xref: /linux/fs/nfs/super.c (revision f49f4ab95c301dbccad0efe85296d908b8ae7ad4)
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/stats.h>
35 #include <linux/sunrpc/metrics.h>
36 #include <linux/sunrpc/xprtsock.h>
37 #include <linux/sunrpc/xprtrdma.h>
38 #include <linux/nfs_fs.h>
39 #include <linux/nfs_mount.h>
40 #include <linux/nfs4_mount.h>
41 #include <linux/lockd/bind.h>
42 #include <linux/seq_file.h>
43 #include <linux/mount.h>
44 #include <linux/namei.h>
45 #include <linux/nfs_idmap.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 "pnfs.h"
67 #include "nfs.h"
68 
69 #define NFSDBG_FACILITY		NFSDBG_VFS
70 #define NFS_TEXT_DATA		1
71 
72 #if IS_ENABLED(CONFIG_NFS_V3)
73 #define NFS_DEFAULT_VERSION 3
74 #else
75 #define NFS_DEFAULT_VERSION 2
76 #endif
77 
78 enum {
79 	/* Mount options that take no arguments */
80 	Opt_soft, Opt_hard,
81 	Opt_posix, Opt_noposix,
82 	Opt_cto, Opt_nocto,
83 	Opt_ac, Opt_noac,
84 	Opt_lock, Opt_nolock,
85 	Opt_udp, Opt_tcp, Opt_rdma,
86 	Opt_acl, Opt_noacl,
87 	Opt_rdirplus, Opt_nordirplus,
88 	Opt_sharecache, Opt_nosharecache,
89 	Opt_resvport, Opt_noresvport,
90 	Opt_fscache, Opt_nofscache,
91 	Opt_migration, Opt_nomigration,
92 
93 	/* Mount options that take integer arguments */
94 	Opt_port,
95 	Opt_rsize, Opt_wsize, Opt_bsize,
96 	Opt_timeo, Opt_retrans,
97 	Opt_acregmin, Opt_acregmax,
98 	Opt_acdirmin, Opt_acdirmax,
99 	Opt_actimeo,
100 	Opt_namelen,
101 	Opt_mountport,
102 	Opt_mountvers,
103 	Opt_minorversion,
104 
105 	/* Mount options that take string arguments */
106 	Opt_nfsvers,
107 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
108 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
109 	Opt_lookupcache,
110 	Opt_fscache_uniq,
111 	Opt_local_lock,
112 
113 	/* Special mount options */
114 	Opt_userspace, Opt_deprecated, Opt_sloppy,
115 
116 	Opt_err
117 };
118 
119 static const match_table_t nfs_mount_option_tokens = {
120 	{ Opt_userspace, "bg" },
121 	{ Opt_userspace, "fg" },
122 	{ Opt_userspace, "retry=%s" },
123 
124 	{ Opt_sloppy, "sloppy" },
125 
126 	{ Opt_soft, "soft" },
127 	{ Opt_hard, "hard" },
128 	{ Opt_deprecated, "intr" },
129 	{ Opt_deprecated, "nointr" },
130 	{ Opt_posix, "posix" },
131 	{ Opt_noposix, "noposix" },
132 	{ Opt_cto, "cto" },
133 	{ Opt_nocto, "nocto" },
134 	{ Opt_ac, "ac" },
135 	{ Opt_noac, "noac" },
136 	{ Opt_lock, "lock" },
137 	{ Opt_nolock, "nolock" },
138 	{ Opt_udp, "udp" },
139 	{ Opt_tcp, "tcp" },
140 	{ Opt_rdma, "rdma" },
141 	{ Opt_acl, "acl" },
142 	{ Opt_noacl, "noacl" },
143 	{ Opt_rdirplus, "rdirplus" },
144 	{ Opt_nordirplus, "nordirplus" },
145 	{ Opt_sharecache, "sharecache" },
146 	{ Opt_nosharecache, "nosharecache" },
147 	{ Opt_resvport, "resvport" },
148 	{ Opt_noresvport, "noresvport" },
149 	{ Opt_fscache, "fsc" },
150 	{ Opt_nofscache, "nofsc" },
151 	{ Opt_migration, "migration" },
152 	{ Opt_nomigration, "nomigration" },
153 
154 	{ Opt_port, "port=%s" },
155 	{ Opt_rsize, "rsize=%s" },
156 	{ Opt_wsize, "wsize=%s" },
157 	{ Opt_bsize, "bsize=%s" },
158 	{ Opt_timeo, "timeo=%s" },
159 	{ Opt_retrans, "retrans=%s" },
160 	{ Opt_acregmin, "acregmin=%s" },
161 	{ Opt_acregmax, "acregmax=%s" },
162 	{ Opt_acdirmin, "acdirmin=%s" },
163 	{ Opt_acdirmax, "acdirmax=%s" },
164 	{ Opt_actimeo, "actimeo=%s" },
165 	{ Opt_namelen, "namlen=%s" },
166 	{ Opt_mountport, "mountport=%s" },
167 	{ Opt_mountvers, "mountvers=%s" },
168 	{ Opt_minorversion, "minorversion=%s" },
169 
170 	{ Opt_nfsvers, "nfsvers=%s" },
171 	{ Opt_nfsvers, "vers=%s" },
172 
173 	{ Opt_sec, "sec=%s" },
174 	{ Opt_proto, "proto=%s" },
175 	{ Opt_mountproto, "mountproto=%s" },
176 	{ Opt_addr, "addr=%s" },
177 	{ Opt_clientaddr, "clientaddr=%s" },
178 	{ Opt_mounthost, "mounthost=%s" },
179 	{ Opt_mountaddr, "mountaddr=%s" },
180 
181 	{ Opt_lookupcache, "lookupcache=%s" },
182 	{ Opt_fscache_uniq, "fsc=%s" },
183 	{ Opt_local_lock, "local_lock=%s" },
184 
185 	/* The following needs to be listed after all other options */
186 	{ Opt_nfsvers, "v%s" },
187 
188 	{ Opt_err, NULL }
189 };
190 
191 enum {
192 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
193 
194 	Opt_xprt_err
195 };
196 
197 static const match_table_t nfs_xprt_protocol_tokens = {
198 	{ Opt_xprt_udp, "udp" },
199 	{ Opt_xprt_udp6, "udp6" },
200 	{ Opt_xprt_tcp, "tcp" },
201 	{ Opt_xprt_tcp6, "tcp6" },
202 	{ Opt_xprt_rdma, "rdma" },
203 
204 	{ Opt_xprt_err, NULL }
205 };
206 
207 enum {
208 	Opt_sec_none, Opt_sec_sys,
209 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
210 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
211 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
212 
213 	Opt_sec_err
214 };
215 
216 static const match_table_t nfs_secflavor_tokens = {
217 	{ Opt_sec_none, "none" },
218 	{ Opt_sec_none, "null" },
219 	{ Opt_sec_sys, "sys" },
220 
221 	{ Opt_sec_krb5, "krb5" },
222 	{ Opt_sec_krb5i, "krb5i" },
223 	{ Opt_sec_krb5p, "krb5p" },
224 
225 	{ Opt_sec_lkey, "lkey" },
226 	{ Opt_sec_lkeyi, "lkeyi" },
227 	{ Opt_sec_lkeyp, "lkeyp" },
228 
229 	{ Opt_sec_spkm, "spkm3" },
230 	{ Opt_sec_spkmi, "spkm3i" },
231 	{ Opt_sec_spkmp, "spkm3p" },
232 
233 	{ Opt_sec_err, NULL }
234 };
235 
236 enum {
237 	Opt_lookupcache_all, Opt_lookupcache_positive,
238 	Opt_lookupcache_none,
239 
240 	Opt_lookupcache_err
241 };
242 
243 static match_table_t nfs_lookupcache_tokens = {
244 	{ Opt_lookupcache_all, "all" },
245 	{ Opt_lookupcache_positive, "pos" },
246 	{ Opt_lookupcache_positive, "positive" },
247 	{ Opt_lookupcache_none, "none" },
248 
249 	{ Opt_lookupcache_err, NULL }
250 };
251 
252 enum {
253 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
254 	Opt_local_lock_none,
255 
256 	Opt_local_lock_err
257 };
258 
259 static match_table_t nfs_local_lock_tokens = {
260 	{ Opt_local_lock_all, "all" },
261 	{ Opt_local_lock_flock, "flock" },
262 	{ Opt_local_lock_posix, "posix" },
263 	{ Opt_local_lock_none, "none" },
264 
265 	{ Opt_local_lock_err, NULL }
266 };
267 
268 enum {
269 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
270 	Opt_vers_4_1,
271 
272 	Opt_vers_err
273 };
274 
275 static match_table_t nfs_vers_tokens = {
276 	{ Opt_vers_2, "2" },
277 	{ Opt_vers_3, "3" },
278 	{ Opt_vers_4, "4" },
279 	{ Opt_vers_4_0, "4.0" },
280 	{ Opt_vers_4_1, "4.1" },
281 
282 	{ Opt_vers_err, NULL }
283 };
284 
285 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
286 		int flags, const char *dev_name, void *raw_data);
287 
288 struct file_system_type nfs_fs_type = {
289 	.owner		= THIS_MODULE,
290 	.name		= "nfs",
291 	.mount		= nfs_fs_mount,
292 	.kill_sb	= nfs_kill_super,
293 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
294 };
295 EXPORT_SYMBOL_GPL(nfs_fs_type);
296 
297 struct file_system_type nfs_xdev_fs_type = {
298 	.owner		= THIS_MODULE,
299 	.name		= "nfs",
300 	.mount		= nfs_xdev_mount,
301 	.kill_sb	= nfs_kill_super,
302 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
303 };
304 
305 const struct super_operations nfs_sops = {
306 	.alloc_inode	= nfs_alloc_inode,
307 	.destroy_inode	= nfs_destroy_inode,
308 	.write_inode	= nfs_write_inode,
309 	.put_super	= nfs_put_super,
310 	.statfs		= nfs_statfs,
311 	.evict_inode	= nfs_evict_inode,
312 	.umount_begin	= nfs_umount_begin,
313 	.show_options	= nfs_show_options,
314 	.show_devname	= nfs_show_devname,
315 	.show_path	= nfs_show_path,
316 	.show_stats	= nfs_show_stats,
317 	.remount_fs	= nfs_remount,
318 };
319 EXPORT_SYMBOL_GPL(nfs_sops);
320 
321 #if IS_ENABLED(CONFIG_NFS_V4)
322 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
323 static int nfs4_validate_mount_data(void *options,
324 	struct nfs_parsed_mount_data *args, const char *dev_name);
325 
326 struct file_system_type nfs4_fs_type = {
327 	.owner		= THIS_MODULE,
328 	.name		= "nfs4",
329 	.mount		= nfs_fs_mount,
330 	.kill_sb	= nfs_kill_super,
331 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
332 };
333 EXPORT_SYMBOL_GPL(nfs4_fs_type);
334 
335 static int __init register_nfs4_fs(void)
336 {
337 	return register_filesystem(&nfs4_fs_type);
338 }
339 
340 static void unregister_nfs4_fs(void)
341 {
342 	unregister_filesystem(&nfs4_fs_type);
343 }
344 #else
345 static int __init register_nfs4_fs(void)
346 {
347 	return 0;
348 }
349 
350 static void unregister_nfs4_fs(void)
351 {
352 }
353 #endif
354 
355 static struct shrinker acl_shrinker = {
356 	.shrink		= nfs_access_cache_shrinker,
357 	.seeks		= DEFAULT_SEEKS,
358 };
359 
360 /*
361  * Register the NFS filesystems
362  */
363 int __init register_nfs_fs(void)
364 {
365 	int ret;
366 
367         ret = register_filesystem(&nfs_fs_type);
368 	if (ret < 0)
369 		goto error_0;
370 
371 	ret = register_nfs4_fs();
372 	if (ret < 0)
373 		goto error_1;
374 
375 	ret = nfs_register_sysctl();
376 	if (ret < 0)
377 		goto error_2;
378 	register_shrinker(&acl_shrinker);
379 	return 0;
380 
381 error_2:
382 	unregister_nfs4_fs();
383 error_1:
384 	unregister_filesystem(&nfs_fs_type);
385 error_0:
386 	return ret;
387 }
388 
389 /*
390  * Unregister the NFS filesystems
391  */
392 void __exit unregister_nfs_fs(void)
393 {
394 	unregister_shrinker(&acl_shrinker);
395 	nfs_unregister_sysctl();
396 	unregister_nfs4_fs();
397 	unregister_filesystem(&nfs_fs_type);
398 }
399 
400 void nfs_sb_active(struct super_block *sb)
401 {
402 	struct nfs_server *server = NFS_SB(sb);
403 
404 	if (atomic_inc_return(&server->active) == 1)
405 		atomic_inc(&sb->s_active);
406 }
407 EXPORT_SYMBOL_GPL(nfs_sb_active);
408 
409 void nfs_sb_deactive(struct super_block *sb)
410 {
411 	struct nfs_server *server = NFS_SB(sb);
412 
413 	if (atomic_dec_and_test(&server->active))
414 		deactivate_super(sb);
415 }
416 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
417 
418 /*
419  * Deliver file system statistics to userspace
420  */
421 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
422 {
423 	struct nfs_server *server = NFS_SB(dentry->d_sb);
424 	unsigned char blockbits;
