xref: /openbmc/linux/fs/nfs/super.c (revision 78700c0a)
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 	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 
535 	seq_printf(m, ",mountproto=");
536 	switch (sap->sa_family) {
537 	case AF_INET:
538 		switch (nfss->mountd_protocol) {
539 		case IPPROTO_UDP:
540 			seq_printf(m, RPCBIND_NETID_UDP);
541 			break;
542 		case IPPROTO_TCP:
543 			seq_printf(m, RPCBIND_NETID_TCP);
544 			break;
545 		default:
546 			if (showdefaults)
547 				seq_printf(m, "auto");
548 		}
549 		break;
550 	case AF_INET6:
551 		switch (nfss->mountd_protocol) {
552 		case IPPROTO_UDP:
553 			seq_printf(m, RPCBIND_NETID_UDP6);
554 			break;
555 		case IPPROTO_TCP:
556 			seq_printf(m, RPCBIND_NETID_TCP6);
557 			break;
558 		default:
559 			if (showdefaults)
560 				seq_printf(m, "auto");
561 		}
562 		break;
563 	default:
564 		if (showdefaults)
565 			seq_printf(m, "auto");
566 	}
567 }
568 
569 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
570 				    int showdefaults)
571 {
572 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
573 
574 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
575 		return;
576 
577 	switch (sap->sa_family) {
578 	case AF_INET: {
579 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
580 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
581 		break;
582 	}
583 	case AF_INET6: {
584 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
585 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
586 		break;
587 	}
588 	default:
589 		if (showdefaults)
590 			seq_printf(m, ",mountaddr=unspecified");
591 	}
592 
593 	if (nfss->mountd_version || showdefaults)
594 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
595 	if ((nfss->mountd_port &&
596 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
597 		showdefaults)
598 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
599 
600 	nfs_show_mountd_netid(m, nfss, showdefaults);
601 }
602 
603 #if IS_ENABLED(CONFIG_NFS_V4)
604 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
605 				    int showdefaults)
606 {
607 	struct nfs_client *clp = nfss->nfs_client;
608 
609 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
610 }
611 #else
612 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
613 				    int showdefaults)
614 {
615 }
616 #endif
617 
618 static void nfs_show_nfs_version(struct seq_file *m,
619 		unsigned int version,
620 		unsigned int minorversion)
621 {
622 	seq_printf(m, ",vers=%u", version);
623 	if (version == 4)
624 		seq_printf(m, ".%u", minorversion);
625 }
626 
627 /*
628  * Describe the mount options in force on this server representation
629  */
630 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
631 				   int showdefaults)
632 {
633 	static const struct proc_nfs_info {
634 		int flag;
635 		const char *str;
636 		const char *nostr;
637 	} nfs_info[] = {
638 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
639 		{ NFS_MOUNT_POSIX, ",posix", "" },
640 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
641 		{ NFS_MOUNT_NOAC, ",noac", "" },
642 		{ NFS_MOUNT_NONLM, ",nolock", "" },
643 		{ NFS_MOUNT_NOACL, ",noacl", "" },
644 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
645 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
646 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
647 		{ 0, NULL, NULL }
648 	};
649 	const struct proc_nfs_info *nfs_infop;
650 	struct nfs_client *clp = nfss->nfs_client;
651 	u32 version = clp->rpc_ops->version;
652 	int local_flock, local_fcntl;
653 
654 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
655 	seq_printf(m, ",rsize=%u", nfss->rsize);
656 	seq_printf(m, ",wsize=%u", nfss->wsize);
657 	if (nfss->bsize != 0)
658 		seq_printf(m, ",bsize=%u", nfss->bsize);
659 	seq_printf(m, ",namlen=%u", nfss->namelen);
660 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
661 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
662 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
663 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
664 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
665 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
666 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
667 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
668 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
669 		if (nfss->flags & nfs_infop->flag)
670 			seq_puts(m, nfs_infop->str);
671 		else
672 			seq_puts(m, nfs_infop->nostr);
673 	}
674 	rcu_read_lock();
675 	seq_printf(m, ",proto=%s",
676 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
677 	rcu_read_unlock();
678 	if (version == 4) {
679 		if (nfss->port != NFS_PORT)
680 			seq_printf(m, ",port=%u", nfss->port);
681 	} else
682 		if (nfss->port)
683 			seq_printf(m, ",port=%u", nfss->port);
684 
685 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
686 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
687 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
688 
689 	if (version != 4)
690 		nfs_show_mountd_options(m, nfss, showdefaults);
691 	else
692 		nfs_show_nfsv4_options(m, nfss, showdefaults);
693 
694 	if (nfss->options & NFS_OPTION_FSCACHE)
695 		seq_printf(m, ",fsc");
696 
697 	if (nfss->options & NFS_OPTION_MIGRATION)
698 		seq_printf(m, ",migration");
699 
700 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
701 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
702 			seq_printf(m, ",lookupcache=none");
703 		else
704 			seq_printf(m, ",lookupcache=pos");
705 	}
706 
707 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
708 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
709 
710 	if (!local_flock && !local_fcntl)
711 		seq_printf(m, ",local_lock=none");
712 	else if (local_flock && local_fcntl)
713 		seq_printf(m, ",local_lock=all");
714 	else if (local_flock)
715 		seq_printf(m, ",local_lock=flock");
716 	else
717 		seq_printf(m, ",local_lock=posix");
718 }
719 
720 /*
721  * Describe the mount options on this VFS mountpoint
722  */
723 int nfs_show_options(struct seq_file *m, struct dentry *root)
724 {
725 	struct nfs_server *nfss = NFS_SB(root->d_sb);
726 
727 	nfs_show_mount_options(m, nfss, 0);
728 
729 	rcu_read_lock();
730 	seq_printf(m, ",addr=%s",
731 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
732 							RPC_DISPLAY_ADDR));
733 	rcu_read_unlock();
734 
735 	return 0;
736 }
737 EXPORT_SYMBOL_GPL(nfs_show_options);
738 
739 #if IS_ENABLED(CONFIG_NFS_V4)
740 #ifdef CONFIG_NFS_V4_1
741 static void show_sessions(struct seq_file *m, struct nfs_server *server)
742 {
743 	if (nfs4_has_session(server->nfs_client))
744 		seq_printf(m, ",sessions");
745 }
746 #else
747 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
748 #endif
749 #endif
750 
751 #ifdef CONFIG_NFS_V4_1
752 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
753 {
754 	seq_printf(m, ",pnfs=");
755 	if (server->pnfs_curr_ld)
756 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
757 	else
758 		seq_printf(m, "not configured");
759 }
760 
761 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
762 {
763 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
764 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
765 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
766 			   "date='%llu,%u'",
767 			   impl_id->name, impl_id->domain,
768 			   impl_id->date.seconds, impl_id->date.nseconds);
769 	}
770 }
771 #else
772 #if IS_ENABLED(CONFIG_NFS_V4)
773 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
774 {
775 }
776 #endif
777 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
778 {
779 }
780 #endif
781 
782 int nfs_show_devname(struct seq_file *m, struct dentry *root)
783 {
784 	char *page = (char *) __get_free_page(GFP_KERNEL);
785 	char *devname, *dummy;
786 	int err = 0;
787 	if (!page)
788 		return -ENOMEM;
789 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
790 	if (IS_ERR(devname))
791 		err = PTR_ERR(devname);
792 	else
793 		seq_escape(m, devname, " \t\n\\");
794 	free_page((unsigned long)page);
795 	return err;
796 }
797 EXPORT_SYMBOL_GPL(nfs_show_devname);
798 
799 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
800 {
801 	seq_puts(m, "/");
802 	return 0;
803 }
804 EXPORT_SYMBOL_GPL(nfs_show_path);
805 
806 /*
807  * Present statistical information for this VFS mountpoint
808  */
809 int nfs_show_stats(struct seq_file *m, struct dentry *root)
810 {
811 	int i, cpu;
812 	struct nfs_server *nfss = NFS_SB(root->d_sb);
813 	struct rpc_auth *auth = nfss->client->cl_auth;
814 	struct nfs_iostats totals = { };
815 
816 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
817 
818 	/*
819 	 * Display all mount option settings
820 	 */
821 	seq_printf(m, "\n\topts:\t");
822 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
823 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
824 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
825 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
826 	nfs_show_mount_options(m, nfss, 1);
827 
828 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
829 
830 	show_implementation_id(m, nfss);
831 
832 	seq_printf(m, "\n\tcaps:\t");
833 	seq_printf(m, "caps=0x%x", nfss->caps);
834 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
835 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
