xref: /linux/fs/nfs/super.c (revision f8324e20f8289dffc646d64366332e05eaacab25)
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/stats.h>
35 #include <linux/sunrpc/metrics.h>
36 #include <linux/sunrpc/xprtsock.h>
37 #include <linux/sunrpc/xprtrdma.h>
38 #include <linux/nfs_fs.h>
39 #include <linux/nfs_mount.h>
40 #include <linux/nfs4_mount.h>
41 #include <linux/lockd/bind.h>
42 #include <linux/smp_lock.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/mnt_namespace.h>
46 #include <linux/namei.h>
47 #include <linux/nfs_idmap.h>
48 #include <linux/vfs.h>
49 #include <linux/inet.h>
50 #include <linux/in6.h>
51 #include <linux/slab.h>
52 #include <net/ipv6.h>
53 #include <linux/netdevice.h>
54 #include <linux/nfs_xdr.h>
55 #include <linux/magic.h>
56 #include <linux/parser.h>
57 
58 #include <asm/system.h>
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 
68 #define NFSDBG_FACILITY		NFSDBG_VFS
69 
70 enum {
71 	/* Mount options that take no arguments */
72 	Opt_soft, Opt_hard,
73 	Opt_posix, Opt_noposix,
74 	Opt_cto, Opt_nocto,
75 	Opt_ac, Opt_noac,
76 	Opt_lock, Opt_nolock,
77 	Opt_v2, Opt_v3, Opt_v4,
78 	Opt_udp, Opt_tcp, Opt_rdma,
79 	Opt_acl, Opt_noacl,
80 	Opt_rdirplus, Opt_nordirplus,
81 	Opt_sharecache, Opt_nosharecache,
82 	Opt_resvport, Opt_noresvport,
83 	Opt_fscache, Opt_nofscache,
84 
85 	/* Mount options that take integer arguments */
86 	Opt_port,
87 	Opt_rsize, Opt_wsize, Opt_bsize,
88 	Opt_timeo, Opt_retrans,
89 	Opt_acregmin, Opt_acregmax,
90 	Opt_acdirmin, Opt_acdirmax,
91 	Opt_actimeo,
92 	Opt_namelen,
93 	Opt_mountport,
94 	Opt_mountvers,
95 	Opt_nfsvers,
96 	Opt_minorversion,
97 
98 	/* Mount options that take string arguments */
99 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
100 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
101 	Opt_lookupcache,
102 	Opt_fscache_uniq,
103 
104 	/* Special mount options */
105 	Opt_userspace, Opt_deprecated, Opt_sloppy,
106 
107 	Opt_err
108 };
109 
110 static const match_table_t nfs_mount_option_tokens = {
111 	{ Opt_userspace, "bg" },
112 	{ Opt_userspace, "fg" },
113 	{ Opt_userspace, "retry=%s" },
114 
115 	{ Opt_sloppy, "sloppy" },
116 
117 	{ Opt_soft, "soft" },
118 	{ Opt_hard, "hard" },
119 	{ Opt_deprecated, "intr" },
120 	{ Opt_deprecated, "nointr" },
121 	{ Opt_posix, "posix" },
122 	{ Opt_noposix, "noposix" },
123 	{ Opt_cto, "cto" },
124 	{ Opt_nocto, "nocto" },
125 	{ Opt_ac, "ac" },
126 	{ Opt_noac, "noac" },
127 	{ Opt_lock, "lock" },
128 	{ Opt_nolock, "nolock" },
129 	{ Opt_v2, "v2" },
130 	{ Opt_v3, "v3" },
131 	{ Opt_v4, "v4" },
132 	{ Opt_udp, "udp" },
133 	{ Opt_tcp, "tcp" },
134 	{ Opt_rdma, "rdma" },
135 	{ Opt_acl, "acl" },
136 	{ Opt_noacl, "noacl" },
137 	{ Opt_rdirplus, "rdirplus" },
138 	{ Opt_nordirplus, "nordirplus" },
139 	{ Opt_sharecache, "sharecache" },
140 	{ Opt_nosharecache, "nosharecache" },
141 	{ Opt_resvport, "resvport" },
142 	{ Opt_noresvport, "noresvport" },
143 	{ Opt_fscache, "fsc" },
144 	{ Opt_nofscache, "nofsc" },
145 
146 	{ Opt_port, "port=%s" },
147 	{ Opt_rsize, "rsize=%s" },
148 	{ Opt_wsize, "wsize=%s" },
149 	{ Opt_bsize, "bsize=%s" },
150 	{ Opt_timeo, "timeo=%s" },
151 	{ Opt_retrans, "retrans=%s" },
152 	{ Opt_acregmin, "acregmin=%s" },
153 	{ Opt_acregmax, "acregmax=%s" },
154 	{ Opt_acdirmin, "acdirmin=%s" },
155 	{ Opt_acdirmax, "acdirmax=%s" },
156 	{ Opt_actimeo, "actimeo=%s" },
157 	{ Opt_namelen, "namlen=%s" },
158 	{ Opt_mountport, "mountport=%s" },
159 	{ Opt_mountvers, "mountvers=%s" },
160 	{ Opt_nfsvers, "nfsvers=%s" },
161 	{ Opt_nfsvers, "vers=%s" },
162 	{ Opt_minorversion, "minorversion=%s" },
163 
164 	{ Opt_sec, "sec=%s" },
165 	{ Opt_proto, "proto=%s" },
166 	{ Opt_mountproto, "mountproto=%s" },
167 	{ Opt_addr, "addr=%s" },
168 	{ Opt_clientaddr, "clientaddr=%s" },
169 	{ Opt_mounthost, "mounthost=%s" },
170 	{ Opt_mountaddr, "mountaddr=%s" },
171 
172 	{ Opt_lookupcache, "lookupcache=%s" },
173 	{ Opt_fscache_uniq, "fsc=%s" },
174 
175 	{ Opt_err, NULL }
176 };
177 
178 enum {
179 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
180 
181 	Opt_xprt_err
182 };
183 
184 static const match_table_t nfs_xprt_protocol_tokens = {
185 	{ Opt_xprt_udp, "udp" },
186 	{ Opt_xprt_udp6, "udp6" },
187 	{ Opt_xprt_tcp, "tcp" },
188 	{ Opt_xprt_tcp6, "tcp6" },
189 	{ Opt_xprt_rdma, "rdma" },
190 
191 	{ Opt_xprt_err, NULL }
192 };
193 
194 enum {
195 	Opt_sec_none, Opt_sec_sys,
196 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
197 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
198 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
199 
200 	Opt_sec_err
201 };
202 
203 static const match_table_t nfs_secflavor_tokens = {
204 	{ Opt_sec_none, "none" },
205 	{ Opt_sec_none, "null" },
206 	{ Opt_sec_sys, "sys" },
207 
208 	{ Opt_sec_krb5, "krb5" },
209 	{ Opt_sec_krb5i, "krb5i" },
210 	{ Opt_sec_krb5p, "krb5p" },
211 
212 	{ Opt_sec_lkey, "lkey" },
213 	{ Opt_sec_lkeyi, "lkeyi" },
214 	{ Opt_sec_lkeyp, "lkeyp" },
215 
216 	{ Opt_sec_spkm, "spkm3" },
217 	{ Opt_sec_spkmi, "spkm3i" },
218 	{ Opt_sec_spkmp, "spkm3p" },
219 
220 	{ Opt_sec_err, NULL }
221 };
222 
223 enum {
224 	Opt_lookupcache_all, Opt_lookupcache_positive,
225 	Opt_lookupcache_none,
226 
227 	Opt_lookupcache_err
228 };
229 
230 static match_table_t nfs_lookupcache_tokens = {
231 	{ Opt_lookupcache_all, "all" },
232 	{ Opt_lookupcache_positive, "pos" },
233 	{ Opt_lookupcache_positive, "positive" },
234 	{ Opt_lookupcache_none, "none" },
235 
236 	{ Opt_lookupcache_err, NULL }
237 };
238 
239 
240 static void nfs_umount_begin(struct super_block *);
241 static int  nfs_statfs(struct dentry *, struct kstatfs *);
242 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
243 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
244 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
245 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
246 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
247 static void nfs_put_super(struct super_block *);
248 static void nfs_kill_super(struct super_block *);
249 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
250 
251 static struct file_system_type nfs_fs_type = {
252 	.owner		= THIS_MODULE,
253 	.name		= "nfs",
254 	.get_sb		= nfs_get_sb,
255 	.kill_sb	= nfs_kill_super,
256 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
257 };
258 
259 struct file_system_type nfs_xdev_fs_type = {
260 	.owner		= THIS_MODULE,
261 	.name		= "nfs",
262 	.get_sb		= nfs_xdev_get_sb,
263 	.kill_sb	= nfs_kill_super,
264 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
265 };
266 
267 static const struct super_operations nfs_sops = {
268 	.alloc_inode	= nfs_alloc_inode,
269 	.destroy_inode	= nfs_destroy_inode,
270 	.write_inode	= nfs_write_inode,
271 	.put_super	= nfs_put_super,
272 	.statfs		= nfs_statfs,
273 	.clear_inode	= nfs_clear_inode,
274 	.umount_begin	= nfs_umount_begin,
275 	.show_options	= nfs_show_options,
276 	.show_stats	= nfs_show_stats,
277 	.remount_fs	= nfs_remount,
278 };
279 
280 #ifdef CONFIG_NFS_V4
281 static int nfs4_validate_text_mount_data(void *options,
282 	struct nfs_parsed_mount_data *args, const char *dev_name);
283 static int nfs4_try_mount(int flags, const char *dev_name,
284 	struct nfs_parsed_mount_data *data, struct vfsmount *mnt);
285 static int nfs4_get_sb(struct file_system_type *fs_type,
286 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
287 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
288 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
289 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
290 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
291 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
292 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
293 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
294 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
295 static void nfs4_kill_super(struct super_block *sb);
296 
297 static struct file_system_type nfs4_fs_type = {
298 	.owner		= THIS_MODULE,
299 	.name		= "nfs4",
300 	.get_sb		= nfs4_get_sb,
301 	.kill_sb	= nfs4_kill_super,
302 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
303 };
304 
305 static struct file_system_type nfs4_remote_fs_type = {
306 	.owner		= THIS_MODULE,
307 	.name		= "nfs4",
308 	.get_sb		= nfs4_remote_get_sb,
309 	.kill_sb	= nfs4_kill_super,
310 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
311 };
312 
313 struct file_system_type nfs4_xdev_fs_type = {
314 	.owner		= THIS_MODULE,
315 	.name		= "nfs4",
316 	.get_sb		= nfs4_xdev_get_sb,
317 	.kill_sb	= nfs4_kill_super,
318 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
319 };
320 
321 static struct file_system_type nfs4_remote_referral_fs_type = {
322 	.owner		= THIS_MODULE,
323 	.name		= "nfs4",
324 	.get_sb		= nfs4_remote_referral_get_sb,
325 	.kill_sb	= nfs4_kill_super,
326 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
327 };
328 
329 struct file_system_type nfs4_referral_fs_type = {
330 	.owner		= THIS_MODULE,
331 	.name		= "nfs4",
332 	.get_sb		= nfs4_referral_get_sb,
333 	.kill_sb	= nfs4_kill_super,
334 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
335 };
336 
337 static const struct super_operations nfs4_sops = {
338 	.alloc_inode	= nfs_alloc_inode,
339 	.destroy_inode	= nfs_destroy_inode,
340 	.write_inode	= nfs_write_inode,
341 	.put_super	= nfs_put_super,
342 	.statfs		= nfs_statfs,
343 	.clear_inode	= nfs4_clear_inode,
344 	.umount_begin	= nfs_umount_begin,
345 	.show_options	= nfs_show_options,
346 	.show_stats	= nfs_show_stats,
347 	.remount_fs	= nfs_remount,
348 };
349 #endif
350 
351 static struct shrinker acl_shrinker = {
352 	.shrink		= nfs_access_cache_shrinker,
353 	.seeks		= DEFAULT_SEEKS,
354 };
355 
356 /*
357  * Register the NFS filesystems
358  */
359 int __init register_nfs_fs(void)
360 {
361 	int ret;
362 
363         ret = register_filesystem(&nfs_fs_type);
364 	if (ret < 0)
365 		goto error_0;
366 
367 	ret = nfs_register_sysctl();
368 	if (ret < 0)
369 		goto error_1;
370 #ifdef CONFIG_NFS_V4
371 	ret = register_filesystem(&nfs4_fs_type);
372 	if (ret < 0)
373 		goto error_2;
374 #endif
375 	register_shrinker(&acl_shrinker);
376 	return 0;
377 
378 #ifdef CONFIG_NFS_V4
379 error_2:
380 	nfs_unregister_sysctl();
381 #endif
382 error_1:
383 	unregister_filesystem(&nfs_fs_type);
384 error_0:
385 	return ret;
386 }
387 
388 /*
389  * Unregister the NFS filesystems
390  */
391 void __exit unregister_nfs_fs(void)
392 {
393 	unregister_shrinker(&acl_shrinker);
394 #ifdef CONFIG_NFS_V4
395 	unregister_filesystem(&nfs4_fs_type);
396 #endif
397 	nfs_unregister_sysctl();
398 	unregister_filesystem(&nfs_fs_type);
399 }
400 
401 void nfs_sb_active(struct super_block *sb)
402 {
403 	struct nfs_server *server = NFS_SB(sb);
404 
405 	if (atomic_inc_return(&server->active) == 1)
406 		atomic_inc(&sb->s_active);
407 }
408 
409 void nfs_sb_deactive(struct super_block *sb)
410 {
411 	struct nfs_server *server = NFS_SB(sb);
412 
413 	if (atomic_dec_and_test(&server->active))
414 		deactivate_super(sb);
415 }
416 
417 /*
418  * Deliver file system statistics to userspace
419  */
420 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
421 {
422 	struct nfs_server *server = NFS_SB(dentry->d_sb);
423 	unsigned char blockbits;
424 	unsigned long blockres;
425 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
426 	struct nfs_fsstat res;
427 	int error = -ENOMEM;
428 
429 	res.fattr = nfs_alloc_fattr();
430 	if (res.fattr == NULL)
431 		goto out_err;
432 
433 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
434 
435 	nfs_free_fattr(res.fattr);
436 	if (error < 0)
437 		goto out_err;
438 
439 	buf->f_type = NFS_SUPER_MAGIC;
440 
441 	/*
442 	 * Current versions of glibc do not correctly handle the
443 	 * case where f_frsize != f_bsize.  Eventually we want to
444 	 * report the value of wtmult in this field.
