xref: /openbmc/linux/fs/nfs/super.c (revision f9a82c48)
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_hard,
82 	Opt_posix, Opt_noposix,
83 	Opt_cto, Opt_nocto,
84 	Opt_ac, Opt_noac,
85 	Opt_lock, Opt_nolock,
86 	Opt_udp, Opt_tcp, Opt_rdma,
87 	Opt_acl, Opt_noacl,
88 	Opt_rdirplus, Opt_nordirplus,
89 	Opt_sharecache, Opt_nosharecache,
90 	Opt_resvport, Opt_noresvport,
91 	Opt_fscache, Opt_nofscache,
92 	Opt_migration, Opt_nomigration,
93 
94 	/* Mount options that take integer arguments */
95 	Opt_port,
96 	Opt_rsize, Opt_wsize, Opt_bsize,
97 	Opt_timeo, Opt_retrans,
98 	Opt_acregmin, Opt_acregmax,
99 	Opt_acdirmin, Opt_acdirmax,
100 	Opt_actimeo,
101 	Opt_namelen,
102 	Opt_mountport,
103 	Opt_mountvers,
104 	Opt_minorversion,
105 
106 	/* Mount options that take string arguments */
107 	Opt_nfsvers,
108 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
109 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
110 	Opt_lookupcache,
111 	Opt_fscache_uniq,
112 	Opt_local_lock,
113 
114 	/* Special mount options */
115 	Opt_userspace, Opt_deprecated, Opt_sloppy,
116 
117 	Opt_err
118 };
119 
120 static const match_table_t nfs_mount_option_tokens = {
121 	{ Opt_userspace, "bg" },
122 	{ Opt_userspace, "fg" },
123 	{ Opt_userspace, "retry=%s" },
124 
125 	{ Opt_sloppy, "sloppy" },
126 
127 	{ Opt_soft, "soft" },
128 	{ Opt_hard, "hard" },
129 	{ Opt_deprecated, "intr" },
130 	{ Opt_deprecated, "nointr" },
131 	{ Opt_posix, "posix" },
132 	{ Opt_noposix, "noposix" },
133 	{ Opt_cto, "cto" },
134 	{ Opt_nocto, "nocto" },
135 	{ Opt_ac, "ac" },
136 	{ Opt_noac, "noac" },
137 	{ Opt_lock, "lock" },
138 	{ Opt_nolock, "nolock" },
139 	{ Opt_udp, "udp" },
140 	{ Opt_tcp, "tcp" },
141 	{ Opt_rdma, "rdma" },
142 	{ Opt_acl, "acl" },
143 	{ Opt_noacl, "noacl" },
144 	{ Opt_rdirplus, "rdirplus" },
145 	{ Opt_nordirplus, "nordirplus" },
146 	{ Opt_sharecache, "sharecache" },
147 	{ Opt_nosharecache, "nosharecache" },
148 	{ Opt_resvport, "resvport" },
149 	{ Opt_noresvport, "noresvport" },
150 	{ Opt_fscache, "fsc" },
151 	{ Opt_nofscache, "nofsc" },
152 	{ Opt_migration, "migration" },
153 	{ Opt_nomigration, "nomigration" },
154 
155 	{ Opt_port, "port=%s" },
156 	{ Opt_rsize, "rsize=%s" },
157 	{ Opt_wsize, "wsize=%s" },
158 	{ Opt_bsize, "bsize=%s" },
159 	{ Opt_timeo, "timeo=%s" },
160 	{ Opt_retrans, "retrans=%s" },
161 	{ Opt_acregmin, "acregmin=%s" },
162 	{ Opt_acregmax, "acregmax=%s" },
163 	{ Opt_acdirmin, "acdirmin=%s" },
164 	{ Opt_acdirmax, "acdirmax=%s" },
165 	{ Opt_actimeo, "actimeo=%s" },
166 	{ Opt_namelen, "namlen=%s" },
167 	{ Opt_mountport, "mountport=%s" },
168 	{ Opt_mountvers, "mountvers=%s" },
169 	{ Opt_minorversion, "minorversion=%s" },
170 
171 	{ Opt_nfsvers, "nfsvers=%s" },
172 	{ Opt_nfsvers, "vers=%s" },
173 
174 	{ Opt_sec, "sec=%s" },
175 	{ Opt_proto, "proto=%s" },
176 	{ Opt_mountproto, "mountproto=%s" },
177 	{ Opt_addr, "addr=%s" },
178 	{ Opt_clientaddr, "clientaddr=%s" },
179 	{ Opt_mounthost, "mounthost=%s" },
180 	{ Opt_mountaddr, "mountaddr=%s" },
181 
182 	{ Opt_lookupcache, "lookupcache=%s" },
183 	{ Opt_fscache_uniq, "fsc=%s" },
184 	{ Opt_local_lock, "local_lock=%s" },
185 
186 	/* The following needs to be listed after all other options */
187 	{ Opt_nfsvers, "v%s" },
188 
189 	{ Opt_err, NULL }
190 };
191 
192 enum {
193 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
194 	Opt_xprt_rdma6,
195 
196 	Opt_xprt_err
197 };
198 
199 static const match_table_t nfs_xprt_protocol_tokens = {
200 	{ Opt_xprt_udp, "udp" },
201 	{ Opt_xprt_udp6, "udp6" },
202 	{ Opt_xprt_tcp, "tcp" },
203 	{ Opt_xprt_tcp6, "tcp6" },
204 	{ Opt_xprt_rdma, "rdma" },
205 	{ Opt_xprt_rdma6, "rdma6" },
206 
207 	{ Opt_xprt_err, NULL }
208 };
209 
210 enum {
211 	Opt_sec_none, Opt_sec_sys,
212 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
213 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
214 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
215 
216 	Opt_sec_err
217 };
218 
219 static const match_table_t nfs_secflavor_tokens = {
220 	{ Opt_sec_none, "none" },
221 	{ Opt_sec_none, "null" },
222 	{ Opt_sec_sys, "sys" },
223 
224 	{ Opt_sec_krb5, "krb5" },
225 	{ Opt_sec_krb5i, "krb5i" },
226 	{ Opt_sec_krb5p, "krb5p" },
227 
228 	{ Opt_sec_lkey, "lkey" },
229 	{ Opt_sec_lkeyi, "lkeyi" },
230 	{ Opt_sec_lkeyp, "lkeyp" },
231 
232 	{ Opt_sec_spkm, "spkm3" },
233 	{ Opt_sec_spkmi, "spkm3i" },
234 	{ Opt_sec_spkmp, "spkm3p" },
235 
236 	{ Opt_sec_err, NULL }
237 };
238 
239 enum {
240 	Opt_lookupcache_all, Opt_lookupcache_positive,
241 	Opt_lookupcache_none,
242 
243 	Opt_lookupcache_err
244 };
245 
246 static match_table_t nfs_lookupcache_tokens = {
247 	{ Opt_lookupcache_all, "all" },
248 	{ Opt_lookupcache_positive, "pos" },
249 	{ Opt_lookupcache_positive, "positive" },
250 	{ Opt_lookupcache_none, "none" },
251 
252 	{ Opt_lookupcache_err, NULL }
253 };
254 
255 enum {
256 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
257 	Opt_local_lock_none,
258 
259 	Opt_local_lock_err
260 };
261 
262 static match_table_t nfs_local_lock_tokens = {
263 	{ Opt_local_lock_all, "all" },
264 	{ Opt_local_lock_flock, "flock" },
265 	{ Opt_local_lock_posix, "posix" },
266 	{ Opt_local_lock_none, "none" },
267 
268 	{ Opt_local_lock_err, NULL }
269 };
270 
271 enum {
272 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
273 	Opt_vers_4_1, Opt_vers_4_2,
274 
275 	Opt_vers_err
276 };
277 
278 static match_table_t nfs_vers_tokens = {
279 	{ Opt_vers_2, "2" },
280 	{ Opt_vers_3, "3" },
281 	{ Opt_vers_4, "4" },
282 	{ Opt_vers_4_0, "4.0" },
283 	{ Opt_vers_4_1, "4.1" },
284 	{ Opt_vers_4_2, "4.2" },
285 
286 	{ Opt_vers_err, NULL }
287 };
288 
289 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
290 		int flags, const char *dev_name, void *raw_data);
291 
292 struct file_system_type nfs_fs_type = {
293 	.owner		= THIS_MODULE,
294 	.name		= "nfs",
295 	.mount		= nfs_fs_mount,
296 	.kill_sb	= nfs_kill_super,
297 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
298 };
299 MODULE_ALIAS_FS("nfs");
300 EXPORT_SYMBOL_GPL(nfs_fs_type);
301 
302 struct file_system_type nfs_xdev_fs_type = {
303 	.owner		= THIS_MODULE,
304 	.name		= "nfs",
305 	.mount		= nfs_xdev_mount,
306 	.kill_sb	= nfs_kill_super,
307 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
308 };
309 
310 const struct super_operations nfs_sops = {
311 	.alloc_inode	= nfs_alloc_inode,
312 	.destroy_inode	= nfs_destroy_inode,
313 	.write_inode	= nfs_write_inode,
314 	.drop_inode	= nfs_drop_inode,
315 	.statfs		= nfs_statfs,
316 	.evict_inode	= nfs_evict_inode,
317 	.umount_begin	= nfs_umount_begin,
318 	.show_options	= nfs_show_options,
319 	.show_devname	= nfs_show_devname,
320 	.show_path	= nfs_show_path,
321 	.show_stats	= nfs_show_stats,
322 	.remount_fs	= nfs_remount,
323 };
324 EXPORT_SYMBOL_GPL(nfs_sops);
325 
326 #if IS_ENABLED(CONFIG_NFS_V4)
327 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
328 static int nfs4_validate_mount_data(void *options,
329 	struct nfs_parsed_mount_data *args, const char *dev_name);
330 
331 struct file_system_type nfs4_fs_type = {
332 	.owner		= THIS_MODULE,
333 	.name		= "nfs4",
334 	.mount		= nfs_fs_mount,
335 	.kill_sb	= nfs_kill_super,
336 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
337 };
338 MODULE_ALIAS_FS("nfs4");
339 MODULE_ALIAS("nfs4");
340 EXPORT_SYMBOL_GPL(nfs4_fs_type);
341 
342 static int __init register_nfs4_fs(void)
343 {
344 	return register_filesystem(&nfs4_fs_type);
345 }
346 
347 static void unregister_nfs4_fs(void)
348 {
349 	unregister_filesystem(&nfs4_fs_type);
350 }
351 #else
352 static int __init register_nfs4_fs(void)
353 {
354 	return 0;
355 }
356 
357 static void unregister_nfs4_fs(void)
358 {
359 }
360 #endif
361 
362 static struct shrinker acl_shrinker = {
363 	.count_objects	= nfs_access_cache_count,
364 	.scan_objects	= nfs_access_cache_scan,
365 	.seeks		= DEFAULT_SEEKS,
366 };
367 
368 /*
369  * Register the NFS filesystems
370  */
371 int __init register_nfs_fs(void)
372 {
373 	int ret;
374 
375         ret = register_filesystem(&nfs_fs_type);
376 	if (ret < 0)
377 		goto error_0;
378 
379 	ret = register_nfs4_fs();
380 	if (ret < 0)
381 		goto error_1;
382 
383 	ret = nfs_register_sysctl();
384 	if (ret < 0)
385 		goto error_2;
386 	ret = register_shrinker(&acl_shrinker);
387 	if (ret < 0)
388 		goto error_3;
389 	return 0;
390 error_3:
391 	nfs_unregister_sysctl();
392 error_2:
393 	unregister_nfs4_fs();
394 error_1:
395 	unregister_filesystem(&nfs_fs_type);
396 error_0:
397 	return ret;
398 }
399 
400 /*
401  * Unregister the NFS filesystems
402  */
403 void __exit unregister_nfs_fs(void)
404 {
405 	unregister_shrinker(&acl_shrinker);
406 	nfs_unregister_sysctl();
407 	unregister_nfs4_fs();
408 	unregister_filesystem(&nfs_fs_type);
409 }
410 
411 bool nfs_sb_active(struct super_block *sb)
412 {
413 	struct nfs_server *server = NFS_SB(sb);
414 
415 	if (!atomic_inc_not_zero(&sb->s_active))
416 		return false;
417 	if (atomic_inc_return(&server->active) != 1)
418 		atomic_dec(&sb->s_active);
419 	return true;
420 }
421 EXPORT_SYMBOL_GPL(nfs_sb_active);
422 
423 void nfs_sb_deactive(struct super_block *sb)
424 {
425 	struct nfs_server *server = NFS_SB(sb);
426 
427 	if (atomic_dec_and_test(&server->active))
428 		deactivate_super(sb);
429 }
430 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
431 
432 /*
433  * Deliver file system statistics to userspace
434  */
435 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
436 {
437 	struct nfs_server *server = NFS_SB(dentry->d_sb);
438 	unsigned char blockbits;
439 	unsigned long blockres;
440 	struct nfs_fh *fh = NFS_FH(d_inode(dentry));
441 	struct nfs_fsstat res;
442 	int error = -ENOMEM;
443 
444 	res.fattr = nfs_alloc_fattr();
445 	if (res.fattr == NULL)
446 		goto out_err;
447 
448 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
449 	if (unlikely(error == -ESTALE)) {
450 		struct dentry *pd_dentry;
451 
452 		pd_dentry = dget_parent(dentry);
453 		if (pd_dentry != NULL) {
454 			nfs_zap_caches(d_inode(pd_dentry));
455 			dput(pd_dentry);
456 		}
457 	}
458 	nfs_free_fattr(res.fattr);
459 	if (error < 0)
460 		goto out_err;
461 
462 	buf->f_type = NFS_SUPER_MAGIC;
463 
464 	/*
465 	 * Current versions of glibc do not correctly handle the
466 	 * case where f_frsize != f_bsize.  Eventually we want to
467 	 * report the value of wtmult in this field.
