xref: /kernel/linux/linux-5.10/fs/nfs/super.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  linux/fs/nfs/super.c
4 *
5 *  Copyright (C) 1992  Rick Sladkey
6 *
7 *  nfs superblock handling functions
8 *
9 *  Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
10 *  experimental NFS changes. Modularisation taken straight from SYS5 fs.
11 *
12 *  Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
13 *  J.S.Peatfield@damtp.cam.ac.uk
14 *
15 *  Split from inode.c by David Howells <dhowells@redhat.com>
16 *
17 * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a
18 *   particular server are held in the same superblock
19 * - NFS superblocks can have several effective roots to the dentry tree
20 * - directory type roots are spliced into the tree when a path from one root reaches the root
21 *   of another (see nfs_lookup())
22 */
23
24#include <linux/module.h>
25#include <linux/init.h>
26
27#include <linux/time.h>
28#include <linux/kernel.h>
29#include <linux/mm.h>
30#include <linux/string.h>
31#include <linux/stat.h>
32#include <linux/errno.h>
33#include <linux/unistd.h>
34#include <linux/sunrpc/clnt.h>
35#include <linux/sunrpc/addr.h>
36#include <linux/sunrpc/stats.h>
37#include <linux/sunrpc/metrics.h>
38#include <linux/sunrpc/xprtsock.h>
39#include <linux/sunrpc/xprtrdma.h>
40#include <linux/nfs_fs.h>
41#include <linux/nfs_mount.h>
42#include <linux/nfs4_mount.h>
43#include <linux/lockd/bind.h>
44#include <linux/seq_file.h>
45#include <linux/mount.h>
46#include <linux/namei.h>
47#include <linux/vfs.h>
48#include <linux/inet.h>
49#include <linux/in6.h>
50#include <linux/slab.h>
51#include <net/ipv6.h>
52#include <linux/netdevice.h>
53#include <linux/nfs_xdr.h>
54#include <linux/magic.h>
55#include <linux/parser.h>
56#include <linux/nsproxy.h>
57#include <linux/rcupdate.h>
58
59#include <linux/uaccess.h>
60#include <linux/nfs_ssc.h>
61
62#include "nfs4_fs.h"
63#include "callback.h"
64#include "delegation.h"
65#include "iostat.h"
66#include "internal.h"
67#include "fscache.h"
68#include "nfs4session.h"
69#include "pnfs.h"
70#include "nfs.h"
71
72#define NFSDBG_FACILITY		NFSDBG_VFS
73
74const struct super_operations nfs_sops = {
75	.alloc_inode	= nfs_alloc_inode,
76	.free_inode	= nfs_free_inode,
77	.write_inode	= nfs_write_inode,
78	.drop_inode	= nfs_drop_inode,
79	.statfs		= nfs_statfs,
80	.evict_inode	= nfs_evict_inode,
81	.umount_begin	= nfs_umount_begin,
82	.show_options	= nfs_show_options,
83	.show_devname	= nfs_show_devname,
84	.show_path	= nfs_show_path,
85	.show_stats	= nfs_show_stats,
86};
87EXPORT_SYMBOL_GPL(nfs_sops);
88
89static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
90	.sco_sb_deactive = nfs_sb_deactive,
91};
92
93#if IS_ENABLED(CONFIG_NFS_V4)
94static int __init register_nfs4_fs(void)
95{
96	return register_filesystem(&nfs4_fs_type);
97}
98
99static void unregister_nfs4_fs(void)
100{
101	unregister_filesystem(&nfs4_fs_type);
102}
103#else
104static int __init register_nfs4_fs(void)
105{
106	return 0;
107}
108
109static void unregister_nfs4_fs(void)
110{
111}
112#endif
113
114static void nfs_ssc_register_ops(void)
115{
116	nfs_ssc_register(&nfs_ssc_clnt_ops_tbl);
117}
118
119static void nfs_ssc_unregister_ops(void)
120{
121	nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl);
122}
123
124static struct shrinker acl_shrinker = {
125	.count_objects	= nfs_access_cache_count,
