Version:  2.0.40 2.2.26 2.4.37 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18

Linux/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/addr.h>
 35 #include <linux/sunrpc/stats.h>
 36 #include <linux/sunrpc/metrics.h>
 37 #include <linux/sunrpc/xprtsock.h>
 38 #include <linux/sunrpc/xprtrdma.h>
 39 #include <linux/nfs_fs.h>
 40 #include <linux/nfs_mount.h>
 41 #include <linux/nfs4_mount.h>
 42 #include <linux/lockd/bind.h>
 43 #include <linux/seq_file.h>
 44 #include <linux/mount.h>
 45 #include <linux/namei.h>
 46 #include <linux/nfs_idmap.h>
 47 #include <linux/vfs.h>
 48 #include <linux/inet.h>
 49 #include <linux/in6.h>
 50 #include <linux/slab.h>
 51 #include <net/ipv6.h>
 52 #include <linux/netdevice.h>
 53 #include <linux/nfs_xdr.h>
 54 #include <linux/magic.h>
 55 #include <linux/parser.h>
 56 #include <linux/nsproxy.h>
 57 #include <linux/rcupdate.h>
 58 
 59 #include <asm/uaccess.h>
 60 
 61 #include "nfs4_fs.h"
 62 #include "callback.h"
 63 #include "delegation.h"
 64 #include "iostat.h"
 65 #include "internal.h"
 66 #include "fscache.h"
 67 #include "nfs4session.h"
 68 #include "pnfs.h"
 69 #include "nfs.h"
 70 
 71 #define NFSDBG_FACILITY         NFSDBG_VFS
 72 #define NFS_TEXT_DATA           1
 73 
 74 #if IS_ENABLED(CONFIG_NFS_V3)
 75 #define NFS_DEFAULT_VERSION 3
 76 #else
 77 #define NFS_DEFAULT_VERSION 2
 78 #endif
 79 
 80 enum {
 81         /* Mount options that take no arguments */
 82         Opt_soft, Opt_hard,
 83         Opt_posix, Opt_noposix,
 84         Opt_cto, Opt_nocto,
 85         Opt_ac, Opt_noac,
 86         Opt_lock, Opt_nolock,
 87         Opt_udp, Opt_tcp, Opt_rdma,
 88         Opt_acl, Opt_noacl,
 89         Opt_rdirplus, Opt_nordirplus,
 90         Opt_sharecache, Opt_nosharecache,
 91         Opt_resvport, Opt_noresvport,
 92         Opt_fscache, Opt_nofscache,
 93         Opt_migration, Opt_nomigration,
 94 
 95         /* Mount options that take integer arguments */
 96         Opt_port,
 97         Opt_rsize, Opt_wsize, Opt_bsize,
 98         Opt_timeo, Opt_retrans,
 99         Opt_acregmin, Opt_acregmax,
100         Opt_acdirmin, Opt_acdirmax,
101         Opt_actimeo,
102         Opt_namelen,
103         Opt_mountport,
104         Opt_mountvers,
105         Opt_minorversion,
106 
107         /* Mount options that take string arguments */
108         Opt_nfsvers,
109         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
110         Opt_addr, Opt_mountaddr, Opt_clientaddr,
111         Opt_lookupcache,
112         Opt_fscache_uniq,
113         Opt_local_lock,
114 
115         /* Special mount options */
116         Opt_userspace, Opt_deprecated, Opt_sloppy,
117 
118         Opt_err
119 };
120 
121 static const match_table_t nfs_mount_option_tokens = {
122         { Opt_userspace, "bg" },
123         { Opt_userspace, "fg" },
124         { Opt_userspace, "retry=%s" },
125 
126         { Opt_sloppy, "sloppy" },
127 
128         { Opt_soft, "soft" },
129         { Opt_hard, "hard" },
130         { Opt_deprecated, "intr" },
131         { Opt_deprecated, "nointr" },
132         { Opt_posix, "posix" },
133         { Opt_noposix, "noposix" },
134         { Opt_cto, "cto" },
135         { Opt_nocto, "nocto" },
136         { Opt_ac, "ac" },
137         { Opt_noac, "noac" },
138         { Opt_lock, "lock" },
139         { Opt_nolock, "nolock" },
140         { Opt_udp, "udp" },
141         { Opt_tcp, "tcp" },
142         { Opt_rdma, "rdma" },
143         { Opt_acl, "acl" },
144         { Opt_noacl, "noacl" },
145         { Opt_rdirplus, "rdirplus" },
146         { Opt_nordirplus, "nordirplus" },
147         { Opt_sharecache, "sharecache" },
148         { Opt_nosharecache, "nosharecache" },
149         { Opt_resvport, "resvport" },
150         { Opt_noresvport, "noresvport" },
151         { Opt_fscache, "fsc" },
152         { Opt_nofscache, "nofsc" },
153         { Opt_migration, "migration" },
154         { Opt_nomigration, "nomigration" },
155 
156         { Opt_port, "port=%s" },
157         { Opt_rsize, "rsize=%s" },
158         { Opt_wsize, "wsize=%s" },
159         { Opt_bsize, "bsize=%s" },
160         { Opt_timeo, "timeo=%s" },
161         { Opt_retrans, "retrans=%s" },
162         { Opt_acregmin, "acregmin=%s" },
163         { Opt_acregmax, "acregmax=%s" },
164         { Opt_acdirmin, "acdirmin=%s" },
165         { Opt_acdirmax, "acdirmax=%s" },
166         { Opt_actimeo, "actimeo=%s" },
167         { Opt_namelen, "namlen=%s" },
168         { Opt_mountport, "mountport=%s" },
169         { Opt_mountvers, "mountvers=%s" },
170         { Opt_minorversion, "minorversion=%s" },
171 
172         { Opt_nfsvers, "nfsvers=%s" },
173         { Opt_nfsvers, "vers=%s" },
174 
175         { Opt_sec, "sec=%s" },
176         { Opt_proto, "proto=%s" },
177         { Opt_mountproto, "mountproto=%s" },
178         { Opt_addr, "addr=%s" },
179         { Opt_clientaddr, "clientaddr=%s" },
180         { Opt_mounthost, "mounthost=%s" },
181         { Opt_mountaddr, "mountaddr=%s" },
182 
183         { Opt_lookupcache, "lookupcache=%s" },
184         { Opt_fscache_uniq, "fsc=%s" },
185         { Opt_local_lock, "local_lock=%s" },
186 
187         /* The following needs to be listed after all other options */
188         { Opt_nfsvers, "v%s" },
189 
190         { Opt_err, NULL }
191 };
192 
193 enum {
194         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
195 
196         Opt_xprt_err
197 };
198 
199 static const match_table_t nfs_xprt_protocol_tokens = {
200         { Opt_xprt_udp, "udp" },
201         { Opt_xprt_udp6, "udp6" },
202         { Opt_xprt_tcp, "tcp" },
203         { Opt_xprt_tcp6, "tcp6" },
204         { Opt_xprt_rdma, "rdma" },
205 
206         { Opt_xprt_err, NULL }
207 };
208 
209 enum {
210         Opt_sec_none, Opt_sec_sys,
211         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
212         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
213         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
214 
215         Opt_sec_err
216 };
217 
218 static const match_table_t nfs_secflavor_tokens = {
219         { Opt_sec_none, "none" },
220         { Opt_sec_none, "null" },
221         { Opt_sec_sys, "sys" },
222 
223         { Opt_sec_krb5, "krb5" },
224         { Opt_sec_krb5i, "krb5i" },
225         { Opt_sec_krb5p, "krb5p" },
226 
227         { Opt_sec_lkey, "lkey" },
228         { Opt_sec_lkeyi, "lkeyi" },
229         { Opt_sec_lkeyp, "lkeyp" },
230 
231         { Opt_sec_spkm, "spkm3" },
232         { Opt_sec_spkmi, "spkm3i" },
233         { Opt_sec_spkmp, "spkm3p" },
234 
235         { Opt_sec_err, NULL }
236 };
237 
238 enum {
239         Opt_lookupcache_all, Opt_lookupcache_positive,
240         Opt_lookupcache_none,
241 
242         Opt_lookupcache_err
243 };
244 
245 static match_table_t nfs_lookupcache_tokens = {
246         { Opt_lookupcache_all, "all" },
247         { Opt_lookupcache_positive, "pos" },
248         { Opt_lookupcache_positive, "positive" },
249         { Opt_lookupcache_none, "none" },
250 
251         { Opt_lookupcache_err, NULL }
252 };
253 
254 enum {
255         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
256         Opt_local_lock_none,
257 
258         Opt_local_lock_err
259 };
260 
261 static match_table_t nfs_local_lock_tokens = {
262         { Opt_local_lock_all, "all" },
263         { Opt_local_lock_flock, "flock" },
264         { Opt_local_lock_posix, "posix" },
265         { Opt_local_lock_none, "none" },
266 
267         { Opt_local_lock_err, NULL }
268 };
269 
270 enum {
271         Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
272         Opt_vers_4_1, Opt_vers_4_2,
273 
274         Opt_vers_err
275 };
276 
277 static match_table_t nfs_vers_tokens = {
278         { Opt_vers_2, "2" },
279         { Opt_vers_3, "3" },
280         { Opt_vers_4, "4" },
281         { Opt_vers_4_0, "4.0" },
282         { Opt_vers_4_1, "4.1" },
283         { Opt_vers_4_2, "4.2" },
284 
285         { Opt_vers_err, NULL }
286 };
287 
288 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
289                 int flags, const char *dev_name, void *raw_data);
290 
291 struct file_system_type nfs_fs_type = {
292         .owner          = THIS_MODULE,
293         .name           = "nfs",
294         .mount          = nfs_fs_mount,
295         .kill_sb        = nfs_kill_super,
296         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
297 };
298 MODULE_ALIAS_FS("nfs");
299 EXPORT_SYMBOL_GPL(nfs_fs_type);
300 
301 struct file_system_type nfs_xdev_fs_type = {
302         .owner          = THIS_MODULE,
303         .name           = "nfs",
304         .mount          = nfs_xdev_mount,
305         .kill_sb        = nfs_kill_super,
306         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
307 };
308 
309 const struct super_operations nfs_sops = {
310         .alloc_inode    = nfs_alloc_inode,
311         .destroy_inode  = nfs_destroy_inode,
312         .write_inode    = nfs_write_inode,
313         .drop_inode     = nfs_drop_inode,
314         .put_super      = nfs_put_super,
315         .statfs         = nfs_statfs,
316         .evict_inode    = nfs_evict_inode,
317         .umount_begin   = nfs_umount_begin,
318         .show_options   = nfs_show_options,
319         .show_devname   = nfs_show_devname,
320         .show_path      = nfs_show_path,
321         .show_stats     = nfs_show_stats,
322         .remount_fs     = nfs_remount,
323 };
324 EXPORT_SYMBOL_GPL(nfs_sops);
325 
326 #if IS_ENABLED(CONFIG_NFS_V4)
327 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
328 static int nfs4_validate_mount_data(void *options,
329         struct nfs_parsed_mount_data *args, const char *dev_name);
330 
331 struct file_system_type nfs4_fs_type = {
332         .owner          = THIS_MODULE,
333         .name           = "nfs4",
334         .mount          = nfs_fs_mount,
335         .kill_sb        = nfs_kill_super,
336         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
337 };
338 MODULE_ALIAS_FS("nfs4");
339 MODULE_ALIAS("nfs4");
340 EXPORT_SYMBOL_GPL(nfs4_fs_type);
341 
342 static int __init register_nfs4_fs(void)
343 {
344         return register_filesystem(&nfs4_fs_type);
345 }
346 
347 static void unregister_nfs4_fs(void)
348 {
349         unregister_filesystem(&nfs4_fs_type);
350 }
351 #else
352 static int __init register_nfs4_fs(void)
353 {
354         return 0;
355 }
356 
357 static void unregister_nfs4_fs(void)
358 {
359 }
360 #endif
361 
362 static struct shrinker acl_shrinker = {
363         .count_objects  = nfs_access_cache_count,
364         .scan_objects   = nfs_access_cache_scan,
365         .seeks          = DEFAULT_SEEKS,
366 };
367 
368 /*
369  * Register the NFS filesystems
370  */
371 int __init register_nfs_fs(void)
372 {
373         int ret;
374 
375         ret = register_filesystem(&nfs_fs_type);
376         if (ret < 0)
377                 goto error_0;
378 
379         ret = register_nfs4_fs();
380         if (ret < 0)
381                 goto error_1;
382 
383         ret = nfs_register_sysctl();
384         if (ret < 0)
385                 goto error_2;
386         register_shrinker(&acl_shrinker);
387         return 0;
388 
389 error_2:
390         unregister_nfs4_fs();
391 error_1:
392         unregister_filesystem(&nfs_fs_type);
393 error_0:
394         return ret;
395 }
396 
397 /*
398  * Unregister the NFS filesystems
399  */
400 void __exit unregister_nfs_fs(void)
401 {
402         unregister_shrinker(&acl_shrinker);
403         nfs_unregister_sysctl();
404         unregister_nfs4_fs();
405         unregister_filesystem(&nfs_fs_type);
406 }
407 
408 void nfs_sb_active(struct super_block *sb)
409 {
410         struct nfs_server *server = NFS_SB(sb);
411 
412         if (atomic_inc_return(&server->active) == 1)
413                 atomic_inc(&sb->s_active);
414 }
415 EXPORT_SYMBOL_GPL(nfs_sb_active);
416 
417 void nfs_sb_deactive(struct super_block *sb)
418 {
419         struct nfs_server *server = NFS_SB(sb);
420 
421         if (atomic_dec_and_test(&server->active))
422                 deactivate_super(sb);
423 }
424 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
425 
426 /*
427  * Deliver file system statistics to userspace
428  */
429 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
430 {
431         struct nfs_server *server = NFS_SB(dentry->d_sb);
432         unsigned char blockbits;
433         unsigned long blockres;
434         struct nfs_fh *fh = NFS_FH(dentry->d_inode);
435         struct nfs_fsstat res;
436         int error = -ENOMEM;
437 
438         res.fattr = nfs_alloc_fattr();
439         if (res.fattr == NULL)
440                 goto out_err;
441 
442         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
443         if (unlikely(error == -ESTALE)) {
444                 struct dentry *pd_dentry;
445 
446                 pd_dentry = dget_parent(dentry);
447                 if (pd_dentry != NULL) {
448                         nfs_zap_caches(pd_dentry->d_inode);
449                         dput(pd_dentry);
450                 }
451         }
452         nfs_free_fattr(res.fattr);
453         if (error < 0)