468 	 */
469 	buf->f_frsize = dentry->d_sb->s_blocksize;
470 
471 	/*
472 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
473 	 * are reported in units of f_frsize.  Linux hasn't had
474 	 * an f_frsize field in its statfs struct until recently,
475 	 * thus historically Linux's sys_statfs reports these
476 	 * fields in units of f_bsize.
477 	 */
478 	buf->f_bsize = dentry->d_sb->s_blocksize;
479 	blockbits = dentry->d_sb->s_blocksize_bits;
480 	blockres = (1 << blockbits) - 1;
481 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
482 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
483 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
484 
485 	buf->f_files = res.tfiles;
486 	buf->f_ffree = res.afiles;
487 
488 	buf->f_namelen = server->namelen;
489 
490 	return 0;
491 
492  out_err:
493 	dprintk("%s: statfs error = %d\n", __func__, -error);
494 	return error;
495 }
496 EXPORT_SYMBOL_GPL(nfs_statfs);
497 
498 /*
499  * Map the security flavour number to a name
500  */
501 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
502 {
503 	static const struct {
504 		rpc_authflavor_t flavour;
505 		const char *str;
506 	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
507 		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
508 		{ RPC_AUTH_NULL, "null" },
509 		{ RPC_AUTH_UNIX, "sys" },
510 		{ RPC_AUTH_GSS_KRB5, "krb5" },
511 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
512 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
513 		{ RPC_AUTH_GSS_LKEY, "lkey" },
514 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
515 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
516 		{ RPC_AUTH_GSS_SPKM, "spkm" },
517 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
518 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
519 		{ UINT_MAX, "unknown" }
520 	};
521 	int i;
522 
523 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
524 		if (sec_flavours[i].flavour == flavour)
525 			break;
526 	}
527 	return sec_flavours[i].str;
528 }
529 
530 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
531 				  int showdefaults)
532 {
533 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
534 	char *proto = NULL;
535 
536 	switch (sap->sa_family) {
537 	case AF_INET:
538 		switch (nfss->mountd_protocol) {
539 		case IPPROTO_UDP:
540 			proto = RPCBIND_NETID_UDP;
541 			break;
542 		case IPPROTO_TCP:
543 			proto = RPCBIND_NETID_TCP;
544 			break;
545 		}
546 		break;
547 	case AF_INET6:
548 		switch (nfss->mountd_protocol) {
549 		case IPPROTO_UDP:
550 			proto = RPCBIND_NETID_UDP6;
551 			break;
552 		case IPPROTO_TCP:
553 			proto = RPCBIND_NETID_TCP6;
554 			break;
555 		}
556 		break;
557 	}
558 	if (proto || showdefaults)
559 		seq_printf(m, ",mountproto=%s", proto ?: "auto");
560 }
561 
562 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
563 				    int showdefaults)
564 {
565 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
566 
567 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
568 		return;
569 
570 	switch (sap->sa_family) {
571 	case AF_INET: {
572 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
573 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
574 		break;
575 	}
576 	case AF_INET6: {
577 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
578 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
579 		break;
580 	}
581 	default:
582 		if (showdefaults)
583 			seq_printf(m, ",mountaddr=unspecified");
584 	}
585 
586 	if (nfss->mountd_version || showdefaults)
587 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
588 	if ((nfss->mountd_port &&
589 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
590 		showdefaults)
591 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
592 
593 	nfs_show_mountd_netid(m, nfss, showdefaults);
594 }
595 
596 #if IS_ENABLED(CONFIG_NFS_V4)
597 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
598 				    int showdefaults)
599 {
600 	struct nfs_client *clp = nfss->nfs_client;
601 
602 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
603 }
604 #else
605 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
606 				    int showdefaults)
607 {
608 }
609 #endif
610 
611 static void nfs_show_nfs_version(struct seq_file *m,
612 		unsigned int version,
613 		unsigned int minorversion)
614 {
615 	seq_printf(m, ",vers=%u", version);
616 	if (version == 4)
617 		seq_printf(m, ".%u", minorversion);
618 }
619 
620 /*
621  * Describe the mount options in force on this server representation
622  */
623 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
624 				   int showdefaults)
625 {
626 	static const struct proc_nfs_info {
627 		int flag;
628 		const char *str;
629 		const char *nostr;
630 	} nfs_info[] = {
631 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
632 		{ NFS_MOUNT_POSIX, ",posix", "" },
633 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
634 		{ NFS_MOUNT_NOAC, ",noac", "" },
635 		{ NFS_MOUNT_NONLM, ",nolock", "" },
636 		{ NFS_MOUNT_NOACL, ",noacl", "" },
637 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
638 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
639 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
640 		{ 0, NULL, NULL }
641 	};
642 	const struct proc_nfs_info *nfs_infop;
643 	struct nfs_client *clp = nfss->nfs_client;
644 	u32 version = clp->rpc_ops->version;
645 	int local_flock, local_fcntl;
646 
647 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
648 	seq_printf(m, ",rsize=%u", nfss->rsize);
649 	seq_printf(m, ",wsize=%u", nfss->wsize);
650 	if (nfss->bsize != 0)
651 		seq_printf(m, ",bsize=%u", nfss->bsize);
652 	seq_printf(m, ",namlen=%u", nfss->namelen);
653 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
654 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
655 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
656 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
657 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
658 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
659 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
660 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
661 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
662 		if (nfss->flags & nfs_infop->flag)
663 			seq_puts(m, nfs_infop->str);
664 		else
665 			seq_puts(m, nfs_infop->nostr);
666 	}
667 	rcu_read_lock();
668 	seq_printf(m, ",proto=%s",
669 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
670 	rcu_read_unlock();
671 	if (version == 4) {
672 		if (nfss->port != NFS_PORT)
673 			seq_printf(m, ",port=%u", nfss->port);
674 	} else
675 		if (nfss->port)
676 			seq_printf(m, ",port=%u", nfss->port);
677 
678 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
679 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
680 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
681 
682 	if (version != 4)
683 		nfs_show_mountd_options(m, nfss, showdefaults);
684 	else
685 		nfs_show_nfsv4_options(m, nfss, showdefaults);
686 
687 	if (nfss->options & NFS_OPTION_FSCACHE)
688 		seq_printf(m, ",fsc");
689 
690 	if (nfss->options & NFS_OPTION_MIGRATION)
691 		seq_printf(m, ",migration");
692 
693 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
694 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
695 			seq_printf(m, ",lookupcache=none");
696 		else
697 			seq_printf(m, ",lookupcache=pos");
698 	}
699 
700 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
701 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
702 
703 	if (!local_flock && !local_fcntl)
704 		seq_printf(m, ",local_lock=none");
705 	else if (local_flock && local_fcntl)
706 		seq_printf(m, ",local_lock=all");
707 	else if (local_flock)
708 		seq_printf(m, ",local_lock=flock");
709 	else
710 		seq_printf(m, ",local_lock=posix");
711 }
712 
713 /*
714  * Describe the mount options on this VFS mountpoint
715  */
716 int nfs_show_options(struct seq_file *m, struct dentry *root)
717 {
718 	struct nfs_server *nfss = NFS_SB(root->d_sb);
719 
720 	nfs_show_mount_options(m, nfss, 0);
721 
722 	rcu_read_lock();
723 	seq_printf(m, ",addr=%s",
724 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
725 							RPC_DISPLAY_ADDR));
726 	rcu_read_unlock();
727 
728 	return 0;
729 }
730 EXPORT_SYMBOL_GPL(nfs_show_options);
731 
732 #if IS_ENABLED(CONFIG_NFS_V4)
733 #ifdef CONFIG_NFS_V4_1
734 static void show_sessions(struct seq_file *m, struct nfs_server *server)
735 {
736 	if (nfs4_has_session(server->nfs_client))
737 		seq_printf(m, ",sessions");
738 }
739 #else
740 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
741 #endif
742 #endif
743 
744 #ifdef CONFIG_NFS_V4_1
745 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
746 {
747 	seq_printf(m, ",pnfs=");
748 	if (server->pnfs_curr_ld)
749 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
750 	else
751 		seq_printf(m, "not configured");
752 }
753 
754 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
755 {
756 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
757 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
758 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
759 			   "date='%llu,%u'",
760 			   impl_id->name, impl_id->domain,
761 			   impl_id->date.seconds, impl_id->date.nseconds);
762 	}
763 }
764 #else
765 #if IS_ENABLED(CONFIG_NFS_V4)
766 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
767 {
768 }
769 #endif
770 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
771 {
772 }
773 #endif
774 
775 int nfs_show_devname(struct seq_file *m, struct dentry *root)
776 {
777 	char *page = (char *) __get_free_page(GFP_KERNEL);
778 	char *devname, *dummy;
779 	int err = 0;
780 	if (!page)
781 		return -ENOMEM;
782 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
783 	if (IS_ERR(devname))
784 		err = PTR_ERR(devname);
785 	else
786 		seq_escape(m, devname, " \t\n\\");
787 	free_page((unsigned long)page);
788 	return err;
789 }
790 EXPORT_SYMBOL_GPL(nfs_show_devname);
791 
792 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
793 {
794 	seq_puts(m, "/");
795 	return 0;
796 }
797 EXPORT_SYMBOL_GPL(nfs_show_path);
798 
799 /*
800  * Present statistical information for this VFS mountpoint
801  */
802 int nfs_show_stats(struct seq_file *m, struct dentry *root)
803 {
804 	int i, cpu;
