xref: /linux/fs/nfs/super.c (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
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/addr.h>
35 #include <linux/sunrpc/stats.h>
36 #include <linux/sunrpc/metrics.h>
37 #include <linux/sunrpc/xprtsock.h>
38 #include <linux/sunrpc/xprtrdma.h>
39 #include <linux/nfs_fs.h>
40 #include <linux/nfs_mount.h>
41 #include <linux/nfs4_mount.h>
42 #include <linux/lockd/bind.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/namei.h>
46 #include <linux/nfs_idmap.h>
47 #include <linux/vfs.h>
48 #include <linux/inet.h>
49 #include <linux/in6.h>
50 #include <linux/slab.h>
51 #include <net/ipv6.h>
52 #include <linux/netdevice.h>
53 #include <linux/nfs_xdr.h>
54 #include <linux/magic.h>
55 #include <linux/parser.h>
56 #include <linux/nsproxy.h>
57 #include <linux/rcupdate.h>
58 
59 #include <asm/uaccess.h>
60 
61 #include "nfs4_fs.h"
62 #include "callback.h"
63 #include "delegation.h"
64 #include "iostat.h"
65 #include "internal.h"
66 #include "fscache.h"
67 #include "nfs4session.h"
68 #include "pnfs.h"
69 #include "nfs.h"
70 
71 #define NFSDBG_FACILITY		NFSDBG_VFS
72 #define NFS_TEXT_DATA		1
73 
74 #if IS_ENABLED(CONFIG_NFS_V3)
75 #define NFS_DEFAULT_VERSION 3
76 #else
77 #define NFS_DEFAULT_VERSION 2
78 #endif
79 
80 enum {
81 	/* Mount options that take no arguments */
82 	Opt_soft, Opt_hard,
83 	Opt_posix, Opt_noposix,
84 	Opt_cto, Opt_nocto,
85 	Opt_ac, Opt_noac,
86 	Opt_lock, Opt_nolock,
87 	Opt_udp, Opt_tcp, Opt_rdma,
88 	Opt_acl, Opt_noacl,
89 	Opt_rdirplus, Opt_nordirplus,
90 	Opt_sharecache, Opt_nosharecache,
91 	Opt_resvport, Opt_noresvport,
92 	Opt_fscache, Opt_nofscache,
93 	Opt_migration, Opt_nomigration,
94 
95 	/* Mount options that take integer arguments */
96 	Opt_port,
97 	Opt_rsize, Opt_wsize, Opt_bsize,
98 	Opt_timeo, Opt_retrans,
99 	Opt_acregmin, Opt_acregmax,
100 	Opt_acdirmin, Opt_acdirmax,
101 	Opt_actimeo,
102 	Opt_namelen,
103 	Opt_mountport,
104 	Opt_mountvers,
105 	Opt_minorversion,
106 
107 	/* Mount options that take string arguments */
108 	Opt_nfsvers,
109 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
110 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
111 	Opt_lookupcache,
112 	Opt_fscache_uniq,
113 	Opt_local_lock,
114 
115 	/* Special mount options */
116 	Opt_userspace, Opt_deprecated, Opt_sloppy,
117 
118 	Opt_err
119 };
120 
121 static const match_table_t nfs_mount_option_tokens = {
122 	{ Opt_userspace, "bg" },
123 	{ Opt_userspace, "fg" },
124 	{ Opt_userspace, "retry=%s" },
125 
126 	{ Opt_sloppy, "sloppy" },
127 
128 	{ Opt_soft, "soft" },
129 	{ Opt_hard, "hard" },
130 	{ Opt_deprecated, "intr" },
131 	{ Opt_deprecated, "nointr" },
132 	{ Opt_posix, "posix" },
133 	{ Opt_noposix, "noposix" },
134 	{ Opt_cto, "cto" },
135 	{ Opt_nocto, "nocto" },
136 	{ Opt_ac, "ac" },
137 	{ Opt_noac, "noac" },
138 	{ Opt_lock, "lock" },
139 	{ Opt_nolock, "nolock" },
140 	{ Opt_udp, "udp" },
141 	{ Opt_tcp, "tcp" },
142 	{ Opt_rdma, "rdma" },
143 	{ Opt_acl, "acl" },
144 	{ Opt_noacl, "noacl" },
145 	{ Opt_rdirplus, "rdirplus" },
146 	{ Opt_nordirplus, "nordirplus" },
147 	{ Opt_sharecache, "sharecache" },
148 	{ Opt_nosharecache, "nosharecache" },
149 	{ Opt_resvport, "resvport" },
150 	{ Opt_noresvport, "noresvport" },
151 	{ Opt_fscache, "fsc" },
152 	{ Opt_nofscache, "nofsc" },
153 	{ Opt_migration, "migration" },
154 	{ Opt_nomigration, "nomigration" },
155 
156 	{ Opt_port, "port=%s" },
157 	{ Opt_rsize, "rsize=%s" },
158 	{ Opt_wsize, "wsize=%s" },
159 	{ Opt_bsize, "bsize=%s" },
160 	{ Opt_timeo, "timeo=%s" },
161 	{ Opt_retrans, "retrans=%s" },
162 	{ Opt_acregmin, "acregmin=%s" },
163 	{ Opt_acregmax, "acregmax=%s" },
164 	{ Opt_acdirmin, "acdirmin=%s" },
165 	{ Opt_acdirmax, "acdirmax=%s" },
166 	{ Opt_actimeo, "actimeo=%s" },
167 	{ Opt_namelen, "namlen=%s" },
168 	{ Opt_mountport, "mountport=%s" },
169 	{ Opt_mountvers, "mountvers=%s" },
170 	{ Opt_minorversion, "minorversion=%s" },
171 
172 	{ Opt_nfsvers, "nfsvers=%s" },
173 	{ Opt_nfsvers, "vers=%s" },
174 
175 	{ Opt_sec, "sec=%s" },
176 	{ Opt_proto, "proto=%s" },
177 	{ Opt_mountproto, "mountproto=%s" },
178 	{ Opt_addr, "addr=%s" },
179 	{ Opt_clientaddr, "clientaddr=%s" },
180 	{ Opt_mounthost, "mounthost=%s" },
181 	{ Opt_mountaddr, "mountaddr=%s" },
182 
183 	{ Opt_lookupcache, "lookupcache=%s" },
184 	{ Opt_fscache_uniq, "fsc=%s" },
185 	{ Opt_local_lock, "local_lock=%s" },
186 
187 	/* The following needs to be listed after all other options */
188 	{ Opt_nfsvers, "v%s" },
189 
190 	{ Opt_err, NULL }
191 };
192 
193 enum {
194 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
195 
196 	Opt_xprt_err
197 };
198 
199 static const match_table_t nfs_xprt_protocol_tokens = {
200 	{ Opt_xprt_udp, "udp" },
201 	{ Opt_xprt_udp6, "udp6" },
202 	{ Opt_xprt_tcp, "tcp" },
203 	{ Opt_xprt_tcp6, "tcp6" },
204 	{ Opt_xprt_rdma, "rdma" },
205 
206 	{ Opt_xprt_err, NULL }
207 };
208 
209 enum {
210 	Opt_sec_none, Opt_sec_sys,
211 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
212 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
213 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
214 
215 	Opt_sec_err
216 };
217 
218 static const match_table_t nfs_secflavor_tokens = {
219 	{ Opt_sec_none, "none" },
220 	{ Opt_sec_none, "null" },
221 	{ Opt_sec_sys, "sys" },
222 
223 	{ Opt_sec_krb5, "krb5" },
224 	{ Opt_sec_krb5i, "krb5i" },
225 	{ Opt_sec_krb5p, "krb5p" },
226 
227 	{ Opt_sec_lkey, "lkey" },
228 	{ Opt_sec_lkeyi, "lkeyi" },
229 	{ Opt_sec_lkeyp, "lkeyp" },
230 
231 	{ Opt_sec_spkm, "spkm3" },
232 	{ Opt_sec_spkmi, "spkm3i" },
233 	{ Opt_sec_spkmp, "spkm3p" },
234 
235 	{ Opt_sec_err, NULL }
236 };
237 
238 enum {
239 	Opt_lookupcache_all, Opt_lookupcache_positive,
240 	Opt_lookupcache_none,
241 
242 	Opt_lookupcache_err
243 };
244 
245 static match_table_t nfs_lookupcache_tokens = {
246 	{ Opt_lookupcache_all, "all" },
247 	{ Opt_lookupcache_positive, "pos" },
248 	{ Opt_lookupcache_positive, "positive" },
249 	{ Opt_lookupcache_none, "none" },
250 
251 	{ Opt_lookupcache_err, NULL }
252 };
253 
254 enum {
255 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
256 	Opt_local_lock_none,
257 
258 	Opt_local_lock_err
259 };
260 
261 static match_table_t nfs_local_lock_tokens = {
262 	{ Opt_local_lock_all, "all" },
263 	{ Opt_local_lock_flock, "flock" },
264 	{ Opt_local_lock_posix, "posix" },
265 	{ Opt_local_lock_none, "none" },
266 
267 	{ Opt_local_lock_err, NULL }
268 };
269 
270 enum {
271 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
272 	Opt_vers_4_1, Opt_vers_4_2,
273 
274 	Opt_vers_err
275 };
276 
277 static match_table_t nfs_vers_tokens = {
278 	{ Opt_vers_2, "2" },
279 	{ Opt_vers_3, "3" },
280 	{ Opt_vers_4, "4" },
281 	{ Opt_vers_4_0, "4.0" },
282 	{ Opt_vers_4_1, "4.1" },
283 	{ Opt_vers_4_2, "4.2" },
284 
285 	{ Opt_vers_err, NULL }
286 };
287 
288 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
289 		int flags, const char *dev_name, void *raw_data);
290 
291 struct file_system_type nfs_fs_type = {
292 	.owner		= THIS_MODULE,
293 	.name		= "nfs",
294 	.mount		= nfs_fs_mount,
295 	.kill_sb	= nfs_kill_super,
296 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
297 };
298 MODULE_ALIAS_FS("nfs");
299 EXPORT_SYMBOL_GPL(nfs_fs_type);
300 
301 struct file_system_type nfs_xdev_fs_type = {
302 	.owner		= THIS_MODULE,
303 	.name		= "nfs",
304 	.mount		= nfs_xdev_mount,
305 	.kill_sb	= nfs_kill_super,
306 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
307 };
308 
309 const struct super_operations nfs_sops = {
310 	.alloc_inode	= nfs_alloc_inode,
311 	.destroy_inode	= nfs_destroy_inode,
312 	.write_inode	= nfs_write_inode,
313 	.drop_inode	= nfs_drop_inode,
314 	.put_super	= nfs_put_super,
315 	.statfs		= nfs_statfs,
316 	.evict_inode	= nfs_evict_inode,
317 	.umount_begin	= nfs_umount_begin,
318 	.show_options	= nfs_show_options,
319 	.show_devname	= nfs_show_devname,
320 	.show_path	= nfs_show_path,
321 	.show_stats	= nfs_show_stats,
322 	.remount_fs	= nfs_remount,
323 };
324 EXPORT_SYMBOL_GPL(nfs_sops);
325 
326 #if IS_ENABLED(CONFIG_NFS_V4)
327 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
328 static int nfs4_validate_mount_data(void *options,
329 	struct nfs_parsed_mount_data *args, const char *dev_name);
330 
331 struct file_system_type nfs4_fs_type = {
332 	.owner		= THIS_MODULE,
333 	.name		= "nfs4",
334 	.mount		= nfs_fs_mount,
335 	.kill_sb	= nfs_kill_super,
336 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
337 };
338 MODULE_ALIAS_FS("nfs4");
339 MODULE_ALIAS("nfs4");
340 EXPORT_SYMBOL_GPL(nfs4_fs_type);
341 
342 static int __init register_nfs4_fs(void)
343 {
344 	return register_filesystem(&nfs4_fs_type);
345 }
346 
347 static void unregister_nfs4_fs(void)
348 {
349 	unregister_filesystem(&nfs4_fs_type);
350 }
351 #else
352 static int __init register_nfs4_fs(void)
353 {
354 	return 0;
355 }
356 
357 static void unregister_nfs4_fs(void)
358 {
359 }
360 #endif
361 
362 static struct shrinker acl_shrinker = {
363 	.count_objects	= nfs_access_cache_count,
364 	.scan_objects	= nfs_access_cache_scan,
365 	.seeks		= DEFAULT_SEEKS,
366 };
367 
368 /*
369  * Register the NFS filesystems
370  */
371 int __init register_nfs_fs(void)
372 {
373 	int ret;
374 
375         ret = register_filesystem(&nfs_fs_type);
376 	if (ret < 0)
377 		goto error_0;
378 
379 	ret = register_nfs4_fs();
380 	if (ret < 0)
381 		goto error_1;
382 
383 	ret = nfs_register_sysctl();
384 	if (ret < 0)
385 		goto error_2;
386 	register_shrinker(&acl_shrinker);
387 	return 0;
388 
389 error_2:
390 	unregister_nfs4_fs();
391 error_1:
392 	unregister_filesystem(&nfs_fs_type);
393 error_0:
394 	return ret;
395 }
396 
397 /*
398  * Unregister the NFS filesystems
399  */
400 void __exit unregister_nfs_fs(void)
401 {
402 	unregister_shrinker(&acl_shrinker);
403 	nfs_unregister_sysctl();
404 	unregister_nfs4_fs();
405 	unregister_filesystem(&nfs_fs_type);
406 }
407 
408 void nfs_sb_active(struct super_block *sb)
409 {
410 	struct nfs_server *server = NFS_SB(sb);
411 
412 	if (atomic_inc_return(&server->active) == 1)
413 		atomic_inc(&sb->s_active);
414 }
415 EXPORT_SYMBOL_GPL(nfs_sb_active);
416 
417 void nfs_sb_deactive(struct super_block *sb)
418 {
419 	struct nfs_server *server = NFS_SB(sb);
420 
421 	if (atomic_dec_and_test(&server->active))
422 		deactivate_super(sb);
423 }
424 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
425 
426 /*
427  * Deliver file system statistics to userspace
428  */
429 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
430 {
431 	struct nfs_server *server = NFS_SB(dentry->d_sb);
432 	unsigned char blockbits;
433 	unsigned long blockres;