454                 goto out_err;
455 
456         buf->f_type = NFS_SUPER_MAGIC;
457 
458         /*
459          * Current versions of glibc do not correctly handle the
460          * case where f_frsize != f_bsize.  Eventually we want to
461          * report the value of wtmult in this field.
462          */
463         buf->f_frsize = dentry->d_sb->s_blocksize;
464 
465         /*
466          * On most *nix systems, f_blocks, f_bfree, and f_bavail
467          * are reported in units of f_frsize.  Linux hasn't had
468          * an f_frsize field in its statfs struct until recently,
469          * thus historically Linux's sys_statfs reports these
470          * fields in units of f_bsize.
471          */
472         buf->f_bsize = dentry->d_sb->s_blocksize;
473         blockbits = dentry->d_sb->s_blocksize_bits;
474         blockres = (1 << blockbits) - 1;
475         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
476         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
477         buf->f_bavail = (res.abytes + blockres) >> blockbits;
478 
479         buf->f_files = res.tfiles;
480         buf->f_ffree = res.afiles;
481 
482         buf->f_namelen = server->namelen;
483 
484         return 0;
485 
486  out_err:
487         dprintk("%s: statfs error = %d\n", __func__, -error);
488         return error;
489 }
490 EXPORT_SYMBOL_GPL(nfs_statfs);
491 
492 /*
493  * Map the security flavour number to a name
494  */
495 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
496 {
497         static const struct {
498                 rpc_authflavor_t flavour;
499                 const char *str;
500         } sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
501                 /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
502                 { RPC_AUTH_NULL, "null" },
503                 { RPC_AUTH_UNIX, "sys" },
504                 { RPC_AUTH_GSS_KRB5, "krb5" },
505                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
506                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
507                 { RPC_AUTH_GSS_LKEY, "lkey" },
508                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
509                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
510                 { RPC_AUTH_GSS_SPKM, "spkm" },
511                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
512                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
513                 { UINT_MAX, "unknown" }
514         };
515         int i;
516 
517         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
518                 if (sec_flavours[i].flavour == flavour)
519                         break;
520         }
521         return sec_flavours[i].str;
522 }
523 
524 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
525                                   int showdefaults)
526 {
527         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
528 
529         seq_printf(m, ",mountproto=");
530         switch (sap->sa_family) {
531         case AF_INET:
532                 switch (nfss->mountd_protocol) {
533                 case IPPROTO_UDP:
534                         seq_printf(m, RPCBIND_NETID_UDP);
535                         break;
536                 case IPPROTO_TCP:
537                         seq_printf(m, RPCBIND_NETID_TCP);
538                         break;
539                 default:
540                         if (showdefaults)
541                                 seq_printf(m, "auto");
542                 }
543                 break;
544         case AF_INET6:
545                 switch (nfss->mountd_protocol) {
546                 case IPPROTO_UDP:
547                         seq_printf(m, RPCBIND_NETID_UDP6);
548                         break;
549                 case IPPROTO_TCP:
550                         seq_printf(m, RPCBIND_NETID_TCP6);
551                         break;
552                 default:
553                         if (showdefaults)
554                                 seq_printf(m, "auto");
555                 }
556                 break;
557         default:
558                 if (showdefaults)
559                         seq_printf(m, "auto");
560         }
561 }
562 
563 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
564                                     int showdefaults)
565 {
566         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
567 
568         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
569                 return;
570 
571         switch (sap->sa_family) {
572         case AF_INET: {
573                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
574                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
575                 break;
576         }
577         case AF_INET6: {
578                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
579                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
580                 break;
581         }
582         default:
583                 if (showdefaults)
584                         seq_printf(m, ",mountaddr=unspecified");
585         }
586 
587         if (nfss->mountd_version || showdefaults)
588                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
589         if ((nfss->mountd_port &&
590                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
591                 showdefaults)
592                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
593 
594         nfs_show_mountd_netid(m, nfss, showdefaults);
595 }
596 
597 #if IS_ENABLED(CONFIG_NFS_V4)
598 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
599                                     int showdefaults)
600 {
601         struct nfs_client *clp = nfss->nfs_client;
602 
603         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
604 }
605 #else
606 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
607                                     int showdefaults)
608 {
609 }
610 #endif
611 
612 static void nfs_show_nfs_version(struct seq_file *m,
613                 unsigned int version,
614                 unsigned int minorversion)
615 {
616         seq_printf(m, ",vers=%u", version);
617         if (version == 4)
618                 seq_printf(m, ".%u", minorversion);
619 }
620 
621 /*
622  * Describe the mount options in force on this server representation
623  */
624 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
625                                    int showdefaults)
626 {
627         static const struct proc_nfs_info {
628                 int flag;
629                 const char *str;
630                 const char *nostr;
631         } nfs_info[] = {
632                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
633                 { NFS_MOUNT_POSIX, ",posix", "" },
634                 { NFS_MOUNT_NOCTO, ",nocto", "" },
635                 { NFS_MOUNT_NOAC, ",noac", "" },
636                 { NFS_MOUNT_NONLM, ",nolock", "" },
637                 { NFS_MOUNT_NOACL, ",noacl", "" },
638                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
639                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
640                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
641                 { 0, NULL, NULL }
642         };
643         const struct proc_nfs_info *nfs_infop;
644         struct nfs_client *clp = nfss->nfs_client;
645         u32 version = clp->rpc_ops->version;
646         int local_flock, local_fcntl;
647 
648         nfs_show_nfs_version(m, version, clp->cl_minorversion);
649         seq_printf(m, ",rsize=%u", nfss->rsize);
650         seq_printf(m, ",wsize=%u", nfss->wsize);
651         if (nfss->bsize != 0)
652                 seq_printf(m, ",bsize=%u", nfss->bsize);
653         seq_printf(m, ",namlen=%u", nfss->namelen);
654         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
655                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
656         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
657                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
658         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
659                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
660         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
661                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
662         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
663                 if (nfss->flags & nfs_infop->flag)
664                         seq_puts(m, nfs_infop->str);
665                 else
666                         seq_puts(m, nfs_infop->nostr);
667         }
668         rcu_read_lock();
669         seq_printf(m, ",proto=%s",
670                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
671         rcu_read_unlock();
672         if (version == 4) {
673                 if (nfss->port != NFS_PORT)
674                         seq_printf(m, ",port=%u", nfss->port);
675         } else
676                 if (nfss->port)
677                         seq_printf(m, ",port=%u", nfss->port);
678 
679         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
680         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
681         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
682 
683         if (version != 4)
684                 nfs_show_mountd_options(m, nfss, showdefaults);
685         else
686                 nfs_show_nfsv4_options(m, nfss, showdefaults);
687 
688         if (nfss->options & NFS_OPTION_FSCACHE)
689                 seq_printf(m, ",fsc");
690 
691         if (nfss->options & NFS_OPTION_MIGRATION)
692                 seq_printf(m, ",migration");
693 
694         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
695                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
696                         seq_printf(m, ",lookupcache=none");
697                 else
698                         seq_printf(m, ",lookupcache=pos");
699         }
700 
701         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
702         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
703 
704         if (!local_flock && !local_fcntl)
705                 seq_printf(m, ",local_lock=none");
706         else if (local_flock && local_fcntl)
707                 seq_printf(m, ",local_lock=all");
708         else if (local_flock)
709                 seq_printf(m, ",local_lock=flock");
710         else
711                 seq_printf(m, ",local_lock=posix");
712 }
713 
714 /*
715  * Describe the mount options on this VFS mountpoint
716  */
717 int nfs_show_options(struct seq_file *m, struct dentry *root)
718 {
719         struct nfs_server *nfss = NFS_SB(root->d_sb);
720 
721         nfs_show_mount_options(m, nfss, 0);
722 
723         rcu_read_lock();
724         seq_printf(m, ",addr=%s",
725                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
726                                                         RPC_DISPLAY_ADDR));
727         rcu_read_unlock();
728 
729         return 0;
730 }
731 EXPORT_SYMBOL_GPL(nfs_show_options);
732 
733 #if IS_ENABLED(CONFIG_NFS_V4)
734 #ifdef CONFIG_NFS_V4_1
735 static void show_sessions(struct seq_file *m, struct nfs_server *server)
736 {
737         if (nfs4_has_session(server->nfs_client))
738                 seq_printf(m, ",sessions");
739 }
740 #else
741 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
742 #endif
743 #endif
744 
745 #ifdef CONFIG_NFS_V4_1
746 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
747 {
748         seq_printf(m, ",pnfs=");
749         if (server->pnfs_curr_ld)
750                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
751         else
752                 seq_printf(m, "not configured");
753 }
754 
755 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
756 {
757         if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
758                 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
759                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
760                            "date='%llu,%u'",
761                            impl_id->name, impl_id->domain,
762                            impl_id->date.seconds, impl_id->date.nseconds);
763         }
764 }
765 #else
766 #if IS_ENABLED(CONFIG_NFS_V4)
767 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
768 {
769 }
770 #endif
771 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
772 {
773 }
774 #endif
775 
776 int nfs_show_devname(struct seq_file *m, struct dentry *root)
777 {
778         char *page = (char *) __get_free_page(GFP_KERNEL);
779         char *devname, *dummy;
780         int err = 0;
781         if (!page)
782                 return -ENOMEM;
783         devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
784         if (IS_ERR(devname))
785                 err = PTR_ERR(devname);
786         else
787                 seq_escape(m, devname, " \t\n\\");
788         free_page((unsigned long)page);
789         return err;
790 }
791 EXPORT_SYMBOL_GPL(nfs_show_devname);
792 
