xref: /openbmc/linux/fs/nfs/super.c (revision e8e0929d)
1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/stats.h>
35 #include <linux/sunrpc/metrics.h>
36 #include <linux/sunrpc/xprtsock.h>
37 #include <linux/sunrpc/xprtrdma.h>
38 #include <linux/nfs_fs.h>
39 #include <linux/nfs_mount.h>
40 #include <linux/nfs4_mount.h>
41 #include <linux/lockd/bind.h>
42 #include <linux/smp_lock.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/mnt_namespace.h>
46 #include <linux/namei.h>
47 #include <linux/nfs_idmap.h>
48 #include <linux/vfs.h>
49 #include <linux/inet.h>
50 #include <linux/in6.h>
51 #include <net/ipv6.h>
52 #include <linux/netdevice.h>
53 #include <linux/nfs_xdr.h>
54 #include <linux/magic.h>
55 #include <linux/parser.h>
56 
57 #include <asm/system.h>
58 #include <asm/uaccess.h>
59 
60 #include "nfs4_fs.h"
61 #include "callback.h"
62 #include "delegation.h"
63 #include "iostat.h"
64 #include "internal.h"
65 #include "fscache.h"
66 
67 #define NFSDBG_FACILITY		NFSDBG_VFS
68 
69 enum {
70 	/* Mount options that take no arguments */
71 	Opt_soft, Opt_hard,
72 	Opt_posix, Opt_noposix,
73 	Opt_cto, Opt_nocto,
74 	Opt_ac, Opt_noac,
75 	Opt_lock, Opt_nolock,
76 	Opt_v2, Opt_v3, Opt_v4,
77 	Opt_udp, Opt_tcp, Opt_rdma,
78 	Opt_acl, Opt_noacl,
79 	Opt_rdirplus, Opt_nordirplus,
80 	Opt_sharecache, Opt_nosharecache,
81 	Opt_resvport, Opt_noresvport,
82 	Opt_fscache, Opt_nofscache,
83 
84 	/* Mount options that take integer arguments */
85 	Opt_port,
86 	Opt_rsize, Opt_wsize, Opt_bsize,
87 	Opt_timeo, Opt_retrans,
88 	Opt_acregmin, Opt_acregmax,
89 	Opt_acdirmin, Opt_acdirmax,
90 	Opt_actimeo,
91 	Opt_namelen,
92 	Opt_mountport,
93 	Opt_mountvers,
94 	Opt_nfsvers,
95 	Opt_minorversion,
96 
97 	/* Mount options that take string arguments */
98 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
99 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
100 	Opt_lookupcache,
101 	Opt_fscache_uniq,
102 
103 	/* Special mount options */
104 	Opt_userspace, Opt_deprecated, Opt_sloppy,
105 
106 	Opt_err
107 };
108 
109 static const match_table_t nfs_mount_option_tokens = {
110 	{ Opt_userspace, "bg" },
111 	{ Opt_userspace, "fg" },
112 	{ Opt_userspace, "retry=%s" },
113 
114 	{ Opt_sloppy, "sloppy" },
115 
116 	{ Opt_soft, "soft" },
117 	{ Opt_hard, "hard" },
118 	{ Opt_deprecated, "intr" },
119 	{ Opt_deprecated, "nointr" },
120 	{ Opt_posix, "posix" },
121 	{ Opt_noposix, "noposix" },
122 	{ Opt_cto, "cto" },
123 	{ Opt_nocto, "nocto" },
124 	{ Opt_ac, "ac" },
125 	{ Opt_noac, "noac" },
126 	{ Opt_lock, "lock" },
127 	{ Opt_nolock, "nolock" },
128 	{ Opt_v2, "v2" },
129 	{ Opt_v3, "v3" },
130 	{ Opt_v4, "v4" },
131 	{ Opt_udp, "udp" },
132 	{ Opt_tcp, "tcp" },
133 	{ Opt_rdma, "rdma" },
134 	{ Opt_acl, "acl" },
135 	{ Opt_noacl, "noacl" },
136 	{ Opt_rdirplus, "rdirplus" },
137 	{ Opt_nordirplus, "nordirplus" },
138 	{ Opt_sharecache, "sharecache" },
139 	{ Opt_nosharecache, "nosharecache" },
140 	{ Opt_resvport, "resvport" },
141 	{ Opt_noresvport, "noresvport" },
142 	{ Opt_fscache, "fsc" },
143 	{ Opt_fscache_uniq, "fsc=%s" },
144 	{ Opt_nofscache, "nofsc" },
145 
146 	{ Opt_port, "port=%s" },
147 	{ Opt_rsize, "rsize=%s" },
148 	{ Opt_wsize, "wsize=%s" },
149 	{ Opt_bsize, "bsize=%s" },
150 	{ Opt_timeo, "timeo=%s" },
151 	{ Opt_retrans, "retrans=%s" },
152 	{ Opt_acregmin, "acregmin=%s" },
153 	{ Opt_acregmax, "acregmax=%s" },
154 	{ Opt_acdirmin, "acdirmin=%s" },
155 	{ Opt_acdirmax, "acdirmax=%s" },
156 	{ Opt_actimeo, "actimeo=%s" },
157 	{ Opt_namelen, "namlen=%s" },
158 	{ Opt_mountport, "mountport=%s" },
159 	{ Opt_mountvers, "mountvers=%s" },
160 	{ Opt_nfsvers, "nfsvers=%s" },
161 	{ Opt_nfsvers, "vers=%s" },
162 	{ Opt_minorversion, "minorversion=%s" },
163 
164 	{ Opt_sec, "sec=%s" },
165 	{ Opt_proto, "proto=%s" },
166 	{ Opt_mountproto, "mountproto=%s" },
167 	{ Opt_addr, "addr=%s" },
168 	{ Opt_clientaddr, "clientaddr=%s" },
169 	{ Opt_mounthost, "mounthost=%s" },
170 	{ Opt_mountaddr, "mountaddr=%s" },
171 
172 	{ Opt_lookupcache, "lookupcache=%s" },
173 
174 	{ Opt_err, NULL }
175 };
176 
177 enum {
178 	Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
179 
180 	Opt_xprt_err
181 };
182 
183 static const match_table_t nfs_xprt_protocol_tokens = {
184 	{ Opt_xprt_udp, "udp" },
185 	{ Opt_xprt_tcp, "tcp" },
186 	{ Opt_xprt_rdma, "rdma" },
187 
188 	{ Opt_xprt_err, NULL }
189 };
190 
191 enum {
192 	Opt_sec_none, Opt_sec_sys,
193 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
194 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
195 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
196 
197 	Opt_sec_err
198 };
199 
200 static const match_table_t nfs_secflavor_tokens = {
201 	{ Opt_sec_none, "none" },
202 	{ Opt_sec_none, "null" },
203 	{ Opt_sec_sys, "sys" },
204 
205 	{ Opt_sec_krb5, "krb5" },
206 	{ Opt_sec_krb5i, "krb5i" },
207 	{ Opt_sec_krb5p, "krb5p" },
208 
209 	{ Opt_sec_lkey, "lkey" },
210 	{ Opt_sec_lkeyi, "lkeyi" },
211 	{ Opt_sec_lkeyp, "lkeyp" },
212 
213 	{ Opt_sec_spkm, "spkm3" },
214 	{ Opt_sec_spkmi, "spkm3i" },
215 	{ Opt_sec_spkmp, "spkm3p" },
216 
217 	{ Opt_sec_err, NULL }
218 };
219 
220 enum {
221 	Opt_lookupcache_all, Opt_lookupcache_positive,
222 	Opt_lookupcache_none,
223 
224 	Opt_lookupcache_err
225 };
226 
227 static match_table_t nfs_lookupcache_tokens = {
228 	{ Opt_lookupcache_all, "all" },
229 	{ Opt_lookupcache_positive, "pos" },
230 	{ Opt_lookupcache_positive, "positive" },
231 	{ Opt_lookupcache_none, "none" },
232 
233 	{ Opt_lookupcache_err, NULL }
234 };
235 
236 
237 static void nfs_umount_begin(struct super_block *);
238 static int  nfs_statfs(struct dentry *, struct kstatfs *);
239 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
240 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
241 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
242 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
243 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
244 static void nfs_kill_super(struct super_block *);
245 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
246 
247 static struct file_system_type nfs_fs_type = {
248 	.owner		= THIS_MODULE,
249 	.name		= "nfs",
250 	.get_sb		= nfs_get_sb,
251 	.kill_sb	= nfs_kill_super,
252 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
253 };
254 
255 struct file_system_type nfs_xdev_fs_type = {
256 	.owner		= THIS_MODULE,
257 	.name		= "nfs",
258 	.get_sb		= nfs_xdev_get_sb,
259 	.kill_sb	= nfs_kill_super,
260 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
261 };
262 
263 static const struct super_operations nfs_sops = {
264 	.alloc_inode	= nfs_alloc_inode,
265 	.destroy_inode	= nfs_destroy_inode,
266 	.write_inode	= nfs_write_inode,
267 	.statfs		= nfs_statfs,
268 	.clear_inode	= nfs_clear_inode,
269 	.umount_begin	= nfs_umount_begin,
270 	.show_options	= nfs_show_options,
271 	.show_stats	= nfs_show_stats,
272 	.remount_fs	= nfs_remount,
273 };
274 
275 #ifdef CONFIG_NFS_V4
276 static int nfs4_validate_text_mount_data(void *options,
277 	struct nfs_parsed_mount_data *args, const char *dev_name);
278 static int nfs4_try_mount(int flags, const char *dev_name,
279 	struct nfs_parsed_mount_data *data, struct vfsmount *mnt);
280 static int nfs4_get_sb(struct file_system_type *fs_type,
281 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
282 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
283 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
284 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
285 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
286 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
287 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
288 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
289 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
290 static void nfs4_kill_super(struct super_block *sb);
291 
292 static struct file_system_type nfs4_fs_type = {
293 	.owner		= THIS_MODULE,
294 	.name		= "nfs4",
295 	.get_sb		= nfs4_get_sb,
296 	.kill_sb	= nfs4_kill_super,
297 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
298 };
299 
300 static struct file_system_type nfs4_remote_fs_type = {
301 	.owner		= THIS_MODULE,
302 	.name		= "nfs4",
303 	.get_sb		= nfs4_remote_get_sb,
304 	.kill_sb	= nfs4_kill_super,
305 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
306 };
307 
308 struct file_system_type nfs4_xdev_fs_type = {
309 	.owner		= THIS_MODULE,
310 	.name		= "nfs4",
311 	.get_sb		= nfs4_xdev_get_sb,
312 	.kill_sb	= nfs4_kill_super,
313 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
314 };
315 
316 static struct file_system_type nfs4_remote_referral_fs_type = {
317 	.owner		= THIS_MODULE,
318 	.name		= "nfs4",
319 	.get_sb		= nfs4_remote_referral_get_sb,
320 	.kill_sb	= nfs4_kill_super,
321 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
322 };
323 
324 struct file_system_type nfs4_referral_fs_type = {
325 	.owner		= THIS_MODULE,
326 	.name		= "nfs4",
327 	.get_sb		= nfs4_referral_get_sb,
328 	.kill_sb	= nfs4_kill_super,
329 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
330 };
331 
332 static const struct super_operations nfs4_sops = {
333 	.alloc_inode	= nfs_alloc_inode,
334 	.destroy_inode	= nfs_destroy_inode,
335 	.write_inode	= nfs_write_inode,
336 	.statfs		= nfs_statfs,
337 	.clear_inode	= nfs4_clear_inode,
338 	.umount_begin	= nfs_umount_begin,
339 	.show_options	= nfs_show_options,
340 	.show_stats	= nfs_show_stats,
341 	.remount_fs	= nfs_remount,
342 };
343 #endif
344 
345 static struct shrinker acl_shrinker = {
346 	.shrink		= nfs_access_cache_shrinker,
347 	.seeks		= DEFAULT_SEEKS,
348 };
349 
350 /*
351  * Register the NFS filesystems
352  */
353 int __init register_nfs_fs(void)
354 {
355 	int ret;
356 
357         ret = register_filesystem(&nfs_fs_type);
358 	if (ret < 0)
359 		goto error_0;
360 
361 	ret = nfs_register_sysctl();
362 	if (ret < 0)
363 		goto error_1;
364 #ifdef CONFIG_NFS_V4
365 	ret = register_filesystem(&nfs4_fs_type);
366 	if (ret < 0)
367 		goto error_2;
368 #endif
369 	register_shrinker(&acl_shrinker);
370 	return 0;
371 
372 #ifdef CONFIG_NFS_V4
373 error_2:
374 	nfs_unregister_sysctl();
375 #endif
376 error_1:
377 	unregister_filesystem(&nfs_fs_type);
378 error_0:
379 	return ret;
380 }
381 
382 /*
383  * Unregister the NFS filesystems
384  */
385 void __exit unregister_nfs_fs(void)
386 {
387 	unregister_shrinker(&acl_shrinker);
388 #ifdef CONFIG_NFS_V4
389 	unregister_filesystem(&nfs4_fs_type);
390 #endif
391 	nfs_unregister_sysctl();
392 	unregister_filesystem(&nfs_fs_type);
393 }
394 
395 void nfs_sb_active(struct super_block *sb)
396 {
397 	struct nfs_server *server = NFS_SB(sb);
398 
399 	if (atomic_inc_return(&server->active) == 1)
400 		atomic_inc(&sb->s_active);
401 }
402 
403 void nfs_sb_deactive(struct super_block *sb)
404 {
405 	struct nfs_server *server = NFS_SB(sb);
406 
407 	if (atomic_dec_and_test(&server->active))
408 		deactivate_super(sb);
409 }
410 
411 /*
412  * Deliver file system statistics to userspace
413  */
414 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
415 {
416 	struct nfs_server *server = NFS_SB(dentry->d_sb);
417 	unsigned char blockbits;
418 	unsigned long blockres;
419 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
420 	struct nfs_fattr fattr;
421 	struct nfs_fsstat res = {
422 			.fattr = &fattr,
423 	};
424 	int error;
425 
426 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
427 	if (error < 0)
428 		goto out_err;
429 	buf->f_type = NFS_SUPER_MAGIC;
430 
431 	/*
432 	 * Current versions of glibc do not correctly handle the
433 	 * case where f_frsize != f_bsize.  Eventually we want to
434 	 * report the value of wtmult in this field.