126	.scan_objects	= nfs_access_cache_scan,
127	.seeks		= DEFAULT_SEEKS,
128};
129
130/*
131 * Register the NFS filesystems
132 */
133int __init register_nfs_fs(void)
134{
135	int ret;
136
137        ret = register_filesystem(&nfs_fs_type);
138	if (ret < 0)
139		goto error_0;
140
141	ret = register_nfs4_fs();
142	if (ret < 0)
143		goto error_1;
144
145	ret = nfs_register_sysctl();
146	if (ret < 0)
147		goto error_2;
148	ret = register_shrinker(&acl_shrinker);
149	if (ret < 0)
150		goto error_3;
151	nfs_ssc_register_ops();
152	return 0;
153error_3:
154	nfs_unregister_sysctl();
155error_2:
156	unregister_nfs4_fs();
157error_1:
158	unregister_filesystem(&nfs_fs_type);
159error_0:
160	return ret;
161}
162
163/*
164 * Unregister the NFS filesystems
165 */
166void __exit unregister_nfs_fs(void)
167{
168	unregister_shrinker(&acl_shrinker);
169	nfs_unregister_sysctl();
170	unregister_nfs4_fs();
171	nfs_ssc_unregister_ops();
172	unregister_filesystem(&nfs_fs_type);
173}
174
175bool nfs_sb_active(struct super_block *sb)
176{
177	struct nfs_server *server = NFS_SB(sb);
178
179	if (!atomic_inc_not_zero(&sb->s_active))
180		return false;
181	if (atomic_inc_return(&server->active) != 1)
182		atomic_dec(&sb->s_active);
183	return true;
184}
185EXPORT_SYMBOL_GPL(nfs_sb_active);
186
187void nfs_sb_deactive(struct super_block *sb)
188{
189	struct nfs_server *server = NFS_SB(sb);
190
191	if (atomic_dec_and_test(&server->active))
192		deactivate_super(sb);
193}
194EXPORT_SYMBOL_GPL(nfs_sb_deactive);
195
196static int __nfs_list_for_each_server(struct list_head *head,
197		int (*fn)(struct nfs_server *, void *),
198		void *data)
199{
200	struct nfs_server *server, *last = NULL;
201	int ret = 0;
202
203	rcu_read_lock();
204	list_for_each_entry_rcu(server, head, client_link) {
205		if (!(server->super && nfs_sb_active(server->super)))
206			continue;
207		rcu_read_unlock();
208		if (last)
209			nfs_sb_deactive(last->super);
210		last = server;
211		ret = fn(server, data);
212		if (ret)
213			goto out;
214		rcu_read_lock();
215	}
216	rcu_read_unlock();
217out:
218	if (last)
219		nfs_sb_deactive(last->super);
220	return ret;
221}
222
223int nfs_client_for_each_server(struct nfs_client *clp,
224		int (*fn)(struct nfs_server *, void *),
225		void *data)
226{
227	return __nfs_list_for_each_server(&clp->cl_superblocks, fn, data);
228}
229EXPORT_SYMBOL_GPL(nfs_client_for_each_server);
230
231/*
232 * Deliver file system statistics to userspace
233 */
234int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
235{
236	struct nfs_server *server = NFS_SB(dentry->d_sb);
237	unsigned char blockbits;
238	unsigned long blockres;
239	struct nfs_fh *fh = NFS_FH(d_inode(dentry));
240	struct nfs_fsstat res;
241	int error = -ENOMEM;
242
243	res.fattr = nfs_alloc_fattr();
244	if (res.fattr == NULL)
245		goto out_err;
246
247	error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
248	if (unlikely(error == -ESTALE)) {
249		struct dentry *pd_dentry;
250
251		pd_dentry = dget_parent(dentry);
252		nfs_zap_caches(d_inode(pd_dentry));
253		dput(pd_dentry);
254	}
255	nfs_free_fattr(res.fattr);
256	if (error < 0)
257		goto out_err;
258
259	buf->f_type = NFS_SUPER_MAGIC;
260
261	/*
262	 * Current versions of glibc do not correctly handle the
263	 * case where f_frsize != f_bsize.  Eventually we want to
264	 * report the value of wtmult in this field.
