xref: /openbmc/linux/fs/nfs/super.c (revision a1e58bbd)
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.Cox@linux.org>, 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/nfs_idmap.h>
46 #include <linux/vfs.h>
47 #include <linux/inet.h>
48 #include <linux/in6.h>
49 #include <net/ipv6.h>
50 #include <linux/nfs_xdr.h>
51 #include <linux/magic.h>
52 #include <linux/parser.h>
53 
54 #include <asm/system.h>
55 #include <asm/uaccess.h>
56 
57 #include "nfs4_fs.h"
58 #include "callback.h"
59 #include "delegation.h"
60 #include "iostat.h"
61 #include "internal.h"
62 
63 #define NFSDBG_FACILITY		NFSDBG_VFS
64 
65 enum {
66 	/* Mount options that take no arguments */
67 	Opt_soft, Opt_hard,
68 	Opt_intr, Opt_nointr,
69 	Opt_posix, Opt_noposix,
70 	Opt_cto, Opt_nocto,
71 	Opt_ac, Opt_noac,
72 	Opt_lock, Opt_nolock,
73 	Opt_v2, Opt_v3,
74 	Opt_udp, Opt_tcp, Opt_rdma,
75 	Opt_acl, Opt_noacl,
76 	Opt_rdirplus, Opt_nordirplus,
77 	Opt_sharecache, Opt_nosharecache,
78 
79 	/* Mount options that take integer arguments */
80 	Opt_port,
81 	Opt_rsize, Opt_wsize, Opt_bsize,
82 	Opt_timeo, Opt_retrans,
83 	Opt_acregmin, Opt_acregmax,
84 	Opt_acdirmin, Opt_acdirmax,
85 	Opt_actimeo,
86 	Opt_namelen,
87 	Opt_mountport,
88 	Opt_mountvers,
89 	Opt_nfsvers,
90 
91 	/* Mount options that take string arguments */
92 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
93 	Opt_addr, Opt_mountaddr, Opt_clientaddr,
94 
95 	/* Mount options that are ignored */
96 	Opt_userspace, Opt_deprecated,
97 
98 	Opt_err
99 };
100 
101 static match_table_t nfs_mount_option_tokens = {
102 	{ Opt_userspace, "bg" },
103 	{ Opt_userspace, "fg" },
104 	{ Opt_soft, "soft" },
105 	{ Opt_hard, "hard" },
106 	{ Opt_intr, "intr" },
107 	{ Opt_nointr, "nointr" },
108 	{ Opt_posix, "posix" },
109 	{ Opt_noposix, "noposix" },
110 	{ Opt_cto, "cto" },
111 	{ Opt_nocto, "nocto" },
112 	{ Opt_ac, "ac" },
113 	{ Opt_noac, "noac" },
114 	{ Opt_lock, "lock" },
115 	{ Opt_nolock, "nolock" },
116 	{ Opt_v2, "v2" },
117 	{ Opt_v3, "v3" },
118 	{ Opt_udp, "udp" },
119 	{ Opt_tcp, "tcp" },
120 	{ Opt_rdma, "rdma" },
121 	{ Opt_acl, "acl" },
122 	{ Opt_noacl, "noacl" },
123 	{ Opt_rdirplus, "rdirplus" },
124 	{ Opt_nordirplus, "nordirplus" },
125 	{ Opt_sharecache, "sharecache" },
126 	{ Opt_nosharecache, "nosharecache" },
127 
128 	{ Opt_port, "port=%u" },
129 	{ Opt_rsize, "rsize=%u" },
130 	{ Opt_wsize, "wsize=%u" },
131 	{ Opt_bsize, "bsize=%u" },
132 	{ Opt_timeo, "timeo=%u" },
133 	{ Opt_retrans, "retrans=%u" },
134 	{ Opt_acregmin, "acregmin=%u" },
135 	{ Opt_acregmax, "acregmax=%u" },
136 	{ Opt_acdirmin, "acdirmin=%u" },
137 	{ Opt_acdirmax, "acdirmax=%u" },
138 	{ Opt_actimeo, "actimeo=%u" },
139 	{ Opt_userspace, "retry=%u" },
140 	{ Opt_namelen, "namlen=%u" },
141 	{ Opt_mountport, "mountport=%u" },
142 	{ Opt_mountvers, "mountvers=%u" },
143 	{ Opt_nfsvers, "nfsvers=%u" },
144 	{ Opt_nfsvers, "vers=%u" },
145 
146 	{ Opt_sec, "sec=%s" },
147 	{ Opt_proto, "proto=%s" },
148 	{ Opt_mountproto, "mountproto=%s" },
149 	{ Opt_addr, "addr=%s" },
150 	{ Opt_clientaddr, "clientaddr=%s" },
151 	{ Opt_mounthost, "mounthost=%s" },
152 	{ Opt_mountaddr, "mountaddr=%s" },
153 
154 	{ Opt_err, NULL }
155 };
156 
157 enum {
158 	Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
159 
160 	Opt_xprt_err
161 };
162 
163 static match_table_t nfs_xprt_protocol_tokens = {
164 	{ Opt_xprt_udp, "udp" },
165 	{ Opt_xprt_tcp, "tcp" },
166 	{ Opt_xprt_rdma, "rdma" },
167 
168 	{ Opt_xprt_err, NULL }
169 };
170 
171 enum {
172 	Opt_sec_none, Opt_sec_sys,
173 	Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
174 	Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
175 	Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
176 
177 	Opt_sec_err
178 };
179 
180 static match_table_t nfs_secflavor_tokens = {
181 	{ Opt_sec_none, "none" },
182 	{ Opt_sec_none, "null" },
183 	{ Opt_sec_sys, "sys" },
184 
185 	{ Opt_sec_krb5, "krb5" },
186 	{ Opt_sec_krb5i, "krb5i" },
187 	{ Opt_sec_krb5p, "krb5p" },
188 
189 	{ Opt_sec_lkey, "lkey" },
190 	{ Opt_sec_lkeyi, "lkeyi" },
191 	{ Opt_sec_lkeyp, "lkeyp" },
192 
193 	{ Opt_sec_spkm, "spkm3" },
194 	{ Opt_sec_spkmi, "spkm3i" },
195 	{ Opt_sec_spkmp, "spkm3p" },
196 
197 	{ Opt_sec_err, NULL }
198 };
199 
200 
201 static void nfs_umount_begin(struct vfsmount *, int);
202 static int  nfs_statfs(struct dentry *, struct kstatfs *);
203 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
204 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
205 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
206 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
207 		int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
208 static void nfs_kill_super(struct super_block *);
209 static void nfs_put_super(struct super_block *);
210 
211 static struct file_system_type nfs_fs_type = {
212 	.owner		= THIS_MODULE,
213 	.name		= "nfs",
214 	.get_sb		= nfs_get_sb,
215 	.kill_sb	= nfs_kill_super,
216 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
217 };
218 
219 struct file_system_type nfs_xdev_fs_type = {
220 	.owner		= THIS_MODULE,
221 	.name		= "nfs",
222 	.get_sb		= nfs_xdev_get_sb,
223 	.kill_sb	= nfs_kill_super,
224 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
225 };
226 
227 static const struct super_operations nfs_sops = {
228 	.alloc_inode	= nfs_alloc_inode,
229 	.destroy_inode	= nfs_destroy_inode,
230 	.write_inode	= nfs_write_inode,
231 	.put_super	= nfs_put_super,
232 	.statfs		= nfs_statfs,
233 	.clear_inode	= nfs_clear_inode,
234 	.umount_begin	= nfs_umount_begin,
235 	.show_options	= nfs_show_options,
236 	.show_stats	= nfs_show_stats,
237 };
238 
239 #ifdef CONFIG_NFS_V4
240 static int nfs4_get_sb(struct file_system_type *fs_type,
241 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
242 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
243 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
244 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
245 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
246 static void nfs4_kill_super(struct super_block *sb);
247 
248 static struct file_system_type nfs4_fs_type = {
249 	.owner		= THIS_MODULE,
250 	.name		= "nfs4",
251 	.get_sb		= nfs4_get_sb,
252 	.kill_sb	= nfs4_kill_super,
253 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
254 };
255 
256 struct file_system_type nfs4_xdev_fs_type = {
257 	.owner		= THIS_MODULE,
258 	.name		= "nfs4",
259 	.get_sb		= nfs4_xdev_get_sb,
260 	.kill_sb	= nfs4_kill_super,
261 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
262 };
263 
264 struct file_system_type nfs4_referral_fs_type = {
265 	.owner		= THIS_MODULE,
266 	.name		= "nfs4",
267 	.get_sb		= nfs4_referral_get_sb,
268 	.kill_sb	= nfs4_kill_super,
269 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
270 };
271 
272 static const struct super_operations nfs4_sops = {
273 	.alloc_inode	= nfs_alloc_inode,
274 	.destroy_inode	= nfs_destroy_inode,
275 	.write_inode	= nfs_write_inode,
276 	.statfs		= nfs_statfs,
277 	.clear_inode	= nfs4_clear_inode,
278 	.umount_begin	= nfs_umount_begin,
279 	.show_options	= nfs_show_options,
280 	.show_stats	= nfs_show_stats,
281 };
282 #endif
283 
284 static struct shrinker acl_shrinker = {
285 	.shrink		= nfs_access_cache_shrinker,
286 	.seeks		= DEFAULT_SEEKS,
287 };
288 
289 /*
290  * Register the NFS filesystems
291  */
292 int __init register_nfs_fs(void)
293 {
294 	int ret;
295 
296         ret = register_filesystem(&nfs_fs_type);
297 	if (ret < 0)
298 		goto error_0;
299 
300 	ret = nfs_register_sysctl();
301 	if (ret < 0)
302 		goto error_1;
303 #ifdef CONFIG_NFS_V4
304 	ret = register_filesystem(&nfs4_fs_type);
305 	if (ret < 0)
306 		goto error_2;
307 #endif
308 	register_shrinker(&acl_shrinker);
309 	return 0;
310 
311 #ifdef CONFIG_NFS_V4
312 error_2:
313 	nfs_unregister_sysctl();
314 #endif
315 error_1:
316 	unregister_filesystem(&nfs_fs_type);
317 error_0:
318 	return ret;
319 }
320 
321 /*
322  * Unregister the NFS filesystems
323  */
324 void __exit unregister_nfs_fs(void)
325 {
326 	unregister_shrinker(&acl_shrinker);
327 #ifdef CONFIG_NFS_V4
328 	unregister_filesystem(&nfs4_fs_type);
329 #endif
330 	nfs_unregister_sysctl();
331 	unregister_filesystem(&nfs_fs_type);
332 }
333 
334 void nfs_sb_active(struct nfs_server *server)
335 {
336 	atomic_inc(&server->active);
337 }
338 
339 void nfs_sb_deactive(struct nfs_server *server)
340 {
341 	if (atomic_dec_and_test(&server->active))
342 		wake_up(&server->active_wq);
343 }
344 
345 static void nfs_put_super(struct super_block *sb)
346 {
347 	struct nfs_server *server = NFS_SB(sb);
348 	/*
349 	 * Make sure there are no outstanding ops to this server.