435 	 */
436 	buf->f_frsize = dentry->d_sb->s_blocksize;
437 
438 	/*
439 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
440 	 * are reported in units of f_frsize.  Linux hasn't had
441 	 * an f_frsize field in its statfs struct until recently,
442 	 * thus historically Linux's sys_statfs reports these
443 	 * fields in units of f_bsize.
444 	 */
445 	buf->f_bsize = dentry->d_sb->s_blocksize;
446 	blockbits = dentry->d_sb->s_blocksize_bits;
447 	blockres = (1 << blockbits) - 1;
448 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
449 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
450 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
451 
452 	buf->f_files = res.tfiles;
453 	buf->f_ffree = res.afiles;
454 
455 	buf->f_namelen = server->namelen;
456 
457 	return 0;
458 
459  out_err:
460 	dprintk("%s: statfs error = %d\n", __func__, -error);
461 	return error;
462 }
463 
464 /*
465  * Map the security flavour number to a name
466  */
467 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
468 {
469 	static const struct {
470 		rpc_authflavor_t flavour;
471 		const char *str;
472 	} sec_flavours[] = {
473 		{ RPC_AUTH_NULL, "null" },
474 		{ RPC_AUTH_UNIX, "sys" },
475 		{ RPC_AUTH_GSS_KRB5, "krb5" },
476 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
477 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
478 		{ RPC_AUTH_GSS_LKEY, "lkey" },
479 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
480 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
481 		{ RPC_AUTH_GSS_SPKM, "spkm" },
482 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
483 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
484 		{ UINT_MAX, "unknown" }
485 	};
486 	int i;
487 
488 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
489 		if (sec_flavours[i].flavour == flavour)
490 			break;
491 	}
492 	return sec_flavours[i].str;
493 }
494 
495 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
496 				    int showdefaults)
497 {
498 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
499 
500 	switch (sap->sa_family) {
501 	case AF_INET: {
502 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
503 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
504 		break;
505 	}
506 	case AF_INET6: {
507 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
508 		seq_printf(m, ",mountaddr=%pI6", &sin6->sin6_addr);
509 		break;
510 	}
511 	default:
512 		if (showdefaults)
513 			seq_printf(m, ",mountaddr=unspecified");
514 	}
515 
516 	if (nfss->mountd_version || showdefaults)
517 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
518 	if (nfss->mountd_port || showdefaults)
519 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
520 
521 	switch (nfss->mountd_protocol) {
522 	case IPPROTO_UDP:
523 		seq_printf(m, ",mountproto=udp");
524 		break;
525 	case IPPROTO_TCP:
526 		seq_printf(m, ",mountproto=tcp");
527 		break;
528 	default:
529 		if (showdefaults)
530 			seq_printf(m, ",mountproto=auto");
531 	}
532 }
533 
534 /*
535  * Describe the mount options in force on this server representation
536  */
537 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
538 				   int showdefaults)
539 {
540 	static const struct proc_nfs_info {
541 		int flag;
542 		const char *str;
543 		const char *nostr;
544 	} nfs_info[] = {
545 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
546 		{ NFS_MOUNT_POSIX, ",posix", "" },
547 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
548 		{ NFS_MOUNT_NOAC, ",noac", "" },
549 		{ NFS_MOUNT_NONLM, ",nolock", "" },
550 		{ NFS_MOUNT_NOACL, ",noacl", "" },
551 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
552 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
553 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
554 		{ 0, NULL, NULL }
555 	};
556 	const struct proc_nfs_info *nfs_infop;
557 	struct nfs_client *clp = nfss->nfs_client;
558 	u32 version = clp->rpc_ops->version;
559 
560 	seq_printf(m, ",vers=%u", version);
561 	seq_printf(m, ",rsize=%u", nfss->rsize);
562 	seq_printf(m, ",wsize=%u", nfss->wsize);
563 	if (nfss->bsize != 0)
564 		seq_printf(m, ",bsize=%u", nfss->bsize);
565 	seq_printf(m, ",namlen=%u", nfss->namelen);
566 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
567 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
568 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
569 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
570 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
571 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
572 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
573 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
574 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
575 		if (nfss->flags & nfs_infop->flag)
576 			seq_puts(m, nfs_infop->str);
577 		else
578 			seq_puts(m, nfs_infop->nostr);
579 	}
580 	seq_printf(m, ",proto=%s",
581 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
582 	if (version == 4) {
583 		if (nfss->port != NFS_PORT)
584 			seq_printf(m, ",port=%u", nfss->port);
585 	} else
586 		if (nfss->port)
587 			seq_printf(m, ",port=%u", nfss->port);
588 
589 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
590 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
591 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
592 
593 	if (version != 4)
594 		nfs_show_mountd_options(m, nfss, showdefaults);
595 
596 #ifdef CONFIG_NFS_V4
597 	if (clp->rpc_ops->version == 4)
598 		seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
599 #endif
600 	if (nfss->options & NFS_OPTION_FSCACHE)
601 		seq_printf(m, ",fsc");
602 }
603 
604 /*
605  * Describe the mount options on this VFS mountpoint
606  */
607 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
608 {
609 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
610 
611 	nfs_show_mount_options(m, nfss, 0);
612 
613 	seq_printf(m, ",addr=%s",
614 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
615 							RPC_DISPLAY_ADDR));
616 
617 	return 0;
618 }
619 
620 /*
621  * Present statistical information for this VFS mountpoint
622  */
623 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
624 {
625 	int i, cpu;
626 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
627 	struct rpc_auth *auth = nfss->client->cl_auth;
628 	struct nfs_iostats totals = { };
629 
630 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
631 
632 	/*
633 	 * Display all mount option settings
634 	 */
635 	seq_printf(m, "\n\topts:\t");
636 	seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
637 	seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
638 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
639 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
640 	nfs_show_mount_options(m, nfss, 1);
641 
642 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
643 
644 	seq_printf(m, "\n\tcaps:\t");
645 	seq_printf(m, "caps=0x%x", nfss->caps);
646 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
647 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
648 	seq_printf(m, ",bsize=%u", nfss->bsize);
649 	seq_printf(m, ",namlen=%u", nfss->namelen);
650 
651 #ifdef CONFIG_NFS_V4
652 	if (nfss->nfs_client->rpc_ops->version == 4) {
653 		seq_printf(m, "\n\tnfsv4:\t");
654 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
655 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
656 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
657 	}
658 #endif
659 
660 	/*
661 	 * Display security flavor in effect for this mount
662 	 */
663 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
664 	if (auth->au_flavor)
665 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
666 
667 	/*
668 	 * Display superblock I/O counters
669 	 */
670 	for_each_possible_cpu(cpu) {
671 		struct nfs_iostats *stats;
672 
673 		preempt_disable();
674 		stats = per_cpu_ptr(nfss->io_stats, cpu);
675 
676 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
677 			totals.events[i] += stats->events[i];
678 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
679 			totals.bytes[i] += stats->bytes[i];
680 #ifdef CONFIG_NFS_FSCACHE
681 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
682 			totals.fscache[i] += stats->fscache[i];
683 #endif
684 
685 		preempt_enable();
686 	}
687 
688 	seq_printf(m, "\n\tevents:\t");
689 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
690 		seq_printf(m, "%lu ", totals.events[i]);
691 	seq_printf(m, "\n\tbytes:\t");
692 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
693 		seq_printf(m, "%Lu ", totals.bytes[i]);
694 #ifdef CONFIG_NFS_FSCACHE
695 	if (nfss->options & NFS_OPTION_FSCACHE) {
696 		seq_printf(m, "\n\tfsc:\t");
697 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
698 			seq_printf(m, "%Lu ", totals.bytes[i]);
699 	}
700 #endif
701 	seq_printf(m, "\n");
702 
703 	rpc_print_iostats(m, nfss->client);
704 
705 	return 0;
706 }
707 
708 /*
709  * Begin unmount by attempting to remove all automounted mountpoints we added
710  * in response to xdev traversals and referrals
711  */
712 static void nfs_umount_begin(struct super_block *sb)
713 {
714 	struct nfs_server *server;
715 	struct rpc_clnt *rpc;
716 
717 	lock_kernel();
718 
719 	server = NFS_SB(sb);
720 	/* -EIO all pending I/O */
721 	rpc = server->client_acl;
722 	if (!IS_ERR(rpc))
723 		rpc_killall_tasks(rpc);
724 	rpc = server->client;
725 	if (!IS_ERR(rpc))
726 		rpc_killall_tasks(rpc);
727 
728 	unlock_kernel();
729 }
730 
731 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(int flags)
732 {
733 	struct nfs_parsed_mount_data *data;
734 
735 	data = kzalloc(sizeof(*data), GFP_KERNEL);
736 	if (data) {
737 		data->flags		= flags;
738 		data->rsize		= NFS_MAX_FILE_IO_SIZE;
739 		data->wsize		= NFS_MAX_FILE_IO_SIZE;
740 		data->acregmin		= NFS_DEF_ACREGMIN;
741 		data->acregmax		= NFS_DEF_ACREGMAX;
742 		data->acdirmin		= NFS_DEF_ACDIRMIN;
743 		data->acdirmax		= NFS_DEF_ACDIRMAX;
744 		data->nfs_server.port	= NFS_UNSPEC_PORT;
745 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
746 		data->auth_flavor_len	= 1;
747 		data->minorversion	= 0;
748 	}
749 	return data;
750 }
751 
752 /*
753  * Sanity-check a server address provided by the mount command.