434 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
435 	struct nfs_fsstat res;
436 	int error = -ENOMEM;
437 
438 	res.fattr = nfs_alloc_fattr();
439 	if (res.fattr == NULL)
440 		goto out_err;
441 
442 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
443 	if (unlikely(error == -ESTALE)) {
444 		struct dentry *pd_dentry;
445 
446 		pd_dentry = dget_parent(dentry);
447 		if (pd_dentry != NULL) {
448 			nfs_zap_caches(pd_dentry->d_inode);
449 			dput(pd_dentry);
450 		}
451 	}
452 	nfs_free_fattr(res.fattr);
453 	if (error < 0)
454 		goto out_err;
455 
456 	buf->f_type = NFS_SUPER_MAGIC;
457 
458 	/*
459 	 * Current versions of glibc do not correctly handle the
460 	 * case where f_frsize != f_bsize.  Eventually we want to
461 	 * report the value of wtmult in this field.
462 	 */
463 	buf->f_frsize = dentry->d_sb->s_blocksize;
464 
465 	/*
466 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
467 	 * are reported in units of f_frsize.  Linux hasn't had
468 	 * an f_frsize field in its statfs struct until recently,
469 	 * thus historically Linux's sys_statfs reports these
470 	 * fields in units of f_bsize.
471 	 */
472 	buf->f_bsize = dentry->d_sb->s_blocksize;
473 	blockbits = dentry->d_sb->s_blocksize_bits;
474 	blockres = (1 << blockbits) - 1;
475 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
476 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
477 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
478 
479 	buf->f_files = res.tfiles;
480 	buf->f_ffree = res.afiles;
481 
482 	buf->f_namelen = server->namelen;
483 
484 	return 0;
485 
486  out_err:
487 	dprintk("%s: statfs error = %d\n", __func__, -error);
488 	return error;
489 }
490 EXPORT_SYMBOL_GPL(nfs_statfs);
491 
492 /*
493  * Map the security flavour number to a name
494  */
495 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
496 {
497 	static const struct {
498 		rpc_authflavor_t flavour;
499 		const char *str;
500 	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
501 		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
502 		{ RPC_AUTH_NULL, "null" },
503 		{ RPC_AUTH_UNIX, "sys" },
504 		{ RPC_AUTH_GSS_KRB5, "krb5" },
505 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
506 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
507 		{ RPC_AUTH_GSS_LKEY, "lkey" },
508 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
509 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
510 		{ RPC_AUTH_GSS_SPKM, "spkm" },
511 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
512 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
513 		{ UINT_MAX, "unknown" }
514 	};
515 	int i;
516 
517 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
518 		if (sec_flavours[i].flavour == flavour)
519 			break;
520 	}
521 	return sec_flavours[i].str;
522 }
523 
524 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
525 				  int showdefaults)
526 {
527 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
528 
529 	seq_printf(m, ",mountproto=");
530 	switch (sap->sa_family) {
531 	case AF_INET:
532 		switch (nfss->mountd_protocol) {
533 		case IPPROTO_UDP:
534 			seq_printf(m, RPCBIND_NETID_UDP);
535 			break;
536 		case IPPROTO_TCP:
537 			seq_printf(m, RPCBIND_NETID_TCP);
538 			break;
539 		default:
540 			if (showdefaults)
541 				seq_printf(m, "auto");
542 		}
543 		break;
544 	case AF_INET6:
545 		switch (nfss->mountd_protocol) {
546 		case IPPROTO_UDP:
547 			seq_printf(m, RPCBIND_NETID_UDP6);
548 			break;
549 		case IPPROTO_TCP:
550 			seq_printf(m, RPCBIND_NETID_TCP6);
551 			break;
552 		default:
553 			if (showdefaults)
554 				seq_printf(m, "auto");
555 		}
556 		break;
557 	default:
558 		if (showdefaults)
559 			seq_printf(m, "auto");
560 	}
561 }
562 
563 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
564 				    int showdefaults)
565 {
566 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
567 
568 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
569 		return;
570 
571 	switch (sap->sa_family) {
572 	case AF_INET: {
573 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
574 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
575 		break;
576 	}
577 	case AF_INET6: {
578 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
579 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
580 		break;
581 	}
582 	default:
583 		if (showdefaults)
584 			seq_printf(m, ",mountaddr=unspecified");
585 	}
586 
587 	if (nfss->mountd_version || showdefaults)
588 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
589 	if ((nfss->mountd_port &&
590 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
591 		showdefaults)
592 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
593 
594 	nfs_show_mountd_netid(m, nfss, showdefaults);
595 }
596 
597 #if IS_ENABLED(CONFIG_NFS_V4)
598 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
599 				    int showdefaults)
600 {
601 	struct nfs_client *clp = nfss->nfs_client;
602 
603 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
604 }
605 #else
606 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
607 				    int showdefaults)
608 {
609 }
610 #endif
611 
612 static void nfs_show_nfs_version(struct seq_file *m,
613 		unsigned int version,
614 		unsigned int minorversion)
615 {
616 	seq_printf(m, ",vers=%u", version);
617 	if (version == 4)
618 		seq_printf(m, ".%u", minorversion);
619 }
620 
621 /*
622  * Describe the mount options in force on this server representation
623  */
624 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
625 				   int showdefaults)
626 {
627 	static const struct proc_nfs_info {
628 		int flag;
629 		const char *str;
630 		const char *nostr;
631 	} nfs_info[] = {
632 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
633 		{ NFS_MOUNT_POSIX, ",posix", "" },
634 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
635 		{ NFS_MOUNT_NOAC, ",noac", "" },
636 		{ NFS_MOUNT_NONLM, ",nolock", "" },
637 		{ NFS_MOUNT_NOACL, ",noacl", "" },
638 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
639 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
640 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
641 		{ 0, NULL, NULL }
642 	};
643 	const struct proc_nfs_info *nfs_infop;
644 	struct nfs_client *clp = nfss->nfs_client;
645 	u32 version = clp->rpc_ops->version;
646 	int local_flock, local_fcntl;
647 
648 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
649 	seq_printf(m, ",rsize=%u", nfss->rsize);
650 	seq_printf(m, ",wsize=%u", nfss->wsize);
651 	if (nfss->bsize != 0)
652 		seq_printf(m, ",bsize=%u", nfss->bsize);
653 	seq_printf(m, ",namlen=%u", nfss->namelen);
654 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
655 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
656 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
657 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
658 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
659 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
660 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
661 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
662 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
663 		if (nfss->flags & nfs_infop->flag)
664 			seq_puts(m, nfs_infop->str);
665 		else
666 			seq_puts(m, nfs_infop->nostr);
667 	}
668 	rcu_read_lock();
669 	seq_printf(m, ",proto=%s",
670 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
671 	rcu_read_unlock();
672 	if (version == 4) {
673 		if (nfss->port != NFS_PORT)
674 			seq_printf(m, ",port=%u", nfss->port);
675 	} else
676 		if (nfss->port)
677 			seq_printf(m, ",port=%u", nfss->port);
678 
679 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
680 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
681 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
682 
683 	if (version != 4)
684 		nfs_show_mountd_options(m, nfss, showdefaults);
685 	else
686 		nfs_show_nfsv4_options(m, nfss, showdefaults);
687 
688 	if (nfss->options & NFS_OPTION_FSCACHE)
689 		seq_printf(m, ",fsc");
690 
691 	if (nfss->options & NFS_OPTION_MIGRATION)
692 		seq_printf(m, ",migration");
693 
694 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
695 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
696 			seq_printf(m, ",lookupcache=none");
697 		else
698 			seq_printf(m, ",lookupcache=pos");
699 	}
700 
701 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
702 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
703 
704 	if (!local_flock && !local_fcntl)
705 		seq_printf(m, ",local_lock=none");
706 	else if (local_flock && local_fcntl)
707 		seq_printf(m, ",local_lock=all");
708 	else if (local_flock)
709 		seq_printf(m, ",local_lock=flock");
710 	else
711 		seq_printf(m, ",local_lock=posix");
712 }
713 
714 /*
715  * Describe the mount options on this VFS mountpoint
716  */
717 int nfs_show_options(struct seq_file *m, struct dentry *root)
718 {
719 	struct nfs_server *nfss = NFS_SB(root->d_sb);
720 
721 	nfs_show_mount_options(m, nfss, 0);
722 
723 	rcu_read_lock();
724 	seq_printf(m, ",addr=%s",
725 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
726 							RPC_DISPLAY_ADDR));
727 	rcu_read_unlock();
728 
729 	return 0;
730 }
731 EXPORT_SYMBOL_GPL(nfs_show_options);
732 
733 #if IS_ENABLED(CONFIG_NFS_V4)
734 #ifdef CONFIG_NFS_V4_1
735 static void show_sessions(struct seq_file *m, struct nfs_server *server)
736 {
737 	if (nfs4_has_session(server->nfs_client))
738 		seq_printf(m, ",sessions");
739 }
740 #else
741 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
742 #endif
743 #endif
744 
745 #ifdef CONFIG_NFS_V4_1
746 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
747 {
748 	seq_printf(m, ",pnfs=");
749 	if (server->pnfs_curr_ld)
750 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
751 	else
752 		seq_printf(m, "not configured");
753 }
754 
755 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
756 {
757 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
758 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
759 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
760 			   "date='%llu,%u'",
761 			   impl_id->name, impl_id->domain,
762 			   impl_id->date.seconds, impl_id->date.nseconds);
763 	}
764 }
765 #else
766 #if IS_ENABLED(CONFIG_NFS_V4)
767 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
768 {
769 }
770 #endif
771 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
772 {
773 }
774 #endif
775 
776 int nfs_show_devname(struct seq_file *m, struct dentry *root)
777 {
778 	char *page = (char *) __get_free_page(GFP_KERNEL);
779 	char *devname, *dummy;
780 	int err = 0;
781 	if (!page)
782 		return -ENOMEM;
783 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
784 	if (IS_ERR(devname))