350 	 * If so, wait for them to finish before allowing the
351 	 * unmount to continue.
352 	 */
353 	wait_event(server->active_wq, atomic_read(&server->active) == 0);
354 }
355 
356 /*
357  * Deliver file system statistics to userspace
358  */
359 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
360 {
361 	struct nfs_server *server = NFS_SB(dentry->d_sb);
362 	unsigned char blockbits;
363 	unsigned long blockres;
364 	struct nfs_fh *fh = NFS_FH(dentry->d_inode);
365 	struct nfs_fattr fattr;
366 	struct nfs_fsstat res = {
367 			.fattr = &fattr,
368 	};
369 	int error;
370 
371 	lock_kernel();
372 
373 	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
374 	if (error < 0)
375 		goto out_err;
376 	buf->f_type = NFS_SUPER_MAGIC;
377 
378 	/*
379 	 * Current versions of glibc do not correctly handle the
380 	 * case where f_frsize != f_bsize.  Eventually we want to
381 	 * report the value of wtmult in this field.
382 	 */
383 	buf->f_frsize = dentry->d_sb->s_blocksize;
384 
385 	/*
386 	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
387 	 * are reported in units of f_frsize.  Linux hasn't had
388 	 * an f_frsize field in its statfs struct until recently,
389 	 * thus historically Linux's sys_statfs reports these
390 	 * fields in units of f_bsize.
391 	 */
392 	buf->f_bsize = dentry->d_sb->s_blocksize;
393 	blockbits = dentry->d_sb->s_blocksize_bits;
394 	blockres = (1 << blockbits) - 1;
395 	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
396 	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
397 	buf->f_bavail = (res.abytes + blockres) >> blockbits;
398 
399 	buf->f_files = res.tfiles;
400 	buf->f_ffree = res.afiles;
401 
402 	buf->f_namelen = server->namelen;
403 
404 	unlock_kernel();
405 	return 0;
406 
407  out_err:
408 	dprintk("%s: statfs error = %d\n", __FUNCTION__, -error);
409 	unlock_kernel();
410 	return error;
411 }
412 
413 /*
414  * Map the security flavour number to a name
415  */
416 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
417 {
418 	static const struct {
419 		rpc_authflavor_t flavour;
420 		const char *str;
421 	} sec_flavours[] = {
422 		{ RPC_AUTH_NULL, "null" },
423 		{ RPC_AUTH_UNIX, "sys" },
424 		{ RPC_AUTH_GSS_KRB5, "krb5" },
425 		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
426 		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
427 		{ RPC_AUTH_GSS_LKEY, "lkey" },
428 		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
429 		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
430 		{ RPC_AUTH_GSS_SPKM, "spkm" },
431 		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
432 		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
433 		{ UINT_MAX, "unknown" }
434 	};
435 	int i;
436 
437 	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
438 		if (sec_flavours[i].flavour == flavour)
439 			break;
440 	}
441 	return sec_flavours[i].str;
442 }
443 
444 /*
445  * Describe the mount options in force on this server representation
446  */
447 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, int showdefaults)
448 {
449 	static const struct proc_nfs_info {
450 		int flag;
451 		const char *str;
452 		const char *nostr;
453 	} nfs_info[] = {
454 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
455 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
456 		{ NFS_MOUNT_NOAC, ",noac", "" },
457 		{ NFS_MOUNT_NONLM, ",nolock", "" },
458 		{ NFS_MOUNT_NOACL, ",noacl", "" },
459 		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
460 		{ NFS_MOUNT_UNSHARED, ",nosharecache", ""},
461 		{ 0, NULL, NULL }
462 	};
463 	const struct proc_nfs_info *nfs_infop;
464 	struct nfs_client *clp = nfss->nfs_client;
465 
466 	seq_printf(m, ",vers=%d", clp->rpc_ops->version);
467 	seq_printf(m, ",rsize=%d", nfss->rsize);
468 	seq_printf(m, ",wsize=%d", nfss->wsize);
469 	if (nfss->acregmin != 3*HZ || showdefaults)
470 		seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
471 	if (nfss->acregmax != 60*HZ || showdefaults)
472 		seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
473 	if (nfss->acdirmin != 30*HZ || showdefaults)
474 		seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
475 	if (nfss->acdirmax != 60*HZ || showdefaults)
476 		seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
477 	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
478 		if (nfss->flags & nfs_infop->flag)
479 			seq_puts(m, nfs_infop->str);
480 		else
481 			seq_puts(m, nfs_infop->nostr);
482 	}
483 	seq_printf(m, ",proto=%s",
484 		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
485 	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
486 	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
487 	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
488 }
489 
490 /*
491  * Describe the mount options on this VFS mountpoint
492  */
493 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
494 {
495 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
496 
497 	nfs_show_mount_options(m, nfss, 0);
498 
499 	seq_printf(m, ",addr=%s",
500 			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
501 							RPC_DISPLAY_ADDR));
502 
503 	return 0;
504 }
505 
506 /*
507  * Present statistical information for this VFS mountpoint
508  */
509 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
510 {
511 	int i, cpu;
512 	struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
513 	struct rpc_auth *auth = nfss->client->cl_auth;
514 	struct nfs_iostats totals = { };
515 
516 	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
517 
518 	/*
519 	 * Display all mount option settings
520 	 */
521 	seq_printf(m, "\n\topts:\t");
522 	seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
523 	seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
524 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
525 	seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
526 	nfs_show_mount_options(m, nfss, 1);
527 
528 	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
529 
530 	seq_printf(m, "\n\tcaps:\t");
531 	seq_printf(m, "caps=0x%x", nfss->caps);
532 	seq_printf(m, ",wtmult=%d", nfss->wtmult);
533 	seq_printf(m, ",dtsize=%d", nfss->dtsize);
534 	seq_printf(m, ",bsize=%d", nfss->bsize);
535 	seq_printf(m, ",namelen=%d", nfss->namelen);
536 
537 #ifdef CONFIG_NFS_V4
538 	if (nfss->nfs_client->rpc_ops->version == 4) {
539 		seq_printf(m, "\n\tnfsv4:\t");
540 		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
541 		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
542 		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
543 	}
544 #endif
545 
546 	/*
547 	 * Display security flavor in effect for this mount
548 	 */
549 	seq_printf(m, "\n\tsec:\tflavor=%d", auth->au_ops->au_flavor);
550 	if (auth->au_flavor)
551 		seq_printf(m, ",pseudoflavor=%d", auth->au_flavor);
552 
553 	/*
554 	 * Display superblock I/O counters
555 	 */
556 	for_each_possible_cpu(cpu) {
557 		struct nfs_iostats *stats;
558 
559 		preempt_disable();
560 		stats = per_cpu_ptr(nfss->io_stats, cpu);
561 
562 		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
563 			totals.events[i] += stats->events[i];
564 		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
565 			totals.bytes[i] += stats->bytes[i];
566 
567 		preempt_enable();
568 	}
569 
570 	seq_printf(m, "\n\tevents:\t");
571 	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
572 		seq_printf(m, "%lu ", totals.events[i]);
573 	seq_printf(m, "\n\tbytes:\t");
574 	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
575 		seq_printf(m, "%Lu ", totals.bytes[i]);
576 	seq_printf(m, "\n");
577 
578 	rpc_print_iostats(m, nfss->client);
579 
580 	return 0;
581 }
582 
583 /*
584  * Begin unmount by attempting to remove all automounted mountpoints we added
585  * in response to xdev traversals and referrals
586  */
587 static void nfs_umount_begin(struct vfsmount *vfsmnt, int flags)
588 {
589 	struct nfs_server *server = NFS_SB(vfsmnt->mnt_sb);
590 	struct rpc_clnt *rpc;
591 
592 	if (!(flags & MNT_FORCE))
593 		return;
594 	/* -EIO all pending I/O */
595 	rpc = server->client_acl;
596 	if (!IS_ERR(rpc))
597 		rpc_killall_tasks(rpc);
598 	rpc = server->client;
599 	if (!IS_ERR(rpc))
600 		rpc_killall_tasks(rpc);
601 }
602 
603 /*
604  * Set the port number in an address.  Be agnostic about the address family.
