xref: /linux/fs/nfs/super.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22 
23 #include <linux/module.h>
24 #include <linux/init.h>
25 
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/stats.h>
35 #include <linux/sunrpc/metrics.h>
36 #include <linux/sunrpc/xprtsock.h>
37 #include <linux/sunrpc/xprtrdma.h>
38 #include <linux/nfs_fs.h>
39 #include <linux/nfs_mount.h>
40 #include <linux/nfs4_mount.h>
41 #include <linux/lockd/bind.h>
42 #include <linux/seq_file.h>
43 #include <linux/mount.h>
44 #include <linux/namei.h>
45 #include <linux/nfs_idmap.h>
46 #include <linux/vfs.h>
47 #include <linux/inet.h>
48 #include <linux/in6.h>
49 #include <linux/slab.h>
50 #include <net/ipv6.h>
51 #include <linux/netdevice.h>
52 #include <linux/nfs_xdr.h>
53 #include <linux/magic.h>
54 #include <linux/parser.h>
55 #include <linux/nsproxy.h>
56 #include <linux/rcupdate.h>
57 
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 #include "pnfs.h"
67 
68 #define NFSDBG_FACILITY		NFSDBG_VFS
69 #define NFS_TEXT_DATA		1
70 
71 #ifdef CONFIG_NFS_V3
72 #define NFS_DEFAULT_VERSION 3
73 #else
74 #define NFS_DEFAULT_VERSION 2
75 #endif
76 
77 enum {
78 	/* Mount options that take no arguments */
79 	Opt_soft, Opt_hard,
80 	Opt_posix, Opt_noposix,
81 	Opt_cto, Opt_nocto,
82 	Opt_ac, Opt_noac,
83 	Opt_lock, Opt_nolock,
84 	Opt_udp, Opt_tcp, Opt_rdma,
85 	Opt_acl, Opt_noacl,
86 	Opt_rdirplus, Opt_nordirplus,
87 	Opt_sharecache, Opt_nosharecache,
88 	Opt_resvport, Opt_noresvport,
89 	Opt_fscache, Opt_nofscache,
90 
91 	/* Mount options that take integer arguments */
92 	Opt_port,
93 	Opt_rsize, Opt_wsize, Opt_bsize,
94 	Opt_timeo, Opt_retrans,
95 	Opt_acregmin, Opt_acregmax,
96 	Opt_acdirmin, Opt_acdirmax,
97 	Opt_actimeo,
98 	Opt_namelen,
99 	Opt_mountport,
100 	Opt_mountvers,
101 	Opt_minorversion,
102 
103 	/* Mount options that take string arguments */
104 	Opt_nfsvers,
105 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
106 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
107 	Opt_lookupcache,
108 	Opt_fscache_uniq,
109 	Opt_local_lock,
110 
111 	/* Special mount options */
112 	Opt_userspace, Opt_deprecated, Opt_sloppy,
113 
114 	Opt_err
115 };
116 
117 static const match_table_t nfs_mount_option_tokens = {
118 	{ Opt_userspace, "bg" },
119 	{ Opt_userspace, "fg" },
120 	{ Opt_userspace, "retry=%s" },
121 
122 	{ Opt_sloppy, "sloppy" },
123 
124 	{ Opt_soft, "soft" },
125 	{ Opt_hard, "hard" },
126 	{ Opt_deprecated, "intr" },
127 	{ Opt_deprecated, "nointr" },
128 	{ Opt_posix, "posix" },
129 	{ Opt_noposix, "noposix" },
130 	{ Opt_cto, "cto" },
131 	{ Opt_nocto, "nocto" },
132 	{ Opt_ac, "ac" },
133 	{ Opt_noac, "noac" },
134 	{ Opt_lock, "lock" },
135 	{ Opt_nolock, "nolock" },
136 	{ Opt_udp, "udp" },
137 	{ Opt_tcp, "tcp" },
138 	{ Opt_rdma, "rdma" },
139 	{ Opt_acl, "acl" },
140 	{ Opt_noacl, "noacl" },
141 	{ Opt_rdirplus, "rdirplus" },
142 	{ Opt_nordirplus, "nordirplus" },
143 	{ Opt_sharecache, "sharecache" },
144 	{ Opt_nosharecache, "nosharecache" },
145 	{ Opt_resvport, "resvport" },
146 	{ Opt_noresvport, "noresvport" },
147 	{ Opt_fscache, "fsc" },
148 	{ Opt_nofscache, "nofsc" },
149 
150 	{ Opt_port, "port=%s" },
151 	{ Opt_rsize, "rsize=%s" },
152 	{ Opt_wsize, "wsize=%s" },
153 	{ Opt_bsize, "bsize=%s" },
154 	{ Opt_timeo, "timeo=%s" },
155 	{ Opt_retrans, "retrans=%s" },
156 	{ Opt_acregmin, "acregmin=%s" },
157 	{ Opt_acregmax, "acregmax=%s" },
158 	{ Opt_acdirmin, "acdirmin=%s" },
159 	{ Opt_acdirmax, "acdirmax=%s" },
160 	{ Opt_actimeo, "actimeo=%s" },
161 	{ Opt_namelen, "namlen=%s" },
162 	{ Opt_mountport, "mountport=%s" },
163 	{ Opt_mountvers, "mountvers=%s" },
164 	{ Opt_minorversion, "minorversion=%s" },
165 
166 	{ Opt_nfsvers, "nfsvers=%s" },
167 	{ Opt_nfsvers, "vers=%s" },
168 
169 	{ Opt_sec, "sec=%s" },
170 	{ Opt_proto, "proto=%s" },
171 	{ Opt_mountproto, "mountproto=%s" },
172 	{ Opt_addr, "addr=%s" },
173 	{ Opt_clientaddr, "clientaddr=%s" },
174 	{ Opt_mounthost, "mounthost=%s" },
175 	{ Opt_mountaddr, "mountaddr=%s" },
176 
177 	{ Opt_lookupcache, "lookupcache=%s" },
178 	{ Opt_fscache_uniq, "fsc=%s" },
179 	{ Opt_local_lock, "local_lock=%s" },
180 
181 	/* The following needs to be listed after all other options */
182 	{ Opt_nfsvers, "v%s" },
183 
184 	{ Opt_err, NULL }
185 };
186 
187 enum {
188 	Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
189 
190 	Opt_xprt_err
191 };
192 
193 static const match_table_t nfs_xprt_protocol_tokens = {
194 	{ Opt_xprt_udp, "udp" },
195 	{ Opt_xprt_udp6, "udp6" },
196 	{ Opt_xprt_tcp, "tcp" },
197 	{ Opt_xprt_tcp6, "tcp6" },
198 	{ Opt_xprt_rdma, "rdma" },
199 
200 	{ Opt_xprt_err, NULL }
201 };
202 
203 enum {
204 	Opt_sec_none, Opt_sec_sys,
205 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
206 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
207 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
208 
209 	Opt_sec_err
210 };
211 
212 static const match_table_t nfs_secflavor_tokens = {
213 	{ Opt_sec_none, "none" },
214 	{ Opt_sec_none, "null" },
215 	{ Opt_sec_sys, "sys" },
216 
217 	{ Opt_sec_krb5, "krb5" },
218 	{ Opt_sec_krb5i, "krb5i" },
219 	{ Opt_sec_krb5p, "krb5p" },
220 
221 	{ Opt_sec_lkey, "lkey" },
222 	{ Opt_sec_lkeyi, "lkeyi" },
223 	{ Opt_sec_lkeyp, "lkeyp" },
224 
225 	{ Opt_sec_spkm, "spkm3" },
226 	{ Opt_sec_spkmi, "spkm3i" },
227 	{ Opt_sec_spkmp, "spkm3p" },
228 
229 	{ Opt_sec_err, NULL }
230 };
231 
232 enum {
233 	Opt_lookupcache_all, Opt_lookupcache_positive,
234 	Opt_lookupcache_none,
235 
236 	Opt_lookupcache_err
237 };
238 
239 static match_table_t nfs_lookupcache_tokens = {
240 	{ Opt_lookupcache_all, "all" },
241 	{ Opt_lookupcache_positive, "pos" },
242 	{ Opt_lookupcache_positive, "positive" },
243 	{ Opt_lookupcache_none, "none" },
244 
245 	{ Opt_lookupcache_err, NULL }
246 };
247 
248 enum {
249 	Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
250 	Opt_local_lock_none,
251 
252 	Opt_local_lock_err
253 };
254 
255 static match_table_t nfs_local_lock_tokens = {
256 	{ Opt_local_lock_all, "all" },
257 	{ Opt_local_lock_flock, "flock" },
258 	{ Opt_local_lock_posix, "posix" },
259 	{ Opt_local_lock_none, "none" },
260 
261 	{ Opt_local_lock_err, NULL }
262 };
263 
264 enum {
265 	Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
266 	Opt_vers_4_1,
267 
268 	Opt_vers_err
269 };
270 
271 static match_table_t nfs_vers_tokens = {
272 	{ Opt_vers_2, "2" },
273 	{ Opt_vers_3, "3" },
274 	{ Opt_vers_4, "4" },
275 	{ Opt_vers_4_0, "4.0" },
276 	{ Opt_vers_4_1, "4.1" },
277 
278 	{ Opt_vers_err, NULL }
279 };
280 
281 struct nfs_mount_info {
282 	void (*fill_super)(struct super_block *, struct nfs_mount_info *);
283 	int (*set_security)(struct super_block *, struct dentry *, struct nfs_mount_info *);
284 	struct nfs_parsed_mount_data *parsed;
285 	struct nfs_clone_mount *cloned;
286 	struct nfs_fh *mntfh;
287 };
288 
289 static void nfs_umount_begin(struct super_block *);
290 static int  nfs_statfs(struct dentry *, struct kstatfs *);
291 static int  nfs_show_options(struct seq_file *, struct dentry *);
292 static int  nfs_show_devname(struct seq_file *, struct dentry *);
293 static int  nfs_show_path(struct seq_file *, struct dentry *);
294 static int  nfs_show_stats(struct seq_file *, struct dentry *);
295 static struct dentry *nfs_fs_mount_common(struct file_system_type *,
296 		struct nfs_server *, int, const char *, struct nfs_mount_info *);
297 static struct dentry *nfs_fs_mount(struct file_system_type *,
298 		int, const char *, void *);
299 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
300 		int flags, const char *dev_name, void *raw_data);
301 static void nfs_put_super(struct super_block *);
302 static void nfs_kill_super(struct super_block *);
303 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
304 
305 static struct file_system_type nfs_fs_type = {
306 	.owner		= THIS_MODULE,
307 	.name		= "nfs",
308 	.mount		= nfs_fs_mount,
309 	.kill_sb	= nfs_kill_super,
310 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
311 };
312 
313 struct file_system_type nfs_xdev_fs_type = {
314 	.owner		= THIS_MODULE,
315 	.name		= "nfs",
316 	.mount		= nfs_xdev_mount,
317 	.kill_sb	= nfs_kill_super,
318 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
319 };
320 
321 static const struct super_operations nfs_sops = {
322 	.alloc_inode	= nfs_alloc_inode,
323 	.destroy_inode	= nfs_destroy_inode,
324 	.write_inode	= nfs_write_inode,
325 	.put_super	= nfs_put_super,
326 	.statfs		= nfs_statfs,
327 	.evict_inode	= nfs_evict_inode,
328 	.umount_begin	= nfs_umount_begin,
329 	.show_options	= nfs_show_options,
330 	.show_devname	= nfs_show_devname,
331 	.show_path	= nfs_show_path,
332 	.show_stats	= nfs_show_stats,
333 	.remount_fs	= nfs_remount,
334 };
335 
336 #ifdef CONFIG_NFS_V4
337 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
338 static int nfs4_validate_mount_data(void *options,
339 	struct nfs_parsed_mount_data *args, const char *dev_name);
340 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
341 	struct nfs_mount_info *mount_info);
342 static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
343 	int flags, const char *dev_name, void *raw_data);
344 static struct dentry *nfs4_xdev_mount(struct file_system_type *fs_type,
345 	int flags, const char *dev_name, void *raw_data);
346 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
347 	int flags, const char *dev_name, void *raw_data);
348 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
349 	int flags, const char *dev_name, void *raw_data);
350 static void nfs4_kill_super(struct super_block *sb);
351 
352 static struct file_system_type nfs4_fs_type = {
353 	.owner		= THIS_MODULE,
354 	.name		= "nfs4",
355 	.mount		= nfs_fs_mount,
356 	.kill_sb	= nfs4_kill_super,
357 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
358 };
359 
360 static struct file_system_type nfs4_remote_fs_type = {
361 	.owner		= THIS_MODULE,
362 	.name		= "nfs4",
363 	.mount		= nfs4_remote_mount,
364 	.kill_sb	= nfs4_kill_super,
365 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
366 };
367 
368 struct file_system_type nfs4_xdev_fs_type = {
369 	.owner		= THIS_MODULE,
370 	.name		= "nfs4",
371 	.mount		= nfs4_xdev_mount,
372 	.kill_sb	= nfs4_kill_super,
373 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
374 };
375 
376 static struct file_system_type nfs4_remote_referral_fs_type = {
377 	.owner		= THIS_MODULE,
378 	.name		= "nfs4",
379 	.mount		= nfs4_remote_referral_mount,
380 	.kill_sb	= nfs4_kill_super,
381 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
382 };
383 
384 struct file_system_type nfs4_referral_fs_type = {
385 	.owner		= THIS_MODULE,
386 	.name		= "nfs4",
387 	.mount		= nfs4_referral_mount,
388 	.kill_sb	= nfs4_kill_super,
389 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
390 };
391 
392 static const struct super_operations nfs4_sops = {
393 	.alloc_inode	= nfs_alloc_inode,
394 	.destroy_inode	= nfs_destroy_inode,
395 	.write_inode	= nfs_write_inode,
396 	.put_super	= nfs_put_super,
397 	.statfs		= nfs_statfs,
398 	.evict_inode	= nfs4_evict_inode,
399 	.umount_begin	= nfs_umount_begin,
400 	.show_options	= nfs_show_options,
401 	.show_devname	= nfs_show_devname,
402 	.show_path	= nfs_show_path,
