xref: /openbmc/linux/fs/nfs/super.c (revision bc5aa3a0)
1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/addr.h>
35 #include <linux/sunrpc/stats.h>
36 #include <linux/sunrpc/metrics.h>
37 #include <linux/sunrpc/xprtsock.h>
38 #include <linux/sunrpc/xprtrdma.h>
39 #include <linux/nfs_fs.h>
40 #include <linux/nfs_mount.h>
41 #include <linux/nfs4_mount.h>
42 #include <linux/lockd/bind.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/namei.h>
46 #include <linux/vfs.h>
47 #include <linux/inet.h>
48 #include <linux/in6.h>
49 #include <linux/slab.h>
50 #include <net/ipv6.h>
51 #include <linux/netdevice.h>
52 #include <linux/nfs_xdr.h>
53 #include <linux/magic.h>
54 #include <linux/parser.h>
55 #include <linux/nsproxy.h>
56 #include <linux/rcupdate.h>
57 
58 #include <asm/uaccess.h>
59 
60 #include "nfs4_fs.h"
61 #include "callback.h"
62 #include "delegation.h"
63 #include "iostat.h"
64 #include "internal.h"
65 #include "fscache.h"
66 #include "nfs4session.h"
67 #include "pnfs.h"
68 #include "nfs.h"
69 
70 #define NFSDBG_FACILITY		NFSDBG_VFS
71 #define NFS_TEXT_DATA		1
72 
73 #if IS_ENABLED(CONFIG_NFS_V3)
74 #define NFS_DEFAULT_VERSION 3
75 #else
76 #define NFS_DEFAULT_VERSION 2
77 #endif
78 
79 enum {
80 	/* Mount options that take no arguments */
81 	Opt_soft, Opt_hard,
82 	Opt_posix, Opt_noposix,
83 	Opt_cto, Opt_nocto,
84 	Opt_ac, Opt_noac,
85 	Opt_lock, Opt_nolock,
86 	Opt_udp, Opt_tcp, Opt_rdma,
87 	Opt_acl, Opt_noacl,
88 	Opt_rdirplus, Opt_nordirplus,
89 	Opt_sharecache, Opt_nosharecache,
90 	Opt_resvport, Opt_noresvport,
91 	Opt_fscache, Opt_nofscache,
92 	Opt_migration, Opt_nomigration,
93 
94 	/* Mount options that take integer arguments */
95 	Opt_port,
96 	Opt_rsize, Opt_wsize, Opt_bsize,
97 	Opt_timeo, Opt_retrans,
98 	Opt_acregmin, Opt_acregmax,
99 	Opt_acdirmin, Opt_acdirmax,
100 	Opt_actimeo,
101 	Opt_namelen,
102 	Opt_mountport,
103 	Opt_mountvers,
104 	Opt_minorversion,
105 
106 	/* Mount options that take string arguments */
107 	Opt_nfsvers,
108 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
109 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
110 	Opt_lookupcache,
111 	Opt_fscache_uniq,
112 	Opt_local_lock,
113 
114 	/* Special mount options */
115 	Opt_userspace, Opt_deprecated, Opt_sloppy,
116 
117 	Opt_err
118 };
119 
120 static const match_table_t nfs_mount_option_tokens = {
121 	{ Opt_userspace, "bg" },
122 	{ Opt_userspace, "fg" },
123 	{ Opt_userspace, "retry=%s" },
124 
125 	{ Opt_sloppy, "sloppy" },
126 
127 	{ Opt_soft, "soft" },
128 	{ Opt_hard, "hard" },
129 	{ Opt_deprecated, "intr" },
130 	{ Opt_deprecated, "nointr" },
131 	{ Opt_posix, "posix" },
132 	{ Opt_noposix, "noposix" },
133 	{ Opt_cto, "cto" },
134 	{ Opt_nocto, "nocto" },
135 	{ Opt_ac, "ac" },
136 	{ Opt_noac, "noac" },
137 	{ Opt_lock, "lock" },
138 	{ Opt_nolock, "nolock" },
139 	{ Opt_udp, "udp" },
140 	{ Opt_tcp, "tcp" },
141 	{ Opt_rdma, "rdma" },
142 	{ Opt_acl, "acl" },
143 	{ Opt_noacl, "noacl" },
144 	{ Opt_rdirplus, "rdirplus" },
145 	{ Opt_nordirplus, "nordirplus" },
146 	{ Opt_sharecache, "sharecache" },
147 	{ Opt_nosharecache, "nosharecache" },
148 	{ Opt_resvport, "resvport" },
149 	{ Opt_noresvport, "noresvport" },
150 	{ Opt_fscache, "fsc" },
151 	{ Opt_nofscache, "nofsc" },
152 	{ Opt_migration, "migration" },
153 	{ Opt_nomigration, "nomigration" },
154 
155 	{ Opt_port, "port=%s" },
156 	{ Opt_rsize, "rsize=%s" },
157 	{ Opt_wsize, "wsize=%s" },
158 	{ Opt_bsize, "bsize=%s" },
159 	{ Opt_timeo, "timeo=%s" },
160 	{ Opt_retrans, "retrans=%s" },
161 	{ Opt_acregmin, "acregmin=%s" },
162 	{ Opt_acregmax, "acregmax=%s" },
163 	{ Opt_acdirmin, "acdirmin=%s" },
164 	{ Opt_acdirmax, "acdirmax=%s" },
165 	{ Opt_actimeo, "actimeo=%s" },
166 	{ Opt_namelen, "namlen=%s" },
167 	{ Opt_mountport, "mountport=%s" },
168 	{ Opt_mountvers, "mountvers=%s" },
169 	{ Opt_minorversion, "minorversion=%s" },
170 
171 	{ Opt_nfsvers, "nfsvers=%s" },
172 	{ Opt_nfsvers, "vers=%s" },
173 
174 	{ Opt_sec, "sec=%s" },
175 	{ Opt_proto, "proto=%s" },
176 	{ Opt_mountproto, "mountproto=%s" },
177 	{ Opt_addr, "addr=%s" },
178 	{ Opt_clientaddr, "clientaddr=%s" },
179 	{ Opt_mounthost, "mounthost=%s" },
180 	{ Opt_mountaddr, "mountaddr=%s" },
181 
182 	{ Opt_lookupcache, "lookupcache=%s" },
183 	{ Opt_fscache_uniq, "fsc=%s" },
184 	{ Opt_local_lock, "local_lock=%s" },
185 
186 	/* The following needs to be listed after all other options */
187 	{ Opt_nfsvers, "v%s" },
188 
189 	{ Opt_err, NULL }
190 };
191 
192 enum {
193 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
194 	Opt_xprt_rdma6,
195 
196 	Opt_xprt_err
197 };
198 
199 static const match_table_t nfs_xprt_protocol_tokens = {
200 	{ Opt_xprt_udp, "udp" },
201 	{ Opt_xprt_udp6, "udp6" },
202 	{ Opt_xprt_tcp, "tcp" },
203 	{ Opt_xprt_tcp6, "tcp6" },
204 	{ Opt_xprt_rdma, "rdma" },
205 	{ Opt_xprt_rdma6, "rdma6" },
206 
207 	{ Opt_xprt_err, NULL }
208 };
209 
210 enum {
211 	Opt_sec_none, Opt_sec_sys,
212 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
213 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
214 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
215 
216 	Opt_sec_err
217 };
218 
219 static const match_table_t nfs_secflavor_tokens = {
220 	{ Opt_sec_none, "none" },
221 	{ Opt_sec_none, "null" },
222 	{ Opt_sec_sys, "sys" },
223 
224 	{ Opt_sec_krb5, "krb5" },
225 	{ Opt_sec_krb5i, "krb5i" },
226 	{ Opt_sec_krb5p, "krb5p" },
227 
228 	{ Opt_sec_lkey, "lkey" },
229 	{ Opt_sec_lkeyi, "lkeyi" },
230 	{ Opt_sec_lkeyp, "lkeyp" },
231 
232 	{ Opt_sec_spkm, "spkm3" },
233 	{ Opt_sec_spkmi, "spkm3i" },
234 	{ Opt_sec_spkmp, "spkm3p" },
235 
236 	{ Opt_sec_err, NULL }
237 };
238 
239 enum {
240 	Opt_lookupcache_all, Opt_lookupcache_positive,
241 	Opt_lookupcache_none,
242 
243 	Opt_lookupcache_err
244 };
245 
246 static match_table_t nfs_lookupcache_tokens = {
247 	{ Opt_lookupcache_all, "all" },
248 	{ Opt_lookupcache_positive, "pos" },
249 	{ Opt_lookupcache_positive, "positive" },
250 	{ Opt_lookupcache_none, "none" },
251 
252 	{ Opt_lookupcache_err, NULL }
253 };
254 
255 enum {
256 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
257 	Opt_local_lock_none,
258 
259 	Opt_local_lock_err
260 };
261 
262 static match_table_t nfs_local_lock_tokens = {
263 	{ Opt_local_lock_all, "all" },
264 	{ Opt_local_lock_flock, "flock" },
265 	{ Opt_local_lock_posix, "posix" },
266 	{ Opt_local_lock_none, "none" },
267 
268 	{ Opt_local_lock_err, NULL }
269 };
270 
271 enum {
272 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
273 	Opt_vers_4_1, Opt_vers_4_2,
274 
275 	Opt_vers_err
276 };
277 
278 static match_table_t nfs_vers_tokens = {
279 	{ Opt_vers_2, "2" },
280 	{ Opt_vers_3, "3" },
281 	{ Opt_vers_4, "4" },
282 	{ Opt_vers_4_0, "4.0" },
283 	{ Opt_vers_4_1, "4.1" },
284 	{ Opt_vers_4_2, "4.2" },
285 
286 	{ Opt_vers_err, NULL }
287 };
288 
289 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
290 		int flags, const char *dev_name, void *raw_data);
291 
292 struct file_system_type nfs_fs_type = {
293 	.owner		= THIS_MODULE,
294 	.name		= "nfs",
295 	.mount		= nfs_fs_mount,
296 	.kill_sb	= nfs_kill_super,
297 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
298 };
299 MODULE_ALIAS_FS("nfs");
300 EXPORT_SYMBOL_GPL(nfs_fs_type);
301 
302 struct file_system_type nfs_xdev_fs_type = {
303 	.owner		= THIS_MODULE,
304 	.name		= "nfs",
305 	.mount		= nfs_xdev_mount,
306 	.kill_sb	= nfs_kill_super,
307 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
308 };
309 
310 const struct super_operations nfs_sops = {
311 	.alloc_inode	= nfs_alloc_inode,
312 	.destroy_inode	= nfs_destroy_inode,
313 	.write_inode	= nfs_write_inode,
314 	.drop_inode	= nfs_drop_inode,
315 	.statfs		= nfs_statfs,
316 	.evict_inode	= nfs_evict_inode,
317 	.umount_begin	= nfs_umount_begin,
318 	.show_options	= nfs_show_options,
319 	.show_devname	= nfs_show_devname,
320 	.show_path	= nfs_show_path,
321 	.show_stats	= nfs_show_stats,
322 	.remount_fs	= nfs_remount,
323 };
324 EXPORT_SYMBOL_GPL(nfs_sops);
325 
326 #if IS_ENABLED(CONFIG_NFS_V4)
327 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
328 static int nfs4_validate_mount_data(void *options,
329 	struct nfs_parsed_mount_data *args, const char *dev_name);
330 
331 struct file_system_type nfs4_fs_type = {
332 	.owner		= THIS_MODULE,
333 	.name		= "nfs4",
334 	.mount		= nfs_fs_mount,
335 	.kill_sb	= nfs_kill_super,
336 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
337 };
338 MODULE_ALIAS_FS("nfs4");
339 MODULE_ALIAS("nfs4");
340 EXPORT_SYMBOL_GPL(nfs4_fs_type);
341 
342 static int __init register_nfs4_fs(void)
343 {
344 	return register_filesystem(&nfs4_fs_type);
345 }
346 
347 static void unregister_nfs4_fs(void)
348 {
349 	unregister_filesystem(&nfs4_fs_type);
350 }
351 #else
352 static int __init register_nfs4_fs(void)
353 {
354 	return 0;
355 }
356 
357 static void unregister_nfs4_fs(void)
358 {
359 }
360 #endif
361 
362 static struct shrinker acl_shrinker = {
363 	.count_objects	= nfs_access_cache_count,
364 	.scan_objects	= nfs_access_cache_scan,
365 	.seeks		= DEFAULT_SEEKS,
366 };
367 
368 /*
369  * Register the NFS filesystems
370  */
371 int __init register_nfs_fs(void)
372 {
373 	int ret;
374 
375         ret = register_filesystem(&nfs_fs_type);
376 	if (ret < 0)
377 		goto error_0;
378 
379 	ret = register_nfs4_fs();
380 	if (ret < 0)
381 		goto error_1;
382 
383 	ret = nfs_register_sysctl();
384 	if (ret < 0)
385 		goto error_2;
386 	ret = register_shrinker(&acl_shrinker);
387 	if (ret < 0)
388 		goto error_3;
389 	return 0;
390 error_3:
391 	nfs_unregister_sysctl();
392 error_2:
393 	unregister_nfs4_fs();
394 error_1:
395 	unregister_filesystem(&nfs_fs_type);
396 error_0:
397 	return ret;
398 }
399 
400 /*
401  * Unregister the NFS filesystems
402  */
403 void __exit unregister_nfs_fs(void)
404 {
405 	unregister_shrinker(&acl_shrinker);
406 	nfs_unregister_sysctl();
407 	unregister_nfs4_fs();
408 	unregister_filesystem(&nfs_fs_type);
409 }
410 
411 bool nfs_sb_active(struct super_block *sb)
