xref: /openbmc/linux/fs/nfs/super.c (revision 5e012745)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/nfs/super.c
4  *
5  *  Copyright (C) 1992  Rick Sladkey
6  *
7  *  nfs superblock handling functions
8  *
9  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
10  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
11  *
12  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
13  *  J.S.Peatfield@damtp.cam.ac.uk
14  *
15  *  Split from inode.c by David Howells <dhowells@redhat.com>
16  *
17  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
18  *   particular server are held in the same superblock
19  * - NFS superblocks can have several effective roots to the dentry tree
20  * - directory type roots are spliced into the tree when a path from one root reaches the root
21  *   of another (see nfs_lookup())
22  */
23 
24 #include <linux/module.h>
25 #include <linux/init.h>
26 
27 #include <linux/time.h>
28 #include <linux/kernel.h>
29 #include <linux/mm.h>
30 #include <linux/string.h>
31 #include <linux/stat.h>
32 #include <linux/errno.h>
33 #include <linux/unistd.h>
34 #include <linux/sunrpc/clnt.h>
35 #include <linux/sunrpc/addr.h>
36 #include <linux/sunrpc/stats.h>
37 #include <linux/sunrpc/metrics.h>
38 #include <linux/sunrpc/xprtsock.h>
39 #include <linux/sunrpc/xprtrdma.h>
40 #include <linux/nfs_fs.h>
41 #include <linux/nfs_mount.h>
42 #include <linux/nfs4_mount.h>
43 #include <linux/lockd/bind.h>
44 #include <linux/seq_file.h>
45 #include <linux/mount.h>
46 #include <linux/namei.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 <linux/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 #define NFS_MAX_CONNECTIONS 16
81 
82 enum {
83 	/* Mount options that take no arguments */
84 	Opt_soft, Opt_softerr, Opt_hard,
85 	Opt_posix, Opt_noposix,
86 	Opt_cto, Opt_nocto,
87 	Opt_ac, Opt_noac,
88 	Opt_lock, Opt_nolock,
89 	Opt_udp, Opt_tcp, Opt_rdma,
90 	Opt_acl, Opt_noacl,
91 	Opt_rdirplus, Opt_nordirplus,
92 	Opt_sharecache, Opt_nosharecache,
93 	Opt_resvport, Opt_noresvport,
94 	Opt_fscache, Opt_nofscache,
95 	Opt_migration, Opt_nomigration,
96 
97 	/* Mount options that take integer arguments */
98 	Opt_port,
99 	Opt_rsize, Opt_wsize, Opt_bsize,
100 	Opt_timeo, Opt_retrans,
101 	Opt_acregmin, Opt_acregmax,
102 	Opt_acdirmin, Opt_acdirmax,
103 	Opt_actimeo,
104 	Opt_namelen,
105 	Opt_mountport,
106 	Opt_mountvers,
107 	Opt_minorversion,
108 
109 	/* Mount options that take string arguments */
110 	Opt_nfsvers,
111 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
112 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
113 	Opt_nconnect,
114 	Opt_lookupcache,
115 	Opt_fscache_uniq,
116 	Opt_local_lock,
117 
118 	/* Special mount options */
119 	Opt_userspace, Opt_deprecated, Opt_sloppy,
120 
121 	Opt_err
122 };
123 
124 static const match_table_t nfs_mount_option_tokens = {
125 	{ Opt_userspace, "bg" },
126 	{ Opt_userspace, "fg" },
127 	{ Opt_userspace, "retry=%s" },
128 
129 	{ Opt_sloppy, "sloppy" },
130 
131 	{ Opt_soft, "soft" },
132 	{ Opt_softerr, "softerr" },
133 	{ Opt_hard, "hard" },
134 	{ Opt_deprecated, "intr" },
135 	{ Opt_deprecated, "nointr" },
136 	{ Opt_posix, "posix" },
137 	{ Opt_noposix, "noposix" },
138 	{ Opt_cto, "cto" },
139 	{ Opt_nocto, "nocto" },
140 	{ Opt_ac, "ac" },
141 	{ Opt_noac, "noac" },
142 	{ Opt_lock, "lock" },
143 	{ Opt_nolock, "nolock" },
144 	{ Opt_udp, "udp" },
145 	{ Opt_tcp, "tcp" },
146 	{ Opt_rdma, "rdma" },
147 	{ Opt_acl, "acl" },
148 	{ Opt_noacl, "noacl" },
149 	{ Opt_rdirplus, "rdirplus" },
150 	{ Opt_nordirplus, "nordirplus" },
151 	{ Opt_sharecache, "sharecache" },
152 	{ Opt_nosharecache, "nosharecache" },
153 	{ Opt_resvport, "resvport" },
154 	{ Opt_noresvport, "noresvport" },
155 	{ Opt_fscache, "fsc" },
156 	{ Opt_nofscache, "nofsc" },
157 	{ Opt_migration, "migration" },
158 	{ Opt_nomigration, "nomigration" },
159 
160 	{ Opt_port, "port=%s" },
161 	{ Opt_rsize, "rsize=%s" },
162 	{ Opt_wsize, "wsize=%s" },
163 	{ Opt_bsize, "bsize=%s" },
164 	{ Opt_timeo, "timeo=%s" },
165 	{ Opt_retrans, "retrans=%s" },
166 	{ Opt_acregmin, "acregmin=%s" },
167 	{ Opt_acregmax, "acregmax=%s" },
168 	{ Opt_acdirmin, "acdirmin=%s" },
169 	{ Opt_acdirmax, "acdirmax=%s" },
170 	{ Opt_actimeo, "actimeo=%s" },
171 	{ Opt_namelen, "namlen=%s" },
172 	{ Opt_mountport, "mountport=%s" },
173 	{ Opt_mountvers, "mountvers=%s" },
174 	{ Opt_minorversion, "minorversion=%s" },
175 
176 	{ Opt_nfsvers, "nfsvers=%s" },
177 	{ Opt_nfsvers, "vers=%s" },
178 
179 	{ Opt_sec, "sec=%s" },
180 	{ Opt_proto, "proto=%s" },
181 	{ Opt_mountproto, "mountproto=%s" },
182 	{ Opt_addr, "addr=%s" },
183 	{ Opt_clientaddr, "clientaddr=%s" },
184 	{ Opt_mounthost, "mounthost=%s" },
185 	{ Opt_mountaddr, "mountaddr=%s" },
186 
187 	{ Opt_nconnect, "nconnect=%s" },
188 
189 	{ Opt_lookupcache, "lookupcache=%s" },
190 	{ Opt_fscache_uniq, "fsc=%s" },
191 	{ Opt_local_lock, "local_lock=%s" },
192 
193 	/* The following needs to be listed after all other options */
194 	{ Opt_nfsvers, "v%s" },
195 
196 	{ Opt_err, NULL }
197 };
198 
199 enum {
200 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
201 	Opt_xprt_rdma6,
202 
203 	Opt_xprt_err
204 };
205 
206 static const match_table_t nfs_xprt_protocol_tokens = {
207 	{ Opt_xprt_udp, "udp" },
208 	{ Opt_xprt_udp6, "udp6" },
209 	{ Opt_xprt_tcp, "tcp" },
210 	{ Opt_xprt_tcp6, "tcp6" },
211 	{ Opt_xprt_rdma, "rdma" },
212 	{ Opt_xprt_rdma6, "rdma6" },
213 
214 	{ Opt_xprt_err, NULL }
215 };
216 
217 enum {
218 	Opt_sec_none, Opt_sec_sys,
219 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
220 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
221 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
222 
223 	Opt_sec_err
224 };
225 
226 static const match_table_t nfs_secflavor_tokens = {
227 	{ Opt_sec_none, "none" },
228 	{ Opt_sec_none, "null" },
229 	{ Opt_sec_sys, "sys" },
230 
231 	{ Opt_sec_krb5, "krb5" },
232 	{ Opt_sec_krb5i, "krb5i" },
233 	{ Opt_sec_krb5p, "krb5p" },
234 
235 	{ Opt_sec_lkey, "lkey" },
236 	{ Opt_sec_lkeyi, "lkeyi" },
237 	{ Opt_sec_lkeyp, "lkeyp" },
238 
239 	{ Opt_sec_spkm, "spkm3" },
240 	{ Opt_sec_spkmi, "spkm3i" },
241 	{ Opt_sec_spkmp, "spkm3p" },
242 
243 	{ Opt_sec_err, NULL }
244 };
245 
246 enum {
247 	Opt_lookupcache_all, Opt_lookupcache_positive,
248 	Opt_lookupcache_none,
249 
250 	Opt_lookupcache_err
251 };
252 
253 static match_table_t nfs_lookupcache_tokens = {
254 	{ Opt_lookupcache_all, "all" },
255 	{ Opt_lookupcache_positive, "pos" },
256 	{ Opt_lookupcache_positive, "positive" },
257 	{ Opt_lookupcache_none, "none" },
258 
259 	{ Opt_lookupcache_err, NULL }
260 };
261 
262 enum {
263 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
264 	Opt_local_lock_none,
265 
266 	Opt_local_lock_err
267 };
268 
269 static match_table_t nfs_local_lock_tokens = {
270 	{ Opt_local_lock_all, "all" },
271 	{ Opt_local_lock_flock, "flock" },
272 	{ Opt_local_lock_posix, "posix" },
273 	{ Opt_local_lock_none, "none" },
274 
275 	{ Opt_local_lock_err, NULL }
276 };
277 
278 enum {
279 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
280 	Opt_vers_4_1, Opt_vers_4_2,
281 
282 	Opt_vers_err
283 };
284 
285 static match_table_t nfs_vers_tokens = {
286 	{ Opt_vers_2, "2" },
287 	{ Opt_vers_3, "3" },
288 	{ Opt_vers_4, "4" },
289 	{ Opt_vers_4_0, "4.0" },
290 	{ Opt_vers_4_1, "4.1" },
291 	{ Opt_vers_4_2, "4.2" },
292 
293 	{ Opt_vers_err, NULL }
294 };
295 
296 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
297 		int flags, const char *dev_name, void *raw_data);
298 
299 struct file_system_type nfs_fs_type = {
300 	.owner		= THIS_MODULE,
301 	.name		= "nfs",
302 	.mount		= nfs_fs_mount,
303 	.kill_sb	= nfs_kill_super,
304 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
305 };
306 MODULE_ALIAS_FS("nfs");
307 EXPORT_SYMBOL_GPL(nfs_fs_type);
308 
309 struct file_system_type nfs_xdev_fs_type = {
310 	.owner		= THIS_MODULE,
311 	.name		= "nfs",
312 	.mount		= nfs_xdev_mount,
313 	.kill_sb	= nfs_kill_super,
314 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
315 };
316 
317 const struct super_operations nfs_sops = {
318 	.alloc_inode	= nfs_alloc_inode,
319 	.free_inode	= nfs_free_inode,
320 	.write_inode	= nfs_write_inode,
321 	.drop_inode	= nfs_drop_inode,
322 	.statfs		= nfs_statfs,
323 	.evict_inode	= nfs_evict_inode,
324 	.umount_begin	= nfs_umount_begin,
325 	.show_options	= nfs_show_options,
326 	.show_devname	= nfs_show_devname,
327 	.show_path	= nfs_show_path,
328 	.show_stats	= nfs_show_stats,
329 	.remount_fs	= nfs_remount,
330 };
331 EXPORT_SYMBOL_GPL(nfs_sops);
332 
333 #if IS_ENABLED(CONFIG_NFS_V4)
334 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
335 static int nfs4_validate_mount_data(void *options,
336 	struct nfs_parsed_mount_data *args, const char *dev_name);
337 
338 struct file_system_type nfs4_fs_type = {
339 	.owner		= THIS_MODULE,
340 	.name		= "nfs4",
341 	.mount		= nfs_fs_mount,
342 	.kill_sb	= nfs_kill_super,
343 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
344 };
345 MODULE_ALIAS_FS("nfs4");
346 MODULE_ALIAS("nfs4");
347 EXPORT_SYMBOL_GPL(nfs4_fs_type);
348 
349 static int __init register_nfs4_fs(void)
350 {
351 	return register_filesystem(&nfs4_fs_type);
352 }
353 
354 static void unregister_nfs4_fs(void)
355 {
356 	unregister_filesystem(&nfs4_fs_type);
357 }
358 #else
359 static int __init register_nfs4_fs(void)
360 {
361 	return 0;
362 }
363 
364 static void unregister_nfs4_fs(void)
365 {
366 }
367 #endif
368 
369 static struct shrinker acl_shrinker = {
370 	.count_objects	= nfs_access_cache_count,
371 	.scan_objects	= nfs_access_cache_scan,
372 	.seeks		= DEFAULT_SEEKS,
373 };
374 
375 /*
376  * Register the NFS filesystems
377  */
378 int __init register_nfs_fs(void)
379 {
380 	int ret;
381 
382         ret = register_filesystem(&nfs_fs_type);
383 	if (ret < 0)
384 		goto error_0;
385 
386 	ret = register_nfs4_fs();
387 	if (ret < 0)
388 		goto error_1;
389 
390 	ret = nfs_register_sysctl();
391 	if (ret < 0)
392 		goto error_2;
393 	ret = register_shrinker(&acl_shrinker);
394 	if (ret < 0)
395 		goto error_3;
396 	return 0;
397 error_3:
398 	nfs_unregister_sysctl();
399 error_2:
400 	unregister_nfs4_fs();
401 error_1:
402 	unregister_filesystem(&nfs_fs_type);
403 error_0:
404 	return ret;
405 }
406 
407 /*
408  * Unregister the NFS filesystems
409  */
410 void __exit unregister_nfs_fs(void)
411 {
412 	unregister_shrinker(&acl_shrinker);
413 	nfs_unregister_sysctl();
414 	unregister_nfs4_fs();
415 	unregister_filesystem(&nfs_fs_type);
416 }
417 
418 bool nfs_sb_active(struct super_block *sb)
419 {
420 	struct nfs_server *server = NFS_SB(sb);
421 
422 	if (!atomic_inc_not_zero(&sb->s_active))
423 		return false;
424 	if (atomic_inc_return(&server->active) != 1)
425 		atomic_dec(&sb->s_active);
426 	return true;
427 }
428 EXPORT_SYMBOL_GPL(nfs_sb_active);
429 
430 void nfs_sb_deactive(struct super_block *sb)
431 {
432 	struct nfs_server *server = NFS_SB(sb);
433 
434 	if (atomic_dec_and_test(&server->active))
435 		deactivate_super(sb);
436 }