445 	 */
446 	buf->f_frsize = dentry->d_sb->s_blocksize;
447 
448 	/*
449 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
450 	 * are reported in units of f_frsize.  Linux hasn't had
451 	 * an f_frsize field in its statfs struct until recently,
452 	 * thus historically Linux's sys_statfs reports these
453 	 * fields in units of f_bsize.
454 	 */
455 	buf->f_bsize = dentry->d_sb->s_blocksize;
456 	blockbits = dentry->d_sb->s_blocksize_bits;
457 	blockres = (1 << blockbits) - 1;
458 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
459 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
460 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
461 
462 	buf->f_files = res.tfiles;
463 	buf->f_ffree = res.afiles;
464 
465 	buf->f_namelen = server->namelen;
466 
467 	return 0;
468 
469  out_err:
470 	dprintk("%s: statfs error = %d\n", __func__, -error);
471 	return error;
472 }
473 
474 /*
475  * Map the security flavour number to a name
476  */
477 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
478 {
479 	static const struct {
480 		rpc_authflavor_t flavour;
481 		const char *str;
482 	} sec_flavours[] = {
483 		{ RPC_AUTH_NULL, "null" },
484 		{ RPC_AUTH_UNIX, "sys" },
485 		{ RPC_AUTH_GSS_KRB5, "krb5" },
486 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
487 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
488 		{ RPC_AUTH_GSS_LKEY, "lkey" },
489 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
490 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
491 		{ RPC_AUTH_GSS_SPKM, "spkm" },
492 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
493 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
494 		{ UINT_MAX, "unknown" }
495 	};
496 	int i;
497 
498 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
499 		if (sec_flavours[i].flavour == flavour)
500 			break;
501 	}
502 	return sec_flavours[i].str;
503 }
504 
505 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
506 				  int showdefaults)
507 {
508 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
509 
510 	seq_printf(m, ",mountproto=");
511 	switch (sap->sa_family) {
512 	case AF_INET:
513 		switch (nfss->mountd_protocol) {
514 		case IPPROTO_UDP:
515 			seq_printf(m, RPCBIND_NETID_UDP);
516 			break;
517 		case IPPROTO_TCP:
518 			seq_printf(m, RPCBIND_NETID_TCP);
519 			break;
520 		default:
521 			if (showdefaults)
522 				seq_printf(m, "auto");
523 		}
524 		break;
525 	case AF_INET6:
526 		switch (nfss->mountd_protocol) {
527 		case IPPROTO_UDP:
528 			seq_printf(m, RPCBIND_NETID_UDP6);
529 			break;
530 		case IPPROTO_TCP:
531 			seq_printf(m, RPCBIND_NETID_TCP6);
532 			break;
533 		default:
534 			if (showdefaults)
535 				seq_printf(m, "auto");
536 		}
537 		break;
538 	default:
539 		if (showdefaults)
540 			seq_printf(m, "auto");
541 	}
542 }
543 
544 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
545 				    int showdefaults)
546 {
547 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
548 
549 	switch (sap->sa_family) {
550 	case AF_INET: {
551 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
552 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
553 		break;
554 	}
555 	case AF_INET6: {
556 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
557 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
558 		break;
559 	}
560 	default:
561 		if (showdefaults)
562 			seq_printf(m, ",mountaddr=unspecified");
563 	}
564 
565 	if (nfss->mountd_version || showdefaults)
566 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
567 	if (nfss->mountd_port || showdefaults)
568 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
569 
570 	nfs_show_mountd_netid(m, nfss, showdefaults);
571 }
572 
573 /*
574  * Describe the mount options in force on this server representation
575  */
576 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
577 				   int showdefaults)
578 {
579 	static const struct proc_nfs_info {
580 		int flag;
581 		const char *str;
582 		const char *nostr;
583 	} nfs_info[] = {
584 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
585 		{ NFS_MOUNT_POSIX, ",posix", "" },
586 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
587 		{ NFS_MOUNT_NOAC, ",noac", "" },
588 		{ NFS_MOUNT_NONLM, ",nolock", "" },
589 		{ NFS_MOUNT_NOACL, ",noacl", "" },
590 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
591 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
592 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
593 		{ 0, NULL, NULL }
594 	};
595 	const struct proc_nfs_info *nfs_infop;
596 	struct nfs_client *clp = nfss->nfs_client;
597 	u32 version = clp->rpc_ops->version;
598 
599 	seq_printf(m, ",vers=%u", version);
600 	seq_printf(m, ",rsize=%u", nfss->rsize);
601 	seq_printf(m, ",wsize=%u", nfss->wsize);
602 	if (nfss->bsize != 0)
603 		seq_printf(m, ",bsize=%u", nfss->bsize);
604 	seq_printf(m, ",namlen=%u", nfss->namelen);
605 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
606 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
607 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
608 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
609 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
610 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
611 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
612 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
613 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
614 		if (nfss->flags & nfs_infop->flag)
615 			seq_puts(m, nfs_infop->str);
616 		else
617 			seq_puts(m, nfs_infop->nostr);
618 	}
619 	seq_printf(m, ",proto=%s",
620 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
621 	if (version == 4) {
622 		if (nfss->port != NFS_PORT)
623 			seq_printf(m, ",port=%u", nfss->port);
624 	} else
625 		if (nfss->port)
626 			seq_printf(m, ",port=%u", nfss->port);
627 
628 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
629 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
630 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
631 
632 	if (version != 4)
633 		nfs_show_mountd_options(m, nfss, showdefaults);
634 
635 #ifdef CONFIG_NFS_V4
636 	if (clp->rpc_ops->version == 4)
637 		seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
638 #endif
639 	if (nfss->options & NFS_OPTION_FSCACHE)
640 		seq_printf(m, ",fsc");
641 }
642 
643 /*
644  * Describe the mount options on this VFS mountpoint
645  */
646 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
647 {
648 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
649 
650 	nfs_show_mount_options(m, nfss, 0);
651 
652 	seq_printf(m, ",addr=%s",
653 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
654 							RPC_DISPLAY_ADDR));
655 
656 	return 0;
657 }
658 
659 /*
660  * Present statistical information for this VFS mountpoint
661  */
662 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
663 {
664 	int i, cpu;
665 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
666 	struct rpc_auth *auth = nfss->client->cl_auth;
667 	struct nfs_iostats totals = { };
668 
669 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
670 
671 	/*
672 	 * Display all mount option settings
673 	 */
674 	seq_printf(m, "\n\topts:\t");
675 	seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
676 	seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
677 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
678 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
679 	nfs_show_mount_options(m, nfss, 1);
680 
681 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
682 
683 	seq_printf(m, "\n\tcaps:\t");
684 	seq_printf(m, "caps=0x%x", nfss->caps);
685 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
686 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
687 	seq_printf(m, ",bsize=%u", nfss->bsize);
688 	seq_printf(m, ",namlen=%u", nfss->namelen);
689 
690 #ifdef CONFIG_NFS_V4
691 	if (nfss->nfs_client->rpc_ops->version == 4) {
692 		seq_printf(m, "\n\tnfsv4:\t");
693 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
694 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
695 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
696 	}
697 #endif
698 
699 	/*
700 	 * Display security flavor in effect for this mount
701 	 */
702 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
703 	if (auth->au_flavor)
704 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
705 
706 	/*
707 	 * Display superblock I/O counters
708 	 */
709 	for_each_possible_cpu(cpu) {
710 		struct nfs_iostats *stats;
711 
712 		preempt_disable();
713 		stats = per_cpu_ptr(nfss->io_stats, cpu);
714 
715 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
716 			totals.events[i] += stats->events[i];
717 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
718 			totals.bytes[i] += stats->bytes[i];
719 #ifdef CONFIG_NFS_FSCACHE
720 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
721 			totals.fscache[i] += stats->fscache[i];
722 #endif
723 
724 		preempt_enable();
725 	}
726 
727 	seq_printf(m, "\n\tevents:\t");
728 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
729 		seq_printf(m, "%lu ", totals.events[i]);
730 	seq_printf(m, "\n\tbytes:\t");
731 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
732 		seq_printf(m, "%Lu ", totals.bytes[i]);
733 #ifdef CONFIG_NFS_FSCACHE
734 	if (nfss->options & NFS_OPTION_FSCACHE) {
735 		seq_printf(m, "\n\tfsc:\t");
736 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
737 			seq_printf(m, "%Lu ", totals.bytes[i]);
738 	}
739 #endif
740 	seq_printf(m, "\n");
741 
742 	rpc_print_iostats(m, nfss->client);
743 
744 	return 0;
745 }
746 
747 /*
748  * Begin unmount by attempting to remove all automounted mountpoints we added
749  * in response to xdev traversals and referrals
750  */
751 static void nfs_umount_begin(struct super_block *sb)
752 {
753 	struct nfs_server *server;
754 	struct rpc_clnt *rpc;
755 
756 	server = NFS_SB(sb);
757 	/* -EIO all pending I/O */
758 	rpc = server->client_acl;
759 	if (!IS_ERR(rpc))
760 		rpc_killall_tasks(rpc);
761 	rpc = server->client;
762 	if (!IS_ERR(rpc))
763 		rpc_killall_tasks(rpc);
764 }
765 
766 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
767 {
768 	struct nfs_parsed_mount_data *data;
769 
770 	data = kzalloc(sizeof(*data), GFP_KERNEL);
771 	if (data) {
772 		data->acregmin		= NFS_DEF_ACREGMIN;
773 		data->acregmax		= NFS_DEF_ACREGMAX;
774 		data->acdirmin		= NFS_DEF_ACDIRMIN;
775 		data->acdirmax		= NFS_DEF_ACDIRMAX;
776 		data->mount_server.port	= NFS_UNSPEC_PORT;
777 		data->nfs_server.port	= NFS_UNSPEC_PORT;
778 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
779 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
780 		data->auth_flavor_len	= 1;
781 		data->version		= version;
782 		data->minorversion	= 0;
783 	}
784 	return data;
785 }
786 
787 /*
788  * Sanity-check a server address provided by the mount command.
