Convert obvious places to deactivate_locked_super()
[linux-2.6.git] / fs / nfs / super.c
1 /*
2  *  linux/fs/nfs/super.c
3  *
4  *  Copyright (C) 1992  Rick Sladkey
5  *
6  *  nfs superblock handling functions
7  *
8  *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22
23 #include <linux/module.h>
24 #include <linux/init.h>
25
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/stats.h>
35 #include <linux/sunrpc/metrics.h>
36 #include <linux/sunrpc/xprtsock.h>
37 #include <linux/sunrpc/xprtrdma.h>
38 #include <linux/nfs_fs.h>
39 #include <linux/nfs_mount.h>
40 #include <linux/nfs4_mount.h>
41 #include <linux/lockd/bind.h>
42 #include <linux/smp_lock.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/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/netdevice.h>
51 #include <linux/nfs_xdr.h>
52 #include <linux/magic.h>
53 #include <linux/parser.h>
54
55 #include <asm/system.h>
56 #include <asm/uaccess.h>
57
58 #include "nfs4_fs.h"
59 #include "callback.h"
60 #include "delegation.h"
61 #include "iostat.h"
62 #include "internal.h"
63 #include "fscache.h"
64
65 #define NFSDBG_FACILITY         NFSDBG_VFS
66
67 enum {
68         /* Mount options that take no arguments */
69         Opt_soft, Opt_hard,
70         Opt_posix, Opt_noposix,
71         Opt_cto, Opt_nocto,
72         Opt_ac, Opt_noac,
73         Opt_lock, Opt_nolock,
74         Opt_v2, Opt_v3,
75         Opt_udp, Opt_tcp, Opt_rdma,
76         Opt_acl, Opt_noacl,
77         Opt_rdirplus, Opt_nordirplus,
78         Opt_sharecache, Opt_nosharecache,
79         Opt_resvport, Opt_noresvport,
80         Opt_fscache, Opt_nofscache,
81
82         /* Mount options that take integer arguments */
83         Opt_port,
84         Opt_rsize, Opt_wsize, Opt_bsize,
85         Opt_timeo, Opt_retrans,
86         Opt_acregmin, Opt_acregmax,
87         Opt_acdirmin, Opt_acdirmax,
88         Opt_actimeo,
89         Opt_namelen,
90         Opt_mountport,
91         Opt_mountvers,
92         Opt_nfsvers,
93
94         /* Mount options that take string arguments */
95         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
96         Opt_addr, Opt_mountaddr, Opt_clientaddr,
97         Opt_lookupcache,
98         Opt_fscache_uniq,
99
100         /* Special mount options */
101         Opt_userspace, Opt_deprecated, Opt_sloppy,
102
103         Opt_err
104 };
105
106 static const match_table_t nfs_mount_option_tokens = {
107         { Opt_userspace, "bg" },
108         { Opt_userspace, "fg" },
109         { Opt_userspace, "retry=%s" },
110
111         { Opt_sloppy, "sloppy" },
112
113         { Opt_soft, "soft" },
114         { Opt_hard, "hard" },
115         { Opt_deprecated, "intr" },
116         { Opt_deprecated, "nointr" },
117         { Opt_posix, "posix" },
118         { Opt_noposix, "noposix" },
119         { Opt_cto, "cto" },
120         { Opt_nocto, "nocto" },
121         { Opt_ac, "ac" },
122         { Opt_noac, "noac" },
123         { Opt_lock, "lock" },
124         { Opt_nolock, "nolock" },
125         { Opt_v2, "v2" },
126         { Opt_v3, "v3" },
127         { Opt_udp, "udp" },
128         { Opt_tcp, "tcp" },
129         { Opt_rdma, "rdma" },
130         { Opt_acl, "acl" },
131         { Opt_noacl, "noacl" },
132         { Opt_rdirplus, "rdirplus" },
133         { Opt_nordirplus, "nordirplus" },
134         { Opt_sharecache, "sharecache" },
135         { Opt_nosharecache, "nosharecache" },
136         { Opt_resvport, "resvport" },
137         { Opt_noresvport, "noresvport" },
138         { Opt_fscache, "fsc" },
139         { Opt_fscache_uniq, "fsc=%s" },
140         { Opt_nofscache, "nofsc" },
141
142         { Opt_port, "port=%u" },
143         { Opt_rsize, "rsize=%u" },
144         { Opt_wsize, "wsize=%u" },
145         { Opt_bsize, "bsize=%u" },
146         { Opt_timeo, "timeo=%u" },
147         { Opt_retrans, "retrans=%u" },
148         { Opt_acregmin, "acregmin=%u" },
149         { Opt_acregmax, "acregmax=%u" },
150         { Opt_acdirmin, "acdirmin=%u" },
151         { Opt_acdirmax, "acdirmax=%u" },
152         { Opt_actimeo, "actimeo=%u" },
153         { Opt_namelen, "namlen=%u" },
154         { Opt_mountport, "mountport=%u" },
155         { Opt_mountvers, "mountvers=%u" },
156         { Opt_nfsvers, "nfsvers=%u" },
157         { Opt_nfsvers, "vers=%u" },
158
159         { Opt_sec, "sec=%s" },
160         { Opt_proto, "proto=%s" },
161         { Opt_mountproto, "mountproto=%s" },
162         { Opt_addr, "addr=%s" },
163         { Opt_clientaddr, "clientaddr=%s" },
164         { Opt_mounthost, "mounthost=%s" },
165         { Opt_mountaddr, "mountaddr=%s" },
166
167         { Opt_lookupcache, "lookupcache=%s" },
168
169         { Opt_err, NULL }
170 };
171
172 enum {
173         Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
174
175         Opt_xprt_err
176 };
177
178 static const match_table_t nfs_xprt_protocol_tokens = {
179         { Opt_xprt_udp, "udp" },
180         { Opt_xprt_tcp, "tcp" },
181         { Opt_xprt_rdma, "rdma" },
182
183         { Opt_xprt_err, NULL }
184 };
185
186 enum {
187         Opt_sec_none, Opt_sec_sys,
188         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
189         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
190         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
191
192         Opt_sec_err
193 };
194
195 static const match_table_t nfs_secflavor_tokens = {
196         { Opt_sec_none, "none" },
197         { Opt_sec_none, "null" },
198         { Opt_sec_sys, "sys" },
199
200         { Opt_sec_krb5, "krb5" },
201         { Opt_sec_krb5i, "krb5i" },
202         { Opt_sec_krb5p, "krb5p" },
203
204         { Opt_sec_lkey, "lkey" },
205         { Opt_sec_lkeyi, "lkeyi" },
206         { Opt_sec_lkeyp, "lkeyp" },
207
208         { Opt_sec_spkm, "spkm3" },
209         { Opt_sec_spkmi, "spkm3i" },
210         { Opt_sec_spkmp, "spkm3p" },
211
212         { Opt_sec_err, NULL }
213 };
214
215 enum {
216         Opt_lookupcache_all, Opt_lookupcache_positive,
217         Opt_lookupcache_none,
218
219         Opt_lookupcache_err
220 };
221
222 static match_table_t nfs_lookupcache_tokens = {
223         { Opt_lookupcache_all, "all" },
224         { Opt_lookupcache_positive, "pos" },
225         { Opt_lookupcache_positive, "positive" },
226         { Opt_lookupcache_none, "none" },
227
228         { Opt_lookupcache_err, NULL }
229 };
230
231
232 static void nfs_umount_begin(struct super_block *);
233 static int  nfs_statfs(struct dentry *, struct kstatfs *);
234 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
235 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
236 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
237 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
238                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
239 static void nfs_kill_super(struct super_block *);
240 static int nfs_remount(struct super_block *sb, int *flags, char *raw_data);
241
242 static struct file_system_type nfs_fs_type = {
243         .owner          = THIS_MODULE,
244         .name           = "nfs",
245         .get_sb         = nfs_get_sb,
246         .kill_sb        = nfs_kill_super,
247         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
248 };
249
250 struct file_system_type nfs_xdev_fs_type = {
251         .owner          = THIS_MODULE,
252         .name           = "nfs",
253         .get_sb         = nfs_xdev_get_sb,
254         .kill_sb        = nfs_kill_super,
255         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
256 };
257
258 static const struct super_operations nfs_sops = {
259         .alloc_inode    = nfs_alloc_inode,
260         .destroy_inode  = nfs_destroy_inode,
261         .write_inode    = nfs_write_inode,
262         .statfs         = nfs_statfs,
263         .clear_inode    = nfs_clear_inode,
264         .umount_begin   = nfs_umount_begin,
265         .show_options   = nfs_show_options,
266         .show_stats     = nfs_show_stats,
267         .remount_fs     = nfs_remount,
268 };
269
270 #ifdef CONFIG_NFS_V4
271 static int nfs4_get_sb(struct file_system_type *fs_type,
272         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
273 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
274         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
275 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
276         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
277 static void nfs4_kill_super(struct super_block *sb);
278
279 static struct file_system_type nfs4_fs_type = {
280         .owner          = THIS_MODULE,
281         .name           = "nfs4",
282         .get_sb         = nfs4_get_sb,
283         .kill_sb        = nfs4_kill_super,
284         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
285 };
286
287 struct file_system_type nfs4_xdev_fs_type = {
288         .owner          = THIS_MODULE,
289         .name           = "nfs4",
290         .get_sb         = nfs4_xdev_get_sb,
291         .kill_sb        = nfs4_kill_super,
292         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
293 };
294
295 struct file_system_type nfs4_referral_fs_type = {
296         .owner          = THIS_MODULE,
297         .name           = "nfs4",
298         .get_sb         = nfs4_referral_get_sb,
299         .kill_sb        = nfs4_kill_super,
300         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
301 };
302
303 static const struct super_operations nfs4_sops = {
304         .alloc_inode    = nfs_alloc_inode,
305         .destroy_inode  = nfs_destroy_inode,
306         .write_inode    = nfs_write_inode,
307         .statfs         = nfs_statfs,
308         .clear_inode    = nfs4_clear_inode,
309         .umount_begin   = nfs_umount_begin,
310         .show_options   = nfs_show_options,
311         .show_stats     = nfs_show_stats,
312         .remount_fs     = nfs_remount,
313 };
314 #endif
315
316 static struct shrinker acl_shrinker = {
317         .shrink         = nfs_access_cache_shrinker,
318         .seeks          = DEFAULT_SEEKS,
319 };
320
321 /*
322  * Register the NFS filesystems
323  */
324 int __init register_nfs_fs(void)
325 {
326         int ret;
327
328         ret = register_filesystem(&nfs_fs_type);
329         if (ret < 0)
330                 goto error_0;
331
332         ret = nfs_register_sysctl();
333         if (ret < 0)
334                 goto error_1;
335 #ifdef CONFIG_NFS_V4
336         ret = register_filesystem(&nfs4_fs_type);
337         if (ret < 0)
338                 goto error_2;
339 #endif
340         register_shrinker(&acl_shrinker);
341         return 0;
342
343 #ifdef CONFIG_NFS_V4
344 error_2:
345         nfs_unregister_sysctl();
346 #endif
347 error_1:
348         unregister_filesystem(&nfs_fs_type);
349 error_0:
350         return ret;
351 }
352
353 /*
354  * Unregister the NFS filesystems
355  */
356 void __exit unregister_nfs_fs(void)
357 {
358         unregister_shrinker(&acl_shrinker);
359 #ifdef CONFIG_NFS_V4
360         unregister_filesystem(&nfs4_fs_type);
361 #endif
362         nfs_unregister_sysctl();
363         unregister_filesystem(&nfs_fs_type);
364 }
365
366 void nfs_sb_active(struct super_block *sb)
367 {
368         struct nfs_server *server = NFS_SB(sb);
369
370         if (atomic_inc_return(&server->active) == 1)
371                 atomic_inc(&sb->s_active);
372 }
373
374 void nfs_sb_deactive(struct super_block *sb)
375 {
376         struct nfs_server *server = NFS_SB(sb);
377
378         if (atomic_dec_and_test(&server->active))
379                 deactivate_super(sb);
380 }
381
382 /*
383  * Deliver file system statistics to userspace
384  */
385 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
386 {
387         struct nfs_server *server = NFS_SB(dentry->d_sb);
388         unsigned char blockbits;
389         unsigned long blockres;
390         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
391         struct nfs_fattr fattr;
392         struct nfs_fsstat res = {
393                         .fattr = &fattr,
394         };
395         int error;
396
397         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
398         if (error < 0)
399                 goto out_err;
400         buf->f_type = NFS_SUPER_MAGIC;
401
402         /*
403          * Current versions of glibc do not correctly handle the
404          * case where f_frsize != f_bsize.  Eventually we want to
405          * report the value of wtmult in this field.