403 	.show_stats	= nfs_show_stats,
404 	.remount_fs	= nfs_remount,
405 };
406 #endif
407 
408 static struct shrinker acl_shrinker = {
409 	.shrink		= nfs_access_cache_shrinker,
410 	.seeks		= DEFAULT_SEEKS,
411 };
412 
413 /*
414  * Register the NFS filesystems
415  */
416 int __init register_nfs_fs(void)
417 {
418 	int ret;
419 
420         ret = register_filesystem(&nfs_fs_type);
421 	if (ret < 0)
422 		goto error_0;
423 
424 	ret = nfs_register_sysctl();
425 	if (ret < 0)
426 		goto error_1;
427 #ifdef CONFIG_NFS_V4
428 	ret = register_filesystem(&nfs4_fs_type);
429 	if (ret < 0)
430 		goto error_2;
431 #endif
432 	register_shrinker(&acl_shrinker);
433 	return 0;
434 
435 #ifdef CONFIG_NFS_V4
436 error_2:
437 	nfs_unregister_sysctl();
438 #endif
439 error_1:
440 	unregister_filesystem(&nfs_fs_type);
441 error_0:
442 	return ret;
443 }
444 
445 /*
446  * Unregister the NFS filesystems
447  */
448 void __exit unregister_nfs_fs(void)
449 {
450 	unregister_shrinker(&acl_shrinker);
451 #ifdef CONFIG_NFS_V4
452 	unregister_filesystem(&nfs4_fs_type);
453 #endif
454 	nfs_unregister_sysctl();
455 	unregister_filesystem(&nfs_fs_type);
456 }
457 
458 void nfs_sb_active(struct super_block *sb)
459 {
460 	struct nfs_server *server = NFS_SB(sb);
461 
462 	if (atomic_inc_return(&server->active) == 1)
463 		atomic_inc(&sb->s_active);
464 }
465 
466 void nfs_sb_deactive(struct super_block *sb)
467 {
468 	struct nfs_server *server = NFS_SB(sb);
469 
470 	if (atomic_dec_and_test(&server->active))
471 		deactivate_super(sb);
472 }
473 
474 /*
475  * Deliver file system statistics to userspace
476  */
477 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
478 {
479 	struct nfs_server *server = NFS_SB(dentry->d_sb);
480 	unsigned char blockbits;
481 	unsigned long blockres;
482 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
483 	struct nfs_fsstat res;
484 	int error = -ENOMEM;
485 
486 	res.fattr = nfs_alloc_fattr();
487 	if (res.fattr == NULL)
488 		goto out_err;
489 
490 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
491 	if (unlikely(error == -ESTALE)) {
492 		struct dentry *pd_dentry;
493 
494 		pd_dentry = dget_parent(dentry);
495 		if (pd_dentry != NULL) {
496 			nfs_zap_caches(pd_dentry->d_inode);
497 			dput(pd_dentry);
498 		}
499 	}
500 	nfs_free_fattr(res.fattr);
501 	if (error < 0)
502 		goto out_err;
503 
504 	buf->f_type = NFS_SUPER_MAGIC;
505 
506 	/*
507 	 * Current versions of glibc do not correctly handle the
508 	 * case where f_frsize != f_bsize.  Eventually we want to
509 	 * report the value of wtmult in this field.
510 	 */
511 	buf->f_frsize = dentry->d_sb->s_blocksize;
512 
513 	/*
514 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
515 	 * are reported in units of f_frsize.  Linux hasn't had
516 	 * an f_frsize field in its statfs struct until recently,
517 	 * thus historically Linux's sys_statfs reports these
518 	 * fields in units of f_bsize.
519 	 */
520 	buf->f_bsize = dentry->d_sb->s_blocksize;
521 	blockbits = dentry->d_sb->s_blocksize_bits;
522 	blockres = (1 << blockbits) - 1;
523 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
524 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
525 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
526 
527 	buf->f_files = res.tfiles;
528 	buf->f_ffree = res.afiles;
529 
530 	buf->f_namelen = server->namelen;
531 
532 	return 0;
533 
534  out_err:
535 	dprintk("%s: statfs error = %d\n", __func__, -error);
536 	return error;
537 }
538 
539 /*
540  * Map the security flavour number to a name
541  */
542 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
543 {
544 	static const struct {
545 		rpc_authflavor_t flavour;
546 		const char *str;
547 	} sec_flavours[] = {
548 		{ RPC_AUTH_NULL, "null" },
549 		{ RPC_AUTH_UNIX, "sys" },
550 		{ RPC_AUTH_GSS_KRB5, "krb5" },
551 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
552 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
553 		{ RPC_AUTH_GSS_LKEY, "lkey" },
554 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
555 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
556 		{ RPC_AUTH_GSS_SPKM, "spkm" },
557 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
558 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
559 		{ UINT_MAX, "unknown" }
560 	};
561 	int i;
562 
563 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
564 		if (sec_flavours[i].flavour == flavour)
565 			break;
566 	}
567 	return sec_flavours[i].str;
568 }
569 
570 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
571 				  int showdefaults)
572 {
573 	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
574 
575 	seq_printf(m, ",mountproto=");
576 	switch (sap->sa_family) {
577 	case AF_INET:
578 		switch (nfss->mountd_protocol) {
579 		case IPPROTO_UDP:
580 			seq_printf(m, RPCBIND_NETID_UDP);
581 			break;
582 		case IPPROTO_TCP:
583 			seq_printf(m, RPCBIND_NETID_TCP);
584 			break;
585 		default:
586 			if (showdefaults)
587 				seq_printf(m, "auto");
588 		}
589 		break;
590 	case AF_INET6:
591 		switch (nfss->mountd_protocol) {
592 		case IPPROTO_UDP:
593 			seq_printf(m, RPCBIND_NETID_UDP6);
594 			break;
595 		case IPPROTO_TCP:
596 			seq_printf(m, RPCBIND_NETID_TCP6);
597 			break;
598 		default:
599 			if (showdefaults)
600 				seq_printf(m, "auto");
601 		}
602 		break;
603 	default:
604 		if (showdefaults)
605 			seq_printf(m, "auto");
606 	}
607 }
608 
609 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
610 				    int showdefaults)
611 {
612 	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
613 
614 	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
615 		return;
616 
617 	switch (sap->sa_family) {
618 	case AF_INET: {
619 		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
620 		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
621 		break;
622 	}
623 	case AF_INET6: {
624 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
625 		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
626 		break;
627 	}
628 	default:
629 		if (showdefaults)
630 			seq_printf(m, ",mountaddr=unspecified");
631 	}
632 
633 	if (nfss->mountd_version || showdefaults)
634 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
635 	if ((nfss->mountd_port &&
636 		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
637 		showdefaults)
638 		seq_printf(m, ",mountport=%u", nfss->mountd_port);
639 
640 	nfs_show_mountd_netid(m, nfss, showdefaults);
641 }
642 
643 #ifdef CONFIG_NFS_V4
644 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
645 				    int showdefaults)
646 {
647 	struct nfs_client *clp = nfss->nfs_client;
648 
649 	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
650 }
651 #else
652 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
653 				    int showdefaults)
654 {
655 }
656 #endif
657 
658 static void nfs_show_nfs_version(struct seq_file *m,
659 		unsigned int version,
660 		unsigned int minorversion)
661 {
662 	seq_printf(m, ",vers=%u", version);
663 	if (version == 4)
664 		seq_printf(m, ".%u", minorversion);
665 }
666 
667 /*
668  * Describe the mount options in force on this server representation
669  */
670 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
671 				   int showdefaults)
672 {
673 	static const struct proc_nfs_info {
674 		int flag;
675 		const char *str;
676 		const char *nostr;
677 	} nfs_info[] = {
678 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
679 		{ NFS_MOUNT_POSIX, ",posix", "" },
680 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
681 		{ NFS_MOUNT_NOAC, ",noac", "" },
682 		{ NFS_MOUNT_NONLM, ",nolock", "" },
683 		{ NFS_MOUNT_NOACL, ",noacl", "" },
684 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
685 		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
686 		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
687 		{ 0, NULL, NULL }
688 	};
689 	const struct proc_nfs_info *nfs_infop;
690 	struct nfs_client *clp = nfss->nfs_client;
691 	u32 version = clp->rpc_ops->version;
692 	int local_flock, local_fcntl;
693 
694 	nfs_show_nfs_version(m, version, clp->cl_minorversion);
695 	seq_printf(m, ",rsize=%u", nfss->rsize);
696 	seq_printf(m, ",wsize=%u", nfss->wsize);
697 	if (nfss->bsize != 0)
698 		seq_printf(m, ",bsize=%u", nfss->bsize);
699 	seq_printf(m, ",namlen=%u", nfss->namelen);
700 	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
701 		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
702 	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
703 		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
704 	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
705 		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
706 	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
707 		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
708 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
709 		if (nfss->flags & nfs_infop->flag)
710 			seq_puts(m, nfs_infop->str);
711 		else
712 			seq_puts(m, nfs_infop->nostr);
713 	}
714 	rcu_read_lock();
715 	seq_printf(m, ",proto=%s",
716 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
717 	rcu_read_unlock();
718 	if (version == 4) {
719 		if (nfss->port != NFS_PORT)
720 			seq_printf(m, ",port=%u", nfss->port);
721 	} else
722 		if (nfss->port)
723 			seq_printf(m, ",port=%u", nfss->port);
724 
725 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
726 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
727 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
728 
729 	if (version != 4)
730 		nfs_show_mountd_options(m, nfss, showdefaults);
731 	else
732 		nfs_show_nfsv4_options(m, nfss, showdefaults);
733 
734 	if (nfss->options & NFS_OPTION_FSCACHE)
735 		seq_printf(m, ",fsc");
736 
737 	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
738 		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
739 			seq_printf(m, ",lookupcache=none");
740 		else
741 			seq_printf(m, ",lookupcache=pos");
742 	}
743 
744 	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
745 	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
746 
747 	if (!local_flock && !local_fcntl)
748 		seq_printf(m, ",local_lock=none");
749 	else if (local_flock && local_fcntl)
750 		seq_printf(m, ",local_lock=all");
751 	else if (local_flock)
752 		seq_printf(m, ",local_lock=flock");
753 	else
754 		seq_printf(m, ",local_lock=posix");
755 }
756 
757 /*
758  * Describe the mount options on this VFS mountpoint
759  */
760 static int nfs_show_options(struct seq_file *m, struct dentry *root)
761 {
762 	struct nfs_server *nfss = NFS_SB(root->d_sb);
763 
764 	nfs_show_mount_options(m, nfss, 0);
765 
766 	rcu_read_lock();
767 	seq_printf(m, ",addr=%s",
768 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
769 							RPC_DISPLAY_ADDR));
770 	rcu_read_unlock();
771 
772 	return 0;
773 }
774 
775 #ifdef CONFIG_NFS_V4
776 #ifdef CONFIG_NFS_V4_1
777 static void show_sessions(struct seq_file *m, struct nfs_server *server)
778 {
779 	if (nfs4_has_session(server->nfs_client))
780 		seq_printf(m, ",sessions");
781 }
782 #else
783 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
784 #endif
785 #endif
786 
787 #ifdef CONFIG_NFS_V4_1
788 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
789 {
790 	seq_printf(m, ",pnfs=");