789  *
790  * Address family must be initialized, and address must not be
791  * the ANY address for that family.
792  */
793 static int nfs_verify_server_address(struct sockaddr *addr)
794 {
795 	switch (addr->sa_family) {
796 	case AF_INET: {
797 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
798 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
799 	}
800 	case AF_INET6: {
801 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
802 		return !ipv6_addr_any(sa);
803 	}
804 	}
805 
806 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
807 	return 0;
808 }
809 
810 /*
811  * Select between a default port value and a user-specified port value.
812  * If a zero value is set, then autobind will be used.
813  */
814 static void nfs_set_port(struct sockaddr *sap, int *port,
815 				 const unsigned short default_port)
816 {
817 	if (*port == NFS_UNSPEC_PORT)
818 		*port = default_port;
819 
820 	rpc_set_port(sap, *port);
821 }
822 
823 /*
824  * Sanity check the NFS transport protocol.
825  *
826  */
827 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
828 {
829 	switch (mnt->nfs_server.protocol) {
830 	case XPRT_TRANSPORT_UDP:
831 	case XPRT_TRANSPORT_TCP:
832 	case XPRT_TRANSPORT_RDMA:
833 		break;
834 	default:
835 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
836 	}
837 }
838 
839 /*
840  * For text based NFSv2/v3 mounts, the mount protocol transport default
841  * settings should depend upon the specified NFS transport.
842  */
843 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
844 {
845 	nfs_validate_transport_protocol(mnt);
846 
847 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
848 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
849 			return;
850 	switch (mnt->nfs_server.protocol) {
851 	case XPRT_TRANSPORT_UDP:
852 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
853 		break;
854 	case XPRT_TRANSPORT_TCP:
855 	case XPRT_TRANSPORT_RDMA:
856 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
857 	}
858 }
859 
860 /*
861  * Parse the value of the 'sec=' option.
862  */
863 static int nfs_parse_security_flavors(char *value,
864 				      struct nfs_parsed_mount_data *mnt)
865 {
866 	substring_t args[MAX_OPT_ARGS];
867 
868 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
869 
870 	switch (match_token(value, nfs_secflavor_tokens, args)) {
871 	case Opt_sec_none:
872 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
873 		break;
874 	case Opt_sec_sys:
875 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
876 		break;
877 	case Opt_sec_krb5:
878 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
879 		break;
880 	case Opt_sec_krb5i:
881 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
882 		break;
883 	case Opt_sec_krb5p:
884 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
885 		break;
886 	case Opt_sec_lkey:
887 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
888 		break;
889 	case Opt_sec_lkeyi:
890 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
891 		break;
892 	case Opt_sec_lkeyp:
893 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
894 		break;
895 	case Opt_sec_spkm:
896 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
897 		break;
898 	case Opt_sec_spkmi:
899 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
900 		break;
901 	case Opt_sec_spkmp:
902 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
903 		break;
904 	default:
905 		return 0;
906 	}
907 
908 	mnt->auth_flavor_len = 1;
909 	return 1;
910 }
911 
912 /*
913  * Error-check and convert a string of mount options from user space into
914  * a data structure.  The whole mount string is processed; bad options are
915  * skipped as they are encountered.  If there were no errors, return 1;
916  * otherwise return 0 (zero).
917  */
918 static int nfs_parse_mount_options(char *raw,
919 				   struct nfs_parsed_mount_data *mnt)
920 {
921 	char *p, *string, *secdata;
922 	int rc, sloppy = 0, invalid_option = 0;
923 	unsigned short protofamily = AF_UNSPEC;
924 	unsigned short mountfamily = AF_UNSPEC;
925 
926 	if (!raw) {
927 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
928 		return 1;
929 	}
930 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
931 
932 	secdata = alloc_secdata();
933 	if (!secdata)
934 		goto out_nomem;
935 
936 	rc = security_sb_copy_data(raw, secdata);
937 	if (rc)
938 		goto out_security_failure;
939 
940 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
941 	if (rc)
942 		goto out_security_failure;
943 
944 	free_secdata(secdata);
945 
946 	while ((p = strsep(&raw, ",")) != NULL) {
947 		substring_t args[MAX_OPT_ARGS];
948 		unsigned long option;
949 		int token;
950 
951 		if (!*p)
952 			continue;
953 
954 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
955 
956 		token = match_token(p, nfs_mount_option_tokens, args);
957 		switch (token) {
958 
959 		/*
960 		 * boolean options:  foo/nofoo
961 		 */
962 		case Opt_soft:
963 			mnt->flags |= NFS_MOUNT_SOFT;
964 			break;
965 		case Opt_hard:
966 			mnt->flags &= ~NFS_MOUNT_SOFT;
967 			break;
968 		case Opt_posix:
969 			mnt->flags |= NFS_MOUNT_POSIX;
970 			break;
971 		case Opt_noposix:
972 			mnt->flags &= ~NFS_MOUNT_POSIX;
973 			break;
974 		case Opt_cto:
975 			mnt->flags &= ~NFS_MOUNT_NOCTO;
976 			break;
977 		case Opt_nocto:
978 			mnt->flags |= NFS_MOUNT_NOCTO;
979 			break;
980 		case Opt_ac:
981 			mnt->flags &= ~NFS_MOUNT_NOAC;
982 			break;
983 		case Opt_noac:
984 			mnt->flags |= NFS_MOUNT_NOAC;
985 			break;
986 		case Opt_lock:
987 			mnt->flags &= ~NFS_MOUNT_NONLM;
988 			break;
989 		case Opt_nolock:
990 			mnt->flags |= NFS_MOUNT_NONLM;
991 			break;
992 		case Opt_v2:
993 			mnt->flags &= ~NFS_MOUNT_VER3;
994 			mnt->version = 2;
995 			break;
996 		case Opt_v3:
997 			mnt->flags |= NFS_MOUNT_VER3;
998 			mnt->version = 3;
999 			break;
1000 #ifdef CONFIG_NFS_V4
1001 		case Opt_v4:
1002 			mnt->flags &= ~NFS_MOUNT_VER3;
1003 			mnt->version = 4;
1004 			break;
1005 #endif
1006 		case Opt_udp:
1007 			mnt->flags &= ~NFS_MOUNT_TCP;
1008 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1009 			break;
1010 		case Opt_tcp:
1011 			mnt->flags |= NFS_MOUNT_TCP;
1012 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1013 			break;
1014 		case Opt_rdma:
1015 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1016 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1017 			xprt_load_transport(p);
1018 			break;
1019 		case Opt_acl:
1020 			mnt->flags &= ~NFS_MOUNT_NOACL;
1021 			break;
1022 		case Opt_noacl:
1023 			mnt->flags |= NFS_MOUNT_NOACL;
1024 			break;
1025 		case Opt_rdirplus:
1026 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1027 			break;
1028 		case Opt_nordirplus:
1029 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1030 			break;
1031 		case Opt_sharecache:
1032 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1033 			break;
1034 		case Opt_nosharecache:
1035 			mnt->flags |= NFS_MOUNT_UNSHARED;
1036 			break;
1037 		case Opt_resvport:
1038 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1039 			break;
1040 		case Opt_noresvport:
1041 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1042 			break;
1043 		case Opt_fscache:
1044 			mnt->options |= NFS_OPTION_FSCACHE;
1045 			kfree(mnt->fscache_uniq);
1046 			mnt->fscache_uniq = NULL;
1047 			break;
1048 		case Opt_nofscache:
1049 			mnt->options &= ~NFS_OPTION_FSCACHE;
1050 			kfree(mnt->fscache_uniq);
1051 			mnt->fscache_uniq = NULL;
1052 			break;
1053 
1054 		/*
1055 		 * options that take numeric values
1056 		 */
1057 		case Opt_port:
1058 			string = match_strdup(args);
1059 			if (string == NULL)
1060 				goto out_nomem;
1061 			rc = strict_strtoul(string, 10, &option);
1062 			kfree(string);
1063 			if (rc != 0 || option > USHRT_MAX)
1064 				goto out_invalid_value;
1065 			mnt->nfs_server.port = option;
1066 			break;
1067 		case Opt_rsize:
1068 			string = match_strdup(args);
1069 			if (string == NULL)
1070 				goto out_nomem;
1071 			rc = strict_strtoul(string, 10, &option);
1072 			kfree(string);
1073 			if (rc != 0)
1074 				goto out_invalid_value;
1075 			mnt->rsize = option;
1076 			break;
1077 		case Opt_wsize:
1078 			string = match_strdup(args);
1079 			if (string == NULL)
1080 				goto out_nomem;
1081 			rc = strict_strtoul(string, 10, &option);
1082 			kfree(string);
1083 			if (rc != 0)
1084 				goto out_invalid_value;
1085 			mnt->wsize = option;
1086 			break;
1087 		case Opt_bsize:
1088 			string = match_strdup(args);
1089 			if (string == NULL)
1090 				goto out_nomem;
1091 			rc = strict_strtoul(string, 10, &option);
1092 			kfree(string);
1093 			if (rc != 0)
1094 				goto out_invalid_value;
1095 			mnt->bsize = option;
1096 			break;
1097 		case Opt_timeo:
1098 			string = match_strdup(args);
1099 			if (string == NULL)
1100 				goto out_nomem;
1101 			rc = strict_strtoul(string, 10, &option);
1102 			kfree(string);
1103 			if (rc != 0 || option == 0)
1104 				goto out_invalid_value;
1105 			mnt->timeo = option;
1106 			break;
1107 		case Opt_retrans:
1108 			string = match_strdup(args);
1109 			if (string == NULL)
1110 				goto out_nomem;
1111 			rc = strict_strtoul(string, 10, &option);
1112 			kfree(string);
1113 			if (rc != 0 || option == 0)
1114 				goto out_invalid_value;
1115 			mnt->retrans = option;
1116 			break;
1117 		case Opt_acregmin:
1118 			string = match_strdup(args);
1119 			if (string == NULL)
1120 				goto out_nomem;
1121 			rc = strict_strtoul(string, 10, &option);
1122 			kfree(string);
1123 			if (rc != 0)
1124 				goto out_invalid_value;
1125 			mnt->acregmin = option;
1126 			break;
1127 		case Opt_acregmax:
1128 			string = match_strdup(args);
1129 			if (string == NULL)
1130 				goto out_nomem;
1131 			rc = strict_strtoul(string, 10, &option);
1132 			kfree(string);
1133 			if (rc != 0)
1134 				goto out_invalid_value;
1135 			mnt->acregmax = option;
1136 			break;
1137 		case Opt_acdirmin:
1138 			string = match_strdup(args);
1139 			if (string == NULL)
1140 				goto out_nomem;
1141 			rc = strict_strtoul(string, 10, &option);
1142 			kfree(string);
1143 			if (rc != 0)
1144 				goto out_invalid_value;
1145 			mnt->acdirmin = option;
1146 			break;
1147 		case Opt_acdirmax:
1148 			string = match_strdup(args);
1149 			if (string == NULL)
1150 				goto out_nomem;
1151 			rc = strict_strtoul(string, 10, &option);
1152 			kfree(string);
1153 			if (rc != 0)
1154 				goto out_invalid_value;
1155 			mnt->acdirmax = option;
1156 			break;
1157 		case Opt_actimeo:
1158 			string = match_strdup(args);
1159 			if (string == NULL)
1160 				goto out_nomem;
1161 			rc = strict_strtoul(string, 10, &option);
1162 			kfree(string);
1163 			if (rc != 0)
1164 				goto out_invalid_value;
1165 			mnt->acregmin = mnt->acregmax =
1166 			mnt->acdirmin = mnt->acdirmax = option;
1167 			break;
1168 		case Opt_namelen:
1169 			string = match_strdup(args);
1170 			if (string == NULL)
1171 				goto out_nomem;
1172 			rc = strict_strtoul(string, 10, &option);
1173 			kfree(string);
1174 			if (rc != 0)
1175 				goto out_invalid_value;
1176 			mnt->namlen = option;
1177 			break;
1178 		case Opt_mountport:
1179 			string = match_strdup(args);
1180 			if (string == NULL)
