xref: /linux/fs/nfs/super.c (revision 615f2e5c531bc57d5a190f321d697988e950ae4d)
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 "nfs4session.h"
67 #include "pnfs.h"
68 #include "nfs.h"
69 
70 #define NFSDBG_FACILITY		NFSDBG_VFS
71 #define NFS_TEXT_DATA		1
72 
73 #if IS_ENABLED(CONFIG_NFS_V3)
74 #define NFS_DEFAULT_VERSION 3
75 #else
76 #define NFS_DEFAULT_VERSION 2
77 #endif
78 
79 enum {
80 	/* Mount options that take no arguments */
81 	Opt_soft, Opt_hard,
82 	Opt_posix, Opt_noposix,
83 	Opt_cto, Opt_nocto,
84 	Opt_ac, Opt_noac,
85 	Opt_lock, Opt_nolock,
86 	Opt_udp, Opt_tcp, Opt_rdma,
87 	Opt_acl, Opt_noacl,
88 	Opt_rdirplus, Opt_nordirplus,
89 	Opt_sharecache, Opt_nosharecache,
90 	Opt_resvport, Opt_noresvport,
91 	Opt_fscache, Opt_nofscache,
92 	Opt_migration, Opt_nomigration,
93 
94 	/* Mount options that take integer arguments */
95 	Opt_port,
96 	Opt_rsize, Opt_wsize, Opt_bsize,
97 	Opt_timeo, Opt_retrans,
98 	Opt_acregmin, Opt_acregmax,
99 	Opt_acdirmin, Opt_acdirmax,
100 	Opt_actimeo,
101 	Opt_namelen,
102 	Opt_mountport,
103 	Opt_mountvers,
104 	Opt_minorversion,
105 
106 	/* Mount options that take string arguments */
107 	Opt_nfsvers,
108 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
109 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
110 	Opt_lookupcache,
111 	Opt_fscache_uniq,
112 	Opt_local_lock,
113 
114 	/* Special mount options */
115 	Opt_userspace, Opt_deprecated, Opt_sloppy,
116 
117 	Opt_err
118 };
119 
120 static const match_table_t nfs_mount_option_tokens = {
121 	{ Opt_userspace, "bg" },
122 	{ Opt_userspace, "fg" },
123 	{ Opt_userspace, "retry=%s" },
124 
125 	{ Opt_sloppy, "sloppy" },
126 
127 	{ Opt_soft, "soft" },
128 	{ Opt_hard, "hard" },
129 	{ Opt_deprecated, "intr" },
130 	{ Opt_deprecated, "nointr" },
131 	{ Opt_posix, "posix" },
132 	{ Opt_noposix, "noposix" },
133 	{ Opt_cto, "cto" },
134 	{ Opt_nocto, "nocto" },
135 	{ Opt_ac, "ac" },
136 	{ Opt_noac, "noac" },
137 	{ Opt_lock, "lock" },
138 	{ Opt_nolock, "nolock" },
139 	{ Opt_udp, "udp" },
140 	{ Opt_tcp, "tcp" },
141 	{ Opt_rdma, "rdma" },
142 	{ Opt_acl, "acl" },
143 	{ Opt_noacl, "noacl" },
144 	{ Opt_rdirplus, "rdirplus" },
145 	{ Opt_nordirplus, "nordirplus" },
146 	{ Opt_sharecache, "sharecache" },
147 	{ Opt_nosharecache, "nosharecache" },
148 	{ Opt_resvport, "resvport" },
149 	{ Opt_noresvport, "noresvport" },
150 	{ Opt_fscache, "fsc" },
151 	{ Opt_nofscache, "nofsc" },
152 	{ Opt_migration, "migration" },
153 	{ Opt_nomigration, "nomigration" },
154 
155 	{ Opt_port, "port=%s" },
156 	{ Opt_rsize, "rsize=%s" },
157 	{ Opt_wsize, "wsize=%s" },
158 	{ Opt_bsize, "bsize=%s" },
159 	{ Opt_timeo, "timeo=%s" },
160 	{ Opt_retrans, "retrans=%s" },
161 	{ Opt_acregmin, "acregmin=%s" },
162 	{ Opt_acregmax, "acregmax=%s" },
163 	{ Opt_acdirmin, "acdirmin=%s" },
164 	{ Opt_acdirmax, "acdirmax=%s" },
165 	{ Opt_actimeo, "actimeo=%s" },
166 	{ Opt_namelen, "namlen=%s" },
167 	{ Opt_mountport, "mountport=%s" },
168 	{ Opt_mountvers, "mountvers=%s" },
169 	{ Opt_minorversion, "minorversion=%s" },
170 
171 	{ Opt_nfsvers, "nfsvers=%s" },
172 	{ Opt_nfsvers, "vers=%s" },
173 
174 	{ Opt_sec, "sec=%s" },
175 	{ Opt_proto, "proto=%s" },
176 	{ Opt_mountproto, "mountproto=%s" },
177 	{ Opt_addr, "addr=%s" },
178 	{ Opt_clientaddr, "clientaddr=%s" },
179 	{ Opt_mounthost, "mounthost=%s" },
180 	{ Opt_mountaddr, "mountaddr=%s" },
181 
182 	{ Opt_lookupcache, "lookupcache=%s" },
183 	{ Opt_fscache_uniq, "fsc=%s" },
184 	{ Opt_local_lock, "local_lock=%s" },
185 
186 	/* The following needs to be listed after all other options */
187 	{ Opt_nfsvers, "v%s" },
188 
189 	{ Opt_err, NULL }
190 };
191 
192 enum {
193 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
194 
195 	Opt_xprt_err
196 };
197 
198 static const match_table_t nfs_xprt_protocol_tokens = {
199 	{ Opt_xprt_udp, "udp" },
200 	{ Opt_xprt_udp6, "udp6" },
201 	{ Opt_xprt_tcp, "tcp" },
202 	{ Opt_xprt_tcp6, "tcp6" },
203 	{ Opt_xprt_rdma, "rdma" },
204 
205 	{ Opt_xprt_err, NULL }
206 };
207 
208 enum {
209 	Opt_sec_none, Opt_sec_sys,
210 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
211 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
212 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
213 
214 	Opt_sec_err
215 };
216 
217 static const match_table_t nfs_secflavor_tokens = {
218 	{ Opt_sec_none, "none" },
219 	{ Opt_sec_none, "null" },
220 	{ Opt_sec_sys, "sys" },
221 
222 	{ Opt_sec_krb5, "krb5" },
223 	{ Opt_sec_krb5i, "krb5i" },
224 	{ Opt_sec_krb5p, "krb5p" },
225 
226 	{ Opt_sec_lkey, "lkey" },
227 	{ Opt_sec_lkeyi, "lkeyi" },
228 	{ Opt_sec_lkeyp, "lkeyp" },
229 
230 	{ Opt_sec_spkm, "spkm3" },
231 	{ Opt_sec_spkmi, "spkm3i" },
232 	{ Opt_sec_spkmp, "spkm3p" },
233 
234 	{ Opt_sec_err, NULL }
235 };
236 
237 enum {
238 	Opt_lookupcache_all, Opt_lookupcache_positive,
239 	Opt_lookupcache_none,
240 
241 	Opt_lookupcache_err
242 };
243 
244 static match_table_t nfs_lookupcache_tokens = {
245 	{ Opt_lookupcache_all, "all" },
246 	{ Opt_lookupcache_positive, "pos" },
247 	{ Opt_lookupcache_positive, "positive" },
248 	{ Opt_lookupcache_none, "none" },
249 
250 	{ Opt_lookupcache_err, NULL }
251 };
252 
253 enum {
254 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
255 	Opt_local_lock_none,
256 
257 	Opt_local_lock_err
258 };
259 
260 static match_table_t nfs_local_lock_tokens = {
261 	{ Opt_local_lock_all, "all" },
262 	{ Opt_local_lock_flock, "flock" },
263 	{ Opt_local_lock_posix, "posix" },
264 	{ Opt_local_lock_none, "none" },
265 
266 	{ Opt_local_lock_err, NULL }
267 };
268 
269 enum {
270 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
271 	Opt_vers_4_1,
272 
273 	Opt_vers_err
274 };
275 
276 static match_table_t nfs_vers_tokens = {
277 	{ Opt_vers_2, "2" },
278 	{ Opt_vers_3, "3" },
279 	{ Opt_vers_4, "4" },
280 	{ Opt_vers_4_0, "4.0" },
281 	{ Opt_vers_4_1, "4.1" },
282 
283 	{ Opt_vers_err, NULL }
284 };
285 
286 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
287 		int flags, const char *dev_name, void *raw_data);
288 
289 struct file_system_type nfs_fs_type = {
290 	.owner		= THIS_MODULE,
291 	.name		= "nfs",
292 	.mount		= nfs_fs_mount,
293 	.kill_sb	= nfs_kill_super,
294 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
295 };
296 EXPORT_SYMBOL_GPL(nfs_fs_type);
297 
298 struct file_system_type nfs_xdev_fs_type = {
299 	.owner		= THIS_MODULE,
300 	.name		= "nfs",
301 	.mount		= nfs_xdev_mount,
302 	.kill_sb	= nfs_kill_super,
303 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
304 };
305 
306 const struct super_operations nfs_sops = {
307 	.alloc_inode	= nfs_alloc_inode,
308 	.destroy_inode	= nfs_destroy_inode,
309 	.write_inode	= nfs_write_inode,
310 	.drop_inode	= nfs_drop_inode,
311 	.put_super	= nfs_put_super,
312 	.statfs		= nfs_statfs,
313 	.evict_inode	= nfs_evict_inode,
314 	.umount_begin	= nfs_umount_begin,
315 	.show_options	= nfs_show_options,
316 	.show_devname	= nfs_show_devname,
317 	.show_path	= nfs_show_path,
318 	.show_stats	= nfs_show_stats,
319 	.remount_fs	= nfs_remount,
320 };
321 EXPORT_SYMBOL_GPL(nfs_sops);
322 
323 #if IS_ENABLED(CONFIG_NFS_V4)
324 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
325 static int nfs4_validate_mount_data(void *options,
326 	struct nfs_parsed_mount_data *args, const char *dev_name);
327 
328 struct file_system_type nfs4_fs_type = {
329 	.owner		= THIS_MODULE,
330 	.name		= "nfs4",
331 	.mount		= nfs_fs_mount,
332 	.kill_sb	= nfs_kill_super,
333 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
334 };
335 EXPORT_SYMBOL_GPL(nfs4_fs_type);
336 
337 static int __init register_nfs4_fs(void)
338 {
339 	return register_filesystem(&nfs4_fs_type);
340 }
341 
342 static void unregister_nfs4_fs(void)
343 {
344 	unregister_filesystem(&nfs4_fs_type);
345 }
346 #else
347 static int __init register_nfs4_fs(void)
348 {
349 	return 0;
350 }
351 
352 static void unregister_nfs4_fs(void)
353 {
354 }
355 #endif
356 
357 static struct shrinker acl_shrinker = {
358 	.shrink		= nfs_access_cache_shrinker,
359 	.seeks		= DEFAULT_SEEKS,
360 };
361 
362 /*
363  * Register the NFS filesystems
364  */
365 int __init register_nfs_fs(void)
366 {
367 	int ret;
368 
369         ret = register_filesystem(&nfs_fs_type);
370 	if (ret < 0)
371 		goto error_0;
372 
373 	ret = register_nfs4_fs();
374 	if (ret < 0)
375 		goto error_1;
376 
377 	ret = nfs_register_sysctl();
378 	if (ret < 0)
379 		goto error_2;
380 	register_shrinker(&acl_shrinker);
381 	return 0;
382 
383 error_2:
384 	unregister_nfs4_fs();
385 error_1:
386 	unregister_filesystem(&nfs_fs_type);
387 error_0:
388 	return ret;
389 }
390 
391 /*
392  * Unregister the NFS filesystems
393  */
394 void __exit unregister_nfs_fs(void)
395 {
396 	unregister_shrinker(&acl_shrinker);
397 	nfs_unregister_sysctl();
398 	unregister_nfs4_fs();
399 	unregister_filesystem(&nfs_fs_type);
400 }
401 
402 void nfs_sb_active(struct super_block *sb)
403 {
404 	struct nfs_server *server = NFS_SB(sb);
405 
406 	if (atomic_inc_return(&server->active) == 1)
407 		atomic_inc(&sb->s_active);
408 }
409 EXPORT_SYMBOL_GPL(nfs_sb_active);
410 
411 void nfs_sb_deactive(struct super_block *sb)
412 {
413 	struct nfs_server *server = NFS_SB(sb);
414 
415 	if (atomic_dec_and_test(&server->active))
416 		deactivate_super(sb);
417 }
418 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
419 
420 /*
421  * Deliver file system statistics to userspace
422  */
423 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
424 {
425 	struct nfs_server *server = NFS_SB(dentry->d_sb);
426 	unsigned char blockbits;
427 	unsigned long blockres;
428 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
429 	struct nfs_fsstat res;
430 	int error = -ENOMEM;
431 
432 	res.fattr = nfs_alloc_fattr();
433 	if (res.fattr == NULL)
434 		goto out_err;
435 