836 	seq_printf(m, ",bsize=%u", nfss->bsize);
837 	seq_printf(m, ",namlen=%u", nfss->namelen);
838 
839 #if IS_ENABLED(CONFIG_NFS_V4)
840 	if (nfss->nfs_client->rpc_ops->version == 4) {
841 		seq_printf(m, "\n\tnfsv4:\t");
842 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
843 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
844 		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
845 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
846 		show_sessions(m, nfss);
847 		show_pnfs(m, nfss);
848 	}
849 #endif
850 
851 	/*
852 	 * Display security flavor in effect for this mount
853 	 */
854 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
855 	if (auth->au_flavor)
856 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
857 
858 	/*
859 	 * Display superblock I/O counters
860 	 */
861 	for_each_possible_cpu(cpu) {
862 		struct nfs_iostats *stats;
863 
864 		preempt_disable();
865 		stats = per_cpu_ptr(nfss->io_stats, cpu);
866 
867 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
868 			totals.events[i] += stats->events[i];
869 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
870 			totals.bytes[i] += stats->bytes[i];
871 #ifdef CONFIG_NFS_FSCACHE
872 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
873 			totals.fscache[i] += stats->fscache[i];
874 #endif
875 
876 		preempt_enable();
877 	}
878 
879 	seq_printf(m, "\n\tevents:\t");
880 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
881 		seq_printf(m, "%lu ", totals.events[i]);
882 	seq_printf(m, "\n\tbytes:\t");
883 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
884 		seq_printf(m, "%Lu ", totals.bytes[i]);
885 #ifdef CONFIG_NFS_FSCACHE
886 	if (nfss->options & NFS_OPTION_FSCACHE) {
887 		seq_printf(m, "\n\tfsc:\t");
888 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
889 			seq_printf(m, "%Lu ", totals.bytes[i]);
890 	}
891 #endif
892 	seq_printf(m, "\n");
893 
894 	rpc_print_iostats(m, nfss->client);
895 
896 	return 0;
897 }
898 EXPORT_SYMBOL_GPL(nfs_show_stats);
899 
900 /*
901  * Begin unmount by attempting to remove all automounted mountpoints we added
902  * in response to xdev traversals and referrals
903  */
904 void nfs_umount_begin(struct super_block *sb)
905 {
906 	struct nfs_server *server;
907 	struct rpc_clnt *rpc;
908 
909 	server = NFS_SB(sb);
910 	/* -EIO all pending I/O */
911 	rpc = server->client_acl;
912 	if (!IS_ERR(rpc))
913 		rpc_killall_tasks(rpc);
914 	rpc = server->client;
915 	if (!IS_ERR(rpc))
916 		rpc_killall_tasks(rpc);
917 }
918 EXPORT_SYMBOL_GPL(nfs_umount_begin);
919 
920 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
921 {
922 	struct nfs_parsed_mount_data *data;
923 
924 	data = kzalloc(sizeof(*data), GFP_KERNEL);
925 	if (data) {
926 		data->acregmin		= NFS_DEF_ACREGMIN;
927 		data->acregmax		= NFS_DEF_ACREGMAX;
928 		data->acdirmin		= NFS_DEF_ACDIRMIN;
929 		data->acdirmax		= NFS_DEF_ACDIRMAX;
930 		data->mount_server.port	= NFS_UNSPEC_PORT;
931 		data->nfs_server.port	= NFS_UNSPEC_PORT;
932 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
933 		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
934 		data->minorversion	= 0;
935 		data->need_mount	= true;
936 		data->net		= current->nsproxy->net_ns;
937 		security_init_mnt_opts(&data->lsm_opts);
938 	}
939 	return data;
940 }
941 
942 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
943 {
944 	if (data) {
945 		kfree(data->client_address);
946 		kfree(data->mount_server.hostname);
947 		kfree(data->nfs_server.export_path);
948 		kfree(data->nfs_server.hostname);
949 		kfree(data->fscache_uniq);
950 		security_free_mnt_opts(&data->lsm_opts);
951 		kfree(data);
952 	}
953 }
954 
955 /*
956  * Sanity-check a server address provided by the mount command.
957  *
958  * Address family must be initialized, and address must not be
959  * the ANY address for that family.
960  */
961 static int nfs_verify_server_address(struct sockaddr *addr)
962 {
963 	switch (addr->sa_family) {
964 	case AF_INET: {
965 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
966 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
967 	}
968 	case AF_INET6: {
969 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
970 		return !ipv6_addr_any(sa);
971 	}
972 	}
973 
974 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
975 	return 0;
976 }
977 
978 /*
979  * Select between a default port value and a user-specified port value.
980  * If a zero value is set, then autobind will be used.
981  */
982 static void nfs_set_port(struct sockaddr *sap, int *port,
983 				 const unsigned short default_port)
984 {
985 	if (*port == NFS_UNSPEC_PORT)
986 		*port = default_port;
987 
988 	rpc_set_port(sap, *port);
989 }
990 
991 /*
992  * Sanity check the NFS transport protocol.
993  *
994  */
995 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
996 {
997 	switch (mnt->nfs_server.protocol) {
998 	case XPRT_TRANSPORT_UDP:
999 	case XPRT_TRANSPORT_TCP:
1000 	case XPRT_TRANSPORT_RDMA:
1001 		break;
1002 	default:
1003 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1004 	}
1005 }
1006 
1007 /*
1008  * For text based NFSv2/v3 mounts, the mount protocol transport default
1009  * settings should depend upon the specified NFS transport.
1010  */
1011 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1012 {
1013 	nfs_validate_transport_protocol(mnt);
1014 
1015 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1016 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1017 			return;
1018 	switch (mnt->nfs_server.protocol) {
1019 	case XPRT_TRANSPORT_UDP:
1020 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1021 		break;
1022 	case XPRT_TRANSPORT_TCP:
1023 	case XPRT_TRANSPORT_RDMA:
1024 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1025 	}
1026 }
1027 
1028 /*
1029  * Add 'flavor' to 'auth_info' if not already present.
1030  * Returns true if 'flavor' ends up in the list, false otherwise
1031  */
1032 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1033 			      rpc_authflavor_t flavor)
1034 {
1035 	unsigned int i;
1036 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1037 
1038 	/* make sure this flavor isn't already in the list */
1039 	for (i = 0; i < auth_info->flavor_len; i++) {
1040 		if (flavor == auth_info->flavors[i])
1041 			return true;
1042 	}
1043 
1044 	if (auth_info->flavor_len + 1 >= max_flavor_len) {
1045 		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1046 		return false;
1047 	}
1048 
1049 	auth_info->flavors[auth_info->flavor_len++] = flavor;
1050 	return true;
1051 }
1052 
1053 /*
1054  * Return true if 'match' is in auth_info or auth_info is empty.
1055  * Return false otherwise.
1056  */
1057 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1058 			 rpc_authflavor_t match)
1059 {
1060 	int i;
1061 
1062 	if (!auth_info->flavor_len)
1063 		return true;
1064 
1065 	for (i = 0; i < auth_info->flavor_len; i++) {
1066 		if (auth_info->flavors[i] == match)
1067 			return true;
1068 	}
1069 	return false;
1070 }
1071 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1072 
1073 /*
1074  * Parse the value of the 'sec=' option.
1075  */
1076 static int nfs_parse_security_flavors(char *value,
1077 				      struct nfs_parsed_mount_data *mnt)
1078 {
1079 	substring_t args[MAX_OPT_ARGS];
1080 	rpc_authflavor_t pseudoflavor;
1081 	char *p;
1082 
1083 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1084 
1085 	while ((p = strsep(&value, ":")) != NULL) {
1086 		switch (match_token(p, nfs_secflavor_tokens, args)) {
1087 		case Opt_sec_none:
1088 			pseudoflavor = RPC_AUTH_NULL;
1089 			break;
1090 		case Opt_sec_sys:
1091 			pseudoflavor = RPC_AUTH_UNIX;
1092 			break;
1093 		case Opt_sec_krb5:
1094 			pseudoflavor = RPC_AUTH_GSS_KRB5;
1095 			break;
1096 		case Opt_sec_krb5i:
1097 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
1098 			break;
1099 		case Opt_sec_krb5p:
1100 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
1101 			break;
1102 		case Opt_sec_lkey:
1103 			pseudoflavor = RPC_AUTH_GSS_LKEY;
1104 			break;
1105 		case Opt_sec_lkeyi:
1106 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
1107 			break;
1108 		case Opt_sec_lkeyp:
1109 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
1110 			break;
1111 		case Opt_sec_spkm:
1112 			pseudoflavor = RPC_AUTH_GSS_SPKM;
1113 			break;
1114 		case Opt_sec_spkmi:
1115 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
1116 			break;
1117 		case Opt_sec_spkmp:
1118 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
1119 			break;
1120 		default:
1121 			dfprintk(MOUNT,
1122 				 "NFS: sec= option '%s' not recognized\n", p);
1123 			return 0;
1124 		}
1125 
1126 		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1127 			return 0;
1128 	}
1129 
1130 	return 1;
1131 }
1132 
1133 static int nfs_parse_version_string(char *string,
1134 		struct nfs_parsed_mount_data *mnt,
1135 		substring_t *args)
1136 {
1137 	mnt->flags &= ~NFS_MOUNT_VER3;
1138 	switch (match_token(string, nfs_vers_tokens, args)) {
1139 	case Opt_vers_2:
1140 		mnt->version = 2;
1141 		break;
1142 	case Opt_vers_3:
1143 		mnt->flags |= NFS_MOUNT_VER3;
1144 		mnt->version = 3;
1145 		break;
1146 	case Opt_vers_4:
1147 		/* Backward compatibility option. In future,
1148 		 * the mount program should always supply
1149 		 * a NFSv4 minor version number.
