Version:  2.0.40 2.2.26 2.4.37 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8

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/vfs.h>
 47 #include <linux/inet.h>
 48 #include <linux/in6.h>
 49 #include <linux/slab.h>
 50 #include <net/ipv6.h>
 51 #include <linux/netdevice.h>
 52 #include <linux/nfs_xdr.h>
 53 #include <linux/magic.h>
 54 #include <linux/parser.h>
 55 #include <linux/nsproxy.h>
 56 #include <linux/rcupdate.h>
 57 
 58 #include <asm/uaccess.h>
 59 
 60 #include "nfs4_fs.h"
 61 #include "callback.h"
 62 #include "delegation.h"
 63 #include "iostat.h"
 64 #include "internal.h"
 65 #include "fscache.h"
 66 #include "nfs4session.h"
 67 #include "pnfs.h"
 68 #include "nfs.h"
 69 
 70 #define NFSDBG_FACILITY         NFSDBG_VFS
 71 #define NFS_TEXT_DATA           1
 72 
 73 #if IS_ENABLED(CONFIG_NFS_V3)
 74 #define NFS_DEFAULT_VERSION 3
 75 #else
 76 #define NFS_DEFAULT_VERSION 2
 77 #endif
 78 
 79 enum {
 80         /* Mount options that take no arguments */
 81         Opt_soft, Opt_hard,
 82         Opt_posix, Opt_noposix,
 83         Opt_cto, Opt_nocto,
 84         Opt_ac, Opt_noac,
 85         Opt_lock, Opt_nolock,
 86         Opt_udp, Opt_tcp, Opt_rdma,
 87         Opt_acl, Opt_noacl,
 88         Opt_rdirplus, Opt_nordirplus,
 89         Opt_sharecache, Opt_nosharecache,
 90         Opt_resvport, Opt_noresvport,
 91         Opt_fscache, Opt_nofscache,
 92         Opt_migration, Opt_nomigration,
 93 
 94         /* Mount options that take integer arguments */
 95         Opt_port,
 96         Opt_rsize, Opt_wsize, Opt_bsize,
 97         Opt_timeo, Opt_retrans,
 98         Opt_acregmin, Opt_acregmax,
 99         Opt_acdirmin, Opt_acdirmax,
100         Opt_actimeo,
101         Opt_namelen,
102         Opt_mountport,
103         Opt_mountvers,
104         Opt_minorversion,
105 
106         /* Mount options that take string arguments */
107         Opt_nfsvers,
108         Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
109         Opt_addr, Opt_mountaddr, Opt_clientaddr,
110         Opt_lookupcache,
111         Opt_fscache_uniq,
112         Opt_local_lock,
113 
114         /* Special mount options */
115         Opt_userspace, Opt_deprecated, Opt_sloppy,
116 
117         Opt_err
118 };
119 
120 static const match_table_t nfs_mount_option_tokens = {
121         { Opt_userspace, "bg" },
122         { Opt_userspace, "fg" },
123         { Opt_userspace, "retry=%s" },
124 
125         { Opt_sloppy, "sloppy" },
126 
127         { Opt_soft, "soft" },
128         { Opt_hard, "hard" },
129         { Opt_deprecated, "intr" },
130         { Opt_deprecated, "nointr" },
131         { Opt_posix, "posix" },
132         { Opt_noposix, "noposix" },
133         { Opt_cto, "cto" },
134         { Opt_nocto, "nocto" },
135         { Opt_ac, "ac" },
136         { Opt_noac, "noac" },
137         { Opt_lock, "lock" },
138         { Opt_nolock, "nolock" },
139         { Opt_udp, "udp" },
140         { Opt_tcp, "tcp" },
141         { Opt_rdma, "rdma" },
142         { Opt_acl, "acl" },
143         { Opt_noacl, "noacl" },
144         { Opt_rdirplus, "rdirplus" },
145         { Opt_nordirplus, "nordirplus" },
146         { Opt_sharecache, "sharecache" },
147         { Opt_nosharecache, "nosharecache" },
148         { Opt_resvport, "resvport" },
149         { Opt_noresvport, "noresvport" },
150         { Opt_fscache, "fsc" },
151         { Opt_nofscache, "nofsc" },
152         { Opt_migration, "migration" },
153         { Opt_nomigration, "nomigration" },
154 
155         { Opt_port, "port=%s" },
156         { Opt_rsize, "rsize=%s" },
157         { Opt_wsize, "wsize=%s" },
158         { Opt_bsize, "bsize=%s" },
159         { Opt_timeo, "timeo=%s" },
160         { Opt_retrans, "retrans=%s" },
161         { Opt_acregmin, "acregmin=%s" },
162         { Opt_acregmax, "acregmax=%s" },
163         { Opt_acdirmin, "acdirmin=%s" },
164         { Opt_acdirmax, "acdirmax=%s" },
165         { Opt_actimeo, "actimeo=%s" },
166         { Opt_namelen, "namlen=%s" },
167         { Opt_mountport, "mountport=%s" },
168         { Opt_mountvers, "mountvers=%s" },
169         { Opt_minorversion, "minorversion=%s" },
170 
171         { Opt_nfsvers, "nfsvers=%s" },
172         { Opt_nfsvers, "vers=%s" },
173 
174         { Opt_sec, "sec=%s" },
175         { Opt_proto, "proto=%s" },
176         { Opt_mountproto, "mountproto=%s" },
177         { Opt_addr, "addr=%s" },
178         { Opt_clientaddr, "clientaddr=%s" },
179         { Opt_mounthost, "mounthost=%s" },
180         { Opt_mountaddr, "mountaddr=%s" },
181 
182         { Opt_lookupcache, "lookupcache=%s" },
183         { Opt_fscache_uniq, "fsc=%s" },
184         { Opt_local_lock, "local_lock=%s" },
185 
186         /* The following needs to be listed after all other options */
187         { Opt_nfsvers, "v%s" },
188 
189         { Opt_err, NULL }
190 };
191 
192 enum {
193         Opt_xprt_udp, Opt_xprt_udp6, Opt_xprt_tcp, Opt_xprt_tcp6, Opt_xprt_rdma,
194         Opt_xprt_rdma6,
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         { Opt_xprt_rdma6, "rdma6" },
206 
207         { Opt_xprt_err, NULL }
208 };
209 
210 enum {
211         Opt_sec_none, Opt_sec_sys,
212         Opt_sec_krb5, Opt_sec_krb5i, Opt_sec_krb5p,
213         Opt_sec_lkey, Opt_sec_lkeyi, Opt_sec_lkeyp,
214         Opt_sec_spkm, Opt_sec_spkmi, Opt_sec_spkmp,
215 
216         Opt_sec_err
217 };
218 
219 static const match_table_t nfs_secflavor_tokens = {
220         { Opt_sec_none, "none" },
221         { Opt_sec_none, "null" },
222         { Opt_sec_sys, "sys" },
223 
224         { Opt_sec_krb5, "krb5" },
225         { Opt_sec_krb5i, "krb5i" },
226         { Opt_sec_krb5p, "krb5p" },
227 
228         { Opt_sec_lkey, "lkey" },
229         { Opt_sec_lkeyi, "lkeyi" },
230         { Opt_sec_lkeyp, "lkeyp" },
231 
232         { Opt_sec_spkm, "spkm3" },
233         { Opt_sec_spkmi, "spkm3i" },
234         { Opt_sec_spkmp, "spkm3p" },
235 
236         { Opt_sec_err, NULL }
237 };
238 
239 enum {
240         Opt_lookupcache_all, Opt_lookupcache_positive,
241         Opt_lookupcache_none,
242 
243         Opt_lookupcache_err
244 };
245 
246 static match_table_t nfs_lookupcache_tokens = {
247         { Opt_lookupcache_all, "all" },
248         { Opt_lookupcache_positive, "pos" },
249         { Opt_lookupcache_positive, "positive" },
250         { Opt_lookupcache_none, "none" },
251 
252         { Opt_lookupcache_err, NULL }
253 };
254 
255 enum {
256         Opt_local_lock_all, Opt_local_lock_flock, Opt_local_lock_posix,
257         Opt_local_lock_none,
258 
259         Opt_local_lock_err
260 };
261 
262 static match_table_t nfs_local_lock_tokens = {
263         { Opt_local_lock_all, "all" },
264         { Opt_local_lock_flock, "flock" },
265         { Opt_local_lock_posix, "posix" },
266         { Opt_local_lock_none, "none" },
267 
268         { Opt_local_lock_err, NULL }
269 };
270 
271 enum {
272         Opt_vers_2, Opt_vers_3, Opt_vers_4, Opt_vers_4_0,
273         Opt_vers_4_1, Opt_vers_4_2,
274 
275         Opt_vers_err
276 };
277 
278 static match_table_t nfs_vers_tokens = {
279         { Opt_vers_2, "2" },
280         { Opt_vers_3, "3" },
281         { Opt_vers_4, "4" },
282         { Opt_vers_4_0, "4.0" },
283         { Opt_vers_4_1, "4.1" },
284         { Opt_vers_4_2, "4.2" },
285 
286         { Opt_vers_err, NULL }
287 };
288 
289 static struct dentry *nfs_xdev_mount(struct file_system_type *fs_type,
290                 int flags, const char *dev_name, void *raw_data);
291 
292 struct file_system_type nfs_fs_type = {
293         .owner          = THIS_MODULE,
294         .name           = "nfs",
295         .mount          = nfs_fs_mount,
296         .kill_sb        = nfs_kill_super,
297         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
298 };
299 MODULE_ALIAS_FS("nfs");
300 EXPORT_SYMBOL_GPL(nfs_fs_type);
301 
302 struct file_system_type nfs_xdev_fs_type = {
303         .owner          = THIS_MODULE,
304         .name           = "nfs",
305         .mount          = nfs_xdev_mount,
306         .kill_sb        = nfs_kill_super,
307         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
308 };
309 
310 const struct super_operations nfs_sops = {
311         .alloc_inode    = nfs_alloc_inode,
312         .destroy_inode  = nfs_destroy_inode,
313         .write_inode    = nfs_write_inode,
314         .drop_inode     = nfs_drop_inode,
315         .statfs         = nfs_statfs,
316         .evict_inode    = nfs_evict_inode,
317         .umount_begin   = nfs_umount_begin,
318         .show_options   = nfs_show_options,
319         .show_devname   = nfs_show_devname,
320         .show_path      = nfs_show_path,
321         .show_stats     = nfs_show_stats,
322         .remount_fs     = nfs_remount,
323 };
324 EXPORT_SYMBOL_GPL(nfs_sops);
325 
326 #if IS_ENABLED(CONFIG_NFS_V4)
327 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *);
328 static int nfs4_validate_mount_data(void *options,
329         struct nfs_parsed_mount_data *args, const char *dev_name);
330 
331 struct file_system_type nfs4_fs_type = {
332         .owner          = THIS_MODULE,
333         .name           = "nfs4",
334         .mount          = nfs_fs_mount,
335         .kill_sb        = nfs_kill_super,
336         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
337 };
338 MODULE_ALIAS_FS("nfs4");
339 MODULE_ALIAS("nfs4");
340 EXPORT_SYMBOL_GPL(nfs4_fs_type);
341 
342 static int __init register_nfs4_fs(void)
343 {
344         return register_filesystem(&nfs4_fs_type);
345 }
346 
347 static void unregister_nfs4_fs(void)
348 {
349         unregister_filesystem(&nfs4_fs_type);
350 }
351 #else
352 static int __init register_nfs4_fs(void)
353 {
354         return 0;
355 }
356 
357 static void unregister_nfs4_fs(void)
358 {
359 }
360 #endif
361 
362 static struct shrinker acl_shrinker = {
363         .count_objects  = nfs_access_cache_count,
364         .scan_objects   = nfs_access_cache_scan,
365         .seeks          = DEFAULT_SEEKS,
366 };
367 
368 /*
369  * Register the NFS filesystems
370  */
371 int __init register_nfs_fs(void)
372 {
373         int ret;
374 
375         ret = register_filesystem(&nfs_fs_type);
376         if (ret < 0)
377                 goto error_0;
378 
379         ret = register_nfs4_fs();
380         if (ret < 0)
381                 goto error_1;
382 
383         ret = nfs_register_sysctl();
384         if (ret < 0)
385                 goto error_2;
386         ret = register_shrinker(&acl_shrinker);
387         if (ret < 0)
388                 goto error_3;
389         return 0;
390 error_3:
391         nfs_unregister_sysctl();
392 error_2:
393         unregister_nfs4_fs();
394 error_1:
395         unregister_filesystem(&nfs_fs_type);
396 error_0:
397         return ret;
398 }
399 
400 /*
401  * Unregister the NFS filesystems
402  */
403 void __exit unregister_nfs_fs(void)
404 {
405         unregister_shrinker(&acl_shrinker);
406         nfs_unregister_sysctl();
407         unregister_nfs4_fs();
408         unregister_filesystem(&nfs_fs_type);
409 }
410 
411 bool nfs_sb_active(struct super_block *sb)
412 {
413         struct nfs_server *server = NFS_SB(sb);
414 
415         if (!atomic_inc_not_zero(&sb->s_active))
416                 return false;
417         if (atomic_inc_return(&server->active) != 1)
418                 atomic_dec(&sb->s_active);
419         return true;
420 }
421 EXPORT_SYMBOL_GPL(nfs_sb_active);
422 
423 void nfs_sb_deactive(struct super_block *sb)
424 {
425         struct nfs_server *server = NFS_SB(sb);
426 
427         if (atomic_dec_and_test(&server->active))
428                 deactivate_super(sb);
429 }
430 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
431 
432 /*
433  * Deliver file system statistics to userspace
434  */
435 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
436 {
437         struct nfs_server *server = NFS_SB(dentry->d_sb);
438         unsigned char blockbits;
439         unsigned long blockres;
440         struct nfs_fh *fh = NFS_FH(d_inode(dentry));
441         struct nfs_fsstat res;
442         int error = -ENOMEM;
443 
444         res.fattr = nfs_alloc_fattr();
445         if (res.fattr == NULL)
446                 goto out_err;
447 
448         error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
449         if (unlikely(error == -ESTALE)) {
450                 struct dentry *pd_dentry;
451 
452                 pd_dentry = dget_parent(dentry);
453                 if (pd_dentry != NULL) {
454                         nfs_zap_caches(d_inode(pd_dentry));
455                         dput(pd_dentry);
456                 }
457         }
458         nfs_free_fattr(res.fattr);
459         if (error < 0)
460                 goto out_err;
461 
462         buf->f_type = NFS_SUPER_MAGIC;
463 
464         /*
465          * Current versions of glibc do not correctly handle the
466          * case where f_frsize != f_bsize.  Eventually we want to
467          * report the value of wtmult in this field.