406          */
407         buf->f_frsize = dentry->d_sb->s_blocksize;
408
409         /*
410          * On most *nix systems, f_blocks, f_bfree, and f_bavail
411          * are reported in units of f_frsize.  Linux hasn't had
412          * an f_frsize field in its statfs struct until recently,
413          * thus historically Linux's sys_statfs reports these
414          * fields in units of f_bsize.
415          */
416         buf->f_bsize = dentry->d_sb->s_blocksize;
417         blockbits = dentry->d_sb->s_blocksize_bits;
418         blockres = (1 << blockbits) - 1;
419         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
420         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
421         buf->f_bavail = (res.abytes + blockres) >> blockbits;
422
423         buf->f_files = res.tfiles;
424         buf->f_ffree = res.afiles;
425
426         buf->f_namelen = server->namelen;
427
428         return 0;
429
430  out_err:
431         dprintk("%s: statfs error = %d\n", __func__, -error);
432         return error;
433 }
434
435 /*
436  * Map the security flavour number to a name
437  */
438 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
439 {
440         static const struct {
441                 rpc_authflavor_t flavour;
442                 const char *str;
443         } sec_flavours[] = {
444                 { RPC_AUTH_NULL, "null" },
445                 { RPC_AUTH_UNIX, "sys" },
446                 { RPC_AUTH_GSS_KRB5, "krb5" },
447                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
448                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
449                 { RPC_AUTH_GSS_LKEY, "lkey" },
450                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
451                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
452                 { RPC_AUTH_GSS_SPKM, "spkm" },
453                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
454                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
455                 { UINT_MAX, "unknown" }
456         };
457         int i;
458
459         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
460                 if (sec_flavours[i].flavour == flavour)
461                         break;
462         }
463         return sec_flavours[i].str;
464 }
465
466 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
467                                     int showdefaults)
468 {
469         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
470
471         switch (sap->sa_family) {
472         case AF_INET: {
473                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
474                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
475                 break;
476         }
477         case AF_INET6: {
478                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
479                 seq_printf(m, ",mountaddr=%pI6", &sin6->sin6_addr);
480                 break;
481         }
482         default:
483                 if (showdefaults)
484                         seq_printf(m, ",mountaddr=unspecified");
485         }
486
487         if (nfss->mountd_version || showdefaults)
488                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
489         if (nfss->mountd_port || showdefaults)
490                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
491
492         switch (nfss->mountd_protocol) {
493         case IPPROTO_UDP:
494                 seq_printf(m, ",mountproto=udp");
495                 break;
496         case IPPROTO_TCP:
497                 seq_printf(m, ",mountproto=tcp");
498                 break;
499         default:
500                 if (showdefaults)
501                         seq_printf(m, ",mountproto=auto");
502         }
503 }
504
505 /*
506  * Describe the mount options in force on this server representation
507  */
508 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
509                                    int showdefaults)
510 {
511         static const struct proc_nfs_info {
512                 int flag;
513                 const char *str;
514                 const char *nostr;
515         } nfs_info[] = {
516                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
517                 { NFS_MOUNT_INTR, ",intr", ",nointr" },
518                 { NFS_MOUNT_POSIX, ",posix", "" },
519                 { NFS_MOUNT_NOCTO, ",nocto", "" },
520                 { NFS_MOUNT_NOAC, ",noac", "" },
521                 { NFS_MOUNT_NONLM, ",nolock", "" },
522                 { NFS_MOUNT_NOACL, ",noacl", "" },
523                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
524                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
525                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
526                 { 0, NULL, NULL }
527         };
528         const struct proc_nfs_info *nfs_infop;
529         struct nfs_client *clp = nfss->nfs_client;
530         u32 version = clp->rpc_ops->version;
531
532         seq_printf(m, ",vers=%u", version);
533         seq_printf(m, ",rsize=%u", nfss->rsize);
534         seq_printf(m, ",wsize=%u", nfss->wsize);
535         if (nfss->bsize != 0)
536                 seq_printf(m, ",bsize=%u", nfss->bsize);
537         seq_printf(m, ",namlen=%u", nfss->namelen);
538         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
539                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
540         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
541                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
542         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
543                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
544         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
545                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
546         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
547                 if (nfss->flags & nfs_infop->flag)
548                         seq_puts(m, nfs_infop->str);
549                 else
550                         seq_puts(m, nfs_infop->nostr);
551         }
552         seq_printf(m, ",proto=%s",
553                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
554         if (version == 4) {
555                 if (nfss->port != NFS_PORT)
556                         seq_printf(m, ",port=%u", nfss->port);
557         } else
558                 if (nfss->port)
559                         seq_printf(m, ",port=%u", nfss->port);
560
561         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
562         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
563         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
564
565         if (version != 4)
566                 nfs_show_mountd_options(m, nfss, showdefaults);
567
568 #ifdef CONFIG_NFS_V4
569         if (clp->rpc_ops->version == 4)
570                 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
571 #endif
572         if (nfss->options & NFS_OPTION_FSCACHE)
573                 seq_printf(m, ",fsc");
574 }
575
576 /*
577  * Describe the mount options on this VFS mountpoint
578  */
579 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
580 {
581         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
582
583         nfs_show_mount_options(m, nfss, 0);
584
585         seq_printf(m, ",addr=%s",
586                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
587                                                         RPC_DISPLAY_ADDR));
588
589         return 0;
590 }
591
592 /*
593  * Present statistical information for this VFS mountpoint
594  */
595 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
596 {
597         int i, cpu;
598         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
599         struct rpc_auth *auth = nfss->client->cl_auth;
600         struct nfs_iostats totals = { };
601
602         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
603
604         /*
605          * Display all mount option settings
606          */
607         seq_printf(m, "\n\topts:\t");
608         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
609         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
610         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
611         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
612         nfs_show_mount_options(m, nfss, 1);
613
614         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
615
616         seq_printf(m, "\n\tcaps:\t");
617         seq_printf(m, "caps=0x%x", nfss->caps);
618         seq_printf(m, ",wtmult=%u", nfss->wtmult);
619         seq_printf(m, ",dtsize=%u", nfss->dtsize);
620         seq_printf(m, ",bsize=%u", nfss->bsize);
621         seq_printf(m, ",namlen=%u", nfss->namelen);
622
623 #ifdef CONFIG_NFS_V4
624         if (nfss->nfs_client->rpc_ops->version == 4) {
625                 seq_printf(m, "\n\tnfsv4:\t");
626                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
627                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
628                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
629         }
630 #endif
631
632         /*
633          * Display security flavor in effect for this mount
634          */
635         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
636         if (auth->au_flavor)
637                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
638
639         /*
640          * Display superblock I/O counters
641          */
642         for_each_possible_cpu(cpu) {
643                 struct nfs_iostats *stats;
644
645                 preempt_disable();
646                 stats = per_cpu_ptr(nfss->io_stats, cpu);
647
648                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
649                         totals.events[i] += stats->events[i];
650                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
651                         totals.bytes[i] += stats->bytes[i];
652 #ifdef CONFIG_NFS_FSCACHE
653                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
654                         totals.fscache[i] += stats->fscache[i];
655 #endif
656
657                 preempt_enable();
658         }
659
660         seq_printf(m, "\n\tevents:\t");
661         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
662                 seq_printf(m, "%lu ", totals.events[i]);
663         seq_printf(m, "\n\tbytes:\t");
664         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
665                 seq_printf(m, "%Lu ", totals.bytes[i]);
666 #ifdef CONFIG_NFS_FSCACHE
667         if (nfss->options & NFS_OPTION_FSCACHE) {
668                 seq_printf(m, "\n\tfsc:\t");
669                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
670                         seq_printf(m, "%Lu ", totals.bytes[i]);
671         }
672 #endif
673         seq_printf(m, "\n");
674
675         rpc_print_iostats(m, nfss->client);
676
677         return 0;
678 }
679
680 /*
681  * Begin unmount by attempting to remove all automounted mountpoints we added
682  * in response to xdev traversals and referrals
683  */
684 static void nfs_umount_begin(struct super_block *sb)
685 {
686         struct nfs_server *server;
687         struct rpc_clnt *rpc;
688
689         lock_kernel();
690
691         server = NFS_SB(sb);
692         /* -EIO all pending I/O */
693         rpc = server->client_acl;
694         if (!IS_ERR(rpc))
695                 rpc_killall_tasks(rpc);
696         rpc = server->client;
697         if (!IS_ERR(rpc))
698                 rpc_killall_tasks(rpc);
699
700         unlock_kernel();
701 }
702
703 /*
704  * Sanity-check a server address provided by the mount command.