805 	struct nfs_server *nfss = NFS_SB(root->d_sb);
806 	struct rpc_auth *auth = nfss->client->cl_auth;
807 	struct nfs_iostats totals = { };
808 
809 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
810 
811 	/*
812 	 * Display all mount option settings
813 	 */
814 	seq_printf(m, "\n\topts:\t");
815 	seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
816 	seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
817 	seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
818 	seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
819 	nfs_show_mount_options(m, nfss, 1);
820 
821 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
822 
823 	show_implementation_id(m, nfss);
824 
825 	seq_printf(m, "\n\tcaps:\t");
826 	seq_printf(m, "caps=0x%x", nfss->caps);
827 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
828 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
829 	seq_printf(m, ",bsize=%u", nfss->bsize);
830 	seq_printf(m, ",namlen=%u", nfss->namelen);
831 
832 #if IS_ENABLED(CONFIG_NFS_V4)
833 	if (nfss->nfs_client->rpc_ops->version == 4) {
834 		seq_printf(m, "\n\tnfsv4:\t");
835 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
836 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
837 		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
838 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
839 		show_sessions(m, nfss);
840 		show_pnfs(m, nfss);
841 	}
842 #endif
843 
844 	/*
845 	 * Display security flavor in effect for this mount
846 	 */
847 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
848 	if (auth->au_flavor)
849 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
850 
851 	/*
852 	 * Display superblock I/O counters
853 	 */
854 	for_each_possible_cpu(cpu) {
855 		struct nfs_iostats *stats;
856 
857 		preempt_disable();
858 		stats = per_cpu_ptr(nfss->io_stats, cpu);
859 
860 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
861 			totals.events[i] += stats->events[i];
862 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
863 			totals.bytes[i] += stats->bytes[i];
864 #ifdef CONFIG_NFS_FSCACHE
865 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
866 			totals.fscache[i] += stats->fscache[i];
867 #endif
868 
869 		preempt_enable();
870 	}
871 
872 	seq_printf(m, "\n\tevents:\t");
873 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
874 		seq_printf(m, "%lu ", totals.events[i]);
875 	seq_printf(m, "\n\tbytes:\t");
876 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
877 		seq_printf(m, "%Lu ", totals.bytes[i]);
878 #ifdef CONFIG_NFS_FSCACHE
879 	if (nfss->options & NFS_OPTION_FSCACHE) {
880 		seq_printf(m, "\n\tfsc:\t");
881 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
882 			seq_printf(m, "%Lu ", totals.fscache[i]);
883 	}
884 #endif
885 	seq_printf(m, "\n");
886 
887 	rpc_clnt_show_stats(m, nfss->client);
888 
889 	return 0;
890 }
891 EXPORT_SYMBOL_GPL(nfs_show_stats);
892 
893 /*
894  * Begin unmount by attempting to remove all automounted mountpoints we added
895  * in response to xdev traversals and referrals
896  */
897 void nfs_umount_begin(struct super_block *sb)
898 {
899 	struct nfs_server *server;
900 	struct rpc_clnt *rpc;
901 
902 	server = NFS_SB(sb);
903 	/* -EIO all pending I/O */
904 	rpc = server->client_acl;
905 	if (!IS_ERR(rpc))
906 		rpc_killall_tasks(rpc);
907 	rpc = server->client;
908 	if (!IS_ERR(rpc))
909 		rpc_killall_tasks(rpc);
910 }
911 EXPORT_SYMBOL_GPL(nfs_umount_begin);
912 
913 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
914 {
915 	struct nfs_parsed_mount_data *data;
916 
917 	data = kzalloc(sizeof(*data), GFP_KERNEL);
918 	if (data) {
919 		data->timeo		= NFS_UNSPEC_TIMEO;
920 		data->retrans		= NFS_UNSPEC_RETRANS;
921 		data->acregmin		= NFS_DEF_ACREGMIN;
922 		data->acregmax		= NFS_DEF_ACREGMAX;
923 		data->acdirmin		= NFS_DEF_ACDIRMIN;
924 		data->acdirmax		= NFS_DEF_ACDIRMAX;
925 		data->mount_server.port	= NFS_UNSPEC_PORT;
926 		data->nfs_server.port	= NFS_UNSPEC_PORT;
927 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
928 		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
929 		data->minorversion	= 0;
930 		data->need_mount	= true;
931 		data->net		= current->nsproxy->net_ns;
932 		data->lsm_opts		= NULL;
933 	}
934 	return data;
935 }
936 
937 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
938 {
939 	if (data) {
940 		kfree(data->client_address);
941 		kfree(data->mount_server.hostname);
942 		kfree(data->nfs_server.export_path);
943 		kfree(data->nfs_server.hostname);
944 		kfree(data->fscache_uniq);
945 		security_free_mnt_opts(&data->lsm_opts);
946 		kfree(data);
947 	}
948 }
949 
950 /*
951  * Sanity-check a server address provided by the mount command.
952  *
953  * Address family must be initialized, and address must not be
954  * the ANY address for that family.
955  */
956 static int nfs_verify_server_address(struct sockaddr *addr)
957 {
958 	switch (addr->sa_family) {
959 	case AF_INET: {
960 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
961 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
962 	}
963 	case AF_INET6: {
964 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
965 		return !ipv6_addr_any(sa);
966 	}
967 	}
968 
969 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
970 	return 0;
971 }
972 
973 /*
974  * Select between a default port value and a user-specified port value.
975  * If a zero value is set, then autobind will be used.
976  */
977 static void nfs_set_port(struct sockaddr *sap, int *port,
978 				 const unsigned short default_port)
979 {
980 	if (*port == NFS_UNSPEC_PORT)
981 		*port = default_port;
982 
983 	rpc_set_port(sap, *port);
984 }
985 
986 /*
987  * Sanity check the NFS transport protocol.
988  *
989  */
990 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
991 {
992 	switch (mnt->nfs_server.protocol) {
993 	case XPRT_TRANSPORT_UDP:
994 	case XPRT_TRANSPORT_TCP:
995 	case XPRT_TRANSPORT_RDMA:
996 		break;
997 	default:
998 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
999 	}
1000 }
1001 
1002 /*
1003  * For text based NFSv2/v3 mounts, the mount protocol transport default
1004  * settings should depend upon the specified NFS transport.
1005  */
1006 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1007 {
1008 	nfs_validate_transport_protocol(mnt);
1009 
1010 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1011 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1012 			return;
1013 	switch (mnt->nfs_server.protocol) {
1014 	case XPRT_TRANSPORT_UDP:
1015 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1016 		break;
1017 	case XPRT_TRANSPORT_TCP:
1018 	case XPRT_TRANSPORT_RDMA:
1019 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1020 	}
1021 }
1022 
1023 /*
1024  * Add 'flavor' to 'auth_info' if not already present.
1025  * Returns true if 'flavor' ends up in the list, false otherwise
1026  */
1027 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1028 			      rpc_authflavor_t flavor)
1029 {
1030 	unsigned int i;
1031 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1032 
1033 	/* make sure this flavor isn't already in the list */
1034 	for (i = 0; i < auth_info->flavor_len; i++) {
1035 		if (flavor == auth_info->flavors[i])
1036 			return true;
1037 	}
1038 
1039 	if (auth_info->flavor_len + 1 >= max_flavor_len) {
1040 		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1041 		return false;
1042 	}
1043 
1044 	auth_info->flavors[auth_info->flavor_len++] = flavor;
1045 	return true;
1046 }
1047 
1048 /*
1049  * Return true if 'match' is in auth_info or auth_info is empty.
1050  * Return false otherwise.
1051  */
1052 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1053 			 rpc_authflavor_t match)
1054 {
1055 	int i;
1056 
1057 	if (!auth_info->flavor_len)
1058 		return true;
1059 
1060 	for (i = 0; i < auth_info->flavor_len; i++) {
1061 		if (auth_info->flavors[i] == match)
1062 			return true;
1063 	}
1064 	return false;
1065 }
1066 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1067 
1068 /*
1069  * Parse the value of the 'sec=' option.
1070  */
1071 static int nfs_parse_security_flavors(char *value,
1072 				      struct nfs_parsed_mount_data *mnt)
1073 {
1074 	substring_t args[MAX_OPT_ARGS];
1075 	rpc_authflavor_t pseudoflavor;
1076 	char *p;
1077 
1078 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1079 
1080 	while ((p = strsep(&value, ":")) != NULL) {
1081 		switch (match_token(p, nfs_secflavor_tokens, args)) {
1082 		case Opt_sec_none:
1083 			pseudoflavor = RPC_AUTH_NULL;
1084 			break;
1085 		case Opt_sec_sys:
1086 			pseudoflavor = RPC_AUTH_UNIX;
1087 			break;
1088 		case Opt_sec_krb5:
1089 			pseudoflavor = RPC_AUTH_GSS_KRB5;
1090 			break;
1091 		case Opt_sec_krb5i:
1092 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
1093 			break;
1094 		case Opt_sec_krb5p:
1095 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
1096 			break;
1097 		case Opt_sec_lkey:
1098 			pseudoflavor = RPC_AUTH_GSS_LKEY;
1099 			break;
1100 		case Opt_sec_lkeyi:
1101 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
1102 			break;
1103 		case Opt_sec_lkeyp:
1104 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
1105 			break;
1106 		case Opt_sec_spkm:
1107 			pseudoflavor = RPC_AUTH_GSS_SPKM;
1108 			break;
1109 		case Opt_sec_spkmi:
1110 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
1111 			break;
1112 		case Opt_sec_spkmp:
1113 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
1114 			break;
1115 		default:
1116 			dfprintk(MOUNT,
1117 				 "NFS: sec= option '%s' not recognized\n", p);
1118 			return 0;
1119 		}
1120 
1121 		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1122 			return 0;
1123 	}
1124 
1125 	return 1;
1126 }
1127 
1128 static int nfs_parse_version_string(char *string,
1129 		struct nfs_parsed_mount_data *mnt,
1130 		substring_t *args)
1131 {
1132 	mnt->flags &= ~NFS_MOUNT_VER3;
1133 	switch (match_token(string, nfs_vers_tokens, args)) {
1134 	case Opt_vers_2:
1135 		mnt->version = 2;
1136 		break;
1137 	case Opt_vers_3:
1138 		mnt->flags |= NFS_MOUNT_VER3;
1139 		mnt->version = 3;
1140 		break;
1141 	case Opt_vers_4:
1142 		/* Backward compatibility option. In future,
1143 		 * the mount program should always supply
1144 		 * a NFSv4 minor version number.