468          */
469         buf->f_frsize = dentry->d_sb->s_blocksize;
470 
471         /*
472          * On most *nix systems, f_blocks, f_bfree, and f_bavail
473          * are reported in units of f_frsize.  Linux hasn't had
474          * an f_frsize field in its statfs struct until recently,
475          * thus historically Linux's sys_statfs reports these
476          * fields in units of f_bsize.
477          */
478         buf->f_bsize = dentry->d_sb->s_blocksize;
479         blockbits = dentry->d_sb->s_blocksize_bits;
480         blockres = (1 << blockbits) - 1;
481         buf->f_blocks = (res.tbytes + blockres) >> blockbits;
482         buf->f_bfree = (res.fbytes + blockres) >> blockbits;
483         buf->f_bavail = (res.abytes + blockres) >> blockbits;
484 
485         buf->f_files = res.tfiles;
486         buf->f_ffree = res.afiles;
487 
488         buf->f_namelen = server->namelen;
489 
490         return 0;
491 
492  out_err:
493         dprintk("%s: statfs error = %d\n", __func__, -error);
494         return error;
495 }
496 EXPORT_SYMBOL_GPL(nfs_statfs);
497 
498 /*
499  * Map the security flavour number to a name
500  */
501 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
502 {
503         static const struct {
504                 rpc_authflavor_t flavour;
505                 const char *str;
506         } sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
507                 /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
508                 { RPC_AUTH_NULL, "null" },
509                 { RPC_AUTH_UNIX, "sys" },
510                 { RPC_AUTH_GSS_KRB5, "krb5" },
511                 { RPC_AUTH_GSS_KRB5I, "krb5i" },
512                 { RPC_AUTH_GSS_KRB5P, "krb5p" },
513                 { RPC_AUTH_GSS_LKEY, "lkey" },
514                 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
515                 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
516                 { RPC_AUTH_GSS_SPKM, "spkm" },
517                 { RPC_AUTH_GSS_SPKMI, "spkmi" },
518                 { RPC_AUTH_GSS_SPKMP, "spkmp" },
519                 { UINT_MAX, "unknown" }
520         };
521         int i;
522 
523         for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
524                 if (sec_flavours[i].flavour == flavour)
525                         break;
526         }
527         return sec_flavours[i].str;
528 }
529 
530 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
531                                   int showdefaults)
532 {
533         struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
534 
535         seq_printf(m, ",mountproto=");
536         switch (sap->sa_family) {
537         case AF_INET:
538                 switch (nfss->mountd_protocol) {
539                 case IPPROTO_UDP:
540                         seq_printf(m, RPCBIND_NETID_UDP);
541                         break;
542                 case IPPROTO_TCP:
543                         seq_printf(m, RPCBIND_NETID_TCP);
544                         break;
545                 default:
546                         if (showdefaults)
547                                 seq_printf(m, "auto");
548                 }
549                 break;
550         case AF_INET6:
551                 switch (nfss->mountd_protocol) {
552                 case IPPROTO_UDP:
553                         seq_printf(m, RPCBIND_NETID_UDP6);
554                         break;
555                 case IPPROTO_TCP:
556                         seq_printf(m, RPCBIND_NETID_TCP6);
557                         break;
558                 default:
559                         if (showdefaults)
560                                 seq_printf(m, "auto");
561                 }
562                 break;
563         default:
564                 if (showdefaults)
565                         seq_printf(m, "auto");
566         }
567 }
568 
569 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
570                                     int showdefaults)
571 {
572         struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
573 
574         if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
575                 return;
576 
577         switch (sap->sa_family) {
578         case AF_INET: {
579                 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
580                 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
581                 break;
582         }
583         case AF_INET6: {
584                 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
585                 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
586                 break;
587         }
588         default:
589                 if (showdefaults)
590                         seq_printf(m, ",mountaddr=unspecified");
591         }
592 
593         if (nfss->mountd_version || showdefaults)
594                 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
595         if ((nfss->mountd_port &&
596                 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
597                 showdefaults)
598                 seq_printf(m, ",mountport=%u", nfss->mountd_port);
599 
600         nfs_show_mountd_netid(m, nfss, showdefaults);
601 }
602 
603 #if IS_ENABLED(CONFIG_NFS_V4)
604 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
605                                     int showdefaults)
606 {
607         struct nfs_client *clp = nfss->nfs_client;
608 
609         seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
610 }
611 #else
612 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
613                                     int showdefaults)
614 {
615 }
616 #endif
617 
618 static void nfs_show_nfs_version(struct seq_file *m,
619                 unsigned int version,
620                 unsigned int minorversion)
621 {
622         seq_printf(m, ",vers=%u", version);
623         if (version == 4)
624                 seq_printf(m, ".%u", minorversion);
625 }
626 
627 /*
628  * Describe the mount options in force on this server representation
629  */
630 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
631                                    int showdefaults)
632 {
633         static const struct proc_nfs_info {
634                 int flag;
635                 const char *str;
636                 const char *nostr;
637         } nfs_info[] = {
638                 { NFS_MOUNT_SOFT, ",soft", ",hard" },
639                 { NFS_MOUNT_POSIX, ",posix", "" },
640                 { NFS_MOUNT_NOCTO, ",nocto", "" },
641                 { NFS_MOUNT_NOAC, ",noac", "" },
642                 { NFS_MOUNT_NONLM, ",nolock", "" },
643                 { NFS_MOUNT_NOACL, ",noacl", "" },
644                 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
645                 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
646                 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
647                 { 0, NULL, NULL }
648         };
649         const struct proc_nfs_info *nfs_infop;
650         struct nfs_client *clp = nfss->nfs_client;
651         u32 version = clp->rpc_ops->version;
652         int local_flock, local_fcntl;
653 
654         nfs_show_nfs_version(m, version, clp->cl_minorversion);
655         seq_printf(m, ",rsize=%u", nfss->rsize);
656         seq_printf(m, ",wsize=%u", nfss->wsize);
657         if (nfss->bsize != 0)
658                 seq_printf(m, ",bsize=%u", nfss->bsize);
659         seq_printf(m, ",namlen=%u", nfss->namelen);
660         if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
661                 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
662         if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
663                 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
664         if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
665                 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
666         if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
667                 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
668         for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
669                 if (nfss->flags & nfs_infop->flag)
670                         seq_puts(m, nfs_infop->str);
671                 else
672                         seq_puts(m, nfs_infop->nostr);
673         }
674         rcu_read_lock();
675         seq_printf(m, ",proto=%s",
676                    rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
677         rcu_read_unlock();
678         if (version == 4) {
679                 if (nfss->port != NFS_PORT)
680                         seq_printf(m, ",port=%u", nfss->port);
681         } else
682                 if (nfss->port)
683                         seq_printf(m, ",port=%u", nfss->port);
684 
685         seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
686         seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
687         seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
688 
689         if (version != 4)
690                 nfs_show_mountd_options(m, nfss, showdefaults);
691         else
692                 nfs_show_nfsv4_options(m, nfss, showdefaults);
693 
694         if (nfss->options & NFS_OPTION_FSCACHE)
695                 seq_printf(m, ",fsc");
696 
697         if (nfss->options & NFS_OPTION_MIGRATION)
698                 seq_printf(m, ",migration");
699 
700         if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
701                 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
702                         seq_printf(m, ",lookupcache=none");
703                 else
704                         seq_printf(m, ",lookupcache=pos");
705         }
706 
707         local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
708         local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
709 
710         if (!local_flock && !local_fcntl)
711                 seq_printf(m, ",local_lock=none");
712         else if (local_flock && local_fcntl)
713                 seq_printf(m, ",local_lock=all");
714         else if (local_flock)
715                 seq_printf(m, ",local_lock=flock");
716         else
717                 seq_printf(m, ",local_lock=posix");
718 }
719 
720 /*
721  * Describe the mount options on this VFS mountpoint
722  */
723 int nfs_show_options(struct seq_file *m, struct dentry *root)
724 {
725         struct nfs_server *nfss = NFS_SB(root->d_sb);
726 
727         nfs_show_mount_options(m, nfss, 0);
728 
729         rcu_read_lock();
730         seq_printf(m, ",addr=%s",
731                         rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
732                                                         RPC_DISPLAY_ADDR));
733         rcu_read_unlock();
734 
735         return 0;
736 }
737 EXPORT_SYMBOL_GPL(nfs_show_options);
738 
739 #if IS_ENABLED(CONFIG_NFS_V4)
740 #ifdef CONFIG_NFS_V4_1
741 static void show_sessions(struct seq_file *m, struct nfs_server *server)
742 {
743         if (nfs4_has_session(server->nfs_client))
744                 seq_printf(m, ",sessions");
745 }
746 #else
747 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
748 #endif
749 #endif
750 
751 #ifdef CONFIG_NFS_V4_1
752 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
753 {
754         seq_printf(m, ",pnfs=");
755         if (server->pnfs_curr_ld)
756                 seq_printf(m, "%s", server->pnfs_curr_ld->name);
757         else
758                 seq_printf(m, "not configured");
759 }
760 
761 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
762 {
763         if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
764                 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
765                 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
766                            "date='%llu,%u'",
767                            impl_id->name, impl_id->domain,
768                            impl_id->date.seconds, impl_id->date.nseconds);
769         }
770 }
771 #else
772 #if IS_ENABLED(CONFIG_NFS_V4)
773 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
774 {
775 }
776 #endif
777 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
778 {
779 }
780 #endif
781 
782 int nfs_show_devname(struct seq_file *m, struct dentry *root)
783 {
784         char *page = (char *) __get_free_page(GFP_KERNEL);
785         char *devname, *dummy;
786         int err = 0;
787         if (!page)
788                 return -ENOMEM;
789         devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
790         if (IS_ERR(devname))
791                 err = PTR_ERR(devname);
792         else
793                 seq_escape(m, devname, " \t\n\\");
794         free_page((unsigned long)page);
795         return err;
796 }
797 EXPORT_SYMBOL_GPL(nfs_show_devname);
798 
799 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
800 {
801         seq_puts(m, "/");
802         return 0;
803 }
804 EXPORT_SYMBOL_GPL(nfs_show_path);
805 
806 /*
807  * Present statistical information for this VFS mountpoint
808  */
809 int nfs_show_stats(struct seq_file *m, struct dentry *root)
810 {
811         int i, cpu;
812         struct nfs_server *nfss = NFS_SB(root->d_sb);
813         struct rpc_auth *auth = nfss->client->cl_auth;
814         struct nfs_iostats totals = { };
815 
816         seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
817 
818         /*
819          * Display all mount option settings
820          */
821         seq_printf(m, "\n\topts:\t");
822         seq_puts(m, root->d_sb->s_flags & MS_RDONLY ? "ro" : "rw");
823         seq_puts(m, root->d_sb->s_flags & MS_SYNCHRONOUS ? ",sync" : "");
824         seq_puts(m, root->d_sb->s_flags & MS_NOATIME ? ",noatime" : "");
825         seq_puts(m, root->d_sb->s_flags & MS_NODIRATIME ? ",nodiratime" : "");
826         nfs_show_mount_options(m, nfss, 1);
827 
828         seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
829 
830         show_implementation_id(m, nfss);
831 
832         seq_printf(m, "\n\tcaps:\t");
833         seq_printf(m, "caps=0x%x", nfss->caps);
