xref: /openbmc/linux/fs/nfs/super.c (revision 752beb5e)
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 <linux/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_softerr, 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_softerr, "softerr" },
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 	Opt_xprt_rdma6,
196 
197 	Opt_xprt_err
198 };
199 
200 static const match_table_t nfs_xprt_protocol_tokens = {
201 	{ Opt_xprt_udp, "udp" },
202 	{ Opt_xprt_udp6, "udp6" },
203 	{ Opt_xprt_tcp, "tcp" },
204 	{ Opt_xprt_tcp6, "tcp6" },
205 	{ Opt_xprt_rdma, "rdma" },
206 	{ Opt_xprt_rdma6, "rdma6" },
207 
208 	{ Opt_xprt_err, NULL }
209 };
210 
211 enum {
212 	Opt_sec_none, Opt_sec_sys,
213 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
214 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
215 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
216 
217 	Opt_sec_err
218 };
219 
220 static const match_table_t nfs_secflavor_tokens = {
221 	{ Opt_sec_none, "none" },
222 	{ Opt_sec_none, "null" },
223 	{ Opt_sec_sys, "sys" },
224 
225 	{ Opt_sec_krb5, "krb5" },
226 	{ Opt_sec_krb5i, "krb5i" },
227 	{ Opt_sec_krb5p, "krb5p" },
228 
229 	{ Opt_sec_lkey, "lkey" },
230 	{ Opt_sec_lkeyi, "lkeyi" },
231 	{ Opt_sec_lkeyp, "lkeyp" },
232 
233 	{ Opt_sec_spkm, "spkm3" },
234 	{ Opt_sec_spkmi, "spkm3i" },
235 	{ Opt_sec_spkmp, "spkm3p" },
236 
237 	{ Opt_sec_err, NULL }
238 };
239 
240 enum {
241 	Opt_lookupcache_all, Opt_lookupcache_positive,
242 	Opt_lookupcache_none,
243 
244 	Opt_lookupcache_err
245 };
246 
247 static match_table_t nfs_lookupcache_tokens = {
248 	{ Opt_lookupcache_all, "all" },
249 	{ Opt_lookupcache_positive, "pos" },
250 	{ Opt_lookupcache_positive, "positive" },
251 	{ Opt_lookupcache_none, "none" },
252 
253 	{ Opt_lookupcache_err, NULL }
254 };
255 
256 enum {
257 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
258 	Opt_local_lock_none,
259 
260 	Opt_local_lock_err
261 };
262 
263 static match_table_t nfs_local_lock_tokens = {
264 	{ Opt_local_lock_all, "all" },
265 	{ Opt_local_lock_flock, "flock" },
266 	{ Opt_local_lock_posix, "posix" },
267 	{ Opt_local_lock_none, "none" },
268 
269 	{ Opt_local_lock_err, NULL }
270 };
271 
272 enum {
273 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
274 	Opt_vers_4_1, Opt_vers_4_2,
275 
276 	Opt_vers_err
277 };
278 
279 static match_table_t nfs_vers_tokens = {
280 	{ Opt_vers_2, "2" },
281 	{ Opt_vers_3, "3" },
282 	{ Opt_vers_4, "4" },
283 	{ Opt_vers_4_0, "4.0" },
284 	{ Opt_vers_4_1, "4.1" },
285 	{ Opt_vers_4_2, "4.2" },
286 
287 	{ Opt_vers_err, NULL }
288 };
289 
290 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
291 		int flags, const char *dev_name, void *raw_data);
292 
293 struct file_system_type nfs_fs_type = {
294 	.owner		= THIS_MODULE,
295 	.name		= "nfs",
296 	.mount		= nfs_fs_mount,
297 	.kill_sb	= nfs_kill_super,
298 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
299 };
300 MODULE_ALIAS_FS("nfs");
301 EXPORT_SYMBOL_GPL(nfs_fs_type);
302 
303 struct file_system_type nfs_xdev_fs_type = {
304 	.owner		= THIS_MODULE,
305 	.name		= "nfs",
306 	.mount		= nfs_xdev_mount,
307 	.kill_sb	= nfs_kill_super,
308 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
309 };
310 
311 const struct super_operations nfs_sops = {
312 	.alloc_inode	= nfs_alloc_inode,
313 	.free_inode	= nfs_free_inode,
314 	.write_inode	= nfs_write_inode,
315 	.drop_inode	= nfs_drop_inode,
316 	.statfs		= nfs_statfs,
317 	.evict_inode	= nfs_evict_inode,
318 	.umount_begin	= nfs_umount_begin,
319 	.show_options	= nfs_show_options,
320 	.show_devname	= nfs_show_devname,
321 	.show_path	= nfs_show_path,
322 	.show_stats	= nfs_show_stats,
323 	.remount_fs	= nfs_remount,
324 };
325 EXPORT_SYMBOL_GPL(nfs_sops);
326 
327 #if IS_ENABLED(CONFIG_NFS_V4)
328 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
329 static int nfs4_validate_mount_data(void *options,
330 	struct nfs_parsed_mount_data *args, const char *dev_name);
331 
332 struct file_system_type nfs4_fs_type = {
333 	.owner		= THIS_MODULE,
334 	.name		= "nfs4",
335 	.mount		= nfs_fs_mount,
336 	.kill_sb	= nfs_kill_super,
337 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
338 };
339 MODULE_ALIAS_FS("nfs4");
340 MODULE_ALIAS("nfs4");
341 EXPORT_SYMBOL_GPL(nfs4_fs_type);
342 
343 static int __init register_nfs4_fs(void)
344 {
345 	return register_filesystem(&nfs4_fs_type);
346 }
347 
348 static void unregister_nfs4_fs(void)
349 {
350 	unregister_filesystem(&nfs4_fs_type);
351 }
352 #else
353 static int __init register_nfs4_fs(void)
354 {
355 	return 0;
356 }
357 
358 static void unregister_nfs4_fs(void)
359 {
360 }
361 #endif
362 
363 static struct shrinker acl_shrinker = {
364 	.count_objects	= nfs_access_cache_count,
365 	.scan_objects	= nfs_access_cache_scan,
366 	.seeks		= DEFAULT_SEEKS,
367 };
368 
369 /*
370  * Register the NFS filesystems
371  */
372 int __init register_nfs_fs(void)
373 {
374 	int ret;
375 
376         ret = register_filesystem(&nfs_fs_type);
377 	if (ret < 0)
378 		goto error_0;
379 
380 	ret = register_nfs4_fs();
381 	if (ret < 0)
382 		goto error_1;
383 
384 	ret = nfs_register_sysctl();
385 	if (ret < 0)
386 		goto error_2;
387 	ret = register_shrinker(&acl_shrinker);
388 	if (ret < 0)
389 		goto error_3;
390 	return 0;
391 error_3:
392 	nfs_unregister_sysctl();
393 error_2:
394 	unregister_nfs4_fs();
395 error_1:
396 	unregister_filesystem(&nfs_fs_type);
397 error_0:
398 	return ret;
399 }
400 
401 /*
402  * Unregister the NFS filesystems
403  */
404 void __exit unregister_nfs_fs(void)
405 {
406 	unregister_shrinker(&acl_shrinker);
407 	nfs_unregister_sysctl();
408 	unregister_nfs4_fs();
409 	unregister_filesystem(&nfs_fs_type);
410 }
411 
412 bool nfs_sb_active(struct super_block *sb)
413 {
414 	struct nfs_server *server = NFS_SB(sb);
415 
416 	if (!atomic_inc_not_zero(&sb->s_active))
417 		return false;
418 	if (atomic_inc_return(&server->active) != 1)
419 		atomic_dec(&sb->s_active);
420 	return true;
421 }
422 EXPORT_SYMBOL_GPL(nfs_sb_active);
423 
424 void nfs_sb_deactive(struct super_block *sb)
425 {
426 	struct nfs_server *server = NFS_SB(sb);
427 
428 	if (atomic_dec_and_test(&server->active))
429 		deactivate_super(sb);
430 }
431 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
432 
433 /*
434  * Deliver file system statistics to userspace
435  */
436 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
437 {
438 	struct nfs_server *server = NFS_SB(dentry->d_sb);
439 	unsigned char blockbits;
440 	unsigned long blockres;
441 	struct nfs_fh *fh = NFS_FH(d_inode(dentry));
442 	struct nfs_fsstat res;
443 	int error = -ENOMEM;
444 
445 	res.fattr = nfs_alloc_fattr();
446 	if (res.fattr == NULL)
447 		goto out_err;
448 
449 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
450 	if (unlikely(error == -ESTALE)) {
451 		struct dentry *pd_dentry;
452 
453 		pd_dentry = dget_parent(dentry);
454 		if (pd_dentry != NULL) {
455 			nfs_zap_caches(d_inode(pd_dentry));
456 			dput(pd_dentry);
457 		}
458 	}
459 	nfs_free_fattr(res.fattr);
460 	if (error < 0)
461 		goto out_err;
462 
463 	buf->f_type = NFS_SUPER_MAGIC;
464 
465 	/*
466 	 * Current versions of glibc do not correctly handle the
467 	 * case where f_frsize != f_bsize.  Eventually we want to
468 	 * report the value of wtmult in this field.
469 	 */
470 	buf->f_frsize = dentry->d_sb->s_blocksize;
471 
472 	/*
473 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
474 	 * are reported in units of f_frsize.  Linux hasn't had
475 	 * an f_frsize field in its statfs struct until recently,
476 	 * thus historically Linux's sys_statfs reports these
477 	 * fields in units of f_bsize.
