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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
61#include "nfs4_fs.h"
62#include "callback.h"
63#include "delegation.h"
64#include "iostat.h"
65#include "internal.h"
66#include "fscache.h"
67#include "nfs4session.h"
68#include "pnfs.h"
69#include "nfs.h"
70
71#define NFSDBG_FACILITY NFSDBG_VFS
72
73const struct super_operations nfs_sops = {
74 .alloc_inode = nfs_alloc_inode,
75 .free_inode = nfs_free_inode,
76 .write_inode = nfs_write_inode,
77 .drop_inode = nfs_drop_inode,
78 .statfs = nfs_statfs,
79 .evict_inode = nfs_evict_inode,
80 .umount_begin = nfs_umount_begin,
81 .show_options = nfs_show_options,
82 .show_devname = nfs_show_devname,
83 .show_path = nfs_show_path,
84 .show_stats = nfs_show_stats,
85};
86EXPORT_SYMBOL_GPL(nfs_sops);
87
88#if IS_ENABLED(CONFIG_NFS_V4)
89static int __init register_nfs4_fs(void)
90{
91 return register_filesystem(&nfs4_fs_type);
92}
93
94static void unregister_nfs4_fs(void)
95{
96 unregister_filesystem(&nfs4_fs_type);
97}
98#else
99static int __init register_nfs4_fs(void)
100{
101 return 0;
102}
103
104static void unregister_nfs4_fs(void)
105{
106}
107#endif
108
109static struct shrinker acl_shrinker = {
110 .count_objects = nfs_access_cache_count,
111 .scan_objects = nfs_access_cache_scan,
112 .seeks = DEFAULT_SEEKS,
113};
114
115/*
116 * Register the NFS filesystems
117 */
118int __init register_nfs_fs(void)
119{
120 int ret;
121
122 ret = register_filesystem(&nfs_fs_type);
123 if (ret < 0)
124 goto error_0;
125
126 ret = register_nfs4_fs();
127 if (ret < 0)
128 goto error_1;
129
130 ret = nfs_register_sysctl();
131 if (ret < 0)
132 goto error_2;
133 ret = register_shrinker(&acl_shrinker);
134 if (ret < 0)
135 goto error_3;
136 return 0;
137error_3:
138 nfs_unregister_sysctl();
139error_2:
140 unregister_nfs4_fs();
141error_1:
142 unregister_filesystem(&nfs_fs_type);
143error_0:
144 return ret;
145}
146
147/*
148 * Unregister the NFS filesystems
149 */
150void __exit unregister_nfs_fs(void)
151{
152 unregister_shrinker(&acl_shrinker);
153 nfs_unregister_sysctl();
154 unregister_nfs4_fs();
155 unregister_filesystem(&nfs_fs_type);
156}
157
158bool nfs_sb_active(struct super_block *sb)
159{
160 struct nfs_server *server = NFS_SB(sb);
161
162 if (!atomic_inc_not_zero(&sb->s_active))
163 return false;
164 if (atomic_inc_return(&server->active) != 1)
165 atomic_dec(&sb->s_active);
166 return true;
167}
168EXPORT_SYMBOL_GPL(nfs_sb_active);
169
170void nfs_sb_deactive(struct super_block *sb)
171{
172 struct nfs_server *server = NFS_SB(sb);
173
174 if (atomic_dec_and_test(&server->active))
175 deactivate_super(sb);
176}
177EXPORT_SYMBOL_GPL(nfs_sb_deactive);
178
179static int __nfs_list_for_each_server(struct list_head *head,
180 int (*fn)(struct nfs_server *, void *),
181 void *data)
182{
183 struct nfs_server *server, *last = NULL;
184 int ret = 0;
185
186 rcu_read_lock();
187 list_for_each_entry_rcu(server, head, client_link) {
188 if (!(server->super && nfs_sb_active(server->super)))
189 continue;
190 rcu_read_unlock();
191 if (last)
192 nfs_sb_deactive(last->super);
193 last = server;
194 ret = fn(server, data);
195 if (ret)
196 goto out;
197 rcu_read_lock();
198 }
199 rcu_read_unlock();
200out:
201 if (last)
202 nfs_sb_deactive(last->super);
203 return ret;
204}
205
206int nfs_client_for_each_server(struct nfs_client *clp,
207 int (*fn)(struct nfs_server *, void *),
208 void *data)
209{
210 return __nfs_list_for_each_server(&clp->cl_superblocks, fn, data);
211}
212EXPORT_SYMBOL_GPL(nfs_client_for_each_server);
213
214/*
215 * Deliver file system statistics to userspace
216 */
217int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
218{
219 struct nfs_server *server = NFS_SB(dentry->d_sb);
220 unsigned char blockbits;
221 unsigned long blockres;
222 struct nfs_fh *fh = NFS_FH(d_inode(dentry));
223 struct nfs_fsstat res;
224 int error = -ENOMEM;
225
226 res.fattr = nfs_alloc_fattr();
227 if (res.fattr == NULL)
228 goto out_err;
229
230 error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
231 if (unlikely(error == -ESTALE)) {
232 struct dentry *pd_dentry;
233
234 pd_dentry = dget_parent(dentry);
235 nfs_zap_caches(d_inode(pd_dentry));
236 dput(pd_dentry);
237 }
238 nfs_free_fattr(res.fattr);
239 if (error < 0)
240 goto out_err;
241
242 buf->f_type = NFS_SUPER_MAGIC;
243
244 /*
245 * Current versions of glibc do not correctly handle the
246 * case where f_frsize != f_bsize. Eventually we want to
247 * report the value of wtmult in this field.
248 */
249 buf->f_frsize = dentry->d_sb->s_blocksize;
250
251 /*
252 * On most *nix systems, f_blocks, f_bfree, and f_bavail
253 * are reported in units of f_frsize. Linux hasn't had
254 * an f_frsize field in its statfs struct until recently,
255 * thus historically Linux's sys_statfs reports these
256 * fields in units of f_bsize.
257 */
258 buf->f_bsize = dentry->d_sb->s_blocksize;
259 blockbits = dentry->d_sb->s_blocksize_bits;
260 blockres = (1 << blockbits) - 1;
261 buf->f_blocks = (res.tbytes + blockres) >> blockbits;
262 buf->f_bfree = (res.fbytes + blockres) >> blockbits;
263 buf->f_bavail = (res.abytes + blockres) >> blockbits;
264
265 buf->f_files = res.tfiles;
266 buf->f_ffree = res.afiles;
267
268 buf->f_namelen = server->namelen;
269
270 return 0;
271
272 out_err:
273 dprintk("%s: statfs error = %d\n", __func__, -error);
274 return error;
275}
276EXPORT_SYMBOL_GPL(nfs_statfs);
277
278/*
279 * Map the security flavour number to a name
280 */
281static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
282{
283 static const struct {
284 rpc_authflavor_t flavour;
285 const char *str;
286 } sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
287 /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
288 { RPC_AUTH_NULL, "null" },
289 { RPC_AUTH_UNIX, "sys" },
290 { RPC_AUTH_GSS_KRB5, "krb5" },
291 { RPC_AUTH_GSS_KRB5I, "krb5i" },
292 { RPC_AUTH_GSS_KRB5P, "krb5p" },
293 { RPC_AUTH_GSS_LKEY, "lkey" },
294 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
295 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
296 { RPC_AUTH_GSS_SPKM, "spkm" },
297 { RPC_AUTH_GSS_SPKMI, "spkmi" },
298 { RPC_AUTH_GSS_SPKMP, "spkmp" },
299 { UINT_MAX, "unknown" }
300 };
301 int i;
302
303 for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
304 if (sec_flavours[i].flavour == flavour)
305 break;
306 }
307 return sec_flavours[i].str;
308}
309
310static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
311 int showdefaults)
312{
313 struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
314 char *proto = NULL;
315
316 switch (sap->sa_family) {
317 case AF_INET:
318 switch (nfss->mountd_protocol) {
319 case IPPROTO_UDP:
320 proto = RPCBIND_NETID_UDP;
321 break;
322 case IPPROTO_TCP:
323 proto = RPCBIND_NETID_TCP;
324 break;
325 }
326 break;
327 case AF_INET6:
328 switch (nfss->mountd_protocol) {
329 case IPPROTO_UDP:
330 proto = RPCBIND_NETID_UDP6;
331 break;
332 case IPPROTO_TCP:
333 proto = RPCBIND_NETID_TCP6;
334 break;
335 }
336 break;
337 }
338 if (proto || showdefaults)
339 seq_printf(m, ",mountproto=%s", proto ?: "auto");
340}
341
342static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
343 int showdefaults)
344{
345 struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
346
347 if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
348 return;
349
350 switch (sap->sa_family) {
351 case AF_INET: {
352 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
353 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
354 break;
355 }
356 case AF_INET6: {
357 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
358 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
359 break;
360 }
361 default:
362 if (showdefaults)
363 seq_puts(m, ",mountaddr=unspecified");
364 }
365
366 if (nfss->mountd_version || showdefaults)
367 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
368 if ((nfss->mountd_port &&
369 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
370 showdefaults)
371 seq_printf(m, ",mountport=%u", nfss->mountd_port);
372
373 nfs_show_mountd_netid(m, nfss, showdefaults);
374}
375
376#if IS_ENABLED(CONFIG_NFS_V4)
377static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
378 int showdefaults)
379{
380 struct nfs_client *clp = nfss->nfs_client;
381
382 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
383}
384#else
385static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
386 int showdefaults)
387{
388}
389#endif
390
391static void nfs_show_nfs_version(struct seq_file *m,
392 unsigned int version,
393 unsigned int minorversion)
394{
395 seq_printf(m, ",vers=%u", version);
396 if (version == 4)
397 seq_printf(m, ".%u", minorversion);
398}
399
400/*
401 * Describe the mount options in force on this server representation
402 */
403static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
404 int showdefaults)
405{
406 static const struct proc_nfs_info {
407 int flag;
408 const char *str;
409 const char *nostr;
410 } nfs_info[] = {
411 { NFS_MOUNT_SOFT, ",soft", "" },
412 { NFS_MOUNT_SOFTERR, ",softerr", "" },
413 { NFS_MOUNT_SOFTREVAL, ",softreval", "" },
414 { NFS_MOUNT_POSIX, ",posix", "" },
415 { NFS_MOUNT_NOCTO, ",nocto", "" },