265	 */
266	buf->f_frsize = dentry->d_sb->s_blocksize;
267
268	/*
269	 * On most *nix systems, f_blocks, f_bfree, and f_bavail
270	 * are reported in units of f_frsize.  Linux hasn't had
271	 * an f_frsize field in its statfs struct until recently,
272	 * thus historically Linux's sys_statfs reports these
273	 * fields in units of f_bsize.
274	 */
275	buf->f_bsize = dentry->d_sb->s_blocksize;
276	blockbits = dentry->d_sb->s_blocksize_bits;
277	blockres = (1 << blockbits) - 1;
278	buf->f_blocks = (res.tbytes + blockres) >> blockbits;
279	buf->f_bfree = (res.fbytes + blockres) >> blockbits;
280	buf->f_bavail = (res.abytes + blockres) >> blockbits;
281
282	buf->f_files = res.tfiles;
283	buf->f_ffree = res.afiles;
284
285	buf->f_namelen = server->namelen;
286
287	return 0;
288
289 out_err:
290	dprintk("%s: statfs error = %d\n", __func__, -error);
291	return error;
292}
293EXPORT_SYMBOL_GPL(nfs_statfs);
294
295/*
296 * Map the security flavour number to a name
297 */
298static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
299{
300	static const struct {
301		rpc_authflavor_t flavour;
302		const char *str;
303	} sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
304		/* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
305		{ RPC_AUTH_NULL, "null" },
306		{ RPC_AUTH_UNIX, "sys" },
307		{ RPC_AUTH_GSS_KRB5, "krb5" },
308		{ RPC_AUTH_GSS_KRB5I, "krb5i" },
309		{ RPC_AUTH_GSS_KRB5P, "krb5p" },
310		{ RPC_AUTH_GSS_LKEY, "lkey" },
311		{ RPC_AUTH_GSS_LKEYI, "lkeyi" },
312		{ RPC_AUTH_GSS_LKEYP, "lkeyp" },
313		{ RPC_AUTH_GSS_SPKM, "spkm" },
314		{ RPC_AUTH_GSS_SPKMI, "spkmi" },
315		{ RPC_AUTH_GSS_SPKMP, "spkmp" },
316		{ UINT_MAX, "unknown" }
317	};
318	int i;
319
320	for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
321		if (sec_flavours[i].flavour == flavour)
322			break;
323	}
324	return sec_flavours[i].str;
325}
326
327static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
328				  int showdefaults)
329{
330	struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
331	char *proto = NULL;
332
333	switch (sap->sa_family) {
334	case AF_INET:
335		switch (nfss->mountd_protocol) {
336		case IPPROTO_UDP:
337			proto = RPCBIND_NETID_UDP;
338			break;
339		case IPPROTO_TCP:
340			proto = RPCBIND_NETID_TCP;
341			break;
342		}
343		break;
344	case AF_INET6:
345		switch (nfss->mountd_protocol) {
346		case IPPROTO_UDP:
347			proto = RPCBIND_NETID_UDP6;
348			break;
349		case IPPROTO_TCP:
350			proto = RPCBIND_NETID_TCP6;
351			break;
352		}
353		break;
354	}
355	if (proto || showdefaults)
356		seq_printf(m, ",mountproto=%s", proto ?: "auto");
357}
358
359static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
360				    int showdefaults)
361{
362	struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
363
364	if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
365		return;
366
367	switch (sap->sa_family) {
368	case AF_INET: {
369		struct sockaddr_in *sin = (struct sockaddr_in *)sap;
370		seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
371		break;
372	}
373	case AF_INET6: {
374		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
375		seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
376		break;
377	}
378	default:
379		if (showdefaults)
380			seq_puts(m, ",mountaddr=unspecified");
381	}
382
383	if (nfss->mountd_version || showdefaults)
384		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
385	if ((nfss->mountd_port &&
386		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
387		showdefaults)
388		seq_printf(m, ",mountport=%u", nfss->mountd_port);
389
390	nfs_show_mountd_netid(m, nfss, showdefaults);
391}
392
393#if IS_ENABLED(CONFIG_NFS_V4)
