xref: /linux/fs/nfs/super.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
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 	.statfs		= nfs_statfs,
315 	.evict_inode	= nfs_evict_inode,
316 	.umount_begin	= nfs_umount_begin,
317 	.show_options	= nfs_show_options,
318 	.show_devname	= nfs_show_devname,
319 	.show_path	= nfs_show_path,
320 	.show_stats	= nfs_show_stats,
321 	.remount_fs	= nfs_remount,
322 };
323 EXPORT_SYMBOL_GPL(nfs_sops);
324 
325 #if IS_ENABLED(CONFIG_NFS_V4)
326 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
327 static int nfs4_validate_mount_data(void *options,
328 	struct nfs_parsed_mount_data *args, const char *dev_name);
329 
330 struct file_system_type nfs4_fs_type = {
331 	.owner		= THIS_MODULE,
332 	.name		= "nfs4",
333 	.mount		= nfs_fs_mount,
334 	.kill_sb	= nfs_kill_super,
335 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
336 };
337 MODULE_ALIAS_FS("nfs4");
338 MODULE_ALIAS("nfs4");
339 EXPORT_SYMBOL_GPL(nfs4_fs_type);
340 
341 static int __init register_nfs4_fs(void)
342 {
343 	return register_filesystem(&nfs4_fs_type);
344 }
345 
346 static void unregister_nfs4_fs(void)
347 {
348 	unregister_filesystem(&nfs4_fs_type);
349 }
350 #else
351 static int __init register_nfs4_fs(void)
352 {
353 	return 0;
354 }
355 
356 static void unregister_nfs4_fs(void)
357 {
358 }
359 #endif
360 
361 static struct shrinker acl_shrinker = {
362 	.count_objects	= nfs_access_cache_count,
363 	.scan_objects	= nfs_access_cache_scan,
364 	.seeks		= DEFAULT_SEEKS,
365 };
366 
367 /*
368  * Register the NFS filesystems
369  */
370 int __init register_nfs_fs(void)
371 {
372 	int ret;
373 
374         ret = register_filesystem(&nfs_fs_type);
375 	if (ret < 0)
376 		goto error_0;
377 
378 	ret = register_nfs4_fs();
379 	if (ret < 0)
380 		goto error_1;
381 
382 	ret = nfs_register_sysctl();
383 	if (ret < 0)
384 		goto error_2;
385 	register_shrinker(&acl_shrinker);
386 	return 0;
387 
388 error_2:
389 	unregister_nfs4_fs();
390 error_1:
391 	unregister_filesystem(&nfs_fs_type);
392 error_0:
393 	return ret;
394 }
395 
396 /*
397  * Unregister the NFS filesystems
398  */
399 void __exit unregister_nfs_fs(void)
400 {
401 	unregister_shrinker(&acl_shrinker);
402 	nfs_unregister_sysctl();
403 	unregister_nfs4_fs();
404 	unregister_filesystem(&nfs_fs_type);
405 }
406 
407 bool nfs_sb_active(struct super_block *sb)
408 {
409 	struct nfs_server *server = NFS_SB(sb);
410 
411 	if (!atomic_inc_not_zero(&sb->s_active))
412 		return false;
413 	if (atomic_inc_return(&server->active) != 1)
414 		atomic_dec(&sb->s_active);
415 	return true;
416 }
417 EXPORT_SYMBOL_GPL(nfs_sb_active);
418 
419 void nfs_sb_deactive(struct super_block *sb)
420 {
421 	struct nfs_server *server = NFS_SB(sb);
422 
423 	if (atomic_dec_and_test(&server->active))
424 		deactivate_super(sb);
425 }
426 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
427 
428 /*
429  * Deliver file system statistics to userspace
430  */
431 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
432 {
433 	struct nfs_server *server = NFS_SB(dentry->d_sb);
434 	unsigned char blockbits;
435 	unsigned long blockres;
436 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
437 	struct nfs_fsstat res;
438 	int error = -ENOMEM;
439 
440 	res.fattr = nfs_alloc_fattr();
441 	if (res.fattr == NULL)
442 		goto out_err;
443 
444 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
445 	if (unlikely(error == -ESTALE)) {
446 		struct dentry *pd_dentry;
447 
448 		pd_dentry = dget_parent(dentry);
449 		if (pd_dentry != NULL) {
450 			nfs_zap_caches(pd_dentry->d_inode);
451 			dput(pd_dentry);
452 		}
453 	}
454 	nfs_free_fattr(res.fattr);
455 	if (error < 0)
456 		goto out_err;
457 
458 	buf->f_type = NFS_SUPER_MAGIC;
459 
460 	/*
461 	 * Current versions of glibc do not correctly handle the
462 	 * case where f_frsize != f_bsize.  Eventually we want to
463 	 * report the value of wtmult in this field.
464 	 */
465 	buf->f_frsize = dentry->d_sb->s_blocksize;
466 
467 	/*
468 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
469 	 * are reported in units of f_frsize.  Linux hasn't had
470 	 * an f_frsize field in its statfs struct until recently,
471 	 * thus historically Linux's sys_statfs reports these
472 	 * fields in units of f_bsize.
473 	 */
474 	buf->f_bsize = dentry->d_sb->s_blocksize;
475 	blockbits = dentry->d_sb->s_blocksize_bits;
476 	blockres = (1 << blockbits) - 1;
477 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
478 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
479 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
480 
481 	buf->f_files = res.tfiles;
482 	buf->f_ffree = res.afiles;
483 
484 	buf->f_namelen = server->namelen;
485 
486 	return 0;
487 
488  out_err:
489 	dprintk("%s: statfs error = %d\n", __func__, -error);
490 	return error;
491 }
492 EXPORT_SYMBOL_GPL(nfs_statfs);
493 
494 /*
495  * Map the security flavour number to a name
496  */
497 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
498 {
499 	static const struct {
500 		rpc_authflavor_t flavour;
501 		const char *str;
502 	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
503 		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
504 		{ RPC_AUTH_NULL, "null" },
505 		{ RPC_AUTH_UNIX, "sys" },
506 		{ RPC_AUTH_GSS_KRB5, "krb5" },
507 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
508 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
509 		{ RPC_AUTH_GSS_LKEY, "lkey" },
510 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
511 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
512 		{ RPC_AUTH_GSS_SPKM, "spkm" },
513 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
514 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
515 		{ UINT_MAX, "unknown" }
516 	};
517 	int i;
518 
519 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
520 		if (sec_flavours[i].flavour == flavour)
521 			break;
522 	}
523 	return sec_flavours[i].str;
524 }
525 
526 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
527 				  int showdefaults)
528 {
529 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
530 
531 	seq_printf(m, ",mountproto=");
532 	switch (sap->sa_family) {
533 	case AF_INET:
534 		switch (nfss->mountd_protocol) {
535 		case IPPROTO_UDP:
536 			seq_printf(m, RPCBIND_NETID_UDP);
537 			break;
538 		case IPPROTO_TCP:
539 			seq_printf(m, RPCBIND_NETID_TCP);
540 			break;
541 		default:
542 			if (showdefaults)
543 				seq_printf(m, "auto");
544 		}
545 		break;
546 	case AF_INET6:
547 		switch (nfss->mountd_protocol) {
548 		case IPPROTO_UDP:
549 			seq_printf(m, RPCBIND_NETID_UDP6);
550 			break;
551 		case IPPROTO_TCP:
552 			seq_printf(m, RPCBIND_NETID_TCP6);
553 			break;
554 		default:
555 			if (showdefaults)
556 				seq_printf(m, "auto");
557 		}
558 		break;
559 	default:
560 		if (showdefaults)
561 			seq_printf(m, "auto");
562 	}
563 }
564 
565 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
566 				    int showdefaults)
567 {
568 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
569 
570 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
571 		return;
572 
573 	switch (sap->sa_family) {
574 	case AF_INET: {
575 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
576 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
577 		break;
578 	}
579 	case AF_INET6: {
580 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
581 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
582 		break;
583 	}
584 	default:
585 		if (showdefaults)
586 			seq_printf(m, ",mountaddr=unspecified");
587 	}
588 
589 	if (nfss->mountd_version || showdefaults)
590 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
591 	if ((nfss->mountd_port &&
592 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
593 		showdefaults)
594 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
595 
596 	nfs_show_mountd_netid(m, nfss, showdefaults);
597 }
598 
599 #if IS_ENABLED(CONFIG_NFS_V4)
600 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
601 				    int showdefaults)
602 {
603 	struct nfs_client *clp = nfss->nfs_client;
604 
605 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
606 }
607 #else
608 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
609 				    int showdefaults)
610 {
611 }
612 #endif
613 
614 static void nfs_show_nfs_version(struct seq_file *m,
615 		unsigned int version,
616 		unsigned int minorversion)
617 {
618 	seq_printf(m, ",vers=%u", version);
619 	if (version == 4)
620 		seq_printf(m, ".%u", minorversion);
621 }
622 
623 /*
624  * Describe the mount options in force on this server representation
625  */
626 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
627 				   int showdefaults)
628 {
629 	static const struct proc_nfs_info {
630 		int flag;
631 		const char *str;
632 		const char *nostr;
633 	} nfs_info[] = {
634 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
635 		{ NFS_MOUNT_POSIX, ",posix", "" },
636 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
637 		{ NFS_MOUNT_NOAC, ",noac", "" },
638 		{ NFS_MOUNT_NONLM, ",nolock", "" },
639 		{ NFS_MOUNT_NOACL, ",noacl", "" },
640 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
641 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
642 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
643 		{ 0, NULL, NULL }
644 	};
645 	const struct proc_nfs_info *nfs_infop;
646 	struct nfs_client *clp = nfss->nfs_client;
647 	u32 version = clp->rpc_ops->version;
648 	int local_flock, local_fcntl;
649 
650 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
651 	seq_printf(m, ",rsize=%u", nfss->rsize);
652 	seq_printf(m, ",wsize=%u", nfss->wsize);
653 	if (nfss->bsize != 0)
654 		seq_printf(m, ",bsize=%u", nfss->bsize);
655 	seq_printf(m, ",namlen=%u", nfss->namelen);
656 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
657 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
658 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
659 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