1181 				goto out_nomem;
1182 			rc = strict_strtoul(string, 10, &option);
1183 			kfree(string);
1184 			if (rc != 0 || option > USHRT_MAX)
1185 				goto out_invalid_value;
1186 			mnt->mount_server.port = option;
1187 			break;
1188 		case Opt_mountvers:
1189 			string = match_strdup(args);
1190 			if (string == NULL)
1191 				goto out_nomem;
1192 			rc = strict_strtoul(string, 10, &option);
1193 			kfree(string);
1194 			if (rc != 0 ||
1195 			    option < NFS_MNT_VERSION ||
1196 			    option > NFS_MNT3_VERSION)
1197 				goto out_invalid_value;
1198 			mnt->mount_server.version = option;
1199 			break;
1200 		case Opt_nfsvers:
1201 			string = match_strdup(args);
1202 			if (string == NULL)
1203 				goto out_nomem;
1204 			rc = strict_strtoul(string, 10, &option);
1205 			kfree(string);
1206 			if (rc != 0)
1207 				goto out_invalid_value;
1208 			switch (option) {
1209 			case NFS2_VERSION:
1210 				mnt->flags &= ~NFS_MOUNT_VER3;
1211 				mnt->version = 2;
1212 				break;
1213 			case NFS3_VERSION:
1214 				mnt->flags |= NFS_MOUNT_VER3;
1215 				mnt->version = 3;
1216 				break;
1217 #ifdef CONFIG_NFS_V4
1218 			case NFS4_VERSION:
1219 				mnt->flags &= ~NFS_MOUNT_VER3;
1220 				mnt->version = 4;
1221 				break;
1222 #endif
1223 			default:
1224 				goto out_invalid_value;
1225 			}
1226 			break;
1227 		case Opt_minorversion:
1228 			string = match_strdup(args);
1229 			if (string == NULL)
1230 				goto out_nomem;
1231 			rc = strict_strtoul(string, 10, &option);
1232 			kfree(string);
1233 			if (rc != 0)
1234 				goto out_invalid_value;
1235 			if (option > NFS4_MAX_MINOR_VERSION)
1236 				goto out_invalid_value;
1237 			mnt->minorversion = option;
1238 			break;
1239 
1240 		/*
1241 		 * options that take text values
1242 		 */
1243 		case Opt_sec:
1244 			string = match_strdup(args);
1245 			if (string == NULL)
1246 				goto out_nomem;
1247 			rc = nfs_parse_security_flavors(string, mnt);
1248 			kfree(string);
1249 			if (!rc) {
1250 				dfprintk(MOUNT, "NFS:   unrecognized "
1251 						"security flavor\n");
1252 				return 0;
1253 			}
1254 			break;
1255 		case Opt_proto:
1256 			string = match_strdup(args);
1257 			if (string == NULL)
1258 				goto out_nomem;
1259 			token = match_token(string,
1260 					    nfs_xprt_protocol_tokens, args);
1261 
1262 			protofamily = AF_INET;
1263 			switch (token) {
1264 			case Opt_xprt_udp6:
1265 				protofamily = AF_INET6;
1266 			case Opt_xprt_udp:
1267 				mnt->flags &= ~NFS_MOUNT_TCP;
1268 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1269 				kfree(string);
1270 				break;
1271 			case Opt_xprt_tcp6:
1272 				protofamily = AF_INET6;
1273 			case Opt_xprt_tcp:
1274 				mnt->flags |= NFS_MOUNT_TCP;
1275 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1276 				kfree(string);
1277 				break;
1278 			case Opt_xprt_rdma:
1279 				/* vector side protocols to TCP */
1280 				mnt->flags |= NFS_MOUNT_TCP;
1281 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1282 				xprt_load_transport(string);
1283 				kfree(string);
1284 				break;
1285 			default:
1286 				dfprintk(MOUNT, "NFS:   unrecognized "
1287 						"transport protocol\n");
1288 				kfree(string);
1289 				return 0;
1290 			}
1291 			break;
1292 		case Opt_mountproto:
1293 			string = match_strdup(args);
1294 			if (string == NULL)
1295 				goto out_nomem;
1296 			token = match_token(string,
1297 					    nfs_xprt_protocol_tokens, args);
1298 			kfree(string);
1299 
1300 			mountfamily = AF_INET;
1301 			switch (token) {
1302 			case Opt_xprt_udp6:
1303 				mountfamily = AF_INET6;
1304 			case Opt_xprt_udp:
1305 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1306 				break;
1307 			case Opt_xprt_tcp6:
1308 				mountfamily = AF_INET6;
1309 			case Opt_xprt_tcp:
1310 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1311 				break;
1312 			case Opt_xprt_rdma: /* not used for side protocols */
1313 			default:
1314 				dfprintk(MOUNT, "NFS:   unrecognized "
1315 						"transport protocol\n");
1316 				return 0;
1317 			}
1318 			break;
1319 		case Opt_addr:
1320 			string = match_strdup(args);
1321 			if (string == NULL)
1322 				goto out_nomem;
1323 			mnt->nfs_server.addrlen =
1324 				rpc_pton(string, strlen(string),
1325 					(struct sockaddr *)
1326 					&mnt->nfs_server.address,
1327 					sizeof(mnt->nfs_server.address));
1328 			kfree(string);
1329 			if (mnt->nfs_server.addrlen == 0)
1330 				goto out_invalid_address;
1331 			break;
1332 		case Opt_clientaddr:
1333 			string = match_strdup(args);
1334 			if (string == NULL)
1335 				goto out_nomem;
1336 			kfree(mnt->client_address);
1337 			mnt->client_address = string;
1338 			break;
1339 		case Opt_mounthost:
1340 			string = match_strdup(args);
1341 			if (string == NULL)
1342 				goto out_nomem;
1343 			kfree(mnt->mount_server.hostname);
1344 			mnt->mount_server.hostname = string;
1345 			break;
1346 		case Opt_mountaddr:
1347 			string = match_strdup(args);
1348 			if (string == NULL)
1349 				goto out_nomem;
1350 			mnt->mount_server.addrlen =
1351 				rpc_pton(string, strlen(string),
1352 					(struct sockaddr *)
1353 					&mnt->mount_server.address,
1354 					sizeof(mnt->mount_server.address));
1355 			kfree(string);
1356 			if (mnt->mount_server.addrlen == 0)
1357 				goto out_invalid_address;
1358 			break;
1359 		case Opt_lookupcache:
1360 			string = match_strdup(args);
1361 			if (string == NULL)
1362 				goto out_nomem;
1363 			token = match_token(string,
1364 					nfs_lookupcache_tokens, args);
1365 			kfree(string);
1366 			switch (token) {
1367 				case Opt_lookupcache_all:
1368 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1369 					break;
1370 				case Opt_lookupcache_positive:
1371 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1372 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1373 					break;
1374 				case Opt_lookupcache_none:
1375 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1376 					break;
1377 				default:
1378 					dfprintk(MOUNT, "NFS:   invalid "
1379 							"lookupcache argument\n");
1380 					return 0;
1381 			};
1382 			break;
1383 		case Opt_fscache_uniq:
1384 			string = match_strdup(args);
1385 			if (string == NULL)
1386 				goto out_nomem;
1387 			kfree(mnt->fscache_uniq);
1388 			mnt->fscache_uniq = string;
1389 			mnt->options |= NFS_OPTION_FSCACHE;
1390 			break;
1391 
1392 		/*
1393 		 * Special options
1394 		 */
1395 		case Opt_sloppy:
1396 			sloppy = 1;
1397 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1398 			break;
1399 		case Opt_userspace:
1400 		case Opt_deprecated:
1401 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1402 					"'%s'\n", p);
1403 			break;
1404 
1405 		default:
1406 			invalid_option = 1;
1407 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1408 					"'%s'\n", p);
1409 		}
1410 	}
1411 
1412 	if (!sloppy && invalid_option)
1413 		return 0;
1414 
1415 	/*
1416 	 * verify that any proto=/mountproto= options match the address
1417 	 * familiies in the addr=/mountaddr= options.
1418 	 */
1419 	if (protofamily != AF_UNSPEC &&
1420 	    protofamily != mnt->nfs_server.address.ss_family)
1421 		goto out_proto_mismatch;
1422 
1423 	if (mountfamily != AF_UNSPEC) {
1424 		if (mnt->mount_server.addrlen) {
1425 			if (mountfamily != mnt->mount_server.address.ss_family)
1426 				goto out_mountproto_mismatch;
1427 		} else {
1428 			if (mountfamily != mnt->nfs_server.address.ss_family)
1429 				goto out_mountproto_mismatch;
1430 		}
1431 	}
1432 
1433 	return 1;
1434 
1435 out_mountproto_mismatch:
1436 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1437 			 "option\n");
1438 	return 0;
1439 out_proto_mismatch:
1440 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1441 	return 0;
1442 out_invalid_address:
1443 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1444 	return 0;
1445 out_invalid_value:
1446 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1447 	return 0;
1448 out_nomem:
1449 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1450 	return 0;
1451 out_security_failure:
1452 	free_secdata(secdata);
1453 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1454 	return 0;
1455 }
1456 
1457 /*
1458  * Match the requested auth flavors with the list returned by
1459  * the server.  Returns zero and sets the mount's authentication
1460  * flavor on success; returns -EACCES if server does not support
1461  * the requested flavor.
1462  */
1463 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1464 			     struct nfs_mount_request *request)
1465 {
1466 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1467 
1468 	/*
1469 	 * Certain releases of Linux's mountd return an empty
1470 	 * flavor list.  To prevent behavioral regression with
1471 	 * these servers (ie. rejecting mounts that used to
1472 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1473 	 * if the returned flavor list is empty.
1474 	 */
1475 	if (server_authlist_len == 0)
1476 		return 0;
1477 
1478 	/*
1479 	 * We avoid sophisticated negotiating here, as there are
1480 	 * plenty of cases where we can get it wrong, providing
1481 	 * either too little or too much security.
1482 	 *
1483 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1484 	 * flavor listed first.  However, some servers list
1485 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1486 	 * preferred default, in args->auth_flavors[0] if user
1487 	 * didn't specify sec= mount option.
1488 	 */
1489 	for (i = 0; i < args->auth_flavor_len; i++)
1490 		for (j = 0; j < server_authlist_len; j++)
1491 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1492 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1493 					request->auth_flavs[j]);
1494 				args->auth_flavors[0] = request->auth_flavs[j];
1495 				return 0;
1496 			}
1497 
1498 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1499 	nfs_umount(request);
1500 	return -EACCES;
1501 }
1502 
1503 /*
1504  * Use the remote server's MOUNT service to request the NFS file handle
1505  * corresponding to the provided path.
1506  */
1507 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1508 			 struct nfs_fh *root_fh)
1509 {
1510 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1511 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1512 	struct nfs_mount_request request = {
1513 		.sap		= (struct sockaddr *)
1514 						&args->mount_server.address,
1515 		.dirpath	= args->nfs_server.export_path,
1516 		.protocol	= args->mount_server.protocol,
1517 		.fh		= root_fh,
1518 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1519 		.auth_flav_len	= &server_authlist_len,
1520 		.auth_flavs	= server_authlist,
1521 	};
1522 	int status;
1523 
1524 	if (args->mount_server.version == 0) {
1525 		switch (args->version) {
1526 			default:
1527 				args->mount_server.version = NFS_MNT3_VERSION;
1528 				break;
1529 			case 2:
1530 				args->mount_server.version = NFS_MNT_VERSION;
1531 		}
1532 	}
1533 	request.version = args->mount_server.version;
1534 
1535 	if (args->mount_server.hostname)
1536 		request.hostname = args->mount_server.hostname;
1537 	else
1538 		request.hostname = args->nfs_server.hostname;
1539 
1540 	/*
1541 	 * Construct the mount server's address.