394static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
395				    int showdefaults)
396{
397	struct nfs_client *clp = nfss->nfs_client;
398
399	seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
400}
401#else
402static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
403				    int showdefaults)
404{
405}
406#endif
407
408static void nfs_show_nfs_version(struct seq_file *m,
409		unsigned int version,
410		unsigned int minorversion)
411{
412	seq_printf(m, ",vers=%u", version);
413	if (version == 4)
414		seq_printf(m, ".%u", minorversion);
415}
416
417/*
418 * Describe the mount options in force on this server representation
419 */
420static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
421				   int showdefaults)
422{
423	static const struct proc_nfs_info {
424		int flag;
425		const char *str;
426		const char *nostr;
427	} nfs_info[] = {
428		{ NFS_MOUNT_SOFT, ",soft", "" },
429		{ NFS_MOUNT_SOFTERR, ",softerr", "" },
430		{ NFS_MOUNT_SOFTREVAL, ",softreval", "" },
431		{ NFS_MOUNT_POSIX, ",posix", "" },
432		{ NFS_MOUNT_NOCTO, ",nocto", "" },
433		{ NFS_MOUNT_NOAC, ",noac", "" },
434		{ NFS_MOUNT_NONLM, ",nolock", "" },
435		{ NFS_MOUNT_NOACL, ",noacl", "" },
436		{ NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
437		{ NFS_MOUNT_UNSHARED, ",nosharecache", "" },
438		{ NFS_MOUNT_NORESVPORT, ",noresvport", "" },
439		{ 0, NULL, NULL }
440	};
441	const struct proc_nfs_info *nfs_infop;
442	struct nfs_client *clp = nfss->nfs_client;
443	u32 version = clp->rpc_ops->version;
444	int local_flock, local_fcntl;
445
446	nfs_show_nfs_version(m, version, clp->cl_minorversion);
447	seq_printf(m, ",rsize=%u", nfss->rsize);
448	seq_printf(m, ",wsize=%u", nfss->wsize);
449	if (nfss->bsize != 0)
450		seq_printf(m, ",bsize=%u", nfss->bsize);
451	seq_printf(m, ",namlen=%u", nfss->namelen);
452	if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
453		seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
454	if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
455		seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
456	if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
457		seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
458	if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
459		seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
460	if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
461			seq_puts(m, ",hard");
462	for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
463		if (nfss->flags & nfs_infop->flag)
464			seq_puts(m, nfs_infop->str);
465		else
466			seq_puts(m, nfs_infop->nostr);
467	}
468	rcu_read_lock();
469	seq_printf(m, ",proto=%s",
470		   rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
471	rcu_read_unlock();
472	if (clp->cl_nconnect > 0)
473		seq_printf(m, ",nconnect=%u", clp->cl_nconnect);
474	if (version == 4) {
475		if (nfss->port != NFS_PORT)
476			seq_printf(m, ",port=%u", nfss->port);
477	} else
478		if (nfss->port)
479			seq_printf(m, ",port=%u", nfss->port);
480
481	seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
482	seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
483	seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
484
485	if (version != 4)
486		nfs_show_mountd_options(m, nfss, showdefaults);
487	else
488		nfs_show_nfsv4_options(m, nfss, showdefaults);
489
490	if (nfss->options & NFS_OPTION_FSCACHE)
491		seq_puts(m, ",fsc");
492
493	if (nfss->options & NFS_OPTION_MIGRATION)
494		seq_puts(m, ",migration");
495
496	if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
497		if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
498			seq_puts(m, ",lookupcache=none");
