xref: /linux/fs/nfs/super.c (revision 61d0b5a4b2777dcf5daef245e212b3c1fa8091ca)
1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/addr.h>
35 #include <linux/sunrpc/stats.h>
36 #include <linux/sunrpc/metrics.h>
37 #include <linux/sunrpc/xprtsock.h>
38 #include <linux/sunrpc/xprtrdma.h>
39 #include <linux/nfs_fs.h>
40 #include <linux/nfs_mount.h>
41 #include <linux/nfs4_mount.h>
42 #include <linux/lockd/bind.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/namei.h>
46 #include <linux/nfs_idmap.h>
47 #include <linux/vfs.h>
48 #include <linux/inet.h>
49 #include <linux/in6.h>
50 #include <linux/slab.h>
51 #include <net/ipv6.h>
52 #include <linux/netdevice.h>
53 #include <linux/nfs_xdr.h>
54 #include <linux/magic.h>
55 #include <linux/parser.h>
56 #include <linux/nsproxy.h>
57 #include <linux/rcupdate.h>
58 
59 #include <asm/uaccess.h>
60 
61 #include "nfs4_fs.h"
62 #include "callback.h"
63 #include "delegation.h"
64 #include "iostat.h"
65 #include "internal.h"
66 #include "fscache.h"
67 #include "nfs4session.h"
68 #include "pnfs.h"
69 #include "nfs.h"
70 
71 #define NFSDBG_FACILITY		NFSDBG_VFS
72 #define NFS_TEXT_DATA		1
73 
74 #if IS_ENABLED(CONFIG_NFS_V3)
75 #define NFS_DEFAULT_VERSION 3
76 #else
77 #define NFS_DEFAULT_VERSION 2
78 #endif
79 
80 enum {
81 	/* Mount options that take no arguments */
82 	Opt_soft, Opt_hard,
83 	Opt_posix, Opt_noposix,
84 	Opt_cto, Opt_nocto,
85 	Opt_ac, Opt_noac,
86 	Opt_lock, Opt_nolock,
87 	Opt_udp, Opt_tcp, Opt_rdma,
88 	Opt_acl, Opt_noacl,
89 	Opt_rdirplus, Opt_nordirplus,
90 	Opt_sharecache, Opt_nosharecache,
91 	Opt_resvport, Opt_noresvport,
92 	Opt_fscache, Opt_nofscache,
93 	Opt_migration, Opt_nomigration,
94 
95 	/* Mount options that take integer arguments */
96 	Opt_port,
97 	Opt_rsize, Opt_wsize, Opt_bsize,
98 	Opt_timeo, Opt_retrans,
99 	Opt_acregmin, Opt_acregmax,
100 	Opt_acdirmin, Opt_acdirmax,
101 	Opt_actimeo,
102 	Opt_namelen,
103 	Opt_mountport,
104 	Opt_mountvers,
105 	Opt_minorversion,
106 
107 	/* Mount options that take string arguments */
108 	Opt_nfsvers,
109 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
110 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
111 	Opt_lookupcache,
112 	Opt_fscache_uniq,
113 	Opt_local_lock,
114 
115 	/* Special mount options */
116 	Opt_userspace, Opt_deprecated, Opt_sloppy,
117 
118 	Opt_err
119 };
120 
121 static const match_table_t nfs_mount_option_tokens = {
122 	{ Opt_userspace, "bg" },
123 	{ Opt_userspace, "fg" },
124 	{ Opt_userspace, "retry=%s" },
125 
126 	{ Opt_sloppy, "sloppy" },
127 
128 	{ Opt_soft, "soft" },
129 	{ Opt_hard, "hard" },
130 	{ Opt_deprecated, "intr" },
131 	{ Opt_deprecated, "nointr" },
132 	{ Opt_posix, "posix" },
133 	{ Opt_noposix, "noposix" },
134 	{ Opt_cto, "cto" },
135 	{ Opt_nocto, "nocto" },
136 	{ Opt_ac, "ac" },
137 	{ Opt_noac, "noac" },
138 	{ Opt_lock, "lock" },
139 	{ Opt_nolock, "nolock" },
140 	{ Opt_udp, "udp" },
141 	{ Opt_tcp, "tcp" },
142 	{ Opt_rdma, "rdma" },
143 	{ Opt_acl, "acl" },
144 	{ Opt_noacl, "noacl" },
145 	{ Opt_rdirplus, "rdirplus" },
146 	{ Opt_nordirplus, "nordirplus" },
147 	{ Opt_sharecache, "sharecache" },
148 	{ Opt_nosharecache, "nosharecache" },
149 	{ Opt_resvport, "resvport" },
150 	{ Opt_noresvport, "noresvport" },
151 	{ Opt_fscache, "fsc" },
152 	{ Opt_nofscache, "nofsc" },
153 	{ Opt_migration, "migration" },
154 	{ Opt_nomigration, "nomigration" },
155 
156 	{ Opt_port, "port=%s" },
157 	{ Opt_rsize, "rsize=%s" },
158 	{ Opt_wsize, "wsize=%s" },
159 	{ Opt_bsize, "bsize=%s" },
160 	{ Opt_timeo, "timeo=%s" },
161 	{ Opt_retrans, "retrans=%s" },
162 	{ Opt_acregmin, "acregmin=%s" },
163 	{ Opt_acregmax, "acregmax=%s" },
164 	{ Opt_acdirmin, "acdirmin=%s" },
165 	{ Opt_acdirmax, "acdirmax=%s" },
166 	{ Opt_actimeo, "actimeo=%s" },
167 	{ Opt_namelen, "namlen=%s" },
168 	{ Opt_mountport, "mountport=%s" },
169 	{ Opt_mountvers, "mountvers=%s" },
170 	{ Opt_minorversion, "minorversion=%s" },
171 
172 	{ Opt_nfsvers, "nfsvers=%s" },
173 	{ Opt_nfsvers, "vers=%s" },
174 
175 	{ Opt_sec, "sec=%s" },
176 	{ Opt_proto, "proto=%s" },
177 	{ Opt_mountproto, "mountproto=%s" },
178 	{ Opt_addr, "addr=%s" },
179 	{ Opt_clientaddr, "clientaddr=%s" },
180 	{ Opt_mounthost, "mounthost=%s" },
181 	{ Opt_mountaddr, "mountaddr=%s" },
182 
183 	{ Opt_lookupcache, "lookupcache=%s" },
184 	{ Opt_fscache_uniq, "fsc=%s" },
185 	{ Opt_local_lock, "local_lock=%s" },
186 
187 	/* The following needs to be listed after all other options */
188 	{ Opt_nfsvers, "v%s" },
189 
190 	{ Opt_err, NULL }
191 };
192 
193 enum {
194 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
195 
196 	Opt_xprt_err
197 };
198 
199 static const match_table_t nfs_xprt_protocol_tokens = {
200 	{ Opt_xprt_udp, "udp" },
201 	{ Opt_xprt_udp6, "udp6" },
202 	{ Opt_xprt_tcp, "tcp" },
203 	{ Opt_xprt_tcp6, "tcp6" },
204 	{ Opt_xprt_rdma, "rdma" },
205 
206 	{ Opt_xprt_err, NULL }
207 };
208 
209 enum {
210 	Opt_sec_none, Opt_sec_sys,
211 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
212 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
213 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
214 
215 	Opt_sec_err
216 };
217 
218 static const match_table_t nfs_secflavor_tokens = {
219 	{ Opt_sec_none, "none" },
220 	{ Opt_sec_none, "null" },
221 	{ Opt_sec_sys, "sys" },
222 
223 	{ Opt_sec_krb5, "krb5" },
224 	{ Opt_sec_krb5i, "krb5i" },
225 	{ Opt_sec_krb5p, "krb5p" },
226 
227 	{ Opt_sec_lkey, "lkey" },
228 	{ Opt_sec_lkeyi, "lkeyi" },
229 	{ Opt_sec_lkeyp, "lkeyp" },
230 
231 	{ Opt_sec_spkm, "spkm3" },
232 	{ Opt_sec_spkmi, "spkm3i" },
233 	{ Opt_sec_spkmp, "spkm3p" },
234 
235 	{ Opt_sec_err, NULL }
236 };
237 
238 enum {
239 	Opt_lookupcache_all, Opt_lookupcache_positive,
240 	Opt_lookupcache_none,
241 
242 	Opt_lookupcache_err
243 };
244 
245 static match_table_t nfs_lookupcache_tokens = {
246 	{ Opt_lookupcache_all, "all" },
247 	{ Opt_lookupcache_positive, "pos" },
248 	{ Opt_lookupcache_positive, "positive" },
249 	{ Opt_lookupcache_none, "none" },
250 
251 	{ Opt_lookupcache_err, NULL }
252 };
253 
254 enum {
255 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
256 	Opt_local_lock_none,
257 
258 	Opt_local_lock_err
259 };
260 
261 static match_table_t nfs_local_lock_tokens = {
262 	{ Opt_local_lock_all, "all" },
263 	{ Opt_local_lock_flock, "flock" },
264 	{ Opt_local_lock_posix, "posix" },
265 	{ Opt_local_lock_none, "none" },
266 
267 	{ Opt_local_lock_err, NULL }
268 };
269 
270 enum {
271 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
272 	Opt_vers_4_1,
273 
274 	Opt_vers_err
275 };
276 
277 static match_table_t nfs_vers_tokens = {
278 	{ Opt_vers_2, "2" },
279 	{ Opt_vers_3, "3" },
280 	{ Opt_vers_4, "4" },
281 	{ Opt_vers_4_0, "4.0" },
282 	{ Opt_vers_4_1, "4.1" },
283 
284 	{ Opt_vers_err, NULL }
285 };
286 
287 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
288 		int flags, const char *dev_name, void *raw_data);
289 
290 struct file_system_type nfs_fs_type = {
291 	.owner		= THIS_MODULE,
292 	.name		= "nfs",
293 	.mount		= nfs_fs_mount,
294 	.kill_sb	= nfs_kill_super,
295 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
296 };
297 EXPORT_SYMBOL_GPL(nfs_fs_type);
298 
299 struct file_system_type nfs_xdev_fs_type = {
300 	.owner		= THIS_MODULE,
301 	.name		= "nfs",
302 	.mount		= nfs_xdev_mount,
303 	.kill_sb	= nfs_kill_super,
304 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
305 };
306 
307 const struct super_operations nfs_sops = {
308 	.alloc_inode	= nfs_alloc_inode,
309 	.destroy_inode	= nfs_destroy_inode,
310 	.write_inode	= nfs_write_inode,
311 	.drop_inode	= nfs_drop_inode,
312 	.put_super	= nfs_put_super,
313 	.statfs		= nfs_statfs,
314 	.evict_inode	= nfs_evict_inode,
315 	.umount_begin	= nfs_umount_begin,
316 	.show_options	= nfs_show_options,
317 	.show_devname	= nfs_show_devname,
318 	.show_path	= nfs_show_path,
319 	.show_stats	= nfs_show_stats,
320 	.remount_fs	= nfs_remount,
321 };
322 EXPORT_SYMBOL_GPL(nfs_sops);
323 
324 #if IS_ENABLED(CONFIG_NFS_V4)
325 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
326 static int nfs4_validate_mount_data(void *options,
327 	struct nfs_parsed_mount_data *args, const char *dev_name);
328 
329 struct file_system_type nfs4_fs_type = {
330 	.owner		= THIS_MODULE,
331 	.name		= "nfs4",
332 	.mount		= nfs_fs_mount,
333 	.kill_sb	= nfs_kill_super,
334 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
335 };
336 EXPORT_SYMBOL_GPL(nfs4_fs_type);
337 
338 static int __init register_nfs4_fs(void)
339 {
340 	return register_filesystem(&nfs4_fs_type);
341 }
342 
343 static void unregister_nfs4_fs(void)
344 {
345 	unregister_filesystem(&nfs4_fs_type);
346 }
347 #else
348 static int __init register_nfs4_fs(void)
349 {
350 	return 0;
351 }
352 
353 static void unregister_nfs4_fs(void)
354 {
355 }
356 #endif
357 
358 static struct shrinker acl_shrinker = {
359 	.shrink		= nfs_access_cache_shrinker,
360 	.seeks		= DEFAULT_SEEKS,
361 };
362 
363 /*
364  * Register the NFS filesystems
365  */
366 int __init register_nfs_fs(void)
367 {
368 	int ret;
369 
370         ret = register_filesystem(&nfs_fs_type);
371 	if (ret < 0)
372 		goto error_0;
373 
374 	ret = register_nfs4_fs();
375 	if (ret < 0)
376 		goto error_1;
377 
378 	ret = nfs_register_sysctl();
379 	if (ret < 0)
380 		goto error_2;
381 	register_shrinker(&acl_shrinker);
382 	return 0;
383 
384 error_2:
385 	unregister_nfs4_fs();
386 error_1:
