xref: /linux/fs/nfs/super.c (revision 6000fc4d6f3e55ad52cce8d76317187fe01af2aa)
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,
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_udp, "udp" },
131 	{ Opt_tcp, "tcp" },
132 	{ Opt_rdma, "rdma" },
133 	{ Opt_acl, "acl" },
134 	{ Opt_noacl, "noacl" },
135 	{ Opt_rdirplus, "rdirplus" },
136 	{ Opt_nordirplus, "nordirplus" },
137 	{ Opt_sharecache, "sharecache" },
138 	{ Opt_nosharecache, "nosharecache" },
139 	{ Opt_resvport, "resvport" },
140 	{ Opt_noresvport, "noresvport" },
141 	{ Opt_fscache, "fsc" },
142 	{ Opt_fscache_uniq, "fsc=%s" },
143 	{ Opt_nofscache, "nofsc" },
144 
145 	{ Opt_port, "port=%s" },
146 	{ Opt_rsize, "rsize=%s" },
147 	{ Opt_wsize, "wsize=%s" },
148 	{ Opt_bsize, "bsize=%s" },
149 	{ Opt_timeo, "timeo=%s" },
150 	{ Opt_retrans, "retrans=%s" },
151 	{ Opt_acregmin, "acregmin=%s" },
152 	{ Opt_acregmax, "acregmax=%s" },
153 	{ Opt_acdirmin, "acdirmin=%s" },
154 	{ Opt_acdirmax, "acdirmax=%s" },
155 	{ Opt_actimeo, "actimeo=%s" },
156 	{ Opt_namelen, "namlen=%s" },
157 	{ Opt_mountport, "mountport=%s" },
158 	{ Opt_mountvers, "mountvers=%s" },
159 	{ Opt_nfsvers, "nfsvers=%s" },
160 	{ Opt_nfsvers, "vers=%s" },
161 	{ Opt_minorversion, "minorversion=%u" },
162 
163 	{ Opt_sec, "sec=%s" },
164 	{ Opt_proto, "proto=%s" },
165 	{ Opt_mountproto, "mountproto=%s" },
166 	{ Opt_addr, "addr=%s" },
167 	{ Opt_clientaddr, "clientaddr=%s" },
168 	{ Opt_mounthost, "mounthost=%s" },
169 	{ Opt_mountaddr, "mountaddr=%s" },
170 
171 	{ Opt_lookupcache, "lookupcache=%s" },
172 
173 	{ Opt_err, NULL }
174 };
175 
176 enum {
177 	Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
178 
179 	Opt_xprt_err
180 };
181 
182 static const match_table_t nfs_xprt_protocol_tokens = {
183 	{ Opt_xprt_udp, "udp" },
184 	{ Opt_xprt_tcp, "tcp" },
185 	{ Opt_xprt_rdma, "rdma" },
186 
187 	{ Opt_xprt_err, NULL }
188 };
189 
190 enum {
191 	Opt_sec_none, Opt_sec_sys,
192 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
193 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
194 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
195 
196 	Opt_sec_err
197 };
198 
199 static const match_table_t nfs_secflavor_tokens = {
200 	{ Opt_sec_none, "none" },
201 	{ Opt_sec_none, "null" },
202 	{ Opt_sec_sys, "sys" },
203 
204 	{ Opt_sec_krb5, "krb5" },
205 	{ Opt_sec_krb5i, "krb5i" },
206 	{ Opt_sec_krb5p, "krb5p" },
207 
208 	{ Opt_sec_lkey, "lkey" },
209 	{ Opt_sec_lkeyi, "lkeyi" },
210 	{ Opt_sec_lkeyp, "lkeyp" },
211 
212 	{ Opt_sec_spkm, "spkm3" },
213 	{ Opt_sec_spkmi, "spkm3i" },
214 	{ Opt_sec_spkmp, "spkm3p" },
215 
216 	{ Opt_sec_err, NULL }
217 };
218 
219 enum {
220 	Opt_lookupcache_all, Opt_lookupcache_positive,
221 	Opt_lookupcache_none,
222 
223 	Opt_lookupcache_err
224 };
225 
226 static match_table_t nfs_lookupcache_tokens = {
227 	{ Opt_lookupcache_all, "all" },
228 	{ Opt_lookupcache_positive, "pos" },
229 	{ Opt_lookupcache_positive, "positive" },
230 	{ Opt_lookupcache_none, "none" },
231 
232 	{ Opt_lookupcache_err, NULL }
233 };
234 
235 
236 static void nfs_umount_begin(struct super_block *);
237 static int  nfs_statfs(struct dentry *, struct kstatfs *);
238 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
239 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
240 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
241 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
242 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
243 static void nfs_kill_super(struct super_block *);
244 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
245 
246 static struct file_system_type nfs_fs_type = {
247 	.owner		= THIS_MODULE,
248 	.name		= "nfs",
249 	.get_sb		= nfs_get_sb,
250 	.kill_sb	= nfs_kill_super,
251 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
252 };
253 
254 struct file_system_type nfs_xdev_fs_type = {
255 	.owner		= THIS_MODULE,
256 	.name		= "nfs",
257 	.get_sb		= nfs_xdev_get_sb,
258 	.kill_sb	= nfs_kill_super,
259 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
260 };
261 
262 static const struct super_operations nfs_sops = {
263 	.alloc_inode	= nfs_alloc_inode,
264 	.destroy_inode	= nfs_destroy_inode,
265 	.write_inode	= nfs_write_inode,
266 	.statfs		= nfs_statfs,
267 	.clear_inode	= nfs_clear_inode,
268 	.umount_begin	= nfs_umount_begin,
269 	.show_options	= nfs_show_options,
270 	.show_stats	= nfs_show_stats,
271 	.remount_fs	= nfs_remount,
272 };
273 
274 #ifdef CONFIG_NFS_V4
275 static int nfs4_get_sb(struct file_system_type *fs_type,
276 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
277 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
278 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
279 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
280 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
281 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
282 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
283 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
284 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
285 static void nfs4_kill_super(struct super_block *sb);
286 
287 static struct file_system_type nfs4_fs_type = {
288 	.owner		= THIS_MODULE,
289 	.name		= "nfs4",
290 	.get_sb		= nfs4_get_sb,
291 	.kill_sb	= nfs4_kill_super,
292 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
293 };
294 
295 static struct file_system_type nfs4_remote_fs_type = {
296 	.owner		= THIS_MODULE,
297 	.name		= "nfs4",
298 	.get_sb		= nfs4_remote_get_sb,
299 	.kill_sb	= nfs4_kill_super,
300 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
301 };
302 
303 struct file_system_type nfs4_xdev_fs_type = {
304 	.owner		= THIS_MODULE,
305 	.name		= "nfs4",
306 	.get_sb		= nfs4_xdev_get_sb,
307 	.kill_sb	= nfs4_kill_super,
308 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
309 };
310 
311 static struct file_system_type nfs4_remote_referral_fs_type = {
312 	.owner		= THIS_MODULE,
313 	.name		= "nfs4",
314 	.get_sb		= nfs4_remote_referral_get_sb,
315 	.kill_sb	= nfs4_kill_super,
316 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
317 };
318 
319 struct file_system_type nfs4_referral_fs_type = {
320 	.owner		= THIS_MODULE,
321 	.name		= "nfs4",
322 	.get_sb		= nfs4_referral_get_sb,
323 	.kill_sb	= nfs4_kill_super,
324 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
325 };
326 
327 static const struct super_operations nfs4_sops = {
328 	.alloc_inode	= nfs_alloc_inode,
329 	.destroy_inode	= nfs_destroy_inode,
330 	.write_inode	= nfs_write_inode,
331 	.statfs		= nfs_statfs,
332 	.clear_inode	= nfs4_clear_inode,
333 	.umount_begin	= nfs_umount_begin,
334 	.show_options	= nfs_show_options,
335 	.show_stats	= nfs_show_stats,
336 	.remount_fs	= nfs_remount,
337 };
338 #endif
339 
340 static struct shrinker acl_shrinker = {
341 	.shrink		= nfs_access_cache_shrinker,
342 	.seeks		= DEFAULT_SEEKS,
343 };
344 
345 /*
346  * Register the NFS filesystems
347  */
348 int __init register_nfs_fs(void)
349 {
350 	int ret;
351 
352         ret = register_filesystem(&nfs_fs_type);
353 	if (ret < 0)
354 		goto error_0;
355 
356 	ret = nfs_register_sysctl();
357 	if (ret < 0)
358 		goto error_1;
359 #ifdef CONFIG_NFS_V4
360 	ret = register_filesystem(&nfs4_fs_type);
361 	if (ret < 0)
362 		goto error_2;
363 #endif
364 	register_shrinker(&acl_shrinker);
365 	return 0;
366 
367 #ifdef CONFIG_NFS_V4
368 error_2:
369 	nfs_unregister_sysctl();
370 #endif
371 error_1:
372 	unregister_filesystem(&nfs_fs_type);
373 error_0:
374 	return ret;
375 }
376 
377 /*
378  * Unregister the NFS filesystems
379  */
380 void __exit unregister_nfs_fs(void)
381 {
382 	unregister_shrinker(&acl_shrinker);
383 #ifdef CONFIG_NFS_V4
384 	unregister_filesystem(&nfs4_fs_type);
385 #endif
386 	nfs_unregister_sysctl();
387 	unregister_filesystem(&nfs_fs_type);
388 }
389 
390 void nfs_sb_active(struct super_block *sb)
391 {
392 	struct nfs_server *server = NFS_SB(sb);
393 
394 	if (atomic_inc_return(&server->active) == 1)
395 		atomic_inc(&sb->s_active);
396 }
397 
398 void nfs_sb_deactive(struct super_block *sb)
399 {
400 	struct nfs_server *server = NFS_SB(sb);
401 
402 	if (atomic_dec_and_test(&server->active))
403 		deactivate_super(sb);
404 }
405 
406 /*
407  * Deliver file system statistics to userspace
408  */
409 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
410 {
411 	struct nfs_server *server = NFS_SB(dentry->d_sb);
412 	unsigned char blockbits;
413 	unsigned long blockres;
414 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
415 	struct nfs_fattr fattr;
416 	struct nfs_fsstat res = {
417 			.fattr = &fattr,
418 	};
419 	int error;
420 
421 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
422 	if (error < 0)
423 		goto out_err;
424 	buf->f_type = NFS_SUPER_MAGIC;
425 
426 	/*
427 	 * Current versions of glibc do not correctly handle the
428 	 * case where f_frsize != f_bsize.  Eventually we want to
429 	 * report the value of wtmult in this field.
430 	 */
431 	buf->f_frsize = dentry->d_sb->s_blocksize;
432 
433 	/*
434 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
435 	 * are reported in units of f_frsize.  Linux hasn't had
436 	 * an f_frsize field in its statfs struct until recently,
437 	 * thus historically Linux's sys_statfs reports these
438 	 * fields in units of f_bsize.