834         seq_printf(m, ",wtmult=%u", nfss->wtmult);
835         seq_printf(m, ",dtsize=%u", nfss->dtsize);
836         seq_printf(m, ",bsize=%u", nfss->bsize);
837         seq_printf(m, ",namlen=%u", nfss->namelen);
838 
839 #if IS_ENABLED(CONFIG_NFS_V4)
840         if (nfss->nfs_client->rpc_ops->version == 4) {
841                 seq_printf(m, "\n\tnfsv4:\t");
842                 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
843                 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
844                 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
845                 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
846                 show_sessions(m, nfss);
847                 show_pnfs(m, nfss);
848         }
849 #endif
850 
851         /*
852          * Display security flavor in effect for this mount
853          */
854         seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
855         if (auth->au_flavor)
856                 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
857 
858         /*
859          * Display superblock I/O counters
860          */
861         for_each_possible_cpu(cpu) {
862                 struct nfs_iostats *stats;
863 
864                 preempt_disable();
865                 stats = per_cpu_ptr(nfss->io_stats, cpu);
866 
867                 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
868                         totals.events[i] += stats->events[i];
869                 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
870                         totals.bytes[i] += stats->bytes[i];
871 #ifdef CONFIG_NFS_FSCACHE
872                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
873                         totals.fscache[i] += stats->fscache[i];
874 #endif
875 
876                 preempt_enable();
877         }
878 
879         seq_printf(m, "\n\tevents:\t");
880         for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
881                 seq_printf(m, "%lu ", totals.events[i]);
882         seq_printf(m, "\n\tbytes:\t");
883         for (i = 0; i < __NFSIOS_BYTESMAX; i++)
884                 seq_printf(m, "%Lu ", totals.bytes[i]);
885 #ifdef CONFIG_NFS_FSCACHE
886         if (nfss->options & NFS_OPTION_FSCACHE) {
887                 seq_printf(m, "\n\tfsc:\t");
888                 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
889                         seq_printf(m, "%Lu ", totals.bytes[i]);
890         }
891 #endif
892         seq_printf(m, "\n");
893 
894         rpc_print_iostats(m, nfss->client);
895 
896         return 0;
897 }
898 EXPORT_SYMBOL_GPL(nfs_show_stats);
899 
900 /*
901  * Begin unmount by attempting to remove all automounted mountpoints we added
902  * in response to xdev traversals and referrals
903  */
904 void nfs_umount_begin(struct super_block *sb)
905 {
906         struct nfs_server *server;
907         struct rpc_clnt *rpc;
908 
909         server = NFS_SB(sb);
910         /* -EIO all pending I/O */
911         rpc = server->client_acl;
912         if (!IS_ERR(rpc))
913                 rpc_killall_tasks(rpc);
914         rpc = server->client;
915         if (!IS_ERR(rpc))
916                 rpc_killall_tasks(rpc);
917 }
918 EXPORT_SYMBOL_GPL(nfs_umount_begin);
919 
920 static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
921 {
922         struct nfs_parsed_mount_data *data;
923 
924         data = kzalloc(sizeof(*data), GFP_KERNEL);
925         if (data) {
926                 data->timeo             = NFS_UNSPEC_TIMEO;
927                 data->retrans           = NFS_UNSPEC_RETRANS;
928                 data->acregmin          = NFS_DEF_ACREGMIN;
929                 data->acregmax          = NFS_DEF_ACREGMAX;
930                 data->acdirmin          = NFS_DEF_ACDIRMIN;
931                 data->acdirmax          = NFS_DEF_ACDIRMAX;
932                 data->mount_server.port = NFS_UNSPEC_PORT;
933                 data->nfs_server.port   = NFS_UNSPEC_PORT;
934                 data->nfs_server.protocol = XPRT_TRANSPORT_TCP;
935                 data->selected_flavor   = RPC_AUTH_MAXFLAVOR;
936                 data->minorversion      = 0;
937                 data->need_mount        = true;
938                 data->net               = current->nsproxy->net_ns;
939                 security_init_mnt_opts(&data->lsm_opts);
940         }
941         return data;
942 }
943 
944 static void nfs_free_parsed_mount_data(struct nfs_parsed_mount_data *data)
945 {
946         if (data) {
947                 kfree(data->client_address);
948                 kfree(data->mount_server.hostname);
949                 kfree(data->nfs_server.export_path);
950                 kfree(data->nfs_server.hostname);
951                 kfree(data->fscache_uniq);
952                 security_free_mnt_opts(&data->lsm_opts);
953                 kfree(data);
954         }
955 }
956 
957 /*
958  * Sanity-check a server address provided by the mount command.
959  *
960  * Address family must be initialized, and address must not be
961  * the ANY address for that family.
962  */
963 static int nfs_verify_server_address(struct sockaddr *addr)
964 {
965         switch (addr->sa_family) {
966         case AF_INET: {
967                 struct sockaddr_in *sa = (struct sockaddr_in *)addr;
968                 return sa->sin_addr.s_addr != htonl(INADDR_ANY);
969         }
970         case AF_INET6: {
971                 struct in6_addr *sa = &((struct sockaddr_in6 *)addr)->sin6_addr;
972                 return !ipv6_addr_any(sa);
973         }
974         }
975 
976         dfprintk(MOUNT, "NFS: Invalid IP address specified\n");
977         return 0;
978 }
979 
980 /*
981  * Select between a default port value and a user-specified port value.
982  * If a zero value is set, then autobind will be used.
983  */
984 static void nfs_set_port(struct sockaddr *sap, int *port,
985                                  const unsigned short default_port)
986 {
987         if (*port == NFS_UNSPEC_PORT)
988                 *port = default_port;
989 
990         rpc_set_port(sap, *port);
991 }
992 
993 /*
994  * Sanity check the NFS transport protocol.
995  *
996  */
997 static void nfs_validate_transport_protocol(struct nfs_parsed_mount_data *mnt)
998 {
999         switch (mnt->nfs_server.protocol) {
1000         case XPRT_TRANSPORT_UDP:
1001         case XPRT_TRANSPORT_TCP:
1002         case XPRT_TRANSPORT_RDMA:
1003                 break;
1004         default:
1005                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1006         }
1007 }
1008 
1009 /*
1010  * For text based NFSv2/v3 mounts, the mount protocol transport default
1011  * settings should depend upon the specified NFS transport.
1012  */
1013 static void nfs_set_mount_transport_protocol(struct nfs_parsed_mount_data *mnt)
1014 {
1015         nfs_validate_transport_protocol(mnt);
1016 
1017         if (mnt->mount_server.protocol == XPRT_TRANSPORT_UDP ||
1018             mnt->mount_server.protocol == XPRT_TRANSPORT_TCP)
1019                         return;
1020         switch (mnt->nfs_server.protocol) {
1021         case XPRT_TRANSPORT_UDP:
1022                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1023                 break;
1024         case XPRT_TRANSPORT_TCP:
1025         case XPRT_TRANSPORT_RDMA:
1026                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1027         }
1028 }
1029 
1030 /*
1031  * Add 'flavor' to 'auth_info' if not already present.
1032  * Returns true if 'flavor' ends up in the list, false otherwise
1033  */
1034 static bool nfs_auth_info_add(struct nfs_auth_info *auth_info,
1035                               rpc_authflavor_t flavor)
1036 {
1037         unsigned int i;
1038         unsigned int max_flavor_len = ARRAY_SIZE(auth_info->flavors);
1039 
1040         /* make sure this flavor isn't already in the list */
1041         for (i = 0; i < auth_info->flavor_len; i++) {
1042                 if (flavor == auth_info->flavors[i])
1043                         return true;
1044         }
1045 
1046         if (auth_info->flavor_len + 1 >= max_flavor_len) {
1047                 dfprintk(MOUNT, "NFS: too many sec= flavors\n");
1048                 return false;
1049         }
1050 
1051         auth_info->flavors[auth_info->flavor_len++] = flavor;
1052         return true;
1053 }
1054 
1055 /*
1056  * Return true if 'match' is in auth_info or auth_info is empty.
1057  * Return false otherwise.
1058  */
1059 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
1060                          rpc_authflavor_t match)
1061 {
1062         int i;
1063 
1064         if (!auth_info->flavor_len)
1065                 return true;
1066 
1067         for (i = 0; i < auth_info->flavor_len; i++) {
1068                 if (auth_info->flavors[i] == match)
1069                         return true;
1070         }
1071         return false;
1072 }
1073 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
1074 
1075 /*
1076  * Parse the value of the 'sec=' option.
1077  */
1078 static int nfs_parse_security_flavors(char *value,
1079                                       struct nfs_parsed_mount_data *mnt)
1080 {
1081         substring_t args[MAX_OPT_ARGS];
1082         rpc_authflavor_t pseudoflavor;
1083         char *p;
1084 
1085         dfprintk(MOUNT, "NFS: parsing sec=%s option\n", value);
1086 
1087         while ((p = strsep(&value, ":")) != NULL) {
1088                 switch (match_token(p, nfs_secflavor_tokens, args)) {
1089                 case Opt_sec_none:
1090                         pseudoflavor = RPC_AUTH_NULL;
1091                         break;
1092                 case Opt_sec_sys:
1093                         pseudoflavor = RPC_AUTH_UNIX;
1094                         break;
1095                 case Opt_sec_krb5:
1096                         pseudoflavor = RPC_AUTH_GSS_KRB5;
1097                         break;
1098                 case Opt_sec_krb5i:
1099                         pseudoflavor = RPC_AUTH_GSS_KRB5I;
1100                         break;
1101                 case Opt_sec_krb5p:
1102                         pseudoflavor = RPC_AUTH_GSS_KRB5P;
1103                         break;
1104                 case Opt_sec_lkey:
1105                         pseudoflavor = RPC_AUTH_GSS_LKEY;
1106                         break;
1107                 case Opt_sec_lkeyi:
1108                         pseudoflavor = RPC_AUTH_GSS_LKEYI;
1109                         break;
1110                 case Opt_sec_lkeyp:
1111                         pseudoflavor = RPC_AUTH_GSS_LKEYP;
1112                         break;
1113                 case Opt_sec_spkm:
1114                         pseudoflavor = RPC_AUTH_GSS_SPKM;
1115                         break;
1116                 case Opt_sec_spkmi:
1117                         pseudoflavor = RPC_AUTH_GSS_SPKMI;
1118                         break;
1119                 case Opt_sec_spkmp:
1120                         pseudoflavor = RPC_AUTH_GSS_SPKMP;
1121                         break;
1122                 default:
1123                         dfprintk(MOUNT,
1124                                  "NFS: sec= option '%s' not recognized\n", p);
1125                         return 0;
1126                 }
1127 
1128                 if (!nfs_auth_info_add(&mnt->auth_info, pseudoflavor))
1129                         return 0;
1130         }
1131 
1132         return 1;
1133 }
1134 
1135 static int nfs_parse_version_string(char *string,
1136                 struct nfs_parsed_mount_data *mnt,
1137                 substring_t *args)
1138 {
1139         mnt->flags &= ~NFS_MOUNT_VER3;
1140         switch (match_token(string, nfs_vers_tokens, args)) {
1141         case Opt_vers_2:
1142                 mnt->version = 2;
1143                 break;
1144         case Opt_vers_3:
1145                 mnt->flags |= NFS_MOUNT_VER3;
1146                 mnt->version = 3;
1147                 break;
1148         case Opt_vers_4:
1149                 /* Backward compatibility option. In future,
1150                  * the mount program should always supply
1151                  * a NFSv4 minor version number.
1152                  */
1153                 mnt->version = 4;
1154                 break;
1155         case Opt_vers_4_0:
1156                 mnt->version = 4;
1157                 mnt->minorversion = 0;
1158                 break;
1159         case Opt_vers_4_1:
1160                 mnt->version = 4;
1161                 mnt->minorversion = 1;
1162                 break;
1163         case Opt_vers_4_2:
1164                 mnt->version = 4;
1165                 mnt->minorversion = 2;
1166                 break;
1167         default:
1168                 return 0;
1169         }
1170         return 1;
1171 }
1172 
1173 static int nfs_get_option_str(substring_t args[], char **option)
1174 {
1175         kfree(*option);
1176         *option = match_strdup(args);
1177         return !*option;
1178 }
1179 
1180 static int nfs_get_option_ul(substring_t args[], unsigned long *option)
1181 {
1182         int rc;
1183         char *string;
1184 
1185         string = match_strdup(args);
1186         if (string == NULL)
1187                 return -ENOMEM;
1188         rc = kstrtoul(string, 10, option);
1189         kfree(string);
1190 
1191         return rc;
1192 }
1193 
1194 static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
1195                 unsigned long l_bound, unsigned long u_bound)
1196 {
1197         int ret;
1198 
1199         ret = nfs_get_option_ul(args, option);
1200         if (ret != 0)
1201                 return ret;
1202         if (*option < l_bound || *option > u_bound)
1203                 return -ERANGE;
1204         return 0;
1205 }
1206 
1207 /*
1208  * Error-check and convert a string of mount options from user space into
1209  * a data structure.  The whole mount string is processed; bad options are
1210  * skipped as they are encountered.  If there were no errors, return 1;
1211  * otherwise return 0 (zero).