416 { NFS_MOUNT_NOAC, ",noac", "" },
417 { NFS_MOUNT_NONLM, ",nolock", "" },
418 { NFS_MOUNT_NOACL, ",noacl", "" },
419 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
420 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
421 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
422 { 0, NULL, NULL }
423 };
424 const struct proc_nfs_info *nfs_infop;
425 struct nfs_client *clp = nfss->nfs_client;
426 u32 version = clp->rpc_ops->version;
427 int local_flock, local_fcntl;
428
429 nfs_show_nfs_version(m, version, clp->cl_minorversion);
430 seq_printf(m, ",rsize=%u", nfss->rsize);
431 seq_printf(m, ",wsize=%u", nfss->wsize);
432 if (nfss->bsize != 0)
433 seq_printf(m, ",bsize=%u", nfss->bsize);
434 seq_printf(m, ",namlen=%u", nfss->namelen);
435 if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
436 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
437 if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
438 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
439 if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
440 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
441 if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
442 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
443 if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
444 seq_puts(m, ",hard");
445 for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
446 if (nfss->flags & nfs_infop->flag)
447 seq_puts(m, nfs_infop->str);
448 else
449 seq_puts(m, nfs_infop->nostr);
450 }
451 rcu_read_lock();
452 seq_printf(m, ",proto=%s",
453 rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
454 rcu_read_unlock();
455 if (clp->cl_nconnect > 0)
456 seq_printf(m, ",nconnect=%u", clp->cl_nconnect);
457 if (version == 4) {
458 if (nfss->port != NFS_PORT)
459 seq_printf(m, ",port=%u", nfss->port);
460 } else
461 if (nfss->port)
462 seq_printf(m, ",port=%u", nfss->port);
463
464 seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
465 seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
466 seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
467
468 if (version != 4)
469 nfs_show_mountd_options(m, nfss, showdefaults);
470 else
471 nfs_show_nfsv4_options(m, nfss, showdefaults);
472
473 if (nfss->options & NFS_OPTION_FSCACHE)
474 seq_puts(m, ",fsc");
475
476 if (nfss->options & NFS_OPTION_MIGRATION)
477 seq_puts(m, ",migration");
478
479 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
480 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
481 seq_puts(m, ",lookupcache=none");
482 else
483 seq_puts(m, ",lookupcache=pos");
484 }
485
486 local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
487 local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
488
489 if (!local_flock && !local_fcntl)
490 seq_puts(m, ",local_lock=none");
491 else if (local_flock && local_fcntl)
492 seq_puts(m, ",local_lock=all");
493 else if (local_flock)
494 seq_puts(m, ",local_lock=flock");
495 else
496 seq_puts(m, ",local_lock=posix");
497}
498
499/*
500 * Describe the mount options on this VFS mountpoint
501 */
502int nfs_show_options(struct seq_file *m, struct dentry *root)
503{
504 struct nfs_server *nfss = NFS_SB(root->d_sb);
505
506 nfs_show_mount_options(m, nfss, 0);
507
508 rcu_read_lock();
509 seq_printf(m, ",addr=%s",
510 rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
511 RPC_DISPLAY_ADDR));
512 rcu_read_unlock();
513
514 return 0;
515}
516EXPORT_SYMBOL_GPL(nfs_show_options);
517
518#if IS_ENABLED(CONFIG_NFS_V4)
519static void show_lease(struct seq_file *m, struct nfs_server *server)
520{
521 struct nfs_client *clp = server->nfs_client;
522 unsigned long expire;
523
524 seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
525 expire = clp->cl_last_renewal + clp->cl_lease_time;
526 seq_printf(m, ",lease_expired=%ld",
527 time_after(expire, jiffies) ? 0 : (jiffies - expire) / HZ);
528}
529#ifdef CONFIG_NFS_V4_1
530static void show_sessions(struct seq_file *m, struct nfs_server *server)
531{
532 if (nfs4_has_session(server->nfs_client))
533 seq_puts(m, ",sessions");
534}
535#else
536static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
537#endif
538#endif
539
540#ifdef CONFIG_NFS_V4_1
541static void show_pnfs(struct seq_file *m, struct nfs_server *server)
542{
543 seq_printf(m, ",pnfs=");
544 if (server->pnfs_curr_ld)
545 seq_printf(m, "%s", server->pnfs_curr_ld->name);
546 else
547 seq_printf(m, "not configured");
548}
549
550static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
551{
552 if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
553 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
554 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
555 "date='%llu,%u'",
556 impl_id->name, impl_id->domain,
557 impl_id->date.seconds, impl_id->date.nseconds);
558 }
559}
560#else
561#if IS_ENABLED(CONFIG_NFS_V4)
562static void show_pnfs(struct seq_file *m, struct nfs_server *server)
563{
564}
565#endif
566static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
567{
568}
569#endif
570
571int nfs_show_devname(struct seq_file *m, struct dentry *root)
572{
573 char *page = (char *) __get_free_page(GFP_KERNEL);
574 char *devname, *dummy;
575 int err = 0;
576 if (!page)
577 return -ENOMEM;
578 devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
579 if (IS_ERR(devname))
580 err = PTR_ERR(devname);
581 else
582 seq_escape(m, devname, " \t\n\\");
583 free_page((unsigned long)page);
584 return err;
585}
586EXPORT_SYMBOL_GPL(nfs_show_devname);
587
588int nfs_show_path(struct seq_file *m, struct dentry *dentry)
589{
590 seq_puts(m, "/");
591 return 0;
592}
593EXPORT_SYMBOL_GPL(nfs_show_path);
594
595/*
596 * Present statistical information for this VFS mountpoint
597 */
598int nfs_show_stats(struct seq_file *m, struct dentry *root)
599{
600 int i, cpu;
601 struct nfs_server *nfss = NFS_SB(root->d_sb);
602 struct rpc_auth *auth = nfss->client->cl_auth;
603 struct nfs_iostats totals = { };
604
605 seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
606
607 /*
608 * Display all mount option settings
609 */
610 seq_puts(m, "\n\topts:\t");
611 seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
612 seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
613 seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
614 seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
615 nfs_show_mount_options(m, nfss, 1);
616
617 seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
618
619 show_implementation_id(m, nfss);
620
621 seq_puts(m, "\n\tcaps:\t");
622 seq_printf(m, "caps=0x%x", nfss->caps);
623 seq_printf(m, ",wtmult=%u", nfss->wtmult);
624 seq_printf(m, ",dtsize=%u", nfss->dtsize);
625 seq_printf(m, ",bsize=%u", nfss->bsize);
626 seq_printf(m, ",namlen=%u", nfss->namelen);
627
628#if IS_ENABLED(CONFIG_NFS_V4)
629 if (nfss->nfs_client->rpc_ops->version == 4) {
630 seq_puts(m, "\n\tnfsv4:\t");
631 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
632 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
633 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
634 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
635 show_sessions(m, nfss);
636 show_pnfs(m, nfss);
637 show_lease(m, nfss);
638 }
639#endif
640
641 /*
642 * Display security flavor in effect for this mount
643 */
644 seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
645 if (auth->au_flavor)
646 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
647
648 /*
649 * Display superblock I/O counters
650 */
651 for_each_possible_cpu(cpu) {
652 struct nfs_iostats *stats;
653
654 preempt_disable();
655 stats = per_cpu_ptr(nfss->io_stats, cpu);
656
657 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
658 totals.events[i] += stats->events[i];
659 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
660 totals.bytes[i] += stats->bytes[i];
661#ifdef CONFIG_NFS_FSCACHE
662 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
663 totals.fscache[i] += stats->fscache[i];
664#endif
665
666 preempt_enable();
667 }
668
669 seq_puts(m, "\n\tevents:\t");
670 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
671 seq_printf(m, "%lu ", totals.events[i]);
672 seq_puts(m, "\n\tbytes:\t");
673 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
674 seq_printf(m, "%Lu ", totals.bytes[i]);
675#ifdef CONFIG_NFS_FSCACHE
676 if (nfss->options & NFS_OPTION_FSCACHE) {
677 seq_puts(m, "\n\tfsc:\t");
678 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
679 seq_printf(m, "%Lu ", totals.fscache[i]);
680 }
681#endif
682 seq_putc(m, '\n');
683
684 rpc_clnt_show_stats(m, nfss->client);
685
686 return 0;
687}
688EXPORT_SYMBOL_GPL(nfs_show_stats);
689
690/*
691 * Begin unmount by attempting to remove all automounted mountpoints we added
692 * in response to xdev traversals and referrals
693 */
694void nfs_umount_begin(struct super_block *sb)
695{
696 struct nfs_server *server;
697 struct rpc_clnt *rpc;
698
699 server = NFS_SB(sb);
700 /* -EIO all pending I/O */
701 rpc = server->client_acl;
702 if (!IS_ERR(rpc))
703 rpc_killall_tasks(rpc);
704 rpc = server->client;
705 if (!IS_ERR(rpc))
706 rpc_killall_tasks(rpc);
707}
708EXPORT_SYMBOL_GPL(nfs_umount_begin);
709
710/*
711 * Return true if 'match' is in auth_info or auth_info is empty.
