xref: /openbmc/linux/fs/nfs/super.c (revision 65ee8aeb)
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/vfs.h>
47 #include <linux/inet.h>
48 #include <linux/in6.h>
49 #include <linux/slab.h>
50 #include <net/ipv6.h>
51 #include <linux/netdevice.h>
52 #include <linux/nfs_xdr.h>
53 #include <linux/magic.h>
54 #include <linux/parser.h>
55 #include <linux/nsproxy.h>
56 #include <linux/rcupdate.h>
57 
58 #include <asm/uaccess.h>
59 
60 #include "nfs4_fs.h"
61 #include "callback.h"
62 #include "delegation.h"
63 #include "iostat.h"
64 #include "internal.h"
65 #include "fscache.h"
66 #include "nfs4session.h"
67 #include "pnfs.h"
68 #include "nfs.h"
69 
70 #define NFSDBG_FACILITY		NFSDBG_VFS
71 #define NFS_TEXT_DATA		1
72 
73 #if IS_ENABLED(CONFIG_NFS_V3)
74 #define NFS_DEFAULT_VERSION 3
75 #else
76 #define NFS_DEFAULT_VERSION 2
77 #endif
78 
79 enum {
80 	/* Mount options that take no arguments */
81 	Opt_soft, Opt_hard,
82 	Opt_posix, Opt_noposix,
83 	Opt_cto, Opt_nocto,
84 	Opt_ac, Opt_noac,
85 	Opt_lock, Opt_nolock,
86 	Opt_udp, Opt_tcp, Opt_rdma,
87 	Opt_acl, Opt_noacl,
88 	Opt_rdirplus, Opt_nordirplus,
89 	Opt_sharecache, Opt_nosharecache,
90 	Opt_resvport, Opt_noresvport,
91 	Opt_fscache, Opt_nofscache,
92 	Opt_migration, Opt_nomigration,
93 
94 	/* Mount options that take integer arguments */
95 	Opt_port,
96 	Opt_rsize, Opt_wsize, Opt_bsize,
97 	Opt_timeo, Opt_retrans,
98 	Opt_acregmin, Opt_acregmax,
99 	Opt_acdirmin, Opt_acdirmax,
100 	Opt_actimeo,
101 	Opt_namelen,
102 	Opt_mountport,
103 	Opt_mountvers,
104 	Opt_minorversion,
105 
106 	/* Mount options that take string arguments */
107 	Opt_nfsvers,
108 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
109 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
110 	Opt_lookupcache,
111 	Opt_fscache_uniq,
112 	Opt_local_lock,
113 
114 	/* Special mount options */
115 	Opt_userspace, Opt_deprecated, Opt_sloppy,
116 
117 	Opt_err
118 };
119 
120 static const match_table_t nfs_mount_option_tokens = {
121 	{ Opt_userspace, "bg" },
122 	{ Opt_userspace, "fg" },
123 	{ Opt_userspace, "retry=%s" },
124 
125 	{ Opt_sloppy, "sloppy" },
126 
127 	{ Opt_soft, "soft" },
128 	{ Opt_hard, "hard" },
129 	{ Opt_deprecated, "intr" },
130 	{ Opt_deprecated, "nointr" },
131 	{ Opt_posix, "posix" },
132 	{ Opt_noposix, "noposix" },
133 	{ Opt_cto, "cto" },
134 	{ Opt_nocto, "nocto" },
135 	{ Opt_ac, "ac" },
136 	{ Opt_noac, "noac" },
137 	{ Opt_lock, "lock" },
138 	{ Opt_nolock, "nolock" },
139 	{ Opt_udp, "udp" },
140 	{ Opt_tcp, "tcp" },
141 	{ Opt_rdma, "rdma" },
142 	{ Opt_acl, "acl" },
143 	{ Opt_noacl, "noacl" },
144 	{ Opt_rdirplus, "rdirplus" },
145 	{ Opt_nordirplus, "nordirplus" },
146 	{ Opt_sharecache, "sharecache" },
147 	{ Opt_nosharecache, "nosharecache" },
148 	{ Opt_resvport, "resvport" },
149 	{ Opt_noresvport, "noresvport" },
150 	{ Opt_fscache, "fsc" },
151 	{ Opt_nofscache, "nofsc" },
152 	{ Opt_migration, "migration" },
153 	{ Opt_nomigration, "nomigration" },
154 
155 	{ Opt_port, "port=%s" },
156 	{ Opt_rsize, "rsize=%s" },
157 	{ Opt_wsize, "wsize=%s" },
158 	{ Opt_bsize, "bsize=%s" },
159 	{ Opt_timeo, "timeo=%s" },
160 	{ Opt_retrans, "retrans=%s" },
161 	{ Opt_acregmin, "acregmin=%s" },
162 	{ Opt_acregmax, "acregmax=%s" },
163 	{ Opt_acdirmin, "acdirmin=%s" },
164 	{ Opt_acdirmax, "acdirmax=%s" },
165 	{ Opt_actimeo, "actimeo=%s" },
166 	{ Opt_namelen, "namlen=%s" },
167 	{ Opt_mountport, "mountport=%s" },
168 	{ Opt_mountvers, "mountvers=%s" },
169 	{ Opt_minorversion, "minorversion=%s" },
170 
171 	{ Opt_nfsvers, "nfsvers=%s" },
172 	{ Opt_nfsvers, "vers=%s" },
173 
174 	{ Opt_sec, "sec=%s" },
175 	{ Opt_proto, "proto=%s" },
176 	{ Opt_mountproto, "mountproto=%s" },
177 	{ Opt_addr, "addr=%s" },
178 	{ Opt_clientaddr, "clientaddr=%s" },
179 	{ Opt_mounthost, "mounthost=%s" },
180 	{ Opt_mountaddr, "mountaddr=%s" },
181 
182 	{ Opt_lookupcache, "lookupcache=%s" },
183 	{ Opt_fscache_uniq, "fsc=%s" },
184 	{ Opt_local_lock, "local_lock=%s" },
185 
186 	/* The following needs to be listed after all other options */
187 	{ Opt_nfsvers, "v%s" },
188 
189 	{ Opt_err, NULL }
190 };
191 
192 enum {
193 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
194 
195 	Opt_xprt_err
196 };
197 
198 static const match_table_t nfs_xprt_protocol_tokens = {
199 	{ Opt_xprt_udp, "udp" },
200 	{ Opt_xprt_udp6, "udp6" },
201 	{ Opt_xprt_tcp, "tcp" },
202 	{ Opt_xprt_tcp6, "tcp6" },
203 	{ Opt_xprt_rdma, "rdma" },
204 
205 	{ Opt_xprt_err, NULL }
206 };
207 
208 enum {
209 	Opt_sec_none, Opt_sec_sys,
210 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
211 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
212 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
213 
214 	Opt_sec_err
215 };
216 
217 static const match_table_t nfs_secflavor_tokens = {
218 	{ Opt_sec_none, "none" },
219 	{ Opt_sec_none, "null" },
220 	{ Opt_sec_sys, "sys" },
221 
222 	{ Opt_sec_krb5, "krb5" },
223 	{ Opt_sec_krb5i, "krb5i" },
224 	{ Opt_sec_krb5p, "krb5p" },
225 
226 	{ Opt_sec_lkey, "lkey" },
227 	{ Opt_sec_lkeyi, "lkeyi" },
228 	{ Opt_sec_lkeyp, "lkeyp" },
229 
230 	{ Opt_sec_spkm, "spkm3" },
231 	{ Opt_sec_spkmi, "spkm3i" },
232 	{ Opt_sec_spkmp, "spkm3p" },
233 
234 	{ Opt_sec_err, NULL }
235 };
236 
237 enum {
238 	Opt_lookupcache_all, Opt_lookupcache_positive,
239 	Opt_lookupcache_none,
240 
241 	Opt_lookupcache_err
242 };
243 
244 static match_table_t nfs_lookupcache_tokens = {
245 	{ Opt_lookupcache_all, "all" },
246 	{ Opt_lookupcache_positive, "pos" },
247 	{ Opt_lookupcache_positive, "positive" },
248 	{ Opt_lookupcache_none, "none" },
249 
250 	{ Opt_lookupcache_err, NULL }
251 };
252 
253 enum {
254 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
255 	Opt_local_lock_none,
256 
257 	Opt_local_lock_err
258 };
259 
260 static match_table_t nfs_local_lock_tokens = {
261 	{ Opt_local_lock_all, "all" },
262 	{ Opt_local_lock_flock, "flock" },
263 	{ Opt_local_lock_posix, "posix" },
264 	{ Opt_local_lock_none, "none" },
265 
266 	{ Opt_local_lock_err, NULL }
267 };
268 
269 enum {
270 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
271 	Opt_vers_4_1, Opt_vers_4_2,
272 
273 	Opt_vers_err
274 };
275 
276 static match_table_t nfs_vers_tokens = {
277 	{ Opt_vers_2, "2" },
278 	{ Opt_vers_3, "3" },
279 	{ Opt_vers_4, "4" },
280 	{ Opt_vers_4_0, "4.0" },
281 	{ Opt_vers_4_1, "4.1" },
282 	{ Opt_vers_4_2, "4.2" },
283 
284 	{ Opt_vers_err, NULL }
285 };
286 
287 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
288 		int flags, const char *dev_name, void *raw_data);
289 
290 struct file_system_type nfs_fs_type = {
291 	.owner		= THIS_MODULE,
292 	.name		= "nfs",
293 	.mount		= nfs_fs_mount,
294 	.kill_sb	= nfs_kill_super,
295 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
296 };
297 MODULE_ALIAS_FS("nfs");
298 EXPORT_SYMBOL_GPL(nfs_fs_type);
299 
300 struct file_system_type nfs_xdev_fs_type = {
301 	.owner		= THIS_MODULE,
302 	.name		= "nfs",
303 	.mount		= nfs_xdev_mount,
304 	.kill_sb	= nfs_kill_super,
305 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
306 };
307 
308 const struct super_operations nfs_sops = {
309 	.alloc_inode	= nfs_alloc_inode,
310 	.destroy_inode	= nfs_destroy_inode,
311 	.write_inode	= nfs_write_inode,
312 	.drop_inode	= nfs_drop_inode,
313 	.statfs		= nfs_statfs,
314 	.evict_inode	= nfs_evict_inode,
315 	.umount_begin	= nfs_umount_begin,
316 	.show_options	= nfs_show_options,
317 	.show_devname	= nfs_show_devname,
318 	.show_path	= nfs_show_path,
319 	.show_stats	= nfs_show_stats,
320 	.remount_fs	= nfs_remount,
321 };
322 EXPORT_SYMBOL_GPL(nfs_sops);
323 
324 #if IS_ENABLED(CONFIG_NFS_V4)
325 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
326 static int nfs4_validate_mount_data(void *options,
327 	struct nfs_parsed_mount_data *args, const char *dev_name);
328 
329 struct file_system_type nfs4_fs_type = {
330 	.owner		= THIS_MODULE,
331 	.name		= "nfs4",
332 	.mount		= nfs_fs_mount,
333 	.kill_sb	= nfs_kill_super,
334 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
335 };
336 MODULE_ALIAS_FS("nfs4");
337 MODULE_ALIAS("nfs4");
338 EXPORT_SYMBOL_GPL(nfs4_fs_type);
339 
340 static int __init register_nfs4_fs(void)
341 {
342 	return register_filesystem(&nfs4_fs_type);
343 }
344 
345 static void unregister_nfs4_fs(void)
346 {
347 	unregister_filesystem(&nfs4_fs_type);
348 }
349 #else
350 static int __init register_nfs4_fs(void)
351 {
352 	return 0;
353 }
354 
355 static void unregister_nfs4_fs(void)
356 {
357 }
358 #endif
359 
360 static struct shrinker acl_shrinker = {
361 	.count_objects	= nfs_access_cache_count,
362 	.scan_objects	= nfs_access_cache_scan,
363 	.seeks		= DEFAULT_SEEKS,
364 };
365 
366 /*
367  * Register the NFS filesystems
368  */
369 int __init register_nfs_fs(void)
370 {
371 	int ret;
372 
373         ret = register_filesystem(&nfs_fs_type);
374 	if (ret < 0)
375 		goto error_0;
376 
377 	ret = register_nfs4_fs();