1212  */
1213 static int nfs_parse_mount_options(char *raw,
1214                                    struct nfs_parsed_mount_data *mnt)
1215 {
1216         char *p, *string, *secdata;
1217         int rc, sloppy = 0, invalid_option = 0;
1218         unsigned short protofamily = AF_UNSPEC;
1219         unsigned short mountfamily = AF_UNSPEC;
1220 
1221         if (!raw) {
1222                 dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
1223                 return 1;
1224         }
1225         dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
1226 
1227         secdata = alloc_secdata();
1228         if (!secdata)
1229                 goto out_nomem;
1230 
1231         rc = security_sb_copy_data(raw, secdata);
1232         if (rc)
1233                 goto out_security_failure;
1234 
1235         rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
1236         if (rc)
1237                 goto out_security_failure;
1238 
1239         free_secdata(secdata);
1240 
1241         while ((p = strsep(&raw, ",")) != NULL) {
1242                 substring_t args[MAX_OPT_ARGS];
1243                 unsigned long option;
1244                 int token;
1245 
1246                 if (!*p)
1247                         continue;
1248 
1249                 dfprintk(MOUNT, "NFS:   parsing nfs mount option '%s'\n", p);
1250 
1251                 token = match_token(p, nfs_mount_option_tokens, args);
1252                 switch (token) {
1253 
1254                 /*
1255                  * boolean options:  foo/nofoo
1256                  */
1257                 case Opt_soft:
1258                         mnt->flags |= NFS_MOUNT_SOFT;
1259                         break;
1260                 case Opt_hard:
1261                         mnt->flags &= ~NFS_MOUNT_SOFT;
1262                         break;
1263                 case Opt_posix:
1264                         mnt->flags |= NFS_MOUNT_POSIX;
1265                         break;
1266                 case Opt_noposix:
1267                         mnt->flags &= ~NFS_MOUNT_POSIX;
1268                         break;
1269                 case Opt_cto:
1270                         mnt->flags &= ~NFS_MOUNT_NOCTO;
1271                         break;
1272                 case Opt_nocto:
1273                         mnt->flags |= NFS_MOUNT_NOCTO;
1274                         break;
1275                 case Opt_ac:
1276                         mnt->flags &= ~NFS_MOUNT_NOAC;
1277                         break;
1278                 case Opt_noac:
1279                         mnt->flags |= NFS_MOUNT_NOAC;
1280                         break;
1281                 case Opt_lock:
1282                         mnt->flags &= ~NFS_MOUNT_NONLM;
1283                         mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1284                                         NFS_MOUNT_LOCAL_FCNTL);
1285                         break;
1286                 case Opt_nolock:
1287                         mnt->flags |= NFS_MOUNT_NONLM;
1288                         mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1289                                        NFS_MOUNT_LOCAL_FCNTL);
1290                         break;
1291                 case Opt_udp:
1292                         mnt->flags &= ~NFS_MOUNT_TCP;
1293                         mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1294                         break;
1295                 case Opt_tcp:
1296                         mnt->flags |= NFS_MOUNT_TCP;
1297                         mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1298                         break;
1299                 case Opt_rdma:
1300                         mnt->flags |= NFS_MOUNT_TCP; /* for side protocols */
1301                         mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1302                         xprt_load_transport(p);
1303                         break;
1304                 case Opt_acl:
1305                         mnt->flags &= ~NFS_MOUNT_NOACL;
1306                         break;
1307                 case Opt_noacl:
1308                         mnt->flags |= NFS_MOUNT_NOACL;
1309                         break;
1310                 case Opt_rdirplus:
1311                         mnt->flags &= ~NFS_MOUNT_NORDIRPLUS;
1312                         break;
1313                 case Opt_nordirplus:
1314                         mnt->flags |= NFS_MOUNT_NORDIRPLUS;
1315                         break;
1316                 case Opt_sharecache:
1317                         mnt->flags &= ~NFS_MOUNT_UNSHARED;
1318                         break;
1319                 case Opt_nosharecache:
1320                         mnt->flags |= NFS_MOUNT_UNSHARED;
1321                         break;
1322                 case Opt_resvport:
1323                         mnt->flags &= ~NFS_MOUNT_NORESVPORT;
1324                         break;
1325                 case Opt_noresvport:
1326                         mnt->flags |= NFS_MOUNT_NORESVPORT;
1327                         break;
1328                 case Opt_fscache:
1329                         mnt->options |= NFS_OPTION_FSCACHE;
1330                         kfree(mnt->fscache_uniq);
1331                         mnt->fscache_uniq = NULL;
1332                         break;
1333                 case Opt_nofscache:
1334                         mnt->options &= ~NFS_OPTION_FSCACHE;
1335                         kfree(mnt->fscache_uniq);
1336                         mnt->fscache_uniq = NULL;
1337                         break;
1338                 case Opt_migration:
1339                         mnt->options |= NFS_OPTION_MIGRATION;
1340                         break;
1341                 case Opt_nomigration:
1342                         mnt->options &= NFS_OPTION_MIGRATION;
1343                         break;
1344 
1345                 /*
1346                  * options that take numeric values
1347                  */
1348                 case Opt_port:
1349                         if (nfs_get_option_ul(args, &option) ||
1350                             option > USHRT_MAX)
1351                                 goto out_invalid_value;
1352                         mnt->nfs_server.port = option;
1353                         break;
1354                 case Opt_rsize:
1355                         if (nfs_get_option_ul(args, &option))
1356                                 goto out_invalid_value;
1357                         mnt->rsize = option;
1358                         break;
1359                 case Opt_wsize:
1360                         if (nfs_get_option_ul(args, &option))
1361                                 goto out_invalid_value;
1362                         mnt->wsize = option;
1363                         break;
1364                 case Opt_bsize:
1365                         if (nfs_get_option_ul(args, &option))
1366                                 goto out_invalid_value;
1367                         mnt->bsize = option;
1368                         break;
1369                 case Opt_timeo:
1370                         if (nfs_get_option_ul_bound(args, &option, 1, INT_MAX))
1371                                 goto out_invalid_value;
1372                         mnt->timeo = option;
1373                         break;
1374                 case Opt_retrans:
1375                         if (nfs_get_option_ul_bound(args, &option, 0, INT_MAX))
1376                                 goto out_invalid_value;
1377                         mnt->retrans = option;
1378                         break;
1379                 case Opt_acregmin:
1380                         if (nfs_get_option_ul(args, &option))
1381                                 goto out_invalid_value;
1382                         mnt->acregmin = option;
1383                         break;
1384                 case Opt_acregmax:
1385                         if (nfs_get_option_ul(args, &option))
1386                                 goto out_invalid_value;
1387                         mnt->acregmax = option;
1388                         break;
1389                 case Opt_acdirmin:
1390                         if (nfs_get_option_ul(args, &option))
1391                                 goto out_invalid_value;
1392                         mnt->acdirmin = option;
1393                         break;
1394                 case Opt_acdirmax:
1395                         if (nfs_get_option_ul(args, &option))
1396                                 goto out_invalid_value;
1397                         mnt->acdirmax = option;
1398                         break;
1399                 case Opt_actimeo:
1400                         if (nfs_get_option_ul(args, &option))
1401                                 goto out_invalid_value;
1402                         mnt->acregmin = mnt->acregmax =
1403                         mnt->acdirmin = mnt->acdirmax = option;
1404                         break;
1405                 case Opt_namelen:
1406                         if (nfs_get_option_ul(args, &option))
1407                                 goto out_invalid_value;
1408                         mnt->namlen = option;
1409                         break;
1410                 case Opt_mountport:
1411                         if (nfs_get_option_ul(args, &option) ||
1412                             option > USHRT_MAX)
1413                                 goto out_invalid_value;
1414                         mnt->mount_server.port = option;
1415                         break;
1416                 case Opt_mountvers:
1417                         if (nfs_get_option_ul(args, &option) ||
1418                             option < NFS_MNT_VERSION ||
1419                             option > NFS_MNT3_VERSION)
1420                                 goto out_invalid_value;
1421                         mnt->mount_server.version = option;
1422                         break;
1423                 case Opt_minorversion:
1424                         if (nfs_get_option_ul(args, &option))
1425                                 goto out_invalid_value;
1426                         if (option > NFS4_MAX_MINOR_VERSION)
1427                                 goto out_invalid_value;
1428                         mnt->minorversion = option;
1429                         break;
1430 
1431                 /*
1432                  * options that take text values
1433                  */
1434                 case Opt_nfsvers:
1435                         string = match_strdup(args);
1436                         if (string == NULL)
1437                                 goto out_nomem;
1438                         rc = nfs_parse_version_string(string, mnt, args);
1439                         kfree(string);
1440                         if (!rc)
1441                                 goto out_invalid_value;
1442                         break;
1443                 case Opt_sec:
1444                         string = match_strdup(args);
1445                         if (string == NULL)
1446                                 goto out_nomem;
1447                         rc = nfs_parse_security_flavors(string, mnt);
1448                         kfree(string);
1449                         if (!rc) {
1450                                 dfprintk(MOUNT, "NFS:   unrecognized "
1451                                                 "security flavor\n");
1452                                 return 0;
1453                         }
1454                         break;
1455                 case Opt_proto:
1456                         string = match_strdup(args);
1457                         if (string == NULL)
1458                                 goto out_nomem;
1459                         token = match_token(string,
1460                                             nfs_xprt_protocol_tokens, args);
1461 
1462                         protofamily = AF_INET;
1463                         switch (token) {
1464                         case Opt_xprt_udp6:
1465                                 protofamily = AF_INET6;
1466                         case Opt_xprt_udp:
1467                                 mnt->flags &= ~NFS_MOUNT_TCP;
1468                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
1469                                 break;
1470                         case Opt_xprt_tcp6:
1471                                 protofamily = AF_INET6;
1472                         case Opt_xprt_tcp:
1473                                 mnt->flags |= NFS_MOUNT_TCP;
1474                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
1475                                 break;
1476                         case Opt_xprt_rdma6:
1477                                 protofamily = AF_INET6;
1478                         case Opt_xprt_rdma:
1479                                 /* vector side protocols to TCP */
1480                                 mnt->flags |= NFS_MOUNT_TCP;
1481                                 mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
1482                                 xprt_load_transport(string);
1483                                 break;
1484                         default:
1485                                 dfprintk(MOUNT, "NFS:   unrecognized "
1486                                                 "transport protocol\n");
1487                                 kfree(string);
1488                                 return 0;
1489                         }
1490                         kfree(string);
1491                         break;
1492                 case Opt_mountproto:
1493                         string = match_strdup(args);
1494                         if (string == NULL)
1495                                 goto out_nomem;
1496                         token = match_token(string,
1497                                             nfs_xprt_protocol_tokens, args);
1498                         kfree(string);
1499 
1500                         mountfamily = AF_INET;
1501                         switch (token) {
1502                         case Opt_xprt_udp6:
1503                                 mountfamily = AF_INET6;
1504                         case Opt_xprt_udp:
1505                                 mnt->mount_server.protocol = XPRT_TRANSPORT_UDP;
1506                                 break;
1507                         case Opt_xprt_tcp6:
1508                                 mountfamily = AF_INET6;
1509                         case Opt_xprt_tcp:
1510                                 mnt->mount_server.protocol = XPRT_TRANSPORT_TCP;
1511                                 break;
1512                         case Opt_xprt_rdma: /* not used for side protocols */
1513                         default:
1514                                 dfprintk(MOUNT, "NFS:   unrecognized "
1515                                                 "transport protocol\n");
1516                                 return 0;
1517                         }
1518                         break;
1519                 case Opt_addr:
1520                         string = match_strdup(args);
1521                         if (string == NULL)
1522                                 goto out_nomem;
1523                         mnt->nfs_server.addrlen =
1524                                 rpc_pton(mnt->net, string, strlen(string),
1525                                         (struct sockaddr *)
1526                                         &mnt->nfs_server.address,
1527                                         sizeof(mnt->nfs_server.address));
1528                         kfree(string);
1529                         if (mnt->nfs_server.addrlen == 0)
1530                                 goto out_invalid_address;
1531                         break;
1532                 case Opt_clientaddr:
1533                         if (nfs_get_option_str(args, &mnt->client_address))
1534                                 goto out_nomem;
1535                         break;
1536                 case Opt_mounthost:
1537                         if (nfs_get_option_str(args,
