1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/fs/nfs/super.c
4 *
5 * Copyright (C) 1992 Rick Sladkey
6 *
7 * nfs superblock handling functions
8 *
9 * Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
10 * experimental NFS changes. Modularisation taken straight from SYS5 fs.
11 *
12 * Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
13 * J.S.Peatfield@damtp.cam.ac.uk
14 *
15 * Split from inode.c by David Howells <dhowells@redhat.com>
16 *
17 * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
18 * particular server are held in the same superblock
19 * - NFS superblocks can have several effective roots to the dentry tree
20 * - directory type roots are spliced into the tree when a path from one root reaches the root
21 * of another (see nfs_lookup())
22 */
23
24 #include <linux/module.h>
25 #include <linux/init.h>
26
27 #include <linux/time.h>
28 #include <linux/kernel.h>
29 #include <linux/mm.h>
30 #include <linux/string.h>
31 #include <linux/stat.h>
32 #include <linux/errno.h>
33 #include <linux/unistd.h>
34 #include <linux/sunrpc/clnt.h>
35 #include <linux/sunrpc/addr.h>
36 #include <linux/sunrpc/stats.h>
37 #include <linux/sunrpc/metrics.h>
38 #include <linux/sunrpc/xprtsock.h>
39 #include <linux/sunrpc/xprtrdma.h>
40 #include <linux/nfs_fs.h>
41 #include <linux/nfs_mount.h>
42 #include <linux/nfs4_mount.h>
43 #include <linux/lockd/bind.h>
44 #include <linux/seq_file.h>
45 #include <linux/mount.h>
46 #include <linux/namei.h>
47 #include <linux/vfs.h>
48 #include <linux/inet.h>
49 #include <linux/in6.h>
50 #include <linux/slab.h>
51 #include <net/ipv6.h>
52 #include <linux/netdevice.h>
53 #include <linux/nfs_xdr.h>
54 #include <linux/magic.h>
55 #include <linux/parser.h>
56 #include <linux/nsproxy.h>
57 #include <linux/rcupdate.h>
58
59 #include <linux/uaccess.h>
60 #include <linux/nfs_ssc.h>
61
62 #include "nfs4_fs.h"
63 #include "callback.h"
64 #include "delegation.h"
65 #include "iostat.h"
66 #include "internal.h"
67 #include "fscache.h"
68 #include "nfs4session.h"
69 #include "pnfs.h"
70 #include "nfs.h"
71
72 #define NFSDBG_FACILITY NFSDBG_VFS
73
74 const struct super_operations nfs_sops = {
75 .alloc_inode = nfs_alloc_inode,
76 .free_inode = nfs_free_inode,
77 .write_inode = nfs_write_inode,
78 .drop_inode = nfs_drop_inode,
79 .statfs = nfs_statfs,
80 .evict_inode = nfs_evict_inode,
81 .umount_begin = nfs_umount_begin,
82 .show_options = nfs_show_options,
83 .show_devname = nfs_show_devname,
84 .show_path = nfs_show_path,
85 .show_stats = nfs_show_stats,
86 };
87 EXPORT_SYMBOL_GPL(nfs_sops);
88
89 #ifdef CONFIG_NFS_V4_2
90 static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
91 .sco_sb_deactive = nfs_sb_deactive,
92 };
93 #endif
94
95 #if IS_ENABLED(CONFIG_NFS_V4)
register_nfs4_fs(void)96 static int __init register_nfs4_fs(void)
97 {
98 return register_filesystem(&nfs4_fs_type);
99 }
100
unregister_nfs4_fs(void)101 static void unregister_nfs4_fs(void)
102 {
103 unregister_filesystem(&nfs4_fs_type);
104 }
105 #else
register_nfs4_fs(void)106 static int __init register_nfs4_fs(void)
107 {
108 return 0;
109 }
110
unregister_nfs4_fs(void)111 static void unregister_nfs4_fs(void)
112 {
113 }
114 #endif
115
116 #ifdef CONFIG_NFS_V4_2
nfs_ssc_register_ops(void)117 static void nfs_ssc_register_ops(void)
118 {
119 nfs_ssc_register(&nfs_ssc_clnt_ops_tbl);
120 }
121
nfs_ssc_unregister_ops(void)122 static void nfs_ssc_unregister_ops(void)
123 {
124 nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl);
125 }
126 #endif /* CONFIG_NFS_V4_2 */
127
128 static struct shrinker acl_shrinker = {
129 .count_objects = nfs_access_cache_count,
130 .scan_objects = nfs_access_cache_scan,
131 .seeks = DEFAULT_SEEKS,
132 };
133
134 /*
135 * Register the NFS filesystems
136 */
register_nfs_fs(void)137 int __init register_nfs_fs(void)
138 {
139 int ret;
140
141 ret = register_filesystem(&nfs_fs_type);
142 if (ret < 0)
143 goto error_0;
144
145 ret = register_nfs4_fs();
146 if (ret < 0)
147 goto error_1;
148
149 ret = nfs_register_sysctl();
150 if (ret < 0)
151 goto error_2;
152 ret = register_shrinker(&acl_shrinker);
153 if (ret < 0)
154 goto error_3;
155 #ifdef CONFIG_NFS_V4_2
156 nfs_ssc_register_ops();
157 #endif
158 return 0;
159 error_3:
160 nfs_unregister_sysctl();
161 error_2:
162 unregister_nfs4_fs();
163 error_1:
164 unregister_filesystem(&nfs_fs_type);
165 error_0:
166 return ret;
167 }
168
169 /*
170 * Unregister the NFS filesystems
171 */
unregister_nfs_fs(void)172 void __exit unregister_nfs_fs(void)
173 {
174 unregister_shrinker(&acl_shrinker);
175 nfs_unregister_sysctl();
176 unregister_nfs4_fs();
177 #ifdef CONFIG_NFS_V4_2
178 nfs_ssc_unregister_ops();
179 #endif
180 unregister_filesystem(&nfs_fs_type);
181 }
182
nfs_sb_active(struct super_block * sb)183 bool nfs_sb_active(struct super_block *sb)
184 {
185 struct nfs_server *server = NFS_SB(sb);
186
187 if (!atomic_inc_not_zero(&sb->s_active))
188 return false;
189 if (atomic_inc_return(&server->active) != 1)
190 atomic_dec(&sb->s_active);
191 return true;
192 }
193 EXPORT_SYMBOL_GPL(nfs_sb_active);
194
nfs_sb_deactive(struct super_block * sb)195 void nfs_sb_deactive(struct super_block *sb)
196 {
197 struct nfs_server *server = NFS_SB(sb);
198
199 if (atomic_dec_and_test(&server->active))
200 deactivate_super(sb);
201 }
202 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
203
__nfs_list_for_each_server(struct list_head * head,int (* fn)(struct nfs_server *,void *),void * data)204 static int __nfs_list_for_each_server(struct list_head *head,
205 int (*fn)(struct nfs_server *, void *),
206 void *data)
207 {
208 struct nfs_server *server, *last = NULL;
209 int ret = 0;
210
211 rcu_read_lock();
212 list_for_each_entry_rcu(server, head, client_link) {
