Version:  2.0.40 2.2.26 2.4.37 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 3.19 4.0

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

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