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