xref: /linux/fs/nfs/super.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
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/seq_file.h>
43 #include <linux/mount.h>
44 #include <linux/namei.h>
45 #include <linux/nfs_idmap.h>
46 #include <linux/vfs.h>
47 #include <linux/inet.h>
48 #include <linux/in6.h>
49 #include <linux/slab.h>
50 #include <net/ipv6.h>
51 #include <linux/netdevice.h>
52 #include <linux/nfs_xdr.h>
53 #include <linux/magic.h>
54 #include <linux/parser.h>
55 
56 #include <asm/system.h>
57 #include <asm/uaccess.h>
58 
59 #include "nfs4_fs.h"
60 #include "callback.h"
61 #include "delegation.h"
62 #include "iostat.h"
63 #include "internal.h"
64 #include "fscache.h"
65 #include "pnfs.h"
66 
67 #define NFSDBG_FACILITY		NFSDBG_VFS
68 
69 #ifdef CONFIG_NFS_V3
70 #define NFS_DEFAULT_VERSION 3
71 #else
72 #define NFS_DEFAULT_VERSION 2
73 #endif
74 
75 enum {
76 	/* Mount options that take no arguments */
77 	Opt_soft, Opt_hard,
78 	Opt_posix, Opt_noposix,
79 	Opt_cto, Opt_nocto,
80 	Opt_ac, Opt_noac,
81 	Opt_lock, Opt_nolock,
82 	Opt_v2, Opt_v3, Opt_v4,
83 	Opt_udp, Opt_tcp, Opt_rdma,
84 	Opt_acl, Opt_noacl,
85 	Opt_rdirplus, Opt_nordirplus,
86 	Opt_sharecache, Opt_nosharecache,
87 	Opt_resvport, Opt_noresvport,
88 	Opt_fscache, Opt_nofscache,
89 
90 	/* Mount options that take integer arguments */
91 	Opt_port,
92 	Opt_rsize, Opt_wsize, Opt_bsize,
93 	Opt_timeo, Opt_retrans,
94 	Opt_acregmin, Opt_acregmax,
95 	Opt_acdirmin, Opt_acdirmax,
96 	Opt_actimeo,
97 	Opt_namelen,
98 	Opt_mountport,
99 	Opt_mountvers,
100 	Opt_nfsvers,
101 	Opt_minorversion,
102 
103 	/* Mount options that take string arguments */
104 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
105 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
106 	Opt_lookupcache,
107 	Opt_fscache_uniq,
108 	Opt_local_lock,
109 
110 	/* Special mount options */
111 	Opt_userspace, Opt_deprecated, Opt_sloppy,
112 
113 	Opt_err
114 };
115 
116 static const match_table_t nfs_mount_option_tokens = {
117 	{ Opt_userspace, "bg" },
118 	{ Opt_userspace, "fg" },
119 	{ Opt_userspace, "retry=%s" },
120 
121 	{ Opt_sloppy, "sloppy" },
122 
123 	{ Opt_soft, "soft" },
124 	{ Opt_hard, "hard" },
125 	{ Opt_deprecated, "intr" },
126 	{ Opt_deprecated, "nointr" },
127 	{ Opt_posix, "posix" },
128 	{ Opt_noposix, "noposix" },
129 	{ Opt_cto, "cto" },
130 	{ Opt_nocto, "nocto" },
131 	{ Opt_ac, "ac" },
132 	{ Opt_noac, "noac" },
133 	{ Opt_lock, "lock" },
134 	{ Opt_nolock, "nolock" },
135 	{ Opt_v2, "v2" },
136 	{ Opt_v3, "v3" },
137 	{ Opt_v4, "v4" },
138 	{ Opt_udp, "udp" },
139 	{ Opt_tcp, "tcp" },
140 	{ Opt_rdma, "rdma" },
141 	{ Opt_acl, "acl" },
142 	{ Opt_noacl, "noacl" },
143 	{ Opt_rdirplus, "rdirplus" },
144 	{ Opt_nordirplus, "nordirplus" },
145 	{ Opt_sharecache, "sharecache" },
146 	{ Opt_nosharecache, "nosharecache" },
147 	{ Opt_resvport, "resvport" },
148 	{ Opt_noresvport, "noresvport" },
149 	{ Opt_fscache, "fsc" },
150 	{ Opt_nofscache, "nofsc" },
151 
152 	{ Opt_port, "port=%s" },
153 	{ Opt_rsize, "rsize=%s" },
154 	{ Opt_wsize, "wsize=%s" },
155 	{ Opt_bsize, "bsize=%s" },
156 	{ Opt_timeo, "timeo=%s" },
157 	{ Opt_retrans, "retrans=%s" },
158 	{ Opt_acregmin, "acregmin=%s" },
159 	{ Opt_acregmax, "acregmax=%s" },
160 	{ Opt_acdirmin, "acdirmin=%s" },
161 	{ Opt_acdirmax, "acdirmax=%s" },
162 	{ Opt_actimeo, "actimeo=%s" },
163 	{ Opt_namelen, "namlen=%s" },
164 	{ Opt_mountport, "mountport=%s" },
165 	{ Opt_mountvers, "mountvers=%s" },
166 	{ Opt_nfsvers, "nfsvers=%s" },
167 	{ Opt_nfsvers, "vers=%s" },
168 	{ Opt_minorversion, "minorversion=%s" },
169 
170 	{ Opt_sec, "sec=%s" },
171 	{ Opt_proto, "proto=%s" },
172 	{ Opt_mountproto, "mountproto=%s" },
173 	{ Opt_addr, "addr=%s" },
174 	{ Opt_clientaddr, "clientaddr=%s" },
175 	{ Opt_mounthost, "mounthost=%s" },
176 	{ Opt_mountaddr, "mountaddr=%s" },
177 
178 	{ Opt_lookupcache, "lookupcache=%s" },
179 	{ Opt_fscache_uniq, "fsc=%s" },
180 	{ Opt_local_lock, "local_lock=%s" },
181 
182 	{ Opt_err, NULL }
183 };
184 
185 enum {
186 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
187 
188 	Opt_xprt_err
189 };
190 
191 static const match_table_t nfs_xprt_protocol_tokens = {
192 	{ Opt_xprt_udp, "udp" },
193 	{ Opt_xprt_udp6, "udp6" },
194 	{ Opt_xprt_tcp, "tcp" },
195 	{ Opt_xprt_tcp6, "tcp6" },
196 	{ Opt_xprt_rdma, "rdma" },
197 
198 	{ Opt_xprt_err, NULL }
199 };
200 
201 enum {
202 	Opt_sec_none, Opt_sec_sys,
203 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
204 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
205 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
206 
207 	Opt_sec_err
208 };
209 
210 static const match_table_t nfs_secflavor_tokens = {
211 	{ Opt_sec_none, "none" },
212 	{ Opt_sec_none, "null" },
213 	{ Opt_sec_sys, "sys" },
214 
215 	{ Opt_sec_krb5, "krb5" },
216 	{ Opt_sec_krb5i, "krb5i" },
217 	{ Opt_sec_krb5p, "krb5p" },
218 
219 	{ Opt_sec_lkey, "lkey" },
220 	{ Opt_sec_lkeyi, "lkeyi" },
221 	{ Opt_sec_lkeyp, "lkeyp" },
222 
223 	{ Opt_sec_spkm, "spkm3" },
224 	{ Opt_sec_spkmi, "spkm3i" },
225 	{ Opt_sec_spkmp, "spkm3p" },
226 
227 	{ Opt_sec_err, NULL }
228 };
229 
230 enum {
231 	Opt_lookupcache_all, Opt_lookupcache_positive,
232 	Opt_lookupcache_none,
233 
234 	Opt_lookupcache_err
235 };
236 
237 static match_table_t nfs_lookupcache_tokens = {
238 	{ Opt_lookupcache_all, "all" },
239 	{ Opt_lookupcache_positive, "pos" },
240 	{ Opt_lookupcache_positive, "positive" },
241 	{ Opt_lookupcache_none, "none" },
242 
243 	{ Opt_lookupcache_err, NULL }
244 };
245 
246 enum {
247 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
248 	Opt_local_lock_none,
249 
250 	Opt_local_lock_err
251 };
252 
253 static match_table_t nfs_local_lock_tokens = {
254 	{ Opt_local_lock_all, "all" },
255 	{ Opt_local_lock_flock, "flock" },
256 	{ Opt_local_lock_posix, "posix" },
257 	{ Opt_local_lock_none, "none" },
258 
259 	{ Opt_local_lock_err, NULL }
260 };
261 
262 
263 static void nfs_umount_begin(struct super_block *);
264 static int  nfs_statfs(struct dentry *, struct kstatfs *);
265 static int  nfs_show_options(struct seq_file *, struct dentry *);
266 static int  nfs_show_devname(struct seq_file *, struct dentry *);
267 static int  nfs_show_path(struct seq_file *, struct dentry *);
268 static int  nfs_show_stats(struct seq_file *, struct dentry *);
269 static struct dentry *nfs_fs_mount(struct file_system_type *,
270 		int, const char *, void *);
271 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
272 		int flags, const char *dev_name, void *raw_data);
273 static void nfs_put_super(struct super_block *);
274 static void nfs_kill_super(struct super_block *);
275 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
276 
277 static struct file_system_type nfs_fs_type = {
278 	.owner		= THIS_MODULE,
279 	.name		= "nfs",
280 	.mount		= nfs_fs_mount,
281 	.kill_sb	= nfs_kill_super,
282 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
283 };
284 
285 struct file_system_type nfs_xdev_fs_type = {
286 	.owner		= THIS_MODULE,
287 	.name		= "nfs",
288 	.mount		= nfs_xdev_mount,
289 	.kill_sb	= nfs_kill_super,
290 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
291 };
292 
293 static const struct super_operations nfs_sops = {
294 	.alloc_inode	= nfs_alloc_inode,
295 	.destroy_inode	= nfs_destroy_inode,
296 	.write_inode	= nfs_write_inode,
297 	.put_super	= nfs_put_super,
298 	.statfs		= nfs_statfs,
299 	.evict_inode	= nfs_evict_inode,
300 	.umount_begin	= nfs_umount_begin,
301 	.show_options	= nfs_show_options,
302 	.show_devname	= nfs_show_devname,
303 	.show_path	= nfs_show_path,
304 	.show_stats	= nfs_show_stats,
305 	.remount_fs	= nfs_remount,
306 };
307 
308 #ifdef CONFIG_NFS_V4
309 static int nfs4_validate_text_mount_data(void *options,
310 	struct nfs_parsed_mount_data *args, const char *dev_name);
311 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
312 	struct nfs_parsed_mount_data *data);
313 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
314 	int flags, const char *dev_name, void *raw_data);
315 static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
316 	int flags, const char *dev_name, void *raw_data);
317 static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type,
318 	int flags, const char *dev_name, void *raw_data);
319 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
320 	int flags, const char *dev_name, void *raw_data);
321 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
322 	int flags, const char *dev_name, void *raw_data);
323 static void nfs4_kill_super(struct super_block *sb);
324 
325 static struct file_system_type nfs4_fs_type = {
326 	.owner		= THIS_MODULE,
327 	.name		= "nfs4",
328 	.mount		= nfs4_mount,
329 	.kill_sb	= nfs4_kill_super,
330 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
331 };
332 
333 static struct file_system_type nfs4_remote_fs_type = {
334 	.owner		= THIS_MODULE,
335 	.name		= "nfs4",
336 	.mount		= nfs4_remote_mount,
337 	.kill_sb	= nfs4_kill_super,
338 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
339 };
340 
341 struct file_system_type nfs4_xdev_fs_type = {
342 	.owner		= THIS_MODULE,
343 	.name		= "nfs4",
344 	.mount		= nfs4_xdev_mount,
345 	.kill_sb	= nfs4_kill_super,
346 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
347 };
348 
349 static struct file_system_type nfs4_remote_referral_fs_type = {
350 	.owner		= THIS_MODULE,
351 	.name		= "nfs4",
352 	.mount		= nfs4_remote_referral_mount,
353 	.kill_sb	= nfs4_kill_super,
354 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
355 };
356 
357 struct file_system_type nfs4_referral_fs_type = {
358 	.owner		= THIS_MODULE,
359 	.name		= "nfs4",
360 	.mount		= nfs4_referral_mount,
361 	.kill_sb	= nfs4_kill_super,
362 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
363 };
364 
365 static const struct super_operations nfs4_sops = {
366 	.alloc_inode	= nfs_alloc_inode,
367 	.destroy_inode	= nfs_destroy_inode,
368 	.write_inode	= nfs_write_inode,
369 	.put_super	= nfs_put_super,
370 	.statfs		= nfs_statfs,
371 	.evict_inode	= nfs4_evict_inode,
372 	.umount_begin	= nfs_umount_begin,
373 	.show_options	= nfs_show_options,
374 	.show_devname	= nfs_show_devname,
375 	.show_path	= nfs_show_path,
376 	.show_stats	= nfs_show_stats,
377 	.remount_fs	= nfs_remount,
378 };
379 #endif
380 
381 static struct shrinker acl_shrinker = {
382 	.shrink		= nfs_access_cache_shrinker,
383 	.seeks		= DEFAULT_SEEKS,
384 };
385 
386 /*
387  * Register the NFS filesystems
388  */
389 int __init register_nfs_fs(void)
390 {
391 	int ret;
392 
393         ret = register_filesystem(&nfs_fs_type);
394 	if (ret < 0)
395 		goto error_0;
396 
397 	ret = nfs_register_sysctl();
398 	if (ret < 0)
399 		goto error_1;
400 #ifdef CONFIG_NFS_V4
401 	ret = register_filesystem(&nfs4_fs_type);
402 	if (ret < 0)
403 		goto error_2;
404 #endif
405 	register_shrinker(&acl_shrinker);
406 	return 0;
407 
408 #ifdef CONFIG_NFS_V4
409 error_2:
410 	nfs_unregister_sysctl();
411 #endif
412 error_1:
413 	unregister_filesystem(&nfs_fs_type);
414 error_0:
415 	return ret;
416 }
417 
418 /*
419  * Unregister the NFS filesystems
420  */
421 void __exit unregister_nfs_fs(void)
422 {
423 	unregister_shrinker(&acl_shrinker);
424 #ifdef CONFIG_NFS_V4
425 	unregister_filesystem(&nfs4_fs_type);
426 #endif
427 	nfs_unregister_sysctl();
428 	unregister_filesystem(&nfs_fs_type);