1542 	 */
1543 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1544 		memcpy(request.sap, &args->nfs_server.address,
1545 		       args->nfs_server.addrlen);
1546 		args->mount_server.addrlen = args->nfs_server.addrlen;
1547 	}
1548 	request.salen = args->mount_server.addrlen;
1549 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1550 
1551 	/*
1552 	 * Now ask the mount server to map our export path
1553 	 * to a file handle.
1554 	 */
1555 	status = nfs_mount(&request);
1556 	if (status != 0) {
1557 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1558 				request.hostname, status);
1559 		return status;
1560 	}
1561 
1562 	/*
1563 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1564 	 */
1565 	if (args->mount_server.version != NFS_MNT3_VERSION)
1566 		return 0;
1567 	return nfs_walk_authlist(args, &request);
1568 }
1569 
1570 static int nfs_parse_simple_hostname(const char *dev_name,
1571 				     char **hostname, size_t maxnamlen,
1572 				     char **export_path, size_t maxpathlen)
1573 {
1574 	size_t len;
1575 	char *colon, *comma;
1576 
1577 	colon = strchr(dev_name, ':');
1578 	if (colon == NULL)
1579 		goto out_bad_devname;
1580 
1581 	len = colon - dev_name;
1582 	if (len > maxnamlen)
1583 		goto out_hostname;
1584 
1585 	/* N.B. caller will free nfs_server.hostname in all cases */
1586 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1587 	if (!*hostname)
1588 		goto out_nomem;
1589 
1590 	/* kill possible hostname list: not supported */
1591 	comma = strchr(*hostname, ',');
1592 	if (comma != NULL) {
1593 		if (comma == *hostname)
1594 			goto out_bad_devname;
1595 		*comma = '\0';
1596 	}
1597 
1598 	colon++;
1599 	len = strlen(colon);
1600 	if (len > maxpathlen)
1601 		goto out_path;
1602 	*export_path = kstrndup(colon, len, GFP_KERNEL);
1603 	if (!*export_path)
1604 		goto out_nomem;
1605 
1606 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1607 	return 0;
1608 
1609 out_bad_devname:
1610 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1611 	return -EINVAL;
1612 
1613 out_nomem:
1614 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1615 	return -ENOMEM;
1616 
1617 out_hostname:
1618 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1619 	return -ENAMETOOLONG;
1620 
1621 out_path:
1622 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1623 	return -ENAMETOOLONG;
1624 }
1625 
1626 /*
1627  * Hostname has square brackets around it because it contains one or
1628  * more colons.  We look for the first closing square bracket, and a
1629  * colon must follow it.
1630  */
1631 static int nfs_parse_protected_hostname(const char *dev_name,
1632 					char **hostname, size_t maxnamlen,
1633 					char **export_path, size_t maxpathlen)
1634 {
1635 	size_t len;
1636 	char *start, *end;
1637 
1638 	start = (char *)(dev_name + 1);
1639 
1640 	end = strchr(start, ']');
1641 	if (end == NULL)
1642 		goto out_bad_devname;
1643 	if (*(end + 1) != ':')
1644 		goto out_bad_devname;
1645 
1646 	len = end - start;
1647 	if (len > maxnamlen)
1648 		goto out_hostname;
1649 
1650 	/* N.B. caller will free nfs_server.hostname in all cases */
1651 	*hostname = kstrndup(start, len, GFP_KERNEL);
1652 	if (*hostname == NULL)
1653 		goto out_nomem;
1654 
1655 	end += 2;
1656 	len = strlen(end);
1657 	if (len > maxpathlen)
1658 		goto out_path;
1659 	*export_path = kstrndup(end, len, GFP_KERNEL);
1660 	if (!*export_path)
1661 		goto out_nomem;
1662 
1663 	return 0;
1664 
1665 out_bad_devname:
1666 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1667 	return -EINVAL;
1668 
1669 out_nomem:
1670 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1671 	return -ENOMEM;
1672 
1673 out_hostname:
1674 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1675 	return -ENAMETOOLONG;
1676 
1677 out_path:
1678 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1679 	return -ENAMETOOLONG;
1680 }
1681 
1682 /*
1683  * Split "dev_name" into "hostname:export_path".
1684  *
1685  * The leftmost colon demarks the split between the server's hostname
1686  * and the export path.  If the hostname starts with a left square
1687  * bracket, then it may contain colons.
1688  *
1689  * Note: caller frees hostname and export path, even on error.
1690  */
1691 static int nfs_parse_devname(const char *dev_name,
1692 			     char **hostname, size_t maxnamlen,
1693 			     char **export_path, size_t maxpathlen)
1694 {
1695 	if (*dev_name == '[')
1696 		return nfs_parse_protected_hostname(dev_name,
1697 						    hostname, maxnamlen,
1698 						    export_path, maxpathlen);
1699 
1700 	return nfs_parse_simple_hostname(dev_name,
1701 					 hostname, maxnamlen,
1702 					 export_path, maxpathlen);
1703 }
1704 
1705 /*
1706  * Validate the NFS2/NFS3 mount data
1707  * - fills in the mount root filehandle
1708  *
1709  * For option strings, user space handles the following behaviors:
1710  *
1711  * + DNS: mapping server host name to IP address ("addr=" option)
1712  *
1713  * + failure mode: how to behave if a mount request can't be handled
1714  *   immediately ("fg/bg" option)
1715  *
1716  * + retry: how often to retry a mount request ("retry=" option)
1717  *
1718  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1719  *   mountproto=tcp after mountproto=udp, and so on
1720  */
1721 static int nfs_validate_mount_data(void *options,
1722 				   struct nfs_parsed_mount_data *args,
1723 				   struct nfs_fh *mntfh,
1724 				   const char *dev_name)
1725 {
1726 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1727 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1728 
1729 	if (data == NULL)
1730 		goto out_no_data;
1731 
1732 	switch (data->version) {
1733 	case 1:
1734 		data->namlen = 0;
1735 	case 2:
1736 		data->bsize = 0;
1737 	case 3:
1738 		if (data->flags & NFS_MOUNT_VER3)
1739 			goto out_no_v3;
1740 		data->root.size = NFS2_FHSIZE;
1741 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1742 	case 4:
1743 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1744 			goto out_no_sec;
1745 	case 5:
1746 		memset(data->context, 0, sizeof(data->context));
1747 	case 6:
1748 		if (data->flags & NFS_MOUNT_VER3) {
1749 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1750 				goto out_invalid_fh;
1751 			mntfh->size = data->root.size;
1752 			args->version = 3;
1753 		} else {
1754 			mntfh->size = NFS2_FHSIZE;
1755 			args->version = 2;
1756 		}
1757 
1758 
1759 		memcpy(mntfh->data, data->root.data, mntfh->size);
1760 		if (mntfh->size < sizeof(mntfh->data))
1761 			memset(mntfh->data + mntfh->size, 0,
1762 			       sizeof(mntfh->data) - mntfh->size);
1763 
1764 		/*
1765 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1766 		 * can deal with.
1767 		 */
1768 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1769 		args->rsize		= data->rsize;
1770 		args->wsize		= data->wsize;
1771 		args->timeo		= data->timeo;
1772 		args->retrans		= data->retrans;
1773 		args->acregmin		= data->acregmin;
1774 		args->acregmax		= data->acregmax;
1775 		args->acdirmin		= data->acdirmin;
1776 		args->acdirmax		= data->acdirmax;
1777 
1778 		memcpy(sap, &data->addr, sizeof(data->addr));
1779 		args->nfs_server.addrlen = sizeof(data->addr);
1780 		if (!nfs_verify_server_address(sap))
1781 			goto out_no_address;
1782 
1783 		if (!(data->flags & NFS_MOUNT_TCP))
1784 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1785 		/* N.B. caller will free nfs_server.hostname in all cases */
1786 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1787 		args->namlen		= data->namlen;
1788 		args->bsize		= data->bsize;
1789 
1790 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1791 			args->auth_flavors[0] = data->pseudoflavor;
1792 		if (!args->nfs_server.hostname)
1793 			goto out_nomem;
1794 
1795 		/*
1796 		 * The legacy version 6 binary mount data from userspace has a
1797 		 * field used only to transport selinux information into the
1798 		 * the kernel.  To continue to support that functionality we
1799 		 * have a touch of selinux knowledge here in the NFS code. The
1800 		 * userspace code converted context=blah to just blah so we are
1801 		 * converting back to the full string selinux understands.
1802 		 */
1803 		if (data->context[0]){
1804 #ifdef CONFIG_SECURITY_SELINUX
1805 			int rc;
1806 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1807 			if (!opts_str)
1808 				return -ENOMEM;
1809 			strcpy(opts_str, "context=");
1810 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1811 			strcat(opts_str, &data->context[0]);
1812 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1813 			kfree(opts_str);
1814 			if (rc)
1815 				return rc;
1816 #else
1817 			return -EINVAL;
1818 #endif
1819 		}
1820 
1821 		break;
1822 	default: {
1823 		int status;
1824 
1825 		if (nfs_parse_mount_options((char *)options, args) == 0)
1826 			return -EINVAL;
1827 
1828 		if (!nfs_verify_server_address(sap))
1829 			goto out_no_address;
1830 
1831 		if (args->version == 4)
1832 #ifdef CONFIG_NFS_V4
1833 			return nfs4_validate_text_mount_data(options,
1834 							     args, dev_name);
1835 #else
1836 			goto out_v4_not_compiled;
1837 #endif
1838 
1839 		nfs_set_port(sap, &args->nfs_server.port, 0);
1840 
1841 		nfs_set_mount_transport_protocol(args);
1842 
1843 		status = nfs_parse_devname(dev_name,
1844 					   &args->nfs_server.hostname,
1845 					   PAGE_SIZE,
1846 					   &args->nfs_server.export_path,
1847 					   NFS_MAXPATHLEN);
1848 		if (!status)
1849 			status = nfs_try_mount(args, mntfh);
1850 
1851 		kfree(args->nfs_server.export_path);
1852 		args->nfs_server.export_path = NULL;
1853 
1854 		if (status)
1855 			return status;
1856 
1857 		break;
1858 		}
1859 	}
1860 
1861 #ifndef CONFIG_NFS_V3
1862 	if (args->version == 3)
1863 		goto out_v3_not_compiled;
1864 #endif /* !CONFIG_NFS_V3 */
1865 
1866 	return 0;
1867 
1868 out_no_data:
1869 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1870 	return -EINVAL;
1871 
1872 out_no_v3:
1873 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1874 		 data->version);
1875 	return -EINVAL;
1876 
1877 out_no_sec:
1878 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1879 	return -EINVAL;
1880 
1881 #ifndef CONFIG_NFS_V3
1882 out_v3_not_compiled:
1883 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1884 	return -EPROTONOSUPPORT;
1885 #endif /* !CONFIG_NFS_V3 */
1886 
1887 #ifndef CONFIG_NFS_V4
1888 out_v4_not_compiled:
1889 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1890 	return -EPROTONOSUPPORT;
1891 #endif /* !CONFIG_NFS_V4 */
1892 
1893 out_nomem:
1894 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1895 	return -ENOMEM;
1896 
1897 out_no_address:
1898 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1899 	return -EINVAL;
1900 
1901 out_invalid_fh:
1902 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1903 	return -EINVAL;
1904 }
1905 
1906 static int
1907 nfs_compare_remount_data(struct nfs_server *nfss,
1908 			 struct nfs_parsed_mount_data *data)
1909 {
1910 	if (data->flags != nfss->flags ||
1911 	    data->rsize != nfss->rsize ||
1912 	    data->wsize != nfss->wsize ||
1913 	    data->retrans != nfss->client->cl_timeout->to_retries ||
1914 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1915 	    data->acregmin != nfss->acregmin / HZ ||
1916 	    data->acregmax != nfss->acregmax / HZ ||
1917 	    data->acdirmin != nfss->acdirmin / HZ ||
1918 	    data->acdirmax != nfss->acdirmax / HZ ||
1919 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1920 	    data->nfs_server.port != nfss->port ||
1921 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1922 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1923 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
1924 		return -EINVAL;
1925 
1926 	return 0;
1927 }
1928 
1929 static int
1930 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1931 {
1932 	int error;
1933 	struct nfs_server *nfss = sb->s_fs_info;
1934 	struct nfs_parsed_mount_data *data;
1935 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1936 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1937 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1938 
1939 	/*
1940 	 * Userspace mount programs that send binary options generally send
1941 	 * them populated with default values. We have no way to know which
1942 	 * ones were explicitly specified. Fall back to legacy behavior and
1943 	 * just return success.