213 if (!(server->super && nfs_sb_active(server->super)))
214 continue;
215 rcu_read_unlock();
216 if (last)
217 nfs_sb_deactive(last->super);
218 last = server;
219 ret = fn(server, data);
220 if (ret)
221 goto out;
222 rcu_read_lock();
223 }
224 rcu_read_unlock();
225 out:
226 if (last)
227 nfs_sb_deactive(last->super);
228 return ret;
229 }
230
nfs_client_for_each_server(struct nfs_client * clp,int (* fn)(struct nfs_server *,void *),void * data)231 int nfs_client_for_each_server(struct nfs_client *clp,
232 int (*fn)(struct nfs_server *, void *),
233 void *data)
234 {
235 return __nfs_list_for_each_server(&clp->cl_superblocks, fn, data);
236 }
237 EXPORT_SYMBOL_GPL(nfs_client_for_each_server);
238
239 /*
240 * Deliver file system statistics to userspace
241 */
nfs_statfs(struct dentry * dentry,struct kstatfs * buf)242 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
243 {
244 struct nfs_server *server = NFS_SB(dentry->d_sb);
245 unsigned char blockbits;
246 unsigned long blockres;
247 struct nfs_fh *fh = NFS_FH(d_inode(dentry));
248 struct nfs_fsstat res;
249 int error = -ENOMEM;
250
251 res.fattr = nfs_alloc_fattr();
252 if (res.fattr == NULL)
253 goto out_err;
254
255 error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
256 if (unlikely(error == -ESTALE)) {
257 struct dentry *pd_dentry;
258
259 pd_dentry = dget_parent(dentry);
260 nfs_zap_caches(d_inode(pd_dentry));
261 dput(pd_dentry);
262 }
263 nfs_free_fattr(res.fattr);
264 if (error < 0)
265 goto out_err;
266
267 buf->f_type = NFS_SUPER_MAGIC;
268
269 /*
270 * Current versions of glibc do not correctly handle the
271 * case where f_frsize != f_bsize. Eventually we want to
272 * report the value of wtmult in this field.
273 */
274 buf->f_frsize = dentry->d_sb->s_blocksize;
275
276 /*
277 * On most *nix systems, f_blocks, f_bfree, and f_bavail
278 * are reported in units of f_frsize. Linux hasn't had
279 * an f_frsize field in its statfs struct until recently,
280 * thus historically Linux's sys_statfs reports these
281 * fields in units of f_bsize.
282 */
283 buf->f_bsize = dentry->d_sb->s_blocksize;
284 blockbits = dentry->d_sb->s_blocksize_bits;
285 blockres = (1 << blockbits) - 1;
286 buf->f_blocks = (res.tbytes + blockres) >> blockbits;
287 buf->f_bfree = (res.fbytes + blockres) >> blockbits;
288 buf->f_bavail = (res.abytes + blockres) >> blockbits;
289
290 buf->f_files = res.tfiles;
291 buf->f_ffree = res.afiles;
292
293 buf->f_namelen = server->namelen;
294
295 return 0;
296
297 out_err:
298 dprintk("%s: statfs error = %d\n", __func__, -error);
299 return error;
300 }
301 EXPORT_SYMBOL_GPL(nfs_statfs);
302
303 /*
304 * Map the security flavour number to a name
305 */
nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)306 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
307 {
308 static const struct {
309 rpc_authflavor_t flavour;
310 const char *str;
311 } sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
312 /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
313 { RPC_AUTH_NULL, "null" },
314 { RPC_AUTH_UNIX, "sys" },
315 { RPC_AUTH_GSS_KRB5, "krb5" },
316 { RPC_AUTH_GSS_KRB5I, "krb5i" },
317 { RPC_AUTH_GSS_KRB5P, "krb5p" },
318 { RPC_AUTH_GSS_LKEY, "lkey" },
319 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
320 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
321 { RPC_AUTH_GSS_SPKM, "spkm" },
322 { RPC_AUTH_GSS_SPKMI, "spkmi" },
323 { RPC_AUTH_GSS_SPKMP, "spkmp" },
324 { UINT_MAX, "unknown" }
325 };
326 int i;
327
328 for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
329 if (sec_flavours[i].flavour == flavour)
330 break;
331 }
332 return sec_flavours[i].str;
333 }
334
nfs_show_mountd_netid(struct seq_file * m,struct nfs_server * nfss,int showdefaults)335 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
336 int showdefaults)
337 {
338 struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
339 char *proto = NULL;
340
341 switch (sap->sa_family) {
342 case AF_INET:
343 switch (nfss->mountd_protocol) {
344 case IPPROTO_UDP:
345 proto = RPCBIND_NETID_UDP;
346 break;
347 case IPPROTO_TCP:
348 proto = RPCBIND_NETID_TCP;
349 break;
350 }
351 break;
352 case AF_INET6:
353 switch (nfss->mountd_protocol) {
354 case IPPROTO_UDP:
355 proto = RPCBIND_NETID_UDP6;
356 break;
357 case IPPROTO_TCP:
358 proto = RPCBIND_NETID_TCP6;
359 break;
360 }
361 break;
362 }
363 if (proto || showdefaults)
364 seq_printf(m, ",mountproto=%s", proto ?: "auto");
365 }
366
nfs_show_mountd_options(struct seq_file * m,struct nfs_server * nfss,int showdefaults)367 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
368 int showdefaults)
369 {
370 struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
371
372 if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
373 return;
374
375 switch (sap->sa_family) {
376 case AF_INET: {
377 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
378 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
379 break;
380 }
381 case AF_INET6: {
382 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
383 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
384 break;
385 }
386 default:
387 if (showdefaults)
388 seq_puts(m, ",mountaddr=unspecified");
389 }
390
391 if (nfss->mountd_version || showdefaults)
392 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
393 if ((nfss->mountd_port &&
394 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
395 showdefaults)
396 seq_printf(m, ",mountport=%u", nfss->mountd_port);
397
398 nfs_show_mountd_netid(m, nfss, showdefaults);
399 }
400
401 #if IS_ENABLED(CONFIG_NFS_V4)
nfs_show_nfsv4_options(struct seq_file * m,struct nfs_server * nfss,int showdefaults)402 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