791 	if (server->pnfs_curr_ld)
792 		seq_printf(m, "%s", server->pnfs_curr_ld->name);
793 	else
794 		seq_printf(m, "not configured");
795 }
796 
797 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
798 {
799 	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
800 		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
801 		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
802 			   "date='%llu,%u'",
803 			   impl_id->name, impl_id->domain,
804 			   impl_id->date.seconds, impl_id->date.nseconds);
805 	}
806 }
807 #else
808 #ifdef CONFIG_NFS_V4
809 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
810 {
811 }
812 #endif
813 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
814 {
815 }
816 #endif
817 
818 static int nfs_show_devname(struct seq_file *m, struct dentry *root)
819 {
820 	char *page = (char *) __get_free_page(GFP_KERNEL);
821 	char *devname, *dummy;
822 	int err = 0;
823 	if (!page)
824 		return -ENOMEM;
825 	devname = nfs_path(&dummy, root, page, PAGE_SIZE);
826 	if (IS_ERR(devname))
827 		err = PTR_ERR(devname);
828 	else
829 		seq_escape(m, devname, " \t\n\\");
830 	free_page((unsigned long)page);
831 	return err;
832 }
833 
834 static int nfs_show_path(struct seq_file *m, struct dentry *dentry)
835 {
836 	seq_puts(m, "/");
837 	return 0;
838 }
839 
840 /*
841  * Present statistical information for this VFS mountpoint
842  */
843 static int nfs_show_stats(struct seq_file *m, struct dentry *root)
844 {
845 	int i, cpu;
846 	struct nfs_server *nfss = NFS_SB(root->d_sb);
847 	struct rpc_auth *auth = nfss->client->cl_auth;
848 	struct nfs_iostats totals = { };
849 
850 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
851 
852 	/*
853 	 * Display all mount option settings
854 	 */
855 	seq_printf(m, "\n\topts:\t");
856 	seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
857 	seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
858 	seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
859 	seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
860 	nfs_show_mount_options(m, nfss, 1);
861 
862 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
863 
864 	show_implementation_id(m, nfss);
865 
866 	seq_printf(m, "\n\tcaps:\t");
867 	seq_printf(m, "caps=0x%x", nfss->caps);
868 	seq_printf(m, ",wtmult=%u", nfss->wtmult);
869 	seq_printf(m, ",dtsize=%u", nfss->dtsize);
870 	seq_printf(m, ",bsize=%u", nfss->bsize);
871 	seq_printf(m, ",namlen=%u", nfss->namelen);
872 
873 #ifdef CONFIG_NFS_V4
874 	if (nfss->nfs_client->rpc_ops->version == 4) {
875 		seq_printf(m, "\n\tnfsv4:\t");
876 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
877 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
878 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
879 		show_sessions(m, nfss);
880 		show_pnfs(m, nfss);
881 	}
882 #endif
883 
884 	/*
885 	 * Display security flavor in effect for this mount
886 	 */
887 	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
888 	if (auth->au_flavor)
889 		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
890 
891 	/*
892 	 * Display superblock I/O counters
893 	 */
894 	for_each_possible_cpu(cpu) {
895 		struct nfs_iostats *stats;
896 
897 		preempt_disable();
898 		stats = per_cpu_ptr(nfss->io_stats, cpu);
899 
900 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
901 			totals.events[i] += stats->events[i];
902 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
903 			totals.bytes[i] += stats->bytes[i];
904 #ifdef CONFIG_NFS_FSCACHE
905 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
906 			totals.fscache[i] += stats->fscache[i];
907 #endif
908 
909 		preempt_enable();
910 	}
911 
912 	seq_printf(m, "\n\tevents:\t");
913 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
914 		seq_printf(m, "%lu ", totals.events[i]);
915 	seq_printf(m, "\n\tbytes:\t");
916 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
917 		seq_printf(m, "%Lu ", totals.bytes[i]);
918 #ifdef CONFIG_NFS_FSCACHE
919 	if (nfss->options & NFS_OPTION_FSCACHE) {
920 		seq_printf(m, "\n\tfsc:\t");
921 		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
922 			seq_printf(m, "%Lu ", totals.bytes[i]);
923 	}
924 #endif
925 	seq_printf(m, "\n");
926 
927 	rpc_print_iostats(m, nfss->client);
928 
929 	return 0;
930 }
931 
932 /*
933  * Begin unmount by attempting to remove all automounted mountpoints we added
934  * in response to xdev traversals and referrals
935  */
936 static void nfs_umount_begin(struct super_block *sb)
937 {
938 	struct nfs_server *server;
939 	struct rpc_clnt *rpc;
940 
941 	server = NFS_SB(sb);
942 	/* -EIO all pending I/O */
943 	rpc = server->client_acl;
944 	if (!IS_ERR(rpc))
945 		rpc_killall_tasks(rpc);
946 	rpc = server->client;
947 	if (!IS_ERR(rpc))
948 		rpc_killall_tasks(rpc);
949 }
950 
951 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
952 {
953 	struct nfs_parsed_mount_data *data;
954 
955 	data = kzalloc(sizeof(*data), GFP_KERNEL);
956 	if (data) {
957 		data->acregmin		= NFS_DEF_ACREGMIN;
958 		data->acregmax		= NFS_DEF_ACREGMAX;
959 		data->acdirmin		= NFS_DEF_ACDIRMIN;
960 		data->acdirmax		= NFS_DEF_ACDIRMAX;
961 		data->mount_server.port	= NFS_UNSPEC_PORT;
962 		data->nfs_server.port	= NFS_UNSPEC_PORT;
963 		data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
964 		data->auth_flavors[0]	= RPC_AUTH_UNIX;
965 		data->auth_flavor_len	= 1;
966 		data->minorversion	= 0;
967 		data->need_mount	= true;
968 		data->net		= current->nsproxy->net_ns;
969 		security_init_mnt_opts(&data->lsm_opts);
970 	}
971 	return data;
972 }
973 
974 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
975 {
976 	if (data) {
977 		kfree(data->client_address);
978 		kfree(data->mount_server.hostname);
979 		kfree(data->nfs_server.export_path);
980 		kfree(data->nfs_server.hostname);
981 		kfree(data->fscache_uniq);
982 		security_free_mnt_opts(&data->lsm_opts);
983 		kfree(data);
984 	}
985 }
986 
987 /*
988  * Sanity-check a server address provided by the mount command.
989  *
990  * Address family must be initialized, and address must not be
991  * the ANY address for that family.
992  */
993 static int nfs_verify_server_address(struct sockaddr *addr)
994 {
995 	switch (addr->sa_family) {
996 	case AF_INET: {
997 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
998 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
999 	}
1000 	case AF_INET6: {
1001 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
1002 		return !ipv6_addr_any(sa);
1003 	}
1004 	}
1005 
1006 	dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
1007 	return 0;
1008 }
1009 
1010 /*
1011  * Select between a default port value and a user-specified port value.
1012  * If a zero value is set, then autobind will be used.
1013  */
1014 static void nfs_set_port(struct sockaddr *sap, int *port,
1015 				 const unsigned short default_port)
1016 {
1017 	if (*port == NFS_UNSPEC_PORT)
1018 		*port = default_port;
1019 
1020 	rpc_set_port(sap, *port);
1021 }
1022 
1023 /*
1024  * Sanity check the NFS transport protocol.
1025  *
1026  */
1027 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
1028 {
1029 	switch (mnt->nfs_server.protocol) {
1030 	case XPRT_TRANSPORT_UDP:
1031 	case XPRT_TRANSPORT_TCP:
1032 	case XPRT_TRANSPORT_RDMA:
1033 		break;
1034 	default:
1035 		mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1036 	}
1037 }
1038 
1039 /*
1040  * For text based NFSv2/v3 mounts, the mount protocol transport default
1041  * settings should depend upon the specified NFS transport.
1042  */
1043 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1044 {
1045 	nfs_validate_transport_protocol(mnt);
1046 
1047 	if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1048 	    mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1049 			return;
1050 	switch (mnt->nfs_server.protocol) {
1051 	case XPRT_TRANSPORT_UDP:
1052 		mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1053 		break;
1054 	case XPRT_TRANSPORT_TCP:
1055 	case XPRT_TRANSPORT_RDMA:
1056 		mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1057 	}
1058 }
1059 
1060 /*
1061  * Parse the value of the 'sec=' option.
1062  */
1063 static int nfs_parse_security_flavors(char *value,
1064 				      struct nfs_parsed_mount_data *mnt)
1065 {
1066 	substring_t args[MAX_OPT_ARGS];
1067 
1068 	dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1069 
1070 	switch (match_token(value, nfs_secflavor_tokens, args)) {
1071 	case Opt_sec_none:
1072 		mnt->auth_flavors[0] = RPC_AUTH_NULL;
1073 		break;
1074 	case Opt_sec_sys:
1075 		mnt->auth_flavors[0] = RPC_AUTH_UNIX;
1076 		break;
1077 	case Opt_sec_krb5:
1078 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
1079 		break;
1080 	case Opt_sec_krb5i:
1081 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
1082 		break;
1083 	case Opt_sec_krb5p:
1084 		mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
1085 		break;
1086 	case Opt_sec_lkey:
1087 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
1088 		break;
1089 	case Opt_sec_lkeyi:
1090 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
1091 		break;
1092 	case Opt_sec_lkeyp:
1093 		mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
1094 		break;
1095 	case Opt_sec_spkm:
1096 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
1097 		break;
1098 	case Opt_sec_spkmi:
1099 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
1100 		break;
1101 	case Opt_sec_spkmp:
1102 		mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
1103 		break;
1104 	default:
1105 		return 0;
1106 	}
1107 
1108 	mnt->flags |= NFS_MOUNT_SECFLAVOUR;
1109 	mnt->auth_flavor_len = 1;
1110 	return 1;
1111 }
1112 
1113 static int nfs_parse_version_string(char *string,
1114 		struct nfs_parsed_mount_data *mnt,
1115 		substring_t *args)
1116 {
1117 	mnt->flags &= ~NFS_MOUNT_VER3;
1118 	switch (match_token(string, nfs_vers_tokens, args)) {
1119 	case Opt_vers_2:
1120 		mnt->version = 2;
1121 		break;
1122 	case Opt_vers_3:
1123 		mnt->flags |= NFS_MOUNT_VER3;
1124 		mnt->version = 3;
1125 		break;
1126 	case Opt_vers_4:
1127 		/* Backward compatibility option. In future,
1128 		 * the mount program should always supply
1129 		 * a NFSv4 minor version number.
1130 		 */
1131 		mnt->version = 4;
1132 		break;
1133 	case Opt_vers_4_0:
1134 		mnt->version = 4;
1135 		mnt->minorversion = 0;
1136 		break;
1137 	case Opt_vers_4_1:
1138 		mnt->version = 4;
1139 		mnt->minorversion = 1;
1140 		break;
1141 	default:
1142 		return 0;
1143 	}
1144 	return 1;
1145 }
1146 
1147 static int nfs_get_option_str(substring_t args[], char **option)
1148 {
1149 	kfree(*option);
1150 	*option = match_strdup(args);
1151 	return !option;
1152 }
1153 
1154 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1155 {
1156 	int rc;
1157 	char *string;
1158 
1159 	string = match_strdup(args);
1160 	if (string == NULL)
1161 		return -ENOMEM;
1162 	rc = strict_strtoul(string, 10, option);
1163 	kfree(string);
1164 
1165 	return rc;
1166 }
1167 
1168 /*
1169  * Error-check and convert a string of mount options from user space into
1170  * a data structure.  The whole mount string is processed; bad options are
1171  * skipped as they are encountered.  If there were no errors, return 1;
1172  * otherwise return 0 (zero).
