xref: /linux/fs/nfs/super.c (revision 27258e448eb301cf89e351df87aa8cb916653bf2)
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 /*
732  * Sanity-check a server address provided by the mount command.
733  *
734  * Address family must be initialized, and address must not be
735  * the ANY address for that family.
736  */
737 static int nfs_verify_server_address(struct sockaddr *addr)
738 {
739 	switch (addr->sa_family) {
740 	case AF_INET: {
741 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
742 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
743 	}
744 	case AF_INET6: {
745 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
746 		return !ipv6_addr_any(sa);
747 	}
748 	}
749 
750 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
751 	return 0;
752 }
753 
754 /*
755  * Select between a default port value and a user-specified port value.
756  * If a zero value is set, then autobind will be used.
757  */
758 static void nfs_set_default_port(struct sockaddr *sap, const int parsed_port,
759 				 const unsigned short default_port)
760 {
761 	unsigned short port = default_port;
762 
763 	if (parsed_port != NFS_UNSPEC_PORT)
764 		port = parsed_port;
765 
766 	rpc_set_port(sap, port);
767 }
768 
769 /*
770  * Sanity check the NFS transport protocol.
771  *
772  */
773 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
774 {
775 	switch (mnt->nfs_server.protocol) {
776 	case XPRT_TRANSPORT_UDP:
777 	case XPRT_TRANSPORT_TCP:
778 	case XPRT_TRANSPORT_RDMA:
779 		break;
780 	default:
781 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
782 	}
783 }
784 
785 /*
786  * For text based NFSv2/v3 mounts, the mount protocol transport default
787  * settings should depend upon the specified NFS transport.
788  */
789 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
790 {
791 	nfs_validate_transport_protocol(mnt);
792 
793 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
794 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
795 			return;
796 	switch (mnt->nfs_server.protocol) {
797 	case XPRT_TRANSPORT_UDP:
798 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
799 		break;
800 	case XPRT_TRANSPORT_TCP:
801 	case XPRT_TRANSPORT_RDMA:
802 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
803 	}
804 }
805 
806 /*
807  * Parse the value of the 'sec=' option.
808  */
809 static int nfs_parse_security_flavors(char *value,
810 				      struct nfs_parsed_mount_data *mnt)
811 {
812 	substring_t args[MAX_OPT_ARGS];
813 
814 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
815 
816 	switch (match_token(value, nfs_secflavor_tokens, args)) {
817 	case Opt_sec_none:
818 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
819 		break;
820 	case Opt_sec_sys:
821 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
822 		break;
823 	case Opt_sec_krb5:
824 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
825 		break;
826 	case Opt_sec_krb5i:
827 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
828 		break;
829 	case Opt_sec_krb5p:
830 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
831 		break;
832 	case Opt_sec_lkey:
833 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
834 		break;
835 	case Opt_sec_lkeyi:
836 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
837 		break;
838 	case Opt_sec_lkeyp:
839 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
840 		break;
841 	case Opt_sec_spkm:
842 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
843 		break;
844 	case Opt_sec_spkmi:
845 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
846 		break;
847 	case Opt_sec_spkmp:
848 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
849 		break;
850 	default:
851 		return 0;
852 	}
853 
854 	mnt->auth_flavor_len = 1;
855 	return 1;
856 }
857 
858 /*
859  * Error-check and convert a string of mount options from user space into
860  * a data structure.  The whole mount string is processed; bad options are
861  * skipped as they are encountered.  If there were no errors, return 1;
862  * otherwise return 0 (zero).
863  */
864 static int nfs_parse_mount_options(char *raw,
865 				   struct nfs_parsed_mount_data *mnt)
866 {
867 	char *p, *string, *secdata;
868 	int rc, sloppy = 0, invalid_option = 0;
869 
870 	if (!raw) {
871 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
872 		return 1;
873 	}
874 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
875 
876 	secdata = alloc_secdata();
877 	if (!secdata)
878 		goto out_nomem;
879 
880 	rc = security_sb_copy_data(raw, secdata);
881 	if (rc)
882 		goto out_security_failure;
883 
884 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
885 	if (rc)
886 		goto out_security_failure;
887 
888 	free_secdata(secdata);
889 
890 	while ((p = strsep(&raw, ",")) != NULL) {
891 		substring_t args[MAX_OPT_ARGS];
892 		unsigned long option;
893 		int token;
894 
895 		if (!*p)
896 			continue;
897 
898 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
899 
900 		token = match_token(p, nfs_mount_option_tokens, args);
901 		switch (token) {
902 
903 		/*
904 		 * boolean options:  foo/nofoo
905 		 */
906 		case Opt_soft:
907 			mnt->flags |= NFS_MOUNT_SOFT;
908 			break;
909 		case Opt_hard:
910 			mnt->flags &= ~NFS_MOUNT_SOFT;
911 			break;
912 		case Opt_posix:
913 			mnt->flags |= NFS_MOUNT_POSIX;
914 			break;
915 		case Opt_noposix:
916 			mnt->flags &= ~NFS_MOUNT_POSIX;
917 			break;
918 		case Opt_cto:
919 			mnt->flags &= ~NFS_MOUNT_NOCTO;
920 			break;
921 		case Opt_nocto:
922 			mnt->flags |= NFS_MOUNT_NOCTO;
923 			break;
924 		case Opt_ac:
925 			mnt->flags &= ~NFS_MOUNT_NOAC;
926 			break;
927 		case Opt_noac:
928 			mnt->flags |= NFS_MOUNT_NOAC;
929 			break;
930 		case Opt_lock:
931 			mnt->flags &= ~NFS_MOUNT_NONLM;
932 			break;
933 		case Opt_nolock:
934 			mnt->flags |= NFS_MOUNT_NONLM;
935 			break;
936 		case Opt_v2:
937 			mnt->flags &= ~NFS_MOUNT_VER3;
938 			mnt->version = 2;
939 			break;
940 		case Opt_v3:
941 			mnt->flags |= NFS_MOUNT_VER3;
942 			mnt->version = 3;
943 			break;
944 #ifdef CONFIG_NFS_V4
945 		case Opt_v4:
946 			mnt->flags &= ~NFS_MOUNT_VER3;
947 			mnt->version = 4;
948 			break;
949 #endif
950 		case Opt_udp:
951 			mnt->flags &= ~NFS_MOUNT_TCP;
952 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
953 			break;
954 		case Opt_tcp:
955 			mnt->flags |= NFS_MOUNT_TCP;
956 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
957 			break;
958 		case Opt_rdma:
959 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
960 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
961 			xprt_load_transport(p);
962 			break;
963 		case Opt_acl:
964 			mnt->flags &= ~NFS_MOUNT_NOACL;
965 			break;
966 		case Opt_noacl:
967 			mnt->flags |= NFS_MOUNT_NOACL;
968 			break;
969 		case Opt_rdirplus:
970 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
971 			break;
972 		case Opt_nordirplus:
973 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
974 			break;
975 		case Opt_sharecache:
976 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
977 			break;
978 		case Opt_nosharecache:
979 			mnt->flags |= NFS_MOUNT_UNSHARED;
980 			break;
981 		case Opt_resvport:
982 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
983 			break;
984 		case Opt_noresvport:
985 			mnt->flags |= NFS_MOUNT_NORESVPORT;
986 			break;
987 		case Opt_fscache:
988 			mnt->options |= NFS_OPTION_FSCACHE;
989 			kfree(mnt->fscache_uniq);
990 			mnt->fscache_uniq = NULL;
991 			break;
992 		case Opt_nofscache:
993 			mnt->options &= ~NFS_OPTION_FSCACHE;
994 			kfree(mnt->fscache_uniq);
995 			mnt->fscache_uniq = NULL;
996 			break;
997 		case Opt_fscache_uniq:
998 			string = match_strdup(args);
999 			if (!string)
1000 				goto out_nomem;
1001 			kfree(mnt->fscache_uniq);
1002 			mnt->fscache_uniq = string;
1003 			mnt->options |= NFS_OPTION_FSCACHE;
1004 			break;
1005 
1006 		/*
1007 		 * options that take numeric values
1008 		 */
1009 		case Opt_port:
1010 			string = match_strdup(args);
1011 			if (string == NULL)
1012 				goto out_nomem;
1013 			rc = strict_strtoul(string, 10, &option);
1014 			kfree(string);
1015 			if (rc != 0 || option > USHORT_MAX)
1016 				goto out_invalid_value;
1017 			mnt->nfs_server.port = option;
1018 			break;
1019 		case Opt_rsize:
1020 			string = match_strdup(args);
1021 			if (string == NULL)
1022 				goto out_nomem;
1023 			rc = strict_strtoul(string, 10, &option);
1024 			kfree(string);
1025 			if (rc != 0)
1026 				goto out_invalid_value;
1027 			mnt->rsize = option;
1028 			break;
1029 		case Opt_wsize:
1030 			string = match_strdup(args);
1031 			if (string == NULL)
1032 				goto out_nomem;
1033 			rc = strict_strtoul(string, 10, &option);
1034 			kfree(string);
1035 			if (rc != 0)
1036 				goto out_invalid_value;
1037 			mnt->wsize = option;
1038 			break;
1039 		case Opt_bsize:
1040 			string = match_strdup(args);
1041 			if (string == NULL)
1042 				goto out_nomem;
1043 			rc = strict_strtoul(string, 10, &option);
1044 			kfree(string);
1045 			if (rc != 0)
1046 				goto out_invalid_value;
1047 			mnt->bsize = option;
1048 			break;
1049 		case Opt_timeo:
1050 			string = match_strdup(args);