605  */
606 static void nfs_set_port(struct sockaddr *sap, unsigned short port)
607 {
608 	switch (sap->sa_family) {
609 	case AF_INET: {
610 		struct sockaddr_in *ap = (struct sockaddr_in *)sap;
611 		ap->sin_port = htons(port);
612 		break;
613 	}
614 	case AF_INET6: {
615 		struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
616 		ap->sin6_port = htons(port);
617 		break;
618 	}
619 	}
620 }
621 
622 /*
623  * Sanity-check a server address provided by the mount command.
624  *
625  * Address family must be initialized, and address must not be
626  * the ANY address for that family.
627  */
628 static int nfs_verify_server_address(struct sockaddr *addr)
629 {
630 	switch (addr->sa_family) {
631 	case AF_INET: {
632 		struct sockaddr_in *sa = (struct sockaddr_in *)addr;
633 		return sa->sin_addr.s_addr != htonl(INADDR_ANY);
634 	}
635 	case AF_INET6: {
636 		struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
637 		return !ipv6_addr_any(sa);
638 	}
639 	}
640 
641 	return 0;
642 }
643 
644 /*
645  * Parse string addresses passed in via a mount option,
646  * and construct a sockaddr based on the result.
647  *
648  * If address parsing fails, set the sockaddr's address
649  * family to AF_UNSPEC to force nfs_verify_server_address()
650  * to punt the mount.
651  */
652 static void nfs_parse_server_address(char *value,
653 				     struct sockaddr *sap,
654 				     size_t *len)
655 {
656 	if (strchr(value, ':')) {
657 		struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
658 		u8 *addr = (u8 *)&ap->sin6_addr.in6_u;
659 
660 		ap->sin6_family = AF_INET6;
661 		*len = sizeof(*ap);
662 		if (in6_pton(value, -1, addr, '\0', NULL))
663 			return;
664 	} else {
665 		struct sockaddr_in *ap = (struct sockaddr_in *)sap;
666 		u8 *addr = (u8 *)&ap->sin_addr.s_addr;
667 
668 		ap->sin_family = AF_INET;
669 		*len = sizeof(*ap);
670 		if (in4_pton(value, -1, addr, '\0', NULL))
671 			return;
672 	}
673 
674 	sap->sa_family = AF_UNSPEC;
675 	*len = 0;
676 }
677 
678 /*
679  * Error-check and convert a string of mount options from user space into
680  * a data structure
681  */
682 static int nfs_parse_mount_options(char *raw,
683 				   struct nfs_parsed_mount_data *mnt)
684 {
685 	char *p, *string, *secdata;
686 	unsigned short port = 0;
687 	int rc;
688 
689 	if (!raw) {
690 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
691 		return 1;
692 	}
693 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
694 
695 	secdata = alloc_secdata();
696 	if (!secdata)
697 		goto out_nomem;
698 
699 	rc = security_sb_copy_data(raw, secdata);
700 	if (rc)
701 		goto out_security_failure;
702 
703 	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
704 	if (rc)
705 		goto out_security_failure;
706 
707 	free_secdata(secdata);
708 
709 	while ((p = strsep(&raw, ",")) != NULL) {
710 		substring_t args[MAX_OPT_ARGS];
711 		int option, token;
712 
713 		if (!*p)
714 			continue;
715 
716 		dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
717 
718 		token = match_token(p, nfs_mount_option_tokens, args);
719 		switch (token) {
720 		case Opt_soft:
721 			mnt->flags |= NFS_MOUNT_SOFT;
722 			break;
723 		case Opt_hard:
724 			mnt->flags &= ~NFS_MOUNT_SOFT;
725 			break;
726 		case Opt_intr:
727 		case Opt_nointr:
728 			break;
729 		case Opt_posix:
730 			mnt->flags |= NFS_MOUNT_POSIX;
731 			break;
732 		case Opt_noposix:
733 			mnt->flags &= ~NFS_MOUNT_POSIX;
734 			break;
735 		case Opt_cto:
736 			mnt->flags &= ~NFS_MOUNT_NOCTO;
737 			break;
738 		case Opt_nocto:
739 			mnt->flags |= NFS_MOUNT_NOCTO;
740 			break;
741 		case Opt_ac:
742 			mnt->flags &= ~NFS_MOUNT_NOAC;
743 			break;
744 		case Opt_noac:
745 			mnt->flags |= NFS_MOUNT_NOAC;
746 			break;
747 		case Opt_lock:
748 			mnt->flags &= ~NFS_MOUNT_NONLM;
749 			break;
750 		case Opt_nolock:
751 			mnt->flags |= NFS_MOUNT_NONLM;
752 			break;
753 		case Opt_v2:
754 			mnt->flags &= ~NFS_MOUNT_VER3;
755 			break;
756 		case Opt_v3:
757 			mnt->flags |= NFS_MOUNT_VER3;
758 			break;
759 		case Opt_udp:
760 			mnt->flags &= ~NFS_MOUNT_TCP;
761 			mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
762 			mnt->timeo = 7;
763 			mnt->retrans = 5;
764 			break;
765 		case Opt_tcp:
766 			mnt->flags |= NFS_MOUNT_TCP;
767 			mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
768 			mnt->timeo = 600;
769 			mnt->retrans = 2;
770 			break;
771 		case Opt_rdma:
772 			mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
773 			mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
774 			mnt->timeo = 600;
775 			mnt->retrans = 2;
776 			break;
777 		case Opt_acl:
778 			mnt->flags &= ~NFS_MOUNT_NOACL;
779 			break;
780 		case Opt_noacl:
781 			mnt->flags |= NFS_MOUNT_NOACL;
782 			break;
783 		case Opt_rdirplus:
784 			mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
785 			break;
786 		case Opt_nordirplus:
787 			mnt->flags |= NFS_MOUNT_NORDIRPLUS;
788 			break;
789 		case Opt_sharecache:
790 			mnt->flags &= ~NFS_MOUNT_UNSHARED;
791 			break;
792 		case Opt_nosharecache:
793 			mnt->flags |= NFS_MOUNT_UNSHARED;
794 			break;
795 
796 		case Opt_port:
797 			if (match_int(args, &option))
798 				return 0;
799 			if (option < 0 || option > 65535)
800 				return 0;
801 			port = option;
802 			break;
803 		case Opt_rsize:
804 			if (match_int(args, &mnt->rsize))
805 				return 0;
806 			break;
807 		case Opt_wsize:
808 			if (match_int(args, &mnt->wsize))
809 				return 0;
810 			break;
811 		case Opt_bsize:
812 			if (match_int(args, &option))
813 				return 0;
814 			if (option < 0)
815 				return 0;
816 			mnt->bsize = option;
817 			break;
818 		case Opt_timeo:
819 			if (match_int(args, &mnt->timeo))
820 				return 0;
821 			break;
822 		case Opt_retrans:
823 			if (match_int(args, &mnt->retrans))
824 				return 0;
825 			break;
826 		case Opt_acregmin:
827 			if (match_int(args, &mnt->acregmin))
828 				return 0;
829 			break;
830 		case Opt_acregmax:
831 			if (match_int(args, &mnt->acregmax))
832 				return 0;
833 			break;
834 		case Opt_acdirmin:
835 			if (match_int(args, &mnt->acdirmin))
836 				return 0;
837 			break;
838 		case Opt_acdirmax:
839 			if (match_int(args, &mnt->acdirmax))
840 				return 0;
841 			break;
842 		case Opt_actimeo:
843 			if (match_int(args, &option))
844 				return 0;
845 			if (option < 0)
846 				return 0;
847 			mnt->acregmin =
848 			mnt->acregmax =
849 			mnt->acdirmin =
850 			mnt->acdirmax = option;
851 			break;
852 		case Opt_namelen:
853 			if (match_int(args, &mnt->namlen))
854 				return 0;
855 			break;
856 		case Opt_mountport:
857 			if (match_int(args, &option))
858 				return 0;
859 			if (option < 0 || option > 65535)
860 				return 0;
861 			mnt->mount_server.port = option;
862 			break;
863 		case Opt_mountvers:
864 			if (match_int(args, &option))
865 				return 0;
866 			if (option < 0)
867 				return 0;
868 			mnt->mount_server.version = option;
869 			break;
870 		case Opt_nfsvers:
871 			if (match_int(args, &option))
872 				return 0;
873 			switch (option) {
874 			case 2:
875 				mnt->flags &= ~NFS_MOUNT_VER3;
876 				break;
877 			case 3:
878 				mnt->flags |= NFS_MOUNT_VER3;
879 				break;
880 			default:
881 				goto out_unrec_vers;
882 			}
883 			break;
884 
885 		case Opt_sec:
886 			string = match_strdup(args);
887 			if (string == NULL)
888 				goto out_nomem;
889 			token = match_token(string, nfs_secflavor_tokens, args);
890 			kfree(string);
891 
892 			/*
893 			 * The flags setting is for v2/v3.  The flavor_len
894 			 * setting is for v4.  v2/v3 also need to know the
895 			 * difference between NULL and UNIX.