403 int showdefaults)
404 {
405 struct nfs_client *clp = nfss->nfs_client;
406
407 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
408 }
409 #else
nfs_show_nfsv4_options(struct seq_file * m,struct nfs_server * nfss,int showdefaults)410 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
411 int showdefaults)
412 {
413 }
414 #endif
415
nfs_show_nfs_version(struct seq_file * m,unsigned int version,unsigned int minorversion)416 static void nfs_show_nfs_version(struct seq_file *m,
417 unsigned int version,
418 unsigned int minorversion)
419 {
420 seq_printf(m, ",vers=%u", version);
421 if (version == 4)
422 seq_printf(m, ".%u", minorversion);
423 }
424
425 /*
426 * Describe the mount options in force on this server representation
427 */
nfs_show_mount_options(struct seq_file * m,struct nfs_server * nfss,int showdefaults)428 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
429 int showdefaults)
430 {
431 static const struct proc_nfs_info {
432 int flag;
433 const char *str;
434 const char *nostr;
435 } nfs_info[] = {
436 { NFS_MOUNT_SOFT, ",soft", "" },
437 { NFS_MOUNT_SOFTERR, ",softerr", "" },
438 { NFS_MOUNT_SOFTREVAL, ",softreval", "" },
439 { NFS_MOUNT_POSIX, ",posix", "" },
440 { NFS_MOUNT_NOCTO, ",nocto", "" },
441 { NFS_MOUNT_NOAC, ",noac", "" },
442 { NFS_MOUNT_NONLM, ",nolock", "" },
443 { NFS_MOUNT_NOACL, ",noacl", "" },
444 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
445 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
446 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
447 { 0, NULL, NULL }
448 };
449 const struct proc_nfs_info *nfs_infop;
450 struct nfs_client *clp = nfss->nfs_client;
451 u32 version = clp->rpc_ops->version;
452 int local_flock, local_fcntl;
453
454 nfs_show_nfs_version(m, version, clp->cl_minorversion);
455 seq_printf(m, ",rsize=%u", nfss->rsize);
456 seq_printf(m, ",wsize=%u", nfss->wsize);
457 if (nfss->bsize != 0)
458 seq_printf(m, ",bsize=%u", nfss->bsize);
459 seq_printf(m, ",namlen=%u", nfss->namelen);
460 if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
461 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
462 if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
463 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
464 if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
465 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
466 if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
467 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
468 if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
469 seq_puts(m, ",hard");
470 for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
471 if (nfss->flags & nfs_infop->flag)
472 seq_puts(m, nfs_infop->str);
473 else
474 seq_puts(m, nfs_infop->nostr);
475 }
476 rcu_read_lock();
477 seq_printf(m, ",proto=%s",
478 rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
479 rcu_read_unlock();
480 if (clp->cl_nconnect > 0)
481 seq_printf(m, ",nconnect=%u", clp->cl_nconnect);
482 if (version == 4) {
483 if (clp->cl_max_connect > 1)
484 seq_printf(m, ",max_connect=%u", clp->cl_max_connect);
485 if (nfss->port != NFS_PORT)
486 seq_printf(m, ",port=%u", nfss->port);
487 } else
488 if (nfss->port)
489 seq_printf(m, ",port=%u", nfss->port);
490
491 seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
492 seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
493 seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
494
495 if (version != 4)
496 nfs_show_mountd_options(m, nfss, showdefaults);
497 else
498 nfs_show_nfsv4_options(m, nfss, showdefaults);
499
500 if (nfss->options & NFS_OPTION_FSCACHE)
501 seq_puts(m, ",fsc");
502
503 if (nfss->options & NFS_OPTION_MIGRATION)
504 seq_puts(m, ",migration");
505
506 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
507 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
508 seq_puts(m, ",lookupcache=none");
509 else
510 seq_puts(m, ",lookupcache=pos");
511 }
512
513 local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
514 local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
515
516 if (!local_flock && !local_fcntl)
517 seq_puts(m, ",local_lock=none");
518 else if (local_flock && local_fcntl)
519 seq_puts(m, ",local_lock=all");
520 else if (local_flock)
521 seq_puts(m, ",local_lock=flock");
522 else
523 seq_puts(m, ",local_lock=posix");
524
525 if (nfss->flags & NFS_MOUNT_WRITE_EAGER) {
526 if (nfss->flags & NFS_MOUNT_WRITE_WAIT)
527 seq_puts(m, ",write=wait");
528 else
529 seq_puts(m, ",write=eager");
530 }
531 }
532
533 /*
534 * Describe the mount options on this VFS mountpoint
535 */
nfs_show_options(struct seq_file * m,struct dentry * root)536 int nfs_show_options(struct seq_file *m, struct dentry *root)
537 {
538 struct nfs_server *nfss = NFS_SB(root->d_sb);
539
540 nfs_show_mount_options(m, nfss, 0);
541
542 rcu_read_lock();
543 seq_printf(m, ",addr=%s",
544 rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
545 RPC_DISPLAY_ADDR));
546 rcu_read_unlock();
547
548 return 0;
549 }
550 EXPORT_SYMBOL_GPL(nfs_show_options);
551
552 #if IS_ENABLED(CONFIG_NFS_V4)
show_lease(struct seq_file * m,struct nfs_server * server)553 static void show_lease(struct seq_file *m, struct nfs_server *server)
554 {
555 struct nfs_client *clp = server->nfs_client;
556 unsigned long expire;
557
558 seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
559 expire = clp->cl_last_renewal + clp->cl_lease_time;
560 seq_printf(m, ",lease_expired=%ld",
561 time_after(expire, jiffies) ? 0 : (jiffies - expire) / HZ);
562 }
563 #ifdef CONFIG_NFS_V4_1
show_sessions(struct seq_file * m,struct nfs_server * server)564 static void show_sessions(struct seq_file *m, struct nfs_server *server)
565 {
566 if (nfs4_has_session(server->nfs_client))