705  *
706  * Address family must be initialized, and address must not be
707  * the ANY address for that family.
708  */
709 static int nfs_verify_server_address(struct sockaddr *addr)
710 {
711         switch (addr->sa_family) {
712         case AF_INET: {
713                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
714                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
715         }
716         case AF_INET6: {
717                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
718                 return !ipv6_addr_any(sa);
719         }
720         }
721
722         return 0;
723 }
724
725 static void nfs_parse_ipv4_address(char *string, size_t str_len,
726                                    struct sockaddr *sap, size_t *addr_len)
727 {
728         struct sockaddr_in *sin = (struct sockaddr_in *)sap;
729         u8 *addr = (u8 *)&sin->sin_addr.s_addr;
730
731         if (str_len <= INET_ADDRSTRLEN) {
732                 dfprintk(MOUNT, "NFS: parsing IPv4 address %*s\n",
733                                 (int)str_len, string);
734
735                 sin->sin_family = AF_INET;
736                 *addr_len = sizeof(*sin);
737                 if (in4_pton(string, str_len, addr, '\0', NULL))
738                         return;
739         }
740
741         sap->sa_family = AF_UNSPEC;
742         *addr_len = 0;
743 }
744
745 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
746 static int nfs_parse_ipv6_scope_id(const char *string, const size_t str_len,
747                                    const char *delim,
748                                    struct sockaddr_in6 *sin6)
749 {
750         char *p;
751         size_t len;
752
753         if ((string + str_len) == delim)
754                 return 1;
755
756         if (*delim != IPV6_SCOPE_DELIMITER)
757                 return 0;
758
759         if (!(ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL))
760                 return 0;
761
762         len = (string + str_len) - delim - 1;
763         p = kstrndup(delim + 1, len, GFP_KERNEL);
764         if (p) {
765                 unsigned long scope_id = 0;
766                 struct net_device *dev;
767
768                 dev = dev_get_by_name(&init_net, p);
769                 if (dev != NULL) {
770                         scope_id = dev->ifindex;
771                         dev_put(dev);
772                 } else {
773                         if (strict_strtoul(p, 10, &scope_id) == 0) {
774                                 kfree(p);
775                                 return 0;
776                         }
777                 }
778
779                 kfree(p);
780
781                 sin6->sin6_scope_id = scope_id;
782                 dfprintk(MOUNT, "NFS: IPv6 scope ID = %lu\n", scope_id);
783                 return 1;
784         }
785
786         return 0;
787 }
788
789 static void nfs_parse_ipv6_address(char *string, size_t str_len,
790                                    struct sockaddr *sap, size_t *addr_len)
791 {
792         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
793         u8 *addr = (u8 *)&sin6->sin6_addr.in6_u;
794         const char *delim;
795
796         if (str_len <= INET6_ADDRSTRLEN) {
797                 dfprintk(MOUNT, "NFS: parsing IPv6 address %*s\n",
798                                 (int)str_len, string);
799
800                 sin6->sin6_family = AF_INET6;
801                 *addr_len = sizeof(*sin6);
802                 if (in6_pton(string, str_len, addr,
803                                         IPV6_SCOPE_DELIMITER, &delim) != 0) {
804                         if (nfs_parse_ipv6_scope_id(string, str_len,
805                                                         delim, sin6) != 0)
806                                 return;
807                 }
808         }
809
810         sap->sa_family = AF_UNSPEC;
811         *addr_len = 0;
812 }
813 #else
814 static void nfs_parse_ipv6_address(char *string, size_t str_len,
815                                    struct sockaddr *sap, size_t *addr_len)
816 {
817         sap->sa_family = AF_UNSPEC;
818         *addr_len = 0;
819 }
820 #endif
821
822 /*
823  * Construct a sockaddr based on the contents of a string that contains
824  * an IP address in presentation format.
825  *
826  * If there is a problem constructing the new sockaddr, set the address
827  * family to AF_UNSPEC.
828  */
829 void nfs_parse_ip_address(char *string, size_t str_len,
830                                  struct sockaddr *sap, size_t *addr_len)
831 {
832         unsigned int i, colons;
833
834         colons = 0;
835         for (i = 0; i < str_len; i++)
836                 if (string[i] == ':')
837                         colons++;
838
839         if (colons >= 2)
840                 nfs_parse_ipv6_address(string, str_len, sap, addr_len);
841         else
842                 nfs_parse_ipv4_address(string, str_len, sap, addr_len);
843 }
844
845 /*
846  * Sanity check the NFS transport protocol.
847  *
848  */
849 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
850 {
851         switch (mnt->nfs_server.protocol) {
852         case XPRT_TRANSPORT_UDP:
853         case XPRT_TRANSPORT_TCP:
854         case XPRT_TRANSPORT_RDMA:
855                 break;
856         default:
857                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
858         }
859 }
860
861 /*
862  * For text based NFSv2/v3 mounts, the mount protocol transport default
863  * settings should depend upon the specified NFS transport.
864  */
865 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
866 {
867         nfs_validate_transport_protocol(mnt);
868
869         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
870             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
871                         return;
872         switch (mnt->nfs_server.protocol) {
873         case XPRT_TRANSPORT_UDP:
874                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
875                 break;
876         case XPRT_TRANSPORT_TCP:
877         case XPRT_TRANSPORT_RDMA:
878                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
879         }
880 }
881
882 /*
883  * Parse the value of the 'sec=' option.
884  *
885  * The flavor_len setting is for v4 mounts.
886  */
887 static int nfs_parse_security_flavors(char *value,
888                                       struct nfs_parsed_mount_data *mnt)
889 {
890         substring_t args[MAX_OPT_ARGS];
891
892         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
893
894         switch (match_token(value, nfs_secflavor_tokens, args)) {
895         case Opt_sec_none:
896                 mnt->auth_flavor_len = 0;
897                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
898                 break;
899         case Opt_sec_sys:
900                 mnt->auth_flavor_len = 0;
901                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
902                 break;
903         case Opt_sec_krb5:
904                 mnt->auth_flavor_len = 1;
905                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
906                 break;
907         case Opt_sec_krb5i:
908                 mnt->auth_flavor_len = 1;
909                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
910                 break;
911         case Opt_sec_krb5p:
912                 mnt->auth_flavor_len = 1;
913                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
914                 break;
915         case Opt_sec_lkey:
916                 mnt->auth_flavor_len = 1;
917                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
918                 break;
919         case Opt_sec_lkeyi:
920                 mnt->auth_flavor_len = 1;
921                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
922                 break;
923         case Opt_sec_lkeyp:
924                 mnt->auth_flavor_len = 1;
925                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
926                 break;
927         case Opt_sec_spkm:
928                 mnt->auth_flavor_len = 1;
929                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
930                 break;
931         case Opt_sec_spkmi:
932                 mnt->auth_flavor_len = 1;
933                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
934                 break;
935         case Opt_sec_spkmp:
936                 mnt->auth_flavor_len = 1;
937                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
938                 break;
939         default:
940                 return 0;
941         }
942
943         return 1;
944 }
945
946 static void nfs_parse_invalid_value(const char *option)
947 {
948         dfprintk(MOUNT, "NFS:   bad value specified for %s option\n", option);
949 }
950
951 /*
952  * Error-check and convert a string of mount options from user space into
953  * a data structure.  The whole mount string is processed; bad options are
954  * skipped as they are encountered.  If there were no errors, return 1;
955  * otherwise return 0 (zero).