1145 		 */
1146 		mnt->version = 4;
1147 		break;
1148 	case Opt_vers_4_0:
1149 		mnt->version = 4;
1150 		mnt->minorversion = 0;
1151 		break;
1152 	case Opt_vers_4_1:
1153 		mnt->version = 4;
1154 		mnt->minorversion = 1;
1155 		break;
1156 	case Opt_vers_4_2:
1157 		mnt->version = 4;
1158 		mnt->minorversion = 2;
1159 		break;
1160 	default:
1161 		return 0;
1162 	}
1163 	return 1;
1164 }
1165 
1166 static int nfs_get_option_str(substring_t args[], char **option)
1167 {
1168 	kfree(*option);
1169 	*option = match_strdup(args);
1170 	return !*option;
1171 }
1172 
1173 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1174 {
1175 	int rc;
1176 	char *string;
1177 
1178 	string = match_strdup(args);
1179 	if (string == NULL)
1180 		return -ENOMEM;
1181 	rc = kstrtoul(string, 10, option);
1182 	kfree(string);
1183 
1184 	return rc;
1185 }
1186 
1187 static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
1188 		unsigned long l_bound, unsigned long u_bound)
1189 {
1190 	int ret;
1191 
1192 	ret = nfs_get_option_ul(args, option);
1193 	if (ret != 0)
1194 		return ret;
1195 	if (*option < l_bound || *option > u_bound)
1196 		return -ERANGE;
1197 	return 0;
1198 }
1199 
1200 /*
1201  * Error-check and convert a string of mount options from user space into
1202  * a data structure.  The whole mount string is processed; bad options are
1203  * skipped as they are encountered.  If there were no errors, return 1;
1204  * otherwise return 0 (zero).
1205  */
1206 static int nfs_parse_mount_options(char *raw,
1207 				   struct nfs_parsed_mount_data *mnt)
1208 {
1209 	char *p, *string;
1210 	int rc, sloppy = 0, invalid_option = 0;
1211 	unsigned short protofamily = AF_UNSPEC;
1212 	unsigned short mountfamily = AF_UNSPEC;
1213 
1214 	if (!raw) {
1215 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1216 		return 1;
1217 	}
1218 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1219 
1220 	rc = security_sb_eat_lsm_opts(raw, &mnt->lsm_opts);
1221 	if (rc)
1222 		goto out_security_failure;
1223 
1224 	while ((p = strsep(&raw, ",")) != NULL) {
1225 		substring_t args[MAX_OPT_ARGS];
1226 		unsigned long option;
1227 		int token;
1228 
1229 		if (!*p)
1230 			continue;
1231 
1232 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1233 
1234 		token = match_token(p, nfs_mount_option_tokens, args);
1235 		switch (token) {
1236 
1237 		/*
1238 		 * boolean options:  foo/nofoo
1239 		 */
1240 		case Opt_soft:
1241 			mnt->flags |= NFS_MOUNT_SOFT;
1242 			break;
1243 		case Opt_hard:
1244 			mnt->flags &= ~NFS_MOUNT_SOFT;
1245 			break;
1246 		case Opt_posix:
1247 			mnt->flags |= NFS_MOUNT_POSIX;
1248 			break;
1249 		case Opt_noposix:
1250 			mnt->flags &= ~NFS_MOUNT_POSIX;
1251 			break;
1252 		case Opt_cto:
1253 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1254 			break;
1255 		case Opt_nocto:
1256 			mnt->flags |= NFS_MOUNT_NOCTO;
1257 			break;
1258 		case Opt_ac:
1259 			mnt->flags &= ~NFS_MOUNT_NOAC;
1260 			break;
1261 		case Opt_noac:
1262 			mnt->flags |= NFS_MOUNT_NOAC;
1263 			break;
1264 		case Opt_lock:
1265 			mnt->flags &= ~NFS_MOUNT_NONLM;
1266 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1267 					NFS_MOUNT_LOCAL_FCNTL);
1268 			break;
1269 		case Opt_nolock:
1270 			mnt->flags |= NFS_MOUNT_NONLM;
1271 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1272 				       NFS_MOUNT_LOCAL_FCNTL);
1273 			break;
1274 		case Opt_udp:
1275 			mnt->flags &= ~NFS_MOUNT_TCP;
1276 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1277 			break;
1278 		case Opt_tcp:
1279 			mnt->flags |= NFS_MOUNT_TCP;
1280 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1281 			break;
1282 		case Opt_rdma:
1283 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1284 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1285 			xprt_load_transport(p);
1286 			break;
1287 		case Opt_acl:
1288 			mnt->flags &= ~NFS_MOUNT_NOACL;
1289 			break;
1290 		case Opt_noacl:
1291 			mnt->flags |= NFS_MOUNT_NOACL;
1292 			break;
1293 		case Opt_rdirplus:
1294 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1295 			break;
1296 		case Opt_nordirplus:
1297 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1298 			break;
1299 		case Opt_sharecache:
1300 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1301 			break;
1302 		case Opt_nosharecache:
1303 			mnt->flags |= NFS_MOUNT_UNSHARED;
1304 			break;
1305 		case Opt_resvport:
1306 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1307 			break;
1308 		case Opt_noresvport:
1309 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1310 			break;
1311 		case Opt_fscache:
1312 			mnt->options |= NFS_OPTION_FSCACHE;
1313 			kfree(mnt->fscache_uniq);
1314 			mnt->fscache_uniq = NULL;
1315 			break;
1316 		case Opt_nofscache:
1317 			mnt->options &= ~NFS_OPTION_FSCACHE;
1318 			kfree(mnt->fscache_uniq);
1319 			mnt->fscache_uniq = NULL;
1320 			break;
1321 		case Opt_migration:
1322 			mnt->options |= NFS_OPTION_MIGRATION;
1323 			break;
1324 		case Opt_nomigration:
1325 			mnt->options &= ~NFS_OPTION_MIGRATION;
1326 			break;
1327 
1328 		/*
1329 		 * options that take numeric values
1330 		 */
1331 		case Opt_port:
1332 			if (nfs_get_option_ul(args, &option) ||
1333 			    option > USHRT_MAX)
1334 				goto out_invalid_value;
1335 			mnt->nfs_server.port = option;
1336 			break;
1337 		case Opt_rsize:
1338 			if (nfs_get_option_ul(args, &option))
1339 				goto out_invalid_value;
1340 			mnt->rsize = option;
1341 			break;
1342 		case Opt_wsize:
1343 			if (nfs_get_option_ul(args, &option))
1344 				goto out_invalid_value;
1345 			mnt->wsize = option;
1346 			break;
1347 		case Opt_bsize:
1348 			if (nfs_get_option_ul(args, &option))
1349 				goto out_invalid_value;
1350 			mnt->bsize = option;
1351 			break;
1352 		case Opt_timeo:
1353 			if (nfs_get_option_ul_bound(args, &option, 1, INT_MAX))
1354 				goto out_invalid_value;
1355 			mnt->timeo = option;
1356 			break;
1357 		case Opt_retrans:
1358 			if (nfs_get_option_ul_bound(args, &option, 0, INT_MAX))
1359 				goto out_invalid_value;
1360 			mnt->retrans = option;
1361 			break;
1362 		case Opt_acregmin:
1363 			if (nfs_get_option_ul(args, &option))
1364 				goto out_invalid_value;
1365 			mnt->acregmin = option;
1366 			break;
1367 		case Opt_acregmax:
1368 			if (nfs_get_option_ul(args, &option))
1369 				goto out_invalid_value;
1370 			mnt->acregmax = option;
1371 			break;
1372 		case Opt_acdirmin:
1373 			if (nfs_get_option_ul(args, &option))
1374 				goto out_invalid_value;
1375 			mnt->acdirmin = option;
1376 			break;
1377 		case Opt_acdirmax:
1378 			if (nfs_get_option_ul(args, &option))
1379 				goto out_invalid_value;
1380 			mnt->acdirmax = option;
1381 			break;
1382 		case Opt_actimeo:
1383 			if (nfs_get_option_ul(args, &option))
1384 				goto out_invalid_value;
1385 			mnt->acregmin = mnt->acregmax =
1386 			mnt->acdirmin = mnt->acdirmax = option;
1387 			break;
1388 		case Opt_namelen:
1389 			if (nfs_get_option_ul(args, &option))
1390 				goto out_invalid_value;
1391 			mnt->namlen = option;
1392 			break;
1393 		case Opt_mountport:
1394 			if (nfs_get_option_ul(args, &option) ||
1395 			    option > USHRT_MAX)
1396 				goto out_invalid_value;
1397 			mnt->mount_server.port = option;
1398 			break;
1399 		case Opt_mountvers:
1400 			if (nfs_get_option_ul(args, &option) ||
1401 			    option < NFS_MNT_VERSION ||
1402 			    option > NFS_MNT3_VERSION)
1403 				goto out_invalid_value;
1404 			mnt->mount_server.version = option;
1405 			break;
1406 		case Opt_minorversion:
1407 			if (nfs_get_option_ul(args, &option))
1408 				goto out_invalid_value;
1409 			if (option > NFS4_MAX_MINOR_VERSION)
1410 				goto out_invalid_value;
1411 			mnt->minorversion = option;
1412 			break;
1413 
1414 		/*
1415 		 * options that take text values
1416 		 */
1417 		case Opt_nfsvers:
1418 			string = match_strdup(args);
1419 			if (string == NULL)
1420 				goto out_nomem;
1421 			rc = nfs_parse_version_string(string, mnt, args);
1422 			kfree(string);
1423 			if (!rc)
1424 				goto out_invalid_value;
1425 			break;
1426 		case Opt_sec:
1427 			string = match_strdup(args);
1428 			if (string == NULL)
1429 				goto out_nomem;
1430 			rc = nfs_parse_security_flavors(string, mnt);
1431 			kfree(string);
1432 			if (!rc) {
1433 				dfprintk(MOUNT, "NFS:   unrecognized "
1434 						"security flavor\n");
1435 				return 0;
1436 			}
1437 			break;
1438 		case Opt_proto:
1439 			string = match_strdup(args);
1440 			if (string == NULL)
1441 				goto out_nomem;
1442 			token = match_token(string,
1443 					    nfs_xprt_protocol_tokens, args);
1444 
1445 			protofamily = AF_INET;
1446 			switch (token) {
1447 			case Opt_xprt_udp6:
1448 				protofamily = AF_INET6;
1449 				/* fall through */
1450 			case Opt_xprt_udp:
1451 				mnt->flags &= ~NFS_MOUNT_TCP;
1452 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1453 				break;
1454 			case Opt_xprt_tcp6:
1455 				protofamily = AF_INET6;
1456 				/* fall through */
1457 			case Opt_xprt_tcp:
1458 				mnt->flags |= NFS_MOUNT_TCP;
1459 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1460 				break;
1461 			case Opt_xprt_rdma6:
1462 				protofamily = AF_INET6;
1463 				/* fall through */
1464 			case Opt_xprt_rdma:
1465 				/* vector side protocols to TCP */
1466 				mnt->flags |= NFS_MOUNT_TCP;
1467 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1468 				xprt_load_transport(string);
1469 				break;
1470 			default:
1471 				dfprintk(MOUNT, "NFS:   unrecognized "
1472 						"transport protocol\n");
1473 				kfree(string);
1474 				return 0;
1475 			}
1476 			kfree(string);
1477 			break;
1478 		case Opt_mountproto:
1479 			string = match_strdup(args);
1480 			if (string == NULL)
1481 				goto out_nomem;
1482 			token = match_token(string,
1483 					    nfs_xprt_protocol_tokens, args);
1484 			kfree(string);
1485 
1486 			mountfamily = AF_INET;
1487 			switch (token) {
1488 			case Opt_xprt_udp6:
1489 				mountfamily = AF_INET6;
1490 				/* fall through */
1491 			case Opt_xprt_udp:
1492 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1493 				break;
1494 			case Opt_xprt_tcp6:
1495 				mountfamily = AF_INET6;
1496 				/* fall through */
1497 			case Opt_xprt_tcp:
1498 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1499 				break;
1500 			case Opt_xprt_rdma: /* not used for side protocols */
1501 			default:
1502 				dfprintk(MOUNT, "NFS:   unrecognized "
1503 						"transport protocol\n");
1504 				return 0;
1505 			}
1506 			break;
1507 		case Opt_addr:
1508 			string = match_strdup(args);
1509 			if (string == NULL)
1510 				goto out_nomem;
1511 			mnt->nfs_server.addrlen =
1512 				rpc_pton(mnt->net, string, strlen(string),
1513 					(struct sockaddr *)
1514 					&mnt->nfs_server.address,
1515 					sizeof(mnt->nfs_server.address));
1516 			kfree(string);
1517 			if (mnt->nfs_server.addrlen == 0)
1518 				goto out_invalid_address;
1519 			break;
1520 		case Opt_clientaddr:
1521 			if (nfs_get_option_str(args, &mnt->client_address))
1522 				goto out_nomem;
1523 			break;
1524 		case Opt_mounthost:
1525 			if (nfs_get_option_str(args,
1526 					       &mnt->mount_server.hostname))
1527 				goto out_nomem;
1528 			break;
1529 		case Opt_mountaddr:
1530 			string = match_strdup(args);
1531 			if (string == NULL)
1532 				goto out_nomem;
1533 			mnt->mount_server.addrlen =
1534 				rpc_pton(mnt->net, string, strlen(string),
1535 					(struct sockaddr *)
1536 					&mnt->mount_server.address,
1537 					sizeof(mnt->mount_server.address));
1538 			kfree(string);
1539 			if (mnt->mount_server.addrlen == 0)
1540 				goto out_invalid_address;
1541 			break;
1542 		case Opt_lookupcache:
1543 			string = match_strdup(args);
1544 			if (string == NULL)
1545 				goto out_nomem;
1546 			token = match_token(string,
1547 					nfs_lookupcache_tokens, args);
1548 			kfree(string);
1549 			switch (token) {
1550 				case Opt_lookupcache_all:
1551 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1552 					break;
1553 				case Opt_lookupcache_positive:
1554 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1555 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1556 					break;
1557 				case Opt_lookupcache_none:
1558 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1559 					break;
1560 				default:
1561 					dfprintk(MOUNT, "NFS:   invalid "
1562 							"lookupcache argument\n");
1563 					return 0;
1564 			};
1565 			break;
1566 		case Opt_fscache_uniq:
1567 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1568 				goto out_nomem;
1569 			mnt->options |= NFS_OPTION_FSCACHE;
1570 			break;
1571 		case Opt_local_lock:
1572 			string = match_strdup(args);
1573 			if (string == NULL)
1574 				goto out_nomem;
1575 			token = match_token(string, nfs_local_lock_tokens,
1576 					args);
1577 			kfree(string);
1578 			switch (token) {
1579 			case Opt_local_lock_all:
1580 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1581 					       NFS_MOUNT_LOCAL_FCNTL);
1582 				break;
1583 			case Opt_local_lock_flock:
1584 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1585 				break;
1586 			case Opt_local_lock_posix:
1587 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1588 				break;
1589 			case Opt_local_lock_none:
1590 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1591 						NFS_MOUNT_LOCAL_FCNTL);
1592 				break;
1593 			default:
1594 				dfprintk(MOUNT, "NFS:	invalid	"
1595 						"local_lock argument\n");
1596 				return 0;
1597 			};
1598 			break;
1599 
1600 		/*
1601 		 * Special options
1602 		 */
1603 		case Opt_sloppy:
1604 			sloppy = 1;
1605 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1606 			break;
1607 		case Opt_userspace:
1608 		case Opt_deprecated:
1609 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1610 					"'%s'\n", p);
1611 			break;
1612 
1613 		default:
1614 			invalid_option = 1;
1615 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1616 					"'%s'\n", p);
1617 		}
1618 	}
1619 
1620 	if (!sloppy && invalid_option)
1621 		return 0;
1622 
1623 	if (mnt->minorversion && mnt->version != 4)
1624 		goto out_minorversion_mismatch;
1625 
1626 	if (mnt->options & NFS_OPTION_MIGRATION &&
1627 	    (mnt->version != 4 || mnt->minorversion != 0))
1628 		goto out_migration_misuse;
1629 
1630 	/*
1631 	 * verify that any proto=/mountproto= options match the address
1632 	 * families in the addr=/mountaddr= options.
1633 	 */
1634 	if (protofamily != AF_UNSPEC &&
1635 	    protofamily != mnt->nfs_server.address.ss_family)
1636 		goto out_proto_mismatch;
1637 
1638 	if (mountfamily != AF_UNSPEC) {
1639 		if (mnt->mount_server.addrlen) {
1640 			if (mountfamily != mnt->mount_server.address.ss_family)
1641 				goto out_mountproto_mismatch;
1642 		} else {
1643 			if (mountfamily != mnt->nfs_server.address.ss_family)
1644 				goto out_mountproto_mismatch;
1645 		}
1646 	}
1647 
1648 	return 1;
1649 
1650 out_mountproto_mismatch:
1651 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1652 			 "option\n");
1653 	return 0;
1654 out_proto_mismatch:
1655 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1656 	return 0;
1657 out_invalid_address:
1658 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1659 	return 0;
1660 out_invalid_value:
1661 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1662 	return 0;
1663 out_minorversion_mismatch:
1664 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1665 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1666 	return 0;
1667 out_migration_misuse:
1668 	printk(KERN_INFO
1669 		"NFS: 'migration' not supported for this NFS version\n");
1670 	return 0;
1671 out_nomem:
1672 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1673 	return 0;
1674 out_security_failure:
1675 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1676 	return 0;
1677 }
1678 
1679 /*
1680  * Ensure that a specified authtype in args->auth_info is supported by
1681  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1682  * -EACCES if not.
1683  */
1684 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1685 			rpc_authflavor_t *server_authlist, unsigned int count)
1686 {
1687 	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1688 	bool found_auth_null = false;
1689 	unsigned int i;
1690 
1691 	/*
1692 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1693 	 * must be in the list returned by the server.
1694 	 *
1695 	 * AUTH_NULL has a special meaning when it's in the server list - it
1696 	 * means that the server will ignore the rpc creds, so any flavor
1697 	 * can be used but still use the sec= that was specified.
1698 	 *
1699 	 * Note also that the MNT procedure in MNTv1 does not return a list
1700 	 * of supported security flavors. In this case, nfs_mount() fabricates
1701 	 * a security flavor list containing just AUTH_NULL.
1702 	 */
1703 	for (i = 0; i < count; i++) {
1704 		flavor = server_authlist[i];
1705 
1706 		if (nfs_auth_info_match(&args->auth_info, flavor))
1707 			goto out;
1708 
1709 		if (flavor == RPC_AUTH_NULL)
1710 			found_auth_null = true;
1711 	}
1712 
1713 	if (found_auth_null) {
1714 		flavor = args->auth_info.flavors[0];
1715 		goto out;
1716 	}
1717 
1718 	dfprintk(MOUNT,
1719 		 "NFS: specified auth flavors not supported by server\n");
1720 	return -EACCES;
1721 
1722 out:
1723 	args->selected_flavor = flavor;
1724 	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1725 	return 0;
1726 }
1727 
1728 /*
1729  * Use the remote server's MOUNT service to request the NFS file handle
1730  * corresponding to the provided path.
1731  */
1732 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1733 			     struct nfs_fh *root_fh,
1734 			     rpc_authflavor_t *server_authlist,
1735 			     unsigned int *server_authlist_len)
1736 {
1737 	struct nfs_mount_request request = {
1738 		.sap		= (struct sockaddr *)
1739 						&args->mount_server.address,
1740 		.dirpath	= args->nfs_server.export_path,
1741 		.protocol	= args->mount_server.protocol,
1742 		.fh		= root_fh,
1743 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1744 		.auth_flav_len	= server_authlist_len,
1745 		.auth_flavs	= server_authlist,
1746 		.net		= args->net,
1747 	};
1748 	int status;
1749 
1750 	if (args->mount_server.version == 0) {
1751 		switch (args->version) {
1752 			default:
1753 				args->mount_server.version = NFS_MNT3_VERSION;
1754 				break;
1755 			case 2:
1756 				args->mount_server.version = NFS_MNT_VERSION;
1757 		}
1758 	}
1759 	request.version = args->mount_server.version;
1760 
1761 	if (args->mount_server.hostname)
1762 		request.hostname = args->mount_server.hostname;
1763 	else
1764 		request.hostname = args->nfs_server.hostname;
1765 
1766 	/*
1767 	 * Construct the mount server's address.
1768 	 */
1769 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1770 		memcpy(request.sap, &args->nfs_server.address,
1771 		       args->nfs_server.addrlen);
1772 		args->mount_server.addrlen = args->nfs_server.addrlen;
1773 	}
1774 	request.salen = args->mount_server.addrlen;
1775 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1776 
1777 	/*
1778 	 * Now ask the mount server to map our export path
1779 	 * to a file handle.
1780 	 */
1781 	status = nfs_mount(&request);
1782 	if (status != 0) {
1783 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1784 				request.hostname, status);
1785 		return status;
1786 	}
1787 
1788 	return 0;
1789 }
1790 
1791 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1792 					struct nfs_subversion *nfs_mod)
1793 {
1794 	int status;
1795 	unsigned int i;
1796 	bool tried_auth_unix = false;
1797 	bool auth_null_in_list = false;
1798 	struct nfs_server *server = ERR_PTR(-EACCES);
1799 	struct nfs_parsed_mount_data *args = mount_info->parsed;
1800 	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1801 	unsigned int authlist_len = ARRAY_SIZE(authlist);
1802 
1803 	status = nfs_request_mount(args, mount_info->mntfh, authlist,
1804 					&authlist_len);
1805 	if (status)
1806 		return ERR_PTR(status);
1807 
1808 	/*
1809 	 * Was a sec= authflavor specified in the options? First, verify
1810 	 * whether the server supports it, and then just try to use it if so.
1811 	 */
1812 	if (args->auth_info.flavor_len > 0) {
1813 		status = nfs_verify_authflavors(args, authlist, authlist_len);
1814 		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1815 			 args->selected_flavor);
1816 		if (status)
1817 			return ERR_PTR(status);
1818 		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1819 	}
1820 
1821 	/*
1822 	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
1823 	 * SHOULD prefer the flavor listed first. However, some servers list
1824 	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1825 	 */
1826 	for (i = 0; i < authlist_len; ++i) {
1827 		rpc_authflavor_t flavor;
1828 		struct rpcsec_gss_info info;
1829 
1830 		flavor = authlist[i];
1831 		switch (flavor) {
1832 		case RPC_AUTH_UNIX:
1833 			tried_auth_unix = true;
1834 			break;
1835 		case RPC_AUTH_NULL:
1836 			auth_null_in_list = true;
1837 			continue;
1838 		default:
1839 			if (rpcauth_get_gssinfo(flavor, &info) != 0)
1840 				continue;
1841 			/* Fallthrough */
1842 		}
1843 		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1844 		args->selected_flavor = flavor;
1845 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1846 		if (!IS_ERR(server))
1847 			return server;
1848 	}
1849 
1850 	/*
1851 	 * Nothing we tried so far worked. At this point, give up if we've
1852 	 * already tried AUTH_UNIX or if the server's list doesn't contain
1853 	 * AUTH_NULL
1854 	 */
1855 	if (tried_auth_unix || !auth_null_in_list)
1856 		return server;
1857 
1858 	/* Last chance! Try AUTH_UNIX */
1859 	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1860 	args->selected_flavor = RPC_AUTH_UNIX;
1861 	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1862 }
1863 
1864 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1865 			     struct nfs_mount_info *mount_info,
1866 			     struct nfs_subversion *nfs_mod)
1867 {
1868 	struct nfs_server *server;
1869 
1870 	if (mount_info->parsed->need_mount)
1871 		server = nfs_try_mount_request(mount_info, nfs_mod);
1872 	else
1873 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1874 
1875 	if (IS_ERR(server))
1876 		return ERR_CAST(server);
1877 
1878 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1879 }
1880 EXPORT_SYMBOL_GPL(nfs_try_mount);
1881 
1882 /*
1883  * Split "dev_name" into "hostname:export_path".