378 	if (ret < 0)
379 		goto error_1;
380 
381 	ret = nfs_register_sysctl();
382 	if (ret < 0)
383 		goto error_2;
384 	register_shrinker(&acl_shrinker);
385 	return 0;
386 
387 error_2:
388 	unregister_nfs4_fs();
389 error_1:
390 	unregister_filesystem(&nfs_fs_type);
391 error_0:
392 	return ret;
393 }
394 
395 /*
396  * Unregister the NFS filesystems
397  */
398 void __exit unregister_nfs_fs(void)
399 {
400 	unregister_shrinker(&acl_shrinker);
401 	nfs_unregister_sysctl();
402 	unregister_nfs4_fs();
403 	unregister_filesystem(&nfs_fs_type);
404 }
405 
406 bool nfs_sb_active(struct super_block *sb)
407 {
408 	struct nfs_server *server = NFS_SB(sb);
409 
410 	if (!atomic_inc_not_zero(&sb->s_active))
411 		return false;
412 	if (atomic_inc_return(&server->active) != 1)
413 		atomic_dec(&sb->s_active);
414 	return true;
415 }
416 EXPORT_SYMBOL_GPL(nfs_sb_active);
417 
418 void nfs_sb_deactive(struct super_block *sb)
419 {
420 	struct nfs_server *server = NFS_SB(sb);
421 
422 	if (atomic_dec_and_test(&server->active))
423 		deactivate_super(sb);
424 }
425 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
426 
427 /*
428  * Deliver file system statistics to userspace
429  */
430 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
431 {
432 	struct nfs_server *server = NFS_SB(dentry->d_sb);
433 	unsigned char blockbits;
434 	unsigned long blockres;
435 	struct nfs_fh *fh = NFS_FH(d_inode(dentry));
436 	struct nfs_fsstat res;
437 	int error = -ENOMEM;
438 
439 	res.fattr = nfs_alloc_fattr();
440 	if (res.fattr == NULL)
441 		goto out_err;
442 
443 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
444 	if (unlikely(error == -ESTALE)) {
445 		struct dentry *pd_dentry;
446 
447 		pd_dentry = dget_parent(dentry);
448 		if (pd_dentry != NULL) {
449 			nfs_zap_caches(d_inode(pd_dentry));
450 			dput(pd_dentry);
451 		}
452 	}
453 	nfs_free_fattr(res.fattr);
454 	if (error < 0)
455 		goto out_err;
456 
457 	buf->f_type = NFS_SUPER_MAGIC;
458 
459 	/*
460 	 * Current versions of glibc do not correctly handle the
461 	 * case where f_frsize != f_bsize.  Eventually we want to
462 	 * report the value of wtmult in this field.
463 	 */
464 	buf->f_frsize = dentry->d_sb->s_blocksize;
465 
466 	/*
467 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
468 	 * are reported in units of f_frsize.  Linux hasn't had
469 	 * an f_frsize field in its statfs struct until recently,
470 	 * thus historically Linux's sys_statfs reports these
471 	 * fields in units of f_bsize.
472 	 */
473 	buf->f_bsize = dentry->d_sb->s_blocksize;
474 	blockbits = dentry->d_sb->s_blocksize_bits;
475 	blockres = (1 << blockbits) - 1;
476 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
477 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
478 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
479 
480 	buf->f_files = res.tfiles;
481 	buf->f_ffree = res.afiles;
482 
483 	buf->f_namelen = server->namelen;
484 
485 	return 0;
486 
487  out_err:
488 	dprintk("%s: statfs error = %d\n", __func__, -error);
489 	return error;
490 }
491 EXPORT_SYMBOL_GPL(nfs_statfs);
492 
493 /*
494  * Map the security flavour number to a name
495  */
496 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
497 {
498 	static const struct {
499 		rpc_authflavor_t flavour;
500 		const char *str;
501 	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
502 		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
503 		{ RPC_AUTH_NULL, "null" },
504 		{ RPC_AUTH_UNIX, "sys" },
505 		{ RPC_AUTH_GSS_KRB5, "krb5" },
506 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
507 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
508 		{ RPC_AUTH_GSS_LKEY, "lkey" },
509 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
510 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
511 		{ RPC_AUTH_GSS_SPKM, "spkm" },
512 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
513 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
514 		{ UINT_MAX, "unknown" }
515 	};
516 	int i;
517 
518 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
519 		if (sec_flavours[i].flavour == flavour)
520 			break;
521 	}
522 	return sec_flavours[i].str;
523 }
524 
525 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
526 				  int showdefaults)
527 {
528 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
529 
530 	seq_printf(m, ",mountproto=");
531 	switch (sap->sa_family) {
532 	case AF_INET:
533 		switch (nfss->mountd_protocol) {
534 		case IPPROTO_UDP:
535 			seq_printf(m, RPCBIND_NETID_UDP);
536 			break;
537 		case IPPROTO_TCP:
538 			seq_printf(m, RPCBIND_NETID_TCP);
539 			break;
540 		default:
541 			if (showdefaults)
542 				seq_printf(m, "auto");
543 		}
544 		break;
545 	case AF_INET6:
546 		switch (nfss->mountd_protocol) {
547 		case IPPROTO_UDP:
548 			seq_printf(m, RPCBIND_NETID_UDP6);
549 			break;
550 		case IPPROTO_TCP:
551 			seq_printf(m, RPCBIND_NETID_TCP6);
552 			break;
553 		default:
554 			if (showdefaults)
555 				seq_printf(m, "auto");
556 		}
557 		break;
558 	default:
559 		if (showdefaults)
560 			seq_printf(m, "auto");
561 	}
562 }
563 
564 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
565 				    int showdefaults)
566 {
567 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
568 
569 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
570 		return;
571 
572 	switch (sap->sa_family) {
573 	case AF_INET: {
574 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
575 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
576 		break;
577 	}
578 	case AF_INET6: {
579 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
580 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
581 		break;
582 	}
583 	default:
584 		if (showdefaults)
585 			seq_printf(m, ",mountaddr=unspecified");
586 	}
587 
588 	if (nfss->mountd_version || showdefaults)
589 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
590 	if ((nfss->mountd_port &&
591 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
592 		showdefaults)
593 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
594 
595 	nfs_show_mountd_netid(m, nfss, showdefaults);
596 }
597 
598 #if IS_ENABLED(CONFIG_NFS_V4)
599 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
600 				    int showdefaults)
601 {
602 	struct nfs_client *clp = nfss->nfs_client;
603 
604 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
605 }
606 #else
607 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
608 				    int showdefaults)
609 {
610 }
611 #endif
612 
613 static void nfs_show_nfs_version(struct seq_file *m,
614 		unsigned int version,
615 		unsigned int minorversion)
616 {
617 	seq_printf(m, ",vers=%u", version);
618 	if (version == 4)
619 		seq_printf(m, ".%u", minorversion);
620 }
621 
622 /*
623  * Describe the mount options in force on this server representation
624  */
625 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
626 				   int showdefaults)
627 {
628 	static const struct proc_nfs_info {
629 		int flag;
630 		const char *str;
631 		const char *nostr;
632 	} nfs_info[] = {
633 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
634 		{ NFS_MOUNT_POSIX, ",posix", "" },
635 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
636 		{ NFS_MOUNT_NOAC, ",noac", "" },
637 		{ NFS_MOUNT_NONLM, ",nolock", "" },
638 		{ NFS_MOUNT_NOACL, ",noacl", "" },
639 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
640 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
641 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
642 		{ 0, NULL, NULL }
643 	};
644 	const struct proc_nfs_info *nfs_infop;
645 	struct nfs_client *clp = nfss->nfs_client;
646 	u32 version = clp->rpc_ops->version;
647 	int local_flock, local_fcntl;
648 
649 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
650 	seq_printf(m, ",rsize=%u", nfss->rsize);
651 	seq_printf(m, ",wsize=%u", nfss->wsize);
652 	if (nfss->bsize != 0)
653 		seq_printf(m, ",bsize=%u", nfss->bsize);
654 	seq_printf(m, ",namlen=%u", nfss->namelen);
655 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
656 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
657 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
658 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
659 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
660 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
661 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
662 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
663 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
664 		if (nfss->flags & nfs_infop->flag)
665 			seq_puts(m, nfs_infop->str);
666 		else
667 			seq_puts(m, nfs_infop->nostr);
668 	}
669 	rcu_read_lock();
670 	seq_printf(m, ",proto=%s",
671 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
672 	rcu_read_unlock();
673 	if (version == 4) {
674 		if (nfss->port != NFS_PORT)
675 			seq_printf(m, ",port=%u", nfss->port);
676 	} else
677 		if (nfss->port)
