dd4dfcd632ec76aa78c1c2e603c88a4e4401644a
[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.Cox@linux.org>, while hacking some
9  *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
10  *
11  *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
12  *  J.S.Peatfield@damtp.cam.ac.uk
13  *
14  *  Split from inode.c by David Howells <dhowells@redhat.com>
15  *
16  * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
17  *   particular server are held in the same superblock
18  * - NFS superblocks can have several effective roots to the dentry tree
19  * - directory type roots are spliced into the tree when a path from one root reaches the root
20  *   of another (see nfs_lookup())
21  */
22
23 #include <linux/module.h>
24 #include <linux/init.h>
25
26 #include <linux/time.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/string.h>
30 #include <linux/stat.h>
31 #include <linux/errno.h>
32 #include <linux/unistd.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/stats.h>
35 #include <linux/sunrpc/metrics.h>
36 #include <linux/sunrpc/xprtsock.h>
37 #include <linux/sunrpc/xprtrdma.h>
38 #include <linux/nfs_fs.h>
39 #include <linux/nfs_mount.h>
40 #include <linux/nfs4_mount.h>
41 #include <linux/lockd/bind.h>
42 #include <linux/smp_lock.h>
43 #include <linux/seq_file.h>
44 #include <linux/mount.h>
45 #include <linux/nfs_idmap.h>
46 #include <linux/vfs.h>
47 #include <linux/inet.h>
48 #include <linux/in6.h>
49 #include <net/ipv6.h>
50 #include <linux/nfs_xdr.h>
51 #include <linux/magic.h>
52 #include <linux/parser.h>
53
54 #include <asm/system.h>
55 #include <asm/uaccess.h>
56
57 #include "nfs4_fs.h"
58 #include "callback.h"
59 #include "delegation.h"
60 #include "iostat.h"
61 #include "internal.h"
62
63 #define NFSDBG_FACILITY         NFSDBG_VFS
64
65 enum {
66         /* Mount options that take no arguments */
67         Opt_soft, Opt_hard,
68         Opt_intr, Opt_nointr,
69         Opt_posix, Opt_noposix,
70         Opt_cto, Opt_nocto,
71         Opt_ac, Opt_noac,
72         Opt_lock, Opt_nolock,
73         Opt_v2, Opt_v3,
74         Opt_udp, Opt_tcp, Opt_rdma,
75         Opt_acl, Opt_noacl,
76         Opt_rdirplus, Opt_nordirplus,
77         Opt_sharecache, Opt_nosharecache,
78
79         /* Mount options that take integer arguments */
80         Opt_port,
81         Opt_rsize, Opt_wsize, Opt_bsize,
82         Opt_timeo, Opt_retrans,
83         Opt_acregmin, Opt_acregmax,
84         Opt_acdirmin, Opt_acdirmax,
85         Opt_actimeo,
86         Opt_namelen,
87         Opt_mountport,
88         Opt_mountvers,
89         Opt_nfsvers,
90
91         /* Mount options that take string arguments */
92         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
93         Opt_addr, Opt_mountaddr, Opt_clientaddr,
94
95         /* Mount options that are ignored */
96         Opt_userspace, Opt_deprecated,
97
98         Opt_err
99 };
100
101 static match_table_t nfs_mount_option_tokens = {
102         { Opt_userspace, "bg" },
103         { Opt_userspace, "fg" },
104         { Opt_soft, "soft" },
105         { Opt_hard, "hard" },
106         { Opt_intr, "intr" },
107         { Opt_nointr, "nointr" },
108         { Opt_posix, "posix" },
109         { Opt_noposix, "noposix" },
110         { Opt_cto, "cto" },
111         { Opt_nocto, "nocto" },
112         { Opt_ac, "ac" },
113         { Opt_noac, "noac" },
114         { Opt_lock, "lock" },
115         { Opt_nolock, "nolock" },
116         { Opt_v2, "v2" },
117         { Opt_v3, "v3" },
118         { Opt_udp, "udp" },
119         { Opt_tcp, "tcp" },
120         { Opt_rdma, "rdma" },
121         { Opt_acl, "acl" },
122         { Opt_noacl, "noacl" },
123         { Opt_rdirplus, "rdirplus" },
124         { Opt_nordirplus, "nordirplus" },
125         { Opt_sharecache, "sharecache" },
126         { Opt_nosharecache, "nosharecache" },
127
128         { Opt_port, "port=%u" },
129         { Opt_rsize, "rsize=%u" },
130         { Opt_wsize, "wsize=%u" },
131         { Opt_bsize, "bsize=%u" },
132         { Opt_timeo, "timeo=%u" },
133         { Opt_retrans, "retrans=%u" },
134         { Opt_acregmin, "acregmin=%u" },
135         { Opt_acregmax, "acregmax=%u" },
136         { Opt_acdirmin, "acdirmin=%u" },
137         { Opt_acdirmax, "acdirmax=%u" },
138         { Opt_actimeo, "actimeo=%u" },
139         { Opt_userspace, "retry=%u" },
140         { Opt_namelen, "namlen=%u" },
141         { Opt_mountport, "mountport=%u" },
142         { Opt_mountvers, "mountvers=%u" },
143         { Opt_nfsvers, "nfsvers=%u" },
144         { Opt_nfsvers, "vers=%u" },
145
146         { Opt_sec, "sec=%s" },
147         { Opt_proto, "proto=%s" },
148         { Opt_mountproto, "mountproto=%s" },
149         { Opt_addr, "addr=%s" },
150         { Opt_clientaddr, "clientaddr=%s" },
151         { Opt_mounthost, "mounthost=%s" },
152         { Opt_mountaddr, "mountaddr=%s" },
153
154         { Opt_err, NULL }
155 };
156
157 enum {
158         Opt_xprt_udp, Opt_xprt_tcp, Opt_xprt_rdma,
159
160         Opt_xprt_err
161 };
162
163 static match_table_t nfs_xprt_protocol_tokens = {
164         { Opt_xprt_udp, "udp" },
165         { Opt_xprt_tcp, "tcp" },
166         { Opt_xprt_rdma, "rdma" },
167
168         { Opt_xprt_err, NULL }
169 };
170
171 enum {
172         Opt_sec_none, Opt_sec_sys,
173         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
174         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
175         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
176
177         Opt_sec_err
178 };
179
180 static match_table_t nfs_secflavor_tokens = {
181         { Opt_sec_none, "none" },
182         { Opt_sec_none, "null" },
183         { Opt_sec_sys, "sys" },
184
185         { Opt_sec_krb5, "krb5" },
186         { Opt_sec_krb5i, "krb5i" },
187         { Opt_sec_krb5p, "krb5p" },
188
189         { Opt_sec_lkey, "lkey" },
190         { Opt_sec_lkeyi, "lkeyi" },
191         { Opt_sec_lkeyp, "lkeyp" },
192
193         { Opt_sec_spkm, "spkm3" },
194         { Opt_sec_spkmi, "spkm3i" },
195         { Opt_sec_spkmp, "spkm3p" },
196
197         { Opt_sec_err, NULL }
198 };
199
200
201 static void nfs_umount_begin(struct vfsmount *, int);
202 static int  nfs_statfs(struct dentry *, struct kstatfs *);
203 static int  nfs_show_options(struct seq_file *, struct vfsmount *);
204 static int  nfs_show_stats(struct seq_file *, struct vfsmount *);
205 static int nfs_get_sb(struct file_system_type *, int, const char *, void *, struct vfsmount *);
206 static int nfs_xdev_get_sb(struct file_system_type *fs_type,
207                 int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
208 static void nfs_kill_super(struct super_block *);
209 static void nfs_put_super(struct super_block *);
210
211 static struct file_system_type nfs_fs_type = {
212         .owner          = THIS_MODULE,
213         .name           = "nfs",
214         .get_sb         = nfs_get_sb,
215         .kill_sb        = nfs_kill_super,
216         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
217 };
218
219 struct file_system_type nfs_xdev_fs_type = {
220         .owner          = THIS_MODULE,
221         .name           = "nfs",
222         .get_sb         = nfs_xdev_get_sb,
223         .kill_sb        = nfs_kill_super,
224         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
225 };
226
227 static const struct super_operations nfs_sops = {
228         .alloc_inode    = nfs_alloc_inode,
229         .destroy_inode  = nfs_destroy_inode,
230         .write_inode    = nfs_write_inode,
231         .put_super      = nfs_put_super,
232         .statfs         = nfs_statfs,
233         .clear_inode    = nfs_clear_inode,
234         .umount_begin   = nfs_umount_begin,
235         .show_options   = nfs_show_options,
236         .show_stats     = nfs_show_stats,
237 };
238
239 #ifdef CONFIG_NFS_V4
240 static int nfs4_get_sb(struct file_system_type *fs_type,
241         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
242 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
243         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
244 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
245         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
246 static void nfs4_kill_super(struct super_block *sb);
247
248 static struct file_system_type nfs4_fs_type = {
249         .owner          = THIS_MODULE,
250         .name           = "nfs4",
251         .get_sb         = nfs4_get_sb,
252         .kill_sb        = nfs4_kill_super,
253         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
254 };
255
256 struct file_system_type nfs4_xdev_fs_type = {
257         .owner          = THIS_MODULE,
258         .name           = "nfs4",
259         .get_sb         = nfs4_xdev_get_sb,
260         .kill_sb        = nfs4_kill_super,
261         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
262 };
263
264 struct file_system_type nfs4_referral_fs_type = {
265         .owner          = THIS_MODULE,
266         .name           = "nfs4",
267         .get_sb         = nfs4_referral_get_sb,
268         .kill_sb        = nfs4_kill_super,
269         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
270 };
271
272 static const struct super_operations nfs4_sops = {
273         .alloc_inode    = nfs_alloc_inode,
274         .destroy_inode  = nfs_destroy_inode,
275         .write_inode    = nfs_write_inode,
276         .statfs         = nfs_statfs,
277         .clear_inode    = nfs4_clear_inode,
278         .umount_begin   = nfs_umount_begin,
279         .show_options   = nfs_show_options,
280         .show_stats     = nfs_show_stats,
281 };
282 #endif
283
284 static struct shrinker acl_shrinker = {
285         .shrink         = nfs_access_cache_shrinker,
286         .seeks          = DEFAULT_SEEKS,
287 };
288
289 /*
290  * Register the NFS filesystems
291  */
292 int __init register_nfs_fs(void)
293 {
294         int ret;
295
296         ret = register_filesystem(&nfs_fs_type);
297         if (ret < 0)
298                 goto error_0;
299
300         ret = nfs_register_sysctl();
301         if (ret < 0)
302                 goto error_1;
303 #ifdef CONFIG_NFS_V4
304         ret = register_filesystem(&nfs4_fs_type);
305         if (ret < 0)
306                 goto error_2;
307 #endif
308         register_shrinker(&acl_shrinker);
309         return 0;
310
311 #ifdef CONFIG_NFS_V4
312 error_2:
313         nfs_unregister_sysctl();
314 #endif
315 error_1:
316         unregister_filesystem(&nfs_fs_type);
317 error_0:
318         return ret;
319 }
320
321 /*
322  * Unregister the NFS filesystems
323  */
324 void __exit unregister_nfs_fs(void)