412 {
413 	struct nfs_server *server = NFS_SB(sb);
414 
415 	if (!atomic_inc_not_zero(&sb->s_active))
416 		return false;
417 	if (atomic_inc_return(&server->active) != 1)
418 		atomic_dec(&sb->s_active);
419 	return true;
420 }
421 EXPORT_SYMBOL_GPL(nfs_sb_active);
422 
423 void nfs_sb_deactive(struct super_block *sb)
424 {
425 	struct nfs_server *server = NFS_SB(sb);
426 
427 	if (atomic_dec_and_test(&server->active))
428 		deactivate_super(sb);
429 }
430 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
431 
432 /*
433  * Deliver file system statistics to userspace
434  */
435 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
436 {
437 	struct nfs_server *server = NFS_SB(dentry->d_sb);
438 	unsigned char blockbits;
439 	unsigned long blockres;
440 	struct nfs_fh *fh = NFS_FH(d_inode(dentry));
441 	struct nfs_fsstat res;
442 	int error = -ENOMEM;
443 
444 	res.fattr = nfs_alloc_fattr();
445 	if (res.fattr == NULL)
446 		goto out_err;
447 
448 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
449 	if (unlikely(error == -ESTALE)) {
450 		struct dentry *pd_dentry;
451 
452 		pd_dentry = dget_parent(dentry);
453 		if (pd_dentry != NULL) {
454 			nfs_zap_caches(d_inode(pd_dentry));
455 			dput(pd_dentry);
456 		}
457 	}
458 	nfs_free_fattr(res.fattr);
459 	if (error < 0)
460 		goto out_err;
461 
462 	buf->f_type = NFS_SUPER_MAGIC;
463 
464 	/*
465 	 * Current versions of glibc do not correctly handle the
466 	 * case where f_frsize != f_bsize.  Eventually we want to
467 	 * report the value of wtmult in this field.
468 	 */
469 	buf->f_frsize = dentry->d_sb->s_blocksize;
470 
471 	/*
472 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
473 	 * are reported in units of f_frsize.  Linux hasn't had
474 	 * an f_frsize field in its statfs struct until recently,
475 	 * thus historically Linux's sys_statfs reports these
476 	 * fields in units of f_bsize.
477 	 */
478 	buf->f_bsize = dentry->d_sb->s_blocksize;
479 	blockbits = dentry->d_sb->s_blocksize_bits;
480 	blockres = (1 << blockbits) - 1;
481 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
482 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
483 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
484 
485 	buf->f_files = res.tfiles;
486 	buf->f_ffree = res.afiles;
487 
488 	buf->f_namelen = server->namelen;
489 
490 	return 0;
491 
492  out_err:
493 	dprintk("%s: statfs error = %d\n", __func__, -error);
494 	return error;
495 }
496 EXPORT_SYMBOL_GPL(nfs_statfs);
497 
498 /*
499  * Map the security flavour number to a name
500  */
501 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
502 {
503 	static const struct {
504 		rpc_authflavor_t flavour;
505 		const char *str;
506 	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
507 		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
508 		{ RPC_AUTH_NULL, "null" },
509 		{ RPC_AUTH_UNIX, "sys" },
510 		{ RPC_AUTH_GSS_KRB5, "krb5" },
511 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
512 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
513 		{ RPC_AUTH_GSS_LKEY, "lkey" },
514 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
515 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
516 		{ RPC_AUTH_GSS_SPKM, "spkm" },
517 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
518 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
519 		{ UINT_MAX, "unknown" }
520 	};
521 	int i;
522 
523 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
524 		if (sec_flavours[i].flavour == flavour)
525 			break;
526 	}
527 	return sec_flavours[i].str;
528 }
529 
530 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
531 				  int showdefaults)
532 {
533 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
534 
535 	seq_printf(m, ",mountproto=");
536 	switch (sap->sa_family) {
537 	case AF_INET:
538 		switch (nfss->mountd_protocol) {
539 		case IPPROTO_UDP:
540 			seq_printf(m, RPCBIND_NETID_UDP);
541 			break;
542 		case IPPROTO_TCP:
543 			seq_printf(m, RPCBIND_NETID_TCP);
544 			break;
545 		default:
546 			if (showdefaults)
547 				seq_printf(m, "auto");
548 		}
549 		break;
550 	case AF_INET6:
551 		switch (nfss->mountd_protocol) {
552 		case IPPROTO_UDP:
553 			seq_printf(m, RPCBIND_NETID_UDP6);
554 			break;
555 		case IPPROTO_TCP:
556 			seq_printf(m, RPCBIND_NETID_TCP6);
557 			break;
558 		default:
559 			if (showdefaults)
560 				seq_printf(m, "auto");
561 		}
562 		break;
563 	default:
564 		if (showdefaults)
565 			seq_printf(m, "auto");
566 	}
567 }
568 
569 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
570 				    int showdefaults)
571 {
572 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
573 
574 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
575 		return;
576 
577 	switch (sap->sa_family) {
578 	case AF_INET: {
579 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
580 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
581 		break;
582 	}
583 	case AF_INET6: {
584 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
585 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
586 		break;
587 	}
588 	default:
589 		if (showdefaults)
590 			seq_printf(m, ",mountaddr=unspecified");
591 	}
592 
593 	if (nfss->mountd_version || showdefaults)
594 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
595 	if ((nfss->mountd_port &&
596 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
597 		showdefaults)
598 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
599 
600 	nfs_show_mountd_netid(m, nfss, showdefaults);
601 }
602 
603 #if IS_ENABLED(CONFIG_NFS_V4)
604 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
605 				    int showdefaults)
606 {
607 	struct nfs_client *clp = nfss->nfs_client;
608 
609 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
610 }
611 #else
612 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
613 				    int showdefaults)
614 {
615 }
616 #endif
617 
618 static void nfs_show_nfs_version(struct seq_file *m,
619 		unsigned int version,
620 		unsigned int minorversion)
621 {
622 	seq_printf(m, ",vers=%u", version);
623 	if (version == 4)
624 		seq_printf(m, ".%u", minorversion);
625 }
626 
627 /*
628  * Describe the mount options in force on this server representation
629  */
630 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
631 				   int showdefaults)
632 {
633 	static const struct proc_nfs_info {
634 		int flag;
635 		const char *str;
636 		const char *nostr;
637 	} nfs_info[] = {
638 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
639 		{ NFS_MOUNT_POSIX, ",posix", "" },
640 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
641 		{ NFS_MOUNT_NOAC, ",noac", "" },
642 		{ NFS_MOUNT_NONLM, ",nolock", "" },
643 		{ NFS_MOUNT_NOACL, ",noacl", "" },
644 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
645 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
646 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
647 		{ 0, NULL, NULL }
648 	};
649 	const struct proc_nfs_info *nfs_infop;
650 	struct nfs_client *clp = nfss->nfs_client;
651 	u32 version = clp->rpc_ops->version;
652 	int local_flock, local_fcntl;
653 
654 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
655 	seq_printf(m, ",rsize=%u", nfss->rsize);
656 	seq_printf(m, ",wsize=%u", nfss->wsize);
657 	if (nfss->bsize != 0)
658 		seq_printf(m, ",bsize=%u", nfss->bsize);
659 	seq_printf(m, ",namlen=%u", nfss->namelen);
660 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
661 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
662 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
663 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
664 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
665 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
666 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
667 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
668 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
669 		if (nfss->flags & nfs_infop->flag)
670 			seq_puts(m, nfs_infop->str);
671 		else
672 			seq_puts(m, nfs_infop->nostr);
673 	}
674 	rcu_read_lock();
675 	seq_printf(m, ",proto=%s",
676 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
677 	rcu_read_unlock();
678 	if (version == 4) {
679 		if (nfss->port != NFS_PORT)
680 			seq_printf(m, ",port=%u", nfss->port);
681 	} else
682 		if (nfss->port)
683 			seq_printf(m, ",port=%u", nfss->port);
684 
685 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
686 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
687 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
688 
689 	if (version != 4)
690 		nfs_show_mountd_options(m, nfss, showdefaults);
691 	else
692 		nfs_show_nfsv4_options(m, nfss, showdefaults);
693 
694 	if (nfss->options & NFS_OPTION_FSCACHE)
695 		seq_printf(m, ",fsc");
696 
697 	if (nfss->options & NFS_OPTION_MIGRATION)
698 		seq_printf(m, ",migration");
699 
700 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
701 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
702 			seq_printf(m, ",lookupcache=none");
703 		else
704 			seq_printf(m, ",lookupcache=pos");
705 	}
706 
707 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
708 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
709 
710 	if (!local_flock && !local_fcntl)
711 		seq_printf(m, ",local_lock=none");
712 	else if (local_flock && local_fcntl)
713 		seq_printf(m, ",local_lock=all");
714 	else if (local_flock)
715 		seq_printf(m, ",local_lock=flock");
716 	else
717 		seq_printf(m, ",local_lock=posix");
718 }
719 
720 /*
721  * Describe the mount options on this VFS mountpoint
722  */
723 int nfs_show_options(struct seq_file *m, struct dentry *root)
724 {
725 	struct nfs_server *nfss = NFS_SB(root->d_sb);
726 
727 	nfs_show_mount_options(m, nfss, 0);
728 
729 	rcu_read_lock();
730 	seq_printf(m, ",addr=%s",
731 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
732 							RPC_DISPLAY_ADDR));
733 	rcu_read_unlock();
734 
735 	return 0;
736 }
737 EXPORT_SYMBOL_GPL(nfs_show_options);
738 
739 #if IS_ENABLED(CONFIG_NFS_V4)