478 	 */
479 	buf->f_bsize = dentry->d_sb->s_blocksize;
480 	blockbits = dentry->d_sb->s_blocksize_bits;
481 	blockres = (1 << blockbits) - 1;
482 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
483 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
484 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
485 
486 	buf->f_files = res.tfiles;
487 	buf->f_ffree = res.afiles;
488 
489 	buf->f_namelen = server->namelen;
490 
491 	return 0;
492 
493  out_err:
494 	dprintk("%s: statfs error = %d\n", __func__, -error);
495 	return error;
496 }
497 EXPORT_SYMBOL_GPL(nfs_statfs);
498 
499 /*
500  * Map the security flavour number to a name
501  */
502 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
503 {
504 	static const struct {
505 		rpc_authflavor_t flavour;
506 		const char *str;
507 	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
508 		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
509 		{ RPC_AUTH_NULL, "null" },
510 		{ RPC_AUTH_UNIX, "sys" },
511 		{ RPC_AUTH_GSS_KRB5, "krb5" },
512 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
513 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
514 		{ RPC_AUTH_GSS_LKEY, "lkey" },
515 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
516 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
517 		{ RPC_AUTH_GSS_SPKM, "spkm" },
518 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
519 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
520 		{ UINT_MAX, "unknown" }
521 	};
522 	int i;
523 
524 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
525 		if (sec_flavours[i].flavour == flavour)
526 			break;
527 	}
528 	return sec_flavours[i].str;
529 }
530 
531 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
532 				  int showdefaults)
533 {
534 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
535 	char *proto = NULL;
536 
537 	switch (sap->sa_family) {
538 	case AF_INET:
539 		switch (nfss->mountd_protocol) {
540 		case IPPROTO_UDP:
541 			proto = RPCBIND_NETID_UDP;
542 			break;
543 		case IPPROTO_TCP:
544 			proto = RPCBIND_NETID_TCP;
545 			break;
546 		}
547 		break;
548 	case AF_INET6:
549 		switch (nfss->mountd_protocol) {
550 		case IPPROTO_UDP:
551 			proto = RPCBIND_NETID_UDP6;
552 			break;
553 		case IPPROTO_TCP:
554 			proto = RPCBIND_NETID_TCP6;
555 			break;
556 		}
557 		break;
558 	}
559 	if (proto || showdefaults)
560 		seq_printf(m, ",mountproto=%s", proto ?: "auto");
561 }
562 
563 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
564 				    int showdefaults)
565 {
566 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
567 
568 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
569 		return;
570 
571 	switch (sap->sa_family) {
572 	case AF_INET: {
573 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
574 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
575 		break;
576 	}
577 	case AF_INET6: {
578 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
579 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
580 		break;
581 	}
582 	default:
583 		if (showdefaults)
584 			seq_printf(m, ",mountaddr=unspecified");
585 	}
586 
587 	if (nfss->mountd_version || showdefaults)
588 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
589 	if ((nfss->mountd_port &&
590 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
591 		showdefaults)
592 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
593 
594 	nfs_show_mountd_netid(m, nfss, showdefaults);
595 }
596 
597 #if IS_ENABLED(CONFIG_NFS_V4)
598 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
599 				    int showdefaults)
600 {
601 	struct nfs_client *clp = nfss->nfs_client;
602 
603 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
604 }
605 #else
606 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
607 				    int showdefaults)
608 {
609 }
610 #endif
611 
612 static void nfs_show_nfs_version(struct seq_file *m,
613 		unsigned int version,
614 		unsigned int minorversion)
615 {
616 	seq_printf(m, ",vers=%u", version);
617 	if (version == 4)
618 		seq_printf(m, ".%u", minorversion);
619 }
620 
621 /*
622  * Describe the mount options in force on this server representation
623  */
624 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
625 				   int showdefaults)
626 {
627 	static const struct proc_nfs_info {
628 		int flag;
629 		const char *str;
630 		const char *nostr;
631 	} nfs_info[] = {
632 		{ NFS_MOUNT_SOFT, ",soft", "" },
633 		{ NFS_MOUNT_SOFTERR, ",softerr", "" },
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 	if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
664 			seq_puts(m, ",hard");
665 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
666 		if (nfss->flags & nfs_infop->flag)
667 			seq_puts(m, nfs_infop->str);
668 		else
669 			seq_puts(m, nfs_infop->nostr);
670 	}
671 	rcu_read_lock();
672 	seq_printf(m, ",proto=%s",
673 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
674 	rcu_read_unlock();
675 	if (version == 4) {
676 		if (nfss->port != NFS_PORT)
677 			seq_printf(m, ",port=%u", nfss->port);
678 	} else
679 		if (nfss->port)
680 			seq_printf(m, ",port=%u", nfss->port);
681 
682 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
683 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
684 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
685 
686 	if (version != 4)
687 		nfs_show_mountd_options(m, nfss, showdefaults);
688 	else
689 		nfs_show_nfsv4_options(m, nfss, showdefaults);
690 
691 	if (nfss->options & NFS_OPTION_FSCACHE)
692 		seq_printf(m, ",fsc");
693 
694 	if (nfss->options & NFS_OPTION_MIGRATION)
695 		seq_printf(m, ",migration");
696 
697 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
698 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
699 			seq_printf(m, ",lookupcache=none");
700 		else
701 			seq_printf(m, ",lookupcache=pos");
702 	}
703 
704 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
705 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
706 
707 	if (!local_flock && !local_fcntl)
708 		seq_printf(m, ",local_lock=none");
709 	else if (local_flock && local_fcntl)
710 		seq_printf(m, ",local_lock=all");
711 	else if (local_flock)
712 		seq_printf(m, ",local_lock=flock");
713 	else
714 		seq_printf(m, ",local_lock=posix");
715 }
716 
717 /*
718  * Describe the mount options on this VFS mountpoint
719  */
720 int nfs_show_options(struct seq_file *m, struct dentry *root)
721 {
722 	struct nfs_server *nfss = NFS_SB(root->d_sb);
723 
724 	nfs_show_mount_options(m, nfss, 0);
725 
726 	rcu_read_lock();
727 	seq_printf(m, ",addr=%s",
728 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
729 							RPC_DISPLAY_ADDR));
730 	rcu_read_unlock();
731 
732 	return 0;
733 }
734 EXPORT_SYMBOL_GPL(nfs_show_options);
735 
736 #if IS_ENABLED(CONFIG_NFS_V4)
737 #ifdef CONFIG_NFS_V4_1
738 static void show_sessions(struct seq_file *m, struct nfs_server *server)
739 {
740 	if (nfs4_has_session(server->nfs_client))
741 		seq_printf(m, ",sessions");
742 }
743 #else
744 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
745 #endif
746 #endif
747 
748 #ifdef CONFIG_NFS_V4_1
749 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
750 {
751 	seq_printf(m, ",pnfs=");
752 	if (server->pnfs_curr_ld)
753 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
754 	else
755 		seq_printf(m, "not configured");
756 }
757 
758 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
759 {
760 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
761 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
762 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
763 			   "date='%llu,%u'",
764 			   impl_id->name, impl_id->domain,
765 			   impl_id->date.seconds, impl_id->date.nseconds);
766 	}
767 }
768 #else
769 #if IS_ENABLED(CONFIG_NFS_V4)
770 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
771 {
772 }
773 #endif
774 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
775 {
776 }
777 #endif
778 
779 int nfs_show_devname(struct seq_file *m, struct dentry *root)
780 {
781 	char *page = (char *) __get_free_page(GFP_KERNEL);
782 	char *devname, *dummy;
783 	int err = 0;
784 	if (!page)
785 		return -ENOMEM;
786 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
787 	if (IS_ERR(devname))
788 		err = PTR_ERR(devname);
789 	else
790 		seq_escape(m, devname, " \t\n\\");
791 	free_page((unsigned long)page);
792 	return err;
793 }
794 EXPORT_SYMBOL_GPL(nfs_show_devname);
795 
796 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
797 {
798 	seq_puts(m, "/");
799 	return 0;
800 }
801 EXPORT_SYMBOL_GPL(nfs_show_path);
802 
803 /*
804  * Present statistical information for this VFS mountpoint
805  */
806 int nfs_show_stats(struct seq_file *m, struct dentry *root)
807 {
808 	int i, cpu;
809 	struct nfs_server *nfss = NFS_SB(root->d_sb);
810 	struct rpc_auth *auth = nfss->client->cl_auth;
811 	struct nfs_iostats totals = { };
812 
813 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
814 
815 	/*
816 	 * Display all mount option settings
817 	 */
818 	seq_printf(m, "\n\topts:\t");
819 	seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
820 	seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
821 	seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
822 	seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
823 	nfs_show_mount_options(m, nfss, 1);
824 
825 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
826 
827 	show_implementation_id(m, nfss);
828 
829 	seq_printf(m, "\n\tcaps:\t");
830 	seq_printf(m, "caps=0x%x", nfss->caps);
831 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
832 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
833 	seq_printf(m, ",bsize=%u", nfss->bsize);
834 	seq_printf(m, ",namlen=%u", nfss->namelen);
835 
836 #if IS_ENABLED(CONFIG_NFS_V4)
837 	if (nfss->nfs_client->rpc_ops->version == 4) {
838 		seq_printf(m, "\n\tnfsv4:\t");
839 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
840 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
841 		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
842 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
843 		show_sessions(m, nfss);
844 		show_pnfs(m, nfss);
845 	}
846 #endif
847 
848 	/*
849 	 * Display security flavor in effect for this mount
850 	 */
851 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
852 	if (auth->au_flavor)
853 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
854 
855 	/*
856 	 * Display superblock I/O counters
857 	 */
858 	for_each_possible_cpu(cpu) {
859 		struct nfs_iostats *stats;
860 
861 		preempt_disable();
862 		stats = per_cpu_ptr(nfss->io_stats, cpu);
863 
864 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
865 			totals.events[i] += stats->events[i];
866 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
867 			totals.bytes[i] += stats->bytes[i];
868 #ifdef CONFIG_NFS_FSCACHE
869 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
870 			totals.fscache[i] += stats->fscache[i];
871 #endif
872 
873 		preempt_enable();
874 	}
875 
876 	seq_printf(m, "\n\tevents:\t");
877 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
878 		seq_printf(m, "%lu ", totals.events[i]);
879 	seq_printf(m, "\n\tbytes:\t");
880 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
881 		seq_printf(m, "%Lu ", totals.bytes[i]);
882 #ifdef CONFIG_NFS_FSCACHE
883 	if (nfss->options & NFS_OPTION_FSCACHE) {
884 		seq_printf(m, "\n\tfsc:\t");
885 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
886 			seq_printf(m, "%Lu ", totals.fscache[i]);
887 	}
888 #endif
889 	seq_printf(m, "\n");
890 
891 	rpc_clnt_show_stats(m, nfss->client);
892 
893 	return 0;
894 }
895 EXPORT_SYMBOL_GPL(nfs_show_stats);
896 
897 /*
898  * Begin unmount by attempting to remove all automounted mountpoints we added
899  * in response to xdev traversals and referrals
900  */
901 void nfs_umount_begin(struct super_block *sb)
902 {
903 	struct nfs_server *server;
904 	struct rpc_clnt *rpc;
905 
906 	server = NFS_SB(sb);
907 	/* -EIO all pending I/O */
908 	rpc = server->client_acl;
909 	if (!IS_ERR(rpc))
910 		rpc_killall_tasks(rpc);
911 	rpc = server->client;
912 	if (!IS_ERR(rpc))
913 		rpc_killall_tasks(rpc);
914 }
915 EXPORT_SYMBOL_GPL(nfs_umount_begin);
916 
917 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
918 {
919 	struct nfs_parsed_mount_data *data;
920 
921 	data = kzalloc(sizeof(*data), GFP_KERNEL);
922 	if (data) {
923 		data->timeo		= NFS_UNSPEC_TIMEO;
924 		data->retrans		= NFS_UNSPEC_RETRANS;
925 		data->acregmin		= NFS_DEF_ACREGMIN;
926 		data->acregmax		= NFS_DEF_ACREGMAX;
927 		data->acdirmin		= NFS_DEF_ACDIRMIN;
928 		data->acdirmax		= NFS_DEF_ACDIRMAX;
929 		data->mount_server.port	= NFS_UNSPEC_PORT;
930 		data->nfs_server.port	= NFS_UNSPEC_PORT;
931 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
932 		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
933 		data->minorversion	= 0;
934 		data->need_mount	= true;
935 		data->net		= current->nsproxy->net_ns;
936 		data->lsm_opts		= NULL;
937 	}
938 	return data;
939 }
940 
941 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
942 {
943 	if (data) {
944 		kfree(data->client_address);
945 		kfree(data->mount_server.hostname);
946 		kfree(data->nfs_server.export_path);
947 		kfree(data->nfs_server.hostname);
948 		kfree(data->fscache_uniq);
949 		security_free_mnt_opts(&data->lsm_opts);
950 		kfree(data);
951 	}
952 }
953 
954 /*
955  * Sanity-check a server address provided by the mount command.