436 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
437 	if (unlikely(error == -ESTALE)) {
438 		struct dentry *pd_dentry;
439 
440 		pd_dentry = dget_parent(dentry);
441 		if (pd_dentry != NULL) {
442 			nfs_zap_caches(pd_dentry->d_inode);
443 			dput(pd_dentry);
444 		}
445 	}
446 	nfs_free_fattr(res.fattr);
447 	if (error < 0)
448 		goto out_err;
449 
450 	buf->f_type = NFS_SUPER_MAGIC;
451 
452 	/*
453 	 * Current versions of glibc do not correctly handle the
454 	 * case where f_frsize != f_bsize.  Eventually we want to
455 	 * report the value of wtmult in this field.
456 	 */
457 	buf->f_frsize = dentry->d_sb->s_blocksize;
458 
459 	/*
460 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
461 	 * are reported in units of f_frsize.  Linux hasn't had
462 	 * an f_frsize field in its statfs struct until recently,
463 	 * thus historically Linux's sys_statfs reports these
464 	 * fields in units of f_bsize.
465 	 */
466 	buf->f_bsize = dentry->d_sb->s_blocksize;
467 	blockbits = dentry->d_sb->s_blocksize_bits;
468 	blockres = (1 << blockbits) - 1;
469 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
470 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
471 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
472 
473 	buf->f_files = res.tfiles;
474 	buf->f_ffree = res.afiles;
475 
476 	buf->f_namelen = server->namelen;
477 
478 	return 0;
479 
480  out_err:
481 	dprintk("%s: statfs error = %d\n", __func__, -error);
482 	return error;
483 }
484 EXPORT_SYMBOL_GPL(nfs_statfs);
485 
486 /*
487  * Map the security flavour number to a name
488  */
489 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
490 {
491 	static const struct {
492 		rpc_authflavor_t flavour;
493 		const char *str;
494 	} sec_flavours[] = {
495 		{ RPC_AUTH_NULL, "null" },
496 		{ RPC_AUTH_UNIX, "sys" },
497 		{ RPC_AUTH_GSS_KRB5, "krb5" },
498 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
499 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
500 		{ RPC_AUTH_GSS_LKEY, "lkey" },
501 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
502 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
503 		{ RPC_AUTH_GSS_SPKM, "spkm" },
504 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
505 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
506 		{ UINT_MAX, "unknown" }
507 	};
508 	int i;
509 
510 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
511 		if (sec_flavours[i].flavour == flavour)
512 			break;
513 	}
514 	return sec_flavours[i].str;
515 }
516 
517 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
518 				  int showdefaults)
519 {
520 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
521 
522 	seq_printf(m, ",mountproto=");
523 	switch (sap->sa_family) {
524 	case AF_INET:
525 		switch (nfss->mountd_protocol) {
526 		case IPPROTO_UDP:
527 			seq_printf(m, RPCBIND_NETID_UDP);
528 			break;
529 		case IPPROTO_TCP:
530 			seq_printf(m, RPCBIND_NETID_TCP);
531 			break;
532 		default:
533 			if (showdefaults)
534 				seq_printf(m, "auto");
535 		}
536 		break;
537 	case AF_INET6:
538 		switch (nfss->mountd_protocol) {
539 		case IPPROTO_UDP:
540 			seq_printf(m, RPCBIND_NETID_UDP6);
541 			break;
542 		case IPPROTO_TCP:
543 			seq_printf(m, RPCBIND_NETID_TCP6);
544 			break;
545 		default:
546 			if (showdefaults)
547 				seq_printf(m, "auto");
548 		}
549 		break;
550 	default:
551 		if (showdefaults)
552 			seq_printf(m, "auto");
553 	}
554 }
555 
556 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
557 				    int showdefaults)
558 {
559 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
560 
561 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
562 		return;
563 
564 	switch (sap->sa_family) {
565 	case AF_INET: {
566 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
567 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
568 		break;
569 	}
570 	case AF_INET6: {
571 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
572 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
573 		break;
574 	}
575 	default:
576 		if (showdefaults)
577 			seq_printf(m, ",mountaddr=unspecified");
578 	}
579 
580 	if (nfss->mountd_version || showdefaults)
581 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
582 	if ((nfss->mountd_port &&
583 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
584 		showdefaults)
585 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
586 
587 	nfs_show_mountd_netid(m, nfss, showdefaults);
588 }
589 
590 #if IS_ENABLED(CONFIG_NFS_V4)
591 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
592 				    int showdefaults)
593 {
594 	struct nfs_client *clp = nfss->nfs_client;
595 
596 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
597 }
598 #else
599 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
600 				    int showdefaults)
601 {
602 }
603 #endif
604 
605 static void nfs_show_nfs_version(struct seq_file *m,
606 		unsigned int version,
607 		unsigned int minorversion)
608 {
609 	seq_printf(m, ",vers=%u", version);
610 	if (version == 4)
611 		seq_printf(m, ".%u", minorversion);
612 }
613 
614 /*
615  * Describe the mount options in force on this server representation
616  */
617 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
618 				   int showdefaults)
619 {
620 	static const struct proc_nfs_info {
621 		int flag;
622 		const char *str;
623 		const char *nostr;
624 	} nfs_info[] = {
625 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
626 		{ NFS_MOUNT_POSIX, ",posix", "" },
627 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
628 		{ NFS_MOUNT_NOAC, ",noac", "" },
629 		{ NFS_MOUNT_NONLM, ",nolock", "" },
630 		{ NFS_MOUNT_NOACL, ",noacl", "" },
631 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
632 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
633 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
634 		{ 0, NULL, NULL }
635 	};
636 	const struct proc_nfs_info *nfs_infop;
637 	struct nfs_client *clp = nfss->nfs_client;
638 	u32 version = clp->rpc_ops->version;
639 	int local_flock, local_fcntl;
640 
641 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
642 	seq_printf(m, ",rsize=%u", nfss->rsize);
643 	seq_printf(m, ",wsize=%u", nfss->wsize);
644 	if (nfss->bsize != 0)
645 		seq_printf(m, ",bsize=%u", nfss->bsize);
646 	seq_printf(m, ",namlen=%u", nfss->namelen);
647 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
648 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
649 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
650 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
651 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
652 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
653 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
654 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
655 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
656 		if (nfss->flags & nfs_infop->flag)
657 			seq_puts(m, nfs_infop->str);
658 		else
659 			seq_puts(m, nfs_infop->nostr);
660 	}
661 	rcu_read_lock();
662 	seq_printf(m, ",proto=%s",
663 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
664 	rcu_read_unlock();
665 	if (version == 4) {
666 		if (nfss->port != NFS_PORT)
667 			seq_printf(m, ",port=%u", nfss->port);
668 	} else
669 		if (nfss->port)
670 			seq_printf(m, ",port=%u", nfss->port);
671 
672 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
673 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
674 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
675 
676 	if (version != 4)
677 		nfs_show_mountd_options(m, nfss, showdefaults);
678 	else
679 		nfs_show_nfsv4_options(m, nfss, showdefaults);
680 
681 	if (nfss->options & NFS_OPTION_FSCACHE)
682 		seq_printf(m, ",fsc");
683 
684 	if (nfss->options & NFS_OPTION_MIGRATION)
685 		seq_printf(m, ",migration");
686 
687 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
688 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
689 			seq_printf(m, ",lookupcache=none");
690 		else
691 			seq_printf(m, ",lookupcache=pos");
692 	}
693 
694 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
695 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
696 
697 	if (!local_flock && !local_fcntl)
698 		seq_printf(m, ",local_lock=none");
699 	else if (local_flock && local_fcntl)
700 		seq_printf(m, ",local_lock=all");
701 	else if (local_flock)
702 		seq_printf(m, ",local_lock=flock");
703 	else
704 		seq_printf(m, ",local_lock=posix");
705 }
706 
707 /*
708  * Describe the mount options on this VFS mountpoint
709  */
710 int nfs_show_options(struct seq_file *m, struct dentry *root)
711 {
712 	struct nfs_server *nfss = NFS_SB(root->d_sb);
713 
714 	nfs_show_mount_options(m, nfss, 0);
715 
716 	rcu_read_lock();
717 	seq_printf(m, ",addr=%s",
718 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
719 							RPC_DISPLAY_ADDR));
720 	rcu_read_unlock();
721 
722 	return 0;
723 }
724 EXPORT_SYMBOL_GPL(nfs_show_options);
725 
726 #if IS_ENABLED(CONFIG_NFS_V4)
727 #ifdef CONFIG_NFS_V4_1
728 static void show_sessions(struct seq_file *m, struct nfs_server *server)
729 {
730 	if (nfs4_has_session(server->nfs_client))
731 		seq_printf(m, ",sessions");
732 }
733 #else
734 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
735 #endif
736 #endif
737 
738 #ifdef CONFIG_NFS_V4_1
739 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
740 {
741 	seq_printf(m, ",pnfs=");
742 	if (server->pnfs_curr_ld)
743 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
744 	else
745 		seq_printf(m, "not configured");
746 }
747 
748 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
749 {
750 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
751 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
752 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
753 			   "date='%llu,%u'",
754 			   impl_id->name, impl_id->domain,