1150 		 */
1151 		mnt->version = 4;
1152 		break;
1153 	case Opt_vers_4_0:
1154 		mnt->version = 4;
1155 		mnt->minorversion = 0;
1156 		break;
1157 	case Opt_vers_4_1:
1158 		mnt->version = 4;
1159 		mnt->minorversion = 1;
1160 		break;
1161 	case Opt_vers_4_2:
1162 		mnt->version = 4;
1163 		mnt->minorversion = 2;
1164 		break;
1165 	default:
1166 		return 0;
1167 	}
1168 	return 1;
1169 }
1170 
1171 static int nfs_get_option_str(substring_t args[], char **option)
1172 {
1173 	kfree(*option);
1174 	*option = match_strdup(args);
1175 	return !*option;
1176 }
1177 
1178 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1179 {
1180 	int rc;
1181 	char *string;
1182 
1183 	string = match_strdup(args);
1184 	if (string == NULL)
1185 		return -ENOMEM;
1186 	rc = kstrtoul(string, 10, option);
1187 	kfree(string);
1188 
1189 	return rc;
1190 }
1191 
1192 /*
1193  * Error-check and convert a string of mount options from user space into
1194  * a data structure.  The whole mount string is processed; bad options are
1195  * skipped as they are encountered.  If there were no errors, return 1;
1196  * otherwise return 0 (zero).
1197  */
1198 static int nfs_parse_mount_options(char *raw,
1199 				   struct nfs_parsed_mount_data *mnt)
1200 {
1201 	char *p, *string, *secdata;
1202 	int rc, sloppy = 0, invalid_option = 0;
1203 	unsigned short protofamily = AF_UNSPEC;
1204 	unsigned short mountfamily = AF_UNSPEC;
1205 
1206 	if (!raw) {
1207 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1208 		return 1;
1209 	}
1210 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1211 
1212 	secdata = alloc_secdata();
1213 	if (!secdata)
1214 		goto out_nomem;
1215 
1216 	rc = security_sb_copy_data(raw, secdata);
1217 	if (rc)
1218 		goto out_security_failure;
1219 
1220 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1221 	if (rc)
1222 		goto out_security_failure;
1223 
1224 	free_secdata(secdata);
1225 
1226 	while ((p = strsep(&raw, ",")) != NULL) {
1227 		substring_t args[MAX_OPT_ARGS];
1228 		unsigned long option;
1229 		int token;
1230 
1231 		if (!*p)
1232 			continue;
1233 
1234 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1235 
1236 		token = match_token(p, nfs_mount_option_tokens, args);
1237 		switch (token) {
1238 
1239 		/*
1240 		 * boolean options:  foo/nofoo
1241 		 */
1242 		case Opt_soft:
1243 			mnt->flags |= NFS_MOUNT_SOFT;
1244 			break;
1245 		case Opt_hard:
1246 			mnt->flags &= ~NFS_MOUNT_SOFT;
1247 			break;
1248 		case Opt_posix:
1249 			mnt->flags |= NFS_MOUNT_POSIX;
1250 			break;
1251 		case Opt_noposix:
1252 			mnt->flags &= ~NFS_MOUNT_POSIX;
1253 			break;
1254 		case Opt_cto:
1255 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1256 			break;
1257 		case Opt_nocto:
1258 			mnt->flags |= NFS_MOUNT_NOCTO;
1259 			break;
1260 		case Opt_ac:
1261 			mnt->flags &= ~NFS_MOUNT_NOAC;
1262 			break;
1263 		case Opt_noac:
1264 			mnt->flags |= NFS_MOUNT_NOAC;
1265 			break;
1266 		case Opt_lock:
1267 			mnt->flags &= ~NFS_MOUNT_NONLM;
1268 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1269 					NFS_MOUNT_LOCAL_FCNTL);
1270 			break;
1271 		case Opt_nolock:
1272 			mnt->flags |= NFS_MOUNT_NONLM;
1273 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1274 				       NFS_MOUNT_LOCAL_FCNTL);
1275 			break;
1276 		case Opt_udp:
1277 			mnt->flags &= ~NFS_MOUNT_TCP;
1278 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1279 			break;
1280 		case Opt_tcp:
1281 			mnt->flags |= NFS_MOUNT_TCP;
1282 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1283 			break;
1284 		case Opt_rdma:
1285 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1286 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1287 			xprt_load_transport(p);
1288 			break;
1289 		case Opt_acl:
1290 			mnt->flags &= ~NFS_MOUNT_NOACL;
1291 			break;
1292 		case Opt_noacl:
1293 			mnt->flags |= NFS_MOUNT_NOACL;
1294 			break;
1295 		case Opt_rdirplus:
1296 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1297 			break;
1298 		case Opt_nordirplus:
1299 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1300 			break;
1301 		case Opt_sharecache:
1302 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1303 			break;
1304 		case Opt_nosharecache:
1305 			mnt->flags |= NFS_MOUNT_UNSHARED;
1306 			break;
1307 		case Opt_resvport:
1308 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1309 			break;
1310 		case Opt_noresvport:
1311 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1312 			break;
1313 		case Opt_fscache:
1314 			mnt->options |= NFS_OPTION_FSCACHE;
1315 			kfree(mnt->fscache_uniq);
1316 			mnt->fscache_uniq = NULL;
1317 			break;
1318 		case Opt_nofscache:
1319 			mnt->options &= ~NFS_OPTION_FSCACHE;
1320 			kfree(mnt->fscache_uniq);
1321 			mnt->fscache_uniq = NULL;
1322 			break;
1323 		case Opt_migration:
1324 			mnt->options |= NFS_OPTION_MIGRATION;
1325 			break;
1326 		case Opt_nomigration:
1327 			mnt->options &= NFS_OPTION_MIGRATION;
1328 			break;
1329 
1330 		/*
1331 		 * options that take numeric values
1332 		 */
1333 		case Opt_port:
1334 			if (nfs_get_option_ul(args, &option) ||
1335 			    option > USHRT_MAX)
1336 				goto out_invalid_value;
1337 			mnt->nfs_server.port = option;
1338 			break;
1339 		case Opt_rsize:
1340 			if (nfs_get_option_ul(args, &option))
1341 				goto out_invalid_value;
1342 			mnt->rsize = option;
1343 			break;
1344 		case Opt_wsize:
1345 			if (nfs_get_option_ul(args, &option))
1346 				goto out_invalid_value;
1347 			mnt->wsize = option;
1348 			break;
1349 		case Opt_bsize:
1350 			if (nfs_get_option_ul(args, &option))
1351 				goto out_invalid_value;
1352 			mnt->bsize = option;
1353 			break;
1354 		case Opt_timeo:
1355 			if (nfs_get_option_ul(args, &option) || option == 0)
1356 				goto out_invalid_value;
1357 			mnt->timeo = option;
1358 			break;
1359 		case Opt_retrans:
1360 			if (nfs_get_option_ul(args, &option) || option == 0)
1361 				goto out_invalid_value;
1362 			mnt->retrans = option;
1363 			break;
1364 		case Opt_acregmin:
1365 			if (nfs_get_option_ul(args, &option))
1366 				goto out_invalid_value;
1367 			mnt->acregmin = option;
1368 			break;
1369 		case Opt_acregmax:
1370 			if (nfs_get_option_ul(args, &option))
1371 				goto out_invalid_value;
1372 			mnt->acregmax = option;
1373 			break;
1374 		case Opt_acdirmin:
1375 			if (nfs_get_option_ul(args, &option))
1376 				goto out_invalid_value;
1377 			mnt->acdirmin = option;
1378 			break;
1379 		case Opt_acdirmax:
1380 			if (nfs_get_option_ul(args, &option))
1381 				goto out_invalid_value;
1382 			mnt->acdirmax = option;
1383 			break;
1384 		case Opt_actimeo:
1385 			if (nfs_get_option_ul(args, &option))
1386 				goto out_invalid_value;
1387 			mnt->acregmin = mnt->acregmax =
1388 			mnt->acdirmin = mnt->acdirmax = option;
1389 			break;
1390 		case Opt_namelen:
1391 			if (nfs_get_option_ul(args, &option))
1392 				goto out_invalid_value;
1393 			mnt->namlen = option;
1394 			break;
1395 		case Opt_mountport:
1396 			if (nfs_get_option_ul(args, &option) ||
1397 			    option > USHRT_MAX)
1398 				goto out_invalid_value;
1399 			mnt->mount_server.port = option;
1400 			break;
1401 		case Opt_mountvers:
1402 			if (nfs_get_option_ul(args, &option) ||
1403 			    option < NFS_MNT_VERSION ||
1404 			    option > NFS_MNT3_VERSION)
1405 				goto out_invalid_value;
1406 			mnt->mount_server.version = option;
1407 			break;
1408 		case Opt_minorversion:
1409 			if (nfs_get_option_ul(args, &option))
1410 				goto out_invalid_value;
1411 			if (option > NFS4_MAX_MINOR_VERSION)
1412 				goto out_invalid_value;
1413 			mnt->minorversion = option;
1414 			break;
1415 
1416 		/*
1417 		 * options that take text values
1418 		 */
1419 		case Opt_nfsvers:
1420 			string = match_strdup(args);
1421 			if (string == NULL)
1422 				goto out_nomem;
1423 			rc = nfs_parse_version_string(string, mnt, args);
1424 			kfree(string);
1425 			if (!rc)
1426 				goto out_invalid_value;
1427 			break;
1428 		case Opt_sec:
1429 			string = match_strdup(args);
1430 			if (string == NULL)
1431 				goto out_nomem;
1432 			rc = nfs_parse_security_flavors(string, mnt);
1433 			kfree(string);
1434 			if (!rc) {
1435 				dfprintk(MOUNT, "NFS:   unrecognized "
1436 						"security flavor\n");
1437 				return 0;
1438 			}
1439 			break;
1440 		case Opt_proto:
1441 			string = match_strdup(args);