1173  */
1174 static int nfs_parse_mount_options(char *raw,
1175 				   struct nfs_parsed_mount_data *mnt)
1176 {
1177 	char *p, *string, *secdata;
1178 	int rc, sloppy = 0, invalid_option = 0;
1179 	unsigned short protofamily = AF_UNSPEC;
1180 	unsigned short mountfamily = AF_UNSPEC;
1181 
1182 	if (!raw) {
1183 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1184 		return 1;
1185 	}
1186 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1187 
1188 	secdata = alloc_secdata();
1189 	if (!secdata)
1190 		goto out_nomem;
1191 
1192 	rc = security_sb_copy_data(raw, secdata);
1193 	if (rc)
1194 		goto out_security_failure;
1195 
1196 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1197 	if (rc)
1198 		goto out_security_failure;
1199 
1200 	free_secdata(secdata);
1201 
1202 	while ((p = strsep(&raw, ",")) != NULL) {
1203 		substring_t args[MAX_OPT_ARGS];
1204 		unsigned long option;
1205 		int token;
1206 
1207 		if (!*p)
1208 			continue;
1209 
1210 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1211 
1212 		token = match_token(p, nfs_mount_option_tokens, args);
1213 		switch (token) {
1214 
1215 		/*
1216 		 * boolean options:  foo/nofoo
1217 		 */
1218 		case Opt_soft:
1219 			mnt->flags |= NFS_MOUNT_SOFT;
1220 			break;
1221 		case Opt_hard:
1222 			mnt->flags &= ~NFS_MOUNT_SOFT;
1223 			break;
1224 		case Opt_posix:
1225 			mnt->flags |= NFS_MOUNT_POSIX;
1226 			break;
1227 		case Opt_noposix:
1228 			mnt->flags &= ~NFS_MOUNT_POSIX;
1229 			break;
1230 		case Opt_cto:
1231 			mnt->flags &= ~NFS_MOUNT_NOCTO;
1232 			break;
1233 		case Opt_nocto:
1234 			mnt->flags |= NFS_MOUNT_NOCTO;
1235 			break;
1236 		case Opt_ac:
1237 			mnt->flags &= ~NFS_MOUNT_NOAC;
1238 			break;
1239 		case Opt_noac:
1240 			mnt->flags |= NFS_MOUNT_NOAC;
1241 			break;
1242 		case Opt_lock:
1243 			mnt->flags &= ~NFS_MOUNT_NONLM;
1244 			mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1245 					NFS_MOUNT_LOCAL_FCNTL);
1246 			break;
1247 		case Opt_nolock:
1248 			mnt->flags |= NFS_MOUNT_NONLM;
1249 			mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1250 				       NFS_MOUNT_LOCAL_FCNTL);
1251 			break;
1252 		case Opt_udp:
1253 			mnt->flags &= ~NFS_MOUNT_TCP;
1254 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1255 			break;
1256 		case Opt_tcp:
1257 			mnt->flags |= NFS_MOUNT_TCP;
1258 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1259 			break;
1260 		case Opt_rdma:
1261 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1262 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1263 			xprt_load_transport(p);
1264 			break;
1265 		case Opt_acl:
1266 			mnt->flags &= ~NFS_MOUNT_NOACL;
1267 			break;
1268 		case Opt_noacl:
1269 			mnt->flags |= NFS_MOUNT_NOACL;
1270 			break;
1271 		case Opt_rdirplus:
1272 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1273 			break;
1274 		case Opt_nordirplus:
1275 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1276 			break;
1277 		case Opt_sharecache:
1278 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
1279 			break;
1280 		case Opt_nosharecache:
1281 			mnt->flags |= NFS_MOUNT_UNSHARED;
1282 			break;
1283 		case Opt_resvport:
1284 			mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1285 			break;
1286 		case Opt_noresvport:
1287 			mnt->flags |= NFS_MOUNT_NORESVPORT;
1288 			break;
1289 		case Opt_fscache:
1290 			mnt->options |= NFS_OPTION_FSCACHE;
1291 			kfree(mnt->fscache_uniq);
1292 			mnt->fscache_uniq = NULL;
1293 			break;
1294 		case Opt_nofscache:
1295 			mnt->options &= ~NFS_OPTION_FSCACHE;
1296 			kfree(mnt->fscache_uniq);
1297 			mnt->fscache_uniq = NULL;
1298 			break;
1299 
1300 		/*
1301 		 * options that take numeric values
1302 		 */
1303 		case Opt_port:
1304 			if (nfs_get_option_ul(args, &option) ||
1305 			    option > USHRT_MAX)
1306 				goto out_invalid_value;
1307 			mnt->nfs_server.port = option;
1308 			break;
1309 		case Opt_rsize:
1310 			if (nfs_get_option_ul(args, &option))
1311 				goto out_invalid_value;
1312 			mnt->rsize = option;
1313 			break;
1314 		case Opt_wsize:
1315 			if (nfs_get_option_ul(args, &option))
1316 				goto out_invalid_value;
1317 			mnt->wsize = option;
1318 			break;
1319 		case Opt_bsize:
1320 			if (nfs_get_option_ul(args, &option))
1321 				goto out_invalid_value;
1322 			mnt->bsize = option;
1323 			break;
1324 		case Opt_timeo:
1325 			if (nfs_get_option_ul(args, &option) || option == 0)
1326 				goto out_invalid_value;
1327 			mnt->timeo = option;
1328 			break;
1329 		case Opt_retrans:
1330 			if (nfs_get_option_ul(args, &option) || option == 0)
1331 				goto out_invalid_value;
1332 			mnt->retrans = option;
1333 			break;
1334 		case Opt_acregmin:
1335 			if (nfs_get_option_ul(args, &option))
1336 				goto out_invalid_value;
1337 			mnt->acregmin = option;
1338 			break;
1339 		case Opt_acregmax:
1340 			if (nfs_get_option_ul(args, &option))
1341 				goto out_invalid_value;
1342 			mnt->acregmax = option;
1343 			break;
1344 		case Opt_acdirmin:
1345 			if (nfs_get_option_ul(args, &option))
1346 				goto out_invalid_value;
1347 			mnt->acdirmin = option;
1348 			break;
1349 		case Opt_acdirmax:
1350 			if (nfs_get_option_ul(args, &option))
1351 				goto out_invalid_value;
1352 			mnt->acdirmax = option;
1353 			break;
1354 		case Opt_actimeo:
1355 			if (nfs_get_option_ul(args, &option))
1356 				goto out_invalid_value;
1357 			mnt->acregmin = mnt->acregmax =
1358 			mnt->acdirmin = mnt->acdirmax = option;
1359 			break;
1360 		case Opt_namelen:
1361 			if (nfs_get_option_ul(args, &option))
1362 				goto out_invalid_value;
1363 			mnt->namlen = option;
1364 			break;
1365 		case Opt_mountport:
1366 			if (nfs_get_option_ul(args, &option) ||
1367 			    option > USHRT_MAX)
1368 				goto out_invalid_value;
1369 			mnt->mount_server.port = option;
1370 			break;
1371 		case Opt_mountvers:
1372 			if (nfs_get_option_ul(args, &option) ||
1373 			    option < NFS_MNT_VERSION ||
1374 			    option > NFS_MNT3_VERSION)
1375 				goto out_invalid_value;
1376 			mnt->mount_server.version = option;
1377 			break;
1378 		case Opt_minorversion:
1379 			if (nfs_get_option_ul(args, &option))
1380 				goto out_invalid_value;
1381 			if (option > NFS4_MAX_MINOR_VERSION)
1382 				goto out_invalid_value;
1383 			mnt->minorversion = option;
1384 			break;
1385 
1386 		/*
1387 		 * options that take text values
1388 		 */
1389 		case Opt_nfsvers:
1390 			string = match_strdup(args);
1391 			if (string == NULL)
1392 				goto out_nomem;
1393 			rc = nfs_parse_version_string(string, mnt, args);
1394 			kfree(string);
1395 			if (!rc)
1396 				goto out_invalid_value;
1397 			break;
1398 		case Opt_sec:
1399 			string = match_strdup(args);
1400 			if (string == NULL)
1401 				goto out_nomem;
1402 			rc = nfs_parse_security_flavors(string, mnt);
1403 			kfree(string);
1404 			if (!rc) {
1405 				dfprintk(MOUNT, "NFS:   unrecognized "
1406 						"security flavor\n");
1407 				return 0;
1408 			}
1409 			break;
1410 		case Opt_proto:
1411 			string = match_strdup(args);
1412 			if (string == NULL)
1413 				goto out_nomem;
1414 			token = match_token(string,
1415 					    nfs_xprt_protocol_tokens, args);
1416 
1417 			protofamily = AF_INET;
1418 			switch (token) {
1419 			case Opt_xprt_udp6:
1420 				protofamily = AF_INET6;
1421 			case Opt_xprt_udp:
1422 				mnt->flags &= ~NFS_MOUNT_TCP;
1423 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1424 				break;
1425 			case Opt_xprt_tcp6:
1426 				protofamily = AF_INET6;
1427 			case Opt_xprt_tcp:
1428 				mnt->flags |= NFS_MOUNT_TCP;
1429 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1430 				break;
1431 			case Opt_xprt_rdma:
1432 				/* vector side protocols to TCP */
1433 				mnt->flags |= NFS_MOUNT_TCP;
1434 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1435 				xprt_load_transport(string);
1436 				break;
1437 			default:
1438 				dfprintk(MOUNT, "NFS:   unrecognized "
1439 						"transport protocol\n");
1440 				kfree(string);
1441 				return 0;
1442 			}
1443 			kfree(string);
1444 			break;
1445 		case Opt_mountproto:
1446 			string = match_strdup(args);
1447 			if (string == NULL)
1448 				goto out_nomem;
1449 			token = match_token(string,
1450 					    nfs_xprt_protocol_tokens, args);
1451 			kfree(string);
1452 
1453 			mountfamily = AF_INET;
1454 			switch (token) {
1455 			case Opt_xprt_udp6:
1456 				mountfamily = AF_INET6;
1457 			case Opt_xprt_udp:
1458 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1459 				break;
1460 			case Opt_xprt_tcp6:
1461 				mountfamily = AF_INET6;
1462 			case Opt_xprt_tcp:
1463 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1464 				break;
1465 			case Opt_xprt_rdma: /* not used for side protocols */
1466 			default:
1467 				dfprintk(MOUNT, "NFS:   unrecognized "
1468 						"transport protocol\n");
1469 				return 0;
1470 			}
1471 			break;
1472 		case Opt_addr:
1473 			string = match_strdup(args);
1474 			if (string == NULL)
1475 				goto out_nomem;
1476 			mnt->nfs_server.addrlen =
1477 				rpc_pton(mnt->net, string, strlen(string),
1478 					(struct sockaddr *)
1479 					&mnt->nfs_server.address,
1480 					sizeof(mnt->nfs_server.address));
1481 			kfree(string);
1482 			if (mnt->nfs_server.addrlen == 0)
1483 				goto out_invalid_address;
1484 			break;
1485 		case Opt_clientaddr:
1486 			if (nfs_get_option_str(args, &mnt->client_address))
1487 				goto out_nomem;
1488 			break;
1489 		case Opt_mounthost:
1490 			if (nfs_get_option_str(args,
1491 					       &mnt->mount_server.hostname))
1492 				goto out_nomem;
1493 			break;
1494 		case Opt_mountaddr:
1495 			string = match_strdup(args);
1496 			if (string == NULL)
1497 				goto out_nomem;
1498 			mnt->mount_server.addrlen =
1499 				rpc_pton(mnt->net, string, strlen(string),
1500 					(struct sockaddr *)
1501 					&mnt->mount_server.address,
1502 					sizeof(mnt->mount_server.address));
1503 			kfree(string);
1504 			if (mnt->mount_server.addrlen == 0)
1505 				goto out_invalid_address;
1506 			break;
1507 		case Opt_lookupcache:
1508 			string = match_strdup(args);
1509 			if (string == NULL)
1510 				goto out_nomem;
1511 			token = match_token(string,
1512 					nfs_lookupcache_tokens, args);
1513 			kfree(string);
1514 			switch (token) {
1515 				case Opt_lookupcache_all:
1516 					mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1517 					break;
1518 				case Opt_lookupcache_positive:
1519 					mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1520 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1521 					break;
1522 				case Opt_lookupcache_none:
1523 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1524 					break;
1525 				default:
1526 					dfprintk(MOUNT, "NFS:   invalid "
1527 							"lookupcache argument\n");
1528 					return 0;
1529 			};
1530 			break;
1531 		case Opt_fscache_uniq:
1532 			if (nfs_get_option_str(args, &mnt->fscache_uniq))
1533 				goto out_nomem;
1534 			mnt->options |= NFS_OPTION_FSCACHE;
1535 			break;
1536 		case Opt_local_lock:
1537 			string = match_strdup(args);
1538 			if (string == NULL)
1539 				goto out_nomem;
1540 			token = match_token(string, nfs_local_lock_tokens,
1541 					args);
1542 			kfree(string);
1543 			switch (token) {
1544 			case Opt_local_lock_all:
1545 				mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1546 					       NFS_MOUNT_LOCAL_FCNTL);
1547 				break;
1548 			case Opt_local_lock_flock:
1549 				mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1550 				break;
1551 			case Opt_local_lock_posix:
1552 				mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1553 				break;
1554 			case Opt_local_lock_none:
1555 				mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1556 						NFS_MOUNT_LOCAL_FCNTL);
1557 				break;
1558 			default:
1559 				dfprintk(MOUNT, "NFS:	invalid	"
1560 						"local_lock argument\n");
1561 				return 0;
1562 			};
1563 			break;
1564 
1565 		/*
1566 		 * Special options
1567 		 */
1568 		case Opt_sloppy:
1569 			sloppy = 1;
1570 			dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1571 			break;
1572 		case Opt_userspace:
1573 		case Opt_deprecated:
1574 			dfprintk(MOUNT, "NFS:   ignoring mount option "
1575 					"'%s'\n", p);
1576 			break;
1577 
1578 		default:
1579 			invalid_option = 1;
1580 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
1581 					"'%s'\n", p);
1582 		}
1583 	}
1584 
1585 	if (!sloppy && invalid_option)
1586 		return 0;
1587 
1588 	if (mnt->minorversion && mnt->version != 4)
1589 		goto out_minorversion_mismatch;
1590 
1591 	/*
1592 	 * verify that any proto=/mountproto= options match the address
1593 	 * familiies in the addr=/mountaddr= options.