437 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
438 
439 /*
440  * Deliver file system statistics to userspace
441  */
442 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
443 {
444 	struct nfs_server *server = NFS_SB(dentry->d_sb);
445 	unsigned char blockbits;
446 	unsigned long blockres;
447 	struct nfs_fh *fh = NFS_FH(d_inode(dentry));
448 	struct nfs_fsstat res;
449 	int error = -ENOMEM;
450 
451 	res.fattr = nfs_alloc_fattr();
452 	if (res.fattr == NULL)
453 		goto out_err;
454 
455 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
456 	if (unlikely(error == -ESTALE)) {
457 		struct dentry *pd_dentry;
458 
459 		pd_dentry = dget_parent(dentry);
460 		nfs_zap_caches(d_inode(pd_dentry));
461 		dput(pd_dentry);
462 	}
463 	nfs_free_fattr(res.fattr);
464 	if (error < 0)
465 		goto out_err;
466 
467 	buf->f_type = NFS_SUPER_MAGIC;
468 
469 	/*
470 	 * Current versions of glibc do not correctly handle the
471 	 * case where f_frsize != f_bsize.  Eventually we want to
472 	 * report the value of wtmult in this field.
473 	 */
474 	buf->f_frsize = dentry->d_sb->s_blocksize;
475 
476 	/*
477 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
478 	 * are reported in units of f_frsize.  Linux hasn't had
479 	 * an f_frsize field in its statfs struct until recently,
480 	 * thus historically Linux's sys_statfs reports these
481 	 * fields in units of f_bsize.
482 	 */
483 	buf->f_bsize = dentry->d_sb->s_blocksize;
484 	blockbits = dentry->d_sb->s_blocksize_bits;
485 	blockres = (1 << blockbits) - 1;
486 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
487 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
488 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
489 
490 	buf->f_files = res.tfiles;
491 	buf->f_ffree = res.afiles;
492 
493 	buf->f_namelen = server->namelen;
494 
495 	return 0;
496 
497  out_err:
498 	dprintk("%s: statfs error = %d\n", __func__, -error);
499 	return error;
500 }
501 EXPORT_SYMBOL_GPL(nfs_statfs);
502 
503 /*
504  * Map the security flavour number to a name
505  */
506 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
507 {
508 	static const struct {
509 		rpc_authflavor_t flavour;
510 		const char *str;
511 	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
512 		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
513 		{ RPC_AUTH_NULL, "null" },
514 		{ RPC_AUTH_UNIX, "sys" },
515 		{ RPC_AUTH_GSS_KRB5, "krb5" },
516 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
517 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
518 		{ RPC_AUTH_GSS_LKEY, "lkey" },
519 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
520 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
521 		{ RPC_AUTH_GSS_SPKM, "spkm" },
522 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
523 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
524 		{ UINT_MAX, "unknown" }
525 	};
526 	int i;
527 
528 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
529 		if (sec_flavours[i].flavour == flavour)
530 			break;
531 	}
532 	return sec_flavours[i].str;
533 }
534 
535 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
536 				  int showdefaults)
537 {
538 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
539 	char *proto = NULL;
540 
541 	switch (sap->sa_family) {
542 	case AF_INET:
543 		switch (nfss->mountd_protocol) {
544 		case IPPROTO_UDP:
545 			proto = RPCBIND_NETID_UDP;
546 			break;
547 		case IPPROTO_TCP:
548 			proto = RPCBIND_NETID_TCP;
549 			break;
550 		}
551 		break;
552 	case AF_INET6:
553 		switch (nfss->mountd_protocol) {
554 		case IPPROTO_UDP:
555 			proto = RPCBIND_NETID_UDP6;
556 			break;
557 		case IPPROTO_TCP:
558 			proto = RPCBIND_NETID_TCP6;
559 			break;
560 		}
561 		break;
562 	}
563 	if (proto || showdefaults)
564 		seq_printf(m, ",mountproto=%s", proto ?: "auto");
565 }
566 
567 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
568 				    int showdefaults)
569 {
570 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
571 
572 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
573 		return;
574 
575 	switch (sap->sa_family) {
576 	case AF_INET: {
577 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
578 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
579 		break;
580 	}
581 	case AF_INET6: {
582 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
583 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
584 		break;
585 	}
586 	default:
587 		if (showdefaults)
588 			seq_puts(m, ",mountaddr=unspecified");
589 	}
590 
591 	if (nfss->mountd_version || showdefaults)
592 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
593 	if ((nfss->mountd_port &&
594 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
595 		showdefaults)
596 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
597 
598 	nfs_show_mountd_netid(m, nfss, showdefaults);
599 }
600 
601 #if IS_ENABLED(CONFIG_NFS_V4)
602 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
603 				    int showdefaults)
604 {
605 	struct nfs_client *clp = nfss->nfs_client;
606 
607 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
608 }
609 #else
610 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
611 				    int showdefaults)
612 {
613 }
614 #endif
615 
616 static void nfs_show_nfs_version(struct seq_file *m,
617 		unsigned int version,
618 		unsigned int minorversion)
619 {
620 	seq_printf(m, ",vers=%u", version);
621 	if (version == 4)
622 		seq_printf(m, ".%u", minorversion);
623 }
624 
625 /*
626  * Describe the mount options in force on this server representation
627  */
628 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
629 				   int showdefaults)
630 {
631 	static const struct proc_nfs_info {
632 		int flag;
633 		const char *str;
634 		const char *nostr;
635 	} nfs_info[] = {
636 		{ NFS_MOUNT_SOFT, ",soft", "" },
637 		{ NFS_MOUNT_SOFTERR, ",softerr", "" },
638 		{ NFS_MOUNT_POSIX, ",posix", "" },
639 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
640 		{ NFS_MOUNT_NOAC, ",noac", "" },
641 		{ NFS_MOUNT_NONLM, ",nolock", "" },
642 		{ NFS_MOUNT_NOACL, ",noacl", "" },
643 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
644 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
645 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
646 		{ 0, NULL, NULL }
647 	};
648 	const struct proc_nfs_info *nfs_infop;
649 	struct nfs_client *clp = nfss->nfs_client;
650 	u32 version = clp->rpc_ops->version;
651 	int local_flock, local_fcntl;
652 
653 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
654 	seq_printf(m, ",rsize=%u", nfss->rsize);
655 	seq_printf(m, ",wsize=%u", nfss->wsize);
656 	if (nfss->bsize != 0)
657 		seq_printf(m, ",bsize=%u", nfss->bsize);
658 	seq_printf(m, ",namlen=%u", nfss->namelen);
659 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
660 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
661 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
662 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
663 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
664 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
665 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
666 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
667 	if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
668 			seq_puts(m, ",hard");
669 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
670 		if (nfss->flags & nfs_infop->flag)
671 			seq_puts(m, nfs_infop->str);
672 		else
673 			seq_puts(m, nfs_infop->nostr);
674 	}
675 	rcu_read_lock();
676 	seq_printf(m, ",proto=%s",
677 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
678 	rcu_read_unlock();
679 	if (clp->cl_nconnect > 0)
680 		seq_printf(m, ",nconnect=%u", clp->cl_nconnect);
681 	if (version == 4) {
682 		if (nfss->port != NFS_PORT)
683 			seq_printf(m, ",port=%u", nfss->port);
684 	} else
685 		if (nfss->port)
686 			seq_printf(m, ",port=%u", nfss->port);
687 
688 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
689 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
690 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
691 
692 	if (version != 4)
693 		nfs_show_mountd_options(m, nfss, showdefaults);
694 	else
695 		nfs_show_nfsv4_options(m, nfss, showdefaults);
696 
697 	if (nfss->options & NFS_OPTION_FSCACHE)
698 		seq_puts(m, ",fsc");
699 
700 	if (nfss->options & NFS_OPTION_MIGRATION)
701 		seq_puts(m, ",migration");
702 
703 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
704 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
705 			seq_puts(m, ",lookupcache=none");
706 		else
707 			seq_puts(m, ",lookupcache=pos");
708 	}
709 
710 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
711 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
712 
713 	if (!local_flock && !local_fcntl)
714 		seq_puts(m, ",local_lock=none");
715 	else if (local_flock && local_fcntl)
716 		seq_puts(m, ",local_lock=all");
717 	else if (local_flock)
718 		seq_puts(m, ",local_lock=flock");
719 	else
720 		seq_puts(m, ",local_lock=posix");
721 }
722 
723 /*
724  * Describe the mount options on this VFS mountpoint
725  */
726 int nfs_show_options(struct seq_file *m, struct dentry *root)
727 {
728 	struct nfs_server *nfss = NFS_SB(root->d_sb);
729 
730 	nfs_show_mount_options(m, nfss, 0);
731 
732 	rcu_read_lock();
733 	seq_printf(m, ",addr=%s",
734 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
735 							RPC_DISPLAY_ADDR));
736 	rcu_read_unlock();
737 
738 	return 0;
739 }
740 EXPORT_SYMBOL_GPL(nfs_show_options);
741 
742 #if IS_ENABLED(CONFIG_NFS_V4)
743 static void show_lease(struct seq_file *m, struct nfs_server *server)
744 {
745 	struct nfs_client *clp = server->nfs_client;
746 	unsigned long expire;
747 
748 	seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
749 	expire = clp->cl_last_renewal + clp->cl_lease_time;
750 	seq_printf(m, ",lease_expired=%ld",
751 		   time_after(expire, jiffies) ?  0 : (jiffies - expire) / HZ);
752 }
753 #ifdef CONFIG_NFS_V4_1
754 static void show_sessions(struct seq_file *m, struct nfs_server *server)
755 {
756 	if (nfs4_has_session(server->nfs_client))
757 		seq_puts(m, ",sessions");
758 }
759 #else
760 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
761 #endif
762 #endif
763 
764 #ifdef CONFIG_NFS_V4_1
765 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
766 {
767 	seq_printf(m, ",pnfs=");
768 	if (server->pnfs_curr_ld)
769 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
770 	else
771 		seq_printf(m, "not configured");
772 }
773 
774 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
775 {
776 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
777 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
778 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
779 			   "date='%llu,%u'",
780 			   impl_id->name, impl_id->domain,
781 			   impl_id->date.seconds, impl_id->date.nseconds);
782 	}
783 }
784 #else
785 #if IS_ENABLED(CONFIG_NFS_V4)
786 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
787 {
788 }
789 #endif
790 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
791 {
792 }
793 #endif
794 
