xref: /openbmc/linux/fs/nfs/super.c (revision eb3fcf00)
1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/addr.h>
35 #include <linux/sunrpc/stats.h>
36 #include <linux/sunrpc/metrics.h>
37 #include <linux/sunrpc/xprtsock.h>
38 #include <linux/sunrpc/xprtrdma.h>
39 #include <linux/nfs_fs.h>
40 #include <linux/nfs_mount.h>
41 #include <linux/nfs4_mount.h>
42 #include <linux/lockd/bind.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/namei.h>
46 #include <linux/vfs.h>
47 #include <linux/inet.h>
48 #include <linux/in6.h>
49 #include <linux/slab.h>
50 #include <net/ipv6.h>
51 #include <linux/netdevice.h>
52 #include <linux/nfs_xdr.h>
53 #include <linux/magic.h>
54 #include <linux/parser.h>
55 #include <linux/nsproxy.h>
56 #include <linux/rcupdate.h>
57 
58 #include <asm/uaccess.h>
59 
60 #include "nfs4_fs.h"
61 #include "callback.h"
62 #include "delegation.h"
63 #include "iostat.h"
64 #include "internal.h"
65 #include "fscache.h"
66 #include "nfs4session.h"
67 #include "pnfs.h"
68 #include "nfs.h"
69 
70 #define NFSDBG_FACILITY		NFSDBG_VFS
71 #define NFS_TEXT_DATA		1
72 
73 #if IS_ENABLED(CONFIG_NFS_V3)
74 #define NFS_DEFAULT_VERSION 3
75 #else
76 #define NFS_DEFAULT_VERSION 2
77 #endif
78 
79 enum {
80 	/* Mount options that take no arguments */
81 	Opt_soft, Opt_hard,
82 	Opt_posix, Opt_noposix,
83 	Opt_cto, Opt_nocto,
84 	Opt_ac, Opt_noac,
85 	Opt_lock, Opt_nolock,
86 	Opt_udp, Opt_tcp, Opt_rdma,
87 	Opt_acl, Opt_noacl,
88 	Opt_rdirplus, Opt_nordirplus,
89 	Opt_sharecache, Opt_nosharecache,
90 	Opt_resvport, Opt_noresvport,
91 	Opt_fscache, Opt_nofscache,
92 	Opt_migration, Opt_nomigration,
93 
94 	/* Mount options that take integer arguments */
95 	Opt_port,
96 	Opt_rsize, Opt_wsize, Opt_bsize,
97 	Opt_timeo, Opt_retrans,
98 	Opt_acregmin, Opt_acregmax,
99 	Opt_acdirmin, Opt_acdirmax,
100 	Opt_actimeo,
101 	Opt_namelen,
102 	Opt_mountport,
103 	Opt_mountvers,
104 	Opt_minorversion,
105 
106 	/* Mount options that take string arguments */
107 	Opt_nfsvers,
108 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
109 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
110 	Opt_lookupcache,
111 	Opt_fscache_uniq,
112 	Opt_local_lock,
113 
114 	/* Special mount options */
115 	Opt_userspace, Opt_deprecated, Opt_sloppy,
116 
117 	Opt_err
118 };
119 
120 static const match_table_t nfs_mount_option_tokens = {
121 	{ Opt_userspace, "bg" },
122 	{ Opt_userspace, "fg" },
123 	{ Opt_userspace, "retry=%s" },
124 
125 	{ Opt_sloppy, "sloppy" },
126 
127 	{ Opt_soft, "soft" },
128 	{ Opt_hard, "hard" },
129 	{ Opt_deprecated, "intr" },
130 	{ Opt_deprecated, "nointr" },
131 	{ Opt_posix, "posix" },
132 	{ Opt_noposix, "noposix" },
133 	{ Opt_cto, "cto" },
134 	{ Opt_nocto, "nocto" },
135 	{ Opt_ac, "ac" },
136 	{ Opt_noac, "noac" },
137 	{ Opt_lock, "lock" },
138 	{ Opt_nolock, "nolock" },
139 	{ Opt_udp, "udp" },
140 	{ Opt_tcp, "tcp" },
141 	{ Opt_rdma, "rdma" },
142 	{ Opt_acl, "acl" },
143 	{ Opt_noacl, "noacl" },
144 	{ Opt_rdirplus, "rdirplus" },
145 	{ Opt_nordirplus, "nordirplus" },
146 	{ Opt_sharecache, "sharecache" },
147 	{ Opt_nosharecache, "nosharecache" },
148 	{ Opt_resvport, "resvport" },
149 	{ Opt_noresvport, "noresvport" },
150 	{ Opt_fscache, "fsc" },
151 	{ Opt_nofscache, "nofsc" },
152 	{ Opt_migration, "migration" },
153 	{ Opt_nomigration, "nomigration" },
154 
155 	{ Opt_port, "port=%s" },
156 	{ Opt_rsize, "rsize=%s" },
157 	{ Opt_wsize, "wsize=%s" },
158 	{ Opt_bsize, "bsize=%s" },
159 	{ Opt_timeo, "timeo=%s" },
160 	{ Opt_retrans, "retrans=%s" },
161 	{ Opt_acregmin, "acregmin=%s" },
162 	{ Opt_acregmax, "acregmax=%s" },
163 	{ Opt_acdirmin, "acdirmin=%s" },
164 	{ Opt_acdirmax, "acdirmax=%s" },
165 	{ Opt_actimeo, "actimeo=%s" },
166 	{ Opt_namelen, "namlen=%s" },
167 	{ Opt_mountport, "mountport=%s" },
168 	{ Opt_mountvers, "mountvers=%s" },
169 	{ Opt_minorversion, "minorversion=%s" },
170 
171 	{ Opt_nfsvers, "nfsvers=%s" },
172 	{ Opt_nfsvers, "vers=%s" },
173 
174 	{ Opt_sec, "sec=%s" },
175 	{ Opt_proto, "proto=%s" },
176 	{ Opt_mountproto, "mountproto=%s" },
177 	{ Opt_addr, "addr=%s" },
178 	{ Opt_clientaddr, "clientaddr=%s" },
179 	{ Opt_mounthost, "mounthost=%s" },
180 	{ Opt_mountaddr, "mountaddr=%s" },
181 
182 	{ Opt_lookupcache, "lookupcache=%s" },
183 	{ Opt_fscache_uniq, "fsc=%s" },
184 	{ Opt_local_lock, "local_lock=%s" },
185 
186 	/* The following needs to be listed after all other options */
187 	{ Opt_nfsvers, "v%s" },
188 
189 	{ Opt_err, NULL }
190 };
191 
192 enum {
193 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
194 
195 	Opt_xprt_err
196 };
197 
198 static const match_table_t nfs_xprt_protocol_tokens = {
199 	{ Opt_xprt_udp, "udp" },
200 	{ Opt_xprt_udp6, "udp6" },
201 	{ Opt_xprt_tcp, "tcp" },
202 	{ Opt_xprt_tcp6, "tcp6" },
203 	{ Opt_xprt_rdma, "rdma" },
204 
205 	{ Opt_xprt_err, NULL }
206 };
207 
208 enum {
209 	Opt_sec_none, Opt_sec_sys,
210 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
211 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
212 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
213 
214 	Opt_sec_err
215 };
216 
217 static const match_table_t nfs_secflavor_tokens = {
218 	{ Opt_sec_none, "none" },
219 	{ Opt_sec_none, "null" },
220 	{ Opt_sec_sys, "sys" },
221 
222 	{ Opt_sec_krb5, "krb5" },
223 	{ Opt_sec_krb5i, "krb5i" },
224 	{ Opt_sec_krb5p, "krb5p" },
225 
226 	{ Opt_sec_lkey, "lkey" },
227 	{ Opt_sec_lkeyi, "lkeyi" },
228 	{ Opt_sec_lkeyp, "lkeyp" },
229 
230 	{ Opt_sec_spkm, "spkm3" },
231 	{ Opt_sec_spkmi, "spkm3i" },
232 	{ Opt_sec_spkmp, "spkm3p" },
233 
234 	{ Opt_sec_err, NULL }
235 };
236 
237 enum {
238 	Opt_lookupcache_all, Opt_lookupcache_positive,
239 	Opt_lookupcache_none,
240 
241 	Opt_lookupcache_err
242 };
243 
244 static match_table_t nfs_lookupcache_tokens = {
245 	{ Opt_lookupcache_all, "all" },
246 	{ Opt_lookupcache_positive, "pos" },
247 	{ Opt_lookupcache_positive, "positive" },
248 	{ Opt_lookupcache_none, "none" },
249 
250 	{ Opt_lookupcache_err, NULL }
251 };
252 
253 enum {
254 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
255 	Opt_local_lock_none,
256 
257 	Opt_local_lock_err
258 };
259 
260 static match_table_t nfs_local_lock_tokens = {
261 	{ Opt_local_lock_all, "all" },
262 	{ Opt_local_lock_flock, "flock" },
263 	{ Opt_local_lock_posix, "posix" },
264 	{ Opt_local_lock_none, "none" },
265 
266 	{ Opt_local_lock_err, NULL }
267 };
268 
269 enum {
270 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
271 	Opt_vers_4_1, Opt_vers_4_2,
272 
273 	Opt_vers_err
274 };
275 
276 static match_table_t nfs_vers_tokens = {
277 	{ Opt_vers_2, "2" },
278 	{ Opt_vers_3, "3" },
279 	{ Opt_vers_4, "4" },
280 	{ Opt_vers_4_0, "4.0" },
281 	{ Opt_vers_4_1, "4.1" },
282 	{ Opt_vers_4_2, "4.2" },
283 
284 	{ Opt_vers_err, NULL }
285 };
286 
287 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
288 		int flags, const char *dev_name, void *raw_data);
289 
290 struct file_system_type nfs_fs_type = {
291 	.owner		= THIS_MODULE,
292 	.name		= "nfs",
293 	.mount		= nfs_fs_mount,
294 	.kill_sb	= nfs_kill_super,
295 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
296 };
297 MODULE_ALIAS_FS("nfs");
298 EXPORT_SYMBOL_GPL(nfs_fs_type);
299 
300 struct file_system_type nfs_xdev_fs_type = {
301 	.owner		= THIS_MODULE,
302 	.name		= "nfs",
303 	.mount		= nfs_xdev_mount,
304 	.kill_sb	= nfs_kill_super,
305 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
306 };
307 
308 const struct super_operations nfs_sops = {
309 	.alloc_inode	= nfs_alloc_inode,
310 	.destroy_inode	= nfs_destroy_inode,
311 	.write_inode	= nfs_write_inode,
312 	.drop_inode	= nfs_drop_inode,
313 	.statfs		= nfs_statfs,
314 	.evict_inode	= nfs_evict_inode,
315 	.umount_begin	= nfs_umount_begin,
316 	.show_options	= nfs_show_options,
317 	.show_devname	= nfs_show_devname,
318 	.show_path	= nfs_show_path,
319 	.show_stats	= nfs_show_stats,
320 	.remount_fs	= nfs_remount,
321 };
322 EXPORT_SYMBOL_GPL(nfs_sops);
323 
324 #if IS_ENABLED(CONFIG_NFS_V4)
325 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
326 static int nfs4_validate_mount_data(void *options,
327 	struct nfs_parsed_mount_data *args, const char *dev_name);
328 
329 struct file_system_type nfs4_fs_type = {
330 	.owner		= THIS_MODULE,
331 	.name		= "nfs4",
332 	.mount		= nfs_fs_mount,
333 	.kill_sb	= nfs_kill_super,
334 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
335 };
336 MODULE_ALIAS_FS("nfs4");
337 MODULE_ALIAS("nfs4");
338 EXPORT_SYMBOL_GPL(nfs4_fs_type);
339 
340 static int __init register_nfs4_fs(void)
341 {
342 	return register_filesystem(&nfs4_fs_type);
343 }
344 
345 static void unregister_nfs4_fs(void)
346 {
347 	unregister_filesystem(&nfs4_fs_type);
348 }
349 #else
350 static int __init register_nfs4_fs(void)
351 {
352 	return 0;
353 }
354 
355 static void unregister_nfs4_fs(void)
356 {
357 }
358 #endif
359 
360 static struct shrinker acl_shrinker = {
361 	.count_objects	= nfs_access_cache_count,
362 	.scan_objects	= nfs_access_cache_scan,
363 	.seeks		= DEFAULT_SEEKS,
364 };
365 
366 /*
367  * Register the NFS filesystems
368  */
369 int __init register_nfs_fs(void)
370 {
371 	int ret;
372 
373         ret = register_filesystem(&nfs_fs_type);
374 	if (ret < 0)
375 		goto error_0;
376 
377 	ret = register_nfs4_fs();
378 	if (ret < 0)
379 		goto error_1;
380 
381 	ret = nfs_register_sysctl();