429 }
430 
431 void nfs_sb_active(struct super_block *sb)
432 {
433 	struct nfs_server *server = NFS_SB(sb);
434 
435 	if (atomic_inc_return(&server->active) == 1)
436 		atomic_inc(&sb->s_active);
437 }
438 
439 void nfs_sb_deactive(struct super_block *sb)
440 {
441 	struct nfs_server *server = NFS_SB(sb);
442 
443 	if (atomic_dec_and_test(&server->active))
444 		deactivate_super(sb);
445 }
446 
447 /*
448  * Deliver file system statistics to userspace
449  */
450 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
451 {
452 	struct nfs_server *server = NFS_SB(dentry->d_sb);
453 	unsigned char blockbits;
454 	unsigned long blockres;
455 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
456 	struct nfs_fsstat res;
457 	int error = -ENOMEM;
458 
459 	res.fattr = nfs_alloc_fattr();
460 	if (res.fattr == NULL)
461 		goto out_err;
462 
463 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
464 	if (unlikely(error == -ESTALE)) {
465 		struct dentry *pd_dentry;
466 
467 		pd_dentry = dget_parent(dentry);
468 		if (pd_dentry != NULL) {
469 			nfs_zap_caches(pd_dentry->d_inode);
470 			dput(pd_dentry);
471 		}
472 	}
473 	nfs_free_fattr(res.fattr);
474 	if (error < 0)
475 		goto out_err;
476 
477 	buf->f_type = NFS_SUPER_MAGIC;
478 
479 	/*
480 	 * Current versions of glibc do not correctly handle the
481 	 * case where f_frsize != f_bsize.  Eventually we want to
482 	 * report the value of wtmult in this field.
483 	 */
484 	buf->f_frsize = dentry->d_sb->s_blocksize;
485 
486 	/*
487 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
488 	 * are reported in units of f_frsize.  Linux hasn't had
489 	 * an f_frsize field in its statfs struct until recently,
490 	 * thus historically Linux's sys_statfs reports these
491 	 * fields in units of f_bsize.
492 	 */
493 	buf->f_bsize = dentry->d_sb->s_blocksize;
494 	blockbits = dentry->d_sb->s_blocksize_bits;
495 	blockres = (1 << blockbits) - 1;
496 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
497 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
498 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
499 
500 	buf->f_files = res.tfiles;
501 	buf->f_ffree = res.afiles;
502 
503 	buf->f_namelen = server->namelen;
504 
505 	return 0;
506 
507  out_err:
508 	dprintk("%s: statfs error = %d\n", __func__, -error);
509 	return error;
510 }
511 
512 /*
513  * Map the security flavour number to a name
514  */
515 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
516 {
517 	static const struct {
518 		rpc_authflavor_t flavour;
519 		const char *str;
520 	} sec_flavours[] = {
521 		{ RPC_AUTH_NULL, "null" },
522 		{ RPC_AUTH_UNIX, "sys" },
523 		{ RPC_AUTH_GSS_KRB5, "krb5" },
524 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
525 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
526 		{ RPC_AUTH_GSS_LKEY, "lkey" },
527 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
528 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
529 		{ RPC_AUTH_GSS_SPKM, "spkm" },
530 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
531 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
532 		{ UINT_MAX, "unknown" }
533 	};
534 	int i;
535 
536 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
537 		if (sec_flavours[i].flavour == flavour)
538 			break;
539 	}
540 	return sec_flavours[i].str;
541 }
542 
543 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
544 				  int showdefaults)
545 {
546 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
547 
548 	seq_printf(m, ",mountproto=");
549 	switch (sap->sa_family) {
550 	case AF_INET:
551 		switch (nfss->mountd_protocol) {
552 		case IPPROTO_UDP:
553 			seq_printf(m, RPCBIND_NETID_UDP);
554 			break;
555 		case IPPROTO_TCP:
556 			seq_printf(m, RPCBIND_NETID_TCP);
557 			break;
558 		default:
559 			if (showdefaults)
560 				seq_printf(m, "auto");
561 		}
562 		break;
563 	case AF_INET6:
564 		switch (nfss->mountd_protocol) {
565 		case IPPROTO_UDP:
566 			seq_printf(m, RPCBIND_NETID_UDP6);
567 			break;
568 		case IPPROTO_TCP:
569 			seq_printf(m, RPCBIND_NETID_TCP6);
570 			break;
571 		default:
572 			if (showdefaults)
573 				seq_printf(m, "auto");
574 		}
575 		break;
576 	default:
577 		if (showdefaults)
578 			seq_printf(m, "auto");
579 	}
580 }
581 
582 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
583 				    int showdefaults)
584 {
585 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
586 
587 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
588 		return;
589 
590 	switch (sap->sa_family) {
591 	case AF_INET: {
592 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
593 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
594 		break;
595 	}
596 	case AF_INET6: {
597 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
598 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
599 		break;
600 	}
601 	default:
602 		if (showdefaults)
603 			seq_printf(m, ",mountaddr=unspecified");
604 	}
605 
606 	if (nfss->mountd_version || showdefaults)
607 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
608 	if ((nfss->mountd_port &&
609 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
610 		showdefaults)
611 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
612 
613 	nfs_show_mountd_netid(m, nfss, showdefaults);
614 }
615 
616 #ifdef CONFIG_NFS_V4
617 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
618 				    int showdefaults)
619 {
620 	struct nfs_client *clp = nfss->nfs_client;
621 
622 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
623 	seq_printf(m, ",minorversion=%u", clp->cl_minorversion);
624 }
625 #else
626 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
627 				    int showdefaults)
628 {
629 }
630 #endif
631 
632 /*
633  * Describe the mount options in force on this server representation
634  */
635 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
636 				   int showdefaults)
637 {
638 	static const struct proc_nfs_info {
639 		int flag;
640 		const char *str;
641 		const char *nostr;
642 	} nfs_info[] = {
643 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
644 		{ NFS_MOUNT_POSIX, ",posix", "" },
645 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
646 		{ NFS_MOUNT_NOAC, ",noac", "" },
647 		{ NFS_MOUNT_NONLM, ",nolock", "" },
648 		{ NFS_MOUNT_NOACL, ",noacl", "" },
649 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
650 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
651 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
652 		{ 0, NULL, NULL }
653 	};
654 	const struct proc_nfs_info *nfs_infop;
655 	struct nfs_client *clp = nfss->nfs_client;
656 	u32 version = clp->rpc_ops->version;
657 	int local_flock, local_fcntl;
658 
659 	seq_printf(m, ",vers=%u", version);
660 	seq_printf(m, ",rsize=%u", nfss->rsize);
661 	seq_printf(m, ",wsize=%u", nfss->wsize);
662 	if (nfss->bsize != 0)
663 		seq_printf(m, ",bsize=%u", nfss->bsize);
664 	seq_printf(m, ",namlen=%u", nfss->namelen);
665 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
666 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
667 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
668 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
669 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
670 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
671 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
672 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
673 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
674 		if (nfss->flags & nfs_infop->flag)
675 			seq_puts(m, nfs_infop->str);
676 		else
677 			seq_puts(m, nfs_infop->nostr);
678 	}
679 	seq_printf(m, ",proto=%s",
680 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
681 	if (version == 4) {
682 		if (nfss->port != NFS_PORT)
683 			seq_printf(m, ",port=%u", nfss->port);
684 	} else
685 		if (nfss->port)
686 			seq_printf(m, ",port=%u", nfss->port);
687 
688 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
689 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
690 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
691 
692 	if (version != 4)
693 		nfs_show_mountd_options(m, nfss, showdefaults);
694 	else
695 		nfs_show_nfsv4_options(m, nfss, showdefaults);
696 
697 	if (nfss->options & NFS_OPTION_FSCACHE)
698 		seq_printf(m, ",fsc");
699 
700 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
701 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
702 			seq_printf(m, ",lookupcache=none");
703 		else
704 			seq_printf(m, ",lookupcache=pos");
705 	}
706 
707 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
708 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
709 
710 	if (!local_flock && !local_fcntl)
711 		seq_printf(m, ",local_lock=none");
712 	else if (local_flock && local_fcntl)
713 		seq_printf(m, ",local_lock=all");
714 	else if (local_flock)
715 		seq_printf(m, ",local_lock=flock");
716 	else
717 		seq_printf(m, ",local_lock=posix");
718 }
719 
720 /*
721  * Describe the mount options on this VFS mountpoint
722  */
723 static int nfs_show_options(struct seq_file *m, struct dentry *root)
724 {
725 	struct nfs_server *nfss = NFS_SB(root->d_sb);
726 
727 	nfs_show_mount_options(m, nfss, 0);
728 
729 	seq_printf(m, ",addr=%s",
730 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
731 							RPC_DISPLAY_ADDR));
732 
733 	return 0;
734 }
735 
736 #ifdef CONFIG_NFS_V4
737 #ifdef CONFIG_NFS_V4_1
738 static void show_sessions(struct seq_file *m, struct nfs_server *server)
739 {
740 	if (nfs4_has_session(server->nfs_client))
741 		seq_printf(m, ",sessions");
742 }
743 #else
744 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
745 #endif
746 #endif
747 
748 #ifdef CONFIG_NFS_V4
749 #ifdef CONFIG_NFS_V4_1
750 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
751 {
752 	seq_printf(m, ",pnfs=");
753 	if (server->pnfs_curr_ld)
754 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
755 	else
756 		seq_printf(m, "not configured");
757 }
758 #else
759 static void show_pnfs(struct seq_file *m, struct nfs_server *server) {}
760 #endif
761 #endif
762 
763 static int nfs_show_devname(struct seq_file *m, struct dentry *root)
764 {
765 	char *page = (char *) __get_free_page(GFP_KERNEL);
766 	char *devname, *dummy;
767 	int err = 0;
768 	if (!page)
769 		return -ENOMEM;
770 	devname = nfs_path(&dummy, root, page, PAGE_SIZE);
771 	if (IS_ERR(devname))
772 		err = PTR_ERR(devname);
773 	else
774 		seq_escape(m, devname, " \t\n\\");
775 	free_page((unsigned long)page);
776 	return err;
777 }
778 
779 static int nfs_show_path(struct seq_file *m, struct dentry *dentry)
780 {
781 	seq_puts(m, "/");
782 	return 0;
783 }
784 
785 /*
786  * Present statistical information for this VFS mountpoint
787  */
788 static int nfs_show_stats(struct seq_file *m, struct dentry *root)
789 {
790 	int i, cpu;
791 	struct nfs_server *nfss = NFS_SB(root->d_sb);
792 	struct rpc_auth *auth = nfss->client->cl_auth;
793 	struct nfs_iostats totals = { };
794 
795 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
796 
797 	/*
798 	 * Display all mount option settings
799 	 */
800 	seq_printf(m, "\n\topts:\t");
801 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
802 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
803 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
804 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
805 	nfs_show_mount_options(m, nfss, 1);