712 * Return false otherwise.
713 */
714bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
715 rpc_authflavor_t match)
716{
717 int i;
718
719 if (!auth_info->flavor_len)
720 return true;
721
722 for (i = 0; i < auth_info->flavor_len; i++) {
723 if (auth_info->flavors[i] == match)
724 return true;
725 }
726 return false;
727}
728EXPORT_SYMBOL_GPL(nfs_auth_info_match);
729
730/*
731 * Ensure that a specified authtype in ctx->auth_info is supported by
732 * the server. Returns 0 and sets ctx->selected_flavor if it's ok, and
733 * -EACCES if not.
734 */
735static int nfs_verify_authflavors(struct nfs_fs_context *ctx,
736 rpc_authflavor_t *server_authlist,
737 unsigned int count)
738{
739 rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
740 bool found_auth_null = false;
741 unsigned int i;
742
743 /*
744 * If the sec= mount option is used, the specified flavor or AUTH_NULL
745 * must be in the list returned by the server.
746 *
747 * AUTH_NULL has a special meaning when it's in the server list - it
748 * means that the server will ignore the rpc creds, so any flavor
749 * can be used but still use the sec= that was specified.
750 *
751 * Note also that the MNT procedure in MNTv1 does not return a list
752 * of supported security flavors. In this case, nfs_mount() fabricates
753 * a security flavor list containing just AUTH_NULL.
754 */
755 for (i = 0; i < count; i++) {
756 flavor = server_authlist[i];
757
758 if (nfs_auth_info_match(&ctx->auth_info, flavor))
759 goto out;
760
761 if (flavor == RPC_AUTH_NULL)
762 found_auth_null = true;
763 }
764
765 if (found_auth_null) {
766 flavor = ctx->auth_info.flavors[0];
767 goto out;
768 }
769
770 dfprintk(MOUNT,
771 "NFS: specified auth flavors not supported by server\n");
772 return -EACCES;
773
774out:
775 ctx->selected_flavor = flavor;
776 dfprintk(MOUNT, "NFS: using auth flavor %u\n", ctx->selected_flavor);
777 return 0;
778}
779
780/*
781 * Use the remote server's MOUNT service to request the NFS file handle
782 * corresponding to the provided path.
783 */
784static int nfs_request_mount(struct fs_context *fc,
785 struct nfs_fh *root_fh,
786 rpc_authflavor_t *server_authlist,
787 unsigned int *server_authlist_len)
788{
789 struct nfs_fs_context *ctx = nfs_fc2context(fc);
790 struct nfs_mount_request request = {
791 .sap = (struct sockaddr *)
792 &ctx->mount_server.address,
793 .dirpath = ctx->nfs_server.export_path,
794 .protocol = ctx->mount_server.protocol,
795 .fh = root_fh,
796 .noresvport = ctx->flags & NFS_MOUNT_NORESVPORT,
797 .auth_flav_len = server_authlist_len,
798 .auth_flavs = server_authlist,
799 .net = fc->net_ns,
800 };
801 int status;
802
803 if (ctx->mount_server.version == 0) {
804 switch (ctx->version) {
805 default:
806 ctx->mount_server.version = NFS_MNT3_VERSION;
807 break;
808 case 2:
809 ctx->mount_server.version = NFS_MNT_VERSION;
810 }
811 }
812 request.version = ctx->mount_server.version;
813
814 if (ctx->mount_server.hostname)
815 request.hostname = ctx->mount_server.hostname;
816 else
817 request.hostname = ctx->nfs_server.hostname;
818
819 /*
820 * Construct the mount server's address.
821 */
822 if (ctx->mount_server.address.sa_family == AF_UNSPEC) {
823 memcpy(request.sap, &ctx->nfs_server.address,
824 ctx->nfs_server.addrlen);
825 ctx->mount_server.addrlen = ctx->nfs_server.addrlen;
826 }
827 request.salen = ctx->mount_server.addrlen;
828 nfs_set_port(request.sap, &ctx->mount_server.port, 0);
829
830 /*
831 * Now ask the mount server to map our export path
832 * to a file handle.
833 */
834 status = nfs_mount(&request);
835 if (status != 0) {
836 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
837 request.hostname, status);
838 return status;
839 }
840
841 return 0;
842}
843
844static struct nfs_server *nfs_try_mount_request(struct fs_context *fc)
845{
846 struct nfs_fs_context *ctx = nfs_fc2context(fc);
847 int status;
848 unsigned int i;
849 bool tried_auth_unix = false;
850 bool auth_null_in_list = false;
851 struct nfs_server *server = ERR_PTR(-EACCES);
852 rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
853 unsigned int authlist_len = ARRAY_SIZE(authlist);
854
855 status = nfs_request_mount(fc, ctx->mntfh, authlist, &authlist_len);
856 if (status)
857 return ERR_PTR(status);
858
859 /*
860 * Was a sec= authflavor specified in the options? First, verify
861 * whether the server supports it, and then just try to use it if so.
862 */
863 if (ctx->auth_info.flavor_len > 0) {
864 status = nfs_verify_authflavors(ctx, authlist, authlist_len);
865 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
866 ctx->selected_flavor);
867 if (status)
868 return ERR_PTR(status);
869 return ctx->nfs_mod->rpc_ops->create_server(fc);
870 }
871
872 /*
873 * No sec= option was provided. RFC 2623, section 2.7 suggests we
874 * SHOULD prefer the flavor listed first. However, some servers list
875 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
876 */
877 for (i = 0; i < authlist_len; ++i) {
878 rpc_authflavor_t flavor;
879 struct rpcsec_gss_info info;
880
881 flavor = authlist[i];
882 switch (flavor) {
883 case RPC_AUTH_UNIX:
884 tried_auth_unix = true;
885 break;
886 case RPC_AUTH_NULL:
887 auth_null_in_list = true;
888 continue;
889 default:
890 if (rpcauth_get_gssinfo(flavor, &info) != 0)
891 continue;
892 /* Fallthrough */
893 }
894 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
895 ctx->selected_flavor = flavor;
896 server = ctx->nfs_mod->rpc_ops->create_server(fc);
897 if (!IS_ERR(server))
898 return server;
899 }
900
901 /*
902 * Nothing we tried so far worked. At this point, give up if we've
903 * already tried AUTH_UNIX or if the server's list doesn't contain
904 * AUTH_NULL
905 */
906 if (tried_auth_unix || !auth_null_in_list)
907 return server;
908
909 /* Last chance! Try AUTH_UNIX */
910 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
911 ctx->selected_flavor = RPC_AUTH_UNIX;
912 return ctx->nfs_mod->rpc_ops->create_server(fc);
913}
914
915int nfs_try_get_tree(struct fs_context *fc)
916{
917 struct nfs_fs_context *ctx = nfs_fc2context(fc);
918
919 if (ctx->need_mount)
920 ctx->server = nfs_try_mount_request(fc);
921 else
922 ctx->server = ctx->nfs_mod->rpc_ops->create_server(fc);
923
924 return nfs_get_tree_common(fc);
925}
926EXPORT_SYMBOL_GPL(nfs_try_get_tree);
927
928
929#define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
930 | NFS_MOUNT_SECURE \
931 | NFS_MOUNT_TCP \
932 | NFS_MOUNT_VER3 \
933 | NFS_MOUNT_KERBEROS \
934 | NFS_MOUNT_NONLM \
935 | NFS_MOUNT_BROKEN_SUID \
936 | NFS_MOUNT_STRICTLOCK \
937 | NFS_MOUNT_LEGACY_INTERFACE)
938
939#define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
940 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
941
942static int
943nfs_compare_remount_data(struct nfs_server *nfss,
944 struct nfs_fs_context *ctx)
945{
946 if ((ctx->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
947 ctx->rsize != nfss->rsize ||
948 ctx->wsize != nfss->wsize ||
949 ctx->version != nfss->nfs_client->rpc_ops->version ||
950 ctx->minorversion != nfss->nfs_client->cl_minorversion ||
951 ctx->retrans != nfss->client->cl_timeout->to_retries ||
952 !nfs_auth_info_match(&ctx->auth_info, nfss->client->cl_auth->au_flavor) ||
953 ctx->acregmin != nfss->acregmin / HZ ||
954 ctx->acregmax != nfss->acregmax / HZ ||
955 ctx->acdirmin != nfss->acdirmin / HZ ||
956 ctx->acdirmax != nfss->acdirmax / HZ ||
957 ctx->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
958 (ctx->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
959 ctx->nfs_server.port != nfss->port ||
960 ctx->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
961 !rpc_cmp_addr((struct sockaddr *)&ctx->nfs_server.address,
962 (struct sockaddr *)&nfss->nfs_client->cl_addr))
963 return -EINVAL;
964
965 return 0;
966}
967
968int nfs_reconfigure(struct fs_context *fc)
969{
970 struct nfs_fs_context *ctx = nfs_fc2context(fc);
971 struct super_block *sb = fc->root->d_sb;
972 struct nfs_server *nfss = sb->s_fs_info;
973
974 sync_filesystem(sb);
975
976 /*
977 * Userspace mount programs that send binary options generally send
978 * them populated with default values. We have no way to know which
979 * ones were explicitly specified. Fall back to legacy behavior and
980 * just return success.