785 		err = PTR_ERR(devname);
786 	else
787 		seq_escape(m, devname, " \t\n\\");
788 	free_page((unsigned long)page);
789 	return err;
790 }
791 EXPORT_SYMBOL_GPL(nfs_show_devname);
792 
793 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
794 {
795 	seq_puts(m, "/");
796 	return 0;
797 }
798 EXPORT_SYMBOL_GPL(nfs_show_path);
799 
800 /*
801  * Present statistical information for this VFS mountpoint
802  */
803 int nfs_show_stats(struct seq_file *m, struct dentry *root)
804 {
805 	int i, cpu;
806 	struct nfs_server *nfss = NFS_SB(root->d_sb);
807 	struct rpc_auth *auth = nfss->client->cl_auth;
808 	struct nfs_iostats totals = { };
809 
810 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
811 
812 	/*
813 	 * Display all mount option settings
814 	 */
815 	seq_printf(m, "\n\topts:\t");
816 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
817 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
818 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
819 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
820 	nfs_show_mount_options(m, nfss, 1);
821 
822 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
823 
824 	show_implementation_id(m, nfss);
825 
826 	seq_printf(m, "\n\tcaps:\t");
827 	seq_printf(m, "caps=0x%x", nfss->caps);
828 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
829 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
830 	seq_printf(m, ",bsize=%u", nfss->bsize);
831 	seq_printf(m, ",namlen=%u", nfss->namelen);
832 
833 #if IS_ENABLED(CONFIG_NFS_V4)
834 	if (nfss->nfs_client->rpc_ops->version == 4) {
835 		seq_printf(m, "\n\tnfsv4:\t");
836 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
837 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
838 		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
839 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
840 		show_sessions(m, nfss);
841 		show_pnfs(m, nfss);
842 	}
843 #endif
844 
845 	/*
846 	 * Display security flavor in effect for this mount
847 	 */
848 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
849 	if (auth->au_flavor)
850 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
851 
852 	/*
853 	 * Display superblock I/O counters
854 	 */
855 	for_each_possible_cpu(cpu) {
856 		struct nfs_iostats *stats;
857 
858 		preempt_disable();
859 		stats = per_cpu_ptr(nfss->io_stats, cpu);
860 
861 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
862 			totals.events[i] += stats->events[i];
863 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
864 			totals.bytes[i] += stats->bytes[i];
865 #ifdef CONFIG_NFS_FSCACHE
866 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
867 			totals.fscache[i] += stats->fscache[i];
868 #endif
869 
870 		preempt_enable();
871 	}
872 
873 	seq_printf(m, "\n\tevents:\t");
874 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
875 		seq_printf(m, "%lu ", totals.events[i]);
876 	seq_printf(m, "\n\tbytes:\t");
877 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
878 		seq_printf(m, "%Lu ", totals.bytes[i]);
879 #ifdef CONFIG_NFS_FSCACHE
880 	if (nfss->options & NFS_OPTION_FSCACHE) {
881 		seq_printf(m, "\n\tfsc:\t");
882 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
883 			seq_printf(m, "%Lu ", totals.bytes[i]);
884 	}
885 #endif
886 	seq_printf(m, "\n");
887 
888 	rpc_print_iostats(m, nfss->client);
889 
890 	return 0;
891 }
892 EXPORT_SYMBOL_GPL(nfs_show_stats);
893 
894 /*
895  * Begin unmount by attempting to remove all automounted mountpoints we added
896  * in response to xdev traversals and referrals
897  */
898 void nfs_umount_begin(struct super_block *sb)
899 {
900 	struct nfs_server *server;
901 	struct rpc_clnt *rpc;
902 
903 	server = NFS_SB(sb);
904 	/* -EIO all pending I/O */
905 	rpc = server->client_acl;
906 	if (!IS_ERR(rpc))
907 		rpc_killall_tasks(rpc);
908 	rpc = server->client;
909 	if (!IS_ERR(rpc))
910 		rpc_killall_tasks(rpc);
911 }
912 EXPORT_SYMBOL_GPL(nfs_umount_begin);
913 
914 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
915 {
916 	struct nfs_parsed_mount_data *data;
917 
918 	data = kzalloc(sizeof(*data), GFP_KERNEL);
919 	if (data) {
920 		data->acregmin		= NFS_DEF_ACREGMIN;
921 		data->acregmax		= NFS_DEF_ACREGMAX;
922 		data->acdirmin		= NFS_DEF_ACDIRMIN;
923 		data->acdirmax		= NFS_DEF_ACDIRMAX;
924 		data->mount_server.port	= NFS_UNSPEC_PORT;
925 		data->nfs_server.port	= NFS_UNSPEC_PORT;
926 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
927 		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
928 		data->minorversion	= 0;
929 		data->need_mount	= true;
930 		data->net		= current->nsproxy->net_ns;
931 		security_init_mnt_opts(&data->lsm_opts);
932 	}
933 	return data;
934 }
935 
936 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
937 {
938 	if (data) {
939 		kfree(data->client_address);
940 		kfree(data->mount_server.hostname);
941 		kfree(data->nfs_server.export_path);
942 		kfree(data->nfs_server.hostname);
943 		kfree(data->fscache_uniq);
944 		security_free_mnt_opts(&data->lsm_opts);
945 		kfree(data);
946 	}
947 }
948 
949 /*
950  * Sanity-check a server address provided by the mount command.
951  *
952  * Address family must be initialized, and address must not be
953  * the ANY address for that family.
954  */
955 static int nfs_verify_server_address(struct sockaddr *addr)
956 {
957 	switch (addr->sa_family) {
958 	case AF_INET: {
959 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
960 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
961 	}
962 	case AF_INET6: {
963 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
964 		return !ipv6_addr_any(sa);
965 	}
966 	}
967 
968 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
969 	return 0;
970 }
971 
972 /*
973  * Select between a default port value and a user-specified port value.
974  * If a zero value is set, then autobind will be used.
975  */
976 static void nfs_set_port(struct sockaddr *sap, int *port,
977 				 const unsigned short default_port)
978 {
979 	if (*port == NFS_UNSPEC_PORT)
980 		*port = default_port;
981 
982 	rpc_set_port(sap, *port);
983 }
984 
985 /*
986  * Sanity check the NFS transport protocol.
987  *
988  */
989 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
990 {
991 	switch (mnt->nfs_server.protocol) {
992 	case XPRT_TRANSPORT_UDP:
993 	case XPRT_TRANSPORT_TCP:
994 	case XPRT_TRANSPORT_RDMA:
995 		break;
996 	default:
997 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
998 	}
999 }
1000 
1001 /*
1002  * For text based NFSv2/v3 mounts, the mount protocol transport default
1003  * settings should depend upon the specified NFS transport.
1004  */
1005 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1006 {
1007 	nfs_validate_transport_protocol(mnt);
1008 
1009 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1010 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1011 			return;
1012 	switch (mnt->nfs_server.protocol) {
1013 	case XPRT_TRANSPORT_UDP:
1014 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1015 		break;
1016 	case XPRT_TRANSPORT_TCP:
1017 	case XPRT_TRANSPORT_RDMA:
1018 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1019 	}
1020 }
1021 
1022 /*
1023  * Add 'flavor' to 'auth_info' if not already present.
1024  * Returns true if 'flavor' ends up in the list, false otherwise
1025  */
1026 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1027 			      rpc_authflavor_t flavor)
1028 {
1029 	unsigned int i;
1030 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1031 
1032 	/* make sure this flavor isn't already in the list */
1033 	for (i = 0; i < auth_info->flavor_len; i++) {
1034 		if (flavor == auth_info->flavors[i])
1035 			return true;
1036 	}
1037 
1038 	if (auth_info->flavor_len + 1 >= max_flavor_len) {
1039 		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1040 		return false;
1041 	}
1042 
1043 	auth_info->flavors[auth_info->flavor_len++] = flavor;
1044 	return true;
1045 }
1046 
1047 /*
1048  * Return true if 'match' is in auth_info or auth_info is empty.
1049  * Return false otherwise.
1050  */
1051 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1052 			 rpc_authflavor_t match)
1053 {
1054 	int i;
1055 
1056 	if (!auth_info->flavor_len)
1057 		return true;
1058 
1059 	for (i = 0; i < auth_info->flavor_len; i++) {
1060 		if (auth_info->flavors[i] == match)
1061 			return true;
1062 	}
1063 	return false;
1064 }
1065 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1066 
1067 /*
1068  * Parse the value of the 'sec=' option.
1069  */
1070 static int nfs_parse_security_flavors(char *value,
1071 				      struct nfs_parsed_mount_data *mnt)
1072 {
1073 	substring_t args[MAX_OPT_ARGS];
1074 	rpc_authflavor_t pseudoflavor;
1075 	char *p;
1076 
1077 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1078 
1079 	while ((p = strsep(&value, ":")) != NULL) {
1080 		switch (match_token(p, nfs_secflavor_tokens, args)) {
1081 		case Opt_sec_none:
1082 			pseudoflavor = RPC_AUTH_NULL;
1083 			break;
1084 		case Opt_sec_sys:
1085 			pseudoflavor = RPC_AUTH_UNIX;
1086 			break;
1087 		case Opt_sec_krb5:
1088 			pseudoflavor = RPC_AUTH_GSS_KRB5;
1089 			break;
1090 		case Opt_sec_krb5i:
1091 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
1092 			break;
1093 		case Opt_sec_krb5p:
1094 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
1095 			break;
1096 		case Opt_sec_lkey:
1097 			pseudoflavor = RPC_AUTH_GSS_LKEY;
1098 			break;
1099 		case Opt_sec_lkeyi:
1100 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
1101 			break;
1102 		case Opt_sec_lkeyp:
1103 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
1104 			break;
1105 		case Opt_sec_spkm:
1106 			pseudoflavor = RPC_AUTH_GSS_SPKM;
1107 			break;
1108 		case Opt_sec_spkmi:
1109 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
1110 			break;
1111 		case Opt_sec_spkmp:
1112 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
1113 			break;
1114 		default:
1115 			dfprintk(MOUNT,
1116 				 "NFS: sec= option '%s' not recognized\n", p);
1117 			return 0;
1118 		}
1119 
1120 		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1121 			return 0;
1122 	}
1123 
1124 	return 1;
1125 }
1126 
1127 static int nfs_parse_version_string(char *string,
1128 		struct nfs_parsed_mount_data *mnt,
1129 		substring_t *args)
1130 {
1131 	mnt->flags &= ~NFS_MOUNT_VER3;
1132 	switch (match_token(string, nfs_vers_tokens, args)) {
1133 	case Opt_vers_2:
1134 		mnt->version = 2;
1135 		break;
1136 	case Opt_vers_3:
1137 		mnt->flags |= NFS_MOUNT_VER3;
1138 		mnt->version = 3;
1139 		break;
1140 	case Opt_vers_4:
1141 		/* Backward compatibility option. In future,
1142 		 * the mount program should always supply
1143 		 * a NFSv4 minor version number.