660 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
661 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
662 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
663 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
664 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
665 		if (nfss->flags & nfs_infop->flag)
666 			seq_puts(m, nfs_infop->str);
667 		else
668 			seq_puts(m, nfs_infop->nostr);
669 	}
670 	rcu_read_lock();
671 	seq_printf(m, ",proto=%s",
672 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
673 	rcu_read_unlock();
674 	if (version == 4) {
675 		if (nfss->port != NFS_PORT)
676 			seq_printf(m, ",port=%u", nfss->port);
677 	} else
678 		if (nfss->port)
679 			seq_printf(m, ",port=%u", nfss->port);
680 
681 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
682 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
683 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
684 
685 	if (version != 4)
686 		nfs_show_mountd_options(m, nfss, showdefaults);
687 	else
688 		nfs_show_nfsv4_options(m, nfss, showdefaults);
689 
690 	if (nfss->options & NFS_OPTION_FSCACHE)
691 		seq_printf(m, ",fsc");
692 
693 	if (nfss->options & NFS_OPTION_MIGRATION)
694 		seq_printf(m, ",migration");
695 
696 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
697 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
698 			seq_printf(m, ",lookupcache=none");
699 		else
700 			seq_printf(m, ",lookupcache=pos");
701 	}
702 
703 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
704 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
705 
706 	if (!local_flock && !local_fcntl)
707 		seq_printf(m, ",local_lock=none");
708 	else if (local_flock && local_fcntl)
709 		seq_printf(m, ",local_lock=all");
710 	else if (local_flock)
711 		seq_printf(m, ",local_lock=flock");
712 	else
713 		seq_printf(m, ",local_lock=posix");
714 }
715 
716 /*
717  * Describe the mount options on this VFS mountpoint
718  */
719 int nfs_show_options(struct seq_file *m, struct dentry *root)
720 {
721 	struct nfs_server *nfss = NFS_SB(root->d_sb);
722 
723 	nfs_show_mount_options(m, nfss, 0);
724 
725 	rcu_read_lock();
726 	seq_printf(m, ",addr=%s",
727 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
728 							RPC_DISPLAY_ADDR));
729 	rcu_read_unlock();
730 
731 	return 0;
732 }
733 EXPORT_SYMBOL_GPL(nfs_show_options);
734 
735 #if IS_ENABLED(CONFIG_NFS_V4)
736 #ifdef CONFIG_NFS_V4_1
737 static void show_sessions(struct seq_file *m, struct nfs_server *server)
738 {
739 	if (nfs4_has_session(server->nfs_client))
740 		seq_printf(m, ",sessions");
741 }
742 #else
743 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
744 #endif
745 #endif
746 
747 #ifdef CONFIG_NFS_V4_1
748 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
749 {
750 	seq_printf(m, ",pnfs=");
751 	if (server->pnfs_curr_ld)
752 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
753 	else
754 		seq_printf(m, "not configured");
755 }
756 
757 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
758 {
759 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
760 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
761 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
762 			   "date='%llu,%u'",
763 			   impl_id->name, impl_id->domain,
764 			   impl_id->date.seconds, impl_id->date.nseconds);
765 	}
766 }
767 #else
768 #if IS_ENABLED(CONFIG_NFS_V4)
769 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
770 {
771 }
772 #endif
773 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
774 {
775 }
776 #endif
777 
778 int nfs_show_devname(struct seq_file *m, struct dentry *root)
779 {
780 	char *page = (char *) __get_free_page(GFP_KERNEL);
781 	char *devname, *dummy;
782 	int err = 0;
783 	if (!page)
784 		return -ENOMEM;
785 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
786 	if (IS_ERR(devname))
787 		err = PTR_ERR(devname);
788 	else
789 		seq_escape(m, devname, " \t\n\\");
790 	free_page((unsigned long)page);
791 	return err;
792 }
793 EXPORT_SYMBOL_GPL(nfs_show_devname);
794 
795 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
796 {
797 	seq_puts(m, "/");
798 	return 0;
799 }
800 EXPORT_SYMBOL_GPL(nfs_show_path);
801 
802 /*
803  * Present statistical information for this VFS mountpoint
804  */
805 int nfs_show_stats(struct seq_file *m, struct dentry *root)
806 {
807 	int i, cpu;
808 	struct nfs_server *nfss = NFS_SB(root->d_sb);
809 	struct rpc_auth *auth = nfss->client->cl_auth;
810 	struct nfs_iostats totals = { };
811 
812 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
813 
814 	/*
815 	 * Display all mount option settings
816 	 */
817 	seq_printf(m, "\n\topts:\t");
818 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
819 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
820 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
821 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
822 	nfs_show_mount_options(m, nfss, 1);
823 
824 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
825 
826 	show_implementation_id(m, nfss);
827 
828 	seq_printf(m, "\n\tcaps:\t");
829 	seq_printf(m, "caps=0x%x", nfss->caps);
830 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
831 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
832 	seq_printf(m, ",bsize=%u", nfss->bsize);
833 	seq_printf(m, ",namlen=%u", nfss->namelen);
834 
835 #if IS_ENABLED(CONFIG_NFS_V4)
836 	if (nfss->nfs_client->rpc_ops->version == 4) {
837 		seq_printf(m, "\n\tnfsv4:\t");
838 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
839 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
840 		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
841 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
842 		show_sessions(m, nfss);
843 		show_pnfs(m, nfss);
844 	}
845 #endif
846 
847 	/*
848 	 * Display security flavor in effect for this mount
849 	 */
850 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
851 	if (auth->au_flavor)
852 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
853 
854 	/*
855 	 * Display superblock I/O counters
856 	 */
857 	for_each_possible_cpu(cpu) {
858 		struct nfs_iostats *stats;
859 
860 		preempt_disable();
861 		stats = per_cpu_ptr(nfss->io_stats, cpu);
862 
863 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
864 			totals.events[i] += stats->events[i];
865 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
866 			totals.bytes[i] += stats->bytes[i];
867 #ifdef CONFIG_NFS_FSCACHE
868 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
869 			totals.fscache[i] += stats->fscache[i];
870 #endif
871 
872 		preempt_enable();
873 	}
874 
875 	seq_printf(m, "\n\tevents:\t");
876 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
877 		seq_printf(m, "%lu ", totals.events[i]);
878 	seq_printf(m, "\n\tbytes:\t");
879 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
880 		seq_printf(m, "%Lu ", totals.bytes[i]);
881 #ifdef CONFIG_NFS_FSCACHE
882 	if (nfss->options & NFS_OPTION_FSCACHE) {
883 		seq_printf(m, "\n\tfsc:\t");
884 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
885 			seq_printf(m, "%Lu ", totals.bytes[i]);
886 	}
887 #endif
888 	seq_printf(m, "\n");
889 
890 	rpc_print_iostats(m, nfss->client);
891 
892 	return 0;
893 }
894 EXPORT_SYMBOL_GPL(nfs_show_stats);
895 
896 /*
897  * Begin unmount by attempting to remove all automounted mountpoints we added
898  * in response to xdev traversals and referrals
899  */
900 void nfs_umount_begin(struct super_block *sb)
901 {
902 	struct nfs_server *server;
903 	struct rpc_clnt *rpc;
904 
905 	server = NFS_SB(sb);
906 	/* -EIO all pending I/O */
907 	rpc = server->client_acl;
908 	if (!IS_ERR(rpc))
909 		rpc_killall_tasks(rpc);
910 	rpc = server->client;
911 	if (!IS_ERR(rpc))
912 		rpc_killall_tasks(rpc);
913 }
914 EXPORT_SYMBOL_GPL(nfs_umount_begin);
915 
916 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
917 {
918 	struct nfs_parsed_mount_data *data;
919 
920 	data = kzalloc(sizeof(*data), GFP_KERNEL);
921 	if (data) {
922 		data->acregmin		= NFS_DEF_ACREGMIN;
923 		data->acregmax		= NFS_DEF_ACREGMAX;
924 		data->acdirmin		= NFS_DEF_ACDIRMIN;
925 		data->acdirmax		= NFS_DEF_ACDIRMAX;
926 		data->mount_server.port	= NFS_UNSPEC_PORT;
927 		data->nfs_server.port	= NFS_UNSPEC_PORT;
928 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
929 		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
930 		data->minorversion	= 0;
931 		data->need_mount	= true;
932 		data->net		= current->nsproxy->net_ns;
933 		security_init_mnt_opts(&data->lsm_opts);
934 	}
935 	return data;
936 }
937 
938 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
939 {
940 	if (data) {
941 		kfree(data->client_address);
942 		kfree(data->mount_server.hostname);
943 		kfree(data->nfs_server.export_path);
944 		kfree(data->nfs_server.hostname);
945 		kfree(data->fscache_uniq);
946 		security_free_mnt_opts(&data->lsm_opts);
947 		kfree(data);
948 	}
949 }
950 
951 /*
952  * Sanity-check a server address provided by the mount command.
953  *
954  * Address family must be initialized, and address must not be
955  * the ANY address for that family.
956  */
957 static int nfs_verify_server_address(struct sockaddr *addr)
958 {
959 	switch (addr->sa_family) {
960 	case AF_INET: {
961 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
962 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
963 	}
964 	case AF_INET6: {
965 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
966 		return !ipv6_addr_any(sa);
967 	}
968 	}
969 
970 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
971 	return 0;
972 }
973 
974 /*
975  * Select between a default port value and a user-specified port value.
976  * If a zero value is set, then autobind will be used.
977  */
978 static void nfs_set_port(struct sockaddr *sap, int *port,
979 				 const unsigned short default_port)
980 {
981 	if (*port == NFS_UNSPEC_PORT)
982 		*port = default_port;
983 
984 	rpc_set_port(sap, *port);
985 }
986 
987 /*
988  * Sanity check the NFS transport protocol.