382 	if (ret < 0)
383 		goto error_2;
384 	ret = register_shrinker(&acl_shrinker);
385 	if (ret < 0)
386 		goto error_3;
387 	return 0;
388 error_3:
389 	nfs_unregister_sysctl();
390 error_2:
391 	unregister_nfs4_fs();
392 error_1:
393 	unregister_filesystem(&nfs_fs_type);
394 error_0:
395 	return ret;
396 }
397 
398 /*
399  * Unregister the NFS filesystems
400  */
401 void __exit unregister_nfs_fs(void)
402 {
403 	unregister_shrinker(&acl_shrinker);
404 	nfs_unregister_sysctl();
405 	unregister_nfs4_fs();
406 	unregister_filesystem(&nfs_fs_type);
407 }
408 
409 bool nfs_sb_active(struct super_block *sb)
410 {
411 	struct nfs_server *server = NFS_SB(sb);
412 
413 	if (!atomic_inc_not_zero(&sb->s_active))
414 		return false;
415 	if (atomic_inc_return(&server->active) != 1)
416 		atomic_dec(&sb->s_active);
417 	return true;
418 }
419 EXPORT_SYMBOL_GPL(nfs_sb_active);
420 
421 void nfs_sb_deactive(struct super_block *sb)
422 {
423 	struct nfs_server *server = NFS_SB(sb);
424 
425 	if (atomic_dec_and_test(&server->active))
426 		deactivate_super(sb);
427 }
428 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
429 
430 /*
431  * Deliver file system statistics to userspace
432  */
433 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
434 {
435 	struct nfs_server *server = NFS_SB(dentry->d_sb);
436 	unsigned char blockbits;
437 	unsigned long blockres;
438 	struct nfs_fh *fh = NFS_FH(d_inode(dentry));
439 	struct nfs_fsstat res;
440 	int error = -ENOMEM;
441 
442 	res.fattr = nfs_alloc_fattr();
443 	if (res.fattr == NULL)
444 		goto out_err;
445 
446 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
447 	if (unlikely(error == -ESTALE)) {
448 		struct dentry *pd_dentry;
449 
450 		pd_dentry = dget_parent(dentry);
451 		if (pd_dentry != NULL) {
452 			nfs_zap_caches(d_inode(pd_dentry));
453 			dput(pd_dentry);
454 		}
455 	}
456 	nfs_free_fattr(res.fattr);
457 	if (error < 0)
458 		goto out_err;
459 
460 	buf->f_type = NFS_SUPER_MAGIC;
461 
462 	/*
463 	 * Current versions of glibc do not correctly handle the
464 	 * case where f_frsize != f_bsize.  Eventually we want to
465 	 * report the value of wtmult in this field.
466 	 */
467 	buf->f_frsize = dentry->d_sb->s_blocksize;
468 
469 	/*
470 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
471 	 * are reported in units of f_frsize.  Linux hasn't had
472 	 * an f_frsize field in its statfs struct until recently,
473 	 * thus historically Linux's sys_statfs reports these
474 	 * fields in units of f_bsize.
475 	 */
476 	buf->f_bsize = dentry->d_sb->s_blocksize;
477 	blockbits = dentry->d_sb->s_blocksize_bits;
478 	blockres = (1 << blockbits) - 1;
479 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
480 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
481 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
482 
483 	buf->f_files = res.tfiles;
484 	buf->f_ffree = res.afiles;
485 
486 	buf->f_namelen = server->namelen;
487 
488 	return 0;
489 
490  out_err:
491 	dprintk("%s: statfs error = %d\n", __func__, -error);
492 	return error;
493 }
494 EXPORT_SYMBOL_GPL(nfs_statfs);
495 
496 /*
497  * Map the security flavour number to a name
498  */
499 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
500 {
501 	static const struct {
502 		rpc_authflavor_t flavour;
503 		const char *str;
504 	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
505 		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
506 		{ RPC_AUTH_NULL, "null" },
507 		{ RPC_AUTH_UNIX, "sys" },
508 		{ RPC_AUTH_GSS_KRB5, "krb5" },
509 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
510 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
511 		{ RPC_AUTH_GSS_LKEY, "lkey" },
512 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
513 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
514 		{ RPC_AUTH_GSS_SPKM, "spkm" },
515 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
516 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
517 		{ UINT_MAX, "unknown" }
518 	};
519 	int i;
520 
521 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
522 		if (sec_flavours[i].flavour == flavour)
523 			break;
524 	}
525 	return sec_flavours[i].str;
526 }
527 
528 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
529 				  int showdefaults)
530 {
531 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
532 
533 	seq_printf(m, ",mountproto=");
534 	switch (sap->sa_family) {
535 	case AF_INET:
536 		switch (nfss->mountd_protocol) {
537 		case IPPROTO_UDP:
538 			seq_printf(m, RPCBIND_NETID_UDP);
539 			break;
540 		case IPPROTO_TCP:
541 			seq_printf(m, RPCBIND_NETID_TCP);
542 			break;
543 		default:
544 			if (showdefaults)
545 				seq_printf(m, "auto");
546 		}
547 		break;
548 	case AF_INET6:
549 		switch (nfss->mountd_protocol) {
550 		case IPPROTO_UDP:
551 			seq_printf(m, RPCBIND_NETID_UDP6);
552 			break;
553 		case IPPROTO_TCP:
554 			seq_printf(m, RPCBIND_NETID_TCP6);
555 			break;
556 		default:
557 			if (showdefaults)
558 				seq_printf(m, "auto");
559 		}
560 		break;
561 	default:
562 		if (showdefaults)
563 			seq_printf(m, "auto");
564 	}
565 }
566 
567 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
568 				    int showdefaults)
569 {
570 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
571 
572 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
573 		return;
574 
575 	switch (sap->sa_family) {
576 	case AF_INET: {
577 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
578 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
579 		break;
580 	}
581 	case AF_INET6: {
582 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
583 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
584 		break;
585 	}
586 	default:
587 		if (showdefaults)
588 			seq_printf(m, ",mountaddr=unspecified");
589 	}
590 
591 	if (nfss->mountd_version || showdefaults)
592 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
593 	if ((nfss->mountd_port &&
594 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
595 		showdefaults)
596 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
597 
598 	nfs_show_mountd_netid(m, nfss, showdefaults);
599 }
600 
601 #if IS_ENABLED(CONFIG_NFS_V4)
602 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
603 				    int showdefaults)
604 {
605 	struct nfs_client *clp = nfss->nfs_client;
606 
607 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
608 }
609 #else
610 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
611 				    int showdefaults)
612 {
613 }
614 #endif
615 
616 static void nfs_show_nfs_version(struct seq_file *m,
617 		unsigned int version,
618 		unsigned int minorversion)
619 {
620 	seq_printf(m, ",vers=%u", version);
621 	if (version == 4)
622 		seq_printf(m, ".%u", minorversion);
623 }
624 
625 /*
626  * Describe the mount options in force on this server representation
627  */
628 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
629 				   int showdefaults)
630 {
631 	static const struct proc_nfs_info {
632 		int flag;
633 		const char *str;
634 		const char *nostr;
635 	} nfs_info[] = {
636 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
637 		{ NFS_MOUNT_POSIX, ",posix", "" },
638 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
639 		{ NFS_MOUNT_NOAC, ",noac", "" },
640 		{ NFS_MOUNT_NONLM, ",nolock", "" },
641 		{ NFS_MOUNT_NOACL, ",noacl", "" },
642 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
643 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
644 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
645 		{ 0, NULL, NULL }
646 	};
647 	const struct proc_nfs_info *nfs_infop;
648 	struct nfs_client *clp = nfss->nfs_client;
649 	u32 version = clp->rpc_ops->version;
650 	int local_flock, local_fcntl;
651 
652 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
653 	seq_printf(m, ",rsize=%u", nfss->rsize);
654 	seq_printf(m, ",wsize=%u", nfss->wsize);
655 	if (nfss->bsize != 0)
656 		seq_printf(m, ",bsize=%u", nfss->bsize);
657 	seq_printf(m, ",namlen=%u", nfss->namelen);
658 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
659 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
660 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
661 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
662 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
663 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
664 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
665 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
666 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
667 		if (nfss->flags & nfs_infop->flag)
668 			seq_puts(m, nfs_infop->str);
669 		else
670 			seq_puts(m, nfs_infop->nostr);
671 	}
672 	rcu_read_lock();
673 	seq_printf(m, ",proto=%s",
674 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
675 	rcu_read_unlock();
676 	if (version == 4) {
677 		if (nfss->port != NFS_PORT)
678 			seq_printf(m, ",port=%u", nfss->port);
679 	} else
680 		if (nfss->port)
681 			seq_printf(m, ",port=%u", nfss->port);
682 
683 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
684 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
685 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
686 
687 	if (version != 4)
688 		nfs_show_mountd_options(m, nfss, showdefaults);
689 	else
690 		nfs_show_nfsv4_options(m, nfss, showdefaults);
691 
692 	if (nfss->options & NFS_OPTION_FSCACHE)