755 			   impl_id->date.seconds, impl_id->date.nseconds);
756 	}
757 }
758 #else
759 #if IS_ENABLED(CONFIG_NFS_V4)
760 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
761 {
762 }
763 #endif
764 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
765 {
766 }
767 #endif
768 
769 int nfs_show_devname(struct seq_file *m, struct dentry *root)
770 {
771 	char *page = (char *) __get_free_page(GFP_KERNEL);
772 	char *devname, *dummy;
773 	int err = 0;
774 	if (!page)
775 		return -ENOMEM;
776 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
777 	if (IS_ERR(devname))
778 		err = PTR_ERR(devname);
779 	else
780 		seq_escape(m, devname, " \t\n\\");
781 	free_page((unsigned long)page);
782 	return err;
783 }
784 EXPORT_SYMBOL_GPL(nfs_show_devname);
785 
786 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
787 {
788 	seq_puts(m, "/");
789 	return 0;
790 }
791 EXPORT_SYMBOL_GPL(nfs_show_path);
792 
793 /*
794  * Present statistical information for this VFS mountpoint
795  */
796 int nfs_show_stats(struct seq_file *m, struct dentry *root)
797 {
798 	int i, cpu;
799 	struct nfs_server *nfss = NFS_SB(root->d_sb);
800 	struct rpc_auth *auth = nfss->client->cl_auth;
801 	struct nfs_iostats totals = { };
802 
803 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
804 
805 	/*
806 	 * Display all mount option settings
807 	 */
808 	seq_printf(m, "\n\topts:\t");
809 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
810 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
811 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
812 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
813 	nfs_show_mount_options(m, nfss, 1);
814 
815 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
816 
817 	show_implementation_id(m, nfss);
818 
819 	seq_printf(m, "\n\tcaps:\t");
820 	seq_printf(m, "caps=0x%x", nfss->caps);
821 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
822 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
823 	seq_printf(m, ",bsize=%u", nfss->bsize);
824 	seq_printf(m, ",namlen=%u", nfss->namelen);
825 
826 #if IS_ENABLED(CONFIG_NFS_V4)
827 	if (nfss->nfs_client->rpc_ops->version == 4) {
828 		seq_printf(m, "\n\tnfsv4:\t");
829 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
830 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
831 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
832 		show_sessions(m, nfss);
833 		show_pnfs(m, nfss);
834 	}
835 #endif
836 
837 	/*
838 	 * Display security flavor in effect for this mount
839 	 */
840 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
841 	if (auth->au_flavor)
842 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
843 
844 	/*
845 	 * Display superblock I/O counters
846 	 */
847 	for_each_possible_cpu(cpu) {
848 		struct nfs_iostats *stats;
849 
850 		preempt_disable();
851 		stats = per_cpu_ptr(nfss->io_stats, cpu);
852 
853 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
854 			totals.events[i] += stats->events[i];
855 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
856 			totals.bytes[i] += stats->bytes[i];
857 #ifdef CONFIG_NFS_FSCACHE
858 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
859 			totals.fscache[i] += stats->fscache[i];
860 #endif
861 
862 		preempt_enable();
863 	}
864 
865 	seq_printf(m, "\n\tevents:\t");
866 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
867 		seq_printf(m, "%lu ", totals.events[i]);
868 	seq_printf(m, "\n\tbytes:\t");
869 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
870 		seq_printf(m, "%Lu ", totals.bytes[i]);
871 #ifdef CONFIG_NFS_FSCACHE
872 	if (nfss->options & NFS_OPTION_FSCACHE) {
873 		seq_printf(m, "\n\tfsc:\t");
874 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
875 			seq_printf(m, "%Lu ", totals.bytes[i]);
876 	}
877 #endif
878 	seq_printf(m, "\n");
879 
880 	rpc_print_iostats(m, nfss->client);
881 
882 	return 0;
883 }
884 EXPORT_SYMBOL_GPL(nfs_show_stats);
885 
886 /*
887  * Begin unmount by attempting to remove all automounted mountpoints we added
888  * in response to xdev traversals and referrals
889  */
890 void nfs_umount_begin(struct super_block *sb)
891 {
892 	struct nfs_server *server;
893 	struct rpc_clnt *rpc;
894 
895 	server = NFS_SB(sb);
896 	/* -EIO all pending I/O */
897 	rpc = server->client_acl;
898 	if (!IS_ERR(rpc))
899 		rpc_killall_tasks(rpc);
900 	rpc = server->client;
901 	if (!IS_ERR(rpc))
902 		rpc_killall_tasks(rpc);
903 }
904 EXPORT_SYMBOL_GPL(nfs_umount_begin);
905 
906 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
907 {
908 	struct nfs_parsed_mount_data *data;
909 
910 	data = kzalloc(sizeof(*data), GFP_KERNEL);
911 	if (data) {
912 		data->acregmin		= NFS_DEF_ACREGMIN;
913 		data->acregmax		= NFS_DEF_ACREGMAX;
914 		data->acdirmin		= NFS_DEF_ACDIRMIN;
915 		data->acdirmax		= NFS_DEF_ACDIRMAX;
916 		data->mount_server.port	= NFS_UNSPEC_PORT;
917 		data->nfs_server.port	= NFS_UNSPEC_PORT;
918 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
919 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
920 		data->auth_flavor_len	= 1;
921 		data->minorversion	= 0;
922 		data->need_mount	= true;
923 		data->net		= current->nsproxy->net_ns;
924 		security_init_mnt_opts(&data->lsm_opts);
925 	}
926 	return data;
927 }
928 
929 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
930 {
931 	if (data) {
932 		kfree(data->client_address);
933 		kfree(data->mount_server.hostname);
934 		kfree(data->nfs_server.export_path);
935 		kfree(data->nfs_server.hostname);
936 		kfree(data->fscache_uniq);
937 		security_free_mnt_opts(&data->lsm_opts);
938 		kfree(data);
939 	}
940 }
941 
942 /*
943  * Sanity-check a server address provided by the mount command.
944  *
945  * Address family must be initialized, and address must not be
946  * the ANY address for that family.
947  */
948 static int nfs_verify_server_address(struct sockaddr *addr)
949 {
950 	switch (addr->sa_family) {
951 	case AF_INET: {
952 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
953 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
954 	}
955 	case AF_INET6: {
956 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
957 		return !ipv6_addr_any(sa);
958 	}
959 	}
960 
961 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
962 	return 0;
963 }
964 
965 /*
966  * Select between a default port value and a user-specified port value.
967  * If a zero value is set, then autobind will be used.
968  */
969 static void nfs_set_port(struct sockaddr *sap, int *port,
970 				 const unsigned short default_port)
971 {
972 	if (*port == NFS_UNSPEC_PORT)
973 		*port = default_port;
974 
975 	rpc_set_port(sap, *port);
976 }
977 
978 /*
979  * Sanity check the NFS transport protocol.
980  *
981  */
982 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
983 {
984 	switch (mnt->nfs_server.protocol) {
985 	case XPRT_TRANSPORT_UDP:
986 	case XPRT_TRANSPORT_TCP:
987 	case XPRT_TRANSPORT_RDMA:
988 		break;
989 	default:
990 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
991 	}
992 }
993 
994 /*
995  * For text based NFSv2/v3 mounts, the mount protocol transport default
996  * settings should depend upon the specified NFS transport.
997  */
998 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
999 {
1000 	nfs_validate_transport_protocol(mnt);
1001 
1002 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1003 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1004 			return;
1005 	switch (mnt->nfs_server.protocol) {
1006 	case XPRT_TRANSPORT_UDP:
1007 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1008 		break;
1009 	case XPRT_TRANSPORT_TCP:
1010 	case XPRT_TRANSPORT_RDMA:
1011 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1012 	}
1013 }
1014 
1015 /*
1016  * Parse the value of the 'sec=' option.
1017  */
1018 static int nfs_parse_security_flavors(char *value,
1019 				      struct nfs_parsed_mount_data *mnt)
1020 {
1021 	substring_t args[MAX_OPT_ARGS];
1022 
1023 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1024 
1025 	switch (match_token(value, nfs_secflavor_tokens, args)) {
1026 	case Opt_sec_none:
1027 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
1028 		break;
1029 	case Opt_sec_sys:
1030 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1031 		break;
1032 	case Opt_sec_krb5:
1033 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1034 		break;
1035 	case Opt_sec_krb5i:
1036 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1037 		break;
1038 	case Opt_sec_krb5p:
1039 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1040 		break;
1041 	case Opt_sec_lkey:
1042 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1043 		break;
1044 	case Opt_sec_lkeyi:
1045 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1046 		break;
1047 	case Opt_sec_lkeyp:
1048 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1049 		break;
1050 	case Opt_sec_spkm:
1051 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1052 		break;
1053 	case Opt_sec_spkmi:
1054 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1055 		break;
1056 	case Opt_sec_spkmp:
1057 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1058 		break;
1059 	default:
1060 		return 0;
1061 	}
1062 
1063 	mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1064 	mnt->auth_flavor_len = 1;
1065 	return 1;
1066 }
1067 
1068 static int nfs_parse_version_string(char *string,
1069 		struct nfs_parsed_mount_data *mnt,
1070 		substring_t *args)
1071 {
1072 	mnt->flags &= ~NFS_MOUNT_VER3;
1073 	switch (match_token(string, nfs_vers_tokens, args)) {
1074 	case Opt_vers_2:
1075 		mnt->version = 2;
1076 		break;
1077 	case Opt_vers_3:
1078 		mnt->flags |= NFS_MOUNT_VER3;
1079 		mnt->version = 3;
1080 		break;
1081 	case Opt_vers_4:
1082 		/* Backward compatibility option. In future,
1083 		 * the mount program should always supply
1084 		 * a NFSv4 minor version number.