1538                                                &mnt->mount_server.hostname))
1539                                 goto out_nomem;
1540                         break;
1541                 case Opt_mountaddr:
1542                         string = match_strdup(args);
1543                         if (string == NULL)
1544                                 goto out_nomem;
1545                         mnt->mount_server.addrlen =
1546                                 rpc_pton(mnt->net, string, strlen(string),
1547                                         (struct sockaddr *)
1548                                         &mnt->mount_server.address,
1549                                         sizeof(mnt->mount_server.address));
1550                         kfree(string);
1551                         if (mnt->mount_server.addrlen == 0)
1552                                 goto out_invalid_address;
1553                         break;
1554                 case Opt_lookupcache:
1555                         string = match_strdup(args);
1556                         if (string == NULL)
1557                                 goto out_nomem;
1558                         token = match_token(string,
1559                                         nfs_lookupcache_tokens, args);
1560                         kfree(string);
1561                         switch (token) {
1562                                 case Opt_lookupcache_all:
1563                                         mnt->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
1564                                         break;
1565                                 case Opt_lookupcache_positive:
1566                                         mnt->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
1567                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
1568                                         break;
1569                                 case Opt_lookupcache_none:
1570                                         mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
1571                                         break;
1572                                 default:
1573                                         dfprintk(MOUNT, "NFS:   invalid "
1574                                                         "lookupcache argument\n");
1575                                         return 0;
1576                         };
1577                         break;
1578                 case Opt_fscache_uniq:
1579                         if (nfs_get_option_str(args, &mnt->fscache_uniq))
1580                                 goto out_nomem;
1581                         mnt->options |= NFS_OPTION_FSCACHE;
1582                         break;
1583                 case Opt_local_lock:
1584                         string = match_strdup(args);
1585                         if (string == NULL)
1586                                 goto out_nomem;
1587                         token = match_token(string, nfs_local_lock_tokens,
1588                                         args);
1589                         kfree(string);
1590                         switch (token) {
1591                         case Opt_local_lock_all:
1592                                 mnt->flags |= (NFS_MOUNT_LOCAL_FLOCK |
1593                                                NFS_MOUNT_LOCAL_FCNTL);
1594                                 break;
1595                         case Opt_local_lock_flock:
1596                                 mnt->flags |= NFS_MOUNT_LOCAL_FLOCK;
1597                                 break;
1598                         case Opt_local_lock_posix:
1599                                 mnt->flags |= NFS_MOUNT_LOCAL_FCNTL;
1600                                 break;
1601                         case Opt_local_lock_none:
1602                                 mnt->flags &= ~(NFS_MOUNT_LOCAL_FLOCK |
1603                                                 NFS_MOUNT_LOCAL_FCNTL);
1604                                 break;
1605                         default:
1606                                 dfprintk(MOUNT, "NFS:   invalid "
1607                                                 "local_lock argument\n");
1608                                 return 0;
1609                         };
1610                         break;
1611 
1612                 /*
1613                  * Special options
1614                  */
1615                 case Opt_sloppy:
1616                         sloppy = 1;
1617                         dfprintk(MOUNT, "NFS:   relaxing parsing rules\n");
1618                         break;
1619                 case Opt_userspace:
1620                 case Opt_deprecated:
1621                         dfprintk(MOUNT, "NFS:   ignoring mount option "
1622                                         "'%s'\n", p);
1623                         break;
1624 
1625                 default:
1626                         invalid_option = 1;
1627                         dfprintk(MOUNT, "NFS:   unrecognized mount option "
1628                                         "'%s'\n", p);
1629                 }
1630         }
1631 
1632         if (!sloppy && invalid_option)
1633                 return 0;
1634 
1635         if (mnt->minorversion && mnt->version != 4)
1636                 goto out_minorversion_mismatch;
1637 
1638         if (mnt->options & NFS_OPTION_MIGRATION &&
1639             (mnt->version != 4 || mnt->minorversion != 0))
1640                 goto out_migration_misuse;
1641 
1642         /*
1643          * verify that any proto=/mountproto= options match the address
1644          * families in the addr=/mountaddr= options.
1645          */
1646         if (protofamily != AF_UNSPEC &&
1647             protofamily != mnt->nfs_server.address.ss_family)
1648                 goto out_proto_mismatch;
1649 
1650         if (mountfamily != AF_UNSPEC) {
1651                 if (mnt->mount_server.addrlen) {
1652                         if (mountfamily != mnt->mount_server.address.ss_family)
1653                                 goto out_mountproto_mismatch;
1654                 } else {
1655                         if (mountfamily != mnt->nfs_server.address.ss_family)
1656                                 goto out_mountproto_mismatch;
1657                 }
1658         }
1659 
1660         return 1;
1661 
1662 out_mountproto_mismatch:
1663         printk(KERN_INFO "NFS: mount server address does not match mountproto= "
1664                          "option\n");
1665         return 0;
1666 out_proto_mismatch:
1667         printk(KERN_INFO "NFS: server address does not match proto= option\n");
1668         return 0;
1669 out_invalid_address:
1670         printk(KERN_INFO "NFS: bad IP address specified: %s\n", p);
1671         return 0;
1672 out_invalid_value:
1673         printk(KERN_INFO "NFS: bad mount option value specified: %s\n", p);
1674         return 0;
1675 out_minorversion_mismatch:
1676         printk(KERN_INFO "NFS: mount option vers=%u does not support "
1677                          "minorversion=%u\n", mnt->version, mnt->minorversion);
1678         return 0;
1679 out_migration_misuse:
1680         printk(KERN_INFO
1681                 "NFS: 'migration' not supported for this NFS version\n");
1682         return 0;
1683 out_nomem:
1684         printk(KERN_INFO "NFS: not enough memory to parse option\n");
1685         return 0;
1686 out_security_failure:
1687         free_secdata(secdata);
1688         printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
1689         return 0;
1690 }
1691 
1692 /*
1693  * Ensure that a specified authtype in args->auth_info is supported by
1694  * the server. Returns 0 and sets args->selected_flavor if it's ok, and
1695  * -EACCES if not.
1696  */
1697 static int nfs_verify_authflavors(struct nfs_parsed_mount_data *args,
1698                         rpc_authflavor_t *server_authlist, unsigned int count)
1699 {
1700         rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
1701         unsigned int i;
1702         int use_auth_null = false;
1703 
1704         /*
1705          * If the sec= mount option is used, the specified flavor or AUTH_NULL
1706          * must be in the list returned by the server.
1707          *
1708          * AUTH_NULL has a special meaning when it's in the server list - it
1709          * means that the server will ignore the rpc creds, so any flavor
1710          * can be used but still use the sec= that was specified.
1711          */
1712         for (i = 0; i < count; i++) {
1713                 flavor = server_authlist[i];
1714 
1715                 if (nfs_auth_info_match(&args->auth_info, flavor))
1716                         goto out;
1717 
1718                 if (flavor == RPC_AUTH_NULL)
1719                         use_auth_null = true;
1720         }
1721 
1722         if (use_auth_null) {
1723                 flavor = RPC_AUTH_NULL;
1724                 goto out;
1725         }
1726 
1727         dfprintk(MOUNT,
1728                  "NFS: specified auth flavors not supported by server\n");
1729         return -EACCES;
1730 
1731 out:
1732         args->selected_flavor = flavor;
1733         dfprintk(MOUNT, "NFS: using auth flavor %u\n", args->selected_flavor);
1734         return 0;
1735 }
1736 
1737 /*
1738  * Use the remote server's MOUNT service to request the NFS file handle
1739  * corresponding to the provided path.
1740  */
1741 static int nfs_request_mount(struct nfs_parsed_mount_data *args,
1742                              struct nfs_fh *root_fh,
1743                              rpc_authflavor_t *server_authlist,
1744                              unsigned int *server_authlist_len)
1745 {
1746         struct nfs_mount_request request = {
1747                 .sap            = (struct sockaddr *)
1748                                                 &args->mount_server.address,
1749                 .dirpath        = args->nfs_server.export_path,
1750                 .protocol       = args->mount_server.protocol,
1751                 .fh             = root_fh,
1752                 .noresvport     = args->flags & NFS_MOUNT_NORESVPORT,
1753                 .auth_flav_len  = server_authlist_len,
1754                 .auth_flavs     = server_authlist,
1755                 .net            = args->net,
1756         };
1757         int status;
1758 
1759         if (args->mount_server.version == 0) {
1760                 switch (args->version) {
1761                         default:
1762                                 args->mount_server.version = NFS_MNT3_VERSION;
1763                                 break;
1764                         case 2:
1765                                 args->mount_server.version = NFS_MNT_VERSION;
1766                 }
1767         }
1768         request.version = args->mount_server.version;
1769 
1770         if (args->mount_server.hostname)
1771                 request.hostname = args->mount_server.hostname;
1772         else
1773                 request.hostname = args->nfs_server.hostname;
1774 
1775         /*
1776          * Construct the mount server's address.
1777          */
1778         if (args->mount_server.address.ss_family == AF_UNSPEC) {
1779                 memcpy(request.sap, &args->nfs_server.address,
1780                        args->nfs_server.addrlen);
1781                 args->mount_server.addrlen = args->nfs_server.addrlen;
1782         }
1783         request.salen = args->mount_server.addrlen;
1784         nfs_set_port(request.sap, &args->mount_server.port, 0);
1785 
1786         /*
1787          * Now ask the mount server to map our export path
1788          * to a file handle.
1789          */
1790         status = nfs_mount(&request);
1791         if (status != 0) {
1792                 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
1793                                 request.hostname, status);
1794                 return status;
1795         }
1796 
1797         return 0;
1798 }
1799 
1800 static struct nfs_server *nfs_try_mount_request(struct nfs_mount_info *mount_info,
1801                                         struct nfs_subversion *nfs_mod)
1802 {
1803         int status;
1804         unsigned int i;
1805         bool tried_auth_unix = false;
1806         bool auth_null_in_list = false;
1807         struct nfs_server *server = ERR_PTR(-EACCES);
1808         struct nfs_parsed_mount_data *args = mount_info->parsed;
1809         rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
1810         unsigned int authlist_len = ARRAY_SIZE(authlist);
1811 
1812         status = nfs_request_mount(args, mount_info->mntfh, authlist,
1813                                         &authlist_len);
1814         if (status)
1815                 return ERR_PTR(status);
1816 
1817         /*
1818          * Was a sec= authflavor specified in the options? First, verify
1819          * whether the server supports it, and then just try to use it if so.
1820          */
1821         if (args->auth_info.flavor_len > 0) {
1822                 status = nfs_verify_authflavors(args, authlist, authlist_len);
1823                 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
1824                          args->selected_flavor);
1825                 if (status)
1826                         return ERR_PTR(status);
1827                 return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1828         }
1829 
1830         /*
1831          * No sec= option was provided. RFC 2623, section 2.7 suggests we
1832          * SHOULD prefer the flavor listed first. However, some servers list
1833          * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
1834          */
1835         for (i = 0; i < authlist_len; ++i) {
1836                 rpc_authflavor_t flavor;
1837                 struct rpcsec_gss_info info;
1838 
1839                 flavor = authlist[i];
1840                 switch (flavor) {
1841                 case RPC_AUTH_UNIX:
1842                         tried_auth_unix = true;
1843                         break;
1844                 case RPC_AUTH_NULL:
1845                         auth_null_in_list = true;
1846                         continue;
1847                 default:
1848                         if (rpcauth_get_gssinfo(flavor, &info) != 0)
1849                                 continue;
1850                         /* Fallthrough */
1851                 }
1852                 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
1853                 args->selected_flavor = flavor;
1854                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1855                 if (!IS_ERR(server))
1856                         return server;
1857         }
1858 
1859         /*
1860          * Nothing we tried so far worked. At this point, give up if we've
1861          * already tried AUTH_UNIX or if the server's list doesn't contain
1862          * AUTH_NULL
1863          */
1864         if (tried_auth_unix || !auth_null_in_list)
1865                 return server;
1866 
1867         /* Last chance! Try AUTH_UNIX */
1868         dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
1869         args->selected_flavor = RPC_AUTH_UNIX;
1870         return nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1871 }
1872 
1873 struct dentry *nfs_try_mount(int flags, const char *dev_name,
1874                              struct nfs_mount_info *mount_info,
1875                              struct nfs_subversion *nfs_mod)
1876 {
1877         struct nfs_server *server;
1878 
1879         if (mount_info->parsed->need_mount)
1880                 server = nfs_try_mount_request(mount_info, nfs_mod);
1881         else
1882                 server = nfs_mod->rpc_ops->create_server(mount_info, nfs_mod);
1883 
1884         if (IS_ERR(server))
1885                 return ERR_CAST(server);
1886 
1887         return nfs_fs_mount_common(server, flags, dev_name, mount_info, nfs_mod);
1888 }
1889 EXPORT_SYMBOL_GPL(nfs_try_mount);
1890 
1891 /*
1892  * Split "dev_name" into "hostname:export_path".