439 	 */
440 	buf->f_bsize = dentry->d_sb->s_blocksize;
441 	blockbits = dentry->d_sb->s_blocksize_bits;
442 	blockres = (1 << blockbits) - 1;
443 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
444 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
445 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
446 
447 	buf->f_files = res.tfiles;
448 	buf->f_ffree = res.afiles;
449 
450 	buf->f_namelen = server->namelen;
451 
452 	return 0;
453 
454  out_err:
455 	dprintk("%s: statfs error = %d\n", __func__, -error);
456 	return error;
457 }
458 
459 /*
460  * Map the security flavour number to a name
461  */
462 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
463 {
464 	static const struct {
465 		rpc_authflavor_t flavour;
466 		const char *str;
467 	} sec_flavours[] = {
468 		{ RPC_AUTH_NULL, "null" },
469 		{ RPC_AUTH_UNIX, "sys" },
470 		{ RPC_AUTH_GSS_KRB5, "krb5" },
471 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
472 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
473 		{ RPC_AUTH_GSS_LKEY, "lkey" },
474 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
475 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
476 		{ RPC_AUTH_GSS_SPKM, "spkm" },
477 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
478 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
479 		{ UINT_MAX, "unknown" }
480 	};
481 	int i;
482 
483 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
484 		if (sec_flavours[i].flavour == flavour)
485 			break;
486 	}
487 	return sec_flavours[i].str;
488 }
489 
490 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
491 				    int showdefaults)
492 {
493 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
494 
495 	switch (sap->sa_family) {
496 	case AF_INET: {
497 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
498 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
499 		break;
500 	}
501 	case AF_INET6: {
502 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
503 		seq_printf(m, ",mountaddr=%pI6", &sin6->sin6_addr);
504 		break;
505 	}
506 	default:
507 		if (showdefaults)
508 			seq_printf(m, ",mountaddr=unspecified");
509 	}
510 
511 	if (nfss->mountd_version || showdefaults)
512 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
513 	if (nfss->mountd_port || showdefaults)
514 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
515 
516 	switch (nfss->mountd_protocol) {
517 	case IPPROTO_UDP:
518 		seq_printf(m, ",mountproto=udp");
519 		break;
520 	case IPPROTO_TCP:
521 		seq_printf(m, ",mountproto=tcp");
522 		break;
523 	default:
524 		if (showdefaults)
525 			seq_printf(m, ",mountproto=auto");
526 	}
527 }
528 
529 /*
530  * Describe the mount options in force on this server representation
531  */
532 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
533 				   int showdefaults)
534 {
535 	static const struct proc_nfs_info {
536 		int flag;
537 		const char *str;
538 		const char *nostr;
539 	} nfs_info[] = {
540 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
541 		{ NFS_MOUNT_POSIX, ",posix", "" },
542 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
543 		{ NFS_MOUNT_NOAC, ",noac", "" },
544 		{ NFS_MOUNT_NONLM, ",nolock", "" },
545 		{ NFS_MOUNT_NOACL, ",noacl", "" },
546 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
547 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
548 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
549 		{ 0, NULL, NULL }
550 	};
551 	const struct proc_nfs_info *nfs_infop;
552 	struct nfs_client *clp = nfss->nfs_client;
553 	u32 version = clp->rpc_ops->version;
554 
555 	seq_printf(m, ",vers=%u", version);
556 	seq_printf(m, ",rsize=%u", nfss->rsize);
557 	seq_printf(m, ",wsize=%u", nfss->wsize);
558 	if (nfss->bsize != 0)
559 		seq_printf(m, ",bsize=%u", nfss->bsize);
560 	seq_printf(m, ",namlen=%u", nfss->namelen);
561 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
562 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
563 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
564 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
565 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
566 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
567 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
568 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
569 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
570 		if (nfss->flags & nfs_infop->flag)
571 			seq_puts(m, nfs_infop->str);
572 		else
573 			seq_puts(m, nfs_infop->nostr);
574 	}
575 	seq_printf(m, ",proto=%s",
576 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
577 	if (version == 4) {
578 		if (nfss->port != NFS_PORT)
579 			seq_printf(m, ",port=%u", nfss->port);
580 	} else
581 		if (nfss->port)
582 			seq_printf(m, ",port=%u", nfss->port);
583 
584 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
585 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
586 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
587 
588 	if (version != 4)
589 		nfs_show_mountd_options(m, nfss, showdefaults);
590 
591 #ifdef CONFIG_NFS_V4
592 	if (clp->rpc_ops->version == 4)
593 		seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
594 #endif
595 	if (nfss->options & NFS_OPTION_FSCACHE)
596 		seq_printf(m, ",fsc");
597 }
598 
599 /*
600  * Describe the mount options on this VFS mountpoint
601  */
602 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
603 {
604 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
605 
606 	nfs_show_mount_options(m, nfss, 0);
607 
608 	seq_printf(m, ",addr=%s",
609 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
610 							RPC_DISPLAY_ADDR));
611 
612 	return 0;
613 }
614 
615 /*
616  * Present statistical information for this VFS mountpoint
617  */
618 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
619 {
620 	int i, cpu;
621 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
622 	struct rpc_auth *auth = nfss->client->cl_auth;
623 	struct nfs_iostats totals = { };
624 
625 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
626 
627 	/*
628 	 * Display all mount option settings
629 	 */
630 	seq_printf(m, "\n\topts:\t");
631 	seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
632 	seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
633 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
634 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
635 	nfs_show_mount_options(m, nfss, 1);
636 
637 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
638 
639 	seq_printf(m, "\n\tcaps:\t");
640 	seq_printf(m, "caps=0x%x", nfss->caps);
641 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
642 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
643 	seq_printf(m, ",bsize=%u", nfss->bsize);
644 	seq_printf(m, ",namlen=%u", nfss->namelen);
645 
646 #ifdef CONFIG_NFS_V4
647 	if (nfss->nfs_client->rpc_ops->version == 4) {
648 		seq_printf(m, "\n\tnfsv4:\t");
649 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
650 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
651 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
652 	}
653 #endif
654 
655 	/*
656 	 * Display security flavor in effect for this mount
657 	 */
658 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
659 	if (auth->au_flavor)
660 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
661 
662 	/*
663 	 * Display superblock I/O counters
664 	 */
665 	for_each_possible_cpu(cpu) {
666 		struct nfs_iostats *stats;
667 
668 		preempt_disable();
669 		stats = per_cpu_ptr(nfss->io_stats, cpu);
670 
671 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
672 			totals.events[i] += stats->events[i];
673 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
674 			totals.bytes[i] += stats->bytes[i];
675 #ifdef CONFIG_NFS_FSCACHE
676 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
677 			totals.fscache[i] += stats->fscache[i];
678 #endif
679 
680 		preempt_enable();
681 	}
682 
683 	seq_printf(m, "\n\tevents:\t");
684 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
685 		seq_printf(m, "%lu ", totals.events[i]);
686 	seq_printf(m, "\n\tbytes:\t");
687 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
688 		seq_printf(m, "%Lu ", totals.bytes[i]);
689 #ifdef CONFIG_NFS_FSCACHE
690 	if (nfss->options & NFS_OPTION_FSCACHE) {
691 		seq_printf(m, "\n\tfsc:\t");
692 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
693 			seq_printf(m, "%Lu ", totals.bytes[i]);
694 	}
695 #endif
696 	seq_printf(m, "\n");
697 
698 	rpc_print_iostats(m, nfss->client);
699 
700 	return 0;
701 }
702 
703 /*
704  * Begin unmount by attempting to remove all automounted mountpoints we added
705  * in response to xdev traversals and referrals
706  */
707 static void nfs_umount_begin(struct super_block *sb)
708 {
709 	struct nfs_server *server;
710 	struct rpc_clnt *rpc;
711 
712 	lock_kernel();
713 
714 	server = NFS_SB(sb);
715 	/* -EIO all pending I/O */
716 	rpc = server->client_acl;
717 	if (!IS_ERR(rpc))
718 		rpc_killall_tasks(rpc);
719 	rpc = server->client;
720 	if (!IS_ERR(rpc))
721 		rpc_killall_tasks(rpc);
722 
723 	unlock_kernel();
724 }
725 
726 /*
727  * Sanity-check a server address provided by the mount command.
728  *
729  * Address family must be initialized, and address must not be
730  * the ANY address for that family.
731  */
732 static int nfs_verify_server_address(struct sockaddr *addr)
733 {
734 	switch (addr->sa_family) {
735 	case AF_INET: {
736 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
737 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
738 	}
739 	case AF_INET6: {
740 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
741 		return !ipv6_addr_any(sa);
742 	}
743 	}
744 
745 	return 0;
746 }
747 
748 static void nfs_parse_ipv4_address(char *string, size_t str_len,
749 				   struct sockaddr *sap, size_t *addr_len)
750 {
751 	struct sockaddr_in *sin = (struct sockaddr_in *)sap;
752 	u8 *addr = (u8 *)&sin->sin_addr.s_addr;
753 
754 	if (str_len <= INET_ADDRSTRLEN) {
755 		dfprintk(MOUNT, "NFS: parsing IPv4 address %*s\n",
756 				(int)str_len, string);
757 
758 		sin->sin_family = AF_INET;
759 		*addr_len = sizeof(*sin);
760 		if (in4_pton(string, str_len, addr, '\0', NULL))
761 			return;
762 	}
763 
764 	sap->sa_family = AF_UNSPEC;
765 	*addr_len = 0;
766 }
767 
768 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
769 static int nfs_parse_ipv6_scope_id(const char *string, const size_t str_len,
770 				   const char *delim,
771 				   struct sockaddr_in6 *sin6)
772 {
773 	char *p;
774 	size_t len;
775 
776 	if ((string + str_len) == delim)
777 		return 1;
778 
779 	if (*delim != IPV6_SCOPE_DELIMITER)
780 		return 0;
781 
782 	if (!(ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL))
783 		return 0;
784 
785 	len = (string + str_len) - delim - 1;
786 	p = kstrndup(delim + 1, len, GFP_KERNEL);
787 	if (p) {
788 		unsigned long scope_id = 0;
789 		struct net_device *dev;
790 
791 		dev = dev_get_by_name(&init_net, p);
792 		if (dev != NULL) {
793 			scope_id = dev->ifindex;
794 			dev_put(dev);
795 		} else {
796 			if (strict_strtoul(p, 10, &scope_id) == 0) {
797 				kfree(p);
798 				return 0;
799 			}
800 		}
801 
802 		kfree(p);
803 
804 		sin6->sin6_scope_id = scope_id;
805 		dfprintk(MOUNT, "NFS: IPv6 scope ID = %lu\n", scope_id);
806 		return 1;
807 	}
808 
809 	return 0;
810 }
811 
812 static void nfs_parse_ipv6_address(char *string, size_t str_len,
813 				   struct sockaddr *sap, size_t *addr_len)
814 {
815 	struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
816 	u8 *addr = (u8 *)&sin6->sin6_addr.in6_u;
817 	const char *delim;
818 
819 	if (str_len <= INET6_ADDRSTRLEN) {
820 		dfprintk(MOUNT, "NFS: parsing IPv6 address %*s\n",
821 				(int)str_len, string);
822 
823 		sin6->sin6_family = AF_INET6;
824 		*addr_len = sizeof(*sin6);
825 		if (in6_pton(string, str_len, addr,
826 					IPV6_SCOPE_DELIMITER, &delim) != 0) {
827 			if (nfs_parse_ipv6_scope_id(string, str_len,
828 							delim, sin6) != 0)
829 				return;
830 		}
831 	}
832 
833 	sap->sa_family = AF_UNSPEC;
834 	*addr_len = 0;
835 }
836 #else
837 static void nfs_parse_ipv6_address(char *string, size_t str_len,
838 				   struct sockaddr *sap, size_t *addr_len)
839 {
840 	sap->sa_family = AF_UNSPEC;
841 	*addr_len = 0;
842 }
843 #endif
844 
845 /*
846  * Construct a sockaddr based on the contents of a string that contains
847  * an IP address in presentation format.