499		else
500			seq_puts(m, ",lookupcache=pos");
501	}
502
503	local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
504	local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
505
506	if (!local_flock && !local_fcntl)
507		seq_puts(m, ",local_lock=none");
508	else if (local_flock && local_fcntl)
509		seq_puts(m, ",local_lock=all");
510	else if (local_flock)
511		seq_puts(m, ",local_lock=flock");
512	else
513		seq_puts(m, ",local_lock=posix");
514}
515
516/*
517 * Describe the mount options on this VFS mountpoint
518 */
519int nfs_show_options(struct seq_file *m, struct dentry *root)
520{
521	struct nfs_server *nfss = NFS_SB(root->d_sb);
522
523	nfs_show_mount_options(m, nfss, 0);
524
525	rcu_read_lock();
526	seq_printf(m, ",addr=%s",
527			rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
528							RPC_DISPLAY_ADDR));
529	rcu_read_unlock();
530
531	return 0;
532}
533EXPORT_SYMBOL_GPL(nfs_show_options);
534
535#if IS_ENABLED(CONFIG_NFS_V4)
536static void show_lease(struct seq_file *m, struct nfs_server *server)
537{
538	struct nfs_client *clp = server->nfs_client;
539	unsigned long expire;
540
541	seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
542	expire = clp->cl_last_renewal + clp->cl_lease_time;
543	seq_printf(m, ",lease_expired=%ld",
544		   time_after(expire, jiffies) ?  0 : (jiffies - expire) / HZ);
545}
546#ifdef CONFIG_NFS_V4_1
547static void show_sessions(struct seq_file *m, struct nfs_server *server)
548{
549	if (nfs4_has_session(server->nfs_client))
550		seq_puts(m, ",sessions");
551}
552#else
553static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
554#endif
555#endif
556
557#ifdef CONFIG_NFS_V4_1
558static void show_pnfs(struct seq_file *m, struct nfs_server *server)
559{
560	seq_printf(m, ",pnfs=");
561	if (server->pnfs_curr_ld)
562		seq_printf(m, "%s", server->pnfs_curr_ld->name);
563	else
564		seq_printf(m, "not configured");
565}
566
567static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
568{
569	if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
570		struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
571		seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
572			   "date='%llu,%u'",
573			   impl_id->name, impl_id->domain,
574			   impl_id->date.seconds, impl_id->date.nseconds);
575	}
576}
577#else
578#if IS_ENABLED(CONFIG_NFS_V4)
579static void show_pnfs(struct seq_file *m, struct nfs_server *server)
580{
581}
582#endif
583static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
584{
585}
586#endif
587
588int nfs_show_devname(struct seq_file *m, struct dentry *root)
589{
590	char *page = (char *) __get_free_page(GFP_KERNEL);
591	char *devname, *dummy;
592	int err = 0;
593	if (!page)
594		return -ENOMEM;
595	devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
596	if (IS_ERR(devname))
597		err = PTR_ERR(devname);
598	else
599		seq_escape(m, devname, " \t\n\\");
600	free_page((unsigned long)page);
601	return err;
602}
603EXPORT_SYMBOL_GPL(nfs_show_devname);
604
605int nfs_show_path(struct seq_file *m, struct dentry *dentry)
606{
607	seq_puts(m, "/");
608	return 0;
609}
610EXPORT_SYMBOL_GPL(nfs_show_path);
611
612/*
613 * Present statistical information for this VFS mountpoint
614 */
615int nfs_show_stats(struct seq_file *m, struct dentry *root)
616{
617	int i, cpu;
618	struct nfs_server *nfss = NFS_SB(root->d_sb);
619	struct rpc_auth *auth = nfss->client->cl_auth;
620	struct nfs_iostats totals = { };
621
622	seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
623
624	/*
625	 * Display all mount option settings
626	 */
627	seq_puts(m, "\n\topts:\t");
628	seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