1893  *
1894  * The leftmost colon demarks the split between the server's hostname
1895  * and the export path.  If the hostname starts with a left square
1896  * bracket, then it may contain colons.
1897  *
1898  * Note: caller frees hostname and export path, even on error.
1899  */
1900 static int nfs_parse_devname(const char *dev_name,
1901                              char **hostname, size_t maxnamlen,
1902                              char **export_path, size_t maxpathlen)
1903 {
1904         size_t len;
1905         char *end;
1906 
1907         /* Is the host name protected with square brakcets? */
1908         if (*dev_name == '[') {
1909                 end = strchr(++dev_name, ']');
1910                 if (end == NULL || end[1] != ':')
1911                         goto out_bad_devname;
1912 
1913                 len = end - dev_name;
1914                 end++;
1915         } else {
1916                 char *comma;
1917 
1918                 end = strchr(dev_name, ':');
1919                 if (end == NULL)
1920                         goto out_bad_devname;
1921                 len = end - dev_name;
1922 
1923                 /* kill possible hostname list: not supported */
1924                 comma = strchr(dev_name, ',');
1925                 if (comma != NULL && comma < end)
1926                         *comma = 0;
1927         }
1928 
1929         if (len > maxnamlen)
1930                 goto out_hostname;
1931 
1932         /* N.B. caller will free nfs_server.hostname in all cases */
1933         *hostname = kstrndup(dev_name, len, GFP_KERNEL);
1934         if (*hostname == NULL)
1935                 goto out_nomem;
1936         len = strlen(++end);
1937         if (len > maxpathlen)
1938                 goto out_path;
1939         *export_path = kstrndup(end, len, GFP_KERNEL);
1940         if (!*export_path)
1941                 goto out_nomem;
1942 
1943         dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", *export_path);
1944         return 0;
1945 
1946 out_bad_devname:
1947         dfprintk(MOUNT, "NFS: device name not in host:path format\n");
1948         return -EINVAL;
1949 
1950 out_nomem:
1951         dfprintk(MOUNT, "NFS: not enough memory to parse device name\n");
1952         return -ENOMEM;
1953 
1954 out_hostname:
1955         dfprintk(MOUNT, "NFS: server hostname too long\n");
1956         return -ENAMETOOLONG;
1957 
1958 out_path:
1959         dfprintk(MOUNT, "NFS: export pathname too long\n");
1960         return -ENAMETOOLONG;
1961 }
1962 
1963 /*
1964  * Validate the NFS2/NFS3 mount data
1965  * - fills in the mount root filehandle
1966  *
1967  * For option strings, user space handles the following behaviors:
1968  *
1969  * + DNS: mapping server host name to IP address ("addr=" option)
1970  *
1971  * + failure mode: how to behave if a mount request can't be handled
1972  *   immediately ("fg/bg" option)
1973  *
1974  * + retry: how often to retry a mount request ("retry=" option)
1975  *
1976  * + breaking back: trying proto=udp after proto=tcp, v2 after v3,
1977  *   mountproto=tcp after mountproto=udp, and so on
1978  */
1979 static int nfs23_validate_mount_data(void *options,
1980                                      struct nfs_parsed_mount_data *args,
1981                                      struct nfs_fh *mntfh,
1982                                      const char *dev_name)
1983 {
1984         struct nfs_mount_data *data = (struct nfs_mount_data *)options;
1985         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
1986         int extra_flags = NFS_MOUNT_LEGACY_INTERFACE;
1987 
1988         if (data == NULL)
1989                 goto out_no_data;
1990 
1991         args->version = NFS_DEFAULT_VERSION;
1992         switch (data->version) {
1993         case 1:
1994                 data->namlen = 0;
1995         case 2:
1996                 data->bsize = 0;
1997         case 3:
1998                 if (data->flags & NFS_MOUNT_VER3)
1999                         goto out_no_v3;
2000                 data->root.size = NFS2_FHSIZE;
2001                 memcpy(data->root.data, data->old_root.data, NFS2_FHSIZE);
2002                 /* Turn off security negotiation */
2003                 extra_flags |= NFS_MOUNT_SECFLAVOUR;
2004         case 4:
2005                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
2006                         goto out_no_sec;
2007         case 5:
2008                 memset(data->context, 0, sizeof(data->context));
2009         case 6:
2010                 if (data->flags & NFS_MOUNT_VER3) {
2011                         if (data->root.size > NFS3_FHSIZE || data->root.size == 0)
2012                                 goto out_invalid_fh;
2013                         mntfh->size = data->root.size;
2014                         args->version = 3;
2015                 } else {
2016                         mntfh->size = NFS2_FHSIZE;
2017                         args->version = 2;
2018                 }
2019 
2020 
2021                 memcpy(mntfh->data, data->root.data, mntfh->size);
2022                 if (mntfh->size < sizeof(mntfh->data))
2023                         memset(mntfh->data + mntfh->size, 0,
2024                                sizeof(mntfh->data) - mntfh->size);
2025 
2026                 /*
2027                  * Translate to nfs_parsed_mount_data, which nfs_fill_super
2028                  * can deal with.
2029                  */
2030                 args->flags             = data->flags & NFS_MOUNT_FLAGMASK;
2031                 args->flags             |= extra_flags;
2032                 args->rsize             = data->rsize;
2033                 args->wsize             = data->wsize;
2034                 args->timeo             = data->timeo;
2035                 args->retrans           = data->retrans;
2036                 args->acregmin          = data->acregmin;
2037                 args->acregmax          = data->acregmax;
2038                 args->acdirmin          = data->acdirmin;
2039                 args->acdirmax          = data->acdirmax;
2040                 args->need_mount        = false;
2041 
2042                 memcpy(sap, &data->addr, sizeof(data->addr));
2043                 args->nfs_server.addrlen = sizeof(data->addr);
2044                 args->nfs_server.port = ntohs(data->addr.sin_port);
2045                 if (!nfs_verify_server_address(sap))
2046                         goto out_no_address;
2047 
2048                 if (!(data->flags & NFS_MOUNT_TCP))
2049                         args->nfs_server.protocol = XPRT_TRANSPORT_UDP;
2050                 /* N.B. caller will free nfs_server.hostname in all cases */
2051                 args->nfs_server.hostname = kstrdup(data->hostname, GFP_KERNEL);
2052                 args->namlen            = data->namlen;
2053                 args->bsize             = data->bsize;
2054 
2055                 if (data->flags & NFS_MOUNT_SECFLAVOUR)
2056                         args->selected_flavor = data->pseudoflavor;
2057                 else
2058                         args->selected_flavor = RPC_AUTH_UNIX;
2059                 if (!args->nfs_server.hostname)
2060                         goto out_nomem;
2061 
2062                 if (!(data->flags & NFS_MOUNT_NONLM))
2063                         args->flags &= ~(NFS_MOUNT_LOCAL_FLOCK|
2064                                          NFS_MOUNT_LOCAL_FCNTL);
2065                 else
2066                         args->flags |= (NFS_MOUNT_LOCAL_FLOCK|
2067                                         NFS_MOUNT_LOCAL_FCNTL);
2068                 /*
2069                  * The legacy version 6 binary mount data from userspace has a
2070                  * field used only to transport selinux information into the
2071                  * the kernel.  To continue to support that functionality we
2072                  * have a touch of selinux knowledge here in the NFS code. The
2073                  * userspace code converted context=blah to just blah so we are
2074                  * converting back to the full string selinux understands.
2075                  */
2076                 if (data->context[0]){
2077 #ifdef CONFIG_SECURITY_SELINUX
2078                         int rc;
2079                         char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
2080                         if (!opts_str)
2081                                 return -ENOMEM;
2082                         strcpy(opts_str, "context=");
2083                         data->context[NFS_MAX_CONTEXT_LEN] = '\0';
2084                         strcat(opts_str, &data->context[0]);
2085                         rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
2086                         kfree(opts_str);
2087                         if (rc)
2088                                 return rc;
2089 #else
2090                         return -EINVAL;
2091 #endif
2092                 }
2093 
2094                 break;
2095         default:
2096                 return NFS_TEXT_DATA;
2097         }
2098 
2099         return 0;
2100 
2101 out_no_data:
2102         dfprintk(MOUNT, "NFS: mount program didn't pass any mount data\n");
2103         return -EINVAL;
2104 
2105 out_no_v3:
2106         dfprintk(MOUNT, "NFS: nfs_mount_data version %d does not support v3\n",
2107                  data->version);
2108         return -EINVAL;
2109 
2110 out_no_sec:
2111         dfprintk(MOUNT, "NFS: nfs_mount_data version supports only AUTH_SYS\n");
2112         return -EINVAL;
2113 
2114 out_nomem:
2115         dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
2116         return -ENOMEM;
2117 
2118 out_no_address:
2119         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2120         return -EINVAL;
2121 
2122 out_invalid_fh:
2123         dfprintk(MOUNT, "NFS: invalid root filehandle\n");
2124         return -EINVAL;
2125 }
2126 
2127 #if IS_ENABLED(CONFIG_NFS_V4)
2128 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2129                                    void *options,
2130                                    struct nfs_parsed_mount_data *args,
2131                                    struct nfs_fh *mntfh,
2132                                    const char *dev_name)
2133 {
2134         if (fs_type == &nfs_fs_type)
2135                 return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2136         return nfs4_validate_mount_data(options, args, dev_name);
2137 }
2138 #else
2139 static int nfs_validate_mount_data(struct file_system_type *fs_type,
2140                                    void *options,
2141                                    struct nfs_parsed_mount_data *args,
2142                                    struct nfs_fh *mntfh,
2143                                    const char *dev_name)
2144 {
2145         return nfs23_validate_mount_data(options, args, mntfh, dev_name);
2146 }
2147 #endif
2148 
2149 static int nfs_validate_text_mount_data(void *options,
2150                                         struct nfs_parsed_mount_data *args,
2151                                         const char *dev_name)
2152 {
2153         int port = 0;
2154         int max_namelen = PAGE_SIZE;
2155         int max_pathlen = NFS_MAXPATHLEN;
2156         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2157 
2158         if (nfs_parse_mount_options((char *)options, args) == 0)
2159                 return -EINVAL;
2160 
2161         if (!nfs_verify_server_address(sap))
2162                 goto out_no_address;
2163 
2164         if (args->version == 4) {
2165 #if IS_ENABLED(CONFIG_NFS_V4)
2166                 port = NFS_PORT;
2167                 max_namelen = NFS4_MAXNAMLEN;
2168                 max_pathlen = NFS4_MAXPATHLEN;
2169                 nfs_validate_transport_protocol(args);
2170                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2171                         goto out_invalid_transport_udp;
2172                 nfs4_validate_mount_flags(args);
2173 #else
2174                 goto out_v4_not_compiled;
2175 #endif /* CONFIG_NFS_V4 */
2176         } else
2177                 nfs_set_mount_transport_protocol(args);
2178 
2179         nfs_set_port(sap, &args->nfs_server.port, port);
2180 
2181         return nfs_parse_devname(dev_name,
2182                                    &args->nfs_server.hostname,
2183                                    max_namelen,
2184                                    &args->nfs_server.export_path,
2185                                    max_pathlen);
2186 
2187 #if !IS_ENABLED(CONFIG_NFS_V4)
2188 out_v4_not_compiled:
2189         dfprintk(MOUNT, "NFS: NFSv4 is not compiled into kernel\n");
2190         return -EPROTONOSUPPORT;
2191 #else
2192 out_invalid_transport_udp:
2193         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2194         return -EINVAL;
2195 #endif /* !CONFIG_NFS_V4 */
2196 
2197 out_no_address:
2198         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
2199         return -EINVAL;
2200 }
2201 
2202 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
2203                 | NFS_MOUNT_SECURE \
2204                 | NFS_MOUNT_TCP \
2205                 | NFS_MOUNT_VER3 \
2206                 | NFS_MOUNT_KERBEROS \
2207                 | NFS_MOUNT_NONLM \
2208                 | NFS_MOUNT_BROKEN_SUID \
2209                 | NFS_MOUNT_STRICTLOCK \
2210                 | NFS_MOUNT_LEGACY_INTERFACE)
2211 
2212 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
2213                 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
2214 
2215 static int
2216 nfs_compare_remount_data(struct nfs_server *nfss,
2217                          struct nfs_parsed_mount_data *data)
2218 {
2219         if ((data->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
2220             data->rsize != nfss->rsize ||
2221             data->wsize != nfss->wsize ||
2222             data->version != nfss->nfs_client->rpc_ops->version ||
2223             data->minorversion != nfss->nfs_client->cl_minorversion ||
2224             data->retrans != nfss->client->cl_timeout->to_retries ||
2225             !nfs_auth_info_match(&data->auth_info, nfss->client->cl_auth->au_flavor) ||
2226             data->acregmin != nfss->acregmin / HZ ||
2227             data->acregmax != nfss->acregmax / HZ ||
2228             data->acdirmin != nfss->acdirmin / HZ ||
2229             data->acdirmax != nfss->acdirmax / HZ ||
2230             data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
2231             data->nfs_server.port != nfss->port ||
2232             data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
2233             !rpc_cmp_addr((struct sockaddr *)&data->nfs_server.address,
2234                           (struct sockaddr *)&nfss->nfs_client->cl_addr))
2235                 return -EINVAL;
2236 
2237         return 0;
2238 }
2239 
2240 int
2241 nfs_remount(struct super_block *sb, int *flags, char *raw_data)
2242 {
2243         int error;
2244         struct nfs_server *nfss = sb->s_fs_info;
2245         struct nfs_parsed_mount_data *data;
2246         struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data;
2247         struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data;
2248         u32 nfsvers = nfss->nfs_client->rpc_ops->version;
2249 
2250         sync_filesystem(sb);
2251 
2252         /*
2253          * Userspace mount programs that send binary options generally send
2254          * them populated with default values. We have no way to know which
2255          * ones were explicitly specified. Fall back to legacy behavior and
2256          * just return success.
