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1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/addr.h>
35 #include <linux/sunrpc/stats.h>
36 #include <linux/sunrpc/metrics.h>
37 #include <linux/sunrpc/xprtsock.h>
38 #include <linux/sunrpc/xprtrdma.h>
39 #include <linux/nfs_fs.h>
40 #include <linux/nfs_mount.h>
41 #include <linux/nfs4_mount.h>
42 #include <linux/lockd/bind.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/namei.h>
46 #include <linux/nfs_idmap.h>
47 #include <linux/vfs.h>
48 #include <linux/inet.h>
49 #include <linux/in6.h>
50 #include <linux/slab.h>
51 #include <net/ipv6.h>
52 #include <linux/netdevice.h>
53 #include <linux/nfs_xdr.h>
54 #include <linux/magic.h>
55 #include <linux/parser.h>
56 #include <linux/nsproxy.h>
57 #include <linux/rcupdate.h>
58 
59 #include <asm/uaccess.h>
60 
61 #include "nfs4_fs.h"
62 #include "callback.h"
63 #include "delegation.h"
64 #include "iostat.h"
65 #include "internal.h"
66 #include "fscache.h"
67 #include "nfs4session.h"
68 #include "pnfs.h"
69 #include "nfs.h"
70 
71 #define NFSDBG_FACILITY		NFSDBG_VFS
72 #define NFS_TEXT_DATA		1
73 
74 #if IS_ENABLED(CONFIG_NFS_V3)
75 #define NFS_DEFAULT_VERSION 3
76 #else
77 #define NFS_DEFAULT_VERSION 2
78 #endif
79 
80 enum {
81 	/* Mount options that take no arguments */
82 	Opt_soft, Opt_hard,
83 	Opt_posix, Opt_noposix,
84 	Opt_cto, Opt_nocto,
85 	Opt_ac, Opt_noac,
86 	Opt_lock, Opt_nolock,
87 	Opt_udp, Opt_tcp, Opt_rdma,
88 	Opt_acl, Opt_noacl,
89 	Opt_rdirplus, Opt_nordirplus,
90 	Opt_sharecache, Opt_nosharecache,
91 	Opt_resvport, Opt_noresvport,
92 	Opt_fscache, Opt_nofscache,
93 	Opt_migration, Opt_nomigration,
94 
95 	/* Mount options that take integer arguments */
96 	Opt_port,
97 	Opt_rsize, Opt_wsize, Opt_bsize,
98 	Opt_timeo, Opt_retrans,
99 	Opt_acregmin, Opt_acregmax,
100 	Opt_acdirmin, Opt_acdirmax,
101 	Opt_actimeo,
102 	Opt_namelen,
103 	Opt_mountport,
104 	Opt_mountvers,
105 	Opt_minorversion,
106 
107 	/* Mount options that take string arguments */
108 	Opt_nfsvers,
109 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
110 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
111 	Opt_lookupcache,
112 	Opt_fscache_uniq,
113 	Opt_local_lock,
114 
115 	/* Special mount options */
116 	Opt_userspace, Opt_deprecated, Opt_sloppy,
117 
118 	Opt_err
119 };
120 
121 static const match_table_t nfs_mount_option_tokens = {
122 	{ Opt_userspace, "bg" },
123 	{ Opt_userspace, "fg" },
124 	{ Opt_userspace, "retry=%s" },
125 
126 	{ Opt_sloppy, "sloppy" },
127 
128 	{ Opt_soft, "soft" },
129 	{ Opt_hard, "hard" },
130 	{ Opt_deprecated, "intr" },
131 	{ Opt_deprecated, "nointr" },
132 	{ Opt_posix, "posix" },
133 	{ Opt_noposix, "noposix" },
134 	{ Opt_cto, "cto" },
135 	{ Opt_nocto, "nocto" },
136 	{ Opt_ac, "ac" },
137 	{ Opt_noac, "noac" },
138 	{ Opt_lock, "lock" },
139 	{ Opt_nolock, "nolock" },
140 	{ Opt_udp, "udp" },
141 	{ Opt_tcp, "tcp" },
142 	{ Opt_rdma, "rdma" },
143 	{ Opt_acl, "acl" },
144 	{ Opt_noacl, "noacl" },
145 	{ Opt_rdirplus, "rdirplus" },
146 	{ Opt_nordirplus, "nordirplus" },
147 	{ Opt_sharecache, "sharecache" },
148 	{ Opt_nosharecache, "nosharecache" },
149 	{ Opt_resvport, "resvport" },
150 	{ Opt_noresvport, "noresvport" },
151 	{ Opt_fscache, "fsc" },
152 	{ Opt_nofscache, "nofsc" },
153 	{ Opt_migration, "migration" },
154 	{ Opt_nomigration, "nomigration" },
155 
156 	{ Opt_port, "port=%s" },
157 	{ Opt_rsize, "rsize=%s" },
158 	{ Opt_wsize, "wsize=%s" },
159 	{ Opt_bsize, "bsize=%s" },
160 	{ Opt_timeo, "timeo=%s" },
161 	{ Opt_retrans, "retrans=%s" },
162 	{ Opt_acregmin, "acregmin=%s" },
163 	{ Opt_acregmax, "acregmax=%s" },
164 	{ Opt_acdirmin, "acdirmin=%s" },
165 	{ Opt_acdirmax, "acdirmax=%s" },
166 	{ Opt_actimeo, "actimeo=%s" },
167 	{ Opt_namelen, "namlen=%s" },
168 	{ Opt_mountport, "mountport=%s" },
169 	{ Opt_mountvers, "mountvers=%s" },
170 	{ Opt_minorversion, "minorversion=%s" },
171 
172 	{ Opt_nfsvers, "nfsvers=%s" },
173 	{ Opt_nfsvers, "vers=%s" },
174 
175 	{ Opt_sec, "sec=%s" },
176 	{ Opt_proto, "proto=%s" },
177 	{ Opt_mountproto, "mountproto=%s" },
178 	{ Opt_addr, "addr=%s" },
179 	{ Opt_clientaddr, "clientaddr=%s" },
180 	{ Opt_mounthost, "mounthost=%s" },
181 	{ Opt_mountaddr, "mountaddr=%s" },
182 
183 	{ Opt_lookupcache, "lookupcache=%s" },
184 	{ Opt_fscache_uniq, "fsc=%s" },
185 	{ Opt_local_lock, "local_lock=%s" },
186 
187 	/* The following needs to be listed after all other options */
188 	{ Opt_nfsvers, "v%s" },
189 
190 	{ Opt_err, NULL }
191 };
192 
193 enum {
194 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
195 
196 	Opt_xprt_err
197 };
198 
199 static const match_table_t nfs_xprt_protocol_tokens = {
200 	{ Opt_xprt_udp, "udp" },
201 	{ Opt_xprt_udp6, "udp6" },
202 	{ Opt_xprt_tcp, "tcp" },
203 	{ Opt_xprt_tcp6, "tcp6" },
204 	{ Opt_xprt_rdma, "rdma" },
205 
206 	{ Opt_xprt_err, NULL }
207 };
208 
209 enum {
210 	Opt_sec_none, Opt_sec_sys,
211 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
212 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
213 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
214 
215 	Opt_sec_err
216 };
217 
218 static const match_table_t nfs_secflavor_tokens = {
219 	{ Opt_sec_none, "none" },
220 	{ Opt_sec_none, "null" },
221 	{ Opt_sec_sys, "sys" },
222 
223 	{ Opt_sec_krb5, "krb5" },
224 	{ Opt_sec_krb5i, "krb5i" },
225 	{ Opt_sec_krb5p, "krb5p" },
226 
227 	{ Opt_sec_lkey, "lkey" },
228 	{ Opt_sec_lkeyi, "lkeyi" },
229 	{ Opt_sec_lkeyp, "lkeyp" },
230 
231 	{ Opt_sec_spkm, "spkm3" },
232 	{ Opt_sec_spkmi, "spkm3i" },
233 	{ Opt_sec_spkmp, "spkm3p" },
234 
235 	{ Opt_sec_err, NULL }
236 };
237 
238 enum {
239 	Opt_lookupcache_all, Opt_lookupcache_positive,
240 	Opt_lookupcache_none,
241 
242 	Opt_lookupcache_err
243 };
244 
245 static match_table_t nfs_lookupcache_tokens = {
246 	{ Opt_lookupcache_all, "all" },
247 	{ Opt_lookupcache_positive, "pos" },
248 	{ Opt_lookupcache_positive, "positive" },
249 	{ Opt_lookupcache_none, "none" },
250 
251 	{ Opt_lookupcache_err, NULL }
252 };
253 
254 enum {
255 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
256 	Opt_local_lock_none,
257 
258 	Opt_local_lock_err
259 };
260 
261 static match_table_t nfs_local_lock_tokens = {
262 	{ Opt_local_lock_all, "all" },
263 	{ Opt_local_lock_flock, "flock" },
264 	{ Opt_local_lock_posix, "posix" },
265 	{ Opt_local_lock_none, "none" },
266 
267 	{ Opt_local_lock_err, NULL }
268 };
269 
270 enum {
271 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
272 	Opt_vers_4_1,
273 
274 	Opt_vers_err
275 };
276 
277 static match_table_t nfs_vers_tokens = {
278 	{ Opt_vers_2, "2" },
279 	{ Opt_vers_3, "3" },
280 	{ Opt_vers_4, "4" },
281 	{ Opt_vers_4_0, "4.0" },
282 	{ Opt_vers_4_1, "4.1" },
283 
284 	{ Opt_vers_err, NULL }
285 };
286 
287 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
288 		int flags, const char *dev_name, void *raw_data);
289 
290 struct file_system_type nfs_fs_type = {
291 	.owner		= THIS_MODULE,
292 	.name		= "nfs",
293 	.mount		= nfs_fs_mount,
294 	.kill_sb	= nfs_kill_super,
295 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
296 };
297 MODULE_ALIAS_FS("nfs");
298 EXPORT_SYMBOL_GPL(nfs_fs_type);
299 
300 struct file_system_type nfs_xdev_fs_type = {
301 	.owner		= THIS_MODULE,
302 	.name		= "nfs",
303 	.mount		= nfs_xdev_mount,
304 	.kill_sb	= nfs_kill_super,
305 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
306 };
307 
308 const struct super_operations nfs_sops = {
309 	.alloc_inode	= nfs_alloc_inode,
310 	.destroy_inode	= nfs_destroy_inode,
311 	.write_inode	= nfs_write_inode,
312 	.drop_inode	= nfs_drop_inode,
313 	.put_super	= nfs_put_super,
314 	.statfs		= nfs_statfs,
315 	.evict_inode	= nfs_evict_inode,
316 	.umount_begin	= nfs_umount_begin,
317 	.show_options	= nfs_show_options,
318 	.show_devname	= nfs_show_devname,
319 	.show_path	= nfs_show_path,
320 	.show_stats	= nfs_show_stats,
321 	.remount_fs	= nfs_remount,
322 };
323 EXPORT_SYMBOL_GPL(nfs_sops);
324 
325 #if IS_ENABLED(CONFIG_NFS_V4)
326 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
327 static int nfs4_validate_mount_data(void *options,
328 	struct nfs_parsed_mount_data *args, const char *dev_name);
329 
330 struct file_system_type nfs4_fs_type = {
331 	.owner		= THIS_MODULE,
332 	.name		= "nfs4",
333 	.mount		= nfs_fs_mount,
334 	.kill_sb	= nfs_kill_super,
335 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
336 };
337 MODULE_ALIAS_FS("nfs4");
338 MODULE_ALIAS("nfs4");
339 EXPORT_SYMBOL_GPL(nfs4_fs_type);
340 
register_nfs4_fs(void)341 static int __init register_nfs4_fs(void)
342 {
343 	return register_filesystem(&nfs4_fs_type);
344 }
345 
unregister_nfs4_fs(void)346 static void unregister_nfs4_fs(void)
347 {
348 	unregister_filesystem(&nfs4_fs_type);
349 }
350 #else
register_nfs4_fs(void)351 static int __init register_nfs4_fs(void)
352 {
353 	return 0;
354 }
355 
unregister_nfs4_fs(void)356 static void unregister_nfs4_fs(void)
357 {
358 }
359 #endif
360 
361 static struct shrinker acl_shrinker = {
362 	.shrink		= nfs_access_cache_shrinker,
363 	.seeks		= DEFAULT_SEEKS,
364 };
365 
366 /*
367  * Register the NFS filesystems
368  */
register_nfs_fs(void)369 int __init register_nfs_fs(void)
370 {
371 	int ret;
372 
373         ret = register_filesystem(&nfs_fs_type);
374 	if (ret < 0)
375 		goto error_0;
376 
377 	ret = register_nfs4_fs();
378 	if (ret < 0)
379 		goto error_1;
380 
381 	ret = nfs_register_sysctl();
382 	if (ret < 0)
383 		goto error_2;
384 	register_shrinker(&acl_shrinker);
385 	return 0;
386 
387 error_2:
388 	unregister_nfs4_fs();
389 error_1:
390 	unregister_filesystem(&nfs_fs_type);
391 error_0:
392 	return ret;
393 }
394 
395 /*
396  * Unregister the NFS filesystems
397  */
unregister_nfs_fs(void)398 void __exit unregister_nfs_fs(void)
399 {
400 	unregister_shrinker(&acl_shrinker);
401 	nfs_unregister_sysctl();
402 	unregister_nfs4_fs();
403 	unregister_filesystem(&nfs_fs_type);
404 }
405 
nfs_sb_active(struct super_block * sb)406 void nfs_sb_active(struct super_block *sb)
407 {
408 	struct nfs_server *server = NFS_SB(sb);
409 
410 	if (atomic_inc_return(&server->active) == 1)
411 		atomic_inc(&sb->s_active);
412 }
413 EXPORT_SYMBOL_GPL(nfs_sb_active);
414 
nfs_sb_deactive(struct super_block * sb)415 void nfs_sb_deactive(struct super_block *sb)
416 {
417 	struct nfs_server *server = NFS_SB(sb);
418 
419 	if (atomic_dec_and_test(&server->active))
420 		deactivate_super(sb);
421 }
422 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
423 
424 /*
425  * Deliver file system statistics to userspace
426  */
nfs_statfs(struct dentry * dentry,struct kstatfs * buf)427 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
428 {
429 	struct nfs_server *server = NFS_SB(dentry->d_sb);
430 	unsigned char blockbits;
431 	unsigned long blockres;