740 #ifdef CONFIG_NFS_V4_1
741 static void show_sessions(struct seq_file *m, struct nfs_server *server)
742 {
743 	if (nfs4_has_session(server->nfs_client))
744 		seq_printf(m, ",sessions");
745 }
746 #else
747 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
748 #endif
749 #endif
750 
751 #ifdef CONFIG_NFS_V4_1
752 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
753 {
754 	seq_printf(m, ",pnfs=");
755 	if (server->pnfs_curr_ld)
756 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
757 	else
758 		seq_printf(m, "not configured");
759 }
760 
761 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
762 {
763 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
764 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
765 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
766 			   "date='%llu,%u'",
767 			   impl_id->name, impl_id->domain,
768 			   impl_id->date.seconds, impl_id->date.nseconds);
769 	}
770 }
771 #else
772 #if IS_ENABLED(CONFIG_NFS_V4)
773 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
774 {
775 }
776 #endif
777 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
778 {
779 }
780 #endif
781 
782 int nfs_show_devname(struct seq_file *m, struct dentry *root)
783 {
784 	char *page = (char *) __get_free_page(GFP_KERNEL);
785 	char *devname, *dummy;
786 	int err = 0;
787 	if (!page)
788 		return -ENOMEM;
789 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
790 	if (IS_ERR(devname))
791 		err = PTR_ERR(devname);
792 	else
793 		seq_escape(m, devname, " \t\n\\");
794 	free_page((unsigned long)page);
795 	return err;
796 }
797 EXPORT_SYMBOL_GPL(nfs_show_devname);
798 
799 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
800 {
801 	seq_puts(m, "/");
802 	return 0;
803 }
804 EXPORT_SYMBOL_GPL(nfs_show_path);
805 
806 /*
807  * Present statistical information for this VFS mountpoint
808  */
809 int nfs_show_stats(struct seq_file *m, struct dentry *root)
810 {
811 	int i, cpu;
812 	struct nfs_server *nfss = NFS_SB(root->d_sb);
813 	struct rpc_auth *auth = nfss->client->cl_auth;
814 	struct nfs_iostats totals = { };
815 
816 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
817 
818 	/*
819 	 * Display all mount option settings
820 	 */
821 	seq_printf(m, "\n\topts:\t");
822 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
823 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
824 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
825 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
826 	nfs_show_mount_options(m, nfss, 1);
827 
828 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
829 
830 	show_implementation_id(m, nfss);
831 
832 	seq_printf(m, "\n\tcaps:\t");
833 	seq_printf(m, "caps=0x%x", nfss->caps);
834 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
835 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
836 	seq_printf(m, ",bsize=%u", nfss->bsize);
837 	seq_printf(m, ",namlen=%u", nfss->namelen);
838 
839 #if IS_ENABLED(CONFIG_NFS_V4)
840 	if (nfss->nfs_client->rpc_ops->version == 4) {
841 		seq_printf(m, "\n\tnfsv4:\t");
842 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
843 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
844 		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
845 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
846 		show_sessions(m, nfss);
847 		show_pnfs(m, nfss);
848 	}
849 #endif
850 
851 	/*
852 	 * Display security flavor in effect for this mount
853 	 */
854 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
855 	if (auth->au_flavor)
856 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
857 
858 	/*
859 	 * Display superblock I/O counters
860 	 */
861 	for_each_possible_cpu(cpu) {
862 		struct nfs_iostats *stats;
863 
864 		preempt_disable();
865 		stats = per_cpu_ptr(nfss->io_stats, cpu);
866 
867 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
868 			totals.events[i] += stats->events[i];
869 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
870 			totals.bytes[i] += stats->bytes[i];
871 #ifdef CONFIG_NFS_FSCACHE
872 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
873 			totals.fscache[i] += stats->fscache[i];
874 #endif
875 
876 		preempt_enable();
877 	}
878 
879 	seq_printf(m, "\n\tevents:\t");
880 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
881 		seq_printf(m, "%lu ", totals.events[i]);
882 	seq_printf(m, "\n\tbytes:\t");
883 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
884 		seq_printf(m, "%Lu ", totals.bytes[i]);
885 #ifdef CONFIG_NFS_FSCACHE
886 	if (nfss->options & NFS_OPTION_FSCACHE) {
887 		seq_printf(m, "\n\tfsc:\t");
888 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
889 			seq_printf(m, "%Lu ", totals.bytes[i]);
890 	}
891 #endif
892 	seq_printf(m, "\n");
893 
894 	rpc_print_iostats(m, nfss->client);
895 
896 	return 0;
897 }
898 EXPORT_SYMBOL_GPL(nfs_show_stats);
899 
900 /*
901  * Begin unmount by attempting to remove all automounted mountpoints we added
902  * in response to xdev traversals and referrals
903  */
904 void nfs_umount_begin(struct super_block *sb)
905 {
906 	struct nfs_server *server;
907 	struct rpc_clnt *rpc;
908 
909 	server = NFS_SB(sb);
910 	/* -EIO all pending I/O */
911 	rpc = server->client_acl;
912 	if (!IS_ERR(rpc))
913 		rpc_killall_tasks(rpc);
914 	rpc = server->client;
915 	if (!IS_ERR(rpc))
916 		rpc_killall_tasks(rpc);
917 }
918 EXPORT_SYMBOL_GPL(nfs_umount_begin);
919 
920 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
921 {
922 	struct nfs_parsed_mount_data *data;
923 
924 	data = kzalloc(sizeof(*data), GFP_KERNEL);
925 	if (data) {
926 		data->timeo		= NFS_UNSPEC_TIMEO;
927 		data->retrans		= NFS_UNSPEC_RETRANS;
928 		data->acregmin		= NFS_DEF_ACREGMIN;
929 		data->acregmax		= NFS_DEF_ACREGMAX;
930 		data->acdirmin		= NFS_DEF_ACDIRMIN;
931 		data->acdirmax		= NFS_DEF_ACDIRMAX;
932 		data->mount_server.port	= NFS_UNSPEC_PORT;
933 		data->nfs_server.port	= NFS_UNSPEC_PORT;
934 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
935 		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
936 		data->minorversion	= 0;
937 		data->need_mount	= true;
938 		data->net		= current->nsproxy->net_ns;
939 		security_init_mnt_opts(&data->lsm_opts);
940 	}
941 	return data;
942 }
943 
944 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
945 {
946 	if (data) {
947 		kfree(data->client_address);
948 		kfree(data->mount_server.hostname);
949 		kfree(data->nfs_server.export_path);
950 		kfree(data->nfs_server.hostname);
951 		kfree(data->fscache_uniq);
952 		security_free_mnt_opts(&data->lsm_opts);
953 		kfree(data);
954 	}
955 }
956 
957 /*
958  * Sanity-check a server address provided by the mount command.
959  *
960  * Address family must be initialized, and address must not be
961  * the ANY address for that family.
962  */
963 static int nfs_verify_server_address(struct sockaddr *addr)
964 {
965 	switch (addr->sa_family) {
966 	case AF_INET: {
967 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
968 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
969 	}
970 	case AF_INET6: {
971 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
972 		return !ipv6_addr_any(sa);
973 	}
974 	}
975 
976 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
977 	return 0;
978 }
979 
980 /*
981  * Select between a default port value and a user-specified port value.
982  * If a zero value is set, then autobind will be used.
983  */
984 static void nfs_set_port(struct sockaddr *sap, int *port,
985 				 const unsigned short default_port)
986 {
987 	if (*port == NFS_UNSPEC_PORT)
988 		*port = default_port;
989 
990 	rpc_set_port(sap, *port);
991 }
992 
993 /*
994  * Sanity check the NFS transport protocol.
995  *
996  */
997 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
998 {
999 	switch (mnt->nfs_server.protocol) {
1000 	case XPRT_TRANSPORT_UDP:
1001 	case XPRT_TRANSPORT_TCP:
1002 	case XPRT_TRANSPORT_RDMA:
1003 		break;
1004 	default:
1005 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1006 	}
1007 }
1008 
1009 /*
1010  * For text based NFSv2/v3 mounts, the mount protocol transport default
1011  * settings should depend upon the specified NFS transport.
1012  */
1013 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1014 {
1015 	nfs_validate_transport_protocol(mnt);
1016 
1017 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1018 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1019 			return;
1020 	switch (mnt->nfs_server.protocol) {
1021 	case XPRT_TRANSPORT_UDP:
1022 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1023 		break;
1024 	case XPRT_TRANSPORT_TCP:
1025 	case XPRT_TRANSPORT_RDMA:
1026 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1027 	}
1028 }
1029 
1030 /*
1031  * Add 'flavor' to 'auth_info' if not already present.
1032  * Returns true if 'flavor' ends up in the list, false otherwise
1033  */
1034 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1035 			      rpc_authflavor_t flavor)
1036 {
1037 	unsigned int i;
1038 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1039 
1040 	/* make sure this flavor isn't already in the list */
1041 	for (i = 0; i < auth_info->flavor_len; i++) {
1042 		if (flavor == auth_info->flavors[i])
1043 			return true;
1044 	}
1045 
1046 	if (auth_info->flavor_len + 1 >= max_flavor_len) {
1047 		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1048 		return false;
1049 	}
1050 
1051 	auth_info->flavors[auth_info->flavor_len++] = flavor;
1052 	return true;
1053 }
1054 
1055 /*
1056  * Return true if 'match' is in auth_info or auth_info is empty.
1057  * Return false otherwise.
1058  */
1059 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1060 			 rpc_authflavor_t match)
1061 {
1062 	int i;
1063 
1064 	if (!auth_info->flavor_len)
1065 		return true;
1066 
1067 	for (i = 0; i < auth_info->flavor_len; i++) {
1068 		if (auth_info->flavors[i] == match)
1069 			return true;
1070 	}
1071 	return false;
1072 }
1073 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1074 
1075 /*
1076  * Parse the value of the 'sec=' option.