387 	unregister_filesystem(&nfs_fs_type);
388 error_0:
389 	return ret;
390 }
391 
392 /*
393  * Unregister the NFS filesystems
394  */
395 void __exit unregister_nfs_fs(void)
396 {
397 	unregister_shrinker(&acl_shrinker);
398 	nfs_unregister_sysctl();
399 	unregister_nfs4_fs();
400 	unregister_filesystem(&nfs_fs_type);
401 }
402 
403 void nfs_sb_active(struct super_block *sb)
404 {
405 	struct nfs_server *server = NFS_SB(sb);
406 
407 	if (atomic_inc_return(&server->active) == 1)
408 		atomic_inc(&sb->s_active);
409 }
410 EXPORT_SYMBOL_GPL(nfs_sb_active);
411 
412 void nfs_sb_deactive(struct super_block *sb)
413 {
414 	struct nfs_server *server = NFS_SB(sb);
415 
416 	if (atomic_dec_and_test(&server->active))
417 		deactivate_super(sb);
418 }
419 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
420 
421 /*
422  * Deliver file system statistics to userspace
423  */
424 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
425 {
426 	struct nfs_server *server = NFS_SB(dentry->d_sb);
427 	unsigned char blockbits;
428 	unsigned long blockres;
429 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
430 	struct nfs_fsstat res;
431 	int error = -ENOMEM;
432 
433 	res.fattr = nfs_alloc_fattr();
434 	if (res.fattr == NULL)
435 		goto out_err;
436 
437 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
438 	if (unlikely(error == -ESTALE)) {
439 		struct dentry *pd_dentry;
440 
441 		pd_dentry = dget_parent(dentry);
442 		if (pd_dentry != NULL) {
443 			nfs_zap_caches(pd_dentry->d_inode);
444 			dput(pd_dentry);
445 		}
446 	}
447 	nfs_free_fattr(res.fattr);
448 	if (error < 0)
449 		goto out_err;
450 
451 	buf->f_type = NFS_SUPER_MAGIC;
452 
453 	/*
454 	 * Current versions of glibc do not correctly handle the
455 	 * case where f_frsize != f_bsize.  Eventually we want to
456 	 * report the value of wtmult in this field.
457 	 */
458 	buf->f_frsize = dentry->d_sb->s_blocksize;
459 
460 	/*
461 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
462 	 * are reported in units of f_frsize.  Linux hasn't had
463 	 * an f_frsize field in its statfs struct until recently,
464 	 * thus historically Linux's sys_statfs reports these
465 	 * fields in units of f_bsize.
466 	 */
467 	buf->f_bsize = dentry->d_sb->s_blocksize;
468 	blockbits = dentry->d_sb->s_blocksize_bits;
469 	blockres = (1 << blockbits) - 1;
470 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
471 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
472 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
473 
474 	buf->f_files = res.tfiles;
475 	buf->f_ffree = res.afiles;
476 
477 	buf->f_namelen = server->namelen;
478 
479 	return 0;
480 
481  out_err:
482 	dprintk("%s: statfs error = %d\n", __func__, -error);
483 	return error;
484 }
485 EXPORT_SYMBOL_GPL(nfs_statfs);
486 
487 /*
488  * Map the security flavour number to a name
489  */
490 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
491 {
492 	static const struct {
493 		rpc_authflavor_t flavour;
494 		const char *str;
495 	} sec_flavours[] = {
496 		{ RPC_AUTH_NULL, "null" },
497 		{ RPC_AUTH_UNIX, "sys" },
498 		{ RPC_AUTH_GSS_KRB5, "krb5" },
499 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
500 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
501 		{ RPC_AUTH_GSS_LKEY, "lkey" },
502 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
503 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
504 		{ RPC_AUTH_GSS_SPKM, "spkm" },
505 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
506 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
507 		{ UINT_MAX, "unknown" }
508 	};
509 	int i;
510 
511 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
512 		if (sec_flavours[i].flavour == flavour)
513 			break;
514 	}
515 	return sec_flavours[i].str;
516 }
517 
518 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
519 				  int showdefaults)
520 {
521 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
522 
523 	seq_printf(m, ",mountproto=");
524 	switch (sap->sa_family) {
525 	case AF_INET:
526 		switch (nfss->mountd_protocol) {
527 		case IPPROTO_UDP:
528 			seq_printf(m, RPCBIND_NETID_UDP);
529 			break;
530 		case IPPROTO_TCP:
531 			seq_printf(m, RPCBIND_NETID_TCP);
532 			break;
533 		default:
534 			if (showdefaults)
535 				seq_printf(m, "auto");
536 		}
537 		break;
538 	case AF_INET6:
539 		switch (nfss->mountd_protocol) {
540 		case IPPROTO_UDP:
541 			seq_printf(m, RPCBIND_NETID_UDP6);
542 			break;
543 		case IPPROTO_TCP:
544 			seq_printf(m, RPCBIND_NETID_TCP6);
545 			break;
546 		default:
547 			if (showdefaults)
548 				seq_printf(m, "auto");
549 		}
550 		break;
551 	default:
552 		if (showdefaults)
553 			seq_printf(m, "auto");
554 	}
555 }
556 
557 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
558 				    int showdefaults)
559 {
560 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
561 
562 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
563 		return;
564 
565 	switch (sap->sa_family) {
566 	case AF_INET: {
567 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
568 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
569 		break;
570 	}
571 	case AF_INET6: {
572 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
573 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
574 		break;
575 	}
576 	default:
577 		if (showdefaults)
578 			seq_printf(m, ",mountaddr=unspecified");
579 	}
580 
581 	if (nfss->mountd_version || showdefaults)
582 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
583 	if ((nfss->mountd_port &&
584 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
585 		showdefaults)
586 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
587 
588 	nfs_show_mountd_netid(m, nfss, showdefaults);
589 }
590 
591 #if IS_ENABLED(CONFIG_NFS_V4)
592 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
593 				    int showdefaults)
594 {
595 	struct nfs_client *clp = nfss->nfs_client;
596 
597 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
598 }
599 #else
600 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
601 				    int showdefaults)
602 {
603 }
604 #endif
605 
606 static void nfs_show_nfs_version(struct seq_file *m,
607 		unsigned int version,
608 		unsigned int minorversion)
609 {
610 	seq_printf(m, ",vers=%u", version);
611 	if (version == 4)
612 		seq_printf(m, ".%u", minorversion);
613 }
614 
615 /*
616  * Describe the mount options in force on this server representation
617  */
618 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
619 				   int showdefaults)
620 {
621 	static const struct proc_nfs_info {
622 		int flag;
623 		const char *str;
624 		const char *nostr;
625 	} nfs_info[] = {
626 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
627 		{ NFS_MOUNT_POSIX, ",posix", "" },
628 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
629 		{ NFS_MOUNT_NOAC, ",noac", "" },
630 		{ NFS_MOUNT_NONLM, ",nolock", "" },
631 		{ NFS_MOUNT_NOACL, ",noacl", "" },
632 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
633 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
634 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
635 		{ 0, NULL, NULL }
636 	};
637 	const struct proc_nfs_info *nfs_infop;
638 	struct nfs_client *clp = nfss->nfs_client;
639 	u32 version = clp->rpc_ops->version;
640 	int local_flock, local_fcntl;
641 
642 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
643 	seq_printf(m, ",rsize=%u", nfss->rsize);
644 	seq_printf(m, ",wsize=%u", nfss->wsize);
645 	if (nfss->bsize != 0)
646 		seq_printf(m, ",bsize=%u", nfss->bsize);
647 	seq_printf(m, ",namlen=%u", nfss->namelen);
648 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
649 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
650 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
651 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
652 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
653 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
654 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
655 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
656 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
657 		if (nfss->flags & nfs_infop->flag)
658 			seq_puts(m, nfs_infop->str);
659 		else
660 			seq_puts(m, nfs_infop->nostr);
661 	}
662 	rcu_read_lock();
663 	seq_printf(m, ",proto=%s",
664 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
665 	rcu_read_unlock();
666 	if (version == 4) {
667 		if (nfss->port != NFS_PORT)
668 			seq_printf(m, ",port=%u", nfss->port);
669 	} else
670 		if (nfss->port)
671 			seq_printf(m, ",port=%u", nfss->port);
672 
673 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
674 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
675 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
676 
677 	if (version != 4)
678 		nfs_show_mountd_options(m, nfss, showdefaults);
679 	else
680 		nfs_show_nfsv4_options(m, nfss, showdefaults);
681 
682 	if (nfss->options & NFS_OPTION_FSCACHE)
683 		seq_printf(m, ",fsc");
684 
685 	if (nfss->options & NFS_OPTION_MIGRATION)
686 		seq_printf(m, ",migration");
687 
688 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
689 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
690 			seq_printf(m, ",lookupcache=none");
691 		else
692 			seq_printf(m, ",lookupcache=pos");
693 	}
694 
695 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
696 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
697 
