
1823 	case 2:
1824 		data->bsize = 0;
1825 	case 3:
1826 		if (data->flags & NFS_MOUNT_VER3)
1827 			goto out_no_v3;
1828 		data->root.size = NFS2_FHSIZE;
1829 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1830 	case 4:
1831 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1832 			goto out_no_sec;
1833 	case 5:
1834 		memset(data->context, 0, sizeof(data->context));
1835 	case 6:
1836 		if (data->flags & NFS_MOUNT_VER3) {
1837 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1838 				goto out_invalid_fh;
1839 			mntfh->size = data->root.size;
1840 			args->version = 3;
1841 		} else {
1842 			mntfh->size = NFS2_FHSIZE;
1843 			args->version = 2;
1844 		}
1845 
1846 
1847 		memcpy(mntfh->data, data->root.data, mntfh->size);
1848 		if (mntfh->size < sizeof(mntfh->data))
1849 			memset(mntfh->data + mntfh->size, 0,
1850 			       sizeof(mntfh->data) - mntfh->size);
1851 
1852 		/*
1853 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1854 		 * can deal with.
1855 		 */
1856 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1857 		args->flags		|= NFS_MOUNT_LEGACY_INTERFACE;
1858 		args->rsize		= data->rsize;
1859 		args->wsize		= data->wsize;
1860 		args->timeo		= data->timeo;
1861 		args->retrans		= data->retrans;
1862 		args->acregmin		= data->acregmin;
1863 		args->acregmax		= data->acregmax;
1864 		args->acdirmin		= data->acdirmin;
1865 		args->acdirmax		= data->acdirmax;
1866 		args->need_mount	= false;
1867 
1868 		memcpy(sap, &data->addr, sizeof(data->addr));
1869 		args->nfs_server.addrlen = sizeof(data->addr);
1870 		if (!nfs_verify_server_address(sap))
1871 			goto out_no_address;
1872 
1873 		if (!(data->flags & NFS_MOUNT_TCP))
1874 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1875 		/* N.B. caller will free nfs_server.hostname in all cases */
1876 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1877 		args->namlen		= data->namlen;
1878 		args->bsize		= data->bsize;
1879 
1880 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1881 			args->auth_flavors[0] = data->pseudoflavor;
1882 		if (!args->nfs_server.hostname)
1883 			goto out_nomem;
1884 
1885 		if (!(data->flags & NFS_MOUNT_NONLM))
1886 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1887 					 NFS_MOUNT_LOCAL_FCNTL);
1888 		else
1889 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1890 					NFS_MOUNT_LOCAL_FCNTL);
1891 		/*
1892 		 * The legacy version 6 binary mount data from userspace has a
1893 		 * field used only to transport selinux information into the
1894 		 * the kernel.  To continue to support that functionality we
1895 		 * have a touch of selinux knowledge here in the NFS code. The
1896 		 * userspace code converted context=blah to just blah so we are
1897 		 * converting back to the full string selinux understands.