1051 			if (string == NULL)
1052 				goto out_nomem;
1053 			rc = strict_strtoul(string, 10, &option);
1054 			kfree(string);
1055 			if (rc != 0 || option == 0)
1056 				goto out_invalid_value;
1057 			mnt->timeo = option;
1058 			break;
1059 		case Opt_retrans:
1060 			string = match_strdup(args);
1061 			if (string == NULL)
1062 				goto out_nomem;
1063 			rc = strict_strtoul(string, 10, &option);
1064 			kfree(string);
1065 			if (rc != 0 || option == 0)
1066 				goto out_invalid_value;
1067 			mnt->retrans = option;
1068 			break;
1069 		case Opt_acregmin:
1070 			string = match_strdup(args);
1071 			if (string == NULL)
1072 				goto out_nomem;
1073 			rc = strict_strtoul(string, 10, &option);
1074 			kfree(string);
1075 			if (rc != 0)
1076 				goto out_invalid_value;
1077 			mnt->acregmin = option;
1078 			break;
1079 		case Opt_acregmax:
1080 			string = match_strdup(args);
1081 			if (string == NULL)
1082 				goto out_nomem;
1083 			rc = strict_strtoul(string, 10, &option);
1084 			kfree(string);
1085 			if (rc != 0)
1086 				goto out_invalid_value;
1087 			mnt->acregmax = option;
1088 			break;
1089 		case Opt_acdirmin:
1090 			string = match_strdup(args);
1091 			if (string == NULL)
1092 				goto out_nomem;
1093 			rc = strict_strtoul(string, 10, &option);
1094 			kfree(string);
1095 			if (rc != 0)
1096 				goto out_invalid_value;
1097 			mnt->acdirmin = option;
1098 			break;
1099 		case Opt_acdirmax:
1100 			string = match_strdup(args);
1101 			if (string == NULL)
1102 				goto out_nomem;
1103 			rc = strict_strtoul(string, 10, &option);
1104 			kfree(string);
1105 			if (rc != 0)
1106 				goto out_invalid_value;
1107 			mnt->acdirmax = option;
1108 			break;
1109 		case Opt_actimeo:
1110 			string = match_strdup(args);
1111 			if (string == NULL)
1112 				goto out_nomem;
1113 			rc = strict_strtoul(string, 10, &option);
1114 			kfree(string);
1115 			if (rc != 0)
1116 				goto out_invalid_value;
1117 			mnt->acregmin = mnt->acregmax =
1118 			mnt->acdirmin = mnt->acdirmax = option;
1119 			break;
1120 		case Opt_namelen:
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->namlen = option;
1129 			break;
1130 		case Opt_mountport:
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 || option > USHORT_MAX)
1137 				goto out_invalid_value;
1138 			mnt->mount_server.port = option;
1139 			break;
1140 		case Opt_mountvers:
1141 			string = match_strdup(args);
1142 			if (string == NULL)
1143 				goto out_nomem;
1144 			rc = strict_strtoul(string, 10, &option);
1145 			kfree(string);
1146 			if (rc != 0 ||
1147 			    option < NFS_MNT_VERSION ||
1148 			    option > NFS_MNT3_VERSION)
1149 				goto out_invalid_value;
1150 			mnt->mount_server.version = option;
1151 			break;
1152 		case Opt_nfsvers:
1153 			string = match_strdup(args);
1154 			if (string == NULL)
1155 				goto out_nomem;
1156 			rc = strict_strtoul(string, 10, &option);
1157 			kfree(string);
1158 			if (rc != 0)
1159 				goto out_invalid_value;
1160 			switch (option) {
1161 			case NFS2_VERSION:
1162 				mnt->flags &= ~NFS_MOUNT_VER3;
1163 				mnt->version = 2;
1164 				break;
1165 			case NFS3_VERSION:
1166 				mnt->flags |= NFS_MOUNT_VER3;
1167 				mnt->version = 3;
1168 				break;
1169 #ifdef CONFIG_NFS_V4
1170 			case NFS4_VERSION:
1171 				mnt->flags &= ~NFS_MOUNT_VER3;
1172 				mnt->version = 4;
1173 				break;
1174 #endif
1175 			default:
1176 				goto out_invalid_value;
1177 			}
1178 			break;
1179 		case Opt_minorversion:
1180 			string = match_strdup(args);
1181 			if (string == NULL)
1182 				goto out_nomem;
1183 			rc = strict_strtoul(string, 10, &option);
1184 			kfree(string);
1185 			if (rc != 0)
1186 				goto out_invalid_value;
1187 			if (option > NFS4_MAX_MINOR_VERSION)
1188 				goto out_invalid_value;
1189 			mnt->minorversion = option;
1190 			break;
1191 
1192 		/*
1193 		 * options that take text values
1194 		 */
1195 		case Opt_sec:
1196 			string = match_strdup(args);
1197 			if (string == NULL)
1198 				goto out_nomem;
1199 			rc = nfs_parse_security_flavors(string, mnt);
1200 			kfree(string);
1201 			if (!rc) {
1202 				dfprintk(MOUNT, "NFS:   unrecognized "
1203 						"security flavor\n");
1204 				return 0;
1205 			}
1206 			break;
1207 		case Opt_proto:
1208 			string = match_strdup(args);
1209 			if (string == NULL)
1210 				goto out_nomem;
1211 			token = match_token(string,
1212 					    nfs_xprt_protocol_tokens, args);
1213 
1214 			switch (token) {
1215 			case Opt_xprt_udp:
1216 				mnt->flags &= ~NFS_MOUNT_TCP;
1217 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1218 				kfree(string);
1219 				break;
1220 			case Opt_xprt_tcp:
1221 				mnt->flags |= NFS_MOUNT_TCP;
1222 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1223 				kfree(string);
1224 				break;
1225 			case Opt_xprt_rdma:
1226 				/* vector side protocols to TCP */
1227 				mnt->flags |= NFS_MOUNT_TCP;
1228 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1229 				xprt_load_transport(string);
1230 				kfree(string);
1231 				break;
1232 			default:
1233 				dfprintk(MOUNT, "NFS:   unrecognized "
1234 						"transport protocol\n");
1235 				return 0;
1236 			}
1237 			break;
1238 		case Opt_mountproto:
1239 			string = match_strdup(args);
1240 			if (string == NULL)
1241 				goto out_nomem;
1242 			token = match_token(string,
1243 					    nfs_xprt_protocol_tokens, args);
1244 			kfree(string);
1245 
1246 			switch (token) {
1247 			case Opt_xprt_udp:
1248 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1249 				break;
1250 			case Opt_xprt_tcp:
1251 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1252 				break;
1253 			case Opt_xprt_rdma: /* not used for side protocols */
1254 			default:
1255 				dfprintk(MOUNT, "NFS:   unrecognized "
1256 						"transport protocol\n");
1257 				return 0;
1258 			}
1259 			break;
1260 		case Opt_addr:
1261 			string = match_strdup(args);
1262 			if (string == NULL)
1263 				goto out_nomem;
1264 			mnt->nfs_server.addrlen =
1265 				rpc_pton(string, strlen(string),
1266 					(struct sockaddr *)
1267 					&mnt->nfs_server.address,
1268 					sizeof(mnt->nfs_server.address));
1269 			kfree(string);
1270 			if (mnt->nfs_server.addrlen == 0)
1271 				goto out_invalid_address;
1272 			break;
1273 		case Opt_clientaddr:
1274 			string = match_strdup(args);
1275 			if (string == NULL)
1276 				goto out_nomem;
1277 			kfree(mnt->client_address);
1278 			mnt->client_address = string;
1279 			break;
1280 		case Opt_mounthost:
1281 			string = match_strdup(args);
1282 			if (string == NULL)
1283 				goto out_nomem;
1284 			kfree(mnt->mount_server.hostname);
1285 			mnt->mount_server.hostname = string;
1286 			break;
1287 		case Opt_mountaddr:
1288 			string = match_strdup(args);
1289 			if (string == NULL)
1290 				goto out_nomem;
1291 			mnt->mount_server.addrlen =
1292 				rpc_pton(string, strlen(string),
1293 					(struct sockaddr *)
1294 					&mnt->mount_server.address,
1295 					sizeof(mnt->mount_server.address));
1296 			kfree(string);
1297 			if (mnt->mount_server.addrlen == 0)
1298 				goto out_invalid_address;
1299 			break;
1300 		case Opt_lookupcache:
1301 			string = match_strdup(args);
1302 			if (string == NULL)
1303 				goto out_nomem;
1304 			token = match_token(string,
1305 					nfs_lookupcache_tokens, args);
1306 			kfree(string);
1307 			switch (token) {
1308 				case Opt_lookupcache_all:
1309 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1310 					break;
1311 				case Opt_lookupcache_positive:
1312 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1313 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1314 					break;
1315 				case Opt_lookupcache_none:
1316 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1317 					break;
1318 				default:
1319 					dfprintk(MOUNT, "NFS:   invalid "
1320 							"lookupcache argument\n");
1321 					return 0;
1322 			};
1323 			break;
1324 
1325 		/*
1326 		 * Special options
1327 		 */
1328 		case Opt_sloppy:
1329 			sloppy = 1;
1330 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1331 			break;
1332 		case Opt_userspace:
1333 		case Opt_deprecated:
1334 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1335 					"'%s'\n", p);
1336 			break;
1337 
1338 		default:
1339 			invalid_option = 1;
1340 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1341 					"'%s'\n", p);
1342 		}
1343 	}
1344 
1345 	if (!sloppy && invalid_option)
1346 		return 0;
1347 
1348 	return 1;
1349 
1350 out_invalid_address:
1351 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1352 	return 0;
1353 out_invalid_value:
1354 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1355 	return 0;
1356 out_nomem:
1357 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1358 	return 0;
1359 out_security_failure:
1360 	free_secdata(secdata);
1361 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1362 	return 0;
1363 }
1364 
1365 /*
1366  * Match the requested auth flavors with the list returned by
1367  * the server.  Returns zero and sets the mount's authentication
1368  * flavor on success; returns -EACCES if server does not support
1369  * the requested flavor.