793 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
794 {
795         seq_puts(m, "/");
796         return 0;
797 }
798 EXPORT_SYMBOL_GPL(nfs_show_path);
799 
800 /*
801  * Present statistical information for this VFS mountpoint
802  */
803 int nfs_show_stats(struct seq_file *m, struct dentry *root)
804 {
805         int i, cpu;
806         struct nfs_server *nfss = NFS_SB(root->d_sb);
807         struct rpc_auth *auth = nfss->client->cl_auth;
808         struct nfs_iostats totals = { };
809 
810         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
811 
812         /*
813          * Display all mount option settings
814          */
815         seq_printf(m, "\n\topts:\t");
816         seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
817         seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
818         seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
819         seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
820         nfs_show_mount_options(m, nfss, 1);
821 
822         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
823 
824         show_implementation_id(m, nfss);
825 
826         seq_printf(m, "\n\tcaps:\t");
827         seq_printf(m, "caps=0x%x", nfss->caps);
828         seq_printf(m, ",wtmult=%u", nfss->wtmult);
829         seq_printf(m, ",dtsize=%u", nfss->dtsize);
830         seq_printf(m, ",bsize=%u", nfss->bsize);
831         seq_printf(m, ",namlen=%u", nfss->namelen);
832 
833 #if IS_ENABLED(CONFIG_NFS_V4)
834         if (nfss->nfs_client->rpc_ops->version == 4) {
835                 seq_printf(m, "\n\tnfsv4:\t");
836                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
837                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
838                 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
839                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
840                 show_sessions(m, nfss);
841                 show_pnfs(m, nfss);
842         }
843 #endif
844 
845         /*
846          * Display security flavor in effect for this mount
847          */
848         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
849         if (auth->au_flavor)
850                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
851 
852         /*
853          * Display superblock I/O counters
854          */
855         for_each_possible_cpu(cpu) {
856                 struct nfs_iostats *stats;
857 
858                 preempt_disable();
859                 stats = per_cpu_ptr(nfss->io_stats, cpu);
860 
861                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
862                         totals.events[i] += stats->events[i];
863                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
864                         totals.bytes[i] += stats->bytes[i];
865 #ifdef CONFIG_NFS_FSCACHE
866                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
867                         totals.fscache[i] += stats->fscache[i];
868 #endif
869 
870                 preempt_enable();
871         }
872 
873         seq_printf(m, "\n\tevents:\t");
874         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
875                 seq_printf(m, "%lu ", totals.events[i]);
876         seq_printf(m, "\n\tbytes:\t");
877         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
878                 seq_printf(m, "%Lu ", totals.bytes[i]);
879 #ifdef CONFIG_NFS_FSCACHE
880         if (nfss->options & NFS_OPTION_FSCACHE) {
881                 seq_printf(m, "\n\tfsc:\t");
882                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
883                         seq_printf(m, "%Lu ", totals.bytes[i]);
884         }
885 #endif
886         seq_printf(m, "\n");
887 
888         rpc_print_iostats(m, nfss->client);
889 
890         return 0;
891 }
892 EXPORT_SYMBOL_GPL(nfs_show_stats);
893 
894 /*
895  * Begin unmount by attempting to remove all automounted mountpoints we added
896  * in response to xdev traversals and referrals
897  */
898 void nfs_umount_begin(struct super_block *sb)
899 {
900         struct nfs_server *server;
901         struct rpc_clnt *rpc;
902 
903         server = NFS_SB(sb);
904         /* -EIO all pending I/O */
905         rpc = server->client_acl;
906         if (!IS_ERR(rpc))
907                 rpc_killall_tasks(rpc);
908         rpc = server->client;
909         if (!IS_ERR(rpc))
910                 rpc_killall_tasks(rpc);
911 }
912 EXPORT_SYMBOL_GPL(nfs_umount_begin);
913 
914 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
915 {
916         struct nfs_parsed_mount_data *data;
917 
918         data = kzalloc(sizeof(*data), GFP_KERNEL);
919         if (data) {
920                 data->acregmin          = NFS_DEF_ACREGMIN;
921                 data->acregmax          = NFS_DEF_ACREGMAX;
922                 data->acdirmin          = NFS_DEF_ACDIRMIN;
923                 data->acdirmax          = NFS_DEF_ACDIRMAX;
924                 data->mount_server.port = NFS_UNSPEC_PORT;
925                 data->nfs_server.port   = NFS_UNSPEC_PORT;
926                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
927                 data->selected_flavor   = RPC_AUTH_MAXFLAVOR;
928                 data->minorversion      = 0;
929                 data->need_mount        = true;
930                 data->net               = current->nsproxy->net_ns;
931                 security_init_mnt_opts(&data->lsm_opts);
932         }
933         return data;
934 }
935 
936 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
937 {
938         if (data) {
939                 kfree(data->client_address);
940                 kfree(data->mount_server.hostname);
941                 kfree(data->nfs_server.export_path);
942                 kfree(data->nfs_server.hostname);
943                 kfree(data->fscache_uniq);
944                 security_free_mnt_opts(&data->lsm_opts);
945                 kfree(data);
946         }
947 }
948 
949 /*
950  * Sanity-check a server address provided by the mount command.
951  *
952  * Address family must be initialized, and address must not be
953  * the ANY address for that family.
954  */
955 static int nfs_verify_server_address(struct sockaddr *addr)
956 {
957         switch (addr->sa_family) {
958         case AF_INET: {
959                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
960                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
961         }
962         case AF_INET6: {
963                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
964                 return !ipv6_addr_any(sa);
965         }
966         }
967 
968         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
969         return 0;
970 }
971 
972 /*
973  * Select between a default port value and a user-specified port value.
974  * If a zero value is set, then autobind will be used.
975  */
976 static void nfs_set_port(struct sockaddr *sap, int *port,
977                                  const unsigned short default_port)
978 {
979         if (*port == NFS_UNSPEC_PORT)
980                 *port = default_port;
981 
982         rpc_set_port(sap, *port);
983 }
984 
985 /*
986  * Sanity check the NFS transport protocol.
987  *
988  */
989 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
990 {
991         switch (mnt->nfs_server.protocol) {
992         case XPRT_TRANSPORT_UDP:
993         case XPRT_TRANSPORT_TCP:
994         case XPRT_TRANSPORT_RDMA:
995                 break;
996         default:
997                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
998         }
999 }
1000 
1001 /*
1002  * For text based NFSv2/v3 mounts, the mount protocol transport default
1003  * settings should depend upon the specified NFS transport.
1004  */
1005 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1006 {
1007         nfs_validate_transport_protocol(mnt);
1008 
1009         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1010             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1011                         return;
1012         switch (mnt->nfs_server.protocol) {
1013         case XPRT_TRANSPORT_UDP:
1014                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1015                 break;
1016         case XPRT_TRANSPORT_TCP:
1017         case XPRT_TRANSPORT_RDMA:
1018                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1019         }
1020 }
1021 
1022 /*
1023  * Add 'flavor' to 'auth_info' if not already present.
1024  * Returns true if 'flavor' ends up in the list, false otherwise
1025  */
1026 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1027                               rpc_authflavor_t flavor)
1028 {
1029         unsigned int i;
1030         unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1031 
1032         /* make sure this flavor isn't already in the list */
1033         for (i = 0; i < auth_info->flavor_len; i++) {
1034                 if (flavor == auth_info->flavors[i])
1035                         return true;
1036         }
1037 
1038         if (auth_info->flavor_len + 1 >= max_flavor_len) {
1039                 dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1040                 return false;
1041         }
1042 
1043         auth_info->flavors[auth_info->flavor_len++] = flavor;
1044         return true;
1045 }
1046 
1047 /*
1048  * Return true if 'match' is in auth_info or auth_info is empty.
1049  * Return false otherwise.
1050  */
1051 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1052                          rpc_authflavor_t match)
1053 {
1054         int i;
1055 
1056         if (!auth_info->flavor_len)
1057                 return true;
1058 
1059         for (i = 0; i < auth_info->flavor_len; i++) {
1060                 if (auth_info->flavors[i] == match)
1061                         return true;
1062         }
1063         return false;
1064 }
1065 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1066 
1067 /*
1068  * Parse the value of the 'sec=' option.
1069  */
1070 static int nfs_parse_security_flavors(char *value,
1071                                       struct nfs_parsed_mount_data *mnt)
1072 {
1073         substring_t args[MAX_OPT_ARGS];
1074         rpc_authflavor_t pseudoflavor;
1075         char *p;
1076 
1077         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1078 
1079         while ((p = strsep(&value, ":")) != NULL) {
1080                 switch (match_token(p, nfs_secflavor_tokens, args)) {
1081                 case Opt_sec_none:
1082                         pseudoflavor = RPC_AUTH_NULL;
1083                         break;
1084                 case Opt_sec_sys:
1085                         pseudoflavor = RPC_AUTH_UNIX;
1086                         break;
1087                 case Opt_sec_krb5:
1088                         pseudoflavor = RPC_AUTH_GSS_KRB5;
1089                         break;
1090                 case Opt_sec_krb5i:
1091                         pseudoflavor = RPC_AUTH_GSS_KRB5I;
1092                         break;
1093                 case Opt_sec_krb5p:
1094                         pseudoflavor = RPC_AUTH_GSS_KRB5P;
1095                         break;
1096                 case Opt_sec_lkey:
1097                         pseudoflavor = RPC_AUTH_GSS_LKEY;
1098                         break;
1099                 case Opt_sec_lkeyi:
1100                         pseudoflavor = RPC_AUTH_GSS_LKEYI;
1101                         break;
1102                 case Opt_sec_lkeyp:
1103                         pseudoflavor = RPC_AUTH_GSS_LKEYP;
1104                         break;
1105                 case Opt_sec_spkm:
1106                         pseudoflavor = RPC_AUTH_GSS_SPKM;
1107                         break;
1108                 case Opt_sec_spkmi:
1109                         pseudoflavor = RPC_AUTH_GSS_SPKMI;
1110                         break;
1111                 case Opt_sec_spkmp:
1112                         pseudoflavor = RPC_AUTH_GSS_SPKMP;
1113                         break;
1114                 default:
1115                         dfprintk(MOUNT,
1116                                  "NFS: sec= option '%s' not recognized\n", p);
1117                         return 0;
1118                 }
1119 
1120                 if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1121                         return 0;
1122         }
1123 
1124         return 1;
1125 }
1126 
1127 static int nfs_parse_version_string(char *string,
1128                 struct nfs_parsed_mount_data *mnt,
1129                 substring_t *args)
1130 {
1131         mnt->flags &= ~NFS_MOUNT_VER3;
1132         switch (match_token(string, nfs_vers_tokens, args)) {
1133         case Opt_vers_2:
1134                 mnt->version = 2;
1135                 break;
1136         case Opt_vers_3:
1137                 mnt->flags |= NFS_MOUNT_VER3;
1138                 mnt->version = 3;
1139                 break;
1140         case Opt_vers_4:
1141                 /* Backward compatibility option. In future,
1142                  * the mount program should always supply
1143                  * a NFSv4 minor version number.