896 			 */
897 			switch (token) {
898 			case Opt_sec_none:
899 				mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
900 				mnt->auth_flavor_len = 0;
901 				mnt->auth_flavors[0] = RPC_AUTH_NULL;
902 				break;
903 			case Opt_sec_sys:
904 				mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
905 				mnt->auth_flavor_len = 0;
906 				mnt->auth_flavors[0] = RPC_AUTH_UNIX;
907 				break;
908 			case Opt_sec_krb5:
909 				mnt->flags |= NFS_MOUNT_SECFLAVOUR;
910 				mnt->auth_flavor_len = 1;
911 				mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
912 				break;
913 			case Opt_sec_krb5i:
914 				mnt->flags |= NFS_MOUNT_SECFLAVOUR;
915 				mnt->auth_flavor_len = 1;
916 				mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
917 				break;
918 			case Opt_sec_krb5p:
919 				mnt->flags |= NFS_MOUNT_SECFLAVOUR;
920 				mnt->auth_flavor_len = 1;
921 				mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
922 				break;
923 			case Opt_sec_lkey:
924 				mnt->flags |= NFS_MOUNT_SECFLAVOUR;
925 				mnt->auth_flavor_len = 1;
926 				mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
927 				break;
928 			case Opt_sec_lkeyi:
929 				mnt->flags |= NFS_MOUNT_SECFLAVOUR;
930 				mnt->auth_flavor_len = 1;
931 				mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
932 				break;
933 			case Opt_sec_lkeyp:
934 				mnt->flags |= NFS_MOUNT_SECFLAVOUR;
935 				mnt->auth_flavor_len = 1;
936 				mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
937 				break;
938 			case Opt_sec_spkm:
939 				mnt->flags |= NFS_MOUNT_SECFLAVOUR;
940 				mnt->auth_flavor_len = 1;
941 				mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
942 				break;
943 			case Opt_sec_spkmi:
944 				mnt->flags |= NFS_MOUNT_SECFLAVOUR;
945 				mnt->auth_flavor_len = 1;
946 				mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
947 				break;
948 			case Opt_sec_spkmp:
949 				mnt->flags |= NFS_MOUNT_SECFLAVOUR;
950 				mnt->auth_flavor_len = 1;
951 				mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
952 				break;
953 			default:
954 				goto out_unrec_sec;
955 			}
956 			break;
957 		case Opt_proto:
958 			string = match_strdup(args);
959 			if (string == NULL)
960 				goto out_nomem;
961 			token = match_token(string,
962 					    nfs_xprt_protocol_tokens, args);
963 			kfree(string);
964 
965 			switch (token) {
966 			case Opt_xprt_udp:
967 				mnt->flags &= ~NFS_MOUNT_TCP;
968 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
969 				mnt->timeo = 7;
970 				mnt->retrans = 5;
971 				break;
972 			case Opt_xprt_tcp:
973 				mnt->flags |= NFS_MOUNT_TCP;
974 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
975 				mnt->timeo = 600;
976 				mnt->retrans = 2;
977 				break;
978 			case Opt_xprt_rdma:
979 				/* vector side protocols to TCP */
980 				mnt->flags |= NFS_MOUNT_TCP;
981 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
982 				mnt->timeo = 600;
983 				mnt->retrans = 2;
984 				break;
985 			default:
986 				goto out_unrec_xprt;
987 			}
988 			break;
989 		case Opt_mountproto:
990 			string = match_strdup(args);
991 			if (string == NULL)
992 				goto out_nomem;
993 			token = match_token(string,
994 					    nfs_xprt_protocol_tokens, args);
995 			kfree(string);
996 
997 			switch (token) {
998 			case Opt_xprt_udp:
999 				mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1000 				break;
1001 			case Opt_xprt_tcp:
1002 				mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1003 				break;
1004 			case Opt_xprt_rdma: /* not used for side protocols */
1005 			default:
1006 				goto out_unrec_xprt;
1007 			}
1008 			break;
1009 		case Opt_addr:
1010 			string = match_strdup(args);
1011 			if (string == NULL)
1012 				goto out_nomem;
1013 			nfs_parse_server_address(string, (struct sockaddr *)
1014 						 &mnt->nfs_server.address,
1015 						 &mnt->nfs_server.addrlen);
1016 			kfree(string);
1017 			break;
1018 		case Opt_clientaddr:
1019 			string = match_strdup(args);
1020 			if (string == NULL)
1021 				goto out_nomem;
1022 			kfree(mnt->client_address);
1023 			mnt->client_address = string;
1024 			break;
1025 		case Opt_mounthost:
1026 			string = match_strdup(args);
1027 			if (string == NULL)
1028 				goto out_nomem;
1029 			kfree(mnt->mount_server.hostname);
1030 			mnt->mount_server.hostname = string;
1031 			break;
1032 		case Opt_mountaddr:
1033 			string = match_strdup(args);
1034 			if (string == NULL)
1035 				goto out_nomem;
1036 			nfs_parse_server_address(string, (struct sockaddr *)
1037 						 &mnt->mount_server.address,
1038 						 &mnt->mount_server.addrlen);
1039 			kfree(string);
1040 			break;
1041 
1042 		case Opt_userspace:
1043 		case Opt_deprecated:
1044 			break;
1045 
1046 		default:
1047 			goto out_unknown;
1048 		}
1049 	}
1050 
1051 	nfs_set_port((struct sockaddr *)&mnt->nfs_server.address, port);
1052 
1053 	return 1;
1054 
1055 out_nomem:
1056 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
1057 	return 0;
1058 out_security_failure:
1059 	free_secdata(secdata);
1060 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1061 	return 0;
1062 out_unrec_vers:
1063 	printk(KERN_INFO "NFS: unrecognized NFS version number\n");
1064 	return 0;
1065 
1066 out_unrec_xprt:
1067 	printk(KERN_INFO "NFS: unrecognized transport protocol\n");
1068 	return 0;
1069 
1070 out_unrec_sec:
1071 	printk(KERN_INFO "NFS: unrecognized security flavor\n");
1072 	return 0;
1073 
1074 out_unknown:
1075 	printk(KERN_INFO "NFS: unknown mount option: %s\n", p);
1076 	return 0;
1077 }
1078 
1079 /*
1080  * Use the remote server's MOUNT service to request the NFS file handle
1081  * corresponding to the provided path.