698 	if (!local_flock && !local_fcntl)
699 		seq_printf(m, ",local_lock=none");
700 	else if (local_flock && local_fcntl)
701 		seq_printf(m, ",local_lock=all");
702 	else if (local_flock)
703 		seq_printf(m, ",local_lock=flock");
704 	else
705 		seq_printf(m, ",local_lock=posix");
706 }
707 
708 /*
709  * Describe the mount options on this VFS mountpoint
710  */
711 int nfs_show_options(struct seq_file *m, struct dentry *root)
712 {
713 	struct nfs_server *nfss = NFS_SB(root->d_sb);
714 
715 	nfs_show_mount_options(m, nfss, 0);
716 
717 	rcu_read_lock();
718 	seq_printf(m, ",addr=%s",
719 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
720 							RPC_DISPLAY_ADDR));
721 	rcu_read_unlock();
722 
723 	return 0;
724 }
725 EXPORT_SYMBOL_GPL(nfs_show_options);
726 
727 #if IS_ENABLED(CONFIG_NFS_V4)
728 #ifdef CONFIG_NFS_V4_1
729 static void show_sessions(struct seq_file *m, struct nfs_server *server)
730 {
731 	if (nfs4_has_session(server->nfs_client))
732 		seq_printf(m, ",sessions");
733 }
734 #else
735 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
736 #endif
737 #endif
738 
739 #ifdef CONFIG_NFS_V4_1
740 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
741 {
742 	seq_printf(m, ",pnfs=");
743 	if (server->pnfs_curr_ld)
744 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
745 	else
746 		seq_printf(m, "not configured");
747 }
748 
749 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
750 {
751 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
752 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
753 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
754 			   "date='%llu,%u'",
755 			   impl_id->name, impl_id->domain,
756 			   impl_id->date.seconds, impl_id->date.nseconds);
757 	}
758 }
759 #else
760 #if IS_ENABLED(CONFIG_NFS_V4)
761 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
762 {
763 }
764 #endif
765 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
766 {
767 }
768 #endif
769 
770 int nfs_show_devname(struct seq_file *m, struct dentry *root)
771 {
772 	char *page = (char *) __get_free_page(GFP_KERNEL);
773 	char *devname, *dummy;
774 	int err = 0;
775 	if (!page)
776 		return -ENOMEM;
777 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
778 	if (IS_ERR(devname))
779 		err = PTR_ERR(devname);
780 	else
781 		seq_escape(m, devname, " \t\n\\");
782 	free_page((unsigned long)page);
783 	return err;
784 }
785 EXPORT_SYMBOL_GPL(nfs_show_devname);
786 
787 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
788 {
789 	seq_puts(m, "/");
790 	return 0;
791 }
792 EXPORT_SYMBOL_GPL(nfs_show_path);
793 
794 /*
795  * Present statistical information for this VFS mountpoint
796  */
797 int nfs_show_stats(struct seq_file *m, struct dentry *root)
798 {
799 	int i, cpu;
800 	struct nfs_server *nfss = NFS_SB(root->d_sb);
801 	struct rpc_auth *auth = nfss->client->cl_auth;
802 	struct nfs_iostats totals = { };
803 
804 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
805 
806 	/*
807 	 * Display all mount option settings
808 	 */
809 	seq_printf(m, "\n\topts:\t");
810 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
811 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
812 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
813 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
814 	nfs_show_mount_options(m, nfss, 1);
815 
816 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
817 
818 	show_implementation_id(m, nfss);
819 
820 	seq_printf(m, "\n\tcaps:\t");
821 	seq_printf(m, "caps=0x%x", nfss->caps);
822 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
823 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
824 	seq_printf(m, ",bsize=%u", nfss->bsize);
825 	seq_printf(m, ",namlen=%u", nfss->namelen);
826 
827 #if IS_ENABLED(CONFIG_NFS_V4)
828 	if (nfss->nfs_client->rpc_ops->version == 4) {
829 		seq_printf(m, "\n\tnfsv4:\t");
830 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
831 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
832 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
833 		show_sessions(m, nfss);
834 		show_pnfs(m, nfss);
835 	}
836 #endif
837 
838 	/*
839 	 * Display security flavor in effect for this mount
840 	 */
841 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
842 	if (auth->au_flavor)
843 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
844 
845 	/*
846 	 * Display superblock I/O counters
847 	 */
848 	for_each_possible_cpu(cpu) {
849 		struct nfs_iostats *stats;
850 
851 		preempt_disable();
852 		stats = per_cpu_ptr(nfss->io_stats, cpu);
853 
854 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
855 			totals.events[i] += stats->events[i];
856 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
857 			totals.bytes[i] += stats->bytes[i];
858 #ifdef CONFIG_NFS_FSCACHE
859 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
860 			totals.fscache[i] += stats->fscache[i];
861 #endif
862 
863 		preempt_enable();
864 	}
865 
866 	seq_printf(m, "\n\tevents:\t");
867 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
868 		seq_printf(m, "%lu ", totals.events[i]);
869 	seq_printf(m, "\n\tbytes:\t");
870 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
871 		seq_printf(m, "%Lu ", totals.bytes[i]);
872 #ifdef CONFIG_NFS_FSCACHE
873 	if (nfss->options & NFS_OPTION_FSCACHE) {
874 		seq_printf(m, "\n\tfsc:\t");
875 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
876 			seq_printf(m, "%Lu ", totals.bytes[i]);
877 	}
878 #endif
879 	seq_printf(m, "\n");
880 
881 	rpc_print_iostats(m, nfss->client);
882 
883 	return 0;
884 }
885 EXPORT_SYMBOL_GPL(nfs_show_stats);
886 
887 /*
888  * Begin unmount by attempting to remove all automounted mountpoints we added
889  * in response to xdev traversals and referrals
890  */
891 void nfs_umount_begin(struct super_block *sb)
892 {
893 	struct nfs_server *server;
894 	struct rpc_clnt *rpc;
895 
896 	server = NFS_SB(sb);
897 	/* -EIO all pending I/O */
898 	rpc = server->client_acl;
899 	if (!IS_ERR(rpc))
900 		rpc_killall_tasks(rpc);
901 	rpc = server->client;
902 	if (!IS_ERR(rpc))
903 		rpc_killall_tasks(rpc);
904 }
905 EXPORT_SYMBOL_GPL(nfs_umount_begin);
906 
907 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
908 {
909 	struct nfs_parsed_mount_data *data;
910 
911 	data = kzalloc(sizeof(*data), GFP_KERNEL);
912 	if (data) {
913 		data->acregmin		= NFS_DEF_ACREGMIN;
914 		data->acregmax		= NFS_DEF_ACREGMAX;
915 		data->acdirmin		= NFS_DEF_ACDIRMIN;
916 		data->acdirmax		= NFS_DEF_ACDIRMAX;
917 		data->mount_server.port	= NFS_UNSPEC_PORT;
918 		data->nfs_server.port	= NFS_UNSPEC_PORT;
919 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
920 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
921 		data->auth_flavor_len	= 1;
922 		data->minorversion	= 0;
923 		data->need_mount	= true;
924 		data->net		= current->nsproxy->net_ns;
925 		security_init_mnt_opts(&data->lsm_opts);
926 	}
927 	return data;
928 }
929 
930 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
931 {
932 	if (data) {
933 		kfree(data->client_address);
934 		kfree(data->mount_server.hostname);
935 		kfree(data->nfs_server.export_path);
936 		kfree(data->nfs_server.hostname);
937 		kfree(data->fscache_uniq);
938 		security_free_mnt_opts(&data->lsm_opts);
939 		kfree(data);
940 	}
941 }
942 
943 /*
944  * Sanity-check a server address provided by the mount command.
945  *
946  * Address family must be initialized, and address must not be
947  * the ANY address for that family.
948  */
949 static int nfs_verify_server_address(struct sockaddr *addr)
950 {
951 	switch (addr->sa_family) {
952 	case AF_INET: {
953 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
954 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
955 	}
956 	case AF_INET6: {
957 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
958 		return !ipv6_addr_any(sa);
959 	}
960 	}
961 
962 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
963 	return 0;
964 }
965 
966 /*
967  * Select between a default port value and a user-specified port value.
968  * If a zero value is set, then autobind will be used.
969  */
970 static void nfs_set_port(struct sockaddr *sap, int *port,
971 				 const unsigned short default_port)
972 {
973 	if (*port == NFS_UNSPEC_PORT)
974 		*port = default_port;
975 
976 	rpc_set_port(sap, *port);
977 }
978 
979 /*
980  * Sanity check the NFS transport protocol.
981  *
982  */
983 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
984 {
985 	switch (mnt->nfs_server.protocol) {
986 	case XPRT_TRANSPORT_UDP:
987 	case XPRT_TRANSPORT_TCP:
988 	case XPRT_TRANSPORT_RDMA:
989 		break;
990 	default:
991 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
992 	}
993 }
994 
995 /*
996  * For text based NFSv2/v3 mounts, the mount protocol transport default
997  * settings should depend upon the specified NFS transport.
998  */
999 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1000 {
1001 	nfs_validate_transport_protocol(mnt);
1002 
1003 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1004 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1005 			return;
1006 	switch (mnt->nfs_server.protocol) {
1007 	case XPRT_TRANSPORT_UDP:
1008 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1009 		break;
1010 	case XPRT_TRANSPORT_TCP:
1011 	case XPRT_TRANSPORT_RDMA:
1012 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1013 	}
1014 }
1015 
1016 /*
1017  * Parse the value of the 'sec=' option.