1594 	 */
1595 	if (protofamily != AF_UNSPEC &&
1596 	    protofamily != mnt->nfs_server.address.ss_family)
1597 		goto out_proto_mismatch;
1598 
1599 	if (mountfamily != AF_UNSPEC) {
1600 		if (mnt->mount_server.addrlen) {
1601 			if (mountfamily != mnt->mount_server.address.ss_family)
1602 				goto out_mountproto_mismatch;
1603 		} else {
1604 			if (mountfamily != mnt->nfs_server.address.ss_family)
1605 				goto out_mountproto_mismatch;
1606 		}
1607 	}
1608 
1609 	return 1;
1610 
1611 out_mountproto_mismatch:
1612 	printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1613 			 "option\n");
1614 	return 0;
1615 out_proto_mismatch:
1616 	printk(KERN_INFO "NFS: server address does not match proto= option\n");
1617 	return 0;
1618 out_invalid_address:
1619 	printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1620 	return 0;
1621 out_invalid_value:
1622 	printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1623 	return 0;
1624 out_minorversion_mismatch:
1625 	printk(KERN_INFO "NFS: mount option vers=%u does not support "
1626 			 "minorversion=%u\n", mnt->version, mnt->minorversion);
1627 	return 0;
1628 out_nomem:
1629 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1630 	return 0;
1631 out_security_failure:
1632 	free_secdata(secdata);
1633 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1634 	return 0;
1635 }
1636 
1637 /*
1638  * Match the requested auth flavors with the list returned by
1639  * the server.  Returns zero and sets the mount's authentication
1640  * flavor on success; returns -EACCES if server does not support
1641  * the requested flavor.
1642  */
1643 static int nfs_walk_authlist(struct nfs_parsed_mount_data *args,
1644 			     struct nfs_mount_request *request)
1645 {
1646 	unsigned int i, j, server_authlist_len = *(request->auth_flav_len);
1647 
1648 	/*
1649 	 * Certain releases of Linux's mountd return an empty
1650 	 * flavor list.  To prevent behavioral regression with
1651 	 * these servers (ie. rejecting mounts that used to
1652 	 * succeed), revert to pre-2.6.32 behavior (no checking)
1653 	 * if the returned flavor list is empty.
1654 	 */
1655 	if (server_authlist_len == 0)
1656 		return 0;
1657 
1658 	/*
1659 	 * We avoid sophisticated negotiating here, as there are
1660 	 * plenty of cases where we can get it wrong, providing
1661 	 * either too little or too much security.
1662 	 *
1663 	 * RFC 2623, section 2.7 suggests we SHOULD prefer the
1664 	 * flavor listed first.  However, some servers list
1665 	 * AUTH_NULL first.  Our caller plants AUTH_SYS, the
1666 	 * preferred default, in args->auth_flavors[0] if user
1667 	 * didn't specify sec= mount option.
1668 	 */
1669 	for (i = 0; i < args->auth_flavor_len; i++)
1670 		for (j = 0; j < server_authlist_len; j++)
1671 			if (args->auth_flavors[i] == request->auth_flavs[j]) {
1672 				dfprintk(MOUNT, "NFS: using auth flavor %d\n",
1673 					request->auth_flavs[j]);
1674 				args->auth_flavors[0] = request->auth_flavs[j];
1675 				return 0;
1676 			}
1677 
1678 	dfprintk(MOUNT, "NFS: server does not support requested auth flavor\n");
1679 	nfs_umount(request);
1680 	return -EACCES;
1681 }
1682 
1683 /*
1684  * Use the remote server's MOUNT service to request the NFS file handle
1685  * corresponding to the provided path.
1686  */
1687 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1688 			     struct nfs_fh *root_fh)
1689 {
1690 	rpc_authflavor_t server_authlist[NFS_MAX_SECFLAVORS];
1691 	unsigned int server_authlist_len = ARRAY_SIZE(server_authlist);
1692 	struct nfs_mount_request request = {
1693 		.sap		= (struct sockaddr *)
1694 						&args->mount_server.address,
1695 		.dirpath	= args->nfs_server.export_path,
1696 		.protocol	= args->mount_server.protocol,
1697 		.fh		= root_fh,
1698 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
1699 		.auth_flav_len	= &server_authlist_len,
1700 		.auth_flavs	= server_authlist,
1701 		.net		= args->net,
1702 	};
1703 	int status;
1704 
1705 	if (args->mount_server.version == 0) {
1706 		switch (args->version) {
1707 			default:
1708 				args->mount_server.version = NFS_MNT3_VERSION;
1709 				break;
1710 			case 2:
1711 				args->mount_server.version = NFS_MNT_VERSION;
1712 		}
1713 	}
1714 	request.version = args->mount_server.version;
1715 
1716 	if (args->mount_server.hostname)
1717 		request.hostname = args->mount_server.hostname;
1718 	else
1719 		request.hostname = args->nfs_server.hostname;
1720 
1721 	/*
1722 	 * Construct the mount server's address.
1723 	 */
1724 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1725 		memcpy(request.sap, &args->nfs_server.address,
1726 		       args->nfs_server.addrlen);
1727 		args->mount_server.addrlen = args->nfs_server.addrlen;
1728 	}
1729 	request.salen = args->mount_server.addrlen;
1730 	nfs_set_port(request.sap, &args->mount_server.port, 0);
1731 
1732 	/*
1733 	 * Now ask the mount server to map our export path
1734 	 * to a file handle.
1735 	 */
1736 	status = nfs_mount(&request);
1737 	if (status != 0) {
1738 		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1739 				request.hostname, status);
1740 		return status;
1741 	}
1742 
1743 	/*
1744 	 * MNTv1 (NFSv2) does not support auth flavor negotiation.
1745 	 */
1746 	if (args->mount_server.version != NFS_MNT3_VERSION)
1747 		return 0;
1748 	return nfs_walk_authlist(args, &request);
1749 }
1750 
1751 static struct dentry *nfs_try_mount(int flags, const char *dev_name,
1752 				    struct nfs_mount_info *mount_info)
1753 {
1754 	int status;
1755 	struct nfs_server *server;
1756 
1757 	if (mount_info->parsed->need_mount) {
1758 		status = nfs_request_mount(mount_info->parsed, mount_info->mntfh);
1759 		if (status)
1760 			return ERR_PTR(status);
1761 	}
1762 
1763 	/* Get a volume representation */
1764 	server = nfs_create_server(mount_info->parsed, mount_info->mntfh);
1765 	if (IS_ERR(server))
1766 		return ERR_CAST(server);
1767 
1768 	return nfs_fs_mount_common(&nfs_fs_type, server, flags, dev_name, mount_info);
1769 }
1770 
1771 /*
1772  * Split "dev_name" into "hostname:export_path".
1773  *
1774  * The leftmost colon demarks the split between the server's hostname
1775  * and the export path.  If the hostname starts with a left square
1776  * bracket, then it may contain colons.
1777  *
1778  * Note: caller frees hostname and export path, even on error.
1779  */
1780 static int nfs_parse_devname(const char *dev_name,
1781 			     char **hostname, size_t maxnamlen,
1782 			     char **export_path, size_t maxpathlen)
1783 {
1784 	size_t len;
1785 	char *end;
1786 
1787 	/* Is the host name protected with square brakcets? */
1788 	if (*dev_name == '[') {
1789 		end = strchr(++dev_name, ']');
1790 		if (end == NULL || end[1] != ':')
1791 			goto out_bad_devname;
1792 
1793 		len = end - dev_name;
1794 		end++;
1795 	} else {
1796 		char *comma;
1797 
1798 		end = strchr(dev_name, ':');
1799 		if (end == NULL)
1800 			goto out_bad_devname;
1801 		len = end - dev_name;
1802 
1803 		/* kill possible hostname list: not supported */
1804 		comma = strchr(dev_name, ',');
1805 		if (comma != NULL && comma < end)
1806 			*comma = 0;
1807 	}
1808 
1809 	if (len > maxnamlen)
1810 		goto out_hostname;
1811 
1812 	/* N.B. caller will free nfs_server.hostname in all cases */
1813 	*hostname = kstrndup(dev_name, len, GFP_KERNEL);
1814 	if (*hostname == NULL)
1815 		goto out_nomem;
1816 	len = strlen(++end);
1817 	if (len > maxpathlen)
1818 		goto out_path;
1819 	*export_path = kstrndup(end, len, GFP_KERNEL);
1820 	if (!*export_path)
1821 		goto out_nomem;
1822 
1823 	dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1824 	return 0;
1825 
1826 out_bad_devname:
1827 	dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1828 	return -EINVAL;
1829 
1830 out_nomem:
1831 	dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1832 	return -ENOMEM;
1833 
1834 out_hostname:
1835 	dfprintk(MOUNT, "NFS: server hostname too long\n");
1836 	return -ENAMETOOLONG;
1837 
1838 out_path:
1839 	dfprintk(MOUNT, "NFS: export pathname too long\n");
1840 	return -ENAMETOOLONG;
1841 }
1842 
1843 /*
1844  * Validate the NFS2/NFS3 mount data
1845  * - fills in the mount root filehandle
1846  *
1847  * For option strings, user space handles the following behaviors:
1848  *
1849  * + DNS: mapping server host name to IP address ("addr=" option)
1850  *
1851  * + failure mode: how to behave if a mount request can't be handled
1852  *   immediately ("fg/bg" option)
1853  *
1854  * + retry: how often to retry a mount request ("retry=" option)
1855  *
1856  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1857  *   mountproto=tcp after mountproto=udp, and so on
1858  */
1859 static int nfs23_validate_mount_data(void *options,
1860 				     struct nfs_parsed_mount_data *args,
1861 				     struct nfs_fh *mntfh,
1862 				     const char *dev_name)
1863 {
1864 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1865 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1866 
1867 	if (data == NULL)
1868 		goto out_no_data;
1869 
1870 	args->version = NFS_DEFAULT_VERSION;
1871 	switch (data->version) {
1872 	case 1:
1873 		data->namlen = 0;
1874 	case 2:
1875 		data->bsize = 0;
1876 	case 3:
1877 		if (data->flags & NFS_MOUNT_VER3)
1878 			goto out_no_v3;
1879 		data->root.size = NFS2_FHSIZE;
1880 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1881 	case 4:
1882 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1883 			goto out_no_sec;
1884 	case 5:
1885 		memset(data->context, 0, sizeof(data->context));
1886 	case 6:
1887 		if (data->flags & NFS_MOUNT_VER3) {
1888 			if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1889 				goto out_invalid_fh;
1890 			mntfh->size = data->root.size;
1891 			args->version = 3;
1892 		} else {
1893 			mntfh->size = NFS2_FHSIZE;
1894 			args->version = 2;
1895 		}
1896 
1897 
1898 		memcpy(mntfh->data, data->root.data, mntfh->size);
1899 		if (mntfh->size < sizeof(mntfh->data))
1900 			memset(mntfh->data + mntfh->size, 0,
1901 			       sizeof(mntfh->data) - mntfh->size);
1902 
1903 		/*
1904 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1905 		 * can deal with.