1442 			if (string == NULL)
1443 				goto out_nomem;
1444 			token = match_token(string,
1445 					    nfs_xprt_protocol_tokens, args);
1446 
1447 			protofamily = AF_INET;
1448 			switch (token) {
1449 			case Opt_xprt_udp6:
1450 				protofamily = AF_INET6;
1451 			case Opt_xprt_udp:
1452 				mnt->flags &= ~NFS_MOUNT_TCP;
1453 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1454 				break;
1455 			case Opt_xprt_tcp6:
1456 				protofamily = AF_INET6;
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 			case Opt_xprt_rdma:
1464 				/* vector side protocols to TCP */
1465 				mnt->flags |= NFS_MOUNT_TCP;
1466 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1467 				xprt_load_transport(string);
1468 				break;
1469 			default:
1470 				dfprintk(MOUNT, "NFS:   unrecognized "
1471 						"transport protocol\n");
1472 				kfree(string);
1473 				return 0;
1474 			}
1475 			kfree(string);
1476 			break;
1477 		case Opt_mountproto:
1478 			string = match_strdup(args);
1479 			if (string == NULL)
1480 				goto out_nomem;
1481 			token = match_token(string,
1482 					    nfs_xprt_protocol_tokens, args);
1483 			kfree(string);
1484 
1485 			mountfamily = AF_INET;
1486 			switch (token) {
1487 			case Opt_xprt_udp6:
1488 				mountfamily = AF_INET6;
1489 			case Opt_xprt_udp:
1490 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1491 				break;
1492 			case Opt_xprt_tcp6:
1493 				mountfamily = AF_INET6;
1494 			case Opt_xprt_tcp:
1495 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1496 				break;
1497 			case Opt_xprt_rdma: /* not used for side protocols */
1498 			default:
1499 				dfprintk(MOUNT, "NFS:   unrecognized "
1500 						"transport protocol\n");
1501 				return 0;
1502 			}
1503 			break;
1504 		case Opt_addr:
1505 			string = match_strdup(args);
1506 			if (string == NULL)
1507 				goto out_nomem;
1508 			mnt->nfs_server.addrlen =
1509 				rpc_pton(mnt->net, string, strlen(string),
1510 					(struct sockaddr *)
1511 					&mnt->nfs_server.address,
1512 					sizeof(mnt->nfs_server.address));
1513 			kfree(string);
1514 			if (mnt->nfs_server.addrlen == 0)
1515 				goto out_invalid_address;
1516 			break;
1517 		case Opt_clientaddr:
1518 			if (nfs_get_option_str(args, &mnt->client_address))
1519 				goto out_nomem;
1520 			break;
1521 		case Opt_mounthost:
1522 			if (nfs_get_option_str(args,
1523 					       &mnt->mount_server.hostname))
1524 				goto out_nomem;
1525 			break;
1526 		case Opt_mountaddr:
1527 			string = match_strdup(args);
1528 			if (string == NULL)
1529 				goto out_nomem;
1530 			mnt->mount_server.addrlen =
1531 				rpc_pton(mnt->net, string, strlen(string),
1532 					(struct sockaddr *)
1533 					&mnt->mount_server.address,
1534 					sizeof(mnt->mount_server.address));
1535 			kfree(string);
1536 			if (mnt->mount_server.addrlen == 0)
1537 				goto out_invalid_address;
1538 			break;
1539 		case Opt_lookupcache:
1540 			string = match_strdup(args);
1541 			if (string == NULL)
1542 				goto out_nomem;
1543 			token = match_token(string,
1544 					nfs_lookupcache_tokens, args);
1545 			kfree(string);
1546 			switch (token) {
1547 				case Opt_lookupcache_all:
1548 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1549 					break;
1550 				case Opt_lookupcache_positive:
1551 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1552 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1553 					break;
1554 				case Opt_lookupcache_none:
1555 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1556 					break;
1557 				default:
1558 					dfprintk(MOUNT, "NFS:   invalid "
1559 							"lookupcache argument\n");
1560 					return 0;
1561 			};
1562 			break;
1563 		case Opt_fscache_uniq:
1564 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1565 				goto out_nomem;
1566 			mnt->options |= NFS_OPTION_FSCACHE;
1567 			break;
1568 		case Opt_local_lock:
1569 			string = match_strdup(args);
1570 			if (string == NULL)
1571 				goto out_nomem;
1572 			token = match_token(string, nfs_local_lock_tokens,
1573 					args);
1574 			kfree(string);
1575 			switch (token) {
1576 			case Opt_local_lock_all:
1577 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1578 					       NFS_MOUNT_LOCAL_FCNTL);
1579 				break;
1580 			case Opt_local_lock_flock:
1581 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1582 				break;
1583 			case Opt_local_lock_posix:
1584 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1585 				break;
1586 			case Opt_local_lock_none:
1587 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1588 						NFS_MOUNT_LOCAL_FCNTL);
1589 				break;
1590 			default:
1591 				dfprintk(MOUNT, "NFS:	invalid	"
1592 						"local_lock argument\n");
1593 				return 0;
1594 			};
1595 			break;
1596 
1597 		/*
1598 		 * Special options
1599 		 */
1600 		case Opt_sloppy:
1601 			sloppy = 1;
1602 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1603 			break;
1604 		case Opt_userspace:
1605 		case Opt_deprecated:
1606 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1607 					"'%s'\n", p);
1608 			break;
1609 
1610 		default:
1611 			invalid_option = 1;
1612 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1613 					"'%s'\n", p);
1614 		}
1615 	}
1616 
1617 	if (!sloppy && invalid_option)
1618 		return 0;
1619 
1620 	if (mnt->minorversion && mnt->version != 4)
1621 		goto out_minorversion_mismatch;
1622 
1623 	if (mnt->options & NFS_OPTION_MIGRATION &&
1624 	    (mnt->version != 4 || mnt->minorversion != 0))
1625 		goto out_migration_misuse;
1626 
1627 	/*
1628 	 * verify that any proto=/mountproto= options match the address
1629 	 * families in the addr=/mountaddr= options.
1630 	 */
1631 	if (protofamily != AF_UNSPEC &&
1632 	    protofamily != mnt->nfs_server.address.ss_family)
1633 		goto out_proto_mismatch;
1634 
1635 	if (mountfamily != AF_UNSPEC) {
1636 		if (mnt->mount_server.addrlen) {
1637 			if (mountfamily != mnt->mount_server.address.ss_family)
1638 				goto out_mountproto_mismatch;
1639 		} else {
1640 			if (mountfamily != mnt->nfs_server.address.ss_family)
1641 				goto out_mountproto_mismatch;
1642 		}
1643 	}
1644 
1645 	return 1;
1646 
1647 out_mountproto_mismatch:
1648 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1649 			 "option\n");
1650 	return 0;
1651 out_proto_mismatch:
1652 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1653 	return 0;
1654 out_invalid_address:
1655 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1656 	return 0;
1657 out_invalid_value:
1658 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1659 	return 0;
1660 out_minorversion_mismatch:
1661 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1662 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1663 	return 0;
1664 out_migration_misuse:
1665 	printk(KERN_INFO
1666 		"NFS: 'migration' not supported for this NFS version\n");
1667 	return 0;
1668 out_nomem:
1669 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1670 	return 0;
1671 out_security_failure:
1672 	free_secdata(secdata);
1673 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1674 	return 0;
1675 }
1676 
1677 /*
1678  * Ensure that a specified authtype in args->auth_info is supported by
1679  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1680  * -EACCES if not.
1681  */
1682 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1683 			rpc_authflavor_t *server_authlist, unsigned int count)
1684 {
1685 	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1686 	unsigned int i;
1687 
1688 	/*
1689 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1690 	 * must be in the list returned by the server.
1691 	 *
1692 	 * AUTH_NULL has a special meaning when it's in the server list - it
1693 	 * means that the server will ignore the rpc creds, so any flavor
1694 	 * can be used.
1695 	 */
1696 	for (i = 0; i < count; i++) {
1697 		flavor = server_authlist[i];
1698 
1699 		if (nfs_auth_info_match(&args->auth_info, flavor) ||
1700 		    flavor == RPC_AUTH_NULL)
1701 			goto out;
1702 	}
1703 
1704 	dfprintk(MOUNT,
1705 		 "NFS: specified auth flavors not supported by server\n");
1706 	return -EACCES;
1707 
1708 out:
1709 	args->selected_flavor = flavor;
1710 	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1711 	return 0;
1712 }
1713 
1714 /*
1715  * Use the remote server's MOUNT service to request the NFS file handle
1716  * corresponding to the provided path.