629	seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
630	seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
631	seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
632	nfs_show_mount_options(m, nfss, 1);
633
634	seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
635
636	show_implementation_id(m, nfss);
637
638	seq_puts(m, "\n\tcaps:\t");
639	seq_printf(m, "caps=0x%x", nfss->caps);
640	seq_printf(m, ",wtmult=%u", nfss->wtmult);
641	seq_printf(m, ",dtsize=%u", nfss->dtsize);
642	seq_printf(m, ",bsize=%u", nfss->bsize);
643	seq_printf(m, ",namlen=%u", nfss->namelen);
644
645#if IS_ENABLED(CONFIG_NFS_V4)
646	if (nfss->nfs_client->rpc_ops->version == 4) {
647		seq_puts(m, "\n\tnfsv4:\t");
648		seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
649		seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
650		seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
651		seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
652		show_sessions(m, nfss);
653		show_pnfs(m, nfss);
654		show_lease(m, nfss);
655	}
656#endif
657
658	/*
659	 * Display security flavor in effect for this mount
660	 */
661	seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
662	if (auth->au_flavor)
663		seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
664
665	/*
666	 * Display superblock I/O counters
667	 */
668	for_each_possible_cpu(cpu) {
669		struct nfs_iostats *stats;
670
671		preempt_disable();
672		stats = per_cpu_ptr(nfss->io_stats, cpu);
673
674		for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
675			totals.events[i] += stats->events[i];
676		for (i = 0; i < __NFSIOS_BYTESMAX; i++)
677			totals.bytes[i] += stats->bytes[i];
678#ifdef CONFIG_NFS_FSCACHE
679		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
680			totals.fscache[i] += stats->fscache[i];
681#endif
682
683		preempt_enable();
684	}
685
686	seq_puts(m, "\n\tevents:\t");
687	for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
688		seq_printf(m, "%lu ", totals.events[i]);
689	seq_puts(m, "\n\tbytes:\t");
690	for (i = 0; i < __NFSIOS_BYTESMAX; i++)
691		seq_printf(m, "%Lu ", totals.bytes[i]);
692#ifdef CONFIG_NFS_FSCACHE
693	if (nfss->options & NFS_OPTION_FSCACHE) {
694		seq_puts(m, "\n\tfsc:\t");
695		for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
696			seq_printf(m, "%Lu ", totals.fscache[i]);
697	}
698#endif
699	seq_putc(m, '\n');
700
701	rpc_clnt_show_stats(m, nfss->client);
702
703	return 0;
704}
705EXPORT_SYMBOL_GPL(nfs_show_stats);
706
707/*
708 * Begin unmount by attempting to remove all automounted mountpoints we added
709 * in response to xdev traversals and referrals
710 */
711void nfs_umount_begin(struct super_block *sb)
712{
713	struct nfs_server *server;
714	struct rpc_clnt *rpc;
715
716	server = NFS_SB(sb);
717	/* -EIO all pending I/O */
718	rpc = server->client_acl;
719	if (!IS_ERR(rpc))
720		rpc_killall_tasks(rpc);
721	rpc = server->client;
722	if (!IS_ERR(rpc))
723		rpc_killall_tasks(rpc);
724}
725EXPORT_SYMBOL_GPL(nfs_umount_begin);
726
727/*
728 * Return true if 'match' is in auth_info or auth_info is empty.
729 * Return false otherwise.
730 */
731bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
732			 rpc_authflavor_t match)
733{
734	int i;
735
736	if (!auth_info->flavor_len)
737		return true;
738
739	for (i = 0; i < auth_info->flavor_len; i++) {
740		if (auth_info->flavors[i] == match)
741			return true;
742	}
743	return false;
744}
745EXPORT_SYMBOL_GPL(nfs_auth_info_match);
746
747/*
748 * Ensure that a specified authtype in ctx->auth_info is supported by
749 * the server. Returns 0 and sets ctx->selected_flavor if it's ok, and
750 * -EACCES if not.