981 */
982 if (ctx->skip_reconfig_option_check)
983 return 0;
984
985 /*
986 * noac is a special case. It implies -o sync, but that's not
987 * necessarily reflected in the mtab options. reconfigure_super
988 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
989 * remount options, so we have to explicitly reset it.
990 */
991 if (ctx->flags & NFS_MOUNT_NOAC) {
992 fc->sb_flags |= SB_SYNCHRONOUS;
993 fc->sb_flags_mask |= SB_SYNCHRONOUS;
994 }
995
996 /* compare new mount options with old ones */
997 return nfs_compare_remount_data(nfss, ctx);
998}
999EXPORT_SYMBOL_GPL(nfs_reconfigure);
1000
1001/*
1002 * Finish setting up an NFS superblock
1003 */
1004static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx)
1005{
1006 struct nfs_server *server = NFS_SB(sb);
1007
1008 sb->s_blocksize_bits = 0;
1009 sb->s_blocksize = 0;
1010 sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
1011 sb->s_op = server->nfs_client->cl_nfs_mod->sops;
1012 if (ctx && ctx->bsize)
1013 sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits);
1014
1015 if (server->nfs_client->rpc_ops->version != 2) {
1016 /* The VFS shouldn't apply the umask to mode bits. We will do
1017 * so ourselves when necessary.
1018 */
1019 sb->s_flags |= SB_POSIXACL;
1020 sb->s_time_gran = 1;
1021 sb->s_export_op = &nfs_export_ops;
1022 } else
1023 sb->s_time_gran = 1000;
1024
1025 if (server->nfs_client->rpc_ops->version != 4) {
1026 sb->s_time_min = 0;
1027 sb->s_time_max = U32_MAX;
1028 } else {
1029 sb->s_time_min = S64_MIN;
1030 sb->s_time_max = S64_MAX;
1031 }
1032
1033 sb->s_magic = NFS_SUPER_MAGIC;
1034
1035 /* We probably want something more informative here */
1036 snprintf(sb->s_id, sizeof(sb->s_id),
1037 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1038
1039 if (sb->s_blocksize == 0)
1040 sb->s_blocksize = nfs_block_bits(server->wsize,
1041 &sb->s_blocksize_bits);
1042
1043 nfs_super_set_maxbytes(sb, server->maxfilesize);
1044}
1045
1046static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b,
1047 const struct fs_context *fc)
1048{
1049 const struct nfs_server *a = s->s_fs_info;
1050 const struct rpc_clnt *clnt_a = a->client;
1051 const struct rpc_clnt *clnt_b = b->client;
1052
1053 if ((s->s_flags & NFS_SB_MASK) != (fc->sb_flags & NFS_SB_MASK))
1054 goto Ebusy;
1055 if (a->nfs_client != b->nfs_client)
1056 goto Ebusy;
1057 if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
1058 goto Ebusy;
1059 if (a->wsize != b->wsize)
1060 goto Ebusy;
1061 if (a->rsize != b->rsize)
1062 goto Ebusy;
1063 if (a->acregmin != b->acregmin)
1064 goto Ebusy;
1065 if (a->acregmax != b->acregmax)
1066 goto Ebusy;
1067 if (a->acdirmin != b->acdirmin)
1068 goto Ebusy;
1069 if (a->acdirmax != b->acdirmax)
1070 goto Ebusy;
1071 if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1072 goto Ebusy;
1073 return 1;
1074Ebusy:
1075 return 0;
1076}
1077
1078static int nfs_set_super(struct super_block *s, struct fs_context *fc)
1079{
1080 struct nfs_server *server = fc->s_fs_info;
1081 int ret;
1082
1083 s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
1084 ret = set_anon_super(s, server);
1085 if (ret == 0)
1086 server->s_dev = s->s_dev;
1087 return ret;
1088}
1089
1090static int nfs_compare_super_address(struct nfs_server *server1,
1091 struct nfs_server *server2)
1092{
1093 struct sockaddr *sap1, *sap2;
1094 struct rpc_xprt *xprt1 = server1->client->cl_xprt;
1095 struct rpc_xprt *xprt2 = server2->client->cl_xprt;
1096
1097 if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
1098 return 0;
1099
1100 sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1101 sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1102
1103 if (sap1->sa_family != sap2->sa_family)
1104 return 0;
1105
1106 switch (sap1->sa_family) {
1107 case AF_INET: {
1108 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1109 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1110 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1111 return 0;
1112 if (sin1->sin_port != sin2->sin_port)
1113 return 0;
1114 break;
1115 }
1116 case AF_INET6: {
1117 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1118 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1119 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1120 return 0;
1121 if (sin1->sin6_port != sin2->sin6_port)
1122 return 0;
1123 break;
1124 }
1125 default:
1126 return 0;
1127 }
1128
1129 return 1;
1130}
1131
1132static int nfs_compare_userns(const struct nfs_server *old,
1133 const struct nfs_server *new)
1134{
1135 const struct user_namespace *oldns = &init_user_ns;
1136 const struct user_namespace *newns = &init_user_ns;
1137
1138 if (old->client && old->client->cl_cred)
1139 oldns = old->client->cl_cred->user_ns;
1140 if (new->client && new->client->cl_cred)
1141 newns = new->client->cl_cred->user_ns;
1142 if (oldns != newns)
1143 return 0;
1144 return 1;
1145}
1146
1147static int nfs_compare_super(struct super_block *sb, struct fs_context *fc)
1148{
1149 struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb);
1150
1151 if (!nfs_compare_super_address(old, server))
1152 return 0;
1153 /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1154 if (old->flags & NFS_MOUNT_UNSHARED)
1155 return 0;
1156 if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1157 return 0;
1158 if (!nfs_compare_userns(old, server))
1159 return 0;
1160 return nfs_compare_mount_options(sb, server, fc);
1161}
1162
1163#ifdef CONFIG_NFS_FSCACHE
1164static void nfs_get_cache_cookie(struct super_block *sb,
1165 struct nfs_fs_context *ctx)
1166{
1167 struct nfs_server *nfss = NFS_SB(sb);
1168 char *uniq = NULL;
1169 int ulen = 0;
1170
1171 nfss->fscache_key = NULL;
1172 nfss->fscache = NULL;
1173
1174 if (!ctx)
1175 return;
1176
1177 if (ctx->clone_data.sb) {
1178 struct nfs_server *mnt_s = NFS_SB(ctx->clone_data.sb);
1179 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
1180 return;
1181 if (mnt_s->fscache_key) {
1182 uniq = mnt_s->fscache_key->key.uniquifier;
1183 ulen = mnt_s->fscache_key->key.uniq_len;
1184 }
1185 } else {
1186 if (!(ctx->options & NFS_OPTION_FSCACHE))
1187 return;
1188 if (ctx->fscache_uniq) {
1189 uniq = ctx->fscache_uniq;
1190 ulen = strlen(ctx->fscache_uniq);
1191 }
1192 }
1193
1194 nfs_fscache_get_super_cookie(sb, uniq, ulen);
1195}
1196#else
1197static void nfs_get_cache_cookie(struct super_block *sb,
1198 struct nfs_fs_context *ctx)
1199{
1200}
1201#endif
1202
1203static void nfs_set_readahead(struct backing_dev_info *bdi,
1204 unsigned long iomax_pages)
1205{
1206 bdi->ra_pages = VM_READAHEAD_PAGES;
1207 bdi->io_pages = iomax_pages;
1208}
1209
1210int nfs_get_tree_common(struct fs_context *fc)
1211{
1212 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1213 struct super_block *s;
1214 int (*compare_super)(struct super_block *, struct fs_context *) = nfs_compare_super;
1215 struct nfs_server *server = ctx->server;
1216 int error;
1217
1218 ctx->server = NULL;
1219 if (IS_ERR(server))
1220 return PTR_ERR(server);
1221
1222 if (server->flags & NFS_MOUNT_UNSHARED)
1223 compare_super = NULL;
1224
1225 /* -o noac implies -o sync */
1226 if (server->flags & NFS_MOUNT_NOAC)
1227 fc->sb_flags |= SB_SYNCHRONOUS;
1228
1229 if (ctx->clone_data.sb)
1230 if (ctx->clone_data.sb->s_flags & SB_SYNCHRONOUS)
1231 fc->sb_flags |= SB_SYNCHRONOUS;
1232
1233 if (server->caps & NFS_CAP_SECURITY_LABEL)
1234 fc->lsm_flags |= SECURITY_LSM_NATIVE_LABELS;
1235
1236 /* Get a superblock - note that we may end up sharing one that already exists */
1237 fc->s_fs_info = server;
1238 s = sget_fc(fc, compare_super, nfs_set_super);
1239 fc->s_fs_info = NULL;
1240 if (IS_ERR(s)) {
1241 error = PTR_ERR(s);
1242 nfs_errorf(fc, "NFS: Couldn't get superblock");
1243 goto out_err_nosb;
1244 }
1245
1246 if (s->s_fs_info != server) {
1247 nfs_free_server(server);
1248 server = NULL;
1249 } else {
1250 error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
1251 MINOR(server->s_dev));
1252 if (error)
1253 goto error_splat_super;
1254 nfs_set_readahead(s->s_bdi, server->rpages);
1255 server->super = s;
1256 }
1257
1258 if (!s->s_root) {
1259 unsigned bsize = ctx->clone_data.inherited_bsize;
1260 /* initial superblock/root creation */
1261 nfs_fill_super(s, ctx);
1262 if (bsize) {
1263 s->s_blocksize_bits = bsize;
1264 s->s_blocksize = 1U << bsize;
1265 }
1266 nfs_get_cache_cookie(s, ctx);
1267 }
1268
1269 error = nfs_get_root(s, fc);
1270 if (error < 0) {
1271 nfs_errorf(fc, "NFS: Couldn't get root dentry");
1272 goto error_splat_super;
1273 }
1274
1275 s->s_flags |= SB_ACTIVE;
1276 error = 0;
1277
1278out:
1279 return error;
1280
1281out_err_nosb:
1282 nfs_free_server(server);