956  */
957 static int nfs_parse_mount_options(char *raw,
958                                    struct nfs_parsed_mount_data *mnt)
959 {
960         char *p, *string, *secdata;
961         int rc, sloppy = 0, errors = 0;
962
963         if (!raw) {
964                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
965                 return 1;
966         }
967         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
968
969         secdata = alloc_secdata();
970         if (!secdata)
971                 goto out_nomem;
972
973         rc = security_sb_copy_data(raw, secdata);
974         if (rc)
975                 goto out_security_failure;
976
977         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
978         if (rc)
979                 goto out_security_failure;
980
981         free_secdata(secdata);
982
983         while ((p = strsep(&raw, ",")) != NULL) {
984                 substring_t args[MAX_OPT_ARGS];
985                 int option, token;
986
987                 if (!*p)
988                         continue;
989
990                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
991
992                 token = match_token(p, nfs_mount_option_tokens, args);
993                 switch (token) {
994
995                 /*
996                  * boolean options:  foo/nofoo
997                  */
998                 case Opt_soft:
999                         mnt->flags |= NFS_MOUNT_SOFT;
1000                         break;
1001                 case Opt_hard:
1002                         mnt->flags &= ~NFS_MOUNT_SOFT;
1003                         break;
1004                 case Opt_posix:
1005                         mnt->flags |= NFS_MOUNT_POSIX;
1006                         break;
1007                 case Opt_noposix:
1008                         mnt->flags &= ~NFS_MOUNT_POSIX;
1009                         break;
1010                 case Opt_cto:
1011                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1012                         break;
1013                 case Opt_nocto:
1014                         mnt->flags |= NFS_MOUNT_NOCTO;
1015                         break;
1016                 case Opt_ac:
1017                         mnt->flags &= ~NFS_MOUNT_NOAC;
1018                         break;
1019                 case Opt_noac:
1020                         mnt->flags |= NFS_MOUNT_NOAC;
1021                         break;
1022                 case Opt_lock:
1023                         mnt->flags &= ~NFS_MOUNT_NONLM;
1024                         break;
1025                 case Opt_nolock:
1026                         mnt->flags |= NFS_MOUNT_NONLM;
1027                         break;
1028                 case Opt_v2:
1029                         mnt->flags &= ~NFS_MOUNT_VER3;
1030                         break;
1031                 case Opt_v3:
1032                         mnt->flags |= NFS_MOUNT_VER3;
1033                         break;
1034                 case Opt_udp:
1035                         mnt->flags &= ~NFS_MOUNT_TCP;
1036                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1037                         break;
1038                 case Opt_tcp:
1039                         mnt->flags |= NFS_MOUNT_TCP;
1040                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1041                         break;
1042                 case Opt_rdma:
1043                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1044                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1045                         xprt_load_transport(p);
1046                         break;
1047                 case Opt_acl:
1048                         mnt->flags &= ~NFS_MOUNT_NOACL;
1049                         break;
1050                 case Opt_noacl:
1051                         mnt->flags |= NFS_MOUNT_NOACL;
1052                         break;
1053                 case Opt_rdirplus:
1054                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1055                         break;
1056                 case Opt_nordirplus:
1057                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1058                         break;
1059                 case Opt_sharecache:
1060                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1061                         break;
1062                 case Opt_nosharecache:
1063                         mnt->flags |= NFS_MOUNT_UNSHARED;
1064                         break;
1065                 case Opt_resvport:
1066                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1067                         break;
1068                 case Opt_noresvport:
1069                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1070                         break;
1071                 case Opt_fscache:
1072                         mnt->options |= NFS_OPTION_FSCACHE;
1073                         kfree(mnt->fscache_uniq);
1074                         mnt->fscache_uniq = NULL;
1075                         break;
1076                 case Opt_nofscache:
1077                         mnt->options &= ~NFS_OPTION_FSCACHE;
1078                         kfree(mnt->fscache_uniq);
1079                         mnt->fscache_uniq = NULL;
1080                         break;
1081                 case Opt_fscache_uniq:
1082                         string = match_strdup(args);
1083                         if (!string)
1084                                 goto out_nomem;
1085                         kfree(mnt->fscache_uniq);
1086                         mnt->fscache_uniq = string;
1087                         mnt->options |= NFS_OPTION_FSCACHE;
1088                         break;
1089
1090                 /*
1091                  * options that take numeric values
1092                  */
1093                 case Opt_port:
1094                         if (match_int(args, &option) ||
1095                             option < 0 || option > USHORT_MAX) {
1096                                 errors++;
1097                                 nfs_parse_invalid_value("port");
1098                         } else
1099                                 mnt->nfs_server.port = option;
1100                         break;
1101                 case Opt_rsize:
1102                         if (match_int(args, &option) || option < 0) {
1103                                 errors++;
1104                                 nfs_parse_invalid_value("rsize");
1105                         } else
1106                                 mnt->rsize = option;
1107                         break;
1108                 case Opt_wsize:
1109                         if (match_int(args, &option) || option < 0) {
1110                                 errors++;
1111                                 nfs_parse_invalid_value("wsize");
1112                         } else
1113                                 mnt->wsize = option;
1114                         break;
1115                 case Opt_bsize:
1116                         if (match_int(args, &option) || option < 0) {
1117                                 errors++;
1118                                 nfs_parse_invalid_value("bsize");
1119                         } else
1120                                 mnt->bsize = option;
1121                         break;
1122                 case Opt_timeo:
1123                         if (match_int(args, &option) || option <= 0) {
1124                                 errors++;
1125                                 nfs_parse_invalid_value("timeo");
1126                         } else
1127                                 mnt->timeo = option;
1128                         break;
1129                 case Opt_retrans:
1130                         if (match_int(args, &option) || option <= 0) {
1131                                 errors++;
1132                                 nfs_parse_invalid_value("retrans");
1133                         } else
1134                                 mnt->retrans = option;
1135                         break;
1136                 case Opt_acregmin:
1137                         if (match_int(args, &option) || option < 0) {
1138                                 errors++;
1139                                 nfs_parse_invalid_value("acregmin");
1140                         } else
1141                                 mnt->acregmin = option;
1142                         break;
1143                 case Opt_acregmax:
1144                         if (match_int(args, &option) || option < 0) {
1145                                 errors++;
1146                                 nfs_parse_invalid_value("acregmax");
1147                         } else
1148                                 mnt->acregmax = option;
1149                         break;
1150                 case Opt_acdirmin:
1151                         if (match_int(args, &option) || option < 0) {
1152                                 errors++;
1153                                 nfs_parse_invalid_value("acdirmin");
1154                         } else
1155                                 mnt->acdirmin = option;
1156                         break;
1157                 case Opt_acdirmax:
1158                         if (match_int(args, &option) || option < 0) {
1159                                 errors++;
1160                                 nfs_parse_invalid_value("acdirmax");
1161                         } else
1162                                 mnt->acdirmax = option;
1163                         break;
1164                 case Opt_actimeo:
1165                         if (match_int(args, &option) || option < 0) {
1166                                 errors++;
1167                                 nfs_parse_invalid_value("actimeo");
1168                         } else
1169                                 mnt->acregmin = mnt->acregmax =
1170                                 mnt->acdirmin = mnt->acdirmax = option;
1171                         break;
1172                 case Opt_namelen:
1173                         if (match_int(args, &option) || option < 0) {
1174                                 errors++;
1175                                 nfs_parse_invalid_value("namlen");
1176                         } else
1177                                 mnt->namlen = option;
1178                         break;
1179                 case Opt_mountport:
1180                         if (match_int(args, &option) ||
1181                             option < 0 || option > USHORT_MAX) {
1182                                 errors++;
1183                                 nfs_parse_invalid_value("mountport");
1184                         } else
1185                                 mnt->mount_server.port = option;
1186                         break;
1187                 case Opt_mountvers:
1188                         if (match_int(args, &option) ||
1189                             option < NFS_MNT_VERSION ||
1190                             option > NFS_MNT3_VERSION) {
1191                                 errors++;
1192                                 nfs_parse_invalid_value("mountvers");
1193                         } else
1194                                 mnt->mount_server.version = option;
1195                         break;
1196                 case Opt_nfsvers:
1197                         if (match_int(args, &option)) {
1198                                 errors++;
1199                                 nfs_parse_invalid_value("nfsvers");
1200                                 break;
1201                         }
1202                         switch (option) {
1203                         case NFS2_VERSION:
1204                                 mnt->flags &= ~NFS_MOUNT_VER3;
1205                                 break;
1206                         case NFS3_VERSION:
1207                                 mnt->flags |= NFS_MOUNT_VER3;
1208                                 break;
1209                         default:
1210                                 errors++;
1211                                 nfs_parse_invalid_value("nfsvers");
1212                         }
1213                         break;
1214
1215                 /*
1216                  * options that take text values
1217                  */
1218                 case Opt_sec:
1219                         string = match_strdup(args);
1220                         if (string == NULL)
1221                                 goto out_nomem;
1222                         rc = nfs_parse_security_flavors(string, mnt);
1223                         kfree(string);
1224                         if (!rc) {
1225                                 errors++;
1226                                 dfprintk(MOUNT, "NFS:   unrecognized "
1227                                                 "security flavor\n");
1228                         }
1229                         break;
1230                 case Opt_proto:
1231                         string = match_strdup(args);
1232                         if (string == NULL)
1233                                 goto out_nomem;
1234                         token = match_token(string,
1235                                             nfs_xprt_protocol_tokens, args);
1236
1237                         switch (token) {
1238                         case Opt_xprt_udp:
1239                                 mnt->flags &= ~NFS_MOUNT_TCP;
1240                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1241                                 break;
1242                         case Opt_xprt_tcp:
1243                                 mnt->flags |= NFS_MOUNT_TCP;
1244                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1245                                 break;
1246                         case Opt_xprt_rdma:
1247                                 /* vector side protocols to TCP */
1248                                 mnt->flags |= NFS_MOUNT_TCP;
1249                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1250                                 xprt_load_transport(string);
1251                                 break;
1252                         default:
1253                                 errors++;
1254                                 dfprintk(MOUNT, "NFS:   unrecognized "
1255                                                 "transport protocol\n");
1256                         }
1257                         kfree(string);
1258                         break;
1259                 case Opt_mountproto:
1260                         string = match_strdup(args);
1261                         if (string == NULL)
1262                                 goto out_nomem;
1263                         token = match_token(string,
1264                                             nfs_xprt_protocol_tokens, args);
1265                         kfree(string);
1266
1267                         switch (token) {
1268                         case Opt_xprt_udp:
1269                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1270                                 break;
1271                         case Opt_xprt_tcp:
1272                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1273                                 break;
1274                         case Opt_xprt_rdma: /* not used for side protocols */
1275                         default:
1276                                 errors++;
1277                                 dfprintk(MOUNT, "NFS:   unrecognized "
1278                                                 "transport protocol\n");
1279                         }
1280                         break;
1281                 case Opt_addr:
1282                         string = match_strdup(args);
1283                         if (string == NULL)
1284                                 goto out_nomem;
1285                         nfs_parse_ip_address(string, strlen(string),
1286                                              (struct sockaddr *)
1287                                                 &mnt->nfs_server.address,
1288                                              &mnt->nfs_server.addrlen);
1289                         kfree(string);
1290                         break;
1291                 case Opt_clientaddr:
1292                         string = match_strdup(args);
1293                         if (string == NULL)
1294                                 goto out_nomem;
1295                         kfree(mnt->client_address);
1296                         mnt->client_address = string;
1297                         break;
1298                 case Opt_mounthost:
1299                         string = match_strdup(args);
1300                         if (string == NULL)
1301                                 goto out_nomem;
1302                         kfree(mnt->mount_server.hostname);
1303                         mnt->mount_server.hostname = string;
1304                         break;
1305                 case Opt_mountaddr:
1306                         string = match_strdup(args);
1307                         if (string == NULL)
1308                                 goto out_nomem;
1309                         nfs_parse_ip_address(string, strlen(string),
1310                                              (struct sockaddr *)
1311                                                 &mnt->mount_server.address,
1312                                              &mnt->mount_server.addrlen);
1313                         kfree(string);
1314                         break;
1315                 case Opt_lookupcache:
1316                         string = match_strdup(args);
1317                         if (string == NULL)
1318                                 goto out_nomem;
1319                         token = match_token(string,
1320                                         nfs_lookupcache_tokens, args);
1321                         kfree(string);
1322                         switch (token) {
1323                                 case Opt_lookupcache_all:
1324                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1325                                         break;
1326                                 case Opt_lookupcache_positive:
1327                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1328                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1329                                         break;
1330                                 case Opt_lookupcache_none:
1331                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1332                                         break;
1333                                 default:
1334                                         errors++;
1335                                         dfprintk(MOUNT, "NFS:   invalid "
1336                                                         "lookupcache argument\n");
1337                         };
1338                         break;
1339
1340                 /*
1341                  * Special options
1342                  */
1343                 case Opt_sloppy:
1344                         sloppy = 1;
1345                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1346                         break;
1347                 case Opt_userspace:
1348                 case Opt_deprecated:
1349                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1350                                         "'%s'\n", p);
1351                         break;
1352
1353                 default:
1354                         errors++;
1355                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1356                                         "'%s'\n", p);
1357                 }
1358         }
1359
1360         if (errors > 0) {
1361                 dfprintk(MOUNT, "NFS: parsing encountered %d error%s\n",
1362                                 errors, (errors == 1 ? "" : "s"));
1363                 if (!sloppy)
1364                         return 0;
1365         }
1366         return 1;
1367
1368 out_nomem:
1369         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1370         return 0;
1371 out_security_failure:
1372         free_secdata(secdata);
1373         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1374         return 0;
1375 }
1376
1377 /*
1378  * Use the remote server's MOUNT service to request the NFS file handle
1379  * corresponding to the provided path.