567 seq_puts(m, ",sessions");
568 }
569 #else
show_sessions(struct seq_file * m,struct nfs_server * server)570 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
571 #endif
572 #endif
573
574 #ifdef CONFIG_NFS_V4_1
show_pnfs(struct seq_file * m,struct nfs_server * server)575 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
576 {
577 seq_printf(m, ",pnfs=");
578 if (server->pnfs_curr_ld)
579 seq_printf(m, "%s", server->pnfs_curr_ld->name);
580 else
581 seq_printf(m, "not configured");
582 }
583
show_implementation_id(struct seq_file * m,struct nfs_server * nfss)584 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
585 {
586 if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
587 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
588 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
589 "date='%llu,%u'",
590 impl_id->name, impl_id->domain,
591 impl_id->date.seconds, impl_id->date.nseconds);
592 }
593 }
594 #else
595 #if IS_ENABLED(CONFIG_NFS_V4)
show_pnfs(struct seq_file * m,struct nfs_server * server)596 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
597 {
598 }
599 #endif
show_implementation_id(struct seq_file * m,struct nfs_server * nfss)600 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
601 {
602 }
603 #endif
604
nfs_show_devname(struct seq_file * m,struct dentry * root)605 int nfs_show_devname(struct seq_file *m, struct dentry *root)
606 {
607 char *page = (char *) __get_free_page(GFP_KERNEL);
608 char *devname, *dummy;
609 int err = 0;
610 if (!page)
611 return -ENOMEM;
612 devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
613 if (IS_ERR(devname))
614 err = PTR_ERR(devname);
615 else
616 seq_escape(m, devname, " \t\n\\");
617 free_page((unsigned long)page);
618 return err;
619 }
620 EXPORT_SYMBOL_GPL(nfs_show_devname);
621
nfs_show_path(struct seq_file * m,struct dentry * dentry)622 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
623 {
624 seq_puts(m, "/");
625 return 0;
626 }
627 EXPORT_SYMBOL_GPL(nfs_show_path);
628
629 /*
630 * Present statistical information for this VFS mountpoint
631 */
nfs_show_stats(struct seq_file * m,struct dentry * root)632 int nfs_show_stats(struct seq_file *m, struct dentry *root)
633 {
634 int i, cpu;
635 struct nfs_server *nfss = NFS_SB(root->d_sb);
636 struct rpc_auth *auth = nfss->client->cl_auth;
637 struct nfs_iostats totals = { };
638
639 seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
640
641 /*
642 * Display all mount option settings
643 */
644 seq_puts(m, "\n\topts:\t");
645 seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
646 seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
647 seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
648 seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
649 nfs_show_mount_options(m, nfss, 1);
650
651 seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
652
653 show_implementation_id(m, nfss);
654
655 seq_puts(m, "\n\tcaps:\t");
656 seq_printf(m, "caps=0x%x", nfss->caps);
657 seq_printf(m, ",wtmult=%u", nfss->wtmult);
658 seq_printf(m, ",dtsize=%u", nfss->dtsize);
659 seq_printf(m, ",bsize=%u", nfss->bsize);
660 seq_printf(m, ",namlen=%u", nfss->namelen);
661
662 #if IS_ENABLED(CONFIG_NFS_V4)
663 if (nfss->nfs_client->rpc_ops->version == 4) {
664 seq_puts(m, "\n\tnfsv4:\t");
665 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
666 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
667 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
668 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
669 show_sessions(m, nfss);
670 show_pnfs(m, nfss);
671 show_lease(m, nfss);
672 }
673 #endif
674
675 /*
676 * Display security flavor in effect for this mount
677 */
678 seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
679 if (auth->au_flavor)
680 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
681
682 /*
683 * Display superblock I/O counters
684 */
685 for_each_possible_cpu(cpu) {
686 struct nfs_iostats *stats;
687
688 preempt_disable();
689 stats = per_cpu_ptr(nfss->io_stats, cpu);
690
691 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
692 totals.events[i] += stats->events[i];
693 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
694 totals.bytes[i] += stats->bytes[i];
695 #ifdef CONFIG_NFS_FSCACHE
696 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
697 totals.fscache[i] += stats->fscache[i];
698 #endif
699
700 preempt_enable();
701 }
702
703 seq_puts(m, "\n\tevents:\t");
704 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
705 seq_printf(m, "%lu ", totals.events[i]);
706 seq_puts(m, "\n\tbytes:\t");
707 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
708 seq_printf(m, "%Lu ", totals.bytes[i]);
709 #ifdef CONFIG_NFS_FSCACHE
710 if (nfss->options & NFS_OPTION_FSCACHE) {
711 seq_puts(m, "\n\tfsc:\t");
712 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
713 seq_printf(m, "%Lu ", totals.fscache[i]);
714 }
715 #endif
716 seq_putc(m, '\n');
717
718 rpc_clnt_show_stats(m, nfss->client);
719
720 return 0;
721 }
722 EXPORT_SYMBOL_GPL(nfs_show_stats);
723
724 /*
725 * Begin unmount by attempting to remove all automounted mountpoints we added
726 * in response to xdev traversals and referrals
727 */
nfs_umount_begin(struct super_block * sb)728 void nfs_umount_begin(struct super_block *sb)
729 {
730 struct nfs_server *server;
731 struct rpc_clnt *rpc;
732
733 server = NFS_SB(sb);
734 /* -EIO all pending I/O */
735 rpc = server->client_acl;
736 if (!IS_ERR(rpc))
737 rpc_killall_tasks(rpc);
738 rpc = server->client;
739 if (!IS_ERR(rpc))
740 rpc_killall_tasks(rpc);
741 }
742 EXPORT_SYMBOL_GPL(nfs_umount_begin);
743
744 /*
745 * Return true if 'match' is in auth_info or auth_info is empty.