806 
807 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
808 
809 	seq_printf(m, "\n\tcaps:\t");
810 	seq_printf(m, "caps=0x%x", nfss->caps);
811 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
812 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
813 	seq_printf(m, ",bsize=%u", nfss->bsize);
814 	seq_printf(m, ",namlen=%u", nfss->namelen);
815 
816 #ifdef CONFIG_NFS_V4
817 	if (nfss->nfs_client->rpc_ops->version == 4) {
818 		seq_printf(m, "\n\tnfsv4:\t");
819 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
820 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
821 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
822 		show_sessions(m, nfss);
823 		show_pnfs(m, nfss);
824 	}
825 #endif
826 
827 	/*
828 	 * Display security flavor in effect for this mount
829 	 */
830 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
831 	if (auth->au_flavor)
832 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
833 
834 	/*
835 	 * Display superblock I/O counters
836 	 */
837 	for_each_possible_cpu(cpu) {
838 		struct nfs_iostats *stats;
839 
840 		preempt_disable();
841 		stats = per_cpu_ptr(nfss->io_stats, cpu);
842 
843 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
844 			totals.events[i] += stats->events[i];
845 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
846 			totals.bytes[i] += stats->bytes[i];
847 #ifdef CONFIG_NFS_FSCACHE
848 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
849 			totals.fscache[i] += stats->fscache[i];
850 #endif
851 
852 		preempt_enable();
853 	}
854 
855 	seq_printf(m, "\n\tevents:\t");
856 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
857 		seq_printf(m, "%lu ", totals.events[i]);
858 	seq_printf(m, "\n\tbytes:\t");
859 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
860 		seq_printf(m, "%Lu ", totals.bytes[i]);
861 #ifdef CONFIG_NFS_FSCACHE
862 	if (nfss->options & NFS_OPTION_FSCACHE) {
863 		seq_printf(m, "\n\tfsc:\t");
864 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
865 			seq_printf(m, "%Lu ", totals.bytes[i]);
866 	}
867 #endif
868 	seq_printf(m, "\n");
869 
870 	rpc_print_iostats(m, nfss->client);
871 
872 	return 0;
873 }
874 
875 /*
876  * Begin unmount by attempting to remove all automounted mountpoints we added
877  * in response to xdev traversals and referrals
878  */
879 static void nfs_umount_begin(struct super_block *sb)
880 {
881 	struct nfs_server *server;
882 	struct rpc_clnt *rpc;
883 
884 	server = NFS_SB(sb);
885 	/* -EIO all pending I/O */
886 	rpc = server->client_acl;
887 	if (!IS_ERR(rpc))
888 		rpc_killall_tasks(rpc);
889 	rpc = server->client;
890 	if (!IS_ERR(rpc))
891 		rpc_killall_tasks(rpc);
892 }
893 
894 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(unsigned int version)
895 {
896 	struct nfs_parsed_mount_data *data;
897 
898 	data = kzalloc(sizeof(*data), GFP_KERNEL);
899 	if (data) {
900 		data->acregmin		= NFS_DEF_ACREGMIN;
901 		data->acregmax		= NFS_DEF_ACREGMAX;
902 		data->acdirmin		= NFS_DEF_ACDIRMIN;
903 		data->acdirmax		= NFS_DEF_ACDIRMAX;
904 		data->mount_server.port	= NFS_UNSPEC_PORT;
905 		data->nfs_server.port	= NFS_UNSPEC_PORT;
906 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
907 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
908 		data->auth_flavor_len	= 1;
909 		data->version		= version;
910 		data->minorversion	= 0;
911 		security_init_mnt_opts(&data->lsm_opts);
912 	}
913 	return data;
914 }
915 
916 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
917 {
918 	if (data) {
919 		kfree(data->client_address);
920 		kfree(data->mount_server.hostname);
921 		kfree(data->nfs_server.export_path);
922 		kfree(data->nfs_server.hostname);
923 		kfree(data->fscache_uniq);
924 		security_free_mnt_opts(&data->lsm_opts);
925 		kfree(data);
926 	}
927 }
928 
929 /*
930  * Sanity-check a server address provided by the mount command.
931  *
932  * Address family must be initialized, and address must not be
933  * the ANY address for that family.
934  */
935 static int nfs_verify_server_address(struct sockaddr *addr)
936 {
937 	switch (addr->sa_family) {
938 	case AF_INET: {
939 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
940 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
941 	}
942 	case AF_INET6: {
943 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
944 		return !ipv6_addr_any(sa);
945 	}
946 	}
947 
948 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
949 	return 0;
950 }
951 
952 /*
953  * Select between a default port value and a user-specified port value.
954  * If a zero value is set, then autobind will be used.
955  */
956 static void nfs_set_port(struct sockaddr *sap, int *port,
957 				 const unsigned short default_port)
958 {
959 	if (*port == NFS_UNSPEC_PORT)
960 		*port = default_port;
961 
962 	rpc_set_port(sap, *port);
963 }
964 
965 /*
966  * Sanity check the NFS transport protocol.
967  *
968  */
969 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
970 {
971 	switch (mnt->nfs_server.protocol) {
972 	case XPRT_TRANSPORT_UDP:
973 	case XPRT_TRANSPORT_TCP:
974 	case XPRT_TRANSPORT_RDMA:
975 		break;
976 	default:
977 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
978 	}
979 }
980 
981 /*
982  * For text based NFSv2/v3 mounts, the mount protocol transport default
983  * settings should depend upon the specified NFS transport.
984  */
985 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
986 {
987 	nfs_validate_transport_protocol(mnt);
988 
989 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
990 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
991 			return;
992 	switch (mnt->nfs_server.protocol) {
993 	case XPRT_TRANSPORT_UDP:
994 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
995 		break;
996 	case XPRT_TRANSPORT_TCP:
997 	case XPRT_TRANSPORT_RDMA:
998 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
999 	}
1000 }
1001 
1002 /*
1003  * Parse the value of the 'sec=' option.
1004  */
1005 static int nfs_parse_security_flavors(char *value,
1006 				      struct nfs_parsed_mount_data *mnt)
1007 {
1008 	substring_t args[MAX_OPT_ARGS];
1009 
1010 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1011 
1012 	switch (match_token(value, nfs_secflavor_tokens, args)) {
1013 	case Opt_sec_none:
1014 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
1015 		break;
1016 	case Opt_sec_sys:
1017 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1018 		break;
1019 	case Opt_sec_krb5:
1020 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1021 		break;
1022 	case Opt_sec_krb5i:
1023 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1024 		break;
1025 	case Opt_sec_krb5p:
1026 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1027 		break;
1028 	case Opt_sec_lkey:
1029 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1030 		break;
1031 	case Opt_sec_lkeyi:
1032 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1033 		break;
1034 	case Opt_sec_lkeyp:
1035 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1036 		break;
1037 	case Opt_sec_spkm:
1038 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1039 		break;
1040 	case Opt_sec_spkmi:
1041 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1042 		break;
1043 	case Opt_sec_spkmp:
1044 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1045 		break;
1046 	default:
1047 		return 0;
1048 	}
1049 
1050 	mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1051 	mnt->auth_flavor_len = 1;
1052 	return 1;
1053 }
1054 
1055 static int nfs_get_option_str(substring_t args[], char **option)
1056 {
1057 	kfree(*option);
1058 	*option = match_strdup(args);
1059 	return !option;
1060 }
1061 
1062 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1063 {
1064 	int rc;
1065 	char *string;
1066 
1067 	string = match_strdup(args);
1068 	if (string == NULL)
1069 		return -ENOMEM;
1070 	rc = strict_strtoul(string, 10, option);
1071 	kfree(string);
1072 
1073 	return rc;
1074 }
1075 
1076 /*
1077  * Error-check and convert a string of mount options from user space into
1078  * a data structure.  The whole mount string is processed; bad options are
1079  * skipped as they are encountered.  If there were no errors, return 1;
1080  * otherwise return 0 (zero).
1081  */
1082 static int nfs_parse_mount_options(char *raw,
1083 				   struct nfs_parsed_mount_data *mnt)
1084 {
1085 	char *p, *string, *secdata;
1086 	int rc, sloppy = 0, invalid_option = 0;
1087 	unsigned short protofamily = AF_UNSPEC;
1088 	unsigned short mountfamily = AF_UNSPEC;
1089 
1090 	if (!raw) {
1091 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1092 		return 1;
1093 	}
1094 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1095 
1096 	secdata = alloc_secdata();
1097 	if (!secdata)
1098 		goto out_nomem;
1099 
1100 	rc = security_sb_copy_data(raw, secdata);
1101 	if (rc)
1102 		goto out_security_failure;
1103 
1104 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1105 	if (rc)
1106 		goto out_security_failure;
1107 
1108 	free_secdata(secdata);
1109 
1110 	while ((p = strsep(&raw, ",")) != NULL) {
1111 		substring_t args[MAX_OPT_ARGS];
1112 		unsigned long option;
1113 		int token;
1114 
1115 		if (!*p)
1116 			continue;
1117 
1118 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1119 
1120 		token = match_token(p, nfs_mount_option_tokens, args);
1121 		switch (token) {
1122 
1123 		/*
1124 		 * boolean options:  foo/nofoo
1125 		 */
1126 		case Opt_soft:
1127 			mnt->flags |= NFS_MOUNT_SOFT;
1128 			break;
1129 		case Opt_hard:
1130 			mnt->flags &= ~NFS_MOUNT_SOFT;
1131 			break;
1132 		case Opt_posix:
1133 			mnt->flags |= NFS_MOUNT_POSIX;
1134 			break;
1135 		case Opt_noposix:
1136 			mnt->flags &= ~NFS_MOUNT_POSIX;
1137 			break;
1138 		case Opt_cto:
1139 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1140 			break;
1141 		case Opt_nocto:
1142 			mnt->flags |= NFS_MOUNT_NOCTO;
1143 			break;
1144 		case Opt_ac:
1145 			mnt->flags &= ~NFS_MOUNT_NOAC;
1146 			break;
1147 		case Opt_noac:
1148 			mnt->flags |= NFS_MOUNT_NOAC;
1149 			break;
1150 		case Opt_lock:
1151 			mnt->flags &= ~NFS_MOUNT_NONLM;
1152 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1153 					NFS_MOUNT_LOCAL_FCNTL);
1154 			break;
1155 		case Opt_nolock:
1156 			mnt->flags |= NFS_MOUNT_NONLM;
1157 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1158 				       NFS_MOUNT_LOCAL_FCNTL);
1159 			break;
1160 		case Opt_v2:
1161 			mnt->flags &= ~NFS_MOUNT_VER3;
1162 			mnt->version = 2;
1163 			break;
1164 		case Opt_v3:
1165 			mnt->flags |= NFS_MOUNT_VER3;
1166 			mnt->version = 3;
1167 			break;
1168 		case Opt_v4:
1169 			mnt->flags &= ~NFS_MOUNT_VER3;
1170 			mnt->version = 4;
1171 			break;
1172 		case Opt_udp:
1173 			mnt->flags &= ~NFS_MOUNT_TCP;
1174 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1175 			break;
1176 		case Opt_tcp:
1177 			mnt->flags |= NFS_MOUNT_TCP;
1178 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1179 			break;
1180 		case Opt_rdma:
1181 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1182 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1183 			xprt_load_transport(p);
1184 			break;
1185 		case Opt_acl:
1186 			mnt->flags &= ~NFS_MOUNT_NOACL;
1187 			break;
1188 		case Opt_noacl:
1189 			mnt->flags |= NFS_MOUNT_NOACL;
1190 			break;
1191 		case Opt_rdirplus:
1192 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1193 			break;