989  *
990  */
991 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
992 {
993 	switch (mnt->nfs_server.protocol) {
994 	case XPRT_TRANSPORT_UDP:
995 	case XPRT_TRANSPORT_TCP:
996 	case XPRT_TRANSPORT_RDMA:
997 		break;
998 	default:
999 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1000 	}
1001 }
1002 
1003 /*
1004  * For text based NFSv2/v3 mounts, the mount protocol transport default
1005  * settings should depend upon the specified NFS transport.
1006  */
1007 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1008 {
1009 	nfs_validate_transport_protocol(mnt);
1010 
1011 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1012 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1013 			return;
1014 	switch (mnt->nfs_server.protocol) {
1015 	case XPRT_TRANSPORT_UDP:
1016 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1017 		break;
1018 	case XPRT_TRANSPORT_TCP:
1019 	case XPRT_TRANSPORT_RDMA:
1020 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1021 	}
1022 }
1023 
1024 /*
1025  * Add 'flavor' to 'auth_info' if not already present.
1026  * Returns true if 'flavor' ends up in the list, false otherwise
1027  */
1028 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1029 			      rpc_authflavor_t flavor)
1030 {
1031 	unsigned int i;
1032 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1033 
1034 	/* make sure this flavor isn't already in the list */
1035 	for (i = 0; i < auth_info->flavor_len; i++) {
1036 		if (flavor == auth_info->flavors[i])
1037 			return true;
1038 	}
1039 
1040 	if (auth_info->flavor_len + 1 >= max_flavor_len) {
1041 		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1042 		return false;
1043 	}
1044 
1045 	auth_info->flavors[auth_info->flavor_len++] = flavor;
1046 	return true;
1047 }
1048 
1049 /*
1050  * Return true if 'match' is in auth_info or auth_info is empty.
1051  * Return false otherwise.
1052  */
1053 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1054 			 rpc_authflavor_t match)
1055 {
1056 	int i;
1057 
1058 	if (!auth_info->flavor_len)
1059 		return true;
1060 
1061 	for (i = 0; i < auth_info->flavor_len; i++) {
1062 		if (auth_info->flavors[i] == match)
1063 			return true;
1064 	}
1065 	return false;
1066 }
1067 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1068 
1069 /*
1070  * Parse the value of the 'sec=' option.
1071  */
1072 static int nfs_parse_security_flavors(char *value,
1073 				      struct nfs_parsed_mount_data *mnt)
1074 {
1075 	substring_t args[MAX_OPT_ARGS];
1076 	rpc_authflavor_t pseudoflavor;
1077 	char *p;
1078 
1079 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1080 
1081 	while ((p = strsep(&value, ":")) != NULL) {
1082 		switch (match_token(p, nfs_secflavor_tokens, args)) {
1083 		case Opt_sec_none:
1084 			pseudoflavor = RPC_AUTH_NULL;
1085 			break;
1086 		case Opt_sec_sys:
1087 			pseudoflavor = RPC_AUTH_UNIX;
1088 			break;
1089 		case Opt_sec_krb5:
1090 			pseudoflavor = RPC_AUTH_GSS_KRB5;
1091 			break;
1092 		case Opt_sec_krb5i:
1093 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
1094 			break;
1095 		case Opt_sec_krb5p:
1096 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
1097 			break;
1098 		case Opt_sec_lkey:
1099 			pseudoflavor = RPC_AUTH_GSS_LKEY;
1100 			break;
1101 		case Opt_sec_lkeyi:
1102 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
1103 			break;
1104 		case Opt_sec_lkeyp:
1105 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
1106 			break;
1107 		case Opt_sec_spkm:
1108 			pseudoflavor = RPC_AUTH_GSS_SPKM;
1109 			break;
1110 		case Opt_sec_spkmi:
1111 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
1112 			break;
1113 		case Opt_sec_spkmp:
1114 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
1115 			break;
1116 		default:
1117 			dfprintk(MOUNT,
1118 				 "NFS: sec= option '%s' not recognized\n", p);
1119 			return 0;
1120 		}
1121 
1122 		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1123 			return 0;
1124 	}
1125 
1126 	return 1;
1127 }
1128 
1129 static int nfs_parse_version_string(char *string,
1130 		struct nfs_parsed_mount_data *mnt,
1131 		substring_t *args)
1132 {
1133 	mnt->flags &= ~NFS_MOUNT_VER3;
1134 	switch (match_token(string, nfs_vers_tokens, args)) {
1135 	case Opt_vers_2:
1136 		mnt->version = 2;
1137 		break;
1138 	case Opt_vers_3:
1139 		mnt->flags |= NFS_MOUNT_VER3;
1140 		mnt->version = 3;
1141 		break;
1142 	case Opt_vers_4:
1143 		/* Backward compatibility option. In future,
1144 		 * the mount program should always supply
1145 		 * a NFSv4 minor version number.
1146 		 */
1147 		mnt->version = 4;
1148 		break;
1149 	case Opt_vers_4_0:
1150 		mnt->version = 4;
1151 		mnt->minorversion = 0;
1152 		break;
1153 	case Opt_vers_4_1:
1154 		mnt->version = 4;
1155 		mnt->minorversion = 1;
1156 		break;
1157 	case Opt_vers_4_2:
1158 		mnt->version = 4;
1159 		mnt->minorversion = 2;
1160 		break;
1161 	default:
1162 		return 0;
1163 	}
1164 	return 1;
1165 }
1166 
1167 static int nfs_get_option_str(substring_t args[], char **option)
1168 {
1169 	kfree(*option);
1170 	*option = match_strdup(args);
1171 	return !*option;
1172 }
1173 
1174 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1175 {
1176 	int rc;
1177 	char *string;
1178 
1179 	string = match_strdup(args);
1180 	if (string == NULL)
1181 		return -ENOMEM;
1182 	rc = kstrtoul(string, 10, option);
1183 	kfree(string);
1184 
1185 	return rc;
1186 }
1187 
1188 /*
1189  * Error-check and convert a string of mount options from user space into
1190  * a data structure.  The whole mount string is processed; bad options are
1191  * skipped as they are encountered.  If there were no errors, return 1;
1192  * otherwise return 0 (zero).
1193  */
1194 static int nfs_parse_mount_options(char *raw,
1195 				   struct nfs_parsed_mount_data *mnt)
1196 {
1197 	char *p, *string, *secdata;
1198 	int rc, sloppy = 0, invalid_option = 0;
1199 	unsigned short protofamily = AF_UNSPEC;
1200 	unsigned short mountfamily = AF_UNSPEC;
1201 
1202 	if (!raw) {
1203 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1204 		return 1;
1205 	}
1206 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1207 
1208 	secdata = alloc_secdata();
1209 	if (!secdata)
1210 		goto out_nomem;
1211 
1212 	rc = security_sb_copy_data(raw, secdata);
1213 	if (rc)
1214 		goto out_security_failure;
1215 
1216 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1217 	if (rc)
1218 		goto out_security_failure;
1219 
1220 	free_secdata(secdata);
1221 
1222 	while ((p = strsep(&raw, ",")) != NULL) {
1223 		substring_t args[MAX_OPT_ARGS];
1224 		unsigned long option;
1225 		int token;
1226 
1227 		if (!*p)
1228 			continue;
1229 
1230 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1231 
1232 		token = match_token(p, nfs_mount_option_tokens, args);
1233 		switch (token) {
1234 
1235 		/*
1236 		 * boolean options:  foo/nofoo
1237 		 */
1238 		case Opt_soft:
1239 			mnt->flags |= NFS_MOUNT_SOFT;
1240 			break;
1241 		case Opt_hard:
1242 			mnt->flags &= ~NFS_MOUNT_SOFT;
1243 			break;
1244 		case Opt_posix:
1245 			mnt->flags |= NFS_MOUNT_POSIX;
1246 			break;
1247 		case Opt_noposix:
1248 			mnt->flags &= ~NFS_MOUNT_POSIX;
1249 			break;
1250 		case Opt_cto:
1251 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1252 			break;
1253 		case Opt_nocto:
1254 			mnt->flags |= NFS_MOUNT_NOCTO;
1255 			break;
1256 		case Opt_ac:
1257 			mnt->flags &= ~NFS_MOUNT_NOAC;
1258 			break;
1259 		case Opt_noac:
1260 			mnt->flags |= NFS_MOUNT_NOAC;
1261 			break;
1262 		case Opt_lock:
1263 			mnt->flags &= ~NFS_MOUNT_NONLM;
1264 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1265 					NFS_MOUNT_LOCAL_FCNTL);
1266 			break;
1267 		case Opt_nolock:
1268 			mnt->flags |= NFS_MOUNT_NONLM;
1269 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1270 				       NFS_MOUNT_LOCAL_FCNTL);
1271 			break;
1272 		case Opt_udp:
1273 			mnt->flags &= ~NFS_MOUNT_TCP;
1274 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1275 			break;
1276 		case Opt_tcp:
1277 			mnt->flags |= NFS_MOUNT_TCP;
1278 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1279 			break;
1280 		case Opt_rdma:
1281 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1282 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1283 			xprt_load_transport(p);
1284 			break;
1285 		case Opt_acl:
1286 			mnt->flags &= ~NFS_MOUNT_NOACL;
1287 			break;
1288 		case Opt_noacl:
1289 			mnt->flags |= NFS_MOUNT_NOACL;
1290 			break;
1291 		case Opt_rdirplus:
1292 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1293 			break;
1294 		case Opt_nordirplus:
1295 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1296 			break;
1297 		case Opt_sharecache:
1298 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1299 			break;
1300 		case Opt_nosharecache:
1301 			mnt->flags |= NFS_MOUNT_UNSHARED;
1302 			break;
1303 		case Opt_resvport:
1304 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1305 			break;
1306 		case Opt_noresvport:
1307 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1308 			break;
1309 		case Opt_fscache:
1310 			mnt->options |= NFS_OPTION_FSCACHE;
1311 			kfree(mnt->fscache_uniq);
1312 			mnt->fscache_uniq = NULL;
1313 			break;
1314 		case Opt_nofscache:
1315 			mnt->options &= ~NFS_OPTION_FSCACHE;
1316 			kfree(mnt->fscache_uniq);
1317 			mnt->fscache_uniq = NULL;