425 	unsigned long blockres;
426 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
427 	struct nfs_fsstat res;
428 	int error = -ENOMEM;
429 
430 	res.fattr = nfs_alloc_fattr();
431 	if (res.fattr == NULL)
432 		goto out_err;
433 
434 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
435 	if (unlikely(error == -ESTALE)) {
436 		struct dentry *pd_dentry;
437 
438 		pd_dentry = dget_parent(dentry);
439 		if (pd_dentry != NULL) {
440 			nfs_zap_caches(pd_dentry->d_inode);
441 			dput(pd_dentry);
442 		}
443 	}
444 	nfs_free_fattr(res.fattr);
445 	if (error < 0)
446 		goto out_err;
447 
448 	buf->f_type = NFS_SUPER_MAGIC;
449 
450 	/*
451 	 * Current versions of glibc do not correctly handle the
452 	 * case where f_frsize != f_bsize.  Eventually we want to
453 	 * report the value of wtmult in this field.
454 	 */
455 	buf->f_frsize = dentry->d_sb->s_blocksize;
456 
457 	/*
458 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
459 	 * are reported in units of f_frsize.  Linux hasn't had
460 	 * an f_frsize field in its statfs struct until recently,
461 	 * thus historically Linux's sys_statfs reports these
462 	 * fields in units of f_bsize.
463 	 */
464 	buf->f_bsize = dentry->d_sb->s_blocksize;
465 	blockbits = dentry->d_sb->s_blocksize_bits;
466 	blockres = (1 << blockbits) - 1;
467 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
468 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
469 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
470 
471 	buf->f_files = res.tfiles;
472 	buf->f_ffree = res.afiles;
473 
474 	buf->f_namelen = server->namelen;
475 
476 	return 0;
477 
478  out_err:
479 	dprintk("%s: statfs error = %d\n", __func__, -error);
480 	return error;
481 }
482 EXPORT_SYMBOL_GPL(nfs_statfs);
483 
484 /*
485  * Map the security flavour number to a name
486  */
487 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
488 {
489 	static const struct {
490 		rpc_authflavor_t flavour;
491 		const char *str;
492 	} sec_flavours[] = {
493 		{ RPC_AUTH_NULL, "null" },
494 		{ RPC_AUTH_UNIX, "sys" },
495 		{ RPC_AUTH_GSS_KRB5, "krb5" },
496 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
497 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
498 		{ RPC_AUTH_GSS_LKEY, "lkey" },
499 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
500 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
501 		{ RPC_AUTH_GSS_SPKM, "spkm" },
502 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
503 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
504 		{ UINT_MAX, "unknown" }
505 	};
506 	int i;
507 
508 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
509 		if (sec_flavours[i].flavour == flavour)
510 			break;
511 	}
512 	return sec_flavours[i].str;
513 }
514 
515 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
516 				  int showdefaults)
517 {
518 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
519 
520 	seq_printf(m, ",mountproto=");
521 	switch (sap->sa_family) {
522 	case AF_INET:
523 		switch (nfss->mountd_protocol) {
524 		case IPPROTO_UDP:
525 			seq_printf(m, RPCBIND_NETID_UDP);
526 			break;
527 		case IPPROTO_TCP:
528 			seq_printf(m, RPCBIND_NETID_TCP);
529 			break;
530 		default:
531 			if (showdefaults)
532 				seq_printf(m, "auto");
533 		}
534 		break;
535 	case AF_INET6:
536 		switch (nfss->mountd_protocol) {
537 		case IPPROTO_UDP:
538 			seq_printf(m, RPCBIND_NETID_UDP6);
539 			break;
540 		case IPPROTO_TCP:
541 			seq_printf(m, RPCBIND_NETID_TCP6);
542 			break;
543 		default:
544 			if (showdefaults)
545 				seq_printf(m, "auto");
546 		}
547 		break;
548 	default:
549 		if (showdefaults)
550 			seq_printf(m, "auto");
551 	}
552 }
553 
554 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
555 				    int showdefaults)
556 {
557 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
558 
559 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
560 		return;
561 
562 	switch (sap->sa_family) {
563 	case AF_INET: {
564 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
565 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
566 		break;
567 	}
568 	case AF_INET6: {
569 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
570 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
571 		break;
572 	}
573 	default:
574 		if (showdefaults)
575 			seq_printf(m, ",mountaddr=unspecified");
576 	}
577 
578 	if (nfss->mountd_version || showdefaults)
579 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
580 	if ((nfss->mountd_port &&
581 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
582 		showdefaults)
583 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
584 
585 	nfs_show_mountd_netid(m, nfss, showdefaults);
586 }
587 
588 #if IS_ENABLED(CONFIG_NFS_V4)
589 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
590 				    int showdefaults)
591 {
592 	struct nfs_client *clp = nfss->nfs_client;
593 
594 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
595 }
596 #else
597 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
598 				    int showdefaults)
599 {
600 }
601 #endif
602 
603 static void nfs_show_nfs_version(struct seq_file *m,
604 		unsigned int version,
605 		unsigned int minorversion)
606 {
607 	seq_printf(m, ",vers=%u", version);
608 	if (version == 4)
609 		seq_printf(m, ".%u", minorversion);
610 }
611 
612 /*
613  * Describe the mount options in force on this server representation
614  */
615 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
616 				   int showdefaults)
617 {
618 	static const struct proc_nfs_info {
619 		int flag;
620 		const char *str;
621 		const char *nostr;
622 	} nfs_info[] = {
623 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
624 		{ NFS_MOUNT_POSIX, ",posix", "" },
625 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
626 		{ NFS_MOUNT_NOAC, ",noac", "" },
627 		{ NFS_MOUNT_NONLM, ",nolock", "" },
628 		{ NFS_MOUNT_NOACL, ",noacl", "" },
629 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
630 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
631 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
632 		{ 0, NULL, NULL }
633 	};
634 	const struct proc_nfs_info *nfs_infop;
635 	struct nfs_client *clp = nfss->nfs_client;
636 	u32 version = clp->rpc_ops->version;
637 	int local_flock, local_fcntl;
638 
639 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
640 	seq_printf(m, ",rsize=%u", nfss->rsize);
641 	seq_printf(m, ",wsize=%u", nfss->wsize);
642 	if (nfss->bsize != 0)
643 		seq_printf(m, ",bsize=%u", nfss->bsize);
644 	seq_printf(m, ",namlen=%u", nfss->namelen);
645 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
646 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
647 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
648 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
649 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
650 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
651 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
652 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
653 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
654 		if (nfss->flags & nfs_infop->flag)
655 			seq_puts(m, nfs_infop->str);
656 		else
657 			seq_puts(m, nfs_infop->nostr);
658 	}
659 	rcu_read_lock();
660 	seq_printf(m, ",proto=%s",
661 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
662 	rcu_read_unlock();
663 	if (version == 4) {
664 		if (nfss->port != NFS_PORT)
665 			seq_printf(m, ",port=%u", nfss->port);
666 	} else
667 		if (nfss->port)
668 			seq_printf(m, ",port=%u", nfss->port);
669 
670 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
671 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
672 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
673 
674 	if (version != 4)
675 		nfs_show_mountd_options(m, nfss, showdefaults);
676 	else
677 		nfs_show_nfsv4_options(m, nfss, showdefaults);
678 
679 	if (nfss->options & NFS_OPTION_FSCACHE)
680 		seq_printf(m, ",fsc");
681 
682 	if (nfss->options & NFS_OPTION_MIGRATION)
683 		seq_printf(m, ",migration");
684 
685 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
686 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
687 			seq_printf(m, ",lookupcache=none");
688 		else
689 			seq_printf(m, ",lookupcache=pos");
690 	}
691 
692 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
693 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
694 
695 	if (!local_flock && !local_fcntl)
696 		seq_printf(m, ",local_lock=none");
697 	else if (local_flock && local_fcntl)
698 		seq_printf(m, ",local_lock=all");
699 	else if (local_flock)
700 		seq_printf(m, ",local_lock=flock");
701 	else
702 		seq_printf(m, ",local_lock=posix");
703 }
704 
705 /*
706  * Describe the mount options on this VFS mountpoint
707  */
708 int nfs_show_options(struct seq_file *m, struct dentry *root)
709 {
710 	struct nfs_server *nfss = NFS_SB(root->d_sb);
711 
712 	nfs_show_mount_options(m, nfss, 0);
713 
714 	rcu_read_lock();
715 	seq_printf(m, ",addr=%s",
716 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
717 							RPC_DISPLAY_ADDR));
718 	rcu_read_unlock();
719 
720 	return 0;
721 }
722 EXPORT_SYMBOL_GPL(nfs_show_options);
723 
724 #if IS_ENABLED(CONFIG_NFS_V4)
725 #ifdef CONFIG_NFS_V4_1
726 static void show_sessions(struct seq_file *m, struct nfs_server *server)
727 {
728 	if (nfs4_has_session(server->nfs_client))
729 		seq_printf(m, ",sessions");
730 }
731 #else
732 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
733 #endif
734 #endif
735 
736 #ifdef CONFIG_NFS_V4_1
737 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
738 {
739 	seq_printf(m, ",pnfs=");
740 	if (server->pnfs_curr_ld)
741 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
742 	else
743 		seq_printf(m, "not configured");
744 }
745 
746 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
747 {
748 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
749 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