325 {
326         unregister_shrinker(&acl_shrinker);
327 #ifdef CONFIG_NFS_V4
328         unregister_filesystem(&nfs4_fs_type);
329 #endif
330         nfs_unregister_sysctl();
331         unregister_filesystem(&nfs_fs_type);
332 }
333
334 void nfs_sb_active(struct nfs_server *server)
335 {
336         atomic_inc(&server->active);
337 }
338
339 void nfs_sb_deactive(struct nfs_server *server)
340 {
341         if (atomic_dec_and_test(&server->active))
342                 wake_up(&server->active_wq);
343 }
344
345 static void nfs_put_super(struct super_block *sb)
346 {
347         struct nfs_server *server = NFS_SB(sb);
348         /*
349          * Make sure there are no outstanding ops to this server.
350          * If so, wait for them to finish before allowing the
351          * unmount to continue.
352          */
353         wait_event(server->active_wq, atomic_read(&server->active) == 0);
354 }
355
356 /*
357  * Deliver file system statistics to userspace
358  */
359 static int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
360 {
361         struct nfs_server *server = NFS_SB(dentry->d_sb);
362         unsigned char blockbits;
363         unsigned long blockres;
364         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
365         struct nfs_fattr fattr;
366         struct nfs_fsstat res = {
367                         .fattr = &fattr,
368         };
369         int error;
370
371         lock_kernel();
372
373         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
374         if (error < 0)
375                 goto out_err;
376         buf->f_type = NFS_SUPER_MAGIC;
377
378         /*
379          * Current versions of glibc do not correctly handle the
380          * case where f_frsize != f_bsize.  Eventually we want to
381          * report the value of wtmult in this field.
382          */
383         buf->f_frsize = dentry->d_sb->s_blocksize;
384
385         /*
386          * On most *nix systems, f_blocks, f_bfree, and f_bavail
387          * are reported in units of f_frsize.  Linux hasn't had
388          * an f_frsize field in its statfs struct until recently,
389          * thus historically Linux's sys_statfs reports these
390          * fields in units of f_bsize.
391          */
392         buf->f_bsize = dentry->d_sb->s_blocksize;
393         blockbits = dentry->d_sb->s_blocksize_bits;
394         blockres = (1 << blockbits) - 1;
395         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
396         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
397         buf->f_bavail = (res.abytes + blockres) >> blockbits;
398
399         buf->f_files = res.tfiles;
400         buf->f_ffree = res.afiles;
401
402         buf->f_namelen = server->namelen;
403
404         unlock_kernel();
405         return 0;
406
407  out_err:
408         dprintk("%s: statfs error = %d\n", __FUNCTION__, -error);
409         unlock_kernel();
410         return error;
411 }
412
413 /*
414  * Map the security flavour number to a name
415  */
416 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
417 {
418         static const struct {
419                 rpc_authflavor_t flavour;
420                 const char *str;
421         } sec_flavours[] = {
422                 { RPC_AUTH_NULL, "null" },
423                 { RPC_AUTH_UNIX, "sys" },
424                 { RPC_AUTH_GSS_KRB5, "krb5" },
425                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
426                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
427                 { RPC_AUTH_GSS_LKEY, "lkey" },
428                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
429                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
430                 { RPC_AUTH_GSS_SPKM, "spkm" },
431                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
432                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
433                 { UINT_MAX, "unknown" }
434         };
435         int i;
436
437         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
438                 if (sec_flavours[i].flavour == flavour)
439                         break;
440         }
441         return sec_flavours[i].str;
442 }
443
444 /*
445  * Describe the mount options in force on this server representation
446  */
447 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, int showdefaults)
448 {
449         static const struct proc_nfs_info {
450                 int flag;
451                 const char *str;
452                 const char *nostr;
453         } nfs_info[] = {
454                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
455                 { NFS_MOUNT_NOCTO, ",nocto", "" },
456                 { NFS_MOUNT_NOAC, ",noac", "" },
457                 { NFS_MOUNT_NONLM, ",nolock", "" },
458                 { NFS_MOUNT_NOACL, ",noacl", "" },
459                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
460                 { NFS_MOUNT_UNSHARED, ",nosharecache", ""},
461                 { 0, NULL, NULL }
462         };
463         const struct proc_nfs_info *nfs_infop;
464         struct nfs_client *clp = nfss->nfs_client;
465
466         seq_printf(m, ",vers=%d", clp->rpc_ops->version);
467         seq_printf(m, ",rsize=%d", nfss->rsize);
468         seq_printf(m, ",wsize=%d", nfss->wsize);
469         if (nfss->acregmin != 3*HZ || showdefaults)
470                 seq_printf(m, ",acregmin=%d", nfss->acregmin/HZ);
471         if (nfss->acregmax != 60*HZ || showdefaults)
472                 seq_printf(m, ",acregmax=%d", nfss->acregmax/HZ);
473         if (nfss->acdirmin != 30*HZ || showdefaults)
474                 seq_printf(m, ",acdirmin=%d", nfss->acdirmin/HZ);
475         if (nfss->acdirmax != 60*HZ || showdefaults)
476                 seq_printf(m, ",acdirmax=%d", nfss->acdirmax/HZ);
477         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
478                 if (nfss->flags & nfs_infop->flag)
479                         seq_puts(m, nfs_infop->str);
480                 else
481                         seq_puts(m, nfs_infop->nostr);
482         }
483         seq_printf(m, ",proto=%s",
484                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_PROTO));
485         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
486         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
487         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
488 }
489
490 /*
491  * Describe the mount options on this VFS mountpoint
492  */
493 static int nfs_show_options(struct seq_file *m, struct vfsmount *mnt)
494 {
495         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
496
497         nfs_show_mount_options(m, nfss, 0);
498
499         seq_printf(m, ",addr=%s",
500                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
501                                                         RPC_DISPLAY_ADDR));
502
503         return 0;
504 }
505
506 /*
507  * Present statistical information for this VFS mountpoint
508  */
509 static int nfs_show_stats(struct seq_file *m, struct vfsmount *mnt)
510 {
511         int i, cpu;
512         struct nfs_server *nfss = NFS_SB(mnt->mnt_sb);
513         struct rpc_auth *auth = nfss->client->cl_auth;
514         struct nfs_iostats totals = { };
515
516         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
517
518         /*
519          * Display all mount option settings
520          */
521         seq_printf(m, "\n\topts:\t");
522         seq_puts(m, mnt->mnt_sb->s_flags & MS_RDONLY ? "ro" : "rw");
523         seq_puts(m, mnt->mnt_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
524         seq_puts(m, mnt->mnt_sb->s_flags & MS_NOATIME ? ",noatime" : "");
525         seq_puts(m, mnt->mnt_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
526         nfs_show_mount_options(m, nfss, 1);
527
528         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
529
530         seq_printf(m, "\n\tcaps:\t");
531         seq_printf(m, "caps=0x%x", nfss->caps);
532         seq_printf(m, ",wtmult=%d", nfss->wtmult);
533         seq_printf(m, ",dtsize=%d", nfss->dtsize);
534         seq_printf(m, ",bsize=%d", nfss->bsize);
535         seq_printf(m, ",namelen=%d", nfss->namelen);
536
537 #ifdef CONFIG_NFS_V4
538         if (nfss->nfs_client->rpc_ops->version == 4) {
539                 seq_printf(m, "\n\tnfsv4:\t");
540                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
541                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
542                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
543         }
544 #endif
545
546         /*
547          * Display security flavor in effect for this mount
548          */
549         seq_printf(m, "\n\tsec:\tflavor=%d", auth->au_ops->au_flavor);
550         if (auth->au_flavor)
551                 seq_printf(m, ",pseudoflavor=%d", auth->au_flavor);
552
553         /*
554          * Display superblock I/O counters
555          */
556         for_each_possible_cpu(cpu) {
557                 struct nfs_iostats *stats;
558
559                 preempt_disable();
560                 stats = per_cpu_ptr(nfss->io_stats, cpu);
561
562                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
563                         totals.events[i] += stats->events[i];
564                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
565                         totals.bytes[i] += stats->bytes[i];
566
567                 preempt_enable();
568         }
569
570         seq_printf(m, "\n\tevents:\t");
571         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
572                 seq_printf(m, "%lu ", totals.events[i]);
573         seq_printf(m, "\n\tbytes:\t");
574         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
575                 seq_printf(m, "%Lu ", totals.bytes[i]);
576         seq_printf(m, "\n");
577
578         rpc_print_iostats(m, nfss->client);
579
580         return 0;
581 }
582
583 /*
584  * Begin unmount by attempting to remove all automounted mountpoints we added
585  * in response to xdev traversals and referrals
586  */
587 static void nfs_umount_begin(struct vfsmount *vfsmnt, int flags)
588 {
589         struct nfs_server *server = NFS_SB(vfsmnt->mnt_sb);
590         struct rpc_clnt *rpc;
591
592         shrink_submounts(vfsmnt, &nfs_automount_list);
593
594         if (!(flags & MNT_FORCE))
595                 return;
596         /* -EIO all pending I/O */
597         rpc = server->client_acl;
598         if (!IS_ERR(rpc))
599                 rpc_killall_tasks(rpc);
600         rpc = server->client;
601         if (!IS_ERR(rpc))