1944 	 */
1945 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1946 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
1947 					   options->version <= 6))))
1948 		return 0;
1949 
1950 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1951 	if (data == NULL)
1952 		return -ENOMEM;
1953 
1954 	/* fill out struct with values from existing mount */
1955 	data->flags = nfss->flags;
1956 	data->rsize = nfss->rsize;
1957 	data->wsize = nfss->wsize;
1958 	data->retrans = nfss->client->cl_timeout->to_retries;
1959 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1960 	data->acregmin = nfss->acregmin / HZ;
1961 	data->acregmax = nfss->acregmax / HZ;
1962 	data->acdirmin = nfss->acdirmin / HZ;
1963 	data->acdirmax = nfss->acdirmax / HZ;
1964 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1965 	data->nfs_server.port = nfss->port;
1966 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1967 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1968 		data->nfs_server.addrlen);
1969 
1970 	/* overwrite those values with any that were specified */
1971 	error = nfs_parse_mount_options((char *)options, data);
1972 	if (error < 0)
1973 		goto out;
1974 
1975 	/* compare new mount options with old ones */
1976 	error = nfs_compare_remount_data(nfss, data);
1977 out:
1978 	kfree(data);
1979 	return error;
1980 }
1981 
1982 /*
1983  * Initialise the common bits of the superblock
1984  */
1985 static inline void nfs_initialise_sb(struct super_block *sb)
1986 {
1987 	struct nfs_server *server = NFS_SB(sb);
1988 
1989 	sb->s_magic = NFS_SUPER_MAGIC;
1990 
1991 	/* We probably want something more informative here */
1992 	snprintf(sb->s_id, sizeof(sb->s_id),
1993 		 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1994 
1995 	if (sb->s_blocksize == 0)
1996 		sb->s_blocksize = nfs_block_bits(server->wsize,
1997 						 &sb->s_blocksize_bits);
1998 
1999 	if (server->flags & NFS_MOUNT_NOAC)
2000 		sb->s_flags |= MS_SYNCHRONOUS;
2001 
2002 	sb->s_bdi = &server->backing_dev_info;
2003 
2004 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2005 }
2006 
2007 /*
2008  * Finish setting up an NFS2/3 superblock
2009  */
2010 static void nfs_fill_super(struct super_block *sb,
2011 			   struct nfs_parsed_mount_data *data)
2012 {
2013 	struct nfs_server *server = NFS_SB(sb);
2014 
2015 	sb->s_blocksize_bits = 0;
2016 	sb->s_blocksize = 0;
2017 	if (data->bsize)
2018 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2019 
2020 	if (server->nfs_client->rpc_ops->version == 3) {
2021 		/* The VFS shouldn't apply the umask to mode bits. We will do
2022 		 * so ourselves when necessary.
2023 		 */
2024 		sb->s_flags |= MS_POSIXACL;
2025 		sb->s_time_gran = 1;
2026 	}
2027 
2028 	sb->s_op = &nfs_sops;
2029  	nfs_initialise_sb(sb);
2030 }
2031 
2032 /*
2033  * Finish setting up a cloned NFS2/3 superblock
2034  */
2035 static void nfs_clone_super(struct super_block *sb,
2036 			    const struct super_block *old_sb)
2037 {
2038 	struct nfs_server *server = NFS_SB(sb);
2039 
2040 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2041 	sb->s_blocksize = old_sb->s_blocksize;
2042 	sb->s_maxbytes = old_sb->s_maxbytes;
2043 
2044 	if (server->nfs_client->rpc_ops->version == 3) {
2045 		/* The VFS shouldn't apply the umask to mode bits. We will do
2046 		 * so ourselves when necessary.
2047 		 */
2048 		sb->s_flags |= MS_POSIXACL;
2049 		sb->s_time_gran = 1;
2050 	}
2051 
2052 	sb->s_op = old_sb->s_op;
2053  	nfs_initialise_sb(sb);
2054 }
2055 
2056 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2057 {
2058 	const struct nfs_server *a = s->s_fs_info;
2059 	const struct rpc_clnt *clnt_a = a->client;
2060 	const struct rpc_clnt *clnt_b = b->client;
2061 
2062 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2063 		goto Ebusy;
2064 	if (a->nfs_client != b->nfs_client)
2065 		goto Ebusy;
2066 	if (a->flags != b->flags)
2067 		goto Ebusy;
2068 	if (a->wsize != b->wsize)
2069 		goto Ebusy;
2070 	if (a->rsize != b->rsize)
2071 		goto Ebusy;
2072 	if (a->acregmin != b->acregmin)
2073 		goto Ebusy;
2074 	if (a->acregmax != b->acregmax)
2075 		goto Ebusy;
2076 	if (a->acdirmin != b->acdirmin)
2077 		goto Ebusy;
2078 	if (a->acdirmax != b->acdirmax)
2079 		goto Ebusy;
2080 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2081 		goto Ebusy;
2082 	return 1;
2083 Ebusy:
2084 	return 0;
2085 }
2086 
2087 struct nfs_sb_mountdata {
2088 	struct nfs_server *server;
2089 	int mntflags;
2090 };
2091 
2092 static int nfs_set_super(struct super_block *s, void *data)
2093 {
2094 	struct nfs_sb_mountdata *sb_mntdata = data;
2095 	struct nfs_server *server = sb_mntdata->server;
2096 	int ret;
2097 
2098 	s->s_flags = sb_mntdata->mntflags;
2099 	s->s_fs_info = server;
2100 	ret = set_anon_super(s, server);
2101 	if (ret == 0)
2102 		server->s_dev = s->s_dev;
2103 	return ret;
2104 }
2105 
2106 static int nfs_compare_super_address(struct nfs_server *server1,
2107 				     struct nfs_server *server2)
2108 {
2109 	struct sockaddr *sap1, *sap2;
2110 
2111 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2112 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2113 
2114 	if (sap1->sa_family != sap2->sa_family)
2115 		return 0;
2116 
2117 	switch (sap1->sa_family) {
2118 	case AF_INET: {
2119 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2120 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2121 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2122 			return 0;
2123 		if (sin1->sin_port != sin2->sin_port)
2124 			return 0;
2125 		break;
2126 	}
2127 	case AF_INET6: {
2128 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2129 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2130 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2131 			return 0;
2132 		if (sin1->sin6_port != sin2->sin6_port)
2133 			return 0;
2134 		break;
2135 	}
2136 	default:
2137 		return 0;
2138 	}
2139 
2140 	return 1;
2141 }
2142 
2143 static int nfs_compare_super(struct super_block *sb, void *data)
2144 {
2145 	struct nfs_sb_mountdata *sb_mntdata = data;
2146 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2147 	int mntflags = sb_mntdata->mntflags;
2148 
2149 	if (!nfs_compare_super_address(old, server))
2150 		return 0;
2151 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2152 	if (old->flags & NFS_MOUNT_UNSHARED)
2153 		return 0;
2154 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2155 		return 0;
2156 	return nfs_compare_mount_options(sb, server, mntflags);
2157 }
2158 
2159 static int nfs_bdi_register(struct nfs_server *server)
2160 {
2161 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2162 }
2163 
2164 static int nfs_get_sb(struct file_system_type *fs_type,
2165 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2166 {
2167 	struct nfs_server *server = NULL;
2168 	struct super_block *s;
2169 	struct nfs_parsed_mount_data *data;
2170 	struct nfs_fh *mntfh;
2171 	struct dentry *mntroot;
2172 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2173 	struct nfs_sb_mountdata sb_mntdata = {
2174 		.mntflags = flags,
2175 	};
2176 	int error = -ENOMEM;
2177 
2178 	data = nfs_alloc_parsed_mount_data(3);
2179 	mntfh = nfs_alloc_fhandle();
2180 	if (data == NULL || mntfh == NULL)
2181 		goto out_free_fh;
2182 
2183 	security_init_mnt_opts(&data->lsm_opts);
2184 
2185 	/* Validate the mount data */
2186 	error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2187 	if (error < 0)
2188 		goto out;
2189 
2190 #ifdef CONFIG_NFS_V4
2191 	if (data->version == 4) {
2192 		error = nfs4_try_mount(flags, dev_name, data, mnt);
2193 		kfree(data->client_address);
2194 		kfree(data->nfs_server.export_path);
2195 		goto out;
2196 	}
2197 #endif	/* CONFIG_NFS_V4 */
2198 
2199 	/* Get a volume representation */
2200 	server = nfs_create_server(data, mntfh);
2201 	if (IS_ERR(server)) {
2202 		error = PTR_ERR(server);
2203 		goto out;
2204 	}
2205 	sb_mntdata.server = server;
2206 
2207 	if (server->flags & NFS_MOUNT_UNSHARED)
2208 		compare_super = NULL;
2209 
2210 	/* Get a superblock - note that we may end up sharing one that already exists */
2211 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2212 	if (IS_ERR(s)) {
2213 		error = PTR_ERR(s);
2214 		goto out_err_nosb;
2215 	}
2216 
2217 	if (s->s_fs_info != server) {
2218 		nfs_free_server(server);
2219 		server = NULL;
2220 	} else {
2221 		error = nfs_bdi_register(server);
2222 		if (error)
2223 			goto error_splat_bdi;
2224 	}
2225 
2226 	if (!s->s_root) {
2227 		/* initial superblock/root creation */
2228 		nfs_fill_super(s, data);
2229 		nfs_fscache_get_super_cookie(
2230 			s, data ? data->fscache_uniq : NULL, NULL);
2231 	}
2232 
2233 	mntroot = nfs_get_root(s, mntfh);
2234 	if (IS_ERR(mntroot)) {
2235 		error = PTR_ERR(mntroot);
2236 		goto error_splat_super;
2237 	}
2238 
2239 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2240 	if (error)
2241 		goto error_splat_root;
2242 
2243 	s->s_flags |= MS_ACTIVE;
2244 	mnt->mnt_sb = s;
2245 	mnt->mnt_root = mntroot;
2246 	error = 0;
2247 
2248 out:
2249 	kfree(data->nfs_server.hostname);
2250 	kfree(data->mount_server.hostname);
2251 	kfree(data->fscache_uniq);
2252 	security_free_mnt_opts(&data->lsm_opts);
2253 out_free_fh:
2254 	nfs_free_fhandle(mntfh);
2255 	kfree(data);
2256 	return error;
2257 
2258 out_err_nosb:
2259 	nfs_free_server(server);
2260 	goto out;
2261 
2262 error_splat_root:
2263 	dput(mntroot);
2264 error_splat_super:
2265 	if (server && !s->s_root)
2266 		bdi_unregister(&server->backing_dev_info);
2267 error_splat_bdi:
2268 	deactivate_locked_super(s);
2269 	goto out;
2270 }
2271 
2272 /*
2273  * Ensure that we unregister the bdi before kill_anon_super
2274  * releases the device name
2275  */
2276 static void nfs_put_super(struct super_block *s)
2277 {
2278 	struct nfs_server *server = NFS_SB(s);
2279 
2280 	bdi_unregister(&server->backing_dev_info);
2281 }
2282 
2283 /*
2284  * Destroy an NFS2/3 superblock
2285  */
2286 static void nfs_kill_super(struct super_block *s)
2287 {
2288 	struct nfs_server *server = NFS_SB(s);
2289 
2290 	kill_anon_super(s);
2291 	nfs_fscache_release_super_cookie(s);
2292 	nfs_free_server(server);
2293 }
2294 
2295 /*
2296  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2297  */
2298 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2299 			   const char *dev_name, void *raw_data,
2300 			   struct vfsmount *mnt)
2301 {
2302 	struct nfs_clone_mount *data = raw_data;
2303 	struct super_block *s;
2304 	struct nfs_server *server;
2305 	struct dentry *mntroot;
2306 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2307 	struct nfs_sb_mountdata sb_mntdata = {
2308 		.mntflags = flags,
