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/sched.h>
51 #include <linux/slab.h>
52 #include <net/ipv6.h>
53 #include <linux/netdevice.h>
54 #include <linux/nfs_xdr.h>
55 #include <linux/magic.h>
56 #include <linux/parser.h>
57 #include <linux/nsproxy.h>
58 #include <linux/rcupdate.h>
59
60 #include <linux/uaccess.h>
61 #include <linux/nfs_ssc.h>
62
63 #include <uapi/linux/tls.h>
64
65 #include "nfs4_fs.h"
66 #include "callback.h"
67 #include "delegation.h"
68 #include "iostat.h"
69 #include "internal.h"
70 #include "fscache.h"
71 #include "nfs4session.h"
72 #include "pnfs.h"
73 #include "nfs.h"
74 #include "netns.h"
75 #include "sysfs.h"
76
77 #define NFSDBG_FACILITY NFSDBG_VFS
78
79 const struct super_operations nfs_sops = {
80 .alloc_inode = nfs_alloc_inode,
81 .free_inode = nfs_free_inode,
82 .write_inode = nfs_write_inode,
83 .drop_inode = nfs_drop_inode,
84 .statfs = nfs_statfs,
85 .evict_inode = nfs_evict_inode,
86 .umount_begin = nfs_umount_begin,
87 .show_options = nfs_show_options,
88 .show_devname = nfs_show_devname,
89 .show_path = nfs_show_path,
90 .show_stats = nfs_show_stats,
91 };
92 EXPORT_SYMBOL_GPL(nfs_sops);
93
94 #ifdef CONFIG_NFS_V4_2
95 static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
96 .sco_sb_deactive = nfs_sb_deactive,
97 };
98 #endif
99
100 #if IS_ENABLED(CONFIG_NFS_V4)
101 static int __init register_nfs4_fs(void)
102 {
103 return register_filesystem(&nfs4_fs_type);
104 }
105
106 static void unregister_nfs4_fs(void)
107 {
108 unregister_filesystem(&nfs4_fs_type);
109 }
110 #else
111 static int __init register_nfs4_fs(void)
112 {
113 return 0;
114 }
115
116 static void unregister_nfs4_fs(void)
117 {
118 }
119 #endif
120
121 #ifdef CONFIG_NFS_V4_2
122 static void nfs_ssc_register_ops(void)
123 {
124 nfs_ssc_register(&nfs_ssc_clnt_ops_tbl);
125 }
126
127 static void nfs_ssc_unregister_ops(void)
128 {
129 nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl);
130 }
131 #endif /* CONFIG_NFS_V4_2 */
132
133 static struct shrinker *acl_shrinker;
134
135 /*
136 * Register the NFS filesystems
137 */
138 int __init register_nfs_fs(void)
139 {
140 int ret;
141
142 ret = register_filesystem(&nfs_fs_type);
143 if (ret < 0)
144 goto error_0;
145
146 ret = register_nfs4_fs();
147 if (ret < 0)
148 goto error_1;
149
150 ret = nfs_register_sysctl();
151 if (ret < 0)
152 goto error_2;
153
154 acl_shrinker = shrinker_alloc(0, "nfs-acl");
155 if (!acl_shrinker) {
156 ret = -ENOMEM;
157 goto error_3;
158 }
159
160 acl_shrinker->count_objects = nfs_access_cache_count;
161 acl_shrinker->scan_objects = nfs_access_cache_scan;
162
163 shrinker_register(acl_shrinker);
164
165 #ifdef CONFIG_NFS_V4_2
166 nfs_ssc_register_ops();
167 #endif
168 return 0;
169 error_3:
170 nfs_unregister_sysctl();
171 error_2:
172 unregister_nfs4_fs();
173 error_1:
174 unregister_filesystem(&nfs_fs_type);
175 error_0:
176 return ret;
177 }
178
179 /*
180 * Unregister the NFS filesystems
181 */
182 void __exit unregister_nfs_fs(void)
183 {
184 shrinker_free(acl_shrinker);
185 nfs_unregister_sysctl();
186 unregister_nfs4_fs();
187 #ifdef CONFIG_NFS_V4_2
188 nfs_ssc_unregister_ops();
189 #endif
190 unregister_filesystem(&nfs_fs_type);
191 }
192
193 bool nfs_sb_active(struct super_block *sb)
194 {
195 struct nfs_server *server = NFS_SB(sb);
196
197 if (!atomic_inc_not_zero(&sb->s_active))
198 return false;
199 if (atomic_inc_return(&server->active) != 1)
200 atomic_dec(&sb->s_active);
201 return true;
202 }
203 EXPORT_SYMBOL_GPL(nfs_sb_active);
204
205 void nfs_sb_deactive(struct super_block *sb)
206 {
207 struct nfs_server *server = NFS_SB(sb);
208
209 if (atomic_dec_and_test(&server->active))
210 deactivate_super(sb);
211 }
212 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
213
214 static int __nfs_list_for_each_server(struct list_head *head,
215 int (*fn)(struct nfs_server *, void *),
216 void *data)
217 {
218 struct nfs_server *server, *last = NULL;
219 int ret = 0;
220
221 rcu_read_lock();
222 list_for_each_entry_rcu(server, head, client_link) {
223 if (!(server->super && nfs_sb_active(server->super)))
224 continue;
225 rcu_read_unlock();
226 if (last)
227 nfs_sb_deactive(last->super);
228 last = server;
229 ret = fn(server, data);
230 if (ret)
231 goto out;
232 cond_resched();
233 rcu_read_lock();
234 }
235 rcu_read_unlock();
236 out:
237 if (last)
238 nfs_sb_deactive(last->super);
239 return ret;
240 }
241
242 int nfs_client_for_each_server(struct nfs_client *clp,
243 int (*fn)(struct nfs_server *, void *),
244 void *data)
245 {
246 return __nfs_list_for_each_server(&clp->cl_superblocks, fn, data);
247 }
248 EXPORT_SYMBOL_GPL(nfs_client_for_each_server);
249
250 /*
251 * Deliver file system statistics to userspace
252 */
253 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
254 {
255 struct nfs_server *server = NFS_SB(dentry->d_sb);
256 unsigned char blockbits;
257 unsigned long blockres;
258 struct nfs_fh *fh = NFS_FH(d_inode(dentry));
259 struct nfs_fsstat res;
260 int error = -ENOMEM;
261
262 res.fattr = nfs_alloc_fattr();
263 if (res.fattr == NULL)
264 goto out_err;
265
266 error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
267 if (unlikely(error == -ESTALE)) {
268 struct dentry *pd_dentry;
269
270 pd_dentry = dget_parent(dentry);
271 nfs_zap_caches(d_inode(pd_dentry));
272 dput(pd_dentry);
273 }
274 nfs_free_fattr(res.fattr);
275 if (error < 0)
276 goto out_err;
277
278 buf->f_type = NFS_SUPER_MAGIC;
279
280 /*
281 * Current versions of glibc do not correctly handle the
282 * case where f_frsize != f_bsize. Eventually we want to
283 * report the value of wtmult in this field.