956  *
957  * Address family must be initialized, and address must not be
958  * the ANY address for that family.
959  */
960 static int nfs_verify_server_address(struct sockaddr *addr)
961 {
962 	switch (addr->sa_family) {
963 	case AF_INET: {
964 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
965 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
966 	}
967 	case AF_INET6: {
968 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
969 		return !ipv6_addr_any(sa);
970 	}
971 	}
972 
973 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
974 	return 0;
975 }
976 
977 /*
978  * Select between a default port value and a user-specified port value.
979  * If a zero value is set, then autobind will be used.
980  */
981 static void nfs_set_port(struct sockaddr *sap, int *port,
982 				 const unsigned short default_port)
983 {
984 	if (*port == NFS_UNSPEC_PORT)
985 		*port = default_port;
986 
987 	rpc_set_port(sap, *port);
988 }
989 
990 /*
991  * Sanity check the NFS transport protocol.
992  *
993  */
994 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
995 {
996 	switch (mnt->nfs_server.protocol) {
997 	case XPRT_TRANSPORT_UDP:
998 	case XPRT_TRANSPORT_TCP:
999 	case XPRT_TRANSPORT_RDMA:
1000 		break;
1001 	default:
1002 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1003 	}
1004 }
1005 
1006 /*
1007  * For text based NFSv2/v3 mounts, the mount protocol transport default
1008  * settings should depend upon the specified NFS transport.
1009  */
1010 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1011 {
1012 	nfs_validate_transport_protocol(mnt);
1013 
1014 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1015 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1016 			return;
1017 	switch (mnt->nfs_server.protocol) {
1018 	case XPRT_TRANSPORT_UDP:
1019 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1020 		break;
1021 	case XPRT_TRANSPORT_TCP:
1022 	case XPRT_TRANSPORT_RDMA:
1023 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1024 	}
1025 }
1026 
1027 /*
1028  * Add 'flavor' to 'auth_info' if not already present.
1029  * Returns true if 'flavor' ends up in the list, false otherwise
1030  */
1031 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1032 			      rpc_authflavor_t flavor)
1033 {
1034 	unsigned int i;
1035 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1036 
1037 	/* make sure this flavor isn't already in the list */
1038 	for (i = 0; i < auth_info->flavor_len; i++) {
1039 		if (flavor == auth_info->flavors[i])
1040 			return true;
1041 	}
1042 
1043 	if (auth_info->flavor_len + 1 >= max_flavor_len) {
1044 		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1045 		return false;
1046 	}
1047 
1048 	auth_info->flavors[auth_info->flavor_len++] = flavor;
1049 	return true;
1050 }
1051 
1052 /*
1053  * Return true if 'match' is in auth_info or auth_info is empty.
1054  * Return false otherwise.
1055  */
1056 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1057 			 rpc_authflavor_t match)
1058 {
1059 	int i;
1060 
1061 	if (!auth_info->flavor_len)
1062 		return true;
1063 
1064 	for (i = 0; i < auth_info->flavor_len; i++) {
1065 		if (auth_info->flavors[i] == match)
1066 			return true;
1067 	}
1068 	return false;
1069 }
1070 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1071 
1072 /*
1073  * Parse the value of the 'sec=' option.
1074  */
1075 static int nfs_parse_security_flavors(char *value,
1076 				      struct nfs_parsed_mount_data *mnt)
1077 {
1078 	substring_t args[MAX_OPT_ARGS];
1079 	rpc_authflavor_t pseudoflavor;
1080 	char *p;
1081 
1082 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1083 
1084 	while ((p = strsep(&value, ":")) != NULL) {
1085 		switch (match_token(p, nfs_secflavor_tokens, args)) {
1086 		case Opt_sec_none:
1087 			pseudoflavor = RPC_AUTH_NULL;
1088 			break;
1089 		case Opt_sec_sys:
1090 			pseudoflavor = RPC_AUTH_UNIX;
1091 			break;
1092 		case Opt_sec_krb5:
1093 			pseudoflavor = RPC_AUTH_GSS_KRB5;
1094 			break;
1095 		case Opt_sec_krb5i:
1096 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
1097 			break;
1098 		case Opt_sec_krb5p:
1099 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
1100 			break;
1101 		case Opt_sec_lkey:
1102 			pseudoflavor = RPC_AUTH_GSS_LKEY;
1103 			break;
1104 		case Opt_sec_lkeyi:
1105 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
1106 			break;
1107 		case Opt_sec_lkeyp:
1108 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
1109 			break;
1110 		case Opt_sec_spkm:
1111 			pseudoflavor = RPC_AUTH_GSS_SPKM;
1112 			break;
1113 		case Opt_sec_spkmi:
1114 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
1115 			break;
1116 		case Opt_sec_spkmp:
1117 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
1118 			break;
1119 		default:
1120 			dfprintk(MOUNT,
1121 				 "NFS: sec= option '%s' not recognized\n", p);
1122 			return 0;
1123 		}
1124 
1125 		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1126 			return 0;
1127 	}
1128 
1129 	return 1;
1130 }
1131 
1132 static int nfs_parse_version_string(char *string,
1133 		struct nfs_parsed_mount_data *mnt,
1134 		substring_t *args)
1135 {
1136 	mnt->flags &= ~NFS_MOUNT_VER3;
1137 	switch (match_token(string, nfs_vers_tokens, args)) {
1138 	case Opt_vers_2:
1139 		mnt->version = 2;
1140 		break;
1141 	case Opt_vers_3:
1142 		mnt->flags |= NFS_MOUNT_VER3;
1143 		mnt->version = 3;
1144 		break;
1145 	case Opt_vers_4:
1146 		/* Backward compatibility option. In future,
1147 		 * the mount program should always supply
1148 		 * a NFSv4 minor version number.
1149 		 */
1150 		mnt->version = 4;
1151 		break;
1152 	case Opt_vers_4_0:
1153 		mnt->version = 4;
1154 		mnt->minorversion = 0;
1155 		break;
1156 	case Opt_vers_4_1:
1157 		mnt->version = 4;
1158 		mnt->minorversion = 1;
1159 		break;
1160 	case Opt_vers_4_2:
1161 		mnt->version = 4;
1162 		mnt->minorversion = 2;
1163 		break;
1164 	default:
1165 		return 0;
1166 	}
1167 	return 1;
1168 }
1169 
1170 static int nfs_get_option_str(substring_t args[], char **option)
1171 {
1172 	kfree(*option);
1173 	*option = match_strdup(args);
1174 	return !*option;
1175 }
1176 
1177 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1178 {
1179 	int rc;
1180 	char *string;
1181 
1182 	string = match_strdup(args);
1183 	if (string == NULL)
1184 		return -ENOMEM;
1185 	rc = kstrtoul(string, 10, option);
1186 	kfree(string);
1187 
1188 	return rc;
1189 }
1190 
1191 static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
1192 		unsigned long l_bound, unsigned long u_bound)
1193 {
1194 	int ret;
1195 
1196 	ret = nfs_get_option_ul(args, option);
1197 	if (ret != 0)
1198 		return ret;
1199 	if (*option < l_bound || *option > u_bound)
1200 		return -ERANGE;
1201 	return 0;
1202 }
1203 
1204 /*
1205  * Error-check and convert a string of mount options from user space into
1206  * a data structure.  The whole mount string is processed; bad options are
1207  * skipped as they are encountered.  If there were no errors, return 1;
1208  * otherwise return 0 (zero).