750 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
751 			   "date='%llu,%u'",
752 			   impl_id->name, impl_id->domain,
753 			   impl_id->date.seconds, impl_id->date.nseconds);
754 	}
755 }
756 #else
757 #if IS_ENABLED(CONFIG_NFS_V4)
758 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
759 {
760 }
761 #endif
762 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
763 {
764 }
765 #endif
766 
767 int nfs_show_devname(struct seq_file *m, struct dentry *root)
768 {
769 	char *page = (char *) __get_free_page(GFP_KERNEL);
770 	char *devname, *dummy;
771 	int err = 0;
772 	if (!page)
773 		return -ENOMEM;
774 	devname = nfs_path(&dummy, root, page, PAGE_SIZE);
775 	if (IS_ERR(devname))
776 		err = PTR_ERR(devname);
777 	else
778 		seq_escape(m, devname, " \t\n\\");
779 	free_page((unsigned long)page);
780 	return err;
781 }
782 EXPORT_SYMBOL_GPL(nfs_show_devname);
783 
784 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
785 {
786 	seq_puts(m, "/");
787 	return 0;
788 }
789 EXPORT_SYMBOL_GPL(nfs_show_path);
790 
791 /*
792  * Present statistical information for this VFS mountpoint
793  */
794 int nfs_show_stats(struct seq_file *m, struct dentry *root)
795 {
796 	int i, cpu;
797 	struct nfs_server *nfss = NFS_SB(root->d_sb);
798 	struct rpc_auth *auth = nfss->client->cl_auth;
799 	struct nfs_iostats totals = { };
800 
801 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
802 
803 	/*
804 	 * Display all mount option settings
805 	 */
806 	seq_printf(m, "\n\topts:\t");
807 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
808 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
809 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
810 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
811 	nfs_show_mount_options(m, nfss, 1);
812 
813 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
814 
815 	show_implementation_id(m, nfss);
816 
817 	seq_printf(m, "\n\tcaps:\t");
818 	seq_printf(m, "caps=0x%x", nfss->caps);
819 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
820 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
821 	seq_printf(m, ",bsize=%u", nfss->bsize);
822 	seq_printf(m, ",namlen=%u", nfss->namelen);
823 
824 #if IS_ENABLED(CONFIG_NFS_V4)
825 	if (nfss->nfs_client->rpc_ops->version == 4) {
826 		seq_printf(m, "\n\tnfsv4:\t");
827 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
828 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
829 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
830 		show_sessions(m, nfss);
831 		show_pnfs(m, nfss);
832 	}
833 #endif
834 
835 	/*
836 	 * Display security flavor in effect for this mount
837 	 */
838 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
839 	if (auth->au_flavor)
840 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
841 
842 	/*
843 	 * Display superblock I/O counters
844 	 */
845 	for_each_possible_cpu(cpu) {
846 		struct nfs_iostats *stats;
847 
848 		preempt_disable();
849 		stats = per_cpu_ptr(nfss->io_stats, cpu);
850 
851 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
852 			totals.events[i] += stats->events[i];
853 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
854 			totals.bytes[i] += stats->bytes[i];
855 #ifdef CONFIG_NFS_FSCACHE
856 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
857 			totals.fscache[i] += stats->fscache[i];
858 #endif
859 
860 		preempt_enable();
861 	}
862 
863 	seq_printf(m, "\n\tevents:\t");
864 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
865 		seq_printf(m, "%lu ", totals.events[i]);
866 	seq_printf(m, "\n\tbytes:\t");
867 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
868 		seq_printf(m, "%Lu ", totals.bytes[i]);
869 #ifdef CONFIG_NFS_FSCACHE
870 	if (nfss->options & NFS_OPTION_FSCACHE) {
871 		seq_printf(m, "\n\tfsc:\t");
872 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
873 			seq_printf(m, "%Lu ", totals.bytes[i]);
874 	}
875 #endif
876 	seq_printf(m, "\n");
877 
878 	rpc_print_iostats(m, nfss->client);
879 
880 	return 0;
881 }
882 EXPORT_SYMBOL_GPL(nfs_show_stats);
883 
884 /*
885  * Begin unmount by attempting to remove all automounted mountpoints we added
886  * in response to xdev traversals and referrals
887  */
888 void nfs_umount_begin(struct super_block *sb)
889 {
890 	struct nfs_server *server;
891 	struct rpc_clnt *rpc;
892 
893 	server = NFS_SB(sb);
894 	/* -EIO all pending I/O */
895 	rpc = server->client_acl;
896 	if (!IS_ERR(rpc))
897 		rpc_killall_tasks(rpc);
898 	rpc = server->client;
899 	if (!IS_ERR(rpc))
900 		rpc_killall_tasks(rpc);
901 }
902 EXPORT_SYMBOL_GPL(nfs_umount_begin);
903 
904 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
905 {
906 	struct nfs_parsed_mount_data *data;
907 
908 	data = kzalloc(sizeof(*data), GFP_KERNEL);
909 	if (data) {
910 		data->acregmin		= NFS_DEF_ACREGMIN;
911 		data->acregmax		= NFS_DEF_ACREGMAX;
912 		data->acdirmin		= NFS_DEF_ACDIRMIN;
913 		data->acdirmax		= NFS_DEF_ACDIRMAX;
914 		data->mount_server.port	= NFS_UNSPEC_PORT;
915 		data->nfs_server.port	= NFS_UNSPEC_PORT;
916 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
917 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
918 		data->auth_flavor_len	= 1;
919 		data->minorversion	= 0;
920 		data->need_mount	= true;
921 		data->net		= current->nsproxy->net_ns;
922 		security_init_mnt_opts(&data->lsm_opts);
923 	}
924 	return data;
925 }
926 
927 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
928 {
929 	if (data) {
930 		kfree(data->client_address);
931 		kfree(data->mount_server.hostname);
932 		kfree(data->nfs_server.export_path);
933 		kfree(data->nfs_server.hostname);
934 		kfree(data->fscache_uniq);
935 		security_free_mnt_opts(&data->lsm_opts);
936 		kfree(data);
937 	}
938 }
939 
940 /*
941  * Sanity-check a server address provided by the mount command.
942  *
943  * Address family must be initialized, and address must not be
944  * the ANY address for that family.
945  */
946 static int nfs_verify_server_address(struct sockaddr *addr)
947 {
948 	switch (addr->sa_family) {
949 	case AF_INET: {
950 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
951 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
952 	}
953 	case AF_INET6: {
954 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
955 		return !ipv6_addr_any(sa);
956 	}
957 	}
958 
959 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
960 	return 0;
961 }
962 
963 /*
964  * Select between a default port value and a user-specified port value.
965  * If a zero value is set, then autobind will be used.
966  */
967 static void nfs_set_port(struct sockaddr *sap, int *port,
968 				 const unsigned short default_port)
969 {
970 	if (*port == NFS_UNSPEC_PORT)
971 		*port = default_port;
972 
973 	rpc_set_port(sap, *port);
974 }
975 
976 /*
977  * Sanity check the NFS transport protocol.
978  *
979  */
980 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
981 {
982 	switch (mnt->nfs_server.protocol) {
983 	case XPRT_TRANSPORT_UDP:
984 	case XPRT_TRANSPORT_TCP:
985 	case XPRT_TRANSPORT_RDMA:
986 		break;
987 	default:
988 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
989 	}
990 }
991 
992 /*
993  * For text based NFSv2/v3 mounts, the mount protocol transport default
994  * settings should depend upon the specified NFS transport.
995  */
996 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
997 {
998 	nfs_validate_transport_protocol(mnt);
999 
1000 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1001 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1002 			return;
1003 	switch (mnt->nfs_server.protocol) {
1004 	case XPRT_TRANSPORT_UDP:
1005 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1006 		break;
1007 	case XPRT_TRANSPORT_TCP:
1008 	case XPRT_TRANSPORT_RDMA:
1009 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1010 	}
1011 }
1012 
1013 /*
1014  * Parse the value of the 'sec=' option.
1015  */
1016 static int nfs_parse_security_flavors(char *value,
1017 				      struct nfs_parsed_mount_data *mnt)
1018 {
1019 	substring_t args[MAX_OPT_ARGS];
1020 
1021 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1022 
1023 	switch (match_token(value, nfs_secflavor_tokens, args)) {
1024 	case Opt_sec_none:
1025 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
1026 		break;
1027 	case Opt_sec_sys:
1028 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1029 		break;
1030 	case Opt_sec_krb5:
1031 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1032 		break;
1033 	case Opt_sec_krb5i:
1034 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1035 		break;
1036 	case Opt_sec_krb5p:
1037 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1038 		break;
1039 	case Opt_sec_lkey:
1040 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1041 		break;
1042 	case Opt_sec_lkeyi:
1043 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1044 		break;
1045 	case Opt_sec_lkeyp:
1046 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1047 		break;
1048 	case Opt_sec_spkm:
1049 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1050 		break;
1051 	case Opt_sec_spkmi:
1052 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1053 		break;
1054 	case Opt_sec_spkmp:
1055 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1056 		break;
1057 	default:
1058 		return 0;
1059 	}
1060 
1061 	mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1062 	mnt->auth_flavor_len = 1;
1063 	return 1;
1064 }
1065 
1066 static int nfs_parse_version_string(char *string,
1067 		struct nfs_parsed_mount_data *mnt,
1068 		substring_t *args)
1069 {
1070 	mnt->flags &= ~NFS_MOUNT_VER3;
1071 	switch (match_token(string, nfs_vers_tokens, args)) {
1072 	case Opt_vers_2:
1073 		mnt->version = 2;
1074 		break;
1075 	case Opt_vers_3:
1076 		mnt->flags |= NFS_MOUNT_VER3;
1077 		mnt->version = 3;
1078 		break;
1079 	case Opt_vers_4:
1080 		/* Backward compatibility option. In future,
1081 		 * the mount program should always supply
1082 		 * a NFSv4 minor version number.