602                 rpc_killall_tasks(rpc);
603 }
604
605 /*
606  * Set the port number in an address.  Be agnostic about the address family.
607  */
608 static void nfs_set_port(struct sockaddr *sap, unsigned short port)
609 {
610         switch (sap->sa_family) {
611         case AF_INET: {
612                 struct sockaddr_in *ap = (struct sockaddr_in *)sap;
613                 ap->sin_port = htons(port);
614                 break;
615         }
616         case AF_INET6: {
617                 struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
618                 ap->sin6_port = htons(port);
619                 break;
620         }
621         }
622 }
623
624 /*
625  * Sanity-check a server address provided by the mount command.
626  *
627  * Address family must be initialized, and address must not be
628  * the ANY address for that family.
629  */
630 static int nfs_verify_server_address(struct sockaddr *addr)
631 {
632         switch (addr->sa_family) {
633         case AF_INET: {
634                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
635                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
636         }
637         case AF_INET6: {
638                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
639                 return !ipv6_addr_any(sa);
640         }
641         }
642
643         return 0;
644 }
645
646 /*
647  * Parse string addresses passed in via a mount option,
648  * and construct a sockaddr based on the result.
649  *
650  * If address parsing fails, set the sockaddr's address
651  * family to AF_UNSPEC to force nfs_verify_server_address()
652  * to punt the mount.
653  */
654 static void nfs_parse_server_address(char *value,
655                                      struct sockaddr *sap,
656                                      size_t *len)
657 {
658         if (strchr(value, ':')) {
659                 struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
660                 u8 *addr = (u8 *)&ap->sin6_addr.in6_u;
661
662                 ap->sin6_family = AF_INET6;
663                 *len = sizeof(*ap);
664                 if (in6_pton(value, -1, addr, '\0', NULL))
665                         return;
666         } else {
667                 struct sockaddr_in *ap = (struct sockaddr_in *)sap;
668                 u8 *addr = (u8 *)&ap->sin_addr.s_addr;
669
670                 ap->sin_family = AF_INET;
671                 *len = sizeof(*ap);
672                 if (in4_pton(value, -1, addr, '\0', NULL))
673                         return;
674         }
675
676         sap->sa_family = AF_UNSPEC;
677         *len = 0;
678 }
679
680 /*
681  * Error-check and convert a string of mount options from user space into
682  * a data structure
683  */
684 static int nfs_parse_mount_options(char *raw,
685                                    struct nfs_parsed_mount_data *mnt)
686 {
687         char *p, *string, *secdata;
688         unsigned short port = 0;
689         int rc;
690
691         if (!raw) {
692                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
693                 return 1;
694         }
695         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
696
697         secdata = alloc_secdata();
698         if (!secdata)
699                 goto out_nomem;
700
701         rc = security_sb_copy_data(raw, secdata);
702         if (rc)
703                 goto out_security_failure;
704
705         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
706         if (rc)
707                 goto out_security_failure;
708
709         free_secdata(secdata);
710
711         while ((p = strsep(&raw, ",")) != NULL) {
712                 substring_t args[MAX_OPT_ARGS];
713                 int option, token;
714
715                 if (!*p)
716                         continue;
717
718                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
719
720                 token = match_token(p, nfs_mount_option_tokens, args);
721                 switch (token) {
722                 case Opt_soft:
723                         mnt->flags |= NFS_MOUNT_SOFT;
724                         break;
725                 case Opt_hard:
726                         mnt->flags &= ~NFS_MOUNT_SOFT;
727                         break;
728                 case Opt_intr:
729                 case Opt_nointr:
730                         break;
731                 case Opt_posix:
732                         mnt->flags |= NFS_MOUNT_POSIX;
733                         break;
734                 case Opt_noposix:
735                         mnt->flags &= ~NFS_MOUNT_POSIX;
736                         break;
737                 case Opt_cto:
738                         mnt->flags &= ~NFS_MOUNT_NOCTO;
739                         break;
740                 case Opt_nocto:
741                         mnt->flags |= NFS_MOUNT_NOCTO;
742                         break;
743                 case Opt_ac:
744                         mnt->flags &= ~NFS_MOUNT_NOAC;
745                         break;
746                 case Opt_noac:
747                         mnt->flags |= NFS_MOUNT_NOAC;
748                         break;
749                 case Opt_lock:
750                         mnt->flags &= ~NFS_MOUNT_NONLM;
751                         break;
752                 case Opt_nolock:
753                         mnt->flags |= NFS_MOUNT_NONLM;
754                         break;
755                 case Opt_v2:
756                         mnt->flags &= ~NFS_MOUNT_VER3;
757                         break;
758                 case Opt_v3:
759                         mnt->flags |= NFS_MOUNT_VER3;
760                         break;
761                 case Opt_udp:
762                         mnt->flags &= ~NFS_MOUNT_TCP;
763                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
764                         mnt->timeo = 7;
765                         mnt->retrans = 5;
766                         break;
767                 case Opt_tcp:
768                         mnt->flags |= NFS_MOUNT_TCP;
769                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
770                         mnt->timeo = 600;
771                         mnt->retrans = 2;
772                         break;
773                 case Opt_rdma:
774                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
775                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
776                         mnt->timeo = 600;
777                         mnt->retrans = 2;
778                         break;
779                 case Opt_acl:
780                         mnt->flags &= ~NFS_MOUNT_NOACL;
781                         break;
782                 case Opt_noacl:
783                         mnt->flags |= NFS_MOUNT_NOACL;
784                         break;
785                 case Opt_rdirplus:
786                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
787                         break;
788                 case Opt_nordirplus:
789                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
790                         break;
791                 case Opt_sharecache:
792                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
793                         break;
794                 case Opt_nosharecache:
795                         mnt->flags |= NFS_MOUNT_UNSHARED;
796                         break;
797
798                 case Opt_port:
799                         if (match_int(args, &option))
800                                 return 0;
801                         if (option < 0 || option > 65535)
802                                 return 0;
803                         port = option;
804                         break;
805                 case Opt_rsize:
806                         if (match_int(args, &mnt->rsize))
807                                 return 0;
808                         break;
809                 case Opt_wsize:
810                         if (match_int(args, &mnt->wsize))
811                                 return 0;
812                         break;
813                 case Opt_bsize:
814                         if (match_int(args, &option))
815                                 return 0;
816                         if (option < 0)
817                                 return 0;
818                         mnt->bsize = option;
819                         break;
820                 case Opt_timeo:
821                         if (match_int(args, &mnt->timeo))
822                                 return 0;
823                         break;
824                 case Opt_retrans:
825                         if (match_int(args, &mnt->retrans))
826                                 return 0;
827                         break;
828                 case Opt_acregmin:
829                         if (match_int(args, &mnt->acregmin))
830                                 return 0;
831                         break;
832                 case Opt_acregmax:
833                         if (match_int(args, &mnt->acregmax))
834                                 return 0;
835                         break;
836                 case Opt_acdirmin:
837                         if (match_int(args, &mnt->acdirmin))
838                                 return 0;
839                         break;
840                 case Opt_acdirmax:
841                         if (match_int(args, &mnt->acdirmax))
842                                 return 0;
843                         break;
844                 case Opt_actimeo:
845                         if (match_int(args, &option))
846                                 return 0;
847                         if (option < 0)
848                                 return 0;
849                         mnt->acregmin =
850                         mnt->acregmax =
851                         mnt->acdirmin =
852                         mnt->acdirmax = option;
853                         break;
854                 case Opt_namelen:
855                         if (match_int(args, &mnt->namlen))
856                                 return 0;
857                         break;
858                 case Opt_mountport:
859                         if (match_int(args, &option))
860                                 return 0;
861                         if (option < 0 || option > 65535)
862                                 return 0;
863                         mnt->mount_server.port = option;
864                         break;
865                 case Opt_mountvers:
866                         if (match_int(args, &option))
867                                 return 0;