678 			seq_printf(m, ",port=%u", nfss->port);
679 
680 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
681 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
682 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
683 
684 	if (version != 4)
685 		nfs_show_mountd_options(m, nfss, showdefaults);
686 	else
687 		nfs_show_nfsv4_options(m, nfss, showdefaults);
688 
689 	if (nfss->options & NFS_OPTION_FSCACHE)
690 		seq_printf(m, ",fsc");
691 
692 	if (nfss->options & NFS_OPTION_MIGRATION)
693 		seq_printf(m, ",migration");
694 
695 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
696 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
697 			seq_printf(m, ",lookupcache=none");
698 		else
699 			seq_printf(m, ",lookupcache=pos");
700 	}
701 
702 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
703 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
704 
705 	if (!local_flock && !local_fcntl)
706 		seq_printf(m, ",local_lock=none");
707 	else if (local_flock && local_fcntl)
708 		seq_printf(m, ",local_lock=all");
709 	else if (local_flock)
710 		seq_printf(m, ",local_lock=flock");
711 	else
712 		seq_printf(m, ",local_lock=posix");
713 }
714 
715 /*
716  * Describe the mount options on this VFS mountpoint
717  */
718 int nfs_show_options(struct seq_file *m, struct dentry *root)
719 {
720 	struct nfs_server *nfss = NFS_SB(root->d_sb);
721 
722 	nfs_show_mount_options(m, nfss, 0);
723 
724 	rcu_read_lock();
725 	seq_printf(m, ",addr=%s",
726 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
727 							RPC_DISPLAY_ADDR));
728 	rcu_read_unlock();
729 
730 	return 0;
731 }
732 EXPORT_SYMBOL_GPL(nfs_show_options);
733 
734 #if IS_ENABLED(CONFIG_NFS_V4)
735 #ifdef CONFIG_NFS_V4_1
736 static void show_sessions(struct seq_file *m, struct nfs_server *server)
737 {
738 	if (nfs4_has_session(server->nfs_client))
739 		seq_printf(m, ",sessions");
740 }
741 #else
742 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
743 #endif
744 #endif
745 
746 #ifdef CONFIG_NFS_V4_1
747 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
748 {
749 	seq_printf(m, ",pnfs=");
750 	if (server->pnfs_curr_ld)
751 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
752 	else
753 		seq_printf(m, "not configured");
754 }
755 
756 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
757 {
758 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
759 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
760 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
761 			   "date='%llu,%u'",
762 			   impl_id->name, impl_id->domain,
763 			   impl_id->date.seconds, impl_id->date.nseconds);
764 	}
765 }
766 #else
767 #if IS_ENABLED(CONFIG_NFS_V4)
768 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
769 {
770 }
771 #endif
772 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
773 {
774 }
775 #endif
776 
777 int nfs_show_devname(struct seq_file *m, struct dentry *root)
778 {
779 	char *page = (char *) __get_free_page(GFP_KERNEL);
780 	char *devname, *dummy;
781 	int err = 0;
782 	if (!page)
783 		return -ENOMEM;
784 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
785 	if (IS_ERR(devname))
786 		err = PTR_ERR(devname);
787 	else
788 		seq_escape(m, devname, " \t\n\\");
789 	free_page((unsigned long)page);
790 	return err;
791 }
792 EXPORT_SYMBOL_GPL(nfs_show_devname);
793 
794 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
795 {
796 	seq_puts(m, "/");
797 	return 0;
798 }
799 EXPORT_SYMBOL_GPL(nfs_show_path);
800 
801 /*
802  * Present statistical information for this VFS mountpoint
803  */
804 int nfs_show_stats(struct seq_file *m, struct dentry *root)
805 {
806 	int i, cpu;
807 	struct nfs_server *nfss = NFS_SB(root->d_sb);
808 	struct rpc_auth *auth = nfss->client->cl_auth;
809 	struct nfs_iostats totals = { };
810 
811 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
812 
813 	/*
814 	 * Display all mount option settings
815 	 */
816 	seq_printf(m, "\n\topts:\t");
817 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
818 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
819 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
820 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
821 	nfs_show_mount_options(m, nfss, 1);
822 
823 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
824 
825 	show_implementation_id(m, nfss);
826 
827 	seq_printf(m, "\n\tcaps:\t");
828 	seq_printf(m, "caps=0x%x", nfss->caps);
829 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
830 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
831 	seq_printf(m, ",bsize=%u", nfss->bsize);
832 	seq_printf(m, ",namlen=%u", nfss->namelen);
833 
834 #if IS_ENABLED(CONFIG_NFS_V4)
835 	if (nfss->nfs_client->rpc_ops->version == 4) {
836 		seq_printf(m, "\n\tnfsv4:\t");
837 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
838 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
839 		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
840 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
841 		show_sessions(m, nfss);
842 		show_pnfs(m, nfss);
843 	}
844 #endif
845 
846 	/*
847 	 * Display security flavor in effect for this mount
848 	 */
849 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
850 	if (auth->au_flavor)
851 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
852 
853 	/*
854 	 * Display superblock I/O counters
855 	 */
856 	for_each_possible_cpu(cpu) {
857 		struct nfs_iostats *stats;
858 
859 		preempt_disable();
860 		stats = per_cpu_ptr(nfss->io_stats, cpu);
861 
862 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
863 			totals.events[i] += stats->events[i];
864 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
865 			totals.bytes[i] += stats->bytes[i];
866 #ifdef CONFIG_NFS_FSCACHE
867 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
868 			totals.fscache[i] += stats->fscache[i];
869 #endif
870 
871 		preempt_enable();
872 	}
873 
874 	seq_printf(m, "\n\tevents:\t");
875 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
876 		seq_printf(m, "%lu ", totals.events[i]);
877 	seq_printf(m, "\n\tbytes:\t");
878 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
879 		seq_printf(m, "%Lu ", totals.bytes[i]);
880 #ifdef CONFIG_NFS_FSCACHE
881 	if (nfss->options & NFS_OPTION_FSCACHE) {
882 		seq_printf(m, "\n\tfsc:\t");
883 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
884 			seq_printf(m, "%Lu ", totals.bytes[i]);
885 	}
886 #endif
887 	seq_printf(m, "\n");
888 
889 	rpc_print_iostats(m, nfss->client);
890 
891 	return 0;
892 }
893 EXPORT_SYMBOL_GPL(nfs_show_stats);
894 
895 /*
896  * Begin unmount by attempting to remove all automounted mountpoints we added
897  * in response to xdev traversals and referrals
898  */
899 void nfs_umount_begin(struct super_block *sb)
900 {
901 	struct nfs_server *server;
902 	struct rpc_clnt *rpc;
903 
904 	server = NFS_SB(sb);
905 	/* -EIO all pending I/O */
906 	rpc = server->client_acl;
907 	if (!IS_ERR(rpc))
908 		rpc_killall_tasks(rpc);
909 	rpc = server->client;
910 	if (!IS_ERR(rpc))
911 		rpc_killall_tasks(rpc);
912 }
913 EXPORT_SYMBOL_GPL(nfs_umount_begin);
914 
915 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
916 {
917 	struct nfs_parsed_mount_data *data;
918 
919 	data = kzalloc(sizeof(*data), GFP_KERNEL);
920 	if (data) {
921 		data->acregmin		= NFS_DEF_ACREGMIN;
922 		data->acregmax		= NFS_DEF_ACREGMAX;
923 		data->acdirmin		= NFS_DEF_ACDIRMIN;
924 		data->acdirmax		= NFS_DEF_ACDIRMAX;
925 		data->mount_server.port	= NFS_UNSPEC_PORT;
926 		data->nfs_server.port	= NFS_UNSPEC_PORT;
927 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
928 		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
929 		data->minorversion	= 0;
930 		data->need_mount	= true;
931 		data->net		= current->nsproxy->net_ns;
932 		security_init_mnt_opts(&data->lsm_opts);
933 	}
934 	return data;
935 }
936 
937 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
938 {
939 	if (data) {
940 		kfree(data->client_address);
941 		kfree(data->mount_server.hostname);
942 		kfree(data->nfs_server.export_path);
943 		kfree(data->nfs_server.hostname);
944 		kfree(data->fscache_uniq);
945 		security_free_mnt_opts(&data->lsm_opts);
946 		kfree(data);
947 	}
948 }
949 
950 /*
951  * Sanity-check a server address provided by the mount command.
952  *
953  * Address family must be initialized, and address must not be
954  * the ANY address for that family.
955  */
956 static int nfs_verify_server_address(struct sockaddr *addr)
957 {
958 	switch (addr->sa_family) {
959 	case AF_INET: {
960 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
961 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
962 	}
963 	case AF_INET6: {
964 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
965 		return !ipv6_addr_any(sa);
966 	}
967 	}
968 
969 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
970 	return 0;
971 }
972 
973 /*
974  * Select between a default port value and a user-specified port value.