1717  */
1718 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1719 			     struct nfs_fh *root_fh,
1720 			     rpc_authflavor_t *server_authlist,
1721 			     unsigned int *server_authlist_len)
1722 {
1723 	struct nfs_mount_request request = {
1724 		.sap		= (struct sockaddr *)
1725 						&args->mount_server.address,
1726 		.dirpath	= args->nfs_server.export_path,
1727 		.protocol	= args->mount_server.protocol,
1728 		.fh		= root_fh,
1729 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1730 		.auth_flav_len	= server_authlist_len,
1731 		.auth_flavs	= server_authlist,
1732 		.net		= args->net,
1733 	};
1734 	int status;
1735 
1736 	if (args->mount_server.version == 0) {
1737 		switch (args->version) {
1738 			default:
1739 				args->mount_server.version = NFS_MNT3_VERSION;
1740 				break;
1741 			case 2:
1742 				args->mount_server.version = NFS_MNT_VERSION;
1743 		}
1744 	}
1745 	request.version = args->mount_server.version;
1746 
1747 	if (args->mount_server.hostname)
1748 		request.hostname = args->mount_server.hostname;
1749 	else
1750 		request.hostname = args->nfs_server.hostname;
1751 
1752 	/*
1753 	 * Construct the mount server's address.
1754 	 */
1755 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1756 		memcpy(request.sap, &args->nfs_server.address,
1757 		       args->nfs_server.addrlen);
1758 		args->mount_server.addrlen = args->nfs_server.addrlen;
1759 	}
1760 	request.salen = args->mount_server.addrlen;
1761 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1762 
1763 	/*
1764 	 * Now ask the mount server to map our export path
1765 	 * to a file handle.
1766 	 */
1767 	status = nfs_mount(&request);
1768 	if (status != 0) {
1769 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1770 				request.hostname, status);
1771 		return status;
1772 	}
1773 
1774 	return 0;
1775 }
1776 
1777 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1778 					struct nfs_subversion *nfs_mod)
1779 {
1780 	int status;
1781 	unsigned int i;
1782 	bool tried_auth_unix = false;
1783 	bool auth_null_in_list = false;
1784 	struct nfs_server *server = ERR_PTR(-EACCES);
1785 	struct nfs_parsed_mount_data *args = mount_info->parsed;
1786 	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1787 	unsigned int authlist_len = ARRAY_SIZE(authlist);
1788 
1789 	status = nfs_request_mount(args, mount_info->mntfh, authlist,
1790 					&authlist_len);
1791 	if (status)
1792 		return ERR_PTR(status);
1793 
1794 	/*
1795 	 * Was a sec= authflavor specified in the options? First, verify
1796 	 * whether the server supports it, and then just try to use it if so.
1797 	 */
1798 	if (args->auth_info.flavor_len > 0) {
1799 		status = nfs_verify_authflavors(args, authlist, authlist_len);
1800 		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1801 			 args->selected_flavor);
1802 		if (status)
1803 			return ERR_PTR(status);
1804 		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1805 	}
1806 
1807 	/*
1808 	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
1809 	 * SHOULD prefer the flavor listed first. However, some servers list
1810 	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1811 	 */
1812 	for (i = 0; i < authlist_len; ++i) {
1813 		rpc_authflavor_t flavor;
1814 		struct rpcsec_gss_info info;
1815 
1816 		flavor = authlist[i];
1817 		switch (flavor) {
1818 		case RPC_AUTH_UNIX:
1819 			tried_auth_unix = true;
1820 			break;
1821 		case RPC_AUTH_NULL:
1822 			auth_null_in_list = true;
1823 			continue;
1824 		default:
1825 			if (rpcauth_get_gssinfo(flavor, &info) != 0)
1826 				continue;
1827 			/* Fallthrough */
1828 		}
1829 		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1830 		args->selected_flavor = flavor;
1831 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1832 		if (!IS_ERR(server))
1833 			return server;
1834 	}
1835 
1836 	/*
1837 	 * Nothing we tried so far worked. At this point, give up if we've
1838 	 * already tried AUTH_UNIX or if the server's list doesn't contain
1839 	 * AUTH_NULL
1840 	 */
1841 	if (tried_auth_unix || !auth_null_in_list)
1842 		return server;
1843 
1844 	/* Last chance! Try AUTH_UNIX */
1845 	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1846 	args->selected_flavor = RPC_AUTH_UNIX;
1847 	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1848 }
1849 
1850 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1851 			     struct nfs_mount_info *mount_info,
1852 			     struct nfs_subversion *nfs_mod)
1853 {
1854 	struct nfs_server *server;
1855 
1856 	if (mount_info->parsed->need_mount)
1857 		server = nfs_try_mount_request(mount_info, nfs_mod);
1858 	else
1859 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1860 
1861 	if (IS_ERR(server))
1862 		return ERR_CAST(server);
1863 
1864 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1865 }
1866 EXPORT_SYMBOL_GPL(nfs_try_mount);
1867 
1868 /*
1869  * Split "dev_name" into "hostname:export_path".
1870  *
1871  * The leftmost colon demarks the split between the server's hostname
1872  * and the export path.  If the hostname starts with a left square
1873  * bracket, then it may contain colons.
1874  *
1875  * Note: caller frees hostname and export path, even on error.
1876  */
1877 static int nfs_parse_devname(const char *dev_name,
1878 			     char **hostname, size_t maxnamlen,
1879 			     char **export_path, size_t maxpathlen)
1880 {
1881 	size_t len;
1882 	char *end;
1883 
1884 	/* Is the host name protected with square brakcets? */
1885 	if (*dev_name == '[') {
1886 		end = strchr(++dev_name, ']');
1887 		if (end == NULL || end[1] != ':')
1888 			goto out_bad_devname;
1889 
1890 		len = end - dev_name;
1891 		end++;
1892 	} else {
1893 		char *comma;
1894 
1895 		end = strchr(dev_name, ':');
1896 		if (end == NULL)
1897 			goto out_bad_devname;
1898 		len = end - dev_name;
1899 
1900 		/* kill possible hostname list: not supported */
1901 		comma = strchr(dev_name, ',');
1902 		if (comma != NULL && comma < end)
1903 			*comma = 0;
1904 	}
1905 
1906 	if (len > maxnamlen)
1907 		goto out_hostname;
1908 
1909 	/* N.B. caller will free nfs_server.hostname in all cases */
1910 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1911 	if (*hostname == NULL)
1912 		goto out_nomem;
1913 	len = strlen(++end);
1914 	if (len > maxpathlen)
1915 		goto out_path;
1916 	*export_path = kstrndup(end, len, GFP_KERNEL);
1917 	if (!*export_path)
1918 		goto out_nomem;
1919 
1920 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1921 	return 0;
1922 
1923 out_bad_devname:
1924 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1925 	return -EINVAL;
1926 
1927 out_nomem:
1928 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1929 	return -ENOMEM;
1930 
1931 out_hostname:
1932 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1933 	return -ENAMETOOLONG;
1934 
1935 out_path:
1936 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1937 	return -ENAMETOOLONG;
1938 }
1939 
1940 /*
1941  * Validate the NFS2/NFS3 mount data
1942  * - fills in the mount root filehandle
1943  *
1944  * For option strings, user space handles the following behaviors:
1945  *
1946  * + DNS: mapping server host name to IP address ("addr=" option)
1947  *
1948  * + failure mode: how to behave if a mount request can't be handled
1949  *   immediately ("fg/bg" option)
1950  *
1951  * + retry: how often to retry a mount request ("retry=" option)
1952  *
1953  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1954  *   mountproto=tcp after mountproto=udp, and so on
1955  */
1956 static int nfs23_validate_mount_data(void *options,
1957 				     struct nfs_parsed_mount_data *args,
1958 				     struct nfs_fh *mntfh,
1959 				     const char *dev_name)
1960 {
1961 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1962 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1963 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1964 
1965 	if (data == NULL)
1966 		goto out_no_data;
1967 
1968 	args->version = NFS_DEFAULT_VERSION;
1969 	switch (data->version) {
1970 	case 1:
1971 		data->namlen = 0;
1972 	case 2:
1973 		data->bsize = 0;
1974 	case 3:
1975 		if (data->flags & NFS_MOUNT_VER3)
1976 			goto out_no_v3;
1977 		data->root.size = NFS2_FHSIZE;
1978 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1979 		/* Turn off security negotiation */
1980 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
1981 	case 4:
1982 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1983 			goto out_no_sec;
1984 	case 5:
1985 		memset(data->context, 0, sizeof(data->context));
1986 	case 6:
1987 		if (data->flags & NFS_MOUNT_VER3) {
1988 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1989 				goto out_invalid_fh;
1990 			mntfh->size = data->root.size;
1991 			args->version = 3;
1992 		} else {
1993 			mntfh->size = NFS2_FHSIZE;
1994 			args->version = 2;
1995 		}
1996 
1997 
1998 		memcpy(mntfh->data, data->root.data, mntfh->size);
1999 		if (mntfh->size < sizeof(mntfh->data))
2000 			memset(mntfh->data + mntfh->size, 0,
2001 			       sizeof(mntfh->data) - mntfh->size);
2002 
2003 		/*
2004 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
2005 		 * can deal with.