1318 			break;
1319 		case Opt_migration:
1320 			mnt->options |= NFS_OPTION_MIGRATION;
1321 			break;
1322 		case Opt_nomigration:
1323 			mnt->options &= NFS_OPTION_MIGRATION;
1324 			break;
1325 
1326 		/*
1327 		 * options that take numeric values
1328 		 */
1329 		case Opt_port:
1330 			if (nfs_get_option_ul(args, &option) ||
1331 			    option > USHRT_MAX)
1332 				goto out_invalid_value;
1333 			mnt->nfs_server.port = option;
1334 			break;
1335 		case Opt_rsize:
1336 			if (nfs_get_option_ul(args, &option))
1337 				goto out_invalid_value;
1338 			mnt->rsize = option;
1339 			break;
1340 		case Opt_wsize:
1341 			if (nfs_get_option_ul(args, &option))
1342 				goto out_invalid_value;
1343 			mnt->wsize = option;
1344 			break;
1345 		case Opt_bsize:
1346 			if (nfs_get_option_ul(args, &option))
1347 				goto out_invalid_value;
1348 			mnt->bsize = option;
1349 			break;
1350 		case Opt_timeo:
1351 			if (nfs_get_option_ul(args, &option) || option == 0)
1352 				goto out_invalid_value;
1353 			mnt->timeo = option;
1354 			break;
1355 		case Opt_retrans:
1356 			if (nfs_get_option_ul(args, &option) || option == 0)
1357 				goto out_invalid_value;
1358 			mnt->retrans = option;
1359 			break;
1360 		case Opt_acregmin:
1361 			if (nfs_get_option_ul(args, &option))
1362 				goto out_invalid_value;
1363 			mnt->acregmin = option;
1364 			break;
1365 		case Opt_acregmax:
1366 			if (nfs_get_option_ul(args, &option))
1367 				goto out_invalid_value;
1368 			mnt->acregmax = option;
1369 			break;
1370 		case Opt_acdirmin:
1371 			if (nfs_get_option_ul(args, &option))
1372 				goto out_invalid_value;
1373 			mnt->acdirmin = option;
1374 			break;
1375 		case Opt_acdirmax:
1376 			if (nfs_get_option_ul(args, &option))
1377 				goto out_invalid_value;
1378 			mnt->acdirmax = option;
1379 			break;
1380 		case Opt_actimeo:
1381 			if (nfs_get_option_ul(args, &option))
1382 				goto out_invalid_value;
1383 			mnt->acregmin = mnt->acregmax =
1384 			mnt->acdirmin = mnt->acdirmax = option;
1385 			break;
1386 		case Opt_namelen:
1387 			if (nfs_get_option_ul(args, &option))
1388 				goto out_invalid_value;
1389 			mnt->namlen = option;
1390 			break;
1391 		case Opt_mountport:
1392 			if (nfs_get_option_ul(args, &option) ||
1393 			    option > USHRT_MAX)
1394 				goto out_invalid_value;
1395 			mnt->mount_server.port = option;
1396 			break;
1397 		case Opt_mountvers:
1398 			if (nfs_get_option_ul(args, &option) ||
1399 			    option < NFS_MNT_VERSION ||
1400 			    option > NFS_MNT3_VERSION)
1401 				goto out_invalid_value;
1402 			mnt->mount_server.version = option;
1403 			break;
1404 		case Opt_minorversion:
1405 			if (nfs_get_option_ul(args, &option))
1406 				goto out_invalid_value;
1407 			if (option > NFS4_MAX_MINOR_VERSION)
1408 				goto out_invalid_value;
1409 			mnt->minorversion = option;
1410 			break;
1411 
1412 		/*
1413 		 * options that take text values
1414 		 */
1415 		case Opt_nfsvers:
1416 			string = match_strdup(args);
1417 			if (string == NULL)
1418 				goto out_nomem;
1419 			rc = nfs_parse_version_string(string, mnt, args);
1420 			kfree(string);
1421 			if (!rc)
1422 				goto out_invalid_value;
1423 			break;
1424 		case Opt_sec:
1425 			string = match_strdup(args);
1426 			if (string == NULL)
1427 				goto out_nomem;
1428 			rc = nfs_parse_security_flavors(string, mnt);
1429 			kfree(string);
1430 			if (!rc) {
1431 				dfprintk(MOUNT, "NFS:   unrecognized "
1432 						"security flavor\n");
1433 				return 0;
1434 			}
1435 			break;
1436 		case Opt_proto:
1437 			string = match_strdup(args);
1438 			if (string == NULL)
1439 				goto out_nomem;
1440 			token = match_token(string,
1441 					    nfs_xprt_protocol_tokens, args);
1442 
1443 			protofamily = AF_INET;
1444 			switch (token) {
1445 			case Opt_xprt_udp6:
1446 				protofamily = AF_INET6;
1447 			case Opt_xprt_udp:
1448 				mnt->flags &= ~NFS_MOUNT_TCP;
1449 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1450 				break;
1451 			case Opt_xprt_tcp6:
1452 				protofamily = AF_INET6;
1453 			case Opt_xprt_tcp:
1454 				mnt->flags |= NFS_MOUNT_TCP;
1455 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1456 				break;
1457 			case Opt_xprt_rdma:
1458 				/* vector side protocols to TCP */
1459 				mnt->flags |= NFS_MOUNT_TCP;
1460 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1461 				xprt_load_transport(string);
1462 				break;
1463 			default:
1464 				dfprintk(MOUNT, "NFS:   unrecognized "
1465 						"transport protocol\n");
1466 				kfree(string);
1467 				return 0;
1468 			}
1469 			kfree(string);
1470 			break;
1471 		case Opt_mountproto:
1472 			string = match_strdup(args);
1473 			if (string == NULL)
1474 				goto out_nomem;
1475 			token = match_token(string,
1476 					    nfs_xprt_protocol_tokens, args);
1477 			kfree(string);
1478 
1479 			mountfamily = AF_INET;
1480 			switch (token) {
1481 			case Opt_xprt_udp6:
1482 				mountfamily = AF_INET6;
1483 			case Opt_xprt_udp:
1484 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1485 				break;
1486 			case Opt_xprt_tcp6:
1487 				mountfamily = AF_INET6;
1488 			case Opt_xprt_tcp:
1489 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1490 				break;
1491 			case Opt_xprt_rdma: /* not used for side protocols */
1492 			default:
1493 				dfprintk(MOUNT, "NFS:   unrecognized "
1494 						"transport protocol\n");
1495 				return 0;
1496 			}
1497 			break;
1498 		case Opt_addr:
1499 			string = match_strdup(args);
1500 			if (string == NULL)
1501 				goto out_nomem;
1502 			mnt->nfs_server.addrlen =
1503 				rpc_pton(mnt->net, string, strlen(string),
1504 					(struct sockaddr *)
1505 					&mnt->nfs_server.address,
1506 					sizeof(mnt->nfs_server.address));
1507 			kfree(string);
1508 			if (mnt->nfs_server.addrlen == 0)
1509 				goto out_invalid_address;
1510 			break;
1511 		case Opt_clientaddr:
1512 			if (nfs_get_option_str(args, &mnt->client_address))
1513 				goto out_nomem;
1514 			break;
1515 		case Opt_mounthost:
1516 			if (nfs_get_option_str(args,
1517 					       &mnt->mount_server.hostname))
1518 				goto out_nomem;
1519 			break;
1520 		case Opt_mountaddr:
1521 			string = match_strdup(args);
1522 			if (string == NULL)
1523 				goto out_nomem;
1524 			mnt->mount_server.addrlen =
1525 				rpc_pton(mnt->net, string, strlen(string),
1526 					(struct sockaddr *)
1527 					&mnt->mount_server.address,
1528 					sizeof(mnt->mount_server.address));
1529 			kfree(string);
1530 			if (mnt->mount_server.addrlen == 0)
1531 				goto out_invalid_address;
1532 			break;
1533 		case Opt_lookupcache:
1534 			string = match_strdup(args);
1535 			if (string == NULL)
1536 				goto out_nomem;
1537 			token = match_token(string,
1538 					nfs_lookupcache_tokens, args);
1539 			kfree(string);
1540 			switch (token) {
1541 				case Opt_lookupcache_all:
1542 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1543 					break;
1544 				case Opt_lookupcache_positive:
1545 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1546 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1547 					break;
1548 				case Opt_lookupcache_none:
1549 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1550 					break;
1551 				default:
1552 					dfprintk(MOUNT, "NFS:   invalid "
1553 							"lookupcache argument\n");
1554 					return 0;
1555 			};
1556 			break;
1557 		case Opt_fscache_uniq:
1558 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1559 				goto out_nomem;
1560 			mnt->options |= NFS_OPTION_FSCACHE;
1561 			break;
1562 		case Opt_local_lock:
1563 			string = match_strdup(args);
1564 			if (string == NULL)
1565 				goto out_nomem;
1566 			token = match_token(string, nfs_local_lock_tokens,
1567 					args);
1568 			kfree(string);
1569 			switch (token) {
1570 			case Opt_local_lock_all:
1571 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1572 					       NFS_MOUNT_LOCAL_FCNTL);
1573 				break;
1574 			case Opt_local_lock_flock:
1575 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1576 				break;
1577 			case Opt_local_lock_posix:
1578 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1579 				break;
1580 			case Opt_local_lock_none:
1581 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1582 						NFS_MOUNT_LOCAL_FCNTL);
1583 				break;
1584 			default:
1585 				dfprintk(MOUNT, "NFS:	invalid	"
1586 						"local_lock argument\n");
1587 				return 0;
1588 			};
1589 			break;
1590 
1591 		/*
1592 		 * Special options
1593 		 */
1594 		case Opt_sloppy:
1595 			sloppy = 1;
1596 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1597 			break;
1598 		case Opt_userspace:
1599 		case Opt_deprecated:
1600 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1601 					"'%s'\n", p);
1602 			break;
1603 
1604 		default:
1605 			invalid_option = 1;
1606 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1607 					"'%s'\n", p);
1608 		}
1609 	}
1610 
1611 	if (!sloppy && invalid_option)
1612 		return 0;
1613 
1614 	if (mnt->minorversion && mnt->version != 4)
1615 		goto out_minorversion_mismatch;
1616 
1617 	if (mnt->options & NFS_OPTION_MIGRATION &&
1618 	    (mnt->version != 4 || mnt->minorversion != 0))
1619 		goto out_migration_misuse;
1620 
1621 	/*
1622 	 * verify that any proto=/mountproto= options match the address
1623 	 * families in the addr=/mountaddr= options.