693 		seq_printf(m, ",fsc");
694 
695 	if (nfss->options & NFS_OPTION_MIGRATION)
696 		seq_printf(m, ",migration");
697 
698 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
699 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
700 			seq_printf(m, ",lookupcache=none");
701 		else
702 			seq_printf(m, ",lookupcache=pos");
703 	}
704 
705 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
706 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
707 
708 	if (!local_flock && !local_fcntl)
709 		seq_printf(m, ",local_lock=none");
710 	else if (local_flock && local_fcntl)
711 		seq_printf(m, ",local_lock=all");
712 	else if (local_flock)
713 		seq_printf(m, ",local_lock=flock");
714 	else
715 		seq_printf(m, ",local_lock=posix");
716 }
717 
718 /*
719  * Describe the mount options on this VFS mountpoint
720  */
721 int nfs_show_options(struct seq_file *m, struct dentry *root)
722 {
723 	struct nfs_server *nfss = NFS_SB(root->d_sb);
724 
725 	nfs_show_mount_options(m, nfss, 0);
726 
727 	rcu_read_lock();
728 	seq_printf(m, ",addr=%s",
729 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
730 							RPC_DISPLAY_ADDR));
731 	rcu_read_unlock();
732 
733 	return 0;
734 }
735 EXPORT_SYMBOL_GPL(nfs_show_options);
736 
737 #if IS_ENABLED(CONFIG_NFS_V4)
738 #ifdef CONFIG_NFS_V4_1
739 static void show_sessions(struct seq_file *m, struct nfs_server *server)
740 {
741 	if (nfs4_has_session(server->nfs_client))
742 		seq_printf(m, ",sessions");
743 }
744 #else
745 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
746 #endif
747 #endif
748 
749 #ifdef CONFIG_NFS_V4_1
750 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
751 {
752 	seq_printf(m, ",pnfs=");
753 	if (server->pnfs_curr_ld)
754 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
755 	else
756 		seq_printf(m, "not configured");
757 }
758 
759 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
760 {
761 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
762 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
763 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
764 			   "date='%llu,%u'",
765 			   impl_id->name, impl_id->domain,
766 			   impl_id->date.seconds, impl_id->date.nseconds);
767 	}
768 }
769 #else
770 #if IS_ENABLED(CONFIG_NFS_V4)
771 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
772 {
773 }
774 #endif
775 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
776 {
777 }
778 #endif
779 
780 int nfs_show_devname(struct seq_file *m, struct dentry *root)
781 {
782 	char *page = (char *) __get_free_page(GFP_KERNEL);
783 	char *devname, *dummy;
784 	int err = 0;
785 	if (!page)
786 		return -ENOMEM;
787 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
788 	if (IS_ERR(devname))
789 		err = PTR_ERR(devname);
790 	else
791 		seq_escape(m, devname, " \t\n\\");
792 	free_page((unsigned long)page);
793 	return err;
794 }
795 EXPORT_SYMBOL_GPL(nfs_show_devname);
796 
797 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
798 {
799 	seq_puts(m, "/");
800 	return 0;
801 }
802 EXPORT_SYMBOL_GPL(nfs_show_path);
803 
804 /*
805  * Present statistical information for this VFS mountpoint
806  */
807 int nfs_show_stats(struct seq_file *m, struct dentry *root)
808 {
809 	int i, cpu;
810 	struct nfs_server *nfss = NFS_SB(root->d_sb);
811 	struct rpc_auth *auth = nfss->client->cl_auth;
812 	struct nfs_iostats totals = { };
813 
814 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
815 
816 	/*
817 	 * Display all mount option settings
818 	 */
819 	seq_printf(m, "\n\topts:\t");
820 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
821 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
822 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
823 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
824 	nfs_show_mount_options(m, nfss, 1);
825 
826 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
827 
828 	show_implementation_id(m, nfss);
829 
830 	seq_printf(m, "\n\tcaps:\t");
831 	seq_printf(m, "caps=0x%x", nfss->caps);
832 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
833 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
834 	seq_printf(m, ",bsize=%u", nfss->bsize);
835 	seq_printf(m, ",namlen=%u", nfss->namelen);
836 
837 #if IS_ENABLED(CONFIG_NFS_V4)
838 	if (nfss->nfs_client->rpc_ops->version == 4) {
839 		seq_printf(m, "\n\tnfsv4:\t");
840 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
841 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
842 		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
843 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
844 		show_sessions(m, nfss);
845 		show_pnfs(m, nfss);
846 	}
847 #endif
848 
849 	/*
850 	 * Display security flavor in effect for this mount
851 	 */
852 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
853 	if (auth->au_flavor)
854 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
855 
856 	/*
857 	 * Display superblock I/O counters
858 	 */
859 	for_each_possible_cpu(cpu) {
860 		struct nfs_iostats *stats;
861 
862 		preempt_disable();
863 		stats = per_cpu_ptr(nfss->io_stats, cpu);
864 
865 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
866 			totals.events[i] += stats->events[i];
867 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
868 			totals.bytes[i] += stats->bytes[i];
869 #ifdef CONFIG_NFS_FSCACHE
870 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
871 			totals.fscache[i] += stats->fscache[i];
872 #endif
873 
874 		preempt_enable();
875 	}
876 
877 	seq_printf(m, "\n\tevents:\t");
878 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
879 		seq_printf(m, "%lu ", totals.events[i]);
880 	seq_printf(m, "\n\tbytes:\t");
881 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
882 		seq_printf(m, "%Lu ", totals.bytes[i]);
883 #ifdef CONFIG_NFS_FSCACHE
884 	if (nfss->options & NFS_OPTION_FSCACHE) {
885 		seq_printf(m, "\n\tfsc:\t");
886 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
887 			seq_printf(m, "%Lu ", totals.bytes[i]);
888 	}
889 #endif
890 	seq_printf(m, "\n");
891 
892 	rpc_print_iostats(m, nfss->client);
893 
894 	return 0;
895 }
896 EXPORT_SYMBOL_GPL(nfs_show_stats);
897 
898 /*
899  * Begin unmount by attempting to remove all automounted mountpoints we added
900  * in response to xdev traversals and referrals
901  */
902 void nfs_umount_begin(struct super_block *sb)
903 {
904 	struct nfs_server *server;
905 	struct rpc_clnt *rpc;
906 
907 	server = NFS_SB(sb);
908 	/* -EIO all pending I/O */
909 	rpc = server->client_acl;
910 	if (!IS_ERR(rpc))
911 		rpc_killall_tasks(rpc);
912 	rpc = server->client;
913 	if (!IS_ERR(rpc))
914 		rpc_killall_tasks(rpc);
915 }
916 EXPORT_SYMBOL_GPL(nfs_umount_begin);
917 
918 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
919 {
920 	struct nfs_parsed_mount_data *data;
921 
922 	data = kzalloc(sizeof(*data), GFP_KERNEL);
923 	if (data) {
924 		data->acregmin		= NFS_DEF_ACREGMIN;
925 		data->acregmax		= NFS_DEF_ACREGMAX;
926 		data->acdirmin		= NFS_DEF_ACDIRMIN;
927 		data->acdirmax		= NFS_DEF_ACDIRMAX;
928 		data->mount_server.port	= NFS_UNSPEC_PORT;
929 		data->nfs_server.port	= NFS_UNSPEC_PORT;
930 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
931 		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
932 		data->minorversion	= 0;
933 		data->need_mount	= true;
934 		data->net		= current->nsproxy->net_ns;
935 		security_init_mnt_opts(&data->lsm_opts);
936 	}
937 	return data;
938 }
939 
940 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
941 {
942 	if (data) {
943 		kfree(data->client_address);
944 		kfree(data->mount_server.hostname);
945 		kfree(data->nfs_server.export_path);
946 		kfree(data->nfs_server.hostname);
947 		kfree(data->fscache_uniq);
948 		security_free_mnt_opts(&data->lsm_opts);
949 		kfree(data);
950 	}
951 }
952 
953 /*
954  * Sanity-check a server address provided by the mount command.
955  *
956  * Address family must be initialized, and address must not be
957  * the ANY address for that family.
958  */
959 static int nfs_verify_server_address(struct sockaddr *addr)
960 {
961 	switch (addr->sa_family) {
962 	case AF_INET: {
963 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
964 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
965 	}
966 	case AF_INET6: {
967 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
968 		return !ipv6_addr_any(sa);
969 	}
970 	}
971 
972 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
973 	return 0;
974 }
975 
976 /*
977  * Select between a default port value and a user-specified port value.
978  * If a zero value is set, then autobind will be used.
979  */
980 static void nfs_set_port(struct sockaddr *sap, int *port,
981 				 const unsigned short default_port)
982 {
983 	if (*port == NFS_UNSPEC_PORT)
984 		*port = default_port;
985 
986 	rpc_set_port(sap, *port);
987 }
988 
989 /*
990  * Sanity check the NFS transport protocol.
991  *
992  */
993 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
994 {
995 	switch (mnt->nfs_server.protocol) {
996 	case XPRT_TRANSPORT_UDP:
997 	case XPRT_TRANSPORT_TCP:
998 	case XPRT_TRANSPORT_RDMA:
999 		break;
1000 	default:
1001 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1002 	}
1003 }
1004 
1005 /*
1006  * For text based NFSv2/v3 mounts, the mount protocol transport default
1007  * settings should depend upon the specified NFS transport.