1082  */
1083 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1084 			 struct nfs_fh *root_fh)
1085 {
1086 	struct sockaddr *sap = (struct sockaddr *)&args->mount_server.address;
1087 	char *hostname;
1088 	int status;
1089 
1090 	if (args->mount_server.version == 0) {
1091 		if (args->flags & NFS_MOUNT_VER3)
1092 			args->mount_server.version = NFS_MNT3_VERSION;
1093 		else
1094 			args->mount_server.version = NFS_MNT_VERSION;
1095 	}
1096 
1097 	if (args->mount_server.hostname)
1098 		hostname = args->mount_server.hostname;
1099 	else
1100 		hostname = args->nfs_server.hostname;
1101 
1102 	/*
1103 	 * Construct the mount server's address.
1104 	 */
1105 	if (args->mount_server.address.ss_family == AF_UNSPEC) {
1106 		memcpy(sap, &args->nfs_server.address,
1107 		       args->nfs_server.addrlen);
1108 		args->mount_server.addrlen = args->nfs_server.addrlen;
1109 	}
1110 
1111 	/*
1112 	 * autobind will be used if mount_server.port == 0
1113 	 */
1114 	nfs_set_port(sap, args->mount_server.port);
1115 
1116 	/*
1117 	 * Now ask the mount server to map our export path
1118 	 * to a file handle.
1119 	 */
1120 	status = nfs_mount(sap,
1121 			   args->mount_server.addrlen,
1122 			   hostname,
1123 			   args->nfs_server.export_path,
1124 			   args->mount_server.version,
1125 			   args->mount_server.protocol,
1126 			   root_fh);
1127 	if (status == 0)
1128 		return 0;
1129 
1130 	dfprintk(MOUNT, "NFS: unable to mount server %s, error %d",
1131 			hostname, status);
1132 	return status;
1133 }
1134 
1135 /*
1136  * Validate the NFS2/NFS3 mount data
1137  * - fills in the mount root filehandle
1138  *
1139  * For option strings, user space handles the following behaviors:
1140  *
1141  * + DNS: mapping server host name to IP address ("addr=" option)
1142  *
1143  * + failure mode: how to behave if a mount request can't be handled
1144  *   immediately ("fg/bg" option)
1145  *
1146  * + retry: how often to retry a mount request ("retry=" option)
1147  *
1148  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1149  *   mountproto=tcp after mountproto=udp, and so on
1150  */
1151 static int nfs_validate_mount_data(void *options,
1152 				   struct nfs_parsed_mount_data *args,
1153 				   struct nfs_fh *mntfh,
1154 				   const char *dev_name)
1155 {
1156 	struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1157 
1158 	memset(args, 0, sizeof(*args));
1159 
1160 	if (data == NULL)
1161 		goto out_no_data;
1162 
1163 	args->flags		= (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1164 	args->rsize		= NFS_MAX_FILE_IO_SIZE;
1165 	args->wsize		= NFS_MAX_FILE_IO_SIZE;
1166 	args->timeo		= 600;
1167 	args->retrans		= 2;
1168 	args->acregmin		= 3;
1169 	args->acregmax		= 60;
1170 	args->acdirmin		= 30;
1171 	args->acdirmax		= 60;
1172 	args->mount_server.protocol = XPRT_TRANSPORT_UDP;
1173 	args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1174 
1175 	switch (data->version) {
1176 	case 1:
1177 		data->namlen = 0;
1178 	case 2:
1179 		data->bsize = 0;
1180 	case 3:
1181 		if (data->flags & NFS_MOUNT_VER3)
1182 			goto out_no_v3;
1183 		data->root.size = NFS2_FHSIZE;
1184 		memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1185 	case 4:
1186 		if (data->flags & NFS_MOUNT_SECFLAVOUR)
1187 			goto out_no_sec;
1188 	case 5:
1189 		memset(data->context, 0, sizeof(data->context));
1190 	case 6:
1191 		if (data->flags & NFS_MOUNT_VER3)
1192 			mntfh->size = data->root.size;
1193 		else
1194 			mntfh->size = NFS2_FHSIZE;
1195 
1196 		if (mntfh->size > sizeof(mntfh->data))
1197 			goto out_invalid_fh;
1198 
1199 		memcpy(mntfh->data, data->root.data, mntfh->size);
1200 		if (mntfh->size < sizeof(mntfh->data))
1201 			memset(mntfh->data + mntfh->size, 0,
1202 			       sizeof(mntfh->data) - mntfh->size);
1203 
1204 		/*
1205 		 * Translate to nfs_parsed_mount_data, which nfs_fill_super
1206 		 * can deal with.
1207 		 */
1208 		args->flags		= data->flags;
1209 		args->rsize		= data->rsize;
1210 		args->wsize		= data->wsize;
1211 		args->flags		= data->flags;
1212 		args->timeo		= data->timeo;
1213 		args->retrans		= data->retrans;
1214 		args->acregmin		= data->acregmin;
1215 		args->acregmax		= data->acregmax;
1216 		args->acdirmin		= data->acdirmin;
1217 		args->acdirmax		= data->acdirmax;
1218 
1219 		memcpy(&args->nfs_server.address, &data->addr,
1220 		       sizeof(data->addr));
1221 		args->nfs_server.addrlen = sizeof(data->addr);
1222 		if (!nfs_verify_server_address((struct sockaddr *)
1223 						&args->nfs_server.address))
1224 			goto out_no_address;
1225 
1226 		if (!(data->flags & NFS_MOUNT_TCP))
1227 			args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1228 		/* N.B. caller will free nfs_server.hostname in all cases */
1229 		args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1230 		args->namlen		= data->namlen;
1231 		args->bsize		= data->bsize;
1232 		args->auth_flavors[0]	= data->pseudoflavor;
1233 
1234 		/*
1235 		 * The legacy version 6 binary mount data from userspace has a
1236 		 * field used only to transport selinux information into the
1237 		 * the kernel.  To continue to support that functionality we
1238 		 * have a touch of selinux knowledge here in the NFS code. The
1239 		 * userspace code converted context=blah to just blah so we are
1240 		 * converting back to the full string selinux understands.
1241 		 */
1242 		if (data->context[0]){
1243 #ifdef CONFIG_SECURITY_SELINUX
1244 			int rc;
1245 			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1246 			if (!opts_str)
1247 				return -ENOMEM;
1248 			strcpy(opts_str, "context=");
1249 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1250 			strcat(opts_str, &data->context[0]);
1251 			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1252 			kfree(opts_str);
1253 			if (rc)
1254 				return rc;
1255 #else
1256 			return -EINVAL;
1257 #endif
1258 		}
1259 
1260 		break;
1261 	default: {
1262 		unsigned int len;
1263 		char *c;
1264 		int status;
1265 
1266 		if (nfs_parse_mount_options((char *)options, args) == 0)
1267 			return -EINVAL;
1268 
1269 		if (!nfs_verify_server_address((struct sockaddr *)
1270 						&args->nfs_server.address))
1271 			goto out_no_address;
1272 
1273 		c = strchr(dev_name, ':');
1274 		if (c == NULL)
1275 			return -EINVAL;
1276 		len = c - dev_name;
1277 		/* N.B. caller will free nfs_server.hostname in all cases */
1278 		args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
1279 
1280 		c++;
1281 		if (strlen(c) > NFS_MAXPATHLEN)
1282 			return -ENAMETOOLONG;
1283 		args->nfs_server.export_path = c;
1284 
1285 		status = nfs_try_mount(args, mntfh);
1286 		if (status)
1287 			return status;
1288 
1289 		break;
1290 		}
1291 	}
1292 
1293 	if (!(args->flags & NFS_MOUNT_SECFLAVOUR))
1294 		args->auth_flavors[0] = RPC_AUTH_UNIX;
1295 
1296 #ifndef CONFIG_NFS_V3
1297 	if (args->flags & NFS_MOUNT_VER3)
1298 		goto out_v3_not_compiled;
1299 #endif /* !CONFIG_NFS_V3 */
1300 
1301 	return 0;
1302 
1303 out_no_data:
1304 	dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1305 	return -EINVAL;
1306 
1307 out_no_v3:
1308 	dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1309 		 data->version);
1310 	return -EINVAL;
1311 
1312 out_no_sec:
1313 	dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1314 	return -EINVAL;
1315 
1316 #ifndef CONFIG_NFS_V3
1317 out_v3_not_compiled:
1318 	dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1319 	return -EPROTONOSUPPORT;
1320 #endif /* !CONFIG_NFS_V3 */
1321 
1322 out_no_address:
1323 	dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1324 	return -EINVAL;
1325 
1326 out_invalid_fh:
1327 	dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1328 	return -EINVAL;
1329 }
1330 
1331 /*
1332  * Initialise the common bits of the superblock
1333  */
1334 static inline void nfs_initialise_sb(struct super_block *sb)
1335 {
1336 	struct nfs_server *server = NFS_SB(sb);
1337 
1338 	sb->s_magic = NFS_SUPER_MAGIC;
1339 
1340 	/* We probably want something more informative here */
1341 	snprintf(sb->s_id, sizeof(sb->s_id),
1342 		 "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1343 
1344 	if (sb->s_blocksize == 0)
1345 		sb->s_blocksize = nfs_block_bits(server->wsize,
1346 						 &sb->s_blocksize_bits);
1347 
1348 	if (server->flags & NFS_MOUNT_NOAC)
1349 		sb->s_flags |= MS_SYNCHRONOUS;
1350 
1351 	nfs_super_set_maxbytes(sb, server->maxfilesize);
1352 }
1353 
1354 /*
1355  * Finish setting up an NFS2/3 superblock
1356  */
1357 static void nfs_fill_super(struct super_block *sb,
1358 			   struct nfs_parsed_mount_data *data)
1359 {
1360 	struct nfs_server *server = NFS_SB(sb);
1361 
1362 	sb->s_blocksize_bits = 0;
1363 	sb->s_blocksize = 0;
1364 	if (data->bsize)
1365 		sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1366 
1367 	if (server->flags & NFS_MOUNT_VER3) {
1368 		/* The VFS shouldn't apply the umask to mode bits. We will do
1369 		 * so ourselves when necessary.