1209  */
1210 static int nfs_parse_mount_options(char *raw,
1211 				   struct nfs_parsed_mount_data *mnt)
1212 {
1213 	char *p, *string;
1214 	int rc, sloppy = 0, invalid_option = 0;
1215 	unsigned short protofamily = AF_UNSPEC;
1216 	unsigned short mountfamily = AF_UNSPEC;
1217 
1218 	if (!raw) {
1219 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1220 		return 1;
1221 	}
1222 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1223 
1224 	rc = security_sb_eat_lsm_opts(raw, &mnt->lsm_opts);
1225 	if (rc)
1226 		goto out_security_failure;
1227 
1228 	while ((p = strsep(&raw, ",")) != NULL) {
1229 		substring_t args[MAX_OPT_ARGS];
1230 		unsigned long option;
1231 		int token;
1232 
1233 		if (!*p)
1234 			continue;
1235 
1236 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1237 
1238 		token = match_token(p, nfs_mount_option_tokens, args);
1239 		switch (token) {
1240 
1241 		/*
1242 		 * boolean options:  foo/nofoo
1243 		 */
1244 		case Opt_soft:
1245 			mnt->flags |= NFS_MOUNT_SOFT;
1246 			mnt->flags &= ~NFS_MOUNT_SOFTERR;
1247 			break;
1248 		case Opt_softerr:
1249 			mnt->flags |= NFS_MOUNT_SOFTERR;
1250 			mnt->flags &= ~NFS_MOUNT_SOFT;
1251 			break;
1252 		case Opt_hard:
1253 			mnt->flags &= ~(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR);
1254 			break;
1255 		case Opt_posix:
1256 			mnt->flags |= NFS_MOUNT_POSIX;
1257 			break;
1258 		case Opt_noposix:
1259 			mnt->flags &= ~NFS_MOUNT_POSIX;
1260 			break;
1261 		case Opt_cto:
1262 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1263 			break;
1264 		case Opt_nocto:
1265 			mnt->flags |= NFS_MOUNT_NOCTO;
1266 			break;
1267 		case Opt_ac:
1268 			mnt->flags &= ~NFS_MOUNT_NOAC;
1269 			break;
1270 		case Opt_noac:
1271 			mnt->flags |= NFS_MOUNT_NOAC;
1272 			break;
1273 		case Opt_lock:
1274 			mnt->flags &= ~NFS_MOUNT_NONLM;
1275 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1276 					NFS_MOUNT_LOCAL_FCNTL);
1277 			break;
1278 		case Opt_nolock:
1279 			mnt->flags |= NFS_MOUNT_NONLM;
1280 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1281 				       NFS_MOUNT_LOCAL_FCNTL);
1282 			break;
1283 		case Opt_udp:
1284 			mnt->flags &= ~NFS_MOUNT_TCP;
1285 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1286 			break;
1287 		case Opt_tcp:
1288 			mnt->flags |= NFS_MOUNT_TCP;
1289 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1290 			break;
1291 		case Opt_rdma:
1292 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1293 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1294 			xprt_load_transport(p);
1295 			break;
1296 		case Opt_acl:
1297 			mnt->flags &= ~NFS_MOUNT_NOACL;
1298 			break;
1299 		case Opt_noacl:
1300 			mnt->flags |= NFS_MOUNT_NOACL;
1301 			break;
1302 		case Opt_rdirplus:
1303 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1304 			break;
1305 		case Opt_nordirplus:
1306 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1307 			break;
1308 		case Opt_sharecache:
1309 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1310 			break;
1311 		case Opt_nosharecache:
1312 			mnt->flags |= NFS_MOUNT_UNSHARED;
1313 			break;
1314 		case Opt_resvport:
1315 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1316 			break;
1317 		case Opt_noresvport:
1318 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1319 			break;
1320 		case Opt_fscache:
1321 			mnt->options |= NFS_OPTION_FSCACHE;
1322 			kfree(mnt->fscache_uniq);
1323 			mnt->fscache_uniq = NULL;
1324 			break;
1325 		case Opt_nofscache:
1326 			mnt->options &= ~NFS_OPTION_FSCACHE;
1327 			kfree(mnt->fscache_uniq);
1328 			mnt->fscache_uniq = NULL;
1329 			break;
1330 		case Opt_migration:
1331 			mnt->options |= NFS_OPTION_MIGRATION;
1332 			break;
1333 		case Opt_nomigration:
1334 			mnt->options &= ~NFS_OPTION_MIGRATION;
1335 			break;
1336 
1337 		/*
1338 		 * options that take numeric values
1339 		 */
1340 		case Opt_port:
1341 			if (nfs_get_option_ul(args, &option) ||
1342 			    option > USHRT_MAX)
1343 				goto out_invalid_value;
1344 			mnt->nfs_server.port = option;
1345 			break;
1346 		case Opt_rsize:
1347 			if (nfs_get_option_ul(args, &option))
1348 				goto out_invalid_value;
1349 			mnt->rsize = option;
1350 			break;
1351 		case Opt_wsize:
1352 			if (nfs_get_option_ul(args, &option))
1353 				goto out_invalid_value;
1354 			mnt->wsize = option;
1355 			break;
1356 		case Opt_bsize:
1357 			if (nfs_get_option_ul(args, &option))
1358 				goto out_invalid_value;
1359 			mnt->bsize = option;
1360 			break;
1361 		case Opt_timeo:
1362 			if (nfs_get_option_ul_bound(args, &option, 1, INT_MAX))
1363 				goto out_invalid_value;
1364 			mnt->timeo = option;
1365 			break;
1366 		case Opt_retrans:
1367 			if (nfs_get_option_ul_bound(args, &option, 0, INT_MAX))
1368 				goto out_invalid_value;
1369 			mnt->retrans = option;
1370 			break;
1371 		case Opt_acregmin:
1372 			if (nfs_get_option_ul(args, &option))
1373 				goto out_invalid_value;
1374 			mnt->acregmin = option;
1375 			break;
1376 		case Opt_acregmax:
1377 			if (nfs_get_option_ul(args, &option))
1378 				goto out_invalid_value;
1379 			mnt->acregmax = option;
1380 			break;
1381 		case Opt_acdirmin:
1382 			if (nfs_get_option_ul(args, &option))
1383 				goto out_invalid_value;
1384 			mnt->acdirmin = option;
1385 			break;
1386 		case Opt_acdirmax:
1387 			if (nfs_get_option_ul(args, &option))
1388 				goto out_invalid_value;
1389 			mnt->acdirmax = option;
1390 			break;
1391 		case Opt_actimeo:
1392 			if (nfs_get_option_ul(args, &option))
1393 				goto out_invalid_value;
1394 			mnt->acregmin = mnt->acregmax =
1395 			mnt->acdirmin = mnt->acdirmax = option;
1396 			break;
1397 		case Opt_namelen:
1398 			if (nfs_get_option_ul(args, &option))
1399 				goto out_invalid_value;
1400 			mnt->namlen = option;
1401 			break;
1402 		case Opt_mountport:
1403 			if (nfs_get_option_ul(args, &option) ||
1404 			    option > USHRT_MAX)
1405 				goto out_invalid_value;
1406 			mnt->mount_server.port = option;
1407 			break;
1408 		case Opt_mountvers:
1409 			if (nfs_get_option_ul(args, &option) ||
1410 			    option < NFS_MNT_VERSION ||
1411 			    option > NFS_MNT3_VERSION)
1412 				goto out_invalid_value;
1413 			mnt->mount_server.version = option;
1414 			break;
1415 		case Opt_minorversion:
1416 			if (nfs_get_option_ul(args, &option))
1417 				goto out_invalid_value;
1418 			if (option > NFS4_MAX_MINOR_VERSION)
1419 				goto out_invalid_value;
1420 			mnt->minorversion = option;
1421 			break;
1422 
1423 		/*
1424 		 * options that take text values
1425 		 */
1426 		case Opt_nfsvers:
1427 			string = match_strdup(args);
1428 			if (string == NULL)
1429 				goto out_nomem;
1430 			rc = nfs_parse_version_string(string, mnt, args);
1431 			kfree(string);
1432 			if (!rc)
1433 				goto out_invalid_value;
1434 			break;
1435 		case Opt_sec:
1436 			string = match_strdup(args);
1437 			if (string == NULL)
1438 				goto out_nomem;
1439 			rc = nfs_parse_security_flavors(string, mnt);
1440 			kfree(string);
1441 			if (!rc) {
1442 				dfprintk(MOUNT, "NFS:   unrecognized "
1443 						"security flavor\n");
1444 				return 0;
1445 			}
1446 			break;
1447 		case Opt_proto:
1448 			string = match_strdup(args);
1449 			if (string == NULL)
1450 				goto out_nomem;
1451 			token = match_token(string,
1452 					    nfs_xprt_protocol_tokens, args);
1453 
1454 			protofamily = AF_INET;
1455 			switch (token) {
1456 			case Opt_xprt_udp6:
1457 				protofamily = AF_INET6;
1458 				/* fall through */
1459 			case Opt_xprt_udp:
1460 				mnt->flags &= ~NFS_MOUNT_TCP;
1461 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1462 				break;
1463 			case Opt_xprt_tcp6:
1464 				protofamily = AF_INET6;
1465 				/* fall through */
1466 			case Opt_xprt_tcp:
1467 				mnt->flags |= NFS_MOUNT_TCP;
1468 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1469 				break;
1470 			case Opt_xprt_rdma6:
1471 				protofamily = AF_INET6;
1472 				/* fall through */
1473 			case Opt_xprt_rdma:
1474 				/* vector side protocols to TCP */
1475 				mnt->flags |= NFS_MOUNT_TCP;
1476 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1477 				xprt_load_transport(string);
1478 				break;
1479 			default:
1480 				dfprintk(MOUNT, "NFS:   unrecognized "
1481 						"transport protocol\n");
1482 				kfree(string);
1483 				return 0;
1484 			}
1485 			kfree(string);
1486 			break;
1487 		case Opt_mountproto:
1488 			string = match_strdup(args);
1489 			if (string == NULL)
1490 				goto out_nomem;
1491 			token = match_token(string,
1492 					    nfs_xprt_protocol_tokens, args);
1493 			kfree(string);
1494 
1495 			mountfamily = AF_INET;
1496 			switch (token) {
1497 			case Opt_xprt_udp6:
1498 				mountfamily = AF_INET6;
1499 				/* fall through */
1500 			case Opt_xprt_udp:
1501 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1502 				break;
1503 			case Opt_xprt_tcp6:
1504 				mountfamily = AF_INET6;
1505 				/* fall through */
1506 			case Opt_xprt_tcp:
1507 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1508 				break;
1509 			case Opt_xprt_rdma: /* not used for side protocols */
1510 			default:
1511 				dfprintk(MOUNT, "NFS:   unrecognized "
1512 						"transport protocol\n");
1513 				return 0;
1514 			}
1515 			break;
1516 		case Opt_addr:
1517 			string = match_strdup(args);
1518 			if (string == NULL)
1519 				goto out_nomem;
1520 			mnt->nfs_server.addrlen =
1521 				rpc_pton(mnt->net, string, strlen(string),
1522 					(struct sockaddr *)
1523 					&mnt->nfs_server.address,
1524 					sizeof(mnt->nfs_server.address));
1525 			kfree(string);
1526 			if (mnt->nfs_server.addrlen == 0)
1527 				goto out_invalid_address;
1528 			break;
1529 		case Opt_clientaddr:
1530 			if (nfs_get_option_str(args, &mnt->client_address))
1531 				goto out_nomem;
1532 			break;
1533 		case Opt_mounthost:
1534 			if (nfs_get_option_str(args,
1535 					       &mnt->mount_server.hostname))
1536 				goto out_nomem;
1537 			break;
1538 		case Opt_mountaddr:
1539 			string = match_strdup(args);
1540 			if (string == NULL)
1541 				goto out_nomem;
1542 			mnt->mount_server.addrlen =
1543 				rpc_pton(mnt->net, string, strlen(string),
1544 					(struct sockaddr *)
1545 					&mnt->mount_server.address,
1546 					sizeof(mnt->mount_server.address));
1547 			kfree(string);
1548 			if (mnt->mount_server.addrlen == 0)
1549 				goto out_invalid_address;
1550 			break;
1551 		case Opt_lookupcache:
1552 			string = match_strdup(args);
1553 			if (string == NULL)
1554 				goto out_nomem;
1555 			token = match_token(string,
1556 					nfs_lookupcache_tokens, args);
1557 			kfree(string);
1558 			switch (token) {
1559 				case Opt_lookupcache_all:
1560 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1561 					break;
1562 				case Opt_lookupcache_positive:
1563 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1564 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1565 					break;
1566 				case Opt_lookupcache_none:
1567 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1568 					break;
1569 				default:
1570 					dfprintk(MOUNT, "NFS:   invalid "
1571 							"lookupcache argument\n");
1572 					return 0;
1573 			};
1574 			break;
1575 		case Opt_fscache_uniq:
1576 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1577 				goto out_nomem;
1578 			mnt->options |= NFS_OPTION_FSCACHE;
1579 			break;
1580 		case Opt_local_lock:
1581 			string = match_strdup(args);
1582 			if (string == NULL)
1583 				goto out_nomem;
1584 			token = match_token(string, nfs_local_lock_tokens,
1585 					args);
1586 			kfree(string);
1587 			switch (token) {
1588 			case Opt_local_lock_all:
1589 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1590 					       NFS_MOUNT_LOCAL_FCNTL);
1591 				break;
1592 			case Opt_local_lock_flock:
1593 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1594 				break;
1595 			case Opt_local_lock_posix:
1596 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1597 				break;
1598 			case Opt_local_lock_none:
1599 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1600 						NFS_MOUNT_LOCAL_FCNTL);
1601 				break;
1602 			default:
1603 				dfprintk(MOUNT, "NFS:	invalid	"
1604 						"local_lock argument\n");
1605 				return 0;
1606 			};
1607 			break;
1608 
1609 		/*
1610 		 * Special options
1611 		 */
1612 		case Opt_sloppy:
1613 			sloppy = 1;
1614 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1615 			break;
1616 		case Opt_userspace:
1617 		case Opt_deprecated:
1618 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1619 					"'%s'\n", p);
1620 			break;
1621 
1622 		default:
1623 			invalid_option = 1;
1624 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1625 					"'%s'\n", p);
1626 		}
1627 	}
1628 
1629 	if (!sloppy && invalid_option)
1630 		return 0;
1631 
1632 	if (mnt->minorversion && mnt->version != 4)
1633 		goto out_minorversion_mismatch;
1634 
1635 	if (mnt->options & NFS_OPTION_MIGRATION &&
1636 	    (mnt->version != 4 || mnt->minorversion != 0))
1637 		goto out_migration_misuse;
1638 
1639 	/*
1640 	 * verify that any proto=/mountproto= options match the address
1641 	 * families in the addr=/mountaddr= options.