284 */
285 buf->f_frsize = dentry->d_sb->s_blocksize;
286
287 /*
288 * On most *nix systems, f_blocks, f_bfree, and f_bavail
289 * are reported in units of f_frsize. Linux hasn't had
290 * an f_frsize field in its statfs struct until recently,
291 * thus historically Linux's sys_statfs reports these
292 * fields in units of f_bsize.
293 */
294 buf->f_bsize = dentry->d_sb->s_blocksize;
295 blockbits = dentry->d_sb->s_blocksize_bits;
296 blockres = (1 << blockbits) - 1;
297 buf->f_blocks = (res.tbytes + blockres) >> blockbits;
298 buf->f_bfree = (res.fbytes + blockres) >> blockbits;
299 buf->f_bavail = (res.abytes + blockres) >> blockbits;
300
301 buf->f_files = res.tfiles;
302 buf->f_ffree = res.afiles;
303
304 buf->f_namelen = server->namelen;
305
306 return 0;
307
308 out_err:
309 dprintk("%s: statfs error = %d\n", __func__, -error);
310 return error;
311 }
312 EXPORT_SYMBOL_GPL(nfs_statfs);
313
314 /*
315 * Map the security flavour number to a name
316 */
317 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
318 {
319 static const struct {
320 rpc_authflavor_t flavour;
321 const char *str;
322 } sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
323 /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
324 { RPC_AUTH_NULL, "null" },
325 { RPC_AUTH_UNIX, "sys" },
326 { RPC_AUTH_GSS_KRB5, "krb5" },
327 { RPC_AUTH_GSS_KRB5I, "krb5i" },
328 { RPC_AUTH_GSS_KRB5P, "krb5p" },
329 { RPC_AUTH_GSS_LKEY, "lkey" },
330 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
331 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
332 { RPC_AUTH_GSS_SPKM, "spkm" },
333 { RPC_AUTH_GSS_SPKMI, "spkmi" },
334 { RPC_AUTH_GSS_SPKMP, "spkmp" },
335 { UINT_MAX, "unknown" }
336 };
337 int i;
338
339 for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
340 if (sec_flavours[i].flavour == flavour)
341 break;
342 }
343 return sec_flavours[i].str;
344 }
345
346 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
347 int showdefaults)
348 {
349 struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
350 char *proto = NULL;
351
352 switch (sap->sa_family) {
353 case AF_INET:
354 switch (nfss->mountd_protocol) {
355 case IPPROTO_UDP:
356 proto = RPCBIND_NETID_UDP;
357 break;
358 case IPPROTO_TCP:
359 proto = RPCBIND_NETID_TCP;
360 break;
361 }
362 break;
363 case AF_INET6:
364 switch (nfss->mountd_protocol) {
365 case IPPROTO_UDP:
366 proto = RPCBIND_NETID_UDP6;
367 break;
368 case IPPROTO_TCP:
369 proto = RPCBIND_NETID_TCP6;
370 break;
371 }
372 break;
373 }
374 if (proto || showdefaults)
375 seq_printf(m, ",mountproto=%s", proto ?: "auto");
376 }
377
378 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
379 int showdefaults)
380 {
381 struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
382
383 if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
384 return;
385
386 switch (sap->sa_family) {
387 case AF_INET: {
388 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
389 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
390 break;
391 }
392 case AF_INET6: {
393 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
394 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
395 break;
396 }
397 default:
398 if (showdefaults)
399 seq_puts(m, ",mountaddr=unspecified");
400 }
401
402 if (nfss->mountd_version || showdefaults)
403 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
404 if ((nfss->mountd_port &&
405 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
406 showdefaults)
407 seq_printf(m, ",mountport=%u", nfss->mountd_port);
408
409 nfs_show_mountd_netid(m, nfss, showdefaults);
410 }
411
412 #if IS_ENABLED(CONFIG_NFS_V4)
413 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
414 int showdefaults)
415 {
416 struct nfs_client *clp = nfss->nfs_client;
417
418 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
419 }
420 #else
421 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
422 int showdefaults)
423 {
424 }
425 #endif
426
427 static void nfs_show_nfs_version(struct seq_file *m,
428 unsigned int version,
429 unsigned int minorversion)
430 {
431 seq_printf(m, ",vers=%u", version);
432 if (version == 4)
433 seq_printf(m, ".%u", minorversion);
434 }
435
436 /*
437 * Describe the mount options in force on this server representation
438 */
439 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
440 int showdefaults)
441 {
442 static const struct proc_nfs_info {
443 int flag;
444 const char *str;
445 const char *nostr;
446 } nfs_info[] = {
447 { NFS_MOUNT_SOFT, ",soft", "" },
448 { NFS_MOUNT_SOFTERR, ",softerr", "" },
449 { NFS_MOUNT_SOFTREVAL, ",softreval", "" },
450 { NFS_MOUNT_POSIX, ",posix", "" },
451 { NFS_MOUNT_NOCTO, ",nocto", "" },
452 { NFS_MOUNT_NOAC, ",noac", "" },
453 { NFS_MOUNT_NONLM, ",nolock", "" },
454 { NFS_MOUNT_NOACL, ",noacl", "" },
455 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
456 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
457 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
458 { 0, NULL, NULL }
459 };
460 const struct proc_nfs_info *nfs_infop;
461 struct nfs_client *clp = nfss->nfs_client;
462 u32 version = clp->rpc_ops->version;
463 int local_flock, local_fcntl;
464