868                         if (option < 0)
869                                 return 0;
870                         mnt->mount_server.version = option;
871                         break;
872                 case Opt_nfsvers:
873                         if (match_int(args, &option))
874                                 return 0;
875                         switch (option) {
876                         case 2:
877                                 mnt->flags &= ~NFS_MOUNT_VER3;
878                                 break;
879                         case 3:
880                                 mnt->flags |= NFS_MOUNT_VER3;
881                                 break;
882                         default:
883                                 goto out_unrec_vers;
884                         }
885                         break;
886
887                 case Opt_sec:
888                         string = match_strdup(args);
889                         if (string == NULL)
890                                 goto out_nomem;
891                         token = match_token(string, nfs_secflavor_tokens, args);
892                         kfree(string);
893
894                         /*
895                          * The flags setting is for v2/v3.  The flavor_len
896                          * setting is for v4.  v2/v3 also need to know the
897                          * difference between NULL and UNIX.
898                          */
899                         switch (token) {
900                         case Opt_sec_none:
901                                 mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
902                                 mnt->auth_flavor_len = 0;
903                                 mnt->auth_flavors[0] = RPC_AUTH_NULL;
904                                 break;
905                         case Opt_sec_sys:
906                                 mnt->flags &= ~NFS_MOUNT_SECFLAVOUR;
907                                 mnt->auth_flavor_len = 0;
908                                 mnt->auth_flavors[0] = RPC_AUTH_UNIX;
909                                 break;
910                         case Opt_sec_krb5:
911                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
912                                 mnt->auth_flavor_len = 1;
913                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5;
914                                 break;
915                         case Opt_sec_krb5i:
916                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
917                                 mnt->auth_flavor_len = 1;
918                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5I;
919                                 break;
920                         case Opt_sec_krb5p:
921                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
922                                 mnt->auth_flavor_len = 1;
923                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_KRB5P;
924                                 break;
925                         case Opt_sec_lkey:
926                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
927                                 mnt->auth_flavor_len = 1;
928                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEY;
929                                 break;
930                         case Opt_sec_lkeyi:
931                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
932                                 mnt->auth_flavor_len = 1;
933                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYI;
934                                 break;
935                         case Opt_sec_lkeyp:
936                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
937                                 mnt->auth_flavor_len = 1;
938                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_LKEYP;
939                                 break;
940                         case Opt_sec_spkm:
941                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
942                                 mnt->auth_flavor_len = 1;
943                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKM;
944                                 break;
945                         case Opt_sec_spkmi:
946                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
947                                 mnt->auth_flavor_len = 1;
948                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMI;
949                                 break;
950                         case Opt_sec_spkmp:
951                                 mnt->flags |= NFS_MOUNT_SECFLAVOUR;
952                                 mnt->auth_flavor_len = 1;
953                                 mnt->auth_flavors[0] = RPC_AUTH_GSS_SPKMP;
954                                 break;
955                         default:
956                                 goto out_unrec_sec;
957                         }
958                         break;
959                 case Opt_proto:
960                         string = match_strdup(args);
961                         if (string == NULL)
962                                 goto out_nomem;
963                         token = match_token(string,
964                                             nfs_xprt_protocol_tokens, args);
965                         kfree(string);
966
967                         switch (token) {
968                         case Opt_xprt_udp:
969                                 mnt->flags &= ~NFS_MOUNT_TCP;
970                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
971                                 mnt->timeo = 7;
972                                 mnt->retrans = 5;
973                                 break;
974                         case Opt_xprt_tcp:
975                                 mnt->flags |= NFS_MOUNT_TCP;
976                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
977                                 mnt->timeo = 600;
978                                 mnt->retrans = 2;
979                                 break;
980                         case Opt_xprt_rdma:
981                                 /* vector side protocols to TCP */
982                                 mnt->flags |= NFS_MOUNT_TCP;
983                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
984                                 mnt->timeo = 600;
985                                 mnt->retrans = 2;
986                                 break;
987                         default:
988                                 goto out_unrec_xprt;
989                         }
990                         break;
991                 case Opt_mountproto:
992                         string = match_strdup(args);
993                         if (string == NULL)
994                                 goto out_nomem;
995                         token = match_token(string,
996                                             nfs_xprt_protocol_tokens, args);
997                         kfree(string);
998
999                         switch (token) {
1000                         case Opt_xprt_udp:
1001                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1002                                 break;
1003                         case Opt_xprt_tcp:
1004                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1005                                 break;
1006                         case Opt_xprt_rdma: /* not used for side protocols */
1007                         default:
1008                                 goto out_unrec_xprt;
1009                         }
1010                         break;
1011                 case Opt_addr:
1012                         string = match_strdup(args);
1013                         if (string == NULL)
1014                                 goto out_nomem;
1015                         nfs_parse_server_address(string, (struct sockaddr *)
1016                                                  &mnt->nfs_server.address,
1017                                                  &mnt->nfs_server.addrlen);
1018                         kfree(string);
1019                         break;
1020                 case Opt_clientaddr:
1021                         string = match_strdup(args);
1022                         if (string == NULL)
1023                                 goto out_nomem;
1024                         kfree(mnt->client_address);
1025                         mnt->client_address = string;
1026                         break;
1027                 case Opt_mounthost:
1028                         string = match_strdup(args);
1029                         if (string == NULL)
1030                                 goto out_nomem;
1031                         kfree(mnt->mount_server.hostname);
1032                         mnt->mount_server.hostname = string;
1033                         break;
1034                 case Opt_mountaddr:
1035                         string = match_strdup(args);
1036                         if (string == NULL)
1037                                 goto out_nomem;
1038                         nfs_parse_server_address(string, (struct sockaddr *)
1039                                                  &mnt->mount_server.address,
1040                                                  &mnt->mount_server.addrlen);
1041                         kfree(string);
1042                         break;
1043
1044                 case Opt_userspace:
1045                 case Opt_deprecated:
1046                         break;
1047
1048                 default:
1049                         goto out_unknown;
1050                 }
1051         }
1052
1053         nfs_set_port((struct sockaddr *)&mnt->nfs_server.address, port);
1054
1055         return 1;
1056
1057 out_nomem:
1058         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1059         return 0;
1060 out_security_failure:
1061         free_secdata(secdata);
1062         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1063         return 0;
1064 out_unrec_vers:
1065         printk(KERN_INFO "NFS: unrecognized NFS version number\n");
1066         return 0;
1067
1068 out_unrec_xprt:
1069         printk(KERN_INFO "NFS: unrecognized transport protocol\n");
1070         return 0;
1071
1072 out_unrec_sec:
1073         printk(KERN_INFO "NFS: unrecognized security flavor\n");
1074         return 0;
1075
1076 out_unknown:
1077         printk(KERN_INFO "NFS: unknown mount option: %s\n", p);
1078         return 0;
1079 }
1080
1081 /*
1082  * Use the remote server's MOUNT service to request the NFS file handle
1083  * corresponding to the provided path.