1898 		 */
1899 		if (data->context[0]){
1900 #ifdef CONFIG_SECURITY_SELINUX
1901 			int rc;
1902 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1903 			if (!opts_str)
1904 				return -ENOMEM;
1905 			strcpy(opts_str, "context=");
1906 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1907 			strcat(opts_str, &data->context[0]);
1908 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1909 			kfree(opts_str);
1910 			if (rc)
1911 				return rc;
1912 #else
1913 			return -EINVAL;
1914 #endif
1915 		}
1916 
1917 		break;
1918 	default:
1919 		return NFS_TEXT_DATA;
1920 	}
1921 
1922 #if !IS_ENABLED(CONFIG_NFS_V3)
1923 	if (args->version == 3)
1924 		goto out_v3_not_compiled;
1925 #endif /* !CONFIG_NFS_V3 */
1926 
1927 	return 0;
1928 
1929 out_no_data:
1930 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1931 	return -EINVAL;
1932 
1933 out_no_v3:
1934 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1935 		 data->version);
1936 	return -EINVAL;
1937 
1938 out_no_sec:
1939 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1940 	return -EINVAL;
1941 
1942 #if !IS_ENABLED(CONFIG_NFS_V3)
1943 out_v3_not_compiled:
1944 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1945 	return -EPROTONOSUPPORT;
1946 #endif /* !CONFIG_NFS_V3 */
1947 
1948 out_nomem:
1949 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1950 	return -ENOMEM;
1951 
1952 out_no_address:
1953 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1954 	return -EINVAL;
1955 
1956 out_invalid_fh:
1957 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1958 	return -EINVAL;
1959 }
1960 
1961 #if IS_ENABLED(CONFIG_NFS_V4)
1962 static int nfs_validate_mount_data(struct file_system_type *fs_type,
1963 				   void *options,
1964 				   struct nfs_parsed_mount_data *args,
1965 				   struct nfs_fh *mntfh,
1966 				   const char *dev_name)
1967 {
1968 	if (fs_type == &nfs_fs_type)
1969 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
1970 	return nfs4_validate_mount_data(options, args, dev_name);
1971 }
1972 #else
1973 static int nfs_validate_mount_data(struct file_system_type *fs_type,
1974 				   void *options,
1975 				   struct nfs_parsed_mount_data *args,
1976 				   struct nfs_fh *mntfh,
1977 				   const char *dev_name)
1978 {
1979 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
1980 }
1981 #endif
1982 
1983 static int nfs_validate_text_mount_data(void *options,
1984 					struct nfs_parsed_mount_data *args,
1985 					const char *dev_name)
1986 {
1987 	int port = 0;
1988 	int max_namelen = PAGE_SIZE;
1989 	int max_pathlen = NFS_MAXPATHLEN;
1990 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1991 
1992 	if (nfs_parse_mount_options((char *)options, args) == 0)
1993 		return -EINVAL;
1994 
1995 	if (!nfs_verify_server_address(sap))
1996 		goto out_no_address;
1997 
1998 	if (args->version == 4) {
1999 #if IS_ENABLED(CONFIG_NFS_V4)
2000 		port = NFS_PORT;
2001 		max_namelen = NFS4_MAXNAMLEN;
2002 		max_pathlen = NFS4_MAXPATHLEN;
2003 		nfs_validate_transport_protocol(args);
2004 		nfs4_validate_mount_flags(args);
2005 #else
2006 		goto out_v4_not_compiled;
2007 #endif /* CONFIG_NFS_V4 */
2008 	} else
2009 		nfs_set_mount_transport_protocol(args);
2010 
2011 	nfs_set_port(sap, &args->nfs_server.port, port);
2012 
2013 	if (args->auth_flavor_len > 1)
2014 		goto out_bad_auth;
2015 
2016 	return nfs_parse_devname(dev_name,
2017 				   &args->nfs_server.hostname,
2018 				   max_namelen,
2019 				   &args->nfs_server.export_path,
2020 				   max_pathlen);
2021 
2022 #if !IS_ENABLED(CONFIG_NFS_V4)
2023 out_v4_not_compiled:
2024 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2025 	return -EPROTONOSUPPORT;
2026 #endif /* !CONFIG_NFS_V4 */
2027 
2028 out_no_address:
2029 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2030 	return -EINVAL;
2031 
2032 out_bad_auth:
2033 	dfprintk(MOUNT, "NFS: Too many RPC auth flavours specified\n");
2034 	return -EINVAL;
2035 }
2036 
2037 static int
2038 nfs_compare_remount_data(struct nfs_server *nfss,
2039 			 struct nfs_parsed_mount_data *data)
2040 {
2041 	if (data->flags != nfss->flags ||
2042 	    data->rsize != nfss->rsize ||
2043 	    data->wsize != nfss->wsize ||
2044 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2045 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2046 	    data->acregmin != nfss->acregmin / HZ ||
2047 	    data->acregmax != nfss->acregmax / HZ ||
2048 	    data->acdirmin != nfss->acdirmin / HZ ||
2049 	    data->acdirmax != nfss->acdirmax / HZ ||
2050 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2051 	    data->nfs_server.port != nfss->port ||
2052 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2053 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2054 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2055 		return -EINVAL;
2056 
2057 	return 0;
2058 }
2059 
2060 int
2061 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2062 {
2063 	int error;
2064 	struct nfs_server *nfss = sb->s_fs_info;
2065 	struct nfs_parsed_mount_data *data;
2066 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2067 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2068 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2069 
2070 	/*
2071 	 * Userspace mount programs that send binary options generally send
2072 	 * them populated with default values. We have no way to know which
2073 	 * ones were explicitly specified. Fall back to legacy behavior and
2074 	 * just return success.