1624 	 */
1625 	if (protofamily != AF_UNSPEC &&
1626 	    protofamily != mnt->nfs_server.address.ss_family)
1627 		goto out_proto_mismatch;
1628 
1629 	if (mountfamily != AF_UNSPEC) {
1630 		if (mnt->mount_server.addrlen) {
1631 			if (mountfamily != mnt->mount_server.address.ss_family)
1632 				goto out_mountproto_mismatch;
1633 		} else {
1634 			if (mountfamily != mnt->nfs_server.address.ss_family)
1635 				goto out_mountproto_mismatch;
1636 		}
1637 	}
1638 
1639 	return 1;
1640 
1641 out_mountproto_mismatch:
1642 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1643 			 "option\n");
1644 	return 0;
1645 out_proto_mismatch:
1646 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1647 	return 0;
1648 out_invalid_address:
1649 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1650 	return 0;
1651 out_invalid_value:
1652 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1653 	return 0;
1654 out_minorversion_mismatch:
1655 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1656 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1657 	return 0;
1658 out_migration_misuse:
1659 	printk(KERN_INFO
1660 		"NFS: 'migration' not supported for this NFS version\n");
1661 	return 0;
1662 out_nomem:
1663 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1664 	return 0;
1665 out_security_failure:
1666 	free_secdata(secdata);
1667 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1668 	return 0;
1669 }
1670 
1671 /*
1672  * Ensure that a specified authtype in args->auth_info is supported by
1673  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1674  * -EACCES if not.
1675  */
1676 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1677 			rpc_authflavor_t *server_authlist, unsigned int count)
1678 {
1679 	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1680 	unsigned int i;
1681 
1682 	/*
1683 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1684 	 * must be in the list returned by the server.
1685 	 *
1686 	 * AUTH_NULL has a special meaning when it's in the server list - it
1687 	 * means that the server will ignore the rpc creds, so any flavor
1688 	 * can be used.
1689 	 */
1690 	for (i = 0; i < count; i++) {
1691 		flavor = server_authlist[i];
1692 
1693 		if (nfs_auth_info_match(&args->auth_info, flavor) ||
1694 		    flavor == RPC_AUTH_NULL)
1695 			goto out;
1696 	}
1697 
1698 	dfprintk(MOUNT,
1699 		 "NFS: specified auth flavors not supported by server\n");
1700 	return -EACCES;
1701 
1702 out:
1703 	args->selected_flavor = flavor;
1704 	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1705 	return 0;
1706 }
1707 
1708 /*
1709  * Use the remote server's MOUNT service to request the NFS file handle
1710  * corresponding to the provided path.
1711  */
1712 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1713 			     struct nfs_fh *root_fh,
1714 			     rpc_authflavor_t *server_authlist,
1715 			     unsigned int *server_authlist_len)
1716 {
1717 	struct nfs_mount_request request = {
1718 		.sap		= (struct sockaddr *)
1719 						&args->mount_server.address,
1720 		.dirpath	= args->nfs_server.export_path,
1721 		.protocol	= args->mount_server.protocol,
1722 		.fh		= root_fh,
1723 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1724 		.auth_flav_len	= server_authlist_len,
1725 		.auth_flavs	= server_authlist,
1726 		.net		= args->net,
1727 	};
1728 	int status;
1729 
1730 	if (args->mount_server.version == 0) {
1731 		switch (args->version) {
1732 			default:
1733 				args->mount_server.version = NFS_MNT3_VERSION;
1734 				break;
1735 			case 2:
1736 				args->mount_server.version = NFS_MNT_VERSION;
1737 		}
1738 	}
1739 	request.version = args->mount_server.version;
1740 
1741 	if (args->mount_server.hostname)
1742 		request.hostname = args->mount_server.hostname;
1743 	else
1744 		request.hostname = args->nfs_server.hostname;
1745 
1746 	/*
1747 	 * Construct the mount server's address.
1748 	 */
1749 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1750 		memcpy(request.sap, &args->nfs_server.address,
1751 		       args->nfs_server.addrlen);
1752 		args->mount_server.addrlen = args->nfs_server.addrlen;
1753 	}
1754 	request.salen = args->mount_server.addrlen;
1755 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1756 
1757 	/*
1758 	 * Now ask the mount server to map our export path
1759 	 * to a file handle.
1760 	 */
1761 	status = nfs_mount(&request);
1762 	if (status != 0) {
1763 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1764 				request.hostname, status);
1765 		return status;
1766 	}
1767 
1768 	return 0;
1769 }
1770 
1771 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1772 					struct nfs_subversion *nfs_mod)
1773 {
1774 	int status;
1775 	unsigned int i;
1776 	bool tried_auth_unix = false;
1777 	bool auth_null_in_list = false;
1778 	struct nfs_server *server = ERR_PTR(-EACCES);
1779 	struct nfs_parsed_mount_data *args = mount_info->parsed;
1780 	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1781 	unsigned int authlist_len = ARRAY_SIZE(authlist);
1782 
1783 	status = nfs_request_mount(args, mount_info->mntfh, authlist,
1784 					&authlist_len);
1785 	if (status)
1786 		return ERR_PTR(status);
1787 
1788 	/*
1789 	 * Was a sec= authflavor specified in the options? First, verify
1790 	 * whether the server supports it, and then just try to use it if so.
1791 	 */
1792 	if (args->auth_info.flavor_len > 0) {
1793 		status = nfs_verify_authflavors(args, authlist, authlist_len);
1794 		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1795 			 args->selected_flavor);
1796 		if (status)
1797 			return ERR_PTR(status);
1798 		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1799 	}
1800 
1801 	/*
1802 	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
1803 	 * SHOULD prefer the flavor listed first. However, some servers list
1804 	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1805 	 */
1806 	for (i = 0; i < authlist_len; ++i) {
1807 		rpc_authflavor_t flavor;
1808 		struct rpcsec_gss_info info;
1809 
1810 		flavor = authlist[i];
1811 		switch (flavor) {
1812 		case RPC_AUTH_UNIX:
1813 			tried_auth_unix = true;
1814 			break;
1815 		case RPC_AUTH_NULL:
1816 			auth_null_in_list = true;
1817 			continue;
1818 		default:
1819 			if (rpcauth_get_gssinfo(flavor, &info) != 0)
1820 				continue;
1821 			/* Fallthrough */
1822 		}
1823 		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1824 		args->selected_flavor = flavor;
1825 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1826 		if (!IS_ERR(server))
1827 			return server;
1828 	}
1829 
1830 	/*
1831 	 * Nothing we tried so far worked. At this point, give up if we've
1832 	 * already tried AUTH_UNIX or if the server's list doesn't contain
1833 	 * AUTH_NULL
1834 	 */
1835 	if (tried_auth_unix || !auth_null_in_list)
1836 		return server;
1837 
1838 	/* Last chance! Try AUTH_UNIX */
1839 	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1840 	args->selected_flavor = RPC_AUTH_UNIX;
1841 	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1842 }
1843 
1844 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1845 			     struct nfs_mount_info *mount_info,
1846 			     struct nfs_subversion *nfs_mod)
1847 {
1848 	struct nfs_server *server;
1849 
1850 	if (mount_info->parsed->need_mount)
1851 		server = nfs_try_mount_request(mount_info, nfs_mod);
1852 	else
1853 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1854 
1855 	if (IS_ERR(server))
1856 		return ERR_CAST(server);
1857 
1858 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1859 }
1860 EXPORT_SYMBOL_GPL(nfs_try_mount);
1861 
1862 /*
1863  * Split "dev_name" into "hostname:export_path".
1864  *
1865  * The leftmost colon demarks the split between the server's hostname
1866  * and the export path.  If the hostname starts with a left square
1867  * bracket, then it may contain colons.
1868  *
1869  * Note: caller frees hostname and export path, even on error.