1283 goto out;
1284error_splat_super:
1285 deactivate_locked_super(s);
1286 goto out;
1287}
1288
1289/*
1290 * Destroy an NFS2/3 superblock
1291 */
1292void nfs_kill_super(struct super_block *s)
1293{
1294 struct nfs_server *server = NFS_SB(s);
1295 dev_t dev = s->s_dev;
1296
1297 generic_shutdown_super(s);
1298
1299 nfs_fscache_release_super_cookie(s);
1300
1301 nfs_free_server(server);
1302 free_anon_bdev(dev);
1303}
1304EXPORT_SYMBOL_GPL(nfs_kill_super);
1305
1306#if IS_ENABLED(CONFIG_NFS_V4)
1307
1308/*
1309 * NFS v4 module parameters need to stay in the
1310 * NFS client for backwards compatibility
1311 */
1312unsigned int nfs_callback_set_tcpport;
1313unsigned short nfs_callback_nr_threads;
1314/* Default cache timeout is 10 minutes */
1315unsigned int nfs_idmap_cache_timeout = 600;
1316/* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
1317bool nfs4_disable_idmapping = true;
1318unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
1319unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
1320unsigned short send_implementation_id = 1;
1321char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
1322bool recover_lost_locks = false;
1323
1324EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
1325EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
1326EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
1327EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
1328EXPORT_SYMBOL_GPL(max_session_slots);
1329EXPORT_SYMBOL_GPL(max_session_cb_slots);
1330EXPORT_SYMBOL_GPL(send_implementation_id);
1331EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
1332EXPORT_SYMBOL_GPL(recover_lost_locks);
1333
1334#define NFS_CALLBACK_MAXPORTNR (65535U)
1335
1336static int param_set_portnr(const char *val, const struct kernel_param *kp)
1337{
1338 unsigned long num;
1339 int ret;
1340
1341 if (!val)
1342 return -EINVAL;
1343 ret = kstrtoul(val, 0, &num);
1344 if (ret || num > NFS_CALLBACK_MAXPORTNR)
1345 return -EINVAL;
1346 *((unsigned int *)kp->arg) = num;
1347 return 0;
1348}
1349static const struct kernel_param_ops param_ops_portnr = {
1350 .set = param_set_portnr,
1351 .get = param_get_uint,
1352};
1353#define param_check_portnr(name, p) __param_check(name, p, unsigned int);
1354
1355module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
1356module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
1357MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
1358 "assigned to the NFSv4 callback channels.");
1359module_param(nfs_idmap_cache_timeout, int, 0644);
1360module_param(nfs4_disable_idmapping, bool, 0644);
1361module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
1362 NFS4_CLIENT_ID_UNIQ_LEN, 0600);
1363MODULE_PARM_DESC(nfs4_disable_idmapping,
1364 "Turn off NFSv4 idmapping when using 'sec=sys'");
1365module_param(max_session_slots, ushort, 0644);
1366MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
1367 "requests the client will negotiate");
1368module_param(max_session_cb_slots, ushort, 0644);
1369MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
1370 "callbacks the client will process for a given server");
1371module_param(send_implementation_id, ushort, 0644);
1372MODULE_PARM_DESC(send_implementation_id,
1373 "Send implementation ID with NFSv4.1 exchange_id");
1374MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
1375
1376module_param(recover_lost_locks, bool, 0644);
1377MODULE_PARM_DESC(recover_lost_locks,
1378 "If the server reports that a lock might be lost, "
1379 "try to recover it risking data corruption.");
1380
1381
1382#endif /* CONFIG_NFS_V4 */
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
78const 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};
91EXPORT_SYMBOL_GPL(nfs_sops);
92
93#ifdef CONFIG_NFS_V4_2
94static 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)
100static int __init register_nfs4_fs(void)
101{
102 return register_filesystem(&nfs4_fs_type);
103}
104
105static void unregister_nfs4_fs(void)
106{
107 unregister_filesystem(&nfs4_fs_type);
108}
109#else
110static int __init register_nfs4_fs(void)
111{
112 return 0;
113}
114
115static void unregister_nfs4_fs(void)
116{
117}
118#endif
119
120#ifdef CONFIG_NFS_V4_2
121static void nfs_ssc_register_ops(void)
122{
123 nfs_ssc_register(&nfs_ssc_clnt_ops_tbl);
124}
125
126static void nfs_ssc_unregister_ops(void)
127{
128 nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl);
129}
130#endif /* CONFIG_NFS_V4_2 */
131
132static struct shrinker *acl_shrinker;
133
134/*
135 * Register the NFS filesystems
136 */
137int __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;
168error_3:
169 nfs_unregister_sysctl();
170error_2:
171 unregister_nfs4_fs();
172error_1:
173 unregister_filesystem(&nfs_fs_type);
174error_0:
175 return ret;
176}
177
178/*
179 * Unregister the NFS filesystems
180 */
181void __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
192bool 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}
202EXPORT_SYMBOL_GPL(nfs_sb_active);
203
204void 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}
211EXPORT_SYMBOL_GPL(nfs_sb_deactive);
212
213static 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();
234out:
235 if (last)
236 nfs_sb_deactive(last->super);
237 return ret;
238}
239
240int 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}
246EXPORT_SYMBOL_GPL(nfs_client_for_each_server);
247
248/*
249 * Deliver file system statistics to userspace
250 */
251int 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}
310EXPORT_SYMBOL_GPL(nfs_statfs);
311
312/*
313 * Map the security flavour number to a name
314 */
315static 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
344static 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
376static 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)
411static 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
419static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
420 int showdefaults)
421{
422}
423#endif
424
425static 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 */
437static 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 seq_puts(m, ",fsc");
521
522 if (nfss->options & NFS_OPTION_MIGRATION)
523 seq_puts(m, ",migration");
524
525 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
526 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
527 seq_puts(m, ",lookupcache=none");
528 else
529 seq_puts(m, ",lookupcache=pos");
530 }
531
532 local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
533 local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
534
535 if (!local_flock && !local_fcntl)
536 seq_puts(m, ",local_lock=none");
537 else if (local_flock && local_fcntl)
538 seq_puts(m, ",local_lock=all");
539 else if (local_flock)
540 seq_puts(m, ",local_lock=flock");
541 else
542 seq_puts(m, ",local_lock=posix");
543
544 if (nfss->flags & NFS_MOUNT_WRITE_EAGER) {
545 if (nfss->flags & NFS_MOUNT_WRITE_WAIT)
546 seq_puts(m, ",write=wait");
547 else
548 seq_puts(m, ",write=eager");
549 }
550}
551
552/*
553 * Describe the mount options on this VFS mountpoint
554 */
555int nfs_show_options(struct seq_file *m, struct dentry *root)
556{
557 struct nfs_server *nfss = NFS_SB(root->d_sb);
558
559 nfs_show_mount_options(m, nfss, 0);
560
561 rcu_read_lock();
562 seq_printf(m, ",addr=%s",
563 rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
564 RPC_DISPLAY_ADDR));
565 rcu_read_unlock();
566
567 return 0;
568}
569EXPORT_SYMBOL_GPL(nfs_show_options);
570
571#if IS_ENABLED(CONFIG_NFS_V4)
572static void show_lease(struct seq_file *m, struct nfs_server *server)
573{
574 struct nfs_client *clp = server->nfs_client;
575 unsigned long expire;
576
577 seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
578 expire = clp->cl_last_renewal + clp->cl_lease_time;
579 seq_printf(m, ",lease_expired=%ld",
580 time_after(expire, jiffies) ? 0 : (jiffies - expire) / HZ);
581}
582#ifdef CONFIG_NFS_V4_1
583static void show_sessions(struct seq_file *m, struct nfs_server *server)
584{
585 if (nfs4_has_session(server->nfs_client))
586 seq_puts(m, ",sessions");
587}
588#else
589static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
590#endif
591#endif
592
593#ifdef CONFIG_NFS_V4_1
594static void show_pnfs(struct seq_file *m, struct nfs_server *server)
595{
596 seq_printf(m, ",pnfs=");
597 if (server->pnfs_curr_ld)
598 seq_printf(m, "%s", server->pnfs_curr_ld->name);
599 else
600 seq_printf(m, "not configured");
601}
602
603static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
604{
605 if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
606 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