1370 		 */
1371 		sb->s_flags |= MS_POSIXACL;
1372 		sb->s_time_gran = 1;
1373 	}
1374 
1375 	sb->s_op = &nfs_sops;
1376  	nfs_initialise_sb(sb);
1377 }
1378 
1379 /*
1380  * Finish setting up a cloned NFS2/3 superblock
1381  */
1382 static void nfs_clone_super(struct super_block *sb,
1383 			    const struct super_block *old_sb)
1384 {
1385 	struct nfs_server *server = NFS_SB(sb);
1386 
1387 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1388 	sb->s_blocksize = old_sb->s_blocksize;
1389 	sb->s_maxbytes = old_sb->s_maxbytes;
1390 
1391 	if (server->flags & NFS_MOUNT_VER3) {
1392 		/* The VFS shouldn't apply the umask to mode bits. We will do
1393 		 * so ourselves when necessary.
1394 		 */
1395 		sb->s_flags |= MS_POSIXACL;
1396 		sb->s_time_gran = 1;
1397 	}
1398 
1399 	sb->s_op = old_sb->s_op;
1400  	nfs_initialise_sb(sb);
1401 }
1402 
1403 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
1404 
1405 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1406 {
1407 	const struct nfs_server *a = s->s_fs_info;
1408 	const struct rpc_clnt *clnt_a = a->client;
1409 	const struct rpc_clnt *clnt_b = b->client;
1410 
1411 	if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1412 		goto Ebusy;
1413 	if (a->nfs_client != b->nfs_client)
1414 		goto Ebusy;
1415 	if (a->flags != b->flags)
1416 		goto Ebusy;
1417 	if (a->wsize != b->wsize)
1418 		goto Ebusy;
1419 	if (a->rsize != b->rsize)
1420 		goto Ebusy;
1421 	if (a->acregmin != b->acregmin)
1422 		goto Ebusy;
1423 	if (a->acregmax != b->acregmax)
1424 		goto Ebusy;
1425 	if (a->acdirmin != b->acdirmin)
1426 		goto Ebusy;
1427 	if (a->acdirmax != b->acdirmax)
1428 		goto Ebusy;
1429 	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1430 		goto Ebusy;
1431 	return 1;
1432 Ebusy:
1433 	return 0;
1434 }
1435 
1436 struct nfs_sb_mountdata {
1437 	struct nfs_server *server;
1438 	int mntflags;
1439 };
1440 
1441 static int nfs_set_super(struct super_block *s, void *data)
1442 {
1443 	struct nfs_sb_mountdata *sb_mntdata = data;
1444 	struct nfs_server *server = sb_mntdata->server;
1445 	int ret;
1446 
1447 	s->s_flags = sb_mntdata->mntflags;
1448 	s->s_fs_info = server;
1449 	ret = set_anon_super(s, server);
1450 	if (ret == 0)
1451 		server->s_dev = s->s_dev;
1452 	return ret;
1453 }
1454 
1455 static int nfs_compare_super_address(struct nfs_server *server1,
1456 				     struct nfs_server *server2)
1457 {
1458 	struct sockaddr *sap1, *sap2;
1459 
1460 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1461 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1462 
1463 	if (sap1->sa_family != sap2->sa_family)
1464 		return 0;
1465 
1466 	switch (sap1->sa_family) {
1467 	case AF_INET: {
1468 		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1469 		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1470 		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1471 			return 0;
1472 		if (sin1->sin_port != sin2->sin_port)
1473 			return 0;
1474 		break;
1475 	}
1476 	case AF_INET6: {
1477 		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1478 		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1479 		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1480 			return 0;
1481 		if (sin1->sin6_port != sin2->sin6_port)
1482 			return 0;
1483 		break;
1484 	}
1485 	default:
1486 		return 0;
1487 	}
1488 
1489 	return 1;
1490 }
1491 
1492 static int nfs_compare_super(struct super_block *sb, void *data)
1493 {
1494 	struct nfs_sb_mountdata *sb_mntdata = data;
1495 	struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
1496 	int mntflags = sb_mntdata->mntflags;
1497 
1498 	if (!nfs_compare_super_address(old, server))
1499 		return 0;
1500 	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1501 	if (old->flags & NFS_MOUNT_UNSHARED)
1502 		return 0;
1503 	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1504 		return 0;
1505 	return nfs_compare_mount_options(sb, server, mntflags);
1506 }
1507 
1508 static int nfs_get_sb(struct file_system_type *fs_type,
1509 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1510 {
1511 	struct nfs_server *server = NULL;
1512 	struct super_block *s;
1513 	struct nfs_fh mntfh;
1514 	struct nfs_parsed_mount_data data;
1515 	struct dentry *mntroot;
1516 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1517 	struct nfs_sb_mountdata sb_mntdata = {
1518 		.mntflags = flags,
1519 	};
1520 	int error;
1521 
1522 	security_init_mnt_opts(&data.lsm_opts);
1523 
1524 	/* Validate the mount data */
1525 	error = nfs_validate_mount_data(raw_data, &data, &mntfh, dev_name);
1526 	if (error < 0)
1527 		goto out;
1528 
1529 	/* Get a volume representation */
1530 	server = nfs_create_server(&data, &mntfh);
1531 	if (IS_ERR(server)) {
1532 		error = PTR_ERR(server);
1533 		goto out;
1534 	}
1535 	sb_mntdata.server = server;
1536 
1537 	if (server->flags & NFS_MOUNT_UNSHARED)
1538 		compare_super = NULL;
1539 
1540 	/* Get a superblock - note that we may end up sharing one that already exists */
1541 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1542 	if (IS_ERR(s)) {
1543 		error = PTR_ERR(s);
1544 		goto out_err_nosb;
1545 	}
1546 
1547 	if (s->s_fs_info != server) {
1548 		nfs_free_server(server);
1549 		server = NULL;
1550 	}
1551 
1552 	if (!s->s_root) {
1553 		/* initial superblock/root creation */
1554 		nfs_fill_super(s, &data);
1555 	}
1556 
1557 	mntroot = nfs_get_root(s, &mntfh);
1558 	if (IS_ERR(mntroot)) {
1559 		error = PTR_ERR(mntroot);
1560 		goto error_splat_super;
1561 	}
1562 
1563 	error = security_sb_set_mnt_opts(s, &data.lsm_opts);
1564 	if (error)
1565 		goto error_splat_root;
1566 
1567 	s->s_flags |= MS_ACTIVE;
1568 	mnt->mnt_sb = s;
1569 	mnt->mnt_root = mntroot;
1570 	error = 0;
1571 
1572 out:
1573 	kfree(data.nfs_server.hostname);
1574 	kfree(data.mount_server.hostname);
1575 	security_free_mnt_opts(&data.lsm_opts);
1576 	return error;
1577 
1578 out_err_nosb:
1579 	nfs_free_server(server);
1580 	goto out;
1581 
1582 error_splat_root:
1583 	dput(mntroot);
1584 error_splat_super:
1585 	up_write(&s->s_umount);
1586 	deactivate_super(s);
1587 	goto out;
1588 }
1589 
1590 /*
1591  * Destroy an NFS2/3 superblock
1592  */
1593 static void nfs_kill_super(struct super_block *s)
1594 {
1595 	struct nfs_server *server = NFS_SB(s);
1596 
1597 	kill_anon_super(s);
1598 	nfs_free_server(server);
1599 }
1600 
1601 /*
1602  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
1603  */
1604 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
1605 			   const char *dev_name, void *raw_data,
1606 			   struct vfsmount *mnt)
1607 {
1608 	struct nfs_clone_mount *data = raw_data;
1609 	struct super_block *s;