795 int nfs_show_devname(struct seq_file *m, struct dentry *root)
796 {
797 	char *page = (char *) __get_free_page(GFP_KERNEL);
798 	char *devname, *dummy;
799 	int err = 0;
800 	if (!page)
801 		return -ENOMEM;
802 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
803 	if (IS_ERR(devname))
804 		err = PTR_ERR(devname);
805 	else
806 		seq_escape(m, devname, " \t\n\\");
807 	free_page((unsigned long)page);
808 	return err;
809 }
810 EXPORT_SYMBOL_GPL(nfs_show_devname);
811 
812 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
813 {
814 	seq_puts(m, "/");
815 	return 0;
816 }
817 EXPORT_SYMBOL_GPL(nfs_show_path);
818 
819 /*
820  * Present statistical information for this VFS mountpoint
821  */
822 int nfs_show_stats(struct seq_file *m, struct dentry *root)
823 {
824 	int i, cpu;
825 	struct nfs_server *nfss = NFS_SB(root->d_sb);
826 	struct rpc_auth *auth = nfss->client->cl_auth;
827 	struct nfs_iostats totals = { };
828 
829 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
830 
831 	/*
832 	 * Display all mount option settings
833 	 */
834 	seq_puts(m, "\n\topts:\t");
835 	seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
836 	seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
837 	seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
838 	seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
839 	nfs_show_mount_options(m, nfss, 1);
840 
841 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
842 
843 	show_implementation_id(m, nfss);
844 
845 	seq_puts(m, "\n\tcaps:\t");
846 	seq_printf(m, "caps=0x%x", nfss->caps);
847 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
848 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
849 	seq_printf(m, ",bsize=%u", nfss->bsize);
850 	seq_printf(m, ",namlen=%u", nfss->namelen);
851 
852 #if IS_ENABLED(CONFIG_NFS_V4)
853 	if (nfss->nfs_client->rpc_ops->version == 4) {
854 		seq_puts(m, "\n\tnfsv4:\t");
855 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
856 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
857 		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
858 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
859 		show_sessions(m, nfss);
860 		show_pnfs(m, nfss);
861 		show_lease(m, nfss);
862 	}
863 #endif
864 
865 	/*
866 	 * Display security flavor in effect for this mount
867 	 */
868 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
869 	if (auth->au_flavor)
870 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
871 
872 	/*
873 	 * Display superblock I/O counters
874 	 */
875 	for_each_possible_cpu(cpu) {
876 		struct nfs_iostats *stats;
877 
878 		preempt_disable();
879 		stats = per_cpu_ptr(nfss->io_stats, cpu);
880 
881 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
882 			totals.events[i] += stats->events[i];
883 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
884 			totals.bytes[i] += stats->bytes[i];
885 #ifdef CONFIG_NFS_FSCACHE
886 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
887 			totals.fscache[i] += stats->fscache[i];
888 #endif
889 
890 		preempt_enable();
891 	}
892 
893 	seq_puts(m, "\n\tevents:\t");
894 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
895 		seq_printf(m, "%lu ", totals.events[i]);
896 	seq_puts(m, "\n\tbytes:\t");
897 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
898 		seq_printf(m, "%Lu ", totals.bytes[i]);
899 #ifdef CONFIG_NFS_FSCACHE
900 	if (nfss->options & NFS_OPTION_FSCACHE) {
901 		seq_puts(m, "\n\tfsc:\t");
902 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
903 			seq_printf(m, "%Lu ", totals.fscache[i]);
904 	}
905 #endif
906 	seq_putc(m, '\n');
907 
908 	rpc_clnt_show_stats(m, nfss->client);
909 
910 	return 0;
911 }
912 EXPORT_SYMBOL_GPL(nfs_show_stats);
913 
914 /*
915  * Begin unmount by attempting to remove all automounted mountpoints we added
916  * in response to xdev traversals and referrals
917  */
918 void nfs_umount_begin(struct super_block *sb)
919 {
920 	struct nfs_server *server;
921 	struct rpc_clnt *rpc;
922 
923 	server = NFS_SB(sb);
924 	/* -EIO all pending I/O */
925 	rpc = server->client_acl;
926 	if (!IS_ERR(rpc))
927 		rpc_killall_tasks(rpc);
928 	rpc = server->client;
929 	if (!IS_ERR(rpc))
930 		rpc_killall_tasks(rpc);
931 }
932 EXPORT_SYMBOL_GPL(nfs_umount_begin);
933 
934 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
935 {
936 	struct nfs_parsed_mount_data *data;
937 
938 	data = kzalloc(sizeof(*data), GFP_KERNEL);
939 	if (data) {
940 		data->timeo		= NFS_UNSPEC_TIMEO;
941 		data->retrans		= NFS_UNSPEC_RETRANS;
942 		data->acregmin		= NFS_DEF_ACREGMIN;
943 		data->acregmax		= NFS_DEF_ACREGMAX;
944 		data->acdirmin		= NFS_DEF_ACDIRMIN;
945 		data->acdirmax		= NFS_DEF_ACDIRMAX;
946 		data->mount_server.port	= NFS_UNSPEC_PORT;
947 		data->nfs_server.port	= NFS_UNSPEC_PORT;
948 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
949 		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
950 		data->minorversion	= 0;
951 		data->need_mount	= true;
952 		data->net		= current->nsproxy->net_ns;
953 		data->lsm_opts		= NULL;
954 	}
955 	return data;
956 }
957 
958 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
959 {
960 	if (data) {
961 		kfree(data->client_address);
962 		kfree(data->mount_server.hostname);
963 		kfree(data->nfs_server.export_path);
964 		kfree(data->nfs_server.hostname);
965 		kfree(data->fscache_uniq);
966 		security_free_mnt_opts(&data->lsm_opts);
967 		kfree(data);
968 	}
969 }
970 
971 /*
972  * Sanity-check a server address provided by the mount command.
973  *
974  * Address family must be initialized, and address must not be
975  * the ANY address for that family.
976  */
977 static int nfs_verify_server_address(struct sockaddr *addr)
978 {
979 	switch (addr->sa_family) {
980 	case AF_INET: {
981 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
982 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
983 	}
984 	case AF_INET6: {
985 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
986 		return !ipv6_addr_any(sa);
987 	}
988 	}
989 
990 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
991 	return 0;
992 }
993 
994 /*
995  * Select between a default port value and a user-specified port value.
996  * If a zero value is set, then autobind will be used.
997  */
998 static void nfs_set_port(struct sockaddr *sap, int *port,
999 				 const unsigned short default_port)
1000 {
1001 	if (*port == NFS_UNSPEC_PORT)
1002 		*port = default_port;
1003 
1004 	rpc_set_port(sap, *port);
1005 }
1006 
1007 /*
1008  * Sanity check the NFS transport protocol.
1009  *
1010  */
1011 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
1012 {
1013 	switch (mnt->nfs_server.protocol) {
1014 	case XPRT_TRANSPORT_UDP:
1015 	case XPRT_TRANSPORT_TCP:
1016 	case XPRT_TRANSPORT_RDMA:
1017 		break;
1018 	default:
1019 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1020 	}
1021 }
1022 
1023 /*
1024  * For text based NFSv2/v3 mounts, the mount protocol transport default
1025  * settings should depend upon the specified NFS transport.
1026  */
1027 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1028 {
1029 	nfs_validate_transport_protocol(mnt);
1030 
1031 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1032 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1033 			return;
1034 	switch (mnt->nfs_server.protocol) {
1035 	case XPRT_TRANSPORT_UDP:
1036 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1037 		break;
1038 	case XPRT_TRANSPORT_TCP:
1039 	case XPRT_TRANSPORT_RDMA:
1040 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1041 	}
1042 }
1043 
1044 /*
1045  * Add 'flavor' to 'auth_info' if not already present.
1046  * Returns true if 'flavor' ends up in the list, false otherwise
1047  */
1048 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1049 			      rpc_authflavor_t flavor)
1050 {
1051 	unsigned int i;
1052 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1053 
1054 	/* make sure this flavor isn't already in the list */
1055 	for (i = 0; i < auth_info->flavor_len; i++) {
1056 		if (flavor == auth_info->flavors[i])
1057 			return true;
1058 	}
1059 
1060 	if (auth_info->flavor_len + 1 >= max_flavor_len) {
1061 		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1062 		return false;
1063 	}
1064 
1065 	auth_info->flavors[auth_info->flavor_len++] = flavor;
1066 	return true;
1067 }
1068 
1069 /*
1070  * Return true if 'match' is in auth_info or auth_info is empty.
1071  * Return false otherwise.
1072  */
1073 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1074 			 rpc_authflavor_t match)
1075 {
1076 	int i;
1077 
1078 	if (!auth_info->flavor_len)
1079 		return true;
1080 
1081 	for (i = 0; i < auth_info->flavor_len; i++) {
1082 		if (auth_info->flavors[i] == match)
1083 			return true;
1084 	}
1085 	return false;
1086 }
1087 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1088 
1089 /*
1090  * Parse the value of the 'sec=' option.
1091  */
1092 static int nfs_parse_security_flavors(char *value,
1093 				      struct nfs_parsed_mount_data *mnt)
1094 {
1095 	substring_t args[MAX_OPT_ARGS];
1096 	rpc_authflavor_t pseudoflavor;
1097 	char *p;
1098 
1099 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1100 
1101 	while ((p = strsep(&value, ":")) != NULL) {
1102 		switch (match_token(p, nfs_secflavor_tokens, args)) {
1103 		case Opt_sec_none:
1104 			pseudoflavor = RPC_AUTH_NULL;
1105 			break;
1106 		case Opt_sec_sys:
1107 			pseudoflavor = RPC_AUTH_UNIX;
1108 			break;
1109 		case Opt_sec_krb5:
1110 			pseudoflavor = RPC_AUTH_GSS_KRB5;
1111 			break;
1112 		case Opt_sec_krb5i:
1113 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
1114 			break;
1115 		case Opt_sec_krb5p:
1116 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
1117 			break;
1118 		case Opt_sec_lkey:
1119 			pseudoflavor = RPC_AUTH_GSS_LKEY;
1120 			break;
1121 		case Opt_sec_lkeyi:
1122 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
1123 			break;
1124 		case Opt_sec_lkeyp:
1125 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
1126 			break;
1127 		case Opt_sec_spkm:
1128 			pseudoflavor = RPC_AUTH_GSS_SPKM;
1129 			break;
1130 		case Opt_sec_spkmi:
1131 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
1132 			break;
1133 		case Opt_sec_spkmp:
1134 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
1135 			break;
1136 		default:
1137 			dfprintk(MOUNT,
1138 				 "NFS: sec= option '%s' not recognized\n", p);
1139 			return 0;
1140 		}
1141 
1142 		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1143 			return 0;
1144 	}
1145 
1146 	return 1;
1147 }
1148 
1149 static int nfs_parse_version_string(char *string,
1150 		struct nfs_parsed_mount_data *mnt,
1151 		substring_t *args)
1152 {
1153 	mnt->flags &= ~NFS_MOUNT_VER3;
1154 	switch (match_token(string, nfs_vers_tokens, args)) {
1155 	case Opt_vers_2:
1156 		mnt->version = 2;
1157 		break;
1158 	case Opt_vers_3:
1159 		mnt->flags |= NFS_MOUNT_VER3;
1160 		mnt->version = 3;
1161 		break;
1162 	case Opt_vers_4:
1163 		/* Backward compatibility option. In future,
1164 		 * the mount program should always supply
1165 		 * a NFSv4 minor version number.