2309 	};
2310 	int error;
2311 
2312 	dprintk("--> nfs_xdev_get_sb()\n");
2313 
2314 	/* create a new volume representation */
2315 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2316 	if (IS_ERR(server)) {
2317 		error = PTR_ERR(server);
2318 		goto out_err_noserver;
2319 	}
2320 	sb_mntdata.server = server;
2321 
2322 	if (server->flags & NFS_MOUNT_UNSHARED)
2323 		compare_super = NULL;
2324 
2325 	/* Get a superblock - note that we may end up sharing one that already exists */
2326 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2327 	if (IS_ERR(s)) {
2328 		error = PTR_ERR(s);
2329 		goto out_err_nosb;
2330 	}
2331 
2332 	if (s->s_fs_info != server) {
2333 		nfs_free_server(server);
2334 		server = NULL;
2335 	} else {
2336 		error = nfs_bdi_register(server);
2337 		if (error)
2338 			goto error_splat_bdi;
2339 	}
2340 
2341 	if (!s->s_root) {
2342 		/* initial superblock/root creation */
2343 		nfs_clone_super(s, data->sb);
2344 		nfs_fscache_get_super_cookie(s, NULL, data);
2345 	}
2346 
2347 	mntroot = nfs_get_root(s, data->fh);
2348 	if (IS_ERR(mntroot)) {
2349 		error = PTR_ERR(mntroot);
2350 		goto error_splat_super;
2351 	}
2352 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2353 		dput(mntroot);
2354 		error = -ESTALE;
2355 		goto error_splat_super;
2356 	}
2357 
2358 	s->s_flags |= MS_ACTIVE;
2359 	mnt->mnt_sb = s;
2360 	mnt->mnt_root = mntroot;
2361 
2362 	/* clone any lsm security options from the parent to the new sb */
2363 	security_sb_clone_mnt_opts(data->sb, s);
2364 
2365 	dprintk("<-- nfs_xdev_get_sb() = 0\n");
2366 	return 0;
2367 
2368 out_err_nosb:
2369 	nfs_free_server(server);
2370 out_err_noserver:
2371 	dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2372 	return error;
2373 
2374 error_splat_super:
2375 	if (server && !s->s_root)
2376 		bdi_unregister(&server->backing_dev_info);
2377 error_splat_bdi:
2378 	deactivate_locked_super(s);
2379 	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2380 	return error;
2381 }
2382 
2383 #ifdef CONFIG_NFS_V4
2384 
2385 /*
2386  * Finish setting up a cloned NFS4 superblock
2387  */
2388 static void nfs4_clone_super(struct super_block *sb,
2389 			    const struct super_block *old_sb)
2390 {
2391 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2392 	sb->s_blocksize = old_sb->s_blocksize;
2393 	sb->s_maxbytes = old_sb->s_maxbytes;
2394 	sb->s_time_gran = 1;
2395 	sb->s_op = old_sb->s_op;
2396  	nfs_initialise_sb(sb);
2397 }
2398 
2399 /*
2400  * Set up an NFS4 superblock
2401  */
2402 static void nfs4_fill_super(struct super_block *sb)
2403 {
2404 	sb->s_time_gran = 1;
2405 	sb->s_op = &nfs4_sops;
2406 	nfs_initialise_sb(sb);
2407 }
2408 
2409 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2410 {
2411 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2412 }
2413 
2414 static int nfs4_validate_text_mount_data(void *options,
2415 					 struct nfs_parsed_mount_data *args,
2416 					 const char *dev_name)
2417 {
2418 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2419 
2420 	nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2421 
2422 	nfs_validate_transport_protocol(args);
2423 
2424 	nfs4_validate_mount_flags(args);
2425 
2426 	if (args->version != 4) {
2427 		dfprintk(MOUNT,
2428 			 "NFS4: Illegal mount version\n");
2429 		return -EINVAL;
2430 	}
2431 
2432 	if (args->auth_flavor_len > 1) {
2433 		dfprintk(MOUNT,
2434 			 "NFS4: Too many RPC auth flavours specified\n");
2435 		return -EINVAL;
2436 	}
2437 
2438 	if (args->client_address == NULL) {
2439 		dfprintk(MOUNT,
2440 			 "NFS4: mount program didn't pass callback address\n");
2441 		return -EINVAL;
2442 	}
2443 
2444 	return nfs_parse_devname(dev_name,
2445 				   &args->nfs_server.hostname,
2446 				   NFS4_MAXNAMLEN,
2447 				   &args->nfs_server.export_path,
2448 				   NFS4_MAXPATHLEN);
2449 }
2450 
2451 /*
2452  * Validate NFSv4 mount options
2453  */
2454 static int nfs4_validate_mount_data(void *options,
2455 				    struct nfs_parsed_mount_data *args,
2456 				    const char *dev_name)
2457 {
2458 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2459 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2460 	char *c;
2461 
2462 	if (data == NULL)
2463 		goto out_no_data;
2464 
2465 	switch (data->version) {
2466 	case 1:
2467 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2468 			goto out_no_address;
2469 		if (data->host_addrlen == 0)
2470 			goto out_no_address;
2471 		args->nfs_server.addrlen = data->host_addrlen;
2472 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2473 			return -EFAULT;
2474 		if (!nfs_verify_server_address(sap))
2475 			goto out_no_address;
2476 
2477 		if (data->auth_flavourlen) {
2478 			if (data->auth_flavourlen > 1)
2479 				goto out_inval_auth;
2480 			if (copy_from_user(&args->auth_flavors[0],
2481 					   data->auth_flavours,
2482 					   sizeof(args->auth_flavors[0])))
2483 				return -EFAULT;
2484 		}
2485 
2486 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2487 		if (IS_ERR(c))
2488 			return PTR_ERR(c);
2489 		args->nfs_server.hostname = c;
2490 
2491 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2492 		if (IS_ERR(c))
2493 			return PTR_ERR(c);
2494 		args->nfs_server.export_path = c;
2495 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2496 
2497 		c = strndup_user(data->client_addr.data, 16);
2498 		if (IS_ERR(c))
2499 			return PTR_ERR(c);
2500 		args->client_address = c;
2501 
2502 		/*
2503 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2504 		 * can deal with.
2505 		 */
2506 
2507 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2508 		args->rsize	= data->rsize;
2509 		args->wsize	= data->wsize;
2510 		args->timeo	= data->timeo;
2511 		args->retrans	= data->retrans;
2512 		args->acregmin	= data->acregmin;
2513 		args->acregmax	= data->acregmax;
2514 		args->acdirmin	= data->acdirmin;
2515 		args->acdirmax	= data->acdirmax;
2516 		args->nfs_server.protocol = data->proto;
2517 		nfs_validate_transport_protocol(args);
2518 
2519 		break;
2520 	default:
2521 		if (nfs_parse_mount_options((char *)options, args) == 0)
2522 			return -EINVAL;
2523 
2524 		if (!nfs_verify_server_address(sap))
2525 			return -EINVAL;
2526 
2527 		return nfs4_validate_text_mount_data(options, args, dev_name);
2528 	}
2529 
2530 	return 0;
2531 
2532 out_no_data:
2533 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2534 	return -EINVAL;
2535 
2536 out_inval_auth:
2537 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2538 		 data->auth_flavourlen);
2539 	return -EINVAL;
2540 
2541 out_no_address:
2542 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2543 	return -EINVAL;
2544 }
2545 
2546 /*
2547  * Get the superblock for the NFS4 root partition
2548  */
2549 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2550 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2551 {
2552 	struct nfs_parsed_mount_data *data = raw_data;
2553 	struct super_block *s;
2554 	struct nfs_server *server;
2555 	struct nfs_fh *mntfh;
2556 	struct dentry *mntroot;
2557 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2558 	struct nfs_sb_mountdata sb_mntdata = {
2559 		.mntflags = flags,
2560 	};
2561 	int error = -ENOMEM;
2562 
2563 	mntfh = nfs_alloc_fhandle();
2564 	if (data == NULL || mntfh == NULL)
2565 		goto out_free_fh;
2566 
2567 	security_init_mnt_opts(&data->lsm_opts);
2568 
2569 	/* Get a volume representation */
2570 	server = nfs4_create_server(data, mntfh);
2571 	if (IS_ERR(server)) {
2572 		error = PTR_ERR(server);
2573 		goto out;
2574 	}
2575 	sb_mntdata.server = server;
2576 
2577 	if (server->flags & NFS4_MOUNT_UNSHARED)
2578 		compare_super = NULL;
2579 
2580 	/* Get a superblock - note that we may end up sharing one that already exists */
2581 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2582 	if (IS_ERR(s)) {
2583 		error = PTR_ERR(s);
2584 		goto out_free;
2585 	}
2586 
2587 	if (s->s_fs_info != server) {
2588 		nfs_free_server(server);
2589 		server = NULL;
2590 	} else {
2591 		error = nfs_bdi_register(server);
2592 		if (error)
2593 			goto error_splat_bdi;
2594 	}
2595 
2596 	if (!s->s_root) {
2597 		/* initial superblock/root creation */
2598 		nfs4_fill_super(s);
2599 		nfs_fscache_get_super_cookie(
2600 			s, data ? data->fscache_uniq : NULL, NULL);
2601 	}
2602 
2603 	mntroot = nfs4_get_root(s, mntfh);
2604 	if (IS_ERR(mntroot)) {
2605 		error = PTR_ERR(mntroot);
2606 		goto error_splat_super;
2607 	}
2608 
2609 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2610 	if (error)
2611 		goto error_splat_root;
2612 
2613 	s->s_flags |= MS_ACTIVE;
2614 	mnt->mnt_sb = s;
2615 	mnt->mnt_root = mntroot;
2616 	error = 0;
2617 
2618 out:
2619 	security_free_mnt_opts(&data->lsm_opts);
2620 out_free_fh:
2621 	nfs_free_fhandle(mntfh);
2622 	return error;
2623 
2624 out_free:
2625 	nfs_free_server(server);
2626 	goto out;
2627 
2628 error_splat_root:
2629 	dput(mntroot);
2630 error_splat_super:
2631 	if (server && !s->s_root)
2632 		bdi_unregister(&server->backing_dev_info);
2633 error_splat_bdi:
2634 	deactivate_locked_super(s);
2635 	goto out;
2636 }
2637 
2638 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2639 		int flags, void *data, const char *hostname)
2640 {
2641 	struct vfsmount *root_mnt;
2642 	char *root_devname;
2643 	size_t len;
2644 
2645 	len = strlen(hostname) + 3;
2646 	root_devname = kmalloc(len, GFP_KERNEL);
2647 	if (root_devname == NULL)
2648 		return ERR_PTR(-ENOMEM);
2649 	snprintf(root_devname, len, "%s:/", hostname);
2650 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2651 	kfree(root_devname);
2652 	return root_mnt;
2653 }
2654 
2655 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2656 {
2657 	char *page = (char *) __get_free_page(GFP_KERNEL);
2658 	char *devname, *tmp;
2659 
2660 	if (page == NULL)
2661 		return;
2662 	devname = nfs_path(path->mnt->mnt_devname,
2663 			path->mnt->mnt_root, path->dentry,
2664 			page, PAGE_SIZE);
2665 	if (IS_ERR(devname))
2666 		goto out_freepage;
2667 	tmp = kstrdup(devname, GFP_KERNEL);
2668 	if (tmp == NULL)
2669 		goto out_freepage;
2670 	kfree(mnt->mnt_devname);
2671 	mnt->mnt_devname = tmp;
2672 out_freepage:
2673 	free_page((unsigned long)page);
2674 }
2675 
2676 struct nfs_referral_count {
2677 	struct list_head list;
2678 	const struct task_struct *task;
2679 	unsigned int referral_count;
2680 };
2681 
2682 static LIST_HEAD(nfs_referral_count_list);
2683 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2684 
2685 static struct nfs_referral_count *nfs_find_referral_count(void)
2686 {
2687 	struct nfs_referral_count *p;
2688 
2689 	list_for_each_entry(p, &nfs_referral_count_list, list) {