1018  */
1019 static int nfs_parse_security_flavors(char *value,
1020 				      struct nfs_parsed_mount_data *mnt)
1021 {
1022 	substring_t args[MAX_OPT_ARGS];
1023 
1024 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1025 
1026 	switch (match_token(value, nfs_secflavor_tokens, args)) {
1027 	case Opt_sec_none:
1028 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
1029 		break;
1030 	case Opt_sec_sys:
1031 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1032 		break;
1033 	case Opt_sec_krb5:
1034 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1035 		break;
1036 	case Opt_sec_krb5i:
1037 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1038 		break;
1039 	case Opt_sec_krb5p:
1040 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1041 		break;
1042 	case Opt_sec_lkey:
1043 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1044 		break;
1045 	case Opt_sec_lkeyi:
1046 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1047 		break;
1048 	case Opt_sec_lkeyp:
1049 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1050 		break;
1051 	case Opt_sec_spkm:
1052 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1053 		break;
1054 	case Opt_sec_spkmi:
1055 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1056 		break;
1057 	case Opt_sec_spkmp:
1058 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1059 		break;
1060 	default:
1061 		return 0;
1062 	}
1063 
1064 	mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1065 	mnt->auth_flavor_len = 1;
1066 	return 1;
1067 }
1068 
1069 static int nfs_parse_version_string(char *string,
1070 		struct nfs_parsed_mount_data *mnt,
1071 		substring_t *args)
1072 {
1073 	mnt->flags &= ~NFS_MOUNT_VER3;
1074 	switch (match_token(string, nfs_vers_tokens, args)) {
1075 	case Opt_vers_2:
1076 		mnt->version = 2;
1077 		break;
1078 	case Opt_vers_3:
1079 		mnt->flags |= NFS_MOUNT_VER3;
1080 		mnt->version = 3;
1081 		break;
1082 	case Opt_vers_4:
1083 		/* Backward compatibility option. In future,
1084 		 * the mount program should always supply
1085 		 * a NFSv4 minor version number.
1086 		 */
1087 		mnt->version = 4;
1088 		break;
1089 	case Opt_vers_4_0:
1090 		mnt->version = 4;
1091 		mnt->minorversion = 0;
1092 		break;
1093 	case Opt_vers_4_1:
1094 		mnt->version = 4;
1095 		mnt->minorversion = 1;
1096 		break;
1097 	default:
1098 		return 0;
1099 	}
1100 	return 1;
1101 }
1102 
1103 static int nfs_get_option_str(substring_t args[], char **option)
1104 {
1105 	kfree(*option);
1106 	*option = match_strdup(args);
1107 	return !*option;
1108 }
1109 
1110 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1111 {
1112 	int rc;
1113 	char *string;
1114 
1115 	string = match_strdup(args);
1116 	if (string == NULL)
1117 		return -ENOMEM;
1118 	rc = kstrtoul(string, 10, option);
1119 	kfree(string);
1120 
1121 	return rc;
1122 }
1123 
1124 /*
1125  * Error-check and convert a string of mount options from user space into
1126  * a data structure.  The whole mount string is processed; bad options are
1127  * skipped as they are encountered.  If there were no errors, return 1;
1128  * otherwise return 0 (zero).
1129  */
1130 static int nfs_parse_mount_options(char *raw,
1131 				   struct nfs_parsed_mount_data *mnt)
1132 {
1133 	char *p, *string, *secdata;
1134 	int rc, sloppy = 0, invalid_option = 0;
1135 	unsigned short protofamily = AF_UNSPEC;
1136 	unsigned short mountfamily = AF_UNSPEC;
1137 
1138 	if (!raw) {
1139 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1140 		return 1;
1141 	}
1142 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1143 
1144 	secdata = alloc_secdata();
1145 	if (!secdata)
1146 		goto out_nomem;
1147 
1148 	rc = security_sb_copy_data(raw, secdata);
1149 	if (rc)
1150 		goto out_security_failure;
1151 
1152 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1153 	if (rc)
1154 		goto out_security_failure;
1155 
1156 	free_secdata(secdata);
1157 
1158 	while ((p = strsep(&raw, ",")) != NULL) {
1159 		substring_t args[MAX_OPT_ARGS];
1160 		unsigned long option;
1161 		int token;
1162 
1163 		if (!*p)
1164 			continue;
1165 
1166 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1167 
1168 		token = match_token(p, nfs_mount_option_tokens, args);
1169 		switch (token) {
1170 
1171 		/*
1172 		 * boolean options:  foo/nofoo
1173 		 */
1174 		case Opt_soft:
1175 			mnt->flags |= NFS_MOUNT_SOFT;
1176 			break;
1177 		case Opt_hard:
1178 			mnt->flags &= ~NFS_MOUNT_SOFT;
1179 			break;
1180 		case Opt_posix:
1181 			mnt->flags |= NFS_MOUNT_POSIX;
1182 			break;
1183 		case Opt_noposix:
1184 			mnt->flags &= ~NFS_MOUNT_POSIX;
1185 			break;
1186 		case Opt_cto:
1187 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1188 			break;
1189 		case Opt_nocto:
1190 			mnt->flags |= NFS_MOUNT_NOCTO;
1191 			break;
1192 		case Opt_ac:
1193 			mnt->flags &= ~NFS_MOUNT_NOAC;
1194 			break;
1195 		case Opt_noac:
1196 			mnt->flags |= NFS_MOUNT_NOAC;
1197 			break;
1198 		case Opt_lock:
1199 			mnt->flags &= ~NFS_MOUNT_NONLM;
1200 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1201 					NFS_MOUNT_LOCAL_FCNTL);
1202 			break;
1203 		case Opt_nolock:
1204 			mnt->flags |= NFS_MOUNT_NONLM;
1205 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1206 				       NFS_MOUNT_LOCAL_FCNTL);
1207 			break;
1208 		case Opt_udp:
1209 			mnt->flags &= ~NFS_MOUNT_TCP;
1210 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1211 			break;
1212 		case Opt_tcp:
1213 			mnt->flags |= NFS_MOUNT_TCP;
1214 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1215 			break;
1216 		case Opt_rdma:
1217 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1218 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1219 			xprt_load_transport(p);
1220 			break;
1221 		case Opt_acl:
1222 			mnt->flags &= ~NFS_MOUNT_NOACL;
1223 			break;
1224 		case Opt_noacl:
1225 			mnt->flags |= NFS_MOUNT_NOACL;
1226 			break;
1227 		case Opt_rdirplus:
1228 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1229 			break;
1230 		case Opt_nordirplus:
1231 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1232 			break;
1233 		case Opt_sharecache:
1234 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1235 			break;
1236 		case Opt_nosharecache:
1237 			mnt->flags |= NFS_MOUNT_UNSHARED;
1238 			break;
1239 		case Opt_resvport:
1240 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1241 			break;
1242 		case Opt_noresvport:
1243 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1244 			break;
1245 		case Opt_fscache:
1246 			mnt->options |= NFS_OPTION_FSCACHE;
1247 			kfree(mnt->fscache_uniq);
1248 			mnt->fscache_uniq = NULL;
1249 			break;
1250 		case Opt_nofscache:
1251 			mnt->options &= ~NFS_OPTION_FSCACHE;
1252 			kfree(mnt->fscache_uniq);
1253 			mnt->fscache_uniq = NULL;
1254 			break;
1255 		case Opt_migration:
1256 			mnt->options |= NFS_OPTION_MIGRATION;
1257 			break;
1258 		case Opt_nomigration:
1259 			mnt->options &= NFS_OPTION_MIGRATION;
1260 			break;
1261 
1262 		/*
1263 		 * options that take numeric values
1264 		 */
1265 		case Opt_port:
1266 			if (nfs_get_option_ul(args, &option) ||
1267 			    option > USHRT_MAX)
1268 				goto out_invalid_value;
1269 			mnt->nfs_server.port = option;
1270 			break;
1271 		case Opt_rsize:
1272 			if (nfs_get_option_ul(args, &option))
1273 				goto out_invalid_value;
1274 			mnt->rsize = option;
1275 			break;
1276 		case Opt_wsize:
1277 			if (nfs_get_option_ul(args, &option))
1278 				goto out_invalid_value;
1279 			mnt->wsize = option;
1280 			break;
1281 		case Opt_bsize:
1282 			if (nfs_get_option_ul(args, &option))
1283 				goto out_invalid_value;
1284 			mnt->bsize = option;
1285 			break;
1286 		case Opt_timeo:
1287 			if (nfs_get_option_ul(args, &option) || option == 0)
1288 				goto out_invalid_value;
1289 			mnt->timeo = option;
1290 			break;
1291 		case Opt_retrans:
1292 			if (nfs_get_option_ul(args, &option) || option == 0)
1293 				goto out_invalid_value;
1294 			mnt->retrans = option;
1295 			break;
1296 		case Opt_acregmin:
1297 			if (nfs_get_option_ul(args, &option))
1298 				goto out_invalid_value;
1299 			mnt->acregmin = option;
1300 			break;
1301 		case Opt_acregmax:
1302 			if (nfs_get_option_ul(args, &option))
1303 				goto out_invalid_value;
1304 			mnt->acregmax = option;
1305 			break;
1306 		case Opt_acdirmin:
1307 			if (nfs_get_option_ul(args, &option))
1308 				goto out_invalid_value;
1309 			mnt->acdirmin = option;
1310 			break;
1311 		case Opt_acdirmax:
1312 			if (nfs_get_option_ul(args, &option))
1313 				goto out_invalid_value;
1314 			mnt->acdirmax = option;
1315 			break;
1316 		case Opt_actimeo:
1317 			if (nfs_get_option_ul(args, &option))
1318 				goto out_invalid_value;
1319 			mnt->acregmin = mnt->acregmax =
1320 			mnt->acdirmin = mnt->acdirmax = option;
1321 			break;
1322 		case Opt_namelen:
1323 			if (nfs_get_option_ul(args, &option))
1324 				goto out_invalid_value;
1325 			mnt->namlen = option;
1326 			break;
1327 		case Opt_mountport:
1328 			if (nfs_get_option_ul(args, &option) ||
1329 			    option > USHRT_MAX)
1330 				goto out_invalid_value;
1331 			mnt->mount_server.port = option;
1332 			break;
1333 		case Opt_mountvers:
1334 			if (nfs_get_option_ul(args, &option) ||
1335 			    option < NFS_MNT_VERSION ||
1336 			    option > NFS_MNT3_VERSION)
1337 				goto out_invalid_value;
1338 			mnt->mount_server.version = option;
1339 			break;
1340 		case Opt_minorversion:
1341 			if (nfs_get_option_ul(args, &option))
1342 				goto out_invalid_value;
1343 			if (option > NFS4_MAX_MINOR_VERSION)
1344 				goto out_invalid_value;
1345 			mnt->minorversion = option;
1346 			break;
1347 
1348 		/*
1349 		 * options that take text values
1350 		 */
1351 		case Opt_nfsvers:
1352 			string = match_strdup(args);
1353 			if (string == NULL)
1354 				goto out_nomem;
1355 			rc = nfs_parse_version_string(string, mnt, args);
1356 			kfree(string);
1357 			if (!rc)
1358 				goto out_invalid_value;
1359 			break;
1360 		case Opt_sec:
1361 			string = match_strdup(args);
1362 			if (string == NULL)
1363 				goto out_nomem;
1364 			rc = nfs_parse_security_flavors(string, mnt);
1365 			kfree(string);
1366 			if (!rc) {
1367 				dfprintk(MOUNT, "NFS:   unrecognized "
1368 						"security flavor\n");
1369 				return 0;
1370 			}
1371 			break;