1194 		case Opt_nordirplus:
1195 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1196 			break;
1197 		case Opt_sharecache:
1198 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1199 			break;
1200 		case Opt_nosharecache:
1201 			mnt->flags |= NFS_MOUNT_UNSHARED;
1202 			break;
1203 		case Opt_resvport:
1204 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1205 			break;
1206 		case Opt_noresvport:
1207 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1208 			break;
1209 		case Opt_fscache:
1210 			mnt->options |= NFS_OPTION_FSCACHE;
1211 			kfree(mnt->fscache_uniq);
1212 			mnt->fscache_uniq = NULL;
1213 			break;
1214 		case Opt_nofscache:
1215 			mnt->options &= ~NFS_OPTION_FSCACHE;
1216 			kfree(mnt->fscache_uniq);
1217 			mnt->fscache_uniq = NULL;
1218 			break;
1219 
1220 		/*
1221 		 * options that take numeric values
1222 		 */
1223 		case Opt_port:
1224 			if (nfs_get_option_ul(args, &option) ||
1225 			    option > USHRT_MAX)
1226 				goto out_invalid_value;
1227 			mnt->nfs_server.port = option;
1228 			break;
1229 		case Opt_rsize:
1230 			if (nfs_get_option_ul(args, &option))
1231 				goto out_invalid_value;
1232 			mnt->rsize = option;
1233 			break;
1234 		case Opt_wsize:
1235 			if (nfs_get_option_ul(args, &option))
1236 				goto out_invalid_value;
1237 			mnt->wsize = option;
1238 			break;
1239 		case Opt_bsize:
1240 			if (nfs_get_option_ul(args, &option))
1241 				goto out_invalid_value;
1242 			mnt->bsize = option;
1243 			break;
1244 		case Opt_timeo:
1245 			if (nfs_get_option_ul(args, &option) || option == 0)
1246 				goto out_invalid_value;
1247 			mnt->timeo = option;
1248 			break;
1249 		case Opt_retrans:
1250 			if (nfs_get_option_ul(args, &option) || option == 0)
1251 				goto out_invalid_value;
1252 			mnt->retrans = option;
1253 			break;
1254 		case Opt_acregmin:
1255 			if (nfs_get_option_ul(args, &option))
1256 				goto out_invalid_value;
1257 			mnt->acregmin = option;
1258 			break;
1259 		case Opt_acregmax:
1260 			if (nfs_get_option_ul(args, &option))
1261 				goto out_invalid_value;
1262 			mnt->acregmax = option;
1263 			break;
1264 		case Opt_acdirmin:
1265 			if (nfs_get_option_ul(args, &option))
1266 				goto out_invalid_value;
1267 			mnt->acdirmin = option;
1268 			break;
1269 		case Opt_acdirmax:
1270 			if (nfs_get_option_ul(args, &option))
1271 				goto out_invalid_value;
1272 			mnt->acdirmax = option;
1273 			break;
1274 		case Opt_actimeo:
1275 			if (nfs_get_option_ul(args, &option))
1276 				goto out_invalid_value;
1277 			mnt->acregmin = mnt->acregmax =
1278 			mnt->acdirmin = mnt->acdirmax = option;
1279 			break;
1280 		case Opt_namelen:
1281 			if (nfs_get_option_ul(args, &option))
1282 				goto out_invalid_value;
1283 			mnt->namlen = option;
1284 			break;
1285 		case Opt_mountport:
1286 			if (nfs_get_option_ul(args, &option) ||
1287 			    option > USHRT_MAX)
1288 				goto out_invalid_value;
1289 			mnt->mount_server.port = option;
1290 			break;
1291 		case Opt_mountvers:
1292 			if (nfs_get_option_ul(args, &option) ||
1293 			    option < NFS_MNT_VERSION ||
1294 			    option > NFS_MNT3_VERSION)
1295 				goto out_invalid_value;
1296 			mnt->mount_server.version = option;
1297 			break;
1298 		case Opt_nfsvers:
1299 			if (nfs_get_option_ul(args, &option))
1300 				goto out_invalid_value;
1301 			switch (option) {
1302 			case NFS2_VERSION:
1303 				mnt->flags &= ~NFS_MOUNT_VER3;
1304 				mnt->version = 2;
1305 				break;
1306 			case NFS3_VERSION:
1307 				mnt->flags |= NFS_MOUNT_VER3;
1308 				mnt->version = 3;
1309 				break;
1310 			case NFS4_VERSION:
1311 				mnt->flags &= ~NFS_MOUNT_VER3;
1312 				mnt->version = 4;
1313 				break;
1314 			default:
1315 				goto out_invalid_value;
1316 			}
1317 			break;
1318 		case Opt_minorversion:
1319 			if (nfs_get_option_ul(args, &option))
1320 				goto out_invalid_value;
1321 			if (option > NFS4_MAX_MINOR_VERSION)
1322 				goto out_invalid_value;
1323 			mnt->minorversion = option;
1324 			break;
1325 
1326 		/*
1327 		 * options that take text values
1328 		 */
1329 		case Opt_sec:
1330 			string = match_strdup(args);
1331 			if (string == NULL)
1332 				goto out_nomem;
1333 			rc = nfs_parse_security_flavors(string, mnt);
1334 			kfree(string);
1335 			if (!rc) {
1336 				dfprintk(MOUNT, "NFS:   unrecognized "
1337 						"security flavor\n");
1338 				return 0;
1339 			}
1340 			break;
1341 		case Opt_proto:
1342 			string = match_strdup(args);
1343 			if (string == NULL)
1344 				goto out_nomem;
1345 			token = match_token(string,
1346 					    nfs_xprt_protocol_tokens, args);
1347 
1348 			protofamily = AF_INET;
1349 			switch (token) {
1350 			case Opt_xprt_udp6:
1351 				protofamily = AF_INET6;
1352 			case Opt_xprt_udp:
1353 				mnt->flags &= ~NFS_MOUNT_TCP;
1354 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1355 				break;
1356 			case Opt_xprt_tcp6:
1357 				protofamily = AF_INET6;
1358 			case Opt_xprt_tcp:
1359 				mnt->flags |= NFS_MOUNT_TCP;
1360 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1361 				break;
1362 			case Opt_xprt_rdma:
1363 				/* vector side protocols to TCP */
1364 				mnt->flags |= NFS_MOUNT_TCP;
1365 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1366 				xprt_load_transport(string);
1367 				break;
1368 			default:
1369 				dfprintk(MOUNT, "NFS:   unrecognized "
1370 						"transport protocol\n");
1371 				kfree(string);
1372 				return 0;
1373 			}
1374 			kfree(string);
1375 			break;
1376 		case Opt_mountproto:
1377 			string = match_strdup(args);
1378 			if (string == NULL)
1379 				goto out_nomem;
1380 			token = match_token(string,
1381 					    nfs_xprt_protocol_tokens, args);
1382 			kfree(string);
1383 
1384 			mountfamily = AF_INET;
1385 			switch (token) {
1386 			case Opt_xprt_udp6:
1387 				mountfamily = AF_INET6;
1388 			case Opt_xprt_udp:
1389 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1390 				break;
1391 			case Opt_xprt_tcp6:
1392 				mountfamily = AF_INET6;
1393 			case Opt_xprt_tcp:
1394 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1395 				break;
1396 			case Opt_xprt_rdma: /* not used for side protocols */
1397 			default:
1398 				dfprintk(MOUNT, "NFS:   unrecognized "
1399 						"transport protocol\n");
1400 				return 0;
1401 			}
1402 			break;
1403 		case Opt_addr:
1404 			string = match_strdup(args);
1405 			if (string == NULL)
1406 				goto out_nomem;
1407 			mnt->nfs_server.addrlen =
1408 				rpc_pton(string, strlen(string),
1409 					(struct sockaddr *)
1410 					&mnt->nfs_server.address,
1411 					sizeof(mnt->nfs_server.address));
1412 			kfree(string);
1413 			if (mnt->nfs_server.addrlen == 0)
1414 				goto out_invalid_address;
1415 			break;
1416 		case Opt_clientaddr:
1417 			if (nfs_get_option_str(args, &mnt->client_address))
1418 				goto out_nomem;
1419 			break;
1420 		case Opt_mounthost:
1421 			if (nfs_get_option_str(args,
1422 					       &mnt->mount_server.hostname))
1423 				goto out_nomem;
1424 			break;
1425 		case Opt_mountaddr:
1426 			string = match_strdup(args);
1427 			if (string == NULL)
1428 				goto out_nomem;
1429 			mnt->mount_server.addrlen =
1430 				rpc_pton(string, strlen(string),
1431 					(struct sockaddr *)
1432 					&mnt->mount_server.address,
1433 					sizeof(mnt->mount_server.address));
1434 			kfree(string);
1435 			if (mnt->mount_server.addrlen == 0)
1436 				goto out_invalid_address;
1437 			break;
1438 		case Opt_lookupcache:
1439 			string = match_strdup(args);
1440 			if (string == NULL)
1441 				goto out_nomem;
1442 			token = match_token(string,
1443 					nfs_lookupcache_tokens, args);
1444 			kfree(string);
1445 			switch (token) {
1446 				case Opt_lookupcache_all:
1447 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1448 					break;
1449 				case Opt_lookupcache_positive:
1450 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1451 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1452 					break;
1453 				case Opt_lookupcache_none:
1454 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1455 					break;
1456 				default:
1457 					dfprintk(MOUNT, "NFS:   invalid "
1458 							"lookupcache argument\n");
1459 					return 0;
1460 			};
1461 			break;
1462 		case Opt_fscache_uniq:
1463 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1464 				goto out_nomem;
1465 			mnt->options |= NFS_OPTION_FSCACHE;
1466 			break;
1467 		case Opt_local_lock:
1468 			string = match_strdup(args);
1469 			if (string == NULL)
1470 				goto out_nomem;
1471 			token = match_token(string, nfs_local_lock_tokens,
1472 					args);
1473 			kfree(string);
1474 			switch (token) {
1475 			case Opt_local_lock_all:
1476 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1477 					       NFS_MOUNT_LOCAL_FCNTL);
1478 				break;
1479 			case Opt_local_lock_flock:
1480 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1481 				break;
1482 			case Opt_local_lock_posix:
1483 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1484 				break;
1485 			case Opt_local_lock_none:
1486 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1487 						NFS_MOUNT_LOCAL_FCNTL);
1488 				break;
1489 			default:
1490 				dfprintk(MOUNT, "NFS:	invalid	"
1491 						"local_lock argument\n");
1492 				return 0;
1493 			};
1494 			break;
1495 
1496 		/*
1497 		 * Special options
1498 		 */
1499 		case Opt_sloppy:
1500 			sloppy = 1;
1501 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1502 			break;
1503 		case Opt_userspace:
1504 		case Opt_deprecated:
1505 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1506 					"'%s'\n", p);
1507 			break;
1508 
1509 		default:
1510 			invalid_option = 1;
1511 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1512 					"'%s'\n", p);
1513 		}
1514 	}
1515 
1516 	if (!sloppy && invalid_option)
1517 		return 0;
1518 
1519 	/*
1520 	 * verify that any proto=/mountproto= options match the address
1521 	 * familiies in the addr=/mountaddr= options.
1522 	 */
1523 	if (protofamily != AF_UNSPEC &&
1524 	    protofamily != mnt->nfs_server.address.ss_family)
1525 		goto out_proto_mismatch;
1526 
1527 	if (mountfamily != AF_UNSPEC) {
1528 		if (mnt->mount_server.addrlen) {
1529 			if (mountfamily != mnt->mount_server.address.ss_family)
1530 				goto out_mountproto_mismatch;
1531 		} else {
1532 			if (mountfamily != mnt->nfs_server.address.ss_family)
1533 				goto out_mountproto_mismatch;
1534 		}
1535 	}
1536 
1537 	return 1;
1538 
1539 out_mountproto_mismatch:
1540 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1541 			 "option\n");
1542 	return 0;
1543 out_proto_mismatch:
1544 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1545 	return 0;
1546 out_invalid_address:
1547 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1548 	return 0;
1549 out_invalid_value:
1550 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1551 	return 0;
1552 out_nomem:
1553 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1554 	return 0;
1555 out_security_failure:
1556 	free_secdata(secdata);
1557 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1558 	return 0;
1559 }
1560 
1561 /*
1562  * Match the requested auth flavors with the list returned by
1563  * the server.  Returns zero and sets the mount's authentication
1564  * flavor on success; returns -EACCES if server does not support
1565  * the requested flavor.