1144                  */
1145                 mnt->version = 4;
1146                 break;
1147         case Opt_vers_4_0:
1148                 mnt->version = 4;
1149                 mnt->minorversion = 0;
1150                 break;
1151         case Opt_vers_4_1:
1152                 mnt->version = 4;
1153                 mnt->minorversion = 1;
1154                 break;
1155         case Opt_vers_4_2:
1156                 mnt->version = 4;
1157                 mnt->minorversion = 2;
1158                 break;
1159         default:
1160                 return 0;
1161         }
1162         return 1;
1163 }
1164 
1165 static int nfs_get_option_str(substring_t args[], char **option)
1166 {
1167         kfree(*option);
1168         *option = match_strdup(args);
1169         return !*option;
1170 }
1171 
1172 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1173 {
1174         int rc;
1175         char *string;
1176 
1177         string = match_strdup(args);
1178         if (string == NULL)
1179                 return -ENOMEM;
1180         rc = kstrtoul(string, 10, option);
1181         kfree(string);
1182 
1183         return rc;
1184 }
1185 
1186 /*
1187  * Error-check and convert a string of mount options from user space into
1188  * a data structure.  The whole mount string is processed; bad options are
1189  * skipped as they are encountered.  If there were no errors, return 1;
1190  * otherwise return 0 (zero).
1191  */
1192 static int nfs_parse_mount_options(char *raw,
1193                                    struct nfs_parsed_mount_data *mnt)
1194 {
1195         char *p, *string, *secdata;
1196         int rc, sloppy = 0, invalid_option = 0;
1197         unsigned short protofamily = AF_UNSPEC;
1198         unsigned short mountfamily = AF_UNSPEC;
1199 
1200         if (!raw) {
1201                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1202                 return 1;
1203         }
1204         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1205 
1206         secdata = alloc_secdata();
1207         if (!secdata)
1208                 goto out_nomem;
1209 
1210         rc = security_sb_copy_data(raw, secdata);
1211         if (rc)
1212                 goto out_security_failure;
1213 
1214         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1215         if (rc)
1216                 goto out_security_failure;
1217 
1218         free_secdata(secdata);
1219 
1220         while ((p = strsep(&raw, ",")) != NULL) {
1221                 substring_t args[MAX_OPT_ARGS];
1222                 unsigned long option;
1223                 int token;
1224 
1225                 if (!*p)
1226                         continue;
1227 
1228                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1229 
1230                 token = match_token(p, nfs_mount_option_tokens, args);
1231                 switch (token) {
1232 
1233                 /*
1234                  * boolean options:  foo/nofoo
1235                  */
1236                 case Opt_soft:
1237                         mnt->flags |= NFS_MOUNT_SOFT;
1238                         break;
1239                 case Opt_hard:
1240                         mnt->flags &= ~NFS_MOUNT_SOFT;
1241                         break;
1242                 case Opt_posix:
1243                         mnt->flags |= NFS_MOUNT_POSIX;
1244                         break;
1245                 case Opt_noposix:
1246                         mnt->flags &= ~NFS_MOUNT_POSIX;
1247                         break;
1248                 case Opt_cto:
1249                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1250                         break;
1251                 case Opt_nocto:
1252                         mnt->flags |= NFS_MOUNT_NOCTO;
1253                         break;
1254                 case Opt_ac:
1255                         mnt->flags &= ~NFS_MOUNT_NOAC;
1256                         break;
1257                 case Opt_noac:
1258                         mnt->flags |= NFS_MOUNT_NOAC;
1259                         break;
1260                 case Opt_lock:
1261                         mnt->flags &= ~NFS_MOUNT_NONLM;
1262                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1263                                         NFS_MOUNT_LOCAL_FCNTL);
1264                         break;
1265                 case Opt_nolock:
1266                         mnt->flags |= NFS_MOUNT_NONLM;
1267                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1268                                        NFS_MOUNT_LOCAL_FCNTL);
1269                         break;
1270                 case Opt_udp:
1271                         mnt->flags &= ~NFS_MOUNT_TCP;
1272                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1273                         break;
1274                 case Opt_tcp:
1275                         mnt->flags |= NFS_MOUNT_TCP;
1276                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1277                         break;
1278                 case Opt_rdma:
1279                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1280                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1281                         xprt_load_transport(p);
1282                         break;
1283                 case Opt_acl:
1284                         mnt->flags &= ~NFS_MOUNT_NOACL;
1285                         break;
1286                 case Opt_noacl:
1287                         mnt->flags |= NFS_MOUNT_NOACL;
1288                         break;
1289                 case Opt_rdirplus:
1290                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1291                         break;
1292                 case Opt_nordirplus:
1293                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1294                         break;
1295                 case Opt_sharecache:
1296                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1297                         break;
1298                 case Opt_nosharecache:
1299                         mnt->flags |= NFS_MOUNT_UNSHARED;
1300                         break;
1301                 case Opt_resvport:
1302                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1303                         break;
1304                 case Opt_noresvport:
1305                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1306                         break;
1307                 case Opt_fscache:
1308                         mnt->options |= NFS_OPTION_FSCACHE;
1309                         kfree(mnt->fscache_uniq);
1310                         mnt->fscache_uniq = NULL;
1311                         break;
1312                 case Opt_nofscache:
1313                         mnt->options &= ~NFS_OPTION_FSCACHE;
1314                         kfree(mnt->fscache_uniq);
1315                         mnt->fscache_uniq = NULL;
1316                         break;
1317                 case Opt_migration:
1318                         mnt->options |= NFS_OPTION_MIGRATION;
1319                         break;
1320                 case Opt_nomigration:
1321                         mnt->options &= NFS_OPTION_MIGRATION;
1322                         break;
1323 
1324                 /*
1325                  * options that take numeric values
1326                  */
1327                 case Opt_port:
1328                         if (nfs_get_option_ul(args, &option) ||
1329                             option > USHRT_MAX)
1330                                 goto out_invalid_value;
1331                         mnt->nfs_server.port = option;
1332                         break;
1333                 case Opt_rsize:
1334                         if (nfs_get_option_ul(args, &option))
1335                                 goto out_invalid_value;
1336                         mnt->rsize = option;
1337                         break;
1338                 case Opt_wsize:
1339                         if (nfs_get_option_ul(args, &option))
1340                                 goto out_invalid_value;
1341                         mnt->wsize = option;
1342                         break;
1343                 case Opt_bsize:
1344                         if (nfs_get_option_ul(args, &option))
1345                                 goto out_invalid_value;
1346                         mnt->bsize = option;
1347                         break;
1348                 case Opt_timeo:
1349                         if (nfs_get_option_ul(args, &option) || option == 0)
1350                                 goto out_invalid_value;
1351                         mnt->timeo = option;
1352                         break;
1353                 case Opt_retrans:
1354                         if (nfs_get_option_ul(args, &option) || option == 0)
1355                                 goto out_invalid_value;
1356                         mnt->retrans = option;
1357                         break;
1358                 case Opt_acregmin:
1359                         if (nfs_get_option_ul(args, &option))
1360                                 goto out_invalid_value;
1361                         mnt->acregmin = option;
1362                         break;
1363                 case Opt_acregmax:
1364                         if (nfs_get_option_ul(args, &option))
1365                                 goto out_invalid_value;
1366                         mnt->acregmax = option;
1367                         break;
1368                 case Opt_acdirmin:
1369                         if (nfs_get_option_ul(args, &option))
1370                                 goto out_invalid_value;
1371                         mnt->acdirmin = option;
1372                         break;
1373                 case Opt_acdirmax:
1374                         if (nfs_get_option_ul(args, &option))
1375                                 goto out_invalid_value;
1376                         mnt->acdirmax = option;
1377                         break;
1378                 case Opt_actimeo:
1379                         if (nfs_get_option_ul(args, &option))
1380                                 goto out_invalid_value;
1381                         mnt->acregmin = mnt->acregmax =
1382                         mnt->acdirmin = mnt->acdirmax = option;
1383                         break;
1384                 case Opt_namelen:
1385                         if (nfs_get_option_ul(args, &option))
1386                                 goto out_invalid_value;
1387                         mnt->namlen = option;
1388                         break;
1389                 case Opt_mountport:
1390                         if (nfs_get_option_ul(args, &option) ||
1391                             option > USHRT_MAX)
1392                                 goto out_invalid_value;
1393                         mnt->mount_server.port = option;
1394                         break;
1395                 case Opt_mountvers:
1396                         if (nfs_get_option_ul(args, &option) ||
1397                             option < NFS_MNT_VERSION ||
1398                             option > NFS_MNT3_VERSION)
1399                                 goto out_invalid_value;
1400                         mnt->mount_server.version = option;
1401                         break;
1402                 case Opt_minorversion:
1403                         if (nfs_get_option_ul(args, &option))
1404                                 goto out_invalid_value;
1405                         if (option > NFS4_MAX_MINOR_VERSION)
1406                                 goto out_invalid_value;
1407                         mnt->minorversion = option;
1408                         break;
1409 
1410                 /*
1411                  * options that take text values
1412                  */
1413                 case Opt_nfsvers:
1414                         string = match_strdup(args);
1415                         if (string == NULL)
1416                                 goto out_nomem;
1417                         rc = nfs_parse_version_string(string, mnt, args);
1418                         kfree(string);
1419                         if (!rc)
1420                                 goto out_invalid_value;
1421                         break;
1422                 case Opt_sec:
1423                         string = match_strdup(args);
1424                         if (string == NULL)
1425                                 goto out_nomem;
1426                         rc = nfs_parse_security_flavors(string, mnt);
1427                         kfree(string);
1428                         if (!rc) {
1429                                 dfprintk(MOUNT, "NFS:   unrecognized "
1430                                                 "security flavor\n");
1431                                 return 0;
1432                         }
1433                         break;
1434                 case Opt_proto:
1435                         string = match_strdup(args);
1436                         if (string == NULL)
1437                                 goto out_nomem;
1438                         token = match_token(string,
1439                                             nfs_xprt_protocol_tokens, args);
1440 
1441                         protofamily = AF_INET;
1442                         switch (token) {
1443                         case Opt_xprt_udp6:
1444                                 protofamily = AF_INET6;
1445                         case Opt_xprt_udp:
1446                                 mnt->flags &= ~NFS_MOUNT_TCP;
1447                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1448                                 break;
1449                         case Opt_xprt_tcp6:
1450                                 protofamily = AF_INET6;
1451                         case Opt_xprt_tcp:
1452                                 mnt->flags |= NFS_MOUNT_TCP;
1453                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1454                                 break;
1455                         case Opt_xprt_rdma:
1456                                 /* vector side protocols to TCP */
1457                                 mnt->flags |= NFS_MOUNT_TCP;
1458                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1459                                 xprt_load_transport(string);
1460                                 break;
1461                         default:
1462                                 dfprintk(MOUNT, "NFS:   unrecognized "
1463                                                 "transport protocol\n");
1464                                 kfree(string);
1465                                 return 0;
1466                         }
1467                         kfree(string);
1468                         break;
1469                 case Opt_mountproto:
1470                         string = match_strdup(args);
1471                         if (string == NULL)
1472                                 goto out_nomem;
1473                         token = match_token(string,
1474                                             nfs_xprt_protocol_tokens, args);
1475                         kfree(string);
1476 
1477                         mountfamily = AF_INET;
1478                         switch (token) {
1479                         case Opt_xprt_udp6:
1480                                 mountfamily = AF_INET6;
1481                         case Opt_xprt_udp:
1482                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1483                                 break;
1484                         case Opt_xprt_tcp6:
1485                                 mountfamily = AF_INET6;
1486                         case Opt_xprt_tcp:
1487                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1488                                 break;
1489                         case Opt_xprt_rdma: /* not used for side protocols */
1490                         default:
1491                                 dfprintk(MOUNT, "NFS:   unrecognized "
1492                                                 "transport protocol\n");
1493                                 return 0;
1494                         }
1495                         break;
1496                 case Opt_addr:
1497                         string = match_strdup(args);
1498                         if (string == NULL)
1499                                 goto out_nomem;
1500                         mnt->nfs_server.addrlen =
1501                                 rpc_pton(mnt->net, string, strlen(string),
1502                                         (struct sockaddr *)
1503                                         &mnt->nfs_server.address,
1504                                         sizeof(mnt->nfs_server.address));
1505                         kfree(string);
1506                         if (mnt->nfs_server.addrlen == 0)
1507                                 goto out_invalid_address;
1508                         break;
1509                 case Opt_clientaddr:
1510                         if (nfs_get_option_str(args, &mnt->client_address))
1511                                 goto out_nomem;
1512                         break;
1513                 case Opt_mounthost:
1514                         if (nfs_get_option_str(args,
1515                                                &mnt->mount_server.hostname))
1516                                 goto out_nomem;
1517                         break;
1518                 case Opt_mountaddr:
1519                         string = match_strdup(args);
1520                         if (string == NULL)
1521                                 goto out_nomem;
1522                         mnt->mount_server.addrlen =
1523                                 rpc_pton(mnt->net, string, strlen(string),
1524                                         (struct sockaddr *)
1525                                         &mnt->mount_server.address,
1526                                         sizeof(mnt->mount_server.address));
1527                         kfree(string);
1528                         if (mnt->mount_server.addrlen == 0)
1529                                 goto out_invalid_address;
1530                         break;
1531                 case Opt_lookupcache:
1532                         string = match_strdup(args);
1533                         if (string == NULL)
1534                                 goto out_nomem;
1535                         token = match_token(string,
1536                                         nfs_lookupcache_tokens, args);
1537                         kfree(string);
1538                         switch (token) {
1539                                 case Opt_lookupcache_all:
1540                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1541                                         break;
1542                                 case Opt_lookupcache_positive:
1543                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1544                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1545                                         break;
1546                                 case Opt_lookupcache_none:
1547                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1548                                         break;
1549                                 default:
1550                                         dfprintk(MOUNT, "NFS:   invalid "
1551                                                         "lookupcache argument\n");
1552                                         return 0;
1553                         };
1554                         break;
1555                 case Opt_fscache_uniq:
1556                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1557                                 goto out_nomem;
1558                         mnt->options |= NFS_OPTION_FSCACHE;
1559                         break;
1560                 case Opt_local_lock:
1561                         string = match_strdup(args);
1562                         if (string == NULL)
1563                                 goto out_nomem;
1564                         token = match_token(string, nfs_local_lock_tokens,
1565                                         args);
1566                         kfree(string);
1567                         switch (token) {
1568                         case Opt_local_lock_all:
1569                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1570                                                NFS_MOUNT_LOCAL_FCNTL);
1571                                 break;
1572                         case Opt_local_lock_flock:
1573                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1574                                 break;
1575                         case Opt_local_lock_posix:
1576                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1577                                 break;
1578                         case Opt_local_lock_none:
1579                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1580                                                 NFS_MOUNT_LOCAL_FCNTL);
1581                                 break;
1582                         default:
1583                                 dfprintk(MOUNT, "NFS:   invalid "
1584                                                 "local_lock argument\n");
1585                                 return 0;
1586                         };
1587                         break;
1588 
1589                 /*
1590                  * Special options
1591                  */
1592                 case Opt_sloppy:
1593                         sloppy = 1;
1594                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1595                         break;
1596                 case Opt_userspace:
1597                 case Opt_deprecated:
1598                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1599                                         "'%s'\n", p);
1600                         break;
1601 
1602                 default:
1603                         invalid_option = 1;
1604                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1605                                         "'%s'\n", p);
1606                 }
1607         }
1608 
1609         if (!sloppy && invalid_option)
1610                 return 0;
1611 
1612         if (mnt->minorversion && mnt->version != 4)
1613                 goto out_minorversion_mismatch;
1614 
1615         if (mnt->options & NFS_OPTION_MIGRATION &&
1616             (mnt->version != 4 || mnt->minorversion != 0))
1617                 goto out_migration_misuse;
1618 
1619         /*
1620          * verify that any proto=/mountproto= options match the address
1621          * families in the addr=/mountaddr= options.
1622          */
1623         if (protofamily != AF_UNSPEC &&
1624             protofamily != mnt->nfs_server.address.ss_family)
1625                 goto out_proto_mismatch;
1626 
1627         if (mountfamily != AF_UNSPEC) {
1628                 if (mnt->mount_server.addrlen) {
1629                         if (mountfamily != mnt->mount_server.address.ss_family)
1630                                 goto out_mountproto_mismatch;
1631                 } else {
1632                         if (mountfamily != mnt->nfs_server.address.ss_family)
1633                                 goto out_mountproto_mismatch;
1634                 }
1635         }
1636 
1637         return 1;
1638 
1639 out_mountproto_mismatch:
1640         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1641                          "option\n");
1642         return 0;
1643 out_proto_mismatch:
1644         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1645         return 0;
1646 out_invalid_address:
1647         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1648         return 0;
1649 out_invalid_value:
1650         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1651         return 0;
1652 out_minorversion_mismatch:
1653         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1654                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1655         return 0;
1656 out_migration_misuse:
1657         printk(KERN_INFO
1658                 "NFS: 'migration' not supported for this NFS version\n");
1659         return 0;
1660 out_nomem:
1661         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1662         return 0;
1663 out_security_failure:
1664         free_secdata(secdata);
1665         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1666         return 0;
1667 }
1668 
1669 /*
1670  * Ensure that a specified authtype in args->auth_info is supported by
1671  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1672  * -EACCES if not.
1673  */
1674 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1675                         rpc_authflavor_t *server_authlist, unsigned int count)
1676 {
1677         rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1678         unsigned int i;
1679 
1680         /*
1681          * If the sec= mount option is used, the specified flavor or AUTH_NULL
1682          * must be in the list returned by the server.
1683          *
1684          * AUTH_NULL has a special meaning when it's in the server list - it
1685          * means that the server will ignore the rpc creds, so any flavor
1686          * can be used.
1687          */
1688         for (i = 0; i < count; i++) {
1689                 flavor = server_authlist[i];
1690 
1691                 if (nfs_auth_info_match(&args->auth_info, flavor) ||
1692                     flavor == RPC_AUTH_NULL)
1693                         goto out;
1694         }
1695 
1696         dfprintk(MOUNT,
1697                  "NFS: specified auth flavors not supported by server\n");
1698         return -EACCES;
1699 
1700 out:
1701         args->selected_flavor = flavor;
1702         dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1703         return 0;
1704 }
1705 
1706 /*
1707  * Use the remote server's MOUNT service to request the NFS file handle
1708  * corresponding to the provided path.
1709  */
1710 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1711                              struct nfs_fh *root_fh,
1712                              rpc_authflavor_t *server_authlist,
1713                              unsigned int *server_authlist_len)
1714 {
1715         struct nfs_mount_request request = {
1716                 .sap            = (struct sockaddr *)
1717                                                 &args->mount_server.address,
1718                 .dirpath        = args->nfs_server.export_path,
1719                 .protocol       = args->mount_server.protocol,
1720                 .fh             = root_fh,
1721                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1722                 .auth_flav_len  = server_authlist_len,
1723                 .auth_flavs     = server_authlist,
1724                 .net            = args->net,
1725         };
1726         int status;
1727 
1728         if (args->mount_server.version == 0) {
1729                 switch (args->version) {
1730                         default:
1731                                 args->mount_server.version = NFS_MNT3_VERSION;
1732                                 break;
1733                         case 2:
1734                                 args->mount_server.version = NFS_MNT_VERSION;
1735                 }
1736         }
1737         request.version = args->mount_server.version;
1738 
1739         if (args->mount_server.hostname)
1740                 request.hostname = args->mount_server.hostname;
1741         else
1742                 request.hostname = args->nfs_server.hostname;
1743 
1744         /*
1745          * Construct the mount server's address.
1746          */
1747         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1748                 memcpy(request.sap, &args->nfs_server.address,
1749                        args->nfs_server.addrlen);
1750                 args->mount_server.addrlen = args->nfs_server.addrlen;
1751         }
1752         request.salen = args->mount_server.addrlen;
1753         nfs_set_port(request.sap, &args->mount_server.port, 0);
1754 
1755         /*
1756          * Now ask the mount server to map our export path
1757          * to a file handle.
1758          */
1759         status = nfs_mount(&request);
1760         if (status != 0) {
1761                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1762                                 request.hostname, status);
1763                 return status;
1764         }
1765 
1766         return 0;
1767 }
1768 
1769 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1770                                         struct nfs_subversion *nfs_mod)
1771 {
1772         int status;
1773         unsigned int i;
1774         bool tried_auth_unix = false;
1775         bool auth_null_in_list = false;
1776         struct nfs_server *server = ERR_PTR(-EACCES);
1777         struct nfs_parsed_mount_data *args = mount_info->parsed;
1778         rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1779         unsigned int authlist_len = ARRAY_SIZE(authlist);
1780 
1781         status = nfs_request_mount(args, mount_info->mntfh, authlist,
1782                                         &authlist_len);
1783         if (status)
1784                 return ERR_PTR(status);
1785 
1786         /*
1787          * Was a sec= authflavor specified in the options? First, verify
1788          * whether the server supports it, and then just try to use it if so.