1144 		 */
1145 		mnt->version = 4;
1146 		break;
1147 	case Opt_vers_4_0:
1148 		mnt->version = 4;
1149 		mnt->minorversion = 0;
1150 		break;
1151 	case Opt_vers_4_1:
1152 		mnt->version = 4;
1153 		mnt->minorversion = 1;
1154 		break;
1155 	case Opt_vers_4_2:
1156 		mnt->version = 4;
1157 		mnt->minorversion = 2;
1158 		break;
1159 	default:
1160 		return 0;
1161 	}
1162 	return 1;
1163 }
1164 
1165 static int nfs_get_option_str(substring_t args[], char **option)
1166 {
1167 	kfree(*option);
1168 	*option = match_strdup(args);
1169 	return !*option;
1170 }
1171 
1172 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1173 {
1174 	int rc;
1175 	char *string;
1176 
1177 	string = match_strdup(args);
1178 	if (string == NULL)
1179 		return -ENOMEM;
1180 	rc = kstrtoul(string, 10, option);
1181 	kfree(string);
1182 
1183 	return rc;
1184 }
1185 
1186 /*
1187  * Error-check and convert a string of mount options from user space into
1188  * a data structure.  The whole mount string is processed; bad options are
1189  * skipped as they are encountered.  If there were no errors, return 1;
1190  * otherwise return 0 (zero).
1191  */
1192 static int nfs_parse_mount_options(char *raw,
1193 				   struct nfs_parsed_mount_data *mnt)
1194 {
1195 	char *p, *string, *secdata;
1196 	int rc, sloppy = 0, invalid_option = 0;
1197 	unsigned short protofamily = AF_UNSPEC;
1198 	unsigned short mountfamily = AF_UNSPEC;
1199 
1200 	if (!raw) {
1201 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1202 		return 1;
1203 	}
1204 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1205 
1206 	secdata = alloc_secdata();
1207 	if (!secdata)
1208 		goto out_nomem;
1209 
1210 	rc = security_sb_copy_data(raw, secdata);
1211 	if (rc)
1212 		goto out_security_failure;
1213 
1214 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1215 	if (rc)
1216 		goto out_security_failure;
1217 
1218 	free_secdata(secdata);
1219 
1220 	while ((p = strsep(&raw, ",")) != NULL) {
1221 		substring_t args[MAX_OPT_ARGS];
1222 		unsigned long option;
1223 		int token;
1224 
1225 		if (!*p)
1226 			continue;
1227 
1228 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1229 
1230 		token = match_token(p, nfs_mount_option_tokens, args);
1231 		switch (token) {
1232 
1233 		/*
1234 		 * boolean options:  foo/nofoo
1235 		 */
1236 		case Opt_soft:
1237 			mnt->flags |= NFS_MOUNT_SOFT;
1238 			break;
1239 		case Opt_hard:
1240 			mnt->flags &= ~NFS_MOUNT_SOFT;
1241 			break;
1242 		case Opt_posix:
1243 			mnt->flags |= NFS_MOUNT_POSIX;
1244 			break;
1245 		case Opt_noposix:
1246 			mnt->flags &= ~NFS_MOUNT_POSIX;
1247 			break;
1248 		case Opt_cto:
1249 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1250 			break;
1251 		case Opt_nocto:
1252 			mnt->flags |= NFS_MOUNT_NOCTO;
1253 			break;
1254 		case Opt_ac:
1255 			mnt->flags &= ~NFS_MOUNT_NOAC;
1256 			break;
1257 		case Opt_noac:
1258 			mnt->flags |= NFS_MOUNT_NOAC;
1259 			break;
1260 		case Opt_lock:
1261 			mnt->flags &= ~NFS_MOUNT_NONLM;
1262 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1263 					NFS_MOUNT_LOCAL_FCNTL);
1264 			break;
1265 		case Opt_nolock:
1266 			mnt->flags |= NFS_MOUNT_NONLM;
1267 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1268 				       NFS_MOUNT_LOCAL_FCNTL);
1269 			break;
1270 		case Opt_udp:
1271 			mnt->flags &= ~NFS_MOUNT_TCP;
1272 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1273 			break;
1274 		case Opt_tcp:
1275 			mnt->flags |= NFS_MOUNT_TCP;
1276 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1277 			break;
1278 		case Opt_rdma:
1279 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1280 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1281 			xprt_load_transport(p);
1282 			break;
1283 		case Opt_acl:
1284 			mnt->flags &= ~NFS_MOUNT_NOACL;
1285 			break;
1286 		case Opt_noacl:
1287 			mnt->flags |= NFS_MOUNT_NOACL;
1288 			break;
1289 		case Opt_rdirplus:
1290 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1291 			break;
1292 		case Opt_nordirplus:
1293 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1294 			break;
1295 		case Opt_sharecache:
1296 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1297 			break;
1298 		case Opt_nosharecache:
1299 			mnt->flags |= NFS_MOUNT_UNSHARED;
1300 			break;
1301 		case Opt_resvport:
1302 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1303 			break;
1304 		case Opt_noresvport:
1305 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1306 			break;
1307 		case Opt_fscache:
1308 			mnt->options |= NFS_OPTION_FSCACHE;
1309 			kfree(mnt->fscache_uniq);
1310 			mnt->fscache_uniq = NULL;
1311 			break;
1312 		case Opt_nofscache:
1313 			mnt->options &= ~NFS_OPTION_FSCACHE;
1314 			kfree(mnt->fscache_uniq);
1315 			mnt->fscache_uniq = NULL;
1316 			break;
1317 		case Opt_migration:
1318 			mnt->options |= NFS_OPTION_MIGRATION;
1319 			break;
1320 		case Opt_nomigration:
1321 			mnt->options &= NFS_OPTION_MIGRATION;
1322 			break;
1323 
1324 		/*
1325 		 * options that take numeric values
1326 		 */
1327 		case Opt_port:
1328 			if (nfs_get_option_ul(args, &option) ||
1329 			    option > USHRT_MAX)
1330 				goto out_invalid_value;
1331 			mnt->nfs_server.port = option;
1332 			break;
1333 		case Opt_rsize:
1334 			if (nfs_get_option_ul(args, &option))
1335 				goto out_invalid_value;
1336 			mnt->rsize = option;
1337 			break;
1338 		case Opt_wsize:
1339 			if (nfs_get_option_ul(args, &option))
1340 				goto out_invalid_value;
1341 			mnt->wsize = option;
1342 			break;
1343 		case Opt_bsize:
1344 			if (nfs_get_option_ul(args, &option))
1345 				goto out_invalid_value;
1346 			mnt->bsize = option;
1347 			break;
1348 		case Opt_timeo:
1349 			if (nfs_get_option_ul(args, &option) || option == 0)
1350 				goto out_invalid_value;
1351 			mnt->timeo = option;
1352 			break;
1353 		case Opt_retrans:
1354 			if (nfs_get_option_ul(args, &option) || option == 0)
1355 				goto out_invalid_value;
1356 			mnt->retrans = option;
1357 			break;
1358 		case Opt_acregmin:
1359 			if (nfs_get_option_ul(args, &option))
1360 				goto out_invalid_value;
1361 			mnt->acregmin = option;
1362 			break;
1363 		case Opt_acregmax:
1364 			if (nfs_get_option_ul(args, &option))
1365 				goto out_invalid_value;
1366 			mnt->acregmax = option;
1367 			break;
1368 		case Opt_acdirmin:
1369 			if (nfs_get_option_ul(args, &option))
1370 				goto out_invalid_value;
1371 			mnt->acdirmin = option;
1372 			break;
1373 		case Opt_acdirmax:
1374 			if (nfs_get_option_ul(args, &option))
1375 				goto out_invalid_value;
1376 			mnt->acdirmax = option;
1377 			break;
1378 		case Opt_actimeo:
1379 			if (nfs_get_option_ul(args, &option))
1380 				goto out_invalid_value;
1381 			mnt->acregmin = mnt->acregmax =
1382 			mnt->acdirmin = mnt->acdirmax = option;
1383 			break;
1384 		case Opt_namelen:
1385 			if (nfs_get_option_ul(args, &option))
1386 				goto out_invalid_value;
1387 			mnt->namlen = option;
1388 			break;
1389 		case Opt_mountport:
1390 			if (nfs_get_option_ul(args, &option) ||
1391 			    option > USHRT_MAX)
1392 				goto out_invalid_value;
1393 			mnt->mount_server.port = option;
1394 			break;
1395 		case Opt_mountvers:
1396 			if (nfs_get_option_ul(args, &option) ||
1397 			    option < NFS_MNT_VERSION ||
1398 			    option > NFS_MNT3_VERSION)
1399 				goto out_invalid_value;
1400 			mnt->mount_server.version = option;
1401 			break;
1402 		case Opt_minorversion:
1403 			if (nfs_get_option_ul(args, &option))
1404 				goto out_invalid_value;
1405 			if (option > NFS4_MAX_MINOR_VERSION)
1406 				goto out_invalid_value;
1407 			mnt->minorversion = option;
1408 			break;
1409 
1410 		/*
1411 		 * options that take text values
1412 		 */
1413 		case Opt_nfsvers:
1414 			string = match_strdup(args);
1415 			if (string == NULL)
1416 				goto out_nomem;
1417 			rc = nfs_parse_version_string(string, mnt, args);
1418 			kfree(string);
1419 			if (!rc)
1420 				goto out_invalid_value;
1421 			break;
1422 		case Opt_sec:
1423 			string = match_strdup(args);
1424 			if (string == NULL)
1425 				goto out_nomem;
1426 			rc = nfs_parse_security_flavors(string, mnt);
1427 			kfree(string);
1428 			if (!rc) {
1429 				dfprintk(MOUNT, "NFS:   unrecognized "
1430 						"security flavor\n");
1431 				return 0;
1432 			}
1433 			break;
1434 		case Opt_proto:
1435 			string = match_strdup(args);
1436 			if (string == NULL)
1437 				goto out_nomem;
1438 			token = match_token(string,
1439 					    nfs_xprt_protocol_tokens, args);
1440 
1441 			protofamily = AF_INET;
1442 			switch (token) {
1443 			case Opt_xprt_udp6:
1444 				protofamily = AF_INET6;
1445 			case Opt_xprt_udp:
1446 				mnt->flags &= ~NFS_MOUNT_TCP;
1447 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1448 				break;
1449 			case Opt_xprt_tcp6:
1450 				protofamily = AF_INET6;
1451 			case Opt_xprt_tcp:
1452 				mnt->flags |= NFS_MOUNT_TCP;
1453 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1454 				break;
1455 			case Opt_xprt_rdma:
1456 				/* vector side protocols to TCP */
1457 				mnt->flags |= NFS_MOUNT_TCP;
1458 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1459 				xprt_load_transport(string);
1460 				break;
1461 			default:
1462 				dfprintk(MOUNT, "NFS:   unrecognized "
1463 						"transport protocol\n");
1464 				kfree(string);
1465 				return 0;
1466 			}
1467 			kfree(string);
1468 			break;
1469 		case Opt_mountproto:
1470 			string = match_strdup(args);
1471 			if (string == NULL)
1472 				goto out_nomem;
1473 			token = match_token(string,
1474 					    nfs_xprt_protocol_tokens, args);
1475 			kfree(string);
1476 
1477 			mountfamily = AF_INET;
1478 			switch (token) {
1479 			case Opt_xprt_udp6:
1480 				mountfamily = AF_INET6;