1370  */
1371 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1372 			     struct nfs_mount_request *request)
1373 {
1374 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1375 
1376 	/*
1377 	 * Certain releases of Linux's mountd return an empty
1378 	 * flavor list.  To prevent behavioral regression with
1379 	 * these servers (ie. rejecting mounts that used to
1380 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1381 	 * if the returned flavor list is empty.
1382 	 */
1383 	if (server_authlist_len == 0)
1384 		return 0;
1385 
1386 	/*
1387 	 * We avoid sophisticated negotiating here, as there are
1388 	 * plenty of cases where we can get it wrong, providing
1389 	 * either too little or too much security.
1390 	 *
1391 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1392 	 * flavor listed first.  However, some servers list
1393 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1394 	 * preferred default, in args->auth_flavors[0] if user
1395 	 * didn't specify sec= mount option.
1396 	 */
1397 	for (i = 0; i < args->auth_flavor_len; i++)
1398 		for (j = 0; j < server_authlist_len; j++)
1399 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1400 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1401 					request->auth_flavs[j]);
1402 				args->auth_flavors[0] = request->auth_flavs[j];
1403 				return 0;
1404 			}
1405 
1406 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1407 	nfs_umount(request);
1408 	return -EACCES;
1409 }
1410 
1411 /*
1412  * Use the remote server's MOUNT service to request the NFS file handle
1413  * corresponding to the provided path.
1414  */
1415 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1416 			 struct nfs_fh *root_fh)
1417 {
1418 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1419 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1420 	struct nfs_mount_request request = {
1421 		.sap		= (struct sockaddr *)
1422 						&args->mount_server.address,
1423 		.dirpath	= args->nfs_server.export_path,
1424 		.protocol	= args->mount_server.protocol,
1425 		.fh		= root_fh,
1426 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1427 		.auth_flav_len	= &server_authlist_len,
1428 		.auth_flavs	= server_authlist,
1429 	};
1430 	int status;
1431 
1432 	if (args->mount_server.version == 0) {
1433 		if (args->flags & NFS_MOUNT_VER3)
1434 			args->mount_server.version = NFS_MNT3_VERSION;
1435 		else
1436 			args->mount_server.version = NFS_MNT_VERSION;
1437 	}
1438 	request.version = args->mount_server.version;
1439 
1440 	if (args->mount_server.hostname)
1441 		request.hostname = args->mount_server.hostname;
1442 	else
1443 		request.hostname = args->nfs_server.hostname;
1444 
1445 	/*
1446 	 * Construct the mount server's address.
1447 	 */
1448 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1449 		memcpy(request.sap, &args->nfs_server.address,
1450 		       args->nfs_server.addrlen);
1451 		args->mount_server.addrlen = args->nfs_server.addrlen;
1452 	}
1453 	request.salen = args->mount_server.addrlen;
1454 	nfs_set_default_port(request.sap, args->mount_server.port, 0);
1455 
1456 	/*
1457 	 * Now ask the mount server to map our export path
1458 	 * to a file handle.
1459 	 */
1460 	status = nfs_mount(&request);
1461 	if (status != 0) {
1462 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1463 				request.hostname, status);
1464 		return status;
1465 	}
1466 
1467 	/*
1468 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1469 	 */
1470 	if (args->mount_server.version != NFS_MNT3_VERSION)
1471 		return 0;
1472 	return nfs_walk_authlist(args, &request);
1473 }
1474 
1475 static int nfs_parse_simple_hostname(const char *dev_name,
1476 				     char **hostname, size_t maxnamlen,
1477 				     char **export_path, size_t maxpathlen)
1478 {
1479 	size_t len;
1480 	char *colon, *comma;
1481 
1482 	colon = strchr(dev_name, ':');
1483 	if (colon == NULL)
1484 		goto out_bad_devname;
1485 
1486 	len = colon - dev_name;
1487 	if (len > maxnamlen)
1488 		goto out_hostname;
1489 
1490 	/* N.B. caller will free nfs_server.hostname in all cases */
1491 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1492 	if (!*hostname)
1493 		goto out_nomem;
1494 
1495 	/* kill possible hostname list: not supported */
1496 	comma = strchr(*hostname, ',');
1497 	if (comma != NULL) {
1498 		if (comma == *hostname)
1499 			goto out_bad_devname;
1500 		*comma = '\0';
1501 	}
1502 
1503 	colon++;
1504 	len = strlen(colon);
1505 	if (len > maxpathlen)
1506 		goto out_path;
1507 	*export_path = kstrndup(colon, len, GFP_KERNEL);
1508 	if (!*export_path)
1509 		goto out_nomem;
1510 
1511 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1512 	return 0;
1513 
1514 out_bad_devname:
1515 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1516 	return -EINVAL;
1517 
1518 out_nomem:
1519 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1520 	return -ENOMEM;
1521 
1522 out_hostname:
1523 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1524 	return -ENAMETOOLONG;
1525 
1526 out_path:
1527 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1528 	return -ENAMETOOLONG;
1529 }
1530 
1531 /*
1532  * Hostname has square brackets around it because it contains one or
1533  * more colons.  We look for the first closing square bracket, and a
1534  * colon must follow it.
1535  */
1536 static int nfs_parse_protected_hostname(const char *dev_name,
1537 					char **hostname, size_t maxnamlen,
1538 					char **export_path, size_t maxpathlen)
1539 {
1540 	size_t len;
1541 	char *start, *end;
1542 
1543 	start = (char *)(dev_name + 1);
1544 
1545 	end = strchr(start, ']');
1546 	if (end == NULL)
1547 		goto out_bad_devname;
1548 	if (*(end + 1) != ':')
1549 		goto out_bad_devname;
1550 
1551 	len = end - start;
1552 	if (len > maxnamlen)
1553 		goto out_hostname;
1554 
1555 	/* N.B. caller will free nfs_server.hostname in all cases */
1556 	*hostname = kstrndup(start, len, GFP_KERNEL);
1557 	if (*hostname == NULL)
1558 		goto out_nomem;
1559 
1560 	end += 2;
1561 	len = strlen(end);
1562 	if (len > maxpathlen)
1563 		goto out_path;
1564 	*export_path = kstrndup(end, len, GFP_KERNEL);
1565 	if (!*export_path)
1566 		goto out_nomem;
1567 
1568 	return 0;
1569 
1570 out_bad_devname:
1571 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1572 	return -EINVAL;
1573 
1574 out_nomem:
1575 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1576 	return -ENOMEM;
1577 
1578 out_hostname:
1579 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1580 	return -ENAMETOOLONG;
1581 
1582 out_path:
1583 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1584 	return -ENAMETOOLONG;
1585 }
1586 
1587 /*
1588  * Split "dev_name" into "hostname:export_path".