432 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
433 	struct nfs_fsstat res;
434 	int error = -ENOMEM;
435 
436 	res.fattr = nfs_alloc_fattr();
437 	if (res.fattr == NULL)
438 		goto out_err;
439 
440 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
441 	if (unlikely(error == -ESTALE)) {
442 		struct dentry *pd_dentry;
443 
444 		pd_dentry = dget_parent(dentry);
445 		if (pd_dentry != NULL) {
446 			nfs_zap_caches(pd_dentry->d_inode);
447 			dput(pd_dentry);
448 		}
449 	}
450 	nfs_free_fattr(res.fattr);
451 	if (error < 0)
452 		goto out_err;
453 
454 	buf->f_type = NFS_SUPER_MAGIC;
455 
456 	/*
457 	 * Current versions of glibc do not correctly handle the
458 	 * case where f_frsize != f_bsize.  Eventually we want to
459 	 * report the value of wtmult in this field.
460 	 */
461 	buf->f_frsize = dentry->d_sb->s_blocksize;
462 
463 	/*
464 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
465 	 * are reported in units of f_frsize.  Linux hasn't had
466 	 * an f_frsize field in its statfs struct until recently,
467 	 * thus historically Linux's sys_statfs reports these
468 	 * fields in units of f_bsize.
469 	 */
470 	buf->f_bsize = dentry->d_sb->s_blocksize;
471 	blockbits = dentry->d_sb->s_blocksize_bits;
472 	blockres = (1 << blockbits) - 1;
473 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
474 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
475 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
476 
477 	buf->f_files = res.tfiles;
478 	buf->f_ffree = res.afiles;
479 
480 	buf->f_namelen = server->namelen;
481 
482 	return 0;
483 
484  out_err:
485 	dprintk("%s: statfs error = %d\n", __func__, -error);
486 	return error;
487 }
488 EXPORT_SYMBOL_GPL(nfs_statfs);
489 
490 /*
491  * Map the security flavour number to a name
492  */
nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)493 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
494 {
495 	static const struct {
496 		rpc_authflavor_t flavour;
497 		const char *str;
498 	} sec_flavours[] = {
499 		{ RPC_AUTH_NULL, "null" },
500 		{ RPC_AUTH_UNIX, "sys" },
501 		{ RPC_AUTH_GSS_KRB5, "krb5" },
502 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
503 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
504 		{ RPC_AUTH_GSS_LKEY, "lkey" },
505 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
506 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
507 		{ RPC_AUTH_GSS_SPKM, "spkm" },
508 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
509 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
510 		{ UINT_MAX, "unknown" }
511 	};
512 	int i;
513 
514 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
515 		if (sec_flavours[i].flavour == flavour)
516 			break;
517 	}
518 	return sec_flavours[i].str;
519 }
520 
nfs_show_mountd_netid(struct seq_file * m,struct nfs_server * nfss,int showdefaults)521 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
522 				  int showdefaults)
523 {
524 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
525 
526 	seq_printf(m, ",mountproto=");
527 	switch (sap->sa_family) {
528 	case AF_INET:
529 		switch (nfss->mountd_protocol) {
530 		case IPPROTO_UDP:
531 			seq_printf(m, RPCBIND_NETID_UDP);
532 			break;
533 		case IPPROTO_TCP:
534 			seq_printf(m, RPCBIND_NETID_TCP);
535 			break;
536 		default:
537 			if (showdefaults)
538 				seq_printf(m, "auto");
539 		}
540 		break;
541 	case AF_INET6:
542 		switch (nfss->mountd_protocol) {
543 		case IPPROTO_UDP:
544 			seq_printf(m, RPCBIND_NETID_UDP6);
545 			break;
546 		case IPPROTO_TCP:
547 			seq_printf(m, RPCBIND_NETID_TCP6);
548 			break;
549 		default:
550 			if (showdefaults)
551 				seq_printf(m, "auto");
552 		}
553 		break;
554 	default:
555 		if (showdefaults)
556 			seq_printf(m, "auto");
557 	}
558 }
559 
nfs_show_mountd_options(struct seq_file * m,struct nfs_server * nfss,int showdefaults)560 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
561 				    int showdefaults)
562 {
563 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
564 
565 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
566 		return;
567 
568 	switch (sap->sa_family) {
569 	case AF_INET: {
570 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
571 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
572 		break;
573 	}
574 	case AF_INET6: {
575 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
576 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
577 		break;
578 	}
579 	default:
580 		if (showdefaults)
581 			seq_printf(m, ",mountaddr=unspecified");
582 	}
583 
584 	if (nfss->mountd_version || showdefaults)
585 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
586 	if ((nfss->mountd_port &&
587 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
588 		showdefaults)
589 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
590 
591 	nfs_show_mountd_netid(m, nfss, showdefaults);
592 }
593 
594 #if IS_ENABLED(CONFIG_NFS_V4)
nfs_show_nfsv4_options(struct seq_file * m,struct nfs_server * nfss,int showdefaults)595 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
596 				    int showdefaults)
597 {
598 	struct nfs_client *clp = nfss->nfs_client;
599 
600 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
601 }
602 #else
nfs_show_nfsv4_options(struct seq_file * m,struct nfs_server * nfss,int showdefaults)603 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
604 				    int showdefaults)
605 {
606 }
607 #endif
608 
nfs_show_nfs_version(struct seq_file * m,unsigned int version,unsigned int minorversion)609 static void nfs_show_nfs_version(struct seq_file *m,
610 		unsigned int version,
611 		unsigned int minorversion)
612 {
613 	seq_printf(m, ",vers=%u", version);
614 	if (version == 4)
615 		seq_printf(m, ".%u", minorversion);
616 }
617 
618 /*
619  * Describe the mount options in force on this server representation
620  */
nfs_show_mount_options(struct seq_file * m,struct nfs_server * nfss,int showdefaults)621 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
622 				   int showdefaults)
623 {
624 	static const struct proc_nfs_info {
625 		int flag;
626 		const char *str;
627 		const char *nostr;
628 	} nfs_info[] = {
629 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
630 		{ NFS_MOUNT_POSIX, ",posix", "" },
631 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
632 		{ NFS_MOUNT_NOAC, ",noac", "" },
633 		{ NFS_MOUNT_NONLM, ",nolock", "" },
634 		{ NFS_MOUNT_NOACL, ",noacl", "" },
635 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
636 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
637 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
638 		{ 0, NULL, NULL }
639 	};
640 	const struct proc_nfs_info *nfs_infop;
641 	struct nfs_client *clp = nfss->nfs_client;
642 	u32 version = clp->rpc_ops->version;
643 	int local_flock, local_fcntl;
644 
645 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
646 	seq_printf(m, ",rsize=%u", nfss->rsize);
647 	seq_printf(m, ",wsize=%u", nfss->wsize);
648 	if (nfss->bsize != 0)
649 		seq_printf(m, ",bsize=%u", nfss->bsize);
650 	seq_printf(m, ",namlen=%u", nfss->namelen);
651 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
652 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
653 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
654 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
655 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
656 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
657 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
658 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
659 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
660 		if (nfss->flags & nfs_infop->flag)
661 			seq_puts(m, nfs_infop->str);
662 		else
663 			seq_puts(m, nfs_infop->nostr);
664 	}
665 	rcu_read_lock();
666 	seq_printf(m, ",proto=%s",
667 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
668 	rcu_read_unlock();
669 	if (version == 4) {
670 		if (nfss->port != NFS_PORT)
671 			seq_printf(m, ",port=%u", nfss->port);
672 	} else
673 		if (nfss->port)
674 			seq_printf(m, ",port=%u", nfss->port);
675 
676 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
677 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
678 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
679 
680 	if (version != 4)
681 		nfs_show_mountd_options(m, nfss, showdefaults);
682 	else
683 		nfs_show_nfsv4_options(m, nfss, showdefaults);
684 
685 	if (nfss->options & NFS_OPTION_FSCACHE)
686 		seq_printf(m, ",fsc");
687 
688 	if (nfss->options & NFS_OPTION_MIGRATION)
689 		seq_printf(m, ",migration");
690 
691 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
692 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
693 			seq_printf(m, ",lookupcache=none");
694 		else
695 			seq_printf(m, ",lookupcache=pos");
696 	}
697 
698 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
699 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
700 
701 	if (!local_flock && !local_fcntl)
702 		seq_printf(m, ",local_lock=none");
703 	else if (local_flock && local_fcntl)
704 		seq_printf(m, ",local_lock=all");
705 	else if (local_flock)
706 		seq_printf(m, ",local_lock=flock");
707 	else
708 		seq_printf(m, ",local_lock=posix");
709 }
710 
711 /*
712  * Describe the mount options on this VFS mountpoint
713  */
nfs_show_options(struct seq_file * m,struct dentry * root)714 int nfs_show_options(struct seq_file *m, struct dentry *root)
715 {
716 	struct nfs_server *nfss = NFS_SB(root->d_sb);
717 
718 	nfs_show_mount_options(m, nfss, 0);
719 
720 	rcu_read_lock();
721 	seq_printf(m, ",addr=%s",
722 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
723 							RPC_DISPLAY_ADDR));
724 	rcu_read_unlock();
725 
726 	return 0;
727 }
728 EXPORT_SYMBOL_GPL(nfs_show_options);
729 
730 #if IS_ENABLED(CONFIG_NFS_V4)
731 #ifdef CONFIG_NFS_V4_1
show_sessions(struct seq_file * m,struct nfs_server * server)732 static void show_sessions(struct seq_file *m, struct nfs_server *server)
733 {
734 	if (nfs4_has_session(server->nfs_client))
735 		seq_printf(m, ",sessions");
736 }
737 #else
show_sessions(struct seq_file * m,struct nfs_server * server)738 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
739 #endif
740 #endif
741 
742 #ifdef CONFIG_NFS_V4_1
show_pnfs(struct seq_file * m,struct nfs_server * server)743 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
744 {
745 	seq_printf(m, ",pnfs=");
746 	if (server->pnfs_curr_ld)
747 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
748 	else
749 		seq_printf(m, "not configured");
750 }
751 
show_implementation_id(struct seq_file * m,struct nfs_server * nfss)752 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
753 {
754 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
755 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
