xref: /linux/fs/nfs/super.c (revision 63307d015b91e626c97bb82e88054af3d0b74643)
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 enum {
81 	/* Mount options that take no arguments */
82 	Opt_soft, Opt_softerr, Opt_hard,
83 	Opt_posix, Opt_noposix,
84 	Opt_cto, Opt_nocto,
85 	Opt_ac, Opt_noac,
86 	Opt_lock, Opt_nolock,
87 	Opt_udp, Opt_tcp, Opt_rdma,
88 	Opt_acl, Opt_noacl,
89 	Opt_rdirplus, Opt_nordirplus,
90 	Opt_sharecache, Opt_nosharecache,
91 	Opt_resvport, Opt_noresvport,
92 	Opt_fscache, Opt_nofscache,
93 	Opt_migration, Opt_nomigration,
94 
95 	/* Mount options that take integer arguments */
96 	Opt_port,
97 	Opt_rsize, Opt_wsize, Opt_bsize,
98 	Opt_timeo, Opt_retrans,
99 	Opt_acregmin, Opt_acregmax,
100 	Opt_acdirmin, Opt_acdirmax,
101 	Opt_actimeo,
102 	Opt_namelen,
103 	Opt_mountport,
104 	Opt_mountvers,
105 	Opt_minorversion,
106 
107 	/* Mount options that take string arguments */
108 	Opt_nfsvers,
109 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
110 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
111 	Opt_lookupcache,
112 	Opt_fscache_uniq,
113 	Opt_local_lock,
114 
115 	/* Special mount options */
116 	Opt_userspace, Opt_deprecated, Opt_sloppy,
117 
118 	Opt_err
119 };
120 
121 static const match_table_t nfs_mount_option_tokens = {
122 	{ Opt_userspace, "bg" },
123 	{ Opt_userspace, "fg" },
124 	{ Opt_userspace, "retry=%s" },
125 
126 	{ Opt_sloppy, "sloppy" },
127 
128 	{ Opt_soft, "soft" },
129 	{ Opt_softerr, "softerr" },
130 	{ Opt_hard, "hard" },
131 	{ Opt_deprecated, "intr" },
132 	{ Opt_deprecated, "nointr" },
133 	{ Opt_posix, "posix" },
134 	{ Opt_noposix, "noposix" },
135 	{ Opt_cto, "cto" },
136 	{ Opt_nocto, "nocto" },
137 	{ Opt_ac, "ac" },
138 	{ Opt_noac, "noac" },
139 	{ Opt_lock, "lock" },
140 	{ Opt_nolock, "nolock" },
141 	{ Opt_udp, "udp" },
142 	{ Opt_tcp, "tcp" },
143 	{ Opt_rdma, "rdma" },
144 	{ Opt_acl, "acl" },
145 	{ Opt_noacl, "noacl" },
146 	{ Opt_rdirplus, "rdirplus" },
147 	{ Opt_nordirplus, "nordirplus" },
148 	{ Opt_sharecache, "sharecache" },
149 	{ Opt_nosharecache, "nosharecache" },
150 	{ Opt_resvport, "resvport" },
151 	{ Opt_noresvport, "noresvport" },
152 	{ Opt_fscache, "fsc" },
153 	{ Opt_nofscache, "nofsc" },
154 	{ Opt_migration, "migration" },
155 	{ Opt_nomigration, "nomigration" },
156 
157 	{ Opt_port, "port=%s" },
158 	{ Opt_rsize, "rsize=%s" },
159 	{ Opt_wsize, "wsize=%s" },
160 	{ Opt_bsize, "bsize=%s" },
161 	{ Opt_timeo, "timeo=%s" },
162 	{ Opt_retrans, "retrans=%s" },
163 	{ Opt_acregmin, "acregmin=%s" },
164 	{ Opt_acregmax, "acregmax=%s" },
165 	{ Opt_acdirmin, "acdirmin=%s" },
166 	{ Opt_acdirmax, "acdirmax=%s" },
167 	{ Opt_actimeo, "actimeo=%s" },
168 	{ Opt_namelen, "namlen=%s" },
169 	{ Opt_mountport, "mountport=%s" },
170 	{ Opt_mountvers, "mountvers=%s" },
171 	{ Opt_minorversion, "minorversion=%s" },
172 
173 	{ Opt_nfsvers, "nfsvers=%s" },
174 	{ Opt_nfsvers, "vers=%s" },
175 
176 	{ Opt_sec, "sec=%s" },
177 	{ Opt_proto, "proto=%s" },
178 	{ Opt_mountproto, "mountproto=%s" },
179 	{ Opt_addr, "addr=%s" },
180 	{ Opt_clientaddr, "clientaddr=%s" },
181 	{ Opt_mounthost, "mounthost=%s" },
182 	{ Opt_mountaddr, "mountaddr=%s" },
183 
184 	{ Opt_lookupcache, "lookupcache=%s" },
185 	{ Opt_fscache_uniq, "fsc=%s" },
186 	{ Opt_local_lock, "local_lock=%s" },
187 
188 	/* The following needs to be listed after all other options */
189 	{ Opt_nfsvers, "v%s" },
190 
191 	{ Opt_err, NULL }
192 };
193 
194 enum {
195 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
196 	Opt_xprt_rdma6,
197 
198 	Opt_xprt_err
199 };
200 
201 static const match_table_t nfs_xprt_protocol_tokens = {
202 	{ Opt_xprt_udp, "udp" },
203 	{ Opt_xprt_udp6, "udp6" },
204 	{ Opt_xprt_tcp, "tcp" },
205 	{ Opt_xprt_tcp6, "tcp6" },
206 	{ Opt_xprt_rdma, "rdma" },
207 	{ Opt_xprt_rdma6, "rdma6" },
208 
209 	{ Opt_xprt_err, NULL }
210 };
211 
212 enum {
213 	Opt_sec_none, Opt_sec_sys,
214 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
215 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
216 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
217 
218 	Opt_sec_err
219 };
220 
221 static const match_table_t nfs_secflavor_tokens = {
222 	{ Opt_sec_none, "none" },
223 	{ Opt_sec_none, "null" },
224 	{ Opt_sec_sys, "sys" },
225 
226 	{ Opt_sec_krb5, "krb5" },
227 	{ Opt_sec_krb5i, "krb5i" },
228 	{ Opt_sec_krb5p, "krb5p" },
229 
230 	{ Opt_sec_lkey, "lkey" },
231 	{ Opt_sec_lkeyi, "lkeyi" },
232 	{ Opt_sec_lkeyp, "lkeyp" },
233 
234 	{ Opt_sec_spkm, "spkm3" },
235 	{ Opt_sec_spkmi, "spkm3i" },
236 	{ Opt_sec_spkmp, "spkm3p" },
237 
238 	{ Opt_sec_err, NULL }
239 };
240 
241 enum {
242 	Opt_lookupcache_all, Opt_lookupcache_positive,
243 	Opt_lookupcache_none,
244 
245 	Opt_lookupcache_err
246 };
247 
248 static match_table_t nfs_lookupcache_tokens = {
249 	{ Opt_lookupcache_all, "all" },
250 	{ Opt_lookupcache_positive, "pos" },
251 	{ Opt_lookupcache_positive, "positive" },
252 	{ Opt_lookupcache_none, "none" },
253 
254 	{ Opt_lookupcache_err, NULL }
255 };
256 
257 enum {
258 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
259 	Opt_local_lock_none,
260 
261 	Opt_local_lock_err
262 };
263 
264 static match_table_t nfs_local_lock_tokens = {
265 	{ Opt_local_lock_all, "all" },
266 	{ Opt_local_lock_flock, "flock" },
267 	{ Opt_local_lock_posix, "posix" },
268 	{ Opt_local_lock_none, "none" },
269 
270 	{ Opt_local_lock_err, NULL }
271 };
272 
273 enum {
274 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
275 	Opt_vers_4_1, Opt_vers_4_2,
276 
277 	Opt_vers_err
278 };
279 
280 static match_table_t nfs_vers_tokens = {
281 	{ Opt_vers_2, "2" },
282 	{ Opt_vers_3, "3" },
283 	{ Opt_vers_4, "4" },
284 	{ Opt_vers_4_0, "4.0" },
285 	{ Opt_vers_4_1, "4.1" },
286 	{ Opt_vers_4_2, "4.2" },
287 
288 	{ Opt_vers_err, NULL }
289 };
290 
291 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
292 		int flags, const char *dev_name, void *raw_data);
293 
294 struct file_system_type nfs_fs_type = {
295 	.owner		= THIS_MODULE,
296 	.name		= "nfs",
297 	.mount		= nfs_fs_mount,
298 	.kill_sb	= nfs_kill_super,
299 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
300 };
301 MODULE_ALIAS_FS("nfs");
302 EXPORT_SYMBOL_GPL(nfs_fs_type);
303 
304 struct file_system_type nfs_xdev_fs_type = {
305 	.owner		= THIS_MODULE,
306 	.name		= "nfs",
307 	.mount		= nfs_xdev_mount,
308 	.kill_sb	= nfs_kill_super,
309 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
310 };
311 
312 const struct super_operations nfs_sops = {
313 	.alloc_inode	= nfs_alloc_inode,
314 	.free_inode	= nfs_free_inode,
315 	.write_inode	= nfs_write_inode,
316 	.drop_inode	= nfs_drop_inode,
317 	.statfs		= nfs_statfs,
318 	.evict_inode	= nfs_evict_inode,
319 	.umount_begin	= nfs_umount_begin,
320 	.show_options	= nfs_show_options,
321 	.show_devname	= nfs_show_devname,
322 	.show_path	= nfs_show_path,
323 	.show_stats	= nfs_show_stats,
324 	.remount_fs	= nfs_remount,
325 };
326 EXPORT_SYMBOL_GPL(nfs_sops);
327 
328 #if IS_ENABLED(CONFIG_NFS_V4)
329 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
330 static int nfs4_validate_mount_data(void *options,
331 	struct nfs_parsed_mount_data *args, const char *dev_name);
332 
333 struct file_system_type nfs4_fs_type = {
334 	.owner		= THIS_MODULE,
335 	.name		= "nfs4",
336 	.mount		= nfs_fs_mount,
337 	.kill_sb	= nfs_kill_super,
338 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
339 };
340 MODULE_ALIAS_FS("nfs4");
341 MODULE_ALIAS("nfs4");
342 EXPORT_SYMBOL_GPL(nfs4_fs_type);
343 
344 static int __init register_nfs4_fs(void)
345 {
346 	return register_filesystem(&nfs4_fs_type);
347 }
348 
349 static void unregister_nfs4_fs(void)
350 {
351 	unregister_filesystem(&nfs4_fs_type);
352 }
353 #else
354 static int __init register_nfs4_fs(void)
355 {
356 	return 0;
357 }
358 
359 static void unregister_nfs4_fs(void)
360 {
361 }
362 #endif
363 
364 static struct shrinker acl_shrinker = {
365 	.count_objects	= nfs_access_cache_count,
366 	.scan_objects	= nfs_access_cache_scan,
367 	.seeks		= DEFAULT_SEEKS,
368 };
369 
370 /*
371  * Register the NFS filesystems
372  */
373 int __init register_nfs_fs(void)
374 {
375 	int ret;
376 
377         ret = register_filesystem(&nfs_fs_type);
378 	if (ret < 0)
379 		goto error_0;
380 
381 	ret = register_nfs4_fs();
382 	if (ret < 0)
383 		goto error_1;
384 
385 	ret = nfs_register_sysctl();
386 	if (ret < 0)
387 		goto error_2;
388 	ret = register_shrinker(&acl_shrinker);
389 	if (ret < 0)
390 		goto error_3;
391 	return 0;
392 error_3:
393 	nfs_unregister_sysctl();
394 error_2:
395 	unregister_nfs4_fs();
396 error_1:
397 	unregister_filesystem(&nfs_fs_type);
398 error_0:
399 	return ret;
400 }
401 
402 /*
403  * Unregister the NFS filesystems
404  */
405 void __exit unregister_nfs_fs(void)
406 {
407 	unregister_shrinker(&acl_shrinker);
408 	nfs_unregister_sysctl();
409 	unregister_nfs4_fs();
410 	unregister_filesystem(&nfs_fs_type);
411 }
412 
413 bool nfs_sb_active(struct super_block *sb)
414 {
415 	struct nfs_server *server = NFS_SB(sb);
416 
417 	if (!atomic_inc_not_zero(&sb->s_active))
418 		return false;
419 	if (atomic_inc_return(&server->active) != 1)
420 		atomic_dec(&sb->s_active);
421 	return true;
422 }
423 EXPORT_SYMBOL_GPL(nfs_sb_active);
424 
425 void nfs_sb_deactive(struct super_block *sb)
426 {
427 	struct nfs_server *server = NFS_SB(sb);
428 
429 	if (atomic_dec_and_test(&server->active))
430 		deactivate_super(sb);
431 }
432 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
433 
434 /*
435  * Deliver file system statistics to userspace
436  */
437 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
438 {
439 	struct nfs_server *server = NFS_SB(dentry->d_sb);
440 	unsigned char blockbits;
441 	unsigned long blockres;
442 	struct nfs_fh *fh = NFS_FH(d_inode(dentry));
443 	struct nfs_fsstat res;
444 	int error = -ENOMEM;
445 
446 	res.fattr = nfs_alloc_fattr();
447 	if (res.fattr == NULL)
448 		goto out_err;
449 
450 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
451 	if (unlikely(error == -ESTALE)) {
452 		struct dentry *pd_dentry;
453 
454 		pd_dentry = dget_parent(dentry);
455 		if (pd_dentry != NULL) {
456 			nfs_zap_caches(d_inode(pd_dentry));
457 			dput(pd_dentry);
458 		}
459 	}
460 	nfs_free_fattr(res.fattr);
461 	if (error < 0)
462 		goto out_err;
463 
464 	buf->f_type = NFS_SUPER_MAGIC;
465 
466 	/*
467 	 * Current versions of glibc do not correctly handle the
468 	 * case where f_frsize != f_bsize.  Eventually we want to
469 	 * report the value of wtmult in this field.