975  * If a zero value is set, then autobind will be used.
976  */
977 static void nfs_set_port(struct sockaddr *sap, int *port,
978 				 const unsigned short default_port)
979 {
980 	if (*port == NFS_UNSPEC_PORT)
981 		*port = default_port;
982 
983 	rpc_set_port(sap, *port);
984 }
985 
986 /*
987  * Sanity check the NFS transport protocol.
988  *
989  */
990 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
991 {
992 	switch (mnt->nfs_server.protocol) {
993 	case XPRT_TRANSPORT_UDP:
994 	case XPRT_TRANSPORT_TCP:
995 	case XPRT_TRANSPORT_RDMA:
996 		break;
997 	default:
998 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
999 	}
1000 }
1001 
1002 /*
1003  * For text based NFSv2/v3 mounts, the mount protocol transport default
1004  * settings should depend upon the specified NFS transport.
1005  */
1006 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1007 {
1008 	nfs_validate_transport_protocol(mnt);
1009 
1010 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1011 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1012 			return;
1013 	switch (mnt->nfs_server.protocol) {
1014 	case XPRT_TRANSPORT_UDP:
1015 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1016 		break;
1017 	case XPRT_TRANSPORT_TCP:
1018 	case XPRT_TRANSPORT_RDMA:
1019 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1020 	}
1021 }
1022 
1023 /*
1024  * Add 'flavor' to 'auth_info' if not already present.
1025  * Returns true if 'flavor' ends up in the list, false otherwise
1026  */
1027 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1028 			      rpc_authflavor_t flavor)
1029 {
1030 	unsigned int i;
1031 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1032 
1033 	/* make sure this flavor isn't already in the list */
1034 	for (i = 0; i < auth_info->flavor_len; i++) {
1035 		if (flavor == auth_info->flavors[i])
1036 			return true;
1037 	}
1038 
1039 	if (auth_info->flavor_len + 1 >= max_flavor_len) {
1040 		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1041 		return false;
1042 	}
1043 
1044 	auth_info->flavors[auth_info->flavor_len++] = flavor;
1045 	return true;
1046 }
1047 
1048 /*
1049  * Return true if 'match' is in auth_info or auth_info is empty.
1050  * Return false otherwise.
1051  */
1052 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1053 			 rpc_authflavor_t match)
1054 {
1055 	int i;
1056 
1057 	if (!auth_info->flavor_len)
1058 		return true;
1059 
1060 	for (i = 0; i < auth_info->flavor_len; i++) {
1061 		if (auth_info->flavors[i] == match)
1062 			return true;
1063 	}
1064 	return false;
1065 }
1066 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1067 
1068 /*
1069  * Parse the value of the 'sec=' option.
1070  */
1071 static int nfs_parse_security_flavors(char *value,
1072 				      struct nfs_parsed_mount_data *mnt)
1073 {
1074 	substring_t args[MAX_OPT_ARGS];
1075 	rpc_authflavor_t pseudoflavor;
1076 	char *p;
1077 
1078 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1079 
1080 	while ((p = strsep(&value, ":")) != NULL) {
1081 		switch (match_token(p, nfs_secflavor_tokens, args)) {
1082 		case Opt_sec_none:
1083 			pseudoflavor = RPC_AUTH_NULL;
1084 			break;
1085 		case Opt_sec_sys:
1086 			pseudoflavor = RPC_AUTH_UNIX;
1087 			break;
1088 		case Opt_sec_krb5:
1089 			pseudoflavor = RPC_AUTH_GSS_KRB5;
1090 			break;
1091 		case Opt_sec_krb5i:
1092 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
1093 			break;
1094 		case Opt_sec_krb5p:
1095 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
1096 			break;
1097 		case Opt_sec_lkey:
1098 			pseudoflavor = RPC_AUTH_GSS_LKEY;
1099 			break;
1100 		case Opt_sec_lkeyi:
1101 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
1102 			break;
1103 		case Opt_sec_lkeyp:
1104 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
1105 			break;
1106 		case Opt_sec_spkm:
1107 			pseudoflavor = RPC_AUTH_GSS_SPKM;
1108 			break;
1109 		case Opt_sec_spkmi:
1110 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
1111 			break;
1112 		case Opt_sec_spkmp:
1113 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
1114 			break;
1115 		default:
1116 			dfprintk(MOUNT,
1117 				 "NFS: sec= option '%s' not recognized\n", p);
1118 			return 0;
1119 		}
1120 
1121 		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1122 			return 0;
1123 	}
1124 
1125 	return 1;
1126 }
1127 
1128 static int nfs_parse_version_string(char *string,
1129 		struct nfs_parsed_mount_data *mnt,
1130 		substring_t *args)
1131 {
1132 	mnt->flags &= ~NFS_MOUNT_VER3;
1133 	switch (match_token(string, nfs_vers_tokens, args)) {
1134 	case Opt_vers_2:
1135 		mnt->version = 2;
1136 		break;
1137 	case Opt_vers_3:
1138 		mnt->flags |= NFS_MOUNT_VER3;
1139 		mnt->version = 3;
1140 		break;
1141 	case Opt_vers_4:
1142 		/* Backward compatibility option. In future,
1143 		 * the mount program should always supply
1144 		 * a NFSv4 minor version number.
1145 		 */
1146 		mnt->version = 4;
1147 		break;
1148 	case Opt_vers_4_0:
1149 		mnt->version = 4;
1150 		mnt->minorversion = 0;
1151 		break;
1152 	case Opt_vers_4_1:
1153 		mnt->version = 4;
1154 		mnt->minorversion = 1;
1155 		break;
1156 	case Opt_vers_4_2:
1157 		mnt->version = 4;
1158 		mnt->minorversion = 2;
1159 		break;
1160 	default:
1161 		return 0;
1162 	}
1163 	return 1;
1164 }
1165 
1166 static int nfs_get_option_str(substring_t args[], char **option)
1167 {
1168 	kfree(*option);
1169 	*option = match_strdup(args);
1170 	return !*option;
1171 }
1172 
1173 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1174 {
1175 	int rc;
1176 	char *string;
1177 
1178 	string = match_strdup(args);
1179 	if (string == NULL)
1180 		return -ENOMEM;
1181 	rc = kstrtoul(string, 10, option);
1182 	kfree(string);
1183 
1184 	return rc;
1185 }
1186 
1187 /*
1188  * Error-check and convert a string of mount options from user space into
1189  * a data structure.  The whole mount string is processed; bad options are
1190  * skipped as they are encountered.  If there were no errors, return 1;
1191  * otherwise return 0 (zero).
1192  */
1193 static int nfs_parse_mount_options(char *raw,
1194 				   struct nfs_parsed_mount_data *mnt)
1195 {
1196 	char *p, *string, *secdata;
1197 	int rc, sloppy = 0, invalid_option = 0;
1198 	unsigned short protofamily = AF_UNSPEC;
1199 	unsigned short mountfamily = AF_UNSPEC;
1200 
1201 	if (!raw) {
1202 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1203 		return 1;
1204 	}
1205 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1206 
1207 	secdata = alloc_secdata();
1208 	if (!secdata)
1209 		goto out_nomem;
1210 
1211 	rc = security_sb_copy_data(raw, secdata);
1212 	if (rc)
1213 		goto out_security_failure;
1214 
1215 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1216 	if (rc)
1217 		goto out_security_failure;
1218 
1219 	free_secdata(secdata);
1220 
1221 	while ((p = strsep(&raw, ",")) != NULL) {
1222 		substring_t args[MAX_OPT_ARGS];
1223 		unsigned long option;
1224 		int token;
1225 
1226 		if (!*p)
1227 			continue;
1228 
1229 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1230 
1231 		token = match_token(p, nfs_mount_option_tokens, args);
1232 		switch (token) {
1233 
1234 		/*
1235 		 * boolean options:  foo/nofoo
1236 		 */
1237 		case Opt_soft:
1238 			mnt->flags |= NFS_MOUNT_SOFT;
1239 			break;
1240 		case Opt_hard:
1241 			mnt->flags &= ~NFS_MOUNT_SOFT;
1242 			break;
1243 		case Opt_posix:
1244 			mnt->flags |= NFS_MOUNT_POSIX;
1245 			break;
1246 		case Opt_noposix:
1247 			mnt->flags &= ~NFS_MOUNT_POSIX;
1248 			break;
1249 		case Opt_cto:
1250 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1251 			break;
1252 		case Opt_nocto:
1253 			mnt->flags |= NFS_MOUNT_NOCTO;
1254 			break;
1255 		case Opt_ac:
1256 			mnt->flags &= ~NFS_MOUNT_NOAC;
1257 			break;
1258 		case Opt_noac:
1259 			mnt->flags |= NFS_MOUNT_NOAC;
1260 			break;
1261 		case Opt_lock:
1262 			mnt->flags &= ~NFS_MOUNT_NONLM;
1263 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1264 					NFS_MOUNT_LOCAL_FCNTL);
1265 			break;
1266 		case Opt_nolock:
1267 			mnt->flags |= NFS_MOUNT_NONLM;
1268 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1269 				       NFS_MOUNT_LOCAL_FCNTL);
1270 			break;
1271 		case Opt_udp:
1272 			mnt->flags &= ~NFS_MOUNT_TCP;
1273 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1274 			break;
1275 		case Opt_tcp:
1276 			mnt->flags |= NFS_MOUNT_TCP;
1277 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1278 			break;
1279 		case Opt_rdma:
1280 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1281 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1282 			xprt_load_transport(p);
1283 			break;
1284 		case Opt_acl:
1285 			mnt->flags &= ~NFS_MOUNT_NOACL;
1286 			break;
1287 		case Opt_noacl:
1288 			mnt->flags |= NFS_MOUNT_NOACL;
1289 			break;
1290 		case Opt_rdirplus:
1291 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1292 			break;
1293 		case Opt_nordirplus:
1294 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1295 			break;
1296 		case Opt_sharecache:
1297 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1298 			break;
1299 		case Opt_nosharecache:
1300 			mnt->flags |= NFS_MOUNT_UNSHARED;
1301 			break;
1302 		case Opt_resvport:
1303 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1304 			break;
1305 		case Opt_noresvport:
1306 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1307 			break;
1308 		case Opt_fscache:
1309 			mnt->options |= NFS_OPTION_FSCACHE;
1310 			kfree(mnt->fscache_uniq);