756 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
757 			   "date='%llu,%u'",
758 			   impl_id->name, impl_id->domain,
759 			   impl_id->date.seconds, impl_id->date.nseconds);
760 	}
761 }
762 #else
763 #if IS_ENABLED(CONFIG_NFS_V4)
show_pnfs(struct seq_file * m,struct nfs_server * server)764 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
765 {
766 }
767 #endif
show_implementation_id(struct seq_file * m,struct nfs_server * nfss)768 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
769 {
770 }
771 #endif
772 
nfs_show_devname(struct seq_file * m,struct dentry * root)773 int nfs_show_devname(struct seq_file *m, struct dentry *root)
774 {
775 	char *page = (char *) __get_free_page(GFP_KERNEL);
776 	char *devname, *dummy;
777 	int err = 0;
778 	if (!page)
779 		return -ENOMEM;
780 	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
781 	if (IS_ERR(devname))
782 		err = PTR_ERR(devname);
783 	else
784 		seq_escape(m, devname, " \t\n\\");
785 	free_page((unsigned long)page);
786 	return err;
787 }
788 EXPORT_SYMBOL_GPL(nfs_show_devname);
789 
nfs_show_path(struct seq_file * m,struct dentry * dentry)790 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
791 {
792 	seq_puts(m, "/");
793 	return 0;
794 }
795 EXPORT_SYMBOL_GPL(nfs_show_path);
796 
797 /*
798  * Present statistical information for this VFS mountpoint
799  */
nfs_show_stats(struct seq_file * m,struct dentry * root)800 int nfs_show_stats(struct seq_file *m, struct dentry *root)
801 {
802 	int i, cpu;
803 	struct nfs_server *nfss = NFS_SB(root->d_sb);
804 	struct rpc_auth *auth = nfss->client->cl_auth;
805 	struct nfs_iostats totals = { };
806 
807 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
808 
809 	/*
810 	 * Display all mount option settings
811 	 */
812 	seq_printf(m, "\n\topts:\t");
813 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
814 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
815 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
816 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
817 	nfs_show_mount_options(m, nfss, 1);
818 
819 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
820 
821 	show_implementation_id(m, nfss);
822 
823 	seq_printf(m, "\n\tcaps:\t");
824 	seq_printf(m, "caps=0x%x", nfss->caps);
825 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
826 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
827 	seq_printf(m, ",bsize=%u", nfss->bsize);
828 	seq_printf(m, ",namlen=%u", nfss->namelen);
829 
830 #if IS_ENABLED(CONFIG_NFS_V4)
831 	if (nfss->nfs_client->rpc_ops->version == 4) {
832 		seq_printf(m, "\n\tnfsv4:\t");
833 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
834 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
835 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
836 		show_sessions(m, nfss);
837 		show_pnfs(m, nfss);
838 	}
839 #endif
840 
841 	/*
842 	 * Display security flavor in effect for this mount
843 	 */
844 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
845 	if (auth->au_flavor)
846 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
847 
848 	/*
849 	 * Display superblock I/O counters
850 	 */
851 	for_each_possible_cpu(cpu) {
852 		struct nfs_iostats *stats;
853 
854 		preempt_disable();
855 		stats = per_cpu_ptr(nfss->io_stats, cpu);
856 
857 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
858 			totals.events[i] += stats->events[i];
859 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
860 			totals.bytes[i] += stats->bytes[i];
861 #ifdef CONFIG_NFS_FSCACHE
862 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
863 			totals.fscache[i] += stats->fscache[i];
864 #endif
865 
866 		preempt_enable();
867 	}
868 
869 	seq_printf(m, "\n\tevents:\t");
870 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
871 		seq_printf(m, "%lu ", totals.events[i]);
872 	seq_printf(m, "\n\tbytes:\t");
873 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
874 		seq_printf(m, "%Lu ", totals.bytes[i]);
875 #ifdef CONFIG_NFS_FSCACHE
876 	if (nfss->options & NFS_OPTION_FSCACHE) {
877 		seq_printf(m, "\n\tfsc:\t");
878 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
879 			seq_printf(m, "%Lu ", totals.bytes[i]);
880 	}
881 #endif
882 	seq_printf(m, "\n");
883 
884 	rpc_print_iostats(m, nfss->client);
885 
886 	return 0;
887 }
888 EXPORT_SYMBOL_GPL(nfs_show_stats);
889 
890 /*
891  * Begin unmount by attempting to remove all automounted mountpoints we added
892  * in response to xdev traversals and referrals
893  */
nfs_umount_begin(struct super_block * sb)894 void nfs_umount_begin(struct super_block *sb)
895 {
896 	struct nfs_server *server;
897 	struct rpc_clnt *rpc;
898 
899 	server = NFS_SB(sb);
900 	/* -EIO all pending I/O */
901 	rpc = server->client_acl;
902 	if (!IS_ERR(rpc))
903 		rpc_killall_tasks(rpc);
904 	rpc = server->client;
905 	if (!IS_ERR(rpc))
906 		rpc_killall_tasks(rpc);
907 }
908 EXPORT_SYMBOL_GPL(nfs_umount_begin);
909 
nfs_alloc_parsed_mount_data(void)910 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
911 {
912 	struct nfs_parsed_mount_data *data;
913 
914 	data = kzalloc(sizeof(*data), GFP_KERNEL);
915 	if (data) {
916 		data->acregmin		= NFS_DEF_ACREGMIN;
917 		data->acregmax		= NFS_DEF_ACREGMAX;
918 		data->acdirmin		= NFS_DEF_ACDIRMIN;
919 		data->acdirmax		= NFS_DEF_ACDIRMAX;
920 		data->mount_server.port	= NFS_UNSPEC_PORT;
921 		data->nfs_server.port	= NFS_UNSPEC_PORT;
922 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
923 		data->auth_flavors[0]	= RPC_AUTH_MAXFLAVOR;
924 		data->auth_flavor_len	= 1;
925 		data->minorversion	= 0;
926 		data->need_mount	= true;
927 		data->net		= current->nsproxy->net_ns;
928 		security_init_mnt_opts(&data->lsm_opts);
929 	}
930 	return data;
931 }
932 
nfs_free_parsed_mount_data(struct nfs_parsed_mount_data * data)933 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
934 {
935 	if (data) {
936 		kfree(data->client_address);
937 		kfree(data->mount_server.hostname);
938 		kfree(data->nfs_server.export_path);
939 		kfree(data->nfs_server.hostname);
940 		kfree(data->fscache_uniq);
941 		security_free_mnt_opts(&data->lsm_opts);
942 		kfree(data);
943 	}
944 }
945 
946 /*
947  * Sanity-check a server address provided by the mount command.
948  *
949  * Address family must be initialized, and address must not be
950  * the ANY address for that family.
951  */
nfs_verify_server_address(struct sockaddr * addr)952 static int nfs_verify_server_address(struct sockaddr *addr)
953 {
954 	switch (addr->sa_family) {
955 	case AF_INET: {
956 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
957 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
958 	}
959 	case AF_INET6: {
960 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
961 		return !ipv6_addr_any(sa);
962 	}
963 	}
964 
965 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
966 	return 0;
967 }
968 
969 /*
970  * Select between a default port value and a user-specified port value.
971  * If a zero value is set, then autobind will be used.
972  */
nfs_set_port(struct sockaddr * sap,int * port,const unsigned short default_port)973 static void nfs_set_port(struct sockaddr *sap, int *port,
974 				 const unsigned short default_port)
975 {
976 	if (*port == NFS_UNSPEC_PORT)
977 		*port = default_port;
978 
979 	rpc_set_port(sap, *port);
980 }
981 
982 /*
983  * Sanity check the NFS transport protocol.
984  *
985  */
nfs_validate_transport_protocol(struct nfs_parsed_mount_data * mnt)986 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
987 {
988 	switch (mnt->nfs_server.protocol) {
989 	case XPRT_TRANSPORT_UDP:
990 	case XPRT_TRANSPORT_TCP:
991 	case XPRT_TRANSPORT_RDMA:
992 		break;
993 	default:
994 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
995 	}
996 }
997 
998 /*
999  * For text based NFSv2/v3 mounts, the mount protocol transport default
1000  * settings should depend upon the specified NFS transport.
1001  */
nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data * mnt)1002 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1003 {
1004 	nfs_validate_transport_protocol(mnt);
1005 
1006 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1007 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1008 			return;
1009 	switch (mnt->nfs_server.protocol) {
1010 	case XPRT_TRANSPORT_UDP:
1011 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1012 		break;
1013 	case XPRT_TRANSPORT_TCP:
1014 	case XPRT_TRANSPORT_RDMA:
1015 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1016 	}
1017 }
1018 
1019 /*
1020  * Parse the value of the 'sec=' option.
1021  */
nfs_parse_security_flavors(char * value,struct nfs_parsed_mount_data * mnt)1022 static int nfs_parse_security_flavors(char *value,
1023 				      struct nfs_parsed_mount_data *mnt)
1024 {
1025 	substring_t args[MAX_OPT_ARGS];
1026 
1027 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1028 
1029 	switch (match_token(value, nfs_secflavor_tokens, args)) {
1030 	case Opt_sec_none:
1031 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
1032 		break;
1033 	case Opt_sec_sys:
1034 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1035 		break;
1036 	case Opt_sec_krb5:
1037 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1038 		break;
1039 	case Opt_sec_krb5i:
1040 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1041 		break;
1042 	case Opt_sec_krb5p:
1043 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1044 		break;
1045 	case Opt_sec_lkey:
1046 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1047 		break;
1048 	case Opt_sec_lkeyi:
1049 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1050 		break;
1051 	case Opt_sec_lkeyp:
1052 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1053 		break;
1054 	case Opt_sec_spkm:
1055 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1056 		break;
1057 	case Opt_sec_spkmi:
1058 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1059 		break;
1060 	case Opt_sec_spkmp:
1061 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1062 		break;
1063 	default:
1064 		return 0;
1065 	}
1066 
1067 	mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1068 	mnt->auth_flavor_len = 1;
1069 	return 1;
1070 }
1071 
nfs_parse_version_string(char * string,struct nfs_parsed_mount_data * mnt,substring_t * args)1072 static int nfs_parse_version_string(char *string,
1073 		struct nfs_parsed_mount_data *mnt,
1074 		substring_t *args)
1075 {
1076 	mnt->flags &= ~NFS_MOUNT_VER3;
1077 	switch (match_token(string, nfs_vers_tokens, args)) {
1078 	case Opt_vers_2:
1079 		mnt->version = 2;
1080 		break;
1081 	case Opt_vers_3:
1082 		mnt->flags |= NFS_MOUNT_VER3;
1083 		mnt->version = 3;
1084 		break;
1085 	case Opt_vers_4:
1086 		/* Backward compatibility option. In future,
1087 		 * the mount program should always supply
1088 		 * a NFSv4 minor version number.