1380  */
1381 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1382                          struct nfs_fh *root_fh)
1383 {
1384         struct nfs_mount_request request = {
1385                 .sap            = (struct sockaddr *)
1386                                                 &args->mount_server.address,
1387                 .dirpath        = args->nfs_server.export_path,
1388                 .protocol       = args->mount_server.protocol,
1389                 .fh             = root_fh,
1390                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1391         };
1392         int status;
1393
1394         if (args->mount_server.version == 0) {
1395                 if (args->flags & NFS_MOUNT_VER3)
1396                         args->mount_server.version = NFS_MNT3_VERSION;
1397                 else
1398                         args->mount_server.version = NFS_MNT_VERSION;
1399         }
1400         request.version = args->mount_server.version;
1401
1402         if (args->mount_server.hostname)
1403                 request.hostname = args->mount_server.hostname;
1404         else
1405                 request.hostname = args->nfs_server.hostname;
1406
1407         /*
1408          * Construct the mount server's address.
1409          */
1410         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1411                 memcpy(request.sap, &args->nfs_server.address,
1412                        args->nfs_server.addrlen);
1413                 args->mount_server.addrlen = args->nfs_server.addrlen;
1414         }
1415         request.salen = args->mount_server.addrlen;
1416
1417         /*
1418          * autobind will be used if mount_server.port == 0
1419          */
1420         nfs_set_port(request.sap, args->mount_server.port);
1421
1422         /*
1423          * Now ask the mount server to map our export path
1424          * to a file handle.
1425          */
1426         status = nfs_mount(&request);
1427         if (status == 0)
1428                 return 0;
1429
1430         dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1431                         request.hostname, status);
1432         return status;
1433 }
1434
1435 static int nfs_parse_simple_hostname(const char *dev_name,
1436                                      char **hostname, size_t maxnamlen,
1437                                      char **export_path, size_t maxpathlen)
1438 {
1439         size_t len;
1440         char *colon, *comma;
1441
1442         colon = strchr(dev_name, ':');
1443         if (colon == NULL)
1444                 goto out_bad_devname;
1445
1446         len = colon - dev_name;
1447         if (len > maxnamlen)
1448                 goto out_hostname;
1449
1450         /* N.B. caller will free nfs_server.hostname in all cases */
1451         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1452         if (!*hostname)
1453                 goto out_nomem;
1454
1455         /* kill possible hostname list: not supported */
1456         comma = strchr(*hostname, ',');
1457         if (comma != NULL) {
1458                 if (comma == *hostname)
1459                         goto out_bad_devname;
1460                 *comma = '\0';
1461         }
1462
1463         colon++;
1464         len = strlen(colon);
1465         if (len > maxpathlen)
1466                 goto out_path;
1467         *export_path = kstrndup(colon, len, GFP_KERNEL);
1468         if (!*export_path)
1469                 goto out_nomem;
1470
1471         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1472         return 0;
1473
1474 out_bad_devname:
1475         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1476         return -EINVAL;
1477
1478 out_nomem:
1479         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1480         return -ENOMEM;
1481
1482 out_hostname:
1483         dfprintk(MOUNT, "NFS: server hostname too long\n");
1484         return -ENAMETOOLONG;
1485
1486 out_path:
1487         dfprintk(MOUNT, "NFS: export pathname too long\n");
1488         return -ENAMETOOLONG;
1489 }
1490
1491 /*
1492  * Hostname has square brackets around it because it contains one or
1493  * more colons.  We look for the first closing square bracket, and a
1494  * colon must follow it.
1495  */
1496 static int nfs_parse_protected_hostname(const char *dev_name,
1497                                         char **hostname, size_t maxnamlen,
1498                                         char **export_path, size_t maxpathlen)
1499 {
1500         size_t len;
1501         char *start, *end;
1502
1503         start = (char *)(dev_name + 1);
1504
1505         end = strchr(start, ']');
1506         if (end == NULL)
1507                 goto out_bad_devname;
1508         if (*(end + 1) != ':')
1509                 goto out_bad_devname;
1510
1511         len = end - start;
1512         if (len > maxnamlen)
1513                 goto out_hostname;
1514
1515         /* N.B. caller will free nfs_server.hostname in all cases */
1516         *hostname = kstrndup(start, len, GFP_KERNEL);
1517         if (*hostname == NULL)
1518                 goto out_nomem;
1519
1520         end += 2;
1521         len = strlen(end);
1522         if (len > maxpathlen)
1523                 goto out_path;
1524         *export_path = kstrndup(end, len, GFP_KERNEL);
1525         if (!*export_path)
1526                 goto out_nomem;
1527
1528         return 0;
1529
1530 out_bad_devname:
1531         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1532         return -EINVAL;
1533
1534 out_nomem:
1535         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1536         return -ENOMEM;
1537
1538 out_hostname:
1539         dfprintk(MOUNT, "NFS: server hostname too long\n");
1540         return -ENAMETOOLONG;
1541
1542 out_path:
1543         dfprintk(MOUNT, "NFS: export pathname too long\n");
1544         return -ENAMETOOLONG;
1545 }
1546
1547 /*
1548  * Split "dev_name" into "hostname:export_path".
1549  *
1550  * The leftmost colon demarks the split between the server's hostname
1551  * and the export path.  If the hostname starts with a left square
1552  * bracket, then it may contain colons.
1553  *
1554  * Note: caller frees hostname and export path, even on error.
1555  */
1556 static int nfs_parse_devname(const char *dev_name,
1557                              char **hostname, size_t maxnamlen,
1558                              char **export_path, size_t maxpathlen)
1559 {
1560         if (*dev_name == '[')
1561                 return nfs_parse_protected_hostname(dev_name,
1562                                                     hostname, maxnamlen,
1563                                                     export_path, maxpathlen);
1564
1565         return nfs_parse_simple_hostname(dev_name,
1566                                          hostname, maxnamlen,
1567                                          export_path, maxpathlen);
1568 }
1569
1570 /*
1571  * Validate the NFS2/NFS3 mount data
1572  * - fills in the mount root filehandle
1573  *
1574  * For option strings, user space handles the following behaviors:
1575  *
1576  * + DNS: mapping server host name to IP address ("addr=" option)
1577  *
1578  * + failure mode: how to behave if a mount request can't be handled
1579  *   immediately ("fg/bg" option)
1580  *
1581  * + retry: how often to retry a mount request ("retry=" option)
1582  *
1583  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1584  *   mountproto=tcp after mountproto=udp, and so on
1585  */
1586 static int nfs_validate_mount_data(void *options,
1587                                    struct nfs_parsed_mount_data *args,
1588                                    struct nfs_fh *mntfh,
1589                                    const char *dev_name)
1590 {
1591         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1592
1593         if (data == NULL)
1594                 goto out_no_data;
1595
1596         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1597         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1598         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1599         args->acregmin          = NFS_DEF_ACREGMIN;
1600         args->acregmax          = NFS_DEF_ACREGMAX;
1601         args->acdirmin          = NFS_DEF_ACDIRMIN;
1602         args->acdirmax          = NFS_DEF_ACDIRMAX;
1603         args->mount_server.port = 0;    /* autobind unless user sets port */
1604         args->nfs_server.port   = 0;    /* autobind unless user sets port */
1605         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1606         args->auth_flavors[0]   = RPC_AUTH_UNIX;
1607
1608         switch (data->version) {
1609         case 1:
1610                 data->namlen = 0;
1611         case 2:
1612                 data->bsize = 0;
1613         case 3:
1614                 if (data->flags & NFS_MOUNT_VER3)
1615                         goto out_no_v3;
1616                 data->root.size = NFS2_FHSIZE;
1617                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1618         case 4:
1619                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1620                         goto out_no_sec;
1621         case 5:
1622                 memset(data->context, 0, sizeof(data->context));
1623         case 6:
1624                 if (data->flags & NFS_MOUNT_VER3) {
1625                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1626                                 goto out_invalid_fh;
1627                         mntfh->size = data->root.size;
1628                 } else
1629                         mntfh->size = NFS2_FHSIZE;
1630
1631
1632                 memcpy(mntfh->data, data->root.data, mntfh->size);
1633                 if (mntfh->size < sizeof(mntfh->data))
1634                         memset(mntfh->data + mntfh->size, 0,
1635                                sizeof(mntfh->data) - mntfh->size);
1636
1637                 /*
1638                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1639                  * can deal with.
1640                  */
1641                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
1642                 args->rsize             = data->rsize;
1643                 args->wsize             = data->wsize;
1644                 args->timeo             = data->timeo;
1645                 args->retrans           = data->retrans;
1646                 args->acregmin          = data->acregmin;
1647                 args->acregmax          = data->acregmax;
1648                 args->acdirmin          = data->acdirmin;
1649                 args->acdirmax          = data->acdirmax;
1650
1651                 memcpy(&args->nfs_server.address, &data->addr,
1652                        sizeof(data->addr));
1653                 args->nfs_server.addrlen = sizeof(data->addr);
1654                 if (!nfs_verify_server_address((struct sockaddr *)
1655                                                 &args->nfs_server.address))
1656                         goto out_no_address;
1657
1658                 if (!(data->flags & NFS_MOUNT_TCP))
1659                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1660                 /* N.B. caller will free nfs_server.hostname in all cases */
1661                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1662                 args->namlen            = data->namlen;
1663                 args->bsize             = data->bsize;
1664
1665                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1666                         args->auth_flavors[0] = data->pseudoflavor;
1667                 if (!args->nfs_server.hostname)
1668                         goto out_nomem;
1669
1670                 /*
1671                  * The legacy version 6 binary mount data from userspace has a
1672                  * field used only to transport selinux information into the
1673                  * the kernel.  To continue to support that functionality we
1674                  * have a touch of selinux knowledge here in the NFS code. The
1675                  * userspace code converted context=blah to just blah so we are
1676                  * converting back to the full string selinux understands.