1166 		 */
1167 		mnt->version = 4;
1168 		break;
1169 	case Opt_vers_4_0:
1170 		mnt->version = 4;
1171 		mnt->minorversion = 0;
1172 		break;
1173 	case Opt_vers_4_1:
1174 		mnt->version = 4;
1175 		mnt->minorversion = 1;
1176 		break;
1177 	case Opt_vers_4_2:
1178 		mnt->version = 4;
1179 		mnt->minorversion = 2;
1180 		break;
1181 	default:
1182 		return 0;
1183 	}
1184 	return 1;
1185 }
1186 
1187 static int nfs_get_option_str(substring_t args[], char **option)
1188 {
1189 	kfree(*option);
1190 	*option = match_strdup(args);
1191 	return !*option;
1192 }
1193 
1194 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1195 {
1196 	int rc;
1197 	char *string;
1198 
1199 	string = match_strdup(args);
1200 	if (string == NULL)
1201 		return -ENOMEM;
1202 	rc = kstrtoul(string, 10, option);
1203 	kfree(string);
1204 
1205 	return rc;
1206 }
1207 
1208 static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
1209 		unsigned long l_bound, unsigned long u_bound)
1210 {
1211 	int ret;
1212 
1213 	ret = nfs_get_option_ul(args, option);
1214 	if (ret != 0)
1215 		return ret;
1216 	if (*option < l_bound || *option > u_bound)
1217 		return -ERANGE;
1218 	return 0;
1219 }
1220 
1221 /*
1222  * Error-check and convert a string of mount options from user space into
1223  * a data structure.  The whole mount string is processed; bad options are
1224  * skipped as they are encountered.  If there were no errors, return 1;
1225  * otherwise return 0 (zero).
1226  */
1227 static int nfs_parse_mount_options(char *raw,
1228 				   struct nfs_parsed_mount_data *mnt)
1229 {
1230 	char *p, *string;
1231 	int rc, sloppy = 0, invalid_option = 0;
1232 	unsigned short protofamily = AF_UNSPEC;
1233 	unsigned short mountfamily = AF_UNSPEC;
1234 
1235 	if (!raw) {
1236 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1237 		return 1;
1238 	}
1239 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1240 
1241 	rc = security_sb_eat_lsm_opts(raw, &mnt->lsm_opts);
1242 	if (rc)
1243 		goto out_security_failure;
1244 
1245 	while ((p = strsep(&raw, ",")) != NULL) {
1246 		substring_t args[MAX_OPT_ARGS];
1247 		unsigned long option;
1248 		int token;
1249 
1250 		if (!*p)
1251 			continue;
1252 
1253 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1254 
1255 		token = match_token(p, nfs_mount_option_tokens, args);
1256 		switch (token) {
1257 
1258 		/*
1259 		 * boolean options:  foo/nofoo
1260 		 */
1261 		case Opt_soft:
1262 			mnt->flags |= NFS_MOUNT_SOFT;
1263 			mnt->flags &= ~NFS_MOUNT_SOFTERR;
1264 			break;
1265 		case Opt_softerr:
1266 			mnt->flags |= NFS_MOUNT_SOFTERR;
1267 			mnt->flags &= ~NFS_MOUNT_SOFT;
1268 			break;
1269 		case Opt_hard:
1270 			mnt->flags &= ~(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR);
1271 			break;
1272 		case Opt_posix:
1273 			mnt->flags |= NFS_MOUNT_POSIX;
1274 			break;
1275 		case Opt_noposix:
1276 			mnt->flags &= ~NFS_MOUNT_POSIX;
1277 			break;
1278 		case Opt_cto:
1279 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1280 			break;
1281 		case Opt_nocto:
1282 			mnt->flags |= NFS_MOUNT_NOCTO;
1283 			break;
1284 		case Opt_ac:
1285 			mnt->flags &= ~NFS_MOUNT_NOAC;
1286 			break;
1287 		case Opt_noac:
1288 			mnt->flags |= NFS_MOUNT_NOAC;
1289 			break;
1290 		case Opt_lock:
1291 			mnt->flags &= ~NFS_MOUNT_NONLM;
1292 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1293 					NFS_MOUNT_LOCAL_FCNTL);
1294 			break;
1295 		case Opt_nolock:
1296 			mnt->flags |= NFS_MOUNT_NONLM;
1297 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1298 				       NFS_MOUNT_LOCAL_FCNTL);
1299 			break;
1300 		case Opt_udp:
1301 			mnt->flags &= ~NFS_MOUNT_TCP;
1302 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1303 			break;
1304 		case Opt_tcp:
1305 			mnt->flags |= NFS_MOUNT_TCP;
1306 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1307 			break;
1308 		case Opt_rdma:
1309 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1310 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1311 			xprt_load_transport(p);
1312 			break;
1313 		case Opt_acl:
1314 			mnt->flags &= ~NFS_MOUNT_NOACL;
1315 			break;
1316 		case Opt_noacl:
1317 			mnt->flags |= NFS_MOUNT_NOACL;
1318 			break;
1319 		case Opt_rdirplus:
1320 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1321 			break;
1322 		case Opt_nordirplus:
1323 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1324 			break;
1325 		case Opt_sharecache:
1326 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1327 			break;
1328 		case Opt_nosharecache:
1329 			mnt->flags |= NFS_MOUNT_UNSHARED;
1330 			break;
1331 		case Opt_resvport:
1332 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1333 			break;
1334 		case Opt_noresvport:
1335 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1336 			break;
1337 		case Opt_fscache:
1338 			mnt->options |= NFS_OPTION_FSCACHE;
1339 			kfree(mnt->fscache_uniq);
1340 			mnt->fscache_uniq = NULL;
1341 			break;
1342 		case Opt_nofscache:
1343 			mnt->options &= ~NFS_OPTION_FSCACHE;
1344 			kfree(mnt->fscache_uniq);
1345 			mnt->fscache_uniq = NULL;
1346 			break;
1347 		case Opt_migration:
1348 			mnt->options |= NFS_OPTION_MIGRATION;
1349 			break;
1350 		case Opt_nomigration:
1351 			mnt->options &= ~NFS_OPTION_MIGRATION;
1352 			break;
1353 
1354 		/*
1355 		 * options that take numeric values
1356 		 */
1357 		case Opt_port:
1358 			if (nfs_get_option_ul(args, &option) ||
1359 			    option > USHRT_MAX)
1360 				goto out_invalid_value;
1361 			mnt->nfs_server.port = option;
1362 			break;
1363 		case Opt_rsize:
1364 			if (nfs_get_option_ul(args, &option))
1365 				goto out_invalid_value;
1366 			mnt->rsize = option;
1367 			break;
1368 		case Opt_wsize:
1369 			if (nfs_get_option_ul(args, &option))
1370 				goto out_invalid_value;
1371 			mnt->wsize = option;
1372 			break;
1373 		case Opt_bsize:
1374 			if (nfs_get_option_ul(args, &option))
1375 				goto out_invalid_value;
1376 			mnt->bsize = option;
1377 			break;
1378 		case Opt_timeo:
1379 			if (nfs_get_option_ul_bound(args, &option, 1, INT_MAX))
1380 				goto out_invalid_value;
1381 			mnt->timeo = option;
1382 			break;
1383 		case Opt_retrans:
1384 			if (nfs_get_option_ul_bound(args, &option, 0, INT_MAX))
1385 				goto out_invalid_value;
1386 			mnt->retrans = option;
1387 			break;
1388 		case Opt_acregmin:
1389 			if (nfs_get_option_ul(args, &option))
1390 				goto out_invalid_value;
1391 			mnt->acregmin = option;
1392 			break;
1393 		case Opt_acregmax:
1394 			if (nfs_get_option_ul(args, &option))
1395 				goto out_invalid_value;
1396 			mnt->acregmax = option;
1397 			break;
1398 		case Opt_acdirmin:
1399 			if (nfs_get_option_ul(args, &option))
1400 				goto out_invalid_value;
1401 			mnt->acdirmin = option;
1402 			break;
1403 		case Opt_acdirmax:
1404 			if (nfs_get_option_ul(args, &option))
1405 				goto out_invalid_value;
1406 			mnt->acdirmax = option;
1407 			break;
1408 		case Opt_actimeo:
1409 			if (nfs_get_option_ul(args, &option))
1410 				goto out_invalid_value;
1411 			mnt->acregmin = mnt->acregmax =
1412 			mnt->acdirmin = mnt->acdirmax = option;
1413 			break;
1414 		case Opt_namelen:
1415 			if (nfs_get_option_ul(args, &option))
1416 				goto out_invalid_value;
1417 			mnt->namlen = option;
1418 			break;
1419 		case Opt_mountport:
1420 			if (nfs_get_option_ul(args, &option) ||
1421 			    option > USHRT_MAX)
1422 				goto out_invalid_value;
1423 			mnt->mount_server.port = option;
1424 			break;
1425 		case Opt_mountvers:
1426 			if (nfs_get_option_ul(args, &option) ||
1427 			    option < NFS_MNT_VERSION ||
1428 			    option > NFS_MNT3_VERSION)
1429 				goto out_invalid_value;
1430 			mnt->mount_server.version = option;
1431 			break;
1432 		case Opt_minorversion:
1433 			if (nfs_get_option_ul(args, &option))
1434 				goto out_invalid_value;
1435 			if (option > NFS4_MAX_MINOR_VERSION)
1436 				goto out_invalid_value;
1437 			mnt->minorversion = option;
1438 			break;
1439 
1440 		/*
1441 		 * options that take text values
1442 		 */
1443 		case Opt_nfsvers:
1444 			string = match_strdup(args);
1445 			if (string == NULL)
1446 				goto out_nomem;
1447 			rc = nfs_parse_version_string(string, mnt, args);
1448 			kfree(string);
1449 			if (!rc)
1450 				goto out_invalid_value;
1451 			break;
1452 		case Opt_sec:
1453 			string = match_strdup(args);
1454 			if (string == NULL)
1455 				goto out_nomem;
1456 			rc = nfs_parse_security_flavors(string, mnt);
1457 			kfree(string);
1458 			if (!rc) {
1459 				dfprintk(MOUNT, "NFS:   unrecognized "
1460 						"security flavor\n");
1461 				return 0;
1462 			}
1463 			break;
1464 		case Opt_proto:
1465 			string = match_strdup(args);
1466 			if (string == NULL)
1467 				goto out_nomem;
1468 			token = match_token(string,
1469 					    nfs_xprt_protocol_tokens, args);
1470 
1471 			protofamily = AF_INET;
1472 			switch (token) {
1473 			case Opt_xprt_udp6:
1474 				protofamily = AF_INET6;
1475 				/* fall through */
1476 			case Opt_xprt_udp:
1477 				mnt->flags &= ~NFS_MOUNT_TCP;
1478 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1479 				break;
1480 			case Opt_xprt_tcp6:
1481 				protofamily = AF_INET6;
1482 				/* fall through */
1483 			case Opt_xprt_tcp:
1484 				mnt->flags |= NFS_MOUNT_TCP;
1485 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1486 				break;
1487 			case Opt_xprt_rdma6:
1488 				protofamily = AF_INET6;
1489 				/* fall through */
1490 			case Opt_xprt_rdma:
1491 				/* vector side protocols to TCP */
1492 				mnt->flags |= NFS_MOUNT_TCP;
1493 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1494 				xprt_load_transport(string);
1495 				break;
1496 			default:
1497 				dfprintk(MOUNT, "NFS:   unrecognized "
1498 						"transport protocol\n");
1499 				kfree(string);
1500 				return 0;
1501 			}
1502 			kfree(string);
1503 			break;
1504 		case Opt_mountproto:
1505 			string = match_strdup(args);
1506 			if (string == NULL)
1507 				goto out_nomem;
1508 			token = match_token(string,
1509 					    nfs_xprt_protocol_tokens, args);
1510 			kfree(string);
1511 
1512 			mountfamily = AF_INET;
1513 			switch (token) {
1514 			case Opt_xprt_udp6:
1515 				mountfamily = AF_INET6;
1516 				/* fall through */
1517 			case Opt_xprt_udp:
1518 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1519 				break;
1520 			case Opt_xprt_tcp6:
1521 				mountfamily = AF_INET6;
1522 				/* fall through */
1523 			case Opt_xprt_tcp:
1524 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1525 				break;
1526 			case Opt_xprt_rdma: /* not used for side protocols */
1527 			default:
1528 				dfprintk(MOUNT, "NFS:   unrecognized "
1529 						"transport protocol\n");
1530 				return 0;
1531 			}
1532 			break;
1533 		case Opt_addr:
1534 			string = match_strdup(args);
1535 			if (string == NULL)
1536 				goto out_nomem;
1537 			mnt->nfs_server.addrlen =
1538 				rpc_pton(mnt->net, string, strlen(string),
1539 					(struct sockaddr *)
1540 					&mnt->nfs_server.address,
1541 					sizeof(mnt->nfs_server.address));
1542 			kfree(string);
1543 			if (mnt->nfs_server.addrlen == 0)
1544 				goto out_invalid_address;
1545 			break;
1546 		case Opt_clientaddr:
1547 			if (nfs_get_option_str(args, &mnt->client_address))
1548 				goto out_nomem;
1549 			break;
1550 		case Opt_mounthost:
1551 			if (nfs_get_option_str(args,
1552 					       &mnt->mount_server.hostname))
1553 				goto out_nomem;
1554 			break;
1555 		case Opt_mountaddr:
1556 			string = match_strdup(args);
1557 			if (string == NULL)
1558 				goto out_nomem;
1559 			mnt->mount_server.addrlen =
1560 				rpc_pton(mnt->net, string, strlen(string),
1561 					(struct sockaddr *)
1562 					&mnt->mount_server.address,
1563 					sizeof(mnt->mount_server.address));
1564 			kfree(string);
1565 			if (mnt->mount_server.addrlen == 0)
1566 				goto out_invalid_address;
1567 			break;
1568 		case Opt_nconnect:
1569 			if (nfs_get_option_ul_bound(args, &option, 1, NFS_MAX_CONNECTIONS))
1570 				goto out_invalid_value;
1571 			mnt->nfs_server.nconnect = option;
1572 			break;
1573 		case Opt_lookupcache:
1574 			string = match_strdup(args);
1575 			if (string == NULL)
1576 				goto out_nomem;
1577 			token = match_token(string,
1578 					nfs_lookupcache_tokens, args);
1579 			kfree(string);
1580 			switch (token) {
1581 				case Opt_lookupcache_all:
1582 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1583 					break;
1584 				case Opt_lookupcache_positive:
1585 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1586 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1587 					break;
1588 				case Opt_lookupcache_none:
1589 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1590 					break;
1591 				default:
1592 					dfprintk(MOUNT, "NFS:   invalid "
1593 							"lookupcache argument\n");
1594 					return 0;
1595 			};
1596 			break;
1597 		case Opt_fscache_uniq:
1598 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1599 				goto out_nomem;
1600 			mnt->options |= NFS_OPTION_FSCACHE;
1601 			break;
1602 		case Opt_local_lock:
1603 			string = match_strdup(args);
1604 			if (string == NULL)
1605 				goto out_nomem;
1606 			token = match_token(string, nfs_local_lock_tokens,
1607 					args);
1608 			kfree(string);
1609 			switch (token) {
1610 			case Opt_local_lock_all:
1611 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1612 					       NFS_MOUNT_LOCAL_FCNTL);
1613 				break;
1614 			case Opt_local_lock_flock:
1615 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1616 				break;
1617 			case Opt_local_lock_posix:
1618 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1619 				break;
1620 			case Opt_local_lock_none:
1621 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1622 						NFS_MOUNT_LOCAL_FCNTL);
1623 				break;
1624 			default:
1625 				dfprintk(MOUNT, "NFS:	invalid	"
1626 						"local_lock argument\n");
1627 				return 0;
1628 			};
1629 			break;
1630 
1631 		/*
1632 		 * Special options
1633 		 */
1634 		case Opt_sloppy:
1635 			sloppy = 1;
1636 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1637 			break;
1638 		case Opt_userspace:
1639 		case Opt_deprecated:
1640 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1641 					"'%s'\n", p);
1642 			break;
1643 
1644 		default:
1645 			invalid_option = 1;
1646 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1647 					"'%s'\n", p);
1648 		}
1649 	}
1650 
1651 	if (!sloppy && invalid_option)
1652 		return 0;
1653 
1654 	if (mnt->minorversion && mnt->version != 4)
1655 		goto out_minorversion_mismatch;
1656 
1657 	if (mnt->options & NFS_OPTION_MIGRATION &&
1658 	    (mnt->version != 4 || mnt->minorversion != 0))
1659 		goto out_migration_misuse;
1660 
1661 	/*
1662 	 * verify that any proto=/mountproto= options match the address
1663 	 * families in the addr=/mountaddr= options.
1664 	 */
1665 	if (protofamily != AF_UNSPEC &&
1666 	    protofamily != mnt->nfs_server.address.ss_family)
1667 		goto out_proto_mismatch;
1668 
1669 	if (mountfamily != AF_UNSPEC) {
1670 		if (mnt->mount_server.addrlen) {
1671 			if (mountfamily != mnt->mount_server.address.ss_family)
1672 				goto out_mountproto_mismatch;
1673 		} else {
1674 			if (mountfamily != mnt->nfs_server.address.ss_family)
1675 				goto out_mountproto_mismatch;
1676 		}
1677 	}
1678 
1679 	return 1;
1680 
1681 out_mountproto_mismatch:
1682 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1683 			 "option\n");
1684 	return 0;
1685 out_proto_mismatch:
1686 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1687 	return 0;
1688 out_invalid_address:
1689 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1690 	return 0;
1691 out_invalid_value:
1692 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1693 	return 0;
1694 out_minorversion_mismatch:
1695 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1696 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1697 	return 0;
1698 out_migration_misuse:
1699 	printk(KERN_INFO
1700 		"NFS: 'migration' not supported for this NFS version\n");
1701 	return 0;
1702 out_nomem:
1703 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1704 	return 0;
1705 out_security_failure:
1706 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1707 	return 0;
1708 }
1709 
1710 /*
1711  * Ensure that a specified authtype in args->auth_info is supported by
1712  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1713  * -EACCES if not.
1714  */
1715 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1716 			rpc_authflavor_t *server_authlist, unsigned int count)
1717 {
1718 	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1719 	bool found_auth_null = false;
1720 	unsigned int i;
1721 
1722 	/*
1723 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1724 	 * must be in the list returned by the server.
1725 	 *
1726 	 * AUTH_NULL has a special meaning when it's in the server list - it
1727 	 * means that the server will ignore the rpc creds, so any flavor
1728 	 * can be used but still use the sec= that was specified.
1729 	 *
1730 	 * Note also that the MNT procedure in MNTv1 does not return a list
1731 	 * of supported security flavors. In this case, nfs_mount() fabricates
1732 	 * a security flavor list containing just AUTH_NULL.
1733 	 */
1734 	for (i = 0; i < count; i++) {
1735 		flavor = server_authlist[i];
1736 
1737 		if (nfs_auth_info_match(&args->auth_info, flavor))
1738 			goto out;
1739 
1740 		if (flavor == RPC_AUTH_NULL)
1741 			found_auth_null = true;
1742 	}
1743 
1744 	if (found_auth_null) {
1745 		flavor = args->auth_info.flavors[0];
1746 		goto out;
1747 	}
1748 
1749 	dfprintk(MOUNT,
1750 		 "NFS: specified auth flavors not supported by server\n");
1751 	return -EACCES;
1752 
1753 out:
1754 	args->selected_flavor = flavor;
1755 	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1756 	return 0;
1757 }
1758 
1759 /*
1760  * Use the remote server's MOUNT service to request the NFS file handle
1761  * corresponding to the provided path.
1762  */
1763 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1764 			     struct nfs_fh *root_fh,
1765 			     rpc_authflavor_t *server_authlist,
1766 			     unsigned int *server_authlist_len)
1767 {
1768 	struct nfs_mount_request request = {
1769 		.sap		= (struct sockaddr *)
1770 						&args->mount_server.address,
1771 		.dirpath	= args->nfs_server.export_path,
1772 		.protocol	= args->mount_server.protocol,
1773 		.fh		= root_fh,
1774 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1775 		.auth_flav_len	= server_authlist_len,
1776 		.auth_flavs	= server_authlist,
1777 		.net		= args->net,
1778 	};
1779 	int status;
1780 
1781 	if (args->mount_server.version == 0) {
1782 		switch (args->version) {
1783 			default:
1784 				args->mount_server.version = NFS_MNT3_VERSION;
1785 				break;
1786 			case 2:
1787 				args->mount_server.version = NFS_MNT_VERSION;
1788 		}
1789 	}
1790 	request.version = args->mount_server.version;
1791 
1792 	if (args->mount_server.hostname)
1793 		request.hostname = args->mount_server.hostname;
1794 	else
1795 		request.hostname = args->nfs_server.hostname;
1796 
1797 	/*
1798 	 * Construct the mount server's address.
1799 	 */
1800 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1801 		memcpy(request.sap, &args->nfs_server.address,
1802 		       args->nfs_server.addrlen);
1803 		args->mount_server.addrlen = args->nfs_server.addrlen;
1804 	}
1805 	request.salen = args->mount_server.addrlen;
1806 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1807 
1808 	/*
1809 	 * Now ask the mount server to map our export path
1810 	 * to a file handle.
1811 	 */
1812 	status = nfs_mount(&request);
1813 	if (status != 0) {
1814 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1815 				request.hostname, status);
1816 		return status;
1817 	}
1818 
1819 	return 0;
1820 }
1821 
1822 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1823 					struct nfs_subversion *nfs_mod)
1824 {
1825 	int status;
1826 	unsigned int i;
1827 	bool tried_auth_unix = false;
1828 	bool auth_null_in_list = false;
1829 	struct nfs_server *server = ERR_PTR(-EACCES);
1830 	struct nfs_parsed_mount_data *args = mount_info->parsed;
1831 	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1832 	unsigned int authlist_len = ARRAY_SIZE(authlist);
1833 
1834 	status = nfs_request_mount(args, mount_info->mntfh, authlist,
1835 					&authlist_len);
1836 	if (status)
1837 		return ERR_PTR(status);
1838 
1839 	/*
1840 	 * Was a sec= authflavor specified in the options? First, verify
1841 	 * whether the server supports it, and then just try to use it if so.