2075 	 */
2076 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2077 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2078 					   options->version <= 6))))
2079 		return 0;
2080 
2081 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2082 	if (data == NULL)
2083 		return -ENOMEM;
2084 
2085 	/* fill out struct with values from existing mount */
2086 	data->flags = nfss->flags;
2087 	data->rsize = nfss->rsize;
2088 	data->wsize = nfss->wsize;
2089 	data->retrans = nfss->client->cl_timeout->to_retries;
2090 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2091 	data->acregmin = nfss->acregmin / HZ;
2092 	data->acregmax = nfss->acregmax / HZ;
2093 	data->acdirmin = nfss->acdirmin / HZ;
2094 	data->acdirmax = nfss->acdirmax / HZ;
2095 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2096 	data->nfs_server.port = nfss->port;
2097 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2098 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2099 		data->nfs_server.addrlen);
2100 
2101 	/* overwrite those values with any that were specified */
2102 	error = nfs_parse_mount_options((char *)options, data);
2103 	if (error < 0)
2104 		goto out;
2105 
2106 	/*
2107 	 * noac is a special case. It implies -o sync, but that's not
2108 	 * necessarily reflected in the mtab options. do_remount_sb
2109 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2110 	 * remount options, so we have to explicitly reset it.
2111 	 */
2112 	if (data->flags & NFS_MOUNT_NOAC)
2113 		*flags |= MS_SYNCHRONOUS;
2114 
2115 	/* compare new mount options with old ones */
2116 	error = nfs_compare_remount_data(nfss, data);
2117 out:
2118 	kfree(data);
2119 	return error;
2120 }
2121 EXPORT_SYMBOL_GPL(nfs_remount);
2122 
2123 /*
2124  * Initialise the common bits of the superblock
2125  */
2126 inline void nfs_initialise_sb(struct super_block *sb)
2127 {
2128 	struct nfs_server *server = NFS_SB(sb);
2129 
2130 	sb->s_magic = NFS_SUPER_MAGIC;
2131 
2132 	/* We probably want something more informative here */
2133 	snprintf(sb->s_id, sizeof(sb->s_id),
2134 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2135 
2136 	if (sb->s_blocksize == 0)
2137 		sb->s_blocksize = nfs_block_bits(server->wsize,
2138 						 &sb->s_blocksize_bits);
2139 
2140 	sb->s_bdi = &server->backing_dev_info;
2141 
2142 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2143 }
2144 
2145 /*
2146  * Finish setting up an NFS2/3 superblock
2147  */
2148 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2149 {
2150 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2151 	struct nfs_server *server = NFS_SB(sb);
2152 
2153 	sb->s_blocksize_bits = 0;
2154 	sb->s_blocksize = 0;
2155 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2156 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2157 	if (data && data->bsize)
2158 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2159 
2160 	if (server->nfs_client->rpc_ops->version != 2) {
2161 		/* The VFS shouldn't apply the umask to mode bits. We will do
2162 		 * so ourselves when necessary.