1677                  */
1678                 if (data->context[0]){
1679 #ifdef CONFIG_SECURITY_SELINUX
1680                         int rc;
1681                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1682                         if (!opts_str)
1683                                 return -ENOMEM;
1684                         strcpy(opts_str, "context=");
1685                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1686                         strcat(opts_str, &data->context[0]);
1687                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1688                         kfree(opts_str);
1689                         if (rc)
1690                                 return rc;
1691 #else
1692                         return -EINVAL;
1693 #endif
1694                 }
1695
1696                 break;
1697         default: {
1698                 int status;
1699
1700                 if (nfs_parse_mount_options((char *)options, args) == 0)
1701                         return -EINVAL;
1702
1703                 if (!nfs_verify_server_address((struct sockaddr *)
1704                                                 &args->nfs_server.address))
1705                         goto out_no_address;
1706
1707                 nfs_set_port((struct sockaddr *)&args->nfs_server.address,
1708                                 args->nfs_server.port);
1709
1710                 nfs_set_mount_transport_protocol(args);
1711
1712                 status = nfs_parse_devname(dev_name,
1713                                            &args->nfs_server.hostname,
1714                                            PAGE_SIZE,
1715                                            &args->nfs_server.export_path,
1716                                            NFS_MAXPATHLEN);
1717                 if (!status)
1718                         status = nfs_try_mount(args, mntfh);
1719
1720                 kfree(args->nfs_server.export_path);
1721                 args->nfs_server.export_path = NULL;
1722
1723                 if (status)
1724                         return status;
1725
1726                 break;
1727                 }
1728         }
1729
1730 #ifndef CONFIG_NFS_V3
1731         if (args->flags & NFS_MOUNT_VER3)
1732                 goto out_v3_not_compiled;
1733 #endif /* !CONFIG_NFS_V3 */
1734
1735         return 0;
1736
1737 out_no_data:
1738         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1739         return -EINVAL;
1740
1741 out_no_v3:
1742         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1743                  data->version);
1744         return -EINVAL;
1745
1746 out_no_sec:
1747         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1748         return -EINVAL;
1749
1750 #ifndef CONFIG_NFS_V3
1751 out_v3_not_compiled:
1752         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1753         return -EPROTONOSUPPORT;
1754 #endif /* !CONFIG_NFS_V3 */
1755
1756 out_nomem:
1757         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
1758         return -ENOMEM;
1759
1760 out_no_address:
1761         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1762         return -EINVAL;
1763
1764 out_invalid_fh:
1765         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1766         return -EINVAL;
1767 }
1768
1769 static int
1770 nfs_compare_remount_data(struct nfs_server *nfss,
1771                          struct nfs_parsed_mount_data *data)
1772 {
1773         if (data->flags != nfss->flags ||
1774             data->rsize != nfss->rsize ||
1775             data->wsize != nfss->wsize ||
1776             data->retrans != nfss->client->cl_timeout->to_retries ||
1777             data->auth_flavors[0] != nfss->client->cl_auth->au_flavor ||
1778             data->acregmin != nfss->acregmin / HZ ||
1779             data->acregmax != nfss->acregmax / HZ ||
1780             data->acdirmin != nfss->acdirmin / HZ ||
1781             data->acdirmax != nfss->acdirmax / HZ ||
1782             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1783             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1784             memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1785                    data->nfs_server.addrlen) != 0)
1786                 return -EINVAL;
1787
1788         return 0;
1789 }
1790
1791 static int
1792 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
1793 {
1794         int error;
1795         struct nfs_server *nfss = sb->s_fs_info;
1796         struct nfs_parsed_mount_data *data;
1797         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
1798         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
1799         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
1800
1801         /*
1802          * Userspace mount programs that send binary options generally send
1803          * them populated with default values. We have no way to know which
1804          * ones were explicitly specified. Fall back to legacy behavior and
1805          * just return success.
1806          */
1807         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
1808             (nfsvers <= 3 && (!options || (options->version >= 1 &&
1809                                            options->version <= 6))))
1810                 return 0;
1811
1812         data = kzalloc(sizeof(*data), GFP_KERNEL);
1813         if (data == NULL)
1814                 return -ENOMEM;
1815
1816         /* fill out struct with values from existing mount */
1817         data->flags = nfss->flags;
1818         data->rsize = nfss->rsize;
1819         data->wsize = nfss->wsize;
1820         data->retrans = nfss->client->cl_timeout->to_retries;
1821         data->auth_flavors[0] = nfss->client->cl_auth->au_flavor;
1822         data->acregmin = nfss->acregmin / HZ;
1823         data->acregmax = nfss->acregmax / HZ;
1824         data->acdirmin = nfss->acdirmin / HZ;
1825         data->acdirmax = nfss->acdirmax / HZ;
1826         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
1827         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
1828         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
1829                 data->nfs_server.addrlen);
1830
1831         /* overwrite those values with any that were specified */
1832         error = nfs_parse_mount_options((char *)options, data);
1833         if (error < 0)
1834                 goto out;
1835
1836         /* compare new mount options with old ones */
1837         error = nfs_compare_remount_data(nfss, data);
1838 out:
1839         kfree(data);
1840         return error;
1841 }
1842
1843 /*
1844  * Initialise the common bits of the superblock
1845  */
1846 static inline void nfs_initialise_sb(struct super_block *sb)
1847 {
1848         struct nfs_server *server = NFS_SB(sb);
1849
1850         sb->s_magic = NFS_SUPER_MAGIC;
1851
1852         /* We probably want something more informative here */
1853         snprintf(sb->s_id, sizeof(sb->s_id),
1854                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1855
1856         if (sb->s_blocksize == 0)
1857                 sb->s_blocksize = nfs_block_bits(server->wsize,
1858                                                  &sb->s_blocksize_bits);
1859
1860         if (server->flags & NFS_MOUNT_NOAC)
1861                 sb->s_flags |= MS_SYNCHRONOUS;
1862
1863         nfs_super_set_maxbytes(sb, server->maxfilesize);
1864 }
1865
1866 /*
1867  * Finish setting up an NFS2/3 superblock
1868  */
1869 static void nfs_fill_super(struct super_block *sb,
1870                            struct nfs_parsed_mount_data *data)
1871 {
1872         struct nfs_server *server = NFS_SB(sb);
1873
1874         sb->s_blocksize_bits = 0;
1875         sb->s_blocksize = 0;
1876         if (data->bsize)
1877                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1878
1879         if (server->flags & NFS_MOUNT_VER3) {
1880                 /* The VFS shouldn't apply the umask to mode bits. We will do
1881                  * so ourselves when necessary.
1882                  */
1883                 sb->s_flags |= MS_POSIXACL;
1884                 sb->s_time_gran = 1;
1885         }
1886
1887         sb->s_op = &nfs_sops;
1888         nfs_initialise_sb(sb);
1889 }
1890
1891 /*
1892  * Finish setting up a cloned NFS2/3 superblock
1893  */
1894 static void nfs_clone_super(struct super_block *sb,
1895                             const struct super_block *old_sb)
1896 {
1897         struct nfs_server *server = NFS_SB(sb);
1898
1899         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1900         sb->s_blocksize = old_sb->s_blocksize;
1901         sb->s_maxbytes = old_sb->s_maxbytes;
1902
1903         if (server->flags & NFS_MOUNT_VER3) {
1904                 /* The VFS shouldn't apply the umask to mode bits. We will do
1905                  * so ourselves when necessary.