1083 		 */
1084 		mnt->version = 4;
1085 		break;
1086 	case Opt_vers_4_0:
1087 		mnt->version = 4;
1088 		mnt->minorversion = 0;
1089 		break;
1090 	case Opt_vers_4_1:
1091 		mnt->version = 4;
1092 		mnt->minorversion = 1;
1093 		break;
1094 	default:
1095 		return 0;
1096 	}
1097 	return 1;
1098 }
1099 
1100 static int nfs_get_option_str(substring_t args[], char **option)
1101 {
1102 	kfree(*option);
1103 	*option = match_strdup(args);
1104 	return !option;
1105 }
1106 
1107 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1108 {
1109 	int rc;
1110 	char *string;
1111 
1112 	string = match_strdup(args);
1113 	if (string == NULL)
1114 		return -ENOMEM;
1115 	rc = kstrtoul(string, 10, option);
1116 	kfree(string);
1117 
1118 	return rc;
1119 }
1120 
1121 /*
1122  * Error-check and convert a string of mount options from user space into
1123  * a data structure.  The whole mount string is processed; bad options are
1124  * skipped as they are encountered.  If there were no errors, return 1;
1125  * otherwise return 0 (zero).
1126  */
1127 static int nfs_parse_mount_options(char *raw,
1128 				   struct nfs_parsed_mount_data *mnt)
1129 {
1130 	char *p, *string, *secdata;
1131 	int rc, sloppy = 0, invalid_option = 0;
1132 	unsigned short protofamily = AF_UNSPEC;
1133 	unsigned short mountfamily = AF_UNSPEC;
1134 
1135 	if (!raw) {
1136 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1137 		return 1;
1138 	}
1139 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1140 
1141 	secdata = alloc_secdata();
1142 	if (!secdata)
1143 		goto out_nomem;
1144 
1145 	rc = security_sb_copy_data(raw, secdata);
1146 	if (rc)
1147 		goto out_security_failure;
1148 
1149 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1150 	if (rc)
1151 		goto out_security_failure;
1152 
1153 	free_secdata(secdata);
1154 
1155 	while ((p = strsep(&raw, ",")) != NULL) {
1156 		substring_t args[MAX_OPT_ARGS];
1157 		unsigned long option;
1158 		int token;
1159 
1160 		if (!*p)
1161 			continue;
1162 
1163 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1164 
1165 		token = match_token(p, nfs_mount_option_tokens, args);
1166 		switch (token) {
1167 
1168 		/*
1169 		 * boolean options:  foo/nofoo
1170 		 */
1171 		case Opt_soft:
1172 			mnt->flags |= NFS_MOUNT_SOFT;
1173 			break;
1174 		case Opt_hard:
1175 			mnt->flags &= ~NFS_MOUNT_SOFT;
1176 			break;
1177 		case Opt_posix:
1178 			mnt->flags |= NFS_MOUNT_POSIX;
1179 			break;
1180 		case Opt_noposix:
1181 			mnt->flags &= ~NFS_MOUNT_POSIX;
1182 			break;
1183 		case Opt_cto:
1184 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1185 			break;
1186 		case Opt_nocto:
1187 			mnt->flags |= NFS_MOUNT_NOCTO;
1188 			break;
1189 		case Opt_ac:
1190 			mnt->flags &= ~NFS_MOUNT_NOAC;
1191 			break;
1192 		case Opt_noac:
1193 			mnt->flags |= NFS_MOUNT_NOAC;
1194 			break;
1195 		case Opt_lock:
1196 			mnt->flags &= ~NFS_MOUNT_NONLM;
1197 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1198 					NFS_MOUNT_LOCAL_FCNTL);
1199 			break;
1200 		case Opt_nolock:
1201 			mnt->flags |= NFS_MOUNT_NONLM;
1202 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1203 				       NFS_MOUNT_LOCAL_FCNTL);
1204 			break;
1205 		case Opt_udp:
1206 			mnt->flags &= ~NFS_MOUNT_TCP;
1207 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1208 			break;
1209 		case Opt_tcp:
1210 			mnt->flags |= NFS_MOUNT_TCP;
1211 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1212 			break;
1213 		case Opt_rdma:
1214 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1215 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1216 			xprt_load_transport(p);
1217 			break;
1218 		case Opt_acl:
1219 			mnt->flags &= ~NFS_MOUNT_NOACL;
1220 			break;
1221 		case Opt_noacl:
1222 			mnt->flags |= NFS_MOUNT_NOACL;
1223 			break;
1224 		case Opt_rdirplus:
1225 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1226 			break;
1227 		case Opt_nordirplus:
1228 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1229 			break;
1230 		case Opt_sharecache:
1231 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1232 			break;
1233 		case Opt_nosharecache:
1234 			mnt->flags |= NFS_MOUNT_UNSHARED;
1235 			break;
1236 		case Opt_resvport:
1237 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1238 			break;
1239 		case Opt_noresvport:
1240 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1241 			break;
1242 		case Opt_fscache:
1243 			mnt->options |= NFS_OPTION_FSCACHE;
1244 			kfree(mnt->fscache_uniq);
1245 			mnt->fscache_uniq = NULL;
1246 			break;
1247 		case Opt_nofscache:
1248 			mnt->options &= ~NFS_OPTION_FSCACHE;
1249 			kfree(mnt->fscache_uniq);
1250 			mnt->fscache_uniq = NULL;
1251 			break;
1252 		case Opt_migration:
1253 			mnt->options |= NFS_OPTION_MIGRATION;
1254 			break;
1255 		case Opt_nomigration:
1256 			mnt->options &= NFS_OPTION_MIGRATION;
1257 			break;
1258 
1259 		/*
1260 		 * options that take numeric values
1261 		 */
1262 		case Opt_port:
1263 			if (nfs_get_option_ul(args, &option) ||
1264 			    option > USHRT_MAX)
1265 				goto out_invalid_value;
1266 			mnt->nfs_server.port = option;
1267 			break;
1268 		case Opt_rsize:
1269 			if (nfs_get_option_ul(args, &option))
1270 				goto out_invalid_value;
1271 			mnt->rsize = option;
1272 			break;
1273 		case Opt_wsize:
1274 			if (nfs_get_option_ul(args, &option))
1275 				goto out_invalid_value;
1276 			mnt->wsize = option;
1277 			break;
1278 		case Opt_bsize:
1279 			if (nfs_get_option_ul(args, &option))
1280 				goto out_invalid_value;
1281 			mnt->bsize = option;
1282 			break;
1283 		case Opt_timeo:
1284 			if (nfs_get_option_ul(args, &option) || option == 0)
1285 				goto out_invalid_value;
1286 			mnt->timeo = option;
1287 			break;
1288 		case Opt_retrans:
1289 			if (nfs_get_option_ul(args, &option) || option == 0)
1290 				goto out_invalid_value;
1291 			mnt->retrans = option;
1292 			break;
1293 		case Opt_acregmin:
1294 			if (nfs_get_option_ul(args, &option))
1295 				goto out_invalid_value;
1296 			mnt->acregmin = option;
1297 			break;
1298 		case Opt_acregmax:
1299 			if (nfs_get_option_ul(args, &option))
1300 				goto out_invalid_value;
1301 			mnt->acregmax = option;
1302 			break;
1303 		case Opt_acdirmin:
1304 			if (nfs_get_option_ul(args, &option))
1305 				goto out_invalid_value;
1306 			mnt->acdirmin = option;
1307 			break;
1308 		case Opt_acdirmax:
1309 			if (nfs_get_option_ul(args, &option))
1310 				goto out_invalid_value;
1311 			mnt->acdirmax = option;
1312 			break;
1313 		case Opt_actimeo:
1314 			if (nfs_get_option_ul(args, &option))
1315 				goto out_invalid_value;
1316 			mnt->acregmin = mnt->acregmax =
1317 			mnt->acdirmin = mnt->acdirmax = option;
1318 			break;
1319 		case Opt_namelen:
1320 			if (nfs_get_option_ul(args, &option))
1321 				goto out_invalid_value;
1322 			mnt->namlen = option;
1323 			break;
1324 		case Opt_mountport:
1325 			if (nfs_get_option_ul(args, &option) ||
1326 			    option > USHRT_MAX)
1327 				goto out_invalid_value;
1328 			mnt->mount_server.port = option;
1329 			break;
1330 		case Opt_mountvers:
1331 			if (nfs_get_option_ul(args, &option) ||
1332 			    option < NFS_MNT_VERSION ||
1333 			    option > NFS_MNT3_VERSION)
1334 				goto out_invalid_value;
1335 			mnt->mount_server.version = option;
1336 			break;
1337 		case Opt_minorversion:
1338 			if (nfs_get_option_ul(args, &option))
1339 				goto out_invalid_value;
1340 			if (option > NFS4_MAX_MINOR_VERSION)
1341 				goto out_invalid_value;
1342 			mnt->minorversion = option;
1343 			break;
1344 
1345 		/*
1346 		 * options that take text values
1347 		 */
1348 		case Opt_nfsvers:
1349 			string = match_strdup(args);
1350 			if (string == NULL)
1351 				goto out_nomem;
1352 			rc = nfs_parse_version_string(string, mnt, args);
1353 			kfree(string);
1354 			if (!rc)
1355 				goto out_invalid_value;
1356 			break;
1357 		case Opt_sec:
1358 			string = match_strdup(args);
1359 			if (string == NULL)
1360 				goto out_nomem;
1361 			rc = nfs_parse_security_flavors(string, mnt);
1362 			kfree(string);
1363 			if (!rc) {
1364 				dfprintk(MOUNT, "NFS:   unrecognized "
1365 						"security flavor\n");
1366 				return 0;
1367 			}
1368 			break;
1369 		case Opt_proto:
1370 			string = match_strdup(args);
1371 			if (string == NULL)
1372 				goto out_nomem;
1373 			token = match_token(string,
1374 					    nfs_xprt_protocol_tokens, args);
1375 
1376 			protofamily = AF_INET;
1377 			switch (token) {
1378 			case Opt_xprt_udp6:
1379 				protofamily = AF_INET6;
1380 			case Opt_xprt_udp:
1381 				mnt->flags &= ~NFS_MOUNT_TCP;
1382 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1383 				break;
1384 			case Opt_xprt_tcp6:
1385 				protofamily = AF_INET6;
1386 			case Opt_xprt_tcp:
1387 				mnt->flags |= NFS_MOUNT_TCP;
1388 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1389 				break;
1390 			case Opt_xprt_rdma:
1391 				/* vector side protocols to TCP */
1392 				mnt->flags |= NFS_MOUNT_TCP;
1393 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1394 				xprt_load_transport(string);
1395 				break;
1396 			default:
1397 				dfprintk(MOUNT, "NFS:   unrecognized "
1398 						"transport protocol\n");
1399 				kfree(string);
1400 				return 0;
1401 			}
1402 			kfree(string);
1403 			break;
1404 		case Opt_mountproto:
1405 			string = match_strdup(args);
1406 			if (string == NULL)
1407 				goto out_nomem;
1408 			token = match_token(string,
1409 					    nfs_xprt_protocol_tokens, args);