2163 		 */
2164 		sb->s_flags |= MS_POSIXACL;
2165 		sb->s_time_gran = 1;
2166 	}
2167 
2168  	nfs_initialise_sb(sb);
2169 }
2170 EXPORT_SYMBOL_GPL(nfs_fill_super);
2171 
2172 /*
2173  * Finish setting up a cloned NFS2/3/4 superblock
2174  */
2175 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2176 {
2177 	const struct super_block *old_sb = mount_info->cloned->sb;
2178 	struct nfs_server *server = NFS_SB(sb);
2179 
2180 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2181 	sb->s_blocksize = old_sb->s_blocksize;
2182 	sb->s_maxbytes = old_sb->s_maxbytes;
2183 	sb->s_xattr = old_sb->s_xattr;
2184 	sb->s_op = old_sb->s_op;
2185 	sb->s_time_gran = 1;
2186 
2187 	if (server->nfs_client->rpc_ops->version != 2) {
2188 		/* The VFS shouldn't apply the umask to mode bits. We will do
2189 		 * so ourselves when necessary.
2190 		 */
2191 		sb->s_flags |= MS_POSIXACL;
2192 	}
2193 
2194  	nfs_initialise_sb(sb);
2195 }
2196 
2197 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2198 {
2199 	const struct nfs_server *a = s->s_fs_info;
2200 	const struct rpc_clnt *clnt_a = a->client;
2201 	const struct rpc_clnt *clnt_b = b->client;
2202 
2203 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2204 		goto Ebusy;
2205 	if (a->nfs_client != b->nfs_client)
2206 		goto Ebusy;
2207 	if (a->flags != b->flags)
2208 		goto Ebusy;
2209 	if (a->wsize != b->wsize)
2210 		goto Ebusy;
2211 	if (a->rsize != b->rsize)
2212 		goto Ebusy;
2213 	if (a->acregmin != b->acregmin)
2214 		goto Ebusy;
2215 	if (a->acregmax != b->acregmax)
2216 		goto Ebusy;
2217 	if (a->acdirmin != b->acdirmin)
2218 		goto Ebusy;
2219 	if (a->acdirmax != b->acdirmax)
2220 		goto Ebusy;
2221 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2222 		goto Ebusy;
2223 	return 1;
2224 Ebusy:
2225 	return 0;
2226 }
2227 
2228 struct nfs_sb_mountdata {
2229 	struct nfs_server *server;
2230 	int mntflags;
2231 };
2232 
2233 static int nfs_set_super(struct super_block *s, void *data)
2234 {
2235 	struct nfs_sb_mountdata *sb_mntdata = data;
2236 	struct nfs_server *server = sb_mntdata->server;
2237 	int ret;
2238 
2239 	s->s_flags = sb_mntdata->mntflags;
2240 	s->s_fs_info = server;
2241 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2242 	ret = set_anon_super(s, server);
2243 	if (ret == 0)
2244 		server->s_dev = s->s_dev;
2245 	return ret;
2246 }
2247 
2248 static int nfs_compare_super_address(struct nfs_server *server1,
2249 				     struct nfs_server *server2)
2250 {
2251 	struct sockaddr *sap1, *sap2;
2252 
2253 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2254 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2255 
2256 	if (sap1->sa_family != sap2->sa_family)
2257 		return 0;
2258 
2259 	switch (sap1->sa_family) {
2260 	case AF_INET: {
2261 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2262 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2263 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2264 			return 0;
2265 		if (sin1->sin_port != sin2->sin_port)
2266 			return 0;
2267 		break;
2268 	}
2269 	case AF_INET6: {
2270 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2271 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2272 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2273 			return 0;
2274 		if (sin1->sin6_port != sin2->sin6_port)
2275 			return 0;
2276 		break;
2277 	}
2278 	default:
2279 		return 0;
2280 	}
2281 
2282 	return 1;
2283 }
2284 
2285 static int nfs_compare_super(struct super_block *sb, void *data)
2286 {
2287 	struct nfs_sb_mountdata *sb_mntdata = data;
2288 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2289 	int mntflags = sb_mntdata->mntflags;
2290 
2291 	if (!nfs_compare_super_address(old, server))
2292 		return 0;
2293 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2294 	if (old->flags & NFS_MOUNT_UNSHARED)
2295 		return 0;
2296 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2297 		return 0;
2298 	return nfs_compare_mount_options(sb, server, mntflags);
2299 }
2300 
2301 #ifdef CONFIG_NFS_FSCACHE
2302 static void nfs_get_cache_cookie(struct super_block *sb,
2303 				 struct nfs_parsed_mount_data *parsed,
2304 				 struct nfs_clone_mount *cloned)
2305 {
2306 	char *uniq = NULL;
2307 	int ulen = 0;
2308 
2309 	if (parsed && parsed->fscache_uniq) {