1906 		 */
1907 		args->flags		= data->flags & NFS_MOUNT_FLAGMASK;
1908 		args->flags		|= NFS_MOUNT_LEGACY_INTERFACE;
1909 		args->rsize		= data->rsize;
1910 		args->wsize		= data->wsize;
1911 		args->timeo		= data->timeo;
1912 		args->retrans		= data->retrans;
1913 		args->acregmin		= data->acregmin;
1914 		args->acregmax		= data->acregmax;
1915 		args->acdirmin		= data->acdirmin;
1916 		args->acdirmax		= data->acdirmax;
1917 		args->need_mount	= false;
1918 
1919 		memcpy(sap, &data->addr, sizeof(data->addr));
1920 		args->nfs_server.addrlen = sizeof(data->addr);
1921 		if (!nfs_verify_server_address(sap))
1922 			goto out_no_address;
1923 
1924 		if (!(data->flags & NFS_MOUNT_TCP))
1925 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1926 		/* N.B. caller will free nfs_server.hostname in all cases */
1927 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1928 		args->namlen		= data->namlen;
1929 		args->bsize		= data->bsize;
1930 
1931 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1932 			args->auth_flavors[0] = data->pseudoflavor;
1933 		if (!args->nfs_server.hostname)
1934 			goto out_nomem;
1935 
1936 		if (!(data->flags & NFS_MOUNT_NONLM))
1937 			args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
1938 					 NFS_MOUNT_LOCAL_FCNTL);
1939 		else
1940 			args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
1941 					NFS_MOUNT_LOCAL_FCNTL);
1942 		/*
1943 		 * The legacy version 6 binary mount data from userspace has a
1944 		 * field used only to transport selinux information into the
1945 		 * the kernel.  To continue to support that functionality we
1946 		 * have a touch of selinux knowledge here in the NFS code. The
1947 		 * userspace code converted context=blah to just blah so we are
1948 		 * converting back to the full string selinux understands.
1949 		 */
1950 		if (data->context[0]){
1951 #ifdef CONFIG_SECURITY_SELINUX
1952 			int rc;
1953 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1954 			if (!opts_str)
1955 				return -ENOMEM;
1956 			strcpy(opts_str, "context=");
1957 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1958 			strcat(opts_str, &data->context[0]);
1959 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1960 			kfree(opts_str);
1961 			if (rc)
1962 				return rc;
1963 #else
1964 			return -EINVAL;
1965 #endif
1966 		}
1967 
1968 		break;
1969 	default:
1970 		return NFS_TEXT_DATA;
1971 	}
1972 
1973 #ifndef CONFIG_NFS_V3
1974 	if (args->version == 3)
1975 		goto out_v3_not_compiled;
1976 #endif /* !CONFIG_NFS_V3 */
1977 
1978 	return 0;
1979 
1980 out_no_data:
1981 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1982 	return -EINVAL;
1983 
1984 out_no_v3:
1985 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1986 		 data->version);
1987 	return -EINVAL;
1988 
1989 out_no_sec:
1990 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1991 	return -EINVAL;
1992 
1993 #ifndef CONFIG_NFS_V3
1994 out_v3_not_compiled:
1995 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1996 	return -EPROTONOSUPPORT;
1997 #endif /* !CONFIG_NFS_V3 */
1998 
1999 out_nomem:
2000 	dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2001 	return -ENOMEM;
2002 
2003 out_no_address:
2004 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2005 	return -EINVAL;
2006 
2007 out_invalid_fh:
2008 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2009 	return -EINVAL;
2010 }
2011 
2012 #ifdef CONFIG_NFS_V4
2013 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2014 				   void *options,
2015 				   struct nfs_parsed_mount_data *args,
2016 				   struct nfs_fh *mntfh,
2017 				   const char *dev_name)
2018 {
2019 	if (fs_type == &nfs_fs_type)
2020 		return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2021 	return nfs4_validate_mount_data(options, args, dev_name);
2022 }
2023 #else
2024 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2025 				   void *options,
2026 				   struct nfs_parsed_mount_data *args,
2027 				   struct nfs_fh *mntfh,
2028 				   const char *dev_name)
2029 {
2030 	return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2031 }
2032 #endif
2033 
2034 static int nfs_validate_text_mount_data(void *options,
2035 					struct nfs_parsed_mount_data *args,
2036 					const char *dev_name)
2037 {
2038 	int port = 0;
2039 	int max_namelen = PAGE_SIZE;
2040 	int max_pathlen = NFS_MAXPATHLEN;
2041 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2042 
2043 	if (nfs_parse_mount_options((char *)options, args) == 0)
2044 		return -EINVAL;
2045 
2046 	if (!nfs_verify_server_address(sap))
2047 		goto out_no_address;
2048 
2049 	if (args->version == 4) {
2050 #ifdef CONFIG_NFS_V4
2051 		port = NFS_PORT;
2052 		max_namelen = NFS4_MAXNAMLEN;
2053 		max_pathlen = NFS4_MAXPATHLEN;
2054 		nfs_validate_transport_protocol(args);
2055 		nfs4_validate_mount_flags(args);
2056 #else
2057 		goto out_v4_not_compiled;
2058 #endif /* CONFIG_NFS_V4 */
2059 	} else
2060 		nfs_set_mount_transport_protocol(args);
2061 
2062 	nfs_set_port(sap, &args->nfs_server.port, port);
2063 
2064 	if (args->auth_flavor_len > 1)
2065 		goto out_bad_auth;
2066 
2067 	return nfs_parse_devname(dev_name,
2068 				   &args->nfs_server.hostname,
2069 				   max_namelen,
2070 				   &args->nfs_server.export_path,
2071 				   max_pathlen);
2072 
2073 #ifndef CONFIG_NFS_V4
2074 out_v4_not_compiled:
2075 	dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2076 	return -EPROTONOSUPPORT;
2077 #endif /* !CONFIG_NFS_V4 */
2078 
2079 out_no_address:
2080 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2081 	return -EINVAL;
2082 
2083 out_bad_auth:
2084 	dfprintk(MOUNT, "NFS: Too many RPC auth flavours specified\n");
2085 	return -EINVAL;
2086 }
2087 
2088 static int
2089 nfs_compare_remount_data(struct nfs_server *nfss,
2090 			 struct nfs_parsed_mount_data *data)
2091 {
2092 	if (data->flags != nfss->flags ||
2093 	    data->rsize != nfss->rsize ||
2094 	    data->wsize != nfss->wsize ||
2095 	    data->retrans != nfss->client->cl_timeout->to_retries ||
2096 	    data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
2097 	    data->acregmin != nfss->acregmin / HZ ||
2098 	    data->acregmax != nfss->acregmax / HZ ||
2099 	    data->acdirmin != nfss->acdirmin / HZ ||
2100 	    data->acdirmax != nfss->acdirmax / HZ ||
2101 	    data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2102 	    data->nfs_server.port != nfss->port ||
2103 	    data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2104 	    !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2105 			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
2106 		return -EINVAL;
2107 
2108 	return 0;
2109 }
2110 
2111 static int
2112 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2113 {
2114 	int error;
2115 	struct nfs_server *nfss = sb->s_fs_info;
2116 	struct nfs_parsed_mount_data *data;
2117 	struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2118 	struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2119 	u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2120 
2121 	/*
2122 	 * Userspace mount programs that send binary options generally send
2123 	 * them populated with default values. We have no way to know which
2124 	 * ones were explicitly specified. Fall back to legacy behavior and
2125 	 * just return success.
2126 	 */
2127 	if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2128 	    (nfsvers <= 3 && (!options || (options->version >= 1 &&
2129 					   options->version <= 6))))
2130 		return 0;
2131 
2132 	data = kzalloc(sizeof(*data), GFP_KERNEL);
2133 	if (data == NULL)
2134 		return -ENOMEM;
2135 
2136 	/* fill out struct with values from existing mount */
2137 	data->flags = nfss->flags;
2138 	data->rsize = nfss->rsize;
2139 	data->wsize = nfss->wsize;
2140 	data->retrans = nfss->client->cl_timeout->to_retries;
2141 	data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
2142 	data->acregmin = nfss->acregmin / HZ;
2143 	data->acregmax = nfss->acregmax / HZ;
2144 	data->acdirmin = nfss->acdirmin / HZ;
2145 	data->acdirmax = nfss->acdirmax / HZ;
2146 	data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2147 	data->nfs_server.port = nfss->port;
2148 	data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2149 	memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2150 		data->nfs_server.addrlen);
2151 
2152 	/* overwrite those values with any that were specified */
2153 	error = nfs_parse_mount_options((char *)options, data);
2154 	if (error < 0)
2155 		goto out;
2156 
2157 	/*
2158 	 * noac is a special case. It implies -o sync, but that's not
2159 	 * necessarily reflected in the mtab options. do_remount_sb
2160 	 * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2161 	 * remount options, so we have to explicitly reset it.
2162 	 */
2163 	if (data->flags & NFS_MOUNT_NOAC)
2164 		*flags |= MS_SYNCHRONOUS;
2165 
2166 	/* compare new mount options with old ones */
2167 	error = nfs_compare_remount_data(nfss, data);
2168 out:
2169 	kfree(data);
2170 	return error;
2171 }
2172 
2173 /*
2174  * Initialise the common bits of the superblock
2175  */
2176 static inline void nfs_initialise_sb(struct super_block *sb)
2177 {
2178 	struct nfs_server *server = NFS_SB(sb);
2179 
2180 	sb->s_magic = NFS_SUPER_MAGIC;
2181 
2182 	/* We probably want something more informative here */
2183 	snprintf(sb->s_id, sizeof(sb->s_id),
2184 		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2185 
2186 	if (sb->s_blocksize == 0)
2187 		sb->s_blocksize = nfs_block_bits(server->wsize,
2188 						 &sb->s_blocksize_bits);
2189 
2190 	sb->s_bdi = &server->backing_dev_info;
2191 
2192 	nfs_super_set_maxbytes(sb, server->maxfilesize);
2193 }
2194 
2195 /*
2196  * Finish setting up an NFS2/3 superblock
2197  */
2198 static void nfs_fill_super(struct super_block *sb,
2199 			   struct nfs_mount_info *mount_info)
2200 {
2201 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2202 	struct nfs_server *server = NFS_SB(sb);
2203 
2204 	sb->s_blocksize_bits = 0;
2205 	sb->s_blocksize = 0;
2206 	if (data->bsize)
2207 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2208 
2209 	if (server->nfs_client->rpc_ops->version == 3) {
2210 		/* The VFS shouldn't apply the umask to mode bits. We will do
2211 		 * so ourselves when necessary.