1008  */
1009 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1010 {
1011 	nfs_validate_transport_protocol(mnt);
1012 
1013 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1014 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1015 			return;
1016 	switch (mnt->nfs_server.protocol) {
1017 	case XPRT_TRANSPORT_UDP:
1018 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1019 		break;
1020 	case XPRT_TRANSPORT_TCP:
1021 	case XPRT_TRANSPORT_RDMA:
1022 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1023 	}
1024 }
1025 
1026 /*
1027  * Add 'flavor' to 'auth_info' if not already present.
1028  * Returns true if 'flavor' ends up in the list, false otherwise
1029  */
1030 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1031 			      rpc_authflavor_t flavor)
1032 {
1033 	unsigned int i;
1034 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1035 
1036 	/* make sure this flavor isn't already in the list */
1037 	for (i = 0; i < auth_info->flavor_len; i++) {
1038 		if (flavor == auth_info->flavors[i])
1039 			return true;
1040 	}
1041 
1042 	if (auth_info->flavor_len + 1 >= max_flavor_len) {
1043 		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1044 		return false;
1045 	}
1046 
1047 	auth_info->flavors[auth_info->flavor_len++] = flavor;
1048 	return true;
1049 }
1050 
1051 /*
1052  * Return true if 'match' is in auth_info or auth_info is empty.
1053  * Return false otherwise.
1054  */
1055 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1056 			 rpc_authflavor_t match)
1057 {
1058 	int i;
1059 
1060 	if (!auth_info->flavor_len)
1061 		return true;
1062 
1063 	for (i = 0; i < auth_info->flavor_len; i++) {
1064 		if (auth_info->flavors[i] == match)
1065 			return true;
1066 	}
1067 	return false;
1068 }
1069 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1070 
1071 /*
1072  * Parse the value of the 'sec=' option.
1073  */
1074 static int nfs_parse_security_flavors(char *value,
1075 				      struct nfs_parsed_mount_data *mnt)
1076 {
1077 	substring_t args[MAX_OPT_ARGS];
1078 	rpc_authflavor_t pseudoflavor;
1079 	char *p;
1080 
1081 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1082 
1083 	while ((p = strsep(&value, ":")) != NULL) {
1084 		switch (match_token(p, nfs_secflavor_tokens, args)) {
1085 		case Opt_sec_none:
1086 			pseudoflavor = RPC_AUTH_NULL;
1087 			break;
1088 		case Opt_sec_sys:
1089 			pseudoflavor = RPC_AUTH_UNIX;
1090 			break;
1091 		case Opt_sec_krb5:
1092 			pseudoflavor = RPC_AUTH_GSS_KRB5;
1093 			break;
1094 		case Opt_sec_krb5i:
1095 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
1096 			break;
1097 		case Opt_sec_krb5p:
1098 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
1099 			break;
1100 		case Opt_sec_lkey:
1101 			pseudoflavor = RPC_AUTH_GSS_LKEY;
1102 			break;
1103 		case Opt_sec_lkeyi:
1104 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
1105 			break;
1106 		case Opt_sec_lkeyp:
1107 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
1108 			break;
1109 		case Opt_sec_spkm:
1110 			pseudoflavor = RPC_AUTH_GSS_SPKM;
1111 			break;
1112 		case Opt_sec_spkmi:
1113 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
1114 			break;
1115 		case Opt_sec_spkmp:
1116 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
1117 			break;
1118 		default:
1119 			dfprintk(MOUNT,
1120 				 "NFS: sec= option '%s' not recognized\n", p);
1121 			return 0;
1122 		}
1123 
1124 		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1125 			return 0;
1126 	}
1127 
1128 	return 1;
1129 }
1130 
1131 static int nfs_parse_version_string(char *string,
1132 		struct nfs_parsed_mount_data *mnt,
1133 		substring_t *args)
1134 {
1135 	mnt->flags &= ~NFS_MOUNT_VER3;
1136 	switch (match_token(string, nfs_vers_tokens, args)) {
1137 	case Opt_vers_2:
1138 		mnt->version = 2;
1139 		break;
1140 	case Opt_vers_3:
1141 		mnt->flags |= NFS_MOUNT_VER3;
1142 		mnt->version = 3;
1143 		break;
1144 	case Opt_vers_4:
1145 		/* Backward compatibility option. In future,
1146 		 * the mount program should always supply
1147 		 * a NFSv4 minor version number.
1148 		 */
1149 		mnt->version = 4;
1150 		break;
1151 	case Opt_vers_4_0:
1152 		mnt->version = 4;
1153 		mnt->minorversion = 0;
1154 		break;
1155 	case Opt_vers_4_1:
1156 		mnt->version = 4;
1157 		mnt->minorversion = 1;
1158 		break;
1159 	case Opt_vers_4_2:
1160 		mnt->version = 4;
1161 		mnt->minorversion = 2;
1162 		break;
1163 	default:
1164 		return 0;
1165 	}
1166 	return 1;
1167 }
1168 
1169 static int nfs_get_option_str(substring_t args[], char **option)
1170 {
1171 	kfree(*option);
1172 	*option = match_strdup(args);
1173 	return !*option;
1174 }
1175 
1176 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1177 {
1178 	int rc;
1179 	char *string;
1180 
1181 	string = match_strdup(args);
1182 	if (string == NULL)
1183 		return -ENOMEM;
1184 	rc = kstrtoul(string, 10, option);
1185 	kfree(string);
1186 
1187 	return rc;
1188 }
1189 
1190 /*
1191  * Error-check and convert a string of mount options from user space into
1192  * a data structure.  The whole mount string is processed; bad options are
1193  * skipped as they are encountered.  If there were no errors, return 1;
1194  * otherwise return 0 (zero).
1195  */
1196 static int nfs_parse_mount_options(char *raw,
1197 				   struct nfs_parsed_mount_data *mnt)
1198 {
1199 	char *p, *string, *secdata;
1200 	int rc, sloppy = 0, invalid_option = 0;
1201 	unsigned short protofamily = AF_UNSPEC;
1202 	unsigned short mountfamily = AF_UNSPEC;
1203 
1204 	if (!raw) {
1205 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1206 		return 1;
1207 	}
1208 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1209 
1210 	secdata = alloc_secdata();
1211 	if (!secdata)
1212 		goto out_nomem;
1213 
1214 	rc = security_sb_copy_data(raw, secdata);
1215 	if (rc)
1216 		goto out_security_failure;
1217 
1218 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1219 	if (rc)
1220 		goto out_security_failure;
1221 
1222 	free_secdata(secdata);
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(args, &option) || option == 0)
1354 				goto out_invalid_value;
1355 			mnt->timeo = option;
1356 			break;
1357 		case Opt_retrans:
1358 			if (nfs_get_option_ul(args, &option) || option == 0)
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 			case Opt_xprt_udp:
1450 				mnt->flags &= ~NFS_MOUNT_TCP;
1451 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1452 				break;
1453 			case Opt_xprt_tcp6:
1454 				protofamily = AF_INET6;
1455 			case Opt_xprt_tcp:
1456 				mnt->flags |= NFS_MOUNT_TCP;
1457 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1458 				break;
1459 			case Opt_xprt_rdma:
1460 				/* vector side protocols to TCP */
1461 				mnt->flags |= NFS_MOUNT_TCP;
1462 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1463 				xprt_load_transport(string);
1464 				break;
1465 			default:
1466 				dfprintk(MOUNT, "NFS:   unrecognized "
1467 						"transport protocol\n");
1468 				kfree(string);
1469 				return 0;
1470 			}
1471 			kfree(string);
1472 			break;
1473 		case Opt_mountproto:
1474 			string = match_strdup(args);
1475 			if (string == NULL)
1476 				goto out_nomem;
1477 			token = match_token(string,
1478 					    nfs_xprt_protocol_tokens, args);
1479 			kfree(string);
1480 
1481 			mountfamily = AF_INET;
1482 			switch (token) {
1483 			case Opt_xprt_udp6:
1484 				mountfamily = AF_INET6;
1485 			case Opt_xprt_udp:
1486 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1487 				break;
1488 			case Opt_xprt_tcp6:
1489 				mountfamily = AF_INET6;
1490 			case Opt_xprt_tcp:
1491 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1492 				break;
1493 			case Opt_xprt_rdma: /* not used for side protocols */
1494 			default:
1495 				dfprintk(MOUNT, "NFS:   unrecognized "
1496 						"transport protocol\n");
1497 				return 0;
1498 			}
1499 			break;
1500 		case Opt_addr:
1501 			string = match_strdup(args);
1502 			if (string == NULL)
1503 				goto out_nomem;
1504 			mnt->nfs_server.addrlen =
1505 				rpc_pton(mnt->net, string, strlen(string),
1506 					(struct sockaddr *)
1507 					&mnt->nfs_server.address,
1508 					sizeof(mnt->nfs_server.address));
1509 			kfree(string);
1510 			if (mnt->nfs_server.addrlen == 0)
1511 				goto out_invalid_address;
1512 			break;
1513 		case Opt_clientaddr:
1514 			if (nfs_get_option_str(args, &mnt->client_address))
1515 				goto out_nomem;
1516 			break;
1517 		case Opt_mounthost:
1518 			if (nfs_get_option_str(args,
1519 					       &mnt->mount_server.hostname))
1520 				goto out_nomem;
1521 			break;
1522 		case Opt_mountaddr:
1523 			string = match_strdup(args);
1524 			if (string == NULL)
1525 				goto out_nomem;
1526 			mnt->mount_server.addrlen =
1527 				rpc_pton(mnt->net, string, strlen(string),
1528 					(struct sockaddr *)
1529 					&mnt->mount_server.address,
1530 					sizeof(mnt->mount_server.address));
1531 			kfree(string);
1532 			if (mnt->mount_server.addrlen == 0)
1533 				goto out_invalid_address;
1534 			break;
1535 		case Opt_lookupcache:
1536 			string = match_strdup(args);
1537 			if (string == NULL)
1538 				goto out_nomem;
1539 			token = match_token(string,
1540 					nfs_lookupcache_tokens, args);
1541 			kfree(string);
1542 			switch (token) {
1543 				case Opt_lookupcache_all:
1544 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1545 					break;
1546 				case Opt_lookupcache_positive:
1547 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1548 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1549 					break;
1550 				case Opt_lookupcache_none:
1551 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1552 					break;
1553 				default:
1554 					dfprintk(MOUNT, "NFS:   invalid "
1555 							"lookupcache argument\n");
1556 					return 0;
1557 			};
1558 			break;
1559 		case Opt_fscache_uniq:
1560 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1561 				goto out_nomem;
1562 			mnt->options |= NFS_OPTION_FSCACHE;
1563 			break;
1564 		case Opt_local_lock:
1565 			string = match_strdup(args);
1566 			if (string == NULL)
1567 				goto out_nomem;
1568 			token = match_token(string, nfs_local_lock_tokens,
1569 					args);
1570 			kfree(string);
1571 			switch (token) {
1572 			case Opt_local_lock_all:
1573 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1574 					       NFS_MOUNT_LOCAL_FCNTL);
1575 				break;
1576 			case Opt_local_lock_flock:
1577 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1578 				break;
1579 			case Opt_local_lock_posix:
1580 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1581 				break;
1582 			case Opt_local_lock_none:
1583 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1584 						NFS_MOUNT_LOCAL_FCNTL);
1585 				break;
1586 			default:
1587 				dfprintk(MOUNT, "NFS:	invalid	"
1588 						"local_lock argument\n");
1589 				return 0;
1590 			};
1591 			break;
1592 
1593 		/*
1594 		 * Special options
1595 		 */
1596 		case Opt_sloppy:
1597 			sloppy = 1;
1598 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1599 			break;
1600 		case Opt_userspace:
1601 		case Opt_deprecated:
1602 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1603 					"'%s'\n", p);
1604 			break;
1605 
1606 		default:
1607 			invalid_option = 1;
1608 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1609 					"'%s'\n", p);
1610 		}
1611 	}
1612 
1613 	if (!sloppy && invalid_option)
1614 		return 0;
1615 
1616 	if (mnt->minorversion && mnt->version != 4)
1617 		goto out_minorversion_mismatch;
1618 
1619 	if (mnt->options & NFS_OPTION_MIGRATION &&
1620 	    (mnt->version != 4 || mnt->minorversion != 0))
1621 		goto out_migration_misuse;
1622 
1623 	/*
1624 	 * verify that any proto=/mountproto= options match the address
1625 	 * families in the addr=/mountaddr= options.