1642 	 */
1643 	if (protofamily != AF_UNSPEC &&
1644 	    protofamily != mnt->nfs_server.address.ss_family)
1645 		goto out_proto_mismatch;
1646 
1647 	if (mountfamily != AF_UNSPEC) {
1648 		if (mnt->mount_server.addrlen) {
1649 			if (mountfamily != mnt->mount_server.address.ss_family)
1650 				goto out_mountproto_mismatch;
1651 		} else {
1652 			if (mountfamily != mnt->nfs_server.address.ss_family)
1653 				goto out_mountproto_mismatch;
1654 		}
1655 	}
1656 
1657 	return 1;
1658 
1659 out_mountproto_mismatch:
1660 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1661 			 "option\n");
1662 	return 0;
1663 out_proto_mismatch:
1664 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1665 	return 0;
1666 out_invalid_address:
1667 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1668 	return 0;
1669 out_invalid_value:
1670 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1671 	return 0;
1672 out_minorversion_mismatch:
1673 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1674 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1675 	return 0;
1676 out_migration_misuse:
1677 	printk(KERN_INFO
1678 		"NFS: 'migration' not supported for this NFS version\n");
1679 	return 0;
1680 out_nomem:
1681 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1682 	return 0;
1683 out_security_failure:
1684 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1685 	return 0;
1686 }
1687 
1688 /*
1689  * Ensure that a specified authtype in args->auth_info is supported by
1690  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1691  * -EACCES if not.
1692  */
1693 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1694 			rpc_authflavor_t *server_authlist, unsigned int count)
1695 {
1696 	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1697 	bool found_auth_null = false;
1698 	unsigned int i;
1699 
1700 	/*
1701 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1702 	 * must be in the list returned by the server.
1703 	 *
1704 	 * AUTH_NULL has a special meaning when it's in the server list - it
1705 	 * means that the server will ignore the rpc creds, so any flavor
1706 	 * can be used but still use the sec= that was specified.
1707 	 *
1708 	 * Note also that the MNT procedure in MNTv1 does not return a list
1709 	 * of supported security flavors. In this case, nfs_mount() fabricates
1710 	 * a security flavor list containing just AUTH_NULL.
1711 	 */
1712 	for (i = 0; i < count; i++) {
1713 		flavor = server_authlist[i];
1714 
1715 		if (nfs_auth_info_match(&args->auth_info, flavor))
1716 			goto out;
1717 
1718 		if (flavor == RPC_AUTH_NULL)
1719 			found_auth_null = true;
1720 	}
1721 
1722 	if (found_auth_null) {
1723 		flavor = args->auth_info.flavors[0];
1724 		goto out;
1725 	}
1726 
1727 	dfprintk(MOUNT,
1728 		 "NFS: specified auth flavors not supported by server\n");
1729 	return -EACCES;
1730 
1731 out:
1732 	args->selected_flavor = flavor;
1733 	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1734 	return 0;
1735 }
1736 
1737 /*
1738  * Use the remote server's MOUNT service to request the NFS file handle
1739  * corresponding to the provided path.
1740  */
1741 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1742 			     struct nfs_fh *root_fh,
1743 			     rpc_authflavor_t *server_authlist,
1744 			     unsigned int *server_authlist_len)
1745 {
1746 	struct nfs_mount_request request = {
1747 		.sap		= (struct sockaddr *)
1748 						&args->mount_server.address,
1749 		.dirpath	= args->nfs_server.export_path,
1750 		.protocol	= args->mount_server.protocol,
1751 		.fh		= root_fh,
1752 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1753 		.auth_flav_len	= server_authlist_len,
1754 		.auth_flavs	= server_authlist,
1755 		.net		= args->net,
1756 	};
1757 	int status;
1758 
1759 	if (args->mount_server.version == 0) {
1760 		switch (args->version) {
1761 			default:
1762 				args->mount_server.version = NFS_MNT3_VERSION;
1763 				break;
1764 			case 2:
1765 				args->mount_server.version = NFS_MNT_VERSION;
1766 		}
1767 	}
1768 	request.version = args->mount_server.version;
1769 
1770 	if (args->mount_server.hostname)
1771 		request.hostname = args->mount_server.hostname;
1772 	else
1773 		request.hostname = args->nfs_server.hostname;
1774 
1775 	/*
1776 	 * Construct the mount server's address.
1777 	 */
1778 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1779 		memcpy(request.sap, &args->nfs_server.address,
1780 		       args->nfs_server.addrlen);
1781 		args->mount_server.addrlen = args->nfs_server.addrlen;
1782 	}
1783 	request.salen = args->mount_server.addrlen;
1784 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1785 
1786 	/*
1787 	 * Now ask the mount server to map our export path
1788 	 * to a file handle.
1789 	 */
1790 	status = nfs_mount(&request);
1791 	if (status != 0) {
1792 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1793 				request.hostname, status);
1794 		return status;
1795 	}
1796 
1797 	return 0;
1798 }
1799 
1800 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1801 					struct nfs_subversion *nfs_mod)
1802 {
1803 	int status;
1804 	unsigned int i;
1805 	bool tried_auth_unix = false;
1806 	bool auth_null_in_list = false;
1807 	struct nfs_server *server = ERR_PTR(-EACCES);
1808 	struct nfs_parsed_mount_data *args = mount_info->parsed;
1809 	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1810 	unsigned int authlist_len = ARRAY_SIZE(authlist);
1811 
1812 	status = nfs_request_mount(args, mount_info->mntfh, authlist,
1813 					&authlist_len);
1814 	if (status)
1815 		return ERR_PTR(status);
1816 
1817 	/*
1818 	 * Was a sec= authflavor specified in the options? First, verify
1819 	 * whether the server supports it, and then just try to use it if so.
1820 	 */
1821 	if (args->auth_info.flavor_len > 0) {
1822 		status = nfs_verify_authflavors(args, authlist, authlist_len);
1823 		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1824 			 args->selected_flavor);
1825 		if (status)
1826 			return ERR_PTR(status);
1827 		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1828 	}
1829 
1830 	/*
1831 	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
1832 	 * SHOULD prefer the flavor listed first. However, some servers list
1833 	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1834 	 */
1835 	for (i = 0; i < authlist_len; ++i) {
1836 		rpc_authflavor_t flavor;
1837 		struct rpcsec_gss_info info;
1838 
1839 		flavor = authlist[i];
1840 		switch (flavor) {
1841 		case RPC_AUTH_UNIX:
1842 			tried_auth_unix = true;
1843 			break;
1844 		case RPC_AUTH_NULL:
1845 			auth_null_in_list = true;
1846 			continue;
1847 		default:
1848 			if (rpcauth_get_gssinfo(flavor, &info) != 0)
1849 				continue;
1850 			/* Fallthrough */
1851 		}
1852 		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1853 		args->selected_flavor = flavor;
1854 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1855 		if (!IS_ERR(server))
1856 			return server;
1857 	}
1858 
1859 	/*
1860 	 * Nothing we tried so far worked. At this point, give up if we've
1861 	 * already tried AUTH_UNIX or if the server's list doesn't contain
1862 	 * AUTH_NULL
1863 	 */
1864 	if (tried_auth_unix || !auth_null_in_list)
1865 		return server;
1866 
1867 	/* Last chance! Try AUTH_UNIX */
1868 	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1869 	args->selected_flavor = RPC_AUTH_UNIX;
1870 	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1871 }
1872 
1873 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1874 			     struct nfs_mount_info *mount_info,
1875 			     struct nfs_subversion *nfs_mod)
1876 {
1877 	struct nfs_server *server;
1878 
1879 	if (mount_info->parsed->need_mount)
1880 		server = nfs_try_mount_request(mount_info, nfs_mod);
1881 	else
1882 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1883 
1884 	if (IS_ERR(server))
1885 		return ERR_CAST(server);
1886 
1887 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1888 }
1889 EXPORT_SYMBOL_GPL(nfs_try_mount);
1890 
1891 /*
1892  * Split "dev_name" into "hostname:export_path".
1893  *
1894  * The leftmost colon demarks the split between the server's hostname
1895  * and the export path.  If the hostname starts with a left square
1896  * bracket, then it may contain colons.
1897  *
1898  * Note: caller frees hostname and export path, even on error.