1566  */
1567 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1568 			     struct nfs_mount_request *request)
1569 {
1570 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1571 
1572 	/*
1573 	 * Certain releases of Linux's mountd return an empty
1574 	 * flavor list.  To prevent behavioral regression with
1575 	 * these servers (ie. rejecting mounts that used to
1576 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1577 	 * if the returned flavor list is empty.
1578 	 */
1579 	if (server_authlist_len == 0)
1580 		return 0;
1581 
1582 	/*
1583 	 * We avoid sophisticated negotiating here, as there are
1584 	 * plenty of cases where we can get it wrong, providing
1585 	 * either too little or too much security.
1586 	 *
1587 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1588 	 * flavor listed first.  However, some servers list
1589 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1590 	 * preferred default, in args->auth_flavors[0] if user
1591 	 * didn't specify sec= mount option.
1592 	 */
1593 	for (i = 0; i < args->auth_flavor_len; i++)
1594 		for (j = 0; j < server_authlist_len; j++)
1595 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1596 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1597 					request->auth_flavs[j]);
1598 				args->auth_flavors[0] = request->auth_flavs[j];
1599 				return 0;
1600 			}
1601 
1602 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1603 	nfs_umount(request);
1604 	return -EACCES;
1605 }
1606 
1607 /*
1608  * Use the remote server's MOUNT service to request the NFS file handle
1609  * corresponding to the provided path.
1610  */
1611 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1612 			 struct nfs_fh *root_fh)
1613 {
1614 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1615 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1616 	struct nfs_mount_request request = {
1617 		.sap		= (struct sockaddr *)
1618 						&args->mount_server.address,
1619 		.dirpath	= args->nfs_server.export_path,
1620 		.protocol	= args->mount_server.protocol,
1621 		.fh		= root_fh,
1622 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1623 		.auth_flav_len	= &server_authlist_len,
1624 		.auth_flavs	= server_authlist,
1625 	};
1626 	int status;
1627 
1628 	if (args->mount_server.version == 0) {
1629 		switch (args->version) {
1630 			default:
1631 				args->mount_server.version = NFS_MNT3_VERSION;
1632 				break;
1633 			case 2:
1634 				args->mount_server.version = NFS_MNT_VERSION;
1635 		}
1636 	}
1637 	request.version = args->mount_server.version;
1638 
1639 	if (args->mount_server.hostname)
1640 		request.hostname = args->mount_server.hostname;
1641 	else
1642 		request.hostname = args->nfs_server.hostname;
1643 
1644 	/*
1645 	 * Construct the mount server's address.
1646 	 */
1647 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1648 		memcpy(request.sap, &args->nfs_server.address,
1649 		       args->nfs_server.addrlen);
1650 		args->mount_server.addrlen = args->nfs_server.addrlen;
1651 	}
1652 	request.salen = args->mount_server.addrlen;
1653 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1654 
1655 	/*
1656 	 * Now ask the mount server to map our export path
1657 	 * to a file handle.
1658 	 */
1659 	status = nfs_mount(&request);
1660 	if (status != 0) {
1661 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1662 				request.hostname, status);
1663 		return status;
1664 	}
1665 
1666 	/*
1667 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1668 	 */
1669 	if (args->mount_server.version != NFS_MNT3_VERSION)
1670 		return 0;
1671 	return nfs_walk_authlist(args, &request);
1672 }
1673 
1674 /*
1675  * Split "dev_name" into "hostname:export_path".
1676  *
1677  * The leftmost colon demarks the split between the server's hostname
1678  * and the export path.  If the hostname starts with a left square
1679  * bracket, then it may contain colons.
1680  *
1681  * Note: caller frees hostname and export path, even on error.
1682  */
1683 static int nfs_parse_devname(const char *dev_name,
1684 			     char **hostname, size_t maxnamlen,
1685 			     char **export_path, size_t maxpathlen)
1686 {
1687 	size_t len;
1688 	char *end;
1689 
1690 	/* Is the host name protected with square brakcets? */
1691 	if (*dev_name == '[') {
1692 		end = strchr(++dev_name, ']');
1693 		if (end == NULL || end[1] != ':')
1694 			goto out_bad_devname;
1695 
1696 		len = end - dev_name;
1697 		end++;
1698 	} else {
1699 		char *comma;
1700 
1701 		end = strchr(dev_name, ':');
1702 		if (end == NULL)
1703 			goto out_bad_devname;
1704 		len = end - dev_name;
1705 
1706 		/* kill possible hostname list: not supported */
1707 		comma = strchr(dev_name, ',');
1708 		if (comma != NULL && comma < end)
1709 			*comma = 0;
1710 	}
1711 
1712 	if (len > maxnamlen)
1713 		goto out_hostname;
1714 
1715 	/* N.B. caller will free nfs_server.hostname in all cases */
1716 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1717 	if (*hostname == NULL)
1718 		goto out_nomem;
1719 	len = strlen(++end);
1720 	if (len > maxpathlen)
1721 		goto out_path;
1722 	*export_path = kstrndup(end, len, GFP_KERNEL);
1723 	if (!*export_path)
1724 		goto out_nomem;
1725 
1726 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1727 	return 0;
1728 
1729 out_bad_devname:
1730 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1731 	return -EINVAL;
1732 
1733 out_nomem:
1734 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1735 	return -ENOMEM;
1736 
1737 out_hostname:
1738 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1739 	return -ENAMETOOLONG;
1740 
1741 out_path:
1742 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1743 	return -ENAMETOOLONG;
1744 }
1745 
1746 /*
1747  * Validate the NFS2/NFS3 mount data
1748  * - fills in the mount root filehandle
1749  *
1750  * For option strings, user space handles the following behaviors:
1751  *
1752  * + DNS: mapping server host name to IP address ("addr=" option)
1753  *
1754  * + failure mode: how to behave if a mount request can't be handled
1755  *   immediately ("fg/bg" option)
1756  *
1757  * + retry: how often to retry a mount request ("retry=" option)
1758  *
1759  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1760  *   mountproto=tcp after mountproto=udp, and so on
1761  */
1762 static int nfs_validate_mount_data(void *options,
1763 				   struct nfs_parsed_mount_data *args,
1764 				   struct nfs_fh *mntfh,
1765 				   const char *dev_name)
1766 {
1767 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1768 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1769 
1770 	if (data == NULL)
1771 		goto out_no_data;
1772 
1773 	switch (data->version) {
1774 	case 1:
1775 		data->namlen = 0;
1776 	case 2:
1777 		data->bsize = 0;
1778 	case 3:
1779 		if (data->flags & NFS_MOUNT_VER3)
1780 			goto out_no_v3;
1781 		data->root.size = NFS2_FHSIZE;
1782 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1783 	case 4:
1784 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1785 			goto out_no_sec;
1786 	case 5:
1787 		memset(data->context, 0, sizeof(data->context));
1788 	case 6:
1789 		if (data->flags & NFS_MOUNT_VER3) {
1790 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1791 				goto out_invalid_fh;
1792 			mntfh->size = data->root.size;
1793 			args->version = 3;
1794 		} else {
1795 			mntfh->size = NFS2_FHSIZE;
1796 			args->version = 2;
1797 		}
1798 
1799 
1800 		memcpy(mntfh->data, data->root.data, mntfh->size);
1801 		if (mntfh->size < sizeof(mntfh->data))
1802 			memset(mntfh->data + mntfh->size, 0,
1803 			       sizeof(mntfh->data) - mntfh->size);
1804 
1805 		/*
1806 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1807 		 * can deal with.
1808 		 */
1809 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1810 		args->flags		|= NFS_MOUNT_LEGACY_INTERFACE;
1811 		args->rsize		= data->rsize;
1812 		args->wsize		= data->wsize;
1813 		args->timeo		= data->timeo;
1814 		args->retrans		= data->retrans;
1815 		args->acregmin		= data->acregmin;
1816 		args->acregmax		= data->acregmax;
1817 		args->acdirmin		= data->acdirmin;
1818 		args->acdirmax		= data->acdirmax;
1819 
1820 		memcpy(sap, &data->addr, sizeof(data->addr));
1821 		args->nfs_server.addrlen = sizeof(data->addr);
1822 		if (!nfs_verify_server_address(sap))
1823 			goto out_no_address;
1824 
1825 		if (!(data->flags & NFS_MOUNT_TCP))
1826 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1827 		/* N.B. caller will free nfs_server.hostname in all cases */
1828 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1829 		args->namlen		= data->namlen;
1830 		args->bsize		= data->bsize;
1831 
1832 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1833 			args->auth_flavors[0] = data->pseudoflavor;
1834 		if (!args->nfs_server.hostname)
1835 			goto out_nomem;
1836 
1837 		if (!(data->flags & NFS_MOUNT_NONLM))
1838 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1839 					 NFS_MOUNT_LOCAL_FCNTL);
1840 		else
1841 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1842 					NFS_MOUNT_LOCAL_FCNTL);
1843 		/*
1844 		 * The legacy version 6 binary mount data from userspace has a
1845 		 * field used only to transport selinux information into the
1846 		 * the kernel.  To continue to support that functionality we
1847 		 * have a touch of selinux knowledge here in the NFS code. The
1848 		 * userspace code converted context=blah to just blah so we are
1849 		 * converting back to the full string selinux understands.
1850 		 */
1851 		if (data->context[0]){
1852 #ifdef CONFIG_SECURITY_SELINUX
1853 			int rc;
1854 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1855 			if (!opts_str)
1856 				return -ENOMEM;
1857 			strcpy(opts_str, "context=");
1858 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1859 			strcat(opts_str, &data->context[0]);
1860 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1861 			kfree(opts_str);
1862 			if (rc)
1863 				return rc;
1864 #else
1865 			return -EINVAL;
1866 #endif
1867 		}
1868 
1869 		break;
1870 	default: {
1871 		int status;
1872 
1873 		if (nfs_parse_mount_options((char *)options, args) == 0)
1874 			return -EINVAL;
1875 
1876 		if (!nfs_verify_server_address(sap))
1877 			goto out_no_address;
1878 
1879 		if (args->version == 4)
1880 #ifdef CONFIG_NFS_V4
1881 			return nfs4_validate_text_mount_data(options,
1882 							     args, dev_name);
1883 #else
1884 			goto out_v4_not_compiled;
1885 #endif
1886 
1887 		nfs_set_port(sap, &args->nfs_server.port, 0);
1888 
1889 		nfs_set_mount_transport_protocol(args);
1890 
1891 		status = nfs_parse_devname(dev_name,
1892 					   &args->nfs_server.hostname,
1893 					   PAGE_SIZE,
1894 					   &args->nfs_server.export_path,
1895 					   NFS_MAXPATHLEN);
1896 		if (!status)
1897 			status = nfs_try_mount(args, mntfh);
1898 
1899 		kfree(args->nfs_server.export_path);
1900 		args->nfs_server.export_path = NULL;
1901 
1902 		if (status)
1903 			return status;
1904 
1905 		break;
1906 		}
1907 	}
1908 
1909 #ifndef CONFIG_NFS_V3
1910 	if (args->version == 3)
1911 		goto out_v3_not_compiled;
1912 #endif /* !CONFIG_NFS_V3 */
1913 
1914 	return 0;
1915 
1916 out_no_data:
1917 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1918 	return -EINVAL;
1919 
1920 out_no_v3:
1921 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1922 		 data->version);
1923 	return -EINVAL;
1924 
1925 out_no_sec:
1926 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1927 	return -EINVAL;
1928 
1929 #ifndef CONFIG_NFS_V3
1930 out_v3_not_compiled:
1931 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1932 	return -EPROTONOSUPPORT;
1933 #endif /* !CONFIG_NFS_V3 */
1934 
1935 #ifndef CONFIG_NFS_V4
1936 out_v4_not_compiled:
1937 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1938 	return -EPROTONOSUPPORT;
1939 #endif /* !CONFIG_NFS_V4 */
1940 
1941 out_nomem:
1942 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1943 	return -ENOMEM;
1944 
1945 out_no_address:
1946 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1947 	return -EINVAL;
1948 
1949 out_invalid_fh:
1950 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1951 	return -EINVAL;
1952 }
1953 
1954 static int
1955 nfs_compare_remount_data(struct nfs_server *nfss,
1956 			 struct nfs_parsed_mount_data *data)
1957 {
1958 	if (data->flags != nfss->flags ||
1959 	    data->rsize != nfss->rsize ||
1960 	    data->wsize != nfss->wsize ||
1961 	    data->retrans != nfss->client->cl_timeout->to_retries ||
1962 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1963 	    data->acregmin != nfss->acregmin / HZ ||
1964 	    data->acregmax != nfss->acregmax / HZ ||
1965 	    data->acdirmin != nfss->acdirmin / HZ ||
1966 	    data->acdirmax != nfss->acdirmax / HZ ||
1967 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1968 	    data->nfs_server.port != nfss->port ||
1969 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1970 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
1971 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
1972 		return -EINVAL;
1973 
1974 	return 0;
1975 }
1976 
1977 static int
1978 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1979 {
1980 	int error;
1981 	struct nfs_server *nfss = sb->s_fs_info;
1982 	struct nfs_parsed_mount_data *data;
1983 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1984 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1985 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1986 
1987 	/*
1988 	 * Userspace mount programs that send binary options generally send
1989 	 * them populated with default values. We have no way to know which
1990 	 * ones were explicitly specified. Fall back to legacy behavior and
1991 	 * just return success.