746 * Return false otherwise.
747 */
nfs_auth_info_match(const struct nfs_auth_info * auth_info,rpc_authflavor_t match)748 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
749 rpc_authflavor_t match)
750 {
751 int i;
752
753 if (!auth_info->flavor_len)
754 return true;
755
756 for (i = 0; i < auth_info->flavor_len; i++) {
757 if (auth_info->flavors[i] == match)
758 return true;
759 }
760 return false;
761 }
762 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
763
764 /*
765 * Ensure that a specified authtype in ctx->auth_info is supported by
766 * the server. Returns 0 and sets ctx->selected_flavor if it's ok, and
767 * -EACCES if not.
768 */
nfs_verify_authflavors(struct nfs_fs_context * ctx,rpc_authflavor_t * server_authlist,unsigned int count)769 static int nfs_verify_authflavors(struct nfs_fs_context *ctx,
770 rpc_authflavor_t *server_authlist,
771 unsigned int count)
772 {
773 rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
774 bool found_auth_null = false;
775 unsigned int i;
776
777 /*
778 * If the sec= mount option is used, the specified flavor or AUTH_NULL
779 * must be in the list returned by the server.
780 *
781 * AUTH_NULL has a special meaning when it's in the server list - it
782 * means that the server will ignore the rpc creds, so any flavor
783 * can be used but still use the sec= that was specified.
784 *
785 * Note also that the MNT procedure in MNTv1 does not return a list
786 * of supported security flavors. In this case, nfs_mount() fabricates
787 * a security flavor list containing just AUTH_NULL.
788 */
789 for (i = 0; i < count; i++) {
790 flavor = server_authlist[i];
791
792 if (nfs_auth_info_match(&ctx->auth_info, flavor))
793 goto out;
794
795 if (flavor == RPC_AUTH_NULL)
796 found_auth_null = true;
797 }
798
799 if (found_auth_null) {
800 flavor = ctx->auth_info.flavors[0];
801 goto out;
802 }
803
804 dfprintk(MOUNT,
805 "NFS: specified auth flavors not supported by server\n");
806 return -EACCES;
807
808 out:
809 ctx->selected_flavor = flavor;
810 dfprintk(MOUNT, "NFS: using auth flavor %u\n", ctx->selected_flavor);
811 return 0;
812 }
813
814 /*
815 * Use the remote server's MOUNT service to request the NFS file handle
816 * corresponding to the provided path.
817 */
nfs_request_mount(struct fs_context * fc,struct nfs_fh * root_fh,rpc_authflavor_t * server_authlist,unsigned int * server_authlist_len)818 static int nfs_request_mount(struct fs_context *fc,
819 struct nfs_fh *root_fh,
820 rpc_authflavor_t *server_authlist,
821 unsigned int *server_authlist_len)
822 {
823 struct nfs_fs_context *ctx = nfs_fc2context(fc);
824 struct nfs_mount_request request = {
825 .sap = (struct sockaddr *)
826 &ctx->mount_server.address,
827 .dirpath = ctx->nfs_server.export_path,
828 .protocol = ctx->mount_server.protocol,
829 .fh = root_fh,
830 .noresvport = ctx->flags & NFS_MOUNT_NORESVPORT,
831 .auth_flav_len = server_authlist_len,
832 .auth_flavs = server_authlist,
833 .net = fc->net_ns,
834 };
835 int status;
836
837 if (ctx->mount_server.version == 0) {
838 switch (ctx->version) {
839 default:
840 ctx->mount_server.version = NFS_MNT3_VERSION;
841 break;
842 case 2:
843 ctx->mount_server.version = NFS_MNT_VERSION;
844 }
845 }
846 request.version = ctx->mount_server.version;
847
848 if (ctx->mount_server.hostname)
849 request.hostname = ctx->mount_server.hostname;
850 else
851 request.hostname = ctx->nfs_server.hostname;
852
853 /*
854 * Construct the mount server's address.
855 */
856 if (ctx->mount_server.address.sa_family == AF_UNSPEC) {
857 memcpy(request.sap, &ctx->nfs_server.address,
858 ctx->nfs_server.addrlen);
859 ctx->mount_server.addrlen = ctx->nfs_server.addrlen;
860 }
861 request.salen = ctx->mount_server.addrlen;
862 nfs_set_port(request.sap, &ctx->mount_server.port, 0);
863
864 /*
865 * Now ask the mount server to map our export path
866 * to a file handle.
867 */
868 status = nfs_mount(&request, ctx->timeo, ctx->retrans);
869 if (status != 0) {
870 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
871 request.hostname, status);
872 return status;
873 }
874
875 return 0;
876 }
877
nfs_try_mount_request(struct fs_context * fc)878 static struct nfs_server *nfs_try_mount_request(struct fs_context *fc)
879 {
880 struct nfs_fs_context *ctx = nfs_fc2context(fc);
881 int status;
882 unsigned int i;
883 bool tried_auth_unix = false;
884 bool auth_null_in_list = false;
885 struct nfs_server *server = ERR_PTR(-EACCES);
886 rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
887 unsigned int authlist_len = ARRAY_SIZE(authlist);
888
889 status = nfs_request_mount(fc, ctx->mntfh, authlist, &authlist_len);
890 if (status)
891 return ERR_PTR(status);
892
893 /*
894 * Was a sec= authflavor specified in the options? First, verify
895 * whether the server supports it, and then just try to use it if so.