1789          */
1790         if (args->auth_info.flavor_len > 0) {
1791                 status = nfs_verify_authflavors(args, authlist, authlist_len);
1792                 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1793                          args->selected_flavor);
1794                 if (status)
1795                         return ERR_PTR(status);
1796                 return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1797         }
1798 
1799         /*
1800          * No sec= option was provided. RFC 2623, section 2.7 suggests we
1801          * SHOULD prefer the flavor listed first. However, some servers list
1802          * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1803          */
1804         for (i = 0; i < authlist_len; ++i) {
1805                 rpc_authflavor_t flavor;
1806                 struct rpcsec_gss_info info;
1807 
1808                 flavor = authlist[i];
1809                 switch (flavor) {
1810                 case RPC_AUTH_UNIX:
1811                         tried_auth_unix = true;
1812                         break;
1813                 case RPC_AUTH_NULL:
1814                         auth_null_in_list = true;
1815                         continue;
1816                 default:
1817                         if (rpcauth_get_gssinfo(flavor, &info) != 0)
1818                                 continue;
1819                         /* Fallthrough */
1820                 }
1821                 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1822                 args->selected_flavor = flavor;
1823                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1824                 if (!IS_ERR(server))
1825                         return server;
1826         }
1827 
1828         /*
1829          * Nothing we tried so far worked. At this point, give up if we've
1830          * already tried AUTH_UNIX or if the server's list doesn't contain
1831          * AUTH_NULL
1832          */
1833         if (tried_auth_unix || !auth_null_in_list)
1834                 return server;
1835 
1836         /* Last chance! Try AUTH_UNIX */
1837         dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1838         args->selected_flavor = RPC_AUTH_UNIX;
1839         return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1840 }
1841 
1842 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1843                              struct nfs_mount_info *mount_info,
1844                              struct nfs_subversion *nfs_mod)
1845 {
1846         struct nfs_server *server;
1847 
1848         if (mount_info->parsed->need_mount)
1849                 server = nfs_try_mount_request(mount_info, nfs_mod);
1850         else
1851                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1852 
1853         if (IS_ERR(server))
1854                 return ERR_CAST(server);
1855 
1856         return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1857 }
1858 EXPORT_SYMBOL_GPL(nfs_try_mount);
1859 
1860 /*
1861  * Split "dev_name" into "hostname:export_path".
1862  *
1863  * The leftmost colon demarks the split between the server's hostname
1864  * and the export path.  If the hostname starts with a left square
1865  * bracket, then it may contain colons.
1866  *
1867  * Note: caller frees hostname and export path, even on error.
1868  */
1869 static int nfs_parse_devname(const char *dev_name,
1870                              char **hostname, size_t maxnamlen,
1871                              char **export_path, size_t maxpathlen)
1872 {
1873         size_t len;
1874         char *end;
1875 
1876         /* Is the host name protected with square brakcets? */
1877         if (*dev_name == '[') {
1878                 end = strchr(++dev_name, ']');
1879                 if (end == NULL || end[1] != ':')
1880                         goto out_bad_devname;
1881 
1882                 len = end - dev_name;
1883                 end++;
1884         } else {
1885                 char *comma;
1886 
1887                 end = strchr(dev_name, ':');
1888                 if (end == NULL)
1889                         goto out_bad_devname;
1890                 len = end - dev_name;
1891 
1892                 /* kill possible hostname list: not supported */
1893                 comma = strchr(dev_name, ',');
1894                 if (comma != NULL && comma < end)
1895                         *comma = 0;
1896         }
1897 
1898         if (len > maxnamlen)
1899                 goto out_hostname;
1900 
1901         /* N.B. caller will free nfs_server.hostname in all cases */
1902         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1903         if (*hostname == NULL)
1904                 goto out_nomem;
1905         len = strlen(++end);
1906         if (len > maxpathlen)
1907                 goto out_path;
1908         *export_path = kstrndup(end, len, GFP_KERNEL);
1909         if (!*export_path)
1910                 goto out_nomem;
1911 
1912         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1913         return 0;
1914 
1915 out_bad_devname:
1916         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1917         return -EINVAL;
1918 
1919 out_nomem:
1920         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1921         return -ENOMEM;
1922 
1923 out_hostname:
1924         dfprintk(MOUNT, "NFS: server hostname too long\n");
1925         return -ENAMETOOLONG;
1926 
1927 out_path:
1928         dfprintk(MOUNT, "NFS: export pathname too long\n");
1929         return -ENAMETOOLONG;
1930 }
1931 
1932 /*
1933  * Validate the NFS2/NFS3 mount data
1934  * - fills in the mount root filehandle
1935  *
1936  * For option strings, user space handles the following behaviors:
1937  *
1938  * + DNS: mapping server host name to IP address ("addr=" option)
1939  *
1940  * + failure mode: how to behave if a mount request can't be handled
1941  *   immediately ("fg/bg" option)
1942  *
1943  * + retry: how often to retry a mount request ("retry=" option)
1944  *
1945  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1946  *   mountproto=tcp after mountproto=udp, and so on
1947  */
1948 static int nfs23_validate_mount_data(void *options,
1949                                      struct nfs_parsed_mount_data *args,
1950                                      struct nfs_fh *mntfh,
1951                                      const char *dev_name)
1952 {
1953         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1954         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1955         int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1956 
1957         if (data == NULL)
1958                 goto out_no_data;
1959 
1960         args->version = NFS_DEFAULT_VERSION;
1961         switch (data->version) {
1962         case 1:
1963                 data->namlen = 0;
1964         case 2:
1965                 data->bsize = 0;
1966         case 3:
1967                 if (data->flags & NFS_MOUNT_VER3)
1968                         goto out_no_v3;
1969                 data->root.size = NFS2_FHSIZE;
1970                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
1971                 /* Turn off security negotiation */
1972                 extra_flags |= NFS_MOUNT_SECFLAVOUR;
1973         case 4:
1974                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
1975                         goto out_no_sec;
1976         case 5:
1977                 memset(data->context, 0, sizeof(data->context));
1978         case 6:
1979                 if (data->flags & NFS_MOUNT_VER3) {
1980                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
1981                                 goto out_invalid_fh;
1982                         mntfh->size = data->root.size;
1983                         args->version = 3;
1984                 } else {
1985                         mntfh->size = NFS2_FHSIZE;
1986                         args->version = 2;
1987                 }
1988 
1989 
1990                 memcpy(mntfh->data, data->root.data, mntfh->size);
1991                 if (mntfh->size < sizeof(mntfh->data))
1992                         memset(mntfh->data + mntfh->size, 0,
1993                                sizeof(mntfh->data) - mntfh->size);
1994 
1995                 /*
1996                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
1997                  * can deal with.
1998                  */
1999                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
2000                 args->flags             |= extra_flags;
2001                 args->rsize             = data->rsize;
2002                 args->wsize             = data->wsize;
2003                 args->timeo             = data->timeo;
2004                 args->retrans           = data->retrans;
2005                 args->acregmin          = data->acregmin;
2006                 args->acregmax          = data->acregmax;
2007                 args->acdirmin          = data->acdirmin;
2008                 args->acdirmax          = data->acdirmax;
2009                 args->need_mount        = false;
2010 
2011                 memcpy(sap, &data->addr, sizeof(data->addr));
2012                 args->nfs_server.addrlen = sizeof(data->addr);
2013                 args->nfs_server.port = ntohs(data->addr.sin_port);
2014                 if (!nfs_verify_server_address(sap))
2015                         goto out_no_address;
2016 
2017                 if (!(data->flags & NFS_MOUNT_TCP))
2018                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2019                 /* N.B. caller will free nfs_server.hostname in all cases */
2020                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2021                 args->namlen            = data->namlen;
2022                 args->bsize             = data->bsize;
2023 
2024                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
2025                         args->selected_flavor = data->pseudoflavor;
2026                 else
2027                         args->selected_flavor = RPC_AUTH_UNIX;
2028                 if (!args->nfs_server.hostname)
2029                         goto out_nomem;
2030 
2031                 if (!(data->flags & NFS_MOUNT_NONLM))
2032                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2033                                          NFS_MOUNT_LOCAL_FCNTL);
2034                 else
2035                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2036                                         NFS_MOUNT_LOCAL_FCNTL);
2037                 /*
2038                  * The legacy version 6 binary mount data from userspace has a
2039                  * field used only to transport selinux information into the
2040                  * the kernel.  To continue to support that functionality we
2041                  * have a touch of selinux knowledge here in the NFS code. The
2042                  * userspace code converted context=blah to just blah so we are
2043                  * converting back to the full string selinux understands.
2044                  */
2045                 if (data->context[0]){
2046 #ifdef CONFIG_SECURITY_SELINUX
2047                         int rc;
2048                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
2049                         if (!opts_str)
2050                                 return -ENOMEM;
2051                         strcpy(opts_str, "context=");
2052                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2053                         strcat(opts_str, &data->context[0]);
2054                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
2055                         kfree(opts_str);
2056                         if (rc)
2057                                 return rc;
2058 #else
2059                         return -EINVAL;
2060 #endif
2061                 }
2062 
2063                 break;
2064         default:
2065                 return NFS_TEXT_DATA;
2066         }
2067 
2068         return 0;
2069 
2070 out_no_data:
2071         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2072         return -EINVAL;
2073 
2074 out_no_v3:
2075         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2076                  data->version);
2077         return -EINVAL;
2078 
2079 out_no_sec:
2080         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2081         return -EINVAL;
2082 
2083 out_nomem:
2084         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2085         return -ENOMEM;
2086 
2087 out_no_address:
2088         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2089         return -EINVAL;
2090 
2091 out_invalid_fh:
2092         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2093         return -EINVAL;
2094 }
2095 
2096 #if IS_ENABLED(CONFIG_NFS_V4)
2097 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2098                                    void *options,
2099                                    struct nfs_parsed_mount_data *args,
2100                                    struct nfs_fh *mntfh,
2101                                    const char *dev_name)
2102 {
2103         if (fs_type == &nfs_fs_type)
2104                 return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2105         return nfs4_validate_mount_data(options, args, dev_name);
2106 }
2107 #else
2108 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2109                                    void *options,
2110                                    struct nfs_parsed_mount_data *args,
2111                                    struct nfs_fh *mntfh,
2112                                    const char *dev_name)
2113 {
2114         return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2115 }
2116 #endif
2117 
2118 static int nfs_validate_text_mount_data(void *options,
2119                                         struct nfs_parsed_mount_data *args,
2120                                         const char *dev_name)
2121 {
2122         int port = 0;
2123         int max_namelen = PAGE_SIZE;
2124         int max_pathlen = NFS_MAXPATHLEN;
2125         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2126 
2127         if (nfs_parse_mount_options((char *)options, args) == 0)
2128                 return -EINVAL;
2129 
2130         if (!nfs_verify_server_address(sap))
2131                 goto out_no_address;
2132 
2133         if (args->version == 4) {
2134 #if IS_ENABLED(CONFIG_NFS_V4)
2135                 port = NFS_PORT;
2136                 max_namelen = NFS4_MAXNAMLEN;
2137                 max_pathlen = NFS4_MAXPATHLEN;
2138                 nfs_validate_transport_protocol(args);
2139                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2140                         goto out_invalid_transport_udp;
2141                 nfs4_validate_mount_flags(args);
2142 #else
2143                 goto out_v4_not_compiled;
2144 #endif /* CONFIG_NFS_V4 */
2145         } else
2146                 nfs_set_mount_transport_protocol(args);
2147 
2148         nfs_set_port(sap, &args->nfs_server.port, port);
2149 
2150         return nfs_parse_devname(dev_name,
2151                                    &args->nfs_server.hostname,
2152                                    max_namelen,
2153                                    &args->nfs_server.export_path,
2154                                    max_pathlen);
2155 
2156 #if !IS_ENABLED(CONFIG_NFS_V4)
2157 out_v4_not_compiled:
2158         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2159         return -EPROTONOSUPPORT;
2160 #else
2161 out_invalid_transport_udp:
2162         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2163         return -EINVAL;
2164 #endif /* !CONFIG_NFS_V4 */
2165 
2166 out_no_address:
2167         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2168         return -EINVAL;
2169 }
2170 
2171 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2172                 | NFS_MOUNT_SECURE \
2173                 | NFS_MOUNT_TCP \
2174                 | NFS_MOUNT_VER3 \
2175                 | NFS_MOUNT_KERBEROS \
2176                 | NFS_MOUNT_NONLM \
2177                 | NFS_MOUNT_BROKEN_SUID \
2178                 | NFS_MOUNT_STRICTLOCK \
2179                 | NFS_MOUNT_LEGACY_INTERFACE)
2180 
2181 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2182                 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2183 
2184 static int
2185 nfs_compare_remount_data(struct nfs_server *nfss,
2186                          struct nfs_parsed_mount_data *data)
2187 {
2188         if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2189             data->rsize != nfss->rsize ||
2190             data->wsize != nfss->wsize ||
2191             data->version != nfss->nfs_client->rpc_ops->version ||
2192             data->minorversion != nfss->nfs_client->cl_minorversion ||
2193             data->retrans != nfss->client->cl_timeout->to_retries ||
2194             data->selected_flavor != nfss->client->cl_auth->au_flavor ||
2195             data->acregmin != nfss->acregmin / HZ ||
2196             data->acregmax != nfss->acregmax / HZ ||
2197             data->acdirmin != nfss->acdirmin / HZ ||
2198             data->acdirmax != nfss->acdirmax / HZ ||
2199             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2200             data->nfs_server.port != nfss->port ||
2201             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2202             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2203                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2204                 return -EINVAL;
2205 
2206         return 0;
2207 }
2208 
2209 int
2210 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2211 {
2212         int error;
2213         struct nfs_server *nfss = sb->s_fs_info;
2214         struct nfs_parsed_mount_data *data;
2215         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2216         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2217         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2218 
2219         sync_filesystem(sb);
2220 
2221         /*
2222          * Userspace mount programs that send binary options generally send
2223          * them populated with default values. We have no way to know which
2224          * ones were explicitly specified. Fall back to legacy behavior and
2225          * just return success.