1085 		 */
1086 		mnt->version = 4;
1087 		break;
1088 	case Opt_vers_4_0:
1089 		mnt->version = 4;
1090 		mnt->minorversion = 0;
1091 		break;
1092 	case Opt_vers_4_1:
1093 		mnt->version = 4;
1094 		mnt->minorversion = 1;
1095 		break;
1096 	default:
1097 		return 0;
1098 	}
1099 	return 1;
1100 }
1101 
1102 static int nfs_get_option_str(substring_t args[], char **option)
1103 {
1104 	kfree(*option);
1105 	*option = match_strdup(args);
1106 	return !*option;
1107 }
1108 
1109 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1110 {
1111 	int rc;
1112 	char *string;
1113 
1114 	string = match_strdup(args);
1115 	if (string == NULL)
1116 		return -ENOMEM;
1117 	rc = kstrtoul(string, 10, option);
1118 	kfree(string);
1119 
1120 	return rc;
1121 }
1122 
1123 /*
1124  * Error-check and convert a string of mount options from user space into
1125  * a data structure.  The whole mount string is processed; bad options are
1126  * skipped as they are encountered.  If there were no errors, return 1;
1127  * otherwise return 0 (zero).
1128  */
1129 static int nfs_parse_mount_options(char *raw,
1130 				   struct nfs_parsed_mount_data *mnt)
1131 {
1132 	char *p, *string, *secdata;
1133 	int rc, sloppy = 0, invalid_option = 0;
1134 	unsigned short protofamily = AF_UNSPEC;
1135 	unsigned short mountfamily = AF_UNSPEC;
1136 
1137 	if (!raw) {
1138 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1139 		return 1;
1140 	}
1141 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1142 
1143 	secdata = alloc_secdata();
1144 	if (!secdata)
1145 		goto out_nomem;
1146 
1147 	rc = security_sb_copy_data(raw, secdata);
1148 	if (rc)
1149 		goto out_security_failure;
1150 
1151 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1152 	if (rc)
1153 		goto out_security_failure;
1154 
1155 	free_secdata(secdata);
1156 
1157 	while ((p = strsep(&raw, ",")) != NULL) {
1158 		substring_t args[MAX_OPT_ARGS];
1159 		unsigned long option;
1160 		int token;
1161 
1162 		if (!*p)
1163 			continue;
1164 
1165 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1166 
1167 		token = match_token(p, nfs_mount_option_tokens, args);
1168 		switch (token) {
1169 
1170 		/*
1171 		 * boolean options:  foo/nofoo
1172 		 */
1173 		case Opt_soft:
1174 			mnt->flags |= NFS_MOUNT_SOFT;
1175 			break;
1176 		case Opt_hard:
1177 			mnt->flags &= ~NFS_MOUNT_SOFT;
1178 			break;
1179 		case Opt_posix:
1180 			mnt->flags |= NFS_MOUNT_POSIX;
1181 			break;
1182 		case Opt_noposix:
1183 			mnt->flags &= ~NFS_MOUNT_POSIX;
1184 			break;
1185 		case Opt_cto:
1186 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1187 			break;
1188 		case Opt_nocto:
1189 			mnt->flags |= NFS_MOUNT_NOCTO;
1190 			break;
1191 		case Opt_ac:
1192 			mnt->flags &= ~NFS_MOUNT_NOAC;
1193 			break;
1194 		case Opt_noac:
1195 			mnt->flags |= NFS_MOUNT_NOAC;
1196 			break;
1197 		case Opt_lock:
1198 			mnt->flags &= ~NFS_MOUNT_NONLM;
1199 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1200 					NFS_MOUNT_LOCAL_FCNTL);
1201 			break;
1202 		case Opt_nolock:
1203 			mnt->flags |= NFS_MOUNT_NONLM;
1204 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1205 				       NFS_MOUNT_LOCAL_FCNTL);
1206 			break;
1207 		case Opt_udp:
1208 			mnt->flags &= ~NFS_MOUNT_TCP;
1209 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1210 			break;
1211 		case Opt_tcp:
1212 			mnt->flags |= NFS_MOUNT_TCP;
1213 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1214 			break;
1215 		case Opt_rdma:
1216 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1217 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1218 			xprt_load_transport(p);
1219 			break;
1220 		case Opt_acl:
1221 			mnt->flags &= ~NFS_MOUNT_NOACL;
1222 			break;
1223 		case Opt_noacl:
1224 			mnt->flags |= NFS_MOUNT_NOACL;
1225 			break;
1226 		case Opt_rdirplus:
1227 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1228 			break;
1229 		case Opt_nordirplus:
1230 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1231 			break;
1232 		case Opt_sharecache:
1233 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1234 			break;
1235 		case Opt_nosharecache:
1236 			mnt->flags |= NFS_MOUNT_UNSHARED;
1237 			break;
1238 		case Opt_resvport:
1239 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1240 			break;
1241 		case Opt_noresvport:
1242 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1243 			break;
1244 		case Opt_fscache:
1245 			mnt->options |= NFS_OPTION_FSCACHE;
1246 			kfree(mnt->fscache_uniq);
1247 			mnt->fscache_uniq = NULL;
1248 			break;
1249 		case Opt_nofscache:
1250 			mnt->options &= ~NFS_OPTION_FSCACHE;
1251 			kfree(mnt->fscache_uniq);
1252 			mnt->fscache_uniq = NULL;
1253 			break;
1254 		case Opt_migration:
1255 			mnt->options |= NFS_OPTION_MIGRATION;
1256 			break;
1257 		case Opt_nomigration:
1258 			mnt->options &= NFS_OPTION_MIGRATION;
1259 			break;
1260 
1261 		/*
1262 		 * options that take numeric values
1263 		 */
1264 		case Opt_port:
1265 			if (nfs_get_option_ul(args, &option) ||
1266 			    option > USHRT_MAX)
1267 				goto out_invalid_value;
1268 			mnt->nfs_server.port = option;
1269 			break;
1270 		case Opt_rsize:
1271 			if (nfs_get_option_ul(args, &option))
1272 				goto out_invalid_value;
1273 			mnt->rsize = option;
1274 			break;
1275 		case Opt_wsize:
1276 			if (nfs_get_option_ul(args, &option))
1277 				goto out_invalid_value;
1278 			mnt->wsize = option;
1279 			break;
1280 		case Opt_bsize:
1281 			if (nfs_get_option_ul(args, &option))
1282 				goto out_invalid_value;
1283 			mnt->bsize = option;
1284 			break;
1285 		case Opt_timeo:
1286 			if (nfs_get_option_ul(args, &option) || option == 0)
1287 				goto out_invalid_value;
1288 			mnt->timeo = option;
1289 			break;
1290 		case Opt_retrans:
1291 			if (nfs_get_option_ul(args, &option) || option == 0)
1292 				goto out_invalid_value;
1293 			mnt->retrans = option;
1294 			break;
1295 		case Opt_acregmin:
1296 			if (nfs_get_option_ul(args, &option))
1297 				goto out_invalid_value;
1298 			mnt->acregmin = option;
1299 			break;
1300 		case Opt_acregmax:
1301 			if (nfs_get_option_ul(args, &option))
1302 				goto out_invalid_value;
1303 			mnt->acregmax = option;
1304 			break;
1305 		case Opt_acdirmin:
1306 			if (nfs_get_option_ul(args, &option))
1307 				goto out_invalid_value;
1308 			mnt->acdirmin = option;
1309 			break;
1310 		case Opt_acdirmax:
1311 			if (nfs_get_option_ul(args, &option))
1312 				goto out_invalid_value;
1313 			mnt->acdirmax = option;
1314 			break;
1315 		case Opt_actimeo:
1316 			if (nfs_get_option_ul(args, &option))
1317 				goto out_invalid_value;
1318 			mnt->acregmin = mnt->acregmax =
1319 			mnt->acdirmin = mnt->acdirmax = option;
1320 			break;
1321 		case Opt_namelen:
1322 			if (nfs_get_option_ul(args, &option))
1323 				goto out_invalid_value;
1324 			mnt->namlen = option;
1325 			break;
1326 		case Opt_mountport:
1327 			if (nfs_get_option_ul(args, &option) ||
1328 			    option > USHRT_MAX)
1329 				goto out_invalid_value;
1330 			mnt->mount_server.port = option;
1331 			break;
1332 		case Opt_mountvers:
1333 			if (nfs_get_option_ul(args, &option) ||
1334 			    option < NFS_MNT_VERSION ||
1335 			    option > NFS_MNT3_VERSION)
1336 				goto out_invalid_value;
1337 			mnt->mount_server.version = option;
1338 			break;
1339 		case Opt_minorversion:
1340 			if (nfs_get_option_ul(args, &option))
1341 				goto out_invalid_value;
1342 			if (option > NFS4_MAX_MINOR_VERSION)
1343 				goto out_invalid_value;
1344 			mnt->minorversion = option;
1345 			break;
1346 
1347 		/*
1348 		 * options that take text values
1349 		 */
1350 		case Opt_nfsvers:
1351 			string = match_strdup(args);
1352 			if (string == NULL)
1353 				goto out_nomem;
1354 			rc = nfs_parse_version_string(string, mnt, args);
1355 			kfree(string);
1356 			if (!rc)
1357 				goto out_invalid_value;
1358 			break;
1359 		case Opt_sec:
1360 			string = match_strdup(args);
1361 			if (string == NULL)
1362 				goto out_nomem;
1363 			rc = nfs_parse_security_flavors(string, mnt);
1364 			kfree(string);
1365 			if (!rc) {
1366 				dfprintk(MOUNT, "NFS:   unrecognized "
1367 						"security flavor\n");
1368 				return 0;
1369 			}
1370 			break;
1371 		case Opt_proto:
1372 			string = match_strdup(args);
1373 			if (string == NULL)
1374 				goto out_nomem;
1375 			token = match_token(string,
1376 					    nfs_xprt_protocol_tokens, args);
1377 
1378 			protofamily = AF_INET;
1379 			switch (token) {
1380 			case Opt_xprt_udp6:
1381 				protofamily = AF_INET6;
1382 			case Opt_xprt_udp:
1383 				mnt->flags &= ~NFS_MOUNT_TCP;
1384 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1385 				break;
1386 			case Opt_xprt_tcp6:
1387 				protofamily = AF_INET6;
1388 			case Opt_xprt_tcp:
1389 				mnt->flags |= NFS_MOUNT_TCP;
1390 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1391 				break;
1392 			case Opt_xprt_rdma:
1393 				/* vector side protocols to TCP */
1394 				mnt->flags |= NFS_MOUNT_TCP;
1395 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1396 				xprt_load_transport(string);
1397 				break;
1398 			default:
1399 				dfprintk(MOUNT, "NFS:   unrecognized "
1400 						"transport protocol\n");
1401 				kfree(string);
1402 				return 0;
1403 			}
1404 			kfree(string);
1405 			break;
1406 		case Opt_mountproto:
1407 			string = match_strdup(args);
1408 			if (string == NULL)
1409 				goto out_nomem;
1410 			token = match_token(string,
1411 					    nfs_xprt_protocol_tokens, args);