1589  *
1590  * The leftmost colon demarks the split between the server's hostname
1591  * and the export path.  If the hostname starts with a left square
1592  * bracket, then it may contain colons.
1593  *
1594  * Note: caller frees hostname and export path, even on error.
1595  */
1596 static int nfs_parse_devname(const char *dev_name,
1597 			     char **hostname, size_t maxnamlen,
1598 			     char **export_path, size_t maxpathlen)
1599 {
1600 	if (*dev_name == '[')
1601 		return nfs_parse_protected_hostname(dev_name,
1602 						    hostname, maxnamlen,
1603 						    export_path, maxpathlen);
1604 
1605 	return nfs_parse_simple_hostname(dev_name,
1606 					 hostname, maxnamlen,
1607 					 export_path, maxpathlen);
1608 }
1609 
1610 /*
1611  * Validate the NFS2/NFS3 mount data
1612  * - fills in the mount root filehandle
1613  *
1614  * For option strings, user space handles the following behaviors:
1615  *
1616  * + DNS: mapping server host name to IP address ("addr=" option)
1617  *
1618  * + failure mode: how to behave if a mount request can't be handled
1619  *   immediately ("fg/bg" option)
1620  *
1621  * + retry: how often to retry a mount request ("retry=" option)
1622  *
1623  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1624  *   mountproto=tcp after mountproto=udp, and so on
1625  */
1626 static int nfs_validate_mount_data(void *options,
1627 				   struct nfs_parsed_mount_data *args,
1628 				   struct nfs_fh *mntfh,
1629 				   const char *dev_name)
1630 {
1631 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1632 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1633 
1634 	if (data == NULL)
1635 		goto out_no_data;
1636 
1637 	args->flags		= (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1638 	args->rsize		= NFS_MAX_FILE_IO_SIZE;
1639 	args->wsize		= NFS_MAX_FILE_IO_SIZE;
1640 	args->acregmin		= NFS_DEF_ACREGMIN;
1641 	args->acregmax		= NFS_DEF_ACREGMAX;
1642 	args->acdirmin		= NFS_DEF_ACDIRMIN;
1643 	args->acdirmax		= NFS_DEF_ACDIRMAX;
1644 	args->mount_server.port	= NFS_UNSPEC_PORT;
1645 	args->nfs_server.port	= NFS_UNSPEC_PORT;
1646 	args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1647 	args->auth_flavors[0]	= RPC_AUTH_UNIX;
1648 	args->auth_flavor_len	= 1;
1649 	args->minorversion	= 0;
1650 
1651 	switch (data->version) {
1652 	case 1:
1653 		data->namlen = 0;
1654 	case 2:
1655 		data->bsize = 0;
1656 	case 3:
1657 		if (data->flags & NFS_MOUNT_VER3)
1658 			goto out_no_v3;
1659 		data->root.size = NFS2_FHSIZE;
1660 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1661 	case 4:
1662 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1663 			goto out_no_sec;
1664 	case 5:
1665 		memset(data->context, 0, sizeof(data->context));
1666 	case 6:
1667 		if (data->flags & NFS_MOUNT_VER3) {
1668 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1669 				goto out_invalid_fh;
1670 			mntfh->size = data->root.size;
1671 			args->version = 3;
1672 		} else {
1673 			mntfh->size = NFS2_FHSIZE;
1674 			args->version = 2;
1675 		}
1676 
1677 
1678 		memcpy(mntfh->data, data->root.data, mntfh->size);
1679 		if (mntfh->size < sizeof(mntfh->data))
1680 			memset(mntfh->data + mntfh->size, 0,
1681 			       sizeof(mntfh->data) - mntfh->size);
1682 
1683 		/*
1684 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1685 		 * can deal with.
1686 		 */
1687 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1688 		args->rsize		= data->rsize;
1689 		args->wsize		= data->wsize;
1690 		args->timeo		= data->timeo;
1691 		args->retrans		= data->retrans;
1692 		args->acregmin		= data->acregmin;
1693 		args->acregmax		= data->acregmax;
1694 		args->acdirmin		= data->acdirmin;
1695 		args->acdirmax		= data->acdirmax;
1696 
1697 		memcpy(sap, &data->addr, sizeof(data->addr));
1698 		args->nfs_server.addrlen = sizeof(data->addr);
1699 		if (!nfs_verify_server_address(sap))
1700 			goto out_no_address;
1701 
1702 		if (!(data->flags & NFS_MOUNT_TCP))
1703 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1704 		/* N.B. caller will free nfs_server.hostname in all cases */
1705 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1706 		args->namlen		= data->namlen;
1707 		args->bsize		= data->bsize;
1708 
1709 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1710 			args->auth_flavors[0] = data->pseudoflavor;
1711 		if (!args->nfs_server.hostname)
1712 			goto out_nomem;
1713 
1714 		/*
1715 		 * The legacy version 6 binary mount data from userspace has a
1716 		 * field used only to transport selinux information into the
1717 		 * the kernel.  To continue to support that functionality we
1718 		 * have a touch of selinux knowledge here in the NFS code. The
1719 		 * userspace code converted context=blah to just blah so we are
1720 		 * converting back to the full string selinux understands.
1721 		 */
1722 		if (data->context[0]){
1723 #ifdef CONFIG_SECURITY_SELINUX
1724 			int rc;
1725 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1726 			if (!opts_str)
1727 				return -ENOMEM;
1728 			strcpy(opts_str, "context=");
1729 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1730 			strcat(opts_str, &data->context[0]);
1731 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1732 			kfree(opts_str);
1733 			if (rc)
1734 				return rc;
1735 #else
1736 			return -EINVAL;
1737 #endif
1738 		}
1739 
1740 		break;
1741 	default: {
1742 		int status;
1743 
1744 		if (nfs_parse_mount_options((char *)options, args) == 0)
1745 			return -EINVAL;
1746 
1747 		if (!nfs_verify_server_address(sap))
1748 			goto out_no_address;
1749 
1750 		if (args->version == 4)
1751 #ifdef CONFIG_NFS_V4
1752 			return nfs4_validate_text_mount_data(options,
1753 							     args, dev_name);
1754 #else
1755 			goto out_v4_not_compiled;
1756 #endif
1757 
1758 		nfs_set_default_port(sap, args->nfs_server.port, 0);
1759 
1760 		nfs_set_mount_transport_protocol(args);
1761 
1762 		status = nfs_parse_devname(dev_name,
1763 					   &args->nfs_server.hostname,
1764 					   PAGE_SIZE,
1765 					   &args->nfs_server.export_path,
1766 					   NFS_MAXPATHLEN);
1767 		if (!status)
1768 			status = nfs_try_mount(args, mntfh);
1769 
1770 		kfree(args->nfs_server.export_path);
1771 		args->nfs_server.export_path = NULL;
1772 
1773 		if (status)
1774 			return status;
1775 
1776 		break;
1777 		}
1778 	}
1779 
1780 #ifndef CONFIG_NFS_V3
1781 	if (args->flags & NFS_MOUNT_VER3)
1782 		goto out_v3_not_compiled;
1783 #endif /* !CONFIG_NFS_V3 */
1784 
1785 	return 0;
1786 
1787 out_no_data:
1788 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1789 	return -EINVAL;
1790 
1791 out_no_v3:
1792 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1793 		 data->version);
1794 	return -EINVAL;
1795 
1796 out_no_sec:
1797 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1798 	return -EINVAL;
1799 
1800 #ifndef CONFIG_NFS_V3
1801 out_v3_not_compiled:
1802 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1803 	return -EPROTONOSUPPORT;
1804 #endif /* !CONFIG_NFS_V3 */
1805 
1806 #ifndef CONFIG_NFS_V4
1807 out_v4_not_compiled:
1808 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
1809 	return -EPROTONOSUPPORT;
1810 #endif /* !CONFIG_NFS_V4 */
1811 
1812 out_nomem:
1813 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1814 	return -ENOMEM;
1815 
1816 out_no_address:
1817 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1818 	return -EINVAL;
1819 
1820 out_invalid_fh:
1821 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1822 	return -EINVAL;
1823 }
1824 
1825 static int
1826 nfs_compare_remount_data(struct nfs_server *nfss,
1827 			 struct nfs_parsed_mount_data *data)
1828 {
1829 	if (data->flags != nfss->flags ||
1830 	    data->rsize != nfss->rsize ||
1831 	    data->wsize != nfss->wsize ||
1832 	    data->retrans != nfss->client->cl_timeout->to_retries ||
1833 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1834 	    data->acregmin != nfss->acregmin / HZ ||
1835 	    data->acregmax != nfss->acregmax / HZ ||
1836 	    data->acdirmin != nfss->acdirmin / HZ ||
1837 	    data->acdirmax != nfss->acdirmax / HZ ||
1838 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1839 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1840 	    memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1841 		   data->nfs_server.addrlen) != 0)
1842 		return -EINVAL;
1843 
1844 	return 0;
1845 }
1846 
1847 static int
1848 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1849 {
1850 	int error;
1851 	struct nfs_server *nfss = sb->s_fs_info;
1852 	struct nfs_parsed_mount_data *data;
1853 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1854 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1855 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1856 
1857 	/*
1858 	 * Userspace mount programs that send binary options generally send
1859 	 * them populated with default values. We have no way to know which
1860 	 * ones were explicitly specified. Fall back to legacy behavior and
1861 	 * just return success.