1842 	 */
1843 	if (args->auth_info.flavor_len > 0) {
1844 		status = nfs_verify_authflavors(args, authlist, authlist_len);
1845 		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1846 			 args->selected_flavor);
1847 		if (status)
1848 			return ERR_PTR(status);
1849 		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1850 	}
1851 
1852 	/*
1853 	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
1854 	 * SHOULD prefer the flavor listed first. However, some servers list
1855 	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1856 	 */
1857 	for (i = 0; i < authlist_len; ++i) {
1858 		rpc_authflavor_t flavor;
1859 		struct rpcsec_gss_info info;
1860 
1861 		flavor = authlist[i];
1862 		switch (flavor) {
1863 		case RPC_AUTH_UNIX:
1864 			tried_auth_unix = true;
1865 			break;
1866 		case RPC_AUTH_NULL:
1867 			auth_null_in_list = true;
1868 			continue;
1869 		default:
1870 			if (rpcauth_get_gssinfo(flavor, &info) != 0)
1871 				continue;
1872 			/* Fallthrough */
1873 		}
1874 		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1875 		args->selected_flavor = flavor;
1876 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1877 		if (!IS_ERR(server))
1878 			return server;
1879 	}
1880 
1881 	/*
1882 	 * Nothing we tried so far worked. At this point, give up if we've
1883 	 * already tried AUTH_UNIX or if the server's list doesn't contain
1884 	 * AUTH_NULL
1885 	 */
1886 	if (tried_auth_unix || !auth_null_in_list)
1887 		return server;
1888 
1889 	/* Last chance! Try AUTH_UNIX */
1890 	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1891 	args->selected_flavor = RPC_AUTH_UNIX;
1892 	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1893 }
1894 
1895 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1896 			     struct nfs_mount_info *mount_info,
1897 			     struct nfs_subversion *nfs_mod)
1898 {
1899 	struct nfs_server *server;
1900 
1901 	if (mount_info->parsed->need_mount)
1902 		server = nfs_try_mount_request(mount_info, nfs_mod);
1903 	else
1904 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1905 
1906 	if (IS_ERR(server))
1907 		return ERR_CAST(server);
1908 
1909 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1910 }
1911 EXPORT_SYMBOL_GPL(nfs_try_mount);
1912 
1913 /*
1914  * Split "dev_name" into "hostname:export_path".
1915  *
1916  * The leftmost colon demarks the split between the server's hostname
1917  * and the export path.  If the hostname starts with a left square
1918  * bracket, then it may contain colons.
1919  *
1920  * Note: caller frees hostname and export path, even on error.
1921  */
1922 static int nfs_parse_devname(const char *dev_name,
1923 			     char **hostname, size_t maxnamlen,
1924 			     char **export_path, size_t maxpathlen)
1925 {
1926 	size_t len;
1927 	char *end;
1928 
1929 	if (unlikely(!dev_name || !*dev_name)) {
1930 		dfprintk(MOUNT, "NFS: device name not specified\n");
1931 		return -EINVAL;
1932 	}
1933 
1934 	/* Is the host name protected with square brakcets? */
1935 	if (*dev_name == '[') {
1936 		end = strchr(++dev_name, ']');
1937 		if (end == NULL || end[1] != ':')
1938 			goto out_bad_devname;
1939 
1940 		len = end - dev_name;
1941 		end++;
1942 	} else {
1943 		char *comma;
1944 
1945 		end = strchr(dev_name, ':');
1946 		if (end == NULL)
1947 			goto out_bad_devname;
1948 		len = end - dev_name;
1949 
1950 		/* kill possible hostname list: not supported */
1951 		comma = strchr(dev_name, ',');
1952 		if (comma != NULL && comma < end)
1953 			len = comma - dev_name;
1954 	}
1955 
1956 	if (len > maxnamlen)
1957 		goto out_hostname;
1958 
1959 	/* N.B. caller will free nfs_server.hostname in all cases */
1960 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1961 	if (*hostname == NULL)
1962 		goto out_nomem;
1963 	len = strlen(++end);
1964 	if (len > maxpathlen)
1965 		goto out_path;
1966 	*export_path = kstrndup(end, len, GFP_KERNEL);
1967 	if (!*export_path)
1968 		goto out_nomem;
1969 
1970 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1971 	return 0;
1972 
1973 out_bad_devname:
1974 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1975 	return -EINVAL;
1976 
1977 out_nomem:
1978 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1979 	return -ENOMEM;
1980 
1981 out_hostname:
1982 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1983 	return -ENAMETOOLONG;
1984 
1985 out_path:
1986 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1987 	return -ENAMETOOLONG;
1988 }
1989 
1990 /*
1991  * Validate the NFS2/NFS3 mount data
1992  * - fills in the mount root filehandle
1993  *
1994  * For option strings, user space handles the following behaviors:
1995  *
1996  * + DNS: mapping server host name to IP address ("addr=" option)
1997  *
1998  * + failure mode: how to behave if a mount request can't be handled
1999  *   immediately ("fg/bg" option)
2000  *
2001  * + retry: how often to retry a mount request ("retry=" option)
2002  *
2003  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
2004  *   mountproto=tcp after mountproto=udp, and so on
2005  */
2006 static int nfs23_validate_mount_data(void *options,
2007 				     struct nfs_parsed_mount_data *args,
2008 				     struct nfs_fh *mntfh,
2009 				     const char *dev_name)
2010 {
2011 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
2012 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2013 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
2014 
2015 	if (data == NULL)
2016 		goto out_no_data;
2017 
2018 	args->version = NFS_DEFAULT_VERSION;
2019 	switch (data->version) {
2020 	case 1:
2021 		data->namlen = 0; /* fall through */
2022 	case 2:
2023 		data->bsize = 0; /* fall through */
2024 	case 3:
2025 		if (data->flags & NFS_MOUNT_VER3)
2026 			goto out_no_v3;
2027 		data->root.size = NFS2_FHSIZE;
2028 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
2029 		/* Turn off security negotiation */
2030 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
2031 		/* fall through */
2032 	case 4:
2033 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2034 			goto out_no_sec;
2035 		/* fall through */
2036 	case 5:
2037 		memset(data->context, 0, sizeof(data->context));
2038 		/* fall through */
2039 	case 6:
2040 		if (data->flags & NFS_MOUNT_VER3) {
2041 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
2042 				goto out_invalid_fh;
2043 			mntfh->size = data->root.size;
2044 			args->version = 3;
2045 		} else {
2046 			mntfh->size = NFS2_FHSIZE;
2047 			args->version = 2;
2048 		}
2049 
2050 
2051 		memcpy(mntfh->data, data->root.data, mntfh->size);
2052 		if (mntfh->size < sizeof(mntfh->data))
2053 			memset(mntfh->data + mntfh->size, 0,
2054 			       sizeof(mntfh->data) - mntfh->size);
2055 
2056 		/*
2057 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
2058 		 * can deal with.
2059 		 */
2060 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
2061 		args->flags		|= extra_flags;
2062 		args->rsize		= data->rsize;
2063 		args->wsize		= data->wsize;
2064 		args->timeo		= data->timeo;
2065 		args->retrans		= data->retrans;
2066 		args->acregmin		= data->acregmin;
2067 		args->acregmax		= data->acregmax;
2068 		args->acdirmin		= data->acdirmin;
2069 		args->acdirmax		= data->acdirmax;
2070 		args->need_mount	= false;
2071 
2072 		memcpy(sap, &data->addr, sizeof(data->addr));
2073 		args->nfs_server.addrlen = sizeof(data->addr);
2074 		args->nfs_server.port = ntohs(data->addr.sin_port);
2075 		if (sap->sa_family != AF_INET ||
2076 		    !nfs_verify_server_address(sap))
2077 			goto out_no_address;
2078 
2079 		if (!(data->flags & NFS_MOUNT_TCP))
2080 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2081 		/* N.B. caller will free nfs_server.hostname in all cases */
2082 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2083 		args->namlen		= data->namlen;
2084 		args->bsize		= data->bsize;
2085 
2086 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2087 			args->selected_flavor = data->pseudoflavor;
2088 		else
2089 			args->selected_flavor = RPC_AUTH_UNIX;
2090 		if (!args->nfs_server.hostname)
2091 			goto out_nomem;
2092 
2093 		if (!(data->flags & NFS_MOUNT_NONLM))
2094 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2095 					 NFS_MOUNT_LOCAL_FCNTL);
2096 		else
2097 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2098 					NFS_MOUNT_LOCAL_FCNTL);
2099 		/*
2100 		 * The legacy version 6 binary mount data from userspace has a
2101 		 * field used only to transport selinux information into the
2102 		 * the kernel.  To continue to support that functionality we
2103 		 * have a touch of selinux knowledge here in the NFS code. The
2104 		 * userspace code converted context=blah to just blah so we are
2105 		 * converting back to the full string selinux understands.
2106 		 */
2107 		if (data->context[0]){
2108 #ifdef CONFIG_SECURITY_SELINUX
2109 			int rc;
2110 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2111 			rc = security_add_mnt_opt("context", data->context,
2112 					strlen(data->context), &args->lsm_opts);
2113 			if (rc)
2114 				return rc;
2115 #else
2116 			return -EINVAL;
2117 #endif
2118 		}
2119 
2120 		break;
2121 	default:
2122 		return NFS_TEXT_DATA;
2123 	}
2124 
2125 	return 0;
2126 
2127 out_no_data:
2128 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2129 	return -EINVAL;
2130 
2131 out_no_v3:
2132 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2133 		 data->version);
2134 	return -EINVAL;
2135 
2136 out_no_sec:
2137 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2138 	return -EINVAL;
2139 
2140 out_nomem:
2141 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2142 	return -ENOMEM;
2143 
2144 out_no_address:
2145 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2146 	return -EINVAL;
2147 
2148 out_invalid_fh:
2149 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2150 	return -EINVAL;
2151 }
2152 
2153 #if IS_ENABLED(CONFIG_NFS_V4)
2154 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2155 				   void *options,
2156 				   struct nfs_parsed_mount_data *args,
2157 				   struct nfs_fh *mntfh,
2158 				   const char *dev_name)
2159 {
2160 	if (fs_type == &nfs_fs_type)
2161 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2162 	return nfs4_validate_mount_data(options, args, dev_name);
2163 }
2164 #else
2165 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2166 				   void *options,
2167 				   struct nfs_parsed_mount_data *args,
2168 				   struct nfs_fh *mntfh,
2169 				   const char *dev_name)
2170 {
2171 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2172 }
2173 #endif
2174 
2175 static int nfs_validate_text_mount_data(void *options,
2176 					struct nfs_parsed_mount_data *args,
2177 					const char *dev_name)
2178 {
2179 	int port = 0;
2180 	int max_namelen = PAGE_SIZE;
2181 	int max_pathlen = NFS_MAXPATHLEN;
2182 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2183 
2184 	if (nfs_parse_mount_options((char *)options, args) == 0)
2185 		return -EINVAL;
2186 
2187 	if (!nfs_verify_server_address(sap))
2188 		goto out_no_address;
2189 
2190 	if (args->version == 4) {
2191 #if IS_ENABLED(CONFIG_NFS_V4)
2192 		if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2193 			port = NFS_RDMA_PORT;
2194 		else
2195 			port = NFS_PORT;
2196 		max_namelen = NFS4_MAXNAMLEN;
2197 		max_pathlen = NFS4_MAXPATHLEN;
2198 		nfs_validate_transport_protocol(args);
2199 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2200 			goto out_invalid_transport_udp;
2201 		nfs4_validate_mount_flags(args);
2202 #else
2203 		goto out_v4_not_compiled;
2204 #endif /* CONFIG_NFS_V4 */
2205 	} else {
2206 		nfs_set_mount_transport_protocol(args);
2207 		if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2208 			port = NFS_RDMA_PORT;
2209 	}
2210 
2211 	nfs_set_port(sap, &args->nfs_server.port, port);
2212 
2213 	return nfs_parse_devname(dev_name,
2214 				   &args->nfs_server.hostname,
2215 				   max_namelen,
2216 				   &args->nfs_server.export_path,
2217 				   max_pathlen);
2218 
2219 #if !IS_ENABLED(CONFIG_NFS_V4)
2220 out_v4_not_compiled:
2221 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2222 	return -EPROTONOSUPPORT;
2223 #else
2224 out_invalid_transport_udp:
2225 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2226 	return -EINVAL;
2227 #endif /* !CONFIG_NFS_V4 */
2228 
2229 out_no_address:
2230 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2231 	return -EINVAL;
2232 }
2233 
2234 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2235 		| NFS_MOUNT_SECURE \
2236 		| NFS_MOUNT_TCP \
2237 		| NFS_MOUNT_VER3 \
2238 		| NFS_MOUNT_KERBEROS \
2239 		| NFS_MOUNT_NONLM \
2240 		| NFS_MOUNT_BROKEN_SUID \
2241 		| NFS_MOUNT_STRICTLOCK \
2242 		| NFS_MOUNT_LEGACY_INTERFACE)
2243 
2244 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2245 		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2246 
2247 static int
2248 nfs_compare_remount_data(struct nfs_server *nfss,
2249 			 struct nfs_parsed_mount_data *data)
2250 {
2251 	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2252 	    data->rsize != nfss->rsize ||
2253 	    data->wsize != nfss->wsize ||
2254 	    data->version != nfss->nfs_client->rpc_ops->version ||
2255 	    data->minorversion != nfss->nfs_client->cl_minorversion ||
2256 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2257 	    !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2258 	    data->acregmin != nfss->acregmin / HZ ||
2259 	    data->acregmax != nfss->acregmax / HZ ||
2260 	    data->acdirmin != nfss->acdirmin / HZ ||
2261 	    data->acdirmax != nfss->acdirmax / HZ ||
2262 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2263 	    (data->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
2264 	    data->nfs_server.port != nfss->port ||
2265 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2266 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2267 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2268 		return -EINVAL;
2269 
2270 	return 0;
2271 }
2272 
2273 int
2274 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2275 {
2276 	int error;
2277 	struct nfs_server *nfss = sb->s_fs_info;
2278 	struct nfs_parsed_mount_data *data;
2279 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2280 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2281 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2282 
2283 	sync_filesystem(sb);
2284 
2285 	/*
2286 	 * Userspace mount programs that send binary options generally send
2287 	 * them populated with default values. We have no way to know which
2288 	 * ones were explicitly specified. Fall back to legacy behavior and
2289 	 * just return success.