1610 	struct nfs_server *server;
1611 	struct dentry *mntroot;
1612 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1613 	struct nfs_sb_mountdata sb_mntdata = {
1614 		.mntflags = flags,
1615 	};
1616 	int error;
1617 
1618 	dprintk("--> nfs_xdev_get_sb()\n");
1619 
1620 	/* create a new volume representation */
1621 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
1622 	if (IS_ERR(server)) {
1623 		error = PTR_ERR(server);
1624 		goto out_err_noserver;
1625 	}
1626 	sb_mntdata.server = server;
1627 
1628 	if (server->flags & NFS_MOUNT_UNSHARED)
1629 		compare_super = NULL;
1630 
1631 	/* Get a superblock - note that we may end up sharing one that already exists */
1632 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
1633 	if (IS_ERR(s)) {
1634 		error = PTR_ERR(s);
1635 		goto out_err_nosb;
1636 	}
1637 
1638 	if (s->s_fs_info != server) {
1639 		nfs_free_server(server);
1640 		server = NULL;
1641 	}
1642 
1643 	if (!s->s_root) {
1644 		/* initial superblock/root creation */
1645 		nfs_clone_super(s, data->sb);
1646 	}
1647 
1648 	mntroot = nfs_get_root(s, data->fh);
1649 	if (IS_ERR(mntroot)) {
1650 		error = PTR_ERR(mntroot);
1651 		goto error_splat_super;
1652 	}
1653 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
1654 		dput(mntroot);
1655 		error = -ESTALE;
1656 		goto error_splat_super;
1657 	}
1658 
1659 	s->s_flags |= MS_ACTIVE;
1660 	mnt->mnt_sb = s;
1661 	mnt->mnt_root = mntroot;
1662 
1663 	/* clone any lsm security options from the parent to the new sb */
1664 	security_sb_clone_mnt_opts(data->sb, s);
1665 
1666 	dprintk("<-- nfs_xdev_get_sb() = 0\n");
1667 	return 0;
1668 
1669 out_err_nosb:
1670 	nfs_free_server(server);
1671 out_err_noserver:
1672 	dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
1673 	return error;
1674 
1675 error_splat_super:
1676 	up_write(&s->s_umount);
1677 	deactivate_super(s);
1678 	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
1679 	return error;
1680 }
1681 
1682 #ifdef CONFIG_NFS_V4
1683 
1684 /*
1685  * Finish setting up a cloned NFS4 superblock
1686  */
1687 static void nfs4_clone_super(struct super_block *sb,
1688 			    const struct super_block *old_sb)
1689 {
1690 	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1691 	sb->s_blocksize = old_sb->s_blocksize;
1692 	sb->s_maxbytes = old_sb->s_maxbytes;
1693 	sb->s_time_gran = 1;
1694 	sb->s_op = old_sb->s_op;
1695  	nfs_initialise_sb(sb);
1696 }
1697 
1698 /*
1699  * Set up an NFS4 superblock
1700  */
1701 static void nfs4_fill_super(struct super_block *sb)
1702 {
1703 	sb->s_time_gran = 1;
1704 	sb->s_op = &nfs4_sops;
1705 	nfs_initialise_sb(sb);
1706 }
1707 
1708 /*
1709  * If the user didn't specify a port, set the port number to
1710  * the NFS version 4 default port.
1711  */
1712 static void nfs4_default_port(struct sockaddr *sap)
1713 {
1714 	switch (sap->sa_family) {
1715 	case AF_INET: {
1716 		struct sockaddr_in *ap = (struct sockaddr_in *)sap;
1717 		if (ap->sin_port == 0)
1718 			ap->sin_port = htons(NFS_PORT);
1719 		break;
1720 	}
1721 	case AF_INET6: {
1722 		struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
1723 		if (ap->sin6_port == 0)
1724 			ap->sin6_port = htons(NFS_PORT);
1725 		break;
1726 	}
1727 	}
1728 }
1729 
1730 /*
1731  * Validate NFSv4 mount options
1732  */
1733 static int nfs4_validate_mount_data(void *options,
1734 				    struct nfs_parsed_mount_data *args,
1735 				    const char *dev_name)
1736 {
1737 	struct sockaddr_in *ap;
1738 	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
1739 	char *c;
1740 
1741 	memset(args, 0, sizeof(*args));
1742 
1743 	if (data == NULL)
1744 		goto out_no_data;
1745 
1746 	args->rsize		= NFS_MAX_FILE_IO_SIZE;
1747 	args->wsize		= NFS_MAX_FILE_IO_SIZE;
1748 	args->timeo		= 600;
1749 	args->retrans		= 2;
1750 	args->acregmin		= 3;
1751 	args->acregmax		= 60;
1752 	args->acdirmin		= 30;
1753 	args->acdirmax		= 60;
1754 	args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1755 
1756 	switch (data->version) {
1757 	case 1:
1758 		ap = (struct sockaddr_in *)&args->nfs_server.address;
1759 		if (data->host_addrlen > sizeof(args->nfs_server.address))
1760 			goto out_no_address;
1761 		if (data->host_addrlen == 0)
1762 			goto out_no_address;
1763 		args->nfs_server.addrlen = data->host_addrlen;
1764 		if (copy_from_user(ap, data->host_addr, data->host_addrlen))
1765 			return -EFAULT;
1766 		if (!nfs_verify_server_address((struct sockaddr *)
1767 						&args->nfs_server.address))
1768 			goto out_no_address;
1769 
1770 		nfs4_default_port((struct sockaddr *)
1771 				  &args->nfs_server.address);
1772 
1773 		switch (data->auth_flavourlen) {
1774 		case 0:
1775 			args->auth_flavors[0] = RPC_AUTH_UNIX;
1776 			break;
1777 		case 1:
1778 			if (copy_from_user(&args->auth_flavors[0],
1779 					   data->auth_flavours,
1780 					   sizeof(args->auth_flavors[0])))
1781 				return -EFAULT;
1782 			break;
1783 		default:
1784 			goto out_inval_auth;
1785 		}
1786 
1787 		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1788 		if (IS_ERR(c))
1789 			return PTR_ERR(c);
1790 		args->nfs_server.hostname = c;
1791 
1792 		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1793 		if (IS_ERR(c))
1794 			return PTR_ERR(c);
1795 		args->nfs_server.export_path = c;
1796 		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
1797 
1798 		c = strndup_user(data->client_addr.data, 16);
1799 		if (IS_ERR(c))
1800 			return PTR_ERR(c);
1801 		args->client_address = c;
1802 
1803 		/*
1804 		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
1805 		 * can deal with.
1806 		 */
1807 
1808 		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
1809 		args->rsize	= data->rsize;
1810 		args->wsize	= data->wsize;
1811 		args->timeo	= data->timeo;
1812 		args->retrans	= data->retrans;
1813 		args->acregmin	= data->acregmin;
1814 		args->acregmax	= data->acregmax;
1815 		args->acdirmin	= data->acdirmin;
1816 		args->acdirmax	= data->acdirmax;
1817 		args->nfs_server.protocol = data->proto;
1818 
1819 		break;
1820 	default: {
1821 		unsigned int len;
1822 
1823 		if (nfs_parse_mount_options((char *)options, args) == 0)
1824 			return -EINVAL;
1825 
1826 		if (!nfs_verify_server_address((struct sockaddr *)
1827 						&args->nfs_server.address))
1828 			return -EINVAL;
1829 
1830 		nfs4_default_port((struct sockaddr *)
1831 				  &args->nfs_server.address);
1832 
1833 		switch (args->auth_flavor_len) {
1834 		case 0:
1835 			args->auth_flavors[0] = RPC_AUTH_UNIX;
1836 			break;
1837 		case 1:
1838 			break;
1839 		default:
1840 			goto out_inval_auth;
1841 		}
1842 
1843 		/*
1844 		 * Split "dev_name" into "hostname:mntpath".