1077  */
1078 static int nfs_parse_security_flavors(char *value,
1079 				      struct nfs_parsed_mount_data *mnt)
1080 {
1081 	substring_t args[MAX_OPT_ARGS];
1082 	rpc_authflavor_t pseudoflavor;
1083 	char *p;
1084 
1085 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1086 
1087 	while ((p = strsep(&value, ":")) != NULL) {
1088 		switch (match_token(p, nfs_secflavor_tokens, args)) {
1089 		case Opt_sec_none:
1090 			pseudoflavor = RPC_AUTH_NULL;
1091 			break;
1092 		case Opt_sec_sys:
1093 			pseudoflavor = RPC_AUTH_UNIX;
1094 			break;
1095 		case Opt_sec_krb5:
1096 			pseudoflavor = RPC_AUTH_GSS_KRB5;
1097 			break;
1098 		case Opt_sec_krb5i:
1099 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
1100 			break;
1101 		case Opt_sec_krb5p:
1102 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
1103 			break;
1104 		case Opt_sec_lkey:
1105 			pseudoflavor = RPC_AUTH_GSS_LKEY;
1106 			break;
1107 		case Opt_sec_lkeyi:
1108 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
1109 			break;
1110 		case Opt_sec_lkeyp:
1111 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
1112 			break;
1113 		case Opt_sec_spkm:
1114 			pseudoflavor = RPC_AUTH_GSS_SPKM;
1115 			break;
1116 		case Opt_sec_spkmi:
1117 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
1118 			break;
1119 		case Opt_sec_spkmp:
1120 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
1121 			break;
1122 		default:
1123 			dfprintk(MOUNT,
1124 				 "NFS: sec= option '%s' not recognized\n", p);
1125 			return 0;
1126 		}
1127 
1128 		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1129 			return 0;
1130 	}
1131 
1132 	return 1;
1133 }
1134 
1135 static int nfs_parse_version_string(char *string,
1136 		struct nfs_parsed_mount_data *mnt,
1137 		substring_t *args)
1138 {
1139 	mnt->flags &= ~NFS_MOUNT_VER3;
1140 	switch (match_token(string, nfs_vers_tokens, args)) {
1141 	case Opt_vers_2:
1142 		mnt->version = 2;
1143 		break;
1144 	case Opt_vers_3:
1145 		mnt->flags |= NFS_MOUNT_VER3;
1146 		mnt->version = 3;
1147 		break;
1148 	case Opt_vers_4:
1149 		/* Backward compatibility option. In future,
1150 		 * the mount program should always supply
1151 		 * a NFSv4 minor version number.
1152 		 */
1153 		mnt->version = 4;
1154 		break;
1155 	case Opt_vers_4_0:
1156 		mnt->version = 4;
1157 		mnt->minorversion = 0;
1158 		break;
1159 	case Opt_vers_4_1:
1160 		mnt->version = 4;
1161 		mnt->minorversion = 1;
1162 		break;
1163 	case Opt_vers_4_2:
1164 		mnt->version = 4;
1165 		mnt->minorversion = 2;
1166 		break;
1167 	default:
1168 		return 0;
1169 	}
1170 	return 1;
1171 }
1172 
1173 static int nfs_get_option_str(substring_t args[], char **option)
1174 {
1175 	kfree(*option);
1176 	*option = match_strdup(args);
1177 	return !*option;
1178 }
1179 
1180 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1181 {
1182 	int rc;
1183 	char *string;
1184 
1185 	string = match_strdup(args);
1186 	if (string == NULL)
1187 		return -ENOMEM;
1188 	rc = kstrtoul(string, 10, option);
1189 	kfree(string);
1190 
1191 	return rc;
1192 }
1193 
1194 static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
1195 		unsigned long l_bound, unsigned long u_bound)
1196 {
1197 	int ret;
1198 
1199 	ret = nfs_get_option_ul(args, option);
1200 	if (ret != 0)
1201 		return ret;
1202 	if (*option < l_bound || *option > u_bound)
1203 		return -ERANGE;
1204 	return 0;
1205 }
1206 
1207 /*
1208  * Error-check and convert a string of mount options from user space into
1209  * a data structure.  The whole mount string is processed; bad options are
1210  * skipped as they are encountered.  If there were no errors, return 1;
1211  * otherwise return 0 (zero).
1212  */
1213 static int nfs_parse_mount_options(char *raw,
1214 				   struct nfs_parsed_mount_data *mnt)
1215 {
1216 	char *p, *string, *secdata;
1217 	int rc, sloppy = 0, invalid_option = 0;
1218 	unsigned short protofamily = AF_UNSPEC;
1219 	unsigned short mountfamily = AF_UNSPEC;
1220 
1221 	if (!raw) {
1222 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1223 		return 1;
1224 	}
1225 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1226 
1227 	secdata = alloc_secdata();
1228 	if (!secdata)
1229 		goto out_nomem;
1230 
1231 	rc = security_sb_copy_data(raw, secdata);
1232 	if (rc)
1233 		goto out_security_failure;
1234 
1235 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1236 	if (rc)
1237 		goto out_security_failure;
1238 
1239 	free_secdata(secdata);
1240 
1241 	while ((p = strsep(&raw, ",")) != NULL) {
1242 		substring_t args[MAX_OPT_ARGS];
1243 		unsigned long option;
1244 		int token;
1245 
1246 		if (!*p)
1247 			continue;
1248 
1249 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1250 
1251 		token = match_token(p, nfs_mount_option_tokens, args);
1252 		switch (token) {
1253 
1254 		/*
1255 		 * boolean options:  foo/nofoo
1256 		 */
1257 		case Opt_soft:
1258 			mnt->flags |= NFS_MOUNT_SOFT;
1259 			break;
1260 		case Opt_hard:
1261 			mnt->flags &= ~NFS_MOUNT_SOFT;
1262 			break;
1263 		case Opt_posix:
1264 			mnt->flags |= NFS_MOUNT_POSIX;
1265 			break;
1266 		case Opt_noposix:
1267 			mnt->flags &= ~NFS_MOUNT_POSIX;
1268 			break;
1269 		case Opt_cto:
1270 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1271 			break;
1272 		case Opt_nocto:
1273 			mnt->flags |= NFS_MOUNT_NOCTO;
1274 			break;
1275 		case Opt_ac:
1276 			mnt->flags &= ~NFS_MOUNT_NOAC;
1277 			break;
1278 		case Opt_noac:
1279 			mnt->flags |= NFS_MOUNT_NOAC;
1280 			break;
1281 		case Opt_lock:
1282 			mnt->flags &= ~NFS_MOUNT_NONLM;
1283 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1284 					NFS_MOUNT_LOCAL_FCNTL);
1285 			break;
1286 		case Opt_nolock:
1287 			mnt->flags |= NFS_MOUNT_NONLM;
1288 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1289 				       NFS_MOUNT_LOCAL_FCNTL);
1290 			break;
1291 		case Opt_udp:
1292 			mnt->flags &= ~NFS_MOUNT_TCP;
1293 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1294 			break;
1295 		case Opt_tcp:
1296 			mnt->flags |= NFS_MOUNT_TCP;
1297 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1298 			break;
1299 		case Opt_rdma:
1300 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1301 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1302 			xprt_load_transport(p);
1303 			break;
1304 		case Opt_acl:
1305 			mnt->flags &= ~NFS_MOUNT_NOACL;
1306 			break;
1307 		case Opt_noacl:
1308 			mnt->flags |= NFS_MOUNT_NOACL;
1309 			break;
1310 		case Opt_rdirplus:
1311 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1312 			break;
1313 		case Opt_nordirplus:
1314 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1315 			break;
1316 		case Opt_sharecache:
1317 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1318 			break;
1319 		case Opt_nosharecache:
1320 			mnt->flags |= NFS_MOUNT_UNSHARED;
1321 			break;
1322 		case Opt_resvport:
1323 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1324 			break;
1325 		case Opt_noresvport:
1326 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1327 			break;
1328 		case Opt_fscache:
1329 			mnt->options |= NFS_OPTION_FSCACHE;
1330 			kfree(mnt->fscache_uniq);
1331 			mnt->fscache_uniq = NULL;
1332 			break;
1333 		case Opt_nofscache:
1334 			mnt->options &= ~NFS_OPTION_FSCACHE;
1335 			kfree(mnt->fscache_uniq);
1336 			mnt->fscache_uniq = NULL;
1337 			break;
1338 		case Opt_migration:
1339 			mnt->options |= NFS_OPTION_MIGRATION;
1340 			break;
1341 		case Opt_nomigration:
1342 			mnt->options &= NFS_OPTION_MIGRATION;
1343 			break;
1344 
1345 		/*
1346 		 * options that take numeric values
1347 		 */
1348 		case Opt_port:
1349 			if (nfs_get_option_ul(args, &option) ||
1350 			    option > USHRT_MAX)
1351 				goto out_invalid_value;
1352 			mnt->nfs_server.port = option;
1353 			break;
1354 		case Opt_rsize:
1355 			if (nfs_get_option_ul(args, &option))
1356 				goto out_invalid_value;
1357 			mnt->rsize = option;
1358 			break;
1359 		case Opt_wsize:
1360 			if (nfs_get_option_ul(args, &option))
1361 				goto out_invalid_value;
1362 			mnt->wsize = option;
1363 			break;
1364 		case Opt_bsize:
1365 			if (nfs_get_option_ul(args, &option))
1366 				goto out_invalid_value;
1367 			mnt->bsize = option;
1368 			break;
1369 		case Opt_timeo:
1370 			if (nfs_get_option_ul_bound(args, &option, 1, INT_MAX))
1371 				goto out_invalid_value;
1372 			mnt->timeo = option;
1373 			break;
1374 		case Opt_retrans:
1375 			if (nfs_get_option_ul_bound(args, &option, 0, INT_MAX))
1376 				goto out_invalid_value;
1377 			mnt->retrans = option;
1378 			break;
1379 		case Opt_acregmin:
1380 			if (nfs_get_option_ul(args, &option))
1381 				goto out_invalid_value;
1382 			mnt->acregmin = option;
1383 			break;
1384 		case Opt_acregmax:
1385 			if (nfs_get_option_ul(args, &option))
1386 				goto out_invalid_value;
1387 			mnt->acregmax = option;
1388 			break;
1389 		case Opt_acdirmin:
1390 			if (nfs_get_option_ul(args, &option))
1391 				goto out_invalid_value;
1392 			mnt->acdirmin = option;
1393 			break;
1394 		case Opt_acdirmax:
1395 			if (nfs_get_option_ul(args, &option))
1396 				goto out_invalid_value;
1397 			mnt->acdirmax = option;
1398 			break;
1399 		case Opt_actimeo:
1400 			if (nfs_get_option_ul(args, &option))
1401 				goto out_invalid_value;
1402 			mnt->acregmin = mnt->acregmax =
1403 			mnt->acdirmin = mnt->acdirmax = option;
1404 			break;
1405 		case Opt_namelen:
1406 			if (nfs_get_option_ul(args, &option))
1407 				goto out_invalid_value;
1408 			mnt->namlen = option;
1409 			break;
1410 		case Opt_mountport:
1411 			if (nfs_get_option_ul(args, &option) ||
1412 			    option > USHRT_MAX)
1413 				goto out_invalid_value;
1414 			mnt->mount_server.port = option;
1415 			break;
1416 		case Opt_mountvers:
1417 			if (nfs_get_option_ul(args, &option) ||
1418 			    option < NFS_MNT_VERSION ||
1419 			    option > NFS_MNT3_VERSION)
1420 				goto out_invalid_value;
1421 			mnt->mount_server.version = option;
1422 			break;
1423 		case Opt_minorversion:
1424 			if (nfs_get_option_ul(args, &option))
1425 				goto out_invalid_value;
1426 			if (option > NFS4_MAX_MINOR_VERSION)
1427 				goto out_invalid_value;
1428 			mnt->minorversion = option;
1429 			break;
1430 
1431 		/*
1432 		 * options that take text values
1433 		 */
1434 		case Opt_nfsvers:
1435 			string = match_strdup(args);
1436 			if (string == NULL)
1437 				goto out_nomem;
1438 			rc = nfs_parse_version_string(string, mnt, args);
1439 			kfree(string);
1440 			if (!rc)
1441 				goto out_invalid_value;
1442 			break;
1443 		case Opt_sec:
1444 			string = match_strdup(args);
1445 			if (string == NULL)
1446 				goto out_nomem;
1447 			rc = nfs_parse_security_flavors(string, mnt);
1448 			kfree(string);
1449 			if (!rc) {
1450 				dfprintk(MOUNT, "NFS:   unrecognized "
1451 						"security flavor\n");
1452 				return 0;
1453 			}
1454 			break;
1455 		case Opt_proto:
1456 			string = match_strdup(args);
1457 			if (string == NULL)
1458 				goto out_nomem;
1459 			token = match_token(string,
1460 					    nfs_xprt_protocol_tokens, args);
1461 
1462 			protofamily = AF_INET;
1463 			switch (token) {