1626 	 */
1627 	if (protofamily != AF_UNSPEC &&
1628 	    protofamily != mnt->nfs_server.address.ss_family)
1629 		goto out_proto_mismatch;
1630 
1631 	if (mountfamily != AF_UNSPEC) {
1632 		if (mnt->mount_server.addrlen) {
1633 			if (mountfamily != mnt->mount_server.address.ss_family)
1634 				goto out_mountproto_mismatch;
1635 		} else {
1636 			if (mountfamily != mnt->nfs_server.address.ss_family)
1637 				goto out_mountproto_mismatch;
1638 		}
1639 	}
1640 
1641 	return 1;
1642 
1643 out_mountproto_mismatch:
1644 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1645 			 "option\n");
1646 	return 0;
1647 out_proto_mismatch:
1648 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1649 	return 0;
1650 out_invalid_address:
1651 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1652 	return 0;
1653 out_invalid_value:
1654 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1655 	return 0;
1656 out_minorversion_mismatch:
1657 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1658 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1659 	return 0;
1660 out_migration_misuse:
1661 	printk(KERN_INFO
1662 		"NFS: 'migration' not supported for this NFS version\n");
1663 	return 0;
1664 out_nomem:
1665 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1666 	return 0;
1667 out_security_failure:
1668 	free_secdata(secdata);
1669 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1670 	return 0;
1671 }
1672 
1673 /*
1674  * Ensure that a specified authtype in args->auth_info is supported by
1675  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1676  * -EACCES if not.
1677  */
1678 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1679 			rpc_authflavor_t *server_authlist, unsigned int count)
1680 {
1681 	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1682 	unsigned int i;
1683 
1684 	/*
1685 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1686 	 * must be in the list returned by the server.
1687 	 *
1688 	 * AUTH_NULL has a special meaning when it's in the server list - it
1689 	 * means that the server will ignore the rpc creds, so any flavor
1690 	 * can be used.
1691 	 */
1692 	for (i = 0; i < count; i++) {
1693 		flavor = server_authlist[i];
1694 
1695 		if (nfs_auth_info_match(&args->auth_info, flavor) ||
1696 		    flavor == RPC_AUTH_NULL)
1697 			goto out;
1698 	}
1699 
1700 	dfprintk(MOUNT,
1701 		 "NFS: specified auth flavors not supported by server\n");
1702 	return -EACCES;
1703 
1704 out:
1705 	args->selected_flavor = flavor;
1706 	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1707 	return 0;
1708 }
1709 
1710 /*
1711  * Use the remote server's MOUNT service to request the NFS file handle
1712  * corresponding to the provided path.
1713  */
1714 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1715 			     struct nfs_fh *root_fh,
1716 			     rpc_authflavor_t *server_authlist,
1717 			     unsigned int *server_authlist_len)
1718 {
1719 	struct nfs_mount_request request = {
1720 		.sap		= (struct sockaddr *)
1721 						&args->mount_server.address,
1722 		.dirpath	= args->nfs_server.export_path,
1723 		.protocol	= args->mount_server.protocol,
1724 		.fh		= root_fh,
1725 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1726 		.auth_flav_len	= server_authlist_len,
1727 		.auth_flavs	= server_authlist,
1728 		.net		= args->net,
1729 	};
1730 	int status;
1731 
1732 	if (args->mount_server.version == 0) {
1733 		switch (args->version) {
1734 			default:
1735 				args->mount_server.version = NFS_MNT3_VERSION;
1736 				break;
1737 			case 2:
1738 				args->mount_server.version = NFS_MNT_VERSION;
1739 		}
1740 	}
1741 	request.version = args->mount_server.version;
1742 
1743 	if (args->mount_server.hostname)
1744 		request.hostname = args->mount_server.hostname;
1745 	else
1746 		request.hostname = args->nfs_server.hostname;
1747 
1748 	/*
1749 	 * Construct the mount server's address.
1750 	 */
1751 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1752 		memcpy(request.sap, &args->nfs_server.address,
1753 		       args->nfs_server.addrlen);
1754 		args->mount_server.addrlen = args->nfs_server.addrlen;
1755 	}
1756 	request.salen = args->mount_server.addrlen;
1757 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1758 
1759 	/*
1760 	 * Now ask the mount server to map our export path
1761 	 * to a file handle.
1762 	 */
1763 	status = nfs_mount(&request);
1764 	if (status != 0) {
1765 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1766 				request.hostname, status);
1767 		return status;
1768 	}
1769 
1770 	return 0;
1771 }
1772 
1773 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1774 					struct nfs_subversion *nfs_mod)
1775 {
1776 	int status;
1777 	unsigned int i;
1778 	bool tried_auth_unix = false;
1779 	bool auth_null_in_list = false;
1780 	struct nfs_server *server = ERR_PTR(-EACCES);
1781 	struct nfs_parsed_mount_data *args = mount_info->parsed;
1782 	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1783 	unsigned int authlist_len = ARRAY_SIZE(authlist);
1784 
1785 	status = nfs_request_mount(args, mount_info->mntfh, authlist,
1786 					&authlist_len);
1787 	if (status)
1788 		return ERR_PTR(status);
1789 
1790 	/*
1791 	 * Was a sec= authflavor specified in the options? First, verify
1792 	 * whether the server supports it, and then just try to use it if so.
1793 	 */
1794 	if (args->auth_info.flavor_len > 0) {
1795 		status = nfs_verify_authflavors(args, authlist, authlist_len);
1796 		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1797 			 args->selected_flavor);
1798 		if (status)
1799 			return ERR_PTR(status);
1800 		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1801 	}
1802 
1803 	/*
1804 	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
1805 	 * SHOULD prefer the flavor listed first. However, some servers list
1806 	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1807 	 */
1808 	for (i = 0; i < authlist_len; ++i) {
1809 		rpc_authflavor_t flavor;
1810 		struct rpcsec_gss_info info;
1811 
1812 		flavor = authlist[i];
1813 		switch (flavor) {
1814 		case RPC_AUTH_UNIX:
1815 			tried_auth_unix = true;
1816 			break;
1817 		case RPC_AUTH_NULL:
1818 			auth_null_in_list = true;
1819 			continue;
1820 		default:
1821 			if (rpcauth_get_gssinfo(flavor, &info) != 0)
1822 				continue;
1823 			/* Fallthrough */
1824 		}
1825 		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1826 		args->selected_flavor = flavor;
1827 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1828 		if (!IS_ERR(server))
1829 			return server;
1830 	}
1831 
1832 	/*
1833 	 * Nothing we tried so far worked. At this point, give up if we've
1834 	 * already tried AUTH_UNIX or if the server's list doesn't contain
1835 	 * AUTH_NULL
1836 	 */
1837 	if (tried_auth_unix || !auth_null_in_list)
1838 		return server;
1839 
1840 	/* Last chance! Try AUTH_UNIX */
1841 	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1842 	args->selected_flavor = RPC_AUTH_UNIX;
1843 	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1844 }
1845 
1846 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1847 			     struct nfs_mount_info *mount_info,
1848 			     struct nfs_subversion *nfs_mod)
1849 {
1850 	struct nfs_server *server;
1851 
1852 	if (mount_info->parsed->need_mount)
1853 		server = nfs_try_mount_request(mount_info, nfs_mod);
1854 	else
1855 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1856 
1857 	if (IS_ERR(server))
1858 		return ERR_CAST(server);
1859 
1860 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1861 }
1862 EXPORT_SYMBOL_GPL(nfs_try_mount);
1863 
1864 /*
1865  * Split "dev_name" into "hostname:export_path".
1866  *
1867  * The leftmost colon demarks the split between the server's hostname
1868  * and the export path.  If the hostname starts with a left square
1869  * bracket, then it may contain colons.
1870  *
1871  * Note: caller frees hostname and export path, even on error.