2006 		 */
2007 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
2008 		args->flags		|= extra_flags;
2009 		args->rsize		= data->rsize;
2010 		args->wsize		= data->wsize;
2011 		args->timeo		= data->timeo;
2012 		args->retrans		= data->retrans;
2013 		args->acregmin		= data->acregmin;
2014 		args->acregmax		= data->acregmax;
2015 		args->acdirmin		= data->acdirmin;
2016 		args->acdirmax		= data->acdirmax;
2017 		args->need_mount	= false;
2018 
2019 		memcpy(sap, &data->addr, sizeof(data->addr));
2020 		args->nfs_server.addrlen = sizeof(data->addr);
2021 		args->nfs_server.port = ntohs(data->addr.sin_port);
2022 		if (!nfs_verify_server_address(sap))
2023 			goto out_no_address;
2024 
2025 		if (!(data->flags & NFS_MOUNT_TCP))
2026 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2027 		/* N.B. caller will free nfs_server.hostname in all cases */
2028 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2029 		args->namlen		= data->namlen;
2030 		args->bsize		= data->bsize;
2031 
2032 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2033 			args->selected_flavor = data->pseudoflavor;
2034 		else
2035 			args->selected_flavor = RPC_AUTH_UNIX;
2036 		if (!args->nfs_server.hostname)
2037 			goto out_nomem;
2038 
2039 		if (!(data->flags & NFS_MOUNT_NONLM))
2040 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2041 					 NFS_MOUNT_LOCAL_FCNTL);
2042 		else
2043 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2044 					NFS_MOUNT_LOCAL_FCNTL);
2045 		/*
2046 		 * The legacy version 6 binary mount data from userspace has a
2047 		 * field used only to transport selinux information into the
2048 		 * the kernel.  To continue to support that functionality we
2049 		 * have a touch of selinux knowledge here in the NFS code. The
2050 		 * userspace code converted context=blah to just blah so we are
2051 		 * converting back to the full string selinux understands.
2052 		 */
2053 		if (data->context[0]){
2054 #ifdef CONFIG_SECURITY_SELINUX
2055 			int rc;
2056 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
2057 			if (!opts_str)
2058 				return -ENOMEM;
2059 			strcpy(opts_str, "context=");
2060 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2061 			strcat(opts_str, &data->context[0]);
2062 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
2063 			kfree(opts_str);
2064 			if (rc)
2065 				return rc;
2066 #else
2067 			return -EINVAL;
2068 #endif
2069 		}
2070 
2071 		break;
2072 	default:
2073 		return NFS_TEXT_DATA;
2074 	}
2075 
2076 	return 0;
2077 
2078 out_no_data:
2079 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2080 	return -EINVAL;
2081 
2082 out_no_v3:
2083 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2084 		 data->version);
2085 	return -EINVAL;
2086 
2087 out_no_sec:
2088 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2089 	return -EINVAL;
2090 
2091 out_nomem:
2092 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2093 	return -ENOMEM;
2094 
2095 out_no_address:
2096 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2097 	return -EINVAL;
2098 
2099 out_invalid_fh:
2100 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2101 	return -EINVAL;
2102 }
2103 
2104 #if IS_ENABLED(CONFIG_NFS_V4)
2105 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2106 				   void *options,
2107 				   struct nfs_parsed_mount_data *args,
2108 				   struct nfs_fh *mntfh,
2109 				   const char *dev_name)
2110 {
2111 	if (fs_type == &nfs_fs_type)
2112 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2113 	return nfs4_validate_mount_data(options, args, dev_name);
2114 }
2115 #else
2116 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2117 				   void *options,
2118 				   struct nfs_parsed_mount_data *args,
2119 				   struct nfs_fh *mntfh,
2120 				   const char *dev_name)
2121 {
2122 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2123 }
2124 #endif
2125 
2126 static int nfs_validate_text_mount_data(void *options,
2127 					struct nfs_parsed_mount_data *args,
2128 					const char *dev_name)
2129 {
2130 	int port = 0;
2131 	int max_namelen = PAGE_SIZE;
2132 	int max_pathlen = NFS_MAXPATHLEN;
2133 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2134 
2135 	if (nfs_parse_mount_options((char *)options, args) == 0)
2136 		return -EINVAL;
2137 
2138 	if (!nfs_verify_server_address(sap))
2139 		goto out_no_address;
2140 
2141 	if (args->version == 4) {
2142 #if IS_ENABLED(CONFIG_NFS_V4)
2143 		port = NFS_PORT;
2144 		max_namelen = NFS4_MAXNAMLEN;
2145 		max_pathlen = NFS4_MAXPATHLEN;
2146 		nfs_validate_transport_protocol(args);
2147 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2148 			goto out_invalid_transport_udp;
2149 		nfs4_validate_mount_flags(args);
2150 #else
2151 		goto out_v4_not_compiled;
2152 #endif /* CONFIG_NFS_V4 */
2153 	} else
2154 		nfs_set_mount_transport_protocol(args);
2155 
2156 	nfs_set_port(sap, &args->nfs_server.port, port);
2157 
2158 	return nfs_parse_devname(dev_name,
2159 				   &args->nfs_server.hostname,
2160 				   max_namelen,
2161 				   &args->nfs_server.export_path,
2162 				   max_pathlen);
2163 
2164 #if !IS_ENABLED(CONFIG_NFS_V4)
2165 out_v4_not_compiled:
2166 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2167 	return -EPROTONOSUPPORT;
2168 #else
2169 out_invalid_transport_udp:
2170 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2171 	return -EINVAL;
2172 #endif /* !CONFIG_NFS_V4 */
2173 
2174 out_no_address:
2175 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2176 	return -EINVAL;
2177 }
2178 
2179 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2180 		| NFS_MOUNT_SECURE \
2181 		| NFS_MOUNT_TCP \
2182 		| NFS_MOUNT_VER3 \
2183 		| NFS_MOUNT_KERBEROS \
2184 		| NFS_MOUNT_NONLM \
2185 		| NFS_MOUNT_BROKEN_SUID \
2186 		| NFS_MOUNT_STRICTLOCK \
2187 		| NFS_MOUNT_LEGACY_INTERFACE)
2188 
2189 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2190 		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2191 
2192 static int
2193 nfs_compare_remount_data(struct nfs_server *nfss,
2194 			 struct nfs_parsed_mount_data *data)
2195 {
2196 	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2197 	    data->rsize != nfss->rsize ||
2198 	    data->wsize != nfss->wsize ||
2199 	    data->version != nfss->nfs_client->rpc_ops->version ||
2200 	    data->minorversion != nfss->nfs_client->cl_minorversion ||
2201 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2202 	    !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2203 	    data->acregmin != nfss->acregmin / HZ ||
2204 	    data->acregmax != nfss->acregmax / HZ ||
2205 	    data->acdirmin != nfss->acdirmin / HZ ||
2206 	    data->acdirmax != nfss->acdirmax / HZ ||
2207 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2208 	    data->nfs_server.port != nfss->port ||
2209 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2210 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2211 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2212 		return -EINVAL;
2213 
2214 	return 0;
2215 }
2216 
2217 int
2218 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2219 {
2220 	int error;
2221 	struct nfs_server *nfss = sb->s_fs_info;
2222 	struct nfs_parsed_mount_data *data;
2223 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2224 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2225 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2226 
2227 	sync_filesystem(sb);
2228 
2229 	/*
2230 	 * Userspace mount programs that send binary options generally send
2231 	 * them populated with default values. We have no way to know which
2232 	 * ones were explicitly specified. Fall back to legacy behavior and
2233 	 * just return success.
2234 	 */
2235 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2236 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2237 					   options->version <= 6))))
2238 		return 0;
2239 
2240 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2241 	if (data == NULL)
2242 		return -ENOMEM;
2243 
2244 	/* fill out struct with values from existing mount */
2245 	data->flags = nfss->flags;
2246 	data->rsize = nfss->rsize;
2247 	data->wsize = nfss->wsize;
2248 	data->retrans = nfss->client->cl_timeout->to_retries;
2249 	data->selected_flavor = nfss->client->cl_auth->au_flavor;
2250 	data->acregmin = nfss->acregmin / HZ;
2251 	data->acregmax = nfss->acregmax / HZ;
2252 	data->acdirmin = nfss->acdirmin / HZ;
2253 	data->acdirmax = nfss->acdirmax / HZ;
2254 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2255 	data->nfs_server.port = nfss->port;
2256 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2257 	data->version = nfsvers;
2258 	data->minorversion = nfss->nfs_client->cl_minorversion;
2259 	data->net = current->nsproxy->net_ns;
2260 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2261 		data->nfs_server.addrlen);
2262 
2263 	/* overwrite those values with any that were specified */
2264 	error = -EINVAL;
2265 	if (!nfs_parse_mount_options((char *)options, data))
2266 		goto out;
2267 
2268 	/*
2269 	 * noac is a special case. It implies -o sync, but that's not
2270 	 * necessarily reflected in the mtab options. do_remount_sb
2271 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2272 	 * remount options, so we have to explicitly reset it.