754  *
755  * Address family must be initialized, and address must not be
756  * the ANY address for that family.
757  */
758 static int nfs_verify_server_address(struct sockaddr *addr)
759 {
760 	switch (addr->sa_family) {
761 	case AF_INET: {
762 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
763 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
764 	}
765 	case AF_INET6: {
766 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
767 		return !ipv6_addr_any(sa);
768 	}
769 	}
770 
771 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
772 	return 0;
773 }
774 
775 /*
776  * Select between a default port value and a user-specified port value.
777  * If a zero value is set, then autobind will be used.
778  */
779 static void nfs_set_default_port(struct sockaddr *sap, const int parsed_port,
780 				 const unsigned short default_port)
781 {
782 	unsigned short port = default_port;
783 
784 	if (parsed_port != NFS_UNSPEC_PORT)
785 		port = parsed_port;
786 
787 	rpc_set_port(sap, port);
788 }
789 
790 /*
791  * Sanity check the NFS transport protocol.
792  *
793  */
794 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
795 {
796 	switch (mnt->nfs_server.protocol) {
797 	case XPRT_TRANSPORT_UDP:
798 	case XPRT_TRANSPORT_TCP:
799 	case XPRT_TRANSPORT_RDMA:
800 		break;
801 	default:
802 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
803 	}
804 }
805 
806 /*
807  * For text based NFSv2/v3 mounts, the mount protocol transport default
808  * settings should depend upon the specified NFS transport.
809  */
810 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
811 {
812 	nfs_validate_transport_protocol(mnt);
813 
814 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
815 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
816 			return;
817 	switch (mnt->nfs_server.protocol) {
818 	case XPRT_TRANSPORT_UDP:
819 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
820 		break;
821 	case XPRT_TRANSPORT_TCP:
822 	case XPRT_TRANSPORT_RDMA:
823 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
824 	}
825 }
826 
827 /*
828  * Parse the value of the 'sec=' option.
829  */
830 static int nfs_parse_security_flavors(char *value,
831 				      struct nfs_parsed_mount_data *mnt)
832 {
833 	substring_t args[MAX_OPT_ARGS];
834 
835 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
836 
837 	switch (match_token(value, nfs_secflavor_tokens, args)) {
838 	case Opt_sec_none:
839 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
840 		break;
841 	case Opt_sec_sys:
842 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
843 		break;
844 	case Opt_sec_krb5:
845 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
846 		break;
847 	case Opt_sec_krb5i:
848 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
849 		break;
850 	case Opt_sec_krb5p:
851 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
852 		break;
853 	case Opt_sec_lkey:
854 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
855 		break;
856 	case Opt_sec_lkeyi:
857 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
858 		break;
859 	case Opt_sec_lkeyp:
860 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
861 		break;
862 	case Opt_sec_spkm:
863 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
864 		break;
865 	case Opt_sec_spkmi:
866 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
867 		break;
868 	case Opt_sec_spkmp:
869 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
870 		break;
871 	default:
872 		return 0;
873 	}
874 
875 	mnt->auth_flavor_len = 1;
876 	return 1;
877 }
878 
879 /*
880  * Error-check and convert a string of mount options from user space into
881  * a data structure.  The whole mount string is processed; bad options are
882  * skipped as they are encountered.  If there were no errors, return 1;
883  * otherwise return 0 (zero).
884  */
885 static int nfs_parse_mount_options(char *raw,
886 				   struct nfs_parsed_mount_data *mnt)
887 {
888 	char *p, *string, *secdata;
889 	int rc, sloppy = 0, invalid_option = 0;
890 
891 	if (!raw) {
892 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
893 		return 1;
894 	}
895 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
896 
897 	secdata = alloc_secdata();
898 	if (!secdata)
899 		goto out_nomem;
900 
901 	rc = security_sb_copy_data(raw, secdata);
902 	if (rc)
903 		goto out_security_failure;
904 
905 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
906 	if (rc)
907 		goto out_security_failure;
908 
909 	free_secdata(secdata);
910 
911 	while ((p = strsep(&raw, ",")) != NULL) {
912 		substring_t args[MAX_OPT_ARGS];
913 		unsigned long option;
914 		int token;
915 
916 		if (!*p)
917 			continue;
918 
919 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
920 
921 		token = match_token(p, nfs_mount_option_tokens, args);
922 		switch (token) {
923 
924 		/*
925 		 * boolean options:  foo/nofoo
926 		 */
927 		case Opt_soft:
928 			mnt->flags |= NFS_MOUNT_SOFT;
929 			break;
930 		case Opt_hard:
931 			mnt->flags &= ~NFS_MOUNT_SOFT;
932 			break;
933 		case Opt_posix:
934 			mnt->flags |= NFS_MOUNT_POSIX;
935 			break;
936 		case Opt_noposix:
937 			mnt->flags &= ~NFS_MOUNT_POSIX;
938 			break;
939 		case Opt_cto:
940 			mnt->flags &= ~NFS_MOUNT_NOCTO;
941 			break;
942 		case Opt_nocto:
943 			mnt->flags |= NFS_MOUNT_NOCTO;
944 			break;
945 		case Opt_ac:
946 			mnt->flags &= ~NFS_MOUNT_NOAC;
947 			break;
948 		case Opt_noac:
949 			mnt->flags |= NFS_MOUNT_NOAC;
950 			break;
951 		case Opt_lock:
952 			mnt->flags &= ~NFS_MOUNT_NONLM;
953 			break;
954 		case Opt_nolock:
955 			mnt->flags |= NFS_MOUNT_NONLM;
956 			break;
957 		case Opt_v2:
958 			mnt->flags &= ~NFS_MOUNT_VER3;
959 			mnt->version = 2;
960 			break;
961 		case Opt_v3:
962 			mnt->flags |= NFS_MOUNT_VER3;
963 			mnt->version = 3;
964 			break;
965 #ifdef CONFIG_NFS_V4
966 		case Opt_v4:
967 			mnt->flags &= ~NFS_MOUNT_VER3;
968 			mnt->version = 4;
969 			break;
970 #endif
971 		case Opt_udp:
972 			mnt->flags &= ~NFS_MOUNT_TCP;
973 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
974 			break;
975 		case Opt_tcp:
976 			mnt->flags |= NFS_MOUNT_TCP;
977 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
978 			break;
979 		case Opt_rdma:
980 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
981 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
982 			xprt_load_transport(p);
983 			break;
984 		case Opt_acl:
985 			mnt->flags &= ~NFS_MOUNT_NOACL;
986 			break;
987 		case Opt_noacl:
988 			mnt->flags |= NFS_MOUNT_NOACL;
989 			break;
990 		case Opt_rdirplus:
991 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
992 			break;
993 		case Opt_nordirplus:
994 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
995 			break;
996 		case Opt_sharecache:
997 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
998 			break;
999 		case Opt_nosharecache:
1000 			mnt->flags |= NFS_MOUNT_UNSHARED;
1001 			break;
1002 		case Opt_resvport:
1003 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1004 			break;
1005 		case Opt_noresvport:
1006 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1007 			break;
1008 		case Opt_fscache:
1009 			mnt->options |= NFS_OPTION_FSCACHE;
1010 			kfree(mnt->fscache_uniq);
1011 			mnt->fscache_uniq = NULL;
1012 			break;
1013 		case Opt_nofscache:
1014 			mnt->options &= ~NFS_OPTION_FSCACHE;
1015 			kfree(mnt->fscache_uniq);
1016 			mnt->fscache_uniq = NULL;
1017 			break;
1018 		case Opt_fscache_uniq:
1019 			string = match_strdup(args);
1020 			if (!string)
1021 				goto out_nomem;
1022 			kfree(mnt->fscache_uniq);
1023 			mnt->fscache_uniq = string;
1024 			mnt->options |= NFS_OPTION_FSCACHE;
1025 			break;
1026 
1027 		/*
1028 		 * options that take numeric values
1029 		 */
1030 		case Opt_port:
1031 			string = match_strdup(args);
1032 			if (string == NULL)
1033 				goto out_nomem;
1034 			rc = strict_strtoul(string, 10, &option);
1035 			kfree(string);
1036 			if (rc != 0 || option > USHORT_MAX)
1037 				goto out_invalid_value;
1038 			mnt->nfs_server.port = option;
1039 			break;
1040 		case Opt_rsize:
1041 			string = match_strdup(args);
1042 			if (string == NULL)
1043 				goto out_nomem;
1044 			rc = strict_strtoul(string, 10, &option);
1045 			kfree(string);
1046 			if (rc != 0)
1047 				goto out_invalid_value;
1048 			mnt->rsize = option;
1049 			break;
1050 		case Opt_wsize:
1051 			string = match_strdup(args);
1052 			if (string == NULL)
1053 				goto out_nomem;
1054 			rc = strict_strtoul(string, 10, &option);
1055 			kfree(string);
1056 			if (rc != 0)
1057 				goto out_invalid_value;
1058 			mnt->wsize = option;
1059 			break;
1060 		case Opt_bsize:
1061 			string = match_strdup(args);
1062 			if (string == NULL)
1063 				goto out_nomem;
1064 			rc = strict_strtoul(string, 10, &option);
1065 			kfree(string);
1066 			if (rc != 0)
1067 				goto out_invalid_value;
1068 			mnt->bsize = option;
1069 			break;
1070 		case Opt_timeo:
1071 			string = match_strdup(args);
1072 			if (string == NULL)
1073 				goto out_nomem;
1074 			rc = strict_strtoul(string, 10, &option);
1075 			kfree(string);
1076 			if (rc != 0 || option == 0)
1077 				goto out_invalid_value;
1078 			mnt->timeo = option;
1079 			break;
1080 		case Opt_retrans:
1081 			string = match_strdup(args);
1082 			if (string == NULL)
1083 				goto out_nomem;
1084 			rc = strict_strtoul(string, 10, &option);
1085 			kfree(string);
1086 			if (rc != 0 || option == 0)
1087 				goto out_invalid_value;
1088 			mnt->retrans = option;
1089 			break;
1090 		case Opt_acregmin:
1091 			string = match_strdup(args);
1092 			if (string == NULL)
1093 				goto out_nomem;
1094 			rc = strict_strtoul(string, 10, &option);
1095 			kfree(string);
1096 			if (rc != 0)
1097 				goto out_invalid_value;
1098 			mnt->acregmin = option;
1099 			break;
1100 		case Opt_acregmax:
1101 			string = match_strdup(args);
1102 			if (string == NULL)
1103 				goto out_nomem;
1104 			rc = strict_strtoul(string, 10, &option);
1105 			kfree(string);
1106 			if (rc != 0)
1107 				goto out_invalid_value;
1108 			mnt->acregmax = option;
1109 			break;
1110 		case Opt_acdirmin:
1111 			string = match_strdup(args);
1112 			if (string == NULL)
1113 				goto out_nomem;
1114 			rc = strict_strtoul(string, 10, &option);
1115 			kfree(string);
1116 			if (rc != 0)
1117 				goto out_invalid_value;
1118 			mnt->acdirmin = option;
1119 			break;
1120 		case Opt_acdirmax:
1121 			string = match_strdup(args);
1122 			if (string == NULL)
1123 				goto out_nomem;
1124 			rc = strict_strtoul(string, 10, &option);
1125 			kfree(string);
1126 			if (rc != 0)