1412 			kfree(string);
1413 
1414 			mountfamily = AF_INET;
1415 			switch (token) {
1416 			case Opt_xprt_udp6:
1417 				mountfamily = AF_INET6;
1418 			case Opt_xprt_udp:
1419 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1420 				break;
1421 			case Opt_xprt_tcp6:
1422 				mountfamily = AF_INET6;
1423 			case Opt_xprt_tcp:
1424 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1425 				break;
1426 			case Opt_xprt_rdma: /* not used for side protocols */
1427 			default:
1428 				dfprintk(MOUNT, "NFS:   unrecognized "
1429 						"transport protocol\n");
1430 				return 0;
1431 			}
1432 			break;
1433 		case Opt_addr:
1434 			string = match_strdup(args);
1435 			if (string == NULL)
1436 				goto out_nomem;
1437 			mnt->nfs_server.addrlen =
1438 				rpc_pton(mnt->net, string, strlen(string),
1439 					(struct sockaddr *)
1440 					&mnt->nfs_server.address,
1441 					sizeof(mnt->nfs_server.address));
1442 			kfree(string);
1443 			if (mnt->nfs_server.addrlen == 0)
1444 				goto out_invalid_address;
1445 			break;
1446 		case Opt_clientaddr:
1447 			if (nfs_get_option_str(args, &mnt->client_address))
1448 				goto out_nomem;
1449 			break;
1450 		case Opt_mounthost:
1451 			if (nfs_get_option_str(args,
1452 					       &mnt->mount_server.hostname))
1453 				goto out_nomem;
1454 			break;
1455 		case Opt_mountaddr:
1456 			string = match_strdup(args);
1457 			if (string == NULL)
1458 				goto out_nomem;
1459 			mnt->mount_server.addrlen =
1460 				rpc_pton(mnt->net, string, strlen(string),
1461 					(struct sockaddr *)
1462 					&mnt->mount_server.address,
1463 					sizeof(mnt->mount_server.address));
1464 			kfree(string);
1465 			if (mnt->mount_server.addrlen == 0)
1466 				goto out_invalid_address;
1467 			break;
1468 		case Opt_lookupcache:
1469 			string = match_strdup(args);
1470 			if (string == NULL)
1471 				goto out_nomem;
1472 			token = match_token(string,
1473 					nfs_lookupcache_tokens, args);
1474 			kfree(string);
1475 			switch (token) {
1476 				case Opt_lookupcache_all:
1477 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1478 					break;
1479 				case Opt_lookupcache_positive:
1480 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1481 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1482 					break;
1483 				case Opt_lookupcache_none:
1484 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1485 					break;
1486 				default:
1487 					dfprintk(MOUNT, "NFS:   invalid "
1488 							"lookupcache argument\n");
1489 					return 0;
1490 			};
1491 			break;
1492 		case Opt_fscache_uniq:
1493 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1494 				goto out_nomem;
1495 			mnt->options |= NFS_OPTION_FSCACHE;
1496 			break;
1497 		case Opt_local_lock:
1498 			string = match_strdup(args);
1499 			if (string == NULL)
1500 				goto out_nomem;
1501 			token = match_token(string, nfs_local_lock_tokens,
1502 					args);
1503 			kfree(string);
1504 			switch (token) {
1505 			case Opt_local_lock_all:
1506 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1507 					       NFS_MOUNT_LOCAL_FCNTL);
1508 				break;
1509 			case Opt_local_lock_flock:
1510 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1511 				break;
1512 			case Opt_local_lock_posix:
1513 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1514 				break;
1515 			case Opt_local_lock_none:
1516 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1517 						NFS_MOUNT_LOCAL_FCNTL);
1518 				break;
1519 			default:
1520 				dfprintk(MOUNT, "NFS:	invalid	"
1521 						"local_lock argument\n");
1522 				return 0;
1523 			};
1524 			break;
1525 
1526 		/*
1527 		 * Special options
1528 		 */
1529 		case Opt_sloppy:
1530 			sloppy = 1;
1531 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1532 			break;
1533 		case Opt_userspace:
1534 		case Opt_deprecated:
1535 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1536 					"'%s'\n", p);
1537 			break;
1538 
1539 		default:
1540 			invalid_option = 1;
1541 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1542 					"'%s'\n", p);
1543 		}
1544 	}
1545 
1546 	if (!sloppy && invalid_option)
1547 		return 0;
1548 
1549 	if (mnt->minorversion && mnt->version != 4)
1550 		goto out_minorversion_mismatch;
1551 
1552 	if (mnt->options & NFS_OPTION_MIGRATION &&
1553 	    mnt->version != 4 && mnt->minorversion != 0)
1554 		goto out_migration_misuse;
1555 
1556 	/*
1557 	 * verify that any proto=/mountproto= options match the address
1558 	 * families in the addr=/mountaddr= options.
1559 	 */
1560 	if (protofamily != AF_UNSPEC &&
1561 	    protofamily != mnt->nfs_server.address.ss_family)
1562 		goto out_proto_mismatch;
1563 
1564 	if (mountfamily != AF_UNSPEC) {
1565 		if (mnt->mount_server.addrlen) {
1566 			if (mountfamily != mnt->mount_server.address.ss_family)
1567 				goto out_mountproto_mismatch;
1568 		} else {
1569 			if (mountfamily != mnt->nfs_server.address.ss_family)
1570 				goto out_mountproto_mismatch;
1571 		}
1572 	}
1573 
1574 	return 1;
1575 
1576 out_mountproto_mismatch:
1577 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1578 			 "option\n");
1579 	return 0;
1580 out_proto_mismatch:
1581 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1582 	return 0;
1583 out_invalid_address:
1584 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1585 	return 0;
1586 out_invalid_value:
1587 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1588 	return 0;
1589 out_minorversion_mismatch:
1590 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1591 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1592 	return 0;
1593 out_migration_misuse:
1594 	printk(KERN_INFO
1595 		"NFS: 'migration' not supported for this NFS version\n");
1596 	return 0;
1597 out_nomem:
1598 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1599 	return 0;
1600 out_security_failure:
1601 	free_secdata(secdata);
1602 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1603 	return 0;
1604 }
1605 
1606 /*
1607  * Match the requested auth flavors with the list returned by
1608  * the server.  Returns zero and sets the mount's authentication
1609  * flavor on success; returns -EACCES if server does not support
1610  * the requested flavor.
1611  */
1612 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1613 			     struct nfs_mount_request *request)
1614 {
1615 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1616 
1617 	/*
1618 	 * Certain releases of Linux's mountd return an empty
1619 	 * flavor list.  To prevent behavioral regression with
1620 	 * these servers (ie. rejecting mounts that used to
1621 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1622 	 * if the returned flavor list is empty.
1623 	 */
1624 	if (server_authlist_len == 0)
1625 		return 0;
1626 
1627 	/*
1628 	 * We avoid sophisticated negotiating here, as there are
1629 	 * plenty of cases where we can get it wrong, providing
1630 	 * either too little or too much security.
1631 	 *
1632 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1633 	 * flavor listed first.  However, some servers list
1634 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1635 	 * preferred default, in args->auth_flavors[0] if user
1636 	 * didn't specify sec= mount option.
1637 	 */
1638 	for (i = 0; i < args->auth_flavor_len; i++)
1639 		for (j = 0; j < server_authlist_len; j++)
1640 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1641 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1642 					request->auth_flavs[j]);
1643 				args->auth_flavors[0] = request->auth_flavs[j];
1644 				return 0;
1645 			}
1646 
1647 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1648 	nfs_umount(request);
1649 	return -EACCES;
1650 }
1651 
1652 /*
1653  * Use the remote server's MOUNT service to request the NFS file handle
1654  * corresponding to the provided path.
1655  */
1656 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1657 			     struct nfs_fh *root_fh)
1658 {
1659 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1660 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1661 	struct nfs_mount_request request = {
1662 		.sap		= (struct sockaddr *)
1663 						&args->mount_server.address,
1664 		.dirpath	= args->nfs_server.export_path,
1665 		.protocol	= args->mount_server.protocol,
1666 		.fh		= root_fh,
1667 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1668 		.auth_flav_len	= &server_authlist_len,
1669 		.auth_flavs	= server_authlist,
1670 		.net		= args->net,
1671 	};
1672 	int status;
1673 
1674 	if (args->mount_server.version == 0) {
1675 		switch (args->version) {
1676 			default:
1677 				args->mount_server.version = NFS_MNT3_VERSION;
1678 				break;
1679 			case 2:
1680 				args->mount_server.version = NFS_MNT_VERSION;
1681 		}
1682 	}
1683 	request.version = args->mount_server.version;
1684 
1685 	if (args->mount_server.hostname)
1686 		request.hostname = args->mount_server.hostname;
1687 	else
1688 		request.hostname = args->nfs_server.hostname;
1689 
1690 	/*
1691 	 * Construct the mount server's address.
1692 	 */
1693 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1694 		memcpy(request.sap, &args->nfs_server.address,
1695 		       args->nfs_server.addrlen);
1696 		args->mount_server.addrlen = args->nfs_server.addrlen;
1697 	}
1698 	request.salen = args->mount_server.addrlen;
1699 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1700 
1701 	/*
1702 	 * Now ask the mount server to map our export path
1703 	 * to a file handle.