2273 	 */
2274 	if (data->flags & NFS_MOUNT_NOAC)
2275 		*flags |= MS_SYNCHRONOUS;
2276 
2277 	/* compare new mount options with old ones */
2278 	error = nfs_compare_remount_data(nfss, data);
2279 out:
2280 	kfree(data);
2281 	return error;
2282 }
2283 EXPORT_SYMBOL_GPL(nfs_remount);
2284 
2285 /*
2286  * Initialise the common bits of the superblock
2287  */
2288 inline void nfs_initialise_sb(struct super_block *sb)
2289 {
2290 	struct nfs_server *server = NFS_SB(sb);
2291 
2292 	sb->s_magic = NFS_SUPER_MAGIC;
2293 
2294 	/* We probably want something more informative here */
2295 	snprintf(sb->s_id, sizeof(sb->s_id),
2296 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2297 
2298 	if (sb->s_blocksize == 0)
2299 		sb->s_blocksize = nfs_block_bits(server->wsize,
2300 						 &sb->s_blocksize_bits);
2301 
2302 	sb->s_bdi = &server->backing_dev_info;
2303 
2304 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2305 }
2306 
2307 /*
2308  * Finish setting up an NFS2/3 superblock
2309  */
2310 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2311 {
2312 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2313 	struct nfs_server *server = NFS_SB(sb);
2314 
2315 	sb->s_blocksize_bits = 0;
2316 	sb->s_blocksize = 0;
2317 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2318 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2319 	if (data && data->bsize)
2320 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2321 
2322 	if (server->nfs_client->rpc_ops->version != 2) {
2323 		/* The VFS shouldn't apply the umask to mode bits. We will do
2324 		 * so ourselves when necessary.
2325 		 */
2326 		sb->s_flags |= MS_POSIXACL;
2327 		sb->s_time_gran = 1;
2328 	}
2329 
2330  	nfs_initialise_sb(sb);
2331 }
2332 EXPORT_SYMBOL_GPL(nfs_fill_super);
2333 
2334 /*
2335  * Finish setting up a cloned NFS2/3/4 superblock
2336  */
2337 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2338 {
2339 	const struct super_block *old_sb = mount_info->cloned->sb;
2340 	struct nfs_server *server = NFS_SB(sb);
2341 
2342 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2343 	sb->s_blocksize = old_sb->s_blocksize;
2344 	sb->s_maxbytes = old_sb->s_maxbytes;
2345 	sb->s_xattr = old_sb->s_xattr;
2346 	sb->s_op = old_sb->s_op;
2347 	sb->s_time_gran = 1;
2348 
2349 	if (server->nfs_client->rpc_ops->version != 2) {
2350 		/* The VFS shouldn't apply the umask to mode bits. We will do
2351 		 * so ourselves when necessary.
2352 		 */
2353 		sb->s_flags |= MS_POSIXACL;
2354 	}
2355 
2356  	nfs_initialise_sb(sb);
2357 }
2358 
2359 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2360 {
2361 	const struct nfs_server *a = s->s_fs_info;
2362 	const struct rpc_clnt *clnt_a = a->client;
2363 	const struct rpc_clnt *clnt_b = b->client;
2364 
2365 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2366 		goto Ebusy;
2367 	if (a->nfs_client != b->nfs_client)
2368 		goto Ebusy;
2369 	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2370 		goto Ebusy;
2371 	if (a->wsize != b->wsize)
2372 		goto Ebusy;
2373 	if (a->rsize != b->rsize)
2374 		goto Ebusy;
2375 	if (a->acregmin != b->acregmin)
2376 		goto Ebusy;
2377 	if (a->acregmax != b->acregmax)
2378 		goto Ebusy;
2379 	if (a->acdirmin != b->acdirmin)
2380 		goto Ebusy;
2381 	if (a->acdirmax != b->acdirmax)
2382 		goto Ebusy;
2383 	if (b->auth_info.flavor_len > 0 &&
2384 	   clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2385 		goto Ebusy;
2386 	return 1;
2387 Ebusy:
2388 	return 0;
2389 }
2390 
2391 struct nfs_sb_mountdata {
2392 	struct nfs_server *server;
2393 	int mntflags;
2394 };
2395 
2396 static int nfs_set_super(struct super_block *s, void *data)
2397 {
2398 	struct nfs_sb_mountdata *sb_mntdata = data;
2399 	struct nfs_server *server = sb_mntdata->server;
2400 	int ret;
2401 
2402 	s->s_flags = sb_mntdata->mntflags;
2403 	s->s_fs_info = server;
2404 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2405 	ret = set_anon_super(s, server);
2406 	if (ret == 0)
2407 		server->s_dev = s->s_dev;
2408 	return ret;
2409 }
2410 
2411 static int nfs_compare_super_address(struct nfs_server *server1,
2412 				     struct nfs_server *server2)
2413 {
2414 	struct sockaddr *sap1, *sap2;
2415 	struct rpc_xprt *xprt1 = server1->client->cl_xprt;
2416 	struct rpc_xprt *xprt2 = server2->client->cl_xprt;
2417 
2418 	if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
2419 		return 0;
2420 
2421 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2422 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2423 
2424 	if (sap1->sa_family != sap2->sa_family)
2425 		return 0;
2426 
2427 	switch (sap1->sa_family) {
2428 	case AF_INET: {
2429 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2430 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2431 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2432 			return 0;
2433 		if (sin1->sin_port != sin2->sin_port)
2434 			return 0;
2435 		break;
2436 	}
2437 	case AF_INET6: {
2438 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2439 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2440 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2441 			return 0;
2442 		if (sin1->sin6_port != sin2->sin6_port)
2443 			return 0;
2444 		break;
2445 	}
2446 	default:
2447 		return 0;
2448 	}
2449 
2450 	return 1;
2451 }
2452 
2453 static int nfs_compare_super(struct super_block *sb, void *data)
2454 {
2455 	struct nfs_sb_mountdata *sb_mntdata = data;
2456 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2457 	int mntflags = sb_mntdata->mntflags;
2458 
2459 	if (!nfs_compare_super_address(old, server))
2460 		return 0;
2461 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2462 	if (old->flags & NFS_MOUNT_UNSHARED)
2463 		return 0;
2464 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2465 		return 0;
2466 	return nfs_compare_mount_options(sb, server, mntflags);
2467 }
2468 
2469 #ifdef CONFIG_NFS_FSCACHE
2470 static void nfs_get_cache_cookie(struct super_block *sb,
2471 				 struct nfs_parsed_mount_data *parsed,
2472 				 struct nfs_clone_mount *cloned)
2473 {
2474 	struct nfs_server *nfss = NFS_SB(sb);
2475 	char *uniq = NULL;
2476 	int ulen = 0;
2477 
2478 	nfss->fscache_key = NULL;
2479 	nfss->fscache = NULL;
2480 
2481 	if (parsed) {
2482 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2483 			return;
2484 		if (parsed->fscache_uniq) {
2485 			uniq = parsed->fscache_uniq;
2486 			ulen = strlen(parsed->fscache_uniq);
2487 		}
2488 	} else if (cloned) {
2489 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2490 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2491 			return;
2492 		if (mnt_s->fscache_key) {
2493 			uniq = mnt_s->fscache_key->key.uniquifier;
2494 			ulen = mnt_s->fscache_key->key.uniq_len;
2495 		};
2496 	} else
2497 		return;
2498 
2499 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2500 }
2501 #else
2502 static void nfs_get_cache_cookie(struct super_block *sb,
2503 				 struct nfs_parsed_mount_data *parsed,
2504 				 struct nfs_clone_mount *cloned)
2505 {
2506 }
2507 #endif
2508 
2509 static int nfs_bdi_register(struct nfs_server *server)
2510 {
2511 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2512 }
2513 
2514 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2515 			struct nfs_mount_info *mount_info)
2516 {
2517 	int error;
2518 	unsigned long kflags = 0, kflags_out = 0;
2519 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2520 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2521 
2522 	error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
2523 						kflags, &kflags_out);
2524 	if (error)
2525 		goto err;
2526 
2527 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2528 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2529 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2530 err:
2531 	return error;
2532 }
2533 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2534 
2535 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2536 			  struct nfs_mount_info *mount_info)
2537 {
2538 	/* clone any lsm security options from the parent to the new sb */
2539 	if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2540 		return -ESTALE;
2541 	return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2542 }
2543 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2544 
2545 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2546 				   int flags, const char *dev_name,
2547 				   struct nfs_mount_info *mount_info,
2548 				   struct nfs_subversion *nfs_mod)
2549 {
2550 	struct super_block *s;
2551 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2552 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2553 	struct nfs_sb_mountdata sb_mntdata = {
2554 		.mntflags = flags,
2555 		.server = server,
2556 	};
2557 	int error;
2558 
2559 	if (server->flags & NFS_MOUNT_UNSHARED)
2560 		compare_super = NULL;
2561 
2562 	/* -o noac implies -o sync */
2563 	if (server->flags & NFS_MOUNT_NOAC)
2564 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2565 
2566 	if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2567 		if (mount_info->cloned->sb->s_flags & MS_SYNCHRONOUS)
2568 			sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2569 
2570 	/* Get a superblock - note that we may end up sharing one that already exists */
2571 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2572 	if (IS_ERR(s)) {
2573 		mntroot = ERR_CAST(s);
2574 		goto out_err_nosb;
2575 	}
2576 
2577 	if (s->s_fs_info != server) {
2578 		nfs_free_server(server);
2579 		server = NULL;
2580 	} else {