1089 		 */
1090 		mnt->version = 4;
1091 		break;
1092 	case Opt_vers_4_0:
1093 		mnt->version = 4;
1094 		mnt->minorversion = 0;
1095 		break;
1096 	case Opt_vers_4_1:
1097 		mnt->version = 4;
1098 		mnt->minorversion = 1;
1099 		break;
1100 	default:
1101 		return 0;
1102 	}
1103 	return 1;
1104 }
1105 
nfs_get_option_str(substring_t args[],char ** option)1106 static int nfs_get_option_str(substring_t args[], char **option)
1107 {
1108 	kfree(*option);
1109 	*option = match_strdup(args);
1110 	return !*option;
1111 }
1112 
nfs_get_option_ul(substring_t args[],unsigned long * option)1113 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1114 {
1115 	int rc;
1116 	char *string;
1117 
1118 	string = match_strdup(args);
1119 	if (string == NULL)
1120 		return -ENOMEM;
1121 	rc = kstrtoul(string, 10, option);
1122 	kfree(string);
1123 
1124 	return rc;
1125 }
1126 
1127 /*
1128  * Error-check and convert a string of mount options from user space into
1129  * a data structure.  The whole mount string is processed; bad options are
1130  * skipped as they are encountered.  If there were no errors, return 1;
1131  * otherwise return 0 (zero).
1132  */
nfs_parse_mount_options(char * raw,struct nfs_parsed_mount_data * mnt)1133 static int nfs_parse_mount_options(char *raw,
1134 				   struct nfs_parsed_mount_data *mnt)
1135 {
1136 	char *p, *string, *secdata;
1137 	int rc, sloppy = 0, invalid_option = 0;
1138 	unsigned short protofamily = AF_UNSPEC;
1139 	unsigned short mountfamily = AF_UNSPEC;
1140 
1141 	if (!raw) {
1142 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1143 		return 1;
1144 	}
1145 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1146 
1147 	secdata = alloc_secdata();
1148 	if (!secdata)
1149 		goto out_nomem;
1150 
1151 	rc = security_sb_copy_data(raw, secdata);
1152 	if (rc)
1153 		goto out_security_failure;
1154 
1155 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1156 	if (rc)
1157 		goto out_security_failure;
1158 
1159 	free_secdata(secdata);
1160 
1161 	while ((p = strsep(&raw, ",")) != NULL) {
1162 		substring_t args[MAX_OPT_ARGS];
1163 		unsigned long option;
1164 		int token;
1165 
1166 		if (!*p)
1167 			continue;
1168 
1169 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1170 
1171 		token = match_token(p, nfs_mount_option_tokens, args);
1172 		switch (token) {
1173 
1174 		/*
1175 		 * boolean options:  foo/nofoo
1176 		 */
1177 		case Opt_soft:
1178 			mnt->flags |= NFS_MOUNT_SOFT;
1179 			break;
1180 		case Opt_hard:
1181 			mnt->flags &= ~NFS_MOUNT_SOFT;
1182 			break;
1183 		case Opt_posix:
1184 			mnt->flags |= NFS_MOUNT_POSIX;
1185 			break;
1186 		case Opt_noposix:
1187 			mnt->flags &= ~NFS_MOUNT_POSIX;
1188 			break;
1189 		case Opt_cto:
1190 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1191 			break;
1192 		case Opt_nocto:
1193 			mnt->flags |= NFS_MOUNT_NOCTO;
1194 			break;
1195 		case Opt_ac:
1196 			mnt->flags &= ~NFS_MOUNT_NOAC;
1197 			break;
1198 		case Opt_noac:
1199 			mnt->flags |= NFS_MOUNT_NOAC;
1200 			break;
1201 		case Opt_lock:
1202 			mnt->flags &= ~NFS_MOUNT_NONLM;
1203 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1204 					NFS_MOUNT_LOCAL_FCNTL);
1205 			break;
1206 		case Opt_nolock:
1207 			mnt->flags |= NFS_MOUNT_NONLM;
1208 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1209 				       NFS_MOUNT_LOCAL_FCNTL);
1210 			break;
1211 		case Opt_udp:
1212 			mnt->flags &= ~NFS_MOUNT_TCP;
1213 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1214 			break;
1215 		case Opt_tcp:
1216 			mnt->flags |= NFS_MOUNT_TCP;
1217 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1218 			break;
1219 		case Opt_rdma:
1220 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1221 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1222 			xprt_load_transport(p);
1223 			break;
1224 		case Opt_acl:
1225 			mnt->flags &= ~NFS_MOUNT_NOACL;
1226 			break;
1227 		case Opt_noacl:
1228 			mnt->flags |= NFS_MOUNT_NOACL;
1229 			break;
1230 		case Opt_rdirplus:
1231 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1232 			break;
1233 		case Opt_nordirplus:
1234 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1235 			break;
1236 		case Opt_sharecache:
1237 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1238 			break;
1239 		case Opt_nosharecache:
1240 			mnt->flags |= NFS_MOUNT_UNSHARED;
1241 			break;
1242 		case Opt_resvport:
1243 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1244 			break;
1245 		case Opt_noresvport:
1246 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1247 			break;
1248 		case Opt_fscache:
1249 			mnt->options |= NFS_OPTION_FSCACHE;
1250 			kfree(mnt->fscache_uniq);
1251 			mnt->fscache_uniq = NULL;
1252 			break;
1253 		case Opt_nofscache:
1254 			mnt->options &= ~NFS_OPTION_FSCACHE;
1255 			kfree(mnt->fscache_uniq);
1256 			mnt->fscache_uniq = NULL;
1257 			break;
1258 		case Opt_migration:
1259 			mnt->options |= NFS_OPTION_MIGRATION;
1260 			break;
1261 		case Opt_nomigration:
1262 			mnt->options &= NFS_OPTION_MIGRATION;
1263 			break;
1264 
1265 		/*
1266 		 * options that take numeric values
1267 		 */
1268 		case Opt_port:
1269 			if (nfs_get_option_ul(args, &option) ||
1270 			    option > USHRT_MAX)
1271 				goto out_invalid_value;
1272 			mnt->nfs_server.port = option;
1273 			break;
1274 		case Opt_rsize:
1275 			if (nfs_get_option_ul(args, &option))
1276 				goto out_invalid_value;
1277 			mnt->rsize = option;
1278 			break;
1279 		case Opt_wsize:
1280 			if (nfs_get_option_ul(args, &option))
1281 				goto out_invalid_value;
1282 			mnt->wsize = option;
1283 			break;
1284 		case Opt_bsize:
1285 			if (nfs_get_option_ul(args, &option))
1286 				goto out_invalid_value;
1287 			mnt->bsize = option;
1288 			break;
1289 		case Opt_timeo:
1290 			if (nfs_get_option_ul(args, &option) || option == 0)
1291 				goto out_invalid_value;
1292 			mnt->timeo = option;
1293 			break;
1294 		case Opt_retrans:
1295 			if (nfs_get_option_ul(args, &option) || option == 0)
1296 				goto out_invalid_value;
1297 			mnt->retrans = option;
1298 			break;
1299 		case Opt_acregmin:
1300 			if (nfs_get_option_ul(args, &option))
1301 				goto out_invalid_value;
1302 			mnt->acregmin = option;
1303 			break;
1304 		case Opt_acregmax:
1305 			if (nfs_get_option_ul(args, &option))
1306 				goto out_invalid_value;
1307 			mnt->acregmax = option;
1308 			break;
1309 		case Opt_acdirmin:
1310 			if (nfs_get_option_ul(args, &option))
1311 				goto out_invalid_value;
1312 			mnt->acdirmin = option;
1313 			break;
1314 		case Opt_acdirmax:
1315 			if (nfs_get_option_ul(args, &option))
1316 				goto out_invalid_value;
1317 			mnt->acdirmax = option;
1318 			break;
1319 		case Opt_actimeo:
1320 			if (nfs_get_option_ul(args, &option))
1321 				goto out_invalid_value;
1322 			mnt->acregmin = mnt->acregmax =
1323 			mnt->acdirmin = mnt->acdirmax = option;
1324 			break;
1325 		case Opt_namelen:
1326 			if (nfs_get_option_ul(args, &option))
1327 				goto out_invalid_value;
1328 			mnt->namlen = option;
1329 			break;
1330 		case Opt_mountport:
1331 			if (nfs_get_option_ul(args, &option) ||
1332 			    option > USHRT_MAX)
1333 				goto out_invalid_value;
1334 			mnt->mount_server.port = option;
1335 			break;
1336 		case Opt_mountvers:
1337 			if (nfs_get_option_ul(args, &option) ||
1338 			    option < NFS_MNT_VERSION ||
1339 			    option > NFS_MNT3_VERSION)
1340 				goto out_invalid_value;
1341 			mnt->mount_server.version = option;
1342 			break;
1343 		case Opt_minorversion:
1344 			if (nfs_get_option_ul(args, &option))
1345 				goto out_invalid_value;
1346 			if (option > NFS4_MAX_MINOR_VERSION)
1347 				goto out_invalid_value;
1348 			mnt->minorversion = option;
1349 			break;
1350 
1351 		/*
1352 		 * options that take text values
1353 		 */
1354 		case Opt_nfsvers:
1355 			string = match_strdup(args);
1356 			if (string == NULL)
1357 				goto out_nomem;
1358 			rc = nfs_parse_version_string(string, mnt, args);
1359 			kfree(string);
1360 			if (!rc)
1361 				goto out_invalid_value;
1362 			break;
1363 		case Opt_sec:
1364 			string = match_strdup(args);
1365 			if (string == NULL)
1366 				goto out_nomem;
1367 			rc = nfs_parse_security_flavors(string, mnt);
1368 			kfree(string);
1369 			if (!rc) {
1370 				dfprintk(MOUNT, "NFS:   unrecognized "
1371 						"security flavor\n");
1372 				return 0;
1373 			}
1374 			break;
1375 		case Opt_proto:
1376 			string = match_strdup(args);
1377 			if (string == NULL)
1378 				goto out_nomem;
1379 			token = match_token(string,
1380 					    nfs_xprt_protocol_tokens, args);
1381 
1382 			protofamily = AF_INET;
1383 			switch (token) {
1384 			case Opt_xprt_udp6:
1385 				protofamily = AF_INET6;
1386 			case Opt_xprt_udp:
1387 				mnt->flags &= ~NFS_MOUNT_TCP;
1388 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1389 				break;
1390 			case Opt_xprt_tcp6:
1391 				protofamily = AF_INET6;
1392 			case Opt_xprt_tcp:
1393 				mnt->flags |= NFS_MOUNT_TCP;
1394 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1395 				break;
1396 			case Opt_xprt_rdma:
1397 				/* vector side protocols to TCP */
1398 				mnt->flags |= NFS_MOUNT_TCP;
1399 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1400 				xprt_load_transport(string);
1401 				break;
1402 			default:
1403 				dfprintk(MOUNT, "NFS:   unrecognized "
1404 						"transport protocol\n");
1405 				kfree(string);
1406 				return 0;
1407 			}
1408 			kfree(string);
1409 			break;
1410 		case Opt_mountproto:
1411 			string = match_strdup(args);
1412 			if (string == NULL)
1413 				goto out_nomem;
1414 			token = match_token(string,
1415 					    nfs_xprt_protocol_tokens, args);
1416 			kfree(string);
1417 
1418 			mountfamily = AF_INET;
1419 			switch (token) {
1420 			case Opt_xprt_udp6:
1421 				mountfamily = AF_INET6;
1422 			case Opt_xprt_udp:
1423 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1424 				break;