2257          */
2258         if ((nfsvers == 4 && (!options4 || options4->version == 1)) ||
2259             (nfsvers <= 3 && (!options || (options->version >= 1 &&
2260                                            options->version <= 6))))
2261                 return 0;
2262 
2263         data = kzalloc(sizeof(*data), GFP_KERNEL);
2264         if (data == NULL)
2265                 return -ENOMEM;
2266 
2267         /* fill out struct with values from existing mount */
2268         data->flags = nfss->flags;
2269         data->rsize = nfss->rsize;
2270         data->wsize = nfss->wsize;
2271         data->retrans = nfss->client->cl_timeout->to_retries;
2272         data->selected_flavor = nfss->client->cl_auth->au_flavor;
2273         data->acregmin = nfss->acregmin / HZ;
2274         data->acregmax = nfss->acregmax / HZ;
2275         data->acdirmin = nfss->acdirmin / HZ;
2276         data->acdirmax = nfss->acdirmax / HZ;
2277         data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ;
2278         data->nfs_server.port = nfss->port;
2279         data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen;
2280         data->version = nfsvers;
2281         data->minorversion = nfss->nfs_client->cl_minorversion;
2282         data->net = current->nsproxy->net_ns;
2283         memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr,
2284                 data->nfs_server.addrlen);
2285 
2286         /* overwrite those values with any that were specified */
2287         error = -EINVAL;
2288         if (!nfs_parse_mount_options((char *)options, data))
2289                 goto out;
2290 
2291         /*
2292          * noac is a special case. It implies -o sync, but that's not
2293          * necessarily reflected in the mtab options. do_remount_sb
2294          * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the
2295          * remount options, so we have to explicitly reset it.
2296          */
2297         if (data->flags & NFS_MOUNT_NOAC)
2298                 *flags |= MS_SYNCHRONOUS;
2299 
2300         /* compare new mount options with old ones */
2301         error = nfs_compare_remount_data(nfss, data);
2302 out:
2303         kfree(data);
2304         return error;
2305 }
2306 EXPORT_SYMBOL_GPL(nfs_remount);
2307 
2308 /*
2309  * Initialise the common bits of the superblock
2310  */
2311 inline void nfs_initialise_sb(struct super_block *sb)
2312 {
2313         struct nfs_server *server = NFS_SB(sb);
2314 
2315         sb->s_magic = NFS_SUPER_MAGIC;
2316 
2317         /* We probably want something more informative here */
2318         snprintf(sb->s_id, sizeof(sb->s_id),
2319                  "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
2320 
2321         if (sb->s_blocksize == 0)
2322                 sb->s_blocksize = nfs_block_bits(server->wsize,
2323                                                  &sb->s_blocksize_bits);
2324 
2325         sb->s_bdi = &server->backing_dev_info;
2326 
2327         nfs_super_set_maxbytes(sb, server->maxfilesize);
2328 }
2329 
2330 /*
2331  * Finish setting up an NFS2/3 superblock
2332  */
2333 void nfs_fill_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2334 {
2335         struct nfs_parsed_mount_data *data = mount_info->parsed;
2336         struct nfs_server *server = NFS_SB(sb);
2337 
2338         sb->s_blocksize_bits = 0;
2339         sb->s_blocksize = 0;
2340         sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
2341         sb->s_op = server->nfs_client->cl_nfs_mod->sops;
2342         if (data && data->bsize)
2343                 sb->s_blocksize = nfs_block_size(data->bsize, &sb->s_blocksize_bits);
2344 
2345         if (server->nfs_client->rpc_ops->version != 2) {
2346                 /* The VFS shouldn't apply the umask to mode bits. We will do
2347                  * so ourselves when necessary.
2348                  */
2349                 sb->s_flags |= MS_POSIXACL;
2350                 sb->s_time_gran = 1;
2351         }
2352 
2353         nfs_initialise_sb(sb);
2354 }
2355 EXPORT_SYMBOL_GPL(nfs_fill_super);
2356 
2357 /*
2358  * Finish setting up a cloned NFS2/3/4 superblock
2359  */
2360 void nfs_clone_super(struct super_block *sb, struct nfs_mount_info *mount_info)
2361 {
2362         const struct super_block *old_sb = mount_info->cloned->sb;
2363         struct nfs_server *server = NFS_SB(sb);
2364 
2365         sb->s_blocksize_bits = old_sb->s_blocksize_bits;
2366         sb->s_blocksize = old_sb->s_blocksize;
2367         sb->s_maxbytes = old_sb->s_maxbytes;
2368         sb->s_xattr = old_sb->s_xattr;
2369         sb->s_op = old_sb->s_op;
2370         sb->s_time_gran = 1;
2371 
2372         if (server->nfs_client->rpc_ops->version != 2) {
2373                 /* The VFS shouldn't apply the umask to mode bits. We will do
2374                  * so ourselves when necessary.
2375                  */
2376                 sb->s_flags |= MS_POSIXACL;
2377         }
2378 
2379         nfs_initialise_sb(sb);
2380 }
2381 
2382 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, int flags)
2383 {
2384         const struct nfs_server *a = s->s_fs_info;
2385         const struct rpc_clnt *clnt_a = a->client;
2386         const struct rpc_clnt *clnt_b = b->client;
2387 
2388         if ((s->s_flags & NFS_MS_MASK) != (flags & NFS_MS_MASK))
2389                 goto Ebusy;
2390         if (a->nfs_client != b->nfs_client)
2391                 goto Ebusy;
2392         if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
2393                 goto Ebusy;
2394         if (a->wsize != b->wsize)
2395                 goto Ebusy;
2396         if (a->rsize != b->rsize)
2397                 goto Ebusy;
2398         if (a->acregmin != b->acregmin)
2399                 goto Ebusy;
2400         if (a->acregmax != b->acregmax)
2401                 goto Ebusy;
2402         if (a->acdirmin != b->acdirmin)
2403                 goto Ebusy;
2404         if (a->acdirmax != b->acdirmax)
2405                 goto Ebusy;
2406         if (b->auth_info.flavor_len > 0 &&
2407            clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
2408                 goto Ebusy;
2409         return 1;
2410 Ebusy:
2411         return 0;
2412 }
2413 
2414 struct nfs_sb_mountdata {
2415         struct nfs_server *server;
2416         int mntflags;
2417 };
2418 
2419 static int nfs_set_super(struct super_block *s, void *data)
2420 {
2421         struct nfs_sb_mountdata *sb_mntdata = data;
2422         struct nfs_server *server = sb_mntdata->server;
2423         int ret;
2424 
2425         s->s_flags = sb_mntdata->mntflags;
2426         s->s_fs_info = server;
2427         s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
2428         ret = set_anon_super(s, server);
2429         if (ret == 0)
2430                 server->s_dev = s->s_dev;
2431         return ret;
2432 }
2433 
2434 static int nfs_compare_super_address(struct nfs_server *server1,
2435                                      struct nfs_server *server2)
2436 {
2437         struct sockaddr *sap1, *sap2;
2438         struct rpc_xprt *xprt1 = server1->client->cl_xprt;
2439         struct rpc_xprt *xprt2 = server2->client->cl_xprt;
2440 
2441         if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
2442                 return 0;
2443 
2444         sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
2445         sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
2446 
2447         if (sap1->sa_family != sap2->sa_family)
2448                 return 0;
2449 
2450         switch (sap1->sa_family) {
2451         case AF_INET: {
2452                 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
2453                 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
2454                 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
2455                         return 0;
2456                 if (sin1->sin_port != sin2->sin_port)
2457                         return 0;
2458                 break;
2459         }
2460         case AF_INET6: {
2461                 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
2462                 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
2463                 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
2464                         return 0;
2465                 if (sin1->sin6_port != sin2->sin6_port)
2466                         return 0;
2467                 break;
2468         }
2469         default:
2470                 return 0;
2471         }
2472 
2473         return 1;
2474 }
2475 
2476 static int nfs_compare_super(struct super_block *sb, void *data)
2477 {
2478         struct nfs_sb_mountdata *sb_mntdata = data;
2479         struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
2480         int mntflags = sb_mntdata->mntflags;
2481 
2482         if (!nfs_compare_super_address(old, server))
2483                 return 0;
2484         /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
2485         if (old->flags & NFS_MOUNT_UNSHARED)
2486                 return 0;
2487         if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
2488                 return 0;
2489         return nfs_compare_mount_options(sb, server, mntflags);
2490 }
2491 
2492 #ifdef CONFIG_NFS_FSCACHE
2493 static void nfs_get_cache_cookie(struct super_block *sb,
2494                                  struct nfs_parsed_mount_data *parsed,
2495                                  struct nfs_clone_mount *cloned)
2496 {
2497         struct nfs_server *nfss = NFS_SB(sb);
2498         char *uniq = NULL;
2499         int ulen = 0;
2500 
2501         nfss->fscache_key = NULL;
2502         nfss->fscache = NULL;
2503 
2504         if (parsed) {
2505                 if (!(parsed->options & NFS_OPTION_FSCACHE))
2506                         return;
2507                 if (parsed->fscache_uniq) {
2508                         uniq = parsed->fscache_uniq;
2509                         ulen = strlen(parsed->fscache_uniq);
2510                 }
2511         } else if (cloned) {
2512                 struct nfs_server *mnt_s = NFS_SB(cloned->sb);
2513                 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
2514                         return;
2515                 if (mnt_s->fscache_key) {
2516                         uniq = mnt_s->fscache_key->key.uniquifier;
2517                         ulen = mnt_s->fscache_key->key.uniq_len;
2518                 };
2519         } else
2520                 return;
2521 
2522         nfs_fscache_get_super_cookie(sb, uniq, ulen);
2523 }
2524 #else
2525 static void nfs_get_cache_cookie(struct super_block *sb,
2526                                  struct nfs_parsed_mount_data *parsed,
2527                                  struct nfs_clone_mount *cloned)
2528 {
2529 }
2530 #endif
2531 
2532 static int nfs_bdi_register(struct nfs_server *server)
2533 {
2534         return bdi_register_dev(&server->backing_dev_info, server->s_dev);
2535 }
2536 
2537 int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
2538                         struct nfs_mount_info *mount_info)
2539 {
2540         int error;
2541         unsigned long kflags = 0, kflags_out = 0;
2542         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
2543                 kflags |= SECURITY_LSM_NATIVE_LABELS;
2544 
2545         error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
2546                                                 kflags, &kflags_out);
2547         if (error)
2548                 goto err;
2549 
2550         if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL &&
2551                 !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
2552                 NFS_SB(s)->caps &= ~NFS_CAP_SECURITY_LABEL;
2553 err:
2554         return error;
2555 }
2556 EXPORT_SYMBOL_GPL(nfs_set_sb_security);
2557 
2558 int nfs_clone_sb_security(struct super_block *s, struct dentry *mntroot,
2559                           struct nfs_mount_info *mount_info)
2560 {
2561         /* clone any lsm security options from the parent to the new sb */
2562         if (d_inode(mntroot)->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops)
2563                 return -ESTALE;
2564         return security_sb_clone_mnt_opts(mount_info->cloned->sb, s);
2565 }
2566 EXPORT_SYMBOL_GPL(nfs_clone_sb_security);
2567 
2568 struct dentry *nfs_fs_mount_common(struct nfs_server *server,
2569                                    int flags, const char *dev_name,
2570                                    struct nfs_mount_info *mount_info,
2571                                    struct nfs_subversion *nfs_mod)
2572 {
2573         struct super_block *s;
2574         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2575         int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
2576         struct nfs_sb_mountdata sb_mntdata = {
2577                 .mntflags = flags,
2578                 .server = server,
2579         };
2580         int error;
2581 
2582         if (server->flags & NFS_MOUNT_UNSHARED)