848  *
849  * If there is a problem constructing the new sockaddr, set the address
850  * family to AF_UNSPEC.
851  */
852 void nfs_parse_ip_address(char *string, size_t str_len,
853 				 struct sockaddr *sap, size_t *addr_len)
854 {
855 	unsigned int i, colons;
856 
857 	colons = 0;
858 	for (i = 0; i < str_len; i++)
859 		if (string[i] == ':')
860 			colons++;
861 
862 	if (colons >= 2)
863 		nfs_parse_ipv6_address(string, str_len, sap, addr_len);
864 	else
865 		nfs_parse_ipv4_address(string, str_len, sap, addr_len);
866 }
867 
868 /*
869  * Sanity check the NFS transport protocol.
870  *
871  */
872 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
873 {
874 	switch (mnt->nfs_server.protocol) {
875 	case XPRT_TRANSPORT_UDP:
876 	case XPRT_TRANSPORT_TCP:
877 	case XPRT_TRANSPORT_RDMA:
878 		break;
879 	default:
880 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
881 	}
882 }
883 
884 /*
885  * For text based NFSv2/v3 mounts, the mount protocol transport default
886  * settings should depend upon the specified NFS transport.
887  */
888 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
889 {
890 	nfs_validate_transport_protocol(mnt);
891 
892 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
893 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
894 			return;
895 	switch (mnt->nfs_server.protocol) {
896 	case XPRT_TRANSPORT_UDP:
897 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
898 		break;
899 	case XPRT_TRANSPORT_TCP:
900 	case XPRT_TRANSPORT_RDMA:
901 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
902 	}
903 }
904 
905 /*
906  * Parse the value of the 'sec=' option.
907  *
908  * The flavor_len setting is for v4 mounts.
909  */
910 static int nfs_parse_security_flavors(char *value,
911 				      struct nfs_parsed_mount_data *mnt)
912 {
913 	substring_t args[MAX_OPT_ARGS];
914 
915 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
916 
917 	switch (match_token(value, nfs_secflavor_tokens, args)) {
918 	case Opt_sec_none:
919 		mnt->auth_flavor_len = 0;
920 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
921 		break;
922 	case Opt_sec_sys:
923 		mnt->auth_flavor_len = 0;
924 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
925 		break;
926 	case Opt_sec_krb5:
927 		mnt->auth_flavor_len = 1;
928 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
929 		break;
930 	case Opt_sec_krb5i:
931 		mnt->auth_flavor_len = 1;
932 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
933 		break;
934 	case Opt_sec_krb5p:
935 		mnt->auth_flavor_len = 1;
936 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
937 		break;
938 	case Opt_sec_lkey:
939 		mnt->auth_flavor_len = 1;
940 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
941 		break;
942 	case Opt_sec_lkeyi:
943 		mnt->auth_flavor_len = 1;
944 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
945 		break;
946 	case Opt_sec_lkeyp:
947 		mnt->auth_flavor_len = 1;
948 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
949 		break;
950 	case Opt_sec_spkm:
951 		mnt->auth_flavor_len = 1;
952 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
953 		break;
954 	case Opt_sec_spkmi:
955 		mnt->auth_flavor_len = 1;
956 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
957 		break;
958 	case Opt_sec_spkmp:
959 		mnt->auth_flavor_len = 1;
960 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
961 		break;
962 	default:
963 		return 0;
964 	}
965 
966 	return 1;
967 }
968 
969 /*
970  * Error-check and convert a string of mount options from user space into
971  * a data structure.  The whole mount string is processed; bad options are
972  * skipped as they are encountered.  If there were no errors, return 1;
973  * otherwise return 0 (zero).
974  */
975 static int nfs_parse_mount_options(char *raw,
976 				   struct nfs_parsed_mount_data *mnt)
977 {
978 	char *p, *string, *secdata;
979 	int rc, sloppy = 0, invalid_option = 0;
980 
981 	if (!raw) {
982 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
983 		return 1;
984 	}
985 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
986 
987 	secdata = alloc_secdata();
988 	if (!secdata)
989 		goto out_nomem;
990 
991 	rc = security_sb_copy_data(raw, secdata);
992 	if (rc)
993 		goto out_security_failure;
994 
995 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
996 	if (rc)
997 		goto out_security_failure;
998 
999 	free_secdata(secdata);
1000 
1001 	while ((p = strsep(&raw, ",")) != NULL) {
1002 		substring_t args[MAX_OPT_ARGS];
1003 		unsigned long option;
1004 		int int_option;
1005 		int token;
1006 
1007 		if (!*p)
1008 			continue;
1009 
1010 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1011 
1012 		token = match_token(p, nfs_mount_option_tokens, args);
1013 		switch (token) {
1014 
1015 		/*
1016 		 * boolean options:  foo/nofoo
1017 		 */
1018 		case Opt_soft:
1019 			mnt->flags |= NFS_MOUNT_SOFT;
1020 			break;
1021 		case Opt_hard:
1022 			mnt->flags &= ~NFS_MOUNT_SOFT;
1023 			break;
1024 		case Opt_posix:
1025 			mnt->flags |= NFS_MOUNT_POSIX;
1026 			break;
1027 		case Opt_noposix:
1028 			mnt->flags &= ~NFS_MOUNT_POSIX;
1029 			break;
1030 		case Opt_cto:
1031 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1032 			break;
1033 		case Opt_nocto:
1034 			mnt->flags |= NFS_MOUNT_NOCTO;
1035 			break;
1036 		case Opt_ac:
1037 			mnt->flags &= ~NFS_MOUNT_NOAC;
1038 			break;
1039 		case Opt_noac:
1040 			mnt->flags |= NFS_MOUNT_NOAC;
1041 			break;
1042 		case Opt_lock:
1043 			mnt->flags &= ~NFS_MOUNT_NONLM;
1044 			break;
1045 		case Opt_nolock:
1046 			mnt->flags |= NFS_MOUNT_NONLM;
1047 			break;
1048 		case Opt_v2:
1049 			mnt->flags &= ~NFS_MOUNT_VER3;
1050 			break;
1051 		case Opt_v3:
1052 			mnt->flags |= NFS_MOUNT_VER3;
1053 			break;
1054 		case Opt_udp:
1055 			mnt->flags &= ~NFS_MOUNT_TCP;
1056 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1057 			break;
1058 		case Opt_tcp:
1059 			mnt->flags |= NFS_MOUNT_TCP;
1060 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1061 			break;
1062 		case Opt_rdma:
1063 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1064 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1065 			xprt_load_transport(p);
1066 			break;
1067 		case Opt_acl:
1068 			mnt->flags &= ~NFS_MOUNT_NOACL;
1069 			break;
1070 		case Opt_noacl:
1071 			mnt->flags |= NFS_MOUNT_NOACL;
1072 			break;
1073 		case Opt_rdirplus:
1074 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1075 			break;
1076 		case Opt_nordirplus:
1077 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1078 			break;
1079 		case Opt_sharecache:
1080 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1081 			break;
1082 		case Opt_nosharecache:
1083 			mnt->flags |= NFS_MOUNT_UNSHARED;
1084 			break;
1085 		case Opt_resvport:
1086 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1087 			break;
1088 		case Opt_noresvport:
1089 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1090 			break;
1091 		case Opt_fscache:
1092 			mnt->options |= NFS_OPTION_FSCACHE;
1093 			kfree(mnt->fscache_uniq);
1094 			mnt->fscache_uniq = NULL;
1095 			break;
1096 		case Opt_nofscache:
1097 			mnt->options &= ~NFS_OPTION_FSCACHE;
1098 			kfree(mnt->fscache_uniq);
1099 			mnt->fscache_uniq = NULL;
1100 			break;
1101 		case Opt_fscache_uniq:
1102 			string = match_strdup(args);
1103 			if (!string)
1104 				goto out_nomem;
1105 			kfree(mnt->fscache_uniq);
1106 			mnt->fscache_uniq = string;
1107 			mnt->options |= NFS_OPTION_FSCACHE;
1108 			break;
1109 
1110 		/*
1111 		 * options that take numeric values
1112 		 */
1113 		case Opt_port:
1114 			string = match_strdup(args);
1115 			if (string == NULL)
1116 				goto out_nomem;
1117 			rc = strict_strtoul(string, 10, &option);
1118 			kfree(string);
1119 			if (rc != 0 || option > USHORT_MAX)
1120 				goto out_invalid_value;
1121 			mnt->nfs_server.port = option;
1122 			break;
1123 		case Opt_rsize:
1124 			string = match_strdup(args);
1125 			if (string == NULL)
1126 				goto out_nomem;
1127 			rc = strict_strtoul(string, 10, &option);
1128 			kfree(string);
1129 			if (rc != 0)
1130 				goto out_invalid_value;
1131 			mnt->rsize = option;
1132 			break;
1133 		case Opt_wsize:
1134 			string = match_strdup(args);
1135 			if (string == NULL)
1136 				goto out_nomem;
1137 			rc = strict_strtoul(string, 10, &option);
1138 			kfree(string);
1139 			if (rc != 0)
1140 				goto out_invalid_value;
1141 			mnt->wsize = option;
1142 			break;
1143 		case Opt_bsize:
1144 			string = match_strdup(args);
1145 			if (string == NULL)
1146 				goto out_nomem;
1147 			rc = strict_strtoul(string, 10, &option);
1148 			kfree(string);
1149 			if (rc != 0)
1150 				goto out_invalid_value;
1151 			mnt->bsize = option;
1152 			break;
1153 		case Opt_timeo:
1154 			string = match_strdup(args);
1155 			if (string == NULL)
1156 				goto out_nomem;
1157 			rc = strict_strtoul(string, 10, &option);
1158 			kfree(string);
1159 			if (rc != 0 || option == 0)
1160 				goto out_invalid_value;
1161 			mnt->timeo = option;
1162 			break;
1163 		case Opt_retrans:
1164 			string = match_strdup(args);
1165 			if (string == NULL)
1166 				goto out_nomem;
1167 			rc = strict_strtoul(string, 10, &option);
1168 			kfree(string);
1169 			if (rc != 0 || option == 0)
1170 				goto out_invalid_value;
1171 			mnt->retrans = option;
1172 			break;
1173 		case Opt_acregmin:
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 			mnt->acregmin = option;