1084  */
1085 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
1086                          struct nfs_fh *root_fh)
1087 {
1088         struct sockaddr *sap = (struct sockaddr *)&args->mount_server.address;
1089         char *hostname;
1090         int status;
1091
1092         if (args->mount_server.version == 0) {
1093                 if (args->flags & NFS_MOUNT_VER3)
1094                         args->mount_server.version = NFS_MNT3_VERSION;
1095                 else
1096                         args->mount_server.version = NFS_MNT_VERSION;
1097         }
1098
1099         if (args->mount_server.hostname)
1100                 hostname = args->mount_server.hostname;
1101         else
1102                 hostname = args->nfs_server.hostname;
1103
1104         /*
1105          * Construct the mount server's address.
1106          */
1107         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1108                 memcpy(sap, &args->nfs_server.address,
1109                        args->nfs_server.addrlen);
1110                 args->mount_server.addrlen = args->nfs_server.addrlen;
1111         }
1112
1113         /*
1114          * autobind will be used if mount_server.port == 0
1115          */
1116         nfs_set_port(sap, args->mount_server.port);
1117
1118         /*
1119          * Now ask the mount server to map our export path
1120          * to a file handle.
1121          */
1122         status = nfs_mount(sap,
1123                            args->mount_server.addrlen,
1124                            hostname,
1125                            args->nfs_server.export_path,
1126                            args->mount_server.version,
1127                            args->mount_server.protocol,
1128                            root_fh);
1129         if (status == 0)
1130                 return 0;
1131
1132         dfprintk(MOUNT, "NFS: unable to mount server %s, error %d",
1133                         hostname, status);
1134         return status;
1135 }
1136
1137 /*
1138  * Validate the NFS2/NFS3 mount data
1139  * - fills in the mount root filehandle
1140  *
1141  * For option strings, user space handles the following behaviors:
1142  *
1143  * + DNS: mapping server host name to IP address ("addr=" option)
1144  *
1145  * + failure mode: how to behave if a mount request can't be handled
1146  *   immediately ("fg/bg" option)
1147  *
1148  * + retry: how often to retry a mount request ("retry=" option)
1149  *
1150  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1151  *   mountproto=tcp after mountproto=udp, and so on
1152  */
1153 static int nfs_validate_mount_data(void *options,
1154                                    struct nfs_parsed_mount_data *args,
1155                                    struct nfs_fh *mntfh,
1156                                    const char *dev_name)
1157 {
1158         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1159
1160         memset(args, 0, sizeof(*args));
1161
1162         if (data == NULL)
1163                 goto out_no_data;
1164
1165         args->flags             = (NFS_MOUNT_VER3 | NFS_MOUNT_TCP);
1166         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1167         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1168         args->timeo             = 600;
1169         args->retrans           = 2;
1170         args->acregmin          = 3;
1171         args->acregmax          = 60;
1172         args->acdirmin          = 30;
1173         args->acdirmax          = 60;
1174         args->mount_server.protocol = XPRT_TRANSPORT_UDP;
1175         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1176
1177         switch (data->version) {
1178         case 1:
1179                 data->namlen = 0;
1180         case 2:
1181                 data->bsize = 0;
1182         case 3:
1183                 if (data->flags & NFS_MOUNT_VER3)
1184                         goto out_no_v3;
1185                 data->root.size = NFS2_FHSIZE;
1186                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1187         case 4:
1188                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1189                         goto out_no_sec;
1190         case 5:
1191                 memset(data->context, 0, sizeof(data->context));
1192         case 6:
1193                 if (data->flags & NFS_MOUNT_VER3)
1194                         mntfh->size = data->root.size;
1195                 else
1196                         mntfh->size = NFS2_FHSIZE;
1197
1198                 if (mntfh->size > sizeof(mntfh->data))
1199                         goto out_invalid_fh;
1200
1201                 memcpy(mntfh->data, data->root.data, mntfh->size);
1202                 if (mntfh->size < sizeof(mntfh->data))
1203                         memset(mntfh->data + mntfh->size, 0,
1204                                sizeof(mntfh->data) - mntfh->size);
1205
1206                 /*
1207                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1208                  * can deal with.
1209                  */
1210                 args->flags             = data->flags;
1211                 args->rsize             = data->rsize;
1212                 args->wsize             = data->wsize;
1213                 args->flags             = data->flags;
1214                 args->timeo             = data->timeo;
1215                 args->retrans           = data->retrans;
1216                 args->acregmin          = data->acregmin;
1217                 args->acregmax          = data->acregmax;
1218                 args->acdirmin          = data->acdirmin;
1219                 args->acdirmax          = data->acdirmax;
1220
1221                 memcpy(&args->nfs_server.address, &data->addr,
1222                        sizeof(data->addr));
1223                 args->nfs_server.addrlen = sizeof(data->addr);
1224                 if (!nfs_verify_server_address((struct sockaddr *)
1225                                                 &args->nfs_server.address))
1226                         goto out_no_address;
1227
1228                 if (!(data->flags & NFS_MOUNT_TCP))
1229                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1230                 /* N.B. caller will free nfs_server.hostname in all cases */
1231                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
1232                 args->namlen            = data->namlen;
1233                 args->bsize             = data->bsize;
1234                 args->auth_flavors[0]   = data->pseudoflavor;
1235
1236                 /*
1237                  * The legacy version 6 binary mount data from userspace has a
1238                  * field used only to transport selinux information into the
1239                  * the kernel.  To continue to support that functionality we
1240                  * have a touch of selinux knowledge here in the NFS code. The
1241                  * userspace code converted context=blah to just blah so we are
1242                  * converting back to the full string selinux understands.
1243                  */
1244                 if (data->context[0]){
1245 #ifdef CONFIG_SECURITY_SELINUX
1246                         int rc;
1247                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
1248                         if (!opts_str)
1249                                 return -ENOMEM;
1250                         strcpy(opts_str, "context=");
1251                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
1252                         strcat(opts_str, &data->context[0]);
1253                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
1254                         kfree(opts_str);
1255                         if (rc)
1256                                 return rc;
1257 #else
1258                         return -EINVAL;
1259 #endif
1260                 }
1261
1262                 break;
1263         default: {
1264                 unsigned int len;
1265                 char *c;
1266                 int status;
1267
1268                 if (nfs_parse_mount_options((char *)options, args) == 0)
1269                         return -EINVAL;
1270
1271                 if (!nfs_verify_server_address((struct sockaddr *)
1272                                                 &args->nfs_server.address))
1273                         goto out_no_address;
1274
1275                 c = strchr(dev_name, ':');
1276                 if (c == NULL)
1277                         return -EINVAL;
1278                 len = c - dev_name;
1279                 /* N.B. caller will free nfs_server.hostname in all cases */
1280                 args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
1281
1282                 c++;
1283                 if (strlen(c) > NFS_MAXPATHLEN)
1284                         return -ENAMETOOLONG;
1285                 args->nfs_server.export_path = c;
1286
1287                 status = nfs_try_mount(args, mntfh);
1288                 if (status)
1289                         return status;
1290
1291                 break;
1292                 }
1293         }
1294
1295         if (!(args->flags & NFS_MOUNT_SECFLAVOUR))
1296                 args->auth_flavors[0] = RPC_AUTH_UNIX;
1297
1298 #ifndef CONFIG_NFS_V3
1299         if (args->flags & NFS_MOUNT_VER3)
1300                 goto out_v3_not_compiled;
1301 #endif /* !CONFIG_NFS_V3 */
1302
1303         return 0;
1304
1305 out_no_data:
1306         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
1307         return -EINVAL;
1308
1309 out_no_v3:
1310         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
1311                  data->version);
1312         return -EINVAL;
1313
1314 out_no_sec:
1315         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
1316         return -EINVAL;
1317
1318 #ifndef CONFIG_NFS_V3
1319 out_v3_not_compiled:
1320         dfprintk(MOUNT, "NFS: NFSv3 is not compiled into kernel\n");
1321         return -EPROTONOSUPPORT;
1322 #endif /* !CONFIG_NFS_V3 */
1323
1324 out_no_address:
1325         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
1326         return -EINVAL;
1327
1328 out_invalid_fh:
1329         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
1330         return -EINVAL;
1331 }
1332
1333 /*
1334  * Initialise the common bits of the superblock
1335  */
1336 static inline void nfs_initialise_sb(struct super_block *sb)
1337 {
1338         struct nfs_server *server = NFS_SB(sb);
1339
1340         sb->s_magic = NFS_SUPER_MAGIC;
1341
1342         /* We probably want something more informative here */
1343         snprintf(sb->s_id, sizeof(sb->s_id),
1344                  "%x:%x", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1345
1346         if (sb->s_blocksize == 0)
1347                 sb->s_blocksize = nfs_block_bits(server->wsize,
1348                                                  &sb->s_blocksize_bits);
1349
1350         if (server->flags & NFS_MOUNT_NOAC)
1351                 sb->s_flags |= MS_SYNCHRONOUS;
1352
1353         nfs_super_set_maxbytes(sb, server->maxfilesize);
1354 }
1355
1356 /*
1357  * Finish setting up an NFS2/3 superblock
1358  */
1359 static void nfs_fill_super(struct super_block *sb,
1360                            struct nfs_parsed_mount_data *data)
1361 {
1362         struct nfs_server *server = NFS_SB(sb);
1363
1364         sb->s_blocksize_bits = 0;
1365         sb->s_blocksize = 0;
1366         if (data->bsize)
1367                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
1368
1369         if (server->flags & NFS_MOUNT_VER3) {
1370                 /* The VFS shouldn't apply the umask to mode bits. We will do
1371                  * so ourselves when necessary.