1425 			case Opt_xprt_tcp6:
1426 				mountfamily = AF_INET6;
1427 			case Opt_xprt_tcp:
1428 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1429 				break;
1430 			case Opt_xprt_rdma: /* not used for side protocols */
1431 			default:
1432 				dfprintk(MOUNT, "NFS:   unrecognized "
1433 						"transport protocol\n");
1434 				return 0;
1435 			}
1436 			break;
1437 		case Opt_addr:
1438 			string = match_strdup(args);
1439 			if (string == NULL)
1440 				goto out_nomem;
1441 			mnt->nfs_server.addrlen =
1442 				rpc_pton(mnt->net, string, strlen(string),
1443 					(struct sockaddr *)
1444 					&mnt->nfs_server.address,
1445 					sizeof(mnt->nfs_server.address));
1446 			kfree(string);
1447 			if (mnt->nfs_server.addrlen == 0)
1448 				goto out_invalid_address;
1449 			break;
1450 		case Opt_clientaddr:
1451 			if (nfs_get_option_str(args, &mnt->client_address))
1452 				goto out_nomem;
1453 			break;
1454 		case Opt_mounthost:
1455 			if (nfs_get_option_str(args,
1456 					       &mnt->mount_server.hostname))
1457 				goto out_nomem;
1458 			break;
1459 		case Opt_mountaddr:
1460 			string = match_strdup(args);
1461 			if (string == NULL)
1462 				goto out_nomem;
1463 			mnt->mount_server.addrlen =
1464 				rpc_pton(mnt->net, string, strlen(string),
1465 					(struct sockaddr *)
1466 					&mnt->mount_server.address,
1467 					sizeof(mnt->mount_server.address));
1468 			kfree(string);
1469 			if (mnt->mount_server.addrlen == 0)
1470 				goto out_invalid_address;
1471 			break;
1472 		case Opt_lookupcache:
1473 			string = match_strdup(args);
1474 			if (string == NULL)
1475 				goto out_nomem;
1476 			token = match_token(string,
1477 					nfs_lookupcache_tokens, args);
1478 			kfree(string);
1479 			switch (token) {
1480 				case Opt_lookupcache_all:
1481 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1482 					break;
1483 				case Opt_lookupcache_positive:
1484 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1485 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1486 					break;
1487 				case Opt_lookupcache_none:
1488 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1489 					break;
1490 				default:
1491 					dfprintk(MOUNT, "NFS:   invalid "
1492 							"lookupcache argument\n");
1493 					return 0;
1494 			};
1495 			break;
1496 		case Opt_fscache_uniq:
1497 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1498 				goto out_nomem;
1499 			mnt->options |= NFS_OPTION_FSCACHE;
1500 			break;
1501 		case Opt_local_lock:
1502 			string = match_strdup(args);
1503 			if (string == NULL)
1504 				goto out_nomem;
1505 			token = match_token(string, nfs_local_lock_tokens,
1506 					args);
1507 			kfree(string);
1508 			switch (token) {
1509 			case Opt_local_lock_all:
1510 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1511 					       NFS_MOUNT_LOCAL_FCNTL);
1512 				break;
1513 			case Opt_local_lock_flock:
1514 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1515 				break;
1516 			case Opt_local_lock_posix:
1517 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1518 				break;
1519 			case Opt_local_lock_none:
1520 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1521 						NFS_MOUNT_LOCAL_FCNTL);
1522 				break;
1523 			default:
1524 				dfprintk(MOUNT, "NFS:	invalid	"
1525 						"local_lock argument\n");
1526 				return 0;
1527 			};
1528 			break;
1529 
1530 		/*
1531 		 * Special options
1532 		 */
1533 		case Opt_sloppy:
1534 			sloppy = 1;
1535 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1536 			break;
1537 		case Opt_userspace:
1538 		case Opt_deprecated:
1539 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1540 					"'%s'\n", p);
1541 			break;
1542 
1543 		default:
1544 			invalid_option = 1;
1545 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1546 					"'%s'\n", p);
1547 		}
1548 	}
1549 
1550 	if (!sloppy && invalid_option)
1551 		return 0;
1552 
1553 	if (mnt->minorversion && mnt->version != 4)
1554 		goto out_minorversion_mismatch;
1555 
1556 	if (mnt->options & NFS_OPTION_MIGRATION &&
1557 	    mnt->version != 4 && mnt->minorversion != 0)
1558 		goto out_migration_misuse;
1559 
1560 	/*
1561 	 * verify that any proto=/mountproto= options match the address
1562 	 * families in the addr=/mountaddr= options.
1563 	 */
1564 	if (protofamily != AF_UNSPEC &&
1565 	    protofamily != mnt->nfs_server.address.ss_family)
1566 		goto out_proto_mismatch;
1567 
1568 	if (mountfamily != AF_UNSPEC) {
1569 		if (mnt->mount_server.addrlen) {
1570 			if (mountfamily != mnt->mount_server.address.ss_family)
1571 				goto out_mountproto_mismatch;
1572 		} else {
1573 			if (mountfamily != mnt->nfs_server.address.ss_family)
1574 				goto out_mountproto_mismatch;
1575 		}
1576 	}
1577 
1578 	return 1;
1579 
1580 out_mountproto_mismatch:
1581 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1582 			 "option\n");
1583 	return 0;
1584 out_proto_mismatch:
1585 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1586 	return 0;
1587 out_invalid_address:
1588 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1589 	return 0;
1590 out_invalid_value:
1591 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1592 	return 0;
1593 out_minorversion_mismatch:
1594 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1595 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1596 	return 0;
1597 out_migration_misuse:
1598 	printk(KERN_INFO
1599 		"NFS: 'migration' not supported for this NFS version\n");
1600 	return 0;
1601 out_nomem:
1602 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1603 	return 0;
1604 out_security_failure:
1605 	free_secdata(secdata);
1606 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1607 	return 0;
1608 }
1609 
1610 /*
1611  * Select a security flavor for this mount.  The selected flavor
1612  * is planted in args->auth_flavors[0].
1613  *
1614  * Returns 0 on success, -EACCES on failure.
1615  */
nfs_select_flavor(struct nfs_parsed_mount_data * args,struct nfs_mount_request * request)1616 static int nfs_select_flavor(struct nfs_parsed_mount_data *args,
1617 			      struct nfs_mount_request *request)
1618 {
1619 	unsigned int i, count = *(request->auth_flav_len);
1620 	rpc_authflavor_t flavor;
1621 
1622 	/*
1623 	 * The NFSv2 MNT operation does not return a flavor list.
1624 	 */
1625 	if (args->mount_server.version != NFS_MNT3_VERSION)
1626 		goto out_default;
1627 
1628 	/*
1629 	 * Certain releases of Linux's mountd return an empty
1630 	 * flavor list in some cases.
1631 	 */
1632 	if (count == 0)
1633 		goto out_default;
1634 
1635 	/*
1636 	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
1637 	 * must be in the list returned by the server.
1638 	 *
1639 	 * AUTH_NULL has a special meaning when it's in the server list - it
1640 	 * means that the server will ignore the rpc creds, so any flavor
1641 	 * can be used.
1642 	 */
1643 	if (args->auth_flavors[0] != RPC_AUTH_MAXFLAVOR) {
1644 		for (i = 0; i < count; i++) {
1645 			if (args->auth_flavors[0] == request->auth_flavs[i] ||
1646 			    request->auth_flavs[i] == RPC_AUTH_NULL)
1647 				goto out;
1648 		}
1649 		dfprintk(MOUNT, "NFS: auth flavor %d not supported by server\n",
1650 			args->auth_flavors[0]);
1651 		goto out_err;
1652 	}
1653 
1654 	/*
1655 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1656 	 * flavor listed first.  However, some servers list
1657 	 * AUTH_NULL first.  Avoid ever choosing AUTH_NULL.
1658 	 */
1659 	for (i = 0; i < count; i++) {
1660 		struct rpcsec_gss_info info;
1661 
1662 		flavor = request->auth_flavs[i];
1663 		switch (flavor) {
1664 		case RPC_AUTH_UNIX:
1665 			goto out_set;
1666 		case RPC_AUTH_NULL:
1667 			continue;
1668 		default:
1669 			if (rpcauth_get_gssinfo(flavor, &info) == 0)
1670 				goto out_set;
1671 		}
1672 	}
1673 
1674 	/*
1675 	 * As a last chance, see if the server list contains AUTH_NULL -
1676 	 * if it does, use the default flavor.
1677 	 */
1678 	for (i = 0; i < count; i++) {
1679 		if (request->auth_flavs[i] == RPC_AUTH_NULL)
1680 			goto out_default;
1681 	}
1682 
1683 	dfprintk(MOUNT, "NFS: no auth flavors in common with server\n");
1684 	goto out_err;
1685 
1686 out_default:
1687 	/* use default if flavor not already set */
1688 	flavor = (args->auth_flavors[0] == RPC_AUTH_MAXFLAVOR) ?
1689 		RPC_AUTH_UNIX : args->auth_flavors[0];
1690 out_set:
1691 	args->auth_flavors[0] = flavor;
1692 out:
1693 	dfprintk(MOUNT, "NFS: using auth flavor %d\n", args->auth_flavors[0]);
1694 	return 0;
1695 out_err:
1696 	return -EACCES;
1697 }
1698 
1699 /*
1700  * Use the remote server's MOUNT service to request the NFS file handle
1701  * corresponding to the provided path.
1702  */
nfs_request_mount(struct nfs_parsed_mount_data * args,struct nfs_fh * root_fh)1703 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1704 			     struct nfs_fh *root_fh)
1705 {
1706 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1707 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1708 	struct nfs_mount_request request = {
1709 		.sap		= (struct sockaddr *)
1710 						&args->mount_server.address,
1711 		.dirpath	= args->nfs_server.export_path,
1712 		.protocol	= args->mount_server.protocol,
1713 		.fh		= root_fh,
1714 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1715 		.auth_flav_len	= &server_authlist_len,
1716 		.auth_flavs	= server_authlist,
1717 		.net		= args->net,
1718 	};
1719 	int status;
1720 
1721 	if (args->mount_server.version == 0) {
1722 		switch (args->version) {
1723 			default:
1724 				args->mount_server.version = NFS_MNT3_VERSION;
1725 				break;
1726 			case 2:
1727 				args->mount_server.version = NFS_MNT_VERSION;
1728 		}
1729 	}
1730 	request.version = args->mount_server.version;
1731 
1732 	if (args->mount_server.hostname)
1733 		request.hostname = args->mount_server.hostname;
1734 	else
1735 		request.hostname = args->nfs_server.hostname;
1736 
1737 	/*
1738 	 * Construct the mount server's address.