2212 		 */
2213 		sb->s_flags |= MS_POSIXACL;
2214 		sb->s_time_gran = 1;
2215 	}
2216 
2217 	sb->s_op = &nfs_sops;
2218  	nfs_initialise_sb(sb);
2219 }
2220 
2221 /*
2222  * Finish setting up a cloned NFS2/3 superblock
2223  */
2224 static void nfs_clone_super(struct super_block *sb,
2225 			    struct nfs_mount_info *mount_info)
2226 {
2227 	const struct super_block *old_sb = mount_info->cloned->sb;
2228 	struct nfs_server *server = NFS_SB(sb);
2229 
2230 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2231 	sb->s_blocksize = old_sb->s_blocksize;
2232 	sb->s_maxbytes = old_sb->s_maxbytes;
2233 
2234 	if (server->nfs_client->rpc_ops->version == 3) {
2235 		/* The VFS shouldn't apply the umask to mode bits. We will do
2236 		 * so ourselves when necessary.
2237 		 */
2238 		sb->s_flags |= MS_POSIXACL;
2239 		sb->s_time_gran = 1;
2240 	}
2241 
2242 	sb->s_op = old_sb->s_op;
2243  	nfs_initialise_sb(sb);
2244 }
2245 
2246 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2247 {
2248 	const struct nfs_server *a = s->s_fs_info;
2249 	const struct rpc_clnt *clnt_a = a->client;
2250 	const struct rpc_clnt *clnt_b = b->client;
2251 
2252 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2253 		goto Ebusy;
2254 	if (a->nfs_client != b->nfs_client)
2255 		goto Ebusy;
2256 	if (a->flags != b->flags)
2257 		goto Ebusy;
2258 	if (a->wsize != b->wsize)
2259 		goto Ebusy;
2260 	if (a->rsize != b->rsize)
2261 		goto Ebusy;
2262 	if (a->acregmin != b->acregmin)
2263 		goto Ebusy;
2264 	if (a->acregmax != b->acregmax)
2265 		goto Ebusy;
2266 	if (a->acdirmin != b->acdirmin)
2267 		goto Ebusy;
2268 	if (a->acdirmax != b->acdirmax)
2269 		goto Ebusy;
2270 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2271 		goto Ebusy;
2272 	return 1;
2273 Ebusy:
2274 	return 0;
2275 }
2276 
2277 struct nfs_sb_mountdata {
2278 	struct nfs_server *server;
2279 	int mntflags;
2280 };
2281 
2282 static int nfs_set_super(struct super_block *s, void *data)
2283 {
2284 	struct nfs_sb_mountdata *sb_mntdata = data;
2285 	struct nfs_server *server = sb_mntdata->server;
2286 	int ret;
2287 
2288 	s->s_flags = sb_mntdata->mntflags;
2289 	s->s_fs_info = server;
2290 	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2291 	ret = set_anon_super(s, server);
2292 	if (ret == 0)
2293 		server->s_dev = s->s_dev;
2294 	return ret;
2295 }
2296 
2297 static int nfs_compare_super_address(struct nfs_server *server1,
2298 				     struct nfs_server *server2)
2299 {
2300 	struct sockaddr *sap1, *sap2;
2301 
2302 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2303 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2304 
2305 	if (sap1->sa_family != sap2->sa_family)
2306 		return 0;
2307 
2308 	switch (sap1->sa_family) {
2309 	case AF_INET: {
2310 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2311 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2312 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2313 			return 0;
2314 		if (sin1->sin_port != sin2->sin_port)
2315 			return 0;
2316 		break;
2317 	}
2318 	case AF_INET6: {
2319 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2320 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2321 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2322 			return 0;
2323 		if (sin1->sin6_port != sin2->sin6_port)
2324 			return 0;
2325 		break;
2326 	}
2327 	default:
2328 		return 0;
2329 	}
2330 
2331 	return 1;
2332 }
2333 
2334 static int nfs_compare_super(struct super_block *sb, void *data)
2335 {
2336 	struct nfs_sb_mountdata *sb_mntdata = data;
2337 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2338 	int mntflags = sb_mntdata->mntflags;
2339 
2340 	if (!nfs_compare_super_address(old, server))
2341 		return 0;
2342 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2343 	if (old->flags & NFS_MOUNT_UNSHARED)
2344 		return 0;
2345 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2346 		return 0;
2347 	return nfs_compare_mount_options(sb, server, mntflags);
2348 }
2349 
2350 #ifdef CONFIG_NFS_FSCACHE
2351 static void nfs_get_cache_cookie(struct super_block *sb,
2352 				 struct nfs_parsed_mount_data *parsed,
2353 				 struct nfs_clone_mount *cloned)
2354 {
2355 	char *uniq = NULL;
2356 	int ulen = 0;
2357 
2358 	if (parsed && parsed->fscache_uniq) {
2359 		uniq = parsed->fscache_uniq;
2360 		ulen = strlen(parsed->fscache_uniq);
2361 	} else if (cloned) {
2362 		struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2363 		if (mnt_s->fscache_key) {
2364 			uniq = mnt_s->fscache_key->key.uniquifier;
2365 			ulen = mnt_s->fscache_key->key.uniq_len;
2366 		};
2367 	}
2368 
2369 	nfs_fscache_get_super_cookie(sb, uniq, ulen);
2370 }
2371 #else
2372 static void nfs_get_cache_cookie(struct super_block *sb,
2373 				 struct nfs_parsed_mount_data *parsed,
2374 				 struct nfs_clone_mount *cloned)
2375 {
2376 }
2377 #endif
2378 
2379 static int nfs_bdi_register(struct nfs_server *server)
2380 {
2381 	return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2382 }
2383 
2384 static int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2385 			       struct nfs_mount_info *mount_info)
2386 {
2387 	return security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts);
2388 }
2389 
2390 static int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2391 				 struct nfs_mount_info *mount_info)
2392 {
2393 	/* clone any lsm security options from the parent to the new sb */
2394 	security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2395 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2396 		return -ESTALE;
2397 	return 0;
2398 }
2399 
2400 static struct dentry *nfs_fs_mount_common(struct file_system_type *fs_type,
2401 					  struct nfs_server *server,
2402 					  int flags, const char *dev_name,
2403 					  struct nfs_mount_info *mount_info)
2404 {
2405 	struct super_block *s;
2406 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2407 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2408 	struct nfs_sb_mountdata sb_mntdata = {
2409 		.mntflags = flags,
2410 		.server = server,
2411 	};
2412 	int error;
2413 
2414 	if (server->flags & NFS_MOUNT_UNSHARED)
2415 		compare_super = NULL;
2416 
2417 	/* -o noac implies -o sync */
2418 	if (server->flags & NFS_MOUNT_NOAC)
2419 		sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2420 
2421 	/* Get a superblock - note that we may end up sharing one that already exists */
2422 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2423 	if (IS_ERR(s)) {
2424 		mntroot = ERR_CAST(s);
2425 		goto out_err_nosb;
2426 	}
2427 
2428 	if (s->s_fs_info != server) {
2429 		nfs_free_server(server);
2430 		server = NULL;
2431 	} else {
2432 		error = nfs_bdi_register(server);
2433 		if (error) {
2434 			mntroot = ERR_PTR(error);
2435 			goto error_splat_bdi;
2436 		}
2437 	}
2438 
2439 	if (!s->s_root) {
2440 		/* initial superblock/root creation */
2441 		mount_info->fill_super(s, mount_info);
2442 		nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2443 	}
2444 
2445 	mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2446 	if (IS_ERR(mntroot))
2447 		goto error_splat_super;
2448 
2449 	error = mount_info->set_security(s, mntroot, mount_info);
2450 	if (error)
2451 		goto error_splat_root;
2452 
2453 	s->s_flags |= MS_ACTIVE;
2454 
2455 out:
2456 	return mntroot;
2457 
2458 out_err_nosb:
2459 	nfs_free_server(server);
2460 	goto out;
2461 
2462 error_splat_root:
2463 	dput(mntroot);
2464 	mntroot = ERR_PTR(error);
2465 error_splat_super:
2466 	if (server && !s->s_root)
2467 		bdi_unregister(&server->backing_dev_info);
2468 error_splat_bdi:
2469 	deactivate_locked_super(s);
2470 	goto out;
2471 }
2472 
2473 static struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2474 	int flags, const char *dev_name, void *raw_data)
2475 {
2476 	struct nfs_mount_info mount_info = {
2477 		.fill_super = nfs_fill_super,
2478 		.set_security = nfs_set_sb_security,
2479 	};
2480 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2481 	int error;
2482 
2483 	mount_info.parsed = nfs_alloc_parsed_mount_data();
2484 	mount_info.mntfh = nfs_alloc_fhandle();
2485 	if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2486 		goto out;
2487 
2488 	/* Validate the mount data */
2489 	error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2490 	if (error == NFS_TEXT_DATA)
2491 		error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2492 	if (error < 0) {
2493 		mntroot = ERR_PTR(error);
2494 		goto out;
2495 	}
2496 
2497 #ifdef CONFIG_NFS_V4
2498 	if (mount_info.parsed->version == 4)
2499 		mntroot = nfs4_try_mount(flags, dev_name, &mount_info);
2500 	else
2501 #endif	/* CONFIG_NFS_V4 */
2502 		mntroot = nfs_try_mount(flags, dev_name, &mount_info);
2503 
2504 out:
2505 	nfs_free_parsed_mount_data(mount_info.parsed);
2506 	nfs_free_fhandle(mount_info.mntfh);
2507 	return mntroot;
2508 }
2509 
2510 /*
2511  * Ensure that we unregister the bdi before kill_anon_super
2512  * releases the device name
2513  */
2514 static void nfs_put_super(struct super_block *s)
2515 {
2516 	struct nfs_server *server = NFS_SB(s);
2517 
2518 	bdi_unregister(&server->backing_dev_info);
2519 }
2520 
2521 /*
2522  * Destroy an NFS2/3 superblock
2523  */
2524 static void nfs_kill_super(struct super_block *s)
2525 {
2526 	struct nfs_server *server = NFS_SB(s);
2527 
2528 	kill_anon_super(s);
2529 	nfs_fscache_release_super_cookie(s);
2530 	nfs_free_server(server);
2531 }
2532 
2533 /*
2534  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2535  */
2536 static struct dentry *
2537 nfs_xdev_mount_common(struct file_system_type *fs_type, int flags,
2538 		const char *dev_name, struct nfs_mount_info *mount_info)
2539 {
2540 	struct nfs_clone_mount *data = mount_info->cloned;
2541 	struct nfs_server *server;
2542 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2543 	int error;
2544 
2545 	dprintk("--> nfs_xdev_mount_common()\n");
2546 
2547 	mount_info->mntfh = data->fh;
2548 
2549 	/* create a new volume representation */
2550 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2551 	if (IS_ERR(server)) {
2552 		error = PTR_ERR(server);
2553 		goto out_err;
2554 	}
2555 
2556 	mntroot = nfs_fs_mount_common(fs_type, server, flags, dev_name, mount_info);
2557 	dprintk("<-- nfs_xdev_mount_common() = 0\n");
2558 out:
2559 	return mntroot;
2560 
2561 out_err:
2562 	dprintk("<-- nfs_xdev_mount_common() = %d [error]\n", error);
2563 	goto out;
2564 }
2565 
2566 /*
2567  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2568  */
2569 static struct dentry *
2570 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2571 		const char *dev_name, void *raw_data)
2572 {
2573 	struct nfs_mount_info mount_info = {
2574 		.fill_super = nfs_clone_super,
2575 		.set_security = nfs_clone_sb_security,
2576 		.cloned   = raw_data,
2577 	};
2578 	return nfs_xdev_mount_common(&nfs_fs_type, flags, dev_name, &mount_info);
2579 }
2580 
2581 #ifdef CONFIG_NFS_V4
2582 
2583 /*
2584  * Finish setting up a cloned NFS4 superblock
2585  */
2586 static void nfs4_clone_super(struct super_block *sb,
2587 			     struct nfs_mount_info *mount_info)
2588 {
2589 	const struct super_block *old_sb = mount_info->cloned->sb;
2590 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2591 	sb->s_blocksize = old_sb->s_blocksize;
2592 	sb->s_maxbytes = old_sb->s_maxbytes;
2593 	sb->s_time_gran = 1;
2594 	sb->s_op = old_sb->s_op;
2595 	/*
2596 	 * The VFS shouldn't apply the umask to mode bits. We will do
2597 	 * so ourselves when necessary.