1872  */
1873 static int nfs_parse_devname(const char *dev_name,
1874 			     char **hostname, size_t maxnamlen,
1875 			     char **export_path, size_t maxpathlen)
1876 {
1877 	size_t len;
1878 	char *end;
1879 
1880 	/* Is the host name protected with square brakcets? */
1881 	if (*dev_name == '[') {
1882 		end = strchr(++dev_name, ']');
1883 		if (end == NULL || end[1] != ':')
1884 			goto out_bad_devname;
1885 
1886 		len = end - dev_name;
1887 		end++;
1888 	} else {
1889 		char *comma;
1890 
1891 		end = strchr(dev_name, ':');
1892 		if (end == NULL)
1893 			goto out_bad_devname;
1894 		len = end - dev_name;
1895 
1896 		/* kill possible hostname list: not supported */
1897 		comma = strchr(dev_name, ',');
1898 		if (comma != NULL && comma < end)
1899 			*comma = 0;
1900 	}
1901 
1902 	if (len > maxnamlen)
1903 		goto out_hostname;
1904 
1905 	/* N.B. caller will free nfs_server.hostname in all cases */
1906 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1907 	if (*hostname == NULL)
1908 		goto out_nomem;
1909 	len = strlen(++end);
1910 	if (len > maxpathlen)
1911 		goto out_path;
1912 	*export_path = kstrndup(end, len, GFP_KERNEL);
1913 	if (!*export_path)
1914 		goto out_nomem;
1915 
1916 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1917 	return 0;
1918 
1919 out_bad_devname:
1920 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1921 	return -EINVAL;
1922 
1923 out_nomem:
1924 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1925 	return -ENOMEM;
1926 
1927 out_hostname:
1928 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1929 	return -ENAMETOOLONG;
1930 
1931 out_path:
1932 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1933 	return -ENAMETOOLONG;
1934 }
1935 
1936 /*
1937  * Validate the NFS2/NFS3 mount data
1938  * - fills in the mount root filehandle
1939  *
1940  * For option strings, user space handles the following behaviors:
1941  *
1942  * + DNS: mapping server host name to IP address ("addr=" option)
1943  *
1944  * + failure mode: how to behave if a mount request can't be handled
1945  *   immediately ("fg/bg" option)
1946  *
1947  * + retry: how often to retry a mount request ("retry=" option)
1948  *
1949  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1950  *   mountproto=tcp after mountproto=udp, and so on
1951  */
1952 static int nfs23_validate_mount_data(void *options,
1953 				     struct nfs_parsed_mount_data *args,
1954 				     struct nfs_fh *mntfh,
1955 				     const char *dev_name)
1956 {
1957 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1958 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1959 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1960 
1961 	if (data == NULL)
1962 		goto out_no_data;
1963 
1964 	args->version = NFS_DEFAULT_VERSION;
1965 	switch (data->version) {
1966 	case 1:
1967 		data->namlen = 0;
1968 	case 2:
1969 		data->bsize = 0;
1970 	case 3:
1971 		if (data->flags & NFS_MOUNT_VER3)
1972 			goto out_no_v3;
1973 		data->root.size = NFS2_FHSIZE;
1974 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1975 		/* Turn off security negotiation */
1976 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
1977 	case 4:
1978 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1979 			goto out_no_sec;
1980 	case 5:
1981 		memset(data->context, 0, sizeof(data->context));
1982 	case 6:
1983 		if (data->flags & NFS_MOUNT_VER3) {
1984 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1985 				goto out_invalid_fh;
1986 			mntfh->size = data->root.size;
1987 			args->version = 3;
1988 		} else {
1989 			mntfh->size = NFS2_FHSIZE;
1990 			args->version = 2;
1991 		}
1992 
1993 
1994 		memcpy(mntfh->data, data->root.data, mntfh->size);
1995 		if (mntfh->size < sizeof(mntfh->data))
1996 			memset(mntfh->data + mntfh->size, 0,
1997 			       sizeof(mntfh->data) - mntfh->size);
1998 
1999 		/*
2000 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
2001 		 * can deal with.
2002 		 */
2003 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
2004 		args->flags		|= extra_flags;
2005 		args->rsize		= data->rsize;
2006 		args->wsize		= data->wsize;
2007 		args->timeo		= data->timeo;
2008 		args->retrans		= data->retrans;
2009 		args->acregmin		= data->acregmin;
2010 		args->acregmax		= data->acregmax;
2011 		args->acdirmin		= data->acdirmin;
2012 		args->acdirmax		= data->acdirmax;
2013 		args->need_mount	= false;
2014 
2015 		memcpy(sap, &data->addr, sizeof(data->addr));
2016 		args->nfs_server.addrlen = sizeof(data->addr);
2017 		args->nfs_server.port = ntohs(data->addr.sin_port);
2018 		if (!nfs_verify_server_address(sap))
2019 			goto out_no_address;
2020 
2021 		if (!(data->flags & NFS_MOUNT_TCP))
2022 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2023 		/* N.B. caller will free nfs_server.hostname in all cases */
2024 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2025 		args->namlen		= data->namlen;
2026 		args->bsize		= data->bsize;
2027 
2028 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2029 			args->selected_flavor = data->pseudoflavor;
2030 		else
2031 			args->selected_flavor = RPC_AUTH_UNIX;
2032 		if (!args->nfs_server.hostname)
2033 			goto out_nomem;
2034 
2035 		if (!(data->flags & NFS_MOUNT_NONLM))
2036 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2037 					 NFS_MOUNT_LOCAL_FCNTL);
2038 		else
2039 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2040 					NFS_MOUNT_LOCAL_FCNTL);
2041 		/*
2042 		 * The legacy version 6 binary mount data from userspace has a
2043 		 * field used only to transport selinux information into the
2044 		 * the kernel.  To continue to support that functionality we
2045 		 * have a touch of selinux knowledge here in the NFS code. The
2046 		 * userspace code converted context=blah to just blah so we are
2047 		 * converting back to the full string selinux understands.
2048 		 */
2049 		if (data->context[0]){
2050 #ifdef CONFIG_SECURITY_SELINUX
2051 			int rc;
2052 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
2053 			if (!opts_str)
2054 				return -ENOMEM;
2055 			strcpy(opts_str, "context=");
2056 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2057 			strcat(opts_str, &data->context[0]);
2058 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
2059 			kfree(opts_str);
2060 			if (rc)
2061 				return rc;
2062 #else
2063 			return -EINVAL;
2064 #endif
2065 		}
2066 
2067 		break;
2068 	default:
2069 		return NFS_TEXT_DATA;
2070 	}
2071 
2072 	return 0;
2073 
2074 out_no_data:
2075 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2076 	return -EINVAL;
2077 
2078 out_no_v3:
2079 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2080 		 data->version);
2081 	return -EINVAL;
2082 
2083 out_no_sec:
2084 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2085 	return -EINVAL;
2086 
2087 out_nomem:
2088 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2089 	return -ENOMEM;
2090 
2091 out_no_address:
2092 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2093 	return -EINVAL;
2094 
2095 out_invalid_fh:
2096 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2097 	return -EINVAL;
2098 }
2099 
2100 #if IS_ENABLED(CONFIG_NFS_V4)
2101 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2102 				   void *options,
2103 				   struct nfs_parsed_mount_data *args,
2104 				   struct nfs_fh *mntfh,
2105 				   const char *dev_name)
2106 {
2107 	if (fs_type == &nfs_fs_type)
2108 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2109 	return nfs4_validate_mount_data(options, args, dev_name);
2110 }
2111 #else
2112 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2113 				   void *options,
2114 				   struct nfs_parsed_mount_data *args,
2115 				   struct nfs_fh *mntfh,
2116 				   const char *dev_name)
2117 {
2118 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2119 }
2120 #endif
2121 
2122 static int nfs_validate_text_mount_data(void *options,
2123 					struct nfs_parsed_mount_data *args,
2124 					const char *dev_name)
2125 {
2126 	int port = 0;
2127 	int max_namelen = PAGE_SIZE;
2128 	int max_pathlen = NFS_MAXPATHLEN;
2129 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2130 
2131 	if (nfs_parse_mount_options((char *)options, args) == 0)
2132 		return -EINVAL;
2133 
2134 	if (!nfs_verify_server_address(sap))
2135 		goto out_no_address;
2136 
2137 	if (args->version == 4) {
2138 #if IS_ENABLED(CONFIG_NFS_V4)
2139 		port = NFS_PORT;
2140 		max_namelen = NFS4_MAXNAMLEN;
2141 		max_pathlen = NFS4_MAXPATHLEN;
2142 		nfs_validate_transport_protocol(args);
2143 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2144 			goto out_invalid_transport_udp;
2145 		nfs4_validate_mount_flags(args);
2146 #else
2147 		goto out_v4_not_compiled;
2148 #endif /* CONFIG_NFS_V4 */
2149 	} else
2150 		nfs_set_mount_transport_protocol(args);
2151 
2152 	nfs_set_port(sap, &args->nfs_server.port, port);
2153 
2154 	return nfs_parse_devname(dev_name,
2155 				   &args->nfs_server.hostname,
2156 				   max_namelen,
2157 				   &args->nfs_server.export_path,
2158 				   max_pathlen);
2159 
2160 #if !IS_ENABLED(CONFIG_NFS_V4)
2161 out_v4_not_compiled:
2162 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2163 	return -EPROTONOSUPPORT;
2164 #else
2165 out_invalid_transport_udp:
2166 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2167 	return -EINVAL;
2168 #endif /* !CONFIG_NFS_V4 */
2169 
2170 out_no_address:
2171 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2172 	return -EINVAL;
2173 }
2174 
2175 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2176 		| NFS_MOUNT_SECURE \
2177 		| NFS_MOUNT_TCP \
2178 		| NFS_MOUNT_VER3 \
2179 		| NFS_MOUNT_KERBEROS \
2180 		| NFS_MOUNT_NONLM \
2181 		| NFS_MOUNT_BROKEN_SUID \
2182 		| NFS_MOUNT_STRICTLOCK \
2183 		| NFS_MOUNT_LEGACY_INTERFACE)
2184 
2185 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2186 		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2187 
2188 static int
2189 nfs_compare_remount_data(struct nfs_server *nfss,
2190 			 struct nfs_parsed_mount_data *data)
2191 {
2192 	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2193 	    data->rsize != nfss->rsize ||
2194 	    data->wsize != nfss->wsize ||
2195 	    data->version != nfss->nfs_client->rpc_ops->version ||
2196 	    data->minorversion != nfss->nfs_client->cl_minorversion ||
2197 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2198 	    !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2199 	    data->acregmin != nfss->acregmin / HZ ||
2200 	    data->acregmax != nfss->acregmax / HZ ||
2201 	    data->acdirmin != nfss->acdirmin / HZ ||
2202 	    data->acdirmax != nfss->acdirmax / HZ ||
2203 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2204 	    data->nfs_server.port != nfss->port ||
2205 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2206 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2207 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2208 		return -EINVAL;
2209 
2210 	return 0;
2211 }
2212 
2213 int
2214 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2215 {
2216 	int error;
2217 	struct nfs_server *nfss = sb->s_fs_info;
2218 	struct nfs_parsed_mount_data *data;
2219 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2220 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2221 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2222 
2223 	sync_filesystem(sb);
2224 
2225 	/*
2226 	 * Userspace mount programs that send binary options generally send
2227 	 * them populated with default values. We have no way to know which
2228 	 * ones were explicitly specified. Fall back to legacy behavior and
2229 	 * just return success.