1739 	 */
1740 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1741 		memcpy(request.sap, &args->nfs_server.address,
1742 		       args->nfs_server.addrlen);
1743 		args->mount_server.addrlen = args->nfs_server.addrlen;
1744 	}
1745 	request.salen = args->mount_server.addrlen;
1746 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1747 
1748 	/*
1749 	 * Now ask the mount server to map our export path
1750 	 * to a file handle.
1751 	 */
1752 	status = nfs_mount(&request);
1753 	if (status != 0) {
1754 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1755 				request.hostname, status);
1756 		return status;
1757 	}
1758 
1759 	return nfs_select_flavor(args, &request);
1760 }
1761 
nfs_try_mount(int flags,const char * dev_name,struct nfs_mount_info * mount_info,struct nfs_subversion * nfs_mod)1762 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1763 			     struct nfs_mount_info *mount_info,
1764 			     struct nfs_subversion *nfs_mod)
1765 {
1766 	int status;
1767 	struct nfs_server *server;
1768 
1769 	if (mount_info->parsed->need_mount) {
1770 		status = nfs_request_mount(mount_info->parsed, mount_info->mntfh);
1771 		if (status)
1772 			return ERR_PTR(status);
1773 	}
1774 
1775 	/* Get a volume representation */
1776 	server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1777 	if (IS_ERR(server))
1778 		return ERR_CAST(server);
1779 
1780 	return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1781 }
1782 EXPORT_SYMBOL_GPL(nfs_try_mount);
1783 
1784 /*
1785  * Split "dev_name" into "hostname:export_path".
1786  *
1787  * The leftmost colon demarks the split between the server's hostname
1788  * and the export path.  If the hostname starts with a left square
1789  * bracket, then it may contain colons.
1790  *
1791  * Note: caller frees hostname and export path, even on error.
1792  */
nfs_parse_devname(const char * dev_name,char ** hostname,size_t maxnamlen,char ** export_path,size_t maxpathlen)1793 static int nfs_parse_devname(const char *dev_name,
1794 			     char **hostname, size_t maxnamlen,
1795 			     char **export_path, size_t maxpathlen)
1796 {
1797 	size_t len;
1798 	char *end;
1799 
1800 	/* Is the host name protected with square brakcets? */
1801 	if (*dev_name == '[') {
1802 		end = strchr(++dev_name, ']');
1803 		if (end == NULL || end[1] != ':')
1804 			goto out_bad_devname;
1805 
1806 		len = end - dev_name;
1807 		end++;
1808 	} else {
1809 		char *comma;
1810 
1811 		end = strchr(dev_name, ':');
1812 		if (end == NULL)
1813 			goto out_bad_devname;
1814 		len = end - dev_name;
1815 
1816 		/* kill possible hostname list: not supported */
1817 		comma = strchr(dev_name, ',');
1818 		if (comma != NULL && comma < end)
1819 			*comma = 0;
1820 	}
1821 
1822 	if (len > maxnamlen)
1823 		goto out_hostname;
1824 
1825 	/* N.B. caller will free nfs_server.hostname in all cases */
1826 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1827 	if (*hostname == NULL)
1828 		goto out_nomem;
1829 	len = strlen(++end);
1830 	if (len > maxpathlen)
1831 		goto out_path;
1832 	*export_path = kstrndup(end, len, GFP_KERNEL);
1833 	if (!*export_path)
1834 		goto out_nomem;
1835 
1836 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1837 	return 0;
1838 
1839 out_bad_devname:
1840 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1841 	return -EINVAL;
1842 
1843 out_nomem:
1844 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1845 	return -ENOMEM;
1846 
1847 out_hostname:
1848 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1849 	return -ENAMETOOLONG;
1850 
1851 out_path:
1852 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1853 	return -ENAMETOOLONG;
1854 }
1855 
1856 /*
1857  * Validate the NFS2/NFS3 mount data
1858  * - fills in the mount root filehandle
1859  *
1860  * For option strings, user space handles the following behaviors:
1861  *
1862  * + DNS: mapping server host name to IP address ("addr=" option)
1863  *
1864  * + failure mode: how to behave if a mount request can't be handled
1865  *   immediately ("fg/bg" option)
1866  *
1867  * + retry: how often to retry a mount request ("retry=" option)
1868  *
1869  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1870  *   mountproto=tcp after mountproto=udp, and so on
1871  */
nfs23_validate_mount_data(void * options,struct nfs_parsed_mount_data * args,struct nfs_fh * mntfh,const char * dev_name)1872 static int nfs23_validate_mount_data(void *options,
1873 				     struct nfs_parsed_mount_data *args,
1874 				     struct nfs_fh *mntfh,
1875 				     const char *dev_name)
1876 {
1877 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1878 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1879 
1880 	if (data == NULL)
1881 		goto out_no_data;
1882 
1883 	args->version = NFS_DEFAULT_VERSION;
1884 	switch (data->version) {
1885 	case 1:
1886 		data->namlen = 0;
1887 	case 2:
1888 		data->bsize = 0;
1889 	case 3:
1890 		if (data->flags & NFS_MOUNT_VER3)
1891 			goto out_no_v3;
1892 		data->root.size = NFS2_FHSIZE;
1893 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1894 	case 4:
1895 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1896 			goto out_no_sec;
1897 	case 5:
1898 		memset(data->context, 0, sizeof(data->context));
1899 	case 6:
1900 		if (data->flags & NFS_MOUNT_VER3) {
1901 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1902 				goto out_invalid_fh;
1903 			mntfh->size = data->root.size;
1904 			args->version = 3;
1905 		} else {
1906 			mntfh->size = NFS2_FHSIZE;
1907 			args->version = 2;
1908 		}
1909 
1910 
1911 		memcpy(mntfh->data, data->root.data, mntfh->size);
1912 		if (mntfh->size < sizeof(mntfh->data))
1913 			memset(mntfh->data + mntfh->size, 0,
1914 			       sizeof(mntfh->data) - mntfh->size);
1915 
1916 		/*
1917 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1918 		 * can deal with.
1919 		 */
1920 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1921 		args->flags		|= NFS_MOUNT_LEGACY_INTERFACE;
1922 		args->rsize		= data->rsize;
1923 		args->wsize		= data->wsize;
1924 		args->timeo		= data->timeo;
1925 		args->retrans		= data->retrans;
1926 		args->acregmin		= data->acregmin;
1927 		args->acregmax		= data->acregmax;
1928 		args->acdirmin		= data->acdirmin;
1929 		args->acdirmax		= data->acdirmax;
1930 		args->need_mount	= false;
1931 
1932 		memcpy(sap, &data->addr, sizeof(data->addr));
1933 		args->nfs_server.addrlen = sizeof(data->addr);
1934 		args->nfs_server.port = ntohs(data->addr.sin_port);
1935 		if (!nfs_verify_server_address(sap))
1936 			goto out_no_address;
1937 
1938 		if (!(data->flags & NFS_MOUNT_TCP))
1939 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1940 		/* N.B. caller will free nfs_server.hostname in all cases */
1941 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1942 		args->namlen		= data->namlen;
1943 		args->bsize		= data->bsize;
1944 
1945 		args->auth_flavors[0] = RPC_AUTH_UNIX;
1946 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1947 			args->auth_flavors[0] = data->pseudoflavor;
1948 		if (!args->nfs_server.hostname)
1949 			goto out_nomem;
1950 
1951 		if (!(data->flags & NFS_MOUNT_NONLM))
1952 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1953 					 NFS_MOUNT_LOCAL_FCNTL);
1954 		else
1955 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1956 					NFS_MOUNT_LOCAL_FCNTL);
1957 		/*
1958 		 * The legacy version 6 binary mount data from userspace has a
1959 		 * field used only to transport selinux information into the
1960 		 * the kernel.  To continue to support that functionality we
1961 		 * have a touch of selinux knowledge here in the NFS code. The
1962 		 * userspace code converted context=blah to just blah so we are
1963 		 * converting back to the full string selinux understands.
1964 		 */
1965 		if (data->context[0]){
1966 #ifdef CONFIG_SECURITY_SELINUX
1967 			int rc;
1968 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1969 			if (!opts_str)
1970 				return -ENOMEM;
1971 			strcpy(opts_str, "context=");
1972 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1973 			strcat(opts_str, &data->context[0]);
1974 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1975 			kfree(opts_str);
1976 			if (rc)
1977 				return rc;
1978 #else
1979 			return -EINVAL;
1980 #endif
1981 		}
1982 
1983 		break;
1984 	default:
1985 		return NFS_TEXT_DATA;
1986 	}
1987 
1988 #if !IS_ENABLED(CONFIG_NFS_V3)
1989 	if (args->version == 3)
1990 		goto out_v3_not_compiled;
1991 #endif /* !CONFIG_NFS_V3 */
1992 
1993 	return 0;
1994 
1995 out_no_data:
1996 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1997 	return -EINVAL;
1998 
1999 out_no_v3:
2000 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2001 		 data->version);
2002 	return -EINVAL;
2003 
2004 out_no_sec:
2005 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2006 	return -EINVAL;
2007 
2008 #if !IS_ENABLED(CONFIG_NFS_V3)
2009 out_v3_not_compiled:
2010 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
2011 	return -EPROTONOSUPPORT;
2012 #endif /* !CONFIG_NFS_V3 */
2013 
2014 out_nomem:
2015 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2016 	return -ENOMEM;
2017 
2018 out_no_address:
2019 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2020 	return -EINVAL;
2021 
2022 out_invalid_fh:
2023 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2024 	return -EINVAL;
2025 }
2026 
2027 #if IS_ENABLED(CONFIG_NFS_V4)
nfs_validate_mount_data(struct file_system_type * fs_type,void * options,struct nfs_parsed_mount_data * args,struct nfs_fh * mntfh,const char * dev_name)2028 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2029 				   void *options,
2030 				   struct nfs_parsed_mount_data *args,
2031 				   struct nfs_fh *mntfh,
2032 				   const char *dev_name)
2033 {
2034 	if (fs_type == &nfs_fs_type)
2035 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2036 	return nfs4_validate_mount_data(options, args, dev_name);
2037 }
2038 #else
nfs_validate_mount_data(struct file_system_type * fs_type,void * options,struct nfs_parsed_mount_data * args,struct nfs_fh * mntfh,const char * dev_name)2039 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2040 				   void *options,
2041 				   struct nfs_parsed_mount_data *args,
2042 				   struct nfs_fh *mntfh,
2043 				   const char *dev_name)
2044 {
2045 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2046 }
2047 #endif
2048 
nfs_validate_text_mount_data(void * options,struct nfs_parsed_mount_data * args,const char * dev_name)2049 static int nfs_validate_text_mount_data(void *options,
2050 					struct nfs_parsed_mount_data *args,
2051 					const char *dev_name)
2052 {
2053 	int port = 0;
2054 	int max_namelen = PAGE_SIZE;
2055 	int max_pathlen = NFS_MAXPATHLEN;
2056 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2057 
2058 	if (nfs_parse_mount_options((char *)options, args) == 0)
2059 		return -EINVAL;
2060 
2061 	if (!nfs_verify_server_address(sap))
2062 		goto out_no_address;
2063 
2064 	if (args->version == 4) {
2065 #if IS_ENABLED(CONFIG_NFS_V4)
2066 		port = NFS_PORT;
2067 		max_namelen = NFS4_MAXNAMLEN;
2068 		max_pathlen = NFS4_MAXPATHLEN;
2069 		nfs_validate_transport_protocol(args);
2070 		nfs4_validate_mount_flags(args);
2071 #else
2072 		goto out_v4_not_compiled;
2073 #endif /* CONFIG_NFS_V4 */
2074 	} else
2075 		nfs_set_mount_transport_protocol(args);
2076 
2077 	nfs_set_port(sap, &args->nfs_server.port, port);
2078 
2079 	if (args->auth_flavor_len > 1)
2080 		goto out_bad_auth;
2081 
2082 	return nfs_parse_devname(dev_name,
2083 				   &args->nfs_server.hostname,
2084 				   max_namelen,
2085 				   &args->nfs_server.export_path,
2086 				   max_pathlen);
2087 
2088 #if !IS_ENABLED(CONFIG_NFS_V4)
2089 out_v4_not_compiled:
2090 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2091 	return -EPROTONOSUPPORT;
2092 #endif /* !CONFIG_NFS_V4 */
2093 
2094 out_no_address:
2095 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2096 	return -EINVAL;
2097 
2098 out_bad_auth:
2099 	dfprintk(MOUNT, "NFS: Too many RPC auth flavours specified\n");
2100 	return -EINVAL;
2101 }
2102 
2103 static int
nfs_compare_remount_data(struct nfs_server * nfss,struct nfs_parsed_mount_data * data)2104 nfs_compare_remount_data(struct nfs_server *nfss,
2105 			 struct nfs_parsed_mount_data *data)
2106 {
2107 	if (data->flags != nfss->flags ||
2108 	    data->rsize != nfss->rsize ||
2109 	    data->wsize != nfss->wsize ||
2110 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2111 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2112 	    data->acregmin != nfss->acregmin / HZ ||
2113 	    data->acregmax != nfss->acregmax / HZ ||
2114 	    data->acdirmin != nfss->acdirmin / HZ ||
2115 	    data->acdirmax != nfss->acdirmax / HZ ||
2116 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2117 	    data->nfs_server.port != nfss->port ||
2118 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2119 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2120 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2121 		return -EINVAL;
2122 
2123 	return 0;
2124 }
2125 
2126 int
nfs_remount(struct super_block * sb,int * flags,char * raw_data)2127 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2128 {
2129 	int error;
2130 	struct nfs_server *nfss = sb->s_fs_info;
2131 	struct nfs_parsed_mount_data *data;
2132 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2133 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2134 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2135 
2136 	sync_filesystem(sb);
2137 
2138 	/*
2139 	 * Userspace mount programs that send binary options generally send
2140 	 * them populated with default values. We have no way to know which
2141 	 * ones were explicitly specified. Fall back to legacy behavior and
2142 	 * just return success.