1410 			kfree(string);
1411 
1412 			mountfamily = AF_INET;
1413 			switch (token) {
1414 			case Opt_xprt_udp6:
1415 				mountfamily = AF_INET6;
1416 			case Opt_xprt_udp:
1417 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1418 				break;
1419 			case Opt_xprt_tcp6:
1420 				mountfamily = AF_INET6;
1421 			case Opt_xprt_tcp:
1422 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1423 				break;
1424 			case Opt_xprt_rdma: /* not used for side protocols */
1425 			default:
1426 				dfprintk(MOUNT, "NFS:   unrecognized "
1427 						"transport protocol\n");
1428 				return 0;
1429 			}
1430 			break;
1431 		case Opt_addr:
1432 			string = match_strdup(args);
1433 			if (string == NULL)
1434 				goto out_nomem;
1435 			mnt->nfs_server.addrlen =
1436 				rpc_pton(mnt->net, string, strlen(string),
1437 					(struct sockaddr *)
1438 					&mnt->nfs_server.address,
1439 					sizeof(mnt->nfs_server.address));
1440 			kfree(string);
1441 			if (mnt->nfs_server.addrlen == 0)
1442 				goto out_invalid_address;
1443 			break;
1444 		case Opt_clientaddr:
1445 			if (nfs_get_option_str(args, &mnt->client_address))
1446 				goto out_nomem;
1447 			break;
1448 		case Opt_mounthost:
1449 			if (nfs_get_option_str(args,
1450 					       &mnt->mount_server.hostname))
1451 				goto out_nomem;
1452 			break;
1453 		case Opt_mountaddr:
1454 			string = match_strdup(args);
1455 			if (string == NULL)
1456 				goto out_nomem;
1457 			mnt->mount_server.addrlen =
1458 				rpc_pton(mnt->net, string, strlen(string),
1459 					(struct sockaddr *)
1460 					&mnt->mount_server.address,
1461 					sizeof(mnt->mount_server.address));
1462 			kfree(string);
1463 			if (mnt->mount_server.addrlen == 0)
1464 				goto out_invalid_address;
1465 			break;
1466 		case Opt_lookupcache:
1467 			string = match_strdup(args);
1468 			if (string == NULL)
1469 				goto out_nomem;
1470 			token = match_token(string,
1471 					nfs_lookupcache_tokens, args);
1472 			kfree(string);
1473 			switch (token) {
1474 				case Opt_lookupcache_all:
1475 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1476 					break;
1477 				case Opt_lookupcache_positive:
1478 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1479 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1480 					break;
1481 				case Opt_lookupcache_none:
1482 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1483 					break;
1484 				default:
1485 					dfprintk(MOUNT, "NFS:   invalid "
1486 							"lookupcache argument\n");
1487 					return 0;
1488 			};
1489 			break;
1490 		case Opt_fscache_uniq:
1491 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1492 				goto out_nomem;
1493 			mnt->options |= NFS_OPTION_FSCACHE;
1494 			break;
1495 		case Opt_local_lock:
1496 			string = match_strdup(args);
1497 			if (string == NULL)
1498 				goto out_nomem;
1499 			token = match_token(string, nfs_local_lock_tokens,
1500 					args);
1501 			kfree(string);
1502 			switch (token) {
1503 			case Opt_local_lock_all:
1504 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1505 					       NFS_MOUNT_LOCAL_FCNTL);
1506 				break;
1507 			case Opt_local_lock_flock:
1508 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1509 				break;
1510 			case Opt_local_lock_posix:
1511 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1512 				break;
1513 			case Opt_local_lock_none:
1514 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1515 						NFS_MOUNT_LOCAL_FCNTL);
1516 				break;
1517 			default:
1518 				dfprintk(MOUNT, "NFS:	invalid	"
1519 						"local_lock argument\n");
1520 				return 0;
1521 			};
1522 			break;
1523 
1524 		/*
1525 		 * Special options
1526 		 */
1527 		case Opt_sloppy:
1528 			sloppy = 1;
1529 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1530 			break;
1531 		case Opt_userspace:
1532 		case Opt_deprecated:
1533 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1534 					"'%s'\n", p);
1535 			break;
1536 
1537 		default:
1538 			invalid_option = 1;
1539 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1540 					"'%s'\n", p);
1541 		}
1542 	}
1543 
1544 	if (!sloppy && invalid_option)
1545 		return 0;
1546 
1547 	if (mnt->minorversion && mnt->version != 4)
1548 		goto out_minorversion_mismatch;
1549 
1550 	if (mnt->options & NFS_OPTION_MIGRATION &&
1551 	    mnt->version != 4 && mnt->minorversion != 0)
1552 		goto out_migration_misuse;
1553 
1554 	/*
1555 	 * verify that any proto=/mountproto= options match the address
1556 	 * families in the addr=/mountaddr= options.
1557 	 */
1558 	if (protofamily != AF_UNSPEC &&
1559 	    protofamily != mnt->nfs_server.address.ss_family)
1560 		goto out_proto_mismatch;
1561 
1562 	if (mountfamily != AF_UNSPEC) {
1563 		if (mnt->mount_server.addrlen) {
1564 			if (mountfamily != mnt->mount_server.address.ss_family)
1565 				goto out_mountproto_mismatch;
1566 		} else {
1567 			if (mountfamily != mnt->nfs_server.address.ss_family)
1568 				goto out_mountproto_mismatch;
1569 		}
1570 	}
1571 
1572 	return 1;
1573 
1574 out_mountproto_mismatch:
1575 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1576 			 "option\n");
1577 	return 0;
1578 out_proto_mismatch:
1579 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1580 	return 0;
1581 out_invalid_address:
1582 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1583 	return 0;
1584 out_invalid_value:
1585 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1586 	return 0;
1587 out_minorversion_mismatch:
1588 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1589 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1590 	return 0;
1591 out_migration_misuse:
1592 	printk(KERN_INFO
1593 		"NFS: 'migration' not supported for this NFS version\n");
1594 	return 0;
1595 out_nomem:
1596 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1597 	return 0;
1598 out_security_failure:
1599 	free_secdata(secdata);
1600 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1601 	return 0;
1602 }
1603 
1604 /*
1605  * Match the requested auth flavors with the list returned by
1606  * the server.  Returns zero and sets the mount's authentication
1607  * flavor on success; returns -EACCES if server does not support
1608  * the requested flavor.
1609  */
1610 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1611 			     struct nfs_mount_request *request)
1612 {
1613 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1614 
1615 	/*
1616 	 * Certain releases of Linux's mountd return an empty
1617 	 * flavor list.  To prevent behavioral regression with
1618 	 * these servers (ie. rejecting mounts that used to
1619 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1620 	 * if the returned flavor list is empty.
1621 	 */
1622 	if (server_authlist_len == 0)
1623 		return 0;
1624 
1625 	/*
1626 	 * We avoid sophisticated negotiating here, as there are
1627 	 * plenty of cases where we can get it wrong, providing
1628 	 * either too little or too much security.
1629 	 *
1630 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1631 	 * flavor listed first.  However, some servers list
1632 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1633 	 * preferred default, in args->auth_flavors[0] if user
1634 	 * didn't specify sec= mount option.
1635 	 */
1636 	for (i = 0; i < args->auth_flavor_len; i++)
1637 		for (j = 0; j < server_authlist_len; j++)
1638 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1639 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1640 					request->auth_flavs[j]);
1641 				args->auth_flavors[0] = request->auth_flavs[j];
1642 				return 0;
1643 			}
1644 
1645 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1646 	nfs_umount(request);
1647 	return -EACCES;
1648 }
1649 
1650 /*
1651  * Use the remote server's MOUNT service to request the NFS file handle
1652  * corresponding to the provided path.
1653  */
1654 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1655 			     struct nfs_fh *root_fh)
1656 {
1657 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1658 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1659 	struct nfs_mount_request request = {
1660 		.sap		= (struct sockaddr *)
1661 						&args->mount_server.address,
1662 		.dirpath	= args->nfs_server.export_path,
1663 		.protocol	= args->mount_server.protocol,
1664 		.fh		= root_fh,
1665 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1666 		.auth_flav_len	= &server_authlist_len,
1667 		.auth_flavs	= server_authlist,
1668 		.net		= args->net,
1669 	};
1670 	int status;
1671 
1672 	if (args->mount_server.version == 0) {
1673 		switch (args->version) {
1674 			default:
1675 				args->mount_server.version = NFS_MNT3_VERSION;
1676 				break;
1677 			case 2:
1678 				args->mount_server.version = NFS_MNT_VERSION;
1679 		}
1680 	}
1681 	request.version = args->mount_server.version;
1682 
1683 	if (args->mount_server.hostname)
1684 		request.hostname = args->mount_server.hostname;
1685 	else
1686 		request.hostname = args->nfs_server.hostname;
1687 
1688 	/*
1689 	 * Construct the mount server's address.
1690 	 */
1691 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1692 		memcpy(request.sap, &args->nfs_server.address,
1693 		       args->nfs_server.addrlen);
1694 		args->mount_server.addrlen = args->nfs_server.addrlen;
1695 	}
1696 	request.salen = args->mount_server.addrlen;
1697 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1698 
1699 	/*
1700 	 * Now ask the mount server to map our export path
1701 	 * to a file handle.