1870  */
1871 static int nfs_parse_devname(const char *dev_name,
1872 			     char **hostname, size_t maxnamlen,
1873 			     char **export_path, size_t maxpathlen)
1874 {
1875 	size_t len;
1876 	char *end;
1877 
1878 	/* Is the host name protected with square brakcets? */
1879 	if (*dev_name == '[') {
1880 		end = strchr(++dev_name, ']');
1881 		if (end == NULL || end[1] != ':')
1882 			goto out_bad_devname;
1883 
1884 		len = end - dev_name;
1885 		end++;
1886 	} else {
1887 		char *comma;
1888 
1889 		end = strchr(dev_name, ':');
1890 		if (end == NULL)
1891 			goto out_bad_devname;
1892 		len = end - dev_name;
1893 
1894 		/* kill possible hostname list: not supported */
1895 		comma = strchr(dev_name, ',');
1896 		if (comma != NULL && comma < end)
1897 			*comma = 0;
1898 	}
1899 
1900 	if (len > maxnamlen)
1901 		goto out_hostname;
1902 
1903 	/* N.B. caller will free nfs_server.hostname in all cases */
1904 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1905 	if (*hostname == NULL)
1906 		goto out_nomem;
1907 	len = strlen(++end);
1908 	if (len > maxpathlen)
1909 		goto out_path;
1910 	*export_path = kstrndup(end, len, GFP_KERNEL);
1911 	if (!*export_path)
1912 		goto out_nomem;
1913 
1914 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1915 	return 0;
1916 
1917 out_bad_devname:
1918 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1919 	return -EINVAL;
1920 
1921 out_nomem:
1922 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1923 	return -ENOMEM;
1924 
1925 out_hostname:
1926 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1927 	return -ENAMETOOLONG;
1928 
1929 out_path:
1930 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1931 	return -ENAMETOOLONG;
1932 }
1933 
1934 /*
1935  * Validate the NFS2/NFS3 mount data
1936  * - fills in the mount root filehandle
1937  *
1938  * For option strings, user space handles the following behaviors:
1939  *
1940  * + DNS: mapping server host name to IP address ("addr=" option)
1941  *
1942  * + failure mode: how to behave if a mount request can't be handled
1943  *   immediately ("fg/bg" option)
1944  *
1945  * + retry: how often to retry a mount request ("retry=" option)
1946  *
1947  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1948  *   mountproto=tcp after mountproto=udp, and so on
1949  */
1950 static int nfs23_validate_mount_data(void *options,
1951 				     struct nfs_parsed_mount_data *args,
1952 				     struct nfs_fh *mntfh,
1953 				     const char *dev_name)
1954 {
1955 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1956 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1957 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1958 
1959 	if (data == NULL)
1960 		goto out_no_data;
1961 
1962 	args->version = NFS_DEFAULT_VERSION;
1963 	switch (data->version) {
1964 	case 1:
1965 		data->namlen = 0;
1966 	case 2:
1967 		data->bsize = 0;
1968 	case 3:
1969 		if (data->flags & NFS_MOUNT_VER3)
1970 			goto out_no_v3;
1971 		data->root.size = NFS2_FHSIZE;
1972 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1973 		/* Turn off security negotiation */
1974 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
1975 	case 4:
1976 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1977 			goto out_no_sec;
1978 	case 5:
1979 		memset(data->context, 0, sizeof(data->context));
1980 	case 6:
1981 		if (data->flags & NFS_MOUNT_VER3) {
1982 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1983 				goto out_invalid_fh;
1984 			mntfh->size = data->root.size;
1985 			args->version = 3;
1986 		} else {
1987 			mntfh->size = NFS2_FHSIZE;
1988 			args->version = 2;
1989 		}
1990 
1991 
1992 		memcpy(mntfh->data, data->root.data, mntfh->size);
1993 		if (mntfh->size < sizeof(mntfh->data))
1994 			memset(mntfh->data + mntfh->size, 0,
1995 			       sizeof(mntfh->data) - mntfh->size);
1996 
1997 		/*
1998 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1999 		 * can deal with.
2000 		 */
2001 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
2002 		args->flags		|= extra_flags;
2003 		args->rsize		= data->rsize;
2004 		args->wsize		= data->wsize;
2005 		args->timeo		= data->timeo;
2006 		args->retrans		= data->retrans;
2007 		args->acregmin		= data->acregmin;
2008 		args->acregmax		= data->acregmax;
2009 		args->acdirmin		= data->acdirmin;
2010 		args->acdirmax		= data->acdirmax;
2011 		args->need_mount	= false;
2012 
2013 		memcpy(sap, &data->addr, sizeof(data->addr));
2014 		args->nfs_server.addrlen = sizeof(data->addr);
2015 		args->nfs_server.port = ntohs(data->addr.sin_port);
2016 		if (!nfs_verify_server_address(sap))
2017 			goto out_no_address;
2018 
2019 		if (!(data->flags & NFS_MOUNT_TCP))
2020 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2021 		/* N.B. caller will free nfs_server.hostname in all cases */
2022 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2023 		args->namlen		= data->namlen;
2024 		args->bsize		= data->bsize;
2025 
2026 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2027 			args->selected_flavor = data->pseudoflavor;
2028 		else
2029 			args->selected_flavor = RPC_AUTH_UNIX;
2030 		if (!args->nfs_server.hostname)
2031 			goto out_nomem;
2032 
2033 		if (!(data->flags & NFS_MOUNT_NONLM))
2034 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2035 					 NFS_MOUNT_LOCAL_FCNTL);
2036 		else
2037 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2038 					NFS_MOUNT_LOCAL_FCNTL);
2039 		/*
2040 		 * The legacy version 6 binary mount data from userspace has a
2041 		 * field used only to transport selinux information into the
2042 		 * the kernel.  To continue to support that functionality we
2043 		 * have a touch of selinux knowledge here in the NFS code. The
2044 		 * userspace code converted context=blah to just blah so we are
2045 		 * converting back to the full string selinux understands.
2046 		 */
2047 		if (data->context[0]){
2048 #ifdef CONFIG_SECURITY_SELINUX
2049 			int rc;
2050 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
2051 			if (!opts_str)
2052 				return -ENOMEM;
2053 			strcpy(opts_str, "context=");
2054 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2055 			strcat(opts_str, &data->context[0]);
2056 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
2057 			kfree(opts_str);
2058 			if (rc)
2059 				return rc;
2060 #else
2061 			return -EINVAL;
2062 #endif
2063 		}
2064 
2065 		break;
2066 	default:
2067 		return NFS_TEXT_DATA;
2068 	}
2069 
2070 	return 0;
2071 
2072 out_no_data:
2073 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2074 	return -EINVAL;
2075 
2076 out_no_v3:
2077 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2078 		 data->version);
2079 	return -EINVAL;
2080 
2081 out_no_sec:
2082 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2083 	return -EINVAL;
2084 
2085 out_nomem:
2086 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2087 	return -ENOMEM;
2088 
2089 out_no_address:
2090 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2091 	return -EINVAL;
2092 
2093 out_invalid_fh:
2094 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2095 	return -EINVAL;
2096 }
2097 
2098 #if IS_ENABLED(CONFIG_NFS_V4)
2099 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2100 				   void *options,
2101 				   struct nfs_parsed_mount_data *args,
2102 				   struct nfs_fh *mntfh,
2103 				   const char *dev_name)
2104 {
2105 	if (fs_type == &nfs_fs_type)
2106 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2107 	return nfs4_validate_mount_data(options, args, dev_name);
2108 }
2109 #else
2110 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2111 				   void *options,
2112 				   struct nfs_parsed_mount_data *args,
2113 				   struct nfs_fh *mntfh,
2114 				   const char *dev_name)
2115 {
2116 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2117 }
2118 #endif
2119 
2120 static int nfs_validate_text_mount_data(void *options,
2121 					struct nfs_parsed_mount_data *args,
2122 					const char *dev_name)
2123 {
2124 	int port = 0;
2125 	int max_namelen = PAGE_SIZE;
2126 	int max_pathlen = NFS_MAXPATHLEN;
2127 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2128 
2129 	if (nfs_parse_mount_options((char *)options, args) == 0)
2130 		return -EINVAL;
2131 
2132 	if (!nfs_verify_server_address(sap))
2133 		goto out_no_address;
2134 
2135 	if (args->version == 4) {
2136 #if IS_ENABLED(CONFIG_NFS_V4)
2137 		port = NFS_PORT;
2138 		max_namelen = NFS4_MAXNAMLEN;
2139 		max_pathlen = NFS4_MAXPATHLEN;
2140 		nfs_validate_transport_protocol(args);
2141 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2142 			goto out_invalid_transport_udp;
2143 		nfs4_validate_mount_flags(args);
2144 #else
2145 		goto out_v4_not_compiled;
2146 #endif /* CONFIG_NFS_V4 */
2147 	} else
2148 		nfs_set_mount_transport_protocol(args);
2149 
2150 	nfs_set_port(sap, &args->nfs_server.port, port);
2151 
2152 	return nfs_parse_devname(dev_name,
2153 				   &args->nfs_server.hostname,
2154 				   max_namelen,
2155 				   &args->nfs_server.export_path,
2156 				   max_pathlen);
2157 
2158 #if !IS_ENABLED(CONFIG_NFS_V4)
2159 out_v4_not_compiled:
2160 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2161 	return -EPROTONOSUPPORT;
2162 #else
2163 out_invalid_transport_udp:
2164 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2165 	return -EINVAL;
2166 #endif /* !CONFIG_NFS_V4 */
2167 
2168 out_no_address:
2169 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2170 	return -EINVAL;
2171 }
2172 
2173 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2174 		| NFS_MOUNT_SECURE \
2175 		| NFS_MOUNT_TCP \
2176 		| NFS_MOUNT_VER3 \
2177 		| NFS_MOUNT_KERBEROS \
2178 		| NFS_MOUNT_NONLM \
2179 		| NFS_MOUNT_BROKEN_SUID \
2180 		| NFS_MOUNT_STRICTLOCK \
2181 		| NFS_MOUNT_LEGACY_INTERFACE)
2182 
2183 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2184 		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2185 
2186 static int
2187 nfs_compare_remount_data(struct nfs_server *nfss,
2188 			 struct nfs_parsed_mount_data *data)
2189 {
2190 	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2191 	    data->rsize != nfss->rsize ||
2192 	    data->wsize != nfss->wsize ||
2193 	    data->version != nfss->nfs_client->rpc_ops->version ||
2194 	    data->minorversion != nfss->nfs_client->cl_minorversion ||
2195 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2196 	    data->selected_flavor != nfss->client->cl_auth->au_flavor ||
2197 	    data->acregmin != nfss->acregmin / HZ ||
2198 	    data->acregmax != nfss->acregmax / HZ ||
2199 	    data->acdirmin != nfss->acdirmin / HZ ||
2200 	    data->acdirmax != nfss->acdirmax / HZ ||
2201 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2202 	    data->nfs_server.port != nfss->port ||
2203 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2204 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2205 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2206 		return -EINVAL;
2207 
2208 	return 0;
2209 }
2210 
2211 int
2212 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2213 {
2214 	int error;
2215 	struct nfs_server *nfss = sb->s_fs_info;
2216 	struct nfs_parsed_mount_data *data;
2217 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2218 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2219 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2220 
2221 	sync_filesystem(sb);
2222 
2223 	/*
2224 	 * Userspace mount programs that send binary options generally send
2225 	 * them populated with default values. We have no way to know which
2226 	 * ones were explicitly specified. Fall back to legacy behavior and
2227 	 * just return success.