1862 	 */
1863 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1864 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
1865 					   options->version <= 6))))
1866 		return 0;
1867 
1868 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1869 	if (data == NULL)
1870 		return -ENOMEM;
1871 
1872 	lock_kernel();
1873 	/* fill out struct with values from existing mount */
1874 	data->flags = nfss->flags;
1875 	data->rsize = nfss->rsize;
1876 	data->wsize = nfss->wsize;
1877 	data->retrans = nfss->client->cl_timeout->to_retries;
1878 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1879 	data->acregmin = nfss->acregmin / HZ;
1880 	data->acregmax = nfss->acregmax / HZ;
1881 	data->acdirmin = nfss->acdirmin / HZ;
1882 	data->acdirmax = nfss->acdirmax / HZ;
1883 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1884 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1885 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1886 		data->nfs_server.addrlen);
1887 
1888 	/* overwrite those values with any that were specified */
1889 	error = nfs_parse_mount_options((char *)options, data);
1890 	if (error < 0)
1891 		goto out;
1892 
1893 	/* compare new mount options with old ones */
1894 	error = nfs_compare_remount_data(nfss, data);
1895 out:
1896 	kfree(data);
1897 	unlock_kernel();
1898 	return error;
1899 }
1900 
1901 /*
1902  * Initialise the common bits of the superblock
1903  */
1904 static inline void nfs_initialise_sb(struct super_block *sb)
1905 {
1906 	struct nfs_server *server = NFS_SB(sb);
1907 
1908 	sb->s_magic = NFS_SUPER_MAGIC;
1909 
1910 	/* We probably want something more informative here */
1911 	snprintf(sb->s_id, sizeof(sb->s_id),
1912 		 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1913 
1914 	if (sb->s_blocksize == 0)
1915 		sb->s_blocksize = nfs_block_bits(server->wsize,
1916 						 &sb->s_blocksize_bits);
1917 
1918 	if (server->flags & NFS_MOUNT_NOAC)
1919 		sb->s_flags |= MS_SYNCHRONOUS;
1920 
1921 	sb->s_bdi = &server->backing_dev_info;
1922 
1923 	nfs_super_set_maxbytes(sb, server->maxfilesize);
1924 }
1925 
1926 /*
1927  * Finish setting up an NFS2/3 superblock
1928  */
1929 static void nfs_fill_super(struct super_block *sb,
1930 			   struct nfs_parsed_mount_data *data)
1931 {
1932 	struct nfs_server *server = NFS_SB(sb);
1933 
1934 	sb->s_blocksize_bits = 0;
1935 	sb->s_blocksize = 0;
1936 	if (data->bsize)
1937 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1938 
1939 	if (server->flags & NFS_MOUNT_VER3) {
1940 		/* The VFS shouldn't apply the umask to mode bits. We will do
1941 		 * so ourselves when necessary.
1942 		 */
1943 		sb->s_flags |= MS_POSIXACL;
1944 		sb->s_time_gran = 1;
1945 	}
1946 
1947 	sb->s_op = &nfs_sops;
1948  	nfs_initialise_sb(sb);
1949 }
1950 
1951 /*
1952  * Finish setting up a cloned NFS2/3 superblock
1953  */
1954 static void nfs_clone_super(struct super_block *sb,
1955 			    const struct super_block *old_sb)
1956 {
1957 	struct nfs_server *server = NFS_SB(sb);
1958 
1959 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1960 	sb->s_blocksize = old_sb->s_blocksize;
1961 	sb->s_maxbytes = old_sb->s_maxbytes;
1962 
1963 	if (server->flags & NFS_MOUNT_VER3) {
1964 		/* The VFS shouldn't apply the umask to mode bits. We will do
1965 		 * so ourselves when necessary.
1966 		 */
1967 		sb->s_flags |= MS_POSIXACL;
1968 		sb->s_time_gran = 1;
1969 	}
1970 
1971 	sb->s_op = old_sb->s_op;
1972  	nfs_initialise_sb(sb);
1973 }
1974 
1975 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1976 {
1977 	const struct nfs_server *a = s->s_fs_info;
1978 	const struct rpc_clnt *clnt_a = a->client;
1979 	const struct rpc_clnt *clnt_b = b->client;
1980 
1981 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1982 		goto Ebusy;
1983 	if (a->nfs_client != b->nfs_client)
1984 		goto Ebusy;
1985 	if (a->flags != b->flags)
1986 		goto Ebusy;
1987 	if (a->wsize != b->wsize)
1988 		goto Ebusy;
1989 	if (a->rsize != b->rsize)
1990 		goto Ebusy;
1991 	if (a->acregmin != b->acregmin)
1992 		goto Ebusy;
1993 	if (a->acregmax != b->acregmax)
1994 		goto Ebusy;
1995 	if (a->acdirmin != b->acdirmin)
1996 		goto Ebusy;
1997 	if (a->acdirmax != b->acdirmax)
1998 		goto Ebusy;
1999 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2000 		goto Ebusy;
2001 	return 1;
2002 Ebusy:
2003 	return 0;
2004 }
2005 
2006 struct nfs_sb_mountdata {
2007 	struct nfs_server *server;
2008 	int mntflags;
2009 };
2010 
2011 static int nfs_set_super(struct super_block *s, void *data)
2012 {
2013 	struct nfs_sb_mountdata *sb_mntdata = data;
2014 	struct nfs_server *server = sb_mntdata->server;
2015 	int ret;
2016 
2017 	s->s_flags = sb_mntdata->mntflags;
2018 	s->s_fs_info = server;
2019 	ret = set_anon_super(s, server);
2020 	if (ret == 0)
2021 		server->s_dev = s->s_dev;
2022 	return ret;
2023 }
2024 
2025 static int nfs_compare_super_address(struct nfs_server *server1,
2026 				     struct nfs_server *server2)
2027 {
2028 	struct sockaddr *sap1, *sap2;
2029 
2030 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2031 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2032 
2033 	if (sap1->sa_family != sap2->sa_family)
2034 		return 0;
2035 
2036 	switch (sap1->sa_family) {
2037 	case AF_INET: {
2038 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2039 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2040 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2041 			return 0;
2042 		if (sin1->sin_port != sin2->sin_port)
2043 			return 0;
2044 		break;
2045 	}
2046 	case AF_INET6: {
2047 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2048 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2049 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2050 			return 0;
2051 		if (sin1->sin6_port != sin2->sin6_port)
2052 			return 0;
2053 		break;
2054 	}
2055 	default:
2056 		return 0;
2057 	}
2058 
2059 	return 1;
2060 }
2061 
2062 static int nfs_compare_super(struct super_block *sb, void *data)
2063 {
2064 	struct nfs_sb_mountdata *sb_mntdata = data;
2065 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2066 	int mntflags = sb_mntdata->mntflags;
2067 
2068 	if (!nfs_compare_super_address(old, server))
2069 		return 0;
2070 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2071 	if (old->flags & NFS_MOUNT_UNSHARED)
2072 		return 0;
2073 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2074 		return 0;
2075 	return nfs_compare_mount_options(sb, server, mntflags);
2076 }
2077 
2078 static int nfs_bdi_register(struct nfs_server *server)
2079 {
2080 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2081 }
2082 
2083 static int nfs_get_sb(struct file_system_type *fs_type,
2084 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2085 {
2086 	struct nfs_server *server = NULL;
2087 	struct super_block *s;
2088 	struct nfs_parsed_mount_data *data;
2089 	struct nfs_fh *mntfh;
2090 	struct dentry *mntroot;
2091 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2092 	struct nfs_sb_mountdata sb_mntdata = {
2093 		.mntflags = flags,
2094 	};
2095 	int error = -ENOMEM;
2096 
2097 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2098 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2099 	if (data == NULL || mntfh == NULL)
2100 		goto out_free_fh;
2101 
2102 	security_init_mnt_opts(&data->lsm_opts);
2103 
2104 	/* Validate the mount data */
2105 	error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2106 	if (error < 0)
2107 		goto out;
2108 
2109 #ifdef CONFIG_NFS_V4
2110 	if (data->version == 4) {
2111 		error = nfs4_try_mount(flags, dev_name, data, mnt);
2112 		kfree(data->client_address);
2113 		goto out;
2114 	}
2115 #endif	/* CONFIG_NFS_V4 */
2116 
2117 	/* Get a volume representation */
2118 	server = nfs_create_server(data, mntfh);
2119 	if (IS_ERR(server)) {
2120 		error = PTR_ERR(server);
2121 		goto out;
2122 	}
2123 	sb_mntdata.server = server;
2124 
2125 	if (server->flags & NFS_MOUNT_UNSHARED)
2126 		compare_super = NULL;
2127 
2128 	/* Get a superblock - note that we may end up sharing one that already exists */