1704 	 */
1705 	status = nfs_mount(&request);
1706 	if (status != 0) {
1707 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1708 				request.hostname, status);
1709 		return status;
1710 	}
1711 
1712 	/*
1713 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1714 	 */
1715 	if (args->mount_server.version != NFS_MNT3_VERSION)
1716 		return 0;
1717 	return nfs_walk_authlist(args, &request);
1718 }
1719 
1720 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1721 			     struct nfs_mount_info *mount_info,
1722 			     struct nfs_subversion *nfs_mod)
1723 {
1724 	int status;
1725 	struct nfs_server *server;
1726 
1727 	if (mount_info->parsed->need_mount) {
1728 		status = nfs_request_mount(mount_info->parsed, mount_info->mntfh);
1729 		if (status)
1730 			return ERR_PTR(status);
1731 	}
1732 
1733 	/* Get a volume representation */
1734 	server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1735 	if (IS_ERR(server))
1736 		return ERR_CAST(server);
1737 
1738 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1739 }
1740 EXPORT_SYMBOL_GPL(nfs_try_mount);
1741 
1742 /*
1743  * Split "dev_name" into "hostname:export_path".
1744  *
1745  * The leftmost colon demarks the split between the server's hostname
1746  * and the export path.  If the hostname starts with a left square
1747  * bracket, then it may contain colons.
1748  *
1749  * Note: caller frees hostname and export path, even on error.
1750  */
1751 static int nfs_parse_devname(const char *dev_name,
1752 			     char **hostname, size_t maxnamlen,
1753 			     char **export_path, size_t maxpathlen)
1754 {
1755 	size_t len;
1756 	char *end;
1757 
1758 	/* Is the host name protected with square brakcets? */
1759 	if (*dev_name == '[') {
1760 		end = strchr(++dev_name, ']');
1761 		if (end == NULL || end[1] != ':')
1762 			goto out_bad_devname;
1763 
1764 		len = end - dev_name;
1765 		end++;
1766 	} else {
1767 		char *comma;
1768 
1769 		end = strchr(dev_name, ':');
1770 		if (end == NULL)
1771 			goto out_bad_devname;
1772 		len = end - dev_name;
1773 
1774 		/* kill possible hostname list: not supported */
1775 		comma = strchr(dev_name, ',');
1776 		if (comma != NULL && comma < end)
1777 			*comma = 0;
1778 	}
1779 
1780 	if (len > maxnamlen)
1781 		goto out_hostname;
1782 
1783 	/* N.B. caller will free nfs_server.hostname in all cases */
1784 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1785 	if (*hostname == NULL)
1786 		goto out_nomem;
1787 	len = strlen(++end);
1788 	if (len > maxpathlen)
1789 		goto out_path;
1790 	*export_path = kstrndup(end, len, GFP_KERNEL);
1791 	if (!*export_path)
1792 		goto out_nomem;
1793 
1794 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1795 	return 0;
1796 
1797 out_bad_devname:
1798 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1799 	return -EINVAL;
1800 
1801 out_nomem:
1802 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1803 	return -ENOMEM;
1804 
1805 out_hostname:
1806 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1807 	return -ENAMETOOLONG;
1808 
1809 out_path:
1810 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1811 	return -ENAMETOOLONG;
1812 }
1813 
1814 /*
1815  * Validate the NFS2/NFS3 mount data
1816  * - fills in the mount root filehandle
1817  *
1818  * For option strings, user space handles the following behaviors:
1819  *
1820  * + DNS: mapping server host name to IP address ("addr=" option)
1821  *
1822  * + failure mode: how to behave if a mount request can't be handled
1823  *   immediately ("fg/bg" option)
1824  *
1825  * + retry: how often to retry a mount request ("retry=" option)
1826  *
1827  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1828  *   mountproto=tcp after mountproto=udp, and so on
1829  */
1830 static int nfs23_validate_mount_data(void *options,
1831 				     struct nfs_parsed_mount_data *args,
1832 				     struct nfs_fh *mntfh,
1833 				     const char *dev_name)
1834 {
1835 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1836 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1837 
1838 	if (data == NULL)
1839 		goto out_no_data;
1840 
1841 	args->version = NFS_DEFAULT_VERSION;
1842 	switch (data->version) {
1843 	case 1:
1844 		data->namlen = 0;
1845 	case 2:
1846 		data->bsize = 0;
1847 	case 3:
1848 		if (data->flags & NFS_MOUNT_VER3)
1849 			goto out_no_v3;
1850 		data->root.size = NFS2_FHSIZE;
1851 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1852 	case 4:
1853 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1854 			goto out_no_sec;
1855 	case 5:
1856 		memset(data->context, 0, sizeof(data->context));
1857 	case 6:
1858 		if (data->flags & NFS_MOUNT_VER3) {
1859 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1860 				goto out_invalid_fh;
1861 			mntfh->size = data->root.size;
1862 			args->version = 3;
1863 		} else {
1864 			mntfh->size = NFS2_FHSIZE;
1865 			args->version = 2;
1866 		}
1867 
1868 
1869 		memcpy(mntfh->data, data->root.data, mntfh->size);
1870 		if (mntfh->size < sizeof(mntfh->data))
1871 			memset(mntfh->data + mntfh->size, 0,
1872 			       sizeof(mntfh->data) - mntfh->size);
1873 
1874 		/*
1875 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1876 		 * can deal with.
1877 		 */
1878 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1879 		args->flags		|= NFS_MOUNT_LEGACY_INTERFACE;
1880 		args->rsize		= data->rsize;
1881 		args->wsize		= data->wsize;
1882 		args->timeo		= data->timeo;
1883 		args->retrans		= data->retrans;
1884 		args->acregmin		= data->acregmin;
1885 		args->acregmax		= data->acregmax;
1886 		args->acdirmin		= data->acdirmin;
1887 		args->acdirmax		= data->acdirmax;
1888 		args->need_mount	= false;
1889 
1890 		memcpy(sap, &data->addr, sizeof(data->addr));
1891 		args->nfs_server.addrlen = sizeof(data->addr);
1892 		args->nfs_server.port = ntohs(data->addr.sin_port);
1893 		if (!nfs_verify_server_address(sap))
1894 			goto out_no_address;
1895 
1896 		if (!(data->flags & NFS_MOUNT_TCP))
1897 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1898 		/* N.B. caller will free nfs_server.hostname in all cases */
1899 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1900 		args->namlen		= data->namlen;
1901 		args->bsize		= data->bsize;
1902 
1903 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1904 			args->auth_flavors[0] = data->pseudoflavor;
1905 		if (!args->nfs_server.hostname)
1906 			goto out_nomem;
1907 
1908 		if (!(data->flags & NFS_MOUNT_NONLM))
1909 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1910 					 NFS_MOUNT_LOCAL_FCNTL);
1911 		else
1912 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1913 					NFS_MOUNT_LOCAL_FCNTL);
1914 		/*
1915 		 * The legacy version 6 binary mount data from userspace has a
1916 		 * field used only to transport selinux information into the
1917 		 * the kernel.  To continue to support that functionality we
1918 		 * have a touch of selinux knowledge here in the NFS code. The
1919 		 * userspace code converted context=blah to just blah so we are
1920 		 * converting back to the full string selinux understands.
1921 		 */
1922 		if (data->context[0]){
1923 #ifdef CONFIG_SECURITY_SELINUX
1924 			int rc;
1925 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1926 			if (!opts_str)
1927 				return -ENOMEM;
1928 			strcpy(opts_str, "context=");
1929 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1930 			strcat(opts_str, &data->context[0]);
1931 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1932 			kfree(opts_str);
1933 			if (rc)
1934 				return rc;
1935 #else
1936 			return -EINVAL;
1937 #endif
1938 		}
1939 
1940 		break;
1941 	default:
1942 		return NFS_TEXT_DATA;
1943 	}
1944 
1945 #if !IS_ENABLED(CONFIG_NFS_V3)
1946 	if (args->version == 3)
1947 		goto out_v3_not_compiled;
1948 #endif /* !CONFIG_NFS_V3 */
1949 
1950 	return 0;
1951 
1952 out_no_data:
1953 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1954 	return -EINVAL;
1955 
1956 out_no_v3:
1957 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1958 		 data->version);
1959 	return -EINVAL;
1960 
1961 out_no_sec:
1962 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1963 	return -EINVAL;
1964 
1965 #if !IS_ENABLED(CONFIG_NFS_V3)
1966 out_v3_not_compiled:
1967 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1968 	return -EPROTONOSUPPORT;
1969 #endif /* !CONFIG_NFS_V3 */
1970 
1971 out_nomem:
1972 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1973 	return -ENOMEM;
1974 
1975 out_no_address:
1976 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1977 	return -EINVAL;
1978 
1979 out_invalid_fh:
1980 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1981 	return -EINVAL;
1982 }
1983 
1984 #if IS_ENABLED(CONFIG_NFS_V4)
1985 static int nfs_validate_mount_data(struct file_system_type *fs_type,
1986 				   void *options,
1987 				   struct nfs_parsed_mount_data *args,
1988 				   struct nfs_fh *mntfh,
1989 				   const char *dev_name)
1990 {
1991 	if (fs_type == &nfs_fs_type)
1992 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
1993 	return nfs4_validate_mount_data(options, args, dev_name);
1994 }
1995 #else
1996 static int nfs_validate_mount_data(struct file_system_type *fs_type,
1997 				   void *options,
1998 				   struct nfs_parsed_mount_data *args,
1999 				   struct nfs_fh *mntfh,
2000 				   const char *dev_name)
2001 {
2002 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2003 }
2004 #endif
2005 
2006 static int nfs_validate_text_mount_data(void *options,
2007 					struct nfs_parsed_mount_data *args,
2008 					const char *dev_name)
2009 {
2010 	int port = 0;
2011 	int max_namelen = PAGE_SIZE;
2012 	int max_pathlen = NFS_MAXPATHLEN;
2013 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2014 
2015 	if (nfs_parse_mount_options((char *)options, args) == 0)
2016 		return -EINVAL;
2017 
2018 	if (!nfs_verify_server_address(sap))
2019 		goto out_no_address;
2020 
2021 	if (args->version == 4) {
2022 #if IS_ENABLED(CONFIG_NFS_V4)
2023 		port = NFS_PORT;
2024 		max_namelen = NFS4_MAXNAMLEN;
2025 		max_pathlen = NFS4_MAXPATHLEN;
2026 		nfs_validate_transport_protocol(args);
2027 		nfs4_validate_mount_flags(args);
2028 #else
2029 		goto out_v4_not_compiled;
2030 #endif /* CONFIG_NFS_V4 */
2031 	} else
2032 		nfs_set_mount_transport_protocol(args);
2033 
2034 	nfs_set_port(sap, &args->nfs_server.port, port);
2035 
2036 	if (args->auth_flavor_len > 1)
2037 		goto out_bad_auth;
2038 
2039 	return nfs_parse_devname(dev_name,
2040 				   &args->nfs_server.hostname,
2041 				   max_namelen,
2042 				   &args->nfs_server.export_path,
2043 				   max_pathlen);
2044 
2045 #if !IS_ENABLED(CONFIG_NFS_V4)
2046 out_v4_not_compiled:
2047 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2048 	return -EPROTONOSUPPORT;
2049 #endif /* !CONFIG_NFS_V4 */
2050 
2051 out_no_address:
2052 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2053 	return -EINVAL;
2054 
2055 out_bad_auth:
2056 	dfprintk(MOUNT, "NFS: Too many RPC auth flavours specified\n");
2057 	return -EINVAL;
2058 }
2059 
2060 static int
2061 nfs_compare_remount_data(struct nfs_server *nfss,
2062 			 struct nfs_parsed_mount_data *data)
2063 {
2064 	if (data->flags != nfss->flags ||
2065 	    data->rsize != nfss->rsize ||
2066 	    data->wsize != nfss->wsize ||
2067 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2068 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2069 	    data->acregmin != nfss->acregmin / HZ ||
2070 	    data->acregmax != nfss->acregmax / HZ ||
2071 	    data->acdirmin != nfss->acdirmin / HZ ||
2072 	    data->acdirmax != nfss->acdirmax / HZ ||
2073 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2074 	    data->nfs_server.port != nfss->port ||
2075 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2076 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2077 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2078 		return -EINVAL;
2079 
2080 	return 0;
2081 }
2082 
2083 int
2084 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2085 {
2086 	int error;
2087 	struct nfs_server *nfss = sb->s_fs_info;
2088 	struct nfs_parsed_mount_data *data;
2089 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2090 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2091 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2092 
2093 	/*
2094 	 * Userspace mount programs that send binary options generally send
2095 	 * them populated with default values. We have no way to know which
2096 	 * ones were explicitly specified. Fall back to legacy behavior and
2097 	 * just return success.