2598 	 */
2599 	sb->s_flags  |= MS_POSIXACL;
2600 	sb->s_xattr  = old_sb->s_xattr;
2601 	nfs_initialise_sb(sb);
2602 }
2603 
2604 /*
2605  * Set up an NFS4 superblock
2606  */
2607 static void nfs4_fill_super(struct super_block *sb,
2608 			    struct nfs_mount_info *mount_info)
2609 {
2610 	sb->s_time_gran = 1;
2611 	sb->s_op = &nfs4_sops;
2612 	/*
2613 	 * The VFS shouldn't apply the umask to mode bits. We will do
2614 	 * so ourselves when necessary.
2615 	 */
2616 	sb->s_flags  |= MS_POSIXACL;
2617 	sb->s_xattr = nfs4_xattr_handlers;
2618 	nfs_initialise_sb(sb);
2619 }
2620 
2621 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2622 {
2623 	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2624 			 NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2625 }
2626 
2627 /*
2628  * Validate NFSv4 mount options
2629  */
2630 static int nfs4_validate_mount_data(void *options,
2631 				    struct nfs_parsed_mount_data *args,
2632 				    const char *dev_name)
2633 {
2634 	struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2635 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2636 	char *c;
2637 
2638 	if (data == NULL)
2639 		goto out_no_data;
2640 
2641 	args->version = 4;
2642 
2643 	switch (data->version) {
2644 	case 1:
2645 		if (data->host_addrlen > sizeof(args->nfs_server.address))
2646 			goto out_no_address;
2647 		if (data->host_addrlen == 0)
2648 			goto out_no_address;
2649 		args->nfs_server.addrlen = data->host_addrlen;
2650 		if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2651 			return -EFAULT;
2652 		if (!nfs_verify_server_address(sap))
2653 			goto out_no_address;
2654 
2655 		if (data->auth_flavourlen) {
2656 			if (data->auth_flavourlen > 1)
2657 				goto out_inval_auth;
2658 			if (copy_from_user(&args->auth_flavors[0],
2659 					   data->auth_flavours,
2660 					   sizeof(args->auth_flavors[0])))
2661 				return -EFAULT;
2662 		}
2663 
2664 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2665 		if (IS_ERR(c))
2666 			return PTR_ERR(c);
2667 		args->nfs_server.hostname = c;
2668 
2669 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2670 		if (IS_ERR(c))
2671 			return PTR_ERR(c);
2672 		args->nfs_server.export_path = c;
2673 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2674 
2675 		c = strndup_user(data->client_addr.data, 16);
2676 		if (IS_ERR(c))
2677 			return PTR_ERR(c);
2678 		args->client_address = c;
2679 
2680 		/*
2681 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2682 		 * can deal with.
2683 		 */
2684 
2685 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
2686 		args->rsize	= data->rsize;
2687 		args->wsize	= data->wsize;
2688 		args->timeo	= data->timeo;
2689 		args->retrans	= data->retrans;
2690 		args->acregmin	= data->acregmin;
2691 		args->acregmax	= data->acregmax;
2692 		args->acdirmin	= data->acdirmin;
2693 		args->acdirmax	= data->acdirmax;
2694 		args->nfs_server.protocol = data->proto;
2695 		nfs_validate_transport_protocol(args);
2696 
2697 		break;
2698 	default:
2699 		return NFS_TEXT_DATA;
2700 	}
2701 
2702 	return 0;
2703 
2704 out_no_data:
2705 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2706 	return -EINVAL;
2707 
2708 out_inval_auth:
2709 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2710 		 data->auth_flavourlen);
2711 	return -EINVAL;
2712 
2713 out_no_address:
2714 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2715 	return -EINVAL;
2716 }
2717 
2718 /*
2719  * Get the superblock for the NFS4 root partition
2720  */
2721 static struct dentry *
2722 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
2723 		  const char *dev_name, void *info)
2724 {
2725 	struct nfs_mount_info *mount_info = info;
2726 	struct nfs_server *server;
2727 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2728 
2729 	mount_info->fill_super = nfs4_fill_super;
2730 	mount_info->set_security = nfs_set_sb_security;
2731 
2732 	/* Get a volume representation */
2733 	server = nfs4_create_server(mount_info->parsed, mount_info->mntfh);
2734 	if (IS_ERR(server)) {
2735 		mntroot = ERR_CAST(server);
2736 		goto out;
2737 	}
2738 
2739 	mntroot = nfs_fs_mount_common(fs_type, server, flags, dev_name, mount_info);
2740 
2741 out:
2742 	return mntroot;
2743 }
2744 
2745 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
2746 		int flags, void *data, const char *hostname)
2747 {
2748 	struct vfsmount *root_mnt;
2749 	char *root_devname;
2750 	size_t len;
2751 
2752 	len = strlen(hostname) + 5;
2753 	root_devname = kmalloc(len, GFP_KERNEL);
2754 	if (root_devname == NULL)
2755 		return ERR_PTR(-ENOMEM);
2756 	/* Does hostname needs to be enclosed in brackets? */
2757 	if (strchr(hostname, ':'))
2758 		snprintf(root_devname, len, "[%s]:/", hostname);
2759 	else
2760 		snprintf(root_devname, len, "%s:/", hostname);
2761 	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
2762 	kfree(root_devname);
2763 	return root_mnt;
2764 }
2765 
2766 struct nfs_referral_count {
2767 	struct list_head list;
2768 	const struct task_struct *task;
2769 	unsigned int referral_count;
2770 };
2771 
2772 static LIST_HEAD(nfs_referral_count_list);
2773 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
2774 
2775 static struct nfs_referral_count *nfs_find_referral_count(void)
2776 {
2777 	struct nfs_referral_count *p;
2778 
2779 	list_for_each_entry(p, &nfs_referral_count_list, list) {
2780 		if (p->task == current)
2781 			return p;
2782 	}
2783 	return NULL;
2784 }
2785 
2786 #define NFS_MAX_NESTED_REFERRALS 2
2787 
2788 static int nfs_referral_loop_protect(void)
2789 {
2790 	struct nfs_referral_count *p, *new;
2791 	int ret = -ENOMEM;
2792 
2793 	new = kmalloc(sizeof(*new), GFP_KERNEL);
2794 	if (!new)
2795 		goto out;
2796 	new->task = current;
2797 	new->referral_count = 1;
2798 
2799 	ret = 0;
2800 	spin_lock(&nfs_referral_count_list_lock);
2801 	p = nfs_find_referral_count();
2802 	if (p != NULL) {
2803 		if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
2804 			ret = -ELOOP;
2805 		else
2806 			p->referral_count++;
2807 	} else {
2808 		list_add(&new->list, &nfs_referral_count_list);
2809 		new = NULL;
2810 	}
2811 	spin_unlock(&nfs_referral_count_list_lock);
2812 	kfree(new);
2813 out:
2814 	return ret;
2815 }
2816 
2817 static void nfs_referral_loop_unprotect(void)
2818 {
2819 	struct nfs_referral_count *p;
2820 
2821 	spin_lock(&nfs_referral_count_list_lock);
2822 	p = nfs_find_referral_count();
2823 	p->referral_count--;
2824 	if (p->referral_count == 0)
2825 		list_del(&p->list);
2826 	else
2827 		p = NULL;
2828 	spin_unlock(&nfs_referral_count_list_lock);
2829 	kfree(p);
2830 }
2831 
2832 static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
2833 		const char *export_path)
2834 {
2835 	struct dentry *dentry;
2836 	int err;
2837 
2838 	if (IS_ERR(root_mnt))
2839 		return ERR_CAST(root_mnt);
2840 
2841 	err = nfs_referral_loop_protect();
2842 	if (err) {
2843 		mntput(root_mnt);
2844 		return ERR_PTR(err);
2845 	}
2846 
2847 	dentry = mount_subtree(root_mnt, export_path);
2848 	nfs_referral_loop_unprotect();
2849 
2850 	return dentry;
2851 }
2852 
2853 static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
2854 			 struct nfs_mount_info *mount_info)
2855 {
2856 	char *export_path;
2857 	struct vfsmount *root_mnt;
2858 	struct dentry *res;
2859 	struct nfs_parsed_mount_data *data = mount_info->parsed;
2860 
2861 	dfprintk(MOUNT, "--> nfs4_try_mount()\n");
2862 
2863 	export_path = data->nfs_server.export_path;
2864 	data->nfs_server.export_path = "/";
2865 	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info,
2866 			data->nfs_server.hostname);
2867 	data->nfs_server.export_path = export_path;
2868 
2869 	res = nfs_follow_remote_path(root_mnt, export_path);
2870 
2871 	dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
2872 			IS_ERR(res) ? PTR_ERR(res) : 0,
2873 			IS_ERR(res) ? " [error]" : "");
2874 	return res;
2875 }
2876 
2877 static void nfs4_kill_super(struct super_block *sb)
2878 {
2879 	struct nfs_server *server = NFS_SB(sb);
2880 
2881 	dprintk("--> %s\n", __func__);
2882 	nfs_super_return_all_delegations(sb);
2883 	kill_anon_super(sb);
2884 	nfs_fscache_release_super_cookie(sb);
2885 	nfs_free_server(server);
2886 	dprintk("<-- %s\n", __func__);
2887 }
2888 
2889 /*
2890  * Clone an NFS4 server record on xdev traversal (FSID-change)
2891  */
2892 static struct dentry *
2893 nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
2894 		 const char *dev_name, void *raw_data)
2895 {
2896 	struct nfs_mount_info mount_info = {
2897 		.fill_super = nfs4_clone_super,
2898 		.set_security = nfs_clone_sb_security,
2899 		.cloned = raw_data,
2900 	};
2901 	return nfs_xdev_mount_common(&nfs4_fs_type, flags, dev_name, &mount_info);
2902 }
2903 
2904 static struct dentry *
2905 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
2906 			   const char *dev_name, void *raw_data)
2907 {
2908 	struct nfs_mount_info mount_info = {
2909 		.fill_super = nfs4_fill_super,
2910 		.set_security = nfs_clone_sb_security,
2911 		.cloned = raw_data,
2912 	};
2913 	struct nfs_server *server;
2914 	struct dentry *mntroot = ERR_PTR(-ENOMEM);
2915 
2916 	dprintk("--> nfs4_referral_get_sb()\n");
2917 
2918 	mount_info.mntfh = nfs_alloc_fhandle();
2919 	if (mount_info.cloned == NULL || mount_info.mntfh == NULL)
2920 		goto out;
2921 
2922 	/* create a new volume representation */
2923 	server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh);
2924 	if (IS_ERR(server)) {
2925 		mntroot = ERR_CAST(server);
2926 		goto out;
2927 	}
2928 
2929 	mntroot = nfs_fs_mount_common(&nfs4_fs_type, server, flags, dev_name, &mount_info);
2930 out:
2931 	nfs_free_fhandle(mount_info.mntfh);
2932 	return mntroot;
2933 }
2934 
2935 /*
2936  * Create an NFS4 server record on referral traversal
2937  */
2938 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
2939 		int flags, const char *dev_name, void *raw_data)
2940 {
2941 	struct nfs_clone_mount *data = raw_data;
2942 	char *export_path;
2943 	struct vfsmount *root_mnt;
2944 	struct dentry *res;
2945 
2946 	dprintk("--> nfs4_referral_mount()\n");
2947 
2948 	export_path = data->mnt_path;
2949 	data->mnt_path = "/";
2950 
2951 	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
2952 			flags, data, data->hostname);
2953 	data->mnt_path = export_path;
2954 
2955 	res = nfs_follow_remote_path(root_mnt, export_path);
2956 	dprintk("<-- nfs4_referral_mount() = %ld%s\n",
2957 			IS_ERR(res) ? PTR_ERR(res) : 0,
2958 			IS_ERR(res) ? " [error]" : "");
2959 	return res;
2960 }
2961 
2962 #endif /* CONFIG_NFS_V4 */
2963