1372 		case Opt_proto:
1373 			string = match_strdup(args);
1374 			if (string == NULL)
1375 				goto out_nomem;
1376 			token = match_token(string,
1377 					    nfs_xprt_protocol_tokens, args);
1378 
1379 			protofamily = AF_INET;
1380 			switch (token) {
1381 			case Opt_xprt_udp6:
1382 				protofamily = AF_INET6;
1383 			case Opt_xprt_udp:
1384 				mnt->flags &= ~NFS_MOUNT_TCP;
1385 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1386 				break;
1387 			case Opt_xprt_tcp6:
1388 				protofamily = AF_INET6;
1389 			case Opt_xprt_tcp:
1390 				mnt->flags |= NFS_MOUNT_TCP;
1391 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1392 				break;
1393 			case Opt_xprt_rdma:
1394 				/* vector side protocols to TCP */
1395 				mnt->flags |= NFS_MOUNT_TCP;
1396 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1397 				xprt_load_transport(string);
1398 				break;
1399 			default:
1400 				dfprintk(MOUNT, "NFS:   unrecognized "
1401 						"transport protocol\n");
1402 				kfree(string);
1403 				return 0;
1404 			}
1405 			kfree(string);
1406 			break;
1407 		case Opt_mountproto:
1408 			string = match_strdup(args);
1409 			if (string == NULL)
1410 				goto out_nomem;
1411 			token = match_token(string,
1412 					    nfs_xprt_protocol_tokens, args);
1413 			kfree(string);
1414 
1415 			mountfamily = AF_INET;
1416 			switch (token) {
1417 			case Opt_xprt_udp6:
1418 				mountfamily = AF_INET6;
1419 			case Opt_xprt_udp:
1420 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1421 				break;
1422 			case Opt_xprt_tcp6:
1423 				mountfamily = AF_INET6;
1424 			case Opt_xprt_tcp:
1425 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1426 				break;
1427 			case Opt_xprt_rdma: /* not used for side protocols */
1428 			default:
1429 				dfprintk(MOUNT, "NFS:   unrecognized "
1430 						"transport protocol\n");
1431 				return 0;
1432 			}
1433 			break;
1434 		case Opt_addr:
1435 			string = match_strdup(args);
1436 			if (string == NULL)
1437 				goto out_nomem;
1438 			mnt->nfs_server.addrlen =
1439 				rpc_pton(mnt->net, string, strlen(string),
1440 					(struct sockaddr *)
1441 					&mnt->nfs_server.address,
1442 					sizeof(mnt->nfs_server.address));
1443 			kfree(string);
1444 			if (mnt->nfs_server.addrlen == 0)
1445 				goto out_invalid_address;
1446 			break;
1447 		case Opt_clientaddr:
1448 			if (nfs_get_option_str(args, &mnt->client_address))
1449 				goto out_nomem;
1450 			break;
1451 		case Opt_mounthost:
1452 			if (nfs_get_option_str(args,
1453 					       &mnt->mount_server.hostname))
1454 				goto out_nomem;
1455 			break;
1456 		case Opt_mountaddr:
1457 			string = match_strdup(args);
1458 			if (string == NULL)
1459 				goto out_nomem;
1460 			mnt->mount_server.addrlen =
1461 				rpc_pton(mnt->net, string, strlen(string),
1462 					(struct sockaddr *)
1463 					&mnt->mount_server.address,
1464 					sizeof(mnt->mount_server.address));
1465 			kfree(string);
1466 			if (mnt->mount_server.addrlen == 0)
1467 				goto out_invalid_address;
1468 			break;
1469 		case Opt_lookupcache:
1470 			string = match_strdup(args);
1471 			if (string == NULL)
1472 				goto out_nomem;
1473 			token = match_token(string,
1474 					nfs_lookupcache_tokens, args);
1475 			kfree(string);
1476 			switch (token) {
1477 				case Opt_lookupcache_all:
1478 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1479 					break;
1480 				case Opt_lookupcache_positive:
1481 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1482 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1483 					break;
1484 				case Opt_lookupcache_none:
1485 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1486 					break;
1487 				default:
1488 					dfprintk(MOUNT, "NFS:   invalid "
1489 							"lookupcache argument\n");
1490 					return 0;
1491 			};
1492 			break;
1493 		case Opt_fscache_uniq:
1494 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1495 				goto out_nomem;
1496 			mnt->options |= NFS_OPTION_FSCACHE;
1497 			break;
1498 		case Opt_local_lock:
1499 			string = match_strdup(args);
1500 			if (string == NULL)
1501 				goto out_nomem;
1502 			token = match_token(string, nfs_local_lock_tokens,
1503 					args);
1504 			kfree(string);
1505 			switch (token) {
1506 			case Opt_local_lock_all:
1507 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1508 					       NFS_MOUNT_LOCAL_FCNTL);
1509 				break;
1510 			case Opt_local_lock_flock:
1511 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1512 				break;
1513 			case Opt_local_lock_posix:
1514 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1515 				break;
1516 			case Opt_local_lock_none:
1517 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1518 						NFS_MOUNT_LOCAL_FCNTL);
1519 				break;
1520 			default:
1521 				dfprintk(MOUNT, "NFS:	invalid	"
1522 						"local_lock argument\n");
1523 				return 0;
1524 			};
1525 			break;
1526 
1527 		/*
1528 		 * Special options
1529 		 */
1530 		case Opt_sloppy:
1531 			sloppy = 1;
1532 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1533 			break;
1534 		case Opt_userspace:
1535 		case Opt_deprecated:
1536 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1537 					"'%s'\n", p);
1538 			break;
1539 
1540 		default:
1541 			invalid_option = 1;
1542 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1543 					"'%s'\n", p);
1544 		}
1545 	}
1546 
1547 	if (!sloppy && invalid_option)
1548 		return 0;
1549 
1550 	if (mnt->minorversion && mnt->version != 4)
1551 		goto out_minorversion_mismatch;
1552 
1553 	if (mnt->options & NFS_OPTION_MIGRATION &&
1554 	    mnt->version != 4 && mnt->minorversion != 0)
1555 		goto out_migration_misuse;
1556 
1557 	/*
1558 	 * verify that any proto=/mountproto= options match the address
1559 	 * families in the addr=/mountaddr= options.
1560 	 */
1561 	if (protofamily != AF_UNSPEC &&
1562 	    protofamily != mnt->nfs_server.address.ss_family)
1563 		goto out_proto_mismatch;
1564 
1565 	if (mountfamily != AF_UNSPEC) {
1566 		if (mnt->mount_server.addrlen) {
1567 			if (mountfamily != mnt->mount_server.address.ss_family)
1568 				goto out_mountproto_mismatch;
1569 		} else {
1570 			if (mountfamily != mnt->nfs_server.address.ss_family)
1571 				goto out_mountproto_mismatch;
1572 		}
1573 	}
1574 
1575 	return 1;
1576 
1577 out_mountproto_mismatch:
1578 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1579 			 "option\n");
1580 	return 0;
1581 out_proto_mismatch:
1582 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1583 	return 0;
1584 out_invalid_address:
1585 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1586 	return 0;
1587 out_invalid_value:
1588 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1589 	return 0;
1590 out_minorversion_mismatch:
1591 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1592 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1593 	return 0;
1594 out_migration_misuse:
1595 	printk(KERN_INFO
1596 		"NFS: 'migration' not supported for this NFS version\n");
1597 	return 0;
1598 out_nomem:
1599 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1600 	return 0;
1601 out_security_failure:
1602 	free_secdata(secdata);
1603 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1604 	return 0;
1605 }
1606 
1607 /*
1608  * Match the requested auth flavors with the list returned by
1609  * the server.  Returns zero and sets the mount's authentication
1610  * flavor on success; returns -EACCES if server does not support
1611  * the requested flavor.
1612  */
1613 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1614 			     struct nfs_mount_request *request)
1615 {
1616 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1617 
1618 	/*
1619 	 * Certain releases of Linux's mountd return an empty
1620 	 * flavor list.  To prevent behavioral regression with
1621 	 * these servers (ie. rejecting mounts that used to
1622 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1623 	 * if the returned flavor list is empty.
1624 	 */
1625 	if (server_authlist_len == 0)
1626 		return 0;
1627 
1628 	/*
1629 	 * We avoid sophisticated negotiating here, as there are
1630 	 * plenty of cases where we can get it wrong, providing
1631 	 * either too little or too much security.
1632 	 *
1633 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1634 	 * flavor listed first.  However, some servers list
1635 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1636 	 * preferred default, in args->auth_flavors[0] if user
1637 	 * didn't specify sec= mount option.
1638 	 */
1639 	for (i = 0; i < args->auth_flavor_len; i++)
1640 		for (j = 0; j < server_authlist_len; j++)
1641 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1642 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1643 					request->auth_flavs[j]);
1644 				args->auth_flavors[0] = request->auth_flavs[j];
1645 				return 0;
1646 			}
1647 
1648 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1649 	nfs_umount(request);
1650 	return -EACCES;
1651 }
1652 
1653 /*
1654  * Use the remote server's MOUNT service to request the NFS file handle
1655  * corresponding to the provided path.
1656  */
1657 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1658 			     struct nfs_fh *root_fh)
1659 {
1660 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1661 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1662 	struct nfs_mount_request request = {
1663 		.sap		= (struct sockaddr *)
1664 						&args->mount_server.address,
1665 		.dirpath	= args->nfs_server.export_path,
1666 		.protocol	= args->mount_server.protocol,
1667 		.fh		= root_fh,
1668 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1669 		.auth_flav_len	= &server_authlist_len,
1670 		.auth_flavs	= server_authlist,
1671 		.net		= args->net,
1672 	};
1673 	int status;
1674 
1675 	if (args->mount_server.version == 0) {
1676 		switch (args->version) {
1677 			default:
1678 				args->mount_server.version = NFS_MNT3_VERSION;
1679 				break;
1680 			case 2:
1681 				args->mount_server.version = NFS_MNT_VERSION;
1682 		}
1683 	}
1684 	request.version = args->mount_server.version;
1685 
1686 	if (args->mount_server.hostname)
1687 		request.hostname = args->mount_server.hostname;
1688 	else
1689 		request.hostname = args->nfs_server.hostname;
1690 
1691 	/*
1692 	 * Construct the mount server's address.