1182 			break;
1183 		case Opt_acregmax:
1184 			string = match_strdup(args);
1185 			if (string == NULL)
1186 				goto out_nomem;
1187 			rc = strict_strtoul(string, 10, &option);
1188 			kfree(string);
1189 			if (rc != 0)
1190 				goto out_invalid_value;
1191 			mnt->acregmax = option;
1192 			break;
1193 		case Opt_acdirmin:
1194 			string = match_strdup(args);
1195 			if (string == NULL)
1196 				goto out_nomem;
1197 			rc = strict_strtoul(string, 10, &option);
1198 			kfree(string);
1199 			if (rc != 0)
1200 				goto out_invalid_value;
1201 			mnt->acdirmin = option;
1202 			break;
1203 		case Opt_acdirmax:
1204 			string = match_strdup(args);
1205 			if (string == NULL)
1206 				goto out_nomem;
1207 			rc = strict_strtoul(string, 10, &option);
1208 			kfree(string);
1209 			if (rc != 0)
1210 				goto out_invalid_value;
1211 			mnt->acdirmax = option;
1212 			break;
1213 		case Opt_actimeo:
1214 			string = match_strdup(args);
1215 			if (string == NULL)
1216 				goto out_nomem;
1217 			rc = strict_strtoul(string, 10, &option);
1218 			kfree(string);
1219 			if (rc != 0)
1220 				goto out_invalid_value;
1221 			mnt->acregmin = mnt->acregmax =
1222 			mnt->acdirmin = mnt->acdirmax = option;
1223 			break;
1224 		case Opt_namelen:
1225 			string = match_strdup(args);
1226 			if (string == NULL)
1227 				goto out_nomem;
1228 			rc = strict_strtoul(string, 10, &option);
1229 			kfree(string);
1230 			if (rc != 0)
1231 				goto out_invalid_value;
1232 			mnt->namlen = option;
1233 			break;
1234 		case Opt_mountport:
1235 			string = match_strdup(args);
1236 			if (string == NULL)
1237 				goto out_nomem;
1238 			rc = strict_strtoul(string, 10, &option);
1239 			kfree(string);
1240 			if (rc != 0 || option > USHORT_MAX)
1241 				goto out_invalid_value;
1242 			mnt->mount_server.port = option;
1243 			break;
1244 		case Opt_mountvers:
1245 			string = match_strdup(args);
1246 			if (string == NULL)
1247 				goto out_nomem;
1248 			rc = strict_strtoul(string, 10, &option);
1249 			kfree(string);
1250 			if (rc != 0 ||
1251 			    option < NFS_MNT_VERSION ||
1252 			    option > NFS_MNT3_VERSION)
1253 				goto out_invalid_value;
1254 			mnt->mount_server.version = option;
1255 			break;
1256 		case Opt_nfsvers:
1257 			string = match_strdup(args);
1258 			if (string == NULL)
1259 				goto out_nomem;
1260 			rc = strict_strtoul(string, 10, &option);
1261 			kfree(string);
1262 			if (rc != 0)
1263 				goto out_invalid_value;
1264 			switch (option) {
1265 			case NFS2_VERSION:
1266 				mnt->flags &= ~NFS_MOUNT_VER3;
1267 				break;
1268 			case NFS3_VERSION:
1269 				mnt->flags |= NFS_MOUNT_VER3;
1270 				break;
1271 			default:
1272 				goto out_invalid_value;
1273 			}
1274 			break;
1275 		case Opt_minorversion:
1276 			if (match_int(args, &int_option))
1277 				return 0;
1278 			if (int_option < 0 || int_option > NFS4_MAX_MINOR_VERSION)
1279 				return 0;
1280 			mnt->minorversion = int_option;
1281 			break;
1282 
1283 		/*
1284 		 * options that take text values
1285 		 */
1286 		case Opt_sec:
1287 			string = match_strdup(args);
1288 			if (string == NULL)
1289 				goto out_nomem;
1290 			rc = nfs_parse_security_flavors(string, mnt);
1291 			kfree(string);
1292 			if (!rc) {
1293 				dfprintk(MOUNT, "NFS:   unrecognized "
1294 						"security flavor\n");
1295 				return 0;
1296 			}
1297 			break;
1298 		case Opt_proto:
1299 			string = match_strdup(args);
1300 			if (string == NULL)
1301 				goto out_nomem;
1302 			token = match_token(string,
1303 					    nfs_xprt_protocol_tokens, args);
1304 
1305 			switch (token) {
1306 			case Opt_xprt_udp:
1307 				mnt->flags &= ~NFS_MOUNT_TCP;
1308 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1309 				kfree(string);
1310 				break;
1311 			case Opt_xprt_tcp:
1312 				mnt->flags |= NFS_MOUNT_TCP;
1313 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1314 				kfree(string);
1315 				break;
1316 			case Opt_xprt_rdma:
1317 				/* vector side protocols to TCP */
1318 				mnt->flags |= NFS_MOUNT_TCP;
1319 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1320 				xprt_load_transport(string);
1321 				kfree(string);
1322 				break;
1323 			default:
1324 				dfprintk(MOUNT, "NFS:   unrecognized "
1325 						"transport protocol\n");
1326 				return 0;
1327 			}
1328 			break;
1329 		case Opt_mountproto:
1330 			string = match_strdup(args);
1331 			if (string == NULL)
1332 				goto out_nomem;
1333 			token = match_token(string,
1334 					    nfs_xprt_protocol_tokens, args);
1335 			kfree(string);
1336 
1337 			switch (token) {
1338 			case Opt_xprt_udp:
1339 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1340 				break;
1341 			case Opt_xprt_tcp:
1342 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1343 				break;
1344 			case Opt_xprt_rdma: /* not used for side protocols */
1345 			default:
1346 				dfprintk(MOUNT, "NFS:   unrecognized "
1347 						"transport protocol\n");
1348 				return 0;
1349 			}
1350 			break;
1351 		case Opt_addr:
1352 			string = match_strdup(args);
1353 			if (string == NULL)
1354 				goto out_nomem;
1355 			nfs_parse_ip_address(string, strlen(string),
1356 					     (struct sockaddr *)
1357 						&mnt->nfs_server.address,
1358 					     &mnt->nfs_server.addrlen);
1359 			kfree(string);
1360 			break;
1361 		case Opt_clientaddr:
1362 			string = match_strdup(args);
1363 			if (string == NULL)
1364 				goto out_nomem;
1365 			kfree(mnt->client_address);
1366 			mnt->client_address = string;
1367 			break;
1368 		case Opt_mounthost:
1369 			string = match_strdup(args);
1370 			if (string == NULL)
1371 				goto out_nomem;
1372 			kfree(mnt->mount_server.hostname);
1373 			mnt->mount_server.hostname = string;
1374 			break;
1375 		case Opt_mountaddr:
1376 			string = match_strdup(args);
1377 			if (string == NULL)
1378 				goto out_nomem;
1379 			nfs_parse_ip_address(string, strlen(string),
1380 					     (struct sockaddr *)
1381 						&mnt->mount_server.address,
1382 					     &mnt->mount_server.addrlen);
1383 			kfree(string);
1384 			break;
1385 		case Opt_lookupcache:
1386 			string = match_strdup(args);
1387 			if (string == NULL)
1388 				goto out_nomem;
1389 			token = match_token(string,
1390 					nfs_lookupcache_tokens, args);
1391 			kfree(string);
1392 			switch (token) {
1393 				case Opt_lookupcache_all:
1394 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1395 					break;
1396 				case Opt_lookupcache_positive:
1397 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1398 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1399 					break;
1400 				case Opt_lookupcache_none:
1401 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1402 					break;
1403 				default:
1404 					dfprintk(MOUNT, "NFS:   invalid "
1405 							"lookupcache argument\n");
1406 					return 0;
1407 			};
1408 			break;
1409 
1410 		/*
1411 		 * Special options
1412 		 */
1413 		case Opt_sloppy:
1414 			sloppy = 1;
1415 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1416 			break;
1417 		case Opt_userspace:
1418 		case Opt_deprecated:
1419 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1420 					"'%s'\n", p);
1421 			break;
1422 
1423 		default:
1424 			invalid_option = 1;
1425 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1426 					"'%s'\n", p);
1427 		}
1428 	}
1429 
1430 	if (!sloppy && invalid_option)
1431 		return 0;
1432 
1433 	return 1;
1434 
1435 out_invalid_value:
1436 	printk(KERN_INFO "NFS: bad mount option value specified: %s \n", p);
1437 	return 0;
1438 out_nomem:
1439 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1440 	return 0;
1441 out_security_failure:
1442 	free_secdata(secdata);
1443 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1444 	return 0;
1445 }
1446 
1447 /*
1448  * Use the remote server's MOUNT service to request the NFS file handle
1449  * corresponding to the provided path.
1450  */
1451 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1452 			 struct nfs_fh *root_fh)
1453 {
1454 	unsigned int auth_flavor_len = 0;
1455 	struct nfs_mount_request request = {
1456 		.sap		= (struct sockaddr *)
1457 						&args->mount_server.address,
1458 		.dirpath	= args->nfs_server.export_path,
1459 		.protocol	= args->mount_server.protocol,
1460 		.fh		= root_fh,
1461 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1462 		.auth_flav_len	= &auth_flavor_len,
1463 	};
1464 	int status;
1465 
1466 	if (args->mount_server.version == 0) {
1467 		if (args->flags & NFS_MOUNT_VER3)
1468 			args->mount_server.version = NFS_MNT3_VERSION;
1469 		else
1470 			args->mount_server.version = NFS_MNT_VERSION;
1471 	}
1472 	request.version = args->mount_server.version;
1473 
1474 	if (args->mount_server.hostname)
1475 		request.hostname = args->mount_server.hostname;
1476 	else
1477 		request.hostname = args->nfs_server.hostname;
1478 
1479 	/*
1480 	 * Construct the mount server's address.
1481 	 */
1482 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1483 		memcpy(request.sap, &args->nfs_server.address,
1484 		       args->nfs_server.addrlen);
1485 		args->mount_server.addrlen = args->nfs_server.addrlen;
1486 	}
1487 	request.salen = args->mount_server.addrlen;
1488 
1489 	/*
1490 	 * autobind will be used if mount_server.port == 0
1491 	 */
1492 	nfs_set_port(request.sap, args->mount_server.port);
1493 
1494 	/*
1495 	 * Now ask the mount server to map our export path
1496 	 * to a file handle.