465 nfs_show_nfs_version(m, version, clp->cl_minorversion);
466 seq_printf(m, ",rsize=%u", nfss->rsize);
467 seq_printf(m, ",wsize=%u", nfss->wsize);
468 if (nfss->bsize != 0)
469 seq_printf(m, ",bsize=%u", nfss->bsize);
470 seq_printf(m, ",namlen=%u", nfss->namelen);
471 if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
472 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
473 if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
474 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
475 if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
476 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
477 if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
478 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
479 if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
480 seq_puts(m, ",hard");
481 for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
482 if (nfss->flags & nfs_infop->flag)
483 seq_puts(m, nfs_infop->str);
484 else
485 seq_puts(m, nfs_infop->nostr);
486 }
487 rcu_read_lock();
488 seq_printf(m, ",proto=%s",
489 rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
490 rcu_read_unlock();
491 if (clp->cl_nconnect > 0)
492 seq_printf(m, ",nconnect=%u", clp->cl_nconnect);
493 if (version == 4) {
494 if (clp->cl_max_connect > 1)
495 seq_printf(m, ",max_connect=%u", clp->cl_max_connect);
496 if (nfss->port != NFS_PORT)
497 seq_printf(m, ",port=%u", nfss->port);
498 } else
499 if (nfss->port)
500 seq_printf(m, ",port=%u", nfss->port);
501
502 seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
503 seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
504 seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
505 switch (clp->cl_xprtsec.policy) {
506 case RPC_XPRTSEC_TLS_ANON:
507 seq_puts(m, ",xprtsec=tls");
508 break;
509 case RPC_XPRTSEC_TLS_X509:
510 seq_puts(m, ",xprtsec=mtls");
511 break;
512 default:
513 break;
514 }
515
516 if (version != 4)
517 nfs_show_mountd_options(m, nfss, showdefaults);
518 else
519 nfs_show_nfsv4_options(m, nfss, showdefaults);
520
521 if (nfss->options & NFS_OPTION_FSCACHE) {
522 #ifdef CONFIG_NFS_FSCACHE
523 if (nfss->fscache_uniq)
524 seq_printf(m, ",fsc=%s", nfss->fscache_uniq);
525 else
526 seq_puts(m, ",fsc");
527 #else
528 seq_puts(m, ",fsc");
529 #endif
530 }
531
532 if (nfss->options & NFS_OPTION_MIGRATION)
533 seq_puts(m, ",migration");
534
535 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
536 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
537 seq_puts(m, ",lookupcache=none");
538 else
539 seq_puts(m, ",lookupcache=pos");
540 }
541
542 local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
543 local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
544
545 if (!local_flock && !local_fcntl)
546 seq_puts(m, ",local_lock=none");
547 else if (local_flock && local_fcntl)
548 seq_puts(m, ",local_lock=all");
549 else if (local_flock)
550 seq_puts(m, ",local_lock=flock");
551 else
552 seq_puts(m, ",local_lock=posix");
553
554 if (nfss->flags & NFS_MOUNT_WRITE_EAGER) {
555 if (nfss->flags & NFS_MOUNT_WRITE_WAIT)
556 seq_puts(m, ",write=wait");
557 else
558 seq_puts(m, ",write=eager");
559 }
560 }
561
562 /*
563 * Describe the mount options on this VFS mountpoint
564 */
565 int nfs_show_options(struct seq_file *m, struct dentry *root)
566 {
567 struct nfs_server *nfss = NFS_SB(root->d_sb);
568
569 nfs_show_mount_options(m, nfss, 0);
570
571 rcu_read_lock();
572 seq_printf(m, ",addr=%s",
573 rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
574 RPC_DISPLAY_ADDR));
575 rcu_read_unlock();
576
577 return 0;
578 }
579 EXPORT_SYMBOL_GPL(nfs_show_options);
580
581 #if IS_ENABLED(CONFIG_NFS_V4)
582 static void show_lease(struct seq_file *m, struct nfs_server *server)
583 {
584 struct nfs_client *clp = server->nfs_client;
585 unsigned long expire;
586
587 seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
588 expire = clp->cl_last_renewal + clp->cl_lease_time;
589 seq_printf(m, ",lease_expired=%ld",
590 time_after(expire, jiffies) ? 0 : (jiffies - expire) / HZ);
591 }
592 #ifdef CONFIG_NFS_V4_1
593 static void show_sessions(struct seq_file *m, struct nfs_server *server)
594 {
595 if (nfs4_has_session(server->nfs_client))
596 seq_puts(m, ",sessions");
597 }
598 #else
599 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
600 #endif
601 #endif
602
603 #ifdef CONFIG_NFS_V4_1
604 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
605 {
606 seq_printf(m, ",pnfs=");
607 if (server->pnfs_curr_ld)
608 seq_printf(m, "%s", server->pnfs_curr_ld->name);
609 else
610 seq_printf(m, "not configured");
611 }
612
613 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
614 {
615 if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
616 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
617 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
618 "date='%llu,%u'",
619 impl_id->name, impl_id->domain,
620 impl_id->date.seconds, impl_id->date.nseconds);
621 }
622 }
623 #else
624 #if IS_ENABLED(CONFIG_NFS_V4)
625 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
626 {
627 }
628 #endif
629 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
630 {
631 }
632 #endif
633
634 int nfs_show_devname(struct seq_file *m, struct dentry *root)