1906                  */
1907                 sb->s_flags |= MS_POSIXACL;
1908                 sb->s_time_gran = 1;
1909         }
1910
1911         sb->s_op = old_sb->s_op;
1912         nfs_initialise_sb(sb);
1913 }
1914
1915 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1916 {
1917         const struct nfs_server *a = s->s_fs_info;
1918         const struct rpc_clnt *clnt_a = a->client;
1919         const struct rpc_clnt *clnt_b = b->client;
1920
1921         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1922                 goto Ebusy;
1923         if (a->nfs_client != b->nfs_client)
1924                 goto Ebusy;
1925         if (a->flags != b->flags)
1926                 goto Ebusy;
1927         if (a->wsize != b->wsize)
1928                 goto Ebusy;
1929         if (a->rsize != b->rsize)
1930                 goto Ebusy;
1931         if (a->acregmin != b->acregmin)
1932                 goto Ebusy;
1933         if (a->acregmax != b->acregmax)
1934                 goto Ebusy;
1935         if (a->acdirmin != b->acdirmin)
1936                 goto Ebusy;
1937         if (a->acdirmax != b->acdirmax)
1938                 goto Ebusy;
1939         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1940                 goto Ebusy;
1941         return 1;
1942 Ebusy:
1943         return 0;
1944 }
1945
1946 struct nfs_sb_mountdata {
1947         struct nfs_server *server;
1948         int mntflags;
1949 };
1950
1951 static int nfs_set_super(struct super_block *s, void *data)
1952 {
1953         struct nfs_sb_mountdata *sb_mntdata = data;
1954         struct nfs_server *server = sb_mntdata->server;
1955         int ret;
1956
1957         s->s_flags = sb_mntdata->mntflags;
1958         s->s_fs_info = server;
1959         ret = set_anon_super(s, server);
1960         if (ret == 0)
1961                 server->s_dev = s->s_dev;
1962         return ret;
1963 }
1964
1965 static int nfs_compare_super_address(struct nfs_server *server1,
1966                                      struct nfs_server *server2)
1967 {
1968         struct sockaddr *sap1, *sap2;
1969
1970         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1971         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1972
1973         if (sap1->sa_family != sap2->sa_family)
1974                 return 0;
1975
1976         switch (sap1->sa_family) {
1977         case AF_INET: {
1978                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1979                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1980                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1981                         return 0;
1982                 if (sin1->sin_port != sin2->sin_port)
1983                         return 0;
1984                 break;
1985         }
1986         case AF_INET6: {
1987                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1988                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1989                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1990                         return 0;
1991                 if (sin1->sin6_port != sin2->sin6_port)
1992                         return 0;
1993                 break;
1994         }
1995         default:
1996                 return 0;
1997         }
1998
1999         return 1;
2000 }
2001
2002 static int nfs_compare_super(struct super_block *sb, void *data)
2003 {
2004         struct nfs_sb_mountdata *sb_mntdata = data;
2005         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2006         int mntflags = sb_mntdata->mntflags;
2007
2008         if (!nfs_compare_super_address(old, server))
2009                 return 0;
2010         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2011         if (old->flags & NFS_MOUNT_UNSHARED)
2012                 return 0;
2013         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2014                 return 0;
2015         return nfs_compare_mount_options(sb, server, mntflags);
2016 }
2017
2018 static int nfs_bdi_register(struct nfs_server *server)
2019 {
2020         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2021 }
2022
2023 static int nfs_get_sb(struct file_system_type *fs_type,
2024         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2025 {
2026         struct nfs_server *server = NULL;
2027         struct super_block *s;
2028         struct nfs_parsed_mount_data *data;
2029         struct nfs_fh *mntfh;
2030         struct dentry *mntroot;
2031         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2032         struct nfs_sb_mountdata sb_mntdata = {
2033                 .mntflags = flags,
2034         };
2035         int error = -ENOMEM;
2036
2037         data = kzalloc(sizeof(*data), GFP_KERNEL);
2038         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2039         if (data == NULL || mntfh == NULL)
2040                 goto out_free_fh;
2041
2042         security_init_mnt_opts(&data->lsm_opts);
2043
2044         /* Validate the mount data */
2045         error = nfs_validate_mount_data(raw_data, data, mntfh, dev_name);
2046         if (error < 0)
2047                 goto out;
2048
2049         /* Get a volume representation */
2050         server = nfs_create_server(data, mntfh);
2051         if (IS_ERR(server)) {
2052                 error = PTR_ERR(server);
2053                 goto out;
2054         }
2055         sb_mntdata.server = server;
2056
2057         if (server->flags & NFS_MOUNT_UNSHARED)
2058                 compare_super = NULL;
2059
2060         /* Get a superblock - note that we may end up sharing one that already exists */
2061         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2062         if (IS_ERR(s)) {
2063                 error = PTR_ERR(s);
2064                 goto out_err_nosb;
2065         }
2066
2067         if (s->s_fs_info != server) {
2068                 nfs_free_server(server);
2069                 server = NULL;
2070         } else {
2071                 error = nfs_bdi_register(server);
2072                 if (error)
2073                         goto error_splat_super;
2074         }
2075
2076         if (!s->s_root) {
2077                 /* initial superblock/root creation */
2078                 nfs_fill_super(s, data);
2079                 nfs_fscache_get_super_cookie(s, data);
2080         }
2081
2082         mntroot = nfs_get_root(s, mntfh);
2083         if (IS_ERR(mntroot)) {
2084                 error = PTR_ERR(mntroot);
2085                 goto error_splat_super;
2086         }
2087
2088         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2089         if (error)
2090                 goto error_splat_root;
2091
2092         s->s_flags |= MS_ACTIVE;
2093         mnt->mnt_sb = s;
2094         mnt->mnt_root = mntroot;
2095         error = 0;
2096
2097 out:
2098         kfree(data->nfs_server.hostname);
2099         kfree(data->mount_server.hostname);
2100         kfree(data->fscache_uniq);
2101         security_free_mnt_opts(&data->lsm_opts);
2102 out_free_fh:
2103         kfree(mntfh);
2104         kfree(data);
2105         return error;
2106
2107 out_err_nosb:
2108         nfs_free_server(server);
2109         goto out;
2110
2111 error_splat_root:
2112         dput(mntroot);
2113 error_splat_super:
2114         deactivate_locked_super(s);
2115         goto out;
2116 }
2117
2118 /*
2119  * Destroy an NFS2/3 superblock
2120  */
2121 static void nfs_kill_super(struct super_block *s)
2122 {
2123         struct nfs_server *server = NFS_SB(s);
2124
2125         bdi_unregister(&server->backing_dev_info);
2126         kill_anon_super(s);
2127         nfs_fscache_release_super_cookie(s);
2128         nfs_free_server(server);
2129 }
2130
2131 /*
2132  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
2133  */
2134 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
2135                            const char *dev_name, void *raw_data,
2136                            struct vfsmount *mnt)
2137 {
2138         struct nfs_clone_mount *data = raw_data;
2139         struct super_block *s;
2140         struct nfs_server *server;
2141         struct dentry *mntroot;
2142         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2143         struct nfs_sb_mountdata sb_mntdata = {
2144                 .mntflags = flags,
2145         };
2146         int error;
2147
2148         dprintk("--> nfs_xdev_get_sb()\n");
2149
2150         /* create a new volume representation */
2151         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2152         if (IS_ERR(server)) {
2153                 error = PTR_ERR(server);
2154                 goto out_err_noserver;
2155         }
2156         sb_mntdata.server = server;
2157
2158         if (server->flags & NFS_MOUNT_UNSHARED)
2159                 compare_super = NULL;
2160
2161         /* Get a superblock - note that we may end up sharing one that already exists */
2162         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2163         if (IS_ERR(s)) {
2164                 error = PTR_ERR(s);
2165                 goto out_err_nosb;
2166         }
2167
2168         if (s->s_fs_info != server) {
2169                 nfs_free_server(server);
2170                 server = NULL;
2171         } else {
2172                 error = nfs_bdi_register(server);
2173                 if (error)
2174                         goto error_splat_super;
2175         }
2176
2177         if (!s->s_root) {
2178                 /* initial superblock/root creation */
2179                 nfs_clone_super(s, data->sb);
2180         }
2181
2182         mntroot = nfs_get_root(s, data->fh);
2183         if (IS_ERR(mntroot)) {
2184                 error = PTR_ERR(mntroot);
2185                 goto error_splat_super;
2186         }
2187         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2188                 dput(mntroot);
2189                 error = -ESTALE;
2190                 goto error_splat_super;
2191         }
2192
2193         s->s_flags |= MS_ACTIVE;
2194         mnt->mnt_sb = s;
2195         mnt->mnt_root = mntroot;
2196
2197         /* clone any lsm security options from the parent to the new sb */
2198         security_sb_clone_mnt_opts(data->sb, s);
2199
2200         dprintk("<-- nfs_xdev_get_sb() = 0\n");
2201         return 0;
2202
2203 out_err_nosb:
2204         nfs_free_server(server);
2205 out_err_noserver:
2206         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
2207         return error;
2208
2209 error_splat_super:
2210         deactivate_locked_super(s);
2211         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
2212         return error;
2213 }
2214
2215 #ifdef CONFIG_NFS_V4
2216
2217 /*
2218  * Finish setting up a cloned NFS4 superblock
2219  */
2220 static void nfs4_clone_super(struct super_block *sb,
2221                             const struct super_block *old_sb)
2222 {
2223         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2224         sb->s_blocksize = old_sb->s_blocksize;
2225         sb->s_maxbytes = old_sb->s_maxbytes;
2226         sb->s_time_gran = 1;
2227         sb->s_op = old_sb->s_op;
2228         nfs_initialise_sb(sb);
2229 }
2230
2231 /*
2232  * Set up an NFS4 superblock
2233  */
2234 static void nfs4_fill_super(struct super_block *sb)
2235 {
2236         sb->s_time_gran = 1;
2237         sb->s_op = &nfs4_sops;
2238         nfs_initialise_sb(sb);
2239 }
2240
2241 /*
2242  * Validate NFSv4 mount options
2243  */
2244 static int nfs4_validate_mount_data(void *options,
2245                                     struct nfs_parsed_mount_data *args,
2246                                     const char *dev_name)
2247 {
2248         struct sockaddr_in *ap;
2249         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2250         char *c;
2251
2252         if (data == NULL)
2253                 goto out_no_data;
2254
2255         args->rsize             = NFS_MAX_FILE_IO_SIZE;
2256         args->wsize             = NFS_MAX_FILE_IO_SIZE;
2257         args->acregmin          = NFS_DEF_ACREGMIN;
2258         args->acregmax          = NFS_DEF_ACREGMAX;
2259         args->acdirmin          = NFS_DEF_ACDIRMIN;
2260         args->acdirmax          = NFS_DEF_ACDIRMAX;
2261         args->nfs_server.port   = NFS_PORT; /* 2049 unless user set port= */
2262         args->auth_flavors[0]   = RPC_AUTH_UNIX;
2263         args->auth_flavor_len   = 0;
2264
2265         switch (data->version) {
2266         case 1:
2267                 ap = (struct sockaddr_in *)&args->nfs_server.address;
2268                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2269                         goto out_no_address;
2270                 if (data->host_addrlen == 0)
2271                         goto out_no_address;
2272                 args->nfs_server.addrlen = data->host_addrlen;
2273                 if (copy_from_user(ap, data->host_addr, data->host_addrlen))
2274                         return -EFAULT;
2275                 if (!nfs_verify_server_address((struct sockaddr *)
2276                                                 &args->nfs_server.address))
2277                         goto out_no_address;
2278
2279                 if (data->auth_flavourlen) {
2280                         if (data->auth_flavourlen > 1)
2281                                 goto out_inval_auth;
2282                         if (copy_from_user(&args->auth_flavors[0],
2283                                            data->auth_flavours,
2284                                            sizeof(args->auth_flavors[0])))
2285                                 return -EFAULT;
2286                 }
2287
2288                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2289                 if (IS_ERR(c))
2290                         return PTR_ERR(c);
2291                 args->nfs_server.hostname = c;
2292
2293                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2294                 if (IS_ERR(c))
2295                         return PTR_ERR(c);
2296                 args->nfs_server.export_path = c;
2297                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2298
2299                 c = strndup_user(data->client_addr.data, 16);
2300                 if (IS_ERR(c))
2301                         return PTR_ERR(c);
2302                 args->client_address = c;
2303
2304                 /*
2305                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2306                  * can deal with.