2581 		error = nfs_bdi_register(server);
2582 		if (error) {
2583 			mntroot = ERR_PTR(error);
2584 			goto error_splat_super;
2585 		}
2586 		server->super = s;
2587 	}
2588 
2589 	if (!s->s_root) {
2590 		/* initial superblock/root creation */
2591 		mount_info->fill_super(s, mount_info);
2592 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2593 	}
2594 
2595 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2596 	if (IS_ERR(mntroot))
2597 		goto error_splat_super;
2598 
2599 	error = mount_info->set_security(s, mntroot, mount_info);
2600 	if (error)
2601 		goto error_splat_root;
2602 
2603 	s->s_flags |= MS_ACTIVE;
2604 
2605 out:
2606 	return mntroot;
2607 
2608 out_err_nosb:
2609 	nfs_free_server(server);
2610 	goto out;
2611 
2612 error_splat_root:
2613 	dput(mntroot);
2614 	mntroot = ERR_PTR(error);
2615 error_splat_super:
2616 	deactivate_locked_super(s);
2617 	goto out;
2618 }
2619 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2620 
2621 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2622 	int flags, const char *dev_name, void *raw_data)
2623 {
2624 	struct nfs_mount_info mount_info = {
2625 		.fill_super = nfs_fill_super,
2626 		.set_security = nfs_set_sb_security,
2627 	};
2628 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2629 	struct nfs_subversion *nfs_mod;
2630 	int error;
2631 
2632 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2633 	mount_info.mntfh = nfs_alloc_fhandle();
2634 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2635 		goto out;
2636 
2637 	/* Validate the mount data */
2638 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2639 	if (error == NFS_TEXT_DATA)
2640 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2641 	if (error < 0) {
2642 		mntroot = ERR_PTR(error);
2643 		goto out;
2644 	}
2645 
2646 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2647 	if (IS_ERR(nfs_mod)) {
2648 		mntroot = ERR_CAST(nfs_mod);
2649 		goto out;
2650 	}
2651 
2652 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2653 
2654 	put_nfs_version(nfs_mod);
2655 out:
2656 	nfs_free_parsed_mount_data(mount_info.parsed);
2657 	nfs_free_fhandle(mount_info.mntfh);
2658 	return mntroot;
2659 }
2660 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2661 
2662 /*
2663  * Destroy an NFS2/3 superblock
2664  */
2665 void nfs_kill_super(struct super_block *s)
2666 {
2667 	struct nfs_server *server = NFS_SB(s);
2668 	dev_t dev = s->s_dev;
2669 
2670 	generic_shutdown_super(s);
2671 
2672 	nfs_fscache_release_super_cookie(s);
2673 
2674 	nfs_free_server(server);
2675 	free_anon_bdev(dev);
2676 }
2677 EXPORT_SYMBOL_GPL(nfs_kill_super);
2678 
2679 /*
2680  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2681  */
2682 static struct dentry *
2683 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2684 		const char *dev_name, void *raw_data)
2685 {
2686 	struct nfs_clone_mount *data = raw_data;
2687 	struct nfs_mount_info mount_info = {
2688 		.fill_super = nfs_clone_super,
2689 		.set_security = nfs_clone_sb_security,
2690 		.cloned = data,
2691 	};
2692 	struct nfs_server *server;
2693 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2694 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2695 
2696 	dprintk("--> nfs_xdev_mount()\n");
2697 
2698 	mount_info.mntfh = mount_info.cloned->fh;
2699 
2700 	/* create a new volume representation */
2701 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2702 
2703 	if (IS_ERR(server))
2704 		mntroot = ERR_CAST(server);
2705 	else
2706 		mntroot = nfs_fs_mount_common(server, flags,
2707 				dev_name, &mount_info, nfs_mod);
2708 
2709 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2710 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2711 	return mntroot;
2712 }
2713 
2714 #if IS_ENABLED(CONFIG_NFS_V4)
2715 
2716 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2717 {
2718 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2719 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2720 }
2721 
2722 /*
2723  * Validate NFSv4 mount options
2724  */
2725 static int nfs4_validate_mount_data(void *options,
2726 				    struct nfs_parsed_mount_data *args,
2727 				    const char *dev_name)
2728 {
2729 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2730 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2731 	char *c;
2732 
2733 	if (data == NULL)
2734 		goto out_no_data;
2735 
2736 	args->version = 4;
2737 
2738 	switch (data->version) {
2739 	case 1:
2740 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2741 			goto out_no_address;
2742 		if (data->host_addrlen == 0)
2743 			goto out_no_address;
2744 		args->nfs_server.addrlen = data->host_addrlen;
2745 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2746 			return -EFAULT;
2747 		if (!nfs_verify_server_address(sap))
2748 			goto out_no_address;
2749 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2750 
2751 		if (data->auth_flavourlen) {
2752 			rpc_authflavor_t pseudoflavor;
2753 			if (data->auth_flavourlen > 1)
2754 				goto out_inval_auth;
2755 			if (copy_from_user(&pseudoflavor,
2756 					   data->auth_flavours,
2757 					   sizeof(pseudoflavor)))
2758 				return -EFAULT;
2759 			args->selected_flavor = pseudoflavor;
2760 		} else
2761 			args->selected_flavor = RPC_AUTH_UNIX;
2762 
2763 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2764 		if (IS_ERR(c))
2765 			return PTR_ERR(c);
2766 		args->nfs_server.hostname = c;
2767 
2768 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2769 		if (IS_ERR(c))
2770 			return PTR_ERR(c);
2771 		args->nfs_server.export_path = c;
2772 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2773 
2774 		c = strndup_user(data->client_addr.data, 16);
2775 		if (IS_ERR(c))
2776 			return PTR_ERR(c);
2777 		args->client_address = c;
2778 
2779 		/*
2780 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2781 		 * can deal with.
2782 		 */
2783 
2784 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2785 		args->rsize	= data->rsize;
2786 		args->wsize	= data->wsize;
2787 		args->timeo	= data->timeo;
2788 		args->retrans	= data->retrans;
2789 		args->acregmin	= data->acregmin;
2790 		args->acregmax	= data->acregmax;
2791 		args->acdirmin	= data->acdirmin;
2792 		args->acdirmax	= data->acdirmax;
2793 		args->nfs_server.protocol = data->proto;
2794 		nfs_validate_transport_protocol(args);
2795 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2796 			goto out_invalid_transport_udp;
2797 
2798 		break;
2799 	default:
2800 		return NFS_TEXT_DATA;
2801 	}
2802 
2803 	return 0;
2804 
2805 out_no_data:
2806 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2807 	return -EINVAL;
2808 
2809 out_inval_auth:
2810 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2811 		 data->auth_flavourlen);
2812 	return -EINVAL;
2813 
2814 out_no_address:
2815 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2816 	return -EINVAL;
2817 
2818 out_invalid_transport_udp:
2819 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2820 	return -EINVAL;
2821 }
2822 
2823 /*
2824  * NFS v4 module parameters need to stay in the
2825  * NFS client for backwards compatibility
2826  */
2827 unsigned int nfs_callback_set_tcpport;
2828 /* Default cache timeout is 10 minutes */
2829 unsigned int nfs_idmap_cache_timeout = 600;
2830 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2831 bool nfs4_disable_idmapping = true;
2832 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2833 unsigned short send_implementation_id = 1;
2834 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2835 bool recover_lost_locks = false;
2836 
2837 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2838 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2839 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2840 EXPORT_SYMBOL_GPL(max_session_slots);
2841 EXPORT_SYMBOL_GPL(send_implementation_id);
2842 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2843 EXPORT_SYMBOL_GPL(recover_lost_locks);
2844 
2845 #define NFS_CALLBACK_MAXPORTNR (65535U)
2846 
2847 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2848 {
2849 	unsigned long num;
2850 	int ret;
2851 
2852 	if (!val)
2853 		return -EINVAL;
2854 	ret = kstrtoul(val, 0, &num);
2855 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2856 		return -EINVAL;
2857 	*((unsigned int *)kp->arg) = num;
2858 	return 0;
2859 }
2860 static const struct kernel_param_ops param_ops_portnr = {
2861 	.set = param_set_portnr,
2862 	.get = param_get_uint,
2863 };
2864 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2865 
2866 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2867 module_param(nfs_idmap_cache_timeout, int, 0644);
2868 module_param(nfs4_disable_idmapping, bool, 0644);
2869 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2870 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2871 MODULE_PARM_DESC(nfs4_disable_idmapping,
2872 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2873 module_param(max_session_slots, ushort, 0644);
2874 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2875 		"requests the client will negotiate");
2876 module_param(send_implementation_id, ushort, 0644);
2877 MODULE_PARM_DESC(send_implementation_id,
2878 		"Send implementation ID with NFSv4.1 exchange_id");
2879 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2880 
2881 module_param(recover_lost_locks, bool, 0644);
2882 MODULE_PARM_DESC(recover_lost_locks,
2883 		 "If the server reports that a lock might be lost, "
2884 		 "try to recover it risking data corruption.");
2885 
2886 
2887 #endif /* CONFIG_NFS_V4 */
2888