2226          */
2227         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2228             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2229                                            options->version <= 6))))
2230                 return 0;
2231 
2232         data = kzalloc(sizeof(*data), GFP_KERNEL);
2233         if (data == NULL)
2234                 return -ENOMEM;
2235 
2236         /* fill out struct with values from existing mount */
2237         data->flags = nfss->flags;
2238         data->rsize = nfss->rsize;
2239         data->wsize = nfss->wsize;
2240         data->retrans = nfss->client->cl_timeout->to_retries;
2241         data->selected_flavor = nfss->client->cl_auth->au_flavor;
2242         data->auth_info = nfss->auth_info;
2243         data->acregmin = nfss->acregmin / HZ;
2244         data->acregmax = nfss->acregmax / HZ;
2245         data->acdirmin = nfss->acdirmin / HZ;
2246         data->acdirmax = nfss->acdirmax / HZ;
2247         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2248         data->nfs_server.port = nfss->port;
2249         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2250         data->version = nfsvers;
2251         data->minorversion = nfss->nfs_client->cl_minorversion;
2252         data->net = current->nsproxy->net_ns;
2253         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2254                 data->nfs_server.addrlen);
2255 
2256         /* overwrite those values with any that were specified */
2257         error = -EINVAL;
2258         if (!nfs_parse_mount_options((char *)options, data))
2259                 goto out;
2260 
2261         /*
2262          * noac is a special case. It implies -o sync, but that's not
2263          * necessarily reflected in the mtab options. do_remount_sb
2264          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2265          * remount options, so we have to explicitly reset it.
2266          */
2267         if (data->flags & NFS_MOUNT_NOAC)
2268                 *flags |= MS_SYNCHRONOUS;
2269 
2270         /* compare new mount options with old ones */
2271         error = nfs_compare_remount_data(nfss, data);
2272 out:
2273         kfree(data);
2274         return error;
2275 }
2276 EXPORT_SYMBOL_GPL(nfs_remount);
2277 
2278 /*
2279  * Initialise the common bits of the superblock
2280  */
2281 inline void nfs_initialise_sb(struct super_block *sb)
2282 {
2283         struct nfs_server *server = NFS_SB(sb);
2284 
2285         sb->s_magic = NFS_SUPER_MAGIC;
2286 
2287         /* We probably want something more informative here */
2288         snprintf(sb->s_id, sizeof(sb->s_id),
2289                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2290 
2291         if (sb->s_blocksize == 0)
2292                 sb->s_blocksize = nfs_block_bits(server->wsize,
2293                                                  &sb->s_blocksize_bits);
2294 
2295         sb->s_bdi = &server->backing_dev_info;
2296 
2297         nfs_super_set_maxbytes(sb, server->maxfilesize);
2298 }
2299 
2300 /*
2301  * Finish setting up an NFS2/3 superblock
2302  */
2303 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2304 {
2305         struct nfs_parsed_mount_data *data = mount_info->parsed;
2306         struct nfs_server *server = NFS_SB(sb);
2307 
2308         sb->s_blocksize_bits = 0;
2309         sb->s_blocksize = 0;
2310         sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2311         sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2312         if (data && data->bsize)
2313                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2314 
2315         if (server->nfs_client->rpc_ops->version != 2) {
2316                 /* The VFS shouldn't apply the umask to mode bits. We will do
2317                  * so ourselves when necessary.
2318                  */
2319                 sb->s_flags |= MS_POSIXACL;
2320                 sb->s_time_gran = 1;
2321         }
2322 
2323         nfs_initialise_sb(sb);
2324 }
2325 EXPORT_SYMBOL_GPL(nfs_fill_super);
2326 
2327 /*
2328  * Finish setting up a cloned NFS2/3/4 superblock
2329  */
2330 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2331 {
2332         const struct super_block *old_sb = mount_info->cloned->sb;
2333         struct nfs_server *server = NFS_SB(sb);
2334 
2335         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2336         sb->s_blocksize = old_sb->s_blocksize;
2337         sb->s_maxbytes = old_sb->s_maxbytes;
2338         sb->s_xattr = old_sb->s_xattr;
2339         sb->s_op = old_sb->s_op;
2340         sb->s_time_gran = 1;
2341 
2342         if (server->nfs_client->rpc_ops->version != 2) {
2343                 /* The VFS shouldn't apply the umask to mode bits. We will do
2344                  * so ourselves when necessary.
2345                  */
2346                 sb->s_flags |= MS_POSIXACL;
2347         }
2348 
2349         nfs_initialise_sb(sb);
2350 }
2351 
2352 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2353 {
2354         const struct nfs_server *a = s->s_fs_info;
2355         const struct rpc_clnt *clnt_a = a->client;
2356         const struct rpc_clnt *clnt_b = b->client;
2357 
2358         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2359                 goto Ebusy;
2360         if (a->nfs_client != b->nfs_client)
2361                 goto Ebusy;
2362         if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2363                 goto Ebusy;
2364         if (a->wsize != b->wsize)
2365                 goto Ebusy;
2366         if (a->rsize != b->rsize)
2367                 goto Ebusy;
2368         if (a->acregmin != b->acregmin)
2369                 goto Ebusy;
2370         if (a->acregmax != b->acregmax)
2371                 goto Ebusy;
2372         if (a->acdirmin != b->acdirmin)
2373                 goto Ebusy;
2374         if (a->acdirmax != b->acdirmax)
2375                 goto Ebusy;
2376         if (b->auth_info.flavor_len > 0 &&
2377            clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2378                 goto Ebusy;
2379         return 1;
2380 Ebusy:
2381         return 0;
2382 }
2383 
2384 struct nfs_sb_mountdata {
2385         struct nfs_server *server;
2386         int mntflags;
2387 };
2388 
2389 static int nfs_set_super(struct super_block *s, void *data)
2390 {
2391         struct nfs_sb_mountdata *sb_mntdata = data;
2392         struct nfs_server *server = sb_mntdata->server;
2393         int ret;
2394 
2395         s->s_flags = sb_mntdata->mntflags;
2396         s->s_fs_info = server;
2397         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2398         ret = set_anon_super(s, server);
2399         if (ret == 0)
2400                 server->s_dev = s->s_dev;
2401         return ret;
2402 }
2403 
2404 static int nfs_compare_super_address(struct nfs_server *server1,
2405                                      struct nfs_server *server2)
2406 {
2407         struct sockaddr *sap1, *sap2;
2408 
2409         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2410         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2411 
2412         if (sap1->sa_family != sap2->sa_family)
2413                 return 0;
2414 
2415         switch (sap1->sa_family) {
2416         case AF_INET: {
2417                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2418                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2419                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2420                         return 0;
2421                 if (sin1->sin_port != sin2->sin_port)
2422                         return 0;
2423                 break;
2424         }
2425         case AF_INET6: {
2426                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2427                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2428                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2429                         return 0;
2430                 if (sin1->sin6_port != sin2->sin6_port)
2431                         return 0;
2432                 break;
2433         }
2434         default:
2435                 return 0;
2436         }
2437 
2438         return 1;
2439 }
2440 
2441 static int nfs_compare_super(struct super_block *sb, void *data)
2442 {
2443         struct nfs_sb_mountdata *sb_mntdata = data;
2444         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2445         int mntflags = sb_mntdata->mntflags;
2446 
2447         if (!nfs_compare_super_address(old, server))
2448                 return 0;
2449         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2450         if (old->flags & NFS_MOUNT_UNSHARED)
2451                 return 0;
2452         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2453                 return 0;
2454         return nfs_compare_mount_options(sb, server, mntflags);
2455 }
2456 
2457 #ifdef CONFIG_NFS_FSCACHE
2458 static void nfs_get_cache_cookie(struct super_block *sb,
2459                                  struct nfs_parsed_mount_data *parsed,
2460                                  struct nfs_clone_mount *cloned)
2461 {
2462         struct nfs_server *nfss = NFS_SB(sb);
2463         char *uniq = NULL;
2464         int ulen = 0;
2465 
2466         nfss->fscache_key = NULL;
2467         nfss->fscache = NULL;
2468 
2469         if (parsed) {
2470                 if (!(parsed->options & NFS_OPTION_FSCACHE))
2471                         return;
2472                 if (parsed->fscache_uniq) {
2473                         uniq = parsed->fscache_uniq;
2474                         ulen = strlen(parsed->fscache_uniq);
2475                 }
2476         } else if (cloned) {
2477                 struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2478                 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2479                         return;
2480                 if (mnt_s->fscache_key) {
2481                         uniq = mnt_s->fscache_key->key.uniquifier;
2482                         ulen = mnt_s->fscache_key->key.uniq_len;
2483                 };
2484         } else
2485                 return;
2486 
2487         nfs_fscache_get_super_cookie(sb, uniq, ulen);
2488 }
2489 #else
2490 static void nfs_get_cache_cookie(struct super_block *sb,
2491                                  struct nfs_parsed_mount_data *parsed,
2492                                  struct nfs_clone_mount *cloned)
2493 {
2494 }
2495 #endif
2496 
2497 static int nfs_bdi_register(struct nfs_server *server)
2498 {
2499         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2500 }
2501 
2502 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2503                         struct nfs_mount_info *mount_info)
2504 {
2505         int error;
2506         unsigned long kflags = 0, kflags_out = 0;
2507         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2508                 kflags |= SECURITY_LSM_NATIVE_LABELS;
2509 
2510         error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
2511                                                 kflags, &kflags_out);
2512         if (error)
2513                 goto err;
2514 
2515         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2516                 !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2517                 NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2518 err:
2519         return error;
2520 }
2521 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2522 
2523 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2524                           struct nfs_mount_info *mount_info)
2525 {
2526         /* clone any lsm security options from the parent to the new sb */
2527         if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2528                 return -ESTALE;
2529         return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2530 }
2531 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2532 
2533 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2534                                    int flags, const char *dev_name,
2535                                    struct nfs_mount_info *mount_info,
2536                                    struct nfs_subversion *nfs_mod)
2537 {
2538         struct super_block *s;
2539         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2540         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2541         struct nfs_sb_mountdata sb_mntdata = {
2542                 .mntflags = flags,
2543                 .server = server,
2544         };
2545         int error;
2546 
2547         if (server->flags & NFS_MOUNT_UNSHARED)
2548                 compare_super = NULL;
2549 
2550         /* -o noac implies -o sync */
2551         if (server->flags & NFS_MOUNT_NOAC)
2552                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2553 