2290 	 */
2291 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2292 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2293 					   options->version <= 6))))
2294 		return 0;
2295 
2296 	data = nfs_alloc_parsed_mount_data();
2297 	if (data == NULL)
2298 		return -ENOMEM;
2299 
2300 	/* fill out struct with values from existing mount */
2301 	data->flags = nfss->flags;
2302 	data->rsize = nfss->rsize;
2303 	data->wsize = nfss->wsize;
2304 	data->retrans = nfss->client->cl_timeout->to_retries;
2305 	data->selected_flavor = nfss->client->cl_auth->au_flavor;
2306 	data->acregmin = nfss->acregmin / HZ;
2307 	data->acregmax = nfss->acregmax / HZ;
2308 	data->acdirmin = nfss->acdirmin / HZ;
2309 	data->acdirmax = nfss->acdirmax / HZ;
2310 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2311 	data->nfs_server.port = nfss->port;
2312 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2313 	data->version = nfsvers;
2314 	data->minorversion = nfss->nfs_client->cl_minorversion;
2315 	data->net = current->nsproxy->net_ns;
2316 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2317 		data->nfs_server.addrlen);
2318 
2319 	/* overwrite those values with any that were specified */
2320 	error = -EINVAL;
2321 	if (!nfs_parse_mount_options((char *)options, data))
2322 		goto out;
2323 
2324 	/*
2325 	 * noac is a special case. It implies -o sync, but that's not
2326 	 * necessarily reflected in the mtab options. do_remount_sb
2327 	 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
2328 	 * remount options, so we have to explicitly reset it.
2329 	 */
2330 	if (data->flags & NFS_MOUNT_NOAC)
2331 		*flags |= SB_SYNCHRONOUS;
2332 
2333 	/* compare new mount options with old ones */
2334 	error = nfs_compare_remount_data(nfss, data);
2335 	if (!error)
2336 		error = security_sb_remount(sb, data->lsm_opts);
2337 out:
2338 	nfs_free_parsed_mount_data(data);
2339 	return error;
2340 }
2341 EXPORT_SYMBOL_GPL(nfs_remount);
2342 
2343 /*
2344  * Initialise the common bits of the superblock
2345  */
2346 static void nfs_initialise_sb(struct super_block *sb)
2347 {
2348 	struct nfs_server *server = NFS_SB(sb);
2349 
2350 	sb->s_magic = NFS_SUPER_MAGIC;
2351 
2352 	/* We probably want something more informative here */
2353 	snprintf(sb->s_id, sizeof(sb->s_id),
2354 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2355 
2356 	if (sb->s_blocksize == 0)
2357 		sb->s_blocksize = nfs_block_bits(server->wsize,
2358 						 &sb->s_blocksize_bits);
2359 
2360 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2361 }
2362 
2363 /*
2364  * Finish setting up an NFS2/3 superblock
2365  */
2366 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2367 {
2368 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2369 	struct nfs_server *server = NFS_SB(sb);
2370 
2371 	sb->s_blocksize_bits = 0;
2372 	sb->s_blocksize = 0;
2373 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2374 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2375 	if (data && data->bsize)
2376 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2377 
2378 	if (server->nfs_client->rpc_ops->version != 2) {
2379 		/* The VFS shouldn't apply the umask to mode bits. We will do
2380 		 * so ourselves when necessary.
2381 		 */
2382 		sb->s_flags |= SB_POSIXACL;
2383 		sb->s_time_gran = 1;
2384 		sb->s_export_op = &nfs_export_ops;
2385 	}
2386 
2387  	nfs_initialise_sb(sb);
2388 }
2389 EXPORT_SYMBOL_GPL(nfs_fill_super);
2390 
2391 /*
2392  * Finish setting up a cloned NFS2/3/4 superblock
2393  */
2394 static void nfs_clone_super(struct super_block *sb,
2395 			    struct nfs_mount_info *mount_info)
2396 {
2397 	const struct super_block *old_sb = mount_info->cloned->sb;
2398 	struct nfs_server *server = NFS_SB(sb);
2399 
2400 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2401 	sb->s_blocksize = old_sb->s_blocksize;
2402 	sb->s_maxbytes = old_sb->s_maxbytes;
2403 	sb->s_xattr = old_sb->s_xattr;
2404 	sb->s_op = old_sb->s_op;
2405 	sb->s_time_gran = 1;
2406 	sb->s_export_op = old_sb->s_export_op;
2407 
2408 	if (server->nfs_client->rpc_ops->version != 2) {
2409 		/* The VFS shouldn't apply the umask to mode bits. We will do
2410 		 * so ourselves when necessary.
2411 		 */
2412 		sb->s_flags |= SB_POSIXACL;
2413 	}
2414 
2415  	nfs_initialise_sb(sb);
2416 }
2417 
2418 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2419 {
2420 	const struct nfs_server *a = s->s_fs_info;
2421 	const struct rpc_clnt *clnt_a = a->client;
2422 	const struct rpc_clnt *clnt_b = b->client;
2423 
2424 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2425 		goto Ebusy;
2426 	if (a->nfs_client != b->nfs_client)
2427 		goto Ebusy;
2428 	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2429 		goto Ebusy;
2430 	if (a->wsize != b->wsize)
2431 		goto Ebusy;
2432 	if (a->rsize != b->rsize)
2433 		goto Ebusy;
2434 	if (a->acregmin != b->acregmin)
2435 		goto Ebusy;
2436 	if (a->acregmax != b->acregmax)
2437 		goto Ebusy;
2438 	if (a->acdirmin != b->acdirmin)
2439 		goto Ebusy;
2440 	if (a->acdirmax != b->acdirmax)
2441 		goto Ebusy;
2442 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2443 		goto Ebusy;
2444 	return 1;
2445 Ebusy:
2446 	return 0;
2447 }
2448 
2449 struct nfs_sb_mountdata {
2450 	struct nfs_server *server;
2451 	int mntflags;
2452 };
2453 
2454 static int nfs_set_super(struct super_block *s, void *data)
2455 {
2456 	struct nfs_sb_mountdata *sb_mntdata = data;
2457 	struct nfs_server *server = sb_mntdata->server;
2458 	int ret;
2459 
2460 	s->s_flags = sb_mntdata->mntflags;
2461 	s->s_fs_info = server;
2462 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2463 	ret = set_anon_super(s, server);
2464 	if (ret == 0)
2465 		server->s_dev = s->s_dev;
2466 	return ret;
2467 }
2468 
2469 static int nfs_compare_super_address(struct nfs_server *server1,
2470 				     struct nfs_server *server2)
2471 {
2472 	struct sockaddr *sap1, *sap2;
2473 	struct rpc_xprt *xprt1 = server1->client->cl_xprt;
2474 	struct rpc_xprt *xprt2 = server2->client->cl_xprt;
2475 
2476 	if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
2477 		return 0;
2478 
2479 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2480 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2481 
2482 	if (sap1->sa_family != sap2->sa_family)
2483 		return 0;
2484 
2485 	switch (sap1->sa_family) {
2486 	case AF_INET: {
2487 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2488 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2489 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2490 			return 0;
2491 		if (sin1->sin_port != sin2->sin_port)
2492 			return 0;
2493 		break;
2494 	}
2495 	case AF_INET6: {
2496 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2497 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2498 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2499 			return 0;
2500 		if (sin1->sin6_port != sin2->sin6_port)
2501 			return 0;
2502 		break;
2503 	}
2504 	default:
2505 		return 0;
2506 	}
2507 
2508 	return 1;
2509 }
2510 
2511 static int nfs_compare_userns(const struct nfs_server *old,
2512 		const struct nfs_server *new)
2513 {
2514 	const struct user_namespace *oldns = &init_user_ns;
2515 	const struct user_namespace *newns = &init_user_ns;
2516 
2517 	if (old->client && old->client->cl_cred)
2518 		oldns = old->client->cl_cred->user_ns;
2519 	if (new->client && new->client->cl_cred)
2520 		newns = new->client->cl_cred->user_ns;
2521 	if (oldns != newns)
2522 		return 0;
2523 	return 1;
2524 }
2525 
2526 static int nfs_compare_super(struct super_block *sb, void *data)
2527 {
2528 	struct nfs_sb_mountdata *sb_mntdata = data;
2529 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2530 	int mntflags = sb_mntdata->mntflags;
2531 
2532 	if (!nfs_compare_super_address(old, server))
2533 		return 0;
2534 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2535 	if (old->flags & NFS_MOUNT_UNSHARED)
2536 		return 0;
2537 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2538 		return 0;
2539 	if (!nfs_compare_userns(old, server))
2540 		return 0;
2541 	return nfs_compare_mount_options(sb, server, mntflags);
2542 }
2543 
2544 #ifdef CONFIG_NFS_FSCACHE
2545 static void nfs_get_cache_cookie(struct super_block *sb,
2546 				 struct nfs_parsed_mount_data *parsed,
2547 				 struct nfs_clone_mount *cloned)
2548 {
2549 	struct nfs_server *nfss = NFS_SB(sb);
2550 	char *uniq = NULL;
2551 	int ulen = 0;
2552 
2553 	nfss->fscache_key = NULL;
2554 	nfss->fscache = NULL;
2555 
2556 	if (parsed) {
2557 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2558 			return;
2559 		if (parsed->fscache_uniq) {
2560 			uniq = parsed->fscache_uniq;
2561 			ulen = strlen(parsed->fscache_uniq);
2562 		}
2563 	} else if (cloned) {
2564 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2565 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2566 			return;
2567 		if (mnt_s->fscache_key) {
2568 			uniq = mnt_s->fscache_key->key.uniquifier;
2569 			ulen = mnt_s->fscache_key->key.uniq_len;
2570 		};
2571 	} else
2572 		return;
2573 
2574 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2575 }
2576 #else
2577 static void nfs_get_cache_cookie(struct super_block *sb,
2578 				 struct nfs_parsed_mount_data *parsed,
2579 				 struct nfs_clone_mount *cloned)
2580 {
2581 }
2582 #endif
2583 
2584 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2585 			struct nfs_mount_info *mount_info)
2586 {
2587 	int error;
2588 	unsigned long kflags = 0, kflags_out = 0;
2589 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2590 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2591 
2592 	error = security_sb_set_mnt_opts(s, mount_info->parsed->lsm_opts,
2593 						kflags, &kflags_out);
2594 	if (error)
2595 		goto err;
2596 
2597 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2598 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2599 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2600 err:
2601 	return error;
2602 }
2603 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2604 
2605 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2606 			  struct nfs_mount_info *mount_info)
2607 {
2608 	int error;
2609 	unsigned long kflags = 0, kflags_out = 0;
2610 
2611 	/* clone any lsm security options from the parent to the new sb */
2612 	if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2613 		return -ESTALE;
2614 
2615 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2616 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2617 
2618 	error = security_sb_clone_mnt_opts(mount_info->cloned->sb, s, kflags,
2619 			&kflags_out);
2620 	if (error)
2621 		return error;
2622 
2623 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2624 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2625 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2626 	return 0;
2627 }
2628 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2629 
2630 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2631 				   int flags, const char *dev_name,
2632 				   struct nfs_mount_info *mount_info,
2633 				   struct nfs_subversion *nfs_mod)
2634 {
2635 	struct super_block *s;
2636 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2637 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2638 	struct nfs_sb_mountdata sb_mntdata = {