1464 			case Opt_xprt_udp6:
1465 				protofamily = AF_INET6;
1466 			case Opt_xprt_udp:
1467 				mnt->flags &= ~NFS_MOUNT_TCP;
1468 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1469 				break;
1470 			case Opt_xprt_tcp6:
1471 				protofamily = AF_INET6;
1472 			case Opt_xprt_tcp:
1473 				mnt->flags |= NFS_MOUNT_TCP;
1474 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1475 				break;
1476 			case Opt_xprt_rdma6:
1477 				protofamily = AF_INET6;
1478 			case Opt_xprt_rdma:
1479 				/* vector side protocols to TCP */
1480 				mnt->flags |= NFS_MOUNT_TCP;
1481 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1482 				xprt_load_transport(string);
1483 				break;
1484 			default:
1485 				dfprintk(MOUNT, "NFS:   unrecognized "
1486 						"transport protocol\n");
1487 				kfree(string);
1488 				return 0;
1489 			}
1490 			kfree(string);
1491 			break;
1492 		case Opt_mountproto:
1493 			string = match_strdup(args);
1494 			if (string == NULL)
1495 				goto out_nomem;
1496 			token = match_token(string,
1497 					    nfs_xprt_protocol_tokens, args);
1498 			kfree(string);
1499 
1500 			mountfamily = AF_INET;
1501 			switch (token) {
1502 			case Opt_xprt_udp6:
1503 				mountfamily = AF_INET6;
1504 			case Opt_xprt_udp:
1505 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1506 				break;
1507 			case Opt_xprt_tcp6:
1508 				mountfamily = AF_INET6;
1509 			case Opt_xprt_tcp:
1510 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1511 				break;
1512 			case Opt_xprt_rdma: /* not used for side protocols */
1513 			default:
1514 				dfprintk(MOUNT, "NFS:   unrecognized "
1515 						"transport protocol\n");
1516 				return 0;
1517 			}
1518 			break;
1519 		case Opt_addr:
1520 			string = match_strdup(args);
1521 			if (string == NULL)
1522 				goto out_nomem;
1523 			mnt->nfs_server.addrlen =
1524 				rpc_pton(mnt->net, string, strlen(string),
1525 					(struct sockaddr *)
1526 					&mnt->nfs_server.address,
1527 					sizeof(mnt->nfs_server.address));
1528 			kfree(string);
1529 			if (mnt->nfs_server.addrlen == 0)
1530 				goto out_invalid_address;
1531 			break;
1532 		case Opt_clientaddr:
1533 			if (nfs_get_option_str(args, &mnt->client_address))
1534 				goto out_nomem;
1535 			break;
1536 		case Opt_mounthost:
1537 			if (nfs_get_option_str(args,
1538 					       &mnt->mount_server.hostname))
1539 				goto out_nomem;
1540 			break;
1541 		case Opt_mountaddr:
1542 			string = match_strdup(args);
1543 			if (string == NULL)
1544 				goto out_nomem;
1545 			mnt->mount_server.addrlen =
1546 				rpc_pton(mnt->net, string, strlen(string),
1547 					(struct sockaddr *)
1548 					&mnt->mount_server.address,
1549 					sizeof(mnt->mount_server.address));
1550 			kfree(string);
1551 			if (mnt->mount_server.addrlen == 0)
1552 				goto out_invalid_address;
1553 			break;
1554 		case Opt_lookupcache:
1555 			string = match_strdup(args);
1556 			if (string == NULL)
1557 				goto out_nomem;
1558 			token = match_token(string,
1559 					nfs_lookupcache_tokens, args);
1560 			kfree(string);
1561 			switch (token) {
1562 				case Opt_lookupcache_all:
1563 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1564 					break;
1565 				case Opt_lookupcache_positive:
1566 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1567 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1568 					break;
1569 				case Opt_lookupcache_none:
1570 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1571 					break;
1572 				default:
1573 					dfprintk(MOUNT, "NFS:   invalid "
1574 							"lookupcache argument\n");
1575 					return 0;
1576 			};
1577 			break;
1578 		case Opt_fscache_uniq:
1579 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1580 				goto out_nomem;
1581 			mnt->options |= NFS_OPTION_FSCACHE;
1582 			break;
1583 		case Opt_local_lock:
1584 			string = match_strdup(args);
1585 			if (string == NULL)
1586 				goto out_nomem;
1587 			token = match_token(string, nfs_local_lock_tokens,
1588 					args);
1589 			kfree(string);
1590 			switch (token) {
1591 			case Opt_local_lock_all:
1592 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1593 					       NFS_MOUNT_LOCAL_FCNTL);
1594 				break;
1595 			case Opt_local_lock_flock:
1596 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1597 				break;
1598 			case Opt_local_lock_posix:
1599 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1600 				break;
1601 			case Opt_local_lock_none:
1602 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1603 						NFS_MOUNT_LOCAL_FCNTL);
1604 				break;
1605 			default:
1606 				dfprintk(MOUNT, "NFS:	invalid	"
1607 						"local_lock argument\n");
1608 				return 0;
1609 			};
1610 			break;
1611 
1612 		/*
1613 		 * Special options
1614 		 */
1615 		case Opt_sloppy:
1616 			sloppy = 1;
1617 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1618 			break;
1619 		case Opt_userspace:
1620 		case Opt_deprecated:
1621 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1622 					"'%s'\n", p);
1623 			break;
1624 
1625 		default:
1626 			invalid_option = 1;
1627 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1628 					"'%s'\n", p);
1629 		}
1630 	}
1631 
1632 	if (!sloppy && invalid_option)
1633 		return 0;
1634 
1635 	if (mnt->minorversion && mnt->version != 4)
1636 		goto out_minorversion_mismatch;
1637 
1638 	if (mnt->options & NFS_OPTION_MIGRATION &&
1639 	    (mnt->version != 4 || mnt->minorversion != 0))
1640 		goto out_migration_misuse;
1641 
1642 	/*
1643 	 * verify that any proto=/mountproto= options match the address
1644 	 * families in the addr=/mountaddr= options.
1645 	 */
1646 	if (protofamily != AF_UNSPEC &&
1647 	    protofamily != mnt->nfs_server.address.ss_family)
1648 		goto out_proto_mismatch;
1649 
1650 	if (mountfamily != AF_UNSPEC) {
1651 		if (mnt->mount_server.addrlen) {
1652 			if (mountfamily != mnt->mount_server.address.ss_family)
1653 				goto out_mountproto_mismatch;
1654 		} else {
1655 			if (mountfamily != mnt->nfs_server.address.ss_family)
1656 				goto out_mountproto_mismatch;
1657 		}
1658 	}
1659 
1660 	return 1;
1661 
1662 out_mountproto_mismatch:
1663 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1664 			 "option\n");
1665 	return 0;
1666 out_proto_mismatch:
1667 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1668 	return 0;
1669 out_invalid_address:
1670 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1671 	return 0;
1672 out_invalid_value:
1673 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1674 	return 0;
1675 out_minorversion_mismatch:
1676 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1677 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1678 	return 0;
1679 out_migration_misuse:
1680 	printk(KERN_INFO
1681 		"NFS: 'migration' not supported for this NFS version\n");
1682 	return 0;
1683 out_nomem:
1684 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1685 	return 0;
1686 out_security_failure:
1687 	free_secdata(secdata);
1688 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1689 	return 0;
1690 }
1691 
1692 /*
1693  * Ensure that a specified authtype in args->auth_info is supported by
1694  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1695  * -EACCES if not.
1696  */
1697 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1698 			rpc_authflavor_t *server_authlist, unsigned int count)
1699 {
1700 	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1701 	unsigned int i;
1702 	int use_auth_null = false;
1703 
1704 	/*
1705 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1706 	 * must be in the list returned by the server.
1707 	 *
1708 	 * AUTH_NULL has a special meaning when it's in the server list - it
1709 	 * means that the server will ignore the rpc creds, so any flavor
1710 	 * can be used but still use the sec= that was specified.
1711 	 */
1712 	for (i = 0; i < count; i++) {
1713 		flavor = server_authlist[i];
1714 
1715 		if (nfs_auth_info_match(&args->auth_info, flavor))
1716 			goto out;
1717 
1718 		if (flavor == RPC_AUTH_NULL)
1719 			use_auth_null = true;
1720 	}
1721 
1722 	if (use_auth_null) {
1723 		flavor = RPC_AUTH_NULL;
1724 		goto out;
1725 	}
1726 
1727 	dfprintk(MOUNT,
1728 		 "NFS: specified auth flavors not supported by server\n");
1729 	return -EACCES;
1730 
1731 out:
1732 	args->selected_flavor = flavor;
1733 	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1734 	return 0;
1735 }
1736 
1737 /*
1738  * Use the remote server's MOUNT service to request the NFS file handle
1739  * corresponding to the provided path.
1740  */
1741 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1742 			     struct nfs_fh *root_fh,
1743 			     rpc_authflavor_t *server_authlist,
1744 			     unsigned int *server_authlist_len)
1745 {
1746 	struct nfs_mount_request request = {
1747 		.sap		= (struct sockaddr *)
1748 						&args->mount_server.address,
1749 		.dirpath	= args->nfs_server.export_path,
1750 		.protocol	= args->mount_server.protocol,
1751 		.fh		= root_fh,
1752 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1753 		.auth_flav_len	= server_authlist_len,
1754 		.auth_flavs	= server_authlist,
1755 		.net		= args->net,
1756 	};
1757 	int status;
1758 
1759 	if (args->mount_server.version == 0) {
1760 		switch (args->version) {
1761 			default:
1762 				args->mount_server.version = NFS_MNT3_VERSION;
1763 				break;
1764 			case 2:
1765 				args->mount_server.version = NFS_MNT_VERSION;
1766 		}
1767 	}
1768 	request.version = args->mount_server.version;
1769 
1770 	if (args->mount_server.hostname)
1771 		request.hostname = args->mount_server.hostname;
1772 	else
1773 		request.hostname = args->nfs_server.hostname;
1774 
1775 	/*
1776 	 * Construct the mount server's address.
1777 	 */
1778 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1779 		memcpy(request.sap, &args->nfs_server.address,
1780 		       args->nfs_server.addrlen);
1781 		args->mount_server.addrlen = args->nfs_server.addrlen;
1782 	}
1783 	request.salen = args->mount_server.addrlen;
1784 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1785 
1786 	/*
1787 	 * Now ask the mount server to map our export path
1788 	 * to a file handle.
1789 	 */
1790 	status = nfs_mount(&request);
1791 	if (status != 0) {
1792 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1793 				request.hostname, status);
1794 		return status;
1795 	}
1796 
1797 	return 0;
1798 }
1799 
1800 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1801 					struct nfs_subversion *nfs_mod)
1802 {
1803 	int status;
1804 	unsigned int i;
1805 	bool tried_auth_unix = false;
1806 	bool auth_null_in_list = false;
1807 	struct nfs_server *server = ERR_PTR(-EACCES);
1808 	struct nfs_parsed_mount_data *args = mount_info->parsed;
1809 	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1810 	unsigned int authlist_len = ARRAY_SIZE(authlist);
1811 
1812 	status = nfs_request_mount(args, mount_info->mntfh, authlist,
1813 					&authlist_len);
1814 	if (status)
1815 		return ERR_PTR(status);
1816 
1817 	/*
1818 	 * Was a sec= authflavor specified in the options? First, verify
1819 	 * whether the server supports it, and then just try to use it if so.