896 */
897 if (ctx->auth_info.flavor_len > 0) {
898 status = nfs_verify_authflavors(ctx, authlist, authlist_len);
899 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
900 ctx->selected_flavor);
901 if (status)
902 return ERR_PTR(status);
903 return ctx->nfs_mod->rpc_ops->create_server(fc);
904 }
905
906 /*
907 * No sec= option was provided. RFC 2623, section 2.7 suggests we
908 * SHOULD prefer the flavor listed first. However, some servers list
909 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
910 */
911 for (i = 0; i < authlist_len; ++i) {
912 rpc_authflavor_t flavor;
913 struct rpcsec_gss_info info;
914
915 flavor = authlist[i];
916 switch (flavor) {
917 case RPC_AUTH_UNIX:
918 tried_auth_unix = true;
919 break;
920 case RPC_AUTH_NULL:
921 auth_null_in_list = true;
922 continue;
923 default:
924 if (rpcauth_get_gssinfo(flavor, &info) != 0)
925 continue;
926 break;
927 }
928 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
929 ctx->selected_flavor = flavor;
930 server = ctx->nfs_mod->rpc_ops->create_server(fc);
931 if (!IS_ERR(server))
932 return server;
933 }
934
935 /*
936 * Nothing we tried so far worked. At this point, give up if we've
937 * already tried AUTH_UNIX or if the server's list doesn't contain
938 * AUTH_NULL
939 */
940 if (tried_auth_unix || !auth_null_in_list)
941 return server;
942
943 /* Last chance! Try AUTH_UNIX */
944 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
945 ctx->selected_flavor = RPC_AUTH_UNIX;
946 return ctx->nfs_mod->rpc_ops->create_server(fc);
947 }
948
nfs_try_get_tree(struct fs_context * fc)949 int nfs_try_get_tree(struct fs_context *fc)
950 {
951 struct nfs_fs_context *ctx = nfs_fc2context(fc);
952
953 if (ctx->need_mount)
954 ctx->server = nfs_try_mount_request(fc);
955 else
956 ctx->server = ctx->nfs_mod->rpc_ops->create_server(fc);
957
958 return nfs_get_tree_common(fc);
959 }
960 EXPORT_SYMBOL_GPL(nfs_try_get_tree);
961
962
963 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
964 | NFS_MOUNT_SECURE \
965 | NFS_MOUNT_TCP \
966 | NFS_MOUNT_VER3 \
967 | NFS_MOUNT_KERBEROS \
968 | NFS_MOUNT_NONLM \
969 | NFS_MOUNT_BROKEN_SUID \
970 | NFS_MOUNT_STRICTLOCK \
971 | NFS_MOUNT_LEGACY_INTERFACE)
972
973 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
974 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
975
976 static int
nfs_compare_remount_data(struct nfs_server * nfss,struct nfs_fs_context * ctx)977 nfs_compare_remount_data(struct nfs_server *nfss,
978 struct nfs_fs_context *ctx)
979 {
980 if ((ctx->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
981 ctx->rsize != nfss->rsize ||
982 ctx->wsize != nfss->wsize ||
983 ctx->version != nfss->nfs_client->rpc_ops->version ||
984 ctx->minorversion != nfss->nfs_client->cl_minorversion ||
985 ctx->retrans != nfss->client->cl_timeout->to_retries ||
986 !nfs_auth_info_match(&ctx->auth_info, nfss->client->cl_auth->au_flavor) ||
987 ctx->acregmin != nfss->acregmin / HZ ||
988 ctx->acregmax != nfss->acregmax / HZ ||
989 ctx->acdirmin != nfss->acdirmin / HZ ||
990 ctx->acdirmax != nfss->acdirmax / HZ ||
991 ctx->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
992 (ctx->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
993 ctx->nfs_server.port != nfss->port ||
994 ctx->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
995 !rpc_cmp_addr((struct sockaddr *)&ctx->nfs_server.address,
996 (struct sockaddr *)&nfss->nfs_client->cl_addr))
997 return -EINVAL;
998
999 return 0;
1000 }
1001
nfs_reconfigure(struct fs_context * fc)1002 int nfs_reconfigure(struct fs_context *fc)
1003 {
1004 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1005 struct super_block *sb = fc->root->d_sb;
1006 struct nfs_server *nfss = sb->s_fs_info;
1007
1008 sync_filesystem(sb);
1009
1010 /*
1011 * Userspace mount programs that send binary options generally send
1012 * them populated with default values. We have no way to know which
1013 * ones were explicitly specified. Fall back to legacy behavior and
1014 * just return success.
1015 */
1016 if (ctx->skip_reconfig_option_check)
1017 return 0;
1018
1019 /*
1020 * noac is a special case. It implies -o sync, but that's not
1021 * necessarily reflected in the mtab options. reconfigure_super
1022 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
1023 * remount options, so we have to explicitly reset it.
1024 */
1025 if (ctx->flags & NFS_MOUNT_NOAC) {
1026 fc->sb_flags |= SB_SYNCHRONOUS;
1027 fc->sb_flags_mask |= SB_SYNCHRONOUS;
1028 }
1029
1030 /* compare new mount options with old ones */
1031 return nfs_compare_remount_data(nfss, ctx);
1032 }
1033 EXPORT_SYMBOL_GPL(nfs_reconfigure);
1034
1035 /*
1036 * Finish setting up an NFS superblock
1037 */
nfs_fill_super(struct super_block * sb,struct nfs_fs_context * ctx)1038 static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx)
1039 {
1040 struct nfs_server *server = NFS_SB(sb);
1041
1042 sb->s_blocksize_bits = 0;
1043 sb->s_blocksize = 0;
1044 sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
1045 sb->s_op = server->nfs_client->cl_nfs_mod->sops;
1046 if (ctx->bsize)
1047 sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits);
1048
1049 switch (server->nfs_client->rpc_ops->version) {
1050 case 2:
1051 sb->s_time_gran = 1000;
1052 sb->s_time_min = 0;
1053 sb->s_time_max = U32_MAX;
1054 break;
1055 case 3:
1056 /*
1057 * The VFS shouldn't apply the umask to mode bits.
1058 * We will do so ourselves when necessary.