1702 	 */
1703 	status = nfs_mount(&request);
1704 	if (status != 0) {
1705 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1706 				request.hostname, status);
1707 		return status;
1708 	}
1709 
1710 	/*
1711 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1712 	 */
1713 	if (args->mount_server.version != NFS_MNT3_VERSION)
1714 		return 0;
1715 	return nfs_walk_authlist(args, &request);
1716 }
1717 
1718 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1719 			     struct nfs_mount_info *mount_info,
1720 			     struct nfs_subversion *nfs_mod)
1721 {
1722 	int status;
1723 	struct nfs_server *server;
1724 
1725 	if (mount_info->parsed->need_mount) {
1726 		status = nfs_request_mount(mount_info->parsed, mount_info->mntfh);
1727 		if (status)
1728 			return ERR_PTR(status);
1729 	}
1730 
1731 	/* Get a volume representation */
1732 	server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1733 	if (IS_ERR(server))
1734 		return ERR_CAST(server);
1735 
1736 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1737 }
1738 EXPORT_SYMBOL_GPL(nfs_try_mount);
1739 
1740 /*
1741  * Split "dev_name" into "hostname:export_path".
1742  *
1743  * The leftmost colon demarks the split between the server's hostname
1744  * and the export path.  If the hostname starts with a left square
1745  * bracket, then it may contain colons.
1746  *
1747  * Note: caller frees hostname and export path, even on error.
1748  */
1749 static int nfs_parse_devname(const char *dev_name,
1750 			     char **hostname, size_t maxnamlen,
1751 			     char **export_path, size_t maxpathlen)
1752 {
1753 	size_t len;
1754 	char *end;
1755 
1756 	/* Is the host name protected with square brakcets? */
1757 	if (*dev_name == '[') {
1758 		end = strchr(++dev_name, ']');
1759 		if (end == NULL || end[1] != ':')
1760 			goto out_bad_devname;
1761 
1762 		len = end - dev_name;
1763 		end++;
1764 	} else {
1765 		char *comma;
1766 
1767 		end = strchr(dev_name, ':');
1768 		if (end == NULL)
1769 			goto out_bad_devname;
1770 		len = end - dev_name;
1771 
1772 		/* kill possible hostname list: not supported */
1773 		comma = strchr(dev_name, ',');
1774 		if (comma != NULL && comma < end)
1775 			*comma = 0;
1776 	}
1777 
1778 	if (len > maxnamlen)
1779 		goto out_hostname;
1780 
1781 	/* N.B. caller will free nfs_server.hostname in all cases */
1782 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1783 	if (*hostname == NULL)
1784 		goto out_nomem;
1785 	len = strlen(++end);
1786 	if (len > maxpathlen)
1787 		goto out_path;
1788 	*export_path = kstrndup(end, len, GFP_KERNEL);
1789 	if (!*export_path)
1790 		goto out_nomem;
1791 
1792 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1793 	return 0;
1794 
1795 out_bad_devname:
1796 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1797 	return -EINVAL;
1798 
1799 out_nomem:
1800 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1801 	return -ENOMEM;
1802 
1803 out_hostname:
1804 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1805 	return -ENAMETOOLONG;
1806 
1807 out_path:
1808 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1809 	return -ENAMETOOLONG;
1810 }
1811 
1812 /*
1813  * Validate the NFS2/NFS3 mount data
1814  * - fills in the mount root filehandle
1815  *
1816  * For option strings, user space handles the following behaviors:
1817  *
1818  * + DNS: mapping server host name to IP address ("addr=" option)
1819  *
1820  * + failure mode: how to behave if a mount request can't be handled
1821  *   immediately ("fg/bg" option)
1822  *
1823  * + retry: how often to retry a mount request ("retry=" option)
1824  *
1825  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1826  *   mountproto=tcp after mountproto=udp, and so on
1827  */
1828 static int nfs23_validate_mount_data(void *options,
1829 				     struct nfs_parsed_mount_data *args,
1830 				     struct nfs_fh *mntfh,
1831 				     const char *dev_name)
1832 {
1833 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1834 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1835 
1836 	if (data == NULL)
1837 		goto out_no_data;
1838 
1839 	args->version = NFS_DEFAULT_VERSION;
1840 	switch (data->version) {
1841 	case 1:
1842 		data->namlen = 0;
1843 	case 2:
1844 		data->bsize = 0;
1845 	case 3:
1846 		if (data->flags & NFS_MOUNT_VER3)
1847 			goto out_no_v3;
1848 		data->root.size = NFS2_FHSIZE;
1849 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1850 	case 4:
1851 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1852 			goto out_no_sec;
1853 	case 5:
1854 		memset(data->context, 0, sizeof(data->context));
1855 	case 6:
1856 		if (data->flags & NFS_MOUNT_VER3) {
1857 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1858 				goto out_invalid_fh;
1859 			mntfh->size = data->root.size;
1860 			args->version = 3;
1861 		} else {
1862 			mntfh->size = NFS2_FHSIZE;
1863 			args->version = 2;
1864 		}
1865 
1866 
1867 		memcpy(mntfh->data, data->root.data, mntfh->size);
1868 		if (mntfh->size < sizeof(mntfh->data))
1869 			memset(mntfh->data + mntfh->size, 0,
1870 			       sizeof(mntfh->data) - mntfh->size);
1871 
1872 		/*
1873 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1874 		 * can deal with.
1875 		 */
1876 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1877 		args->flags		|= NFS_MOUNT_LEGACY_INTERFACE;
1878 		args->rsize		= data->rsize;
1879 		args->wsize		= data->wsize;
1880 		args->timeo		= data->timeo;
1881 		args->retrans		= data->retrans;
1882 		args->acregmin		= data->acregmin;
1883 		args->acregmax		= data->acregmax;
1884 		args->acdirmin		= data->acdirmin;
1885 		args->acdirmax		= data->acdirmax;
1886 		args->need_mount	= false;
1887 
1888 		memcpy(sap, &data->addr, sizeof(data->addr));
1889 		args->nfs_server.addrlen = sizeof(data->addr);
1890 		args->nfs_server.port = ntohs(data->addr.sin_port);
1891 		if (!nfs_verify_server_address(sap))
1892 			goto out_no_address;
1893 
1894 		if (!(data->flags & NFS_MOUNT_TCP))
1895 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1896 		/* N.B. caller will free nfs_server.hostname in all cases */
1897 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1898 		args->namlen		= data->namlen;
1899 		args->bsize		= data->bsize;
1900 
1901 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1902 			args->auth_flavors[0] = data->pseudoflavor;
1903 		if (!args->nfs_server.hostname)
1904 			goto out_nomem;
1905 
1906 		if (!(data->flags & NFS_MOUNT_NONLM))
1907 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1908 					 NFS_MOUNT_LOCAL_FCNTL);
1909 		else
1910 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1911 					NFS_MOUNT_LOCAL_FCNTL);
1912 		/*
1913 		 * The legacy version 6 binary mount data from userspace has a
1914 		 * field used only to transport selinux information into the
1915 		 * the kernel.  To continue to support that functionality we
1916 		 * have a touch of selinux knowledge here in the NFS code. The
1917 		 * userspace code converted context=blah to just blah so we are
1918 		 * converting back to the full string selinux understands.
1919 		 */
1920 		if (data->context[0]){
1921 #ifdef CONFIG_SECURITY_SELINUX
1922 			int rc;
1923 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1924 			if (!opts_str)
1925 				return -ENOMEM;
1926 			strcpy(opts_str, "context=");
1927 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1928 			strcat(opts_str, &data->context[0]);
1929 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1930 			kfree(opts_str);
1931 			if (rc)
1932 				return rc;
1933 #else
1934 			return -EINVAL;
1935 #endif
1936 		}
1937 
1938 		break;
1939 	default:
1940 		return NFS_TEXT_DATA;
1941 	}
1942 
1943 #if !IS_ENABLED(CONFIG_NFS_V3)
1944 	if (args->version == 3)
1945 		goto out_v3_not_compiled;
1946 #endif /* !CONFIG_NFS_V3 */
1947 
1948 	return 0;
1949 
1950 out_no_data:
1951 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1952 	return -EINVAL;
1953 
1954 out_no_v3:
1955 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1956 		 data->version);
1957 	return -EINVAL;
1958 
1959 out_no_sec:
1960 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1961 	return -EINVAL;
1962 
1963 #if !IS_ENABLED(CONFIG_NFS_V3)
1964 out_v3_not_compiled:
1965 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1966 	return -EPROTONOSUPPORT;
1967 #endif /* !CONFIG_NFS_V3 */
1968 
1969 out_nomem:
1970 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1971 	return -ENOMEM;
1972 
1973 out_no_address:
1974 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1975 	return -EINVAL;
1976 
1977 out_invalid_fh:
1978 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1979 	return -EINVAL;
1980 }
1981 
1982 #if IS_ENABLED(CONFIG_NFS_V4)
1983 static int nfs_validate_mount_data(struct file_system_type *fs_type,
1984 				   void *options,
1985 				   struct nfs_parsed_mount_data *args,
1986 				   struct nfs_fh *mntfh,
1987 				   const char *dev_name)
1988 {
1989 	if (fs_type == &nfs_fs_type)
1990 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
1991 	return nfs4_validate_mount_data(options, args, dev_name);
1992 }
1993 #else
1994 static int nfs_validate_mount_data(struct file_system_type *fs_type,
1995 				   void *options,
1996 				   struct nfs_parsed_mount_data *args,
1997 				   struct nfs_fh *mntfh,
1998 				   const char *dev_name)
1999 {
2000 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2001 }
2002 #endif
2003 
2004 static int nfs_validate_text_mount_data(void *options,
2005 					struct nfs_parsed_mount_data *args,
2006 					const char *dev_name)
2007 {
2008 	int port = 0;
2009 	int max_namelen = PAGE_SIZE;
2010 	int max_pathlen = NFS_MAXPATHLEN;
2011 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2012 
2013 	if (nfs_parse_mount_options((char *)options, args) == 0)
2014 		return -EINVAL;
2015 
2016 	if (!nfs_verify_server_address(sap))
2017 		goto out_no_address;
2018 
2019 	if (args->version == 4) {
2020 #if IS_ENABLED(CONFIG_NFS_V4)
2021 		port = NFS_PORT;
2022 		max_namelen = NFS4_MAXNAMLEN;
2023 		max_pathlen = NFS4_MAXPATHLEN;
2024 		nfs_validate_transport_protocol(args);
2025 		nfs4_validate_mount_flags(args);
2026 #else
2027 		goto out_v4_not_compiled;
2028 #endif /* CONFIG_NFS_V4 */
2029 	} else
2030 		nfs_set_mount_transport_protocol(args);
2031 
2032 	nfs_set_port(sap, &args->nfs_server.port, port);
2033 
2034 	if (args->auth_flavor_len > 1)
2035 		goto out_bad_auth;
2036 
2037 	return nfs_parse_devname(dev_name,
2038 				   &args->nfs_server.hostname,
2039 				   max_namelen,
2040 				   &args->nfs_server.export_path,
2041 				   max_pathlen);
2042 
2043 #if !IS_ENABLED(CONFIG_NFS_V4)
2044 out_v4_not_compiled:
2045 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2046 	return -EPROTONOSUPPORT;
2047 #endif /* !CONFIG_NFS_V4 */
2048 
2049 out_no_address:
2050 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2051 	return -EINVAL;
2052 
2053 out_bad_auth:
2054 	dfprintk(MOUNT, "NFS: Too many RPC auth flavours specified\n");
2055 	return -EINVAL;
2056 }
2057 
2058 static int
2059 nfs_compare_remount_data(struct nfs_server *nfss,
2060 			 struct nfs_parsed_mount_data *data)
2061 {
2062 	if (data->flags != nfss->flags ||
2063 	    data->rsize != nfss->rsize ||
2064 	    data->wsize != nfss->wsize ||
2065 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2066 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2067 	    data->acregmin != nfss->acregmin / HZ ||
2068 	    data->acregmax != nfss->acregmax / HZ ||
2069 	    data->acdirmin != nfss->acdirmin / HZ ||
2070 	    data->acdirmax != nfss->acdirmax / HZ ||
2071 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2072 	    data->nfs_server.port != nfss->port ||
2073 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2074 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2075 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2076 		return -EINVAL;
2077 
2078 	return 0;
2079 }
2080 
2081 int
2082 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2083 {
2084 	int error;
2085 	struct nfs_server *nfss = sb->s_fs_info;
2086 	struct nfs_parsed_mount_data *data;
2087 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2088 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2089 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2090 
2091 	/*
2092 	 * Userspace mount programs that send binary options generally send
2093 	 * them populated with default values. We have no way to know which
2094 	 * ones were explicitly specified. Fall back to legacy behavior and
2095 	 * just return success.