635 {
636 char *page = (char *) __get_free_page(GFP_KERNEL);
637 char *devname, *dummy;
638 int err = 0;
639 if (!page)
640 return -ENOMEM;
641 devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
642 if (IS_ERR(devname))
643 err = PTR_ERR(devname);
644 else
645 seq_escape(m, devname, " \t\n\\");
646 free_page((unsigned long)page);
647 return err;
648 }
649 EXPORT_SYMBOL_GPL(nfs_show_devname);
650
651 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
652 {
653 seq_puts(m, "/");
654 return 0;
655 }
656 EXPORT_SYMBOL_GPL(nfs_show_path);
657
658 /*
659 * Present statistical information for this VFS mountpoint
660 */
661 int nfs_show_stats(struct seq_file *m, struct dentry *root)
662 {
663 int i, cpu;
664 struct nfs_server *nfss = NFS_SB(root->d_sb);
665 struct rpc_auth *auth = nfss->client->cl_auth;
666 struct nfs_iostats totals = { };
667
668 seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
669
670 /*
671 * Display all mount option settings
672 */
673 seq_puts(m, "\n\topts:\t");
674 seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
675 seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
676 seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
677 seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
678 nfs_show_mount_options(m, nfss, 1);
679
680 seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
681
682 show_implementation_id(m, nfss);
683
684 seq_puts(m, "\n\tcaps:\t");
685 seq_printf(m, "caps=0x%x", nfss->caps);
686 seq_printf(m, ",wtmult=%u", nfss->wtmult);
687 seq_printf(m, ",dtsize=%u", nfss->dtsize);
688 seq_printf(m, ",bsize=%u", nfss->bsize);
689 seq_printf(m, ",namlen=%u", nfss->namelen);
690
691 #if IS_ENABLED(CONFIG_NFS_V4)
692 if (nfss->nfs_client->rpc_ops->version == 4) {
693 seq_puts(m, "\n\tnfsv4:\t");
694 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
695 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
696 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
697 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
698 show_sessions(m, nfss);
699 show_pnfs(m, nfss);
700 show_lease(m, nfss);
701 }
702 #endif
703
704 /*
705 * Display security flavor in effect for this mount
706 */
707 seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
708 if (auth->au_flavor)
709 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
710
711 /*
712 * Display superblock I/O counters
713 */
714 for_each_possible_cpu(cpu) {
715 struct nfs_iostats *stats;
716
717 preempt_disable();
718 stats = per_cpu_ptr(nfss->io_stats, cpu);
719
720 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
721 totals.events[i] += stats->events[i];
722 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
723 totals.bytes[i] += stats->bytes[i];
724
725 preempt_enable();
726 }
727
728 seq_puts(m, "\n\tevents:\t");
729 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
730 seq_printf(m, "%lu ", totals.events[i]);
731 seq_puts(m, "\n\tbytes:\t");
732 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
733 seq_printf(m, "%Lu ", totals.bytes[i]);
734 seq_putc(m, '\n');
735
736 rpc_clnt_show_stats(m, nfss->client);
737
738 return 0;
739 }
740 EXPORT_SYMBOL_GPL(nfs_show_stats);
741
742 /*
743 * Begin unmount by attempting to remove all automounted mountpoints we added
744 * in response to xdev traversals and referrals
745 */
746 void nfs_umount_begin(struct super_block *sb)
747 {
748 struct nfs_server *server;
749 struct rpc_clnt *rpc;
750
751 server = NFS_SB(sb);
752 /* -EIO all pending I/O */
753 rpc = server->client_acl;
754 if (!IS_ERR(rpc))
755 rpc_killall_tasks(rpc);
756 rpc = server->client;
757 if (!IS_ERR(rpc))
758 rpc_killall_tasks(rpc);
759 }
760 EXPORT_SYMBOL_GPL(nfs_umount_begin);
761
762 /*
763 * Return true if 'match' is in auth_info or auth_info is empty.
764 * Return false otherwise.
765 */
766 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
767 rpc_authflavor_t match)
768 {
769 int i;
770
771 if (!auth_info->flavor_len)
772 return true;
773
774 for (i = 0; i < auth_info->flavor_len; i++) {
775 if (auth_info->flavors[i] == match)
776 return true;
777 }
778 return false;
779 }
780 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
781
782 /*
783 * Ensure that a specified authtype in ctx->auth_info is supported by
784 * the server. Returns 0 and sets ctx->selected_flavor if it's ok, and
785 * -EACCES if not.
786 */
787 static int nfs_verify_authflavors(struct nfs_fs_context *ctx,
788 rpc_authflavor_t *server_authlist,
789 unsigned int count)
790 {
791 rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
792 bool found_auth_null = false;
793 unsigned int i;
794
795 /*
796 * If the sec= mount option is used, the specified flavor or AUTH_NULL
797 * must be in the list returned by the server.
798 *
799 * AUTH_NULL has a special meaning when it's in the server list - it
800 * means that the server will ignore the rpc creds, so any flavor
801 * can be used but still use the sec= that was specified.
802 *
803 * Note also that the MNT procedure in MNTv1 does not return a list
804 * of supported security flavors. In this case, nfs_mount() fabricates
805 * a security flavor list containing just AUTH_NULL.