1497 	 */
1498 	status = nfs_mount(&request);
1499 	if (status == 0)
1500 		return 0;
1501 
1502 	dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1503 			request.hostname, status);
1504 	return status;
1505 }
1506 
1507 static int nfs_parse_simple_hostname(const char *dev_name,
1508 				     char **hostname, size_t maxnamlen,
1509 				     char **export_path, size_t maxpathlen)
1510 {
1511 	size_t len;
1512 	char *colon, *comma;
1513 
1514 	colon = strchr(dev_name, ':');
1515 	if (colon == NULL)
1516 		goto out_bad_devname;
1517 
1518 	len = colon - dev_name;
1519 	if (len > maxnamlen)
1520 		goto out_hostname;
1521 
1522 	/* N.B. caller will free nfs_server.hostname in all cases */
1523 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1524 	if (!*hostname)
1525 		goto out_nomem;
1526 
1527 	/* kill possible hostname list: not supported */
1528 	comma = strchr(*hostname, ',');
1529 	if (comma != NULL) {
1530 		if (comma == *hostname)
1531 			goto out_bad_devname;
1532 		*comma = '\0';
1533 	}
1534 
1535 	colon++;
1536 	len = strlen(colon);
1537 	if (len > maxpathlen)
1538 		goto out_path;
1539 	*export_path = kstrndup(colon, len, GFP_KERNEL);
1540 	if (!*export_path)
1541 		goto out_nomem;
1542 
1543 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1544 	return 0;
1545 
1546 out_bad_devname:
1547 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1548 	return -EINVAL;
1549 
1550 out_nomem:
1551 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1552 	return -ENOMEM;
1553 
1554 out_hostname:
1555 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1556 	return -ENAMETOOLONG;
1557 
1558 out_path:
1559 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1560 	return -ENAMETOOLONG;
1561 }
1562 
1563 /*
1564  * Hostname has square brackets around it because it contains one or
1565  * more colons.  We look for the first closing square bracket, and a
1566  * colon must follow it.
1567  */
1568 static int nfs_parse_protected_hostname(const char *dev_name,
1569 					char **hostname, size_t maxnamlen,
1570 					char **export_path, size_t maxpathlen)
1571 {
1572 	size_t len;
1573 	char *start, *end;
1574 
1575 	start = (char *)(dev_name + 1);
1576 
1577 	end = strchr(start, ']');
1578 	if (end == NULL)
1579 		goto out_bad_devname;
1580 	if (*(end + 1) != ':')
1581 		goto out_bad_devname;
1582 
1583 	len = end - start;
1584 	if (len > maxnamlen)
1585 		goto out_hostname;
1586 
1587 	/* N.B. caller will free nfs_server.hostname in all cases */
1588 	*hostname = kstrndup(start, len, GFP_KERNEL);
1589 	if (*hostname == NULL)
1590 		goto out_nomem;
1591 
1592 	end += 2;
1593 	len = strlen(end);
1594 	if (len > maxpathlen)
1595 		goto out_path;
1596 	*export_path = kstrndup(end, len, GFP_KERNEL);
1597 	if (!*export_path)
1598 		goto out_nomem;
1599 
1600 	return 0;
1601 
1602 out_bad_devname:
1603 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1604 	return -EINVAL;
1605 
1606 out_nomem:
1607 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1608 	return -ENOMEM;
1609 
1610 out_hostname:
1611 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1612 	return -ENAMETOOLONG;
1613 
1614 out_path:
1615 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1616 	return -ENAMETOOLONG;
1617 }
1618 
1619 /*
1620  * Split "dev_name" into "hostname:export_path".
1621  *
1622  * The leftmost colon demarks the split between the server's hostname
1623  * and the export path.  If the hostname starts with a left square
1624  * bracket, then it may contain colons.
1625  *
1626  * Note: caller frees hostname and export path, even on error.
1627  */
1628 static int nfs_parse_devname(const char *dev_name,
1629 			     char **hostname, size_t maxnamlen,
1630 			     char **export_path, size_t maxpathlen)
1631 {
1632 	if (*dev_name == '[')
1633 		return nfs_parse_protected_hostname(dev_name,
1634 						    hostname, maxnamlen,
1635 						    export_path, maxpathlen);
1636 
1637 	return nfs_parse_simple_hostname(dev_name,
1638 					 hostname, maxnamlen,
1639 					 export_path, maxpathlen);
1640 }
1641 
1642 /*
1643  * Validate the NFS2/NFS3 mount data
1644  * - fills in the mount root filehandle
1645  *
1646  * For option strings, user space handles the following behaviors:
1647  *
1648  * + DNS: mapping server host name to IP address ("addr=" option)
1649  *
1650  * + failure mode: how to behave if a mount request can't be handled
1651  *   immediately ("fg/bg" option)
1652  *
1653  * + retry: how often to retry a mount request ("retry=" option)
1654  *
1655  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1656  *   mountproto=tcp after mountproto=udp, and so on
1657  */
1658 static int nfs_validate_mount_data(void *options,
1659 				   struct nfs_parsed_mount_data *args,
1660 				   struct nfs_fh *mntfh,
1661 				   const char *dev_name)
1662 {
1663 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1664 
1665 	if (data == NULL)
1666 		goto out_no_data;
1667 
1668 	args->flags		= (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1669 	args->rsize		= NFS_MAX_FILE_IO_SIZE;
1670 	args->wsize		= NFS_MAX_FILE_IO_SIZE;
1671 	args->acregmin		= NFS_DEF_ACREGMIN;
1672 	args->acregmax		= NFS_DEF_ACREGMAX;
1673 	args->acdirmin		= NFS_DEF_ACDIRMIN;
1674 	args->acdirmax		= NFS_DEF_ACDIRMAX;
1675 	args->mount_server.port	= 0;	/* autobind unless user sets port */
1676 	args->nfs_server.port	= 0;	/* autobind unless user sets port */
1677 	args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1678 	args->auth_flavors[0]	= RPC_AUTH_UNIX;
1679 
1680 	switch (data->version) {
1681 	case 1:
1682 		data->namlen = 0;
1683 	case 2:
1684 		data->bsize = 0;
1685 	case 3:
1686 		if (data->flags & NFS_MOUNT_VER3)
1687 			goto out_no_v3;
1688 		data->root.size = NFS2_FHSIZE;
1689 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1690 	case 4:
1691 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1692 			goto out_no_sec;
1693 	case 5:
1694 		memset(data->context, 0, sizeof(data->context));
1695 	case 6:
1696 		if (data->flags & NFS_MOUNT_VER3) {
1697 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1698 				goto out_invalid_fh;
1699 			mntfh->size = data->root.size;
1700 		} else
1701 			mntfh->size = NFS2_FHSIZE;
1702 
1703 
1704 		memcpy(mntfh->data, data->root.data, mntfh->size);
1705 		if (mntfh->size < sizeof(mntfh->data))
1706 			memset(mntfh->data + mntfh->size, 0,
1707 			       sizeof(mntfh->data) - mntfh->size);
1708 
1709 		/*
1710 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1711 		 * can deal with.
1712 		 */
1713 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1714 		args->rsize		= data->rsize;
1715 		args->wsize		= data->wsize;
1716 		args->timeo		= data->timeo;
1717 		args->retrans		= data->retrans;
1718 		args->acregmin		= data->acregmin;
1719 		args->acregmax		= data->acregmax;
1720 		args->acdirmin		= data->acdirmin;
1721 		args->acdirmax		= data->acdirmax;
1722 
1723 		memcpy(&args->nfs_server.address, &data->addr,
1724 		       sizeof(data->addr));
1725 		args->nfs_server.addrlen = sizeof(data->addr);
1726 		if (!nfs_verify_server_address((struct sockaddr *)
1727 						&args->nfs_server.address))
1728 			goto out_no_address;
1729 
1730 		if (!(data->flags & NFS_MOUNT_TCP))
1731 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1732 		/* N.B. caller will free nfs_server.hostname in all cases */
1733 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1734 		args->namlen		= data->namlen;
1735 		args->bsize		= data->bsize;
1736 
1737 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1738 			args->auth_flavors[0] = data->pseudoflavor;
1739 		if (!args->nfs_server.hostname)
1740 			goto out_nomem;
1741 
1742 		/*
1743 		 * The legacy version 6 binary mount data from userspace has a
1744 		 * field used only to transport selinux information into the
1745 		 * the kernel.  To continue to support that functionality we
1746 		 * have a touch of selinux knowledge here in the NFS code. The
1747 		 * userspace code converted context=blah to just blah so we are
1748 		 * converting back to the full string selinux understands.
1749 		 */
1750 		if (data->context[0]){
1751 #ifdef CONFIG_SECURITY_SELINUX
1752 			int rc;
1753 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1754 			if (!opts_str)
1755 				return -ENOMEM;
1756 			strcpy(opts_str, "context=");
1757 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1758 			strcat(opts_str, &data->context[0]);
1759 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1760 			kfree(opts_str);
1761 			if (rc)
1762 				return rc;
1763 #else
1764 			return -EINVAL;
1765 #endif
1766 		}
1767 
1768 		break;
1769 	default: {
1770 		int status;
1771 
1772 		if (nfs_parse_mount_options((char *)options, args) == 0)
1773 			return -EINVAL;
1774 
1775 		if (!nfs_verify_server_address((struct sockaddr *)
1776 						&args->nfs_server.address))
1777 			goto out_no_address;
1778 
1779 		nfs_set_port((struct sockaddr *)&args->nfs_server.address,
1780 				args->nfs_server.port);
1781 
1782 		nfs_set_mount_transport_protocol(args);
1783 
1784 		status = nfs_parse_devname(dev_name,
1785 					   &args->nfs_server.hostname,
1786 					   PAGE_SIZE,
1787 					   &args->nfs_server.export_path,
1788 					   NFS_MAXPATHLEN);
1789 		if (!status)
1790 			status = nfs_try_mount(args, mntfh);
1791 
1792 		kfree(args->nfs_server.export_path);
1793 		args->nfs_server.export_path = NULL;
1794 
1795 		if (status)
1796 			return status;
1797 
1798 		break;
1799 		}
1800 	}
1801 
1802 #ifndef CONFIG_NFS_V3
1803 	if (args->flags & NFS_MOUNT_VER3)
1804 		goto out_v3_not_compiled;
1805 #endif /* !CONFIG_NFS_V3 */
1806 
1807 	return 0;
1808 
1809 out_no_data:
1810 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1811 	return -EINVAL;
1812 
1813 out_no_v3:
1814 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1815 		 data->version);
1816 	return -EINVAL;
1817 
1818 out_no_sec:
1819 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1820 	return -EINVAL;
1821 
1822 #ifndef CONFIG_NFS_V3
1823 out_v3_not_compiled:
1824 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1825 	return -EPROTONOSUPPORT;
1826 #endif /* !CONFIG_NFS_V3 */
1827 
1828 out_nomem:
1829 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1830 	return -ENOMEM;
1831 
1832 out_no_address:
1833 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1834 	return -EINVAL;
1835 
1836 out_invalid_fh:
1837 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1838 	return -EINVAL;
1839 }
1840 
1841 static int
1842 nfs_compare_remount_data(struct nfs_server *nfss,
1843 			 struct nfs_parsed_mount_data *data)
1844 {
1845 	if (data->flags != nfss->flags ||
1846 	    data->rsize != nfss->rsize ||
1847 	    data->wsize != nfss->wsize ||
1848 	    data->retrans != nfss->client->cl_timeout->to_retries ||
1849 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1850 	    data->acregmin != nfss->acregmin / HZ ||
1851 	    data->acregmax != nfss->acregmax / HZ ||
1852 	    data->acdirmin != nfss->acdirmin / HZ ||
1853 	    data->acdirmax != nfss->acdirmax / HZ ||
1854 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1855 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1856 	    memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1857 		   data->nfs_server.addrlen) != 0)
1858 		return -EINVAL;
1859 
1860 	return 0;
1861 }
1862 
1863 static int
1864 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1865 {
1866 	int error;
1867 	struct nfs_server *nfss = sb->s_fs_info;
1868 	struct nfs_parsed_mount_data *data;
1869 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1870 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1871 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1872 
1873 	/*
1874 	 * Userspace mount programs that send binary options generally send
1875 	 * them populated with default values. We have no way to know which
1876 	 * ones were explicitly specified. Fall back to legacy behavior and
1877 	 * just return success.