2228 	 */
2229 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2230 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2231 					   options->version <= 6))))
2232 		return 0;
2233 
2234 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2235 	if (data == NULL)
2236 		return -ENOMEM;
2237 
2238 	/* fill out struct with values from existing mount */
2239 	data->flags = nfss->flags;
2240 	data->rsize = nfss->rsize;
2241 	data->wsize = nfss->wsize;
2242 	data->retrans = nfss->client->cl_timeout->to_retries;
2243 	data->selected_flavor = nfss->client->cl_auth->au_flavor;
2244 	data->auth_info = nfss->auth_info;
2245 	data->acregmin = nfss->acregmin / HZ;
2246 	data->acregmax = nfss->acregmax / HZ;
2247 	data->acdirmin = nfss->acdirmin / HZ;
2248 	data->acdirmax = nfss->acdirmax / HZ;
2249 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2250 	data->nfs_server.port = nfss->port;
2251 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2252 	data->version = nfsvers;
2253 	data->minorversion = nfss->nfs_client->cl_minorversion;
2254 	data->net = current->nsproxy->net_ns;
2255 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2256 		data->nfs_server.addrlen);
2257 
2258 	/* overwrite those values with any that were specified */
2259 	error = -EINVAL;
2260 	if (!nfs_parse_mount_options((char *)options, data))
2261 		goto out;
2262 
2263 	/*
2264 	 * noac is a special case. It implies -o sync, but that's not
2265 	 * necessarily reflected in the mtab options. do_remount_sb
2266 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2267 	 * remount options, so we have to explicitly reset it.
2268 	 */
2269 	if (data->flags & NFS_MOUNT_NOAC)
2270 		*flags |= MS_SYNCHRONOUS;
2271 
2272 	/* compare new mount options with old ones */
2273 	error = nfs_compare_remount_data(nfss, data);
2274 out:
2275 	kfree(data);
2276 	return error;
2277 }
2278 EXPORT_SYMBOL_GPL(nfs_remount);
2279 
2280 /*
2281  * Initialise the common bits of the superblock
2282  */
2283 inline void nfs_initialise_sb(struct super_block *sb)
2284 {
2285 	struct nfs_server *server = NFS_SB(sb);
2286 
2287 	sb->s_magic = NFS_SUPER_MAGIC;
2288 
2289 	/* We probably want something more informative here */
2290 	snprintf(sb->s_id, sizeof(sb->s_id),
2291 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2292 
2293 	if (sb->s_blocksize == 0)
2294 		sb->s_blocksize = nfs_block_bits(server->wsize,
2295 						 &sb->s_blocksize_bits);
2296 
2297 	sb->s_bdi = &server->backing_dev_info;
2298 
2299 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2300 }
2301 
2302 /*
2303  * Finish setting up an NFS2/3 superblock
2304  */
2305 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2306 {
2307 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2308 	struct nfs_server *server = NFS_SB(sb);
2309 
2310 	sb->s_blocksize_bits = 0;
2311 	sb->s_blocksize = 0;
2312 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2313 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2314 	if (data && data->bsize)
2315 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2316 
2317 	if (server->nfs_client->rpc_ops->version != 2) {
2318 		/* The VFS shouldn't apply the umask to mode bits. We will do
2319 		 * so ourselves when necessary.
2320 		 */
2321 		sb->s_flags |= MS_POSIXACL;
2322 		sb->s_time_gran = 1;
2323 	}
2324 
2325  	nfs_initialise_sb(sb);
2326 }
2327 EXPORT_SYMBOL_GPL(nfs_fill_super);
2328 
2329 /*
2330  * Finish setting up a cloned NFS2/3/4 superblock
2331  */
2332 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2333 {
2334 	const struct super_block *old_sb = mount_info->cloned->sb;
2335 	struct nfs_server *server = NFS_SB(sb);
2336 
2337 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2338 	sb->s_blocksize = old_sb->s_blocksize;
2339 	sb->s_maxbytes = old_sb->s_maxbytes;
2340 	sb->s_xattr = old_sb->s_xattr;
2341 	sb->s_op = old_sb->s_op;
2342 	sb->s_time_gran = 1;
2343 
2344 	if (server->nfs_client->rpc_ops->version != 2) {
2345 		/* The VFS shouldn't apply the umask to mode bits. We will do
2346 		 * so ourselves when necessary.
2347 		 */
2348 		sb->s_flags |= MS_POSIXACL;
2349 	}
2350 
2351  	nfs_initialise_sb(sb);
2352 }
2353 
2354 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2355 {
2356 	const struct nfs_server *a = s->s_fs_info;
2357 	const struct rpc_clnt *clnt_a = a->client;
2358 	const struct rpc_clnt *clnt_b = b->client;
2359 
2360 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2361 		goto Ebusy;
2362 	if (a->nfs_client != b->nfs_client)
2363 		goto Ebusy;
2364 	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2365 		goto Ebusy;
2366 	if (a->wsize != b->wsize)
2367 		goto Ebusy;
2368 	if (a->rsize != b->rsize)
2369 		goto Ebusy;
2370 	if (a->acregmin != b->acregmin)
2371 		goto Ebusy;
2372 	if (a->acregmax != b->acregmax)
2373 		goto Ebusy;
2374 	if (a->acdirmin != b->acdirmin)
2375 		goto Ebusy;
2376 	if (a->acdirmax != b->acdirmax)
2377 		goto Ebusy;
2378 	if (b->auth_info.flavor_len > 0 &&
2379 	   clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2380 		goto Ebusy;
2381 	return 1;
2382 Ebusy:
2383 	return 0;
2384 }
2385 
2386 struct nfs_sb_mountdata {
2387 	struct nfs_server *server;
2388 	int mntflags;
2389 };
2390 
2391 static int nfs_set_super(struct super_block *s, void *data)
2392 {
2393 	struct nfs_sb_mountdata *sb_mntdata = data;
2394 	struct nfs_server *server = sb_mntdata->server;
2395 	int ret;
2396 
2397 	s->s_flags = sb_mntdata->mntflags;
2398 	s->s_fs_info = server;
2399 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2400 	ret = set_anon_super(s, server);
2401 	if (ret == 0)
2402 		server->s_dev = s->s_dev;
2403 	return ret;
2404 }
2405 
2406 static int nfs_compare_super_address(struct nfs_server *server1,
2407 				     struct nfs_server *server2)
2408 {
2409 	struct sockaddr *sap1, *sap2;
2410 
2411 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2412 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2413 
2414 	if (sap1->sa_family != sap2->sa_family)
2415 		return 0;
2416 
2417 	switch (sap1->sa_family) {
2418 	case AF_INET: {
2419 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2420 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2421 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2422 			return 0;
2423 		if (sin1->sin_port != sin2->sin_port)
2424 			return 0;
2425 		break;
2426 	}
2427 	case AF_INET6: {
2428 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2429 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2430 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2431 			return 0;
2432 		if (sin1->sin6_port != sin2->sin6_port)
2433 			return 0;
2434 		break;
2435 	}
2436 	default:
2437 		return 0;
2438 	}
2439 
2440 	return 1;
2441 }
2442 
2443 static int nfs_compare_super(struct super_block *sb, void *data)
2444 {
2445 	struct nfs_sb_mountdata *sb_mntdata = data;
2446 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2447 	int mntflags = sb_mntdata->mntflags;
2448 
2449 	if (!nfs_compare_super_address(old, server))
2450 		return 0;
2451 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2452 	if (old->flags & NFS_MOUNT_UNSHARED)
2453 		return 0;
2454 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2455 		return 0;
2456 	return nfs_compare_mount_options(sb, server, mntflags);
2457 }
2458 
2459 #ifdef CONFIG_NFS_FSCACHE
2460 static void nfs_get_cache_cookie(struct super_block *sb,
2461 				 struct nfs_parsed_mount_data *parsed,
2462 				 struct nfs_clone_mount *cloned)
2463 {
2464 	struct nfs_server *nfss = NFS_SB(sb);
2465 	char *uniq = NULL;
2466 	int ulen = 0;
2467 
2468 	nfss->fscache_key = NULL;
2469 	nfss->fscache = NULL;
2470 
2471 	if (parsed) {
2472 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2473 			return;
2474 		if (parsed->fscache_uniq) {
2475 			uniq = parsed->fscache_uniq;
2476 			ulen = strlen(parsed->fscache_uniq);
2477 		}
2478 	} else if (cloned) {
2479 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2480 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2481 			return;
2482 		if (mnt_s->fscache_key) {
2483 			uniq = mnt_s->fscache_key->key.uniquifier;
2484 			ulen = mnt_s->fscache_key->key.uniq_len;
2485 		};
2486 	} else
2487 		return;
2488 
2489 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2490 }
2491 #else
2492 static void nfs_get_cache_cookie(struct super_block *sb,
2493 				 struct nfs_parsed_mount_data *parsed,
2494 				 struct nfs_clone_mount *cloned)
2495 {
2496 }
2497 #endif
2498 
2499 static int nfs_bdi_register(struct nfs_server *server)
2500 {
2501 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2502 }
2503 
2504 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2505 			struct nfs_mount_info *mount_info)
2506 {
2507 	int error;
2508 	unsigned long kflags = 0, kflags_out = 0;
2509 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2510 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2511 
2512 	error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
2513 						kflags, &kflags_out);
2514 	if (error)
2515 		goto err;
2516 
2517 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2518 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2519 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2520 err:
2521 	return error;
2522 }
2523 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2524 
2525 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2526 			  struct nfs_mount_info *mount_info)
2527 {
2528 	/* clone any lsm security options from the parent to the new sb */
2529 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2530 		return -ESTALE;
2531 	return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2532 }
2533 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2534 
2535 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2536 				   int flags, const char *dev_name,
2537 				   struct nfs_mount_info *mount_info,
2538 				   struct nfs_subversion *nfs_mod)
2539 {
2540 	struct super_block *s;
2541 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2542 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2543 	struct nfs_sb_mountdata sb_mntdata = {
2544 		.mntflags = flags,
2545 		.server = server,
2546 	};
2547 	int error;
2548 
2549 	if (server->flags & NFS_MOUNT_UNSHARED)
2550 		compare_super = NULL;
2551 
2552 	/* -o noac implies -o sync */