806 */
807 for (i = 0; i < count; i++) {
808 flavor = server_authlist[i];
809
810 if (nfs_auth_info_match(&ctx->auth_info, flavor))
811 goto out;
812
813 if (flavor == RPC_AUTH_NULL)
814 found_auth_null = true;
815 }
816
817 if (found_auth_null) {
818 flavor = ctx->auth_info.flavors[0];
819 goto out;
820 }
821
822 dfprintk(MOUNT,
823 "NFS: specified auth flavors not supported by server\n");
824 return -EACCES;
825
826 out:
827 ctx->selected_flavor = flavor;
828 dfprintk(MOUNT, "NFS: using auth flavor %u\n", ctx->selected_flavor);
829 return 0;
830 }
831
832 /*
833 * Use the remote server's MOUNT service to request the NFS file handle
834 * corresponding to the provided path.
835 */
836 static int nfs_request_mount(struct fs_context *fc,
837 struct nfs_fh *root_fh,
838 rpc_authflavor_t *server_authlist,
839 unsigned int *server_authlist_len)
840 {
841 struct nfs_fs_context *ctx = nfs_fc2context(fc);
842 struct nfs_mount_request request = {
843 .sap = &ctx->mount_server._address,
844 .dirpath = ctx->nfs_server.export_path,
845 .protocol = ctx->mount_server.protocol,
846 .fh = root_fh,
847 .noresvport = ctx->flags & NFS_MOUNT_NORESVPORT,
848 .auth_flav_len = server_authlist_len,
849 .auth_flavs = server_authlist,
850 .net = fc->net_ns,
851 };
852 int status;
853
854 if (ctx->mount_server.version == 0) {
855 switch (ctx->version) {
856 default:
857 ctx->mount_server.version = NFS_MNT3_VERSION;
858 break;
859 case 2:
860 ctx->mount_server.version = NFS_MNT_VERSION;
861 }
862 }
863 request.version = ctx->mount_server.version;
864
865 if (ctx->mount_server.hostname)
866 request.hostname = ctx->mount_server.hostname;
867 else
868 request.hostname = ctx->nfs_server.hostname;
869
870 /*
871 * Construct the mount server's address.
872 */
873 if (ctx->mount_server.address.sa_family == AF_UNSPEC) {
874 memcpy(request.sap, &ctx->nfs_server._address,
875 ctx->nfs_server.addrlen);
876 ctx->mount_server.addrlen = ctx->nfs_server.addrlen;
877 }
878 request.salen = ctx->mount_server.addrlen;
879 nfs_set_port(request.sap, &ctx->mount_server.port, 0);
880
881 /*
882 * Now ask the mount server to map our export path
883 * to a file handle.
884 */
885 status = nfs_mount(&request, ctx->timeo, ctx->retrans);
886 if (status != 0) {
887 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
888 request.hostname, status);
889 return status;
890 }
891
892 return 0;
893 }
894
895 static struct nfs_server *nfs_try_mount_request(struct fs_context *fc)
896 {
897 struct nfs_fs_context *ctx = nfs_fc2context(fc);
898 int status;
899 unsigned int i;
900 bool tried_auth_unix = false;
901 bool auth_null_in_list = false;
902 struct nfs_server *server = ERR_PTR(-EACCES);
903 rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
904 unsigned int authlist_len = ARRAY_SIZE(authlist);
905
906 /* make sure 'nolock'/'lock' override the 'local_lock' mount option */
907 if (ctx->lock_status) {
908 if (ctx->lock_status == NFS_LOCK_NOLOCK) {
909 ctx->flags |= NFS_MOUNT_NONLM;
910 ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
911 } else {
912 ctx->flags &= ~NFS_MOUNT_NONLM;
913 ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL);
914 }
915 }
916 status = nfs_request_mount(fc, ctx->mntfh, authlist, &authlist_len);
917 if (status)
918 return ERR_PTR(status);
919
920 /*
921 * Was a sec= authflavor specified in the options? First, verify
922 * whether the server supports it, and then just try to use it if so.
923 */
924 if (ctx->auth_info.flavor_len > 0) {
925 status = nfs_verify_authflavors(ctx, authlist, authlist_len);
926 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
927 ctx->selected_flavor);
928 if (status)
929 return ERR_PTR(status);
930 return ctx->nfs_mod->rpc_ops->create_server(fc);
931 }
932
933 /*
934 * No sec= option was provided. RFC 2623, section 2.7 suggests we
935 * SHOULD prefer the flavor listed first. However, some servers list
936 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
937 */
938 for (i = 0; i < authlist_len; ++i) {
939 rpc_authflavor_t flavor;
940 struct rpcsec_gss_info info;
941
942 flavor = authlist[i];
943 switch (flavor) {
944 case RPC_AUTH_UNIX:
945 tried_auth_unix = true;
946 break;
947 case RPC_AUTH_NULL:
948 auth_null_in_list = true;
949 continue;
950 default:
951 if (rpcauth_get_gssinfo(flavor, &info) != 0)
952 continue;
953 break;
954 }
955 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