470 	 */
471 	buf->f_frsize = dentry->d_sb->s_blocksize;
472 
473 	/*
474 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
475 	 * are reported in units of f_frsize.  Linux hasn't had
476 	 * an f_frsize field in its statfs struct until recently,
477 	 * thus historically Linux's sys_statfs reports these
478 	 * fields in units of f_bsize.
479 	 */
480 	buf->f_bsize = dentry->d_sb->s_blocksize;
481 	blockbits = dentry->d_sb->s_blocksize_bits;
482 	blockres = (1 << blockbits) - 1;
483 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
484 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
485 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
486 
487 	buf->f_files = res.tfiles;
488 	buf->f_ffree = res.afiles;
489 
490 	buf->f_namelen = server->namelen;
491 
492 	return 0;
493 
494  out_err:
495 	dprintk("%s: statfs error = %d\n", __func__, -error);
496 	return error;
497 }
498 EXPORT_SYMBOL_GPL(nfs_statfs);
499 
500 /*
501  * Map the security flavour number to a name
502  */
503 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
504 {
505 	static const struct {
506 		rpc_authflavor_t flavour;
507 		const char *str;
508 	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
509 		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
510 		{ RPC_AUTH_NULL, "null" },
511 		{ RPC_AUTH_UNIX, "sys" },
512 		{ RPC_AUTH_GSS_KRB5, "krb5" },
513 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
514 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
515 		{ RPC_AUTH_GSS_LKEY, "lkey" },
516 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
517 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
518 		{ RPC_AUTH_GSS_SPKM, "spkm" },
519 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
520 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
521 		{ UINT_MAX, "unknown" }
522 	};
523 	int i;
524 
525 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
526 		if (sec_flavours[i].flavour == flavour)
527 			break;
528 	}
529 	return sec_flavours[i].str;
530 }
531 
532 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
533 				  int showdefaults)
534 {
535 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
536 	char *proto = NULL;
537 
538 	switch (sap->sa_family) {
539 	case AF_INET:
540 		switch (nfss->mountd_protocol) {
541 		case IPPROTO_UDP:
542 			proto = RPCBIND_NETID_UDP;
543 			break;
544 		case IPPROTO_TCP:
545 			proto = RPCBIND_NETID_TCP;
546 			break;
547 		}
548 		break;
549 	case AF_INET6:
550 		switch (nfss->mountd_protocol) {
551 		case IPPROTO_UDP:
552 			proto = RPCBIND_NETID_UDP6;
553 			break;
554 		case IPPROTO_TCP:
555 			proto = RPCBIND_NETID_TCP6;
556 			break;
557 		}
558 		break;
559 	}
560 	if (proto || showdefaults)
561 		seq_printf(m, ",mountproto=%s", proto ?: "auto");
562 }
563 
564 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
565 				    int showdefaults)
566 {
567 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
568 
569 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
570 		return;
571 
572 	switch (sap->sa_family) {
573 	case AF_INET: {
574 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
575 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
576 		break;
577 	}
578 	case AF_INET6: {
579 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
580 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
581 		break;
582 	}
583 	default:
584 		if (showdefaults)
585 			seq_printf(m, ",mountaddr=unspecified");
586 	}
587 
588 	if (nfss->mountd_version || showdefaults)
589 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
590 	if ((nfss->mountd_port &&
591 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
592 		showdefaults)
593 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
594 
595 	nfs_show_mountd_netid(m, nfss, showdefaults);
596 }
597 
598 #if IS_ENABLED(CONFIG_NFS_V4)
599 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
600 				    int showdefaults)
601 {
602 	struct nfs_client *clp = nfss->nfs_client;
603 
604 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
605 }
606 #else
607 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
608 				    int showdefaults)
609 {
610 }
611 #endif
612 
613 static void nfs_show_nfs_version(struct seq_file *m,
614 		unsigned int version,
615 		unsigned int minorversion)
616 {
617 	seq_printf(m, ",vers=%u", version);
618 	if (version == 4)
619 		seq_printf(m, ".%u", minorversion);
620 }
621 
622 /*
623  * Describe the mount options in force on this server representation
624  */
625 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
626 				   int showdefaults)
627 {
628 	static const struct proc_nfs_info {
629 		int flag;
630 		const char *str;
631 		const char *nostr;
632 	} nfs_info[] = {
633 		{ NFS_MOUNT_SOFT, ",soft", "" },
634 		{ NFS_MOUNT_SOFTERR, ",softerr", "" },
635 		{ NFS_MOUNT_POSIX, ",posix", "" },
636 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
637 		{ NFS_MOUNT_NOAC, ",noac", "" },
638 		{ NFS_MOUNT_NONLM, ",nolock", "" },
639 		{ NFS_MOUNT_NOACL, ",noacl", "" },
640 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
641 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
642 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
643 		{ 0, NULL, NULL }
644 	};
645 	const struct proc_nfs_info *nfs_infop;
646 	struct nfs_client *clp = nfss->nfs_client;
647 	u32 version = clp->rpc_ops->version;
648 	int local_flock, local_fcntl;
649 
650 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
651 	seq_printf(m, ",rsize=%u", nfss->rsize);
652 	seq_printf(m, ",wsize=%u", nfss->wsize);
653 	if (nfss->bsize != 0)
654 		seq_printf(m, ",bsize=%u", nfss->bsize);
655 	seq_printf(m, ",namlen=%u", nfss->namelen);
656 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
657 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
658 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
659 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
660 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
661 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
662 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
663 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
664 	if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
665 			seq_puts(m, ",hard");
666 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
667 		if (nfss->flags & nfs_infop->flag)
668 			seq_puts(m, nfs_infop->str);
669 		else
670 			seq_puts(m, nfs_infop->nostr);
671 	}
672 	rcu_read_lock();
673 	seq_printf(m, ",proto=%s",
674 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
675 	rcu_read_unlock();
676 	if (version == 4) {
677 		if (nfss->port != NFS_PORT)
678 			seq_printf(m, ",port=%u", nfss->port);
679 	} else
680 		if (nfss->port)
681 			seq_printf(m, ",port=%u", nfss->port);
682 
683 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
684 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
685 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
686 
687 	if (version != 4)
688 		nfs_show_mountd_options(m, nfss, showdefaults);
689 	else
690 		nfs_show_nfsv4_options(m, nfss, showdefaults);
691 
692 	if (nfss->options & NFS_OPTION_FSCACHE)
693 		seq_printf(m, ",fsc");
694 
695 	if (nfss->options & NFS_OPTION_MIGRATION)
696 		seq_printf(m, ",migration");
697 
698 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
699 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
700 			seq_printf(m, ",lookupcache=none");
701 		else
702 			seq_printf(m, ",lookupcache=pos");
703 	}
704 
705 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
706 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
707 
708 	if (!local_flock && !local_fcntl)
709 		seq_printf(m, ",local_lock=none");
710 	else if (local_flock && local_fcntl)
711 		seq_printf(m, ",local_lock=all");
712 	else if (local_flock)
713 		seq_printf(m, ",local_lock=flock");
714 	else
715 		seq_printf(m, ",local_lock=posix");
716 }
717 
718 /*
719  * Describe the mount options on this VFS mountpoint
720  */
721 int nfs_show_options(struct seq_file *m, struct dentry *root)
722 {
723 	struct nfs_server *nfss = NFS_SB(root->d_sb);
724 
725 	nfs_show_mount_options(m, nfss, 0);
726 
727 	rcu_read_lock();
728 	seq_printf(m, ",addr=%s",
729 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
730 							RPC_DISPLAY_ADDR));
731 	rcu_read_unlock();
732 
733 	return 0;
734 }
735 EXPORT_SYMBOL_GPL(nfs_show_options);
736 
737 #if IS_ENABLED(CONFIG_NFS_V4)
738 #ifdef CONFIG_NFS_V4_1
739 static void show_sessions(struct seq_file *m, struct nfs_server *server)
740 {
741 	if (nfs4_has_session(server->nfs_client))
742 		seq_printf(m, ",sessions");
743 }
744 #else
745 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
746 #endif
747 #endif
748 
749 #ifdef CONFIG_NFS_V4_1
750 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
751 {
752 	seq_printf(m, ",pnfs=");
753 	if (server->pnfs_curr_ld)
754 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
755 	else
756 		seq_printf(m, "not configured");
757 }
758 
759 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
760 {
761 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
762 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
763 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
764 			   "date='%llu,%u'",
765 			   impl_id->name, impl_id->domain,
766 			   impl_id->date.seconds, impl_id->date.nseconds);
767 	}
768 }
769 #else
770 #if IS_ENABLED(CONFIG_NFS_V4)
771 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
772 {
773 }
774 #endif
775 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
776 {
777 }
778 #endif
779 
780 int nfs_show_devname(struct seq_file *m, struct dentry *root)
781 {
782 	char *page = (char *) __get_free_page(GFP_KERNEL);
783 	char *devname, *dummy;
784 	int err = 0;
785 	if (!page)
786 		return -ENOMEM;
787 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
788 	if (IS_ERR(devname))
789 		err = PTR_ERR(devname);
790 	else
791 		seq_escape(m, devname, " \t\n\\");
792 	free_page((unsigned long)page);
793 	return err;
794 }
795 EXPORT_SYMBOL_GPL(nfs_show_devname);
796 
797 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
798 {
799 	seq_puts(m, "/");
800 	return 0;
801 }
802 EXPORT_SYMBOL_GPL(nfs_show_path);
803 
804 /*
805  * Present statistical information for this VFS mountpoint
806  */