1311 			mnt->fscache_uniq = NULL;
1312 			break;
1313 		case Opt_nofscache:
1314 			mnt->options &= ~NFS_OPTION_FSCACHE;
1315 			kfree(mnt->fscache_uniq);
1316 			mnt->fscache_uniq = NULL;
1317 			break;
1318 		case Opt_migration:
1319 			mnt->options |= NFS_OPTION_MIGRATION;
1320 			break;
1321 		case Opt_nomigration:
1322 			mnt->options &= NFS_OPTION_MIGRATION;
1323 			break;
1324 
1325 		/*
1326 		 * options that take numeric values
1327 		 */
1328 		case Opt_port:
1329 			if (nfs_get_option_ul(args, &option) ||
1330 			    option > USHRT_MAX)
1331 				goto out_invalid_value;
1332 			mnt->nfs_server.port = option;
1333 			break;
1334 		case Opt_rsize:
1335 			if (nfs_get_option_ul(args, &option))
1336 				goto out_invalid_value;
1337 			mnt->rsize = option;
1338 			break;
1339 		case Opt_wsize:
1340 			if (nfs_get_option_ul(args, &option))
1341 				goto out_invalid_value;
1342 			mnt->wsize = option;
1343 			break;
1344 		case Opt_bsize:
1345 			if (nfs_get_option_ul(args, &option))
1346 				goto out_invalid_value;
1347 			mnt->bsize = option;
1348 			break;
1349 		case Opt_timeo:
1350 			if (nfs_get_option_ul(args, &option) || option == 0)
1351 				goto out_invalid_value;
1352 			mnt->timeo = option;
1353 			break;
1354 		case Opt_retrans:
1355 			if (nfs_get_option_ul(args, &option) || option == 0)
1356 				goto out_invalid_value;
1357 			mnt->retrans = option;
1358 			break;
1359 		case Opt_acregmin:
1360 			if (nfs_get_option_ul(args, &option))
1361 				goto out_invalid_value;
1362 			mnt->acregmin = option;
1363 			break;
1364 		case Opt_acregmax:
1365 			if (nfs_get_option_ul(args, &option))
1366 				goto out_invalid_value;
1367 			mnt->acregmax = option;
1368 			break;
1369 		case Opt_acdirmin:
1370 			if (nfs_get_option_ul(args, &option))
1371 				goto out_invalid_value;
1372 			mnt->acdirmin = option;
1373 			break;
1374 		case Opt_acdirmax:
1375 			if (nfs_get_option_ul(args, &option))
1376 				goto out_invalid_value;
1377 			mnt->acdirmax = option;
1378 			break;
1379 		case Opt_actimeo:
1380 			if (nfs_get_option_ul(args, &option))
1381 				goto out_invalid_value;
1382 			mnt->acregmin = mnt->acregmax =
1383 			mnt->acdirmin = mnt->acdirmax = option;
1384 			break;
1385 		case Opt_namelen:
1386 			if (nfs_get_option_ul(args, &option))
1387 				goto out_invalid_value;
1388 			mnt->namlen = option;
1389 			break;
1390 		case Opt_mountport:
1391 			if (nfs_get_option_ul(args, &option) ||
1392 			    option > USHRT_MAX)
1393 				goto out_invalid_value;
1394 			mnt->mount_server.port = option;
1395 			break;
1396 		case Opt_mountvers:
1397 			if (nfs_get_option_ul(args, &option) ||
1398 			    option < NFS_MNT_VERSION ||
1399 			    option > NFS_MNT3_VERSION)
1400 				goto out_invalid_value;
1401 			mnt->mount_server.version = option;
1402 			break;
1403 		case Opt_minorversion:
1404 			if (nfs_get_option_ul(args, &option))
1405 				goto out_invalid_value;
1406 			if (option > NFS4_MAX_MINOR_VERSION)
1407 				goto out_invalid_value;
1408 			mnt->minorversion = option;
1409 			break;
1410 
1411 		/*
1412 		 * options that take text values
1413 		 */
1414 		case Opt_nfsvers:
1415 			string = match_strdup(args);
1416 			if (string == NULL)
1417 				goto out_nomem;
1418 			rc = nfs_parse_version_string(string, mnt, args);
1419 			kfree(string);
1420 			if (!rc)
1421 				goto out_invalid_value;
1422 			break;
1423 		case Opt_sec:
1424 			string = match_strdup(args);
1425 			if (string == NULL)
1426 				goto out_nomem;
1427 			rc = nfs_parse_security_flavors(string, mnt);
1428 			kfree(string);
1429 			if (!rc) {
1430 				dfprintk(MOUNT, "NFS:   unrecognized "
1431 						"security flavor\n");
1432 				return 0;
1433 			}
1434 			break;
1435 		case Opt_proto:
1436 			string = match_strdup(args);
1437 			if (string == NULL)
1438 				goto out_nomem;
1439 			token = match_token(string,
1440 					    nfs_xprt_protocol_tokens, args);
1441 
1442 			protofamily = AF_INET;
1443 			switch (token) {
1444 			case Opt_xprt_udp6:
1445 				protofamily = AF_INET6;
1446 			case Opt_xprt_udp:
1447 				mnt->flags &= ~NFS_MOUNT_TCP;
1448 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1449 				break;
1450 			case Opt_xprt_tcp6:
1451 				protofamily = AF_INET6;
1452 			case Opt_xprt_tcp:
1453 				mnt->flags |= NFS_MOUNT_TCP;
1454 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1455 				break;
1456 			case Opt_xprt_rdma:
1457 				/* vector side protocols to TCP */
1458 				mnt->flags |= NFS_MOUNT_TCP;
1459 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1460 				xprt_load_transport(string);
1461 				break;
1462 			default:
1463 				dfprintk(MOUNT, "NFS:   unrecognized "
1464 						"transport protocol\n");
1465 				kfree(string);
1466 				return 0;
1467 			}
1468 			kfree(string);
1469 			break;
1470 		case Opt_mountproto:
1471 			string = match_strdup(args);
1472 			if (string == NULL)
1473 				goto out_nomem;
1474 			token = match_token(string,
1475 					    nfs_xprt_protocol_tokens, args);
1476 			kfree(string);
1477 
1478 			mountfamily = AF_INET;
1479 			switch (token) {
1480 			case Opt_xprt_udp6:
1481 				mountfamily = AF_INET6;
1482 			case Opt_xprt_udp:
1483 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1484 				break;
1485 			case Opt_xprt_tcp6:
1486 				mountfamily = AF_INET6;
1487 			case Opt_xprt_tcp:
1488 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1489 				break;
1490 			case Opt_xprt_rdma: /* not used for side protocols */
1491 			default:
1492 				dfprintk(MOUNT, "NFS:   unrecognized "
1493 						"transport protocol\n");
1494 				return 0;
1495 			}
1496 			break;
1497 		case Opt_addr:
1498 			string = match_strdup(args);
1499 			if (string == NULL)
1500 				goto out_nomem;
1501 			mnt->nfs_server.addrlen =
1502 				rpc_pton(mnt->net, string, strlen(string),
1503 					(struct sockaddr *)
1504 					&mnt->nfs_server.address,
1505 					sizeof(mnt->nfs_server.address));
1506 			kfree(string);
1507 			if (mnt->nfs_server.addrlen == 0)
1508 				goto out_invalid_address;
1509 			break;
1510 		case Opt_clientaddr:
1511 			if (nfs_get_option_str(args, &mnt->client_address))
1512 				goto out_nomem;
1513 			break;
1514 		case Opt_mounthost:
1515 			if (nfs_get_option_str(args,
1516 					       &mnt->mount_server.hostname))
1517 				goto out_nomem;
1518 			break;
1519 		case Opt_mountaddr:
1520 			string = match_strdup(args);
1521 			if (string == NULL)
1522 				goto out_nomem;
1523 			mnt->mount_server.addrlen =
1524 				rpc_pton(mnt->net, string, strlen(string),
1525 					(struct sockaddr *)
1526 					&mnt->mount_server.address,
1527 					sizeof(mnt->mount_server.address));
1528 			kfree(string);
1529 			if (mnt->mount_server.addrlen == 0)
1530 				goto out_invalid_address;
1531 			break;
1532 		case Opt_lookupcache:
1533 			string = match_strdup(args);
1534 			if (string == NULL)
1535 				goto out_nomem;
1536 			token = match_token(string,
1537 					nfs_lookupcache_tokens, args);
1538 			kfree(string);
1539 			switch (token) {
1540 				case Opt_lookupcache_all:
1541 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1542 					break;
1543 				case Opt_lookupcache_positive:
1544 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1545 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1546 					break;
1547 				case Opt_lookupcache_none:
1548 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1549 					break;
1550 				default:
1551 					dfprintk(MOUNT, "NFS:   invalid "
1552 							"lookupcache argument\n");
1553 					return 0;
1554 			};
1555 			break;
1556 		case Opt_fscache_uniq:
1557 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1558 				goto out_nomem;
1559 			mnt->options |= NFS_OPTION_FSCACHE;
1560 			break;
1561 		case Opt_local_lock:
1562 			string = match_strdup(args);
1563 			if (string == NULL)
1564 				goto out_nomem;
1565 			token = match_token(string, nfs_local_lock_tokens,
1566 					args);
1567 			kfree(string);
1568 			switch (token) {
1569 			case Opt_local_lock_all:
1570 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1571 					       NFS_MOUNT_LOCAL_FCNTL);
1572 				break;
1573 			case Opt_local_lock_flock:
1574 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1575 				break;
1576 			case Opt_local_lock_posix:
1577 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1578 				break;
1579 			case Opt_local_lock_none:
1580 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1581 						NFS_MOUNT_LOCAL_FCNTL);
1582 				break;
1583 			default:
1584 				dfprintk(MOUNT, "NFS:	invalid	"
1585 						"local_lock argument\n");
1586 				return 0;
1587 			};
1588 			break;
1589 
1590 		/*
1591 		 * Special options
1592 		 */
1593 		case Opt_sloppy:
1594 			sloppy = 1;
1595 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1596 			break;
1597 		case Opt_userspace:
1598 		case Opt_deprecated:
1599 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1600 					"'%s'\n", p);
1601 			break;
1602 
1603 		default:
1604 			invalid_option = 1;
1605 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1606 					"'%s'\n", p);
1607 		}
1608 	}
1609 
1610 	if (!sloppy && invalid_option)
1611 		return 0;
1612 
1613 	if (mnt->minorversion && mnt->version != 4)
1614 		goto out_minorversion_mismatch;
1615 
1616 	if (mnt->options & NFS_OPTION_MIGRATION &&
1617 	    (mnt->version != 4 || mnt->minorversion != 0))
1618 		goto out_migration_misuse;
1619 
1620 	/*
1621 	 * verify that any proto=/mountproto= options match the address
1622 	 * families in the addr=/mountaddr= options.