1059 */
1060 sb->s_flags |= SB_POSIXACL;
1061 sb->s_time_gran = 1;
1062 sb->s_time_min = 0;
1063 sb->s_time_max = U32_MAX;
1064 sb->s_export_op = &nfs_export_ops;
1065 break;
1066 case 4:
1067 sb->s_flags |= SB_POSIXACL;
1068 sb->s_time_gran = 1;
1069 sb->s_time_min = S64_MIN;
1070 sb->s_time_max = S64_MAX;
1071 if (server->caps & NFS_CAP_ATOMIC_OPEN_V1)
1072 sb->s_export_op = &nfs_export_ops;
1073 break;
1074 }
1075
1076 sb->s_magic = NFS_SUPER_MAGIC;
1077
1078 /* We probably want something more informative here */
1079 snprintf(sb->s_id, sizeof(sb->s_id),
1080 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1081
1082 if (sb->s_blocksize == 0)
1083 sb->s_blocksize = nfs_block_bits(server->wsize,
1084 &sb->s_blocksize_bits);
1085
1086 nfs_super_set_maxbytes(sb, server->maxfilesize);
1087 server->has_sec_mnt_opts = ctx->has_sec_mnt_opts;
1088 }
1089
nfs_compare_mount_options(const struct super_block * s,const struct nfs_server * b,const struct fs_context * fc)1090 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b,
1091 const struct fs_context *fc)
1092 {
1093 const struct nfs_server *a = s->s_fs_info;
1094 const struct rpc_clnt *clnt_a = a->client;
1095 const struct rpc_clnt *clnt_b = b->client;
1096
1097 if ((s->s_flags & NFS_SB_MASK) != (fc->sb_flags & NFS_SB_MASK))
1098 goto Ebusy;
1099 if (a->nfs_client != b->nfs_client)
1100 goto Ebusy;
1101 if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
1102 goto Ebusy;
1103 if (a->wsize != b->wsize)
1104 goto Ebusy;
1105 if (a->rsize != b->rsize)
1106 goto Ebusy;
1107 if (a->acregmin != b->acregmin)
1108 goto Ebusy;
1109 if (a->acregmax != b->acregmax)
1110 goto Ebusy;
1111 if (a->acdirmin != b->acdirmin)
1112 goto Ebusy;
1113 if (a->acdirmax != b->acdirmax)
1114 goto Ebusy;
1115 if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1116 goto Ebusy;
1117 return 1;
1118 Ebusy:
1119 return 0;
1120 }
1121
nfs_set_super(struct super_block * s,struct fs_context * fc)1122 static int nfs_set_super(struct super_block *s, struct fs_context *fc)
1123 {
1124 struct nfs_server *server = fc->s_fs_info;
1125 int ret;
1126
1127 s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
1128 ret = set_anon_super(s, server);
1129 if (ret == 0)
1130 server->s_dev = s->s_dev;
1131 return ret;
1132 }
1133
nfs_compare_super_address(struct nfs_server * server1,struct nfs_server * server2)1134 static int nfs_compare_super_address(struct nfs_server *server1,
1135 struct nfs_server *server2)
1136 {
1137 struct sockaddr *sap1, *sap2;
1138 struct rpc_xprt *xprt1 = server1->client->cl_xprt;
1139 struct rpc_xprt *xprt2 = server2->client->cl_xprt;
1140
1141 if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
1142 return 0;
1143
1144 sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1145 sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1146
1147 if (sap1->sa_family != sap2->sa_family)
1148 return 0;
1149
1150 switch (sap1->sa_family) {
1151 case AF_INET: {
1152 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1153 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1154 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1155 return 0;
1156 if (sin1->sin_port != sin2->sin_port)
1157 return 0;
1158 break;
1159 }
1160 case AF_INET6: {
1161 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1162 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1163 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1164 return 0;
1165 if (sin1->sin6_port != sin2->sin6_port)
1166 return 0;
1167 break;
1168 }
1169 default:
1170 return 0;
1171 }
1172
1173 return 1;
1174 }
1175
nfs_compare_userns(const struct nfs_server * old,const struct nfs_server * new)1176 static int nfs_compare_userns(const struct nfs_server *old,
1177 const struct nfs_server *new)
1178 {
1179 const struct user_namespace *oldns = &init_user_ns;
1180 const struct user_namespace *newns = &init_user_ns;
1181
1182 if (old->client && old->client->cl_cred)
1183 oldns = old->client->cl_cred->user_ns;
1184 if (new->client && new->client->cl_cred)
1185 newns = new->client->cl_cred->user_ns;
1186 if (oldns != newns)
1187 return 0;
1188 return 1;
1189 }
1190
nfs_compare_super(struct super_block * sb,struct fs_context * fc)1191 static int nfs_compare_super(struct super_block *sb, struct fs_context *fc)
1192 {
1193 struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb);
1194
1195 if (!nfs_compare_super_address(old, server))
1196 return 0;
1197 /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1198 if (old->flags & NFS_MOUNT_UNSHARED)
1199 return 0;
1200 if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1201 return 0;
1202 if (!nfs_compare_userns(old, server))
1203 return 0;
1204 if ((old->has_sec_mnt_opts || fc->security) &&
1205 security_sb_mnt_opts_compat(sb, fc->security))
1206 return 0;
1207 return nfs_compare_mount_options(sb, server, fc);
1208 }
1209
1210 #ifdef CONFIG_NFS_FSCACHE
nfs_get_cache_cookie(struct super_block * sb,struct nfs_fs_context * ctx)1211 static void nfs_get_cache_cookie(struct super_block *sb,
1212 struct nfs_fs_context *ctx)
1213 {
1214 struct nfs_server *nfss = NFS_SB(sb);
1215 char *uniq = NULL;
1216 int ulen = 0;
1217
1218 nfss->fscache_key = NULL;
1219 nfss->fscache = NULL;
1220
1221 if (!ctx)
1222 return;
1223
1224 if (ctx->clone_data.sb) {
1225 struct nfs_server *mnt_s = NFS_SB(ctx->clone_data.sb);
1226 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
1227 return;
1228 if (mnt_s->fscache_key) {
1229 uniq = mnt_s->fscache_key->key.uniquifier;
1230 ulen = mnt_s->fscache_key->key.uniq_len;
1231 }
1232 } else {
1233 if (!(ctx->options & NFS_OPTION_FSCACHE))
1234 return;
1235 if (ctx->fscache_uniq) {
1236 uniq = ctx->fscache_uniq;
1237 ulen = strlen(ctx->fscache_uniq);
1238 }
1239 }
1240
1241 nfs_fscache_get_super_cookie(sb, uniq, ulen);
1242 }
1243 #else
nfs_get_cache_cookie(struct super_block * sb,struct nfs_fs_context * ctx)1244 static void nfs_get_cache_cookie(struct super_block *sb,