2690 		if (p->task == current)
2691 			return p;
2692 	}
2693 	return NULL;
2694 }
2695 
2696 #define NFS_MAX_NESTED_REFERRALS 2
2697 
2698 static int nfs_referral_loop_protect(void)
2699 {
2700 	struct nfs_referral_count *p, *new;
2701 	int ret = -ENOMEM;
2702 
2703 	new = kmalloc(sizeof(*new), GFP_KERNEL);
2704 	if (!new)
2705 		goto out;
2706 	new->task = current;
2707 	new->referral_count = 1;
2708 
2709 	ret = 0;
2710 	spin_lock(&nfs_referral_count_list_lock);
2711 	p = nfs_find_referral_count();
2712 	if (p != NULL) {
2713 		if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2714 			ret = -ELOOP;
2715 		else
2716 			p->referral_count++;
2717 	} else {
2718 		list_add(&new->list, &nfs_referral_count_list);
2719 		new = NULL;
2720 	}
2721 	spin_unlock(&nfs_referral_count_list_lock);
2722 	kfree(new);
2723 out:
2724 	return ret;
2725 }
2726 
2727 static void nfs_referral_loop_unprotect(void)
2728 {
2729 	struct nfs_referral_count *p;
2730 
2731 	spin_lock(&nfs_referral_count_list_lock);
2732 	p = nfs_find_referral_count();
2733 	p->referral_count--;
2734 	if (p->referral_count == 0)
2735 		list_del(&p->list);
2736 	else
2737 		p = NULL;
2738 	spin_unlock(&nfs_referral_count_list_lock);
2739 	kfree(p);
2740 }
2741 
2742 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2743 		const char *export_path, struct vfsmount *mnt_target)
2744 {
2745 	struct nameidata *nd = NULL;
2746 	struct mnt_namespace *ns_private;
2747 	struct super_block *s;
2748 	int ret;
2749 
2750 	nd = kmalloc(sizeof(*nd), GFP_KERNEL);
2751 	if (nd == NULL)
2752 		return -ENOMEM;
2753 
2754 	ns_private = create_mnt_ns(root_mnt);
2755 	ret = PTR_ERR(ns_private);
2756 	if (IS_ERR(ns_private))
2757 		goto out_mntput;
2758 
2759 	ret = nfs_referral_loop_protect();
2760 	if (ret != 0)
2761 		goto out_put_mnt_ns;
2762 
2763 	ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2764 			export_path, LOOKUP_FOLLOW, nd);
2765 
2766 	nfs_referral_loop_unprotect();
2767 	put_mnt_ns(ns_private);
2768 
2769 	if (ret != 0)
2770 		goto out_err;
2771 
2772 	s = nd->path.mnt->mnt_sb;
2773 	atomic_inc(&s->s_active);
2774 	mnt_target->mnt_sb = s;
2775 	mnt_target->mnt_root = dget(nd->path.dentry);
2776 
2777 	/* Correct the device pathname */
2778 	nfs_fix_devname(&nd->path, mnt_target);
2779 
2780 	path_put(&nd->path);
2781 	kfree(nd);
2782 	down_write(&s->s_umount);
2783 	return 0;
2784 out_put_mnt_ns:
2785 	put_mnt_ns(ns_private);
2786 out_mntput:
2787 	mntput(root_mnt);
2788 out_err:
2789 	kfree(nd);
2790 	return ret;
2791 }
2792 
2793 static int nfs4_try_mount(int flags, const char *dev_name,
2794 			 struct nfs_parsed_mount_data *data,
2795 			 struct vfsmount *mnt)
2796 {
2797 	char *export_path;
2798 	struct vfsmount *root_mnt;
2799 	int error;
2800 
2801 	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2802 
2803 	export_path = data->nfs_server.export_path;
2804 	data->nfs_server.export_path = "/";
2805 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2806 			data->nfs_server.hostname);
2807 	data->nfs_server.export_path = export_path;
2808 
2809 	error = PTR_ERR(root_mnt);
2810 	if (IS_ERR(root_mnt))
2811 		goto out;
2812 
2813 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2814 
2815 out:
2816 	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2817 			error != 0 ? " [error]" : "");
2818 	return error;
2819 }
2820 
2821 /*
2822  * Get the superblock for an NFS4 mountpoint
2823  */
2824 static int nfs4_get_sb(struct file_system_type *fs_type,
2825 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2826 {
2827 	struct nfs_parsed_mount_data *data;
2828 	int error = -ENOMEM;
2829 
2830 	data = nfs_alloc_parsed_mount_data(4);
2831 	if (data == NULL)
2832 		goto out_free_data;
2833 
2834 	/* Validate the mount data */
2835 	error = nfs4_validate_mount_data(raw_data, data, dev_name);
2836 	if (error < 0)
2837 		goto out;
2838 
2839 	error = nfs4_try_mount(flags, dev_name, data, mnt);
2840 
2841 out:
2842 	kfree(data->client_address);
2843 	kfree(data->nfs_server.export_path);
2844 	kfree(data->nfs_server.hostname);
2845 	kfree(data->fscache_uniq);
2846 out_free_data:
2847 	kfree(data);
2848 	dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2849 			error != 0 ? " [error]" : "");
2850 	return error;
2851 }
2852 
2853 static void nfs4_kill_super(struct super_block *sb)
2854 {
2855 	struct nfs_server *server = NFS_SB(sb);
2856 
2857 	dprintk("--> %s\n", __func__);
2858 	nfs_super_return_all_delegations(sb);
2859 	kill_anon_super(sb);
2860 	nfs_fscache_release_super_cookie(sb);
2861 	nfs_free_server(server);
2862 	dprintk("<-- %s\n", __func__);
2863 }
2864 
2865 /*
2866  * Clone an NFS4 server record on xdev traversal (FSID-change)
2867  */
2868 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2869 			    const char *dev_name, void *raw_data,
2870 			    struct vfsmount *mnt)
2871 {
2872 	struct nfs_clone_mount *data = raw_data;
2873 	struct super_block *s;
2874 	struct nfs_server *server;
2875 	struct dentry *mntroot;
2876 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2877 	struct nfs_sb_mountdata sb_mntdata = {
2878 		.mntflags = flags,
2879 	};
2880 	int error;
2881 
2882 	dprintk("--> nfs4_xdev_get_sb()\n");
2883 
2884 	/* create a new volume representation */
2885 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2886 	if (IS_ERR(server)) {
2887 		error = PTR_ERR(server);
2888 		goto out_err_noserver;
2889 	}
2890 	sb_mntdata.server = server;
2891 
2892 	if (server->flags & NFS4_MOUNT_UNSHARED)
2893 		compare_super = NULL;
2894 
2895 	/* Get a superblock - note that we may end up sharing one that already exists */
2896 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2897 	if (IS_ERR(s)) {
2898 		error = PTR_ERR(s);
2899 		goto out_err_nosb;
2900 	}
2901 
2902 	if (s->s_fs_info != server) {
2903 		nfs_free_server(server);
2904 		server = NULL;
2905 	} else {
2906 		error = nfs_bdi_register(server);
2907 		if (error)
2908 			goto error_splat_bdi;
2909 	}
2910 
2911 	if (!s->s_root) {
2912 		/* initial superblock/root creation */
2913 		nfs4_clone_super(s, data->sb);
2914 		nfs_fscache_get_super_cookie(s, NULL, data);
2915 	}
2916 
2917 	mntroot = nfs4_get_root(s, data->fh);
2918 	if (IS_ERR(mntroot)) {
2919 		error = PTR_ERR(mntroot);
2920 		goto error_splat_super;
2921 	}
2922 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2923 		dput(mntroot);
2924 		error = -ESTALE;
2925 		goto error_splat_super;
2926 	}
2927 
2928 	s->s_flags |= MS_ACTIVE;
2929 	mnt->mnt_sb = s;
2930 	mnt->mnt_root = mntroot;
2931 
2932 	security_sb_clone_mnt_opts(data->sb, s);
2933 
2934 	dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2935 	return 0;
2936 
2937 out_err_nosb:
2938 	nfs_free_server(server);
2939 out_err_noserver:
2940 	dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2941 	return error;
2942 
2943 error_splat_super:
2944 	if (server && !s->s_root)
2945 		bdi_unregister(&server->backing_dev_info);
2946 error_splat_bdi:
2947 	deactivate_locked_super(s);
2948 	dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2949 	return error;
2950 }
2951 
2952 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2953 		int flags, const char *dev_name, void *raw_data,
2954 		struct vfsmount *mnt)
2955 {
2956 	struct nfs_clone_mount *data = raw_data;
2957 	struct super_block *s;
2958 	struct nfs_server *server;
2959 	struct dentry *mntroot;
2960 	struct nfs_fh *mntfh;
2961 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2962 	struct nfs_sb_mountdata sb_mntdata = {
2963 		.mntflags = flags,
2964 	};
2965 	int error = -ENOMEM;
2966 
2967 	dprintk("--> nfs4_referral_get_sb()\n");
2968 
2969 	mntfh = nfs_alloc_fhandle();
2970 	if (mntfh == NULL)
2971 		goto out_err_nofh;
2972 
2973 	/* create a new volume representation */
2974 	server = nfs4_create_referral_server(data, mntfh);
2975 	if (IS_ERR(server)) {
2976 		error = PTR_ERR(server);
2977 		goto out_err_noserver;
2978 	}
2979 	sb_mntdata.server = server;
2980 
2981 	if (server->flags & NFS4_MOUNT_UNSHARED)
2982 		compare_super = NULL;
2983 
2984 	/* Get a superblock - note that we may end up sharing one that already exists */
2985 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2986 	if (IS_ERR(s)) {
2987 		error = PTR_ERR(s);
2988 		goto out_err_nosb;
2989 	}
2990 
2991 	if (s->s_fs_info != server) {
2992 		nfs_free_server(server);
2993 		server = NULL;
2994 	} else {
2995 		error = nfs_bdi_register(server);
2996 		if (error)
2997 			goto error_splat_bdi;
2998 	}
2999 
3000 	if (!s->s_root) {
3001 		/* initial superblock/root creation */
3002 		nfs4_fill_super(s);
3003 		nfs_fscache_get_super_cookie(s, NULL, data);
3004 	}
3005 
3006 	mntroot = nfs4_get_root(s, mntfh);
3007 	if (IS_ERR(mntroot)) {
3008 		error = PTR_ERR(mntroot);
3009 		goto error_splat_super;
3010 	}
3011 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3012 		dput(mntroot);
3013 		error = -ESTALE;
3014 		goto error_splat_super;
3015 	}
3016 
3017 	s->s_flags |= MS_ACTIVE;
3018 	mnt->mnt_sb = s;
3019 	mnt->mnt_root = mntroot;
3020 
3021 	security_sb_clone_mnt_opts(data->sb, s);
3022 
3023 	nfs_free_fhandle(mntfh);
3024 	dprintk("<-- nfs4_referral_get_sb() = 0\n");
3025 	return 0;
3026 
3027 out_err_nosb:
3028 	nfs_free_server(server);
3029 out_err_noserver:
3030 	nfs_free_fhandle(mntfh);
3031 out_err_nofh:
3032 	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3033 	return error;
3034 
3035 error_splat_super:
3036 	if (server && !s->s_root)
3037 		bdi_unregister(&server->backing_dev_info);
3038 error_splat_bdi:
3039 	deactivate_locked_super(s);
3040 	nfs_free_fhandle(mntfh);
3041 	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3042 	return error;
3043 }
3044 
3045 /*
3046  * Create an NFS4 server record on referral traversal
3047  */
3048 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
3049 		int flags, const char *dev_name, void *raw_data,
3050 		struct vfsmount *mnt)
3051 {
3052 	struct nfs_clone_mount *data = raw_data;
3053 	char *export_path;
3054 	struct vfsmount *root_mnt;
3055 	int error;
3056 
3057 	dprintk("--> nfs4_referral_get_sb()\n");
3058 
3059 	export_path = data->mnt_path;
3060 	data->mnt_path = "/";
3061 
3062 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3063 			flags, data, data->hostname);
3064 	data->mnt_path = export_path;
3065 
3066 	error = PTR_ERR(root_mnt);
3067 	if (IS_ERR(root_mnt))
3068 		goto out;
3069 
3070 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
3071 out:
3072 	dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
3073 			error != 0 ? " [error]" : "");
3074 	return error;
3075 }
3076 
3077 #endif /* CONFIG_NFS_V4 */
3078