2310 		uniq = parsed->fscache_uniq;
2311 		ulen = strlen(parsed->fscache_uniq);
2312 	} else if (cloned) {
2313 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2314 		if (mnt_s->fscache_key) {
2315 			uniq = mnt_s->fscache_key->key.uniquifier;
2316 			ulen = mnt_s->fscache_key->key.uniq_len;
2317 		};
2318 	}
2319 
2320 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2321 }
2322 #else
2323 static void nfs_get_cache_cookie(struct super_block *sb,
2324 				 struct nfs_parsed_mount_data *parsed,
2325 				 struct nfs_clone_mount *cloned)
2326 {
2327 }
2328 #endif
2329 
2330 static int nfs_bdi_register(struct nfs_server *server)
2331 {
2332 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2333 }
2334 
2335 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2336 			struct nfs_mount_info *mount_info)
2337 {
2338 	return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts);
2339 }
2340 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2341 
2342 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2343 			  struct nfs_mount_info *mount_info)
2344 {
2345 	/* clone any lsm security options from the parent to the new sb */
2346 	security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2347 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2348 		return -ESTALE;
2349 	return 0;
2350 }
2351 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2352 
2353 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2354 				   int flags, const char *dev_name,
2355 				   struct nfs_mount_info *mount_info,
2356 				   struct nfs_subversion *nfs_mod)
2357 {
2358 	struct super_block *s;
2359 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2360 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2361 	struct nfs_sb_mountdata sb_mntdata = {
2362 		.mntflags = flags,
2363 		.server = server,
2364 	};
2365 	int error;
2366 
2367 	if (server->flags & NFS_MOUNT_UNSHARED)
2368 		compare_super = NULL;
2369 
2370 	/* -o noac implies -o sync */
2371 	if (server->flags & NFS_MOUNT_NOAC)
2372 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2373 
2374 	/* Get a superblock - note that we may end up sharing one that already exists */
2375 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2376 	if (IS_ERR(s)) {
2377 		mntroot = ERR_CAST(s);
2378 		goto out_err_nosb;
2379 	}
2380 
2381 	if (s->s_fs_info != server) {
2382 		nfs_free_server(server);
2383 		server = NULL;
2384 	} else {
2385 		error = nfs_bdi_register(server);
2386 		if (error) {
2387 			mntroot = ERR_PTR(error);
2388 			goto error_splat_bdi;
2389 		}
2390 	}
2391 
2392 	if (!s->s_root) {
2393 		/* initial superblock/root creation */
2394 		mount_info->fill_super(s, mount_info);
2395 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2396 	}
2397 
2398 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2399 	if (IS_ERR(mntroot))
2400 		goto error_splat_super;
2401 
2402 	error = mount_info->set_security(s, mntroot, mount_info);
2403 	if (error)
2404 		goto error_splat_root;
2405 
2406 	s->s_flags |= MS_ACTIVE;
2407 
2408 out:
2409 	return mntroot;
2410 
2411 out_err_nosb:
2412 	nfs_free_server(server);
2413 	goto out;
2414 
2415 error_splat_root:
2416 	dput(mntroot);
2417 	mntroot = ERR_PTR(error);
2418 error_splat_super:
2419 	if (server && !s->s_root)
2420 		bdi_unregister(&server->backing_dev_info);
2421 error_splat_bdi:
2422 	deactivate_locked_super(s);
2423 	goto out;
2424 }
2425 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2426 
2427 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2428 	int flags, const char *dev_name, void *raw_data)
2429 {
2430 	struct nfs_mount_info mount_info = {
2431 		.fill_super = nfs_fill_super,
2432 		.set_security = nfs_set_sb_security,
2433 	};
2434 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2435 	struct nfs_subversion *nfs_mod;
2436 	int error;
2437 
2438 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2439 	mount_info.mntfh = nfs_alloc_fhandle();
2440 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2441 		goto out;
2442 
2443 	/* Validate the mount data */
2444 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2445 	if (error == NFS_TEXT_DATA)
2446 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2447 	if (error < 0) {