1878 	 */
1879 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1880 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
1881 					   options->version <= 6))))
1882 		return 0;
1883 
1884 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1885 	if (data == NULL)
1886 		return -ENOMEM;
1887 
1888 	lock_kernel();
1889 	/* fill out struct with values from existing mount */
1890 	data->flags = nfss->flags;
1891 	data->rsize = nfss->rsize;
1892 	data->wsize = nfss->wsize;
1893 	data->retrans = nfss->client->cl_timeout->to_retries;
1894 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1895 	data->acregmin = nfss->acregmin / HZ;
1896 	data->acregmax = nfss->acregmax / HZ;
1897 	data->acdirmin = nfss->acdirmin / HZ;
1898 	data->acdirmax = nfss->acdirmax / HZ;
1899 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1900 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1901 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1902 		data->nfs_server.addrlen);
1903 
1904 	/* overwrite those values with any that were specified */
1905 	error = nfs_parse_mount_options((char *)options, data);
1906 	if (error < 0)
1907 		goto out;
1908 
1909 	/* compare new mount options with old ones */
1910 	error = nfs_compare_remount_data(nfss, data);
1911 out:
1912 	kfree(data);
1913 	unlock_kernel();
1914 	return error;
1915 }
1916 
1917 /*
1918  * Initialise the common bits of the superblock
1919  */
1920 static inline void nfs_initialise_sb(struct super_block *sb)
1921 {
1922 	struct nfs_server *server = NFS_SB(sb);
1923 
1924 	sb->s_magic = NFS_SUPER_MAGIC;
1925 
1926 	/* We probably want something more informative here */
1927 	snprintf(sb->s_id, sizeof(sb->s_id),
1928 		 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1929 
1930 	if (sb->s_blocksize == 0)
1931 		sb->s_blocksize = nfs_block_bits(server->wsize,
1932 						 &sb->s_blocksize_bits);
1933 
1934 	if (server->flags & NFS_MOUNT_NOAC)
1935 		sb->s_flags |= MS_SYNCHRONOUS;
1936 
1937 	nfs_super_set_maxbytes(sb, server->maxfilesize);
1938 }
1939 
1940 /*
1941  * Finish setting up an NFS2/3 superblock
1942  */
1943 static void nfs_fill_super(struct super_block *sb,
1944 			   struct nfs_parsed_mount_data *data)
1945 {
1946 	struct nfs_server *server = NFS_SB(sb);
1947 
1948 	sb->s_blocksize_bits = 0;
1949 	sb->s_blocksize = 0;
1950 	if (data->bsize)
1951 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1952 
1953 	if (server->flags & NFS_MOUNT_VER3) {
1954 		/* The VFS shouldn't apply the umask to mode bits. We will do
1955 		 * so ourselves when necessary.
1956 		 */
1957 		sb->s_flags |= MS_POSIXACL;
1958 		sb->s_time_gran = 1;
1959 	}
1960 
1961 	sb->s_op = &nfs_sops;
1962  	nfs_initialise_sb(sb);
1963 }
1964 
1965 /*
1966  * Finish setting up a cloned NFS2/3 superblock
1967  */
1968 static void nfs_clone_super(struct super_block *sb,
1969 			    const struct super_block *old_sb)
1970 {
1971 	struct nfs_server *server = NFS_SB(sb);
1972 
1973 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1974 	sb->s_blocksize = old_sb->s_blocksize;
1975 	sb->s_maxbytes = old_sb->s_maxbytes;
1976 
1977 	if (server->flags & NFS_MOUNT_VER3) {
1978 		/* The VFS shouldn't apply the umask to mode bits. We will do
1979 		 * so ourselves when necessary.
1980 		 */
1981 		sb->s_flags |= MS_POSIXACL;
1982 		sb->s_time_gran = 1;
1983 	}
1984 
1985 	sb->s_op = old_sb->s_op;
1986  	nfs_initialise_sb(sb);
1987 }
1988 
1989 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1990 {
1991 	const struct nfs_server *a = s->s_fs_info;
1992 	const struct rpc_clnt *clnt_a = a->client;
1993 	const struct rpc_clnt *clnt_b = b->client;
1994 
1995 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1996 		goto Ebusy;
1997 	if (a->nfs_client != b->nfs_client)
1998 		goto Ebusy;
1999 	if (a->flags != b->flags)
2000 		goto Ebusy;
2001 	if (a->wsize != b->wsize)
2002 		goto Ebusy;
2003 	if (a->rsize != b->rsize)
2004 		goto Ebusy;
2005 	if (a->acregmin != b->acregmin)
2006 		goto Ebusy;
2007 	if (a->acregmax != b->acregmax)
2008 		goto Ebusy;
2009 	if (a->acdirmin != b->acdirmin)
2010 		goto Ebusy;
2011 	if (a->acdirmax != b->acdirmax)
2012 		goto Ebusy;
2013 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2014 		goto Ebusy;
2015 	return 1;
2016 Ebusy:
2017 	return 0;
2018 }
2019 
2020 struct nfs_sb_mountdata {
2021 	struct nfs_server *server;
2022 	int mntflags;
2023 };
2024 
2025 static int nfs_set_super(struct super_block *s, void *data)
2026 {
2027 	struct nfs_sb_mountdata *sb_mntdata = data;
2028 	struct nfs_server *server = sb_mntdata->server;
2029 	int ret;
2030 
2031 	s->s_flags = sb_mntdata->mntflags;
2032 	s->s_fs_info = server;
2033 	ret = set_anon_super(s, server);
2034 	if (ret == 0)
2035 		server->s_dev = s->s_dev;
2036 	return ret;
2037 }
2038 
2039 static int nfs_compare_super_address(struct nfs_server *server1,
2040 				     struct nfs_server *server2)
2041 {
2042 	struct sockaddr *sap1, *sap2;
2043 
2044 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2045 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2046 
2047 	if (sap1->sa_family != sap2->sa_family)
2048 		return 0;
2049 
2050 	switch (sap1->sa_family) {
2051 	case AF_INET: {
2052 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2053 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2054 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2055 			return 0;
2056 		if (sin1->sin_port != sin2->sin_port)
2057 			return 0;
2058 		break;
2059 	}
2060 	case AF_INET6: {
2061 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2062 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2063 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2064 			return 0;
2065 		if (sin1->sin6_port != sin2->sin6_port)
2066 			return 0;
2067 		break;
2068 	}
2069 	default:
2070 		return 0;
2071 	}
2072 
2073 	return 1;
2074 }
2075 
2076 static int nfs_compare_super(struct super_block *sb, void *data)
2077 {
2078 	struct nfs_sb_mountdata *sb_mntdata = data;
2079 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2080 	int mntflags = sb_mntdata->mntflags;
2081 
2082 	if (!nfs_compare_super_address(old, server))
2083 		return 0;
2084 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2085 	if (old->flags & NFS_MOUNT_UNSHARED)
2086 		return 0;
2087 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2088 		return 0;
2089 	return nfs_compare_mount_options(sb, server, mntflags);
2090 }
2091 
2092 static int nfs_bdi_register(struct nfs_server *server)
2093 {
2094 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2095 }
2096 
2097 static int nfs_get_sb(struct file_system_type *fs_type,
2098 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2099 {
2100 	struct nfs_server *server = NULL;
2101 	struct super_block *s;
2102 	struct nfs_parsed_mount_data *data;
2103 	struct nfs_fh *mntfh;
2104 	struct dentry *mntroot;
2105 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2106 	struct nfs_sb_mountdata sb_mntdata = {
2107 		.mntflags = flags,
2108 	};
2109 	int error = -ENOMEM;
2110 
2111 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2112 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2113 	if (data == NULL || mntfh == NULL)
2114 		goto out_free_fh;
2115 
2116 	security_init_mnt_opts(&data->lsm_opts);
2117 
2118 	/* Validate the mount data */
2119 	error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2120 	if (error < 0)
2121 		goto out;
2122 
2123 	/* Get a volume representation */
2124 	server = nfs_create_server(data, mntfh);
2125 	if (IS_ERR(server)) {
2126 		error = PTR_ERR(server);
2127 		goto out;
2128 	}
2129 	sb_mntdata.server = server;
2130 
2131 	if (server->flags & NFS_MOUNT_UNSHARED)
2132 		compare_super = NULL;
2133 
2134 	/* Get a superblock - note that we may end up sharing one that already exists */
2135 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2136 	if (IS_ERR(s)) {
2137 		error = PTR_ERR(s);
2138 		goto out_err_nosb;
2139 	}
2140 
2141 	if (s->s_fs_info != server) {
2142 		nfs_free_server(server);
2143 		server = NULL;
2144 	} else {
2145 		error = nfs_bdi_register(server);
2146 		if (error)
2147 			goto error_splat_super;
2148 	}
2149 
2150 	if (!s->s_root) {
2151 		/* initial superblock/root creation */
2152 		nfs_fill_super(s, data);
2153 		nfs_fscache_get_super_cookie(s, data);
2154 	}
2155 
2156 	mntroot = nfs_get_root(s, mntfh);
2157 	if (IS_ERR(mntroot)) {
2158 		error = PTR_ERR(mntroot);
2159 		goto error_splat_super;
2160 	}
2161 
2162 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2163 	if (error)
2164 		goto error_splat_root;
2165 
2166 	s->s_flags |= MS_ACTIVE;
2167 	mnt->mnt_sb = s;
2168 	mnt->mnt_root = mntroot;
2169 	error = 0;
2170 
2171 out:
2172 	kfree(data->nfs_server.hostname);
2173 	kfree(data->mount_server.hostname);
2174 	kfree(data->fscache_uniq);
2175 	security_free_mnt_opts(&data->lsm_opts);
2176 out_free_fh:
2177 	kfree(mntfh);
2178 	kfree(data);
2179 	return error;
2180 
2181 out_err_nosb:
2182 	nfs_free_server(server);
2183 	goto out;
2184 
2185 error_splat_root:
2186 	dput(mntroot);
2187 error_splat_super:
2188 	deactivate_locked_super(s);
2189 	goto out;
2190 }
2191 
2192 /*
2193  * Destroy an NFS2/3 superblock
2194  */
2195 static void nfs_kill_super(struct super_block *s)
2196 {
2197 	struct nfs_server *server = NFS_SB(s);
2198 
2199 	bdi_unregister(&server->backing_dev_info);
2200 	kill_anon_super(s);
2201 	nfs_fscache_release_super_cookie(s);
2202 	nfs_free_server(server);