956 ctx->selected_flavor = flavor;
957 server = ctx->nfs_mod->rpc_ops->create_server(fc);
958 if (!IS_ERR(server))
959 return server;
960 }
961
962 /*
963 * Nothing we tried so far worked. At this point, give up if we've
964 * already tried AUTH_UNIX or if the server's list doesn't contain
965 * AUTH_NULL
966 */
967 if (tried_auth_unix || !auth_null_in_list)
968 return server;
969
970 /* Last chance! Try AUTH_UNIX */
971 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
972 ctx->selected_flavor = RPC_AUTH_UNIX;
973 return ctx->nfs_mod->rpc_ops->create_server(fc);
974 }
975
976 int nfs_try_get_tree(struct fs_context *fc)
977 {
978 struct nfs_fs_context *ctx = nfs_fc2context(fc);
979
980 if (ctx->need_mount)
981 ctx->server = nfs_try_mount_request(fc);
982 else
983 ctx->server = ctx->nfs_mod->rpc_ops->create_server(fc);
984
985 return nfs_get_tree_common(fc);
986 }
987 EXPORT_SYMBOL_GPL(nfs_try_get_tree);
988
989
990 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
991 | NFS_MOUNT_SECURE \
992 | NFS_MOUNT_TCP \
993 | NFS_MOUNT_VER3 \
994 | NFS_MOUNT_KERBEROS \
995 | NFS_MOUNT_NONLM \
996 | NFS_MOUNT_BROKEN_SUID \
997 | NFS_MOUNT_STRICTLOCK \
998 | NFS_MOUNT_LEGACY_INTERFACE)
999
1000 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
1001 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
1002
1003 static int
1004 nfs_compare_remount_data(struct nfs_server *nfss,
1005 struct nfs_fs_context *ctx)
1006 {
1007 if ((ctx->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
1008 ctx->rsize != nfss->rsize ||
1009 ctx->wsize != nfss->wsize ||
1010 ctx->version != nfss->nfs_client->rpc_ops->version ||
1011 ctx->minorversion != nfss->nfs_client->cl_minorversion ||
1012 ctx->retrans != nfss->client->cl_timeout->to_retries ||
1013 !nfs_auth_info_match(&ctx->auth_info, nfss->client->cl_auth->au_flavor) ||
1014 ctx->acregmin != nfss->acregmin / HZ ||
1015 ctx->acregmax != nfss->acregmax / HZ ||
1016 ctx->acdirmin != nfss->acdirmin / HZ ||
1017 ctx->acdirmax != nfss->acdirmax / HZ ||
1018 ctx->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
1019 (ctx->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
1020 ctx->nfs_server.port != nfss->port ||
1021 ctx->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1022 !rpc_cmp_addr((struct sockaddr *)&ctx->nfs_server.address,
1023 (struct sockaddr *)&nfss->nfs_client->cl_addr))
1024 return -EINVAL;
1025
1026 return 0;
1027 }
1028
1029 int nfs_reconfigure(struct fs_context *fc)
1030 {
1031 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1032 struct super_block *sb = fc->root->d_sb;
1033 struct nfs_server *nfss = sb->s_fs_info;
1034 int ret;
1035
1036 sync_filesystem(sb);
1037
1038 /*
1039 * Userspace mount programs that send binary options generally send
1040 * them populated with default values. We have no way to know which
1041 * ones were explicitly specified. Fall back to legacy behavior and
1042 * just return success.
1043 */
1044 if (ctx->skip_reconfig_option_check)
1045 return 0;
1046
1047 /*
1048 * noac is a special case. It implies -o sync, but that's not
1049 * necessarily reflected in the mtab options. reconfigure_super
1050 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
1051 * remount options, so we have to explicitly reset it.
1052 */
1053 if (ctx->flags & NFS_MOUNT_NOAC) {
1054 fc->sb_flags |= SB_SYNCHRONOUS;
1055 fc->sb_flags_mask |= SB_SYNCHRONOUS;
1056 }
1057
1058 /* compare new mount options with old ones */
1059 ret = nfs_compare_remount_data(nfss, ctx);
1060 if (ret)
1061 return ret;
1062
1063 return nfs_probe_server(nfss, NFS_FH(d_inode(fc->root)));
1064 }
1065 EXPORT_SYMBOL_GPL(nfs_reconfigure);
1066
1067 /*
1068 * Finish setting up an NFS superblock
1069 */
1070 static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx)
1071 {
1072 struct nfs_server *server = NFS_SB(sb);
1073
1074 sb->s_blocksize_bits = 0;
1075 sb->s_blocksize = 0;
1076 sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
1077 sb->s_op = server->nfs_client->cl_nfs_mod->sops;
1078 if (ctx->bsize)
1079 sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits);
1080
1081 switch (server->nfs_client->rpc_ops->version) {
1082 case 2:
1083 sb->s_time_gran = 1000;
1084 sb->s_time_min = 0;
1085 sb->s_time_max = U32_MAX;
1086 break;
1087 case 3:
1088 /*
1089 * The VFS shouldn't apply the umask to mode bits.
1090 * We will do so ourselves when necessary.