2143 	 */
2144 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2145 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2146 					   options->version <= 6))))
2147 		return 0;
2148 
2149 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2150 	if (data == NULL)
2151 		return -ENOMEM;
2152 
2153 	/* fill out struct with values from existing mount */
2154 	data->flags = nfss->flags;
2155 	data->rsize = nfss->rsize;
2156 	data->wsize = nfss->wsize;
2157 	data->retrans = nfss->client->cl_timeout->to_retries;
2158 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2159 	data->acregmin = nfss->acregmin / HZ;
2160 	data->acregmax = nfss->acregmax / HZ;
2161 	data->acdirmin = nfss->acdirmin / HZ;
2162 	data->acdirmax = nfss->acdirmax / HZ;
2163 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2164 	data->nfs_server.port = nfss->port;
2165 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2166 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2167 		data->nfs_server.addrlen);
2168 
2169 	/* overwrite those values with any that were specified */
2170 	error = nfs_parse_mount_options((char *)options, data);
2171 	if (error < 0)
2172 		goto out;
2173 
2174 	/*
2175 	 * noac is a special case. It implies -o sync, but that's not
2176 	 * necessarily reflected in the mtab options. do_remount_sb
2177 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2178 	 * remount options, so we have to explicitly reset it.
2179 	 */
2180 	if (data->flags & NFS_MOUNT_NOAC)
2181 		*flags |= MS_SYNCHRONOUS;
2182 
2183 	/* compare new mount options with old ones */
2184 	error = nfs_compare_remount_data(nfss, data);
2185 out:
2186 	kfree(data);
2187 	return error;
2188 }
2189 EXPORT_SYMBOL_GPL(nfs_remount);
2190 
2191 /*
2192  * Initialise the common bits of the superblock
2193  */
nfs_initialise_sb(struct super_block * sb)2194 inline void nfs_initialise_sb(struct super_block *sb)
2195 {
2196 	struct nfs_server *server = NFS_SB(sb);
2197 
2198 	sb->s_magic = NFS_SUPER_MAGIC;
2199 
2200 	/* We probably want something more informative here */
2201 	snprintf(sb->s_id, sizeof(sb->s_id),
2202 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2203 
2204 	if (sb->s_blocksize == 0)
2205 		sb->s_blocksize = nfs_block_bits(server->wsize,
2206 						 &sb->s_blocksize_bits);
2207 
2208 	sb->s_bdi = &server->backing_dev_info;
2209 
2210 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2211 }
2212 
2213 /*
2214  * Finish setting up an NFS2/3 superblock
2215  */
nfs_fill_super(struct super_block * sb,struct nfs_mount_info * mount_info)2216 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2217 {
2218 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2219 	struct nfs_server *server = NFS_SB(sb);
2220 
2221 	sb->s_blocksize_bits = 0;
2222 	sb->s_blocksize = 0;
2223 	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2224 	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2225 	if (data && data->bsize)
2226 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2227 
2228 	if (server->nfs_client->rpc_ops->version != 2) {
2229 		/* The VFS shouldn't apply the umask to mode bits. We will do
2230 		 * so ourselves when necessary.
2231 		 */
2232 		sb->s_flags |= MS_POSIXACL;
2233 		sb->s_time_gran = 1;
2234 	}
2235 
2236  	nfs_initialise_sb(sb);
2237 }
2238 EXPORT_SYMBOL_GPL(nfs_fill_super);
2239 
2240 /*
2241  * Finish setting up a cloned NFS2/3/4 superblock
2242  */
nfs_clone_super(struct super_block * sb,struct nfs_mount_info * mount_info)2243 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2244 {
2245 	const struct super_block *old_sb = mount_info->cloned->sb;
2246 	struct nfs_server *server = NFS_SB(sb);
2247 
2248 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2249 	sb->s_blocksize = old_sb->s_blocksize;
2250 	sb->s_maxbytes = old_sb->s_maxbytes;
2251 	sb->s_xattr = old_sb->s_xattr;
2252 	sb->s_op = old_sb->s_op;
2253 	sb->s_time_gran = 1;
2254 
2255 	if (server->nfs_client->rpc_ops->version != 2) {
2256 		/* The VFS shouldn't apply the umask to mode bits. We will do
2257 		 * so ourselves when necessary.
2258 		 */
2259 		sb->s_flags |= MS_POSIXACL;
2260 	}
2261 
2262  	nfs_initialise_sb(sb);
2263 }
2264 
nfs_compare_mount_options(const struct super_block * s,const struct nfs_server * b,int flags)2265 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2266 {
2267 	const struct nfs_server *a = s->s_fs_info;
2268 	const struct rpc_clnt *clnt_a = a->client;
2269 	const struct rpc_clnt *clnt_b = b->client;
2270 
2271 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2272 		goto Ebusy;
2273 	if (a->nfs_client != b->nfs_client)
2274 		goto Ebusy;
2275 	if (a->flags != b->flags)
2276 		goto Ebusy;
2277 	if (a->wsize != b->wsize)
2278 		goto Ebusy;
2279 	if (a->rsize != b->rsize)
2280 		goto Ebusy;
2281 	if (a->acregmin != b->acregmin)
2282 		goto Ebusy;
2283 	if (a->acregmax != b->acregmax)
2284 		goto Ebusy;
2285 	if (a->acdirmin != b->acdirmin)
2286 		goto Ebusy;
2287 	if (a->acdirmax != b->acdirmax)
2288 		goto Ebusy;
2289 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2290 		goto Ebusy;
2291 	return 1;
2292 Ebusy:
2293 	return 0;
2294 }
2295 
2296 struct nfs_sb_mountdata {
2297 	struct nfs_server *server;
2298 	int mntflags;
2299 };
2300 
nfs_set_super(struct super_block * s,void * data)2301 static int nfs_set_super(struct super_block *s, void *data)
2302 {
2303 	struct nfs_sb_mountdata *sb_mntdata = data;
2304 	struct nfs_server *server = sb_mntdata->server;
2305 	int ret;
2306 
2307 	s->s_flags = sb_mntdata->mntflags;
2308 	s->s_fs_info = server;
2309 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2310 	ret = set_anon_super(s, server);
2311 	if (ret == 0)
2312 		server->s_dev = s->s_dev;
2313 	return ret;
2314 }
2315 
nfs_compare_super_address(struct nfs_server * server1,struct nfs_server * server2)2316 static int nfs_compare_super_address(struct nfs_server *server1,
2317 				     struct nfs_server *server2)
2318 {
2319 	struct sockaddr *sap1, *sap2;
2320 
2321 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2322 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2323 
2324 	if (sap1->sa_family != sap2->sa_family)
2325 		return 0;
2326 
2327 	switch (sap1->sa_family) {
2328 	case AF_INET: {
2329 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2330 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2331 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2332 			return 0;
2333 		if (sin1->sin_port != sin2->sin_port)
2334 			return 0;
2335 		break;
2336 	}
2337 	case AF_INET6: {
2338 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2339 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2340 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2341 			return 0;
2342 		if (sin1->sin6_port != sin2->sin6_port)
2343 			return 0;
2344 		break;
2345 	}
2346 	default:
2347 		return 0;
2348 	}
2349 
2350 	return 1;
2351 }
2352 
nfs_compare_super(struct super_block * sb,void * data)2353 static int nfs_compare_super(struct super_block *sb, void *data)
2354 {
2355 	struct nfs_sb_mountdata *sb_mntdata = data;
2356 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2357 	int mntflags = sb_mntdata->mntflags;
2358 
2359 	if (!nfs_compare_super_address(old, server))
2360 		return 0;
2361 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2362 	if (old->flags & NFS_MOUNT_UNSHARED)
2363 		return 0;
2364 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2365 		return 0;
2366 	return nfs_compare_mount_options(sb, server, mntflags);
2367 }
2368 
2369 #ifdef CONFIG_NFS_FSCACHE
nfs_get_cache_cookie(struct super_block * sb,struct nfs_parsed_mount_data * parsed,struct nfs_clone_mount * cloned)2370 static void nfs_get_cache_cookie(struct super_block *sb,
2371 				 struct nfs_parsed_mount_data *parsed,
2372 				 struct nfs_clone_mount *cloned)
2373 {
2374 	struct nfs_server *nfss = NFS_SB(sb);
2375 	char *uniq = NULL;
2376 	int ulen = 0;
2377 
2378 	nfss->fscache_key = NULL;
2379 	nfss->fscache = NULL;
2380 
2381 	if (parsed) {
2382 		if (!(parsed->options & NFS_OPTION_FSCACHE))
2383 			return;
2384 		if (parsed->fscache_uniq) {
2385 			uniq = parsed->fscache_uniq;
2386 			ulen = strlen(parsed->fscache_uniq);
2387 		}
2388 	} else if (cloned) {
2389 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2390 		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2391 			return;
2392 		if (mnt_s->fscache_key) {
2393 			uniq = mnt_s->fscache_key->key.uniquifier;
2394 			ulen = mnt_s->fscache_key->key.uniq_len;
2395 		};
2396 	} else
2397 		return;
2398 
2399 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2400 }
2401 #else
nfs_get_cache_cookie(struct super_block * sb,struct nfs_parsed_mount_data * parsed,struct nfs_clone_mount * cloned)2402 static void nfs_get_cache_cookie(struct super_block *sb,
2403 				 struct nfs_parsed_mount_data *parsed,
2404 				 struct nfs_clone_mount *cloned)
2405 {
2406 }
2407 #endif
2408 
nfs_bdi_register(struct nfs_server * server)2409 static int nfs_bdi_register(struct nfs_server *server)
2410 {
2411 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2412 }
2413 
nfs_set_sb_security(struct super_block * s,struct dentry * mntroot,struct nfs_mount_info * mount_info)2414 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2415 			struct nfs_mount_info *mount_info)
2416 {
2417 	return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts);
2418 }
2419 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2420 
nfs_clone_sb_security(struct super_block * s,struct dentry * mntroot,struct nfs_mount_info * mount_info)2421 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2422 			  struct nfs_mount_info *mount_info)
2423 {
2424 	/* clone any lsm security options from the parent to the new sb */
2425 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2426 		return -ESTALE;
2427 	return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2428 }
2429 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2430 
nfs_fs_mount_common(struct nfs_server * server,int flags,const char * dev_name,struct nfs_mount_info * mount_info,struct nfs_subversion * nfs_mod)2431 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2432 				   int flags, const char *dev_name,
2433 				   struct nfs_mount_info *mount_info,
2434 				   struct nfs_subversion *nfs_mod)
2435 {
2436 	struct super_block *s;
2437 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2438 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2439 	struct nfs_sb_mountdata sb_mntdata = {