2203 }
2204 
2205 /*
2206  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2207  */
2208 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2209 			   const char *dev_name, void *raw_data,
2210 			   struct vfsmount *mnt)
2211 {
2212 	struct nfs_clone_mount *data = raw_data;
2213 	struct super_block *s;
2214 	struct nfs_server *server;
2215 	struct dentry *mntroot;
2216 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2217 	struct nfs_sb_mountdata sb_mntdata = {
2218 		.mntflags = flags,
2219 	};
2220 	int error;
2221 
2222 	dprintk("--> nfs_xdev_get_sb()\n");
2223 
2224 	/* create a new volume representation */
2225 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2226 	if (IS_ERR(server)) {
2227 		error = PTR_ERR(server);
2228 		goto out_err_noserver;
2229 	}
2230 	sb_mntdata.server = server;
2231 
2232 	if (server->flags & NFS_MOUNT_UNSHARED)
2233 		compare_super = NULL;
2234 
2235 	/* Get a superblock - note that we may end up sharing one that already exists */
2236 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2237 	if (IS_ERR(s)) {
2238 		error = PTR_ERR(s);
2239 		goto out_err_nosb;
2240 	}
2241 
2242 	if (s->s_fs_info != server) {
2243 		nfs_free_server(server);
2244 		server = NULL;
2245 	} else {
2246 		error = nfs_bdi_register(server);
2247 		if (error)
2248 			goto error_splat_super;
2249 	}
2250 
2251 	if (!s->s_root) {
2252 		/* initial superblock/root creation */
2253 		nfs_clone_super(s, data->sb);
2254 	}
2255 
2256 	mntroot = nfs_get_root(s, data->fh);
2257 	if (IS_ERR(mntroot)) {
2258 		error = PTR_ERR(mntroot);
2259 		goto error_splat_super;
2260 	}
2261 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2262 		dput(mntroot);
2263 		error = -ESTALE;
2264 		goto error_splat_super;
2265 	}
2266 
2267 	s->s_flags |= MS_ACTIVE;
2268 	mnt->mnt_sb = s;
2269 	mnt->mnt_root = mntroot;
2270 
2271 	/* clone any lsm security options from the parent to the new sb */
2272 	security_sb_clone_mnt_opts(data->sb, s);
2273 
2274 	dprintk("<-- nfs_xdev_get_sb() = 0\n");
2275 	return 0;
2276 
2277 out_err_nosb:
2278 	nfs_free_server(server);
2279 out_err_noserver:
2280 	dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2281 	return error;
2282 
2283 error_splat_super:
2284 	deactivate_locked_super(s);
2285 	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2286 	return error;
2287 }
2288 
2289 #ifdef CONFIG_NFS_V4
2290 
2291 /*
2292  * Finish setting up a cloned NFS4 superblock
2293  */
2294 static void nfs4_clone_super(struct super_block *sb,
2295 			    const struct super_block *old_sb)
2296 {
2297 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2298 	sb->s_blocksize = old_sb->s_blocksize;
2299 	sb->s_maxbytes = old_sb->s_maxbytes;
2300 	sb->s_time_gran = 1;
2301 	sb->s_op = old_sb->s_op;
2302  	nfs_initialise_sb(sb);
2303 }
2304 
2305 /*
2306  * Set up an NFS4 superblock
2307  */
2308 static void nfs4_fill_super(struct super_block *sb)
2309 {
2310 	sb->s_time_gran = 1;
2311 	sb->s_op = &nfs4_sops;
2312 	nfs_initialise_sb(sb);
2313 }
2314 
2315 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2316 {
2317 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
2318 }
2319 
2320 /*
2321  * Validate NFSv4 mount options
2322  */
2323 static int nfs4_validate_mount_data(void *options,
2324 				    struct nfs_parsed_mount_data *args,
2325 				    const char *dev_name)
2326 {
2327 	struct sockaddr_in *ap;
2328 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2329 	char *c;
2330 
2331 	if (data == NULL)
2332 		goto out_no_data;
2333 
2334 	args->rsize		= NFS_MAX_FILE_IO_SIZE;
2335 	args->wsize		= NFS_MAX_FILE_IO_SIZE;
2336 	args->acregmin		= NFS_DEF_ACREGMIN;
2337 	args->acregmax		= NFS_DEF_ACREGMAX;
2338 	args->acdirmin		= NFS_DEF_ACDIRMIN;
2339 	args->acdirmax		= NFS_DEF_ACDIRMAX;
2340 	args->nfs_server.port	= NFS_PORT; /* 2049 unless user set port= */
2341 	args->auth_flavors[0]	= RPC_AUTH_UNIX;
2342 	args->auth_flavor_len	= 0;
2343 	args->minorversion	= 0;
2344 
2345 	switch (data->version) {
2346 	case 1:
2347 		ap = (struct sockaddr_in *)&args->nfs_server.address;
2348 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2349 			goto out_no_address;
2350 		if (data->host_addrlen == 0)
2351 			goto out_no_address;
2352 		args->nfs_server.addrlen = data->host_addrlen;
2353 		if (copy_from_user(ap, data->host_addr, data->host_addrlen))
2354 			return -EFAULT;
2355 		if (!nfs_verify_server_address((struct sockaddr *)
2356 						&args->nfs_server.address))
2357 			goto out_no_address;
2358 
2359 		if (data->auth_flavourlen) {
2360 			if (data->auth_flavourlen > 1)
2361 				goto out_inval_auth;
2362 			if (copy_from_user(&args->auth_flavors[0],
2363 					   data->auth_flavours,
2364 					   sizeof(args->auth_flavors[0])))
2365 				return -EFAULT;
2366 		}
2367 
2368 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2369 		if (IS_ERR(c))
2370 			return PTR_ERR(c);
2371 		args->nfs_server.hostname = c;
2372 
2373 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2374 		if (IS_ERR(c))
2375 			return PTR_ERR(c);
2376 		args->nfs_server.export_path = c;
2377 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2378 
2379 		c = strndup_user(data->client_addr.data, 16);
2380 		if (IS_ERR(c))
2381 			return PTR_ERR(c);
2382 		args->client_address = c;
2383 
2384 		/*
2385 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2386 		 * can deal with.
2387 		 */
2388 
2389 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2390 		args->rsize	= data->rsize;
2391 		args->wsize	= data->wsize;
2392 		args->timeo	= data->timeo;
2393 		args->retrans	= data->retrans;
2394 		args->acregmin	= data->acregmin;
2395 		args->acregmax	= data->acregmax;
2396 		args->acdirmin	= data->acdirmin;
2397 		args->acdirmax	= data->acdirmax;
2398 		args->nfs_server.protocol = data->proto;
2399 		nfs_validate_transport_protocol(args);
2400 
2401 		break;
2402 	default: {
2403 		int status;
2404 
2405 		if (nfs_parse_mount_options((char *)options, args) == 0)
2406 			return -EINVAL;
2407 
2408 		if (!nfs_verify_server_address((struct sockaddr *)
2409 						&args->nfs_server.address))
2410 			return -EINVAL;
2411 
2412 		nfs_set_port((struct sockaddr *)&args->nfs_server.address,
2413 				args->nfs_server.port);
2414 
2415 		nfs_validate_transport_protocol(args);
2416 
2417 		nfs4_validate_mount_flags(args);
2418 
2419 		if (args->auth_flavor_len > 1)
2420 			goto out_inval_auth;
2421 
2422 		if (args->client_address == NULL)
2423 			goto out_no_client_address;
2424 
2425 		status = nfs_parse_devname(dev_name,
2426 					   &args->nfs_server.hostname,
2427 					   NFS4_MAXNAMLEN,
2428 					   &args->nfs_server.export_path,
2429 					   NFS4_MAXPATHLEN);
2430 		if (status < 0)
2431 			return status;
2432 
2433 		break;
2434 		}
2435 	}
2436 
2437 	return 0;
2438 
2439 out_no_data:
2440 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2441 	return -EINVAL;
2442 
2443 out_inval_auth:
2444 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2445 		 data->auth_flavourlen);
2446 	return -EINVAL;
2447 
2448 out_no_address:
2449 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2450 	return -EINVAL;
2451 
2452 out_no_client_address:
2453 	dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
2454 	return -EINVAL;
2455 }
2456 
2457 /*
2458  * Get the superblock for the NFS4 root partition
2459  */
2460 static int nfs4_remote_get_sb(struct file_system_type *fs_type,
2461 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2462 {
2463 	struct nfs_parsed_mount_data *data = raw_data;
2464 	struct super_block *s;
2465 	struct nfs_server *server;
2466 	struct nfs_fh *mntfh;
2467 	struct dentry *mntroot;
2468 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2469 	struct nfs_sb_mountdata sb_mntdata = {
2470 		.mntflags = flags,
2471 	};
2472 	int error = -ENOMEM;
2473 
2474 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2475 	if (data == NULL || mntfh == NULL)
2476 		goto out_free_fh;
2477 
2478 	security_init_mnt_opts(&data->lsm_opts);
2479 
2480 	/* Get a volume representation */
2481 	server = nfs4_create_server(data, mntfh);
2482 	if (IS_ERR(server)) {
2483 		error = PTR_ERR(server);
2484 		goto out;
2485 	}
2486 	sb_mntdata.server = server;
2487 
2488 	if (server->flags & NFS4_MOUNT_UNSHARED)
2489 		compare_super = NULL;
2490 
2491 	/* Get a superblock - note that we may end up sharing one that already exists */
2492 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2493 	if (IS_ERR(s)) {
2494 		error = PTR_ERR(s);
2495 		goto out_free;
2496 	}
2497 
2498 	if (s->s_fs_info != server) {
2499 		nfs_free_server(server);
2500 		server = NULL;
2501 	} else {
2502 		error = nfs_bdi_register(server);
2503 		if (error)
2504 			goto error_splat_super;
2505 	}
2506 
2507 	if (!s->s_root) {
2508 		/* initial superblock/root creation */
2509 		nfs4_fill_super(s);
2510 		nfs_fscache_get_super_cookie(s, data);
2511 	}
2512 
2513 	mntroot = nfs4_get_root(s, mntfh);
2514 	if (IS_ERR(mntroot)) {
2515 		error = PTR_ERR(mntroot);
2516 		goto error_splat_super;
2517 	}
2518 
2519 	error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2520 	if (error)
2521 		goto error_splat_root;
2522 
2523 	s->s_flags |= MS_ACTIVE;
2524 	mnt->mnt_sb = s;
2525 	mnt->mnt_root = mntroot;
2526 	error = 0;
2527 
2528 out:
2529 	security_free_mnt_opts(&data->lsm_opts);
2530 out_free_fh:
2531 	kfree(mntfh);
2532 	return error;
2533 
2534 out_free:
2535 	nfs_free_server(server);