1992 	 */
1993 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1994 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
1995 					   options->version <= 6))))
1996 		return 0;
1997 
1998 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1999 	if (data == NULL)
2000 		return -ENOMEM;
2001 
2002 	/* fill out struct with values from existing mount */
2003 	data->flags = nfss->flags;
2004 	data->rsize = nfss->rsize;
2005 	data->wsize = nfss->wsize;
2006 	data->retrans = nfss->client->cl_timeout->to_retries;
2007 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2008 	data->acregmin = nfss->acregmin / HZ;
2009 	data->acregmax = nfss->acregmax / HZ;
2010 	data->acdirmin = nfss->acdirmin / HZ;
2011 	data->acdirmax = nfss->acdirmax / HZ;
2012 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2013 	data->nfs_server.port = nfss->port;
2014 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2015 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2016 		data->nfs_server.addrlen);
2017 
2018 	/* overwrite those values with any that were specified */
2019 	error = nfs_parse_mount_options((char *)options, data);
2020 	if (error < 0)
2021 		goto out;
2022 
2023 	/*
2024 	 * noac is a special case. It implies -o sync, but that's not
2025 	 * necessarily reflected in the mtab options. do_remount_sb
2026 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2027 	 * remount options, so we have to explicitly reset it.
2028 	 */
2029 	if (data->flags & NFS_MOUNT_NOAC)
2030 		*flags |= MS_SYNCHRONOUS;
2031 
2032 	/* compare new mount options with old ones */
2033 	error = nfs_compare_remount_data(nfss, data);
2034 out:
2035 	kfree(data);
2036 	return error;
2037 }
2038 
2039 /*
2040  * Initialise the common bits of the superblock
2041  */
2042 static inline void nfs_initialise_sb(struct super_block *sb)
2043 {
2044 	struct nfs_server *server = NFS_SB(sb);
2045 
2046 	sb->s_magic = NFS_SUPER_MAGIC;
2047 
2048 	/* We probably want something more informative here */
2049 	snprintf(sb->s_id, sizeof(sb->s_id),
2050 		 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2051 
2052 	if (sb->s_blocksize == 0)
2053 		sb->s_blocksize = nfs_block_bits(server->wsize,
2054 						 &sb->s_blocksize_bits);
2055 
2056 	sb->s_bdi = &server->backing_dev_info;
2057 
2058 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2059 }
2060 
2061 /*
2062  * Finish setting up an NFS2/3 superblock
2063  */
2064 static void nfs_fill_super(struct super_block *sb,
2065 			   struct nfs_parsed_mount_data *data)
2066 {
2067 	struct nfs_server *server = NFS_SB(sb);
2068 
2069 	sb->s_blocksize_bits = 0;
2070 	sb->s_blocksize = 0;
2071 	if (data->bsize)
2072 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2073 
2074 	if (server->nfs_client->rpc_ops->version == 3) {
2075 		/* The VFS shouldn't apply the umask to mode bits. We will do
2076 		 * so ourselves when necessary.
2077 		 */
2078 		sb->s_flags |= MS_POSIXACL;
2079 		sb->s_time_gran = 1;
2080 	}
2081 
2082 	sb->s_op = &nfs_sops;
2083  	nfs_initialise_sb(sb);
2084 }
2085 
2086 /*
2087  * Finish setting up a cloned NFS2/3 superblock
2088  */
2089 static void nfs_clone_super(struct super_block *sb,
2090 			    const struct super_block *old_sb)
2091 {
2092 	struct nfs_server *server = NFS_SB(sb);
2093 
2094 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2095 	sb->s_blocksize = old_sb->s_blocksize;
2096 	sb->s_maxbytes = old_sb->s_maxbytes;
2097 
2098 	if (server->nfs_client->rpc_ops->version == 3) {
2099 		/* The VFS shouldn't apply the umask to mode bits. We will do
2100 		 * so ourselves when necessary.
2101 		 */
2102 		sb->s_flags |= MS_POSIXACL;
2103 		sb->s_time_gran = 1;
2104 	}
2105 
2106 	sb->s_op = old_sb->s_op;
2107  	nfs_initialise_sb(sb);
2108 }
2109 
2110 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2111 {
2112 	const struct nfs_server *a = s->s_fs_info;
2113 	const struct rpc_clnt *clnt_a = a->client;
2114 	const struct rpc_clnt *clnt_b = b->client;
2115 
2116 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2117 		goto Ebusy;
2118 	if (a->nfs_client != b->nfs_client)
2119 		goto Ebusy;
2120 	if (a->flags != b->flags)
2121 		goto Ebusy;
2122 	if (a->wsize != b->wsize)
2123 		goto Ebusy;
2124 	if (a->rsize != b->rsize)
2125 		goto Ebusy;
2126 	if (a->acregmin != b->acregmin)
2127 		goto Ebusy;
2128 	if (a->acregmax != b->acregmax)
2129 		goto Ebusy;
2130 	if (a->acdirmin != b->acdirmin)
2131 		goto Ebusy;
2132 	if (a->acdirmax != b->acdirmax)
2133 		goto Ebusy;
2134 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2135 		goto Ebusy;
2136 	return 1;
2137 Ebusy:
2138 	return 0;
2139 }
2140 
2141 struct nfs_sb_mountdata {
2142 	struct nfs_server *server;
2143 	int mntflags;
2144 };
2145 
2146 static int nfs_set_super(struct super_block *s, void *data)
2147 {
2148 	struct nfs_sb_mountdata *sb_mntdata = data;
2149 	struct nfs_server *server = sb_mntdata->server;
2150 	int ret;
2151 
2152 	s->s_flags = sb_mntdata->mntflags;
2153 	s->s_fs_info = server;
2154 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2155 	ret = set_anon_super(s, server);
2156 	if (ret == 0)
2157 		server->s_dev = s->s_dev;
2158 	return ret;
2159 }
2160 
2161 static int nfs_compare_super_address(struct nfs_server *server1,
2162 				     struct nfs_server *server2)
2163 {
2164 	struct sockaddr *sap1, *sap2;
2165 
2166 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2167 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2168 
2169 	if (sap1->sa_family != sap2->sa_family)
2170 		return 0;
2171 
2172 	switch (sap1->sa_family) {
2173 	case AF_INET: {
2174 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2175 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2176 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2177 			return 0;
2178 		if (sin1->sin_port != sin2->sin_port)
2179 			return 0;
2180 		break;
2181 	}
2182 	case AF_INET6: {
2183 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2184 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2185 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2186 			return 0;
2187 		if (sin1->sin6_port != sin2->sin6_port)
2188 			return 0;
2189 		break;
2190 	}
2191 	default:
2192 		return 0;
2193 	}
2194 
2195 	return 1;
2196 }
2197 
2198 static int nfs_compare_super(struct super_block *sb, void *data)
2199 {
2200 	struct nfs_sb_mountdata *sb_mntdata = data;
2201 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2202 	int mntflags = sb_mntdata->mntflags;
2203 
2204 	if (!nfs_compare_super_address(old, server))
2205 		return 0;
2206 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2207 	if (old->flags & NFS_MOUNT_UNSHARED)
2208 		return 0;
2209 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2210 		return 0;
2211 	return nfs_compare_mount_options(sb, server, mntflags);
2212 }
2213 
2214 static int nfs_bdi_register(struct nfs_server *server)
2215 {
2216 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2217 }
2218 
2219 static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2220 	int flags, const char *dev_name, void *raw_data)
2221 {
2222 	struct nfs_server *server = NULL;
2223 	struct super_block *s;
2224 	struct nfs_parsed_mount_data *data;
2225 	struct nfs_fh *mntfh;
2226 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2227 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2228 	struct nfs_sb_mountdata sb_mntdata = {
2229 		.mntflags = flags,
2230 	};
2231 	int error;
2232 
2233 	data = nfs_alloc_parsed_mount_data(NFS_DEFAULT_VERSION);
2234 	mntfh = nfs_alloc_fhandle();
2235 	if (data == NULL || mntfh == NULL)
2236 		goto out;
2237 
2238 	/* Validate the mount data */
2239 	error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2240 	if (error < 0) {
2241 		mntroot = ERR_PTR(error);
2242 		goto out;
2243 	}
2244 
2245 #ifdef CONFIG_NFS_V4
2246 	if (data->version == 4) {
2247 		mntroot = nfs4_try_mount(flags, dev_name, data);
2248 		goto out;
2249 	}
2250 #endif	/* CONFIG_NFS_V4 */
2251 
2252 	/* Get a volume representation */
2253 	server = nfs_create_server(data, mntfh);
2254 	if (IS_ERR(server)) {
2255 		mntroot = ERR_CAST(server);
2256 		goto out;
2257 	}
2258 	sb_mntdata.server = server;
2259 
2260 	if (server->flags & NFS_MOUNT_UNSHARED)
2261 		compare_super = NULL;
2262 
2263 	/* -o noac implies -o sync */
2264 	if (server->flags & NFS_MOUNT_NOAC)
2265 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2266 
2267 	/* Get a superblock - note that we may end up sharing one that already exists */
2268 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2269 	if (IS_ERR(s)) {
2270 		mntroot = ERR_CAST(s);
2271 		goto out_err_nosb;
2272 	}
2273 
2274 	if (s->s_fs_info != server) {
2275 		nfs_free_server(server);
2276 		server = NULL;
2277 	} else {
2278 		error = nfs_bdi_register(server);
2279 		if (error) {
2280 			mntroot = ERR_PTR(error);
2281 			goto error_splat_bdi;
2282 		}
2283 	}
2284 
2285 	if (!s->s_root) {
2286 		/* initial superblock/root creation */
2287 		nfs_fill_super(s, data);
2288 		nfs_fscache_get_super_cookie(s, data->fscache_uniq, NULL);
2289 	}
2290 
2291 	mntroot = nfs_get_root(s, mntfh, dev_name);
2292 	if (IS_ERR(mntroot))
2293 		goto error_splat_super;
2294 
2295 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2296 	if (error)
2297 		goto error_splat_root;
2298 
2299 	s->s_flags |= MS_ACTIVE;
2300 
2301 out:
2302 	nfs_free_parsed_mount_data(data);
2303 	nfs_free_fhandle(mntfh);
2304 	return mntroot;
2305 
2306 out_err_nosb:
2307 	nfs_free_server(server);
2308 	goto out;
2309 
2310 error_splat_root:
2311 	dput(mntroot);
2312 	mntroot = ERR_PTR(error);
2313 error_splat_super:
2314 	if (server && !s->s_root)
2315 		bdi_unregister(&server->backing_dev_info);
2316 error_splat_bdi:
2317 	deactivate_locked_super(s);
2318 	goto out;
2319 }
2320 
2321 /*
2322  * Ensure that we unregister the bdi before kill_anon_super
2323  * releases the device name
2324  */
2325 static void nfs_put_super(struct super_block *s)
2326 {
2327 	struct nfs_server *server = NFS_SB(s);
2328 
2329 	bdi_unregister(&server->backing_dev_info);
2330 }
2331 
2332 /*
2333  * Destroy an NFS2/3 superblock
2334  */
2335 static void nfs_kill_super(struct super_block *s)
2336 {
2337 	struct nfs_server *server = NFS_SB(s);
2338 
2339 	kill_anon_super(s);
2340 	nfs_fscache_release_super_cookie(s);
2341 	nfs_free_server(server);
2342 }
2343 
2344 /*
2345  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2346  */
2347 static struct dentry *