1372                  */
1373                 sb->s_flags |= MS_POSIXACL;
1374                 sb->s_time_gran = 1;
1375         }
1376
1377         sb->s_op = &nfs_sops;
1378         nfs_initialise_sb(sb);
1379 }
1380
1381 /*
1382  * Finish setting up a cloned NFS2/3 superblock
1383  */
1384 static void nfs_clone_super(struct super_block *sb,
1385                             const struct super_block *old_sb)
1386 {
1387         struct nfs_server *server = NFS_SB(sb);
1388
1389         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1390         sb->s_blocksize = old_sb->s_blocksize;
1391         sb->s_maxbytes = old_sb->s_maxbytes;
1392
1393         if (server->flags & NFS_MOUNT_VER3) {
1394                 /* The VFS shouldn't apply the umask to mode bits. We will do
1395                  * so ourselves when necessary.
1396                  */
1397                 sb->s_flags |= MS_POSIXACL;
1398                 sb->s_time_gran = 1;
1399         }
1400
1401         sb->s_op = old_sb->s_op;
1402         nfs_initialise_sb(sb);
1403 }
1404
1405 #define NFS_MS_MASK (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS)
1406
1407 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
1408 {
1409         const struct nfs_server *a = s->s_fs_info;
1410         const struct rpc_clnt *clnt_a = a->client;
1411         const struct rpc_clnt *clnt_b = b->client;
1412
1413         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
1414                 goto Ebusy;
1415         if (a->nfs_client != b->nfs_client)
1416                 goto Ebusy;
1417         if (a->flags != b->flags)
1418                 goto Ebusy;
1419         if (a->wsize != b->wsize)
1420                 goto Ebusy;
1421         if (a->rsize != b->rsize)
1422                 goto Ebusy;
1423         if (a->acregmin != b->acregmin)
1424                 goto Ebusy;
1425         if (a->acregmax != b->acregmax)
1426                 goto Ebusy;
1427         if (a->acdirmin != b->acdirmin)
1428                 goto Ebusy;
1429         if (a->acdirmax != b->acdirmax)
1430                 goto Ebusy;
1431         if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1432                 goto Ebusy;
1433         return 1;
1434 Ebusy:
1435         return 0;
1436 }
1437
1438 struct nfs_sb_mountdata {
1439         struct nfs_server *server;
1440         int mntflags;
1441 };
1442
1443 static int nfs_set_super(struct super_block *s, void *data)
1444 {
1445         struct nfs_sb_mountdata *sb_mntdata = data;
1446         struct nfs_server *server = sb_mntdata->server;
1447         int ret;
1448
1449         s->s_flags = sb_mntdata->mntflags;
1450         s->s_fs_info = server;
1451         ret = set_anon_super(s, server);
1452         if (ret == 0)
1453                 server->s_dev = s->s_dev;
1454         return ret;
1455 }
1456
1457 static int nfs_compare_super_address(struct nfs_server *server1,
1458                                      struct nfs_server *server2)
1459 {
1460         struct sockaddr *sap1, *sap2;
1461
1462         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1463         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1464
1465         if (sap1->sa_family != sap2->sa_family)
1466                 return 0;
1467
1468         switch (sap1->sa_family) {
1469         case AF_INET: {
1470                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1471                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1472                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1473                         return 0;
1474                 if (sin1->sin_port != sin2->sin_port)
1475                         return 0;
1476                 break;
1477         }
1478         case AF_INET6: {
1479                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1480                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1481                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1482                         return 0;
1483                 if (sin1->sin6_port != sin2->sin6_port)
1484                         return 0;
1485                 break;
1486         }
1487         default:
1488                 return 0;
1489         }
1490
1491         return 1;
1492 }
1493
1494 static int nfs_compare_super(struct super_block *sb, void *data)
1495 {
1496         struct nfs_sb_mountdata *sb_mntdata = data;
1497         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
1498         int mntflags = sb_mntdata->mntflags;
1499
1500         if (!nfs_compare_super_address(old, server))
1501                 return 0;
1502         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1503         if (old->flags & NFS_MOUNT_UNSHARED)
1504                 return 0;
1505         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1506                 return 0;
1507         return nfs_compare_mount_options(sb, server, mntflags);
1508 }
1509
1510 static int nfs_get_sb(struct file_system_type *fs_type,
1511         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1512 {
1513         struct nfs_server *server = NULL;
1514         struct super_block *s;
1515         struct nfs_fh mntfh;
1516         struct nfs_parsed_mount_data data;
1517         struct dentry *mntroot;
1518         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1519         struct nfs_sb_mountdata sb_mntdata = {
1520                 .mntflags = flags,
1521         };
1522         int error;
1523
1524         security_init_mnt_opts(&data.lsm_opts);
1525
1526         /* Validate the mount data */
1527         error = nfs_validate_mount_data(raw_data, &data, &mntfh, dev_name);
1528         if (error < 0)
1529                 goto out;
1530
1531         /* Get a volume representation */
1532         server = nfs_create_server(&data, &mntfh);
1533         if (IS_ERR(server)) {
1534                 error = PTR_ERR(server);
1535                 goto out;
1536         }
1537         sb_mntdata.server = server;
1538
1539         if (server->flags & NFS_MOUNT_UNSHARED)
1540                 compare_super = NULL;
1541
1542         /* Get a superblock - note that we may end up sharing one that already exists */
1543         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1544         if (IS_ERR(s)) {
1545                 error = PTR_ERR(s);
1546                 goto out_err_nosb;
1547         }
1548
1549         if (s->s_fs_info != server) {
1550                 nfs_free_server(server);
1551                 server = NULL;
1552         }
1553
1554         if (!s->s_root) {
1555                 /* initial superblock/root creation */
1556                 nfs_fill_super(s, &data);
1557         }
1558
1559         mntroot = nfs_get_root(s, &mntfh);
1560         if (IS_ERR(mntroot)) {
1561                 error = PTR_ERR(mntroot);
1562                 goto error_splat_super;
1563         }
1564
1565         error = security_sb_set_mnt_opts(s, &data.lsm_opts);
1566         if (error)
1567                 goto error_splat_root;
1568
1569         s->s_flags |= MS_ACTIVE;
1570         mnt->mnt_sb = s;
1571         mnt->mnt_root = mntroot;
1572         error = 0;
1573
1574 out:
1575         kfree(data.nfs_server.hostname);
1576         kfree(data.mount_server.hostname);
1577         security_free_mnt_opts(&data.lsm_opts);
1578         return error;
1579
1580 out_err_nosb:
1581         nfs_free_server(server);
1582         goto out;
1583
1584 error_splat_root:
1585         dput(mntroot);
1586 error_splat_super:
1587         up_write(&s->s_umount);
1588         deactivate_super(s);
1589         goto out;
1590 }
1591
1592 /*
1593  * Destroy an NFS2/3 superblock
1594  */
1595 static void nfs_kill_super(struct super_block *s)
1596 {
1597         struct nfs_server *server = NFS_SB(s);
1598
1599         kill_anon_super(s);
1600         nfs_free_server(server);
1601 }
1602
1603 /*
1604  * Clone an NFS2/3 server record on xdev traversal (FSID-change)
1605  */
1606 static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags,
1607                            const char *dev_name, void *raw_data,
1608                            struct vfsmount *mnt)
1609 {
1610         struct nfs_clone_mount *data = raw_data;
1611         struct super_block *s;
1612         struct nfs_server *server;
1613         struct dentry *mntroot;
1614         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1615         struct nfs_sb_mountdata sb_mntdata = {
1616                 .mntflags = flags,
1617         };
1618         int error;
1619
1620         dprintk("--> nfs_xdev_get_sb()\n");
1621