807 int nfs_show_stats(struct seq_file *m, struct dentry *root)
808 {
809 	int i, cpu;
810 	struct nfs_server *nfss = NFS_SB(root->d_sb);
811 	struct rpc_auth *auth = nfss->client->cl_auth;
812 	struct nfs_iostats totals = { };
813 
814 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
815 
816 	/*
817 	 * Display all mount option settings
818 	 */
819 	seq_printf(m, "\n\topts:\t");
820 	seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
821 	seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
822 	seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
823 	seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
824 	nfs_show_mount_options(m, nfss, 1);
825 
826 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
827 
828 	show_implementation_id(m, nfss);
829 
830 	seq_printf(m, "\n\tcaps:\t");
831 	seq_printf(m, "caps=0x%x", nfss->caps);
832 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
833 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
834 	seq_printf(m, ",bsize=%u", nfss->bsize);
835 	seq_printf(m, ",namlen=%u", nfss->namelen);
836 
837 #if IS_ENABLED(CONFIG_NFS_V4)
838 	if (nfss->nfs_client->rpc_ops->version == 4) {
839 		seq_printf(m, "\n\tnfsv4:\t");
840 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
841 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
842 		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
843 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
844 		show_sessions(m, nfss);
845 		show_pnfs(m, nfss);
846 	}
847 #endif
848 
849 	/*
850 	 * Display security flavor in effect for this mount
851 	 */
852 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
853 	if (auth->au_flavor)
854 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
855 
856 	/*
857 	 * Display superblock I/O counters
858 	 */
859 	for_each_possible_cpu(cpu) {
860 		struct nfs_iostats *stats;
861 
862 		preempt_disable();
863 		stats = per_cpu_ptr(nfss->io_stats, cpu);
864 
865 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
866 			totals.events[i] += stats->events[i];
867 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
868 			totals.bytes[i] += stats->bytes[i];
869 #ifdef CONFIG_NFS_FSCACHE
870 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
871 			totals.fscache[i] += stats->fscache[i];
872 #endif
873 
874 		preempt_enable();
875 	}
876 
877 	seq_printf(m, "\n\tevents:\t");
878 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
879 		seq_printf(m, "%lu ", totals.events[i]);
880 	seq_printf(m, "\n\tbytes:\t");
881 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
882 		seq_printf(m, "%Lu ", totals.bytes[i]);
883 #ifdef CONFIG_NFS_FSCACHE
884 	if (nfss->options & NFS_OPTION_FSCACHE) {
885 		seq_printf(m, "\n\tfsc:\t");
886 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
887 			seq_printf(m, "%Lu ", totals.fscache[i]);
888 	}
889 #endif
890 	seq_printf(m, "\n");
891 
892 	rpc_clnt_show_stats(m, nfss->client);
893 
894 	return 0;
895 }
896 EXPORT_SYMBOL_GPL(nfs_show_stats);
897 
898 /*
899  * Begin unmount by attempting to remove all automounted mountpoints we added
900  * in response to xdev traversals and referrals
901  */
902 void nfs_umount_begin(struct super_block *sb)
903 {
904 	struct nfs_server *server;
905 	struct rpc_clnt *rpc;
906 
907 	server = NFS_SB(sb);
908 	/* -EIO all pending I/O */
909 	rpc = server->client_acl;
910 	if (!IS_ERR(rpc))
911 		rpc_killall_tasks(rpc);
912 	rpc = server->client;
913 	if (!IS_ERR(rpc))
914 		rpc_killall_tasks(rpc);
915 }
916 EXPORT_SYMBOL_GPL(nfs_umount_begin);
917 
918 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
919 {
920 	struct nfs_parsed_mount_data *data;
921 
922 	data = kzalloc(sizeof(*data), GFP_KERNEL);
923 	if (data) {
924 		data->timeo		= NFS_UNSPEC_TIMEO;
925 		data->retrans		= NFS_UNSPEC_RETRANS;
926 		data->acregmin		= NFS_DEF_ACREGMIN;
927 		data->acregmax		= NFS_DEF_ACREGMAX;
928 		data->acdirmin		= NFS_DEF_ACDIRMIN;
929 		data->acdirmax		= NFS_DEF_ACDIRMAX;
930 		data->mount_server.port	= NFS_UNSPEC_PORT;
931 		data->nfs_server.port	= NFS_UNSPEC_PORT;
932 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
933 		data->selected_flavor	= RPC_AUTH_MAXFLAVOR;
934 		data->minorversion	= 0;
935 		data->need_mount	= true;
936 		data->net		= current->nsproxy->net_ns;
937 		data->lsm_opts		= NULL;
938 	}
939 	return data;
940 }
941 
942 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
943 {
944 	if (data) {
945 		kfree(data->client_address);
946 		kfree(data->mount_server.hostname);
947 		kfree(data->nfs_server.export_path);
948 		kfree(data->nfs_server.hostname);
949 		kfree(data->fscache_uniq);
950 		security_free_mnt_opts(&data->lsm_opts);
951 		kfree(data);
952 	}
953 }
954 
955 /*
956  * Sanity-check a server address provided by the mount command.
957  *
958  * Address family must be initialized, and address must not be
959  * the ANY address for that family.
960  */
961 static int nfs_verify_server_address(struct sockaddr *addr)
962 {
963 	switch (addr->sa_family) {
964 	case AF_INET: {
965 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
966 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
967 	}
968 	case AF_INET6: {
969 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
970 		return !ipv6_addr_any(sa);
971 	}
972 	}
973 
974 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
975 	return 0;
976 }
977 
978 /*
979  * Select between a default port value and a user-specified port value.
980  * If a zero value is set, then autobind will be used.
981  */
982 static void nfs_set_port(struct sockaddr *sap, int *port,
983 				 const unsigned short default_port)
984 {
985 	if (*port == NFS_UNSPEC_PORT)
986 		*port = default_port;
987 
988 	rpc_set_port(sap, *port);
989 }
990 
991 /*
992  * Sanity check the NFS transport protocol.
993  *
994  */
995 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
996 {
997 	switch (mnt->nfs_server.protocol) {
998 	case XPRT_TRANSPORT_UDP:
999 	case XPRT_TRANSPORT_TCP:
1000 	case XPRT_TRANSPORT_RDMA:
1001 		break;
1002 	default:
1003 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1004 	}
1005 }
1006 
1007 /*
1008  * For text based NFSv2/v3 mounts, the mount protocol transport default
1009  * settings should depend upon the specified NFS transport.
1010  */
1011 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1012 {
1013 	nfs_validate_transport_protocol(mnt);
1014 
1015 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1016 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1017 			return;
1018 	switch (mnt->nfs_server.protocol) {
1019 	case XPRT_TRANSPORT_UDP:
1020 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1021 		break;
1022 	case XPRT_TRANSPORT_TCP:
1023 	case XPRT_TRANSPORT_RDMA:
1024 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1025 	}
1026 }
1027 
1028 /*
1029  * Add 'flavor' to 'auth_info' if not already present.
1030  * Returns true if 'flavor' ends up in the list, false otherwise
1031  */
1032 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1033 			      rpc_authflavor_t flavor)
1034 {
1035 	unsigned int i;
1036 	unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1037 
1038 	/* make sure this flavor isn't already in the list */
1039 	for (i = 0; i < auth_info->flavor_len; i++) {
1040 		if (flavor == auth_info->flavors[i])
1041 			return true;
1042 	}
1043 
1044 	if (auth_info->flavor_len + 1 >= max_flavor_len) {
1045 		dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1046 		return false;
1047 	}
1048 
1049 	auth_info->flavors[auth_info->flavor_len++] = flavor;
1050 	return true;
1051 }
1052 
1053 /*
1054  * Return true if 'match' is in auth_info or auth_info is empty.
1055  * Return false otherwise.
1056  */
1057 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1058 			 rpc_authflavor_t match)
1059 {
1060 	int i;
1061 
1062 	if (!auth_info->flavor_len)
1063 		return true;
1064 
1065 	for (i = 0; i < auth_info->flavor_len; i++) {
1066 		if (auth_info->flavors[i] == match)
1067 			return true;
1068 	}
1069 	return false;
1070 }
1071 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1072 
1073 /*
1074  * Parse the value of the 'sec=' option.
1075  */
1076 static int nfs_parse_security_flavors(char *value,
1077 				      struct nfs_parsed_mount_data *mnt)
1078 {
1079 	substring_t args[MAX_OPT_ARGS];
1080 	rpc_authflavor_t pseudoflavor;
1081 	char *p;
1082 
1083 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1084 
1085 	while ((p = strsep(&value, ":")) != NULL) {
1086 		switch (match_token(p, nfs_secflavor_tokens, args)) {
1087 		case Opt_sec_none:
1088 			pseudoflavor = RPC_AUTH_NULL;
1089 			break;
1090 		case Opt_sec_sys:
1091 			pseudoflavor = RPC_AUTH_UNIX;
1092 			break;
1093 		case Opt_sec_krb5:
1094 			pseudoflavor = RPC_AUTH_GSS_KRB5;
1095 			break;
1096 		case Opt_sec_krb5i:
1097 			pseudoflavor = RPC_AUTH_GSS_KRB5I;
1098 			break;
1099 		case Opt_sec_krb5p:
1100 			pseudoflavor = RPC_AUTH_GSS_KRB5P;
1101 			break;
1102 		case Opt_sec_lkey:
1103 			pseudoflavor = RPC_AUTH_GSS_LKEY;
1104 			break;
1105 		case Opt_sec_lkeyi:
1106 			pseudoflavor = RPC_AUTH_GSS_LKEYI;
1107 			break;
1108 		case Opt_sec_lkeyp:
1109 			pseudoflavor = RPC_AUTH_GSS_LKEYP;
1110 			break;
1111 		case Opt_sec_spkm:
1112 			pseudoflavor = RPC_AUTH_GSS_SPKM;
1113 			break;
1114 		case Opt_sec_spkmi:
1115 			pseudoflavor = RPC_AUTH_GSS_SPKMI;
1116 			break;
1117 		case Opt_sec_spkmp:
1118 			pseudoflavor = RPC_AUTH_GSS_SPKMP;
1119 			break;
1120 		default:
1121 			dfprintk(MOUNT,
1122 				 "NFS: sec= option '%s' not recognized\n", p);
1123 			return 0;
1124 		}
1125 
1126 		if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1127 			return 0;
1128 	}
1129 
1130 	return 1;
1131 }
1132 
1133 static int nfs_parse_version_string(char *string,
1134 		struct nfs_parsed_mount_data *mnt,
1135 		substring_t *args)
1136 {
1137 	mnt->flags &= ~NFS_MOUNT_VER3;
1138 	switch (match_token(string, nfs_vers_tokens, args)) {
1139 	case Opt_vers_2:
1140 		mnt->version = 2;
1141 		break;
1142 	case Opt_vers_3:
1143 		mnt->flags |= NFS_MOUNT_VER3;
1144 		mnt->version = 3;
1145 		break;
1146 	case Opt_vers_4:
1147 		/* Backward compatibility option. In future,
1148 		 * the mount program should always supply
1149 		 * a NFSv4 minor version number.