1820 	 */
1821 	if (args->auth_info.flavor_len > 0) {
1822 		status = nfs_verify_authflavors(args, authlist, authlist_len);
1823 		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1824 			 args->selected_flavor);
1825 		if (status)
1826 			return ERR_PTR(status);
1827 		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1828 	}
1829 
1830 	/*
1831 	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
1832 	 * SHOULD prefer the flavor listed first. However, some servers list
1833 	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1834 	 */
1835 	for (i = 0; i < authlist_len; ++i) {
1836 		rpc_authflavor_t flavor;
1837 		struct rpcsec_gss_info info;
1838 
1839 		flavor = authlist[i];
1840 		switch (flavor) {
1841 		case RPC_AUTH_UNIX:
1842 			tried_auth_unix = true;
1843 			break;
1844 		case RPC_AUTH_NULL:
1845 			auth_null_in_list = true;
1846 			continue;
1847 		default:
1848 			if (rpcauth_get_gssinfo(flavor, &info) != 0)
1849 				continue;
1850 			/* Fallthrough */
1851 		}
1852 		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1853 		args->selected_flavor = flavor;
1854 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1855 		if (!IS_ERR(server))
1856 			return server;
1857 	}
1858 
1859 	/*
1860 	 * Nothing we tried so far worked. At this point, give up if we've
1861 	 * already tried AUTH_UNIX or if the server's list doesn't contain
1862 	 * AUTH_NULL
1863 	 */
1864 	if (tried_auth_unix || !auth_null_in_list)
1865 		return server;
1866 
1867 	/* Last chance! Try AUTH_UNIX */
1868 	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1869 	args->selected_flavor = RPC_AUTH_UNIX;
1870 	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1871 }
1872 
1873 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1874 			     struct nfs_mount_info *mount_info,
1875 			     struct nfs_subversion *nfs_mod)
1876 {
1877 	struct nfs_server *server;
1878 
1879 	if (mount_info->parsed->need_mount)
1880 		server = nfs_try_mount_request(mount_info, nfs_mod);
1881 	else
1882 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1883 
1884 	if (IS_ERR(server))
1885 		return ERR_CAST(server);
1886 
1887 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1888 }
1889 EXPORT_SYMBOL_GPL(nfs_try_mount);
1890 
1891 /*
1892  * Split "dev_name" into "hostname:export_path".
1893  *
1894  * The leftmost colon demarks the split between the server's hostname
1895  * and the export path.  If the hostname starts with a left square
1896  * bracket, then it may contain colons.
1897  *
1898  * Note: caller frees hostname and export path, even on error.
1899  */
1900 static int nfs_parse_devname(const char *dev_name,
1901 			     char **hostname, size_t maxnamlen,
1902 			     char **export_path, size_t maxpathlen)
1903 {
1904 	size_t len;
1905 	char *end;
1906 
1907 	/* Is the host name protected with square brakcets? */
1908 	if (*dev_name == '[') {
1909 		end = strchr(++dev_name, ']');
1910 		if (end == NULL || end[1] != ':')
1911 			goto out_bad_devname;
1912 
1913 		len = end - dev_name;
1914 		end++;
1915 	} else {
1916 		char *comma;
1917 
1918 		end = strchr(dev_name, ':');
1919 		if (end == NULL)
1920 			goto out_bad_devname;
1921 		len = end - dev_name;
1922 
1923 		/* kill possible hostname list: not supported */
1924 		comma = strchr(dev_name, ',');
1925 		if (comma != NULL && comma < end)
1926 			*comma = 0;
1927 	}
1928 
1929 	if (len > maxnamlen)
1930 		goto out_hostname;
1931 
1932 	/* N.B. caller will free nfs_server.hostname in all cases */
1933 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1934 	if (*hostname == NULL)
1935 		goto out_nomem;
1936 	len = strlen(++end);
1937 	if (len > maxpathlen)
1938 		goto out_path;
1939 	*export_path = kstrndup(end, len, GFP_KERNEL);
1940 	if (!*export_path)
1941 		goto out_nomem;
1942 
1943 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1944 	return 0;
1945 
1946 out_bad_devname:
1947 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1948 	return -EINVAL;
1949 
1950 out_nomem:
1951 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1952 	return -ENOMEM;
1953 
1954 out_hostname:
1955 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1956 	return -ENAMETOOLONG;
1957 
1958 out_path:
1959 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1960 	return -ENAMETOOLONG;
1961 }
1962 
1963 /*
1964  * Validate the NFS2/NFS3 mount data
1965  * - fills in the mount root filehandle
1966  *
1967  * For option strings, user space handles the following behaviors:
1968  *
1969  * + DNS: mapping server host name to IP address ("addr=" option)
1970  *
1971  * + failure mode: how to behave if a mount request can't be handled
1972  *   immediately ("fg/bg" option)
1973  *
1974  * + retry: how often to retry a mount request ("retry=" option)
1975  *
1976  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1977  *   mountproto=tcp after mountproto=udp, and so on
1978  */
1979 static int nfs23_validate_mount_data(void *options,
1980 				     struct nfs_parsed_mount_data *args,
1981 				     struct nfs_fh *mntfh,
1982 				     const char *dev_name)
1983 {
1984 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1985 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1986 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1987 
1988 	if (data == NULL)
1989 		goto out_no_data;
1990 
1991 	args->version = NFS_DEFAULT_VERSION;
1992 	switch (data->version) {
1993 	case 1:
1994 		data->namlen = 0;
1995 	case 2:
1996 		data->bsize = 0;
1997 	case 3:
1998 		if (data->flags & NFS_MOUNT_VER3)
1999 			goto out_no_v3;
2000 		data->root.size = NFS2_FHSIZE;
2001 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
2002 		/* Turn off security negotiation */
2003 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
2004 	case 4:
2005 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2006 			goto out_no_sec;
2007 	case 5:
2008 		memset(data->context, 0, sizeof(data->context));
2009 	case 6:
2010 		if (data->flags & NFS_MOUNT_VER3) {
2011 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
2012 				goto out_invalid_fh;
2013 			mntfh->size = data->root.size;
2014 			args->version = 3;
2015 		} else {
2016 			mntfh->size = NFS2_FHSIZE;
2017 			args->version = 2;
2018 		}
2019 
2020 
2021 		memcpy(mntfh->data, data->root.data, mntfh->size);
2022 		if (mntfh->size < sizeof(mntfh->data))
2023 			memset(mntfh->data + mntfh->size, 0,
2024 			       sizeof(mntfh->data) - mntfh->size);
2025 
2026 		/*
2027 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
2028 		 * can deal with.
2029 		 */
2030 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
2031 		args->flags		|= extra_flags;
2032 		args->rsize		= data->rsize;
2033 		args->wsize		= data->wsize;
2034 		args->timeo		= data->timeo;
2035 		args->retrans		= data->retrans;
2036 		args->acregmin		= data->acregmin;
2037 		args->acregmax		= data->acregmax;
2038 		args->acdirmin		= data->acdirmin;
2039 		args->acdirmax		= data->acdirmax;
2040 		args->need_mount	= false;
2041 
2042 		memcpy(sap, &data->addr, sizeof(data->addr));
2043 		args->nfs_server.addrlen = sizeof(data->addr);
2044 		args->nfs_server.port = ntohs(data->addr.sin_port);
2045 		if (!nfs_verify_server_address(sap))
2046 			goto out_no_address;
2047 
2048 		if (!(data->flags & NFS_MOUNT_TCP))
2049 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2050 		/* N.B. caller will free nfs_server.hostname in all cases */
2051 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2052 		args->namlen		= data->namlen;
2053 		args->bsize		= data->bsize;
2054 
2055 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2056 			args->selected_flavor = data->pseudoflavor;
2057 		else
2058 			args->selected_flavor = RPC_AUTH_UNIX;
2059 		if (!args->nfs_server.hostname)
2060 			goto out_nomem;
2061 
2062 		if (!(data->flags & NFS_MOUNT_NONLM))
2063 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2064 					 NFS_MOUNT_LOCAL_FCNTL);
2065 		else
2066 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2067 					NFS_MOUNT_LOCAL_FCNTL);
2068 		/*
2069 		 * The legacy version 6 binary mount data from userspace has a
2070 		 * field used only to transport selinux information into the
2071 		 * the kernel.  To continue to support that functionality we
2072 		 * have a touch of selinux knowledge here in the NFS code. The
2073 		 * userspace code converted context=blah to just blah so we are
2074 		 * converting back to the full string selinux understands.