751 */
752static int nfs_verify_authflavors(struct nfs_fs_context *ctx,
753				  rpc_authflavor_t *server_authlist,
754				  unsigned int count)
755{
756	rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
757	bool found_auth_null = false;
758	unsigned int i;
759
760	/*
761	 * If the sec= mount option is used, the specified flavor or AUTH_NULL
762	 * must be in the list returned by the server.
763	 *
764	 * AUTH_NULL has a special meaning when it's in the server list - it
765	 * means that the server will ignore the rpc creds, so any flavor
766	 * can be used but still use the sec= that was specified.
767	 *
768	 * Note also that the MNT procedure in MNTv1 does not return a list
769	 * of supported security flavors. In this case, nfs_mount() fabricates
770	 * a security flavor list containing just AUTH_NULL.
771	 */
772	for (i = 0; i < count; i++) {
773		flavor = server_authlist[i];
774
775		if (nfs_auth_info_match(&ctx->auth_info, flavor))
776			goto out;
777
778		if (flavor == RPC_AUTH_NULL)
779			found_auth_null = true;
780	}
781
782	if (found_auth_null) {
783		flavor = ctx->auth_info.flavors[0];
784		goto out;
785	}
786
787	dfprintk(MOUNT,
788		 "NFS: specified auth flavors not supported by server\n");
789	return -EACCES;
790
791out:
792	ctx->selected_flavor = flavor;
793	dfprintk(MOUNT, "NFS: using auth flavor %u\n", ctx->selected_flavor);
794	return 0;
795}
796
797/*
798 * Use the remote server's MOUNT service to request the NFS file handle
799 * corresponding to the provided path.
800 */
801static int nfs_request_mount(struct fs_context *fc,
802			     struct nfs_fh *root_fh,
803			     rpc_authflavor_t *server_authlist,
804			     unsigned int *server_authlist_len)
805{
806	struct nfs_fs_context *ctx = nfs_fc2context(fc);
807	struct nfs_mount_request request = {
808		.sap		= (struct sockaddr *)
809						&ctx->mount_server.address,
810		.dirpath	= ctx->nfs_server.export_path,
811		.protocol	= ctx->mount_server.protocol,
812		.fh		= root_fh,
813		.noresvport	= ctx->flags & NFS_MOUNT_NORESVPORT,
814		.auth_flav_len	= server_authlist_len,
815		.auth_flavs	= server_authlist,
816		.net		= fc->net_ns,
817	};
818	int status;
819
820	if (ctx->mount_server.version == 0) {
821		switch (ctx->version) {
822			default:
823				ctx->mount_server.version = NFS_MNT3_VERSION;
824				break;
825			case 2:
826				ctx->mount_server.version = NFS_MNT_VERSION;
827		}
828	}
829	request.version = ctx->mount_server.version;
830
831	if (ctx->mount_server.hostname)
832		request.hostname = ctx->mount_server.hostname;
833	else
834		request.hostname = ctx->nfs_server.hostname;
835
836	/*
837	 * Construct the mount server's address.
838	 */
839	if (ctx->mount_server.address.sa_family == AF_UNSPEC) {
840		memcpy(request.sap, &ctx->nfs_server.address,
841		       ctx->nfs_server.addrlen);
842		ctx->mount_server.addrlen = ctx->nfs_server.addrlen;
843	}
844	request.salen = ctx->mount_server.addrlen;
845	nfs_set_port(request.sap, &ctx->mount_server.port, 0);
846
847	/*
848	 * Now ask the mount server to map our export path
849	 * to a file handle.