607 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
608 "date='%llu,%u'",
609 impl_id->name, impl_id->domain,
610 impl_id->date.seconds, impl_id->date.nseconds);
611 }
612}
613#else
614#if IS_ENABLED(CONFIG_NFS_V4)
615static void show_pnfs(struct seq_file *m, struct nfs_server *server)
616{
617}
618#endif
619static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
620{
621}
622#endif
623
624int nfs_show_devname(struct seq_file *m, struct dentry *root)
625{
626 char *page = (char *) __get_free_page(GFP_KERNEL);
627 char *devname, *dummy;
628 int err = 0;
629 if (!page)
630 return -ENOMEM;
631 devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
632 if (IS_ERR(devname))
633 err = PTR_ERR(devname);
634 else
635 seq_escape(m, devname, " \t\n\\");
636 free_page((unsigned long)page);
637 return err;
638}
639EXPORT_SYMBOL_GPL(nfs_show_devname);
640
641int nfs_show_path(struct seq_file *m, struct dentry *dentry)
642{
643 seq_puts(m, "/");
644 return 0;
645}
646EXPORT_SYMBOL_GPL(nfs_show_path);
647
648/*
649 * Present statistical information for this VFS mountpoint
650 */
651int nfs_show_stats(struct seq_file *m, struct dentry *root)
652{
653 int i, cpu;
654 struct nfs_server *nfss = NFS_SB(root->d_sb);
655 struct rpc_auth *auth = nfss->client->cl_auth;
656 struct nfs_iostats totals = { };
657
658 seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
659
660 /*
661 * Display all mount option settings
662 */
663 seq_puts(m, "\n\topts:\t");
664 seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
665 seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
666 seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
667 seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
668 nfs_show_mount_options(m, nfss, 1);
669
670 seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
671
672 show_implementation_id(m, nfss);
673
674 seq_puts(m, "\n\tcaps:\t");
675 seq_printf(m, "caps=0x%x", nfss->caps);
676 seq_printf(m, ",wtmult=%u", nfss->wtmult);
677 seq_printf(m, ",dtsize=%u", nfss->dtsize);
678 seq_printf(m, ",bsize=%u", nfss->bsize);
679 seq_printf(m, ",namlen=%u", nfss->namelen);
680
681#if IS_ENABLED(CONFIG_NFS_V4)
682 if (nfss->nfs_client->rpc_ops->version == 4) {
683 seq_puts(m, "\n\tnfsv4:\t");
684 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
685 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
686 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
687 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
688 show_sessions(m, nfss);
689 show_pnfs(m, nfss);
690 show_lease(m, nfss);
691 }
692#endif
693
694 /*
695 * Display security flavor in effect for this mount
696 */
697 seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
698 if (auth->au_flavor)
699 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
700
701 /*
702 * Display superblock I/O counters
703 */
704 for_each_possible_cpu(cpu) {
705 struct nfs_iostats *stats;
706
707 preempt_disable();
708 stats = per_cpu_ptr(nfss->io_stats, cpu);
709
710 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
711 totals.events[i] += stats->events[i];
712 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
713 totals.bytes[i] += stats->bytes[i];
714
715 preempt_enable();
716 }
717
718 seq_puts(m, "\n\tevents:\t");
719 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
720 seq_printf(m, "%lu ", totals.events[i]);
721 seq_puts(m, "\n\tbytes:\t");
722 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
723 seq_printf(m, "%Lu ", totals.bytes[i]);
724 seq_putc(m, '\n');
725
726 rpc_clnt_show_stats(m, nfss->client);
727
728 return 0;
729}
730EXPORT_SYMBOL_GPL(nfs_show_stats);
731
732/*
733 * Begin unmount by attempting to remove all automounted mountpoints we added
734 * in response to xdev traversals and referrals
735 */
736void nfs_umount_begin(struct super_block *sb)
737{
738 struct nfs_server *server;
739 struct rpc_clnt *rpc;
740
741 server = NFS_SB(sb);
742 /* -EIO all pending I/O */
743 rpc = server->client_acl;
744 if (!IS_ERR(rpc))
745 rpc_killall_tasks(rpc);
746 rpc = server->client;
747 if (!IS_ERR(rpc))
748 rpc_killall_tasks(rpc);
749}
750EXPORT_SYMBOL_GPL(nfs_umount_begin);
751
752/*
753 * Return true if 'match' is in auth_info or auth_info is empty.
754 * Return false otherwise.
755 */
756bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
757 rpc_authflavor_t match)
758{
759 int i;
760
761 if (!auth_info->flavor_len)
762 return true;
763
764 for (i = 0; i < auth_info->flavor_len; i++) {
765 if (auth_info->flavors[i] == match)
766 return true;
767 }
768 return false;
769}
770EXPORT_SYMBOL_GPL(nfs_auth_info_match);
771
772/*
773 * Ensure that a specified authtype in ctx->auth_info is supported by
774 * the server. Returns 0 and sets ctx->selected_flavor if it's ok, and
775 * -EACCES if not.
776 */
777static int nfs_verify_authflavors(struct nfs_fs_context *ctx,
778 rpc_authflavor_t *server_authlist,
779 unsigned int count)
780{
781 rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
782 bool found_auth_null = false;
783 unsigned int i;
784
785 /*
786 * If the sec= mount option is used, the specified flavor or AUTH_NULL
787 * must be in the list returned by the server.
788 *
789 * AUTH_NULL has a special meaning when it's in the server list - it
790 * means that the server will ignore the rpc creds, so any flavor
791 * can be used but still use the sec= that was specified.
792 *
793 * Note also that the MNT procedure in MNTv1 does not return a list
794 * of supported security flavors. In this case, nfs_mount() fabricates
795 * a security flavor list containing just AUTH_NULL.
796 */
797 for (i = 0; i < count; i++) {
798 flavor = server_authlist[i];
799
800 if (nfs_auth_info_match(&ctx->auth_info, flavor))
801 goto out;
802
803 if (flavor == RPC_AUTH_NULL)
804 found_auth_null = true;
805 }
806
807 if (found_auth_null) {
808 flavor = ctx->auth_info.flavors[0];
809 goto out;
810 }
811
812 dfprintk(MOUNT,
813 "NFS: specified auth flavors not supported by server\n");
814 return -EACCES;
815
816out:
817 ctx->selected_flavor = flavor;
818 dfprintk(MOUNT, "NFS: using auth flavor %u\n", ctx->selected_flavor);
819 return 0;
820}
821
822/*
823 * Use the remote server's MOUNT service to request the NFS file handle
824 * corresponding to the provided path.
825 */
826static int nfs_request_mount(struct fs_context *fc,
827 struct nfs_fh *root_fh,
828 rpc_authflavor_t *server_authlist,
829 unsigned int *server_authlist_len)
830{
831 struct nfs_fs_context *ctx = nfs_fc2context(fc);
832 struct nfs_mount_request request = {
833 .sap = &ctx->mount_server._address,
834 .dirpath = ctx->nfs_server.export_path,
835 .protocol = ctx->mount_server.protocol,
836 .fh = root_fh,
837 .noresvport = ctx->flags & NFS_MOUNT_NORESVPORT,
838 .auth_flav_len = server_authlist_len,
839 .auth_flavs = server_authlist,
840 .net = fc->net_ns,
841 };
842 int status;
843
844 if (ctx->mount_server.version == 0) {
845 switch (ctx->version) {
846 default:
847 ctx->mount_server.version = NFS_MNT3_VERSION;
848 break;
849 case 2:
850 ctx->mount_server.version = NFS_MNT_VERSION;
851 }
852 }
853 request.version = ctx->mount_server.version;
854
855 if (ctx->mount_server.hostname)
856 request.hostname = ctx->mount_server.hostname;
857 else
858 request.hostname = ctx->nfs_server.hostname;
859
860 /*
861 * Construct the mount server's address.
862 */
863 if (ctx->mount_server.address.sa_family == AF_UNSPEC) {
864 memcpy(request.sap, &ctx->nfs_server._address,
865 ctx->nfs_server.addrlen);
866 ctx->mount_server.addrlen = ctx->nfs_server.addrlen;
867 }
868 request.salen = ctx->mount_server.addrlen;
869 nfs_set_port(request.sap, &ctx->mount_server.port, 0);
870
871 /*
872 * Now ask the mount server to map our export path
873 * to a file handle.
874 */
875 status = nfs_mount(&request, ctx->timeo, ctx->retrans);
876 if (status != 0) {
877 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
878 request.hostname, status);
879 return status;
880 }
881
882 return 0;
883}
884
885static struct nfs_server *nfs_try_mount_request(struct fs_context *fc)
886{
887 struct nfs_fs_context *ctx = nfs_fc2context(fc);
888 int status;
889 unsigned int i;
890 bool tried_auth_unix = false;
891 bool auth_null_in_list = false;
892 struct nfs_server *server = ERR_PTR(-EACCES);
893 rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
894 unsigned int authlist_len = ARRAY_SIZE(authlist);
895
896 status = nfs_request_mount(fc, ctx->mntfh, authlist, &authlist_len);
897 if (status)
898 return ERR_PTR(status);
899
900 /*
901 * Was a sec= authflavor specified in the options? First, verify
902 * whether the server supports it, and then just try to use it if so.