1150 		 */
1151 		mnt->version = 4;
1152 		break;
1153 	case Opt_vers_4_0:
1154 		mnt->version = 4;
1155 		mnt->minorversion = 0;
1156 		break;
1157 	case Opt_vers_4_1:
1158 		mnt->version = 4;
1159 		mnt->minorversion = 1;
1160 		break;
1161 	case Opt_vers_4_2:
1162 		mnt->version = 4;
1163 		mnt->minorversion = 2;
1164 		break;
1165 	default:
1166 		return 0;
1167 	}
1168 	return 1;
1169 }
1170 
1171 static int nfs_get_option_str(substring_t args[], char **option)
1172 {
1173 	kfree(*option);
1174 	*option = match_strdup(args);
1175 	return !*option;
1176 }
1177 
1178 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1179 {
1180 	int rc;
1181 	char *string;
1182 
1183 	string = match_strdup(args);
1184 	if (string == NULL)
1185 		return -ENOMEM;
1186 	rc = kstrtoul(string, 10, option);
1187 	kfree(string);
1188 
1189 	return rc;
1190 }
1191 
1192 static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
1193 		unsigned long l_bound, unsigned long u_bound)
1194 {
1195 	int ret;
1196 
1197 	ret = nfs_get_option_ul(args, option);
1198 	if (ret != 0)
1199 		return ret;
1200 	if (*option < l_bound || *option > u_bound)
1201 		return -ERANGE;
1202 	return 0;
1203 }
1204 
1205 /*
1206  * Error-check and convert a string of mount options from user space into
1207  * a data structure.  The whole mount string is processed; bad options are
1208  * skipped as they are encountered.  If there were no errors, return 1;
1209  * otherwise return 0 (zero).
1210  */
1211 static int nfs_parse_mount_options(char *raw,
1212 				   struct nfs_parsed_mount_data *mnt)
1213 {
1214 	char *p, *string;
1215 	int rc, sloppy = 0, invalid_option = 0;
1216 	unsigned short protofamily = AF_UNSPEC;
1217 	unsigned short mountfamily = AF_UNSPEC;
1218 
1219 	if (!raw) {
1220 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1221 		return 1;
1222 	}
1223 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1224 
1225 	rc = security_sb_eat_lsm_opts(raw, &mnt->lsm_opts);
1226 	if (rc)
1227 		goto out_security_failure;
1228 
1229 	while ((p = strsep(&raw, ",")) != NULL) {
1230 		substring_t args[MAX_OPT_ARGS];
1231 		unsigned long option;
1232 		int token;
1233 
1234 		if (!*p)
1235 			continue;
1236 
1237 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1238 
1239 		token = match_token(p, nfs_mount_option_tokens, args);
1240 		switch (token) {
1241 
1242 		/*
1243 		 * boolean options:  foo/nofoo
1244 		 */
1245 		case Opt_soft:
1246 			mnt->flags |= NFS_MOUNT_SOFT;
1247 			mnt->flags &= ~NFS_MOUNT_SOFTERR;
1248 			break;
1249 		case Opt_softerr:
1250 			mnt->flags |= NFS_MOUNT_SOFTERR;
1251 			mnt->flags &= ~NFS_MOUNT_SOFT;
1252 			break;
1253 		case Opt_hard:
1254 			mnt->flags &= ~(NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR);
1255 			break;
1256 		case Opt_posix:
1257 			mnt->flags |= NFS_MOUNT_POSIX;
1258 			break;
1259 		case Opt_noposix:
1260 			mnt->flags &= ~NFS_MOUNT_POSIX;
1261 			break;
1262 		case Opt_cto:
1263 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1264 			break;
1265 		case Opt_nocto:
1266 			mnt->flags |= NFS_MOUNT_NOCTO;
1267 			break;
1268 		case Opt_ac:
1269 			mnt->flags &= ~NFS_MOUNT_NOAC;
1270 			break;
1271 		case Opt_noac:
1272 			mnt->flags |= NFS_MOUNT_NOAC;
1273 			break;
1274 		case Opt_lock:
1275 			mnt->flags &= ~NFS_MOUNT_NONLM;
1276 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1277 					NFS_MOUNT_LOCAL_FCNTL);
1278 			break;
1279 		case Opt_nolock:
1280 			mnt->flags |= NFS_MOUNT_NONLM;
1281 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1282 				       NFS_MOUNT_LOCAL_FCNTL);
1283 			break;
1284 		case Opt_udp:
1285 			mnt->flags &= ~NFS_MOUNT_TCP;
1286 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1287 			break;
1288 		case Opt_tcp:
1289 			mnt->flags |= NFS_MOUNT_TCP;
1290 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1291 			break;
1292 		case Opt_rdma:
1293 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1294 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1295 			xprt_load_transport(p);
1296 			break;
1297 		case Opt_acl:
1298 			mnt->flags &= ~NFS_MOUNT_NOACL;
1299 			break;
1300 		case Opt_noacl:
1301 			mnt->flags |= NFS_MOUNT_NOACL;
1302 			break;
1303 		case Opt_rdirplus:
1304 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1305 			break;
1306 		case Opt_nordirplus:
1307 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1308 			break;
1309 		case Opt_sharecache:
1310 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1311 			break;
1312 		case Opt_nosharecache:
1313 			mnt->flags |= NFS_MOUNT_UNSHARED;
1314 			break;
1315 		case Opt_resvport:
1316 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1317 			break;
1318 		case Opt_noresvport:
1319 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1320 			break;
1321 		case Opt_fscache:
1322 			mnt->options |= NFS_OPTION_FSCACHE;
1323 			kfree(mnt->fscache_uniq);
1324 			mnt->fscache_uniq = NULL;
1325 			break;
1326 		case Opt_nofscache:
1327 			mnt->options &= ~NFS_OPTION_FSCACHE;
1328 			kfree(mnt->fscache_uniq);
1329 			mnt->fscache_uniq = NULL;
1330 			break;
1331 		case Opt_migration:
1332 			mnt->options |= NFS_OPTION_MIGRATION;
1333 			break;
1334 		case Opt_nomigration:
1335 			mnt->options &= ~NFS_OPTION_MIGRATION;
1336 			break;
1337 
1338 		/*
1339 		 * options that take numeric values
1340 		 */
1341 		case Opt_port:
1342 			if (nfs_get_option_ul(args, &option) ||
1343 			    option > USHRT_MAX)
1344 				goto out_invalid_value;
1345 			mnt->nfs_server.port = option;
1346 			break;
1347 		case Opt_rsize:
1348 			if (nfs_get_option_ul(args, &option))
1349 				goto out_invalid_value;
1350 			mnt->rsize = option;
1351 			break;
1352 		case Opt_wsize:
1353 			if (nfs_get_option_ul(args, &option))
1354 				goto out_invalid_value;
1355 			mnt->wsize = option;
1356 			break;
1357 		case Opt_bsize:
1358 			if (nfs_get_option_ul(args, &option))
1359 				goto out_invalid_value;
1360 			mnt->bsize = option;
1361 			break;
1362 		case Opt_timeo:
1363 			if (nfs_get_option_ul_bound(args, &option, 1, INT_MAX))
1364 				goto out_invalid_value;
1365 			mnt->timeo = option;
1366 			break;
1367 		case Opt_retrans:
1368 			if (nfs_get_option_ul_bound(args, &option, 0, INT_MAX))
1369 				goto out_invalid_value;
1370 			mnt->retrans = option;
1371 			break;
1372 		case Opt_acregmin:
1373 			if (nfs_get_option_ul(args, &option))
1374 				goto out_invalid_value;
1375 			mnt->acregmin = option;
1376 			break;
1377 		case Opt_acregmax:
1378 			if (nfs_get_option_ul(args, &option))
1379 				goto out_invalid_value;
1380 			mnt->acregmax = option;
1381 			break;
1382 		case Opt_acdirmin:
1383 			if (nfs_get_option_ul(args, &option))
1384 				goto out_invalid_value;
1385 			mnt->acdirmin = option;
1386 			break;
1387 		case Opt_acdirmax:
1388 			if (nfs_get_option_ul(args, &option))
1389 				goto out_invalid_value;
1390 			mnt->acdirmax = option;
1391 			break;
1392 		case Opt_actimeo:
1393 			if (nfs_get_option_ul(args, &option))
1394 				goto out_invalid_value;
1395 			mnt->acregmin = mnt->acregmax =
1396 			mnt->acdirmin = mnt->acdirmax = option;
1397 			break;
1398 		case Opt_namelen:
1399 			if (nfs_get_option_ul(args, &option))
1400 				goto out_invalid_value;
1401 			mnt->namlen = option;
1402 			break;
1403 		case Opt_mountport:
1404 			if (nfs_get_option_ul(args, &option) ||
1405 			    option > USHRT_MAX)
1406 				goto out_invalid_value;
1407 			mnt->mount_server.port = option;
1408 			break;
1409 		case Opt_mountvers:
1410 			if (nfs_get_option_ul(args, &option) ||
1411 			    option < NFS_MNT_VERSION ||
1412 			    option > NFS_MNT3_VERSION)
1413 				goto out_invalid_value;
1414 			mnt->mount_server.version = option;
1415 			break;
1416 		case Opt_minorversion:
1417 			if (nfs_get_option_ul(args, &option))
1418 				goto out_invalid_value;
1419 			if (option > NFS4_MAX_MINOR_VERSION)
1420 				goto out_invalid_value;
1421 			mnt->minorversion = option;
1422 			break;
1423 
1424 		/*
1425 		 * options that take text values
1426 		 */
1427 		case Opt_nfsvers:
1428 			string = match_strdup(args);
1429 			if (string == NULL)
1430 				goto out_nomem;
1431 			rc = nfs_parse_version_string(string, mnt, args);
1432 			kfree(string);
1433 			if (!rc)
1434 				goto out_invalid_value;
1435 			break;
1436 		case Opt_sec:
1437 			string = match_strdup(args);
1438 			if (string == NULL)
1439 				goto out_nomem;
1440 			rc = nfs_parse_security_flavors(string, mnt);
1441 			kfree(string);
1442 			if (!rc) {
1443 				dfprintk(MOUNT, "NFS:   unrecognized "
1444 						"security flavor\n");
1445 				return 0;
1446 			}
1447 			break;
1448 		case Opt_proto:
1449 			string = match_strdup(args);
1450 			if (string == NULL)
1451 				goto out_nomem;
1452 			token = match_token(string,
1453 					    nfs_xprt_protocol_tokens, args);
1454 
1455 			protofamily = AF_INET;
1456 			switch (token) {
1457 			case Opt_xprt_udp6:
1458 				protofamily = AF_INET6;
1459 				/* fall through */
1460 			case Opt_xprt_udp:
1461 				mnt->flags &= ~NFS_MOUNT_TCP;
1462 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1463 				break;
1464 			case Opt_xprt_tcp6:
1465 				protofamily = AF_INET6;
1466 				/* fall through */
1467 			case Opt_xprt_tcp:
1468 				mnt->flags |= NFS_MOUNT_TCP;
1469 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1470 				break;
1471 			case Opt_xprt_rdma6:
1472 				protofamily = AF_INET6;
1473 				/* fall through */
1474 			case Opt_xprt_rdma:
1475 				/* vector side protocols to TCP */
1476 				mnt->flags |= NFS_MOUNT_TCP;
1477 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1478 				xprt_load_transport(string);
1479 				break;
1480 			default:
1481 				dfprintk(MOUNT, "NFS:   unrecognized "
1482 						"transport protocol\n");
1483 				kfree(string);
1484 				return 0;
1485 			}
1486 			kfree(string);
1487 			break;
1488 		case Opt_mountproto:
1489 			string = match_strdup(args);
1490 			if (string == NULL)
1491 				goto out_nomem;
1492 			token = match_token(string,
1493 					    nfs_xprt_protocol_tokens, args);
1494 			kfree(string);
1495 
1496 			mountfamily = AF_INET;
1497 			switch (token) {
1498 			case Opt_xprt_udp6:
1499 				mountfamily = AF_INET6;
1500 				/* fall through */
1501 			case Opt_xprt_udp:
1502 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1503 				break;
1504 			case Opt_xprt_tcp6:
1505 				mountfamily = AF_INET6;
1506 				/* fall through */
1507 			case Opt_xprt_tcp:
1508 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1509 				break;
1510 			case Opt_xprt_rdma: /* not used for side protocols */
1511 			default:
1512 				dfprintk(MOUNT, "NFS:   unrecognized "
1513 						"transport protocol\n");
1514 				return 0;
1515 			}
1516 			break;
1517 		case Opt_addr:
1518 			string = match_strdup(args);
1519 			if (string == NULL)
1520 				goto out_nomem;
1521 			mnt->nfs_server.addrlen =
1522 				rpc_pton(mnt->net, string, strlen(string),
1523 					(struct sockaddr *)
1524 					&mnt->nfs_server.address,
1525 					sizeof(mnt->nfs_server.address));
1526 			kfree(string);
1527 			if (mnt->nfs_server.addrlen == 0)
1528 				goto out_invalid_address;
1529 			break;
1530 		case Opt_clientaddr:
1531 			if (nfs_get_option_str(args, &mnt->client_address))
1532 				goto out_nomem;
1533 			break;
1534 		case Opt_mounthost:
1535 			if (nfs_get_option_str(args,