2348 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2349 		const char *dev_name, void *raw_data)
2350 {
2351 	struct nfs_clone_mount *data = raw_data;
2352 	struct super_block *s;
2353 	struct nfs_server *server;
2354 	struct dentry *mntroot;
2355 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2356 	struct nfs_sb_mountdata sb_mntdata = {
2357 		.mntflags = flags,
2358 	};
2359 	int error;
2360 
2361 	dprintk("--> nfs_xdev_mount()\n");
2362 
2363 	/* create a new volume representation */
2364 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2365 	if (IS_ERR(server)) {
2366 		error = PTR_ERR(server);
2367 		goto out_err_noserver;
2368 	}
2369 	sb_mntdata.server = server;
2370 
2371 	if (server->flags & NFS_MOUNT_UNSHARED)
2372 		compare_super = NULL;
2373 
2374 	/* -o noac implies -o sync */
2375 	if (server->flags & NFS_MOUNT_NOAC)
2376 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2377 
2378 	/* Get a superblock - note that we may end up sharing one that already exists */
2379 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2380 	if (IS_ERR(s)) {
2381 		error = PTR_ERR(s);
2382 		goto out_err_nosb;
2383 	}
2384 
2385 	if (s->s_fs_info != server) {
2386 		nfs_free_server(server);
2387 		server = NULL;
2388 	} else {
2389 		error = nfs_bdi_register(server);
2390 		if (error)
2391 			goto error_splat_bdi;
2392 	}
2393 
2394 	if (!s->s_root) {
2395 		/* initial superblock/root creation */
2396 		nfs_clone_super(s, data->sb);
2397 		nfs_fscache_get_super_cookie(s, NULL, data);
2398 	}
2399 
2400 	mntroot = nfs_get_root(s, data->fh, dev_name);
2401 	if (IS_ERR(mntroot)) {
2402 		error = PTR_ERR(mntroot);
2403 		goto error_splat_super;
2404 	}
2405 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2406 		dput(mntroot);
2407 		error = -ESTALE;
2408 		goto error_splat_super;
2409 	}
2410 
2411 	s->s_flags |= MS_ACTIVE;
2412 
2413 	/* clone any lsm security options from the parent to the new sb */
2414 	security_sb_clone_mnt_opts(data->sb, s);
2415 
2416 	dprintk("<-- nfs_xdev_mount() = 0\n");
2417 	return mntroot;
2418 
2419 out_err_nosb:
2420 	nfs_free_server(server);
2421 out_err_noserver:
2422 	dprintk("<-- nfs_xdev_mount() = %d [error]\n", error);
2423 	return ERR_PTR(error);
2424 
2425 error_splat_super:
2426 	if (server && !s->s_root)
2427 		bdi_unregister(&server->backing_dev_info);
2428 error_splat_bdi:
2429 	deactivate_locked_super(s);
2430 	dprintk("<-- nfs_xdev_mount() = %d [splat]\n", error);
2431 	return ERR_PTR(error);
2432 }
2433 
2434 #ifdef CONFIG_NFS_V4
2435 
2436 /*
2437  * Finish setting up a cloned NFS4 superblock
2438  */
2439 static void nfs4_clone_super(struct super_block *sb,
2440 			    const struct super_block *old_sb)
2441 {
2442 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2443 	sb->s_blocksize = old_sb->s_blocksize;
2444 	sb->s_maxbytes = old_sb->s_maxbytes;
2445 	sb->s_time_gran = 1;
2446 	sb->s_op = old_sb->s_op;
2447 	/*
2448 	 * The VFS shouldn't apply the umask to mode bits. We will do
2449 	 * so ourselves when necessary.
2450 	 */
2451 	sb->s_flags  |= MS_POSIXACL;
2452 	sb->s_xattr  = old_sb->s_xattr;
2453 	nfs_initialise_sb(sb);
2454 }
2455 
2456 /*
2457  * Set up an NFS4 superblock
2458  */
2459 static void nfs4_fill_super(struct super_block *sb)
2460 {
2461 	sb->s_time_gran = 1;
2462 	sb->s_op = &nfs4_sops;
2463 	/*
2464 	 * The VFS shouldn't apply the umask to mode bits. We will do
2465 	 * so ourselves when necessary.
2466 	 */
2467 	sb->s_flags  |= MS_POSIXACL;
2468 	sb->s_xattr = nfs4_xattr_handlers;
2469 	nfs_initialise_sb(sb);
2470 }
2471 
2472 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2473 {
2474 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2475 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2476 }
2477 
2478 static int nfs4_validate_text_mount_data(void *options,
2479 					 struct nfs_parsed_mount_data *args,
2480 					 const char *dev_name)
2481 {
2482 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2483 
2484 	nfs_set_port(sap, &args->nfs_server.port, NFS_PORT);
2485 
2486 	nfs_validate_transport_protocol(args);
2487 
2488 	nfs4_validate_mount_flags(args);
2489 
2490 	if (args->version != 4) {
2491 		dfprintk(MOUNT,
2492 			 "NFS4: Illegal mount version\n");
2493 		return -EINVAL;
2494 	}
2495 
2496 	if (args->auth_flavor_len > 1) {
2497 		dfprintk(MOUNT,
2498 			 "NFS4: Too many RPC auth flavours specified\n");
2499 		return -EINVAL;
2500 	}
2501 
2502 	if (args->client_address == NULL) {
2503 		dfprintk(MOUNT,
2504 			 "NFS4: mount program didn't pass callback address\n");
2505 		return -EINVAL;
2506 	}
2507 
2508 	return nfs_parse_devname(dev_name,
2509 				   &args->nfs_server.hostname,
2510 				   NFS4_MAXNAMLEN,
2511 				   &args->nfs_server.export_path,
2512 				   NFS4_MAXPATHLEN);
2513 }
2514 
2515 /*
2516  * Validate NFSv4 mount options
2517  */
2518 static int nfs4_validate_mount_data(void *options,
2519 				    struct nfs_parsed_mount_data *args,
2520 				    const char *dev_name)
2521 {
2522 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2523 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2524 	char *c;
2525 
2526 	if (data == NULL)
2527 		goto out_no_data;
2528 
2529 	switch (data->version) {
2530 	case 1:
2531 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2532 			goto out_no_address;
2533 		if (data->host_addrlen == 0)
2534 			goto out_no_address;
2535 		args->nfs_server.addrlen = data->host_addrlen;
2536 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2537 			return -EFAULT;
2538 		if (!nfs_verify_server_address(sap))
2539 			goto out_no_address;
2540 
2541 		if (data->auth_flavourlen) {
2542 			if (data->auth_flavourlen > 1)
2543 				goto out_inval_auth;
2544 			if (copy_from_user(&args->auth_flavors[0],
2545 					   data->auth_flavours,
2546 					   sizeof(args->auth_flavors[0])))
2547 				return -EFAULT;
2548 		}
2549 
2550 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2551 		if (IS_ERR(c))
2552 			return PTR_ERR(c);
2553 		args->nfs_server.hostname = c;
2554 
2555 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2556 		if (IS_ERR(c))
2557 			return PTR_ERR(c);
2558 		args->nfs_server.export_path = c;
2559 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2560 
2561 		c = strndup_user(data->client_addr.data, 16);
2562 		if (IS_ERR(c))
2563 			return PTR_ERR(c);
2564 		args->client_address = c;
2565 
2566 		/*
2567 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2568 		 * can deal with.
2569 		 */
2570 
2571 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2572 		args->rsize	= data->rsize;
2573 		args->wsize	= data->wsize;
2574 		args->timeo	= data->timeo;
2575 		args->retrans	= data->retrans;
2576 		args->acregmin	= data->acregmin;
2577 		args->acregmax	= data->acregmax;
2578 		args->acdirmin	= data->acdirmin;
2579 		args->acdirmax	= data->acdirmax;
2580 		args->nfs_server.protocol = data->proto;
2581 		nfs_validate_transport_protocol(args);
2582 
2583 		break;
2584 	default:
2585 		if (nfs_parse_mount_options((char *)options, args) == 0)
2586 			return -EINVAL;
2587 
2588 		if (!nfs_verify_server_address(sap))
2589 			return -EINVAL;
2590 
2591 		return nfs4_validate_text_mount_data(options, args, dev_name);
2592 	}
2593 
2594 	return 0;
2595 
2596 out_no_data:
2597 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2598 	return -EINVAL;
2599 
2600 out_inval_auth:
2601 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2602 		 data->auth_flavourlen);
2603 	return -EINVAL;
2604 
2605 out_no_address:
2606 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2607 	return -EINVAL;
2608 }
2609 
2610 /*
2611  * Get the superblock for the NFS4 root partition
2612  */
2613 static struct dentry *
2614 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
2615 		  const char *dev_name, void *raw_data)
2616 {
2617 	struct nfs_parsed_mount_data *data = raw_data;
2618 	struct super_block *s;
2619 	struct nfs_server *server;
2620 	struct nfs_fh *mntfh;
2621 	struct dentry *mntroot;
2622 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2623 	struct nfs_sb_mountdata sb_mntdata = {
2624 		.mntflags = flags,
2625 	};
2626 	int error = -ENOMEM;
2627 
2628 	mntfh = nfs_alloc_fhandle();
2629 	if (data == NULL || mntfh == NULL)
2630 		goto out;
2631 
2632 	/* Get a volume representation */
2633 	server = nfs4_create_server(data, mntfh);
2634 	if (IS_ERR(server)) {
2635 		error = PTR_ERR(server);
2636 		goto out;
2637 	}
2638 	sb_mntdata.server = server;
2639 
2640 	if (server->flags & NFS4_MOUNT_UNSHARED)
2641 		compare_super = NULL;
2642 
2643 	/* -o noac implies -o sync */
2644 	if (server->flags & NFS_MOUNT_NOAC)
2645 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2646 
2647 	/* Get a superblock - note that we may end up sharing one that already exists */
2648 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2649 	if (IS_ERR(s)) {
2650 		error = PTR_ERR(s);
2651 		goto out_free;
2652 	}
2653 
2654 	if (s->s_fs_info != server) {
2655 		nfs_free_server(server);
2656 		server = NULL;
2657 	} else {
2658 		error = nfs_bdi_register(server);
2659 		if (error)
2660 			goto error_splat_bdi;
2661 	}
2662 
2663 	if (!s->s_root) {
2664 		/* initial superblock/root creation */
2665 		nfs4_fill_super(s);
2666 		nfs_fscache_get_super_cookie(
2667 			s, data ? data->fscache_uniq : NULL, NULL);
2668 	}
2669 
2670 	mntroot = nfs4_get_root(s, mntfh, dev_name);
2671 	if (IS_ERR(mntroot)) {
2672 		error = PTR_ERR(mntroot);
2673 		goto error_splat_super;
2674 	}
2675 
2676 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2677 	if (error)
2678 		goto error_splat_root;
2679 
2680 	s->s_flags |= MS_ACTIVE;
2681 
2682 	nfs_free_fhandle(mntfh);
2683 	return mntroot;
2684 
2685 out:
2686 	nfs_free_fhandle(mntfh);
2687 	return ERR_PTR(error);
2688 
2689 out_free:
2690 	nfs_free_server(server);
2691 	goto out;
2692 
2693 error_splat_root:
2694 	dput(mntroot);
2695 error_splat_super:
2696 	if (server && !s->s_root)
2697 		bdi_unregister(&server->backing_dev_info);
2698 error_splat_bdi:
2699 	deactivate_locked_super(s);
2700 	goto out;
2701 }
2702 
2703 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2704 		int flags, void *data, const char *hostname)
2705 {
2706 	struct vfsmount *root_mnt;
2707 	char *root_devname;
2708 	size_t len;
2709 
2710 	len = strlen(hostname) + 3;
2711 	root_devname = kmalloc(len, GFP_KERNEL);
2712 	if (root_devname == NULL)
2713 		return ERR_PTR(-ENOMEM);