2098 	 */
2099 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2100 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2101 					   options->version <= 6))))
2102 		return 0;
2103 
2104 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2105 	if (data == NULL)
2106 		return -ENOMEM;
2107 
2108 	/* fill out struct with values from existing mount */
2109 	data->flags = nfss->flags;
2110 	data->rsize = nfss->rsize;
2111 	data->wsize = nfss->wsize;
2112 	data->retrans = nfss->client->cl_timeout->to_retries;
2113 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2114 	data->acregmin = nfss->acregmin / HZ;
2115 	data->acregmax = nfss->acregmax / HZ;
2116 	data->acdirmin = nfss->acdirmin / HZ;
2117 	data->acdirmax = nfss->acdirmax / HZ;
2118 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2119 	data->nfs_server.port = nfss->port;
2120 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2121 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2122 		data->nfs_server.addrlen);
2123 
2124 	/* overwrite those values with any that were specified */
2125 	error = nfs_parse_mount_options((char *)options, data);
2126 	if (error < 0)
2127 		goto out;
2128 
2129 	/*
2130 	 * noac is a special case. It implies -o sync, but that's not
2131 	 * necessarily reflected in the mtab options. do_remount_sb
2132 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2133 	 * remount options, so we have to explicitly reset it.
2134 	 */
2135 	if (data->flags & NFS_MOUNT_NOAC)
2136 		*flags |= MS_SYNCHRONOUS;
2137 
2138 	/* compare new mount options with old ones */
2139 	error = nfs_compare_remount_data(nfss, data);
2140 out:
2141 	kfree(data);
2142 	return error;
2143 }
2144 EXPORT_SYMBOL_GPL(nfs_remount);
2145 
2146 /*
2147  * Initialise the common bits of the superblock
2148  */
2149 inline void nfs_initialise_sb(struct super_block *sb)
2150 {
2151 	struct nfs_server *server = NFS_SB(sb);
2152 
2153 	sb->s_magic = NFS_SUPER_MAGIC;
2154 
2155 	/* We probably want something more informative here */
2156 	snprintf(sb->s_id, sizeof(sb->s_id),
2157 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2158 
2159 	if (sb->s_blocksize == 0)
2160 		sb->s_blocksize = nfs_block_bits(server->wsize,
2161 						 &sb->s_blocksize_bits);
2162 
2163 	sb->s_bdi = &server->backing_dev_info;
2164 
2165 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2166 }
2167 
2168 /*
2169  * Finish setting up an NFS2/3 superblock
2170  */
2171 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2172 {
2173 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2174 	struct nfs_server *server = NFS_SB(sb);
2175 
2176 	sb->s_blocksize_bits = 0;
2177 	sb->s_blocksize = 0;
2178 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2179 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2180 	if (data && data->bsize)
2181 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2182 
2183 	if (server->nfs_client->rpc_ops->version != 2) {
2184 		/* The VFS shouldn't apply the umask to mode bits. We will do
2185 		 * so ourselves when necessary.
2186 		 */
2187 		sb->s_flags |= MS_POSIXACL;
2188 		sb->s_time_gran = 1;
2189 	}
2190 
2191  	nfs_initialise_sb(sb);
2192 }
2193 EXPORT_SYMBOL_GPL(nfs_fill_super);
2194 
2195 /*
2196  * Finish setting up a cloned NFS2/3/4 superblock
2197  */
2198 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2199 {
2200 	const struct super_block *old_sb = mount_info->cloned->sb;
2201 	struct nfs_server *server = NFS_SB(sb);
2202 
2203 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2204 	sb->s_blocksize = old_sb->s_blocksize;
2205 	sb->s_maxbytes = old_sb->s_maxbytes;
2206 	sb->s_xattr = old_sb->s_xattr;
2207 	sb->s_op = old_sb->s_op;
2208 	sb->s_time_gran = 1;
2209 
2210 	if (server->nfs_client->rpc_ops->version != 2) {
2211 		/* The VFS shouldn't apply the umask to mode bits. We will do
2212 		 * so ourselves when necessary.
2213 		 */
2214 		sb->s_flags |= MS_POSIXACL;
2215 	}
2216 
2217  	nfs_initialise_sb(sb);
2218 }
2219 
2220 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2221 {
2222 	const struct nfs_server *a = s->s_fs_info;
2223 	const struct rpc_clnt *clnt_a = a->client;
2224 	const struct rpc_clnt *clnt_b = b->client;
2225 
2226 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2227 		goto Ebusy;
2228 	if (a->nfs_client != b->nfs_client)
2229 		goto Ebusy;
2230 	if (a->flags != b->flags)
2231 		goto Ebusy;
2232 	if (a->wsize != b->wsize)
2233 		goto Ebusy;
2234 	if (a->rsize != b->rsize)
2235 		goto Ebusy;
2236 	if (a->acregmin != b->acregmin)
2237 		goto Ebusy;
2238 	if (a->acregmax != b->acregmax)
2239 		goto Ebusy;
2240 	if (a->acdirmin != b->acdirmin)
2241 		goto Ebusy;
2242 	if (a->acdirmax != b->acdirmax)
2243 		goto Ebusy;
2244 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2245 		goto Ebusy;
2246 	return 1;
2247 Ebusy:
2248 	return 0;
2249 }
2250 
2251 struct nfs_sb_mountdata {
2252 	struct nfs_server *server;
2253 	int mntflags;
2254 };
2255 
2256 static int nfs_set_super(struct super_block *s, void *data)
2257 {
2258 	struct nfs_sb_mountdata *sb_mntdata = data;
2259 	struct nfs_server *server = sb_mntdata->server;
2260 	int ret;
2261 
2262 	s->s_flags = sb_mntdata->mntflags;
2263 	s->s_fs_info = server;
2264 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2265 	ret = set_anon_super(s, server);
2266 	if (ret == 0)
2267 		server->s_dev = s->s_dev;
2268 	return ret;
2269 }
2270 
2271 static int nfs_compare_super_address(struct nfs_server *server1,
2272 				     struct nfs_server *server2)
2273 {
2274 	struct sockaddr *sap1, *sap2;
2275 
2276 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2277 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2278 
2279 	if (sap1->sa_family != sap2->sa_family)
2280 		return 0;
2281 
2282 	switch (sap1->sa_family) {
2283 	case AF_INET: {
2284 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2285 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2286 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2287 			return 0;
2288 		if (sin1->sin_port != sin2->sin_port)
2289 			return 0;
2290 		break;
2291 	}
2292 	case AF_INET6: {
2293 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2294 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2295 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2296 			return 0;
2297 		if (sin1->sin6_port != sin2->sin6_port)
2298 			return 0;
2299 		break;
2300 	}
2301 	default:
2302 		return 0;
2303 	}
2304 
2305 	return 1;
2306 }
2307 
2308 static int nfs_compare_super(struct super_block *sb, void *data)
2309 {
2310 	struct nfs_sb_mountdata *sb_mntdata = data;
2311 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2312 	int mntflags = sb_mntdata->mntflags;
2313 
2314 	if (!nfs_compare_super_address(old, server))
2315 		return 0;
2316 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2317 	if (old->flags & NFS_MOUNT_UNSHARED)
2318 		return 0;
2319 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2320 		return 0;
2321 	return nfs_compare_mount_options(sb, server, mntflags);
2322 }
2323 
2324 #ifdef CONFIG_NFS_FSCACHE
2325 static void nfs_get_cache_cookie(struct super_block *sb,
2326 				 struct nfs_parsed_mount_data *parsed,
2327 				 struct nfs_clone_mount *cloned)
2328 {
2329 	struct nfs_server *nfss = NFS_SB(sb);
2330 	char *uniq = NULL;
2331 	int ulen = 0;
2332 
2333 	nfss->fscache_key = NULL;
2334 	nfss->fscache = NULL;
2335 
2336 	if (parsed) {
2337 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2338 			return;
2339 		if (parsed->fscache_uniq) {
2340 			uniq = parsed->fscache_uniq;
2341 			ulen = strlen(parsed->fscache_uniq);
2342 		}
2343 	} else if (cloned) {
2344 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2345 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2346 			return;
2347 		if (mnt_s->fscache_key) {
2348 			uniq = mnt_s->fscache_key->key.uniquifier;
2349 			ulen = mnt_s->fscache_key->key.uniq_len;
2350 		};
2351 	} else
2352 		return;
2353 
2354 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2355 }
2356 #else
2357 static void nfs_get_cache_cookie(struct super_block *sb,
2358 				 struct nfs_parsed_mount_data *parsed,
2359 				 struct nfs_clone_mount *cloned)
2360 {
2361 }
2362 #endif
2363 
2364 static int nfs_bdi_register(struct nfs_server *server)
2365 {
2366 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2367 }
2368 
2369 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2370 			struct nfs_mount_info *mount_info)
2371 {
2372 	return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts);
2373 }
2374 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2375 
2376 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2377 			  struct nfs_mount_info *mount_info)
2378 {
2379 	/* clone any lsm security options from the parent to the new sb */
2380 	security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2381 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2382 		return -ESTALE;
2383 	return 0;
2384 }
2385 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2386 
2387 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2388 				   int flags, const char *dev_name,
2389 				   struct nfs_mount_info *mount_info,
2390 				   struct nfs_subversion *nfs_mod)
2391 {
2392 	struct super_block *s;
2393 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2394 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2395 	struct nfs_sb_mountdata sb_mntdata = {
2396 		.mntflags = flags,
2397 		.server = server,
2398 	};
2399 	int error;
2400 
2401 	if (server->flags & NFS_MOUNT_UNSHARED)
2402 		compare_super = NULL;
2403 
2404 	/* -o noac implies -o sync */
2405 	if (server->flags & NFS_MOUNT_NOAC)
2406 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2407 