1884  *
1885  * The leftmost colon demarks the split between the server's hostname
1886  * and the export path.  If the hostname starts with a left square
1887  * bracket, then it may contain colons.
1888  *
1889  * Note: caller frees hostname and export path, even on error.
1890  */
1891 static int nfs_parse_devname(const char *dev_name,
1892 			     char **hostname, size_t maxnamlen,
1893 			     char **export_path, size_t maxpathlen)
1894 {
1895 	size_t len;
1896 	char *end;
1897 
1898 	if (unlikely(!dev_name || !*dev_name)) {
1899 		dfprintk(MOUNT, "NFS: device name not specified\n");
1900 		return -EINVAL;
1901 	}
1902 
1903 	/* Is the host name protected with square brakcets? */
1904 	if (*dev_name == '[') {
1905 		end = strchr(++dev_name, ']');
1906 		if (end == NULL || end[1] != ':')
1907 			goto out_bad_devname;
1908 
1909 		len = end - dev_name;
1910 		end++;
1911 	} else {
1912 		char *comma;
1913 
1914 		end = strchr(dev_name, ':');
1915 		if (end == NULL)
1916 			goto out_bad_devname;
1917 		len = end - dev_name;
1918 
1919 		/* kill possible hostname list: not supported */
1920 		comma = strchr(dev_name, ',');
1921 		if (comma != NULL && comma < end)
1922 			len = comma - dev_name;
1923 	}
1924 
1925 	if (len > maxnamlen)
1926 		goto out_hostname;
1927 
1928 	/* N.B. caller will free nfs_server.hostname in all cases */
1929 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1930 	if (*hostname == NULL)
1931 		goto out_nomem;
1932 	len = strlen(++end);
1933 	if (len > maxpathlen)
1934 		goto out_path;
1935 	*export_path = kstrndup(end, len, GFP_KERNEL);
1936 	if (!*export_path)
1937 		goto out_nomem;
1938 
1939 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1940 	return 0;
1941 
1942 out_bad_devname:
1943 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1944 	return -EINVAL;
1945 
1946 out_nomem:
1947 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1948 	return -ENOMEM;
1949 
1950 out_hostname:
1951 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1952 	return -ENAMETOOLONG;
1953 
1954 out_path:
1955 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1956 	return -ENAMETOOLONG;
1957 }
1958 
1959 /*
1960  * Validate the NFS2/NFS3 mount data
1961  * - fills in the mount root filehandle
1962  *
1963  * For option strings, user space handles the following behaviors:
1964  *
1965  * + DNS: mapping server host name to IP address ("addr=" option)
1966  *
1967  * + failure mode: how to behave if a mount request can't be handled
1968  *   immediately ("fg/bg" option)
1969  *
1970  * + retry: how often to retry a mount request ("retry=" option)
1971  *
1972  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1973  *   mountproto=tcp after mountproto=udp, and so on
1974  */
1975 static int nfs23_validate_mount_data(void *options,
1976 				     struct nfs_parsed_mount_data *args,
1977 				     struct nfs_fh *mntfh,
1978 				     const char *dev_name)
1979 {
1980 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1981 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1982 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1983 
1984 	if (data == NULL)
1985 		goto out_no_data;
1986 
1987 	args->version = NFS_DEFAULT_VERSION;
1988 	switch (data->version) {
1989 	case 1:
1990 		data->namlen = 0; /* fall through */
1991 	case 2:
1992 		data->bsize = 0; /* fall through */
1993 	case 3:
1994 		if (data->flags & NFS_MOUNT_VER3)
1995 			goto out_no_v3;
1996 		data->root.size = NFS2_FHSIZE;
1997 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1998 		/* Turn off security negotiation */
1999 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
2000 		/* fall through */
2001 	case 4:
2002 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2003 			goto out_no_sec;
2004 		/* fall through */
2005 	case 5:
2006 		memset(data->context, 0, sizeof(data->context));
2007 		/* fall through */
2008 	case 6:
2009 		if (data->flags & NFS_MOUNT_VER3) {
2010 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
2011 				goto out_invalid_fh;
2012 			mntfh->size = data->root.size;
2013 			args->version = 3;
2014 		} else {
2015 			mntfh->size = NFS2_FHSIZE;
2016 			args->version = 2;
2017 		}
2018 
2019 
2020 		memcpy(mntfh->data, data->root.data, mntfh->size);
2021 		if (mntfh->size < sizeof(mntfh->data))
2022 			memset(mntfh->data + mntfh->size, 0,
2023 			       sizeof(mntfh->data) - mntfh->size);
2024 
2025 		/*
2026 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
2027 		 * can deal with.
2028 		 */
2029 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
2030 		args->flags		|= extra_flags;
2031 		args->rsize		= data->rsize;
2032 		args->wsize		= data->wsize;
2033 		args->timeo		= data->timeo;
2034 		args->retrans		= data->retrans;
2035 		args->acregmin		= data->acregmin;
2036 		args->acregmax		= data->acregmax;
2037 		args->acdirmin		= data->acdirmin;
2038 		args->acdirmax		= data->acdirmax;
2039 		args->need_mount	= false;
2040 
2041 		memcpy(sap, &data->addr, sizeof(data->addr));
2042 		args->nfs_server.addrlen = sizeof(data->addr);
2043 		args->nfs_server.port = ntohs(data->addr.sin_port);
2044 		if (!nfs_verify_server_address(sap))
2045 			goto out_no_address;
2046 
2047 		if (!(data->flags & NFS_MOUNT_TCP))
2048 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2049 		/* N.B. caller will free nfs_server.hostname in all cases */
2050 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2051 		args->namlen		= data->namlen;
2052 		args->bsize		= data->bsize;
2053 
2054 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2055 			args->selected_flavor = data->pseudoflavor;
2056 		else
2057 			args->selected_flavor = RPC_AUTH_UNIX;
2058 		if (!args->nfs_server.hostname)
2059 			goto out_nomem;
2060 
2061 		if (!(data->flags & NFS_MOUNT_NONLM))
2062 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2063 					 NFS_MOUNT_LOCAL_FCNTL);
2064 		else
2065 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2066 					NFS_MOUNT_LOCAL_FCNTL);
2067 		/*
2068 		 * The legacy version 6 binary mount data from userspace has a
2069 		 * field used only to transport selinux information into the
2070 		 * the kernel.  To continue to support that functionality we
2071 		 * have a touch of selinux knowledge here in the NFS code. The
2072 		 * userspace code converted context=blah to just blah so we are
2073 		 * converting back to the full string selinux understands.
2074 		 */
2075 		if (data->context[0]){
2076 #ifdef CONFIG_SECURITY_SELINUX
2077 			int rc;
2078 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2079 			rc = security_add_mnt_opt("context", data->context,
2080 					strlen(data->context), &args->lsm_opts);
2081 			if (rc)
2082 				return rc;
2083 #else
2084 			return -EINVAL;
2085 #endif
2086 		}
2087 
2088 		break;
2089 	default:
2090 		return NFS_TEXT_DATA;
2091 	}
2092 
2093 	return 0;
2094 
2095 out_no_data:
2096 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2097 	return -EINVAL;
2098 
2099 out_no_v3:
2100 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2101 		 data->version);
2102 	return -EINVAL;
2103 
2104 out_no_sec:
2105 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2106 	return -EINVAL;
2107 
2108 out_nomem:
2109 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2110 	return -ENOMEM;
2111 
2112 out_no_address:
2113 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2114 	return -EINVAL;
2115 
2116 out_invalid_fh:
2117 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2118 	return -EINVAL;
2119 }
2120 
2121 #if IS_ENABLED(CONFIG_NFS_V4)
2122 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2123 				   void *options,
2124 				   struct nfs_parsed_mount_data *args,
2125 				   struct nfs_fh *mntfh,
2126 				   const char *dev_name)
2127 {
2128 	if (fs_type == &nfs_fs_type)
2129 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2130 	return nfs4_validate_mount_data(options, args, dev_name);
2131 }
2132 #else
2133 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2134 				   void *options,
2135 				   struct nfs_parsed_mount_data *args,
2136 				   struct nfs_fh *mntfh,
2137 				   const char *dev_name)
2138 {
2139 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2140 }
2141 #endif
2142 
2143 static int nfs_validate_text_mount_data(void *options,
2144 					struct nfs_parsed_mount_data *args,
2145 					const char *dev_name)
2146 {
2147 	int port = 0;
2148 	int max_namelen = PAGE_SIZE;
2149 	int max_pathlen = NFS_MAXPATHLEN;
2150 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2151 
2152 	if (nfs_parse_mount_options((char *)options, args) == 0)
2153 		return -EINVAL;
2154 
2155 	if (!nfs_verify_server_address(sap))
2156 		goto out_no_address;
2157 
2158 	if (args->version == 4) {
2159 #if IS_ENABLED(CONFIG_NFS_V4)
2160 		if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2161 			port = NFS_RDMA_PORT;
2162 		else
2163 			port = NFS_PORT;
2164 		max_namelen = NFS4_MAXNAMLEN;
2165 		max_pathlen = NFS4_MAXPATHLEN;
2166 		nfs_validate_transport_protocol(args);
2167 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2168 			goto out_invalid_transport_udp;
2169 		nfs4_validate_mount_flags(args);
2170 #else
2171 		goto out_v4_not_compiled;
2172 #endif /* CONFIG_NFS_V4 */
2173 	} else {
2174 		nfs_set_mount_transport_protocol(args);
2175 		if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2176 			port = NFS_RDMA_PORT;
2177 	}
2178 
2179 	nfs_set_port(sap, &args->nfs_server.port, port);
2180 
2181 	return nfs_parse_devname(dev_name,
2182 				   &args->nfs_server.hostname,
2183 				   max_namelen,
2184 				   &args->nfs_server.export_path,
2185 				   max_pathlen);
2186 
2187 #if !IS_ENABLED(CONFIG_NFS_V4)
2188 out_v4_not_compiled:
2189 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2190 	return -EPROTONOSUPPORT;
2191 #else
2192 out_invalid_transport_udp:
2193 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2194 	return -EINVAL;
2195 #endif /* !CONFIG_NFS_V4 */
2196 
2197 out_no_address:
2198 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2199 	return -EINVAL;
2200 }
2201 
2202 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2203 		| NFS_MOUNT_SECURE \
2204 		| NFS_MOUNT_TCP \
2205 		| NFS_MOUNT_VER3 \
2206 		| NFS_MOUNT_KERBEROS \
2207 		| NFS_MOUNT_NONLM \
2208 		| NFS_MOUNT_BROKEN_SUID \
2209 		| NFS_MOUNT_STRICTLOCK \
2210 		| NFS_MOUNT_LEGACY_INTERFACE)
2211 
2212 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2213 		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2214 
2215 static int
2216 nfs_compare_remount_data(struct nfs_server *nfss,
2217 			 struct nfs_parsed_mount_data *data)
2218 {
2219 	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2220 	    data->rsize != nfss->rsize ||
2221 	    data->wsize != nfss->wsize ||
2222 	    data->version != nfss->nfs_client->rpc_ops->version ||
2223 	    data->minorversion != nfss->nfs_client->cl_minorversion ||
2224 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2225 	    !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2226 	    data->acregmin != nfss->acregmin / HZ ||
2227 	    data->acregmax != nfss->acregmax / HZ ||
2228 	    data->acdirmin != nfss->acdirmin / HZ ||
2229 	    data->acdirmax != nfss->acdirmax / HZ ||
2230 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2231 	    data->nfs_server.port != nfss->port ||
2232 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2233 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2234 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2235 		return -EINVAL;
2236 
2237 	return 0;
2238 }
2239 
2240 int
2241 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2242 {
2243 	int error;
2244 	struct nfs_server *nfss = sb->s_fs_info;
2245 	struct nfs_parsed_mount_data *data;
2246 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2247 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2248 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2249 
2250 	sync_filesystem(sb);
2251 
2252 	/*
2253 	 * Userspace mount programs that send binary options generally send
2254 	 * them populated with default values. We have no way to know which
2255 	 * ones were explicitly specified. Fall back to legacy behavior and
2256 	 * just return success.