2714 	snprintf(root_devname, len, "%s:/", hostname);
2715 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2716 	kfree(root_devname);
2717 	return root_mnt;
2718 }
2719 
2720 struct nfs_referral_count {
2721 	struct list_head list;
2722 	const struct task_struct *task;
2723 	unsigned int referral_count;
2724 };
2725 
2726 static LIST_HEAD(nfs_referral_count_list);
2727 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2728 
2729 static struct nfs_referral_count *nfs_find_referral_count(void)
2730 {
2731 	struct nfs_referral_count *p;
2732 
2733 	list_for_each_entry(p, &nfs_referral_count_list, list) {
2734 		if (p->task == current)
2735 			return p;
2736 	}
2737 	return NULL;
2738 }
2739 
2740 #define NFS_MAX_NESTED_REFERRALS 2
2741 
2742 static int nfs_referral_loop_protect(void)
2743 {
2744 	struct nfs_referral_count *p, *new;
2745 	int ret = -ENOMEM;
2746 
2747 	new = kmalloc(sizeof(*new), GFP_KERNEL);
2748 	if (!new)
2749 		goto out;
2750 	new->task = current;
2751 	new->referral_count = 1;
2752 
2753 	ret = 0;
2754 	spin_lock(&nfs_referral_count_list_lock);
2755 	p = nfs_find_referral_count();
2756 	if (p != NULL) {
2757 		if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2758 			ret = -ELOOP;
2759 		else
2760 			p->referral_count++;
2761 	} else {
2762 		list_add(&new->list, &nfs_referral_count_list);
2763 		new = NULL;
2764 	}
2765 	spin_unlock(&nfs_referral_count_list_lock);
2766 	kfree(new);
2767 out:
2768 	return ret;
2769 }
2770 
2771 static void nfs_referral_loop_unprotect(void)
2772 {
2773 	struct nfs_referral_count *p;
2774 
2775 	spin_lock(&nfs_referral_count_list_lock);
2776 	p = nfs_find_referral_count();
2777 	p->referral_count--;
2778 	if (p->referral_count == 0)
2779 		list_del(&p->list);
2780 	else
2781 		p = NULL;
2782 	spin_unlock(&nfs_referral_count_list_lock);
2783 	kfree(p);
2784 }
2785 
2786 static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
2787 		const char *export_path)
2788 {
2789 	struct dentry *dentry;
2790 	int err;
2791 
2792 	if (IS_ERR(root_mnt))
2793 		return ERR_CAST(root_mnt);
2794 
2795 	err = nfs_referral_loop_protect();
2796 	if (err) {
2797 		mntput(root_mnt);
2798 		return ERR_PTR(err);
2799 	}
2800 
2801 	dentry = mount_subtree(root_mnt, export_path);
2802 	nfs_referral_loop_unprotect();
2803 
2804 	return dentry;
2805 }
2806 
2807 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
2808 			 struct nfs_parsed_mount_data *data)
2809 {
2810 	char *export_path;
2811 	struct vfsmount *root_mnt;
2812 	struct dentry *res;
2813 
2814 	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2815 
2816 	export_path = data->nfs_server.export_path;
2817 	data->nfs_server.export_path = "/";
2818 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2819 			data->nfs_server.hostname);
2820 	data->nfs_server.export_path = export_path;
2821 
2822 	res = nfs_follow_remote_path(root_mnt, export_path);
2823 
2824 	dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
2825 			IS_ERR(res) ? PTR_ERR(res) : 0,
2826 			IS_ERR(res) ? " [error]" : "");
2827 	return res;
2828 }
2829 
2830 /*
2831  * Get the superblock for an NFS4 mountpoint
2832  */
2833 static struct dentry *nfs4_mount(struct file_system_type *fs_type,
2834 	int flags, const char *dev_name, void *raw_data)
2835 {
2836 	struct nfs_parsed_mount_data *data;
2837 	int error = -ENOMEM;
2838 	struct dentry *res = ERR_PTR(-ENOMEM);
2839 
2840 	data = nfs_alloc_parsed_mount_data(4);
2841 	if (data == NULL)
2842 		goto out;
2843 
2844 	/* Validate the mount data */
2845 	error = nfs4_validate_mount_data(raw_data, data, dev_name);
2846 	if (error < 0) {
2847 		res = ERR_PTR(error);
2848 		goto out;
2849 	}
2850 
2851 	res = nfs4_try_mount(flags, dev_name, data);
2852 	if (IS_ERR(res))
2853 		error = PTR_ERR(res);
2854 
2855 out:
2856 	nfs_free_parsed_mount_data(data);
2857 	dprintk("<-- nfs4_mount() = %d%s\n", error,
2858 			error != 0 ? " [error]" : "");
2859 	return res;
2860 }
2861 
2862 static void nfs4_kill_super(struct super_block *sb)
2863 {
2864 	struct nfs_server *server = NFS_SB(sb);
2865 
2866 	dprintk("--> %s\n", __func__);
2867 	nfs_super_return_all_delegations(sb);
2868 	kill_anon_super(sb);
2869 	nfs_fscache_release_super_cookie(sb);
2870 	nfs_free_server(server);
2871 	dprintk("<-- %s\n", __func__);
2872 }
2873 
2874 /*
2875  * Clone an NFS4 server record on xdev traversal (FSID-change)
2876  */
2877 static struct dentry *
2878 nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
2879 		 const char *dev_name, void *raw_data)
2880 {
2881 	struct nfs_clone_mount *data = raw_data;
2882 	struct super_block *s;
2883 	struct nfs_server *server;
2884 	struct dentry *mntroot;
2885 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2886 	struct nfs_sb_mountdata sb_mntdata = {
2887 		.mntflags = flags,
2888 	};
2889 	int error;
2890 
2891 	dprintk("--> nfs4_xdev_mount()\n");
2892 
2893 	/* create a new volume representation */
2894 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2895 	if (IS_ERR(server)) {
2896 		error = PTR_ERR(server);
2897 		goto out_err_noserver;
2898 	}
2899 	sb_mntdata.server = server;
2900 
2901 	if (server->flags & NFS4_MOUNT_UNSHARED)
2902 		compare_super = NULL;
2903 
2904 	/* -o noac implies -o sync */
2905 	if (server->flags & NFS_MOUNT_NOAC)
2906 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2907 
2908 	/* Get a superblock - note that we may end up sharing one that already exists */
2909 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2910 	if (IS_ERR(s)) {
2911 		error = PTR_ERR(s);
2912 		goto out_err_nosb;
2913 	}
2914 
2915 	if (s->s_fs_info != server) {
2916 		nfs_free_server(server);
2917 		server = NULL;
2918 	} else {
2919 		error = nfs_bdi_register(server);
2920 		if (error)
2921 			goto error_splat_bdi;
2922 	}
2923 
2924 	if (!s->s_root) {
2925 		/* initial superblock/root creation */
2926 		nfs4_clone_super(s, data->sb);
2927 		nfs_fscache_get_super_cookie(s, NULL, data);
2928 	}
2929 
2930 	mntroot = nfs4_get_root(s, data->fh, dev_name);
2931 	if (IS_ERR(mntroot)) {
2932 		error = PTR_ERR(mntroot);
2933 		goto error_splat_super;
2934 	}
2935 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2936 		dput(mntroot);
2937 		error = -ESTALE;
2938 		goto error_splat_super;
2939 	}
2940 
2941 	s->s_flags |= MS_ACTIVE;
2942 
2943 	security_sb_clone_mnt_opts(data->sb, s);
2944 
2945 	dprintk("<-- nfs4_xdev_mount() = 0\n");
2946 	return mntroot;
2947 
2948 out_err_nosb:
2949 	nfs_free_server(server);
2950 out_err_noserver:
2951 	dprintk("<-- nfs4_xdev_mount() = %d [error]\n", error);
2952 	return ERR_PTR(error);
2953 
2954 error_splat_super:
2955 	if (server && !s->s_root)
2956 		bdi_unregister(&server->backing_dev_info);
2957 error_splat_bdi:
2958 	deactivate_locked_super(s);
2959 	dprintk("<-- nfs4_xdev_mount() = %d [splat]\n", error);
2960 	return ERR_PTR(error);
2961 }
2962 
2963 static struct dentry *
2964 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
2965 			   const char *dev_name, void *raw_data)
2966 {
2967 	struct nfs_clone_mount *data = raw_data;
2968 	struct super_block *s;
2969 	struct nfs_server *server;
2970 	struct dentry *mntroot;
2971 	struct nfs_fh *mntfh;
2972 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2973 	struct nfs_sb_mountdata sb_mntdata = {
2974 		.mntflags = flags,
2975 	};
2976 	int error = -ENOMEM;
2977 
2978 	dprintk("--> nfs4_referral_get_sb()\n");
2979 
2980 	mntfh = nfs_alloc_fhandle();
2981 	if (mntfh == NULL)
2982 		goto out_err_nofh;
2983 
2984 	/* create a new volume representation */
2985 	server = nfs4_create_referral_server(data, mntfh);
2986 	if (IS_ERR(server)) {
2987 		error = PTR_ERR(server);
2988 		goto out_err_noserver;
2989 	}
2990 	sb_mntdata.server = server;
2991 
2992 	if (server->flags & NFS4_MOUNT_UNSHARED)
2993 		compare_super = NULL;
2994 
2995 	/* -o noac implies -o sync */
2996 	if (server->flags & NFS_MOUNT_NOAC)
2997 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2998 
2999 	/* Get a superblock - note that we may end up sharing one that already exists */
3000 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
3001 	if (IS_ERR(s)) {
3002 		error = PTR_ERR(s);
3003 		goto out_err_nosb;
3004 	}
3005 
3006 	if (s->s_fs_info != server) {
3007 		nfs_free_server(server);
3008 		server = NULL;
3009 	} else {
3010 		error = nfs_bdi_register(server);
3011 		if (error)
3012 			goto error_splat_bdi;
3013 	}
3014 
3015 	if (!s->s_root) {
3016 		/* initial superblock/root creation */
3017 		nfs4_fill_super(s);
3018 		nfs_fscache_get_super_cookie(s, NULL, data);
3019 	}
3020 
3021 	mntroot = nfs4_get_root(s, mntfh, dev_name);
3022 	if (IS_ERR(mntroot)) {
3023 		error = PTR_ERR(mntroot);
3024 		goto error_splat_super;
3025 	}
3026 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
3027 		dput(mntroot);
3028 		error = -ESTALE;
3029 		goto error_splat_super;
3030 	}
3031 
3032 	s->s_flags |= MS_ACTIVE;
3033 
3034 	security_sb_clone_mnt_opts(data->sb, s);
3035 
3036 	nfs_free_fhandle(mntfh);
3037 	dprintk("<-- nfs4_referral_get_sb() = 0\n");
3038 	return mntroot;
3039 
3040 out_err_nosb:
3041 	nfs_free_server(server);
3042 out_err_noserver:
3043 	nfs_free_fhandle(mntfh);
3044 out_err_nofh:
3045 	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
3046 	return ERR_PTR(error);
3047 
3048 error_splat_super:
3049 	if (server && !s->s_root)
3050 		bdi_unregister(&server->backing_dev_info);
3051 error_splat_bdi:
3052 	deactivate_locked_super(s);
3053 	nfs_free_fhandle(mntfh);
3054 	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
3055 	return ERR_PTR(error);
3056 }
3057 
3058 /*
3059  * Create an NFS4 server record on referral traversal
3060  */
3061 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
3062 		int flags, const char *dev_name, void *raw_data)
3063 {
3064 	struct nfs_clone_mount *data = raw_data;
3065 	char *export_path;
3066 	struct vfsmount *root_mnt;
3067 	struct dentry *res;
3068 
3069 	dprintk("--> nfs4_referral_mount()\n");
3070 
3071 	export_path = data->mnt_path;
3072 	data->mnt_path = "/";
3073 
3074 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
3075 			flags, data, data->hostname);
3076 	data->mnt_path = export_path;
3077 
3078 	res = nfs_follow_remote_path(root_mnt, export_path);
3079 	dprintk("<-- nfs4_referral_mount() = %ld%s\n",
3080 			IS_ERR(res) ? PTR_ERR(res) : 0,
3081 			IS_ERR(res) ? " [error]" : "");
3082 	return res;
3083 }
3084 
3085 #endif /* CONFIG_NFS_V4 */
3086