2075 		 */
2076 		if (data->context[0]){
2077 #ifdef CONFIG_SECURITY_SELINUX
2078 			int rc;
2079 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
2080 			if (!opts_str)
2081 				return -ENOMEM;
2082 			strcpy(opts_str, "context=");
2083 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2084 			strcat(opts_str, &data->context[0]);
2085 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
2086 			kfree(opts_str);
2087 			if (rc)
2088 				return rc;
2089 #else
2090 			return -EINVAL;
2091 #endif
2092 		}
2093 
2094 		break;
2095 	default:
2096 		return NFS_TEXT_DATA;
2097 	}
2098 
2099 	return 0;
2100 
2101 out_no_data:
2102 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2103 	return -EINVAL;
2104 
2105 out_no_v3:
2106 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2107 		 data->version);
2108 	return -EINVAL;
2109 
2110 out_no_sec:
2111 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2112 	return -EINVAL;
2113 
2114 out_nomem:
2115 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2116 	return -ENOMEM;
2117 
2118 out_no_address:
2119 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2120 	return -EINVAL;
2121 
2122 out_invalid_fh:
2123 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2124 	return -EINVAL;
2125 }
2126 
2127 #if IS_ENABLED(CONFIG_NFS_V4)
2128 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2129 				   void *options,
2130 				   struct nfs_parsed_mount_data *args,
2131 				   struct nfs_fh *mntfh,
2132 				   const char *dev_name)
2133 {
2134 	if (fs_type == &nfs_fs_type)
2135 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2136 	return nfs4_validate_mount_data(options, args, dev_name);
2137 }
2138 #else
2139 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2140 				   void *options,
2141 				   struct nfs_parsed_mount_data *args,
2142 				   struct nfs_fh *mntfh,
2143 				   const char *dev_name)
2144 {
2145 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2146 }
2147 #endif
2148 
2149 static int nfs_validate_text_mount_data(void *options,
2150 					struct nfs_parsed_mount_data *args,
2151 					const char *dev_name)
2152 {
2153 	int port = 0;
2154 	int max_namelen = PAGE_SIZE;
2155 	int max_pathlen = NFS_MAXPATHLEN;
2156 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2157 
2158 	if (nfs_parse_mount_options((char *)options, args) == 0)
2159 		return -EINVAL;
2160 
2161 	if (!nfs_verify_server_address(sap))
2162 		goto out_no_address;
2163 
2164 	if (args->version == 4) {
2165 #if IS_ENABLED(CONFIG_NFS_V4)
2166 		port = NFS_PORT;
2167 		max_namelen = NFS4_MAXNAMLEN;
2168 		max_pathlen = NFS4_MAXPATHLEN;
2169 		nfs_validate_transport_protocol(args);
2170 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2171 			goto out_invalid_transport_udp;
2172 		nfs4_validate_mount_flags(args);
2173 #else
2174 		goto out_v4_not_compiled;
2175 #endif /* CONFIG_NFS_V4 */
2176 	} else
2177 		nfs_set_mount_transport_protocol(args);
2178 
2179 	nfs_set_port(sap, &args->nfs_server.port, port);
2180 
2181 	return nfs_parse_devname(dev_name,
2182 				   &args->nfs_server.hostname,
2183 				   max_namelen,
2184 				   &args->nfs_server.export_path,
2185 				   max_pathlen);
2186 
2187 #if !IS_ENABLED(CONFIG_NFS_V4)
2188 out_v4_not_compiled:
2189 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2190 	return -EPROTONOSUPPORT;
2191 #else
2192 out_invalid_transport_udp:
2193 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2194 	return -EINVAL;
2195 #endif /* !CONFIG_NFS_V4 */
2196 
2197 out_no_address:
2198 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2199 	return -EINVAL;
2200 }
2201 
2202 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2203 		| NFS_MOUNT_SECURE \
2204 		| NFS_MOUNT_TCP \
2205 		| NFS_MOUNT_VER3 \
2206 		| NFS_MOUNT_KERBEROS \
2207 		| NFS_MOUNT_NONLM \
2208 		| NFS_MOUNT_BROKEN_SUID \
2209 		| NFS_MOUNT_STRICTLOCK \
2210 		| NFS_MOUNT_LEGACY_INTERFACE)
2211 
2212 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2213 		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2214 
2215 static int
2216 nfs_compare_remount_data(struct nfs_server *nfss,
2217 			 struct nfs_parsed_mount_data *data)
2218 {
2219 	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2220 	    data->rsize != nfss->rsize ||
2221 	    data->wsize != nfss->wsize ||
2222 	    data->version != nfss->nfs_client->rpc_ops->version ||
2223 	    data->minorversion != nfss->nfs_client->cl_minorversion ||
2224 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2225 	    !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2226 	    data->acregmin != nfss->acregmin / HZ ||
2227 	    data->acregmax != nfss->acregmax / HZ ||
2228 	    data->acdirmin != nfss->acdirmin / HZ ||
2229 	    data->acdirmax != nfss->acdirmax / HZ ||
2230 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2231 	    data->nfs_server.port != nfss->port ||
2232 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2233 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2234 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2235 		return -EINVAL;
2236 
2237 	return 0;
2238 }
2239 
2240 int
2241 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2242 {
2243 	int error;
2244 	struct nfs_server *nfss = sb->s_fs_info;
2245 	struct nfs_parsed_mount_data *data;
2246 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2247 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2248 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2249 
2250 	sync_filesystem(sb);
2251 
2252 	/*
2253 	 * Userspace mount programs that send binary options generally send
2254 	 * them populated with default values. We have no way to know which
2255 	 * ones were explicitly specified. Fall back to legacy behavior and
2256 	 * just return success.
2257 	 */
2258 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2259 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2260 					   options->version <= 6))))
2261 		return 0;
2262 
2263 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2264 	if (data == NULL)
2265 		return -ENOMEM;
2266 
2267 	/* fill out struct with values from existing mount */
2268 	data->flags = nfss->flags;
2269 	data->rsize = nfss->rsize;
2270 	data->wsize = nfss->wsize;
2271 	data->retrans = nfss->client->cl_timeout->to_retries;
2272 	data->selected_flavor = nfss->client->cl_auth->au_flavor;
2273 	data->acregmin = nfss->acregmin / HZ;
2274 	data->acregmax = nfss->acregmax / HZ;
2275 	data->acdirmin = nfss->acdirmin / HZ;
2276 	data->acdirmax = nfss->acdirmax / HZ;
2277 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2278 	data->nfs_server.port = nfss->port;
2279 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2280 	data->version = nfsvers;
2281 	data->minorversion = nfss->nfs_client->cl_minorversion;
2282 	data->net = current->nsproxy->net_ns;
2283 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2284 		data->nfs_server.addrlen);
2285 
2286 	/* overwrite those values with any that were specified */
2287 	error = -EINVAL;
2288 	if (!nfs_parse_mount_options((char *)options, data))
2289 		goto out;
2290 
2291 	/*
2292 	 * noac is a special case. It implies -o sync, but that's not
2293 	 * necessarily reflected in the mtab options. do_remount_sb
2294 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2295 	 * remount options, so we have to explicitly reset it.
2296 	 */
2297 	if (data->flags & NFS_MOUNT_NOAC)
2298 		*flags |= MS_SYNCHRONOUS;
2299 
2300 	/* compare new mount options with old ones */
2301 	error = nfs_compare_remount_data(nfss, data);
2302 out:
2303 	kfree(data);
2304 	return error;
2305 }
2306 EXPORT_SYMBOL_GPL(nfs_remount);
2307 
2308 /*
2309  * Initialise the common bits of the superblock
2310  */
2311 inline void nfs_initialise_sb(struct super_block *sb)
2312 {
2313 	struct nfs_server *server = NFS_SB(sb);
2314 
2315 	sb->s_magic = NFS_SUPER_MAGIC;
2316 
2317 	/* We probably want something more informative here */
2318 	snprintf(sb->s_id, sizeof(sb->s_id),
2319 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2320 
2321 	if (sb->s_blocksize == 0)
2322 		sb->s_blocksize = nfs_block_bits(server->wsize,
2323 						 &sb->s_blocksize_bits);
2324 
2325 	sb->s_bdi = &server->backing_dev_info;
2326 
2327 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2328 }
2329 
2330 /*
2331  * Finish setting up an NFS2/3 superblock
2332  */
2333 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2334 {
2335 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2336 	struct nfs_server *server = NFS_SB(sb);
2337 
2338 	sb->s_blocksize_bits = 0;
2339 	sb->s_blocksize = 0;
2340 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2341 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2342 	if (data && data->bsize)
2343 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2344 
2345 	if (server->nfs_client->rpc_ops->version != 2) {
2346 		/* The VFS shouldn't apply the umask to mode bits. We will do
2347 		 * so ourselves when necessary.
2348 		 */
2349 		sb->s_flags |= MS_POSIXACL;
2350 		sb->s_time_gran = 1;
2351 	}
2352 
2353  	nfs_initialise_sb(sb);
2354 }
2355 EXPORT_SYMBOL_GPL(nfs_fill_super);
2356 
2357 /*
2358  * Finish setting up a cloned NFS2/3/4 superblock
2359  */
2360 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2361 {
2362 	const struct super_block *old_sb = mount_info->cloned->sb;
2363 	struct nfs_server *server = NFS_SB(sb);
2364 
2365 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2366 	sb->s_blocksize = old_sb->s_blocksize;
2367 	sb->s_maxbytes = old_sb->s_maxbytes;
2368 	sb->s_xattr = old_sb->s_xattr;
2369 	sb->s_op = old_sb->s_op;
2370 	sb->s_time_gran = 1;
2371 
2372 	if (server->nfs_client->rpc_ops->version != 2) {
2373 		/* The VFS shouldn't apply the umask to mode bits. We will do
2374 		 * so ourselves when necessary.
2375 		 */
2376 		sb->s_flags |= MS_POSIXACL;
2377 	}
2378 
2379  	nfs_initialise_sb(sb);
2380 }
2381 
2382 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2383 {
2384 	const struct nfs_server *a = s->s_fs_info;
2385 	const struct rpc_clnt *clnt_a = a->client;
2386 	const struct rpc_clnt *clnt_b = b->client;
2387 
2388 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2389 		goto Ebusy;
2390 	if (a->nfs_client != b->nfs_client)
2391 		goto Ebusy;
2392 	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2393 		goto Ebusy;
2394 	if (a->wsize != b->wsize)
2395 		goto Ebusy;
2396 	if (a->rsize != b->rsize)
2397 		goto Ebusy;
2398 	if (a->acregmin != b->acregmin)
2399 		goto Ebusy;
2400 	if (a->acregmax != b->acregmax)
2401 		goto Ebusy;
2402 	if (a->acdirmin != b->acdirmin)
2403 		goto Ebusy;
2404 	if (a->acdirmax != b->acdirmax)
2405 		goto Ebusy;
2406 	if (b->auth_info.flavor_len > 0 &&
2407 	   clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2408 		goto Ebusy;
2409 	return 1;
2410 Ebusy:
2411 	return 0;
2412 }
2413 
2414 struct nfs_sb_mountdata {
2415 	struct nfs_server *server;
2416 	int mntflags;
2417 };
2418 
2419 static int nfs_set_super(struct super_block *s, void *data)
2420 {
2421 	struct nfs_sb_mountdata *sb_mntdata = data;
2422 	struct nfs_server *server = sb_mntdata->server;
2423 	int ret;
2424 
2425 	s->s_flags = sb_mntdata->mntflags;
2426 	s->s_fs_info = server;
2427 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2428 	ret = set_anon_super(s, server);
2429 	if (ret == 0)
2430 		server->s_dev = s->s_dev;
2431 	return ret;
2432 }
2433 
2434 static int nfs_compare_super_address(struct nfs_server *server1,
2435 				     struct nfs_server *server2)
2436 {
2437 	struct sockaddr *sap1, *sap2;
2438 	struct rpc_xprt *xprt1 = server1->client->cl_xprt;
2439 	struct rpc_xprt *xprt2 = server2->client->cl_xprt;
2440 
2441 	if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
2442 		return 0;
2443 
2444 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2445 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2446 
2447 	if (sap1->sa_family != sap2->sa_family)
2448 		return 0;
2449 
2450 	switch (sap1->sa_family) {
2451 	case AF_INET: {
2452 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2453 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2454 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2455 			return 0;
2456 		if (sin1->sin_port != sin2->sin_port)
2457 			return 0;
2458 		break;
2459 	}
2460 	case AF_INET6: {
2461 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2462 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2463 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2464 			return 0;
2465 		if (sin1->sin6_port != sin2->sin6_port)
2466 			return 0;
2467 		break;
2468 	}
2469 	default:
2470 		return 0;
2471 	}
2472 
2473 	return 1;
2474 }
2475 
2476 static int nfs_compare_super(struct super_block *sb, void *data)
2477 {
2478 	struct nfs_sb_mountdata *sb_mntdata = data;
2479 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2480 	int mntflags = sb_mntdata->mntflags;
2481 
2482 	if (!nfs_compare_super_address(old, server))
2483 		return 0;
2484 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2485 	if (old->flags & NFS_MOUNT_UNSHARED)
2486 		return 0;
2487 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2488 		return 0;
2489 	return nfs_compare_mount_options(sb, server, mntflags);