1091 */
1092 sb->s_flags |= SB_POSIXACL;
1093 sb->s_time_gran = 1;
1094 sb->s_time_min = 0;
1095 sb->s_time_max = U32_MAX;
1096 sb->s_export_op = &nfs_export_ops;
1097 break;
1098 case 4:
1099 sb->s_iflags |= SB_I_NOUMASK;
1100 sb->s_time_gran = 1;
1101 sb->s_time_min = S64_MIN;
1102 sb->s_time_max = S64_MAX;
1103 if (server->caps & NFS_CAP_ATOMIC_OPEN_V1)
1104 sb->s_export_op = &nfs_export_ops;
1105 break;
1106 }
1107
1108 sb->s_magic = NFS_SUPER_MAGIC;
1109
1110 /* We probably want something more informative here */
1111 snprintf(sb->s_id, sizeof(sb->s_id),
1112 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1113
1114 if (sb->s_blocksize == 0)
1115 sb->s_blocksize = nfs_block_bits(server->wsize,
1116 &sb->s_blocksize_bits);
1117
1118 nfs_super_set_maxbytes(sb, server->maxfilesize);
1119 nfs_sysfs_move_server_to_sb(sb);
1120 server->has_sec_mnt_opts = ctx->has_sec_mnt_opts;
1121 }
1122
1123 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b,
1124 const struct fs_context *fc)
1125 {
1126 const struct nfs_server *a = s->s_fs_info;
1127 const struct rpc_clnt *clnt_a = a->client;
1128 const struct rpc_clnt *clnt_b = b->client;
1129
1130 if ((s->s_flags & NFS_SB_MASK) != (fc->sb_flags & NFS_SB_MASK))
1131 goto Ebusy;
1132 if (a->nfs_client != b->nfs_client)
1133 goto Ebusy;
1134 if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
1135 goto Ebusy;
1136 if (a->wsize != b->wsize)
1137 goto Ebusy;
1138 if (a->rsize != b->rsize)
1139 goto Ebusy;
1140 if (a->acregmin != b->acregmin)
1141 goto Ebusy;
1142 if (a->acregmax != b->acregmax)
1143 goto Ebusy;
1144 if (a->acdirmin != b->acdirmin)
1145 goto Ebusy;
1146 if (a->acdirmax != b->acdirmax)
1147 goto Ebusy;
1148 if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1149 goto Ebusy;
1150 return 1;
1151 Ebusy:
1152 return 0;
1153 }
1154
1155 static int nfs_set_super(struct super_block *s, struct fs_context *fc)
1156 {
1157 struct nfs_server *server = fc->s_fs_info;
1158 int ret;
1159
1160 s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
1161 ret = set_anon_super(s, server);
1162 if (ret == 0)
1163 server->s_dev = s->s_dev;
1164 return ret;
1165 }
1166
1167 static int nfs_compare_super_address(struct nfs_server *server1,
1168 struct nfs_server *server2)
1169 {
1170 struct sockaddr *sap1, *sap2;
1171 struct rpc_xprt *xprt1 = server1->client->cl_xprt;
1172 struct rpc_xprt *xprt2 = server2->client->cl_xprt;
1173
1174 if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
1175 return 0;
1176
1177 sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1178 sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1179
1180 if (sap1->sa_family != sap2->sa_family)
1181 return 0;
1182
1183 switch (sap1->sa_family) {
1184 case AF_INET: {
1185 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1186 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1187 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1188 return 0;
1189 if (sin1->sin_port != sin2->sin_port)
1190 return 0;
1191 break;
1192 }
1193 case AF_INET6: {
1194 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1195 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1196 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1197 return 0;
1198 if (sin1->sin6_port != sin2->sin6_port)
1199 return 0;
1200 break;
1201 }
1202 default:
1203 return 0;
1204 }
1205
1206 return 1;
1207 }
1208
1209 static int nfs_compare_userns(const struct nfs_server *old,
1210 const struct nfs_server *new)
1211 {
1212 const struct user_namespace *oldns = &init_user_ns;
1213 const struct user_namespace *newns = &init_user_ns;
1214
1215 if (old->client && old->client->cl_cred)
1216 oldns = old->client->cl_cred->user_ns;
1217 if (new->client && new->client->cl_cred)
1218 newns = new->client->cl_cred->user_ns;
1219 if (oldns != newns)
1220 return 0;
1221 return 1;
1222 }
1223
1224 static int nfs_compare_super(struct super_block *sb, struct fs_context *fc)
1225 {
1226 struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb);
1227
1228 if (!nfs_compare_super_address(old, server))
1229 return 0;
1230 /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1231 if (old->flags & NFS_MOUNT_UNSHARED)
1232 return 0;
1233 if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1234 return 0;
1235 if (!nfs_compare_userns(old, server))
1236 return 0;
1237 if ((old->has_sec_mnt_opts || fc->security) &&
1238 security_sb_mnt_opts_compat(sb, fc->security))
1239 return 0;
1240 return nfs_compare_mount_options(sb, server, fc);
1241 }
1242
1243 #ifdef CONFIG_NFS_FSCACHE
1244 static int nfs_get_cache_cookie(struct super_block *sb,
1245 struct nfs_fs_context *ctx)
1246 {
1247 struct nfs_server *nfss = NFS_SB(sb);
1248 char *uniq = NULL;
1249 int ulen = 0;
1250
1251 nfss->fscache = NULL;
1252
1253 if (!ctx)
1254 return 0;
1255
1256 if (ctx->clone_data.sb) {
1257 struct nfs_server *mnt_s = NFS_SB(ctx->clone_data.sb);
1258 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
1259 return 0;
1260 if (mnt_s->fscache_uniq) {
1261 uniq = mnt_s->fscache_uniq;
1262 ulen = strlen(uniq);
1263 }
1264 } else {
1265 if (!(ctx->options & NFS_OPTION_FSCACHE))
1266 return 0;
1267 if (ctx->fscache_uniq) {
1268 uniq = ctx->fscache_uniq;
1269 ulen = strlen(ctx->fscache_uniq);
1270 }
1271 }
1272
1273 return nfs_fscache_get_super_cookie(sb, uniq, ulen);
1274 }
1275 #else
1276 static int nfs_get_cache_cookie(struct super_block *sb,
1277 struct nfs_fs_context *ctx)
1278 {
1279 return 0;
1280 }
1281 #endif
1282
1283 int nfs_get_tree_common(struct fs_context *fc)
1284 {
1285 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1286 struct super_block *s;
1287 int (*compare_super)(struct super_block *, struct fs_context *) = nfs_compare_super;
1288 struct nfs_server *server = ctx->server;