1899  */
1900 static int nfs_parse_devname(const char *dev_name,
1901 			     char **hostname, size_t maxnamlen,
1902 			     char **export_path, size_t maxpathlen)
1903 {
1904 	size_t len;
1905 	char *end;
1906 
1907 	if (unlikely(!dev_name || !*dev_name)) {
1908 		dfprintk(MOUNT, "NFS: device name not specified\n");
1909 		return -EINVAL;
1910 	}
1911 
1912 	/* Is the host name protected with square brakcets? */
1913 	if (*dev_name == '[') {
1914 		end = strchr(++dev_name, ']');
1915 		if (end == NULL || end[1] != ':')
1916 			goto out_bad_devname;
1917 
1918 		len = end - dev_name;
1919 		end++;
1920 	} else {
1921 		char *comma;
1922 
1923 		end = strchr(dev_name, ':');
1924 		if (end == NULL)
1925 			goto out_bad_devname;
1926 		len = end - dev_name;
1927 
1928 		/* kill possible hostname list: not supported */
1929 		comma = strchr(dev_name, ',');
1930 		if (comma != NULL && comma < end)
1931 			len = comma - dev_name;
1932 	}
1933 
1934 	if (len > maxnamlen)
1935 		goto out_hostname;
1936 
1937 	/* N.B. caller will free nfs_server.hostname in all cases */
1938 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1939 	if (*hostname == NULL)
1940 		goto out_nomem;
1941 	len = strlen(++end);
1942 	if (len > maxpathlen)
1943 		goto out_path;
1944 	*export_path = kstrndup(end, len, GFP_KERNEL);
1945 	if (!*export_path)
1946 		goto out_nomem;
1947 
1948 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1949 	return 0;
1950 
1951 out_bad_devname:
1952 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1953 	return -EINVAL;
1954 
1955 out_nomem:
1956 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1957 	return -ENOMEM;
1958 
1959 out_hostname:
1960 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1961 	return -ENAMETOOLONG;
1962 
1963 out_path:
1964 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1965 	return -ENAMETOOLONG;
1966 }
1967 
1968 /*
1969  * Validate the NFS2/NFS3 mount data
1970  * - fills in the mount root filehandle
1971  *
1972  * For option strings, user space handles the following behaviors:
1973  *
1974  * + DNS: mapping server host name to IP address ("addr=" option)
1975  *
1976  * + failure mode: how to behave if a mount request can't be handled
1977  *   immediately ("fg/bg" option)
1978  *
1979  * + retry: how often to retry a mount request ("retry=" option)
1980  *
1981  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1982  *   mountproto=tcp after mountproto=udp, and so on
1983  */
1984 static int nfs23_validate_mount_data(void *options,
1985 				     struct nfs_parsed_mount_data *args,
1986 				     struct nfs_fh *mntfh,
1987 				     const char *dev_name)
1988 {
1989 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1990 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1991 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1992 
1993 	if (data == NULL)
1994 		goto out_no_data;
1995 
1996 	args->version = NFS_DEFAULT_VERSION;
1997 	switch (data->version) {
1998 	case 1:
1999 		data->namlen = 0; /* fall through */
2000 	case 2:
2001 		data->bsize = 0; /* fall through */
2002 	case 3:
2003 		if (data->flags & NFS_MOUNT_VER3)
2004 			goto out_no_v3;
2005 		data->root.size = NFS2_FHSIZE;
2006 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
2007 		/* Turn off security negotiation */
2008 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
2009 		/* fall through */
2010 	case 4:
2011 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2012 			goto out_no_sec;
2013 		/* fall through */
2014 	case 5:
2015 		memset(data->context, 0, sizeof(data->context));
2016 		/* fall through */
2017 	case 6:
2018 		if (data->flags & NFS_MOUNT_VER3) {
2019 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
2020 				goto out_invalid_fh;
2021 			mntfh->size = data->root.size;
2022 			args->version = 3;
2023 		} else {
2024 			mntfh->size = NFS2_FHSIZE;
2025 			args->version = 2;
2026 		}
2027 
2028 
2029 		memcpy(mntfh->data, data->root.data, mntfh->size);
2030 		if (mntfh->size < sizeof(mntfh->data))
2031 			memset(mntfh->data + mntfh->size, 0,
2032 			       sizeof(mntfh->data) - mntfh->size);
2033 
2034 		/*
2035 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
2036 		 * can deal with.
2037 		 */
2038 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
2039 		args->flags		|= extra_flags;
2040 		args->rsize		= data->rsize;
2041 		args->wsize		= data->wsize;
2042 		args->timeo		= data->timeo;
2043 		args->retrans		= data->retrans;
2044 		args->acregmin		= data->acregmin;
2045 		args->acregmax		= data->acregmax;
2046 		args->acdirmin		= data->acdirmin;
2047 		args->acdirmax		= data->acdirmax;
2048 		args->need_mount	= false;
2049 
2050 		memcpy(sap, &data->addr, sizeof(data->addr));
2051 		args->nfs_server.addrlen = sizeof(data->addr);
2052 		args->nfs_server.port = ntohs(data->addr.sin_port);
2053 		if (sap->sa_family != AF_INET ||
2054 		    !nfs_verify_server_address(sap))
2055 			goto out_no_address;
2056 
2057 		if (!(data->flags & NFS_MOUNT_TCP))
2058 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2059 		/* N.B. caller will free nfs_server.hostname in all cases */
2060 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2061 		args->namlen		= data->namlen;
2062 		args->bsize		= data->bsize;
2063 
2064 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2065 			args->selected_flavor = data->pseudoflavor;
2066 		else
2067 			args->selected_flavor = RPC_AUTH_UNIX;
2068 		if (!args->nfs_server.hostname)
2069 			goto out_nomem;
2070 
2071 		if (!(data->flags & NFS_MOUNT_NONLM))
2072 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2073 					 NFS_MOUNT_LOCAL_FCNTL);
2074 		else
2075 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2076 					NFS_MOUNT_LOCAL_FCNTL);
2077 		/*
2078 		 * The legacy version 6 binary mount data from userspace has a
2079 		 * field used only to transport selinux information into the
2080 		 * the kernel.  To continue to support that functionality we
2081 		 * have a touch of selinux knowledge here in the NFS code. The
2082 		 * userspace code converted context=blah to just blah so we are
2083 		 * converting back to the full string selinux understands.
2084 		 */
2085 		if (data->context[0]){
2086 #ifdef CONFIG_SECURITY_SELINUX
2087 			int rc;
2088 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2089 			rc = security_add_mnt_opt("context", data->context,
2090 					strlen(data->context), &args->lsm_opts);
2091 			if (rc)
2092 				return rc;
2093 #else
2094 			return -EINVAL;
2095 #endif
2096 		}
2097 
2098 		break;
2099 	default:
2100 		return NFS_TEXT_DATA;
2101 	}
2102 
2103 	return 0;
2104 
2105 out_no_data:
2106 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2107 	return -EINVAL;
2108 
2109 out_no_v3:
2110 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2111 		 data->version);
2112 	return -EINVAL;
2113 
2114 out_no_sec:
2115 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2116 	return -EINVAL;
2117 
2118 out_nomem:
2119 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2120 	return -ENOMEM;
2121 
2122 out_no_address:
2123 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2124 	return -EINVAL;
2125 
2126 out_invalid_fh:
2127 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2128 	return -EINVAL;
2129 }
2130 
2131 #if IS_ENABLED(CONFIG_NFS_V4)
2132 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2133 				   void *options,
2134 				   struct nfs_parsed_mount_data *args,
2135 				   struct nfs_fh *mntfh,
2136 				   const char *dev_name)
2137 {
2138 	if (fs_type == &nfs_fs_type)
2139 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2140 	return nfs4_validate_mount_data(options, args, dev_name);
2141 }
2142 #else
2143 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2144 				   void *options,
2145 				   struct nfs_parsed_mount_data *args,
2146 				   struct nfs_fh *mntfh,
2147 				   const char *dev_name)
2148 {
2149 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2150 }
2151 #endif
2152 
2153 static int nfs_validate_text_mount_data(void *options,
2154 					struct nfs_parsed_mount_data *args,
2155 					const char *dev_name)
2156 {
2157 	int port = 0;
2158 	int max_namelen = PAGE_SIZE;
2159 	int max_pathlen = NFS_MAXPATHLEN;
2160 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2161 
2162 	if (nfs_parse_mount_options((char *)options, args) == 0)
2163 		return -EINVAL;
2164 
2165 	if (!nfs_verify_server_address(sap))
2166 		goto out_no_address;
2167 
2168 	if (args->version == 4) {
2169 #if IS_ENABLED(CONFIG_NFS_V4)
2170 		if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2171 			port = NFS_RDMA_PORT;
2172 		else
2173 			port = NFS_PORT;
2174 		max_namelen = NFS4_MAXNAMLEN;
2175 		max_pathlen = NFS4_MAXPATHLEN;
2176 		nfs_validate_transport_protocol(args);
2177 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2178 			goto out_invalid_transport_udp;
2179 		nfs4_validate_mount_flags(args);
2180 #else
2181 		goto out_v4_not_compiled;
2182 #endif /* CONFIG_NFS_V4 */
2183 	} else {
2184 		nfs_set_mount_transport_protocol(args);
2185 		if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2186 			port = NFS_RDMA_PORT;
2187 	}
2188 
2189 	nfs_set_port(sap, &args->nfs_server.port, port);
2190 
2191 	return nfs_parse_devname(dev_name,
2192 				   &args->nfs_server.hostname,
2193 				   max_namelen,
2194 				   &args->nfs_server.export_path,
2195 				   max_pathlen);
2196 
2197 #if !IS_ENABLED(CONFIG_NFS_V4)
2198 out_v4_not_compiled:
2199 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2200 	return -EPROTONOSUPPORT;
2201 #else
2202 out_invalid_transport_udp:
2203 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2204 	return -EINVAL;
2205 #endif /* !CONFIG_NFS_V4 */
2206 
2207 out_no_address:
2208 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2209 	return -EINVAL;
2210 }
2211 
2212 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2213 		| NFS_MOUNT_SECURE \
2214 		| NFS_MOUNT_TCP \
2215 		| NFS_MOUNT_VER3 \
2216 		| NFS_MOUNT_KERBEROS \
2217 		| NFS_MOUNT_NONLM \
2218 		| NFS_MOUNT_BROKEN_SUID \
2219 		| NFS_MOUNT_STRICTLOCK \
2220 		| NFS_MOUNT_LEGACY_INTERFACE)
2221 
2222 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2223 		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2224 
2225 static int
2226 nfs_compare_remount_data(struct nfs_server *nfss,
2227 			 struct nfs_parsed_mount_data *data)
2228 {
2229 	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2230 	    data->rsize != nfss->rsize ||
2231 	    data->wsize != nfss->wsize ||
2232 	    data->version != nfss->nfs_client->rpc_ops->version ||
2233 	    data->minorversion != nfss->nfs_client->cl_minorversion ||
2234 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2235 	    !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2236 	    data->acregmin != nfss->acregmin / HZ ||
2237 	    data->acregmax != nfss->acregmax / HZ ||
2238 	    data->acdirmin != nfss->acdirmin / HZ ||
2239 	    data->acdirmax != nfss->acdirmax / HZ ||
2240 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2241 	    data->nfs_server.port != nfss->port ||
2242 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2243 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2244 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2245 		return -EINVAL;
2246 
2247 	return 0;
2248 }
2249 
2250 int
2251 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2252 {
2253 	int error;
2254 	struct nfs_server *nfss = sb->s_fs_info;
2255 	struct nfs_parsed_mount_data *data;
2256 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2257 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2258 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2259 
2260 	sync_filesystem(sb);
2261 
2262 	/*
2263 	 * Userspace mount programs that send binary options generally send
2264 	 * them populated with default values. We have no way to know which
2265 	 * ones were explicitly specified. Fall back to legacy behavior and
2266 	 * just return success.