1623 	 */
1624 	if (protofamily != AF_UNSPEC &&
1625 	    protofamily != mnt->nfs_server.address.ss_family)
1626 		goto out_proto_mismatch;
1627 
1628 	if (mountfamily != AF_UNSPEC) {
1629 		if (mnt->mount_server.addrlen) {
1630 			if (mountfamily != mnt->mount_server.address.ss_family)
1631 				goto out_mountproto_mismatch;
1632 		} else {
1633 			if (mountfamily != mnt->nfs_server.address.ss_family)
1634 				goto out_mountproto_mismatch;
1635 		}
1636 	}
1637 
1638 	return 1;
1639 
1640 out_mountproto_mismatch:
1641 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1642 			 "option\n");
1643 	return 0;
1644 out_proto_mismatch:
1645 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1646 	return 0;
1647 out_invalid_address:
1648 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1649 	return 0;
1650 out_invalid_value:
1651 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1652 	return 0;
1653 out_minorversion_mismatch:
1654 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1655 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1656 	return 0;
1657 out_migration_misuse:
1658 	printk(KERN_INFO
1659 		"NFS: 'migration' not supported for this NFS version\n");
1660 	return 0;
1661 out_nomem:
1662 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1663 	return 0;
1664 out_security_failure:
1665 	free_secdata(secdata);
1666 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1667 	return 0;
1668 }
1669 
1670 /*
1671  * Ensure that a specified authtype in args->auth_info is supported by
1672  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1673  * -EACCES if not.
1674  */
1675 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1676 			rpc_authflavor_t *server_authlist, unsigned int count)
1677 {
1678 	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1679 	unsigned int i;
1680 
1681 	/*
1682 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1683 	 * must be in the list returned by the server.
1684 	 *
1685 	 * AUTH_NULL has a special meaning when it's in the server list - it
1686 	 * means that the server will ignore the rpc creds, so any flavor
1687 	 * can be used.
1688 	 */
1689 	for (i = 0; i < count; i++) {
1690 		flavor = server_authlist[i];
1691 
1692 		if (nfs_auth_info_match(&args->auth_info, flavor) ||
1693 		    flavor == RPC_AUTH_NULL)
1694 			goto out;
1695 	}
1696 
1697 	dfprintk(MOUNT,
1698 		 "NFS: specified auth flavors not supported by server\n");
1699 	return -EACCES;
1700 
1701 out:
1702 	args->selected_flavor = flavor;
1703 	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1704 	return 0;
1705 }
1706 
1707 /*
1708  * Use the remote server's MOUNT service to request the NFS file handle
1709  * corresponding to the provided path.
1710  */
1711 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1712 			     struct nfs_fh *root_fh,
1713 			     rpc_authflavor_t *server_authlist,
1714 			     unsigned int *server_authlist_len)
1715 {
1716 	struct nfs_mount_request request = {
1717 		.sap		= (struct sockaddr *)
1718 						&args->mount_server.address,
1719 		.dirpath	= args->nfs_server.export_path,
1720 		.protocol	= args->mount_server.protocol,
1721 		.fh		= root_fh,
1722 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1723 		.auth_flav_len	= server_authlist_len,
1724 		.auth_flavs	= server_authlist,
1725 		.net		= args->net,
1726 	};
1727 	int status;
1728 
1729 	if (args->mount_server.version == 0) {
1730 		switch (args->version) {
1731 			default:
1732 				args->mount_server.version = NFS_MNT3_VERSION;
1733 				break;
1734 			case 2:
1735 				args->mount_server.version = NFS_MNT_VERSION;
1736 		}
1737 	}
1738 	request.version = args->mount_server.version;
1739 
1740 	if (args->mount_server.hostname)
1741 		request.hostname = args->mount_server.hostname;
1742 	else
1743 		request.hostname = args->nfs_server.hostname;
1744 
1745 	/*
1746 	 * Construct the mount server's address.
1747 	 */
1748 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1749 		memcpy(request.sap, &args->nfs_server.address,
1750 		       args->nfs_server.addrlen);
1751 		args->mount_server.addrlen = args->nfs_server.addrlen;
1752 	}
1753 	request.salen = args->mount_server.addrlen;
1754 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1755 
1756 	/*
1757 	 * Now ask the mount server to map our export path
1758 	 * to a file handle.
1759 	 */
1760 	status = nfs_mount(&request);
1761 	if (status != 0) {
1762 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1763 				request.hostname, status);
1764 		return status;
1765 	}
1766 
1767 	return 0;
1768 }
1769 
1770 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1771 					struct nfs_subversion *nfs_mod)
1772 {
1773 	int status;
1774 	unsigned int i;
1775 	bool tried_auth_unix = false;
1776 	bool auth_null_in_list = false;
1777 	struct nfs_server *server = ERR_PTR(-EACCES);
1778 	struct nfs_parsed_mount_data *args = mount_info->parsed;
1779 	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1780 	unsigned int authlist_len = ARRAY_SIZE(authlist);
1781 
1782 	status = nfs_request_mount(args, mount_info->mntfh, authlist,
1783 					&authlist_len);
1784 	if (status)
1785 		return ERR_PTR(status);
1786 
1787 	/*
1788 	 * Was a sec= authflavor specified in the options? First, verify
1789 	 * whether the server supports it, and then just try to use it if so.
1790 	 */
1791 	if (args->auth_info.flavor_len > 0) {
1792 		status = nfs_verify_authflavors(args, authlist, authlist_len);
1793 		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1794 			 args->selected_flavor);
1795 		if (status)
1796 			return ERR_PTR(status);
1797 		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1798 	}
1799 
1800 	/*
1801 	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
1802 	 * SHOULD prefer the flavor listed first. However, some servers list
1803 	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1804 	 */
1805 	for (i = 0; i < authlist_len; ++i) {
1806 		rpc_authflavor_t flavor;
1807 		struct rpcsec_gss_info info;
1808 
1809 		flavor = authlist[i];
1810 		switch (flavor) {
1811 		case RPC_AUTH_UNIX:
1812 			tried_auth_unix = true;
1813 			break;
1814 		case RPC_AUTH_NULL:
1815 			auth_null_in_list = true;
1816 			continue;
1817 		default:
1818 			if (rpcauth_get_gssinfo(flavor, &info) != 0)
1819 				continue;
1820 			/* Fallthrough */
1821 		}
1822 		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1823 		args->selected_flavor = flavor;
1824 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1825 		if (!IS_ERR(server))
1826 			return server;
1827 	}
1828 
1829 	/*
1830 	 * Nothing we tried so far worked. At this point, give up if we've
1831 	 * already tried AUTH_UNIX or if the server's list doesn't contain
1832 	 * AUTH_NULL
1833 	 */
1834 	if (tried_auth_unix || !auth_null_in_list)
1835 		return server;
1836 
1837 	/* Last chance! Try AUTH_UNIX */
1838 	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1839 	args->selected_flavor = RPC_AUTH_UNIX;
1840 	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1841 }
1842 
1843 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1844 			     struct nfs_mount_info *mount_info,
1845 			     struct nfs_subversion *nfs_mod)
1846 {
1847 	struct nfs_server *server;
1848 
1849 	if (mount_info->parsed->need_mount)
1850 		server = nfs_try_mount_request(mount_info, nfs_mod);
1851 	else
1852 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1853 
1854 	if (IS_ERR(server))
1855 		return ERR_CAST(server);
1856 
1857 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1858 }
1859 EXPORT_SYMBOL_GPL(nfs_try_mount);
1860 
1861 /*
1862  * Split "dev_name" into "hostname:export_path".
1863  *
1864  * The leftmost colon demarks the split between the server's hostname
1865  * and the export path.  If the hostname starts with a left square
1866  * bracket, then it may contain colons.
1867  *
1868  * Note: caller frees hostname and export path, even on error.