2096 	 */
2097 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2098 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2099 					   options->version <= 6))))
2100 		return 0;
2101 
2102 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2103 	if (data == NULL)
2104 		return -ENOMEM;
2105 
2106 	/* fill out struct with values from existing mount */
2107 	data->flags = nfss->flags;
2108 	data->rsize = nfss->rsize;
2109 	data->wsize = nfss->wsize;
2110 	data->retrans = nfss->client->cl_timeout->to_retries;
2111 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2112 	data->acregmin = nfss->acregmin / HZ;
2113 	data->acregmax = nfss->acregmax / HZ;
2114 	data->acdirmin = nfss->acdirmin / HZ;
2115 	data->acdirmax = nfss->acdirmax / HZ;
2116 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2117 	data->nfs_server.port = nfss->port;
2118 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2119 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2120 		data->nfs_server.addrlen);
2121 
2122 	/* overwrite those values with any that were specified */
2123 	error = nfs_parse_mount_options((char *)options, data);
2124 	if (error < 0)
2125 		goto out;
2126 
2127 	/*
2128 	 * noac is a special case. It implies -o sync, but that's not
2129 	 * necessarily reflected in the mtab options. do_remount_sb
2130 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2131 	 * remount options, so we have to explicitly reset it.
2132 	 */
2133 	if (data->flags & NFS_MOUNT_NOAC)
2134 		*flags |= MS_SYNCHRONOUS;
2135 
2136 	/* compare new mount options with old ones */
2137 	error = nfs_compare_remount_data(nfss, data);
2138 out:
2139 	kfree(data);
2140 	return error;
2141 }
2142 EXPORT_SYMBOL_GPL(nfs_remount);
2143 
2144 /*
2145  * Initialise the common bits of the superblock
2146  */
2147 inline void nfs_initialise_sb(struct super_block *sb)
2148 {
2149 	struct nfs_server *server = NFS_SB(sb);
2150 
2151 	sb->s_magic = NFS_SUPER_MAGIC;
2152 
2153 	/* We probably want something more informative here */
2154 	snprintf(sb->s_id, sizeof(sb->s_id),
2155 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2156 
2157 	if (sb->s_blocksize == 0)
2158 		sb->s_blocksize = nfs_block_bits(server->wsize,
2159 						 &sb->s_blocksize_bits);
2160 
2161 	sb->s_bdi = &server->backing_dev_info;
2162 
2163 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2164 }
2165 
2166 /*
2167  * Finish setting up an NFS2/3 superblock
2168  */
2169 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2170 {
2171 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2172 	struct nfs_server *server = NFS_SB(sb);
2173 
2174 	sb->s_blocksize_bits = 0;
2175 	sb->s_blocksize = 0;
2176 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2177 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2178 	if (data && data->bsize)
2179 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2180 
2181 	if (server->nfs_client->rpc_ops->version != 2) {
2182 		/* The VFS shouldn't apply the umask to mode bits. We will do
2183 		 * so ourselves when necessary.
2184 		 */
2185 		sb->s_flags |= MS_POSIXACL;
2186 		sb->s_time_gran = 1;
2187 	}
2188 
2189  	nfs_initialise_sb(sb);
2190 }
2191 EXPORT_SYMBOL_GPL(nfs_fill_super);
2192 
2193 /*
2194  * Finish setting up a cloned NFS2/3/4 superblock
2195  */
2196 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2197 {
2198 	const struct super_block *old_sb = mount_info->cloned->sb;
2199 	struct nfs_server *server = NFS_SB(sb);
2200 
2201 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2202 	sb->s_blocksize = old_sb->s_blocksize;
2203 	sb->s_maxbytes = old_sb->s_maxbytes;
2204 	sb->s_xattr = old_sb->s_xattr;
2205 	sb->s_op = old_sb->s_op;
2206 	sb->s_time_gran = 1;
2207 
2208 	if (server->nfs_client->rpc_ops->version != 2) {
2209 		/* The VFS shouldn't apply the umask to mode bits. We will do
2210 		 * so ourselves when necessary.
2211 		 */
2212 		sb->s_flags |= MS_POSIXACL;
2213 	}
2214 
2215  	nfs_initialise_sb(sb);
2216 }
2217 
2218 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2219 {
2220 	const struct nfs_server *a = s->s_fs_info;
2221 	const struct rpc_clnt *clnt_a = a->client;
2222 	const struct rpc_clnt *clnt_b = b->client;
2223 
2224 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2225 		goto Ebusy;
2226 	if (a->nfs_client != b->nfs_client)
2227 		goto Ebusy;
2228 	if (a->flags != b->flags)
2229 		goto Ebusy;
2230 	if (a->wsize != b->wsize)
2231 		goto Ebusy;
2232 	if (a->rsize != b->rsize)
2233 		goto Ebusy;
2234 	if (a->acregmin != b->acregmin)
2235 		goto Ebusy;
2236 	if (a->acregmax != b->acregmax)
2237 		goto Ebusy;
2238 	if (a->acdirmin != b->acdirmin)
2239 		goto Ebusy;
2240 	if (a->acdirmax != b->acdirmax)
2241 		goto Ebusy;
2242 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2243 		goto Ebusy;
2244 	return 1;
2245 Ebusy:
2246 	return 0;
2247 }
2248 
2249 struct nfs_sb_mountdata {
2250 	struct nfs_server *server;
2251 	int mntflags;
2252 };
2253 
2254 static int nfs_set_super(struct super_block *s, void *data)
2255 {
2256 	struct nfs_sb_mountdata *sb_mntdata = data;
2257 	struct nfs_server *server = sb_mntdata->server;
2258 	int ret;
2259 
2260 	s->s_flags = sb_mntdata->mntflags;
2261 	s->s_fs_info = server;
2262 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2263 	ret = set_anon_super(s, server);
2264 	if (ret == 0)
2265 		server->s_dev = s->s_dev;
2266 	return ret;
2267 }
2268 
2269 static int nfs_compare_super_address(struct nfs_server *server1,
2270 				     struct nfs_server *server2)
2271 {
2272 	struct sockaddr *sap1, *sap2;
2273 
2274 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2275 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2276 
2277 	if (sap1->sa_family != sap2->sa_family)
2278 		return 0;
2279 
2280 	switch (sap1->sa_family) {
2281 	case AF_INET: {
2282 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2283 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2284 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2285 			return 0;
2286 		if (sin1->sin_port != sin2->sin_port)
2287 			return 0;
2288 		break;
2289 	}
2290 	case AF_INET6: {
2291 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2292 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2293 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2294 			return 0;
2295 		if (sin1->sin6_port != sin2->sin6_port)
2296 			return 0;
2297 		break;
2298 	}
2299 	default:
2300 		return 0;
2301 	}
2302 
2303 	return 1;
2304 }
2305 
2306 static int nfs_compare_super(struct super_block *sb, void *data)
2307 {
2308 	struct nfs_sb_mountdata *sb_mntdata = data;
2309 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2310 	int mntflags = sb_mntdata->mntflags;
2311 
2312 	if (!nfs_compare_super_address(old, server))
2313 		return 0;
2314 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2315 	if (old->flags & NFS_MOUNT_UNSHARED)
2316 		return 0;
2317 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2318 		return 0;
2319 	return nfs_compare_mount_options(sb, server, mntflags);
2320 }
2321 
2322 #ifdef CONFIG_NFS_FSCACHE
2323 static void nfs_get_cache_cookie(struct super_block *sb,
2324 				 struct nfs_parsed_mount_data *parsed,
2325 				 struct nfs_clone_mount *cloned)
2326 {
2327 	char *uniq = NULL;
2328 	int ulen = 0;
2329 
2330 	if (parsed && parsed->fscache_uniq) {
2331 		uniq = parsed->fscache_uniq;
2332 		ulen = strlen(parsed->fscache_uniq);
2333 	} else if (cloned) {
2334 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2335 		if (mnt_s->fscache_key) {
2336 			uniq = mnt_s->fscache_key->key.uniquifier;
2337 			ulen = mnt_s->fscache_key->key.uniq_len;
2338 		};
2339 	}
2340 
2341 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2342 }
2343 #else
2344 static void nfs_get_cache_cookie(struct super_block *sb,
2345 				 struct nfs_parsed_mount_data *parsed,
2346 				 struct nfs_clone_mount *cloned)
2347 {
2348 }
2349 #endif
2350 
2351 static int nfs_bdi_register(struct nfs_server *server)
2352 {
2353 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2354 }
2355 
2356 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2357 			struct nfs_mount_info *mount_info)
2358 {
2359 	return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts);
2360 }
2361 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2362 
2363 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2364 			  struct nfs_mount_info *mount_info)
2365 {
2366 	/* clone any lsm security options from the parent to the new sb */
2367 	security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2368 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2369 		return -ESTALE;
2370 	return 0;
2371 }
2372 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2373 
2374 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2375 				   int flags, const char *dev_name,
2376 				   struct nfs_mount_info *mount_info,
2377 				   struct nfs_subversion *nfs_mod)
2378 {
2379 	struct super_block *s;
2380 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2381 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2382 	struct nfs_sb_mountdata sb_mntdata = {
2383 		.mntflags = flags,
2384 		.server = server,
2385 	};
2386 	int error;
2387 
2388 	if (server->flags & NFS_MOUNT_UNSHARED)
2389 		compare_super = NULL;
2390 
2391 	/* -o noac implies -o sync */
2392 	if (server->flags & NFS_MOUNT_NOAC)
2393 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2394 
2395 	/* Get a superblock - note that we may end up sharing one that already exists */
2396 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2397 	if (IS_ERR(s)) {