1536 					       &mnt->mount_server.hostname))
1537 				goto out_nomem;
1538 			break;
1539 		case Opt_mountaddr:
1540 			string = match_strdup(args);
1541 			if (string == NULL)
1542 				goto out_nomem;
1543 			mnt->mount_server.addrlen =
1544 				rpc_pton(mnt->net, string, strlen(string),
1545 					(struct sockaddr *)
1546 					&mnt->mount_server.address,
1547 					sizeof(mnt->mount_server.address));
1548 			kfree(string);
1549 			if (mnt->mount_server.addrlen == 0)
1550 				goto out_invalid_address;
1551 			break;
1552 		case Opt_lookupcache:
1553 			string = match_strdup(args);
1554 			if (string == NULL)
1555 				goto out_nomem;
1556 			token = match_token(string,
1557 					nfs_lookupcache_tokens, args);
1558 			kfree(string);
1559 			switch (token) {
1560 				case Opt_lookupcache_all:
1561 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1562 					break;
1563 				case Opt_lookupcache_positive:
1564 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1565 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1566 					break;
1567 				case Opt_lookupcache_none:
1568 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1569 					break;
1570 				default:
1571 					dfprintk(MOUNT, "NFS:   invalid "
1572 							"lookupcache argument\n");
1573 					return 0;
1574 			};
1575 			break;
1576 		case Opt_fscache_uniq:
1577 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1578 				goto out_nomem;
1579 			mnt->options |= NFS_OPTION_FSCACHE;
1580 			break;
1581 		case Opt_local_lock:
1582 			string = match_strdup(args);
1583 			if (string == NULL)
1584 				goto out_nomem;
1585 			token = match_token(string, nfs_local_lock_tokens,
1586 					args);
1587 			kfree(string);
1588 			switch (token) {
1589 			case Opt_local_lock_all:
1590 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1591 					       NFS_MOUNT_LOCAL_FCNTL);
1592 				break;
1593 			case Opt_local_lock_flock:
1594 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1595 				break;
1596 			case Opt_local_lock_posix:
1597 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1598 				break;
1599 			case Opt_local_lock_none:
1600 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1601 						NFS_MOUNT_LOCAL_FCNTL);
1602 				break;
1603 			default:
1604 				dfprintk(MOUNT, "NFS:	invalid	"
1605 						"local_lock argument\n");
1606 				return 0;
1607 			};
1608 			break;
1609 
1610 		/*
1611 		 * Special options
1612 		 */
1613 		case Opt_sloppy:
1614 			sloppy = 1;
1615 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1616 			break;
1617 		case Opt_userspace:
1618 		case Opt_deprecated:
1619 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1620 					"'%s'\n", p);
1621 			break;
1622 
1623 		default:
1624 			invalid_option = 1;
1625 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1626 					"'%s'\n", p);
1627 		}
1628 	}
1629 
1630 	if (!sloppy && invalid_option)
1631 		return 0;
1632 
1633 	if (mnt->minorversion && mnt->version != 4)
1634 		goto out_minorversion_mismatch;
1635 
1636 	if (mnt->options & NFS_OPTION_MIGRATION &&
1637 	    (mnt->version != 4 || mnt->minorversion != 0))
1638 		goto out_migration_misuse;
1639 
1640 	/*
1641 	 * verify that any proto=/mountproto= options match the address
1642 	 * families in the addr=/mountaddr= options.
1643 	 */
1644 	if (protofamily != AF_UNSPEC &&
1645 	    protofamily != mnt->nfs_server.address.ss_family)
1646 		goto out_proto_mismatch;
1647 
1648 	if (mountfamily != AF_UNSPEC) {
1649 		if (mnt->mount_server.addrlen) {
1650 			if (mountfamily != mnt->mount_server.address.ss_family)
1651 				goto out_mountproto_mismatch;
1652 		} else {
1653 			if (mountfamily != mnt->nfs_server.address.ss_family)
1654 				goto out_mountproto_mismatch;
1655 		}
1656 	}
1657 
1658 	return 1;
1659 
1660 out_mountproto_mismatch:
1661 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1662 			 "option\n");
1663 	return 0;
1664 out_proto_mismatch:
1665 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1666 	return 0;
1667 out_invalid_address:
1668 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1669 	return 0;
1670 out_invalid_value:
1671 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1672 	return 0;
1673 out_minorversion_mismatch:
1674 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1675 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1676 	return 0;
1677 out_migration_misuse:
1678 	printk(KERN_INFO
1679 		"NFS: 'migration' not supported for this NFS version\n");
1680 	return 0;
1681 out_nomem:
1682 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1683 	return 0;
1684 out_security_failure:
1685 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1686 	return 0;
1687 }
1688 
1689 /*
1690  * Ensure that a specified authtype in args->auth_info is supported by
1691  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1692  * -EACCES if not.
1693  */
1694 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1695 			rpc_authflavor_t *server_authlist, unsigned int count)
1696 {
1697 	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1698 	bool found_auth_null = false;
1699 	unsigned int i;
1700 
1701 	/*
1702 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1703 	 * must be in the list returned by the server.
1704 	 *
1705 	 * AUTH_NULL has a special meaning when it's in the server list - it
1706 	 * means that the server will ignore the rpc creds, so any flavor
1707 	 * can be used but still use the sec= that was specified.
1708 	 *
1709 	 * Note also that the MNT procedure in MNTv1 does not return a list
1710 	 * of supported security flavors. In this case, nfs_mount() fabricates
1711 	 * a security flavor list containing just AUTH_NULL.
1712 	 */
1713 	for (i = 0; i < count; i++) {
1714 		flavor = server_authlist[i];
1715 
1716 		if (nfs_auth_info_match(&args->auth_info, flavor))
1717 			goto out;
1718 
1719 		if (flavor == RPC_AUTH_NULL)
1720 			found_auth_null = true;
1721 	}
1722 
1723 	if (found_auth_null) {
1724 		flavor = args->auth_info.flavors[0];
1725 		goto out;
1726 	}
1727 
1728 	dfprintk(MOUNT,
1729 		 "NFS: specified auth flavors not supported by server\n");
1730 	return -EACCES;
1731 
1732 out:
1733 	args->selected_flavor = flavor;
1734 	dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1735 	return 0;
1736 }
1737 
1738 /*
1739  * Use the remote server's MOUNT service to request the NFS file handle
1740  * corresponding to the provided path.
1741  */
1742 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1743 			     struct nfs_fh *root_fh,
1744 			     rpc_authflavor_t *server_authlist,
1745 			     unsigned int *server_authlist_len)
1746 {
1747 	struct nfs_mount_request request = {
1748 		.sap		= (struct sockaddr *)
1749 						&args->mount_server.address,
1750 		.dirpath	= args->nfs_server.export_path,
1751 		.protocol	= args->mount_server.protocol,
1752 		.fh		= root_fh,
1753 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1754 		.auth_flav_len	= server_authlist_len,
1755 		.auth_flavs	= server_authlist,
1756 		.net		= args->net,
1757 	};
1758 	int status;
1759 
1760 	if (args->mount_server.version == 0) {
1761 		switch (args->version) {
1762 			default:
1763 				args->mount_server.version = NFS_MNT3_VERSION;
1764 				break;
1765 			case 2:
1766 				args->mount_server.version = NFS_MNT_VERSION;
1767 		}
1768 	}
1769 	request.version = args->mount_server.version;
1770 
1771 	if (args->mount_server.hostname)
1772 		request.hostname = args->mount_server.hostname;
1773 	else
1774 		request.hostname = args->nfs_server.hostname;
1775 
1776 	/*
1777 	 * Construct the mount server's address.
1778 	 */
1779 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1780 		memcpy(request.sap, &args->nfs_server.address,
1781 		       args->nfs_server.addrlen);
1782 		args->mount_server.addrlen = args->nfs_server.addrlen;
1783 	}
1784 	request.salen = args->mount_server.addrlen;
1785 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1786 
1787 	/*
1788 	 * Now ask the mount server to map our export path
1789 	 * to a file handle.
1790 	 */
1791 	status = nfs_mount(&request);
1792 	if (status != 0) {
1793 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1794 				request.hostname, status);
1795 		return status;
1796 	}
1797 
1798 	return 0;
1799 }
1800 
1801 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1802 					struct nfs_subversion *nfs_mod)
1803 {
1804 	int status;
1805 	unsigned int i;
1806 	bool tried_auth_unix = false;
1807 	bool auth_null_in_list = false;
1808 	struct nfs_server *server = ERR_PTR(-EACCES);
1809 	struct nfs_parsed_mount_data *args = mount_info->parsed;
1810 	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1811 	unsigned int authlist_len = ARRAY_SIZE(authlist);
1812 
1813 	status = nfs_request_mount(args, mount_info->mntfh, authlist,
1814 					&authlist_len);
1815 	if (status)
1816 		return ERR_PTR(status);
1817 
1818 	/*
1819 	 * Was a sec= authflavor specified in the options? First, verify
1820 	 * whether the server supports it, and then just try to use it if so.
1821 	 */
1822 	if (args->auth_info.flavor_len > 0) {
1823 		status = nfs_verify_authflavors(args, authlist, authlist_len);
1824 		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1825 			 args->selected_flavor);
1826 		if (status)
1827 			return ERR_PTR(status);
1828 		return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1829 	}
1830 
1831 	/*
1832 	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
1833 	 * SHOULD prefer the flavor listed first. However, some servers list
1834 	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1835 	 */
1836 	for (i = 0; i < authlist_len; ++i) {
1837 		rpc_authflavor_t flavor;
1838 		struct rpcsec_gss_info info;
1839 
1840 		flavor = authlist[i];
1841 		switch (flavor) {
1842 		case RPC_AUTH_UNIX:
1843 			tried_auth_unix = true;
1844 			break;
1845 		case RPC_AUTH_NULL:
1846 			auth_null_in_list = true;
1847 			continue;
1848 		default:
1849 			if (rpcauth_get_gssinfo(flavor, &info) != 0)
1850 				continue;
1851 			/* Fallthrough */
1852 		}
1853 		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1854 		args->selected_flavor = flavor;
1855 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1856 		if (!IS_ERR(server))
1857 			return server;
1858 	}
1859 
1860 	/*
1861 	 * Nothing we tried so far worked. At this point, give up if we've
1862 	 * already tried AUTH_UNIX or if the server's list doesn't contain
1863 	 * AUTH_NULL
1864 	 */
1865 	if (tried_auth_unix || !auth_null_in_list)
1866 		return server;
1867 
1868 	/* Last chance! Try AUTH_UNIX */
1869 	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1870 	args->selected_flavor = RPC_AUTH_UNIX;
1871 	return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1872 }
1873 
1874 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1875 			     struct nfs_mount_info *mount_info,
1876 			     struct nfs_subversion *nfs_mod)
1877 {
1878 	struct nfs_server *server;
1879 
1880 	if (mount_info->parsed->need_mount)
1881 		server = nfs_try_mount_request(mount_info, nfs_mod);
1882 	else
1883 		server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1884 
1885 	if (IS_ERR(server))
1886 		return ERR_CAST(server);
1887 
1888 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1889 }
1890 EXPORT_SYMBOL_GPL(nfs_try_mount);
1891 
1892 /*
1893  * Split "dev_name" into "hostname:export_path".