903 */
904 if (ctx->auth_info.flavor_len > 0) {
905 status = nfs_verify_authflavors(ctx, authlist, authlist_len);
906 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
907 ctx->selected_flavor);
908 if (status)
909 return ERR_PTR(status);
910 return ctx->nfs_mod->rpc_ops->create_server(fc);
911 }
912
913 /*
914 * No sec= option was provided. RFC 2623, section 2.7 suggests we
915 * SHOULD prefer the flavor listed first. However, some servers list
916 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
917 */
918 for (i = 0; i < authlist_len; ++i) {
919 rpc_authflavor_t flavor;
920 struct rpcsec_gss_info info;
921
922 flavor = authlist[i];
923 switch (flavor) {
924 case RPC_AUTH_UNIX:
925 tried_auth_unix = true;
926 break;
927 case RPC_AUTH_NULL:
928 auth_null_in_list = true;
929 continue;
930 default:
931 if (rpcauth_get_gssinfo(flavor, &info) != 0)
932 continue;
933 break;
934 }
935 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
936 ctx->selected_flavor = flavor;
937 server = ctx->nfs_mod->rpc_ops->create_server(fc);
938 if (!IS_ERR(server))
939 return server;
940 }
941
942 /*
943 * Nothing we tried so far worked. At this point, give up if we've
944 * already tried AUTH_UNIX or if the server's list doesn't contain
945 * AUTH_NULL
946 */
947 if (tried_auth_unix || !auth_null_in_list)
948 return server;
949
950 /* Last chance! Try AUTH_UNIX */
951 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
952 ctx->selected_flavor = RPC_AUTH_UNIX;
953 return ctx->nfs_mod->rpc_ops->create_server(fc);
954}
955
956int nfs_try_get_tree(struct fs_context *fc)
957{
958 struct nfs_fs_context *ctx = nfs_fc2context(fc);
959
960 if (ctx->need_mount)
961 ctx->server = nfs_try_mount_request(fc);
962 else
963 ctx->server = ctx->nfs_mod->rpc_ops->create_server(fc);
964
965 return nfs_get_tree_common(fc);
966}
967EXPORT_SYMBOL_GPL(nfs_try_get_tree);
968
969
970#define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
971 | NFS_MOUNT_SECURE \
972 | NFS_MOUNT_TCP \
973 | NFS_MOUNT_VER3 \
974 | NFS_MOUNT_KERBEROS \
975 | NFS_MOUNT_NONLM \
976 | NFS_MOUNT_BROKEN_SUID \
977 | NFS_MOUNT_STRICTLOCK \
978 | NFS_MOUNT_LEGACY_INTERFACE)
979
980#define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
981 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
982
983static int
984nfs_compare_remount_data(struct nfs_server *nfss,
985 struct nfs_fs_context *ctx)
986{
987 if ((ctx->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
988 ctx->rsize != nfss->rsize ||
989 ctx->wsize != nfss->wsize ||
990 ctx->version != nfss->nfs_client->rpc_ops->version ||
991 ctx->minorversion != nfss->nfs_client->cl_minorversion ||
992 ctx->retrans != nfss->client->cl_timeout->to_retries ||
993 !nfs_auth_info_match(&ctx->auth_info, nfss->client->cl_auth->au_flavor) ||
994 ctx->acregmin != nfss->acregmin / HZ ||
995 ctx->acregmax != nfss->acregmax / HZ ||
996 ctx->acdirmin != nfss->acdirmin / HZ ||
997 ctx->acdirmax != nfss->acdirmax / HZ ||
998 ctx->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
999 (ctx->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
1000 ctx->nfs_server.port != nfss->port ||
1001 ctx->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
1002 !rpc_cmp_addr((struct sockaddr *)&ctx->nfs_server.address,
1003 (struct sockaddr *)&nfss->nfs_client->cl_addr))
1004 return -EINVAL;
1005
1006 return 0;
1007}
1008
1009int nfs_reconfigure(struct fs_context *fc)
1010{
1011 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1012 struct super_block *sb = fc->root->d_sb;
1013 struct nfs_server *nfss = sb->s_fs_info;
1014 int ret;
1015
1016 sync_filesystem(sb);
1017
1018 /*
1019 * Userspace mount programs that send binary options generally send
1020 * them populated with default values. We have no way to know which
1021 * ones were explicitly specified. Fall back to legacy behavior and
1022 * just return success.
1023 */
1024 if (ctx->skip_reconfig_option_check)
1025 return 0;
1026
1027 /*
1028 * noac is a special case. It implies -o sync, but that's not
1029 * necessarily reflected in the mtab options. reconfigure_super
1030 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
1031 * remount options, so we have to explicitly reset it.
1032 */
1033 if (ctx->flags & NFS_MOUNT_NOAC) {
1034 fc->sb_flags |= SB_SYNCHRONOUS;
1035 fc->sb_flags_mask |= SB_SYNCHRONOUS;
1036 }
1037
1038 /* compare new mount options with old ones */
1039 ret = nfs_compare_remount_data(nfss, ctx);
1040 if (ret)
1041 return ret;
1042
1043 return nfs_probe_server(nfss, NFS_FH(d_inode(fc->root)));
1044}
1045EXPORT_SYMBOL_GPL(nfs_reconfigure);
1046
1047/*
1048 * Finish setting up an NFS superblock
1049 */
1050static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx)
1051{
1052 struct nfs_server *server = NFS_SB(sb);
1053
1054 sb->s_blocksize_bits = 0;
1055 sb->s_blocksize = 0;
1056 sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
1057 sb->s_op = server->nfs_client->cl_nfs_mod->sops;
1058 if (ctx->bsize)
1059 sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits);
1060
1061 switch (server->nfs_client->rpc_ops->version) {
1062 case 2:
1063 sb->s_time_gran = 1000;
1064 sb->s_time_min = 0;
1065 sb->s_time_max = U32_MAX;
1066 break;
1067 case 3:
1068 /*
1069 * The VFS shouldn't apply the umask to mode bits.
1070 * We will do so ourselves when necessary.
1071 */
1072 sb->s_flags |= SB_POSIXACL;
1073 sb->s_time_gran = 1;
1074 sb->s_time_min = 0;
1075 sb->s_time_max = U32_MAX;
1076 sb->s_export_op = &nfs_export_ops;
1077 break;
1078 case 4:
1079 sb->s_iflags |= SB_I_NOUMASK;
1080 sb->s_time_gran = 1;
1081 sb->s_time_min = S64_MIN;
1082 sb->s_time_max = S64_MAX;
1083 if (server->caps & NFS_CAP_ATOMIC_OPEN_V1)
1084 sb->s_export_op = &nfs_export_ops;
1085 break;
1086 }
1087
1088 sb->s_magic = NFS_SUPER_MAGIC;
1089
1090 /* We probably want something more informative here */
1091 snprintf(sb->s_id, sizeof(sb->s_id),
1092 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1093
1094 if (sb->s_blocksize == 0)
1095 sb->s_blocksize = nfs_block_bits(server->wsize,
1096 &sb->s_blocksize_bits);
1097
1098 nfs_super_set_maxbytes(sb, server->maxfilesize);
1099 nfs_sysfs_move_server_to_sb(sb);
1100 server->has_sec_mnt_opts = ctx->has_sec_mnt_opts;
1101}
1102
1103static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b,
1104 const struct fs_context *fc)
1105{
1106 const struct nfs_server *a = s->s_fs_info;
1107 const struct rpc_clnt *clnt_a = a->client;
1108 const struct rpc_clnt *clnt_b = b->client;
1109
1110 if ((s->s_flags & NFS_SB_MASK) != (fc->sb_flags & NFS_SB_MASK))
1111 goto Ebusy;
1112 if (a->nfs_client != b->nfs_client)
1113 goto Ebusy;
1114 if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
1115 goto Ebusy;
1116 if (a->wsize != b->wsize)
1117 goto Ebusy;
1118 if (a->rsize != b->rsize)
1119 goto Ebusy;
1120 if (a->acregmin != b->acregmin)
1121 goto Ebusy;
1122 if (a->acregmax != b->acregmax)
1123 goto Ebusy;
1124 if (a->acdirmin != b->acdirmin)
1125 goto Ebusy;
1126 if (a->acdirmax != b->acdirmax)
1127 goto Ebusy;
1128 if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1129 goto Ebusy;
1130 return 1;
1131Ebusy:
1132 return 0;
1133}
1134
1135static int nfs_set_super(struct super_block *s, struct fs_context *fc)
1136{
1137 struct nfs_server *server = fc->s_fs_info;
1138 int ret;
1139
1140 s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
1141 ret = set_anon_super(s, server);
1142 if (ret == 0)
1143 server->s_dev = s->s_dev;
1144 return ret;
1145}
1146
1147static int nfs_compare_super_address(struct nfs_server *server1,
1148 struct nfs_server *server2)
1149{
1150 struct sockaddr *sap1, *sap2;
1151 struct rpc_xprt *xprt1 = server1->client->cl_xprt;
1152 struct rpc_xprt *xprt2 = server2->client->cl_xprt;
1153
1154 if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
1155 return 0;
1156
1157 sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1158 sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1159
1160 if (sap1->sa_family != sap2->sa_family)
1161 return 0;
1162
1163 switch (sap1->sa_family) {
1164 case AF_INET: {
1165 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1166 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1167 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1168 return 0;
1169 if (sin1->sin_port != sin2->sin_port)
1170 return 0;
1171 break;
1172 }
1173 case AF_INET6: {