1127 				goto out_invalid_value;
1128 			mnt->acdirmax = option;
1129 			break;
1130 		case Opt_actimeo:
1131 			string = match_strdup(args);
1132 			if (string == NULL)
1133 				goto out_nomem;
1134 			rc = strict_strtoul(string, 10, &option);
1135 			kfree(string);
1136 			if (rc != 0)
1137 				goto out_invalid_value;
1138 			mnt->acregmin = mnt->acregmax =
1139 			mnt->acdirmin = mnt->acdirmax = option;
1140 			break;
1141 		case Opt_namelen:
1142 			string = match_strdup(args);
1143 			if (string == NULL)
1144 				goto out_nomem;
1145 			rc = strict_strtoul(string, 10, &option);
1146 			kfree(string);
1147 			if (rc != 0)
1148 				goto out_invalid_value;
1149 			mnt->namlen = option;
1150 			break;
1151 		case Opt_mountport:
1152 			string = match_strdup(args);
1153 			if (string == NULL)
1154 				goto out_nomem;
1155 			rc = strict_strtoul(string, 10, &option);
1156 			kfree(string);
1157 			if (rc != 0 || option > USHORT_MAX)
1158 				goto out_invalid_value;
1159 			mnt->mount_server.port = option;
1160 			break;
1161 		case Opt_mountvers:
1162 			string = match_strdup(args);
1163 			if (string == NULL)
1164 				goto out_nomem;
1165 			rc = strict_strtoul(string, 10, &option);
1166 			kfree(string);
1167 			if (rc != 0 ||
1168 			    option < NFS_MNT_VERSION ||
1169 			    option > NFS_MNT3_VERSION)
1170 				goto out_invalid_value;
1171 			mnt->mount_server.version = option;
1172 			break;
1173 		case Opt_nfsvers:
1174 			string = match_strdup(args);
1175 			if (string == NULL)
1176 				goto out_nomem;
1177 			rc = strict_strtoul(string, 10, &option);
1178 			kfree(string);
1179 			if (rc != 0)
1180 				goto out_invalid_value;
1181 			switch (option) {
1182 			case NFS2_VERSION:
1183 				mnt->flags &= ~NFS_MOUNT_VER3;
1184 				mnt->version = 2;
1185 				break;
1186 			case NFS3_VERSION:
1187 				mnt->flags |= NFS_MOUNT_VER3;
1188 				mnt->version = 3;
1189 				break;
1190 #ifdef CONFIG_NFS_V4
1191 			case NFS4_VERSION:
1192 				mnt->flags &= ~NFS_MOUNT_VER3;
1193 				mnt->version = 4;
1194 				break;
1195 #endif
1196 			default:
1197 				goto out_invalid_value;
1198 			}
1199 			break;
1200 		case Opt_minorversion:
1201 			string = match_strdup(args);
1202 			if (string == NULL)
1203 				goto out_nomem;
1204 			rc = strict_strtoul(string, 10, &option);
1205 			kfree(string);
1206 			if (rc != 0)
1207 				goto out_invalid_value;
1208 			if (option > NFS4_MAX_MINOR_VERSION)
1209 				goto out_invalid_value;
1210 			mnt->minorversion = option;
1211 			break;
1212 
1213 		/*
1214 		 * options that take text values
1215 		 */
1216 		case Opt_sec:
1217 			string = match_strdup(args);
1218 			if (string == NULL)
1219 				goto out_nomem;
1220 			rc = nfs_parse_security_flavors(string, mnt);
1221 			kfree(string);
1222 			if (!rc) {
1223 				dfprintk(MOUNT, "NFS:   unrecognized "
1224 						"security flavor\n");
1225 				return 0;
1226 			}
1227 			break;
1228 		case Opt_proto:
1229 			string = match_strdup(args);
1230 			if (string == NULL)
1231 				goto out_nomem;
1232 			token = match_token(string,
1233 					    nfs_xprt_protocol_tokens, args);
1234 
1235 			switch (token) {
1236 			case Opt_xprt_udp:
1237 				mnt->flags &= ~NFS_MOUNT_TCP;
1238 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1239 				kfree(string);
1240 				break;
1241 			case Opt_xprt_tcp:
1242 				mnt->flags |= NFS_MOUNT_TCP;
1243 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1244 				kfree(string);
1245 				break;
1246 			case Opt_xprt_rdma:
1247 				/* vector side protocols to TCP */
1248 				mnt->flags |= NFS_MOUNT_TCP;
1249 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1250 				xprt_load_transport(string);
1251 				kfree(string);
1252 				break;
1253 			default:
1254 				dfprintk(MOUNT, "NFS:   unrecognized "
1255 						"transport protocol\n");
1256 				return 0;
1257 			}
1258 			break;
1259 		case Opt_mountproto:
1260 			string = match_strdup(args);
1261 			if (string == NULL)
1262 				goto out_nomem;
1263 			token = match_token(string,
1264 					    nfs_xprt_protocol_tokens, args);
1265 			kfree(string);
1266 
1267 			switch (token) {
1268 			case Opt_xprt_udp:
1269 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1270 				break;
1271 			case Opt_xprt_tcp:
1272 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1273 				break;
1274 			case Opt_xprt_rdma: /* not used for side protocols */
1275 			default:
1276 				dfprintk(MOUNT, "NFS:   unrecognized "
1277 						"transport protocol\n");
1278 				return 0;
1279 			}
1280 			break;
1281 		case Opt_addr:
1282 			string = match_strdup(args);
1283 			if (string == NULL)
1284 				goto out_nomem;
1285 			mnt->nfs_server.addrlen =
1286 				rpc_pton(string, strlen(string),
1287 					(struct sockaddr *)
1288 					&mnt->nfs_server.address,
1289 					sizeof(mnt->nfs_server.address));
1290 			kfree(string);
1291 			if (mnt->nfs_server.addrlen == 0)
1292 				goto out_invalid_address;
1293 			break;
1294 		case Opt_clientaddr:
1295 			string = match_strdup(args);
1296 			if (string == NULL)
1297 				goto out_nomem;
1298 			kfree(mnt->client_address);
1299 			mnt->client_address = string;
1300 			break;
1301 		case Opt_mounthost:
1302 			string = match_strdup(args);
1303 			if (string == NULL)
1304 				goto out_nomem;
1305 			kfree(mnt->mount_server.hostname);
1306 			mnt->mount_server.hostname = string;
1307 			break;
1308 		case Opt_mountaddr:
1309 			string = match_strdup(args);
1310 			if (string == NULL)
1311 				goto out_nomem;
1312 			mnt->mount_server.addrlen =
1313 				rpc_pton(string, strlen(string),
1314 					(struct sockaddr *)
1315 					&mnt->mount_server.address,
1316 					sizeof(mnt->mount_server.address));
1317 			kfree(string);
1318 			if (mnt->mount_server.addrlen == 0)
1319 				goto out_invalid_address;
1320 			break;
1321 		case Opt_lookupcache:
1322 			string = match_strdup(args);
1323 			if (string == NULL)
1324 				goto out_nomem;
1325 			token = match_token(string,
1326 					nfs_lookupcache_tokens, args);
1327 			kfree(string);
1328 			switch (token) {
1329 				case Opt_lookupcache_all:
1330 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1331 					break;
1332 				case Opt_lookupcache_positive:
1333 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1334 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1335 					break;
1336 				case Opt_lookupcache_none:
1337 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1338 					break;
1339 				default:
1340 					dfprintk(MOUNT, "NFS:   invalid "
1341 							"lookupcache argument\n");
1342 					return 0;
1343 			};
1344 			break;
1345 
1346 		/*
1347 		 * Special options
1348 		 */
1349 		case Opt_sloppy:
1350 			sloppy = 1;
1351 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1352 			break;
1353 		case Opt_userspace:
1354 		case Opt_deprecated:
1355 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1356 					"'%s'\n", p);
1357 			break;
1358 
1359 		default:
1360 			invalid_option = 1;
1361 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1362 					"'%s'\n", p);
1363 		}
1364 	}
1365 
1366 	if (!sloppy && invalid_option)
1367 		return 0;
1368 
1369 	return 1;
1370 
1371 out_invalid_address:
1372 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1373 	return 0;
1374 out_invalid_value:
1375 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1376 	return 0;
1377 out_nomem:
1378 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1379 	return 0;
1380 out_security_failure:
1381 	free_secdata(secdata);
1382 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1383 	return 0;
1384 }
1385 
1386 /*
1387  * Match the requested auth flavors with the list returned by
1388  * the server.  Returns zero and sets the mount's authentication
1389  * flavor on success; returns -EACCES if server does not support
1390  * the requested flavor.
1391  */
1392 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1393 			     struct nfs_mount_request *request)
1394 {
1395 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1396 
1397 	/*
1398 	 * Certain releases of Linux's mountd return an empty
1399 	 * flavor list.  To prevent behavioral regression with
1400 	 * these servers (ie. rejecting mounts that used to
1401 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1402 	 * if the returned flavor list is empty.
1403 	 */
1404 	if (server_authlist_len == 0)
1405 		return 0;
1406 
1407 	/*
1408 	 * We avoid sophisticated negotiating here, as there are
1409 	 * plenty of cases where we can get it wrong, providing
1410 	 * either too little or too much security.
1411 	 *
1412 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1413 	 * flavor listed first.  However, some servers list
1414 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1415 	 * preferred default, in args->auth_flavors[0] if user
1416 	 * didn't specify sec= mount option.
1417 	 */
1418 	for (i = 0; i < args->auth_flavor_len; i++)
1419 		for (j = 0; j < server_authlist_len; j++)
1420 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1421 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1422 					request->auth_flavs[j]);
1423 				args->auth_flavors[0] = request->auth_flavs[j];
1424 				return 0;
1425 			}
1426 
1427 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1428 	nfs_umount(request);
1429 	return -EACCES;
1430 }
1431 
1432 /*
1433  * Use the remote server's MOUNT service to request the NFS file handle
1434  * corresponding to the provided path.
1435  */
1436 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1437 			 struct nfs_fh *root_fh)
1438 {
1439 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1440 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1441 	struct nfs_mount_request request = {
1442 		.sap		= (struct sockaddr *)
1443 						&args->mount_server.address,
1444 		.dirpath	= args->nfs_server.export_path,
1445 		.protocol	= args->mount_server.protocol,
1446 		.fh		= root_fh,
1447 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1448 		.auth_flav_len	= &server_authlist_len,
1449 		.auth_flavs	= server_authlist,
1450 	};
1451 	int status;
1452 
1453 	if (args->mount_server.version == 0) {
1454 		switch (args->version) {
1455 			default:
1456 				args->mount_server.version = NFS_MNT3_VERSION;
1457 				break;
1458 			case 2:
1459 				args->mount_server.version = NFS_MNT_VERSION;
1460 		}
1461 	}
1462 	request.version = args->mount_server.version;
1463 
1464 	if (args->mount_server.hostname)
1465 		request.hostname = args->mount_server.hostname;
1466 	else
1467 		request.hostname = args->nfs_server.hostname;
1468 
1469 	/*
1470 	 * Construct the mount server's address.