2639 		.mntflags = flags,
2640 		.server = server,
2641 	};
2642 	int error;
2643 
2644 	if (server->flags & NFS_MOUNT_UNSHARED)
2645 		compare_super = NULL;
2646 
2647 	/* -o noac implies -o sync */
2648 	if (server->flags & NFS_MOUNT_NOAC)
2649 		sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2650 
2651 	if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2652 		if (mount_info->cloned->sb->s_flags & SB_SYNCHRONOUS)
2653 			sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2654 
2655 	/* Get a superblock - note that we may end up sharing one that already exists */
2656 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2657 	if (IS_ERR(s)) {
2658 		mntroot = ERR_CAST(s);
2659 		goto out_err_nosb;
2660 	}
2661 
2662 	if (s->s_fs_info != server) {
2663 		nfs_free_server(server);
2664 		server = NULL;
2665 	} else {
2666 		error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
2667 					     MINOR(server->s_dev));
2668 		if (error) {
2669 			mntroot = ERR_PTR(error);
2670 			goto error_splat_super;
2671 		}
2672 		s->s_bdi->ra_pages = server->rpages * NFS_MAX_READAHEAD;
2673 		server->super = s;
2674 	}
2675 
2676 	if (!s->s_root) {
2677 		/* initial superblock/root creation */
2678 		mount_info->fill_super(s, mount_info);
2679 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2680 		if (!(server->flags & NFS_MOUNT_UNSHARED))
2681 			s->s_iflags |= SB_I_MULTIROOT;
2682 	}
2683 
2684 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2685 	if (IS_ERR(mntroot))
2686 		goto error_splat_super;
2687 
2688 	error = mount_info->set_security(s, mntroot, mount_info);
2689 	if (error)
2690 		goto error_splat_root;
2691 
2692 	s->s_flags |= SB_ACTIVE;
2693 
2694 out:
2695 	return mntroot;
2696 
2697 out_err_nosb:
2698 	nfs_free_server(server);
2699 	goto out;
2700 
2701 error_splat_root:
2702 	dput(mntroot);
2703 	mntroot = ERR_PTR(error);
2704 error_splat_super:
2705 	deactivate_locked_super(s);
2706 	goto out;
2707 }
2708 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2709 
2710 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2711 	int flags, const char *dev_name, void *raw_data)
2712 {
2713 	struct nfs_mount_info mount_info = {
2714 		.fill_super = nfs_fill_super,
2715 		.set_security = nfs_set_sb_security,
2716 	};
2717 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2718 	struct nfs_subversion *nfs_mod;
2719 	int error;
2720 
2721 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2722 	mount_info.mntfh = nfs_alloc_fhandle();
2723 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2724 		goto out;
2725 
2726 	/* Validate the mount data */
2727 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2728 	if (error == NFS_TEXT_DATA)
2729 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2730 	if (error < 0) {
2731 		mntroot = ERR_PTR(error);
2732 		goto out;
2733 	}
2734 
2735 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2736 	if (IS_ERR(nfs_mod)) {
2737 		mntroot = ERR_CAST(nfs_mod);
2738 		goto out;
2739 	}
2740 
2741 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2742 
2743 	put_nfs_version(nfs_mod);
2744 out:
2745 	nfs_free_parsed_mount_data(mount_info.parsed);
2746 	nfs_free_fhandle(mount_info.mntfh);
2747 	return mntroot;
2748 }
2749 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2750 
2751 /*
2752  * Destroy an NFS2/3 superblock
2753  */
2754 void nfs_kill_super(struct super_block *s)
2755 {
2756 	struct nfs_server *server = NFS_SB(s);
2757 	dev_t dev = s->s_dev;
2758 
2759 	generic_shutdown_super(s);
2760 
2761 	nfs_fscache_release_super_cookie(s);
2762 
2763 	nfs_free_server(server);
2764 	free_anon_bdev(dev);
2765 }
2766 EXPORT_SYMBOL_GPL(nfs_kill_super);
2767 
2768 /*
2769  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2770  */
2771 static struct dentry *
2772 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2773 		const char *dev_name, void *raw_data)
2774 {
2775 	struct nfs_clone_mount *data = raw_data;
2776 	struct nfs_mount_info mount_info = {
2777 		.fill_super = nfs_clone_super,
2778 		.set_security = nfs_clone_sb_security,
2779 		.cloned = data,
2780 	};
2781 	struct nfs_server *server;
2782 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2783 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2784 
2785 	dprintk("--> nfs_xdev_mount()\n");
2786 
2787 	mount_info.mntfh = mount_info.cloned->fh;
2788 
2789 	/* create a new volume representation */
2790 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2791 
2792 	if (IS_ERR(server))
2793 		mntroot = ERR_CAST(server);
2794 	else
2795 		mntroot = nfs_fs_mount_common(server, flags,
2796 				dev_name, &mount_info, nfs_mod);
2797 
2798 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2799 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2800 	return mntroot;
2801 }
2802 
2803 #if IS_ENABLED(CONFIG_NFS_V4)
2804 
2805 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2806 {
2807 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2808 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2809 }
2810 
2811 /*
2812  * Validate NFSv4 mount options
2813  */
2814 static int nfs4_validate_mount_data(void *options,
2815 				    struct nfs_parsed_mount_data *args,
2816 				    const char *dev_name)
2817 {
2818 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2819 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2820 	char *c;
2821 
2822 	if (data == NULL)
2823 		goto out_no_data;
2824 
2825 	args->version = 4;
2826 
2827 	switch (data->version) {
2828 	case 1:
2829 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2830 			goto out_no_address;
2831 		if (data->host_addrlen == 0)
2832 			goto out_no_address;
2833 		args->nfs_server.addrlen = data->host_addrlen;
2834 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2835 			return -EFAULT;
2836 		if (!nfs_verify_server_address(sap))
2837 			goto out_no_address;
2838 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2839 
2840 		if (data->auth_flavourlen) {
2841 			rpc_authflavor_t pseudoflavor;
2842 			if (data->auth_flavourlen > 1)
2843 				goto out_inval_auth;
2844 			if (copy_from_user(&pseudoflavor,
2845 					   data->auth_flavours,
2846 					   sizeof(pseudoflavor)))
2847 				return -EFAULT;
2848 			args->selected_flavor = pseudoflavor;
2849 		} else
2850 			args->selected_flavor = RPC_AUTH_UNIX;
2851 
2852 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2853 		if (IS_ERR(c))
2854 			return PTR_ERR(c);
2855 		args->nfs_server.hostname = c;
2856 
2857 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2858 		if (IS_ERR(c))
2859 			return PTR_ERR(c);
2860 		args->nfs_server.export_path = c;
2861 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2862 
2863 		c = strndup_user(data->client_addr.data, 16);
2864 		if (IS_ERR(c))
2865 			return PTR_ERR(c);
2866 		args->client_address = c;
2867 
2868 		/*
2869 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2870 		 * can deal with.
2871 		 */
2872 
2873 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2874 		args->rsize	= data->rsize;
2875 		args->wsize	= data->wsize;
2876 		args->timeo	= data->timeo;
2877 		args->retrans	= data->retrans;
2878 		args->acregmin	= data->acregmin;
2879 		args->acregmax	= data->acregmax;
2880 		args->acdirmin	= data->acdirmin;
2881 		args->acdirmax	= data->acdirmax;
2882 		args->nfs_server.protocol = data->proto;
2883 		nfs_validate_transport_protocol(args);
2884 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2885 			goto out_invalid_transport_udp;
2886 
2887 		break;
2888 	default:
2889 		return NFS_TEXT_DATA;
2890 	}
2891 
2892 	return 0;
2893 
2894 out_no_data:
2895 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2896 	return -EINVAL;
2897 
2898 out_inval_auth:
2899 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2900 		 data->auth_flavourlen);
2901 	return -EINVAL;
2902 
2903 out_no_address:
2904 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2905 	return -EINVAL;
2906 
2907 out_invalid_transport_udp:
2908 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2909 	return -EINVAL;
2910 }
2911 
2912 /*
2913  * NFS v4 module parameters need to stay in the
2914  * NFS client for backwards compatibility
2915  */
2916 unsigned int nfs_callback_set_tcpport;
2917 unsigned short nfs_callback_nr_threads;
2918 /* Default cache timeout is 10 minutes */
2919 unsigned int nfs_idmap_cache_timeout = 600;
2920 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2921 bool nfs4_disable_idmapping = true;
2922 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2923 unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
2924 unsigned short send_implementation_id = 1;
2925 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2926 bool recover_lost_locks = false;
2927 
2928 EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
2929 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2930 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2931 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2932 EXPORT_SYMBOL_GPL(max_session_slots);
2933 EXPORT_SYMBOL_GPL(max_session_cb_slots);
2934 EXPORT_SYMBOL_GPL(send_implementation_id);
2935 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2936 EXPORT_SYMBOL_GPL(recover_lost_locks);
2937 
2938 #define NFS_CALLBACK_MAXPORTNR (65535U)
2939 
2940 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2941 {
2942 	unsigned long num;
2943 	int ret;
2944 
2945 	if (!val)
2946 		return -EINVAL;
2947 	ret = kstrtoul(val, 0, &num);
2948 	if (ret || num > NFS_CALLBACK_MAXPORTNR)
2949 		return -EINVAL;
2950 	*((unsigned int *)kp->arg) = num;
2951 	return 0;
2952 }
2953 static const struct kernel_param_ops param_ops_portnr = {
2954 	.set = param_set_portnr,
2955 	.get = param_get_uint,
2956 };
2957 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2958 
2959 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2960 module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
2961 MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
2962 		"assigned to the NFSv4 callback channels.");
2963 module_param(nfs_idmap_cache_timeout, int, 0644);
2964 module_param(nfs4_disable_idmapping, bool, 0644);
2965 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2966 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2967 MODULE_PARM_DESC(nfs4_disable_idmapping,
2968 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2969 module_param(max_session_slots, ushort, 0644);
2970 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2971 		"requests the client will negotiate");
2972 module_param(max_session_cb_slots, ushort, 0644);
2973 MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
2974 		"callbacks the client will process for a given server");
2975 module_param(send_implementation_id, ushort, 0644);
2976 MODULE_PARM_DESC(send_implementation_id,
2977 		"Send implementation ID with NFSv4.1 exchange_id");
2978 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2979 
2980 module_param(recover_lost_locks, bool, 0644);
2981 MODULE_PARM_DESC(recover_lost_locks,
2982 		 "If the server reports that a lock might be lost, "
2983 		 "try to recover it risking data corruption.");
2984 
2985 
2986 #endif /* CONFIG_NFS_V4 */
2987