1289 int error;
1290
1291 ctx->server = NULL;
1292 if (IS_ERR(server))
1293 return PTR_ERR(server);
1294
1295 if (server->flags & NFS_MOUNT_UNSHARED)
1296 compare_super = NULL;
1297
1298 /* -o noac implies -o sync */
1299 if (server->flags & NFS_MOUNT_NOAC)
1300 fc->sb_flags |= SB_SYNCHRONOUS;
1301
1302 if (ctx->clone_data.sb)
1303 if (ctx->clone_data.sb->s_flags & SB_SYNCHRONOUS)
1304 fc->sb_flags |= SB_SYNCHRONOUS;
1305
1306 /* Get a superblock - note that we may end up sharing one that already exists */
1307 fc->s_fs_info = server;
1308 s = sget_fc(fc, compare_super, nfs_set_super);
1309 fc->s_fs_info = NULL;
1310 if (IS_ERR(s)) {
1311 error = PTR_ERR(s);
1312 nfs_errorf(fc, "NFS: Couldn't get superblock");
1313 goto out_err_nosb;
1314 }
1315
1316 if (s->s_fs_info != server) {
1317 nfs_free_server(server);
1318 server = NULL;
1319 } else {
1320 error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
1321 MINOR(server->s_dev));
1322 if (error)
1323 goto error_splat_super;
1324 s->s_bdi->io_pages = server->rpages;
1325 server->super = s;
1326 }
1327
1328 if (!s->s_root) {
1329 unsigned bsize = ctx->clone_data.inherited_bsize;
1330 /* initial superblock/root creation */
1331 nfs_fill_super(s, ctx);
1332 if (bsize) {
1333 s->s_blocksize_bits = bsize;
1334 s->s_blocksize = 1U << bsize;
1335 }
1336 error = nfs_get_cache_cookie(s, ctx);
1337 if (error < 0)
1338 goto error_splat_super;
1339 }
1340
1341 error = nfs_get_root(s, fc);
1342 if (error < 0) {
1343 nfs_errorf(fc, "NFS: Couldn't get root dentry");
1344 goto error_splat_super;
1345 }
1346
1347 s->s_flags |= SB_ACTIVE;
1348 error = 0;
1349
1350 out:
1351 return error;
1352
1353 out_err_nosb:
1354 nfs_free_server(server);
1355 goto out;
1356 error_splat_super:
1357 deactivate_locked_super(s);
1358 goto out;
1359 }
1360
1361 /*
1362 * Destroy an NFS superblock
1363 */
1364 void nfs_kill_super(struct super_block *s)
1365 {
1366 struct nfs_server *server = NFS_SB(s);
1367
1368 nfs_sysfs_move_sb_to_server(server);
1369 kill_anon_super(s);
1370
1371 nfs_fscache_release_super_cookie(s);
1372
1373 nfs_free_server(server);
1374 }
1375 EXPORT_SYMBOL_GPL(nfs_kill_super);
1376
1377 #if IS_ENABLED(CONFIG_NFS_V4)
1378
1379 /*
1380 * NFS v4 module parameters need to stay in the
1381 * NFS client for backwards compatibility
1382 */
1383 unsigned int nfs_callback_set_tcpport;
1384 unsigned short nfs_callback_nr_threads;
1385 /* Default cache timeout is 10 minutes */
1386 unsigned int nfs_idmap_cache_timeout = 600;
1387 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
1388 bool nfs4_disable_idmapping = true;
1389 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
1390 unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
1391 unsigned short send_implementation_id = 1;
1392 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
1393 bool recover_lost_locks = false;
1394 short nfs_delay_retrans = -1;
1395
1396 EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
1397 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
1398 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
1399 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
1400 EXPORT_SYMBOL_GPL(max_session_slots);
1401 EXPORT_SYMBOL_GPL(max_session_cb_slots);
1402 EXPORT_SYMBOL_GPL(send_implementation_id);
1403 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
1404 EXPORT_SYMBOL_GPL(recover_lost_locks);
1405 EXPORT_SYMBOL_GPL(nfs_delay_retrans);
1406
1407 #define NFS_CALLBACK_MAXPORTNR (65535U)
1408
1409 static int param_set_portnr(const char *val, const struct kernel_param *kp)
1410 {
1411 unsigned long num;
1412 int ret;
1413
1414 if (!val)
1415 return -EINVAL;
1416 ret = kstrtoul(val, 0, &num);
1417 if (ret || num > NFS_CALLBACK_MAXPORTNR)
1418 return -EINVAL;
1419 *((unsigned int *)kp->arg) = num;
1420 return 0;
1421 }
1422 static const struct kernel_param_ops param_ops_portnr = {
1423 .set = param_set_portnr,
1424 .get = param_get_uint,
1425 };
1426 #define param_check_portnr(name, p) __param_check(name, p, unsigned int)
1427
1428 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
1429 module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
1430 MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
1431 "assigned to the NFSv4 callback channels.");
1432 module_param(nfs_idmap_cache_timeout, int, 0644);
1433 module_param(nfs4_disable_idmapping, bool, 0644);
1434 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
1435 NFS4_CLIENT_ID_UNIQ_LEN, 0600);
1436 MODULE_PARM_DESC(nfs4_disable_idmapping,
1437 "Turn off NFSv4 idmapping when using 'sec=sys'");
1438 module_param(max_session_slots, ushort, 0644);
1439 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
1440 "requests the client will negotiate");
1441 module_param(max_session_cb_slots, ushort, 0644);
1442 MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
1443 "callbacks the client will process for a given server");
1444 module_param(send_implementation_id, ushort, 0644);
1445 MODULE_PARM_DESC(send_implementation_id,
1446 "Send implementation ID with NFSv4.1 exchange_id");
1447 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
1448
1449 module_param(recover_lost_locks, bool, 0644);
1450 MODULE_PARM_DESC(recover_lost_locks,
1451 "If the server reports that a lock might be lost, "
1452 "try to recover it risking data corruption.");
1453
1454 module_param_named(delay_retrans, nfs_delay_retrans, short, 0644);
1455 MODULE_PARM_DESC(delay_retrans,
1456 "Unless negative, specifies the number of times the NFSv4 "
1457 "client retries a request before returning an EAGAIN error, "
1458 "after a reply of NFS4ERR_DELAY from the server.");
1459 #endif /* CONFIG_NFS_V4 */
1460
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