1471 	 */
1472 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1473 		memcpy(request.sap, &args->nfs_server.address,
1474 		       args->nfs_server.addrlen);
1475 		args->mount_server.addrlen = args->nfs_server.addrlen;
1476 	}
1477 	request.salen = args->mount_server.addrlen;
1478 	nfs_set_default_port(request.sap, args->mount_server.port, 0);
1479 
1480 	/*
1481 	 * Now ask the mount server to map our export path
1482 	 * to a file handle.
1483 	 */
1484 	status = nfs_mount(&request);
1485 	if (status != 0) {
1486 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1487 				request.hostname, status);
1488 		return status;
1489 	}
1490 
1491 	/*
1492 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1493 	 */
1494 	if (args->mount_server.version != NFS_MNT3_VERSION)
1495 		return 0;
1496 	return nfs_walk_authlist(args, &request);
1497 }
1498 
1499 static int nfs_parse_simple_hostname(const char *dev_name,
1500 				     char **hostname, size_t maxnamlen,
1501 				     char **export_path, size_t maxpathlen)
1502 {
1503 	size_t len;
1504 	char *colon, *comma;
1505 
1506 	colon = strchr(dev_name, ':');
1507 	if (colon == NULL)
1508 		goto out_bad_devname;
1509 
1510 	len = colon - dev_name;
1511 	if (len > maxnamlen)
1512 		goto out_hostname;
1513 
1514 	/* N.B. caller will free nfs_server.hostname in all cases */
1515 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1516 	if (!*hostname)
1517 		goto out_nomem;
1518 
1519 	/* kill possible hostname list: not supported */
1520 	comma = strchr(*hostname, ',');
1521 	if (comma != NULL) {
1522 		if (comma == *hostname)
1523 			goto out_bad_devname;
1524 		*comma = '\0';
1525 	}
1526 
1527 	colon++;
1528 	len = strlen(colon);
1529 	if (len > maxpathlen)
1530 		goto out_path;
1531 	*export_path = kstrndup(colon, len, GFP_KERNEL);
1532 	if (!*export_path)
1533 		goto out_nomem;
1534 
1535 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1536 	return 0;
1537 
1538 out_bad_devname:
1539 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1540 	return -EINVAL;
1541 
1542 out_nomem:
1543 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1544 	return -ENOMEM;
1545 
1546 out_hostname:
1547 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1548 	return -ENAMETOOLONG;
1549 
1550 out_path:
1551 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1552 	return -ENAMETOOLONG;
1553 }
1554 
1555 /*
1556  * Hostname has square brackets around it because it contains one or
1557  * more colons.  We look for the first closing square bracket, and a
1558  * colon must follow it.
1559  */
1560 static int nfs_parse_protected_hostname(const char *dev_name,
1561 					char **hostname, size_t maxnamlen,
1562 					char **export_path, size_t maxpathlen)
1563 {
1564 	size_t len;
1565 	char *start, *end;
1566 
1567 	start = (char *)(dev_name + 1);
1568 
1569 	end = strchr(start, ']');
1570 	if (end == NULL)
1571 		goto out_bad_devname;
1572 	if (*(end + 1) != ':')
1573 		goto out_bad_devname;
1574 
1575 	len = end - start;
1576 	if (len > maxnamlen)
1577 		goto out_hostname;
1578 
1579 	/* N.B. caller will free nfs_server.hostname in all cases */
1580 	*hostname = kstrndup(start, len, GFP_KERNEL);
1581 	if (*hostname == NULL)
1582 		goto out_nomem;
1583 
1584 	end += 2;
1585 	len = strlen(end);
1586 	if (len > maxpathlen)
1587 		goto out_path;
1588 	*export_path = kstrndup(end, len, GFP_KERNEL);
1589 	if (!*export_path)
1590 		goto out_nomem;
1591 
1592 	return 0;
1593 
1594 out_bad_devname:
1595 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1596 	return -EINVAL;
1597 
1598 out_nomem:
1599 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1600 	return -ENOMEM;
1601 
1602 out_hostname:
1603 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1604 	return -ENAMETOOLONG;
1605 
1606 out_path:
1607 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1608 	return -ENAMETOOLONG;
1609 }
1610 
1611 /*
1612  * Split "dev_name" into "hostname:export_path".
1613  *
1614  * The leftmost colon demarks the split between the server's hostname
1615  * and the export path.  If the hostname starts with a left square
1616  * bracket, then it may contain colons.
1617  *
1618  * Note: caller frees hostname and export path, even on error.
1619  */
1620 static int nfs_parse_devname(const char *dev_name,
1621 			     char **hostname, size_t maxnamlen,
1622 			     char **export_path, size_t maxpathlen)
1623 {
1624 	if (*dev_name == '[')
1625 		return nfs_parse_protected_hostname(dev_name,
1626 						    hostname, maxnamlen,
1627 						    export_path, maxpathlen);
1628 
1629 	return nfs_parse_simple_hostname(dev_name,
1630 					 hostname, maxnamlen,
1631 					 export_path, maxpathlen);
1632 }
1633 
1634 /*
1635  * Validate the NFS2/NFS3 mount data
1636  * - fills in the mount root filehandle
1637  *
1638  * For option strings, user space handles the following behaviors:
1639  *
1640  * + DNS: mapping server host name to IP address ("addr=" option)
1641  *
1642  * + failure mode: how to behave if a mount request can't be handled
1643  *   immediately ("fg/bg" option)
1644  *
1645  * + retry: how often to retry a mount request ("retry=" option)
1646  *
1647  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1648  *   mountproto=tcp after mountproto=udp, and so on
1649  */
1650 static int nfs_validate_mount_data(void *options,
1651 				   struct nfs_parsed_mount_data *args,
1652 				   struct nfs_fh *mntfh,
1653 				   const char *dev_name)
1654 {
1655 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1656 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1657 
1658 	if (data == NULL)
1659 		goto out_no_data;
1660 
1661 	switch (data->version) {
1662 	case 1:
1663 		data->namlen = 0;
1664 	case 2:
1665 		data->bsize = 0;
1666 	case 3:
1667 		if (data->flags & NFS_MOUNT_VER3)
1668 			goto out_no_v3;
1669 		data->root.size = NFS2_FHSIZE;
1670 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1671 	case 4:
1672 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1673 			goto out_no_sec;
1674 	case 5:
1675 		memset(data->context, 0, sizeof(data->context));
1676 	case 6:
1677 		if (data->flags & NFS_MOUNT_VER3) {
1678 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1679 				goto out_invalid_fh;
1680 			mntfh->size = data->root.size;
1681 			args->version = 3;
1682 		} else {
1683 			mntfh->size = NFS2_FHSIZE;
1684 			args->version = 2;
1685 		}
1686 
1687 
1688 		memcpy(mntfh->data, data->root.data, mntfh->size);
1689 		if (mntfh->size < sizeof(mntfh->data))
1690 			memset(mntfh->data + mntfh->size, 0,
1691 			       sizeof(mntfh->data) - mntfh->size);
1692 
1693 		/*
1694 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1695 		 * can deal with.
1696 		 */
1697 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1698 		args->rsize		= data->rsize;
1699 		args->wsize		= data->wsize;
1700 		args->timeo		= data->timeo;
1701 		args->retrans		= data->retrans;
1702 		args->acregmin		= data->acregmin;
1703 		args->acregmax		= data->acregmax;
1704 		args->acdirmin		= data->acdirmin;
1705 		args->acdirmax		= data->acdirmax;
1706 
1707 		memcpy(sap, &data->addr, sizeof(data->addr));
1708 		args->nfs_server.addrlen = sizeof(data->addr);
1709 		if (!nfs_verify_server_address(sap))
1710 			goto out_no_address;
1711 
1712 		if (!(data->flags & NFS_MOUNT_TCP))
1713 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1714 		else
1715 			args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1716 		/* N.B. caller will free nfs_server.hostname in all cases */
1717 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1718 		args->namlen		= data->namlen;
1719 		args->bsize		= data->bsize;
1720 
1721 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1722 			args->auth_flavors[0] = data->pseudoflavor;
1723 		if (!args->nfs_server.hostname)
1724 			goto out_nomem;
1725 
1726 		/*
1727 		 * The legacy version 6 binary mount data from userspace has a
1728 		 * field used only to transport selinux information into the
1729 		 * the kernel.  To continue to support that functionality we
1730 		 * have a touch of selinux knowledge here in the NFS code. The
1731 		 * userspace code converted context=blah to just blah so we are
1732 		 * converting back to the full string selinux understands.
1733 		 */
1734 		if (data->context[0]){
1735 #ifdef CONFIG_SECURITY_SELINUX
1736 			int rc;
1737 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1738 			if (!opts_str)
1739 				return -ENOMEM;
1740 			strcpy(opts_str, "context=");
1741 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1742 			strcat(opts_str, &data->context[0]);
1743 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1744 			kfree(opts_str);
1745 			if (rc)
1746 				return rc;
1747 #else
1748 			return -EINVAL;
1749 #endif
1750 		}
1751 
1752 		break;
1753 	default: {
1754 		int status;
1755 
1756 		if (nfs_parse_mount_options((char *)options, args) == 0)
1757 			return -EINVAL;
1758 
1759 		if (!nfs_verify_server_address(sap))
1760 			goto out_no_address;
1761 
1762 		if (args->version == 4)
1763 #ifdef CONFIG_NFS_V4
1764 			return nfs4_validate_text_mount_data(options,
1765 							     args, dev_name);
1766 #else
1767 			goto out_v4_not_compiled;
1768 #endif
1769 
1770 		nfs_set_default_port(sap, args->nfs_server.port, 0);
1771 
1772 		nfs_set_mount_transport_protocol(args);
1773 
1774 		status = nfs_parse_devname(dev_name,
1775 					   &args->nfs_server.hostname,
1776 					   PAGE_SIZE,
1777 					   &args->nfs_server.export_path,
1778 					   NFS_MAXPATHLEN);
1779 		if (!status)
1780 			status = nfs_try_mount(args, mntfh);
1781 
1782 		kfree(args->nfs_server.export_path);
1783 		args->nfs_server.export_path = NULL;
1784 
1785 		if (status)
1786 			return status;
1787 
1788 		break;
1789 		}
1790 	}
1791 
1792 #ifndef CONFIG_NFS_V3
1793 	if (args->version == 3)
1794 		goto out_v3_not_compiled;
1795 #endif /* !CONFIG_NFS_V3 */
1796 
1797 	return 0;
1798 
1799 out_no_data:
1800 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1801 	return -EINVAL;
1802 
1803 out_no_v3:
1804 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1805 		 data->version);
1806 	return -EINVAL;
1807 
1808 out_no_sec:
1809 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1810 	return -EINVAL;
1811 
1812 #ifndef CONFIG_NFS_V3
1813 out_v3_not_compiled:
1814 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1815 	return -EPROTONOSUPPORT;
1816 #endif /* !CONFIG_NFS_V3 */
1817 
1818 #ifndef CONFIG_NFS_V4
1819 out_v4_not_compiled:
1820 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1821 	return -EPROTONOSUPPORT;
1822 #endif /* !CONFIG_NFS_V4 */
1823 
1824 out_nomem:
1825 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1826 	return -ENOMEM;
1827 
1828 out_no_address:
1829 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1830 	return -EINVAL;
1831 
1832 out_invalid_fh:
1833 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1834 	return -EINVAL;
1835 }
1836 
1837 static int
1838 nfs_compare_remount_data(struct nfs_server *nfss,
1839 			 struct nfs_parsed_mount_data *data)
1840 {
1841 	if (data->flags != nfss->flags ||
1842 	    data->rsize != nfss->rsize ||
1843 	    data->wsize != nfss->wsize ||
1844 	    data->retrans != nfss->client->cl_timeout->to_retries ||
1845 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1846 	    data->acregmin != nfss->acregmin / HZ ||
1847 	    data->acregmax != nfss->acregmax / HZ ||
1848 	    data->acdirmin != nfss->acdirmin / HZ ||
1849 	    data->acdirmax != nfss->acdirmax / HZ ||
1850 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1851 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1852 	    memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1853 		   data->nfs_server.addrlen) != 0)
1854 		return -EINVAL;
1855 
1856 	return 0;
1857 }
1858 
1859 static int
1860 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1861 {
1862 	int error;
1863 	struct nfs_server *nfss = sb->s_fs_info;
1864 	struct nfs_parsed_mount_data *data;
1865 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1866 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1867 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1868 
1869 	/*
1870 	 * Userspace mount programs that send binary options generally send
1871 	 * them populated with default values. We have no way to know which
1872 	 * ones were explicitly specified. Fall back to legacy behavior and
1873 	 * just return success.