1693 	 */
1694 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1695 		memcpy(request.sap, &args->nfs_server.address,
1696 		       args->nfs_server.addrlen);
1697 		args->mount_server.addrlen = args->nfs_server.addrlen;
1698 	}
1699 	request.salen = args->mount_server.addrlen;
1700 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1701 
1702 	/*
1703 	 * Now ask the mount server to map our export path
1704 	 * to a file handle.
1705 	 */
1706 	status = nfs_mount(&request);
1707 	if (status != 0) {
1708 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1709 				request.hostname, status);
1710 		return status;
1711 	}
1712 
1713 	/*
1714 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1715 	 */
1716 	if (args->mount_server.version != NFS_MNT3_VERSION)
1717 		return 0;
1718 	return nfs_walk_authlist(args, &request);
1719 }
1720 
1721 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1722 			     struct nfs_mount_info *mount_info,
1723 			     struct nfs_subversion *nfs_mod)
1724 {
1725 	int status;
1726 	struct nfs_server *server;
1727 
1728 	if (mount_info->parsed->need_mount) {
1729 		status = nfs_request_mount(mount_info->parsed, mount_info->mntfh);
1730 		if (status)
1731 			return ERR_PTR(status);
1732 	}
1733 
1734 	/* Get a volume representation */
1735 	server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1736 	if (IS_ERR(server))
1737 		return ERR_CAST(server);
1738 
1739 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1740 }
1741 EXPORT_SYMBOL_GPL(nfs_try_mount);
1742 
1743 /*
1744  * Split "dev_name" into "hostname:export_path".
1745  *
1746  * The leftmost colon demarks the split between the server's hostname
1747  * and the export path.  If the hostname starts with a left square
1748  * bracket, then it may contain colons.
1749  *
1750  * Note: caller frees hostname and export path, even on error.
1751  */
1752 static int nfs_parse_devname(const char *dev_name,
1753 			     char **hostname, size_t maxnamlen,
1754 			     char **export_path, size_t maxpathlen)
1755 {
1756 	size_t len;
1757 	char *end;
1758 
1759 	/* Is the host name protected with square brakcets? */
1760 	if (*dev_name == '[') {
1761 		end = strchr(++dev_name, ']');
1762 		if (end == NULL || end[1] != ':')
1763 			goto out_bad_devname;
1764 
1765 		len = end - dev_name;
1766 		end++;
1767 	} else {
1768 		char *comma;
1769 
1770 		end = strchr(dev_name, ':');
1771 		if (end == NULL)
1772 			goto out_bad_devname;
1773 		len = end - dev_name;
1774 
1775 		/* kill possible hostname list: not supported */
1776 		comma = strchr(dev_name, ',');
1777 		if (comma != NULL && comma < end)
1778 			*comma = 0;
1779 	}
1780 
1781 	if (len > maxnamlen)
1782 		goto out_hostname;
1783 
1784 	/* N.B. caller will free nfs_server.hostname in all cases */
1785 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1786 	if (*hostname == NULL)
1787 		goto out_nomem;
1788 	len = strlen(++end);
1789 	if (len > maxpathlen)
1790 		goto out_path;
1791 	*export_path = kstrndup(end, len, GFP_KERNEL);
1792 	if (!*export_path)
1793 		goto out_nomem;
1794 
1795 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1796 	return 0;
1797 
1798 out_bad_devname:
1799 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1800 	return -EINVAL;
1801 
1802 out_nomem:
1803 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1804 	return -ENOMEM;
1805 
1806 out_hostname:
1807 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1808 	return -ENAMETOOLONG;
1809 
1810 out_path:
1811 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1812 	return -ENAMETOOLONG;
1813 }
1814 
1815 /*
1816  * Validate the NFS2/NFS3 mount data
1817  * - fills in the mount root filehandle
1818  *
1819  * For option strings, user space handles the following behaviors:
1820  *
1821  * + DNS: mapping server host name to IP address ("addr=" option)
1822  *
1823  * + failure mode: how to behave if a mount request can't be handled
1824  *   immediately ("fg/bg" option)
1825  *
1826  * + retry: how often to retry a mount request ("retry=" option)
1827  *
1828  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1829  *   mountproto=tcp after mountproto=udp, and so on
1830  */
1831 static int nfs23_validate_mount_data(void *options,
1832 				     struct nfs_parsed_mount_data *args,
1833 				     struct nfs_fh *mntfh,
1834 				     const char *dev_name)
1835 {
1836 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1837 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1838 
1839 	if (data == NULL)
1840 		goto out_no_data;
1841 
1842 	args->version = NFS_DEFAULT_VERSION;
1843 	switch (data->version) {
1844 	case 1:
1845 		data->namlen = 0;
1846 	case 2:
1847 		data->bsize = 0;
1848 	case 3:
1849 		if (data->flags & NFS_MOUNT_VER3)
1850 			goto out_no_v3;
1851 		data->root.size = NFS2_FHSIZE;
1852 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1853 	case 4:
1854 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1855 			goto out_no_sec;
1856 	case 5:
1857 		memset(data->context, 0, sizeof(data->context));
1858 	case 6:
1859 		if (data->flags & NFS_MOUNT_VER3) {
1860 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1861 				goto out_invalid_fh;
1862 			mntfh->size = data->root.size;
1863 			args->version = 3;
1864 		} else {
1865 			mntfh->size = NFS2_FHSIZE;
1866 			args->version = 2;
1867 		}
1868 
1869 
1870 		memcpy(mntfh->data, data->root.data, mntfh->size);
1871 		if (mntfh->size < sizeof(mntfh->data))
1872 			memset(mntfh->data + mntfh->size, 0,
1873 			       sizeof(mntfh->data) - mntfh->size);
1874 
1875 		/*
1876 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1877 		 * can deal with.
1878 		 */
1879 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1880 		args->flags		|= NFS_MOUNT_LEGACY_INTERFACE;
1881 		args->rsize		= data->rsize;
1882 		args->wsize		= data->wsize;
1883 		args->timeo		= data->timeo;
1884 		args->retrans		= data->retrans;
1885 		args->acregmin		= data->acregmin;
1886 		args->acregmax		= data->acregmax;
1887 		args->acdirmin		= data->acdirmin;
1888 		args->acdirmax		= data->acdirmax;
1889 		args->need_mount	= false;
1890 
1891 		memcpy(sap, &data->addr, sizeof(data->addr));
1892 		args->nfs_server.addrlen = sizeof(data->addr);
1893 		args->nfs_server.port = ntohs(data->addr.sin_port);
1894 		if (!nfs_verify_server_address(sap))
1895 			goto out_no_address;
1896 
1897 		if (!(data->flags & NFS_MOUNT_TCP))
1898 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1899 		/* N.B. caller will free nfs_server.hostname in all cases */
1900 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1901 		args->namlen		= data->namlen;
1902 		args->bsize		= data->bsize;
1903 
1904 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1905 			args->auth_flavors[0] = data->pseudoflavor;
1906 		if (!args->nfs_server.hostname)
1907 			goto out_nomem;
1908 
1909 		if (!(data->flags & NFS_MOUNT_NONLM))
1910 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1911 					 NFS_MOUNT_LOCAL_FCNTL);
1912 		else
1913 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1914 					NFS_MOUNT_LOCAL_FCNTL);
1915 		/*
1916 		 * The legacy version 6 binary mount data from userspace has a
1917 		 * field used only to transport selinux information into the
1918 		 * the kernel.  To continue to support that functionality we
1919 		 * have a touch of selinux knowledge here in the NFS code. The
1920 		 * userspace code converted context=blah to just blah so we are
1921 		 * converting back to the full string selinux understands.
1922 		 */
1923 		if (data->context[0]){
1924 #ifdef CONFIG_SECURITY_SELINUX
1925 			int rc;
1926 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1927 			if (!opts_str)
1928 				return -ENOMEM;
1929 			strcpy(opts_str, "context=");
1930 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1931 			strcat(opts_str, &data->context[0]);
1932 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1933 			kfree(opts_str);
1934 			if (rc)
1935 				return rc;
1936 #else
1937 			return -EINVAL;
1938 #endif
1939 		}
1940 
1941 		break;
1942 	default:
1943 		return NFS_TEXT_DATA;
1944 	}
1945 
1946 #if !IS_ENABLED(CONFIG_NFS_V3)
1947 	if (args->version == 3)
1948 		goto out_v3_not_compiled;
1949 #endif /* !CONFIG_NFS_V3 */
1950 
1951 	return 0;
1952 
1953 out_no_data:
1954 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1955 	return -EINVAL;
1956 
1957 out_no_v3:
1958 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1959 		 data->version);
1960 	return -EINVAL;
1961 
1962 out_no_sec:
1963 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1964 	return -EINVAL;
1965 
1966 #if !IS_ENABLED(CONFIG_NFS_V3)
1967 out_v3_not_compiled:
1968 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1969 	return -EPROTONOSUPPORT;
1970 #endif /* !CONFIG_NFS_V3 */
1971 
1972 out_nomem:
1973 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1974 	return -ENOMEM;
1975 
1976 out_no_address:
1977 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1978 	return -EINVAL;
1979 
1980 out_invalid_fh:
1981 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1982 	return -EINVAL;
1983 }
1984 
1985 #if IS_ENABLED(CONFIG_NFS_V4)
1986 static int nfs_validate_mount_data(struct file_system_type *fs_type,
1987 				   void *options,
1988 				   struct nfs_parsed_mount_data *args,
1989 				   struct nfs_fh *mntfh,
1990 				   const char *dev_name)
1991 {
1992 	if (fs_type == &nfs_fs_type)
1993 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
1994 	return nfs4_validate_mount_data(options, args, dev_name);
1995 }
1996 #else
1997 static int nfs_validate_mount_data(struct file_system_type *fs_type,
1998 				   void *options,
1999 				   struct nfs_parsed_mount_data *args,
2000 				   struct nfs_fh *mntfh,
2001 				   const char *dev_name)
2002 {
2003 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2004 }
2005 #endif
2006 
2007 static int nfs_validate_text_mount_data(void *options,
2008 					struct nfs_parsed_mount_data *args,
2009 					const char *dev_name)
2010 {
2011 	int port = 0;
2012 	int max_namelen = PAGE_SIZE;
2013 	int max_pathlen = NFS_MAXPATHLEN;
2014 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2015 
2016 	if (nfs_parse_mount_options((char *)options, args) == 0)
2017 		return -EINVAL;
2018 
2019 	if (!nfs_verify_server_address(sap))
2020 		goto out_no_address;
2021 
2022 	if (args->version == 4) {
2023 #if IS_ENABLED(CONFIG_NFS_V4)
2024 		port = NFS_PORT;
2025 		max_namelen = NFS4_MAXNAMLEN;
2026 		max_pathlen = NFS4_MAXPATHLEN;
2027 		nfs_validate_transport_protocol(args);
2028 		nfs4_validate_mount_flags(args);
2029 #else
2030 		goto out_v4_not_compiled;
2031 #endif /* CONFIG_NFS_V4 */
2032 	} else
2033 		nfs_set_mount_transport_protocol(args);
2034 
2035 	nfs_set_port(sap, &args->nfs_server.port, port);
2036 
2037 	if (args->auth_flavor_len > 1)
2038 		goto out_bad_auth;
2039 
2040 	return nfs_parse_devname(dev_name,
2041 				   &args->nfs_server.hostname,
2042 				   max_namelen,
2043 				   &args->nfs_server.export_path,
2044 				   max_pathlen);
2045 
2046 #if !IS_ENABLED(CONFIG_NFS_V4)
2047 out_v4_not_compiled:
2048 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2049 	return -EPROTONOSUPPORT;
2050 #endif /* !CONFIG_NFS_V4 */
2051 
2052 out_no_address:
2053 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2054 	return -EINVAL;
2055 
2056 out_bad_auth:
2057 	dfprintk(MOUNT, "NFS: Too many RPC auth flavours specified\n");
2058 	return -EINVAL;
2059 }
2060 
2061 static int
2062 nfs_compare_remount_data(struct nfs_server *nfss,
2063 			 struct nfs_parsed_mount_data *data)
2064 {
2065 	if (data->flags != nfss->flags ||
2066 	    data->rsize != nfss->rsize ||
2067 	    data->wsize != nfss->wsize ||
2068 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2069 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2070 	    data->acregmin != nfss->acregmin / HZ ||
2071 	    data->acregmax != nfss->acregmax / HZ ||
2072 	    data->acdirmin != nfss->acdirmin / HZ ||
2073 	    data->acdirmax != nfss->acdirmax / HZ ||
2074 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2075 	    data->nfs_server.port != nfss->port ||
2076 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2077 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2078 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2079 		return -EINVAL;
2080 
2081 	return 0;
2082 }
2083 
2084 int
2085 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2086 {
2087 	int error;
2088 	struct nfs_server *nfss = sb->s_fs_info;
2089 	struct nfs_parsed_mount_data *data;
2090 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2091 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2092 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2093 
2094 	/*
2095 	 * Userspace mount programs that send binary options generally send
2096 	 * them populated with default values. We have no way to know which
2097 	 * ones were explicitly specified. Fall back to legacy behavior and
2098 	 * just return success.