2257 	 */
2258 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2259 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2260 					   options->version <= 6))))
2261 		return 0;
2262 
2263 	data = nfs_alloc_parsed_mount_data();
2264 	if (data == NULL)
2265 		return -ENOMEM;
2266 
2267 	/* fill out struct with values from existing mount */
2268 	data->flags = nfss->flags;
2269 	data->rsize = nfss->rsize;
2270 	data->wsize = nfss->wsize;
2271 	data->retrans = nfss->client->cl_timeout->to_retries;
2272 	data->selected_flavor = nfss->client->cl_auth->au_flavor;
2273 	data->acregmin = nfss->acregmin / HZ;
2274 	data->acregmax = nfss->acregmax / HZ;
2275 	data->acdirmin = nfss->acdirmin / HZ;
2276 	data->acdirmax = nfss->acdirmax / HZ;
2277 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2278 	data->nfs_server.port = nfss->port;
2279 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2280 	data->version = nfsvers;
2281 	data->minorversion = nfss->nfs_client->cl_minorversion;
2282 	data->net = current->nsproxy->net_ns;
2283 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2284 		data->nfs_server.addrlen);
2285 
2286 	/* overwrite those values with any that were specified */
2287 	error = -EINVAL;
2288 	if (!nfs_parse_mount_options((char *)options, data))
2289 		goto out;
2290 
2291 	/*
2292 	 * noac is a special case. It implies -o sync, but that's not
2293 	 * necessarily reflected in the mtab options. do_remount_sb
2294 	 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
2295 	 * remount options, so we have to explicitly reset it.
2296 	 */
2297 	if (data->flags & NFS_MOUNT_NOAC)
2298 		*flags |= SB_SYNCHRONOUS;
2299 
2300 	/* compare new mount options with old ones */
2301 	error = nfs_compare_remount_data(nfss, data);
2302 	if (!error)
2303 		error = security_sb_remount(sb, data->lsm_opts);
2304 out:
2305 	nfs_free_parsed_mount_data(data);
2306 	return error;
2307 }
2308 EXPORT_SYMBOL_GPL(nfs_remount);
2309 
2310 /*
2311  * Initialise the common bits of the superblock
2312  */
2313 static void nfs_initialise_sb(struct super_block *sb)
2314 {
2315 	struct nfs_server *server = NFS_SB(sb);
2316 
2317 	sb->s_magic = NFS_SUPER_MAGIC;
2318 
2319 	/* We probably want something more informative here */
2320 	snprintf(sb->s_id, sizeof(sb->s_id),
2321 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2322 
2323 	if (sb->s_blocksize == 0)
2324 		sb->s_blocksize = nfs_block_bits(server->wsize,
2325 						 &sb->s_blocksize_bits);
2326 
2327 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2328 }
2329 
2330 /*
2331  * Finish setting up an NFS2/3 superblock
2332  */
2333 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2334 {
2335 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2336 	struct nfs_server *server = NFS_SB(sb);
2337 
2338 	sb->s_blocksize_bits = 0;
2339 	sb->s_blocksize = 0;
2340 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2341 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2342 	if (data && data->bsize)
2343 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2344 
2345 	if (server->nfs_client->rpc_ops->version != 2) {
2346 		/* The VFS shouldn't apply the umask to mode bits. We will do
2347 		 * so ourselves when necessary.
2348 		 */
2349 		sb->s_flags |= SB_POSIXACL;
2350 		sb->s_time_gran = 1;
2351 		sb->s_export_op = &nfs_export_ops;
2352 	}
2353 
2354  	nfs_initialise_sb(sb);
2355 }
2356 EXPORT_SYMBOL_GPL(nfs_fill_super);
2357 
2358 /*
2359  * Finish setting up a cloned NFS2/3/4 superblock
2360  */
2361 static void nfs_clone_super(struct super_block *sb,
2362 			    struct nfs_mount_info *mount_info)
2363 {
2364 	const struct super_block *old_sb = mount_info->cloned->sb;
2365 	struct nfs_server *server = NFS_SB(sb);
2366 
2367 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2368 	sb->s_blocksize = old_sb->s_blocksize;
2369 	sb->s_maxbytes = old_sb->s_maxbytes;
2370 	sb->s_xattr = old_sb->s_xattr;
2371 	sb->s_op = old_sb->s_op;
2372 	sb->s_time_gran = 1;
2373 	sb->s_export_op = old_sb->s_export_op;
2374 
2375 	if (server->nfs_client->rpc_ops->version != 2) {
2376 		/* The VFS shouldn't apply the umask to mode bits. We will do
2377 		 * so ourselves when necessary.
2378 		 */
2379 		sb->s_flags |= SB_POSIXACL;
2380 	}
2381 
2382  	nfs_initialise_sb(sb);
2383 }
2384 
2385 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2386 {
2387 	const struct nfs_server *a = s->s_fs_info;
2388 	const struct rpc_clnt *clnt_a = a->client;
2389 	const struct rpc_clnt *clnt_b = b->client;
2390 
2391 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2392 		goto Ebusy;
2393 	if (a->nfs_client != b->nfs_client)
2394 		goto Ebusy;
2395 	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2396 		goto Ebusy;
2397 	if (a->wsize != b->wsize)
2398 		goto Ebusy;
2399 	if (a->rsize != b->rsize)
2400 		goto Ebusy;
2401 	if (a->acregmin != b->acregmin)
2402 		goto Ebusy;
2403 	if (a->acregmax != b->acregmax)
2404 		goto Ebusy;
2405 	if (a->acdirmin != b->acdirmin)
2406 		goto Ebusy;
2407 	if (a->acdirmax != b->acdirmax)
2408 		goto Ebusy;
2409 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2410 		goto Ebusy;
2411 	return 1;
2412 Ebusy:
2413 	return 0;
2414 }
2415 
2416 struct nfs_sb_mountdata {
2417 	struct nfs_server *server;
2418 	int mntflags;
2419 };
2420 
2421 static int nfs_set_super(struct super_block *s, void *data)
2422 {
2423 	struct nfs_sb_mountdata *sb_mntdata = data;
2424 	struct nfs_server *server = sb_mntdata->server;
2425 	int ret;
2426 
2427 	s->s_flags = sb_mntdata->mntflags;
2428 	s->s_fs_info = server;
2429 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2430 	ret = set_anon_super(s, server);
2431 	if (ret == 0)
2432 		server->s_dev = s->s_dev;
2433 	return ret;
2434 }
2435 
2436 static int nfs_compare_super_address(struct nfs_server *server1,
2437 				     struct nfs_server *server2)
2438 {
2439 	struct sockaddr *sap1, *sap2;
2440 	struct rpc_xprt *xprt1 = server1->client->cl_xprt;
2441 	struct rpc_xprt *xprt2 = server2->client->cl_xprt;
2442 
2443 	if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
2444 		return 0;
2445 
2446 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2447 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2448 
2449 	if (sap1->sa_family != sap2->sa_family)
2450 		return 0;
2451 
2452 	switch (sap1->sa_family) {
2453 	case AF_INET: {
2454 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2455 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2456 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2457 			return 0;
2458 		if (sin1->sin_port != sin2->sin_port)
2459 			return 0;
2460 		break;
2461 	}
2462 	case AF_INET6: {
2463 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2464 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2465 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2466 			return 0;
2467 		if (sin1->sin6_port != sin2->sin6_port)
2468 			return 0;
2469 		break;
2470 	}
2471 	default:
2472 		return 0;
2473 	}
2474 
2475 	return 1;
2476 }
2477 
2478 static int nfs_compare_super(struct super_block *sb, void *data)
2479 {
2480 	struct nfs_sb_mountdata *sb_mntdata = data;
2481 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2482 	int mntflags = sb_mntdata->mntflags;
2483 
2484 	if (!nfs_compare_super_address(old, server))
2485 		return 0;
2486 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2487 	if (old->flags & NFS_MOUNT_UNSHARED)
2488 		return 0;
2489 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2490 		return 0;
2491 	return nfs_compare_mount_options(sb, server, mntflags);
2492 }
2493 
2494 #ifdef CONFIG_NFS_FSCACHE
2495 static void nfs_get_cache_cookie(struct super_block *sb,
2496 				 struct nfs_parsed_mount_data *parsed,
2497 				 struct nfs_clone_mount *cloned)
2498 {
2499 	struct nfs_server *nfss = NFS_SB(sb);
2500 	char *uniq = NULL;
2501 	int ulen = 0;
2502 
2503 	nfss->fscache_key = NULL;
2504 	nfss->fscache = NULL;
2505 
2506 	if (parsed) {
2507 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2508 			return;
2509 		if (parsed->fscache_uniq) {
2510 			uniq = parsed->fscache_uniq;
2511 			ulen = strlen(parsed->fscache_uniq);
2512 		}
2513 	} else if (cloned) {
2514 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2515 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2516 			return;
2517 		if (mnt_s->fscache_key) {
2518 			uniq = mnt_s->fscache_key->key.uniquifier;
2519 			ulen = mnt_s->fscache_key->key.uniq_len;
2520 		};
2521 	} else
2522 		return;
2523 
2524 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2525 }
2526 #else
2527 static void nfs_get_cache_cookie(struct super_block *sb,
2528 				 struct nfs_parsed_mount_data *parsed,
2529 				 struct nfs_clone_mount *cloned)
2530 {
2531 }
2532 #endif
2533 
2534 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2535 			struct nfs_mount_info *mount_info)
2536 {
2537 	int error;
2538 	unsigned long kflags = 0, kflags_out = 0;
2539 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2540 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2541 
2542 	error = security_sb_set_mnt_opts(s, mount_info->parsed->lsm_opts,
2543 						kflags, &kflags_out);
2544 	if (error)
2545 		goto err;
2546 
2547 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2548 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2549 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2550 err:
2551 	return error;
2552 }
2553 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2554 
2555 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2556 			  struct nfs_mount_info *mount_info)
2557 {
2558 	int error;
2559 	unsigned long kflags = 0, kflags_out = 0;
2560 
2561 	/* clone any lsm security options from the parent to the new sb */
2562 	if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2563 		return -ESTALE;
2564 
2565 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2566 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2567 
2568 	error = security_sb_clone_mnt_opts(mount_info->cloned->sb, s, kflags,
2569 			&kflags_out);
2570 	if (error)
2571 		return error;
2572 
2573 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2574 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2575 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2576 	return 0;
2577 }
2578 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2579 
2580 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2581 				   int flags, const char *dev_name,
2582 				   struct nfs_mount_info *mount_info,
2583 				   struct nfs_subversion *nfs_mod)
2584 {
2585 	struct super_block *s;
2586 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2587 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2588 	struct nfs_sb_mountdata sb_mntdata = {
2589 		.mntflags = flags,
2590 		.server = server,
2591 	};
2592 	int error;
2593 
2594 	if (server->flags & NFS_MOUNT_UNSHARED)
2595 		compare_super = NULL;
2596 
2597 	/* -o noac implies -o sync */
2598 	if (server->flags & NFS_MOUNT_NOAC)