1874 	 */
1875 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1876 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
1877 					   options->version <= 6))))
1878 		return 0;
1879 
1880 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1881 	if (data == NULL)
1882 		return -ENOMEM;
1883 
1884 	lock_kernel();
1885 	/* fill out struct with values from existing mount */
1886 	data->flags = nfss->flags;
1887 	data->rsize = nfss->rsize;
1888 	data->wsize = nfss->wsize;
1889 	data->retrans = nfss->client->cl_timeout->to_retries;
1890 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1891 	data->acregmin = nfss->acregmin / HZ;
1892 	data->acregmax = nfss->acregmax / HZ;
1893 	data->acdirmin = nfss->acdirmin / HZ;
1894 	data->acdirmax = nfss->acdirmax / HZ;
1895 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1896 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1897 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1898 		data->nfs_server.addrlen);
1899 
1900 	/* overwrite those values with any that were specified */
1901 	error = nfs_parse_mount_options((char *)options, data);
1902 	if (error < 0)
1903 		goto out;
1904 
1905 	/* compare new mount options with old ones */
1906 	error = nfs_compare_remount_data(nfss, data);
1907 out:
1908 	kfree(data);
1909 	unlock_kernel();
1910 	return error;
1911 }
1912 
1913 /*
1914  * Initialise the common bits of the superblock
1915  */
1916 static inline void nfs_initialise_sb(struct super_block *sb)
1917 {
1918 	struct nfs_server *server = NFS_SB(sb);
1919 
1920 	sb->s_magic = NFS_SUPER_MAGIC;
1921 
1922 	/* We probably want something more informative here */
1923 	snprintf(sb->s_id, sizeof(sb->s_id),
1924 		 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1925 
1926 	if (sb->s_blocksize == 0)
1927 		sb->s_blocksize = nfs_block_bits(server->wsize,
1928 						 &sb->s_blocksize_bits);
1929 
1930 	if (server->flags & NFS_MOUNT_NOAC)
1931 		sb->s_flags |= MS_SYNCHRONOUS;
1932 
1933 	sb->s_bdi = &server->backing_dev_info;
1934 
1935 	nfs_super_set_maxbytes(sb, server->maxfilesize);
1936 }
1937 
1938 /*
1939  * Finish setting up an NFS2/3 superblock
1940  */
1941 static void nfs_fill_super(struct super_block *sb,
1942 			   struct nfs_parsed_mount_data *data)
1943 {
1944 	struct nfs_server *server = NFS_SB(sb);
1945 
1946 	sb->s_blocksize_bits = 0;
1947 	sb->s_blocksize = 0;
1948 	if (data->bsize)
1949 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1950 
1951 	if (server->nfs_client->rpc_ops->version == 3) {
1952 		/* The VFS shouldn't apply the umask to mode bits. We will do
1953 		 * so ourselves when necessary.
1954 		 */
1955 		sb->s_flags |= MS_POSIXACL;
1956 		sb->s_time_gran = 1;
1957 	}
1958 
1959 	sb->s_op = &nfs_sops;
1960  	nfs_initialise_sb(sb);
1961 }
1962 
1963 /*
1964  * Finish setting up a cloned NFS2/3 superblock
1965  */
1966 static void nfs_clone_super(struct super_block *sb,
1967 			    const struct super_block *old_sb)
1968 {
1969 	struct nfs_server *server = NFS_SB(sb);
1970 
1971 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1972 	sb->s_blocksize = old_sb->s_blocksize;
1973 	sb->s_maxbytes = old_sb->s_maxbytes;
1974 
1975 	if (server->nfs_client->rpc_ops->version == 3) {
1976 		/* The VFS shouldn't apply the umask to mode bits. We will do
1977 		 * so ourselves when necessary.
1978 		 */
1979 		sb->s_flags |= MS_POSIXACL;
1980 		sb->s_time_gran = 1;
1981 	}
1982 
1983 	sb->s_op = old_sb->s_op;
1984  	nfs_initialise_sb(sb);
1985 }
1986 
1987 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1988 {
1989 	const struct nfs_server *a = s->s_fs_info;
1990 	const struct rpc_clnt *clnt_a = a->client;
1991 	const struct rpc_clnt *clnt_b = b->client;
1992 
1993 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1994 		goto Ebusy;
1995 	if (a->nfs_client != b->nfs_client)
1996 		goto Ebusy;
1997 	if (a->flags != b->flags)
1998 		goto Ebusy;
1999 	if (a->wsize != b->wsize)
2000 		goto Ebusy;
2001 	if (a->rsize != b->rsize)
2002 		goto Ebusy;
2003 	if (a->acregmin != b->acregmin)
2004 		goto Ebusy;
2005 	if (a->acregmax != b->acregmax)
2006 		goto Ebusy;
2007 	if (a->acdirmin != b->acdirmin)
2008 		goto Ebusy;
2009 	if (a->acdirmax != b->acdirmax)
2010 		goto Ebusy;
2011 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2012 		goto Ebusy;
2013 	return 1;
2014 Ebusy:
2015 	return 0;
2016 }
2017 
2018 struct nfs_sb_mountdata {
2019 	struct nfs_server *server;
2020 	int mntflags;
2021 };
2022 
2023 static int nfs_set_super(struct super_block *s, void *data)
2024 {
2025 	struct nfs_sb_mountdata *sb_mntdata = data;
2026 	struct nfs_server *server = sb_mntdata->server;
2027 	int ret;
2028 
2029 	s->s_flags = sb_mntdata->mntflags;
2030 	s->s_fs_info = server;
2031 	ret = set_anon_super(s, server);
2032 	if (ret == 0)
2033 		server->s_dev = s->s_dev;
2034 	return ret;
2035 }
2036 
2037 static int nfs_compare_super_address(struct nfs_server *server1,
2038 				     struct nfs_server *server2)
2039 {
2040 	struct sockaddr *sap1, *sap2;
2041 
2042 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2043 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2044 
2045 	if (sap1->sa_family != sap2->sa_family)
2046 		return 0;
2047 
2048 	switch (sap1->sa_family) {
2049 	case AF_INET: {
2050 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2051 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2052 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2053 			return 0;
2054 		if (sin1->sin_port != sin2->sin_port)
2055 			return 0;
2056 		break;
2057 	}
2058 	case AF_INET6: {
2059 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2060 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2061 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2062 			return 0;
2063 		if (sin1->sin6_port != sin2->sin6_port)
2064 			return 0;
2065 		break;
2066 	}
2067 	default:
2068 		return 0;
2069 	}
2070 
2071 	return 1;
2072 }
2073 
2074 static int nfs_compare_super(struct super_block *sb, void *data)
2075 {
2076 	struct nfs_sb_mountdata *sb_mntdata = data;
2077 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2078 	int mntflags = sb_mntdata->mntflags;
2079 
2080 	if (!nfs_compare_super_address(old, server))
2081 		return 0;
2082 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2083 	if (old->flags & NFS_MOUNT_UNSHARED)
2084 		return 0;
2085 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2086 		return 0;
2087 	return nfs_compare_mount_options(sb, server, mntflags);
2088 }
2089 
2090 static int nfs_bdi_register(struct nfs_server *server)
2091 {
2092 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2093 }
2094 
2095 static int nfs_get_sb(struct file_system_type *fs_type,
2096 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2097 {
2098 	struct nfs_server *server = NULL;
2099 	struct super_block *s;
2100 	struct nfs_parsed_mount_data *data;
2101 	struct nfs_fh *mntfh;
2102 	struct dentry *mntroot;
2103 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2104 	struct nfs_sb_mountdata sb_mntdata = {
2105 		.mntflags = flags,
2106 	};
2107 	int error = -ENOMEM;
2108 
2109 	data = nfs_alloc_parsed_mount_data(NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
2110 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2111 	if (data == NULL || mntfh == NULL)
2112 		goto out_free_fh;
2113 
2114 	security_init_mnt_opts(&data->lsm_opts);
2115 
2116 	/* Validate the mount data */
2117 	error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2118 	if (error < 0)
2119 		goto out;
2120 
2121 #ifdef CONFIG_NFS_V4
2122 	if (data->version == 4) {
2123 		error = nfs4_try_mount(flags, dev_name, data, mnt);
2124 		kfree(data->client_address);
2125 		goto out;
2126 	}
2127 #endif	/* CONFIG_NFS_V4 */
2128 
2129 	/* Get a volume representation */
2130 	server = nfs_create_server(data, mntfh);
2131 	if (IS_ERR(server)) {
2132 		error = PTR_ERR(server);
2133 		goto out;
2134 	}
2135 	sb_mntdata.server = server;
2136 
2137 	if (server->flags & NFS_MOUNT_UNSHARED)
2138 		compare_super = NULL;
2139 
2140 	/* Get a superblock - note that we may end up sharing one that already exists */
2141 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2142 	if (IS_ERR(s)) {
2143 		error = PTR_ERR(s);
2144 		goto out_err_nosb;
2145 	}
2146 
2147 	if (s->s_fs_info != server) {
2148 		nfs_free_server(server);
2149 		server = NULL;
2150 	} else {
2151 		error = nfs_bdi_register(server);
2152 		if (error)
2153 			goto error_splat_super;
2154 	}
2155 
2156 	if (!s->s_root) {
2157 		/* initial superblock/root creation */
2158 		nfs_fill_super(s, data);
2159 		nfs_fscache_get_super_cookie(
2160 			s, data ? data->fscache_uniq : NULL, NULL);
2161 	}
2162 
2163 	mntroot = nfs_get_root(s, mntfh);
2164 	if (IS_ERR(mntroot)) {
2165 		error = PTR_ERR(mntroot);
2166 		goto error_splat_super;
2167 	}
2168 
2169 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2170 	if (error)
2171 		goto error_splat_root;
2172 
2173 	s->s_flags |= MS_ACTIVE;
2174 	mnt->mnt_sb = s;
2175 	mnt->mnt_root = mntroot;
2176 	error = 0;
2177 
2178 out:
2179 	kfree(data->nfs_server.hostname);
2180 	kfree(data->mount_server.hostname);
2181 	kfree(data->fscache_uniq);
2182 	security_free_mnt_opts(&data->lsm_opts);
2183 out_free_fh:
2184 	kfree(mntfh);
2185 	kfree(data);
2186 	return error;
2187 
2188 out_err_nosb:
2189 	nfs_free_server(server);
2190 	goto out;
2191 
2192 error_splat_root:
2193 	dput(mntroot);
2194 error_splat_super:
2195 	deactivate_locked_super(s);
2196 	goto out;
2197 }
2198 
2199 /*
2200  * Destroy an NFS2/3 superblock
2201  */
2202 static void nfs_kill_super(struct super_block *s)
2203 {
2204 	struct nfs_server *server = NFS_SB(s);
2205 
2206 	kill_anon_super(s);