1481 			case Opt_xprt_udp:
1482 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1483 				break;
1484 			case Opt_xprt_tcp6:
1485 				mountfamily = AF_INET6;
1486 			case Opt_xprt_tcp:
1487 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1488 				break;
1489 			case Opt_xprt_rdma: /* not used for side protocols */
1490 			default:
1491 				dfprintk(MOUNT, "NFS:   unrecognized "
1492 						"transport protocol\n");
1493 				return 0;
1494 			}
1495 			break;
1496 		case Opt_addr:
1497 			string = match_strdup(args);
1498 			if (string == NULL)
1499 				goto out_nomem;
1500 			mnt->nfs_server.addrlen =
1501 				rpc_pton(mnt->net, string, strlen(string),
1502 					(struct sockaddr *)
1503 					&mnt->nfs_server.address,
1504 					sizeof(mnt->nfs_server.address));
1505 			kfree(string);
1506 			if (mnt->nfs_server.addrlen == 0)
1507 				goto out_invalid_address;
1508 			break;
1509 		case Opt_clientaddr:
1510 			if (nfs_get_option_str(args, &mnt->client_address))
1511 				goto out_nomem;
1512 			break;
1513 		case Opt_mounthost:
1514 			if (nfs_get_option_str(args,
1515 					       &mnt->mount_server.hostname))
1516 				goto out_nomem;
1517 			break;
1518 		case Opt_mountaddr:
1519 			string = match_strdup(args);
1520 			if (string == NULL)
1521 				goto out_nomem;
1522 			mnt->mount_server.addrlen =
1523 				rpc_pton(mnt->net, string, strlen(string),
1524 					(struct sockaddr *)
1525 					&mnt->mount_server.address,
1526 					sizeof(mnt->mount_server.address));
1527 			kfree(string);
1528 			if (mnt->mount_server.addrlen == 0)
1529 				goto out_invalid_address;
1530 			break;
1531 		case Opt_lookupcache:
1532 			string = match_strdup(args);
1533 			if (string == NULL)
1534 				goto out_nomem;
1535 			token = match_token(string,
1536 					nfs_lookupcache_tokens, args);
1537 			kfree(string);
1538 			switch (token) {
1539 				case Opt_lookupcache_all:
1540 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1541 					break;
1542 				case Opt_lookupcache_positive:
1543 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1544 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1545 					break;
1546 				case Opt_lookupcache_none:
1547 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1548 					break;
1549 				default:
1550 					dfprintk(MOUNT, "NFS:   invalid "
1551 							"lookupcache argument\n");
1552 					return 0;
1553 			};
1554 			break;
1555 		case Opt_fscache_uniq:
1556 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1557 				goto out_nomem;
1558 			mnt->options |= NFS_OPTION_FSCACHE;
1559 			break;
1560 		case Opt_local_lock:
1561 			string = match_strdup(args);
1562 			if (string == NULL)
1563 				goto out_nomem;
1564 			token = match_token(string, nfs_local_lock_tokens,
1565 					args);
1566 			kfree(string);
1567 			switch (token) {
1568 			case Opt_local_lock_all:
1569 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1570 					       NFS_MOUNT_LOCAL_FCNTL);
1571 				break;
1572 			case Opt_local_lock_flock:
1573 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1574 				break;
1575 			case Opt_local_lock_posix:
1576 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1577 				break;
1578 			case Opt_local_lock_none:
1579 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1580 						NFS_MOUNT_LOCAL_FCNTL);
1581 				break;
1582 			default:
1583 				dfprintk(MOUNT, "NFS:	invalid	"
1584 						"local_lock argument\n");
1585 				return 0;
1586 			};
1587 			break;
1588 
1589 		/*
1590 		 * Special options
1591 		 */
1592 		case Opt_sloppy:
1593 			sloppy = 1;
1594 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1595 			break;
1596 		case Opt_userspace:
1597 		case Opt_deprecated:
1598 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1599 					"'%s'\n", p);
1600 			break;
1601 
1602 		default:
1603 			invalid_option = 1;
1604 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1605 					"'%s'\n", p);
1606 		}
1607 	}
1608 
1609 	if (!sloppy && invalid_option)
1610 		return 0;
1611 
1612 	if (mnt->minorversion && mnt->version != 4)
1613 		goto out_minorversion_mismatch;
1614 
1615 	if (mnt->options & NFS_OPTION_MIGRATION &&
1616 	    (mnt->version != 4 || mnt->minorversion != 0))
1617 		goto out_migration_misuse;
1618 
1619 	/*
1620 	 * verify that any proto=/mountproto= options match the address
1621 	 * families in the addr=/mountaddr= options.
1622 	 */
1623 	if (protofamily != AF_UNSPEC &&
1624 	    protofamily != mnt->nfs_server.address.ss_family)
1625 		goto out_proto_mismatch;
1626 
1627 	if (mountfamily != AF_UNSPEC) {
1628 		if (mnt->mount_server.addrlen) {
1629 			if (mountfamily != mnt->mount_server.address.ss_family)
1630 				goto out_mountproto_mismatch;
1631 		} else {
1632 			if (mountfamily != mnt->nfs_server.address.ss_family)
1633 				goto out_mountproto_mismatch;
1634 		}
1635 	}
1636 
1637 	return 1;
1638 
1639 out_mountproto_mismatch:
1640 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1641 			 "option\n");
1642 	return 0;
1643 out_proto_mismatch:
1644 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1645 	return 0;
1646 out_invalid_address:
1647 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1648 	return 0;
1649 out_invalid_value:
1650 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1651 	return 0;
1652 out_minorversion_mismatch:
1653 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1654 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1655 	return 0;
1656 out_migration_misuse:
1657 	printk(KERN_INFO
1658 		"NFS: 'migration' not supported for this NFS version\n");
1659 	return 0;
1660 out_nomem:
1661 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1662 	return 0;
1663 out_security_failure:
1664 	free_secdata(secdata);
1665 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1666 	return 0;
1667 }
1668 
1669 /*
1670  * Ensure that a specified authtype in args->auth_info is supported by
1671  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1672  * -EACCES if not.
1673  */
1674 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1675 			rpc_authflavor_t *server_authlist, unsigned int count)
1676 {
1677 	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1678 	unsigned int i;
1679 
1680 	/*
1681 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1682 	 * must be in the list returned by the server.
1683 	 *
1684 	 * AUTH_NULL has a special meaning when it's in the server list - it
1685 	 * means that the server will ignore the rpc creds, so any flavor
1686 	 * can be used.
1687 	 */
1688 	for (i = 0; i < count; i++) {
1689 		flavor = server_authlist[i];
1690 
1691 		if (nfs_auth_info_match(&args->auth_info, flavor) ||
1692 		    flavor == RPC_AUTH_NULL)
1693 			goto out;
1694 	}
1695 
1696 	dfprintk(MOUNT,
1697 		 "NFS: specified auth flavors not supported by server\n");
1698 	return -EACCES;
1699 
1700 out:
1701 	args->selected_flavor = flavor;
1702 	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1703 	return 0;
1704 }
1705 
1706 /*
1707  * Use the remote server's MOUNT service to request the NFS file handle
1708  * corresponding to the provided path.
1709  */
1710 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1711 			     struct nfs_fh *root_fh,
1712 			     rpc_authflavor_t *server_authlist,
1713 			     unsigned int *server_authlist_len)
1714 {
1715 	struct nfs_mount_request request = {
1716 		.sap		= (struct sockaddr *)
1717 						&args->mount_server.address,
1718 		.dirpath	= args->nfs_server.export_path,
1719 		.protocol	= args->mount_server.protocol,
1720 		.fh		= root_fh,
1721 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1722 		.auth_flav_len	= server_authlist_len,
1723 		.auth_flavs	= server_authlist,
1724 		.net		= args->net,
1725 	};
1726 	int status;
1727 
1728 	if (args->mount_server.version == 0) {
1729 		switch (args->version) {
1730 			default:
1731 				args->mount_server.version = NFS_MNT3_VERSION;
1732 				break;
1733 			case 2:
1734 				args->mount_server.version = NFS_MNT_VERSION;
1735 		}
1736 	}
1737 	request.version = args->mount_server.version;
1738 
1739 	if (args->mount_server.hostname)
1740 		request.hostname = args->mount_server.hostname;
1741 	else
1742 		request.hostname = args->nfs_server.hostname;
1743 
1744 	/*
1745 	 * Construct the mount server's address.
1746 	 */
1747 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1748 		memcpy(request.sap, &args->nfs_server.address,
1749 		       args->nfs_server.addrlen);
1750 		args->mount_server.addrlen = args->nfs_server.addrlen;
1751 	}
1752 	request.salen = args->mount_server.addrlen;
1753 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1754 
1755 	/*
1756 	 * Now ask the mount server to map our export path
1757 	 * to a file handle.
1758 	 */
1759 	status = nfs_mount(&request);
1760 	if (status != 0) {
1761 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1762 				request.hostname, status);
1763 		return status;
1764 	}
1765 
1766 	return 0;
1767 }
1768 
1769 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1770 					struct nfs_subversion *nfs_mod)
1771 {
1772 	int status;
1773 	unsigned int i;
1774 	bool tried_auth_unix = false;
1775 	bool auth_null_in_list = false;
1776 	struct nfs_server *server = ERR_PTR(-EACCES);
1777 	struct nfs_parsed_mount_data *args = mount_info->parsed;
1778 	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1779 	unsigned int authlist_len = ARRAY_SIZE(authlist);
1780 
1781 	status = nfs_request_mount(args, mount_info->mntfh, authlist,
1782 					&authlist_len);
1783 	if (status)
1784 		return ERR_PTR(status);
1785 
1786 	/*
1787 	 * Was a sec= authflavor specified in the options? First, verify
1788 	 * whether the server supports it, and then just try to use it if so.