2440 		.mntflags = flags,
2441 		.server = server,
2442 	};
2443 	int error;
2444 
2445 	if (server->flags & NFS_MOUNT_UNSHARED)
2446 		compare_super = NULL;
2447 
2448 	/* -o noac implies -o sync */
2449 	if (server->flags & NFS_MOUNT_NOAC)
2450 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2451 
2452 	/* Get a superblock - note that we may end up sharing one that already exists */
2453 	s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2454 	if (IS_ERR(s)) {
2455 		mntroot = ERR_CAST(s);
2456 		goto out_err_nosb;
2457 	}
2458 
2459 	if (s->s_fs_info != server) {
2460 		nfs_free_server(server);
2461 		server = NULL;
2462 	} else {
2463 		error = nfs_bdi_register(server);
2464 		if (error) {
2465 			mntroot = ERR_PTR(error);
2466 			goto error_splat_bdi;
2467 		}
2468 	}
2469 
2470 	if (!s->s_root) {
2471 		/* initial superblock/root creation */
2472 		mount_info->fill_super(s, mount_info);
2473 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2474 	}
2475 
2476 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2477 	if (IS_ERR(mntroot))
2478 		goto error_splat_super;
2479 
2480 	error = mount_info->set_security(s, mntroot, mount_info);
2481 	if (error)
2482 		goto error_splat_root;
2483 
2484 	s->s_flags |= MS_ACTIVE;
2485 
2486 out:
2487 	return mntroot;
2488 
2489 out_err_nosb:
2490 	nfs_free_server(server);
2491 	goto out;
2492 
2493 error_splat_root:
2494 	dput(mntroot);
2495 	mntroot = ERR_PTR(error);
2496 error_splat_super:
2497 	if (server && !s->s_root)
2498 		bdi_unregister(&server->backing_dev_info);
2499 error_splat_bdi:
2500 	deactivate_locked_super(s);
2501 	goto out;
2502 }
2503 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2504 
nfs_fs_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * raw_data)2505 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2506 	int flags, const char *dev_name, void *raw_data)
2507 {
2508 	struct nfs_mount_info mount_info = {
2509 		.fill_super = nfs_fill_super,
2510 		.set_security = nfs_set_sb_security,
2511 	};
2512 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2513 	struct nfs_subversion *nfs_mod;
2514 	int error;
2515 
2516 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2517 	mount_info.mntfh = nfs_alloc_fhandle();
2518 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2519 		goto out;
2520 
2521 	/* Validate the mount data */
2522 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2523 	if (error == NFS_TEXT_DATA)
2524 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2525 	if (error < 0) {
2526 		mntroot = ERR_PTR(error);
2527 		goto out;
2528 	}
2529 
2530 	nfs_mod = get_nfs_version(mount_info.parsed->version);
2531 	if (IS_ERR(nfs_mod)) {
2532 		mntroot = ERR_CAST(nfs_mod);
2533 		goto out;
2534 	}
2535 
2536 	mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2537 
2538 	put_nfs_version(nfs_mod);
2539 out:
2540 	nfs_free_parsed_mount_data(mount_info.parsed);
2541 	nfs_free_fhandle(mount_info.mntfh);
2542 	return mntroot;
2543 }
2544 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2545 
2546 /*
2547  * Ensure that we unregister the bdi before kill_anon_super
2548  * releases the device name
2549  */
nfs_put_super(struct super_block * s)2550 void nfs_put_super(struct super_block *s)
2551 {
2552 	struct nfs_server *server = NFS_SB(s);
2553 
2554 	bdi_unregister(&server->backing_dev_info);
2555 }
2556 EXPORT_SYMBOL_GPL(nfs_put_super);
2557 
2558 /*
2559  * Destroy an NFS2/3 superblock
2560  */
nfs_kill_super(struct super_block * s)2561 void nfs_kill_super(struct super_block *s)
2562 {
2563 	struct nfs_server *server = NFS_SB(s);
2564 
2565 	kill_anon_super(s);
2566 	nfs_fscache_release_super_cookie(s);
2567 	nfs_free_server(server);
2568 }
2569 EXPORT_SYMBOL_GPL(nfs_kill_super);
2570 
2571 /*
2572  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2573  */
2574 static struct dentry *
nfs_xdev_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * raw_data)2575 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2576 		const char *dev_name, void *raw_data)
2577 {
2578 	struct nfs_clone_mount *data = raw_data;
2579 	struct nfs_mount_info mount_info = {
2580 		.fill_super = nfs_clone_super,
2581 		.set_security = nfs_clone_sb_security,
2582 		.cloned = data,
2583 	};
2584 	struct nfs_server *server;
2585 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2586 	struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2587 
2588 	dprintk("--> nfs_xdev_mount()\n");
2589 
2590 	mount_info.mntfh = mount_info.cloned->fh;
2591 
2592 	/* create a new volume representation */
2593 	server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2594 
2595 	if (IS_ERR(server))
2596 		mntroot = ERR_CAST(server);
2597 	else
2598 		mntroot = nfs_fs_mount_common(server, flags,
2599 				dev_name, &mount_info, nfs_mod);
2600 
2601 	dprintk("<-- nfs_xdev_mount() = %ld\n",
2602 			IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2603 	return mntroot;
2604 }
2605 
2606 #if IS_ENABLED(CONFIG_NFS_V4)
2607 
nfs4_validate_mount_flags(struct nfs_parsed_mount_data * args)2608 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2609 {
2610 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2611 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2612 }
2613 
2614 /*
2615  * Validate NFSv4 mount options
2616  */
nfs4_validate_mount_data(void * options,struct nfs_parsed_mount_data * args,const char * dev_name)2617 static int nfs4_validate_mount_data(void *options,
2618 				    struct nfs_parsed_mount_data *args,
2619 				    const char *dev_name)
2620 {
2621 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2622 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2623 	char *c;
2624 
2625 	if (data == NULL)
2626 		goto out_no_data;
2627 
2628 	args->version = 4;
2629 
2630 	switch (data->version) {
2631 	case 1:
2632 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2633 			goto out_no_address;
2634 		if (data->host_addrlen == 0)
2635 			goto out_no_address;
2636 		args->nfs_server.addrlen = data->host_addrlen;
2637 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2638 			return -EFAULT;
2639 		if (!nfs_verify_server_address(sap))
2640 			goto out_no_address;
2641 		args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2642 
2643 		args->auth_flavors[0] = RPC_AUTH_UNIX;
2644 		if (data->auth_flavourlen) {
2645 			if (data->auth_flavourlen > 1)
2646 				goto out_inval_auth;
2647 			if (copy_from_user(&args->auth_flavors[0],
2648 					   data->auth_flavours,
2649 					   sizeof(args->auth_flavors[0])))
2650 				return -EFAULT;
2651 		}
2652 
2653 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2654 		if (IS_ERR(c))
2655 			return PTR_ERR(c);
2656 		args->nfs_server.hostname = c;
2657 
2658 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2659 		if (IS_ERR(c))
2660 			return PTR_ERR(c);
2661 		args->nfs_server.export_path = c;
2662 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2663 
2664 		c = strndup_user(data->client_addr.data, 16);
2665 		if (IS_ERR(c))
2666 			return PTR_ERR(c);
2667 		args->client_address = c;
2668 
2669 		/*
2670 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2671 		 * can deal with.
2672 		 */
2673 
2674 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2675 		args->rsize	= data->rsize;
2676 		args->wsize	= data->wsize;
2677 		args->timeo	= data->timeo;
2678 		args->retrans	= data->retrans;
2679 		args->acregmin	= data->acregmin;
2680 		args->acregmax	= data->acregmax;
2681 		args->acdirmin	= data->acdirmin;
2682 		args->acdirmax	= data->acdirmax;
2683 		args->nfs_server.protocol = data->proto;
2684 		nfs_validate_transport_protocol(args);
2685 
2686 		break;
2687 	default:
2688 		return NFS_TEXT_DATA;
2689 	}
2690 
2691 	return 0;
2692 
2693 out_no_data:
2694 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2695 	return -EINVAL;
2696 
2697 out_inval_auth:
2698 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2699 		 data->auth_flavourlen);
2700 	return -EINVAL;
2701 
2702 out_no_address:
2703 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2704 	return -EINVAL;
2705 }
2706 
2707 /*
2708  * NFS v4 module parameters need to stay in the
2709  * NFS client for backwards compatibility
2710  */
2711 unsigned int nfs_callback_set_tcpport;
2712 unsigned short nfs_callback_tcpport;
2713 /* Default cache timeout is 10 minutes */
2714 unsigned int nfs_idmap_cache_timeout = 600;
2715 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2716 bool nfs4_disable_idmapping = true;
2717 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2718 unsigned short send_implementation_id = 1;
2719 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2720 
2721 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2722 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2723 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2724 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2725 EXPORT_SYMBOL_GPL(max_session_slots);
2726 EXPORT_SYMBOL_GPL(send_implementation_id);
2727 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2728 
2729 #define NFS_CALLBACK_MAXPORTNR (65535U)
2730 
param_set_portnr(const char * val,const struct kernel_param * kp)2731 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2732 {
2733 	unsigned long num;
2734 	int ret;
2735 
2736 	if (!val)
2737 		return -EINVAL;
2738 	ret = kstrtoul(val, 0, &num);
2739 	if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2740 		return -EINVAL;
2741 	*((unsigned int *)kp->arg) = num;
2742 	return 0;
2743 }
2744 static struct kernel_param_ops param_ops_portnr = {
2745 	.set = param_set_portnr,
2746 	.get = param_get_uint,
2747 };
2748 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2749 
2750 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2751 module_param(nfs_idmap_cache_timeout, int, 0644);
2752 module_param(nfs4_disable_idmapping, bool, 0644);
2753 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2754 			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2755 MODULE_PARM_DESC(nfs4_disable_idmapping,
2756 		"Turn off NFSv4 idmapping when using 'sec=sys'");
2757 module_param(max_session_slots, ushort, 0644);
2758 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2759 		"requests the client will negotiate");
2760 module_param(send_implementation_id, ushort, 0644);
2761 MODULE_PARM_DESC(send_implementation_id,
2762 		"Send implementation ID with NFSv4.1 exchange_id");
2763 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2764 
2765 #endif /* CONFIG_NFS_V4 */
2766