2207 	bdi_unregister(&server->backing_dev_info);
2208 	nfs_fscache_release_super_cookie(s);
2209 	nfs_free_server(server);
2210 }
2211 
2212 /*
2213  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2214  */
2215 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2216 			   const char *dev_name, void *raw_data,
2217 			   struct vfsmount *mnt)
2218 {
2219 	struct nfs_clone_mount *data = raw_data;
2220 	struct super_block *s;
2221 	struct nfs_server *server;
2222 	struct dentry *mntroot;
2223 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2224 	struct nfs_sb_mountdata sb_mntdata = {
2225 		.mntflags = flags,
2226 	};
2227 	int error;
2228 
2229 	dprintk("--> nfs_xdev_get_sb()\n");
2230 
2231 	/* create a new volume representation */
2232 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2233 	if (IS_ERR(server)) {
2234 		error = PTR_ERR(server);
2235 		goto out_err_noserver;
2236 	}
2237 	sb_mntdata.server = server;
2238 
2239 	if (server->flags & NFS_MOUNT_UNSHARED)
2240 		compare_super = NULL;
2241 
2242 	/* Get a superblock - note that we may end up sharing one that already exists */
2243 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2244 	if (IS_ERR(s)) {
2245 		error = PTR_ERR(s);
2246 		goto out_err_nosb;
2247 	}
2248 
2249 	if (s->s_fs_info != server) {
2250 		nfs_free_server(server);
2251 		server = NULL;
2252 	} else {
2253 		error = nfs_bdi_register(server);
2254 		if (error)
2255 			goto error_splat_super;
2256 	}
2257 
2258 	if (!s->s_root) {
2259 		/* initial superblock/root creation */
2260 		nfs_clone_super(s, data->sb);
2261 		nfs_fscache_get_super_cookie(s, NULL, data);
2262 	}
2263 
2264 	mntroot = nfs_get_root(s, data->fh);
2265 	if (IS_ERR(mntroot)) {
2266 		error = PTR_ERR(mntroot);
2267 		goto error_splat_super;
2268 	}
2269 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2270 		dput(mntroot);
2271 		error = -ESTALE;
2272 		goto error_splat_super;
2273 	}
2274 
2275 	s->s_flags |= MS_ACTIVE;
2276 	mnt->mnt_sb = s;
2277 	mnt->mnt_root = mntroot;
2278 
2279 	/* clone any lsm security options from the parent to the new sb */
2280 	security_sb_clone_mnt_opts(data->sb, s);
2281 
2282 	dprintk("<-- nfs_xdev_get_sb() = 0\n");
2283 	return 0;
2284 
2285 out_err_nosb:
2286 	nfs_free_server(server);
2287 out_err_noserver:
2288 	dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2289 	return error;
2290 
2291 error_splat_super:
2292 	deactivate_locked_super(s);
2293 	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2294 	return error;
2295 }
2296 
2297 #ifdef CONFIG_NFS_V4
2298 
2299 /*
2300  * Finish setting up a cloned NFS4 superblock
2301  */
2302 static void nfs4_clone_super(struct super_block *sb,
2303 			    const struct super_block *old_sb)
2304 {
2305 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2306 	sb->s_blocksize = old_sb->s_blocksize;
2307 	sb->s_maxbytes = old_sb->s_maxbytes;
2308 	sb->s_time_gran = 1;
2309 	sb->s_op = old_sb->s_op;
2310  	nfs_initialise_sb(sb);
2311 }
2312 
2313 /*
2314  * Set up an NFS4 superblock
2315  */
2316 static void nfs4_fill_super(struct super_block *sb)
2317 {
2318 	sb->s_time_gran = 1;
2319 	sb->s_op = &nfs4_sops;
2320 	nfs_initialise_sb(sb);
2321 }
2322 
2323 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2324 {
2325 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2326 }
2327 
2328 static int nfs4_validate_text_mount_data(void *options,
2329 					 struct nfs_parsed_mount_data *args,
2330 					 const char *dev_name)
2331 {
2332 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2333 
2334 	nfs_set_default_port(sap, args->nfs_server.port, NFS_PORT);
2335 
2336 	nfs_validate_transport_protocol(args);
2337 
2338 	nfs4_validate_mount_flags(args);
2339 
2340 	if (args->version != 4) {
2341 		dfprintk(MOUNT,
2342 			 "NFS4: Illegal mount version\n");
2343 		return -EINVAL;
2344 	}
2345 
2346 	if (args->auth_flavor_len > 1) {
2347 		dfprintk(MOUNT,
2348 			 "NFS4: Too many RPC auth flavours specified\n");
2349 		return -EINVAL;
2350 	}
2351 
2352 	if (args->client_address == NULL) {
2353 		dfprintk(MOUNT,
2354 			 "NFS4: mount program didn't pass callback address\n");
2355 		return -EINVAL;
2356 	}
2357 
2358 	return nfs_parse_devname(dev_name,
2359 				   &args->nfs_server.hostname,
2360 				   NFS4_MAXNAMLEN,
2361 				   &args->nfs_server.export_path,
2362 				   NFS4_MAXPATHLEN);
2363 }
2364 
2365 /*
2366  * Validate NFSv4 mount options
2367  */
2368 static int nfs4_validate_mount_data(void *options,
2369 				    struct nfs_parsed_mount_data *args,
2370 				    const char *dev_name)
2371 {
2372 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2373 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2374 	char *c;
2375 
2376 	if (data == NULL)
2377 		goto out_no_data;
2378 
2379 	args->version		= 4;
2380 	switch (data->version) {
2381 	case 1:
2382 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2383 			goto out_no_address;
2384 		if (data->host_addrlen == 0)
2385 			goto out_no_address;
2386 		args->nfs_server.addrlen = data->host_addrlen;
2387 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2388 			return -EFAULT;
2389 		if (!nfs_verify_server_address(sap))
2390 			goto out_no_address;
2391 
2392 		if (data->auth_flavourlen) {
2393 			if (data->auth_flavourlen > 1)
2394 				goto out_inval_auth;
2395 			if (copy_from_user(&args->auth_flavors[0],
2396 					   data->auth_flavours,
2397 					   sizeof(args->auth_flavors[0])))
2398 				return -EFAULT;
2399 		}
2400 
2401 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2402 		if (IS_ERR(c))
2403 			return PTR_ERR(c);
2404 		args->nfs_server.hostname = c;
2405 
2406 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2407 		if (IS_ERR(c))
2408 			return PTR_ERR(c);
2409 		args->nfs_server.export_path = c;
2410 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2411 
2412 		c = strndup_user(data->client_addr.data, 16);
2413 		if (IS_ERR(c))
2414 			return PTR_ERR(c);
2415 		args->client_address = c;
2416 
2417 		/*
2418 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2419 		 * can deal with.
2420 		 */
2421 
2422 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2423 		args->rsize	= data->rsize;
2424 		args->wsize	= data->wsize;
2425 		args->timeo	= data->timeo;
2426 		args->retrans	= data->retrans;
2427 		args->acregmin	= data->acregmin;
2428 		args->acregmax	= data->acregmax;
2429 		args->acdirmin	= data->acdirmin;
2430 		args->acdirmax	= data->acdirmax;
2431 		args->nfs_server.protocol = data->proto;
2432 		nfs_validate_transport_protocol(args);
2433 
2434 		break;
2435 	default:
2436 		if (nfs_parse_mount_options((char *)options, args) == 0)
2437 			return -EINVAL;
2438 
2439 		if (!nfs_verify_server_address(sap))
2440 			return -EINVAL;
2441 
2442 		return nfs4_validate_text_mount_data(options, args, dev_name);
2443 	}
2444 
2445 	return 0;
2446 
2447 out_no_data:
2448 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2449 	return -EINVAL;
2450 
2451 out_inval_auth:
2452 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2453 		 data->auth_flavourlen);
2454 	return -EINVAL;
2455 
2456 out_no_address:
2457 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2458 	return -EINVAL;
2459 }
2460 
2461 /*
2462  * Get the superblock for the NFS4 root partition
2463  */
2464 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2465 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2466 {
2467 	struct nfs_parsed_mount_data *data = raw_data;
2468 	struct super_block *s;
2469 	struct nfs_server *server;
2470 	struct nfs_fh *mntfh;
2471 	struct dentry *mntroot;
2472 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2473 	struct nfs_sb_mountdata sb_mntdata = {
2474 		.mntflags = flags,
2475 	};
2476 	int error = -ENOMEM;
2477 
2478 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2479 	if (data == NULL || mntfh == NULL)
2480 		goto out_free_fh;
2481 
2482 	security_init_mnt_opts(&data->lsm_opts);
2483 
2484 	/* Get a volume representation */
2485 	server = nfs4_create_server(data, mntfh);
2486 	if (IS_ERR(server)) {
2487 		error = PTR_ERR(server);
2488 		goto out;
2489 	}
2490 	sb_mntdata.server = server;
2491 
2492 	if (server->flags & NFS4_MOUNT_UNSHARED)
2493 		compare_super = NULL;
2494 
2495 	/* Get a superblock - note that we may end up sharing one that already exists */
2496 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2497 	if (IS_ERR(s)) {
2498 		error = PTR_ERR(s);
2499 		goto out_free;
2500 	}
2501 
2502 	if (s->s_fs_info != server) {
2503 		nfs_free_server(server);
2504 		server = NULL;
2505 	} else {
2506 		error = nfs_bdi_register(server);
2507 		if (error)
2508 			goto error_splat_super;
2509 	}
2510 
2511 	if (!s->s_root) {
2512 		/* initial superblock/root creation */
2513 		nfs4_fill_super(s);
2514 		nfs_fscache_get_super_cookie(
2515 			s, data ? data->fscache_uniq : NULL, NULL);
2516 	}
2517 
2518 	mntroot = nfs4_get_root(s, mntfh);
2519 	if (IS_ERR(mntroot)) {
2520 		error = PTR_ERR(mntroot);
2521 		goto error_splat_super;
2522 	}
2523 
2524 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2525 	if (error)
2526 		goto error_splat_root;
2527 
2528 	s->s_flags |= MS_ACTIVE;
2529 	mnt->mnt_sb = s;
2530 	mnt->mnt_root = mntroot;
2531 	error = 0;
2532 
2533 out:
2534 	security_free_mnt_opts(&data->lsm_opts);
2535 out_free_fh:
2536 	kfree(mntfh);
2537 	return error;
2538 
2539 out_free:
2540 	nfs_free_server(server);
2541 	goto out;
2542 
2543 error_splat_root:
2544 	dput(mntroot);
2545 error_splat_super:
2546 	deactivate_locked_super(s);
2547 	goto out;
2548 }
2549 
2550 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2551 		int flags, void *data, const char *hostname)