2583                 compare_super = NULL;
2584 
2585         /* -o noac implies -o sync */
2586         if (server->flags & NFS_MOUNT_NOAC)
2587                 sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2588 
2589         if (mount_info->cloned != NULL && mount_info->cloned->sb != NULL)
2590                 if (mount_info->cloned->sb->s_flags & MS_SYNCHRONOUS)
2591                         sb_mntdata.mntflags |= MS_SYNCHRONOUS;
2592 
2593         /* Get a superblock - note that we may end up sharing one that already exists */
2594         s = sget(nfs_mod->nfs_fs, compare_super, nfs_set_super, flags, &sb_mntdata);
2595         if (IS_ERR(s)) {
2596                 mntroot = ERR_CAST(s);
2597                 goto out_err_nosb;
2598         }
2599 
2600         if (s->s_fs_info != server) {
2601                 nfs_free_server(server);
2602                 server = NULL;
2603         } else {
2604                 error = nfs_bdi_register(server);
2605                 if (error) {
2606                         mntroot = ERR_PTR(error);
2607                         goto error_splat_super;
2608                 }
2609                 server->super = s;
2610         }
2611 
2612         if (!s->s_root) {
2613                 /* initial superblock/root creation */
2614                 mount_info->fill_super(s, mount_info);
2615                 nfs_get_cache_cookie(s, mount_info->parsed, mount_info->cloned);
2616         }
2617 
2618         mntroot = nfs_get_root(s, mount_info->mntfh, dev_name);
2619         if (IS_ERR(mntroot))
2620                 goto error_splat_super;
2621 
2622         error = mount_info->set_security(s, mntroot, mount_info);
2623         if (error)
2624                 goto error_splat_root;
2625 
2626         s->s_flags |= MS_ACTIVE;
2627 
2628 out:
2629         return mntroot;
2630 
2631 out_err_nosb:
2632         nfs_free_server(server);
2633         goto out;
2634 
2635 error_splat_root:
2636         dput(mntroot);
2637         mntroot = ERR_PTR(error);
2638 error_splat_super:
2639         deactivate_locked_super(s);
2640         goto out;
2641 }
2642 EXPORT_SYMBOL_GPL(nfs_fs_mount_common);
2643 
2644 struct dentry *nfs_fs_mount(struct file_system_type *fs_type,
2645         int flags, const char *dev_name, void *raw_data)
2646 {
2647         struct nfs_mount_info mount_info = {
2648                 .fill_super = nfs_fill_super,
2649                 .set_security = nfs_set_sb_security,
2650         };
2651         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2652         struct nfs_subversion *nfs_mod;
2653         int error;
2654 
2655         mount_info.parsed = nfs_alloc_parsed_mount_data();
2656         mount_info.mntfh = nfs_alloc_fhandle();
2657         if (mount_info.parsed == NULL || mount_info.mntfh == NULL)
2658                 goto out;
2659 
2660         /* Validate the mount data */
2661         error = nfs_validate_mount_data(fs_type, raw_data, mount_info.parsed, mount_info.mntfh, dev_name);
2662         if (error == NFS_TEXT_DATA)
2663                 error = nfs_validate_text_mount_data(raw_data, mount_info.parsed, dev_name);
2664         if (error < 0) {
2665                 mntroot = ERR_PTR(error);
2666                 goto out;
2667         }
2668 
2669         nfs_mod = get_nfs_version(mount_info.parsed->version);
2670         if (IS_ERR(nfs_mod)) {
2671                 mntroot = ERR_CAST(nfs_mod);
2672                 goto out;
2673         }
2674 
2675         mntroot = nfs_mod->rpc_ops->try_mount(flags, dev_name, &mount_info, nfs_mod);
2676 
2677         put_nfs_version(nfs_mod);
2678 out:
2679         nfs_free_parsed_mount_data(mount_info.parsed);
2680         nfs_free_fhandle(mount_info.mntfh);
2681         return mntroot;
2682 }
2683 EXPORT_SYMBOL_GPL(nfs_fs_mount);
2684 
2685 /*
2686  * Destroy an NFS2/3 superblock
2687  */
2688 void nfs_kill_super(struct super_block *s)
2689 {
2690         struct nfs_server *server = NFS_SB(s);
2691         dev_t dev = s->s_dev;
2692 
2693         generic_shutdown_super(s);
2694 
2695         nfs_fscache_release_super_cookie(s);
2696 
2697         nfs_free_server(server);
2698         free_anon_bdev(dev);
2699 }
2700 EXPORT_SYMBOL_GPL(nfs_kill_super);
2701 
2702 /*
2703  * Clone an NFS2/3/4 server record on xdev traversal (FSID-change)
2704  */
2705 static struct dentry *
2706 nfs_xdev_mount(struct file_system_type *fs_type, int flags,
2707                 const char *dev_name, void *raw_data)
2708 {
2709         struct nfs_clone_mount *data = raw_data;
2710         struct nfs_mount_info mount_info = {
2711                 .fill_super = nfs_clone_super,
2712                 .set_security = nfs_clone_sb_security,
2713                 .cloned = data,
2714         };
2715         struct nfs_server *server;
2716         struct dentry *mntroot = ERR_PTR(-ENOMEM);
2717         struct nfs_subversion *nfs_mod = NFS_SB(data->sb)->nfs_client->cl_nfs_mod;
2718 
2719         dprintk("--> nfs_xdev_mount()\n");
2720 
2721         mount_info.mntfh = mount_info.cloned->fh;
2722 
2723         /* create a new volume representation */
2724         server = nfs_mod->rpc_ops->clone_server(NFS_SB(data->sb), data->fh, data->fattr, data->authflavor);
2725 
2726         if (IS_ERR(server))
2727                 mntroot = ERR_CAST(server);
2728         else
2729                 mntroot = nfs_fs_mount_common(server, flags,
2730                                 dev_name, &mount_info, nfs_mod);
2731 
2732         dprintk("<-- nfs_xdev_mount() = %ld\n",
2733                         IS_ERR(mntroot) ? PTR_ERR(mntroot) : 0L);
2734         return mntroot;
2735 }
2736 
2737 #if IS_ENABLED(CONFIG_NFS_V4)
2738 
2739 static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
2740 {
2741         args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3|
2742                          NFS_MOUNT_LOCAL_FLOCK|NFS_MOUNT_LOCAL_FCNTL);
2743 }
2744 
2745 /*
2746  * Validate NFSv4 mount options
2747  */
2748 static int nfs4_validate_mount_data(void *options,
2749                                     struct nfs_parsed_mount_data *args,
2750                                     const char *dev_name)
2751 {
2752         struct sockaddr *sap = (struct sockaddr *)&args->nfs_server.address;
2753         struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
2754         char *c;
2755 
2756         if (data == NULL)
2757                 goto out_no_data;
2758 
2759         args->version = 4;
2760 
2761         switch (data->version) {
2762         case 1:
2763                 if (data->host_addrlen > sizeof(args->nfs_server.address))
2764                         goto out_no_address;
2765                 if (data->host_addrlen == 0)
2766                         goto out_no_address;
2767                 args->nfs_server.addrlen = data->host_addrlen;
2768                 if (copy_from_user(sap, data->host_addr, data->host_addrlen))
2769                         return -EFAULT;
2770                 if (!nfs_verify_server_address(sap))
2771                         goto out_no_address;
2772                 args->nfs_server.port = ntohs(((struct sockaddr_in *)sap)->sin_port);
2773 
2774                 if (data->auth_flavourlen) {
2775                         rpc_authflavor_t pseudoflavor;
2776                         if (data->auth_flavourlen > 1)
2777                                 goto out_inval_auth;
2778                         if (copy_from_user(&pseudoflavor,
2779                                            data->auth_flavours,
2780                                            sizeof(pseudoflavor)))
2781                                 return -EFAULT;
2782                         args->selected_flavor = pseudoflavor;
2783                 } else
2784                         args->selected_flavor = RPC_AUTH_UNIX;
2785 
2786                 c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
2787                 if (IS_ERR(c))
2788                         return PTR_ERR(c);
2789                 args->nfs_server.hostname = c;
2790 
2791                 c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
2792                 if (IS_ERR(c))
2793                         return PTR_ERR(c);
2794                 args->nfs_server.export_path = c;
2795                 dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);
2796 
2797                 c = strndup_user(data->client_addr.data, 16);
2798                 if (IS_ERR(c))
2799                         return PTR_ERR(c);
2800                 args->client_address = c;
2801 
2802                 /*
2803                  * Translate to nfs_parsed_mount_data, which nfs4_fill_super
2804                  * can deal with.
2805                  */
2806 
2807                 args->flags     = data->flags & NFS4_MOUNT_FLAGMASK;
2808                 args->rsize     = data->rsize;
2809                 args->wsize     = data->wsize;
2810                 args->timeo     = data->timeo;
2811                 args->retrans   = data->retrans;
2812                 args->acregmin  = data->acregmin;
2813                 args->acregmax  = data->acregmax;
2814                 args->acdirmin  = data->acdirmin;
2815                 args->acdirmax  = data->acdirmax;
2816                 args->nfs_server.protocol = data->proto;
2817                 nfs_validate_transport_protocol(args);
2818                 if (args->nfs_server.protocol == XPRT_TRANSPORT_UDP)
2819                         goto out_invalid_transport_udp;
2820 
2821                 break;
2822         default:
2823                 return NFS_TEXT_DATA;
2824         }
2825 
2826         return 0;
2827 
2828 out_no_data:
2829         dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
2830         return -EINVAL;
2831 
2832 out_inval_auth:
2833         dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
2834                  data->auth_flavourlen);
2835         return -EINVAL;
2836 
2837 out_no_address:
2838         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
2839         return -EINVAL;
2840 
2841 out_invalid_transport_udp:
2842         dfprintk(MOUNT, "NFSv4: Unsupported transport protocol udp\n");
2843         return -EINVAL;
2844 }
2845 
2846 /*
2847  * NFS v4 module parameters need to stay in the
2848  * NFS client for backwards compatibility
2849  */
2850 unsigned int nfs_callback_set_tcpport;
2851 /* Default cache timeout is 10 minutes */
2852 unsigned int nfs_idmap_cache_timeout = 600;
2853 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
2854 bool nfs4_disable_idmapping = true;
2855 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
2856 unsigned short send_implementation_id = 1;
2857 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
2858 bool recover_lost_locks = false;
2859 
2860 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
2861 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
2862 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
2863 EXPORT_SYMBOL_GPL(max_session_slots);
2864 EXPORT_SYMBOL_GPL(send_implementation_id);
2865 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
2866 EXPORT_SYMBOL_GPL(recover_lost_locks);
2867 
2868 #define NFS_CALLBACK_MAXPORTNR (65535U)
2869 
2870 static int param_set_portnr(const char *val, const struct kernel_param *kp)
2871 {
2872         unsigned long num;
2873         int ret;
2874 
2875         if (!val)
2876                 return -EINVAL;
2877         ret = kstrtoul(val, 0, &num);
2878         if (ret == -EINVAL || num > NFS_CALLBACK_MAXPORTNR)
2879                 return -EINVAL;
2880         *((unsigned int *)kp->arg) = num;
2881         return 0;
2882 }
2883 static const struct kernel_param_ops param_ops_portnr = {
2884         .set = param_set_portnr,
2885         .get = param_get_uint,
2886 };
2887 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
2888 
2889 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
2890 module_param(nfs_idmap_cache_timeout, int, 0644);
2891 module_param(nfs4_disable_idmapping, bool, 0644);
2892 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
2893                         NFS4_CLIENT_ID_UNIQ_LEN, 0600);
2894 MODULE_PARM_DESC(nfs4_disable_idmapping,
2895                 "Turn off NFSv4 idmapping when using 'sec=sys'");
2896 module_param(max_session_slots, ushort, 0644);
2897 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
2898                 "requests the client will negotiate");
2899 module_param(send_implementation_id, ushort, 0644);
2900 MODULE_PARM_DESC(send_implementation_id,
2901                 "Send implementation ID with NFSv4.1 exchange_id");
2902 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
2903 
2904 module_param(recover_lost_locks, bool, 0644);
2905 MODULE_PARM_DESC(recover_lost_locks,
2906                  "If the server reports that a lock might be lost, "
2907                  "try to recover it risking data corruption.");
2908 
2909 
2910 #endif /* CONFIG_NFS_V4 */
2911 

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