2129 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2130 	if (IS_ERR(s)) {
2131 		error = PTR_ERR(s);
2132 		goto out_err_nosb;
2133 	}
2134 
2135 	if (s->s_fs_info != server) {
2136 		nfs_free_server(server);
2137 		server = NULL;
2138 	} else {
2139 		error = nfs_bdi_register(server);
2140 		if (error)
2141 			goto error_splat_super;
2142 	}
2143 
2144 	if (!s->s_root) {
2145 		/* initial superblock/root creation */
2146 		nfs_fill_super(s, data);
2147 		nfs_fscache_get_super_cookie(s, data);
2148 	}
2149 
2150 	mntroot = nfs_get_root(s, mntfh);
2151 	if (IS_ERR(mntroot)) {
2152 		error = PTR_ERR(mntroot);
2153 		goto error_splat_super;
2154 	}
2155 
2156 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2157 	if (error)
2158 		goto error_splat_root;
2159 
2160 	s->s_flags |= MS_ACTIVE;
2161 	mnt->mnt_sb = s;
2162 	mnt->mnt_root = mntroot;
2163 	error = 0;
2164 
2165 out:
2166 	kfree(data->nfs_server.hostname);
2167 	kfree(data->mount_server.hostname);
2168 	kfree(data->fscache_uniq);
2169 	security_free_mnt_opts(&data->lsm_opts);
2170 out_free_fh:
2171 	kfree(mntfh);
2172 	kfree(data);
2173 	return error;
2174 
2175 out_err_nosb:
2176 	nfs_free_server(server);
2177 	goto out;
2178 
2179 error_splat_root:
2180 	dput(mntroot);
2181 error_splat_super:
2182 	deactivate_locked_super(s);
2183 	goto out;
2184 }
2185 
2186 /*
2187  * Destroy an NFS2/3 superblock
2188  */
2189 static void nfs_kill_super(struct super_block *s)
2190 {
2191 	struct nfs_server *server = NFS_SB(s);
2192 
2193 	kill_anon_super(s);
2194 	bdi_unregister(&server->backing_dev_info);
2195 	nfs_fscache_release_super_cookie(s);
2196 	nfs_free_server(server);
2197 }
2198 
2199 /*
2200  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2201  */
2202 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2203 			   const char *dev_name, void *raw_data,
2204 			   struct vfsmount *mnt)
2205 {
2206 	struct nfs_clone_mount *data = raw_data;
2207 	struct super_block *s;
2208 	struct nfs_server *server;
2209 	struct dentry *mntroot;
2210 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2211 	struct nfs_sb_mountdata sb_mntdata = {
2212 		.mntflags = flags,
2213 	};
2214 	int error;
2215 
2216 	dprintk("--> nfs_xdev_get_sb()\n");
2217 
2218 	/* create a new volume representation */
2219 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2220 	if (IS_ERR(server)) {
2221 		error = PTR_ERR(server);
2222 		goto out_err_noserver;
2223 	}
2224 	sb_mntdata.server = server;
2225 
2226 	if (server->flags & NFS_MOUNT_UNSHARED)
2227 		compare_super = NULL;
2228 
2229 	/* Get a superblock - note that we may end up sharing one that already exists */
2230 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2231 	if (IS_ERR(s)) {
2232 		error = PTR_ERR(s);
2233 		goto out_err_nosb;
2234 	}
2235 
2236 	if (s->s_fs_info != server) {
2237 		nfs_free_server(server);
2238 		server = NULL;
2239 	} else {
2240 		error = nfs_bdi_register(server);
2241 		if (error)
2242 			goto error_splat_super;
2243 	}
2244 
2245 	if (!s->s_root) {
2246 		/* initial superblock/root creation */
2247 		nfs_clone_super(s, data->sb);
2248 	}
2249 
2250 	mntroot = nfs_get_root(s, data->fh);
2251 	if (IS_ERR(mntroot)) {
2252 		error = PTR_ERR(mntroot);
2253 		goto error_splat_super;
2254 	}
2255 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2256 		dput(mntroot);
2257 		error = -ESTALE;
2258 		goto error_splat_super;
2259 	}
2260 
2261 	s->s_flags |= MS_ACTIVE;
2262 	mnt->mnt_sb = s;
2263 	mnt->mnt_root = mntroot;
2264 
2265 	/* clone any lsm security options from the parent to the new sb */
2266 	security_sb_clone_mnt_opts(data->sb, s);
2267 
2268 	dprintk("<-- nfs_xdev_get_sb() = 0\n");
2269 	return 0;
2270 
2271 out_err_nosb:
2272 	nfs_free_server(server);
2273 out_err_noserver:
2274 	dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2275 	return error;
2276 
2277 error_splat_super:
2278 	deactivate_locked_super(s);
2279 	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2280 	return error;
2281 }
2282 
2283 #ifdef CONFIG_NFS_V4
2284 
2285 /*
2286  * Finish setting up a cloned NFS4 superblock
2287  */
2288 static void nfs4_clone_super(struct super_block *sb,
2289 			    const struct super_block *old_sb)
2290 {
2291 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2292 	sb->s_blocksize = old_sb->s_blocksize;
2293 	sb->s_maxbytes = old_sb->s_maxbytes;
2294 	sb->s_time_gran = 1;
2295 	sb->s_op = old_sb->s_op;
2296  	nfs_initialise_sb(sb);
2297 }
2298 
2299 /*
2300  * Set up an NFS4 superblock
2301  */
2302 static void nfs4_fill_super(struct super_block *sb)
2303 {
2304 	sb->s_time_gran = 1;
2305 	sb->s_op = &nfs4_sops;
2306 	nfs_initialise_sb(sb);
2307 }
2308 
2309 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2310 {
2311 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2312 }
2313 
2314 static int nfs4_validate_text_mount_data(void *options,
2315 					 struct nfs_parsed_mount_data *args,
2316 					 const char *dev_name)
2317 {
2318 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2319 
2320 	nfs_set_default_port(sap, args->nfs_server.port, NFS_PORT);
2321 
2322 	nfs_validate_transport_protocol(args);
2323 
2324 	nfs4_validate_mount_flags(args);
2325 
2326 	if (args->version != 4) {
2327 		dfprintk(MOUNT,
2328 			 "NFS4: Illegal mount version\n");
2329 		return -EINVAL;
2330 	}
2331 
2332 	if (args->auth_flavor_len > 1) {
2333 		dfprintk(MOUNT,
2334 			 "NFS4: Too many RPC auth flavours specified\n");
2335 		return -EINVAL;
2336 	}
2337 
2338 	if (args->client_address == NULL) {
2339 		dfprintk(MOUNT,
2340 			 "NFS4: mount program didn't pass callback address\n");
2341 		return -EINVAL;
2342 	}
2343 
2344 	return nfs_parse_devname(dev_name,
2345 				   &args->nfs_server.hostname,
2346 				   NFS4_MAXNAMLEN,
2347 				   &args->nfs_server.export_path,
2348 				   NFS4_MAXPATHLEN);
2349 }
2350 
2351 /*
2352  * Validate NFSv4 mount options
2353  */
2354 static int nfs4_validate_mount_data(void *options,
2355 				    struct nfs_parsed_mount_data *args,
2356 				    const char *dev_name)
2357 {
2358 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2359 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2360 	char *c;
2361 
2362 	if (data == NULL)
2363 		goto out_no_data;
2364 
2365 	args->rsize		= NFS_MAX_FILE_IO_SIZE;
2366 	args->wsize		= NFS_MAX_FILE_IO_SIZE;
2367 	args->acregmin		= NFS_DEF_ACREGMIN;
2368 	args->acregmax		= NFS_DEF_ACREGMAX;
2369 	args->acdirmin		= NFS_DEF_ACDIRMIN;
2370 	args->acdirmax		= NFS_DEF_ACDIRMAX;
2371 	args->nfs_server.port	= NFS_UNSPEC_PORT;
2372 	args->auth_flavors[0]	= RPC_AUTH_UNIX;
2373 	args->auth_flavor_len	= 1;
2374 	args->version		= 4;
2375 	args->minorversion	= 0;
2376 
2377 	switch (data->version) {
2378 	case 1:
2379 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2380 			goto out_no_address;
2381 		if (data->host_addrlen == 0)
2382 			goto out_no_address;
2383 		args->nfs_server.addrlen = data->host_addrlen;
2384 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2385 			return -EFAULT;
2386 		if (!nfs_verify_server_address(sap))
2387 			goto out_no_address;
2388 
2389 		if (data->auth_flavourlen) {
2390 			if (data->auth_flavourlen > 1)
2391 				goto out_inval_auth;
2392 			if (copy_from_user(&args->auth_flavors[0],
2393 					   data->auth_flavours,
2394 					   sizeof(args->auth_flavors[0])))
2395 				return -EFAULT;
2396 		}
2397 
2398 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2399 		if (IS_ERR(c))
2400 			return PTR_ERR(c);
2401 		args->nfs_server.hostname = c;
2402 
2403 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2404 		if (IS_ERR(c))
2405 			return PTR_ERR(c);
2406 		args->nfs_server.export_path = c;
2407 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2408 
2409 		c = strndup_user(data->client_addr.data, 16);
2410 		if (IS_ERR(c))
2411 			return PTR_ERR(c);
2412 		args->client_address = c;
2413 
2414 		/*
2415 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2416 		 * can deal with.