2099 	 */
2100 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2101 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2102 					   options->version <= 6))))
2103 		return 0;
2104 
2105 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2106 	if (data == NULL)
2107 		return -ENOMEM;
2108 
2109 	/* fill out struct with values from existing mount */
2110 	data->flags = nfss->flags;
2111 	data->rsize = nfss->rsize;
2112 	data->wsize = nfss->wsize;
2113 	data->retrans = nfss->client->cl_timeout->to_retries;
2114 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2115 	data->acregmin = nfss->acregmin / HZ;
2116 	data->acregmax = nfss->acregmax / HZ;
2117 	data->acdirmin = nfss->acdirmin / HZ;
2118 	data->acdirmax = nfss->acdirmax / HZ;
2119 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2120 	data->nfs_server.port = nfss->port;
2121 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2122 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2123 		data->nfs_server.addrlen);
2124 
2125 	/* overwrite those values with any that were specified */
2126 	error = nfs_parse_mount_options((char *)options, data);
2127 	if (error < 0)
2128 		goto out;
2129 
2130 	/*
2131 	 * noac is a special case. It implies -o sync, but that's not
2132 	 * necessarily reflected in the mtab options. do_remount_sb
2133 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2134 	 * remount options, so we have to explicitly reset it.
2135 	 */
2136 	if (data->flags & NFS_MOUNT_NOAC)
2137 		*flags |= MS_SYNCHRONOUS;
2138 
2139 	/* compare new mount options with old ones */
2140 	error = nfs_compare_remount_data(nfss, data);
2141 out:
2142 	kfree(data);
2143 	return error;
2144 }
2145 EXPORT_SYMBOL_GPL(nfs_remount);
2146 
2147 /*
2148  * Initialise the common bits of the superblock
2149  */
2150 inline void nfs_initialise_sb(struct super_block *sb)
2151 {
2152 	struct nfs_server *server = NFS_SB(sb);
2153 
2154 	sb->s_magic = NFS_SUPER_MAGIC;
2155 
2156 	/* We probably want something more informative here */
2157 	snprintf(sb->s_id, sizeof(sb->s_id),
2158 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2159 
2160 	if (sb->s_blocksize == 0)
2161 		sb->s_blocksize = nfs_block_bits(server->wsize,
2162 						 &sb->s_blocksize_bits);
2163 
2164 	sb->s_bdi = &server->backing_dev_info;
2165 
2166 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2167 }
2168 
2169 /*
2170  * Finish setting up an NFS2/3 superblock
2171  */
2172 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2173 {
2174 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2175 	struct nfs_server *server = NFS_SB(sb);
2176 
2177 	sb->s_blocksize_bits = 0;
2178 	sb->s_blocksize = 0;
2179 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2180 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2181 	if (data && data->bsize)
2182 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2183 
2184 	if (server->nfs_client->rpc_ops->version != 2) {
2185 		/* The VFS shouldn't apply the umask to mode bits. We will do
2186 		 * so ourselves when necessary.
2187 		 */
2188 		sb->s_flags |= MS_POSIXACL;
2189 		sb->s_time_gran = 1;
2190 	}
2191 
2192  	nfs_initialise_sb(sb);
2193 }
2194 EXPORT_SYMBOL_GPL(nfs_fill_super);
2195 
2196 /*
2197  * Finish setting up a cloned NFS2/3/4 superblock
2198  */
2199 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2200 {
2201 	const struct super_block *old_sb = mount_info->cloned->sb;
2202 	struct nfs_server *server = NFS_SB(sb);
2203 
2204 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2205 	sb->s_blocksize = old_sb->s_blocksize;
2206 	sb->s_maxbytes = old_sb->s_maxbytes;
2207 	sb->s_xattr = old_sb->s_xattr;
2208 	sb->s_op = old_sb->s_op;
2209 	sb->s_time_gran = 1;
2210 
2211 	if (server->nfs_client->rpc_ops->version != 2) {
2212 		/* The VFS shouldn't apply the umask to mode bits. We will do
2213 		 * so ourselves when necessary.
2214 		 */
2215 		sb->s_flags |= MS_POSIXACL;
2216 	}
2217 
2218  	nfs_initialise_sb(sb);
2219 }
2220 
2221 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2222 {
2223 	const struct nfs_server *a = s->s_fs_info;
2224 	const struct rpc_clnt *clnt_a = a->client;
2225 	const struct rpc_clnt *clnt_b = b->client;
2226 
2227 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2228 		goto Ebusy;
2229 	if (a->nfs_client != b->nfs_client)
2230 		goto Ebusy;
2231 	if (a->flags != b->flags)
2232 		goto Ebusy;
2233 	if (a->wsize != b->wsize)
2234 		goto Ebusy;
2235 	if (a->rsize != b->rsize)
2236 		goto Ebusy;
2237 	if (a->acregmin != b->acregmin)
2238 		goto Ebusy;
2239 	if (a->acregmax != b->acregmax)
2240 		goto Ebusy;
2241 	if (a->acdirmin != b->acdirmin)
2242 		goto Ebusy;
2243 	if (a->acdirmax != b->acdirmax)
2244 		goto Ebusy;
2245 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2246 		goto Ebusy;
2247 	return 1;
2248 Ebusy:
2249 	return 0;
2250 }
2251 
2252 struct nfs_sb_mountdata {
2253 	struct nfs_server *server;
2254 	int mntflags;
2255 };
2256 
2257 static int nfs_set_super(struct super_block *s, void *data)
2258 {
2259 	struct nfs_sb_mountdata *sb_mntdata = data;
2260 	struct nfs_server *server = sb_mntdata->server;
2261 	int ret;
2262 
2263 	s->s_flags = sb_mntdata->mntflags;
2264 	s->s_fs_info = server;
2265 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2266 	ret = set_anon_super(s, server);
2267 	if (ret == 0)
2268 		server->s_dev = s->s_dev;
2269 	return ret;
2270 }
2271 
2272 static int nfs_compare_super_address(struct nfs_server *server1,
2273 				     struct nfs_server *server2)
2274 {
2275 	struct sockaddr *sap1, *sap2;
2276 
2277 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2278 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2279 
2280 	if (sap1->sa_family != sap2->sa_family)
2281 		return 0;
2282 
2283 	switch (sap1->sa_family) {
2284 	case AF_INET: {
2285 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2286 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2287 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2288 			return 0;
2289 		if (sin1->sin_port != sin2->sin_port)
2290 			return 0;
2291 		break;
2292 	}
2293 	case AF_INET6: {
2294 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2295 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2296 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2297 			return 0;
2298 		if (sin1->sin6_port != sin2->sin6_port)
2299 			return 0;
2300 		break;
2301 	}
2302 	default:
2303 		return 0;
2304 	}
2305 
2306 	return 1;
2307 }
2308 
2309 static int nfs_compare_super(struct super_block *sb, void *data)
2310 {
2311 	struct nfs_sb_mountdata *sb_mntdata = data;
2312 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2313 	int mntflags = sb_mntdata->mntflags;
2314 
2315 	if (!nfs_compare_super_address(old, server))
2316 		return 0;
2317 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2318 	if (old->flags & NFS_MOUNT_UNSHARED)
2319 		return 0;
2320 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2321 		return 0;
2322 	return nfs_compare_mount_options(sb, server, mntflags);
2323 }
2324 
2325 #ifdef CONFIG_NFS_FSCACHE
2326 static void nfs_get_cache_cookie(struct super_block *sb,
2327 				 struct nfs_parsed_mount_data *parsed,
2328 				 struct nfs_clone_mount *cloned)
2329 {
2330 	struct nfs_server *nfss = NFS_SB(sb);
2331 	char *uniq = NULL;
2332 	int ulen = 0;
2333 
2334 	nfss->fscache_key = NULL;
2335 	nfss->fscache = NULL;
2336 
2337 	if (parsed) {
2338 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2339 			return;
2340 		if (parsed->fscache_uniq) {
2341 			uniq = parsed->fscache_uniq;
2342 			ulen = strlen(parsed->fscache_uniq);
2343 		}
2344 	} else if (cloned) {
2345 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2346 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2347 			return;
2348 		if (mnt_s->fscache_key) {
2349 			uniq = mnt_s->fscache_key->key.uniquifier;
2350 			ulen = mnt_s->fscache_key->key.uniq_len;
2351 		};
2352 	} else
2353 		return;
2354 
2355 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2356 }
2357 #else
2358 static void nfs_get_cache_cookie(struct super_block *sb,
2359 				 struct nfs_parsed_mount_data *parsed,
2360 				 struct nfs_clone_mount *cloned)
2361 {
2362 }
2363 #endif
2364 
2365 static int nfs_bdi_register(struct nfs_server *server)
2366 {
2367 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2368 }
2369 
2370 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2371 			struct nfs_mount_info *mount_info)
2372 {
2373 	return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts);
2374 }
2375 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2376 
2377 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2378 			  struct nfs_mount_info *mount_info)
2379 {
2380 	/* clone any lsm security options from the parent to the new sb */
2381 	security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2382 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2383 		return -ESTALE;
2384 	return 0;
2385 }
2386 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2387 
2388 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2389 				   int flags, const char *dev_name,
2390 				   struct nfs_mount_info *mount_info,
2391 				   struct nfs_subversion *nfs_mod)
2392 {
2393 	struct super_block *s;
2394 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2395 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2396 	struct nfs_sb_mountdata sb_mntdata = {
2397 		.mntflags = flags,
2398 		.server = server,
2399 	};
2400 	int error;
2401 
2402 	if (server->flags & NFS_MOUNT_UNSHARED)
2403 		compare_super = NULL;
2404 
2405 	/* -o noac implies -o sync */
2406 	if (server->flags & NFS_MOUNT_NOAC)
2407 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2408 