2554         if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2555                 if (mount_info->cloned->sb->s_flags & MS_SYNCHRONOUS)
2556                         sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2557 
2558         /* Get a superblock - note that we may end up sharing one that already exists */
2559         s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2560         if (IS_ERR(s)) {
2561                 mntroot = ERR_CAST(s);
2562                 goto out_err_nosb;
2563         }
2564 
2565         if (s->s_fs_info != server) {
2566                 nfs_free_server(server);
2567                 server = NULL;
2568         } else {
2569                 error = nfs_bdi_register(server);
2570                 if (error) {
2571                         mntroot = ERR_PTR(error);
2572                         goto error_splat_bdi;
2573                 }
2574                 server->super = s;
2575         }
2576 
2577         if (!s->s_root) {
2578                 /* initial superblock/root creation */
2579                 mount_info->fill_super(s, mount_info);
2580                 nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2581         }
2582 
2583         mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2584         if (IS_ERR(mntroot))
2585                 goto error_splat_super;
2586 
2587         error = mount_info->set_security(s, mntroot, mount_info);
2588         if (error)
2589                 goto error_splat_root;
2590 
2591         s->s_flags |= MS_ACTIVE;
2592 
2593 out:
2594         return mntroot;
2595 
2596 out_err_nosb:
2597         nfs_free_server(server);
2598         goto out;
2599 
2600 error_splat_root:
2601         dput(mntroot);
2602         mntroot = ERR_PTR(error);
2603 error_splat_super:
2604         if (server && !s->s_root)
2605                 bdi_unregister(&server->backing_dev_info);
2606 error_splat_bdi:
2607         deactivate_locked_super(s);
2608         goto out;
2609 }
2610 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2611 
2612 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2613         int flags, const char *dev_name, void *raw_data)
2614 {
2615         struct nfs_mount_info mount_info = {
2616                 .fill_super = nfs_fill_super,
2617                 .set_security = nfs_set_sb_security,
2618         };
2619         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2620         struct nfs_subversion *nfs_mod;
2621         int error;
2622 
2623         mount_info.parsed = nfs_alloc_parsed_mount_data();
2624         mount_info.mntfh = nfs_alloc_fhandle();
2625         if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2626                 goto out;
2627 
2628         /* Validate the mount data */
2629         error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2630         if (error == NFS_TEXT_DATA)
2631                 error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2632         if (error < 0) {
2633                 mntroot = ERR_PTR(error);
2634                 goto out;
2635         }
2636 
2637         nfs_mod = get_nfs_version(mount_info.parsed->version);
2638         if (IS_ERR(nfs_mod)) {
2639                 mntroot = ERR_CAST(nfs_mod);
2640                 goto out;
2641         }
2642 
2643         mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2644 
2645         put_nfs_version(nfs_mod);
2646 out:
2647         nfs_free_parsed_mount_data(mount_info.parsed);
2648         nfs_free_fhandle(mount_info.mntfh);
2649         return mntroot;
2650 }
2651 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2652 
2653 /*
2654  * Ensure that we unregister the bdi before kill_anon_super
2655  * releases the device name
2656  */
2657 void nfs_put_super(struct super_block *s)
2658 {
2659         struct nfs_server *server = NFS_SB(s);
2660 
2661         bdi_unregister(&server->backing_dev_info);
2662 }
2663 EXPORT_SYMBOL_GPL(nfs_put_super);
2664 
2665 /*
2666  * Destroy an NFS2/3 superblock
2667  */
2668 void nfs_kill_super(struct super_block *s)
2669 {
2670         struct nfs_server *server = NFS_SB(s);
2671 
2672         kill_anon_super(s);
2673         nfs_fscache_release_super_cookie(s);
2674         nfs_free_server(server);
2675 }
2676 EXPORT_SYMBOL_GPL(nfs_kill_super);
2677 
2678 /*
2679  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2680  */
2681 static struct dentry *
2682 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2683                 const char *dev_name, void *raw_data)
2684 {
2685         struct nfs_clone_mount *data = raw_data;
2686         struct nfs_mount_info mount_info = {
2687                 .fill_super = nfs_clone_super,
2688                 .set_security = nfs_clone_sb_security,
2689                 .cloned = data,
2690         };
2691         struct nfs_server *server;
2692         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2693         struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2694 
2695         dprintk("--> nfs_xdev_mount()\n");
2696 
2697         mount_info.mntfh = mount_info.cloned->fh;
2698 
2699         /* create a new volume representation */
2700         server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2701 
2702         if (IS_ERR(server))
2703                 mntroot = ERR_CAST(server);
2704         else
2705                 mntroot = nfs_fs_mount_common(server, flags,
2706                                 dev_name, &mount_info, nfs_mod);
2707 
2708         dprintk("<-- nfs_xdev_mount() = %ld\n",
2709                         IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2710         return mntroot;
2711 }
2712 
2713 #if IS_ENABLED(CONFIG_NFS_V4)
2714 
2715 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2716 {
2717         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2718                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2719 }
2720 
2721 /*
2722  * Validate NFSv4 mount options
2723  */
2724 static int nfs4_validate_mount_data(void *options,
2725                                     struct nfs_parsed_mount_data *args,
2726                                     const char *dev_name)
2727 {
2728         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2729         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2730         char *c;
2731 
2732         if (data == NULL)
2733                 goto out_no_data;
2734 
2735         args->version = 4;
2736 
2737         switch (data->version) {
2738         case 1:
2739                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2740                         goto out_no_address;
2741                 if (data->host_addrlen == 0)
2742                         goto out_no_address;
2743                 args->nfs_server.addrlen = data->host_addrlen;
2744                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2745                         return -EFAULT;
2746                 if (!nfs_verify_server_address(sap))
2747                         goto out_no_address;
2748                 args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2749 
2750                 if (data->auth_flavourlen) {
2751                         rpc_authflavor_t pseudoflavor;
2752                         if (data->auth_flavourlen > 1)
2753                                 goto out_inval_auth;
2754                         if (copy_from_user(&pseudoflavor,
2755                                            data->auth_flavours,
2756                                            sizeof(pseudoflavor)))
2757                                 return -EFAULT;
2758                         args->selected_flavor = pseudoflavor;
2759                 } else
2760                         args->selected_flavor = RPC_AUTH_UNIX;
2761 
2762                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2763                 if (IS_ERR(c))
2764                         return PTR_ERR(c);
2765                 args->nfs_server.hostname = c;
2766 
2767                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2768                 if (IS_ERR(c))
2769                         return PTR_ERR(c);
2770                 args->nfs_server.export_path = c;
2771                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2772 
2773                 c = strndup_user(data->client_addr.data, 16);
2774                 if (IS_ERR(c))
2775                         return PTR_ERR(c);
2776                 args->client_address = c;
2777 
2778                 /*
2779                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2780                  * can deal with.
2781                  */
2782 
2783                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2784                 args->rsize     = data->rsize;
2785                 args->wsize     = data->wsize;
2786                 args->timeo     = data->timeo;
2787                 args->retrans   = data->retrans;
2788                 args->acregmin  = data->acregmin;
2789                 args->acregmax  = data->acregmax;
2790                 args->acdirmin  = data->acdirmin;
2791                 args->acdirmax  = data->acdirmax;
2792                 args->nfs_server.protocol = data->proto;
2793                 nfs_validate_transport_protocol(args);
2794                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2795                         goto out_invalid_transport_udp;
2796 
2797                 break;
2798         default:
2799                 return NFS_TEXT_DATA;
2800         }
2801 
2802         return 0;
2803 
2804 out_no_data:
2805         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2806         return -EINVAL;
2807 
2808 out_inval_auth:
2809         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2810                  data->auth_flavourlen);
2811         return -EINVAL;
2812 
2813 out_no_address:
2814         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2815         return -EINVAL;
2816 
2817 out_invalid_transport_udp:
2818         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2819         return -EINVAL;
2820 }
2821 
2822 /*
2823  * NFS v4 module parameters need to stay in the
2824  * NFS client for backwards compatibility
2825  */
2826 unsigned int nfs_callback_set_tcpport;
2827 unsigned short nfs_callback_tcpport;
2828 /* Default cache timeout is 10 minutes */
2829 unsigned int nfs_idmap_cache_timeout = 600;
2830 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2831 bool nfs4_disable_idmapping = true;
2832 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2833 unsigned short send_implementation_id = 1;
2834 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2835 bool recover_lost_locks = false;
2836 
2837 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2838 EXPORT_SYMBOL_GPL(nfs_callback_tcpport);
2839 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2840 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2841 EXPORT_SYMBOL_GPL(max_session_slots);
2842 EXPORT_SYMBOL_GPL(send_implementation_id);
2843 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2844 EXPORT_SYMBOL_GPL(recover_lost_locks);
2845 
2846 #define NFS_CALLBACK_MAXPORTNR (65535U)
2847 
2848 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2849 {
2850         unsigned long num;
2851         int ret;
2852 
2853         if (!val)
2854                 return -EINVAL;
2855         ret = kstrtoul(val, 0, &num);
2856         if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2857                 return -EINVAL;
2858         *((unsigned int *)kp->arg) = num;
2859         return 0;
2860 }
2861 static struct kernel_param_ops param_ops_portnr = {
2862         .set = param_set_portnr,
2863         .get = param_get_uint,
2864 };
2865 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2866 
2867 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2868 module_param(nfs_idmap_cache_timeout, int, 0644);
2869 module_param(nfs4_disable_idmapping, bool, 0644);
2870 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2871                         NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2872 MODULE_PARM_DESC(nfs4_disable_idmapping,
2873                 "Turn off NFSv4 idmapping when using 'sec=sys'");
2874 module_param(max_session_slots, ushort, 0644);
2875 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2876                 "requests the client will negotiate");
2877 module_param(send_implementation_id, ushort, 0644);
2878 MODULE_PARM_DESC(send_implementation_id,
2879                 "Send implementation ID with NFSv4.1 exchange_id");
2880 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2881 
2882 module_param(recover_lost_locks, bool, 0644);
2883 MODULE_PARM_DESC(recover_lost_locks,
2884                  "If the server reports that a lock might be lost, "
2885                  "try to recover it risking data corruption.");
2886 
2887 
2888 #endif /* CONFIG_NFS_V4 */
2889 

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