2417 		 */
2418 
2419 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2420 		args->rsize	= data->rsize;
2421 		args->wsize	= data->wsize;
2422 		args->timeo	= data->timeo;
2423 		args->retrans	= data->retrans;
2424 		args->acregmin	= data->acregmin;
2425 		args->acregmax	= data->acregmax;
2426 		args->acdirmin	= data->acdirmin;
2427 		args->acdirmax	= data->acdirmax;
2428 		args->nfs_server.protocol = data->proto;
2429 		nfs_validate_transport_protocol(args);
2430 
2431 		break;
2432 	default:
2433 		if (nfs_parse_mount_options((char *)options, args) == 0)
2434 			return -EINVAL;
2435 
2436 		if (!nfs_verify_server_address(sap))
2437 			return -EINVAL;
2438 
2439 		return nfs4_validate_text_mount_data(options, args, dev_name);
2440 	}
2441 
2442 	return 0;
2443 
2444 out_no_data:
2445 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2446 	return -EINVAL;
2447 
2448 out_inval_auth:
2449 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2450 		 data->auth_flavourlen);
2451 	return -EINVAL;
2452 
2453 out_no_address:
2454 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2455 	return -EINVAL;
2456 }
2457 
2458 /*
2459  * Get the superblock for the NFS4 root partition
2460  */
2461 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2462 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2463 {
2464 	struct nfs_parsed_mount_data *data = raw_data;
2465 	struct super_block *s;
2466 	struct nfs_server *server;
2467 	struct nfs_fh *mntfh;
2468 	struct dentry *mntroot;
2469 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2470 	struct nfs_sb_mountdata sb_mntdata = {
2471 		.mntflags = flags,
2472 	};
2473 	int error = -ENOMEM;
2474 
2475 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2476 	if (data == NULL || mntfh == NULL)
2477 		goto out_free_fh;
2478 
2479 	security_init_mnt_opts(&data->lsm_opts);
2480 
2481 	/* Get a volume representation */
2482 	server = nfs4_create_server(data, mntfh);
2483 	if (IS_ERR(server)) {
2484 		error = PTR_ERR(server);
2485 		goto out;
2486 	}
2487 	sb_mntdata.server = server;
2488 
2489 	if (server->flags & NFS4_MOUNT_UNSHARED)
2490 		compare_super = NULL;
2491 
2492 	/* Get a superblock - note that we may end up sharing one that already exists */
2493 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2494 	if (IS_ERR(s)) {
2495 		error = PTR_ERR(s);
2496 		goto out_free;
2497 	}
2498 
2499 	if (s->s_fs_info != server) {
2500 		nfs_free_server(server);
2501 		server = NULL;
2502 	} else {
2503 		error = nfs_bdi_register(server);
2504 		if (error)
2505 			goto error_splat_super;
2506 	}
2507 
2508 	if (!s->s_root) {
2509 		/* initial superblock/root creation */
2510 		nfs4_fill_super(s);
2511 		nfs_fscache_get_super_cookie(s, data);
2512 	}
2513 
2514 	mntroot = nfs4_get_root(s, mntfh);
2515 	if (IS_ERR(mntroot)) {
2516 		error = PTR_ERR(mntroot);
2517 		goto error_splat_super;
2518 	}
2519 
2520 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2521 	if (error)
2522 		goto error_splat_root;
2523 
2524 	s->s_flags |= MS_ACTIVE;
2525 	mnt->mnt_sb = s;
2526 	mnt->mnt_root = mntroot;
2527 	error = 0;
2528 
2529 out:
2530 	security_free_mnt_opts(&data->lsm_opts);
2531 out_free_fh:
2532 	kfree(mntfh);
2533 	return error;
2534 
2535 out_free:
2536 	nfs_free_server(server);
2537 	goto out;
2538 
2539 error_splat_root:
2540 	dput(mntroot);
2541 error_splat_super:
2542 	deactivate_locked_super(s);
2543 	goto out;
2544 }
2545 
2546 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2547 		int flags, void *data, const char *hostname)
2548 {
2549 	struct vfsmount *root_mnt;
2550 	char *root_devname;
2551 	size_t len;
2552 
2553 	len = strlen(hostname) + 3;
2554 	root_devname = kmalloc(len, GFP_KERNEL);
2555 	if (root_devname == NULL)
2556 		return ERR_PTR(-ENOMEM);
2557 	snprintf(root_devname, len, "%s:/", hostname);
2558 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2559 	kfree(root_devname);
2560 	return root_mnt;
2561 }
2562 
2563 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2564 {
2565 	char *page = (char *) __get_free_page(GFP_KERNEL);
2566 	char *devname, *tmp;
2567 
2568 	if (page == NULL)
2569 		return;
2570 	devname = nfs_path(path->mnt->mnt_devname,
2571 			path->mnt->mnt_root, path->dentry,
2572 			page, PAGE_SIZE);
2573 	if (devname == NULL)
2574 		goto out_freepage;
2575 	tmp = kstrdup(devname, GFP_KERNEL);
2576 	if (tmp == NULL)
2577 		goto out_freepage;
2578 	kfree(mnt->mnt_devname);
2579 	mnt->mnt_devname = tmp;
2580 out_freepage:
2581 	free_page((unsigned long)page);
2582 }
2583 
2584 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2585 		const char *export_path, struct vfsmount *mnt_target)
2586 {
2587 	struct mnt_namespace *ns_private;
2588 	struct nameidata nd;
2589 	struct super_block *s;
2590 	int ret;
2591 
2592 	ns_private = create_mnt_ns(root_mnt);
2593 	ret = PTR_ERR(ns_private);
2594 	if (IS_ERR(ns_private))
2595 		goto out_mntput;
2596 
2597 	ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2598 			export_path, LOOKUP_FOLLOW, &nd);
2599 
2600 	put_mnt_ns(ns_private);
2601 
2602 	if (ret != 0)
2603 		goto out_err;
2604 
2605 	s = nd.path.mnt->mnt_sb;
2606 	atomic_inc(&s->s_active);
2607 	mnt_target->mnt_sb = s;
2608 	mnt_target->mnt_root = dget(nd.path.dentry);
2609 
2610 	/* Correct the device pathname */
2611 	nfs_fix_devname(&nd.path, mnt_target);
2612 
2613 	path_put(&nd.path);
2614 	down_write(&s->s_umount);
2615 	return 0;
2616 out_mntput:
2617 	mntput(root_mnt);
2618 out_err:
2619 	return ret;
2620 }
2621 
2622 static int nfs4_try_mount(int flags, const char *dev_name,
2623 			 struct nfs_parsed_mount_data *data,
2624 			 struct vfsmount *mnt)
2625 {
2626 	char *export_path;
2627 	struct vfsmount *root_mnt;
2628 	int error;
2629 
2630 	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2631 
2632 	export_path = data->nfs_server.export_path;
2633 	data->nfs_server.export_path = "/";
2634 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2635 			data->nfs_server.hostname);
2636 	data->nfs_server.export_path = export_path;
2637 
2638 	error = PTR_ERR(root_mnt);
2639 	if (IS_ERR(root_mnt))
2640 		goto out;
2641 
2642 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2643 
2644 out:
2645 	dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n", error,
2646 			error != 0 ? " [error]" : "");
2647 	return error;
2648 }
2649 
2650 /*
2651  * Get the superblock for an NFS4 mountpoint
2652  */
2653 static int nfs4_get_sb(struct file_system_type *fs_type,
2654 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2655 {
2656 	struct nfs_parsed_mount_data *data;