1894  *
1895  * The leftmost colon demarks the split between the server's hostname
1896  * and the export path.  If the hostname starts with a left square
1897  * bracket, then it may contain colons.
1898  *
1899  * Note: caller frees hostname and export path, even on error.
1900  */
1901 static int nfs_parse_devname(const char *dev_name,
1902 			     char **hostname, size_t maxnamlen,
1903 			     char **export_path, size_t maxpathlen)
1904 {
1905 	size_t len;
1906 	char *end;
1907 
1908 	if (unlikely(!dev_name || !*dev_name)) {
1909 		dfprintk(MOUNT, "NFS: device name not specified\n");
1910 		return -EINVAL;
1911 	}
1912 
1913 	/* Is the host name protected with square brakcets? */
1914 	if (*dev_name == '[') {
1915 		end = strchr(++dev_name, ']');
1916 		if (end == NULL || end[1] != ':')
1917 			goto out_bad_devname;
1918 
1919 		len = end - dev_name;
1920 		end++;
1921 	} else {
1922 		char *comma;
1923 
1924 		end = strchr(dev_name, ':');
1925 		if (end == NULL)
1926 			goto out_bad_devname;
1927 		len = end - dev_name;
1928 
1929 		/* kill possible hostname list: not supported */
1930 		comma = strchr(dev_name, ',');
1931 		if (comma != NULL && comma < end)
1932 			len = comma - dev_name;
1933 	}
1934 
1935 	if (len > maxnamlen)
1936 		goto out_hostname;
1937 
1938 	/* N.B. caller will free nfs_server.hostname in all cases */
1939 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1940 	if (*hostname == NULL)
1941 		goto out_nomem;
1942 	len = strlen(++end);
1943 	if (len > maxpathlen)
1944 		goto out_path;
1945 	*export_path = kstrndup(end, len, GFP_KERNEL);
1946 	if (!*export_path)
1947 		goto out_nomem;
1948 
1949 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1950 	return 0;
1951 
1952 out_bad_devname:
1953 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1954 	return -EINVAL;
1955 
1956 out_nomem:
1957 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1958 	return -ENOMEM;
1959 
1960 out_hostname:
1961 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1962 	return -ENAMETOOLONG;
1963 
1964 out_path:
1965 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1966 	return -ENAMETOOLONG;
1967 }
1968 
1969 /*
1970  * Validate the NFS2/NFS3 mount data
1971  * - fills in the mount root filehandle
1972  *
1973  * For option strings, user space handles the following behaviors:
1974  *
1975  * + DNS: mapping server host name to IP address ("addr=" option)
1976  *
1977  * + failure mode: how to behave if a mount request can't be handled
1978  *   immediately ("fg/bg" option)
1979  *
1980  * + retry: how often to retry a mount request ("retry=" option)
1981  *
1982  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1983  *   mountproto=tcp after mountproto=udp, and so on
1984  */
1985 static int nfs23_validate_mount_data(void *options,
1986 				     struct nfs_parsed_mount_data *args,
1987 				     struct nfs_fh *mntfh,
1988 				     const char *dev_name)
1989 {
1990 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1991 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1992 	int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1993 
1994 	if (data == NULL)
1995 		goto out_no_data;
1996 
1997 	args->version = NFS_DEFAULT_VERSION;
1998 	switch (data->version) {
1999 	case 1:
2000 		data->namlen = 0; /* fall through */
2001 	case 2:
2002 		data->bsize = 0; /* fall through */
2003 	case 3:
2004 		if (data->flags & NFS_MOUNT_VER3)
2005 			goto out_no_v3;
2006 		data->root.size = NFS2_FHSIZE;
2007 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
2008 		/* Turn off security negotiation */
2009 		extra_flags |= NFS_MOUNT_SECFLAVOUR;
2010 		/* fall through */
2011 	case 4:
2012 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2013 			goto out_no_sec;
2014 		/* fall through */
2015 	case 5:
2016 		memset(data->context, 0, sizeof(data->context));
2017 		/* fall through */
2018 	case 6:
2019 		if (data->flags & NFS_MOUNT_VER3) {
2020 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
2021 				goto out_invalid_fh;
2022 			mntfh->size = data->root.size;
2023 			args->version = 3;
2024 		} else {
2025 			mntfh->size = NFS2_FHSIZE;
2026 			args->version = 2;
2027 		}
2028 
2029 
2030 		memcpy(mntfh->data, data->root.data, mntfh->size);
2031 		if (mntfh->size < sizeof(mntfh->data))
2032 			memset(mntfh->data + mntfh->size, 0,
2033 			       sizeof(mntfh->data) - mntfh->size);
2034 
2035 		/*
2036 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
2037 		 * can deal with.
2038 		 */
2039 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
2040 		args->flags		|= extra_flags;
2041 		args->rsize		= data->rsize;
2042 		args->wsize		= data->wsize;
2043 		args->timeo		= data->timeo;
2044 		args->retrans		= data->retrans;
2045 		args->acregmin		= data->acregmin;
2046 		args->acregmax		= data->acregmax;
2047 		args->acdirmin		= data->acdirmin;
2048 		args->acdirmax		= data->acdirmax;
2049 		args->need_mount	= false;
2050 
2051 		memcpy(sap, &data->addr, sizeof(data->addr));
2052 		args->nfs_server.addrlen = sizeof(data->addr);
2053 		args->nfs_server.port = ntohs(data->addr.sin_port);
2054 		if (sap->sa_family != AF_INET ||
2055 		    !nfs_verify_server_address(sap))
2056 			goto out_no_address;
2057 
2058 		if (!(data->flags & NFS_MOUNT_TCP))
2059 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2060 		/* N.B. caller will free nfs_server.hostname in all cases */
2061 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2062 		args->namlen		= data->namlen;
2063 		args->bsize		= data->bsize;
2064 
2065 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
2066 			args->selected_flavor = data->pseudoflavor;
2067 		else
2068 			args->selected_flavor = RPC_AUTH_UNIX;
2069 		if (!args->nfs_server.hostname)
2070 			goto out_nomem;
2071 
2072 		if (!(data->flags & NFS_MOUNT_NONLM))
2073 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2074 					 NFS_MOUNT_LOCAL_FCNTL);
2075 		else
2076 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2077 					NFS_MOUNT_LOCAL_FCNTL);
2078 		/*
2079 		 * The legacy version 6 binary mount data from userspace has a
2080 		 * field used only to transport selinux information into the
2081 		 * the kernel.  To continue to support that functionality we
2082 		 * have a touch of selinux knowledge here in the NFS code. The
2083 		 * userspace code converted context=blah to just blah so we are
2084 		 * converting back to the full string selinux understands.
2085 		 */
2086 		if (data->context[0]){
2087 #ifdef CONFIG_SECURITY_SELINUX
2088 			int rc;
2089 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2090 			rc = security_add_mnt_opt("context", data->context,
2091 					strlen(data->context), &args->lsm_opts);
2092 			if (rc)
2093 				return rc;
2094 #else
2095 			return -EINVAL;
2096 #endif
2097 		}
2098 
2099 		break;
2100 	default:
2101 		return NFS_TEXT_DATA;
2102 	}
2103 
2104 	return 0;
2105 
2106 out_no_data:
2107 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2108 	return -EINVAL;
2109 
2110 out_no_v3:
2111 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2112 		 data->version);
2113 	return -EINVAL;
2114 
2115 out_no_sec:
2116 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2117 	return -EINVAL;
2118 
2119 out_nomem:
2120 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2121 	return -ENOMEM;
2122 
2123 out_no_address:
2124 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2125 	return -EINVAL;
2126 
2127 out_invalid_fh:
2128 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2129 	return -EINVAL;
2130 }
2131 
2132 #if IS_ENABLED(CONFIG_NFS_V4)
2133 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2134 				   void *options,
2135 				   struct nfs_parsed_mount_data *args,
2136 				   struct nfs_fh *mntfh,
2137 				   const char *dev_name)
2138 {
2139 	if (fs_type == &nfs_fs_type)
2140 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2141 	return nfs4_validate_mount_data(options, args, dev_name);
2142 }
2143 #else
2144 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2145 				   void *options,
2146 				   struct nfs_parsed_mount_data *args,
2147 				   struct nfs_fh *mntfh,
2148 				   const char *dev_name)
2149 {
2150 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2151 }
2152 #endif
2153 
2154 static int nfs_validate_text_mount_data(void *options,
2155 					struct nfs_parsed_mount_data *args,
2156 					const char *dev_name)
2157 {
2158 	int port = 0;
2159 	int max_namelen = PAGE_SIZE;
2160 	int max_pathlen = NFS_MAXPATHLEN;
2161 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2162 
2163 	if (nfs_parse_mount_options((char *)options, args) == 0)
2164 		return -EINVAL;
2165 
2166 	if (!nfs_verify_server_address(sap))
2167 		goto out_no_address;
2168 
2169 	if (args->version == 4) {
2170 #if IS_ENABLED(CONFIG_NFS_V4)
2171 		if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2172 			port = NFS_RDMA_PORT;
2173 		else
2174 			port = NFS_PORT;
2175 		max_namelen = NFS4_MAXNAMLEN;
2176 		max_pathlen = NFS4_MAXPATHLEN;
2177 		nfs_validate_transport_protocol(args);
2178 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2179 			goto out_invalid_transport_udp;
2180 		nfs4_validate_mount_flags(args);
2181 #else
2182 		goto out_v4_not_compiled;
2183 #endif /* CONFIG_NFS_V4 */
2184 	} else {
2185 		nfs_set_mount_transport_protocol(args);
2186 		if (args->nfs_server.protocol == XPRT_TRANSPORT_RDMA)
2187 			port = NFS_RDMA_PORT;
2188 	}
2189 
2190 	nfs_set_port(sap, &args->nfs_server.port, port);
2191 
2192 	return nfs_parse_devname(dev_name,
2193 				   &args->nfs_server.hostname,
2194 				   max_namelen,
2195 				   &args->nfs_server.export_path,
2196 				   max_pathlen);
2197 
2198 #if !IS_ENABLED(CONFIG_NFS_V4)
2199 out_v4_not_compiled:
2200 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2201 	return -EPROTONOSUPPORT;
2202 #else
2203 out_invalid_transport_udp:
2204 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2205 	return -EINVAL;
2206 #endif /* !CONFIG_NFS_V4 */
2207 
2208 out_no_address:
2209 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2210 	return -EINVAL;
2211 }
2212 
2213 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2214 		| NFS_MOUNT_SECURE \
2215 		| NFS_MOUNT_TCP \
2216 		| NFS_MOUNT_VER3 \
2217 		| NFS_MOUNT_KERBEROS \
2218 		| NFS_MOUNT_NONLM \
2219 		| NFS_MOUNT_BROKEN_SUID \
2220 		| NFS_MOUNT_STRICTLOCK \
2221 		| NFS_MOUNT_LEGACY_INTERFACE)
2222 
2223 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2224 		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2225 
2226 static int
2227 nfs_compare_remount_data(struct nfs_server *nfss,
2228 			 struct nfs_parsed_mount_data *data)
2229 {
2230 	if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2231 	    data->rsize != nfss->rsize ||
2232 	    data->wsize != nfss->wsize ||
2233 	    data->version != nfss->nfs_client->rpc_ops->version ||
2234 	    data->minorversion != nfss->nfs_client->cl_minorversion ||
2235 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2236 	    !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2237 	    data->acregmin != nfss->acregmin / HZ ||
2238 	    data->acregmax != nfss->acregmax / HZ ||
2239 	    data->acdirmin != nfss->acdirmin / HZ ||
2240 	    data->acdirmax != nfss->acdirmax / HZ ||
2241 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2242 	    data->nfs_server.port != nfss->port ||
2243 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2244 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2245 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2246 		return -EINVAL;
2247 
2248 	return 0;
2249 }
2250 
2251 int
2252 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2253 {
2254 	int error;
2255 	struct nfs_server *nfss = sb->s_fs_info;
2256 	struct nfs_parsed_mount_data *data;
2257 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2258 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2259 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2260 
2261 	sync_filesystem(sb);
2262 
2263 	/*
2264 	 * Userspace mount programs that send binary options generally send
2265 	 * them populated with default values. We have no way to know which
2266 	 * ones were explicitly specified. Fall back to legacy behavior and
2267 	 * just return success.