2536 	goto out;
2537 
2538 error_splat_root:
2539 	dput(mntroot);
2540 error_splat_super:
2541 	deactivate_locked_super(s);
2542 	goto out;
2543 }
2544 
2545 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2546 		int flags, void *data, const char *hostname)
2547 {
2548 	struct vfsmount *root_mnt;
2549 	char *root_devname;
2550 	size_t len;
2551 
2552 	len = strlen(hostname) + 3;
2553 	root_devname = kmalloc(len, GFP_KERNEL);
2554 	if (root_devname == NULL)
2555 		return ERR_PTR(-ENOMEM);
2556 	snprintf(root_devname, len, "%s:/", hostname);
2557 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2558 	kfree(root_devname);
2559 	return root_mnt;
2560 }
2561 
2562 static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
2563 {
2564 	char *page = (char *) __get_free_page(GFP_KERNEL);
2565 	char *devname, *tmp;
2566 
2567 	if (page == NULL)
2568 		return;
2569 	devname = nfs_path(path->mnt->mnt_devname,
2570 			path->mnt->mnt_root, path->dentry,
2571 			page, PAGE_SIZE);
2572 	if (devname == NULL)
2573 		goto out_freepage;
2574 	tmp = kstrdup(devname, GFP_KERNEL);
2575 	if (tmp == NULL)
2576 		goto out_freepage;
2577 	kfree(mnt->mnt_devname);
2578 	mnt->mnt_devname = tmp;
2579 out_freepage:
2580 	free_page((unsigned long)page);
2581 }
2582 
2583 static int nfs_follow_remote_path(struct vfsmount *root_mnt,
2584 		const char *export_path, struct vfsmount *mnt_target)
2585 {
2586 	struct mnt_namespace *ns_private;
2587 	struct nameidata nd;
2588 	struct super_block *s;
2589 	int ret;
2590 
2591 	ns_private = create_mnt_ns(root_mnt);
2592 	ret = PTR_ERR(ns_private);
2593 	if (IS_ERR(ns_private))
2594 		goto out_mntput;
2595 
2596 	ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
2597 			export_path, LOOKUP_FOLLOW, &nd);
2598 
2599 	put_mnt_ns(ns_private);
2600 
2601 	if (ret != 0)
2602 		goto out_err;
2603 
2604 	s = nd.path.mnt->mnt_sb;
2605 	atomic_inc(&s->s_active);
2606 	mnt_target->mnt_sb = s;
2607 	mnt_target->mnt_root = dget(nd.path.dentry);
2608 
2609 	/* Correct the device pathname */
2610 	nfs_fix_devname(&nd.path, mnt_target);
2611 
2612 	path_put(&nd.path);
2613 	down_write(&s->s_umount);
2614 	return 0;
2615 out_mntput:
2616 	mntput(root_mnt);
2617 out_err:
2618 	return ret;
2619 }
2620 
2621 /*
2622  * Get the superblock for an NFS4 mountpoint
2623  */
2624 static int nfs4_get_sb(struct file_system_type *fs_type,
2625 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2626 {
2627 	struct nfs_parsed_mount_data *data;
2628 	char *export_path;
2629 	struct vfsmount *root_mnt;
2630 	int error = -ENOMEM;
2631 
2632 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2633 	if (data == NULL)
2634 		goto out_free_data;
2635 
2636 	/* Validate the mount data */
2637 	error = nfs4_validate_mount_data(raw_data, data, dev_name);
2638 	if (error < 0)
2639 		goto out;
2640 
2641 	export_path = data->nfs_server.export_path;
2642 	data->nfs_server.export_path = "/";
2643 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
2644 			data->nfs_server.hostname);
2645 	data->nfs_server.export_path = export_path;
2646 
2647 	error = PTR_ERR(root_mnt);
2648 	if (IS_ERR(root_mnt))
2649 		goto out;
2650 
2651 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2652 
2653 out:
2654 	kfree(data->client_address);
2655 	kfree(data->nfs_server.export_path);
2656 	kfree(data->nfs_server.hostname);
2657 	kfree(data->fscache_uniq);
2658 out_free_data:
2659 	kfree(data);
2660 	dprintk("<-- nfs4_get_sb() = %d%s\n", error,
2661 			error != 0 ? " [error]" : "");
2662 	return error;
2663 }
2664 
2665 static void nfs4_kill_super(struct super_block *sb)
2666 {
2667 	struct nfs_server *server = NFS_SB(sb);
2668 
2669 	dprintk("--> %s\n", __func__);
2670 	nfs_super_return_all_delegations(sb);
2671 	kill_anon_super(sb);
2672 	nfs4_renewd_prepare_shutdown(server);
2673 	nfs_fscache_release_super_cookie(sb);
2674 	nfs_free_server(server);
2675 	dprintk("<-- %s\n", __func__);
2676 }
2677 
2678 /*
2679  * Clone an NFS4 server record on xdev traversal (FSID-change)
2680  */
2681 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2682 			    const char *dev_name, void *raw_data,
2683 			    struct vfsmount *mnt)
2684 {
2685 	struct nfs_clone_mount *data = raw_data;
2686 	struct super_block *s;
2687 	struct nfs_server *server;
2688 	struct dentry *mntroot;
2689 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2690 	struct nfs_sb_mountdata sb_mntdata = {
2691 		.mntflags = flags,
2692 	};
2693 	int error;
2694 
2695 	dprintk("--> nfs4_xdev_get_sb()\n");
2696 
2697 	/* create a new volume representation */
2698 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2699 	if (IS_ERR(server)) {
2700 		error = PTR_ERR(server);
2701 		goto out_err_noserver;
2702 	}
2703 	sb_mntdata.server = server;
2704 
2705 	if (server->flags & NFS4_MOUNT_UNSHARED)
2706 		compare_super = NULL;
2707 
2708 	/* Get a superblock - note that we may end up sharing one that already exists */
2709 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2710 	if (IS_ERR(s)) {
2711 		error = PTR_ERR(s);
2712 		goto out_err_nosb;
2713 	}
2714 
2715 	if (s->s_fs_info != server) {
2716 		nfs_free_server(server);
2717 		server = NULL;
2718 	} else {
2719 		error = nfs_bdi_register(server);
2720 		if (error)
2721 			goto error_splat_super;
2722 	}
2723 
2724 	if (!s->s_root) {
2725 		/* initial superblock/root creation */
2726 		nfs4_clone_super(s, data->sb);
2727 	}
2728 
2729 	mntroot = nfs4_get_root(s, data->fh);
2730 	if (IS_ERR(mntroot)) {
2731 		error = PTR_ERR(mntroot);
2732 		goto error_splat_super;
2733 	}
2734 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2735 		dput(mntroot);
2736 		error = -ESTALE;
2737 		goto error_splat_super;
2738 	}
2739 
2740 	s->s_flags |= MS_ACTIVE;
2741 	mnt->mnt_sb = s;
2742 	mnt->mnt_root = mntroot;
2743 
2744 	security_sb_clone_mnt_opts(data->sb, s);
2745 
2746 	dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2747 	return 0;
2748 
2749 out_err_nosb:
2750 	nfs_free_server(server);
2751 out_err_noserver:
2752 	dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2753 	return error;
2754 
2755 error_splat_super:
2756 	deactivate_locked_super(s);
2757 	dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2758 	return error;
2759 }
2760 
2761 static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
2762 		int flags, const char *dev_name, void *raw_data,
2763 		struct vfsmount *mnt)
2764 {
2765 	struct nfs_clone_mount *data = raw_data;
2766 	struct super_block *s;
2767 	struct nfs_server *server;
2768 	struct dentry *mntroot;
2769 	struct nfs_fh mntfh;
2770 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2771 	struct nfs_sb_mountdata sb_mntdata = {
2772 		.mntflags = flags,
2773 	};
2774 	int error;
2775 
2776 	dprintk("--> nfs4_referral_get_sb()\n");
2777 
2778 	/* create a new volume representation */
2779 	server = nfs4_create_referral_server(data, &mntfh);
2780 	if (IS_ERR(server)) {
2781 		error = PTR_ERR(server);
2782 		goto out_err_noserver;
2783 	}
2784 	sb_mntdata.server = server;
2785 
2786 	if (server->flags & NFS4_MOUNT_UNSHARED)
2787 		compare_super = NULL;
2788 
2789 	/* Get a superblock - note that we may end up sharing one that already exists */
2790 	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2791 	if (IS_ERR(s)) {
2792 		error = PTR_ERR(s);
2793 		goto out_err_nosb;
2794 	}
2795 
2796 	if (s->s_fs_info != server) {
2797 		nfs_free_server(server);
2798 		server = NULL;
2799 	} else {
2800 		error = nfs_bdi_register(server);
2801 		if (error)
2802 			goto error_splat_super;
2803 	}
2804 
2805 	if (!s->s_root) {
2806 		/* initial superblock/root creation */
2807 		nfs4_fill_super(s);
2808 	}
2809 
2810 	mntroot = nfs4_get_root(s, &mntfh);
2811 	if (IS_ERR(mntroot)) {
2812 		error = PTR_ERR(mntroot);
2813 		goto error_splat_super;
2814 	}
2815 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2816 		dput(mntroot);
2817 		error = -ESTALE;
2818 		goto error_splat_super;
2819 	}
2820 
2821 	s->s_flags |= MS_ACTIVE;
2822 	mnt->mnt_sb = s;
2823 	mnt->mnt_root = mntroot;
2824 
2825 	security_sb_clone_mnt_opts(data->sb, s);
2826 
2827 	dprintk("<-- nfs4_referral_get_sb() = 0\n");
2828 	return 0;
2829 
2830 out_err_nosb:
2831 	nfs_free_server(server);
2832 out_err_noserver:
2833 	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2834 	return error;
2835 
2836 error_splat_super:
2837 	deactivate_locked_super(s);
2838 	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2839 	return error;
2840 }
2841 
2842 /*
2843  * Create an NFS4 server record on referral traversal
2844  */
2845 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
2846 		int flags, const char *dev_name, void *raw_data,
2847 		struct vfsmount *mnt)
2848 {
2849 	struct nfs_clone_mount *data = raw_data;
2850 	char *export_path;
2851 	struct vfsmount *root_mnt;
2852 	int error;
2853 
2854 	dprintk("--> nfs4_referral_get_sb()\n");
2855 
2856 	export_path = data->mnt_path;
2857 	data->mnt_path = "/";
2858 
2859 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2860 			flags, data, data->hostname);
2861 	data->mnt_path = export_path;
2862 
2863 	error = PTR_ERR(root_mnt);
2864 	if (IS_ERR(root_mnt))
2865 		goto out;
2866 
2867 	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
2868 out:
2869 	dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
2870 			error != 0 ? " [error]" : "");
2871 	return error;
2872 }
2873 
2874 #endif /* CONFIG_NFS_V4 */
2875