2657 	int error = -ENOMEM;
2658 
2659 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2660 	if (data == NULL)
2661 		goto out_free_data;
2662 
2663 	/* Validate the mount data */
2664 	error = nfs4_validate_mount_data(raw_data, data, dev_name);
2665 	if (error < 0)
2666 		goto out;
2667 
2668 	error = nfs4_try_mount(flags, dev_name, data, mnt);
2669 
2670 out:
2671 	kfree(data->client_address);
2672 	kfree(data->nfs_server.export_path);
2673 	kfree(data->nfs_server.hostname);
2674 	kfree(data->fscache_uniq);
2675 out_free_data:
2676 	kfree(data);
2677 	dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2678 			error != 0 ? " [error]" : "");
2679 	return error;
2680 }
2681 
2682 static void nfs4_kill_super(struct super_block *sb)
2683 {
2684 	struct nfs_server *server = NFS_SB(sb);
2685 
2686 	dprintk("--> %s\n", __func__);
2687 	nfs_super_return_all_delegations(sb);
2688 	kill_anon_super(sb);
2689 	nfs4_renewd_prepare_shutdown(server);
2690 	nfs_fscache_release_super_cookie(sb);
2691 	nfs_free_server(server);
2692 	dprintk("<-- %s\n", __func__);
2693 }
2694 
2695 /*
2696  * Clone an NFS4 server record on xdev traversal (FSID-change)
2697  */
2698 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2699 			    const char *dev_name, void *raw_data,
2700 			    struct vfsmount *mnt)
2701 {
2702 	struct nfs_clone_mount *data = raw_data;
2703 	struct super_block *s;
2704 	struct nfs_server *server;
2705 	struct dentry *mntroot;
2706 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2707 	struct nfs_sb_mountdata sb_mntdata = {
2708 		.mntflags = flags,
2709 	};
2710 	int error;
2711 
2712 	dprintk("--> nfs4_xdev_get_sb()\n");
2713 
2714 	/* create a new volume representation */
2715 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2716 	if (IS_ERR(server)) {
2717 		error = PTR_ERR(server);
2718 		goto out_err_noserver;
2719 	}
2720 	sb_mntdata.server = server;
2721 
2722 	if (server->flags & NFS4_MOUNT_UNSHARED)
2723 		compare_super = NULL;
2724 
2725 	/* Get a superblock - note that we may end up sharing one that already exists */
2726 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2727 	if (IS_ERR(s)) {
2728 		error = PTR_ERR(s);
2729 		goto out_err_nosb;
2730 	}
2731 
2732 	if (s->s_fs_info != server) {
2733 		nfs_free_server(server);
2734 		server = NULL;
2735 	} else {
2736 		error = nfs_bdi_register(server);
2737 		if (error)
2738 			goto error_splat_super;
2739 	}
2740 
2741 	if (!s->s_root) {
2742 		/* initial superblock/root creation */
2743 		nfs4_clone_super(s, data->sb);
2744 	}
2745 
2746 	mntroot = nfs4_get_root(s, data->fh);
2747 	if (IS_ERR(mntroot)) {
2748 		error = PTR_ERR(mntroot);
2749 		goto error_splat_super;
2750 	}
2751 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2752 		dput(mntroot);
2753 		error = -ESTALE;
2754 		goto error_splat_super;
2755 	}
2756 
2757 	s->s_flags |= MS_ACTIVE;
2758 	mnt->mnt_sb = s;
2759 	mnt->mnt_root = mntroot;
2760 
2761 	security_sb_clone_mnt_opts(data->sb, s);
2762 
2763 	dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2764 	return 0;
2765 
2766 out_err_nosb:
2767 	nfs_free_server(server);
2768 out_err_noserver:
2769 	dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2770 	return error;
2771 
2772 error_splat_super:
2773 	deactivate_locked_super(s);
2774 	dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2775 	return error;
2776 }
2777 
2778 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2779 		int flags, const char *dev_name, void *raw_data,
2780 		struct vfsmount *mnt)
2781 {
2782 	struct nfs_clone_mount *data = raw_data;
2783 	struct super_block *s;
2784 	struct nfs_server *server;
2785 	struct dentry *mntroot;
2786 	struct nfs_fh mntfh;
2787 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2788 	struct nfs_sb_mountdata sb_mntdata = {
2789 		.mntflags = flags,
2790 	};
2791 	int error;
2792 
2793 	dprintk("--> nfs4_referral_get_sb()\n");
2794 
2795 	/* create a new volume representation */
2796 	server = nfs4_create_referral_server(data, &mntfh);
2797 	if (IS_ERR(server)) {
2798 		error = PTR_ERR(server);
2799 		goto out_err_noserver;
2800 	}
2801 	sb_mntdata.server = server;
2802 
2803 	if (server->flags & NFS4_MOUNT_UNSHARED)
2804 		compare_super = NULL;
2805 
2806 	/* Get a superblock - note that we may end up sharing one that already exists */
2807 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2808 	if (IS_ERR(s)) {
2809 		error = PTR_ERR(s);
2810 		goto out_err_nosb;
2811 	}
2812 
2813 	if (s->s_fs_info != server) {
2814 		nfs_free_server(server);
2815 		server = NULL;
2816 	} else {
2817 		error = nfs_bdi_register(server);
2818 		if (error)
2819 			goto error_splat_super;
2820 	}
2821 
2822 	if (!s->s_root) {
2823 		/* initial superblock/root creation */
2824 		nfs4_fill_super(s);
2825 	}
2826 
2827 	mntroot = nfs4_get_root(s, &mntfh);
2828 	if (IS_ERR(mntroot)) {
2829 		error = PTR_ERR(mntroot);
2830 		goto error_splat_super;
2831 	}
2832 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2833 		dput(mntroot);
2834 		error = -ESTALE;
2835 		goto error_splat_super;
2836 	}
2837 
2838 	s->s_flags |= MS_ACTIVE;
2839 	mnt->mnt_sb = s;
2840 	mnt->mnt_root = mntroot;
2841 
2842 	security_sb_clone_mnt_opts(data->sb, s);
2843 
2844 	dprintk("<-- nfs4_referral_get_sb() = 0\n");
2845 	return 0;
2846 
2847 out_err_nosb:
2848 	nfs_free_server(server);
2849 out_err_noserver:
2850 	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2851 	return error;
2852 
2853 error_splat_super:
2854 	deactivate_locked_super(s);
2855 	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2856 	return error;
2857 }
2858 
2859 /*
2860  * Create an NFS4 server record on referral traversal
2861  */
2862 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2863 		int flags, const char *dev_name, void *raw_data,
2864 		struct vfsmount *mnt)
2865 {
2866 	struct nfs_clone_mount *data = raw_data;
2867 	char *export_path;
2868 	struct vfsmount *root_mnt;
2869 	int error;
2870 
2871 	dprintk("--> nfs4_referral_get_sb()\n");
2872 
2873 	export_path = data->mnt_path;
2874 	data->mnt_path = "/";
2875 
2876 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2877 			flags, data, data->hostname);
2878 	data->mnt_path = export_path;
2879 
2880 	error = PTR_ERR(root_mnt);
2881 	if (IS_ERR(root_mnt))
2882 		goto out;
2883 
2884 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2885 out:
2886 	dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2887 			error != 0 ? " [error]" : "");
2888 	return error;
2889 }
2890 
2891 #endif /* CONFIG_NFS_V4 */
2892