1869  */
1870 static int nfs_parse_devname(const char *dev_name,
1871 			     char **hostname, size_t maxnamlen,
1872 			     char **export_path, size_t maxpathlen)
1873 {
1874 	size_t len;
1875 	char *end;
1876 
1877 	/* Is the host name protected with square brakcets? */
1878 	if (*dev_name == '[') {
1879 		end = strchr(++dev_name, ']');
1880 		if (end == NULL || end[1] != ':')
1881 			goto out_bad_devname;
1882 
1883 		len = end - dev_name;
1884 		end++;
1885 	} else {
1886 		char *comma;
1887 
1888 		end = strchr(dev_name, ':');
1889 		if (end == NULL)
1890 			goto out_bad_devname;
1891 		len = end - dev_name;
1892 
1893 		/* kill possible hostname list: not supported */
1894 		comma = strchr(dev_name, ',');
1895 		if (comma != NULL && comma < end)
1896 			*comma = 0;
1897 	}
1898 
1899 	if (len > maxnamlen)
1900 		goto out_hostname;
1901 
1902 	/* N.B. caller will free nfs_server.hostname in all cases */
1903 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1904 	if (*hostname == NULL)
1905 		goto out_nomem;
1906 	len = strlen(++end);
1907 	if (len > maxpathlen)
1908 		goto out_path;
1909 	*export_path = kstrndup(end, len, GFP_KERNEL);
1910 	if (!*export_path)
1911 		goto out_nomem;
1912 
1913 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1914 	return 0;
1915 
1916 out_bad_devname:
1917 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1918 	return -EINVAL;
1919 
1920 out_nomem:
1921 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1922 	return -ENOMEM;
1923 
1924 out_hostname:
1925 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1926 	return -ENAMETOOLONG;
1927 
1928 out_path:
1929 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1930 	return -ENAMETOOLONG;
1931 }
1932 
1933 /*
1934  * Validate the NFS2/NFS3 mount data
1935  * - fills in the mount root filehandle
1936  *
1937  * For option strings, user space handles the following behaviors:
1938  *
1939  * + DNS: mapping server host name to IP address ("addr=" option)
1940  *
1941  * + failure mode: how to behave if a mount request can't be handled
1942  *   immediately ("fg/bg" option)
1943  *
1944  * + retry: how often to retry a mount request ("retry=" option)
1945  *
1946  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1947  *   mountproto=tcp after mountproto=udp, and so on
1948  */
1949 static int nfs23_validate_mount_data(void *options,
1950 				     struct nfs_parsed_mount_data *args,
1951 				     struct nfs_fh *mntfh,
1952 				     const char *dev_name)
1953 {
1954 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1955 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1956 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1957 
1958 	if (data == NULL)
1959 		goto out_no_data;
1960 
1961 	args->version = NFS_DEFAULT_VERSION;
1962 	switch (data->version) {
1963 	case 1:
1964 		data->namlen = 0;
1965 	case 2:
1966 		data->bsize = 0;
1967 	case 3:
1968 		if (data->flags & NFS_MOUNT_VER3)
1969 			goto out_no_v3;
1970 		data->root.size = NFS2_FHSIZE;
1971 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1972 		/* Turn off security negotiation */
1973 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
1974 	case 4:
1975 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1976 			goto out_no_sec;
1977 	case 5:
1978 		memset(data->context, 0, sizeof(data->context));
1979 	case 6:
1980 		if (data->flags & NFS_MOUNT_VER3) {
1981 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1982 				goto out_invalid_fh;
1983 			mntfh->size = data->root.size;
1984 			args->version = 3;
1985 		} else {
1986 			mntfh->size = NFS2_FHSIZE;
1987 			args->version = 2;
1988 		}
1989 
1990 
1991 		memcpy(mntfh->data, data->root.data, mntfh->size);
1992 		if (mntfh->size < sizeof(mntfh->data))
1993 			memset(mntfh->data + mntfh->size, 0,
1994 			       sizeof(mntfh->data) - mntfh->size);
1995 
1996 		/*
1997 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1998 		 * can deal with.
1999 		 */
2000 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
2001 		args->flags		|= extra_flags;
2002 		args->rsize		= data->rsize;
2003 		args->wsize		= data->wsize;
2004 		args->timeo		= data->timeo;
2005 		args->retrans		= data->retrans;
2006 		args->acregmin		= data->acregmin;
2007 		args->acregmax		= data->acregmax;
2008 		args->acdirmin		= data->acdirmin;
2009 		args->acdirmax		= data->acdirmax;
2010 		args->need_mount	= false;
2011 
2012 		memcpy(sap, &data->addr, sizeof(data->addr));
2013 		args->nfs_server.addrlen = sizeof(data->addr);
2014 		args->nfs_server.port = ntohs(data->addr.sin_port);
2015 		if (!nfs_verify_server_address(sap))
2016 			goto out_no_address;
2017 
2018 		if (!(data->flags & NFS_MOUNT_TCP))
2019 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2020 		/* N.B. caller will free nfs_server.hostname in all cases */
2021 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2022 		args->namlen		= data->namlen;
2023 		args->bsize		= data->bsize;
2024 
2025 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2026 			args->selected_flavor = data->pseudoflavor;
2027 		else
2028 			args->selected_flavor = RPC_AUTH_UNIX;
2029 		if (!args->nfs_server.hostname)
2030 			goto out_nomem;
2031 
2032 		if (!(data->flags & NFS_MOUNT_NONLM))
2033 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2034 					 NFS_MOUNT_LOCAL_FCNTL);
2035 		else
2036 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2037 					NFS_MOUNT_LOCAL_FCNTL);
2038 		/*
2039 		 * The legacy version 6 binary mount data from userspace has a
2040 		 * field used only to transport selinux information into the
2041 		 * the kernel.  To continue to support that functionality we
2042 		 * have a touch of selinux knowledge here in the NFS code. The
2043 		 * userspace code converted context=blah to just blah so we are
2044 		 * converting back to the full string selinux understands.
2045 		 */
2046 		if (data->context[0]){
2047 #ifdef CONFIG_SECURITY_SELINUX
2048 			int rc;
2049 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
2050 			if (!opts_str)
2051 				return -ENOMEM;
2052 			strcpy(opts_str, "context=");
2053 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2054 			strcat(opts_str, &data->context[0]);
2055 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
2056 			kfree(opts_str);
2057 			if (rc)
2058 				return rc;
2059 #else
2060 			return -EINVAL;
2061 #endif
2062 		}
2063 
2064 		break;
2065 	default:
2066 		return NFS_TEXT_DATA;
2067 	}
2068 
2069 	return 0;
2070 
2071 out_no_data:
2072 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2073 	return -EINVAL;
2074 
2075 out_no_v3:
2076 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2077 		 data->version);
2078 	return -EINVAL;
2079 
2080 out_no_sec:
2081 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2082 	return -EINVAL;
2083 
2084 out_nomem:
2085 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2086 	return -ENOMEM;
2087 
2088 out_no_address:
2089 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2090 	return -EINVAL;
2091 
2092 out_invalid_fh:
2093 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2094 	return -EINVAL;
2095 }
2096 
2097 #if IS_ENABLED(CONFIG_NFS_V4)
2098 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2099 				   void *options,
2100 				   struct nfs_parsed_mount_data *args,
2101 				   struct nfs_fh *mntfh,
2102 				   const char *dev_name)
2103 {
2104 	if (fs_type == &nfs_fs_type)
2105 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2106 	return nfs4_validate_mount_data(options, args, dev_name);
2107 }
2108 #else
2109 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2110 				   void *options,
2111 				   struct nfs_parsed_mount_data *args,
2112 				   struct nfs_fh *mntfh,
2113 				   const char *dev_name)
2114 {
2115 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2116 }
2117 #endif
2118 
2119 static int nfs_validate_text_mount_data(void *options,
2120 					struct nfs_parsed_mount_data *args,
2121 					const char *dev_name)
2122 {
2123 	int port = 0;
2124 	int max_namelen = PAGE_SIZE;
2125 	int max_pathlen = NFS_MAXPATHLEN;
2126 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2127 
2128 	if (nfs_parse_mount_options((char *)options, args) == 0)
2129 		return -EINVAL;
2130 
2131 	if (!nfs_verify_server_address(sap))
2132 		goto out_no_address;
2133 
2134 	if (args->version == 4) {
2135 #if IS_ENABLED(CONFIG_NFS_V4)
2136 		port = NFS_PORT;
2137 		max_namelen = NFS4_MAXNAMLEN;
2138 		max_pathlen = NFS4_MAXPATHLEN;
2139 		nfs_validate_transport_protocol(args);
2140 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2141 			goto out_invalid_transport_udp;
2142 		nfs4_validate_mount_flags(args);
2143 #else
2144 		goto out_v4_not_compiled;
2145 #endif /* CONFIG_NFS_V4 */
2146 	} else
2147 		nfs_set_mount_transport_protocol(args);
2148 
2149 	nfs_set_port(sap, &args->nfs_server.port, port);
2150 
2151 	return nfs_parse_devname(dev_name,
2152 				   &args->nfs_server.hostname,
2153 				   max_namelen,
2154 				   &args->nfs_server.export_path,
2155 				   max_pathlen);
2156 
2157 #if !IS_ENABLED(CONFIG_NFS_V4)
2158 out_v4_not_compiled:
2159 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2160 	return -EPROTONOSUPPORT;
2161 #else
2162 out_invalid_transport_udp:
2163 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2164 	return -EINVAL;
2165 #endif /* !CONFIG_NFS_V4 */
2166 
2167 out_no_address:
2168 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2169 	return -EINVAL;
2170 }
2171 
2172 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2173 		| NFS_MOUNT_SECURE \
2174 		| NFS_MOUNT_TCP \
2175 		| NFS_MOUNT_VER3 \
2176 		| NFS_MOUNT_KERBEROS \
2177 		| NFS_MOUNT_NONLM \
2178 		| NFS_MOUNT_BROKEN_SUID \
2179 		| NFS_MOUNT_STRICTLOCK \
2180 		| NFS_MOUNT_LEGACY_INTERFACE)
2181 
2182 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2183 		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2184 
2185 static int
2186 nfs_compare_remount_data(struct nfs_server *nfss,
2187 			 struct nfs_parsed_mount_data *data)
2188 {
2189 	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2190 	    data->rsize != nfss->rsize ||
2191 	    data->wsize != nfss->wsize ||
2192 	    data->version != nfss->nfs_client->rpc_ops->version ||
2193 	    data->minorversion != nfss->nfs_client->cl_minorversion ||
2194 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2195 	    !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2196 	    data->acregmin != nfss->acregmin / HZ ||
2197 	    data->acregmax != nfss->acregmax / HZ ||
2198 	    data->acdirmin != nfss->acdirmin / HZ ||
2199 	    data->acdirmax != nfss->acdirmax / HZ ||
2200 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2201 	    data->nfs_server.port != nfss->port ||
2202 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2203 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2204 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2205 		return -EINVAL;
2206 
2207 	return 0;
2208 }
2209 
2210 int
2211 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2212 {
2213 	int error;
2214 	struct nfs_server *nfss = sb->s_fs_info;
2215 	struct nfs_parsed_mount_data *data;
2216 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2217 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2218 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2219 
2220 	sync_filesystem(sb);
2221 
2222 	/*
2223 	 * Userspace mount programs that send binary options generally send
2224 	 * them populated with default values. We have no way to know which
2225 	 * ones were explicitly specified. Fall back to legacy behavior and
2226 	 * just return success.