2230 	 */
2231 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2232 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2233 					   options->version <= 6))))
2234 		return 0;
2235 
2236 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2237 	if (data == NULL)
2238 		return -ENOMEM;
2239 
2240 	/* fill out struct with values from existing mount */
2241 	data->flags = nfss->flags;
2242 	data->rsize = nfss->rsize;
2243 	data->wsize = nfss->wsize;
2244 	data->retrans = nfss->client->cl_timeout->to_retries;
2245 	data->selected_flavor = nfss->client->cl_auth->au_flavor;
2246 	data->acregmin = nfss->acregmin / HZ;
2247 	data->acregmax = nfss->acregmax / HZ;
2248 	data->acdirmin = nfss->acdirmin / HZ;
2249 	data->acdirmax = nfss->acdirmax / HZ;
2250 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2251 	data->nfs_server.port = nfss->port;
2252 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2253 	data->version = nfsvers;
2254 	data->minorversion = nfss->nfs_client->cl_minorversion;
2255 	data->net = current->nsproxy->net_ns;
2256 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2257 		data->nfs_server.addrlen);
2258 
2259 	/* overwrite those values with any that were specified */
2260 	error = -EINVAL;
2261 	if (!nfs_parse_mount_options((char *)options, data))
2262 		goto out;
2263 
2264 	/*
2265 	 * noac is a special case. It implies -o sync, but that's not
2266 	 * necessarily reflected in the mtab options. do_remount_sb
2267 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2268 	 * remount options, so we have to explicitly reset it.
2269 	 */
2270 	if (data->flags & NFS_MOUNT_NOAC)
2271 		*flags |= MS_SYNCHRONOUS;
2272 
2273 	/* compare new mount options with old ones */
2274 	error = nfs_compare_remount_data(nfss, data);
2275 out:
2276 	kfree(data);
2277 	return error;
2278 }
2279 EXPORT_SYMBOL_GPL(nfs_remount);
2280 
2281 /*
2282  * Initialise the common bits of the superblock
2283  */
2284 inline void nfs_initialise_sb(struct super_block *sb)
2285 {
2286 	struct nfs_server *server = NFS_SB(sb);
2287 
2288 	sb->s_magic = NFS_SUPER_MAGIC;
2289 
2290 	/* We probably want something more informative here */
2291 	snprintf(sb->s_id, sizeof(sb->s_id),
2292 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2293 
2294 	if (sb->s_blocksize == 0)
2295 		sb->s_blocksize = nfs_block_bits(server->wsize,
2296 						 &sb->s_blocksize_bits);
2297 
2298 	sb->s_bdi = &server->backing_dev_info;
2299 
2300 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2301 }
2302 
2303 /*
2304  * Finish setting up an NFS2/3 superblock
2305  */
2306 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2307 {
2308 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2309 	struct nfs_server *server = NFS_SB(sb);
2310 
2311 	sb->s_blocksize_bits = 0;
2312 	sb->s_blocksize = 0;
2313 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2314 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2315 	if (data && data->bsize)
2316 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2317 
2318 	if (server->nfs_client->rpc_ops->version != 2) {
2319 		/* The VFS shouldn't apply the umask to mode bits. We will do
2320 		 * so ourselves when necessary.
2321 		 */
2322 		sb->s_flags |= MS_POSIXACL;
2323 		sb->s_time_gran = 1;
2324 	}
2325 
2326  	nfs_initialise_sb(sb);
2327 }
2328 EXPORT_SYMBOL_GPL(nfs_fill_super);
2329 
2330 /*
2331  * Finish setting up a cloned NFS2/3/4 superblock
2332  */
2333 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2334 {
2335 	const struct super_block *old_sb = mount_info->cloned->sb;
2336 	struct nfs_server *server = NFS_SB(sb);
2337 
2338 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2339 	sb->s_blocksize = old_sb->s_blocksize;
2340 	sb->s_maxbytes = old_sb->s_maxbytes;
2341 	sb->s_xattr = old_sb->s_xattr;
2342 	sb->s_op = old_sb->s_op;
2343 	sb->s_time_gran = 1;
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 |= MS_POSIXACL;
2350 	}
2351 
2352  	nfs_initialise_sb(sb);
2353 }
2354 
2355 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2356 {
2357 	const struct nfs_server *a = s->s_fs_info;
2358 	const struct rpc_clnt *clnt_a = a->client;
2359 	const struct rpc_clnt *clnt_b = b->client;
2360 
2361 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2362 		goto Ebusy;
2363 	if (a->nfs_client != b->nfs_client)
2364 		goto Ebusy;
2365 	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2366 		goto Ebusy;
2367 	if (a->wsize != b->wsize)
2368 		goto Ebusy;
2369 	if (a->rsize != b->rsize)
2370 		goto Ebusy;
2371 	if (a->acregmin != b->acregmin)
2372 		goto Ebusy;
2373 	if (a->acregmax != b->acregmax)
2374 		goto Ebusy;
2375 	if (a->acdirmin != b->acdirmin)
2376 		goto Ebusy;
2377 	if (a->acdirmax != b->acdirmax)
2378 		goto Ebusy;
2379 	if (b->auth_info.flavor_len > 0 &&
2380 	   clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2381 		goto Ebusy;
2382 	return 1;
2383 Ebusy:
2384 	return 0;
2385 }
2386 
2387 struct nfs_sb_mountdata {
2388 	struct nfs_server *server;
2389 	int mntflags;
2390 };
2391 
2392 static int nfs_set_super(struct super_block *s, void *data)
2393 {
2394 	struct nfs_sb_mountdata *sb_mntdata = data;
2395 	struct nfs_server *server = sb_mntdata->server;
2396 	int ret;
2397 
2398 	s->s_flags = sb_mntdata->mntflags;
2399 	s->s_fs_info = server;
2400 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2401 	ret = set_anon_super(s, server);
2402 	if (ret == 0)
2403 		server->s_dev = s->s_dev;
2404 	return ret;
2405 }
2406 
2407 static int nfs_compare_super_address(struct nfs_server *server1,
2408 				     struct nfs_server *server2)
2409 {
2410 	struct sockaddr *sap1, *sap2;
2411 
2412 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2413 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2414 
2415 	if (sap1->sa_family != sap2->sa_family)
2416 		return 0;
2417 
2418 	switch (sap1->sa_family) {
2419 	case AF_INET: {
2420 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2421 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2422 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2423 			return 0;
2424 		if (sin1->sin_port != sin2->sin_port)
2425 			return 0;
2426 		break;
2427 	}
2428 	case AF_INET6: {
2429 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2430 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2431 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2432 			return 0;
2433 		if (sin1->sin6_port != sin2->sin6_port)
2434 			return 0;
2435 		break;
2436 	}
2437 	default:
2438 		return 0;
2439 	}
2440 
2441 	return 1;
2442 }
2443 
2444 static int nfs_compare_super(struct super_block *sb, void *data)
2445 {
2446 	struct nfs_sb_mountdata *sb_mntdata = data;
2447 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2448 	int mntflags = sb_mntdata->mntflags;
2449 
2450 	if (!nfs_compare_super_address(old, server))
2451 		return 0;
2452 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2453 	if (old->flags & NFS_MOUNT_UNSHARED)
2454 		return 0;
2455 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2456 		return 0;
2457 	return nfs_compare_mount_options(sb, server, mntflags);
2458 }
2459 
2460 #ifdef CONFIG_NFS_FSCACHE
2461 static void nfs_get_cache_cookie(struct super_block *sb,
2462 				 struct nfs_parsed_mount_data *parsed,
2463 				 struct nfs_clone_mount *cloned)
2464 {
2465 	struct nfs_server *nfss = NFS_SB(sb);
2466 	char *uniq = NULL;
2467 	int ulen = 0;
2468 
2469 	nfss->fscache_key = NULL;
2470 	nfss->fscache = NULL;
2471 
2472 	if (parsed) {
2473 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2474 			return;
2475 		if (parsed->fscache_uniq) {
2476 			uniq = parsed->fscache_uniq;
2477 			ulen = strlen(parsed->fscache_uniq);
2478 		}
2479 	} else if (cloned) {
2480 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2481 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2482 			return;
2483 		if (mnt_s->fscache_key) {
2484 			uniq = mnt_s->fscache_key->key.uniquifier;
2485 			ulen = mnt_s->fscache_key->key.uniq_len;
2486 		};
2487 	} else
2488 		return;
2489 
2490 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2491 }
2492 #else
2493 static void nfs_get_cache_cookie(struct super_block *sb,
2494 				 struct nfs_parsed_mount_data *parsed,
2495 				 struct nfs_clone_mount *cloned)
2496 {
2497 }
2498 #endif
2499 
2500 static int nfs_bdi_register(struct nfs_server *server)
2501 {
2502 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2503 }
2504 
2505 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2506 			struct nfs_mount_info *mount_info)
2507 {
2508 	int error;
2509 	unsigned long kflags = 0, kflags_out = 0;
2510 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2511 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2512 
2513 	error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
2514 						kflags, &kflags_out);
2515 	if (error)
2516 		goto err;
2517 
2518 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2519 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2520 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2521 err:
2522 	return error;
2523 }
2524 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2525 
2526 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2527 			  struct nfs_mount_info *mount_info)
2528 {
2529 	/* clone any lsm security options from the parent to the new sb */
2530 	if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2531 		return -ESTALE;
2532 	return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2533 }
2534 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2535 
2536 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2537 				   int flags, const char *dev_name,
2538 				   struct nfs_mount_info *mount_info,
2539 				   struct nfs_subversion *nfs_mod)
2540 {
2541 	struct super_block *s;
2542 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2543 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2544 	struct nfs_sb_mountdata sb_mntdata = {
2545 		.mntflags = flags,
2546 		.server = server,
2547 	};
2548 	int error;
2549 
2550 	if (server->flags & NFS_MOUNT_UNSHARED)
2551 		compare_super = NULL;
2552 
2553 	/* -o noac implies -o sync */
2554 	if (server->flags & NFS_MOUNT_NOAC)
2555 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2556 