2268 	 */
2269 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2270 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2271 					   options->version <= 6))))
2272 		return 0;
2273 
2274 	data = nfs_alloc_parsed_mount_data();
2275 	if (data == NULL)
2276 		return -ENOMEM;
2277 
2278 	/* fill out struct with values from existing mount */
2279 	data->flags = nfss->flags;
2280 	data->rsize = nfss->rsize;
2281 	data->wsize = nfss->wsize;
2282 	data->retrans = nfss->client->cl_timeout->to_retries;
2283 	data->selected_flavor = nfss->client->cl_auth->au_flavor;
2284 	data->acregmin = nfss->acregmin / HZ;
2285 	data->acregmax = nfss->acregmax / HZ;
2286 	data->acdirmin = nfss->acdirmin / HZ;
2287 	data->acdirmax = nfss->acdirmax / HZ;
2288 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2289 	data->nfs_server.port = nfss->port;
2290 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2291 	data->version = nfsvers;
2292 	data->minorversion = nfss->nfs_client->cl_minorversion;
2293 	data->net = current->nsproxy->net_ns;
2294 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2295 		data->nfs_server.addrlen);
2296 
2297 	/* overwrite those values with any that were specified */
2298 	error = -EINVAL;
2299 	if (!nfs_parse_mount_options((char *)options, data))
2300 		goto out;
2301 
2302 	/*
2303 	 * noac is a special case. It implies -o sync, but that's not
2304 	 * necessarily reflected in the mtab options. do_remount_sb
2305 	 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
2306 	 * remount options, so we have to explicitly reset it.
2307 	 */
2308 	if (data->flags & NFS_MOUNT_NOAC)
2309 		*flags |= SB_SYNCHRONOUS;
2310 
2311 	/* compare new mount options with old ones */
2312 	error = nfs_compare_remount_data(nfss, data);
2313 	if (!error)
2314 		error = security_sb_remount(sb, data->lsm_opts);
2315 out:
2316 	nfs_free_parsed_mount_data(data);
2317 	return error;
2318 }
2319 EXPORT_SYMBOL_GPL(nfs_remount);
2320 
2321 /*
2322  * Initialise the common bits of the superblock
2323  */
2324 static void nfs_initialise_sb(struct super_block *sb)
2325 {
2326 	struct nfs_server *server = NFS_SB(sb);
2327 
2328 	sb->s_magic = NFS_SUPER_MAGIC;
2329 
2330 	/* We probably want something more informative here */
2331 	snprintf(sb->s_id, sizeof(sb->s_id),
2332 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2333 
2334 	if (sb->s_blocksize == 0)
2335 		sb->s_blocksize = nfs_block_bits(server->wsize,
2336 						 &sb->s_blocksize_bits);
2337 
2338 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2339 }
2340 
2341 /*
2342  * Finish setting up an NFS2/3 superblock
2343  */
2344 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2345 {
2346 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2347 	struct nfs_server *server = NFS_SB(sb);
2348 
2349 	sb->s_blocksize_bits = 0;
2350 	sb->s_blocksize = 0;
2351 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2352 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2353 	if (data && data->bsize)
2354 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2355 
2356 	if (server->nfs_client->rpc_ops->version != 2) {
2357 		/* The VFS shouldn't apply the umask to mode bits. We will do
2358 		 * so ourselves when necessary.
2359 		 */
2360 		sb->s_flags |= SB_POSIXACL;
2361 		sb->s_time_gran = 1;
2362 		sb->s_export_op = &nfs_export_ops;
2363 	}
2364 
2365  	nfs_initialise_sb(sb);
2366 }
2367 EXPORT_SYMBOL_GPL(nfs_fill_super);
2368 
2369 /*
2370  * Finish setting up a cloned NFS2/3/4 superblock
2371  */
2372 static void nfs_clone_super(struct super_block *sb,
2373 			    struct nfs_mount_info *mount_info)
2374 {
2375 	const struct super_block *old_sb = mount_info->cloned->sb;
2376 	struct nfs_server *server = NFS_SB(sb);
2377 
2378 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2379 	sb->s_blocksize = old_sb->s_blocksize;
2380 	sb->s_maxbytes = old_sb->s_maxbytes;
2381 	sb->s_xattr = old_sb->s_xattr;
2382 	sb->s_op = old_sb->s_op;
2383 	sb->s_time_gran = 1;
2384 	sb->s_export_op = old_sb->s_export_op;
2385 
2386 	if (server->nfs_client->rpc_ops->version != 2) {
2387 		/* The VFS shouldn't apply the umask to mode bits. We will do
2388 		 * so ourselves when necessary.
2389 		 */
2390 		sb->s_flags |= SB_POSIXACL;
2391 	}
2392 
2393  	nfs_initialise_sb(sb);
2394 }
2395 
2396 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2397 {
2398 	const struct nfs_server *a = s->s_fs_info;
2399 	const struct rpc_clnt *clnt_a = a->client;
2400 	const struct rpc_clnt *clnt_b = b->client;
2401 
2402 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2403 		goto Ebusy;
2404 	if (a->nfs_client != b->nfs_client)
2405 		goto Ebusy;
2406 	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2407 		goto Ebusy;
2408 	if (a->wsize != b->wsize)
2409 		goto Ebusy;
2410 	if (a->rsize != b->rsize)
2411 		goto Ebusy;
2412 	if (a->acregmin != b->acregmin)
2413 		goto Ebusy;
2414 	if (a->acregmax != b->acregmax)
2415 		goto Ebusy;
2416 	if (a->acdirmin != b->acdirmin)
2417 		goto Ebusy;
2418 	if (a->acdirmax != b->acdirmax)
2419 		goto Ebusy;
2420 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2421 		goto Ebusy;
2422 	return 1;
2423 Ebusy:
2424 	return 0;
2425 }
2426 
2427 struct nfs_sb_mountdata {
2428 	struct nfs_server *server;
2429 	int mntflags;
2430 };
2431 
2432 static int nfs_set_super(struct super_block *s, void *data)
2433 {
2434 	struct nfs_sb_mountdata *sb_mntdata = data;
2435 	struct nfs_server *server = sb_mntdata->server;
2436 	int ret;
2437 
2438 	s->s_flags = sb_mntdata->mntflags;
2439 	s->s_fs_info = server;
2440 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2441 	ret = set_anon_super(s, server);
2442 	if (ret == 0)
2443 		server->s_dev = s->s_dev;
2444 	return ret;
2445 }
2446 
2447 static int nfs_compare_super_address(struct nfs_server *server1,
2448 				     struct nfs_server *server2)
2449 {
2450 	struct sockaddr *sap1, *sap2;
2451 	struct rpc_xprt *xprt1 = server1->client->cl_xprt;
2452 	struct rpc_xprt *xprt2 = server2->client->cl_xprt;
2453 
2454 	if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
2455 		return 0;
2456 
2457 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2458 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2459 
2460 	if (sap1->sa_family != sap2->sa_family)
2461 		return 0;
2462 
2463 	switch (sap1->sa_family) {
2464 	case AF_INET: {
2465 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2466 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2467 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2468 			return 0;
2469 		if (sin1->sin_port != sin2->sin_port)
2470 			return 0;
2471 		break;
2472 	}
2473 	case AF_INET6: {
2474 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2475 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2476 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2477 			return 0;
2478 		if (sin1->sin6_port != sin2->sin6_port)
2479 			return 0;
2480 		break;
2481 	}
2482 	default:
2483 		return 0;
2484 	}
2485 
2486 	return 1;
2487 }
2488 
2489 static int nfs_compare_userns(const struct nfs_server *old,
2490 		const struct nfs_server *new)
2491 {
2492 	const struct user_namespace *oldns = &init_user_ns;
2493 	const struct user_namespace *newns = &init_user_ns;
2494 
2495 	if (old->client && old->client->cl_cred)
2496 		oldns = old->client->cl_cred->user_ns;
2497 	if (new->client && new->client->cl_cred)
2498 		newns = new->client->cl_cred->user_ns;
2499 	if (oldns != newns)
2500 		return 0;
2501 	return 1;
2502 }
2503 
2504 static int nfs_compare_super(struct super_block *sb, void *data)
2505 {
2506 	struct nfs_sb_mountdata *sb_mntdata = data;
2507 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2508 	int mntflags = sb_mntdata->mntflags;
2509 
2510 	if (!nfs_compare_super_address(old, server))
2511 		return 0;
2512 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2513 	if (old->flags & NFS_MOUNT_UNSHARED)
2514 		return 0;
2515 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2516 		return 0;
2517 	if (!nfs_compare_userns(old, server))
2518 		return 0;
2519 	return nfs_compare_mount_options(sb, server, mntflags);
2520 }
2521 
2522 #ifdef CONFIG_NFS_FSCACHE
2523 static void nfs_get_cache_cookie(struct super_block *sb,
2524 				 struct nfs_parsed_mount_data *parsed,
2525 				 struct nfs_clone_mount *cloned)
2526 {
2527 	struct nfs_server *nfss = NFS_SB(sb);
2528 	char *uniq = NULL;
2529 	int ulen = 0;
2530 
2531 	nfss->fscache_key = NULL;
2532 	nfss->fscache = NULL;
2533 
2534 	if (parsed) {
2535 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2536 			return;
2537 		if (parsed->fscache_uniq) {
2538 			uniq = parsed->fscache_uniq;
2539 			ulen = strlen(parsed->fscache_uniq);
2540 		}
2541 	} else if (cloned) {
2542 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2543 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2544 			return;
2545 		if (mnt_s->fscache_key) {
2546 			uniq = mnt_s->fscache_key->key.uniquifier;
2547 			ulen = mnt_s->fscache_key->key.uniq_len;
2548 		};
2549 	} else
2550 		return;
2551 
2552 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2553 }
2554 #else
2555 static void nfs_get_cache_cookie(struct super_block *sb,
2556 				 struct nfs_parsed_mount_data *parsed,
2557 				 struct nfs_clone_mount *cloned)
2558 {
2559 }
2560 #endif
2561 
2562 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2563 			struct nfs_mount_info *mount_info)
2564 {
2565 	int error;
2566 	unsigned long kflags = 0, kflags_out = 0;
2567 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2568 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2569 
2570 	error = security_sb_set_mnt_opts(s, mount_info->parsed->lsm_opts,
2571 						kflags, &kflags_out);
2572 	if (error)
2573 		goto err;
2574 
2575 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2576 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2577 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2578 err:
2579 	return error;
2580 }
2581 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2582 
2583 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2584 			  struct nfs_mount_info *mount_info)
2585 {
2586 	int error;
2587 	unsigned long kflags = 0, kflags_out = 0;
2588 
2589 	/* clone any lsm security options from the parent to the new sb */
2590 	if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2591 		return -ESTALE;
2592 
2593 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2594 		kflags |= SECURITY_LSM_NATIVE_LABELS;
2595 
2596 	error = security_sb_clone_mnt_opts(mount_info->cloned->sb, s, kflags,
2597 			&kflags_out);
2598 	if (error)
2599 		return error;
2600 
2601 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2602 		!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2603 		NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2604 	return 0;
2605 }
2606 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2607 
2608 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2609 				   int flags, const char *dev_name,
2610 				   struct nfs_mount_info *mount_info,
2611 				   struct nfs_subversion *nfs_mod)
2612 {
2613 	struct super_block *s;
2614 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2615 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2616 	struct nfs_sb_mountdata sb_mntdata = {