2553 	if (server->flags & NFS_MOUNT_NOAC)
2554 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2555 
2556 	if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2557 		if (mount_info->cloned->sb->s_flags & MS_SYNCHRONOUS)
2558 			sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2559 
2560 	/* Get a superblock - note that we may end up sharing one that already exists */
2561 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2562 	if (IS_ERR(s)) {
2563 		mntroot = ERR_CAST(s);
2564 		goto out_err_nosb;
2565 	}
2566 
2567 	if (s->s_fs_info != server) {
2568 		nfs_free_server(server);
2569 		server = NULL;
2570 	} else {
2571 		error = nfs_bdi_register(server);
2572 		if (error) {
2573 			mntroot = ERR_PTR(error);
2574 			goto error_splat_super;
2575 		}
2576 		server->super = s;
2577 	}
2578 
2579 	if (!s->s_root) {
2580 		/* initial superblock/root creation */
2581 		mount_info->fill_super(s, mount_info);
2582 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2583 	}
2584 
2585 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2586 	if (IS_ERR(mntroot))
2587 		goto error_splat_super;
2588 
2589 	error = mount_info->set_security(s, mntroot, mount_info);
2590 	if (error)
2591 		goto error_splat_root;
2592 
2593 	s->s_flags |= MS_ACTIVE;
2594 
2595 out:
2596 	return mntroot;
2597 
2598 out_err_nosb:
2599 	nfs_free_server(server);
2600 	goto out;
2601 
2602 error_splat_root:
2603 	dput(mntroot);
2604 	mntroot = ERR_PTR(error);
2605 error_splat_super:
2606 	deactivate_locked_super(s);
2607 	goto out;
2608 }
2609 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2610 
2611 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2612 	int flags, const char *dev_name, void *raw_data)
2613 {
2614 	struct nfs_mount_info mount_info = {
2615 		.fill_super = nfs_fill_super,
2616 		.set_security = nfs_set_sb_security,
2617 	};
2618 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2619 	struct nfs_subversion *nfs_mod;
2620 	int error;
2621 
2622 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2623 	mount_info.mntfh = nfs_alloc_fhandle();
2624 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2625 		goto out;
2626 
2627 	/* Validate the mount data */
2628 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2629 	if (error == NFS_TEXT_DATA)
2630 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2631 	if (error < 0) {
2632 		mntroot = ERR_PTR(error);
2633 		goto out;
2634 	}
2635 
2636 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2637 	if (IS_ERR(nfs_mod)) {
2638 		mntroot = ERR_CAST(nfs_mod);
2639 		goto out;
2640 	}
2641 
2642 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2643 
2644 	put_nfs_version(nfs_mod);
2645 out:
2646 	nfs_free_parsed_mount_data(mount_info.parsed);
2647 	nfs_free_fhandle(mount_info.mntfh);
2648 	return mntroot;
2649 }
2650 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2651 
2652 /*
2653  * Destroy an NFS2/3 superblock
2654  */
2655 void nfs_kill_super(struct super_block *s)
2656 {
2657 	struct nfs_server *server = NFS_SB(s);
2658 	dev_t dev = s->s_dev;
2659 
2660 	generic_shutdown_super(s);
2661 
2662 	nfs_fscache_release_super_cookie(s);
2663 
2664 	nfs_free_server(server);
2665 	free_anon_bdev(dev);
2666 }
2667 EXPORT_SYMBOL_GPL(nfs_kill_super);
2668 
2669 /*
2670  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2671  */
2672 static struct dentry *
2673 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2674 		const char *dev_name, void *raw_data)
2675 {
2676 	struct nfs_clone_mount *data = raw_data;
2677 	struct nfs_mount_info mount_info = {
2678 		.fill_super = nfs_clone_super,
2679 		.set_security = nfs_clone_sb_security,
2680 		.cloned = data,
2681 	};
2682 	struct nfs_server *server;
2683 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2684 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2685 
2686 	dprintk("--> nfs_xdev_mount()\n");
2687 
2688 	mount_info.mntfh = mount_info.cloned->fh;
2689 
2690 	/* create a new volume representation */
2691 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2692 
2693 	if (IS_ERR(server))
2694 		mntroot = ERR_CAST(server);
2695 	else
2696 		mntroot = nfs_fs_mount_common(server, flags,
2697 				dev_name, &mount_info, nfs_mod);
2698 
2699 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2700 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2701 	return mntroot;
2702 }
2703 
2704 #if IS_ENABLED(CONFIG_NFS_V4)
2705 
2706 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2707 {
2708 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2709 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2710 }
2711 
2712 /*
2713  * Validate NFSv4 mount options
2714  */
2715 static int nfs4_validate_mount_data(void *options,
2716 				    struct nfs_parsed_mount_data *args,
2717 				    const char *dev_name)
2718 {
2719 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2720 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2721 	char *c;
2722 
2723 	if (data == NULL)
2724 		goto out_no_data;
2725 
2726 	args->version = 4;
2727 
2728 	switch (data->version) {
2729 	case 1:
2730 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2731 			goto out_no_address;
2732 		if (data->host_addrlen == 0)
2733 			goto out_no_address;
2734 		args->nfs_server.addrlen = data->host_addrlen;
2735 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2736 			return -EFAULT;
2737 		if (!nfs_verify_server_address(sap))
2738 			goto out_no_address;
2739 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2740 
2741 		if (data->auth_flavourlen) {
2742 			rpc_authflavor_t pseudoflavor;
2743 			if (data->auth_flavourlen > 1)
2744 				goto out_inval_auth;
2745 			if (copy_from_user(&pseudoflavor,
2746 					   data->auth_flavours,
2747 					   sizeof(pseudoflavor)))
2748 				return -EFAULT;
2749 			args->selected_flavor = pseudoflavor;
2750 		} else
2751 			args->selected_flavor = RPC_AUTH_UNIX;
2752 
2753 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2754 		if (IS_ERR(c))
2755 			return PTR_ERR(c);
2756 		args->nfs_server.hostname = c;
2757 
2758 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2759 		if (IS_ERR(c))
2760 			return PTR_ERR(c);
2761 		args->nfs_server.export_path = c;
2762 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2763 
2764 		c = strndup_user(data->client_addr.data, 16);
2765 		if (IS_ERR(c))
2766 			return PTR_ERR(c);
2767 		args->client_address = c;
2768 
2769 		/*
2770 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2771 		 * can deal with.
2772 		 */
2773 
2774 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2775 		args->rsize	= data->rsize;
2776 		args->wsize	= data->wsize;
2777 		args->timeo	= data->timeo;
2778 		args->retrans	= data->retrans;
2779 		args->acregmin	= data->acregmin;
2780 		args->acregmax	= data->acregmax;
2781 		args->acdirmin	= data->acdirmin;
2782 		args->acdirmax	= data->acdirmax;
2783 		args->nfs_server.protocol = data->proto;
2784 		nfs_validate_transport_protocol(args);
2785 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2786 			goto out_invalid_transport_udp;
2787 
2788 		break;
2789 	default:
2790 		return NFS_TEXT_DATA;
2791 	}
2792 
2793 	return 0;
2794 
2795 out_no_data:
2796 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2797 	return -EINVAL;
2798 
2799 out_inval_auth:
2800 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2801 		 data->auth_flavourlen);
2802 	return -EINVAL;
2803 
2804 out_no_address:
2805 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2806 	return -EINVAL;
2807 
2808 out_invalid_transport_udp:
2809 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2810 	return -EINVAL;
2811 }
2812 
2813 /*
2814  * NFS v4 module parameters need to stay in the
2815  * NFS client for backwards compatibility
2816  */
2817 unsigned int nfs_callback_set_tcpport;
2818 unsigned short nfs_callback_tcpport;
2819 /* Default cache timeout is 10 minutes */
2820 unsigned int nfs_idmap_cache_timeout = 600;
2821 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2822 bool nfs4_disable_idmapping = true;
2823 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2824 unsigned short send_implementation_id = 1;
2825 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2826 bool recover_lost_locks = false;
2827 
2828 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2829 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2830 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2831 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2832 EXPORT_SYMBOL_GPL(max_session_slots);
2833 EXPORT_SYMBOL_GPL(send_implementation_id);
2834 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2835 EXPORT_SYMBOL_GPL(recover_lost_locks);
2836 
2837 #define NFS_CALLBACK_MAXPORTNR (65535U)
2838 
2839 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2840 {
2841 	unsigned long num;
2842 	int ret;
2843 
2844 	if (!val)
2845 		return -EINVAL;
2846 	ret = kstrtoul(val, 0, &num);
2847 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2848 		return -EINVAL;
2849 	*((unsigned int *)kp->arg) = num;
2850 	return 0;
2851 }
2852 static struct kernel_param_ops param_ops_portnr = {
2853 	.set = param_set_portnr,
2854 	.get = param_get_uint,
2855 };
2856 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2857 
2858 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2859 module_param(nfs_idmap_cache_timeout, int, 0644);
2860 module_param(nfs4_disable_idmapping, bool, 0644);
2861 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2862 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2863 MODULE_PARM_DESC(nfs4_disable_idmapping,
2864 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2865 module_param(max_session_slots, ushort, 0644);
2866 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2867 		"requests the client will negotiate");
2868 module_param(send_implementation_id, ushort, 0644);
2869 MODULE_PARM_DESC(send_implementation_id,
2870 		"Send implementation ID with NFSv4.1 exchange_id");
2871 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2872 
2873 module_param(recover_lost_locks, bool, 0644);
2874 MODULE_PARM_DESC(recover_lost_locks,
2875 		 "If the server reports that a lock might be lost, "
2876 		 "try to recover it risking data corruption.");
2877 
2878 
2879 #endif /* CONFIG_NFS_V4 */
2880