1789 	 */
1790 	if (args->auth_info.flavor_len > 0) {
1791 		status = nfs_verify_authflavors(args, authlist, authlist_len);
1792 		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1793 			 args->selected_flavor);
1794 		if (status)
1795 			return ERR_PTR(status);
1796 		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1797 	}
1798 
1799 	/*
1800 	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
1801 	 * SHOULD prefer the flavor listed first. However, some servers list
1802 	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1803 	 */
1804 	for (i = 0; i < authlist_len; ++i) {
1805 		rpc_authflavor_t flavor;
1806 		struct rpcsec_gss_info info;
1807 
1808 		flavor = authlist[i];
1809 		switch (flavor) {
1810 		case RPC_AUTH_UNIX:
1811 			tried_auth_unix = true;
1812 			break;
1813 		case RPC_AUTH_NULL:
1814 			auth_null_in_list = true;
1815 			continue;
1816 		default:
1817 			if (rpcauth_get_gssinfo(flavor, &info) != 0)
1818 				continue;
1819 			/* Fallthrough */
1820 		}
1821 		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1822 		args->selected_flavor = flavor;
1823 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1824 		if (!IS_ERR(server))
1825 			return server;
1826 	}
1827 
1828 	/*
1829 	 * Nothing we tried so far worked. At this point, give up if we've
1830 	 * already tried AUTH_UNIX or if the server's list doesn't contain
1831 	 * AUTH_NULL
1832 	 */
1833 	if (tried_auth_unix || !auth_null_in_list)
1834 		return server;
1835 
1836 	/* Last chance! Try AUTH_UNIX */
1837 	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1838 	args->selected_flavor = RPC_AUTH_UNIX;
1839 	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1840 }
1841 
1842 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1843 			     struct nfs_mount_info *mount_info,
1844 			     struct nfs_subversion *nfs_mod)
1845 {
1846 	struct nfs_server *server;
1847 
1848 	if (mount_info->parsed->need_mount)
1849 		server = nfs_try_mount_request(mount_info, nfs_mod);
1850 	else
1851 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1852 
1853 	if (IS_ERR(server))
1854 		return ERR_CAST(server);
1855 
1856 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1857 }
1858 EXPORT_SYMBOL_GPL(nfs_try_mount);
1859 
1860 /*
1861  * Split "dev_name" into "hostname:export_path".
1862  *
1863  * The leftmost colon demarks the split between the server's hostname
1864  * and the export path.  If the hostname starts with a left square
1865  * bracket, then it may contain colons.
1866  *
1867  * Note: caller frees hostname and export path, even on error.
1868  */
1869 static int nfs_parse_devname(const char *dev_name,
1870 			     char **hostname, size_t maxnamlen,
1871 			     char **export_path, size_t maxpathlen)
1872 {
1873 	size_t len;
1874 	char *end;
1875 
1876 	/* Is the host name protected with square brakcets? */
1877 	if (*dev_name == '[') {
1878 		end = strchr(++dev_name, ']');
1879 		if (end == NULL || end[1] != ':')
1880 			goto out_bad_devname;
1881 
1882 		len = end - dev_name;
1883 		end++;
1884 	} else {
1885 		char *comma;
1886 
1887 		end = strchr(dev_name, ':');
1888 		if (end == NULL)
1889 			goto out_bad_devname;
1890 		len = end - dev_name;
1891 
1892 		/* kill possible hostname list: not supported */
1893 		comma = strchr(dev_name, ',');
1894 		if (comma != NULL && comma < end)
1895 			*comma = 0;
1896 	}
1897 
1898 	if (len > maxnamlen)
1899 		goto out_hostname;
1900 
1901 	/* N.B. caller will free nfs_server.hostname in all cases */
1902 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1903 	if (*hostname == NULL)
1904 		goto out_nomem;
1905 	len = strlen(++end);
1906 	if (len > maxpathlen)
1907 		goto out_path;
1908 	*export_path = kstrndup(end, len, GFP_KERNEL);
1909 	if (!*export_path)
1910 		goto out_nomem;
1911 
1912 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1913 	return 0;
1914 
1915 out_bad_devname:
1916 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1917 	return -EINVAL;
1918 
1919 out_nomem:
1920 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1921 	return -ENOMEM;
1922 
1923 out_hostname:
1924 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1925 	return -ENAMETOOLONG;
1926 
1927 out_path:
1928 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1929 	return -ENAMETOOLONG;
1930 }
1931 
1932 /*
1933  * Validate the NFS2/NFS3 mount data
1934  * - fills in the mount root filehandle
1935  *
1936  * For option strings, user space handles the following behaviors:
1937  *
1938  * + DNS: mapping server host name to IP address ("addr=" option)
1939  *
1940  * + failure mode: how to behave if a mount request can't be handled
1941  *   immediately ("fg/bg" option)
1942  *
1943  * + retry: how often to retry a mount request ("retry=" option)
1944  *
1945  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1946  *   mountproto=tcp after mountproto=udp, and so on
1947  */
1948 static int nfs23_validate_mount_data(void *options,
1949 				     struct nfs_parsed_mount_data *args,
1950 				     struct nfs_fh *mntfh,
1951 				     const char *dev_name)
1952 {
1953 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1954 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1955 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1956 
1957 	if (data == NULL)
1958 		goto out_no_data;
1959 
1960 	args->version = NFS_DEFAULT_VERSION;
1961 	switch (data->version) {
1962 	case 1:
1963 		data->namlen = 0;
1964 	case 2:
1965 		data->bsize = 0;
1966 	case 3:
1967 		if (data->flags & NFS_MOUNT_VER3)
1968 			goto out_no_v3;
1969 		data->root.size = NFS2_FHSIZE;
1970 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1971 		/* Turn off security negotiation */
1972 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
1973 	case 4:
1974 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1975 			goto out_no_sec;
1976 	case 5:
1977 		memset(data->context, 0, sizeof(data->context));
1978 	case 6:
1979 		if (data->flags & NFS_MOUNT_VER3) {
1980 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1981 				goto out_invalid_fh;
1982 			mntfh->size = data->root.size;
1983 			args->version = 3;
1984 		} else {
1985 			mntfh->size = NFS2_FHSIZE;
1986 			args->version = 2;
1987 		}
1988 
1989 
1990 		memcpy(mntfh->data, data->root.data, mntfh->size);
1991 		if (mntfh->size < sizeof(mntfh->data))
1992 			memset(mntfh->data + mntfh->size, 0,
1993 			       sizeof(mntfh->data) - mntfh->size);
1994 
1995 		/*
1996 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1997 		 * can deal with.
1998 		 */
1999 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
2000 		args->flags		|= extra_flags;
2001 		args->rsize		= data->rsize;
2002 		args->wsize		= data->wsize;
2003 		args->timeo		= data->timeo;
2004 		args->retrans		= data->retrans;
2005 		args->acregmin		= data->acregmin;
2006 		args->acregmax		= data->acregmax;
2007 		args->acdirmin		= data->acdirmin;
2008 		args->acdirmax		= data->acdirmax;
2009 		args->need_mount	= false;
2010 
2011 		memcpy(sap, &data->addr, sizeof(data->addr));
2012 		args->nfs_server.addrlen = sizeof(data->addr);
2013 		args->nfs_server.port = ntohs(data->addr.sin_port);
2014 		if (!nfs_verify_server_address(sap))
2015 			goto out_no_address;
2016 
2017 		if (!(data->flags & NFS_MOUNT_TCP))
2018 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2019 		/* N.B. caller will free nfs_server.hostname in all cases */
2020 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2021 		args->namlen		= data->namlen;
2022 		args->bsize		= data->bsize;
2023 
2024 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2025 			args->selected_flavor = data->pseudoflavor;
2026 		else
2027 			args->selected_flavor = RPC_AUTH_UNIX;
2028 		if (!args->nfs_server.hostname)
2029 			goto out_nomem;
2030 
2031 		if (!(data->flags & NFS_MOUNT_NONLM))
2032 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2033 					 NFS_MOUNT_LOCAL_FCNTL);
2034 		else
2035 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2036 					NFS_MOUNT_LOCAL_FCNTL);
2037 		/*
2038 		 * The legacy version 6 binary mount data from userspace has a
2039 		 * field used only to transport selinux information into the
2040 		 * the kernel.  To continue to support that functionality we
2041 		 * have a touch of selinux knowledge here in the NFS code. The
2042 		 * userspace code converted context=blah to just blah so we are
2043 		 * converting back to the full string selinux understands.
2044 		 */
2045 		if (data->context[0]){
2046 #ifdef CONFIG_SECURITY_SELINUX
2047 			int rc;
2048 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
2049 			if (!opts_str)
2050 				return -ENOMEM;
2051 			strcpy(opts_str, "context=");
2052 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2053 			strcat(opts_str, &data->context[0]);
2054 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
2055 			kfree(opts_str);
2056 			if (rc)
2057 				return rc;
2058 #else
2059 			return -EINVAL;
2060 #endif
2061 		}
2062 
2063 		break;
2064 	default:
2065 		return NFS_TEXT_DATA;
2066 	}
2067 
2068 	return 0;
2069 
2070 out_no_data:
2071 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2072 	return -EINVAL;
2073 
2074 out_no_v3:
2075 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2076 		 data->version);
2077 	return -EINVAL;
2078 
2079 out_no_sec:
2080 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2081 	return -EINVAL;
2082 
2083 out_nomem:
2084 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2085 	return -ENOMEM;
2086 
2087 out_no_address:
2088 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2089 	return -EINVAL;
2090 
2091 out_invalid_fh:
2092 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2093 	return -EINVAL;
2094 }
2095 
2096 #if IS_ENABLED(CONFIG_NFS_V4)
2097 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2098 				   void *options,
2099 				   struct nfs_parsed_mount_data *args,
2100 				   struct nfs_fh *mntfh,
2101 				   const char *dev_name)
2102 {
2103 	if (fs_type == &nfs_fs_type)
2104 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2105 	return nfs4_validate_mount_data(options, args, dev_name);
2106 }
2107 #else
2108 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2109 				   void *options,
2110 				   struct nfs_parsed_mount_data *args,
2111 				   struct nfs_fh *mntfh,
2112 				   const char *dev_name)
2113 {
2114 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2115 }
2116 #endif
2117 
2118 static int nfs_validate_text_mount_data(void *options,
2119 					struct nfs_parsed_mount_data *args,
2120 					const char *dev_name)
2121 {
2122 	int port = 0;
2123 	int max_namelen = PAGE_SIZE;
2124 	int max_pathlen = NFS_MAXPATHLEN;
2125 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2126 
2127 	if (nfs_parse_mount_options((char *)options, args) == 0)
2128 		return -EINVAL;
2129 
2130 	if (!nfs_verify_server_address(sap))
2131 		goto out_no_address;
2132 
2133 	if (args->version == 4) {
2134 #if IS_ENABLED(CONFIG_NFS_V4)
2135 		port = NFS_PORT;
2136 		max_namelen = NFS4_MAXNAMLEN;
2137 		max_pathlen = NFS4_MAXPATHLEN;
2138 		nfs_validate_transport_protocol(args);
2139 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2140 			goto out_invalid_transport_udp;
2141 		nfs4_validate_mount_flags(args);
2142 #else
2143 		goto out_v4_not_compiled;
2144 #endif /* CONFIG_NFS_V4 */
2145 	} else
2146 		nfs_set_mount_transport_protocol(args);
2147 
2148 	nfs_set_port(sap, &args->nfs_server.port, port);
2149 
2150 	return nfs_parse_devname(dev_name,
2151 				   &args->nfs_server.hostname,
2152 				   max_namelen,
2153 				   &args->nfs_server.export_path,
2154 				   max_pathlen);
2155 
2156 #if !IS_ENABLED(CONFIG_NFS_V4)
2157 out_v4_not_compiled:
2158 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2159 	return -EPROTONOSUPPORT;
2160 #else
2161 out_invalid_transport_udp:
2162 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2163 	return -EINVAL;
2164 #endif /* !CONFIG_NFS_V4 */
2165 
2166 out_no_address:
2167 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2168 	return -EINVAL;
2169 }
2170 
2171 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2172 		| NFS_MOUNT_SECURE \
2173 		| NFS_MOUNT_TCP \
2174 		| NFS_MOUNT_VER3 \
2175 		| NFS_MOUNT_KERBEROS \
2176 		| NFS_MOUNT_NONLM \
2177 		| NFS_MOUNT_BROKEN_SUID \
2178 		| NFS_MOUNT_STRICTLOCK \
2179 		| NFS_MOUNT_LEGACY_INTERFACE)
2180 
2181 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2182 		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2183 
2184 static int
2185 nfs_compare_remount_data(struct nfs_server *nfss,
2186 			 struct nfs_parsed_mount_data *data)
2187 {
2188 	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2189 	    data->rsize != nfss->rsize ||
2190 	    data->wsize != nfss->wsize ||
2191 	    data->version != nfss->nfs_client->rpc_ops->version ||
2192 	    data->minorversion != nfss->nfs_client->cl_minorversion ||
2193 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2194 	    data->selected_flavor != nfss->client->cl_auth->au_flavor ||
2195 	    data->acregmin != nfss->acregmin / HZ ||
2196 	    data->acregmax != nfss->acregmax / HZ ||
2197 	    data->acdirmin != nfss->acdirmin / HZ ||
2198 	    data->acdirmax != nfss->acdirmax / HZ ||
2199 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2200 	    data->nfs_server.port != nfss->port ||
2201 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2202 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2203 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2204 		return -EINVAL;
2205 
2206 	return 0;
2207 }
2208 
2209 int
2210 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2211 {
2212 	int error;
2213 	struct nfs_server *nfss = sb->s_fs_info;
2214 	struct nfs_parsed_mount_data *data;
2215 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2216 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2217 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2218 
2219 	sync_filesystem(sb);
2220 
2221 	/*
2222 	 * Userspace mount programs that send binary options generally send
2223 	 * them populated with default values. We have no way to know which
2224 	 * ones were explicitly specified. Fall back to legacy behavior and
2225 	 * just return success.