2267 	 */
2268 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2269 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2270 					   options->version <= 6))))
2271 		return 0;
2272 
2273 	data = nfs_alloc_parsed_mount_data();
2274 	if (data == NULL)
2275 		return -ENOMEM;
2276 
2277 	/* fill out struct with values from existing mount */
2278 	data->flags = nfss->flags;
2279 	data->rsize = nfss->rsize;
2280 	data->wsize = nfss->wsize;
2281 	data->retrans = nfss->client->cl_timeout->to_retries;
2282 	data->selected_flavor = nfss->client->cl_auth->au_flavor;
2283 	data->acregmin = nfss->acregmin / HZ;
2284 	data->acregmax = nfss->acregmax / HZ;
2285 	data->acdirmin = nfss->acdirmin / HZ;
2286 	data->acdirmax = nfss->acdirmax / HZ;
2287 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2288 	data->nfs_server.port = nfss->port;
2289 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2290 	data->version = nfsvers;
2291 	data->minorversion = nfss->nfs_client->cl_minorversion;
2292 	data->net = current->nsproxy->net_ns;
2293 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2294 		data->nfs_server.addrlen);
2295 
2296 	/* overwrite those values with any that were specified */
2297 	error = -EINVAL;
2298 	if (!nfs_parse_mount_options((char *)options, data))
2299 		goto out;
2300 
2301 	/*
2302 	 * noac is a special case. It implies -o sync, but that's not
2303 	 * necessarily reflected in the mtab options. do_remount_sb
2304 	 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
2305 	 * remount options, so we have to explicitly reset it.
2306 	 */
2307 	if (data->flags & NFS_MOUNT_NOAC)
2308 		*flags |= SB_SYNCHRONOUS;
2309 
2310 	/* compare new mount options with old ones */
2311 	error = nfs_compare_remount_data(nfss, data);
2312 	if (!error)
2313 		error = security_sb_remount(sb, data->lsm_opts);
2314 out:
2315 	nfs_free_parsed_mount_data(data);
2316 	return error;
2317 }
2318 EXPORT_SYMBOL_GPL(nfs_remount);
2319 
2320 /*
2321  * Initialise the common bits of the superblock
2322  */
2323 static void nfs_initialise_sb(struct super_block *sb)
2324 {
2325 	struct nfs_server *server = NFS_SB(sb);
2326 
2327 	sb->s_magic = NFS_SUPER_MAGIC;
2328 
2329 	/* We probably want something more informative here */
2330 	snprintf(sb->s_id, sizeof(sb->s_id),
2331 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2332 
2333 	if (sb->s_blocksize == 0)
2334 		sb->s_blocksize = nfs_block_bits(server->wsize,
2335 						 &sb->s_blocksize_bits);
2336 
2337 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2338 }
2339 
2340 /*
2341  * Finish setting up an NFS2/3 superblock
2342  */
2343 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2344 {
2345 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2346 	struct nfs_server *server = NFS_SB(sb);
2347 
2348 	sb->s_blocksize_bits = 0;
2349 	sb->s_blocksize = 0;
2350 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2351 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2352 	if (data && data->bsize)
2353 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2354 
2355 	if (server->nfs_client->rpc_ops->version != 2) {
2356 		/* The VFS shouldn't apply the umask to mode bits. We will do
2357 		 * so ourselves when necessary.
2358 		 */
2359 		sb->s_flags |= SB_POSIXACL;
2360 		sb->s_time_gran = 1;
2361 		sb->s_export_op = &nfs_export_ops;
2362 	}
2363 
2364  	nfs_initialise_sb(sb);
2365 }
2366 EXPORT_SYMBOL_GPL(nfs_fill_super);
2367 
2368 /*
2369  * Finish setting up a cloned NFS2/3/4 superblock
2370  */
2371 static void nfs_clone_super(struct super_block *sb,
2372 			    struct nfs_mount_info *mount_info)
2373 {
2374 	const struct super_block *old_sb = mount_info->cloned->sb;
2375 	struct nfs_server *server = NFS_SB(sb);
2376 
2377 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2378 	sb->s_blocksize = old_sb->s_blocksize;
2379 	sb->s_maxbytes = old_sb->s_maxbytes;
2380 	sb->s_xattr = old_sb->s_xattr;
2381 	sb->s_op = old_sb->s_op;
2382 	sb->s_time_gran = 1;
2383 	sb->s_export_op = old_sb->s_export_op;
2384 
2385 	if (server->nfs_client->rpc_ops->version != 2) {
2386 		/* The VFS shouldn't apply the umask to mode bits. We will do
2387 		 * so ourselves when necessary.
2388 		 */
2389 		sb->s_flags |= SB_POSIXACL;
2390 	}
2391 
2392  	nfs_initialise_sb(sb);
2393 }
2394 
2395 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2396 {
2397 	const struct nfs_server *a = s->s_fs_info;
2398 	const struct rpc_clnt *clnt_a = a->client;
2399 	const struct rpc_clnt *clnt_b = b->client;
2400 
2401 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2402 		goto Ebusy;
2403 	if (a->nfs_client != b->nfs_client)
2404 		goto Ebusy;
2405 	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2406 		goto Ebusy;
2407 	if (a->wsize != b->wsize)
2408 		goto Ebusy;
2409 	if (a->rsize != b->rsize)
2410 		goto Ebusy;
2411 	if (a->acregmin != b->acregmin)
2412 		goto Ebusy;
2413 	if (a->acregmax != b->acregmax)
2414 		goto Ebusy;
2415 	if (a->acdirmin != b->acdirmin)
2416 		goto Ebusy;
2417 	if (a->acdirmax != b->acdirmax)
2418 		goto Ebusy;
2419 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2420 		goto Ebusy;
2421 	return 1;
2422 Ebusy:
2423 	return 0;
2424 }
2425 
2426 struct nfs_sb_mountdata {
2427 	struct nfs_server *server;
2428 	int mntflags;
2429 };
2430 
2431 static int nfs_set_super(struct super_block *s, void *data)
2432 {
2433 	struct nfs_sb_mountdata *sb_mntdata = data;
2434 	struct nfs_server *server = sb_mntdata->server;
2435 	int ret;
2436 
2437 	s->s_flags = sb_mntdata->mntflags;
2438 	s->s_fs_info = server;
2439 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2440 	ret = set_anon_super(s, server);
2441 	if (ret == 0)
2442 		server->s_dev = s->s_dev;
2443 	return ret;
2444 }
2445 
2446 static int nfs_compare_super_address(struct nfs_server *server1,
2447 				     struct nfs_server *server2)
2448 {
2449 	struct sockaddr *sap1, *sap2;
2450 	struct rpc_xprt *xprt1 = server1->client->cl_xprt;
2451 	struct rpc_xprt *xprt2 = server2->client->cl_xprt;
2452 
2453 	if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
2454 		return 0;
2455 
2456 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2457 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2458 
2459 	if (sap1->sa_family != sap2->sa_family)
2460 		return 0;
2461 
2462 	switch (sap1->sa_family) {
2463 	case AF_INET: {
2464 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2465 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2466 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2467 			return 0;
2468 		if (sin1->sin_port != sin2->sin_port)
2469 			return 0;
2470 		break;
2471 	}
2472 	case AF_INET6: {
2473 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2474 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2475 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2476 			return 0;
2477 		if (sin1->sin6_port != sin2->sin6_port)
2478 			return 0;
2479 		break;
2480 	}
2481 	default:
2482 		return 0;
2483 	}
2484 
2485 	return 1;
2486 }
2487 
2488 static int nfs_compare_userns(const struct nfs_server *old,
2489 		const struct nfs_server *new)
2490 {
2491 	const struct user_namespace *oldns = &init_user_ns;
2492 	const struct user_namespace *newns = &init_user_ns;
2493 
2494 	if (old->client && old->client->cl_cred)
2495 		oldns = old->client->cl_cred->user_ns;
2496 	if (new->client && new->client->cl_cred)
2497 		newns = new->client->cl_cred->user_ns;
2498 	if (oldns != newns)
2499 		return 0;
2500 	return 1;
2501 }
2502 
2503 static int nfs_compare_super(struct super_block *sb, void *data)
2504 {
2505 	struct nfs_sb_mountdata *sb_mntdata = data;
2506 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2507 	int mntflags = sb_mntdata->mntflags;
2508 
2509 	if (!nfs_compare_super_address(old, server))
2510 		return 0;
2511 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2512 	if (old->flags & NFS_MOUNT_UNSHARED)
2513 		return 0;
2514 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2515 		return 0;
2516 	if (!nfs_compare_userns(old, server))
2517 		return 0;
2518 	return nfs_compare_mount_options(sb, server, mntflags);
2519 }
2520 
2521 #ifdef CONFIG_NFS_FSCACHE
2522 static void nfs_get_cache_cookie(struct super_block *sb,
2523 				 struct nfs_parsed_mount_data *parsed,
2524 				 struct nfs_clone_mount *cloned)
2525 {
2526 	struct nfs_server *nfss = NFS_SB(sb);
2527 	char *uniq = NULL;
2528 	int ulen = 0;
2529 
2530 	nfss->fscache_key = NULL;
2531 	nfss->fscache = NULL;
2532 
2533 	if (parsed) {
2534 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2535 			return;
2536 		if (parsed->fscache_uniq) {
2537 			uniq = parsed->fscache_uniq;
2538 			ulen = strlen(parsed->fscache_uniq);
2539 		}
2540 	} else if (cloned) {
2541 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2542 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2543 			return;
2544 		if (mnt_s->fscache_key) {
2545 			uniq = mnt_s->fscache_key->key.uniquifier;
2546 			ulen = mnt_s->fscache_key->key.uniq_len;
2547 		};
2548 	} else
2549 		return;
2550 
2551 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2552 }
2553 #else
2554 static void nfs_get_cache_cookie(struct super_block *sb,
2555 				 struct nfs_parsed_mount_data *parsed,
2556 				 struct nfs_clone_mount *cloned)
2557 {
2558 }
2559 #endif
2560 
2561 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2562 			struct nfs_mount_info *mount_info)
2563 {
2564 	int error;
2565 	unsigned long kflags = 0, kflags_out = 0;
2566 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2567 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2568 
2569 	error = security_sb_set_mnt_opts(s, mount_info->parsed->lsm_opts,
2570 						kflags, &kflags_out);
2571 	if (error)
2572 		goto err;
2573 
2574 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2575 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2576 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2577 err:
2578 	return error;
2579 }
2580 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2581 
2582 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2583 			  struct nfs_mount_info *mount_info)
2584 {
2585 	int error;
2586 	unsigned long kflags = 0, kflags_out = 0;
2587 
2588 	/* clone any lsm security options from the parent to the new sb */
2589 	if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2590 		return -ESTALE;
2591 
2592 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2593 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2594 
2595 	error = security_sb_clone_mnt_opts(mount_info->cloned->sb, s, kflags,
2596 			&kflags_out);
2597 	if (error)
2598 		return error;
2599 
2600 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2601 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2602 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2603 	return 0;
2604 }
2605 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2606 
2607 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2608 				   int flags, const char *dev_name,
2609 				   struct nfs_mount_info *mount_info,
2610 				   struct nfs_subversion *nfs_mod)
2611 {
2612 	struct super_block *s;
2613 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2614 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2615 	struct nfs_sb_mountdata sb_mntdata = {