2448 		mntroot = ERR_PTR(error);
2449 		goto out;
2450 	}
2451 
2452 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2453 	if (IS_ERR(nfs_mod)) {
2454 		mntroot = ERR_CAST(nfs_mod);
2455 		goto out;
2456 	}
2457 
2458 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2459 
2460 	put_nfs_version(nfs_mod);
2461 out:
2462 	nfs_free_parsed_mount_data(mount_info.parsed);
2463 	nfs_free_fhandle(mount_info.mntfh);
2464 	return mntroot;
2465 }
2466 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2467 
2468 /*
2469  * Ensure that we unregister the bdi before kill_anon_super
2470  * releases the device name
2471  */
2472 void nfs_put_super(struct super_block *s)
2473 {
2474 	struct nfs_server *server = NFS_SB(s);
2475 
2476 	bdi_unregister(&server->backing_dev_info);
2477 }
2478 EXPORT_SYMBOL_GPL(nfs_put_super);
2479 
2480 /*
2481  * Destroy an NFS2/3 superblock
2482  */
2483 void nfs_kill_super(struct super_block *s)
2484 {
2485 	struct nfs_server *server = NFS_SB(s);
2486 
2487 	kill_anon_super(s);
2488 	nfs_fscache_release_super_cookie(s);
2489 	nfs_free_server(server);
2490 }
2491 EXPORT_SYMBOL_GPL(nfs_kill_super);
2492 
2493 /*
2494  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2495  */
2496 struct dentry *
2497 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2498 		const char *dev_name, void *raw_data)
2499 {
2500 	struct nfs_clone_mount *data = raw_data;
2501 	struct nfs_mount_info mount_info = {
2502 		.fill_super = nfs_clone_super,
2503 		.set_security = nfs_clone_sb_security,
2504 		.cloned = data,
2505 	};
2506 	struct nfs_server *server;
2507 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2508 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2509 	int error;
2510 
2511 	dprintk("--> nfs_xdev_mount_common()\n");
2512 
2513 	mount_info.mntfh = mount_info.cloned->fh;
2514 
2515 	/* create a new volume representation */
2516 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2517 	if (IS_ERR(server)) {
2518 		error = PTR_ERR(server);
2519 		goto out_err;
2520 	}
2521 
2522 	mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, nfs_mod);
2523 	dprintk("<-- nfs_xdev_mount_common() = 0\n");
2524 out:
2525 	return mntroot;
2526 
2527 out_err:
2528 	dprintk("<-- nfs_xdev_mount_common() = %d [error]\n", error);
2529 	goto out;
2530 }
2531 
2532 #if IS_ENABLED(CONFIG_NFS_V4)
2533 
2534 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2535 {
2536 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2537 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2538 }
2539 
2540 /*
2541  * Validate NFSv4 mount options
2542  */
2543 static int nfs4_validate_mount_data(void *options,
2544 				    struct nfs_parsed_mount_data *args,
2545 				    const char *dev_name)
2546 {
2547 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2548 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2549 	char *c;
2550 
2551 	if (data == NULL)
2552 		goto out_no_data;
2553 
2554 	args->version = 4;
2555 
2556 	switch (data->version) {
2557 	case 1:
2558 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2559 			goto out_no_address;
2560 		if (data->host_addrlen == 0)
2561 			goto out_no_address;
2562 		args->nfs_server.addrlen = data->host_addrlen;
2563 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2564 			return -EFAULT;
2565 		if (!nfs_verify_server_address(sap))
2566 			goto out_no_address;
2567 
2568 		if (data->auth_flavourlen) {
2569 			if (data->auth_flavourlen > 1)
2570 				goto out_inval_auth;
2571 			if (copy_from_user(&args->auth_flavors[0],
2572 					   data->auth_flavours,
2573 					   sizeof(args->auth_flavors[0])))
2574 				return -EFAULT;
2575 		}
2576 
2577 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2578 		if (IS_ERR(c))
2579 			return PTR_ERR(c);
2580 		args->nfs_server.hostname = c;
2581 
2582 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2583 		if (IS_ERR(c))
2584 			return PTR_ERR(c);
2585 		args->nfs_server.export_path = c;
2586 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2587 
2588 		c = strndup_user(data->client_addr.data, 16);
2589 		if (IS_ERR(c))
2590 			return PTR_ERR(c);
2591 		args->client_address = c;
2592 
2593 		/*
2594 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2595 		 * can deal with.