1622         /* create a new volume representation */
1623         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
1624         if (IS_ERR(server)) {
1625                 error = PTR_ERR(server);
1626                 goto out_err_noserver;
1627         }
1628         sb_mntdata.server = server;
1629
1630         if (server->flags & NFS_MOUNT_UNSHARED)
1631                 compare_super = NULL;
1632
1633         /* Get a superblock - note that we may end up sharing one that already exists */
1634         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
1635         if (IS_ERR(s)) {
1636                 error = PTR_ERR(s);
1637                 goto out_err_nosb;
1638         }
1639
1640         if (s->s_fs_info != server) {
1641                 nfs_free_server(server);
1642                 server = NULL;
1643         }
1644
1645         if (!s->s_root) {
1646                 /* initial superblock/root creation */
1647                 nfs_clone_super(s, data->sb);
1648         }
1649
1650         mntroot = nfs_get_root(s, data->fh);
1651         if (IS_ERR(mntroot)) {
1652                 error = PTR_ERR(mntroot);
1653                 goto error_splat_super;
1654         }
1655         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
1656                 dput(mntroot);
1657                 error = -ESTALE;
1658                 goto error_splat_super;
1659         }
1660
1661         s->s_flags |= MS_ACTIVE;
1662         mnt->mnt_sb = s;
1663         mnt->mnt_root = mntroot;
1664
1665         /* clone any lsm security options from the parent to the new sb */
1666         security_sb_clone_mnt_opts(data->sb, s);
1667
1668         dprintk("<-- nfs_xdev_get_sb() = 0\n");
1669         return 0;
1670
1671 out_err_nosb:
1672         nfs_free_server(server);
1673 out_err_noserver:
1674         dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
1675         return error;
1676
1677 error_splat_super:
1678         up_write(&s->s_umount);
1679         deactivate_super(s);
1680         dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
1681         return error;
1682 }
1683
1684 #ifdef CONFIG_NFS_V4
1685
1686 /*
1687  * Finish setting up a cloned NFS4 superblock
1688  */
1689 static void nfs4_clone_super(struct super_block *sb,
1690                             const struct super_block *old_sb)
1691 {
1692         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
1693         sb->s_blocksize = old_sb->s_blocksize;
1694         sb->s_maxbytes = old_sb->s_maxbytes;
1695         sb->s_time_gran = 1;
1696         sb->s_op = old_sb->s_op;
1697         nfs_initialise_sb(sb);
1698 }
1699
1700 /*
1701  * Set up an NFS4 superblock
1702  */
1703 static void nfs4_fill_super(struct super_block *sb)
1704 {
1705         sb->s_time_gran = 1;
1706         sb->s_op = &nfs4_sops;
1707         nfs_initialise_sb(sb);
1708 }
1709
1710 /*
1711  * If the user didn't specify a port, set the port number to
1712  * the NFS version 4 default port.
1713  */
1714 static void nfs4_default_port(struct sockaddr *sap)
1715 {
1716         switch (sap->sa_family) {
1717         case AF_INET: {
1718                 struct sockaddr_in *ap = (struct sockaddr_in *)sap;
1719                 if (ap->sin_port == 0)
1720                         ap->sin_port = htons(NFS_PORT);
1721                 break;
1722         }
1723         case AF_INET6: {
1724                 struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
1725                 if (ap->sin6_port == 0)
1726                         ap->sin6_port = htons(NFS_PORT);
1727                 break;
1728         }
1729         }
1730 }
1731
1732 /*
1733  * Validate NFSv4 mount options
1734  */
1735 static int nfs4_validate_mount_data(void *options,
1736                                     struct nfs_parsed_mount_data *args,
1737                                     const char *dev_name)
1738 {
1739         struct sockaddr_in *ap;
1740         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
1741         char *c;
1742
1743         memset(args, 0, sizeof(*args));
1744
1745         if (data == NULL)
1746                 goto out_no_data;
1747
1748         args->rsize             = NFS_MAX_FILE_IO_SIZE;
1749         args->wsize             = NFS_MAX_FILE_IO_SIZE;
1750         args->timeo             = 600;
1751         args->retrans           = 2;
1752         args->acregmin          = 3;
1753         args->acregmax          = 60;
1754         args->acdirmin          = 30;
1755         args->acdirmax          = 60;
1756         args->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1757
1758         switch (data->version) {
1759         case 1:
1760                 ap = (struct sockaddr_in *)&args->nfs_server.address;
1761                 if (data->host_addrlen > sizeof(args->nfs_server.address))
1762                         goto out_no_address;
1763                 if (data->host_addrlen == 0)
1764                         goto out_no_address;
1765                 args->nfs_server.addrlen = data->host_addrlen;
1766                 if (copy_from_user(ap, data->host_addr, data->host_addrlen))
1767                         return -EFAULT;
1768                 if (!nfs_verify_server_address((struct sockaddr *)
1769                                                 &args->nfs_server.address))
1770                         goto out_no_address;
1771
1772                 nfs4_default_port((struct sockaddr *)
1773                                   &args->nfs_server.address);
1774
1775                 switch (data->auth_flavourlen) {
1776                 case 0:
1777                         args->auth_flavors[0] = RPC_AUTH_UNIX;
1778                         break;
1779                 case 1:
1780                         if (copy_from_user(&args->auth_flavors[0],
1781                                            data->auth_flavours,
1782                                            sizeof(args->auth_flavors[0])))
1783                                 return -EFAULT;
1784                         break;
1785                 default:
1786                         goto out_inval_auth;
1787                 }
1788
1789                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
1790                 if (IS_ERR(c))
1791                         return PTR_ERR(c);
1792                 args->nfs_server.hostname = c;
1793
1794                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
1795                 if (IS_ERR(c))
1796                         return PTR_ERR(c);
1797                 args->nfs_server.export_path = c;
1798                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
1799
1800                 c = strndup_user(data->client_addr.data, 16);
1801                 if (IS_ERR(c))
1802                         return PTR_ERR(c);
1803                 args->client_address = c;
1804
1805                 /*
1806                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
1807                  * can deal with.
1808                  */
1809
1810                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
1811                 args->rsize     = data->rsize;
1812                 args->wsize     = data->wsize;
1813                 args->timeo     = data->timeo;
1814                 args->retrans   = data->retrans;
1815                 args->acregmin  = data->acregmin;
1816                 args->acregmax  = data->acregmax;
1817                 args->acdirmin  = data->acdirmin;
1818                 args->acdirmax  = data->acdirmax;
1819                 args->nfs_server.protocol = data->proto;
1820
1821                 break;
1822         default: {
1823                 unsigned int len;
1824
1825                 if (nfs_parse_mount_options((char *)options, args) == 0)
1826                         return -EINVAL;
1827
1828                 if (!nfs_verify_server_address((struct sockaddr *)
1829                                                 &args->nfs_server.address))
1830                         return -EINVAL;
1831
1832                 nfs4_default_port((struct sockaddr *)
1833                                   &args->nfs_server.address);
1834
1835                 switch (args->auth_flavor_len) {
1836                 case 0:
1837                         args->auth_flavors[0] = RPC_AUTH_UNIX;
1838                         break;
1839                 case 1:
1840                         break;
1841                 default:
1842                         goto out_inval_auth;
1843                 }
1844
1845                 /*
1846                  * Split "dev_name" into "hostname:mntpath".