2226 	 */
2227 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2228 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2229 					   options->version <= 6))))
2230 		return 0;
2231 
2232 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2233 	if (data == NULL)
2234 		return -ENOMEM;
2235 
2236 	/* fill out struct with values from existing mount */
2237 	data->flags = nfss->flags;
2238 	data->rsize = nfss->rsize;
2239 	data->wsize = nfss->wsize;
2240 	data->retrans = nfss->client->cl_timeout->to_retries;
2241 	data->selected_flavor = nfss->client->cl_auth->au_flavor;
2242 	data->auth_info = nfss->auth_info;
2243 	data->acregmin = nfss->acregmin / HZ;
2244 	data->acregmax = nfss->acregmax / HZ;
2245 	data->acdirmin = nfss->acdirmin / HZ;
2246 	data->acdirmax = nfss->acdirmax / HZ;
2247 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2248 	data->nfs_server.port = nfss->port;
2249 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2250 	data->version = nfsvers;
2251 	data->minorversion = nfss->nfs_client->cl_minorversion;
2252 	data->net = current->nsproxy->net_ns;
2253 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2254 		data->nfs_server.addrlen);
2255 
2256 	/* overwrite those values with any that were specified */
2257 	error = -EINVAL;
2258 	if (!nfs_parse_mount_options((char *)options, data))
2259 		goto out;
2260 
2261 	/*
2262 	 * noac is a special case. It implies -o sync, but that's not
2263 	 * necessarily reflected in the mtab options. do_remount_sb
2264 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2265 	 * remount options, so we have to explicitly reset it.
2266 	 */
2267 	if (data->flags & NFS_MOUNT_NOAC)
2268 		*flags |= MS_SYNCHRONOUS;
2269 
2270 	/* compare new mount options with old ones */
2271 	error = nfs_compare_remount_data(nfss, data);
2272 out:
2273 	kfree(data);
2274 	return error;
2275 }
2276 EXPORT_SYMBOL_GPL(nfs_remount);
2277 
2278 /*
2279  * Initialise the common bits of the superblock
2280  */
2281 inline void nfs_initialise_sb(struct super_block *sb)
2282 {
2283 	struct nfs_server *server = NFS_SB(sb);
2284 
2285 	sb->s_magic = NFS_SUPER_MAGIC;
2286 
2287 	/* We probably want something more informative here */
2288 	snprintf(sb->s_id, sizeof(sb->s_id),
2289 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2290 
2291 	if (sb->s_blocksize == 0)
2292 		sb->s_blocksize = nfs_block_bits(server->wsize,
2293 						 &sb->s_blocksize_bits);
2294 
2295 	sb->s_bdi = &server->backing_dev_info;
2296 
2297 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2298 }
2299 
2300 /*
2301  * Finish setting up an NFS2/3 superblock
2302  */
2303 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2304 {
2305 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2306 	struct nfs_server *server = NFS_SB(sb);
2307 
2308 	sb->s_blocksize_bits = 0;
2309 	sb->s_blocksize = 0;
2310 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2311 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2312 	if (data && data->bsize)
2313 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2314 
2315 	if (server->nfs_client->rpc_ops->version != 2) {
2316 		/* The VFS shouldn't apply the umask to mode bits. We will do
2317 		 * so ourselves when necessary.
2318 		 */
2319 		sb->s_flags |= MS_POSIXACL;
2320 		sb->s_time_gran = 1;
2321 	}
2322 
2323  	nfs_initialise_sb(sb);
2324 }
2325 EXPORT_SYMBOL_GPL(nfs_fill_super);
2326 
2327 /*
2328  * Finish setting up a cloned NFS2/3/4 superblock
2329  */
2330 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2331 {
2332 	const struct super_block *old_sb = mount_info->cloned->sb;
2333 	struct nfs_server *server = NFS_SB(sb);
2334 
2335 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2336 	sb->s_blocksize = old_sb->s_blocksize;
2337 	sb->s_maxbytes = old_sb->s_maxbytes;
2338 	sb->s_xattr = old_sb->s_xattr;
2339 	sb->s_op = old_sb->s_op;
2340 	sb->s_time_gran = 1;
2341 
2342 	if (server->nfs_client->rpc_ops->version != 2) {
2343 		/* The VFS shouldn't apply the umask to mode bits. We will do
2344 		 * so ourselves when necessary.
2345 		 */
2346 		sb->s_flags |= MS_POSIXACL;
2347 	}
2348 
2349  	nfs_initialise_sb(sb);
2350 }
2351 
2352 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2353 {
2354 	const struct nfs_server *a = s->s_fs_info;
2355 	const struct rpc_clnt *clnt_a = a->client;
2356 	const struct rpc_clnt *clnt_b = b->client;
2357 
2358 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2359 		goto Ebusy;
2360 	if (a->nfs_client != b->nfs_client)
2361 		goto Ebusy;
2362 	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2363 		goto Ebusy;
2364 	if (a->wsize != b->wsize)
2365 		goto Ebusy;
2366 	if (a->rsize != b->rsize)
2367 		goto Ebusy;
2368 	if (a->acregmin != b->acregmin)
2369 		goto Ebusy;
2370 	if (a->acregmax != b->acregmax)
2371 		goto Ebusy;
2372 	if (a->acdirmin != b->acdirmin)
2373 		goto Ebusy;
2374 	if (a->acdirmax != b->acdirmax)
2375 		goto Ebusy;
2376 	if (b->auth_info.flavor_len > 0 &&
2377 	   clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2378 		goto Ebusy;
2379 	return 1;
2380 Ebusy:
2381 	return 0;
2382 }
2383 
2384 struct nfs_sb_mountdata {
2385 	struct nfs_server *server;
2386 	int mntflags;
2387 };
2388 
2389 static int nfs_set_super(struct super_block *s, void *data)
2390 {
2391 	struct nfs_sb_mountdata *sb_mntdata = data;
2392 	struct nfs_server *server = sb_mntdata->server;
2393 	int ret;
2394 
2395 	s->s_flags = sb_mntdata->mntflags;
2396 	s->s_fs_info = server;
2397 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2398 	ret = set_anon_super(s, server);
2399 	if (ret == 0)
2400 		server->s_dev = s->s_dev;
2401 	return ret;
2402 }
2403 
2404 static int nfs_compare_super_address(struct nfs_server *server1,
2405 				     struct nfs_server *server2)
2406 {
2407 	struct sockaddr *sap1, *sap2;
2408 
2409 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2410 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2411 
2412 	if (sap1->sa_family != sap2->sa_family)
2413 		return 0;
2414 
2415 	switch (sap1->sa_family) {
2416 	case AF_INET: {
2417 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2418 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2419 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2420 			return 0;
2421 		if (sin1->sin_port != sin2->sin_port)
2422 			return 0;
2423 		break;
2424 	}
2425 	case AF_INET6: {
2426 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2427 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2428 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2429 			return 0;
2430 		if (sin1->sin6_port != sin2->sin6_port)
2431 			return 0;
2432 		break;
2433 	}
2434 	default:
2435 		return 0;
2436 	}
2437 
2438 	return 1;
2439 }
2440 
2441 static int nfs_compare_super(struct super_block *sb, void *data)
2442 {
2443 	struct nfs_sb_mountdata *sb_mntdata = data;
2444 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2445 	int mntflags = sb_mntdata->mntflags;
2446 
2447 	if (!nfs_compare_super_address(old, server))
2448 		return 0;
2449 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2450 	if (old->flags & NFS_MOUNT_UNSHARED)
2451 		return 0;
2452 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2453 		return 0;
2454 	return nfs_compare_mount_options(sb, server, mntflags);
2455 }
2456 
2457 #ifdef CONFIG_NFS_FSCACHE
2458 static void nfs_get_cache_cookie(struct super_block *sb,
2459 				 struct nfs_parsed_mount_data *parsed,
2460 				 struct nfs_clone_mount *cloned)
2461 {
2462 	struct nfs_server *nfss = NFS_SB(sb);
2463 	char *uniq = NULL;
2464 	int ulen = 0;
2465 
2466 	nfss->fscache_key = NULL;
2467 	nfss->fscache = NULL;
2468 
2469 	if (parsed) {
2470 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2471 			return;
2472 		if (parsed->fscache_uniq) {
2473 			uniq = parsed->fscache_uniq;
2474 			ulen = strlen(parsed->fscache_uniq);
2475 		}
2476 	} else if (cloned) {
2477 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2478 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2479 			return;
2480 		if (mnt_s->fscache_key) {
2481 			uniq = mnt_s->fscache_key->key.uniquifier;
2482 			ulen = mnt_s->fscache_key->key.uniq_len;
2483 		};
2484 	} else
2485 		return;
2486 
2487 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2488 }
2489 #else
2490 static void nfs_get_cache_cookie(struct super_block *sb,
2491 				 struct nfs_parsed_mount_data *parsed,
2492 				 struct nfs_clone_mount *cloned)
2493 {
2494 }
2495 #endif
2496 
2497 static int nfs_bdi_register(struct nfs_server *server)
2498 {
2499 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2500 }
2501 
2502 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2503 			struct nfs_mount_info *mount_info)
2504 {
2505 	int error;
2506 	unsigned long kflags = 0, kflags_out = 0;
2507 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2508 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2509 
2510 	error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
2511 						kflags, &kflags_out);
2512 	if (error)
2513 		goto err;
2514 
2515 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2516 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2517 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2518 err:
2519 	return error;
2520 }
2521 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2522 
2523 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2524 			  struct nfs_mount_info *mount_info)
2525 {
2526 	/* clone any lsm security options from the parent to the new sb */
2527 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2528 		return -ESTALE;
2529 	return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2530 }
2531 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2532 
2533 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2534 				   int flags, const char *dev_name,
2535 				   struct nfs_mount_info *mount_info,
2536 				   struct nfs_subversion *nfs_mod)
2537 {
2538 	struct super_block *s;
2539 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2540 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2541 	struct nfs_sb_mountdata sb_mntdata = {
2542 		.mntflags = flags,
2543 		.server = server,
2544 	};
2545 	int error;
2546 
2547 	if (server->flags & NFS_MOUNT_UNSHARED)
2548 		compare_super = NULL;
2549 
2550 	/* -o noac implies -o sync */
2551 	if (server->flags & NFS_MOUNT_NOAC)
2552 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2553 