2599 		sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2600 
2601 	if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2602 		if (mount_info->cloned->sb->s_flags & SB_SYNCHRONOUS)
2603 			sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2604 
2605 	/* Get a superblock - note that we may end up sharing one that already exists */
2606 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2607 	if (IS_ERR(s)) {
2608 		mntroot = ERR_CAST(s);
2609 		goto out_err_nosb;
2610 	}
2611 
2612 	if (s->s_fs_info != server) {
2613 		nfs_free_server(server);
2614 		server = NULL;
2615 	} else {
2616 		error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
2617 					     MINOR(server->s_dev));
2618 		if (error) {
2619 			mntroot = ERR_PTR(error);
2620 			goto error_splat_super;
2621 		}
2622 		s->s_bdi->ra_pages = server->rpages * NFS_MAX_READAHEAD;
2623 		server->super = s;
2624 	}
2625 
2626 	if (!s->s_root) {
2627 		/* initial superblock/root creation */
2628 		mount_info->fill_super(s, mount_info);
2629 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2630 		if (!(server->flags & NFS_MOUNT_UNSHARED))
2631 			s->s_iflags |= SB_I_MULTIROOT;
2632 	}
2633 
2634 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2635 	if (IS_ERR(mntroot))
2636 		goto error_splat_super;
2637 
2638 	error = mount_info->set_security(s, mntroot, mount_info);
2639 	if (error)
2640 		goto error_splat_root;
2641 
2642 	s->s_flags |= SB_ACTIVE;
2643 
2644 out:
2645 	return mntroot;
2646 
2647 out_err_nosb:
2648 	nfs_free_server(server);
2649 	goto out;
2650 
2651 error_splat_root:
2652 	dput(mntroot);
2653 	mntroot = ERR_PTR(error);
2654 error_splat_super:
2655 	deactivate_locked_super(s);
2656 	goto out;
2657 }
2658 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2659 
2660 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2661 	int flags, const char *dev_name, void *raw_data)
2662 {
2663 	struct nfs_mount_info mount_info = {
2664 		.fill_super = nfs_fill_super,
2665 		.set_security = nfs_set_sb_security,
2666 	};
2667 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2668 	struct nfs_subversion *nfs_mod;
2669 	int error;
2670 
2671 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2672 	mount_info.mntfh = nfs_alloc_fhandle();
2673 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2674 		goto out;
2675 
2676 	/* Validate the mount data */
2677 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2678 	if (error == NFS_TEXT_DATA)
2679 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2680 	if (error < 0) {
2681 		mntroot = ERR_PTR(error);
2682 		goto out;
2683 	}
2684 
2685 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2686 	if (IS_ERR(nfs_mod)) {
2687 		mntroot = ERR_CAST(nfs_mod);
2688 		goto out;
2689 	}
2690 
2691 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2692 
2693 	put_nfs_version(nfs_mod);
2694 out:
2695 	nfs_free_parsed_mount_data(mount_info.parsed);
2696 	nfs_free_fhandle(mount_info.mntfh);
2697 	return mntroot;
2698 }
2699 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2700 
2701 /*
2702  * Destroy an NFS2/3 superblock
2703  */
2704 void nfs_kill_super(struct super_block *s)
2705 {
2706 	struct nfs_server *server = NFS_SB(s);
2707 	dev_t dev = s->s_dev;
2708 
2709 	generic_shutdown_super(s);
2710 
2711 	nfs_fscache_release_super_cookie(s);
2712 
2713 	nfs_free_server(server);
2714 	free_anon_bdev(dev);
2715 }
2716 EXPORT_SYMBOL_GPL(nfs_kill_super);
2717 
2718 /*
2719  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2720  */
2721 static struct dentry *
2722 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2723 		const char *dev_name, void *raw_data)
2724 {
2725 	struct nfs_clone_mount *data = raw_data;
2726 	struct nfs_mount_info mount_info = {
2727 		.fill_super = nfs_clone_super,
2728 		.set_security = nfs_clone_sb_security,
2729 		.cloned = data,
2730 	};
2731 	struct nfs_server *server;
2732 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2733 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2734 
2735 	dprintk("--> nfs_xdev_mount()\n");
2736 
2737 	mount_info.mntfh = mount_info.cloned->fh;
2738 
2739 	/* create a new volume representation */
2740 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2741 
2742 	if (IS_ERR(server))
2743 		mntroot = ERR_CAST(server);
2744 	else
2745 		mntroot = nfs_fs_mount_common(server, flags,
2746 				dev_name, &mount_info, nfs_mod);
2747 
2748 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2749 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2750 	return mntroot;
2751 }
2752 
2753 #if IS_ENABLED(CONFIG_NFS_V4)
2754 
2755 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2756 {
2757 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2758 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2759 }
2760 
2761 /*
2762  * Validate NFSv4 mount options
2763  */
2764 static int nfs4_validate_mount_data(void *options,
2765 				    struct nfs_parsed_mount_data *args,
2766 				    const char *dev_name)
2767 {
2768 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2769 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2770 	char *c;
2771 
2772 	if (data == NULL)
2773 		goto out_no_data;
2774 
2775 	args->version = 4;
2776 
2777 	switch (data->version) {
2778 	case 1:
2779 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2780 			goto out_no_address;
2781 		if (data->host_addrlen == 0)
2782 			goto out_no_address;
2783 		args->nfs_server.addrlen = data->host_addrlen;
2784 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2785 			return -EFAULT;
2786 		if (!nfs_verify_server_address(sap))
2787 			goto out_no_address;
2788 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2789 
2790 		if (data->auth_flavourlen) {
2791 			rpc_authflavor_t pseudoflavor;
2792 			if (data->auth_flavourlen > 1)
2793 				goto out_inval_auth;
2794 			if (copy_from_user(&pseudoflavor,
2795 					   data->auth_flavours,
2796 					   sizeof(pseudoflavor)))
2797 				return -EFAULT;
2798 			args->selected_flavor = pseudoflavor;
2799 		} else
2800 			args->selected_flavor = RPC_AUTH_UNIX;
2801 
2802 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2803 		if (IS_ERR(c))
2804 			return PTR_ERR(c);
2805 		args->nfs_server.hostname = c;
2806 
2807 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2808 		if (IS_ERR(c))
2809 			return PTR_ERR(c);
2810 		args->nfs_server.export_path = c;
2811 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2812 
2813 		c = strndup_user(data->client_addr.data, 16);
2814 		if (IS_ERR(c))
2815 			return PTR_ERR(c);
2816 		args->client_address = c;
2817 
2818 		/*
2819 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2820 		 * can deal with.
2821 		 */
2822 
2823 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2824 		args->rsize	= data->rsize;
2825 		args->wsize	= data->wsize;
2826 		args->timeo	= data->timeo;
2827 		args->retrans	= data->retrans;
2828 		args->acregmin	= data->acregmin;
2829 		args->acregmax	= data->acregmax;
2830 		args->acdirmin	= data->acdirmin;
2831 		args->acdirmax	= data->acdirmax;
2832 		args->nfs_server.protocol = data->proto;
2833 		nfs_validate_transport_protocol(args);
2834 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2835 			goto out_invalid_transport_udp;
2836 
2837 		break;
2838 	default:
2839 		return NFS_TEXT_DATA;
2840 	}
2841 
2842 	return 0;
2843 
2844 out_no_data:
2845 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2846 	return -EINVAL;
2847 
2848 out_inval_auth:
2849 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2850 		 data->auth_flavourlen);
2851 	return -EINVAL;
2852 
2853 out_no_address:
2854 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2855 	return -EINVAL;
2856 
2857 out_invalid_transport_udp:
2858 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2859 	return -EINVAL;
2860 }
2861 
2862 /*
2863  * NFS v4 module parameters need to stay in the
2864  * NFS client for backwards compatibility
2865  */
2866 unsigned int nfs_callback_set_tcpport;
2867 unsigned short nfs_callback_nr_threads;
2868 /* Default cache timeout is 10 minutes */
2869 unsigned int nfs_idmap_cache_timeout = 600;
2870 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2871 bool nfs4_disable_idmapping = true;
2872 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2873 unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
2874 unsigned short send_implementation_id = 1;
2875 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2876 bool recover_lost_locks = false;
2877 
2878 EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
2879 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2880 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2881 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2882 EXPORT_SYMBOL_GPL(max_session_slots);
2883 EXPORT_SYMBOL_GPL(max_session_cb_slots);
2884 EXPORT_SYMBOL_GPL(send_implementation_id);
2885 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2886 EXPORT_SYMBOL_GPL(recover_lost_locks);
2887 
2888 #define NFS_CALLBACK_MAXPORTNR (65535U)
2889 
2890 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2891 {
2892 	unsigned long num;
2893 	int ret;
2894 
2895 	if (!val)
2896 		return -EINVAL;
2897 	ret = kstrtoul(val, 0, &num);
2898 	if (ret || num > NFS_CALLBACK_MAXPORTNR)
2899 		return -EINVAL;
2900 	*((unsigned int *)kp->arg) = num;
2901 	return 0;
2902 }
2903 static const struct kernel_param_ops param_ops_portnr = {
2904 	.set = param_set_portnr,
2905 	.get = param_get_uint,
2906 };
2907 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2908 
2909 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2910 module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
2911 MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
2912 		"assigned to the NFSv4 callback channels.");
2913 module_param(nfs_idmap_cache_timeout, int, 0644);
2914 module_param(nfs4_disable_idmapping, bool, 0644);
2915 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2916 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2917 MODULE_PARM_DESC(nfs4_disable_idmapping,
2918 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2919 module_param(max_session_slots, ushort, 0644);
2920 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2921 		"requests the client will negotiate");
2922 module_param(max_session_cb_slots, ushort, 0644);
2923 MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
2924 		"callbacks the client will process for a given server");
2925 module_param(send_implementation_id, ushort, 0644);
2926 MODULE_PARM_DESC(send_implementation_id,
2927 		"Send implementation ID with NFSv4.1 exchange_id");
2928 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2929 
2930 module_param(recover_lost_locks, bool, 0644);
2931 MODULE_PARM_DESC(recover_lost_locks,
2932 		 "If the server reports that a lock might be lost, "
2933 		 "try to recover it risking data corruption.");
2934 
2935 
2936 #endif /* CONFIG_NFS_V4 */
2937