2227 	 */
2228 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2229 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2230 					   options->version <= 6))))
2231 		return 0;
2232 
2233 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2234 	if (data == NULL)
2235 		return -ENOMEM;
2236 
2237 	/* fill out struct with values from existing mount */
2238 	data->flags = nfss->flags;
2239 	data->rsize = nfss->rsize;
2240 	data->wsize = nfss->wsize;
2241 	data->retrans = nfss->client->cl_timeout->to_retries;
2242 	data->selected_flavor = nfss->client->cl_auth->au_flavor;
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 (d_inode(mntroot)->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_super;
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 	deactivate_locked_super(s);
2605 	goto out;
2606 }
2607 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2608 
2609 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2610 	int flags, const char *dev_name, void *raw_data)
2611 {
2612 	struct nfs_mount_info mount_info = {
2613 		.fill_super = nfs_fill_super,
2614 		.set_security = nfs_set_sb_security,
2615 	};
2616 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2617 	struct nfs_subversion *nfs_mod;
2618 	int error;
2619 
2620 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2621 	mount_info.mntfh = nfs_alloc_fhandle();
2622 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2623 		goto out;
2624 
2625 	/* Validate the mount data */
2626 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2627 	if (error == NFS_TEXT_DATA)
2628 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2629 	if (error < 0) {
2630 		mntroot = ERR_PTR(error);
2631 		goto out;
2632 	}
2633 
2634 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2635 	if (IS_ERR(nfs_mod)) {
2636 		mntroot = ERR_CAST(nfs_mod);
2637 		goto out;
2638 	}
2639 
2640 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2641 
2642 	put_nfs_version(nfs_mod);
2643 out:
2644 	nfs_free_parsed_mount_data(mount_info.parsed);
2645 	nfs_free_fhandle(mount_info.mntfh);
2646 	return mntroot;
2647 }
2648 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2649 
2650 /*
2651  * Destroy an NFS2/3 superblock
2652  */
2653 void nfs_kill_super(struct super_block *s)
2654 {
2655 	struct nfs_server *server = NFS_SB(s);
2656 	dev_t dev = s->s_dev;
2657 
2658 	generic_shutdown_super(s);
2659 
2660 	nfs_fscache_release_super_cookie(s);
2661 
2662 	nfs_free_server(server);
2663 	free_anon_bdev(dev);
2664 }
2665 EXPORT_SYMBOL_GPL(nfs_kill_super);
2666 
2667 /*
2668  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2669  */
2670 static struct dentry *
2671 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2672 		const char *dev_name, void *raw_data)
2673 {
2674 	struct nfs_clone_mount *data = raw_data;
2675 	struct nfs_mount_info mount_info = {
2676 		.fill_super = nfs_clone_super,
2677 		.set_security = nfs_clone_sb_security,
2678 		.cloned = data,
2679 	};
2680 	struct nfs_server *server;
2681 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2682 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2683 
2684 	dprintk("--> nfs_xdev_mount()\n");
2685 
2686 	mount_info.mntfh = mount_info.cloned->fh;
2687 
2688 	/* create a new volume representation */
2689 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2690 
2691 	if (IS_ERR(server))
2692 		mntroot = ERR_CAST(server);
2693 	else
2694 		mntroot = nfs_fs_mount_common(server, flags,
2695 				dev_name, &mount_info, nfs_mod);
2696 
2697 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2698 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2699 	return mntroot;
2700 }
2701 
2702 #if IS_ENABLED(CONFIG_NFS_V4)
2703 
2704 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2705 {
2706 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2707 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2708 }
2709 
2710 /*
2711  * Validate NFSv4 mount options
2712  */
2713 static int nfs4_validate_mount_data(void *options,
2714 				    struct nfs_parsed_mount_data *args,
2715 				    const char *dev_name)
2716 {
2717 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2718 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2719 	char *c;
2720 
2721 	if (data == NULL)
2722 		goto out_no_data;
2723 
2724 	args->version = 4;
2725 
2726 	switch (data->version) {
2727 	case 1:
2728 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2729 			goto out_no_address;
2730 		if (data->host_addrlen == 0)
2731 			goto out_no_address;
2732 		args->nfs_server.addrlen = data->host_addrlen;
2733 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2734 			return -EFAULT;
2735 		if (!nfs_verify_server_address(sap))
2736 			goto out_no_address;
2737 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2738 
2739 		if (data->auth_flavourlen) {
2740 			rpc_authflavor_t pseudoflavor;
2741 			if (data->auth_flavourlen > 1)
2742 				goto out_inval_auth;
2743 			if (copy_from_user(&pseudoflavor,
2744 					   data->auth_flavours,
2745 					   sizeof(pseudoflavor)))
2746 				return -EFAULT;
2747 			args->selected_flavor = pseudoflavor;
2748 		} else
2749 			args->selected_flavor = RPC_AUTH_UNIX;
2750 
2751 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2752 		if (IS_ERR(c))
2753 			return PTR_ERR(c);
2754 		args->nfs_server.hostname = c;
2755 
2756 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2757 		if (IS_ERR(c))
2758 			return PTR_ERR(c);
2759 		args->nfs_server.export_path = c;
2760 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2761 
2762 		c = strndup_user(data->client_addr.data, 16);
2763 		if (IS_ERR(c))
2764 			return PTR_ERR(c);
2765 		args->client_address = c;
2766 
2767 		/*
2768 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2769 		 * can deal with.
2770 		 */
2771 
2772 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2773 		args->rsize	= data->rsize;
2774 		args->wsize	= data->wsize;
2775 		args->timeo	= data->timeo;
2776 		args->retrans	= data->retrans;
2777 		args->acregmin	= data->acregmin;
2778 		args->acregmax	= data->acregmax;
2779 		args->acdirmin	= data->acdirmin;
2780 		args->acdirmax	= data->acdirmax;
2781 		args->nfs_server.protocol = data->proto;
2782 		nfs_validate_transport_protocol(args);
2783 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2784 			goto out_invalid_transport_udp;
2785 
2786 		break;
2787 	default:
2788 		return NFS_TEXT_DATA;
2789 	}
2790 
2791 	return 0;
2792 
2793 out_no_data:
2794 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2795 	return -EINVAL;
2796 
2797 out_inval_auth:
2798 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2799 		 data->auth_flavourlen);
2800 	return -EINVAL;
2801 
2802 out_no_address:
2803 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2804 	return -EINVAL;
2805 
2806 out_invalid_transport_udp:
2807 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2808 	return -EINVAL;
2809 }
2810 
2811 /*
2812  * NFS v4 module parameters need to stay in the
2813  * NFS client for backwards compatibility
2814  */
2815 unsigned int nfs_callback_set_tcpport;
2816 unsigned short nfs_callback_tcpport;
2817 /* Default cache timeout is 10 minutes */
2818 unsigned int nfs_idmap_cache_timeout = 600;
2819 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2820 bool nfs4_disable_idmapping = true;
2821 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2822 unsigned short send_implementation_id = 1;
2823 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2824 bool recover_lost_locks = false;
2825 
2826 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2827 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2828 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2829 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2830 EXPORT_SYMBOL_GPL(max_session_slots);
2831 EXPORT_SYMBOL_GPL(send_implementation_id);
2832 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2833 EXPORT_SYMBOL_GPL(recover_lost_locks);
2834 
2835 #define NFS_CALLBACK_MAXPORTNR (65535U)
2836 
2837 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2838 {
2839 	unsigned long num;
2840 	int ret;
2841 
2842 	if (!val)
2843 		return -EINVAL;
2844 	ret = kstrtoul(val, 0, &num);
2845 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2846 		return -EINVAL;
2847 	*((unsigned int *)kp->arg) = num;
2848 	return 0;
2849 }
2850 static struct kernel_param_ops param_ops_portnr = {
2851 	.set = param_set_portnr,
2852 	.get = param_get_uint,
2853 };
2854 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2855 
2856 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2857 module_param(nfs_idmap_cache_timeout, int, 0644);
2858 module_param(nfs4_disable_idmapping, bool, 0644);
2859 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2860 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2861 MODULE_PARM_DESC(nfs4_disable_idmapping,
2862 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2863 module_param(max_session_slots, ushort, 0644);
2864 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2865 		"requests the client will negotiate");
2866 module_param(send_implementation_id, ushort, 0644);
2867 MODULE_PARM_DESC(send_implementation_id,
2868 		"Send implementation ID with NFSv4.1 exchange_id");
2869 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2870 
2871 module_param(recover_lost_locks, bool, 0644);
2872 MODULE_PARM_DESC(recover_lost_locks,
2873 		 "If the server reports that a lock might be lost, "
2874 		 "try to recover it risking data corruption.");
2875 
2876 
2877 #endif /* CONFIG_NFS_V4 */
2878