2554 	if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2555 		if (mount_info->cloned->sb->s_flags & MS_SYNCHRONOUS)
2556 			sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2557 
2558 	/* Get a superblock - note that we may end up sharing one that already exists */
2559 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2560 	if (IS_ERR(s)) {
2561 		mntroot = ERR_CAST(s);
2562 		goto out_err_nosb;
2563 	}
2564 
2565 	if (s->s_fs_info != server) {
2566 		nfs_free_server(server);
2567 		server = NULL;
2568 	} else {
2569 		error = nfs_bdi_register(server);
2570 		if (error) {
2571 			mntroot = ERR_PTR(error);
2572 			goto error_splat_bdi;
2573 		}
2574 		server->super = s;
2575 	}
2576 
2577 	if (!s->s_root) {
2578 		/* initial superblock/root creation */
2579 		mount_info->fill_super(s, mount_info);
2580 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2581 	}
2582 
2583 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2584 	if (IS_ERR(mntroot))
2585 		goto error_splat_super;
2586 
2587 	error = mount_info->set_security(s, mntroot, mount_info);
2588 	if (error)
2589 		goto error_splat_root;
2590 
2591 	s->s_flags |= MS_ACTIVE;
2592 
2593 out:
2594 	return mntroot;
2595 
2596 out_err_nosb:
2597 	nfs_free_server(server);
2598 	goto out;
2599 
2600 error_splat_root:
2601 	dput(mntroot);
2602 	mntroot = ERR_PTR(error);
2603 error_splat_super:
2604 	if (server && !s->s_root)
2605 		bdi_unregister(&server->backing_dev_info);
2606 error_splat_bdi:
2607 	deactivate_locked_super(s);
2608 	goto out;
2609 }
2610 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2611 
2612 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2613 	int flags, const char *dev_name, void *raw_data)
2614 {
2615 	struct nfs_mount_info mount_info = {
2616 		.fill_super = nfs_fill_super,
2617 		.set_security = nfs_set_sb_security,
2618 	};
2619 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2620 	struct nfs_subversion *nfs_mod;
2621 	int error;
2622 
2623 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2624 	mount_info.mntfh = nfs_alloc_fhandle();
2625 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2626 		goto out;
2627 
2628 	/* Validate the mount data */
2629 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2630 	if (error == NFS_TEXT_DATA)
2631 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2632 	if (error < 0) {
2633 		mntroot = ERR_PTR(error);
2634 		goto out;
2635 	}
2636 
2637 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2638 	if (IS_ERR(nfs_mod)) {
2639 		mntroot = ERR_CAST(nfs_mod);
2640 		goto out;
2641 	}
2642 
2643 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2644 
2645 	put_nfs_version(nfs_mod);
2646 out:
2647 	nfs_free_parsed_mount_data(mount_info.parsed);
2648 	nfs_free_fhandle(mount_info.mntfh);
2649 	return mntroot;
2650 }
2651 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2652 
2653 /*
2654  * Ensure that we unregister the bdi before kill_anon_super
2655  * releases the device name
2656  */
2657 void nfs_put_super(struct super_block *s)
2658 {
2659 	struct nfs_server *server = NFS_SB(s);
2660 
2661 	bdi_unregister(&server->backing_dev_info);
2662 }
2663 EXPORT_SYMBOL_GPL(nfs_put_super);
2664 
2665 /*
2666  * Destroy an NFS2/3 superblock
2667  */
2668 void nfs_kill_super(struct super_block *s)
2669 {
2670 	struct nfs_server *server = NFS_SB(s);
2671 
2672 	kill_anon_super(s);
2673 	nfs_fscache_release_super_cookie(s);
2674 	nfs_free_server(server);
2675 }
2676 EXPORT_SYMBOL_GPL(nfs_kill_super);
2677 
2678 /*
2679  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2680  */
2681 static struct dentry *
2682 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2683 		const char *dev_name, void *raw_data)
2684 {
2685 	struct nfs_clone_mount *data = raw_data;
2686 	struct nfs_mount_info mount_info = {
2687 		.fill_super = nfs_clone_super,
2688 		.set_security = nfs_clone_sb_security,
2689 		.cloned = data,
2690 	};
2691 	struct nfs_server *server;
2692 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2693 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2694 
2695 	dprintk("--> nfs_xdev_mount()\n");
2696 
2697 	mount_info.mntfh = mount_info.cloned->fh;
2698 
2699 	/* create a new volume representation */
2700 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2701 
2702 	if (IS_ERR(server))
2703 		mntroot = ERR_CAST(server);
2704 	else
2705 		mntroot = nfs_fs_mount_common(server, flags,
2706 				dev_name, &mount_info, nfs_mod);
2707 
2708 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2709 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2710 	return mntroot;
2711 }
2712 
2713 #if IS_ENABLED(CONFIG_NFS_V4)
2714 
2715 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2716 {
2717 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2718 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2719 }
2720 
2721 /*
2722  * Validate NFSv4 mount options
2723  */
2724 static int nfs4_validate_mount_data(void *options,
2725 				    struct nfs_parsed_mount_data *args,
2726 				    const char *dev_name)
2727 {
2728 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2729 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2730 	char *c;
2731 
2732 	if (data == NULL)
2733 		goto out_no_data;
2734 
2735 	args->version = 4;
2736 
2737 	switch (data->version) {
2738 	case 1:
2739 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2740 			goto out_no_address;
2741 		if (data->host_addrlen == 0)
2742 			goto out_no_address;
2743 		args->nfs_server.addrlen = data->host_addrlen;
2744 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2745 			return -EFAULT;
2746 		if (!nfs_verify_server_address(sap))
2747 			goto out_no_address;
2748 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2749 
2750 		if (data->auth_flavourlen) {
2751 			rpc_authflavor_t pseudoflavor;
2752 			if (data->auth_flavourlen > 1)
2753 				goto out_inval_auth;
2754 			if (copy_from_user(&pseudoflavor,
2755 					   data->auth_flavours,
2756 					   sizeof(pseudoflavor)))
2757 				return -EFAULT;
2758 			args->selected_flavor = pseudoflavor;
2759 		} else
2760 			args->selected_flavor = RPC_AUTH_UNIX;
2761 
2762 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2763 		if (IS_ERR(c))
2764 			return PTR_ERR(c);
2765 		args->nfs_server.hostname = c;
2766 
2767 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2768 		if (IS_ERR(c))
2769 			return PTR_ERR(c);
2770 		args->nfs_server.export_path = c;
2771 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2772 
2773 		c = strndup_user(data->client_addr.data, 16);
2774 		if (IS_ERR(c))
2775 			return PTR_ERR(c);
2776 		args->client_address = c;
2777 
2778 		/*
2779 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2780 		 * can deal with.
2781 		 */
2782 
2783 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2784 		args->rsize	= data->rsize;
2785 		args->wsize	= data->wsize;
2786 		args->timeo	= data->timeo;
2787 		args->retrans	= data->retrans;
2788 		args->acregmin	= data->acregmin;
2789 		args->acregmax	= data->acregmax;
2790 		args->acdirmin	= data->acdirmin;
2791 		args->acdirmax	= data->acdirmax;
2792 		args->nfs_server.protocol = data->proto;
2793 		nfs_validate_transport_protocol(args);
2794 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2795 			goto out_invalid_transport_udp;
2796 
2797 		break;
2798 	default:
2799 		return NFS_TEXT_DATA;
2800 	}
2801 
2802 	return 0;
2803 
2804 out_no_data:
2805 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2806 	return -EINVAL;
2807 
2808 out_inval_auth:
2809 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2810 		 data->auth_flavourlen);
2811 	return -EINVAL;
2812 
2813 out_no_address:
2814 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2815 	return -EINVAL;
2816 
2817 out_invalid_transport_udp:
2818 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2819 	return -EINVAL;
2820 }
2821 
2822 /*
2823  * NFS v4 module parameters need to stay in the
2824  * NFS client for backwards compatibility
2825  */
2826 unsigned int nfs_callback_set_tcpport;
2827 unsigned short nfs_callback_tcpport;
2828 /* Default cache timeout is 10 minutes */
2829 unsigned int nfs_idmap_cache_timeout = 600;
2830 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2831 bool nfs4_disable_idmapping = true;
2832 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2833 unsigned short send_implementation_id = 1;
2834 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2835 bool recover_lost_locks = false;
2836 
2837 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2838 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2839 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2840 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2841 EXPORT_SYMBOL_GPL(max_session_slots);
2842 EXPORT_SYMBOL_GPL(send_implementation_id);
2843 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2844 EXPORT_SYMBOL_GPL(recover_lost_locks);
2845 
2846 #define NFS_CALLBACK_MAXPORTNR (65535U)
2847 
2848 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2849 {
2850 	unsigned long num;
2851 	int ret;
2852 
2853 	if (!val)
2854 		return -EINVAL;
2855 	ret = kstrtoul(val, 0, &num);
2856 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2857 		return -EINVAL;
2858 	*((unsigned int *)kp->arg) = num;
2859 	return 0;
2860 }
2861 static struct kernel_param_ops param_ops_portnr = {
2862 	.set = param_set_portnr,
2863 	.get = param_get_uint,
2864 };
2865 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2866 
2867 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2868 module_param(nfs_idmap_cache_timeout, int, 0644);
2869 module_param(nfs4_disable_idmapping, bool, 0644);
2870 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2871 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2872 MODULE_PARM_DESC(nfs4_disable_idmapping,
2873 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2874 module_param(max_session_slots, ushort, 0644);
2875 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2876 		"requests the client will negotiate");
2877 module_param(send_implementation_id, ushort, 0644);
2878 MODULE_PARM_DESC(send_implementation_id,
2879 		"Send implementation ID with NFSv4.1 exchange_id");
2880 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2881 
2882 module_param(recover_lost_locks, bool, 0644);
2883 MODULE_PARM_DESC(recover_lost_locks,
2884 		 "If the server reports that a lock might be lost, "
2885 		 "try to recover it risking data corruption.");
2886 
2887 
2888 #endif /* CONFIG_NFS_V4 */
2889