2408 	/* Get a superblock - note that we may end up sharing one that already exists */
2409 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2410 	if (IS_ERR(s)) {
2411 		mntroot = ERR_CAST(s);
2412 		goto out_err_nosb;
2413 	}
2414 
2415 	if (s->s_fs_info != server) {
2416 		nfs_free_server(server);
2417 		server = NULL;
2418 	} else {
2419 		error = nfs_bdi_register(server);
2420 		if (error) {
2421 			mntroot = ERR_PTR(error);
2422 			goto error_splat_bdi;
2423 		}
2424 	}
2425 
2426 	if (!s->s_root) {
2427 		/* initial superblock/root creation */
2428 		mount_info->fill_super(s, mount_info);
2429 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2430 	}
2431 
2432 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2433 	if (IS_ERR(mntroot))
2434 		goto error_splat_super;
2435 
2436 	error = mount_info->set_security(s, mntroot, mount_info);
2437 	if (error)
2438 		goto error_splat_root;
2439 
2440 	s->s_flags |= MS_ACTIVE;
2441 
2442 out:
2443 	return mntroot;
2444 
2445 out_err_nosb:
2446 	nfs_free_server(server);
2447 	goto out;
2448 
2449 error_splat_root:
2450 	dput(mntroot);
2451 	mntroot = ERR_PTR(error);
2452 error_splat_super:
2453 	if (server && !s->s_root)
2454 		bdi_unregister(&server->backing_dev_info);
2455 error_splat_bdi:
2456 	deactivate_locked_super(s);
2457 	goto out;
2458 }
2459 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2460 
2461 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2462 	int flags, const char *dev_name, void *raw_data)
2463 {
2464 	struct nfs_mount_info mount_info = {
2465 		.fill_super = nfs_fill_super,
2466 		.set_security = nfs_set_sb_security,
2467 	};
2468 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2469 	struct nfs_subversion *nfs_mod;
2470 	int error;
2471 
2472 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2473 	mount_info.mntfh = nfs_alloc_fhandle();
2474 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2475 		goto out;
2476 
2477 	/* Validate the mount data */
2478 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2479 	if (error == NFS_TEXT_DATA)
2480 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2481 	if (error < 0) {
2482 		mntroot = ERR_PTR(error);
2483 		goto out;
2484 	}
2485 
2486 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2487 	if (IS_ERR(nfs_mod)) {
2488 		mntroot = ERR_CAST(nfs_mod);
2489 		goto out;
2490 	}
2491 
2492 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2493 
2494 	put_nfs_version(nfs_mod);
2495 out:
2496 	nfs_free_parsed_mount_data(mount_info.parsed);
2497 	nfs_free_fhandle(mount_info.mntfh);
2498 	return mntroot;
2499 }
2500 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2501 
2502 /*
2503  * Ensure that we unregister the bdi before kill_anon_super
2504  * releases the device name
2505  */
2506 void nfs_put_super(struct super_block *s)
2507 {
2508 	struct nfs_server *server = NFS_SB(s);
2509 
2510 	bdi_unregister(&server->backing_dev_info);
2511 }
2512 EXPORT_SYMBOL_GPL(nfs_put_super);
2513 
2514 /*
2515  * Destroy an NFS2/3 superblock
2516  */
2517 void nfs_kill_super(struct super_block *s)
2518 {
2519 	struct nfs_server *server = NFS_SB(s);
2520 
2521 	kill_anon_super(s);
2522 	nfs_fscache_release_super_cookie(s);
2523 	nfs_free_server(server);
2524 }
2525 EXPORT_SYMBOL_GPL(nfs_kill_super);
2526 
2527 /*
2528  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2529  */
2530 static struct dentry *
2531 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2532 		const char *dev_name, void *raw_data)
2533 {
2534 	struct nfs_clone_mount *data = raw_data;
2535 	struct nfs_mount_info mount_info = {
2536 		.fill_super = nfs_clone_super,
2537 		.set_security = nfs_clone_sb_security,
2538 		.cloned = data,
2539 	};
2540 	struct nfs_server *server;
2541 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2542 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2543 
2544 	dprintk("--> nfs_xdev_mount()\n");
2545 
2546 	mount_info.mntfh = mount_info.cloned->fh;
2547 
2548 	/* create a new volume representation */
2549 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2550 
2551 	if (IS_ERR(server))
2552 		mntroot = ERR_CAST(server);
2553 	else
2554 		mntroot = nfs_fs_mount_common(server, flags,
2555 				dev_name, &mount_info, nfs_mod);
2556 
2557 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2558 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2559 	return mntroot;
2560 }
2561 
2562 #if IS_ENABLED(CONFIG_NFS_V4)
2563 
2564 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2565 {
2566 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2567 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2568 }
2569 
2570 /*
2571  * Validate NFSv4 mount options
2572  */
2573 static int nfs4_validate_mount_data(void *options,
2574 				    struct nfs_parsed_mount_data *args,
2575 				    const char *dev_name)
2576 {
2577 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2578 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2579 	char *c;
2580 
2581 	if (data == NULL)
2582 		goto out_no_data;
2583 
2584 	args->version = 4;
2585 
2586 	switch (data->version) {
2587 	case 1:
2588 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2589 			goto out_no_address;
2590 		if (data->host_addrlen == 0)
2591 			goto out_no_address;
2592 		args->nfs_server.addrlen = data->host_addrlen;
2593 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2594 			return -EFAULT;
2595 		if (!nfs_verify_server_address(sap))
2596 			goto out_no_address;
2597 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2598 
2599 		if (data->auth_flavourlen) {
2600 			if (data->auth_flavourlen > 1)
2601 				goto out_inval_auth;
2602 			if (copy_from_user(&args->auth_flavors[0],
2603 					   data->auth_flavours,
2604 					   sizeof(args->auth_flavors[0])))
2605 				return -EFAULT;
2606 		}
2607 
2608 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2609 		if (IS_ERR(c))
2610 			return PTR_ERR(c);
2611 		args->nfs_server.hostname = c;
2612 
2613 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2614 		if (IS_ERR(c))
2615 			return PTR_ERR(c);
2616 		args->nfs_server.export_path = c;
2617 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2618 
2619 		c = strndup_user(data->client_addr.data, 16);
2620 		if (IS_ERR(c))
2621 			return PTR_ERR(c);
2622 		args->client_address = c;
2623 
2624 		/*
2625 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2626 		 * can deal with.
2627 		 */
2628 
2629 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2630 		args->rsize	= data->rsize;
2631 		args->wsize	= data->wsize;
2632 		args->timeo	= data->timeo;
2633 		args->retrans	= data->retrans;
2634 		args->acregmin	= data->acregmin;
2635 		args->acregmax	= data->acregmax;
2636 		args->acdirmin	= data->acdirmin;
2637 		args->acdirmax	= data->acdirmax;
2638 		args->nfs_server.protocol = data->proto;
2639 		nfs_validate_transport_protocol(args);
2640 
2641 		break;
2642 	default:
2643 		return NFS_TEXT_DATA;
2644 	}
2645 
2646 	return 0;
2647 
2648 out_no_data:
2649 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2650 	return -EINVAL;
2651 
2652 out_inval_auth:
2653 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2654 		 data->auth_flavourlen);
2655 	return -EINVAL;
2656 
2657 out_no_address:
2658 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2659 	return -EINVAL;
2660 }
2661 
2662 /*
2663  * NFS v4 module parameters need to stay in the
2664  * NFS client for backwards compatibility
2665  */
2666 unsigned int nfs_callback_set_tcpport;
2667 unsigned short nfs_callback_tcpport;
2668 /* Default cache timeout is 10 minutes */
2669 unsigned int nfs_idmap_cache_timeout = 600;
2670 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2671 bool nfs4_disable_idmapping = true;
2672 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2673 unsigned short send_implementation_id = 1;
2674 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2675 
2676 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2677 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2678 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2679 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2680 EXPORT_SYMBOL_GPL(max_session_slots);
2681 EXPORT_SYMBOL_GPL(send_implementation_id);
2682 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2683 
2684 #define NFS_CALLBACK_MAXPORTNR (65535U)
2685 
2686 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2687 {
2688 	unsigned long num;
2689 	int ret;
2690 
2691 	if (!val)
2692 		return -EINVAL;
2693 	ret = kstrtoul(val, 0, &num);
2694 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2695 		return -EINVAL;
2696 	*((unsigned int *)kp->arg) = num;
2697 	return 0;
2698 }
2699 static struct kernel_param_ops param_ops_portnr = {
2700 	.set = param_set_portnr,
2701 	.get = param_get_uint,
2702 };
2703 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2704 
2705 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2706 module_param(nfs_idmap_cache_timeout, int, 0644);
2707 module_param(nfs4_disable_idmapping, bool, 0644);
2708 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2709 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2710 MODULE_PARM_DESC(nfs4_disable_idmapping,
2711 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2712 module_param(max_session_slots, ushort, 0644);
2713 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2714 		"requests the client will negotiate");
2715 module_param(send_implementation_id, ushort, 0644);
2716 MODULE_PARM_DESC(send_implementation_id,
2717 		"Send implementation ID with NFSv4.1 exchange_id");
2718 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2719 MODULE_ALIAS("nfs4");
2720 
2721 #endif /* CONFIG_NFS_V4 */
2722