2409 	/* Get a superblock - note that we may end up sharing one that already exists */
2410 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2411 	if (IS_ERR(s)) {
2412 		mntroot = ERR_CAST(s);
2413 		goto out_err_nosb;
2414 	}
2415 
2416 	if (s->s_fs_info != server) {
2417 		nfs_free_server(server);
2418 		server = NULL;
2419 	} else {
2420 		error = nfs_bdi_register(server);
2421 		if (error) {
2422 			mntroot = ERR_PTR(error);
2423 			goto error_splat_bdi;
2424 		}
2425 	}
2426 
2427 	if (!s->s_root) {
2428 		/* initial superblock/root creation */
2429 		mount_info->fill_super(s, mount_info);
2430 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2431 	}
2432 
2433 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2434 	if (IS_ERR(mntroot))
2435 		goto error_splat_super;
2436 
2437 	error = mount_info->set_security(s, mntroot, mount_info);
2438 	if (error)
2439 		goto error_splat_root;
2440 
2441 	s->s_flags |= MS_ACTIVE;
2442 
2443 out:
2444 	return mntroot;
2445 
2446 out_err_nosb:
2447 	nfs_free_server(server);
2448 	goto out;
2449 
2450 error_splat_root:
2451 	dput(mntroot);
2452 	mntroot = ERR_PTR(error);
2453 error_splat_super:
2454 	if (server && !s->s_root)
2455 		bdi_unregister(&server->backing_dev_info);
2456 error_splat_bdi:
2457 	deactivate_locked_super(s);
2458 	goto out;
2459 }
2460 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2461 
2462 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2463 	int flags, const char *dev_name, void *raw_data)
2464 {
2465 	struct nfs_mount_info mount_info = {
2466 		.fill_super = nfs_fill_super,
2467 		.set_security = nfs_set_sb_security,
2468 	};
2469 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2470 	struct nfs_subversion *nfs_mod;
2471 	int error;
2472 
2473 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2474 	mount_info.mntfh = nfs_alloc_fhandle();
2475 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2476 		goto out;
2477 
2478 	/* Validate the mount data */
2479 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2480 	if (error == NFS_TEXT_DATA)
2481 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2482 	if (error < 0) {
2483 		mntroot = ERR_PTR(error);
2484 		goto out;
2485 	}
2486 
2487 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2488 	if (IS_ERR(nfs_mod)) {
2489 		mntroot = ERR_CAST(nfs_mod);
2490 		goto out;
2491 	}
2492 
2493 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2494 
2495 	put_nfs_version(nfs_mod);
2496 out:
2497 	nfs_free_parsed_mount_data(mount_info.parsed);
2498 	nfs_free_fhandle(mount_info.mntfh);
2499 	return mntroot;
2500 }
2501 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2502 
2503 /*
2504  * Ensure that we unregister the bdi before kill_anon_super
2505  * releases the device name
2506  */
2507 void nfs_put_super(struct super_block *s)
2508 {
2509 	struct nfs_server *server = NFS_SB(s);
2510 
2511 	bdi_unregister(&server->backing_dev_info);
2512 }
2513 EXPORT_SYMBOL_GPL(nfs_put_super);
2514 
2515 /*
2516  * Destroy an NFS2/3 superblock
2517  */
2518 void nfs_kill_super(struct super_block *s)
2519 {
2520 	struct nfs_server *server = NFS_SB(s);
2521 
2522 	kill_anon_super(s);
2523 	nfs_fscache_release_super_cookie(s);
2524 	nfs_free_server(server);
2525 }
2526 EXPORT_SYMBOL_GPL(nfs_kill_super);
2527 
2528 /*
2529  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2530  */
2531 static struct dentry *
2532 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2533 		const char *dev_name, void *raw_data)
2534 {
2535 	struct nfs_clone_mount *data = raw_data;
2536 	struct nfs_mount_info mount_info = {
2537 		.fill_super = nfs_clone_super,
2538 		.set_security = nfs_clone_sb_security,
2539 		.cloned = data,
2540 	};
2541 	struct nfs_server *server;
2542 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2543 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2544 
2545 	dprintk("--> nfs_xdev_mount()\n");
2546 
2547 	mount_info.mntfh = mount_info.cloned->fh;
2548 
2549 	/* create a new volume representation */
2550 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2551 
2552 	if (IS_ERR(server))
2553 		mntroot = ERR_CAST(server);
2554 	else
2555 		mntroot = nfs_fs_mount_common(server, flags,
2556 				dev_name, &mount_info, nfs_mod);
2557 
2558 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2559 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2560 	return mntroot;
2561 }
2562 
2563 #if IS_ENABLED(CONFIG_NFS_V4)
2564 
2565 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2566 {
2567 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2568 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2569 }
2570 
2571 /*
2572  * Validate NFSv4 mount options
2573  */
2574 static int nfs4_validate_mount_data(void *options,
2575 				    struct nfs_parsed_mount_data *args,
2576 				    const char *dev_name)
2577 {
2578 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2579 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2580 	char *c;
2581 
2582 	if (data == NULL)
2583 		goto out_no_data;
2584 
2585 	args->version = 4;
2586 
2587 	switch (data->version) {
2588 	case 1:
2589 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2590 			goto out_no_address;
2591 		if (data->host_addrlen == 0)
2592 			goto out_no_address;
2593 		args->nfs_server.addrlen = data->host_addrlen;
2594 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2595 			return -EFAULT;
2596 		if (!nfs_verify_server_address(sap))
2597 			goto out_no_address;
2598 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2599 
2600 		if (data->auth_flavourlen) {
2601 			if (data->auth_flavourlen > 1)
2602 				goto out_inval_auth;
2603 			if (copy_from_user(&args->auth_flavors[0],
2604 					   data->auth_flavours,
2605 					   sizeof(args->auth_flavors[0])))
2606 				return -EFAULT;
2607 		}
2608 
2609 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2610 		if (IS_ERR(c))
2611 			return PTR_ERR(c);
2612 		args->nfs_server.hostname = c;
2613 
2614 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2615 		if (IS_ERR(c))
2616 			return PTR_ERR(c);
2617 		args->nfs_server.export_path = c;
2618 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2619 
2620 		c = strndup_user(data->client_addr.data, 16);
2621 		if (IS_ERR(c))
2622 			return PTR_ERR(c);
2623 		args->client_address = c;
2624 
2625 		/*
2626 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2627 		 * can deal with.
2628 		 */
2629 
2630 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2631 		args->rsize	= data->rsize;
2632 		args->wsize	= data->wsize;
2633 		args->timeo	= data->timeo;
2634 		args->retrans	= data->retrans;
2635 		args->acregmin	= data->acregmin;
2636 		args->acregmax	= data->acregmax;
2637 		args->acdirmin	= data->acdirmin;
2638 		args->acdirmax	= data->acdirmax;
2639 		args->nfs_server.protocol = data->proto;
2640 		nfs_validate_transport_protocol(args);
2641 
2642 		break;
2643 	default:
2644 		return NFS_TEXT_DATA;
2645 	}
2646 
2647 	return 0;
2648 
2649 out_no_data:
2650 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2651 	return -EINVAL;
2652 
2653 out_inval_auth:
2654 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2655 		 data->auth_flavourlen);
2656 	return -EINVAL;
2657 
2658 out_no_address:
2659 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2660 	return -EINVAL;
2661 }
2662 
2663 /*
2664  * NFS v4 module parameters need to stay in the
2665  * NFS client for backwards compatibility
2666  */
2667 unsigned int nfs_callback_set_tcpport;
2668 unsigned short nfs_callback_tcpport;
2669 /* Default cache timeout is 10 minutes */
2670 unsigned int nfs_idmap_cache_timeout = 600;
2671 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2672 bool nfs4_disable_idmapping = true;
2673 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2674 unsigned short send_implementation_id = 1;
2675 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2676 
2677 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2678 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2679 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2680 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2681 EXPORT_SYMBOL_GPL(max_session_slots);
2682 EXPORT_SYMBOL_GPL(send_implementation_id);
2683 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2684 
2685 #define NFS_CALLBACK_MAXPORTNR (65535U)
2686 
2687 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2688 {
2689 	unsigned long num;
2690 	int ret;
2691 
2692 	if (!val)
2693 		return -EINVAL;
2694 	ret = kstrtoul(val, 0, &num);
2695 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2696 		return -EINVAL;
2697 	*((unsigned int *)kp->arg) = num;
2698 	return 0;
2699 }
2700 static struct kernel_param_ops param_ops_portnr = {
2701 	.set = param_set_portnr,
2702 	.get = param_get_uint,
2703 };
2704 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2705 
2706 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2707 module_param(nfs_idmap_cache_timeout, int, 0644);
2708 module_param(nfs4_disable_idmapping, bool, 0644);
2709 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2710 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2711 MODULE_PARM_DESC(nfs4_disable_idmapping,
2712 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2713 module_param(max_session_slots, ushort, 0644);
2714 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2715 		"requests the client will negotiate");
2716 module_param(send_implementation_id, ushort, 0644);
2717 MODULE_PARM_DESC(send_implementation_id,
2718 		"Send implementation ID with NFSv4.1 exchange_id");
2719 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2720 MODULE_ALIAS("nfs4");
2721 
2722 #endif /* CONFIG_NFS_V4 */
2723