2552 {
2553 	struct vfsmount *root_mnt;
2554 	char *root_devname;
2555 	size_t len;
2556 
2557 	len = strlen(hostname) + 3;
2558 	root_devname = kmalloc(len, GFP_KERNEL);
2559 	if (root_devname == NULL)
2560 		return ERR_PTR(-ENOMEM);
2561 	snprintf(root_devname, len, "%s:/", hostname);
2562 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2563 	kfree(root_devname);
2564 	return root_mnt;
2565 }
2566 
2567 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2568 {
2569 	char *page = (char *) __get_free_page(GFP_KERNEL);
2570 	char *devname, *tmp;
2571 
2572 	if (page == NULL)
2573 		return;
2574 	devname = nfs_path(path->mnt->mnt_devname,
2575 			path->mnt->mnt_root, path->dentry,
2576 			page, PAGE_SIZE);
2577 	if (devname == NULL)
2578 		goto out_freepage;
2579 	tmp = kstrdup(devname, GFP_KERNEL);
2580 	if (tmp == NULL)
2581 		goto out_freepage;
2582 	kfree(mnt->mnt_devname);
2583 	mnt->mnt_devname = tmp;
2584 out_freepage:
2585 	free_page((unsigned long)page);
2586 }
2587 
2588 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2589 		const char *export_path, struct vfsmount *mnt_target)
2590 {
2591 	struct mnt_namespace *ns_private;
2592 	struct nameidata nd;
2593 	struct super_block *s;
2594 	int ret;
2595 
2596 	ns_private = create_mnt_ns(root_mnt);
2597 	ret = PTR_ERR(ns_private);
2598 	if (IS_ERR(ns_private))
2599 		goto out_mntput;
2600 
2601 	ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2602 			export_path, LOOKUP_FOLLOW, &nd);
2603 
2604 	put_mnt_ns(ns_private);
2605 
2606 	if (ret != 0)
2607 		goto out_err;
2608 
2609 	s = nd.path.mnt->mnt_sb;
2610 	atomic_inc(&s->s_active);
2611 	mnt_target->mnt_sb = s;
2612 	mnt_target->mnt_root = dget(nd.path.dentry);
2613 
2614 	/* Correct the device pathname */
2615 	nfs_fix_devname(&nd.path, mnt_target);
2616 
2617 	path_put(&nd.path);
2618 	down_write(&s->s_umount);
2619 	return 0;
2620 out_mntput:
2621 	mntput(root_mnt);
2622 out_err:
2623 	return ret;
2624 }
2625 
2626 static int nfs4_try_mount(int flags, const char *dev_name,
2627 			 struct nfs_parsed_mount_data *data,
2628 			 struct vfsmount *mnt)
2629 {
2630 	char *export_path;
2631 	struct vfsmount *root_mnt;
2632 	int error;
2633 
2634 	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2635 
2636 	export_path = data->nfs_server.export_path;
2637 	data->nfs_server.export_path = "/";
2638 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2639 			data->nfs_server.hostname);
2640 	data->nfs_server.export_path = export_path;
2641 
2642 	error = PTR_ERR(root_mnt);
2643 	if (IS_ERR(root_mnt))
2644 		goto out;
2645 
2646 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2647 
2648 out:
2649 	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2650 			error != 0 ? " [error]" : "");
2651 	return error;
2652 }
2653 
2654 /*
2655  * Get the superblock for an NFS4 mountpoint
2656  */
2657 static int nfs4_get_sb(struct file_system_type *fs_type,
2658 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2659 {
2660 	struct nfs_parsed_mount_data *data;
2661 	int error = -ENOMEM;
2662 
2663 	data = nfs_alloc_parsed_mount_data(0);
2664 	if (data == NULL)
2665 		goto out_free_data;
2666 
2667 	/* Validate the mount data */
2668 	error = nfs4_validate_mount_data(raw_data, data, dev_name);
2669 	if (error < 0)
2670 		goto out;
2671 
2672 	error = nfs4_try_mount(flags, dev_name, data, mnt);
2673 
2674 out:
2675 	kfree(data->client_address);
2676 	kfree(data->nfs_server.export_path);
2677 	kfree(data->nfs_server.hostname);
2678 	kfree(data->fscache_uniq);
2679 out_free_data:
2680 	kfree(data);
2681 	dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2682 			error != 0 ? " [error]" : "");
2683 	return error;
2684 }
2685 
2686 static void nfs4_kill_super(struct super_block *sb)
2687 {
2688 	struct nfs_server *server = NFS_SB(sb);
2689 
2690 	dprintk("--> %s\n", __func__);
2691 	nfs_super_return_all_delegations(sb);
2692 	kill_anon_super(sb);
2693 	nfs4_renewd_prepare_shutdown(server);
2694 	nfs_fscache_release_super_cookie(sb);
2695 	nfs_free_server(server);
2696 	dprintk("<-- %s\n", __func__);
2697 }
2698 
2699 /*
2700  * Clone an NFS4 server record on xdev traversal (FSID-change)
2701  */
2702 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2703 			    const char *dev_name, void *raw_data,
2704 			    struct vfsmount *mnt)
2705 {
2706 	struct nfs_clone_mount *data = raw_data;
2707 	struct super_block *s;
2708 	struct nfs_server *server;
2709 	struct dentry *mntroot;
2710 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2711 	struct nfs_sb_mountdata sb_mntdata = {
2712 		.mntflags = flags,
2713 	};
2714 	int error;
2715 
2716 	dprintk("--> nfs4_xdev_get_sb()\n");
2717 
2718 	/* create a new volume representation */
2719 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2720 	if (IS_ERR(server)) {
2721 		error = PTR_ERR(server);
2722 		goto out_err_noserver;
2723 	}
2724 	sb_mntdata.server = server;
2725 
2726 	if (server->flags & NFS4_MOUNT_UNSHARED)
2727 		compare_super = NULL;
2728 
2729 	/* Get a superblock - note that we may end up sharing one that already exists */
2730 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2731 	if (IS_ERR(s)) {
2732 		error = PTR_ERR(s);
2733 		goto out_err_nosb;
2734 	}
2735 
2736 	if (s->s_fs_info != server) {
2737 		nfs_free_server(server);
2738 		server = NULL;
2739 	} else {
2740 		error = nfs_bdi_register(server);
2741 		if (error)
2742 			goto error_splat_super;
2743 	}
2744 
2745 	if (!s->s_root) {
2746 		/* initial superblock/root creation */
2747 		nfs4_clone_super(s, data->sb);
2748 		nfs_fscache_get_super_cookie(s, NULL, data);
2749 	}
2750 
2751 	mntroot = nfs4_get_root(s, data->fh);
2752 	if (IS_ERR(mntroot)) {
2753 		error = PTR_ERR(mntroot);
2754 		goto error_splat_super;
2755 	}
2756 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2757 		dput(mntroot);
2758 		error = -ESTALE;
2759 		goto error_splat_super;
2760 	}
2761 
2762 	s->s_flags |= MS_ACTIVE;
2763 	mnt->mnt_sb = s;
2764 	mnt->mnt_root = mntroot;
2765 
2766 	security_sb_clone_mnt_opts(data->sb, s);
2767 
2768 	dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2769 	return 0;
2770 
2771 out_err_nosb:
2772 	nfs_free_server(server);
2773 out_err_noserver:
2774 	dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2775 	return error;
2776 
2777 error_splat_super:
2778 	deactivate_locked_super(s);
2779 	dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2780 	return error;
2781 }
2782 
2783 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2784 		int flags, const char *dev_name, void *raw_data,
2785 		struct vfsmount *mnt)
2786 {
2787 	struct nfs_clone_mount *data = raw_data;
2788 	struct super_block *s;
2789 	struct nfs_server *server;
2790 	struct dentry *mntroot;
2791 	struct nfs_fh mntfh;
2792 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2793 	struct nfs_sb_mountdata sb_mntdata = {
2794 		.mntflags = flags,
2795 	};
2796 	int error;
2797 
2798 	dprintk("--> nfs4_referral_get_sb()\n");
2799 
2800 	/* create a new volume representation */
2801 	server = nfs4_create_referral_server(data, &mntfh);
2802 	if (IS_ERR(server)) {
2803 		error = PTR_ERR(server);
2804 		goto out_err_noserver;
2805 	}
2806 	sb_mntdata.server = server;
2807 
2808 	if (server->flags & NFS4_MOUNT_UNSHARED)
2809 		compare_super = NULL;
2810 
2811 	/* Get a superblock - note that we may end up sharing one that already exists */
2812 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2813 	if (IS_ERR(s)) {
2814 		error = PTR_ERR(s);
2815 		goto out_err_nosb;
2816 	}
2817 
2818 	if (s->s_fs_info != server) {
2819 		nfs_free_server(server);
2820 		server = NULL;
2821 	} else {
2822 		error = nfs_bdi_register(server);
2823 		if (error)
2824 			goto error_splat_super;
2825 	}
2826 
2827 	if (!s->s_root) {
2828 		/* initial superblock/root creation */
2829 		nfs4_fill_super(s);
2830 		nfs_fscache_get_super_cookie(s, NULL, data);
2831 	}
2832 
2833 	mntroot = nfs4_get_root(s, &mntfh);
2834 	if (IS_ERR(mntroot)) {
2835 		error = PTR_ERR(mntroot);
2836 		goto error_splat_super;
2837 	}
2838 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2839 		dput(mntroot);
2840 		error = -ESTALE;
2841 		goto error_splat_super;
2842 	}
2843 
2844 	s->s_flags |= MS_ACTIVE;
2845 	mnt->mnt_sb = s;
2846 	mnt->mnt_root = mntroot;
2847 
2848 	security_sb_clone_mnt_opts(data->sb, s);
2849 
2850 	dprintk("<-- nfs4_referral_get_sb() = 0\n");
2851 	return 0;
2852 
2853 out_err_nosb:
2854 	nfs_free_server(server);
2855 out_err_noserver:
2856 	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2857 	return error;
2858 
2859 error_splat_super:
2860 	deactivate_locked_super(s);
2861 	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2862 	return error;
2863 }
2864 
2865 /*
2866  * Create an NFS4 server record on referral traversal
2867  */
2868 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2869 		int flags, const char *dev_name, void *raw_data,
2870 		struct vfsmount *mnt)
2871 {
2872 	struct nfs_clone_mount *data = raw_data;
2873 	char *export_path;
2874 	struct vfsmount *root_mnt;
2875 	int error;
2876 
2877 	dprintk("--> nfs4_referral_get_sb()\n");
2878 
2879 	export_path = data->mnt_path;
2880 	data->mnt_path = "/";
2881 
2882 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2883 			flags, data, data->hostname);
2884 	data->mnt_path = export_path;
2885 
2886 	error = PTR_ERR(root_mnt);
2887 	if (IS_ERR(root_mnt))
2888 		goto out;
2889 
2890 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2891 out:
2892 	dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2893 			error != 0 ? " [error]" : "");
2894 	return error;
2895 }
2896 
2897 #endif /* CONFIG_NFS_V4 */
2898