2490 }
2491 
2492 #ifdef CONFIG_NFS_FSCACHE
2493 static void nfs_get_cache_cookie(struct super_block *sb,
2494 				 struct nfs_parsed_mount_data *parsed,
2495 				 struct nfs_clone_mount *cloned)
2496 {
2497 	struct nfs_server *nfss = NFS_SB(sb);
2498 	char *uniq = NULL;
2499 	int ulen = 0;
2500 
2501 	nfss->fscache_key = NULL;
2502 	nfss->fscache = NULL;
2503 
2504 	if (parsed) {
2505 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2506 			return;
2507 		if (parsed->fscache_uniq) {
2508 			uniq = parsed->fscache_uniq;
2509 			ulen = strlen(parsed->fscache_uniq);
2510 		}
2511 	} else if (cloned) {
2512 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2513 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2514 			return;
2515 		if (mnt_s->fscache_key) {
2516 			uniq = mnt_s->fscache_key->key.uniquifier;
2517 			ulen = mnt_s->fscache_key->key.uniq_len;
2518 		};
2519 	} else
2520 		return;
2521 
2522 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2523 }
2524 #else
2525 static void nfs_get_cache_cookie(struct super_block *sb,
2526 				 struct nfs_parsed_mount_data *parsed,
2527 				 struct nfs_clone_mount *cloned)
2528 {
2529 }
2530 #endif
2531 
2532 static int nfs_bdi_register(struct nfs_server *server)
2533 {
2534 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2535 }
2536 
2537 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2538 			struct nfs_mount_info *mount_info)
2539 {
2540 	int error;
2541 	unsigned long kflags = 0, kflags_out = 0;
2542 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2543 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2544 
2545 	error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
2546 						kflags, &kflags_out);
2547 	if (error)
2548 		goto err;
2549 
2550 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2551 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2552 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2553 err:
2554 	return error;
2555 }
2556 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2557 
2558 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2559 			  struct nfs_mount_info *mount_info)
2560 {
2561 	/* clone any lsm security options from the parent to the new sb */
2562 	if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2563 		return -ESTALE;
2564 	return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2565 }
2566 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2567 
2568 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2569 				   int flags, const char *dev_name,
2570 				   struct nfs_mount_info *mount_info,
2571 				   struct nfs_subversion *nfs_mod)
2572 {
2573 	struct super_block *s;
2574 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2575 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2576 	struct nfs_sb_mountdata sb_mntdata = {
2577 		.mntflags = flags,
2578 		.server = server,
2579 	};
2580 	int error;
2581 
2582 	if (server->flags & NFS_MOUNT_UNSHARED)
2583 		compare_super = NULL;
2584 
2585 	/* -o noac implies -o sync */
2586 	if (server->flags & NFS_MOUNT_NOAC)
2587 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2588 
2589 	if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2590 		if (mount_info->cloned->sb->s_flags & MS_SYNCHRONOUS)
2591 			sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2592 
2593 	/* Get a superblock - note that we may end up sharing one that already exists */
2594 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2595 	if (IS_ERR(s)) {
2596 		mntroot = ERR_CAST(s);
2597 		goto out_err_nosb;
2598 	}
2599 
2600 	if (s->s_fs_info != server) {
2601 		nfs_free_server(server);
2602 		server = NULL;
2603 	} else {
2604 		error = nfs_bdi_register(server);
2605 		if (error) {
2606 			mntroot = ERR_PTR(error);
2607 			goto error_splat_super;
2608 		}
2609 		server->super = s;
2610 	}
2611 
2612 	if (!s->s_root) {
2613 		/* initial superblock/root creation */
2614 		mount_info->fill_super(s, mount_info);
2615 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2616 	}
2617 
2618 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2619 	if (IS_ERR(mntroot))
2620 		goto error_splat_super;
2621 
2622 	error = mount_info->set_security(s, mntroot, mount_info);
2623 	if (error)
2624 		goto error_splat_root;
2625 
2626 	s->s_flags |= MS_ACTIVE;
2627 
2628 out:
2629 	return mntroot;
2630 
2631 out_err_nosb:
2632 	nfs_free_server(server);
2633 	goto out;
2634 
2635 error_splat_root:
2636 	dput(mntroot);
2637 	mntroot = ERR_PTR(error);
2638 error_splat_super:
2639 	deactivate_locked_super(s);
2640 	goto out;
2641 }
2642 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2643 
2644 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2645 	int flags, const char *dev_name, void *raw_data)
2646 {
2647 	struct nfs_mount_info mount_info = {
2648 		.fill_super = nfs_fill_super,
2649 		.set_security = nfs_set_sb_security,
2650 	};
2651 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2652 	struct nfs_subversion *nfs_mod;
2653 	int error;
2654 
2655 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2656 	mount_info.mntfh = nfs_alloc_fhandle();
2657 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2658 		goto out;
2659 
2660 	/* Validate the mount data */
2661 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2662 	if (error == NFS_TEXT_DATA)
2663 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2664 	if (error < 0) {
2665 		mntroot = ERR_PTR(error);
2666 		goto out;
2667 	}
2668 
2669 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2670 	if (IS_ERR(nfs_mod)) {
2671 		mntroot = ERR_CAST(nfs_mod);
2672 		goto out;
2673 	}
2674 
2675 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2676 
2677 	put_nfs_version(nfs_mod);
2678 out:
2679 	nfs_free_parsed_mount_data(mount_info.parsed);
2680 	nfs_free_fhandle(mount_info.mntfh);
2681 	return mntroot;
2682 }
2683 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2684 
2685 /*
2686  * Destroy an NFS2/3 superblock
2687  */
2688 void nfs_kill_super(struct super_block *s)
2689 {
2690 	struct nfs_server *server = NFS_SB(s);
2691 	dev_t dev = s->s_dev;
2692 
2693 	generic_shutdown_super(s);
2694 
2695 	nfs_fscache_release_super_cookie(s);
2696 
2697 	nfs_free_server(server);
2698 	free_anon_bdev(dev);
2699 }
2700 EXPORT_SYMBOL_GPL(nfs_kill_super);
2701 
2702 /*
2703  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2704  */
2705 static struct dentry *
2706 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2707 		const char *dev_name, void *raw_data)
2708 {
2709 	struct nfs_clone_mount *data = raw_data;
2710 	struct nfs_mount_info mount_info = {
2711 		.fill_super = nfs_clone_super,
2712 		.set_security = nfs_clone_sb_security,
2713 		.cloned = data,
2714 	};
2715 	struct nfs_server *server;
2716 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2717 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2718 
2719 	dprintk("--> nfs_xdev_mount()\n");
2720 
2721 	mount_info.mntfh = mount_info.cloned->fh;
2722 
2723 	/* create a new volume representation */
2724 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2725 
2726 	if (IS_ERR(server))
2727 		mntroot = ERR_CAST(server);
2728 	else
2729 		mntroot = nfs_fs_mount_common(server, flags,
2730 				dev_name, &mount_info, nfs_mod);
2731 
2732 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2733 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2734 	return mntroot;
2735 }
2736 
2737 #if IS_ENABLED(CONFIG_NFS_V4)
2738 
2739 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2740 {
2741 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2742 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2743 }
2744 
2745 /*
2746  * Validate NFSv4 mount options
2747  */
2748 static int nfs4_validate_mount_data(void *options,
2749 				    struct nfs_parsed_mount_data *args,
2750 				    const char *dev_name)
2751 {
2752 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2753 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2754 	char *c;
2755 
2756 	if (data == NULL)
2757 		goto out_no_data;
2758 
2759 	args->version = 4;
2760 
2761 	switch (data->version) {
2762 	case 1:
2763 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2764 			goto out_no_address;
2765 		if (data->host_addrlen == 0)
2766 			goto out_no_address;
2767 		args->nfs_server.addrlen = data->host_addrlen;
2768 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2769 			return -EFAULT;
2770 		if (!nfs_verify_server_address(sap))
2771 			goto out_no_address;
2772 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2773 
2774 		if (data->auth_flavourlen) {
2775 			rpc_authflavor_t pseudoflavor;
2776 			if (data->auth_flavourlen > 1)
2777 				goto out_inval_auth;
2778 			if (copy_from_user(&pseudoflavor,
2779 					   data->auth_flavours,
2780 					   sizeof(pseudoflavor)))
2781 				return -EFAULT;
2782 			args->selected_flavor = pseudoflavor;
2783 		} else
2784 			args->selected_flavor = RPC_AUTH_UNIX;
2785 
2786 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2787 		if (IS_ERR(c))
2788 			return PTR_ERR(c);
2789 		args->nfs_server.hostname = c;
2790 
2791 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2792 		if (IS_ERR(c))
2793 			return PTR_ERR(c);
2794 		args->nfs_server.export_path = c;
2795 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2796 
2797 		c = strndup_user(data->client_addr.data, 16);
2798 		if (IS_ERR(c))
2799 			return PTR_ERR(c);
2800 		args->client_address = c;
2801 
2802 		/*
2803 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2804 		 * can deal with.
2805 		 */
2806 
2807 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2808 		args->rsize	= data->rsize;
2809 		args->wsize	= data->wsize;
2810 		args->timeo	= data->timeo;
2811 		args->retrans	= data->retrans;
2812 		args->acregmin	= data->acregmin;
2813 		args->acregmax	= data->acregmax;
2814 		args->acdirmin	= data->acdirmin;
2815 		args->acdirmax	= data->acdirmax;
2816 		args->nfs_server.protocol = data->proto;
2817 		nfs_validate_transport_protocol(args);
2818 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2819 			goto out_invalid_transport_udp;
2820 
2821 		break;
2822 	default:
2823 		return NFS_TEXT_DATA;
2824 	}
2825 
2826 	return 0;
2827 
2828 out_no_data:
2829 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2830 	return -EINVAL;
2831 
2832 out_inval_auth:
2833 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2834 		 data->auth_flavourlen);
2835 	return -EINVAL;
2836 
2837 out_no_address:
2838 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2839 	return -EINVAL;
2840 
2841 out_invalid_transport_udp:
2842 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2843 	return -EINVAL;
2844 }
2845 
2846 /*
2847  * NFS v4 module parameters need to stay in the
2848  * NFS client for backwards compatibility
2849  */
2850 unsigned int nfs_callback_set_tcpport;
2851 /* Default cache timeout is 10 minutes */
2852 unsigned int nfs_idmap_cache_timeout = 600;
2853 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2854 bool nfs4_disable_idmapping = true;
2855 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2856 unsigned short send_implementation_id = 1;
2857 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2858 bool recover_lost_locks = false;
2859 
2860 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2861 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2862 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2863 EXPORT_SYMBOL_GPL(max_session_slots);
2864 EXPORT_SYMBOL_GPL(send_implementation_id);
2865 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2866 EXPORT_SYMBOL_GPL(recover_lost_locks);
2867 
2868 #define NFS_CALLBACK_MAXPORTNR (65535U)
2869 
2870 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2871 {
2872 	unsigned long num;
2873 	int ret;
2874 
2875 	if (!val)
2876 		return -EINVAL;
2877 	ret = kstrtoul(val, 0, &num);
2878 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2879 		return -EINVAL;
2880 	*((unsigned int *)kp->arg) = num;
2881 	return 0;
2882 }
2883 static const struct kernel_param_ops param_ops_portnr = {
2884 	.set = param_set_portnr,
2885 	.get = param_get_uint,
2886 };
2887 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2888 
2889 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2890 module_param(nfs_idmap_cache_timeout, int, 0644);
2891 module_param(nfs4_disable_idmapping, bool, 0644);
2892 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2893 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2894 MODULE_PARM_DESC(nfs4_disable_idmapping,
2895 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2896 module_param(max_session_slots, ushort, 0644);
2897 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2898 		"requests the client will negotiate");
2899 module_param(send_implementation_id, ushort, 0644);
2900 MODULE_PARM_DESC(send_implementation_id,
2901 		"Send implementation ID with NFSv4.1 exchange_id");
2902 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2903 
2904 module_param(recover_lost_locks, bool, 0644);
2905 MODULE_PARM_DESC(recover_lost_locks,
2906 		 "If the server reports that a lock might be lost, "
2907 		 "try to recover it risking data corruption.");
2908 
2909 
2910 #endif /* CONFIG_NFS_V4 */
2911