1845 		 */
1846 		c = strchr(dev_name, ':');
1847 		if (c == NULL)
1848 			return -EINVAL;
1849 		/* while calculating len, pretend ':' is '\0' */
1850 		len = c - dev_name;
1851 		if (len > NFS4_MAXNAMLEN)
1852 			return -ENAMETOOLONG;
1853 		/* N.B. caller will free nfs_server.hostname in all cases */
1854 		args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
1855 
1856 		c++;			/* step over the ':' */
1857 		len = strlen(c);
1858 		if (len > NFS4_MAXPATHLEN)
1859 			return -ENAMETOOLONG;
1860 		args->nfs_server.export_path = kstrndup(c, len, GFP_KERNEL);
1861 
1862 		dprintk("NFS: MNTPATH: '%s'\n", args->nfs_server.export_path);
1863 
1864 		if (args->client_address == NULL)
1865 			goto out_no_client_address;
1866 
1867 		break;
1868 		}
1869 	}
1870 
1871 	return 0;
1872 
1873 out_no_data:
1874 	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
1875 	return -EINVAL;
1876 
1877 out_inval_auth:
1878 	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
1879 		 data->auth_flavourlen);
1880 	return -EINVAL;
1881 
1882 out_no_address:
1883 	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
1884 	return -EINVAL;
1885 
1886 out_no_client_address:
1887 	dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
1888 	return -EINVAL;
1889 }
1890 
1891 /*
1892  * Get the superblock for an NFS4 mountpoint
1893  */
1894 static int nfs4_get_sb(struct file_system_type *fs_type,
1895 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1896 {
1897 	struct nfs_parsed_mount_data data;
1898 	struct super_block *s;
1899 	struct nfs_server *server;
1900 	struct nfs_fh mntfh;
1901 	struct dentry *mntroot;
1902 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1903 	struct nfs_sb_mountdata sb_mntdata = {
1904 		.mntflags = flags,
1905 	};
1906 	int error;
1907 
1908 	security_init_mnt_opts(&data.lsm_opts);
1909 
1910 	/* Validate the mount data */
1911 	error = nfs4_validate_mount_data(raw_data, &data, dev_name);
1912 	if (error < 0)
1913 		goto out;
1914 
1915 	/* Get a volume representation */
1916 	server = nfs4_create_server(&data, &mntfh);
1917 	if (IS_ERR(server)) {
1918 		error = PTR_ERR(server);
1919 		goto out;
1920 	}
1921 	sb_mntdata.server = server;
1922 
1923 	if (server->flags & NFS4_MOUNT_UNSHARED)
1924 		compare_super = NULL;
1925 
1926 	/* Get a superblock - note that we may end up sharing one that already exists */
1927 	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1928 	if (IS_ERR(s)) {
1929 		error = PTR_ERR(s);
1930 		goto out_free;
1931 	}
1932 
1933 	if (s->s_fs_info != server) {
1934 		nfs_free_server(server);
1935 		server = NULL;
1936 	}
1937 
1938 	if (!s->s_root) {
1939 		/* initial superblock/root creation */
1940 		nfs4_fill_super(s);
1941 	}
1942 
1943 	mntroot = nfs4_get_root(s, &mntfh);
1944 	if (IS_ERR(mntroot)) {
1945 		error = PTR_ERR(mntroot);
1946 		goto error_splat_super;
1947 	}
1948 
1949 	s->s_flags |= MS_ACTIVE;
1950 	mnt->mnt_sb = s;
1951 	mnt->mnt_root = mntroot;
1952 	error = 0;
1953 
1954 out:
1955 	kfree(data.client_address);
1956 	kfree(data.nfs_server.export_path);
1957 	kfree(data.nfs_server.hostname);
1958 	security_free_mnt_opts(&data.lsm_opts);
1959 	return error;
1960 
1961 out_free:
1962 	nfs_free_server(server);
1963 	goto out;
1964 
1965 error_splat_super:
1966 	up_write(&s->s_umount);
1967 	deactivate_super(s);
1968 	goto out;
1969 }
1970 
1971 static void nfs4_kill_super(struct super_block *sb)
1972 {
1973 	struct nfs_server *server = NFS_SB(sb);
1974 
1975 	nfs_return_all_delegations(sb);
1976 	kill_anon_super(sb);
1977 
1978 	nfs4_renewd_prepare_shutdown(server);
1979 	nfs_free_server(server);
1980 }
1981 
1982 /*
1983  * Clone an NFS4 server record on xdev traversal (FSID-change)
1984  */
1985 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
1986 			    const char *dev_name, void *raw_data,
1987 			    struct vfsmount *mnt)
1988 {
1989 	struct nfs_clone_mount *data = raw_data;
1990 	struct super_block *s;
1991 	struct nfs_server *server;
1992 	struct dentry *mntroot;
1993 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1994 	struct nfs_sb_mountdata sb_mntdata = {
1995 		.mntflags = flags,
1996 	};
1997 	int error;
1998 
1999 	dprintk("--> nfs4_xdev_get_sb()\n");
2000 
2001 	/* create a new volume representation */
2002 	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2003 	if (IS_ERR(server)) {
2004 		error = PTR_ERR(server);
2005 		goto out_err_noserver;
2006 	}
2007 	sb_mntdata.server = server;
2008 
2009 	if (server->flags & NFS4_MOUNT_UNSHARED)
2010 		compare_super = NULL;
2011 
2012 	/* Get a superblock - note that we may end up sharing one that already exists */
2013 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2014 	if (IS_ERR(s)) {
2015 		error = PTR_ERR(s);
2016 		goto out_err_nosb;
2017 	}
2018 
2019 	if (s->s_fs_info != server) {
2020 		nfs_free_server(server);
2021 		server = NULL;
2022 	}
2023 
2024 	if (!s->s_root) {
2025 		/* initial superblock/root creation */
2026 		nfs4_clone_super(s, data->sb);
2027 	}
2028 
2029 	mntroot = nfs4_get_root(s, data->fh);
2030 	if (IS_ERR(mntroot)) {
2031 		error = PTR_ERR(mntroot);
2032 		goto error_splat_super;
2033 	}
2034 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2035 		dput(mntroot);
2036 		error = -ESTALE;
2037 		goto error_splat_super;
2038 	}
2039 
2040 	s->s_flags |= MS_ACTIVE;
2041 	mnt->mnt_sb = s;
2042 	mnt->mnt_root = mntroot;
2043 
2044 	dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2045 	return 0;
2046 
2047 out_err_nosb:
2048 	nfs_free_server(server);
2049 out_err_noserver:
2050 	dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2051 	return error;
2052 
2053 error_splat_super:
2054 	up_write(&s->s_umount);
2055 	deactivate_super(s);
2056 	dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2057 	return error;
2058 }
2059 
2060 /*
2061  * Create an NFS4 server record on referral traversal
2062  */
2063 static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
2064 				const char *dev_name, void *raw_data,
2065 				struct vfsmount *mnt)
2066 {
2067 	struct nfs_clone_mount *data = raw_data;
2068 	struct super_block *s;
2069 	struct nfs_server *server;
2070 	struct dentry *mntroot;
2071 	struct nfs_fh mntfh;
2072 	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2073 	struct nfs_sb_mountdata sb_mntdata = {
2074 		.mntflags = flags,
2075 	};
2076 	int error;
2077 
2078 	dprintk("--> nfs4_referral_get_sb()\n");
2079 
2080 	/* create a new volume representation */
2081 	server = nfs4_create_referral_server(data, &mntfh);
2082 	if (IS_ERR(server)) {
2083 		error = PTR_ERR(server);
2084 		goto out_err_noserver;
2085 	}
2086 	sb_mntdata.server = server;
2087 
2088 	if (server->flags & NFS4_MOUNT_UNSHARED)
2089 		compare_super = NULL;
2090 
2091 	/* Get a superblock - note that we may end up sharing one that already exists */
2092 	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2093 	if (IS_ERR(s)) {
2094 		error = PTR_ERR(s);
2095 		goto out_err_nosb;
2096 	}
2097 
2098 	if (s->s_fs_info != server) {
2099 		nfs_free_server(server);
2100 		server = NULL;
2101 	}
2102 
2103 	if (!s->s_root) {
2104 		/* initial superblock/root creation */
2105 		nfs4_fill_super(s);
2106 	}
2107 
2108 	mntroot = nfs4_get_root(s, &mntfh);
2109 	if (IS_ERR(mntroot)) {
2110 		error = PTR_ERR(mntroot);
2111 		goto error_splat_super;
2112 	}
2113 	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2114 		dput(mntroot);
2115 		error = -ESTALE;
2116 		goto error_splat_super;
2117 	}
2118 
2119 	s->s_flags |= MS_ACTIVE;
2120 	mnt->mnt_sb = s;
2121 	mnt->mnt_root = mntroot;
2122 
2123 	dprintk("<-- nfs4_referral_get_sb() = 0\n");
2124 	return 0;
2125 
2126 out_err_nosb:
2127 	nfs_free_server(server);
2128 out_err_noserver:
2129 	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2130 	return error;
2131 
2132 error_splat_super:
2133 	up_write(&s->s_umount);
2134 	deactivate_super(s);
2135 	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2136 	return error;
2137 }
2138 
2139 #endif /* CONFIG_NFS_V4 */
2140