2616 		.mntflags = flags,
2617 		.server = server,
2618 	};
2619 	int error;
2620 
2621 	if (server->flags & NFS_MOUNT_UNSHARED)
2622 		compare_super = NULL;
2623 
2624 	/* -o noac implies -o sync */
2625 	if (server->flags & NFS_MOUNT_NOAC)
2626 		sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2627 
2628 	if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2629 		if (mount_info->cloned->sb->s_flags & SB_SYNCHRONOUS)
2630 			sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2631 
2632 	/* Get a superblock - note that we may end up sharing one that already exists */
2633 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2634 	if (IS_ERR(s)) {
2635 		mntroot = ERR_CAST(s);
2636 		goto out_err_nosb;
2637 	}
2638 
2639 	if (s->s_fs_info != server) {
2640 		nfs_free_server(server);
2641 		server = NULL;
2642 	} else {
2643 		error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
2644 					     MINOR(server->s_dev));
2645 		if (error) {
2646 			mntroot = ERR_PTR(error);
2647 			goto error_splat_super;
2648 		}
2649 		s->s_bdi->ra_pages = server->rpages * NFS_MAX_READAHEAD;
2650 		server->super = s;
2651 	}
2652 
2653 	if (!s->s_root) {
2654 		/* initial superblock/root creation */
2655 		mount_info->fill_super(s, mount_info);
2656 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2657 		if (!(server->flags & NFS_MOUNT_UNSHARED))
2658 			s->s_iflags |= SB_I_MULTIROOT;
2659 	}
2660 
2661 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2662 	if (IS_ERR(mntroot))
2663 		goto error_splat_super;
2664 
2665 	error = mount_info->set_security(s, mntroot, mount_info);
2666 	if (error)
2667 		goto error_splat_root;
2668 
2669 	s->s_flags |= SB_ACTIVE;
2670 
2671 out:
2672 	return mntroot;
2673 
2674 out_err_nosb:
2675 	nfs_free_server(server);
2676 	goto out;
2677 
2678 error_splat_root:
2679 	dput(mntroot);
2680 	mntroot = ERR_PTR(error);
2681 error_splat_super:
2682 	deactivate_locked_super(s);
2683 	goto out;
2684 }
2685 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2686 
2687 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2688 	int flags, const char *dev_name, void *raw_data)
2689 {
2690 	struct nfs_mount_info mount_info = {
2691 		.fill_super = nfs_fill_super,
2692 		.set_security = nfs_set_sb_security,
2693 	};
2694 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2695 	struct nfs_subversion *nfs_mod;
2696 	int error;
2697 
2698 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2699 	mount_info.mntfh = nfs_alloc_fhandle();
2700 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2701 		goto out;
2702 
2703 	/* Validate the mount data */
2704 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2705 	if (error == NFS_TEXT_DATA)
2706 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2707 	if (error < 0) {
2708 		mntroot = ERR_PTR(error);
2709 		goto out;
2710 	}
2711 
2712 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2713 	if (IS_ERR(nfs_mod)) {
2714 		mntroot = ERR_CAST(nfs_mod);
2715 		goto out;
2716 	}
2717 
2718 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2719 
2720 	put_nfs_version(nfs_mod);
2721 out:
2722 	nfs_free_parsed_mount_data(mount_info.parsed);
2723 	nfs_free_fhandle(mount_info.mntfh);
2724 	return mntroot;
2725 }
2726 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2727 
2728 /*
2729  * Destroy an NFS2/3 superblock
2730  */
2731 void nfs_kill_super(struct super_block *s)
2732 {
2733 	struct nfs_server *server = NFS_SB(s);
2734 	dev_t dev = s->s_dev;
2735 
2736 	generic_shutdown_super(s);
2737 
2738 	nfs_fscache_release_super_cookie(s);
2739 
2740 	nfs_free_server(server);
2741 	free_anon_bdev(dev);
2742 }
2743 EXPORT_SYMBOL_GPL(nfs_kill_super);
2744 
2745 /*
2746  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2747  */
2748 static struct dentry *
2749 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2750 		const char *dev_name, void *raw_data)
2751 {
2752 	struct nfs_clone_mount *data = raw_data;
2753 	struct nfs_mount_info mount_info = {
2754 		.fill_super = nfs_clone_super,
2755 		.set_security = nfs_clone_sb_security,
2756 		.cloned = data,
2757 	};
2758 	struct nfs_server *server;
2759 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2760 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2761 
2762 	dprintk("--> nfs_xdev_mount()\n");
2763 
2764 	mount_info.mntfh = mount_info.cloned->fh;
2765 
2766 	/* create a new volume representation */
2767 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2768 
2769 	if (IS_ERR(server))
2770 		mntroot = ERR_CAST(server);
2771 	else
2772 		mntroot = nfs_fs_mount_common(server, flags,
2773 				dev_name, &mount_info, nfs_mod);
2774 
2775 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2776 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2777 	return mntroot;
2778 }
2779 
2780 #if IS_ENABLED(CONFIG_NFS_V4)
2781 
2782 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2783 {
2784 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2785 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2786 }
2787 
2788 /*
2789  * Validate NFSv4 mount options
2790  */
2791 static int nfs4_validate_mount_data(void *options,
2792 				    struct nfs_parsed_mount_data *args,
2793 				    const char *dev_name)
2794 {
2795 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2796 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2797 	char *c;
2798 
2799 	if (data == NULL)
2800 		goto out_no_data;
2801 
2802 	args->version = 4;
2803 
2804 	switch (data->version) {
2805 	case 1:
2806 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2807 			goto out_no_address;
2808 		if (data->host_addrlen == 0)
2809 			goto out_no_address;
2810 		args->nfs_server.addrlen = data->host_addrlen;
2811 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2812 			return -EFAULT;
2813 		if (!nfs_verify_server_address(sap))
2814 			goto out_no_address;
2815 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2816 
2817 		if (data->auth_flavourlen) {
2818 			rpc_authflavor_t pseudoflavor;
2819 			if (data->auth_flavourlen > 1)
2820 				goto out_inval_auth;
2821 			if (copy_from_user(&pseudoflavor,
2822 					   data->auth_flavours,
2823 					   sizeof(pseudoflavor)))
2824 				return -EFAULT;
2825 			args->selected_flavor = pseudoflavor;
2826 		} else
2827 			args->selected_flavor = RPC_AUTH_UNIX;
2828 
2829 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2830 		if (IS_ERR(c))
2831 			return PTR_ERR(c);
2832 		args->nfs_server.hostname = c;
2833 
2834 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2835 		if (IS_ERR(c))
2836 			return PTR_ERR(c);
2837 		args->nfs_server.export_path = c;
2838 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2839 
2840 		c = strndup_user(data->client_addr.data, 16);
2841 		if (IS_ERR(c))
2842 			return PTR_ERR(c);
2843 		args->client_address = c;
2844 
2845 		/*
2846 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2847 		 * can deal with.
2848 		 */
2849 
2850 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2851 		args->rsize	= data->rsize;
2852 		args->wsize	= data->wsize;
2853 		args->timeo	= data->timeo;
2854 		args->retrans	= data->retrans;
2855 		args->acregmin	= data->acregmin;
2856 		args->acregmax	= data->acregmax;
2857 		args->acdirmin	= data->acdirmin;
2858 		args->acdirmax	= data->acdirmax;
2859 		args->nfs_server.protocol = data->proto;
2860 		nfs_validate_transport_protocol(args);
2861 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2862 			goto out_invalid_transport_udp;
2863 
2864 		break;
2865 	default:
2866 		return NFS_TEXT_DATA;
2867 	}
2868 
2869 	return 0;
2870 
2871 out_no_data:
2872 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2873 	return -EINVAL;
2874 
2875 out_inval_auth:
2876 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2877 		 data->auth_flavourlen);
2878 	return -EINVAL;
2879 
2880 out_no_address:
2881 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2882 	return -EINVAL;
2883 
2884 out_invalid_transport_udp:
2885 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2886 	return -EINVAL;
2887 }
2888 
2889 /*
2890  * NFS v4 module parameters need to stay in the
2891  * NFS client for backwards compatibility
2892  */
2893 unsigned int nfs_callback_set_tcpport;
2894 unsigned short nfs_callback_nr_threads;
2895 /* Default cache timeout is 10 minutes */
2896 unsigned int nfs_idmap_cache_timeout = 600;
2897 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2898 bool nfs4_disable_idmapping = true;
2899 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2900 unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
2901 unsigned short send_implementation_id = 1;
2902 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2903 bool recover_lost_locks = false;
2904 
2905 EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
2906 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2907 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2908 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2909 EXPORT_SYMBOL_GPL(max_session_slots);
2910 EXPORT_SYMBOL_GPL(max_session_cb_slots);
2911 EXPORT_SYMBOL_GPL(send_implementation_id);
2912 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2913 EXPORT_SYMBOL_GPL(recover_lost_locks);
2914 
2915 #define NFS_CALLBACK_MAXPORTNR (65535U)
2916 
2917 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2918 {
2919 	unsigned long num;
2920 	int ret;
2921 
2922 	if (!val)
2923 		return -EINVAL;
2924 	ret = kstrtoul(val, 0, &num);
2925 	if (ret || num > NFS_CALLBACK_MAXPORTNR)
2926 		return -EINVAL;
2927 	*((unsigned int *)kp->arg) = num;
2928 	return 0;
2929 }
2930 static const struct kernel_param_ops param_ops_portnr = {
2931 	.set = param_set_portnr,
2932 	.get = param_get_uint,
2933 };
2934 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2935 
2936 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2937 module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
2938 MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
2939 		"assigned to the NFSv4 callback channels.");
2940 module_param(nfs_idmap_cache_timeout, int, 0644);
2941 module_param(nfs4_disable_idmapping, bool, 0644);
2942 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2943 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2944 MODULE_PARM_DESC(nfs4_disable_idmapping,
2945 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2946 module_param(max_session_slots, ushort, 0644);
2947 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2948 		"requests the client will negotiate");
2949 module_param(max_session_cb_slots, ushort, 0644);
2950 MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
2951 		"callbacks the client will process for a given server");
2952 module_param(send_implementation_id, ushort, 0644);
2953 MODULE_PARM_DESC(send_implementation_id,
2954 		"Send implementation ID with NFSv4.1 exchange_id");
2955 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2956 
2957 module_param(recover_lost_locks, bool, 0644);
2958 MODULE_PARM_DESC(recover_lost_locks,
2959 		 "If the server reports that a lock might be lost, "
2960 		 "try to recover it risking data corruption.");
2961 
2962 
2963 #endif /* CONFIG_NFS_V4 */
2964