2398 		mntroot = ERR_CAST(s);
2399 		goto out_err_nosb;
2400 	}
2401 
2402 	if (s->s_fs_info != server) {
2403 		nfs_free_server(server);
2404 		server = NULL;
2405 	} else {
2406 		error = nfs_bdi_register(server);
2407 		if (error) {
2408 			mntroot = ERR_PTR(error);
2409 			goto error_splat_bdi;
2410 		}
2411 	}
2412 
2413 	if (!s->s_root) {
2414 		/* initial superblock/root creation */
2415 		mount_info->fill_super(s, mount_info);
2416 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2417 	}
2418 
2419 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2420 	if (IS_ERR(mntroot))
2421 		goto error_splat_super;
2422 
2423 	error = mount_info->set_security(s, mntroot, mount_info);
2424 	if (error)
2425 		goto error_splat_root;
2426 
2427 	s->s_flags |= MS_ACTIVE;
2428 
2429 out:
2430 	return mntroot;
2431 
2432 out_err_nosb:
2433 	nfs_free_server(server);
2434 	goto out;
2435 
2436 error_splat_root:
2437 	dput(mntroot);
2438 	mntroot = ERR_PTR(error);
2439 error_splat_super:
2440 	if (server && !s->s_root)
2441 		bdi_unregister(&server->backing_dev_info);
2442 error_splat_bdi:
2443 	deactivate_locked_super(s);
2444 	goto out;
2445 }
2446 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2447 
2448 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2449 	int flags, const char *dev_name, void *raw_data)
2450 {
2451 	struct nfs_mount_info mount_info = {
2452 		.fill_super = nfs_fill_super,
2453 		.set_security = nfs_set_sb_security,
2454 	};
2455 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2456 	struct nfs_subversion *nfs_mod;
2457 	int error;
2458 
2459 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2460 	mount_info.mntfh = nfs_alloc_fhandle();
2461 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2462 		goto out;
2463 
2464 	/* Validate the mount data */
2465 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2466 	if (error == NFS_TEXT_DATA)
2467 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2468 	if (error < 0) {
2469 		mntroot = ERR_PTR(error);
2470 		goto out;
2471 	}
2472 
2473 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2474 	if (IS_ERR(nfs_mod)) {
2475 		mntroot = ERR_CAST(nfs_mod);
2476 		goto out;
2477 	}
2478 
2479 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2480 
2481 	put_nfs_version(nfs_mod);
2482 out:
2483 	nfs_free_parsed_mount_data(mount_info.parsed);
2484 	nfs_free_fhandle(mount_info.mntfh);
2485 	return mntroot;
2486 }
2487 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2488 
2489 /*
2490  * Ensure that we unregister the bdi before kill_anon_super
2491  * releases the device name
2492  */
2493 void nfs_put_super(struct super_block *s)
2494 {
2495 	struct nfs_server *server = NFS_SB(s);
2496 
2497 	bdi_unregister(&server->backing_dev_info);
2498 }
2499 EXPORT_SYMBOL_GPL(nfs_put_super);
2500 
2501 /*
2502  * Destroy an NFS2/3 superblock
2503  */
2504 void nfs_kill_super(struct super_block *s)
2505 {
2506 	struct nfs_server *server = NFS_SB(s);
2507 
2508 	kill_anon_super(s);
2509 	nfs_fscache_release_super_cookie(s);
2510 	nfs_free_server(server);
2511 }
2512 EXPORT_SYMBOL_GPL(nfs_kill_super);
2513 
2514 /*
2515  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2516  */
2517 static struct dentry *
2518 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2519 		const char *dev_name, void *raw_data)
2520 {
2521 	struct nfs_clone_mount *data = raw_data;
2522 	struct nfs_mount_info mount_info = {
2523 		.fill_super = nfs_clone_super,
2524 		.set_security = nfs_clone_sb_security,
2525 		.cloned = data,
2526 	};
2527 	struct nfs_server *server;
2528 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2529 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2530 	int error;
2531 
2532 	dprintk("--> nfs_xdev_mount_common()\n");
2533 
2534 	mount_info.mntfh = mount_info.cloned->fh;
2535 
2536 	/* create a new volume representation */
2537 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2538 	if (IS_ERR(server)) {
2539 		error = PTR_ERR(server);
2540 		goto out_err;
2541 	}
2542 
2543 	mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, nfs_mod);
2544 	dprintk("<-- nfs_xdev_mount_common() = 0\n");
2545 out:
2546 	return mntroot;
2547 
2548 out_err:
2549 	dprintk("<-- nfs_xdev_mount_common() = %d [error]\n", error);
2550 	goto out;
2551 }
2552 
2553 #if IS_ENABLED(CONFIG_NFS_V4)
2554 
2555 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2556 {
2557 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2558 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2559 }
2560 
2561 /*
2562  * Validate NFSv4 mount options
2563  */
2564 static int nfs4_validate_mount_data(void *options,
2565 				    struct nfs_parsed_mount_data *args,
2566 				    const char *dev_name)
2567 {
2568 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2569 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2570 	char *c;
2571 
2572 	if (data == NULL)
2573 		goto out_no_data;
2574 
2575 	args->version = 4;
2576 
2577 	switch (data->version) {
2578 	case 1:
2579 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2580 			goto out_no_address;
2581 		if (data->host_addrlen == 0)
2582 			goto out_no_address;
2583 		args->nfs_server.addrlen = data->host_addrlen;
2584 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2585 			return -EFAULT;
2586 		if (!nfs_verify_server_address(sap))
2587 			goto out_no_address;
2588 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2589 
2590 		if (data->auth_flavourlen) {
2591 			if (data->auth_flavourlen > 1)
2592 				goto out_inval_auth;
2593 			if (copy_from_user(&args->auth_flavors[0],
2594 					   data->auth_flavours,
2595 					   sizeof(args->auth_flavors[0])))
2596 				return -EFAULT;
2597 		}
2598 
2599 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2600 		if (IS_ERR(c))
2601 			return PTR_ERR(c);
2602 		args->nfs_server.hostname = c;
2603 
2604 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2605 		if (IS_ERR(c))
2606 			return PTR_ERR(c);
2607 		args->nfs_server.export_path = c;
2608 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2609 
2610 		c = strndup_user(data->client_addr.data, 16);
2611 		if (IS_ERR(c))
2612 			return PTR_ERR(c);
2613 		args->client_address = c;
2614 
2615 		/*
2616 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2617 		 * can deal with.
2618 		 */
2619 
2620 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2621 		args->rsize	= data->rsize;
2622 		args->wsize	= data->wsize;
2623 		args->timeo	= data->timeo;
2624 		args->retrans	= data->retrans;
2625 		args->acregmin	= data->acregmin;
2626 		args->acregmax	= data->acregmax;
2627 		args->acdirmin	= data->acdirmin;
2628 		args->acdirmax	= data->acdirmax;
2629 		args->nfs_server.protocol = data->proto;
2630 		nfs_validate_transport_protocol(args);
2631 
2632 		break;
2633 	default:
2634 		return NFS_TEXT_DATA;
2635 	}
2636 
2637 	return 0;
2638 
2639 out_no_data:
2640 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2641 	return -EINVAL;
2642 
2643 out_inval_auth:
2644 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2645 		 data->auth_flavourlen);
2646 	return -EINVAL;
2647 
2648 out_no_address:
2649 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2650 	return -EINVAL;
2651 }
2652 
2653 /*
2654  * NFS v4 module parameters need to stay in the
2655  * NFS client for backwards compatibility
2656  */
2657 unsigned int nfs_callback_set_tcpport;
2658 unsigned short nfs_callback_tcpport;
2659 /* Default cache timeout is 10 minutes */
2660 unsigned int nfs_idmap_cache_timeout = 600;
2661 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2662 bool nfs4_disable_idmapping = true;
2663 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2664 unsigned short send_implementation_id = 1;
2665 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2666 
2667 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2668 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2669 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2670 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2671 EXPORT_SYMBOL_GPL(max_session_slots);
2672 EXPORT_SYMBOL_GPL(send_implementation_id);
2673 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2674 
2675 #define NFS_CALLBACK_MAXPORTNR (65535U)
2676 
2677 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2678 {
2679 	unsigned long num;
2680 	int ret;
2681 
2682 	if (!val)
2683 		return -EINVAL;
2684 	ret = kstrtoul(val, 0, &num);
2685 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2686 		return -EINVAL;
2687 	*((unsigned int *)kp->arg) = num;
2688 	return 0;
2689 }
2690 static struct kernel_param_ops param_ops_portnr = {
2691 	.set = param_set_portnr,
2692 	.get = param_get_uint,
2693 };
2694 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2695 
2696 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2697 module_param(nfs_idmap_cache_timeout, int, 0644);
2698 module_param(nfs4_disable_idmapping, bool, 0644);
2699 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2700 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2701 MODULE_PARM_DESC(nfs4_disable_idmapping,
2702 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2703 module_param(max_session_slots, ushort, 0644);
2704 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2705 		"requests the client will negotiate");
2706 module_param(send_implementation_id, ushort, 0644);
2707 MODULE_PARM_DESC(send_implementation_id,
2708 		"Send implementation ID with NFSv4.1 exchange_id");
2709 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2710 MODULE_ALIAS("nfs4");
2711 
2712 #endif /* CONFIG_NFS_V4 */
2713