2596 		 */
2597 
2598 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2599 		args->rsize	= data->rsize;
2600 		args->wsize	= data->wsize;
2601 		args->timeo	= data->timeo;
2602 		args->retrans	= data->retrans;
2603 		args->acregmin	= data->acregmin;
2604 		args->acregmax	= data->acregmax;
2605 		args->acdirmin	= data->acdirmin;
2606 		args->acdirmax	= data->acdirmax;
2607 		args->nfs_server.protocol = data->proto;
2608 		nfs_validate_transport_protocol(args);
2609 
2610 		break;
2611 	default:
2612 		return NFS_TEXT_DATA;
2613 	}
2614 
2615 	return 0;
2616 
2617 out_no_data:
2618 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2619 	return -EINVAL;
2620 
2621 out_inval_auth:
2622 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2623 		 data->auth_flavourlen);
2624 	return -EINVAL;
2625 
2626 out_no_address:
2627 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2628 	return -EINVAL;
2629 }
2630 
2631 /*
2632  * NFS v4 module parameters need to stay in the
2633  * NFS client for backwards compatibility
2634  */
2635 unsigned int nfs_callback_set_tcpport;
2636 unsigned short nfs_callback_tcpport;
2637 /* Default cache timeout is 10 minutes */
2638 unsigned int nfs_idmap_cache_timeout = 600;
2639 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2640 bool nfs4_disable_idmapping = true;
2641 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2642 unsigned short send_implementation_id = 1;
2643 
2644 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2645 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2646 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2647 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2648 EXPORT_SYMBOL_GPL(max_session_slots);
2649 EXPORT_SYMBOL_GPL(send_implementation_id);
2650 
2651 #define NFS_CALLBACK_MAXPORTNR (65535U)
2652 
2653 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2654 {
2655 	unsigned long num;
2656 	int ret;
2657 
2658 	if (!val)
2659 		return -EINVAL;
2660 	ret = strict_strtoul(val, 0, &num);
2661 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2662 		return -EINVAL;
2663 	*((unsigned int *)kp->arg) = num;
2664 	return 0;
2665 }
2666 static struct kernel_param_ops param_ops_portnr = {
2667 	.set = param_set_portnr,
2668 	.get = param_get_uint,
2669 };
2670 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2671 
2672 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2673 module_param(nfs_idmap_cache_timeout, int, 0644);
2674 module_param(nfs4_disable_idmapping, bool, 0644);
2675 MODULE_PARM_DESC(nfs4_disable_idmapping,
2676 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2677 module_param(max_session_slots, ushort, 0644);
2678 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2679 		"requests the client will negotiate");
2680 module_param(send_implementation_id, ushort, 0644);
2681 MODULE_PARM_DESC(send_implementation_id,
2682 		"Send implementation ID with NFSv4.1 exchange_id");
2683 MODULE_ALIAS("nfs4");
2684 
2685 #endif /* CONFIG_NFS_V4 */
2686