2617 		.mntflags = flags,
2618 		.server = server,
2619 	};
2620 	int error;
2621 
2622 	if (server->flags & NFS_MOUNT_UNSHARED)
2623 		compare_super = NULL;
2624 
2625 	/* -o noac implies -o sync */
2626 	if (server->flags & NFS_MOUNT_NOAC)
2627 		sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2628 
2629 	if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2630 		if (mount_info->cloned->sb->s_flags & SB_SYNCHRONOUS)
2631 			sb_mntdata.mntflags |= SB_SYNCHRONOUS;
2632 
2633 	/* Get a superblock - note that we may end up sharing one that already exists */
2634 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2635 	if (IS_ERR(s)) {
2636 		mntroot = ERR_CAST(s);
2637 		goto out_err_nosb;
2638 	}
2639 
2640 	if (s->s_fs_info != server) {
2641 		nfs_free_server(server);
2642 		server = NULL;
2643 	} else {
2644 		error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
2645 					     MINOR(server->s_dev));
2646 		if (error) {
2647 			mntroot = ERR_PTR(error);
2648 			goto error_splat_super;
2649 		}
2650 		s->s_bdi->ra_pages = server->rpages * NFS_MAX_READAHEAD;
2651 		server->super = s;
2652 	}
2653 
2654 	if (!s->s_root) {
2655 		/* initial superblock/root creation */
2656 		mount_info->fill_super(s, mount_info);
2657 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2658 		if (!(server->flags & NFS_MOUNT_UNSHARED))
2659 			s->s_iflags |= SB_I_MULTIROOT;
2660 	}
2661 
2662 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2663 	if (IS_ERR(mntroot))
2664 		goto error_splat_super;
2665 
2666 	error = mount_info->set_security(s, mntroot, mount_info);
2667 	if (error)
2668 		goto error_splat_root;
2669 
2670 	s->s_flags |= SB_ACTIVE;
2671 
2672 out:
2673 	return mntroot;
2674 
2675 out_err_nosb:
2676 	nfs_free_server(server);
2677 	goto out;
2678 
2679 error_splat_root:
2680 	dput(mntroot);
2681 	mntroot = ERR_PTR(error);
2682 error_splat_super:
2683 	deactivate_locked_super(s);
2684 	goto out;
2685 }
2686 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2687 
2688 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2689 	int flags, const char *dev_name, void *raw_data)
2690 {
2691 	struct nfs_mount_info mount_info = {
2692 		.fill_super = nfs_fill_super,
2693 		.set_security = nfs_set_sb_security,
2694 	};
2695 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2696 	struct nfs_subversion *nfs_mod;
2697 	int error;
2698 
2699 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2700 	mount_info.mntfh = nfs_alloc_fhandle();
2701 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2702 		goto out;
2703 
2704 	/* Validate the mount data */
2705 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2706 	if (error == NFS_TEXT_DATA)
2707 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2708 	if (error < 0) {
2709 		mntroot = ERR_PTR(error);
2710 		goto out;
2711 	}
2712 
2713 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2714 	if (IS_ERR(nfs_mod)) {
2715 		mntroot = ERR_CAST(nfs_mod);
2716 		goto out;
2717 	}
2718 
2719 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2720 
2721 	put_nfs_version(nfs_mod);
2722 out:
2723 	nfs_free_parsed_mount_data(mount_info.parsed);
2724 	nfs_free_fhandle(mount_info.mntfh);
2725 	return mntroot;
2726 }
2727 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2728 
2729 /*
2730  * Destroy an NFS2/3 superblock
2731  */
2732 void nfs_kill_super(struct super_block *s)
2733 {
2734 	struct nfs_server *server = NFS_SB(s);
2735 	dev_t dev = s->s_dev;
2736 
2737 	generic_shutdown_super(s);
2738 
2739 	nfs_fscache_release_super_cookie(s);
2740 
2741 	nfs_free_server(server);
2742 	free_anon_bdev(dev);
2743 }
2744 EXPORT_SYMBOL_GPL(nfs_kill_super);
2745 
2746 /*
2747  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2748  */
2749 static struct dentry *
2750 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2751 		const char *dev_name, void *raw_data)
2752 {
2753 	struct nfs_clone_mount *data = raw_data;
2754 	struct nfs_mount_info mount_info = {
2755 		.fill_super = nfs_clone_super,
2756 		.set_security = nfs_clone_sb_security,
2757 		.cloned = data,
2758 	};
2759 	struct nfs_server *server;
2760 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2761 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2762 
2763 	dprintk("--> nfs_xdev_mount()\n");
2764 
2765 	mount_info.mntfh = mount_info.cloned->fh;
2766 
2767 	/* create a new volume representation */
2768 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2769 
2770 	if (IS_ERR(server))
2771 		mntroot = ERR_CAST(server);
2772 	else
2773 		mntroot = nfs_fs_mount_common(server, flags,
2774 				dev_name, &mount_info, nfs_mod);
2775 
2776 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2777 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2778 	return mntroot;
2779 }
2780 
2781 #if IS_ENABLED(CONFIG_NFS_V4)
2782 
2783 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2784 {
2785 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2786 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2787 }
2788 
2789 /*
2790  * Validate NFSv4 mount options
2791  */
2792 static int nfs4_validate_mount_data(void *options,
2793 				    struct nfs_parsed_mount_data *args,
2794 				    const char *dev_name)
2795 {
2796 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2797 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2798 	char *c;
2799 
2800 	if (data == NULL)
2801 		goto out_no_data;
2802 
2803 	args->version = 4;
2804 
2805 	switch (data->version) {
2806 	case 1:
2807 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2808 			goto out_no_address;
2809 		if (data->host_addrlen == 0)
2810 			goto out_no_address;
2811 		args->nfs_server.addrlen = data->host_addrlen;
2812 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2813 			return -EFAULT;
2814 		if (!nfs_verify_server_address(sap))
2815 			goto out_no_address;
2816 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2817 
2818 		if (data->auth_flavourlen) {
2819 			rpc_authflavor_t pseudoflavor;
2820 			if (data->auth_flavourlen > 1)
2821 				goto out_inval_auth;
2822 			if (copy_from_user(&pseudoflavor,
2823 					   data->auth_flavours,
2824 					   sizeof(pseudoflavor)))
2825 				return -EFAULT;
2826 			args->selected_flavor = pseudoflavor;
2827 		} else
2828 			args->selected_flavor = RPC_AUTH_UNIX;
2829 
2830 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2831 		if (IS_ERR(c))
2832 			return PTR_ERR(c);
2833 		args->nfs_server.hostname = c;
2834 
2835 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2836 		if (IS_ERR(c))
2837 			return PTR_ERR(c);
2838 		args->nfs_server.export_path = c;
2839 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2840 
2841 		c = strndup_user(data->client_addr.data, 16);
2842 		if (IS_ERR(c))
2843 			return PTR_ERR(c);
2844 		args->client_address = c;
2845 
2846 		/*
2847 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2848 		 * can deal with.
2849 		 */
2850 
2851 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2852 		args->rsize	= data->rsize;
2853 		args->wsize	= data->wsize;
2854 		args->timeo	= data->timeo;
2855 		args->retrans	= data->retrans;
2856 		args->acregmin	= data->acregmin;
2857 		args->acregmax	= data->acregmax;
2858 		args->acdirmin	= data->acdirmin;
2859 		args->acdirmax	= data->acdirmax;
2860 		args->nfs_server.protocol = data->proto;
2861 		nfs_validate_transport_protocol(args);
2862 		if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2863 			goto out_invalid_transport_udp;
2864 
2865 		break;
2866 	default:
2867 		return NFS_TEXT_DATA;
2868 	}
2869 
2870 	return 0;
2871 
2872 out_no_data:
2873 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2874 	return -EINVAL;
2875 
2876 out_inval_auth:
2877 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2878 		 data->auth_flavourlen);
2879 	return -EINVAL;
2880 
2881 out_no_address:
2882 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2883 	return -EINVAL;
2884 
2885 out_invalid_transport_udp:
2886 	dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2887 	return -EINVAL;
2888 }
2889 
2890 /*
2891  * NFS v4 module parameters need to stay in the
2892  * NFS client for backwards compatibility
2893  */
2894 unsigned int nfs_callback_set_tcpport;
2895 unsigned short nfs_callback_nr_threads;
2896 /* Default cache timeout is 10 minutes */
2897 unsigned int nfs_idmap_cache_timeout = 600;
2898 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2899 bool nfs4_disable_idmapping = true;
2900 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2901 unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
2902 unsigned short send_implementation_id = 1;
2903 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2904 bool recover_lost_locks = false;
2905 
2906 EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
2907 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2908 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2909 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2910 EXPORT_SYMBOL_GPL(max_session_slots);
2911 EXPORT_SYMBOL_GPL(max_session_cb_slots);
2912 EXPORT_SYMBOL_GPL(send_implementation_id);
2913 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2914 EXPORT_SYMBOL_GPL(recover_lost_locks);
2915 
2916 #define NFS_CALLBACK_MAXPORTNR (65535U)
2917 
2918 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2919 {
2920 	unsigned long num;
2921 	int ret;
2922 
2923 	if (!val)
2924 		return -EINVAL;
2925 	ret = kstrtoul(val, 0, &num);
2926 	if (ret || num > NFS_CALLBACK_MAXPORTNR)
2927 		return -EINVAL;
2928 	*((unsigned int *)kp->arg) = num;
2929 	return 0;
2930 }
2931 static const struct kernel_param_ops param_ops_portnr = {
2932 	.set = param_set_portnr,
2933 	.get = param_get_uint,
2934 };
2935 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2936 
2937 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2938 module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
2939 MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
2940 		"assigned to the NFSv4 callback channels.");
2941 module_param(nfs_idmap_cache_timeout, int, 0644);
2942 module_param(nfs4_disable_idmapping, bool, 0644);
2943 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2944 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2945 MODULE_PARM_DESC(nfs4_disable_idmapping,
2946 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2947 module_param(max_session_slots, ushort, 0644);
2948 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2949 		"requests the client will negotiate");
2950 module_param(max_session_cb_slots, ushort, 0644);
2951 MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
2952 		"callbacks the client will process for a given server");
2953 module_param(send_implementation_id, ushort, 0644);
2954 MODULE_PARM_DESC(send_implementation_id,
2955 		"Send implementation ID with NFSv4.1 exchange_id");
2956 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2957 
2958 module_param(recover_lost_locks, bool, 0644);
2959 MODULE_PARM_DESC(recover_lost_locks,
2960 		 "If the server reports that a lock might be lost, "
2961 		 "try to recover it risking data corruption.");
2962 
2963 
2964 #endif /* CONFIG_NFS_V4 */
2965