1174 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1175 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1176 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1177 return 0;
1178 if (sin1->sin6_port != sin2->sin6_port)
1179 return 0;
1180 break;
1181 }
1182 default:
1183 return 0;
1184 }
1185
1186 return 1;
1187}
1188
1189static int nfs_compare_userns(const struct nfs_server *old,
1190 const struct nfs_server *new)
1191{
1192 const struct user_namespace *oldns = &init_user_ns;
1193 const struct user_namespace *newns = &init_user_ns;
1194
1195 if (old->client && old->client->cl_cred)
1196 oldns = old->client->cl_cred->user_ns;
1197 if (new->client && new->client->cl_cred)
1198 newns = new->client->cl_cred->user_ns;
1199 if (oldns != newns)
1200 return 0;
1201 return 1;
1202}
1203
1204static int nfs_compare_super(struct super_block *sb, struct fs_context *fc)
1205{
1206 struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb);
1207
1208 if (!nfs_compare_super_address(old, server))
1209 return 0;
1210 /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1211 if (old->flags & NFS_MOUNT_UNSHARED)
1212 return 0;
1213 if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1214 return 0;
1215 if (!nfs_compare_userns(old, server))
1216 return 0;
1217 if ((old->has_sec_mnt_opts || fc->security) &&
1218 security_sb_mnt_opts_compat(sb, fc->security))
1219 return 0;
1220 return nfs_compare_mount_options(sb, server, fc);
1221}
1222
1223#ifdef CONFIG_NFS_FSCACHE
1224static int nfs_get_cache_cookie(struct super_block *sb,
1225 struct nfs_fs_context *ctx)
1226{
1227 struct nfs_server *nfss = NFS_SB(sb);
1228 char *uniq = NULL;
1229 int ulen = 0;
1230
1231 nfss->fscache = NULL;
1232
1233 if (!ctx)
1234 return 0;
1235
1236 if (ctx->clone_data.sb) {
1237 struct nfs_server *mnt_s = NFS_SB(ctx->clone_data.sb);
1238 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
1239 return 0;
1240 if (mnt_s->fscache_uniq) {
1241 uniq = mnt_s->fscache_uniq;
1242 ulen = strlen(uniq);
1243 }
1244 } else {
1245 if (!(ctx->options & NFS_OPTION_FSCACHE))
1246 return 0;
1247 if (ctx->fscache_uniq) {
1248 uniq = ctx->fscache_uniq;
1249 ulen = strlen(ctx->fscache_uniq);
1250 }
1251 }
1252
1253 return nfs_fscache_get_super_cookie(sb, uniq, ulen);
1254}
1255#else
1256static int nfs_get_cache_cookie(struct super_block *sb,
1257 struct nfs_fs_context *ctx)
1258{
1259 return 0;
1260}
1261#endif
1262
1263int nfs_get_tree_common(struct fs_context *fc)
1264{
1265 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1266 struct super_block *s;
1267 int (*compare_super)(struct super_block *, struct fs_context *) = nfs_compare_super;
1268 struct nfs_server *server = ctx->server;
1269 int error;
1270
1271 ctx->server = NULL;
1272 if (IS_ERR(server))
1273 return PTR_ERR(server);
1274
1275 if (server->flags & NFS_MOUNT_UNSHARED)
1276 compare_super = NULL;
1277
1278 /* -o noac implies -o sync */
1279 if (server->flags & NFS_MOUNT_NOAC)
1280 fc->sb_flags |= SB_SYNCHRONOUS;
1281
1282 if (ctx->clone_data.sb)
1283 if (ctx->clone_data.sb->s_flags & SB_SYNCHRONOUS)
1284 fc->sb_flags |= SB_SYNCHRONOUS;
1285
1286 /* Get a superblock - note that we may end up sharing one that already exists */
1287 fc->s_fs_info = server;
1288 s = sget_fc(fc, compare_super, nfs_set_super);
1289 fc->s_fs_info = NULL;
1290 if (IS_ERR(s)) {
1291 error = PTR_ERR(s);
1292 nfs_errorf(fc, "NFS: Couldn't get superblock");
1293 goto out_err_nosb;
1294 }
1295
1296 if (s->s_fs_info != server) {
1297 nfs_free_server(server);
1298 server = NULL;
1299 } else {
1300 error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
1301 MINOR(server->s_dev));
1302 if (error)
1303 goto error_splat_super;
1304 s->s_bdi->io_pages = server->rpages;
1305 server->super = s;
1306 }
1307
1308 if (!s->s_root) {
1309 unsigned bsize = ctx->clone_data.inherited_bsize;
1310 /* initial superblock/root creation */
1311 nfs_fill_super(s, ctx);
1312 if (bsize) {
1313 s->s_blocksize_bits = bsize;
1314 s->s_blocksize = 1U << bsize;
1315 }
1316 error = nfs_get_cache_cookie(s, ctx);
1317 if (error < 0)
1318 goto error_splat_super;
1319 }
1320
1321 error = nfs_get_root(s, fc);
1322 if (error < 0) {
1323 nfs_errorf(fc, "NFS: Couldn't get root dentry");
1324 goto error_splat_super;
1325 }
1326
1327 s->s_flags |= SB_ACTIVE;
1328 error = 0;
1329
1330out:
1331 return error;
1332
1333out_err_nosb:
1334 nfs_free_server(server);
1335 goto out;
1336error_splat_super:
1337 deactivate_locked_super(s);
1338 goto out;
1339}
1340
1341/*
1342 * Destroy an NFS superblock
1343 */
1344void nfs_kill_super(struct super_block *s)
1345{
1346 struct nfs_server *server = NFS_SB(s);
1347
1348 nfs_sysfs_move_sb_to_server(server);
1349 kill_anon_super(s);
1350
1351 nfs_fscache_release_super_cookie(s);
1352
1353 nfs_free_server(server);
1354}
1355EXPORT_SYMBOL_GPL(nfs_kill_super);
1356
1357#if IS_ENABLED(CONFIG_NFS_V4)
1358
1359/*
1360 * NFS v4 module parameters need to stay in the
1361 * NFS client for backwards compatibility
1362 */
1363unsigned int nfs_callback_set_tcpport;
1364unsigned short nfs_callback_nr_threads;
1365/* Default cache timeout is 10 minutes */
1366unsigned int nfs_idmap_cache_timeout = 600;
1367/* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
1368bool nfs4_disable_idmapping = true;
1369unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
1370unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
1371unsigned short send_implementation_id = 1;
1372char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
1373bool recover_lost_locks = false;
1374short nfs_delay_retrans = -1;
1375
1376EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
1377EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
1378EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
1379EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
1380EXPORT_SYMBOL_GPL(max_session_slots);
1381EXPORT_SYMBOL_GPL(max_session_cb_slots);
1382EXPORT_SYMBOL_GPL(send_implementation_id);
1383EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
1384EXPORT_SYMBOL_GPL(recover_lost_locks);
1385EXPORT_SYMBOL_GPL(nfs_delay_retrans);
1386
1387#define NFS_CALLBACK_MAXPORTNR (65535U)
1388
1389static int param_set_portnr(const char *val, const struct kernel_param *kp)
1390{
1391 unsigned long num;
1392 int ret;
1393
1394 if (!val)
1395 return -EINVAL;
1396 ret = kstrtoul(val, 0, &num);
1397 if (ret || num > NFS_CALLBACK_MAXPORTNR)
1398 return -EINVAL;
1399 *((unsigned int *)kp->arg) = num;
1400 return 0;
1401}
1402static const struct kernel_param_ops param_ops_portnr = {
1403 .set = param_set_portnr,
1404 .get = param_get_uint,
1405};
1406#define param_check_portnr(name, p) __param_check(name, p, unsigned int)
1407
1408module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
1409module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
1410MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
1411 "assigned to the NFSv4 callback channels.");
1412module_param(nfs_idmap_cache_timeout, int, 0644);
1413module_param(nfs4_disable_idmapping, bool, 0644);
1414module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
1415 NFS4_CLIENT_ID_UNIQ_LEN, 0600);
1416MODULE_PARM_DESC(nfs4_disable_idmapping,
1417 "Turn off NFSv4 idmapping when using 'sec=sys'");
1418module_param(max_session_slots, ushort, 0644);
1419MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
1420 "requests the client will negotiate");
1421module_param(max_session_cb_slots, ushort, 0644);
1422MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
1423 "callbacks the client will process for a given server");
1424module_param(send_implementation_id, ushort, 0644);
1425MODULE_PARM_DESC(send_implementation_id,
1426 "Send implementation ID with NFSv4.1 exchange_id");
1427MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
1428
1429module_param(recover_lost_locks, bool, 0644);
1430MODULE_PARM_DESC(recover_lost_locks,
1431 "If the server reports that a lock might be lost, "
1432 "try to recover it risking data corruption.");
1433
1434module_param_named(delay_retrans, nfs_delay_retrans, short, 0644);
1435MODULE_PARM_DESC(delay_retrans,
1436 "Unless negative, specifies the number of times the NFSv4 "
1437 "client retries a request before returning an EAGAIN error, "
1438 "after a reply of NFS4ERR_DELAY from the server.");
1439#endif /* CONFIG_NFS_V4 */