1245 struct nfs_fs_context *ctx)
1246 {
1247 }
1248 #endif
1249
nfs_get_tree_common(struct fs_context * fc)1250 int nfs_get_tree_common(struct fs_context *fc)
1251 {
1252 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1253 struct super_block *s;
1254 int (*compare_super)(struct super_block *, struct fs_context *) = nfs_compare_super;
1255 struct nfs_server *server = ctx->server;
1256 int error;
1257
1258 ctx->server = NULL;
1259 if (IS_ERR(server))
1260 return PTR_ERR(server);
1261
1262 if (server->flags & NFS_MOUNT_UNSHARED)
1263 compare_super = NULL;
1264
1265 /* -o noac implies -o sync */
1266 if (server->flags & NFS_MOUNT_NOAC)
1267 fc->sb_flags |= SB_SYNCHRONOUS;
1268
1269 if (ctx->clone_data.sb)
1270 if (ctx->clone_data.sb->s_flags & SB_SYNCHRONOUS)
1271 fc->sb_flags |= SB_SYNCHRONOUS;
1272
1273 if (server->caps & NFS_CAP_SECURITY_LABEL)
1274 fc->lsm_flags |= SECURITY_LSM_NATIVE_LABELS;
1275
1276 /* Get a superblock - note that we may end up sharing one that already exists */
1277 fc->s_fs_info = server;
1278 s = sget_fc(fc, compare_super, nfs_set_super);
1279 fc->s_fs_info = NULL;
1280 if (IS_ERR(s)) {
1281 error = PTR_ERR(s);
1282 nfs_errorf(fc, "NFS: Couldn't get superblock");
1283 goto out_err_nosb;
1284 }
1285
1286 if (s->s_fs_info != server) {
1287 nfs_free_server(server);
1288 server = NULL;
1289 } else {
1290 error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
1291 MINOR(server->s_dev));
1292 if (error)
1293 goto error_splat_super;
1294 s->s_bdi->io_pages = server->rpages;
1295 server->super = s;
1296 }
1297
1298 if (!s->s_root) {
1299 unsigned bsize = ctx->clone_data.inherited_bsize;
1300 /* initial superblock/root creation */
1301 nfs_fill_super(s, ctx);
1302 if (bsize) {
1303 s->s_blocksize_bits = bsize;
1304 s->s_blocksize = 1U << bsize;
1305 }
1306 nfs_get_cache_cookie(s, ctx);
1307 }
1308
1309 error = nfs_get_root(s, fc);
1310 if (error < 0) {
1311 nfs_errorf(fc, "NFS: Couldn't get root dentry");
1312 goto error_splat_super;
1313 }
1314
1315 s->s_flags |= SB_ACTIVE;
1316 error = 0;
1317
1318 out:
1319 return error;
1320
1321 out_err_nosb:
1322 nfs_free_server(server);
1323 goto out;
1324 error_splat_super:
1325 deactivate_locked_super(s);
1326 goto out;
1327 }
1328
1329 /*
1330 * Destroy an NFS2/3 superblock
1331 */
nfs_kill_super(struct super_block * s)1332 void nfs_kill_super(struct super_block *s)
1333 {
1334 struct nfs_server *server = NFS_SB(s);
1335 dev_t dev = s->s_dev;
1336
1337 generic_shutdown_super(s);
1338
1339 nfs_fscache_release_super_cookie(s);
1340
1341 nfs_free_server(server);
1342 free_anon_bdev(dev);
1343 }
1344 EXPORT_SYMBOL_GPL(nfs_kill_super);
1345
1346 #if IS_ENABLED(CONFIG_NFS_V4)
1347
1348 /*
1349 * NFS v4 module parameters need to stay in the
1350 * NFS client for backwards compatibility
1351 */
1352 unsigned int nfs_callback_set_tcpport;
1353 unsigned short nfs_callback_nr_threads;
1354 /* Default cache timeout is 10 minutes */
1355 unsigned int nfs_idmap_cache_timeout = 600;
1356 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
1357 bool nfs4_disable_idmapping = true;
1358 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
1359 unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
1360 unsigned short send_implementation_id = 1;
1361 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
1362 bool recover_lost_locks = false;
1363
1364 EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
1365 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
1366 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
1367 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
1368 EXPORT_SYMBOL_GPL(max_session_slots);
1369 EXPORT_SYMBOL_GPL(max_session_cb_slots);
1370 EXPORT_SYMBOL_GPL(send_implementation_id);
1371 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
1372 EXPORT_SYMBOL_GPL(recover_lost_locks);
1373
1374 #define NFS_CALLBACK_MAXPORTNR (65535U)
1375
param_set_portnr(const char * val,const struct kernel_param * kp)1376 static int param_set_portnr(const char *val, const struct kernel_param *kp)
1377 {
1378 unsigned long num;
1379 int ret;
1380
1381 if (!val)
1382 return -EINVAL;
1383 ret = kstrtoul(val, 0, &num);
1384 if (ret || num > NFS_CALLBACK_MAXPORTNR)
1385 return -EINVAL;
1386 *((unsigned int *)kp->arg) = num;
1387 return 0;
1388 }
1389 static const struct kernel_param_ops param_ops_portnr = {
1390 .set = param_set_portnr,
1391 .get = param_get_uint,
1392 };
1393 #define param_check_portnr(name, p) __param_check(name, p, unsigned int)
1394
1395 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
1396 module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
1397 MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
1398 "assigned to the NFSv4 callback channels.");
1399 module_param(nfs_idmap_cache_timeout, int, 0644);
1400 module_param(nfs4_disable_idmapping, bool, 0644);
1401 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
1402 NFS4_CLIENT_ID_UNIQ_LEN, 0600);
1403 MODULE_PARM_DESC(nfs4_disable_idmapping,
1404 "Turn off NFSv4 idmapping when using 'sec=sys'");
1405 module_param(max_session_slots, ushort, 0644);
1406 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
1407 "requests the client will negotiate");
1408 module_param(max_session_cb_slots, ushort, 0644);
1409 MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
1410 "callbacks the client will process for a given server");
1411 module_param(send_implementation_id, ushort, 0644);
1412 MODULE_PARM_DESC(send_implementation_id,
1413 "Send implementation ID with NFSv4.1 exchange_id");
1414 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
1415
1416 module_param(recover_lost_locks, bool, 0644);
1417 MODULE_PARM_DESC(recover_lost_locks,
1418 "If the server reports that a lock might be lost, "
1419 "try to recover it risking data corruption.");
1420
1421
1422 #endif /* CONFIG_NFS_V4 */
1423