2307                  */
2308
2309                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2310                 args->rsize     = data->rsize;
2311                 args->wsize     = data->wsize;
2312                 args->timeo     = data->timeo;
2313                 args->retrans   = data->retrans;
2314                 args->acregmin  = data->acregmin;
2315                 args->acregmax  = data->acregmax;
2316                 args->acdirmin  = data->acdirmin;
2317                 args->acdirmax  = data->acdirmax;
2318                 args->nfs_server.protocol = data->proto;
2319                 nfs_validate_transport_protocol(args);
2320
2321                 break;
2322         default: {
2323                 int status;
2324
2325                 if (nfs_parse_mount_options((char *)options, args) == 0)
2326                         return -EINVAL;
2327
2328                 if (!nfs_verify_server_address((struct sockaddr *)
2329                                                 &args->nfs_server.address))
2330                         return -EINVAL;
2331
2332                 nfs_set_port((struct sockaddr *)&args->nfs_server.address,
2333                                 args->nfs_server.port);
2334
2335                 nfs_validate_transport_protocol(args);
2336
2337                 if (args->auth_flavor_len > 1)
2338                         goto out_inval_auth;
2339
2340                 if (args->client_address == NULL)
2341                         goto out_no_client_address;
2342
2343                 status = nfs_parse_devname(dev_name,
2344                                            &args->nfs_server.hostname,
2345                                            NFS4_MAXNAMLEN,
2346                                            &args->nfs_server.export_path,
2347                                            NFS4_MAXPATHLEN);
2348                 if (status < 0)
2349                         return status;
2350
2351                 break;
2352                 }
2353         }
2354
2355         return 0;
2356
2357 out_no_data:
2358         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2359         return -EINVAL;
2360
2361 out_inval_auth:
2362         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2363                  data->auth_flavourlen);
2364         return -EINVAL;
2365
2366 out_no_address:
2367         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2368         return -EINVAL;
2369
2370 out_no_client_address:
2371         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
2372         return -EINVAL;
2373 }
2374
2375 /*
2376  * Get the superblock for an NFS4 mountpoint
2377  */
2378 static int nfs4_get_sb(struct file_system_type *fs_type,
2379         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
2380 {
2381         struct nfs_parsed_mount_data *data;
2382         struct super_block *s;
2383         struct nfs_server *server;
2384         struct nfs_fh *mntfh;
2385         struct dentry *mntroot;
2386         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2387         struct nfs_sb_mountdata sb_mntdata = {
2388                 .mntflags = flags,
2389         };
2390         int error = -ENOMEM;
2391
2392         data = kzalloc(sizeof(*data), GFP_KERNEL);
2393         mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
2394         if (data == NULL || mntfh == NULL)
2395                 goto out_free_fh;
2396
2397         security_init_mnt_opts(&data->lsm_opts);
2398
2399         /* Validate the mount data */
2400         error = nfs4_validate_mount_data(raw_data, data, dev_name);
2401         if (error < 0)
2402                 goto out;
2403
2404         /* Get a volume representation */
2405         server = nfs4_create_server(data, mntfh);
2406         if (IS_ERR(server)) {
2407                 error = PTR_ERR(server);
2408                 goto out;
2409         }
2410         sb_mntdata.server = server;
2411
2412         if (server->flags & NFS4_MOUNT_UNSHARED)
2413                 compare_super = NULL;
2414
2415         /* Get a superblock - note that we may end up sharing one that already exists */
2416         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
2417         if (IS_ERR(s)) {
2418                 error = PTR_ERR(s);
2419                 goto out_free;
2420         }
2421
2422         if (s->s_fs_info != server) {
2423                 nfs_free_server(server);
2424                 server = NULL;
2425         } else {
2426                 error = nfs_bdi_register(server);
2427                 if (error)
2428                         goto error_splat_super;
2429         }
2430
2431         if (!s->s_root) {
2432                 /* initial superblock/root creation */
2433                 nfs4_fill_super(s);
2434                 nfs_fscache_get_super_cookie(s, data);
2435         }
2436
2437         mntroot = nfs4_get_root(s, mntfh);
2438         if (IS_ERR(mntroot)) {
2439                 error = PTR_ERR(mntroot);
2440                 goto error_splat_super;
2441         }
2442
2443         error = security_sb_set_mnt_opts(s, &data->lsm_opts);
2444         if (error)
2445                 goto error_splat_root;
2446
2447         s->s_flags |= MS_ACTIVE;
2448         mnt->mnt_sb = s;
2449         mnt->mnt_root = mntroot;
2450         error = 0;
2451
2452 out:
2453         kfree(data->client_address);
2454         kfree(data->nfs_server.export_path);
2455         kfree(data->nfs_server.hostname);
2456         kfree(data->fscache_uniq);
2457         security_free_mnt_opts(&data->lsm_opts);
2458 out_free_fh:
2459         kfree(mntfh);
2460         kfree(data);
2461         return error;
2462
2463 out_free:
2464         nfs_free_server(server);
2465         goto out;
2466
2467 error_splat_root:
2468         dput(mntroot);
2469 error_splat_super:
2470         deactivate_locked_super(s);
2471         goto out;
2472 }
2473
2474 static void nfs4_kill_super(struct super_block *sb)
2475 {
2476         struct nfs_server *server = NFS_SB(sb);
2477
2478         nfs_super_return_all_delegations(sb);
2479         kill_anon_super(sb);
2480
2481         nfs4_renewd_prepare_shutdown(server);
2482         nfs_fscache_release_super_cookie(sb);
2483         nfs_free_server(server);
2484 }
2485
2486 /*
2487  * Clone an NFS4 server record on xdev traversal (FSID-change)
2488  */
2489 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
2490                             const char *dev_name, void *raw_data,
2491                             struct vfsmount *mnt)
2492 {
2493         struct nfs_clone_mount *data = raw_data;
2494         struct super_block *s;
2495         struct nfs_server *server;
2496         struct dentry *mntroot;
2497         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2498         struct nfs_sb_mountdata sb_mntdata = {
2499                 .mntflags = flags,
2500         };
2501         int error;
2502
2503         dprintk("--> nfs4_xdev_get_sb()\n");
2504
2505         /* create a new volume representation */
2506         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2507         if (IS_ERR(server)) {
2508                 error = PTR_ERR(server);
2509                 goto out_err_noserver;
2510         }
2511         sb_mntdata.server = server;
2512
2513         if (server->flags & NFS4_MOUNT_UNSHARED)
2514                 compare_super = NULL;
2515
2516         /* Get a superblock - note that we may end up sharing one that already exists */
2517         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2518         if (IS_ERR(s)) {
2519                 error = PTR_ERR(s);
2520                 goto out_err_nosb;
2521         }
2522
2523         if (s->s_fs_info != server) {
2524                 nfs_free_server(server);
2525                 server = NULL;
2526         } else {
2527                 error = nfs_bdi_register(server);
2528                 if (error)
2529                         goto error_splat_super;
2530         }
2531
2532         if (!s->s_root) {
2533                 /* initial superblock/root creation */
2534                 nfs4_clone_super(s, data->sb);
2535         }
2536
2537         mntroot = nfs4_get_root(s, data->fh);
2538         if (IS_ERR(mntroot)) {
2539                 error = PTR_ERR(mntroot);
2540                 goto error_splat_super;
2541         }
2542         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2543                 dput(mntroot);
2544                 error = -ESTALE;
2545                 goto error_splat_super;
2546         }
2547
2548         s->s_flags |= MS_ACTIVE;
2549         mnt->mnt_sb = s;
2550         mnt->mnt_root = mntroot;
2551
2552         security_sb_clone_mnt_opts(data->sb, s);
2553
2554         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2555         return 0;
2556
2557 out_err_nosb:
2558         nfs_free_server(server);
2559 out_err_noserver:
2560         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2561         return error;
2562
2563 error_splat_super:
2564         deactivate_locked_super(s);
2565         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2566         return error;
2567 }
2568
2569 /*
2570  * Create an NFS4 server record on referral traversal
2571  */
2572 static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
2573                                 const char *dev_name, void *raw_data,
2574                                 struct vfsmount *mnt)
2575 {
2576         struct nfs_clone_mount *data = raw_data;
2577         struct super_block *s;
2578         struct nfs_server *server;
2579         struct dentry *mntroot;
2580         struct nfs_fh mntfh;
2581         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2582         struct nfs_sb_mountdata sb_mntdata = {
2583                 .mntflags = flags,
2584         };
2585         int error;
2586
2587         dprintk("--> nfs4_referral_get_sb()\n");
2588
2589         /* create a new volume representation */
2590         server = nfs4_create_referral_server(data, &mntfh);
2591         if (IS_ERR(server)) {
2592                 error = PTR_ERR(server);
2593                 goto out_err_noserver;
2594         }
2595         sb_mntdata.server = server;
2596
2597         if (server->flags & NFS4_MOUNT_UNSHARED)
2598                 compare_super = NULL;
2599
2600         /* Get a superblock - note that we may end up sharing one that already exists */
2601         s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2602         if (IS_ERR(s)) {
2603                 error = PTR_ERR(s);
2604                 goto out_err_nosb;
2605         }
2606
2607         if (s->s_fs_info != server) {
2608                 nfs_free_server(server);
2609                 server = NULL;
2610         } else {
2611                 error = nfs_bdi_register(server);
2612                 if (error)
2613                         goto error_splat_super;
2614         }
2615
2616         if (!s->s_root) {
2617                 /* initial superblock/root creation */
2618                 nfs4_fill_super(s);
2619         }
2620
2621         mntroot = nfs4_get_root(s, &mntfh);
2622         if (IS_ERR(mntroot)) {
2623                 error = PTR_ERR(mntroot);
2624                 goto error_splat_super;
2625         }
2626         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2627                 dput(mntroot);
2628                 error = -ESTALE;
2629                 goto error_splat_super;
2630         }
2631
2632         s->s_flags |= MS_ACTIVE;
2633         mnt->mnt_sb = s;
2634         mnt->mnt_root = mntroot;
2635
2636         security_sb_clone_mnt_opts(data->sb, s);
2637
2638         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2639         return 0;
2640
2641 out_err_nosb:
2642         nfs_free_server(server);
2643 out_err_noserver:
2644         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2645         return error;
2646
2647 error_splat_super:
2648         deactivate_locked_super(s);
2649         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2650         return error;
2651 }
2652
2653 #endif /* CONFIG_NFS_V4 */