2557 	if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2558 		if (mount_info->cloned->sb->s_flags & MS_SYNCHRONOUS)
2559 			sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2560 
2561 	/* Get a superblock - note that we may end up sharing one that already exists */
2562 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2563 	if (IS_ERR(s)) {
2564 		mntroot = ERR_CAST(s);
2565 		goto out_err_nosb;
2566 	}
2567 
2568 	if (s->s_fs_info != server) {
2569 		nfs_free_server(server);
2570 		server = NULL;
2571 	} else {
2572 		error = nfs_bdi_register(server);
2573 		if (error) {
2574 			mntroot = ERR_PTR(error);
2575 			goto error_splat_super;
2576 		}
2577 		server->super = s;
2578 	}
2579 
2580 	if (!s->s_root) {
2581 		/* initial superblock/root creation */
2582 		mount_info->fill_super(s, mount_info);
2583 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2584 	}
2585 
2586 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2587 	if (IS_ERR(mntroot))
2588 		goto error_splat_super;
2589 
2590 	error = mount_info->set_security(s, mntroot, mount_info);
2591 	if (error)
2592 		goto error_splat_root;
2593 
2594 	s->s_flags |= MS_ACTIVE;
2595 
2596 out:
2597 	return mntroot;
2598 
2599 out_err_nosb:
2600 	nfs_free_server(server);
2601 	goto out;
2602 
2603 error_splat_root:
2604 	dput(mntroot);
2605 	mntroot = ERR_PTR(error);
2606 error_splat_super:
2607 	deactivate_locked_super(s);
2608 	goto out;
2609 }
2610 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2611 
2612 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2613 	int flags, const char *dev_name, void *raw_data)
2614 {
2615 	struct nfs_mount_info mount_info = {
2616 		.fill_super = nfs_fill_super,
2617 		.set_security = nfs_set_sb_security,
2618 	};
2619 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2620 	struct nfs_subversion *nfs_mod;
2621 	int error;
2622 
2623 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2624 	mount_info.mntfh = nfs_alloc_fhandle();
2625 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2626 		goto out;
2627 
2628 	/* Validate the mount data */
2629 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2630 	if (error == NFS_TEXT_DATA)
2631 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2632 	if (error < 0) {
2633 		mntroot = ERR_PTR(error);
2634 		goto out;
2635 	}
2636 
2637 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2638 	if (IS_ERR(nfs_mod)) {
2639 		mntroot = ERR_CAST(nfs_mod);
2640 		goto out;
2641 	}
2642 
2643 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2644 
2645 	put_nfs_version(nfs_mod);
2646 out:
2647 	nfs_free_parsed_mount_data(mount_info.parsed);
2648 	nfs_free_fhandle(mount_info.mntfh);
2649 	return mntroot;
2650 }
2651 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2652 
2653 /*
2654  * Destroy an NFS2/3 superblock
2655  */
2656 void nfs_kill_super(struct super_block *s)
2657 {
2658 	struct nfs_server *server = NFS_SB(s);
2659 	dev_t dev = s->s_dev;
2660 
2661 	generic_shutdown_super(s);
2662 
2663 	nfs_fscache_release_super_cookie(s);
2664 
2665 	nfs_free_server(server);
2666 	free_anon_bdev(dev);
2667 }
2668 EXPORT_SYMBOL_GPL(nfs_kill_super);
2669 
2670 /*
2671  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2672  */
2673 static struct dentry *
2674 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2675 		const char *dev_name, void *raw_data)
2676 {
2677 	struct nfs_clone_mount *data = raw_data;
2678 	struct nfs_mount_info mount_info = {
2679 		.fill_super = nfs_clone_super,
2680 		.set_security = nfs_clone_sb_security,
2681 		.cloned = data,
2682 	};
2683 	struct nfs_server *server;
2684 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2685 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2686 
2687 	dprintk("--> nfs_xdev_mount()\n");
2688 
2689 	mount_info.mntfh = mount_info.cloned->fh;
2690 
2691 	/* create a new volume representation */
2692 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2693 
2694 	if (IS_ERR(server))
2695 		mntroot = ERR_CAST(server);
2696 	else
2697 		mntroot = nfs_fs_mount_common(server, flags,
2698 				dev_name, &mount_info, nfs_mod);
2699 
2700 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2701 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2702 	return mntroot;
2703 }
2704 
2705 #if IS_ENABLED(CONFIG_NFS_V4)
2706 
2707 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2708 {
2709 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2710 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2711 }
2712 
2713 /*
2714  * Validate NFSv4 mount options
2715  */
2716 static int nfs4_validate_mount_data(void *options,
2717 				    struct nfs_parsed_mount_data *args,
2718 				    const char *dev_name)
2719 {
2720 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2721 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2722 	char *c;
2723 
2724 	if (data == NULL)
2725 		goto out_no_data;
2726 
2727 	args->version = 4;
2728 
2729 	switch (data->version) {
2730 	case 1:
2731 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2732 			goto out_no_address;
2733 		if (data->host_addrlen == 0)
2734 			goto out_no_address;
2735 		args->nfs_server.addrlen = data->host_addrlen;
2736 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2737 			return -EFAULT;
2738 		if (!nfs_verify_server_address(sap))
2739 			goto out_no_address;
2740 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2741 
2742 		if (data->auth_flavourlen) {
2743 			rpc_authflavor_t pseudoflavor;
2744 			if (data->auth_flavourlen > 1)
2745 				goto out_inval_auth;
2746 			if (copy_from_user(&pseudoflavor,
2747 					   data->auth_flavours,
2748 					   sizeof(pseudoflavor)))
2749 				return -EFAULT;
2750 			args->selected_flavor = pseudoflavor;
2751 		} else
2752 			args->selected_flavor = RPC_AUTH_UNIX;
2753 
2754 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2755 		if (IS_ERR(c))
2756 			return PTR_ERR(c);
2757 		args->nfs_server.hostname = c;
2758 
2759 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2760 		if (IS_ERR(c))
2761 			return PTR_ERR(c);
2762 		args->nfs_server.export_path = c;
2763 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2764 
2765 		c = strndup_user(data->client_addr.data, 16);
2766 		if (IS_ERR(c))
2767 			return PTR_ERR(c);
2768 		args->client_address = c;
2769 
2770 		/*
2771 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2772 		 * can deal with.
2773 		 */
2774 
2775 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2776 		args->rsize	= data->rsize;
2777 		args->wsize	= data->wsize;
2778 		args->timeo	= data->timeo;
2779 		args->retrans	= data->retrans;
2780 		args->acregmin	= data->acregmin;
2781 		args->acregmax	= data->acregmax;
2782 		args->acdirmin	= data->acdirmin;
2783 		args->acdirmax	= data->acdirmax;
2784 		args->nfs_server.protocol = data->proto;
2785 		nfs_validate_transport_protocol(args);
2786 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2787 			goto out_invalid_transport_udp;
2788 
2789 		break;
2790 	default:
2791 		return NFS_TEXT_DATA;
2792 	}
2793 
2794 	return 0;
2795 
2796 out_no_data:
2797 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2798 	return -EINVAL;
2799 
2800 out_inval_auth:
2801 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2802 		 data->auth_flavourlen);
2803 	return -EINVAL;
2804 
2805 out_no_address:
2806 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2807 	return -EINVAL;
2808 
2809 out_invalid_transport_udp:
2810 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2811 	return -EINVAL;
2812 }
2813 
2814 /*
2815  * NFS v4 module parameters need to stay in the
2816  * NFS client for backwards compatibility
2817  */
2818 unsigned int nfs_callback_set_tcpport;
2819 unsigned short nfs_callback_tcpport;
2820 /* Default cache timeout is 10 minutes */
2821 unsigned int nfs_idmap_cache_timeout = 600;
2822 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2823 bool nfs4_disable_idmapping = true;
2824 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2825 unsigned short send_implementation_id = 1;
2826 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2827 bool recover_lost_locks = false;
2828 
2829 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2830 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2831 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2832 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2833 EXPORT_SYMBOL_GPL(max_session_slots);
2834 EXPORT_SYMBOL_GPL(send_implementation_id);
2835 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2836 EXPORT_SYMBOL_GPL(recover_lost_locks);
2837 
2838 #define NFS_CALLBACK_MAXPORTNR (65535U)
2839 
2840 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2841 {
2842 	unsigned long num;
2843 	int ret;
2844 
2845 	if (!val)
2846 		return -EINVAL;
2847 	ret = kstrtoul(val, 0, &num);
2848 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2849 		return -EINVAL;
2850 	*((unsigned int *)kp->arg) = num;
2851 	return 0;
2852 }
2853 static const struct kernel_param_ops param_ops_portnr = {
2854 	.set = param_set_portnr,
2855 	.get = param_get_uint,
2856 };
2857 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2858 
2859 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2860 module_param(nfs_idmap_cache_timeout, int, 0644);
2861 module_param(nfs4_disable_idmapping, bool, 0644);
2862 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2863 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2864 MODULE_PARM_DESC(nfs4_disable_idmapping,
2865 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2866 module_param(max_session_slots, ushort, 0644);
2867 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2868 		"requests the client will negotiate");
2869 module_param(send_implementation_id, ushort, 0644);
2870 MODULE_PARM_DESC(send_implementation_id,
2871 		"Send implementation ID with NFSv4.1 exchange_id");
2872 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2873 
2874 module_param(recover_lost_locks, bool, 0644);
2875 MODULE_PARM_DESC(recover_lost_locks,
2876 		 "If the server reports that a lock might be lost, "
2877 		 "try to recover it risking data corruption.");
2878 
2879 
2880 #endif /* CONFIG_NFS_V4 */
2881