1847                  */
1848                 c = strchr(dev_name, ':');
1849                 if (c == NULL)
1850                         return -EINVAL;
1851                 /* while calculating len, pretend ':' is '\0' */
1852                 len = c - dev_name;
1853                 if (len > NFS4_MAXNAMLEN)
1854                         return -ENAMETOOLONG;
1855                 /* N.B. caller will free nfs_server.hostname in all cases */
1856                 args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
1857
1858                 c++;                    /* step over the ':' */
1859                 len = strlen(c);
1860                 if (len > NFS4_MAXPATHLEN)
1861                         return -ENAMETOOLONG;
1862                 args->nfs_server.export_path = kstrndup(c, len, GFP_KERNEL);
1863
1864                 dprintk("NFS: MNTPATH: '%s'\n", args->nfs_server.export_path);
1865
1866                 if (args->client_address == NULL)
1867                         goto out_no_client_address;
1868
1869                 break;
1870                 }
1871         }
1872
1873         return 0;
1874
1875 out_no_data:
1876         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
1877         return -EINVAL;
1878
1879 out_inval_auth:
1880         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
1881                  data->auth_flavourlen);
1882         return -EINVAL;
1883
1884 out_no_address:
1885         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
1886         return -EINVAL;
1887
1888 out_no_client_address:
1889         dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
1890         return -EINVAL;
1891 }
1892
1893 /*
1894  * Get the superblock for an NFS4 mountpoint
1895  */
1896 static int nfs4_get_sb(struct file_system_type *fs_type,
1897         int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
1898 {
1899         struct nfs_parsed_mount_data data;
1900         struct super_block *s;
1901         struct nfs_server *server;
1902         struct nfs_fh mntfh;
1903         struct dentry *mntroot;
1904         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1905         struct nfs_sb_mountdata sb_mntdata = {
1906                 .mntflags = flags,
1907         };
1908         int error;
1909
1910         security_init_mnt_opts(&data.lsm_opts);
1911
1912         /* Validate the mount data */
1913         error = nfs4_validate_mount_data(raw_data, &data, dev_name);
1914         if (error < 0)
1915                 goto out;
1916
1917         /* Get a volume representation */
1918         server = nfs4_create_server(&data, &mntfh);
1919         if (IS_ERR(server)) {
1920                 error = PTR_ERR(server);
1921                 goto out;
1922         }
1923         sb_mntdata.server = server;
1924
1925         if (server->flags & NFS4_MOUNT_UNSHARED)
1926                 compare_super = NULL;
1927
1928         /* Get a superblock - note that we may end up sharing one that already exists */
1929         s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
1930         if (IS_ERR(s)) {
1931                 error = PTR_ERR(s);
1932                 goto out_free;
1933         }
1934
1935         if (s->s_fs_info != server) {
1936                 nfs_free_server(server);
1937                 server = NULL;
1938         }
1939
1940         if (!s->s_root) {
1941                 /* initial superblock/root creation */
1942                 nfs4_fill_super(s);
1943         }
1944
1945         mntroot = nfs4_get_root(s, &mntfh);
1946         if (IS_ERR(mntroot)) {
1947                 error = PTR_ERR(mntroot);
1948                 goto error_splat_super;
1949         }
1950
1951         s->s_flags |= MS_ACTIVE;
1952         mnt->mnt_sb = s;
1953         mnt->mnt_root = mntroot;
1954         error = 0;
1955
1956 out:
1957         kfree(data.client_address);
1958         kfree(data.nfs_server.export_path);
1959         kfree(data.nfs_server.hostname);
1960         security_free_mnt_opts(&data.lsm_opts);
1961         return error;
1962
1963 out_free:
1964         nfs_free_server(server);
1965         goto out;
1966
1967 error_splat_super:
1968         up_write(&s->s_umount);
1969         deactivate_super(s);
1970         goto out;
1971 }
1972
1973 static void nfs4_kill_super(struct super_block *sb)
1974 {
1975         struct nfs_server *server = NFS_SB(sb);
1976
1977         nfs_return_all_delegations(sb);
1978         kill_anon_super(sb);
1979
1980         nfs4_renewd_prepare_shutdown(server);
1981         nfs_free_server(server);
1982 }
1983
1984 /*
1985  * Clone an NFS4 server record on xdev traversal (FSID-change)
1986  */
1987 static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
1988                             const char *dev_name, void *raw_data,
1989                             struct vfsmount *mnt)
1990 {
1991         struct nfs_clone_mount *data = raw_data;
1992         struct super_block *s;
1993         struct nfs_server *server;
1994         struct dentry *mntroot;
1995         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
1996         struct nfs_sb_mountdata sb_mntdata = {
1997                 .mntflags = flags,
1998         };
1999         int error;
2000
2001         dprintk("--> nfs4_xdev_get_sb()\n");
2002
2003         /* create a new volume representation */
2004         server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
2005         if (IS_ERR(server)) {
2006                 error = PTR_ERR(server);
2007                 goto out_err_noserver;
2008         }
2009         sb_mntdata.server = server;
2010
2011         if (server->flags & NFS4_MOUNT_UNSHARED)
2012                 compare_super = NULL;
2013
2014         /* Get a superblock - note that we may end up sharing one that already exists */
2015         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2016         if (IS_ERR(s)) {
2017                 error = PTR_ERR(s);
2018                 goto out_err_nosb;
2019         }
2020
2021         if (s->s_fs_info != server) {
2022                 nfs_free_server(server);
2023                 server = NULL;
2024         }
2025
2026         if (!s->s_root) {
2027                 /* initial superblock/root creation */
2028                 nfs4_clone_super(s, data->sb);
2029         }
2030
2031         mntroot = nfs4_get_root(s, data->fh);
2032         if (IS_ERR(mntroot)) {
2033                 error = PTR_ERR(mntroot);
2034                 goto error_splat_super;
2035         }
2036         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2037                 dput(mntroot);
2038                 error = -ESTALE;
2039                 goto error_splat_super;
2040         }
2041
2042         s->s_flags |= MS_ACTIVE;
2043         mnt->mnt_sb = s;
2044         mnt->mnt_root = mntroot;
2045
2046         dprintk("<-- nfs4_xdev_get_sb() = 0\n");
2047         return 0;
2048
2049 out_err_nosb:
2050         nfs_free_server(server);
2051 out_err_noserver:
2052         dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
2053         return error;
2054
2055 error_splat_super:
2056         up_write(&s->s_umount);
2057         deactivate_super(s);
2058         dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
2059         return error;
2060 }
2061
2062 /*
2063  * Create an NFS4 server record on referral traversal
2064  */
2065 static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
2066                                 const char *dev_name, void *raw_data,
2067                                 struct vfsmount *mnt)
2068 {
2069         struct nfs_clone_mount *data = raw_data;
2070         struct super_block *s;
2071         struct nfs_server *server;
2072         struct dentry *mntroot;
2073         struct nfs_fh mntfh;
2074         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2075         struct nfs_sb_mountdata sb_mntdata = {
2076                 .mntflags = flags,
2077         };
2078         int error;
2079
2080         dprintk("--> nfs4_referral_get_sb()\n");
2081
2082         /* create a new volume representation */
2083         server = nfs4_create_referral_server(data, &mntfh);
2084         if (IS_ERR(server)) {
2085                 error = PTR_ERR(server);
2086                 goto out_err_noserver;
2087         }
2088         sb_mntdata.server = server;
2089
2090         if (server->flags & NFS4_MOUNT_UNSHARED)
2091                 compare_super = NULL;
2092
2093         /* Get a superblock - note that we may end up sharing one that already exists */
2094         s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
2095         if (IS_ERR(s)) {
2096                 error = PTR_ERR(s);
2097                 goto out_err_nosb;
2098         }
2099
2100         if (s->s_fs_info != server) {
2101                 nfs_free_server(server);
2102                 server = NULL;
2103         }
2104
2105         if (!s->s_root) {
2106                 /* initial superblock/root creation */
2107                 nfs4_fill_super(s);
2108         }
2109
2110         mntroot = nfs4_get_root(s, &mntfh);
2111         if (IS_ERR(mntroot)) {
2112                 error = PTR_ERR(mntroot);
2113                 goto error_splat_super;
2114         }
2115         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
2116                 dput(mntroot);
2117                 error = -ESTALE;
2118                 goto error_splat_super;
2119         }
2120
2121         s->s_flags |= MS_ACTIVE;
2122         mnt->mnt_sb = s;
2123         mnt->mnt_root = mntroot;
2124
2125         dprintk("<-- nfs4_referral_get_sb() = 0\n");
2126         return 0;
2127
2128 out_err_nosb:
2129         nfs_free_server(server);
2130 out_err_noserver:
2131         dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
2132         return error;
2133
2134 error_splat_super:
2135         up_write(&s->s_umount);
2136         deactivate_super(s);
2137         dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
2138         return error;
2139 }
2140
2141 #endif /* CONFIG_NFS_V4 */