850	 */
851	status = nfs_mount(&request);
852	if (status != 0) {
853		dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
854				request.hostname, status);
855		return status;
856	}
857
858	return 0;
859}
860
861static struct nfs_server *nfs_try_mount_request(struct fs_context *fc)
862{
863	struct nfs_fs_context *ctx = nfs_fc2context(fc);
864	int status;
865	unsigned int i;
866	bool tried_auth_unix = false;
867	bool auth_null_in_list = false;
868	struct nfs_server *server = ERR_PTR(-EACCES);
869	rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
870	unsigned int authlist_len = ARRAY_SIZE(authlist);
871
872	status = nfs_request_mount(fc, ctx->mntfh, authlist, &authlist_len);
873	if (status)
874		return ERR_PTR(status);
875
876	/*
877	 * Was a sec= authflavor specified in the options? First, verify
878	 * whether the server supports it, and then just try to use it if so.
879	 */
880	if (ctx->auth_info.flavor_len > 0) {
881		status = nfs_verify_authflavors(ctx, authlist, authlist_len);
882		dfprintk(MOUNT, "NFS: using auth flavor %u\n",
883			 ctx->selected_flavor);
884		if (status)
885			return ERR_PTR(status);
886		return ctx->nfs_mod->rpc_ops->create_server(fc);
887	}
888
889	/*
890	 * No sec= option was provided. RFC 2623, section 2.7 suggests we
891	 * SHOULD prefer the flavor listed first. However, some servers list
892	 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
893	 */
894	for (i = 0; i < authlist_len; ++i) {
895		rpc_authflavor_t flavor;
896		struct rpcsec_gss_info info;
897
898		flavor = authlist[i];
899		switch (flavor) {
900		case RPC_AUTH_UNIX:
901			tried_auth_unix = true;
902			break;
903		case RPC_AUTH_NULL:
904			auth_null_in_list = true;
905			continue;
906		default:
907			if (rpcauth_get_gssinfo(flavor, &info) != 0)
908				continue;
909			break;
910		}
911		dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
912		ctx->selected_flavor = flavor;
913		server = ctx->nfs_mod->rpc_ops->create_server(fc);
914		if (!IS_ERR(server))
915			return server;
916	}
917
918	/*
919	 * Nothing we tried so far worked. At this point, give up if we've
920	 * already tried AUTH_UNIX or if the server's list doesn't contain
921	 * AUTH_NULL
922	 */
923	if (tried_auth_unix || !auth_null_in_list)
924		return server;
925
926	/* Last chance! Try AUTH_UNIX */
927	dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
928	ctx->selected_flavor = RPC_AUTH_UNIX;
929	return ctx->nfs_mod->rpc_ops->create_server(fc);
930}
931
932int nfs_try_get_tree(struct fs_context *fc)
933{
934	struct nfs_fs_context *ctx = nfs_fc2context(fc);
935
936	if (ctx->need_mount)
937		ctx->server = nfs_try_mount_request(fc);
938	else
939		ctx->server = ctx->nfs_mod->rpc_ops->create_server(fc);
940
941	return nfs_get_tree_common(fc);
942}
943EXPORT_SYMBOL_GPL(nfs_try_get_tree);
944
945
946#define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
947		| NFS_MOUNT_SECURE \
948		| NFS_MOUNT_TCP \
949		| NFS_MOUNT_VER3 \
950		| NFS_MOUNT_KERBEROS \
951		| NFS_MOUNT_NONLM \
952		| NFS_MOUNT_BROKEN_SUID \
953		| NFS_MOUNT_STRICTLOCK \
954		| NFS_MOUNT_LEGACY_INTERFACE)
955
956#define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
957		~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
958
959static int
960nfs_compare_remount_data(struct nfs_server *nfss,
961			 struct nfs_fs_context *ctx)
962{
963	if ((ctx->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
964	    ctx->rsize != nfss->rsize ||
965	    ctx->wsize != nfss->wsize ||
966	    ctx->version != nfss->nfs_client->rpc_ops->version ||
967	    ctx->minorversion != nfss->nfs_client->cl_minorversion ||
968	    ctx->retrans != nfss->client->cl_timeout->to_retries ||
969	    !nfs_auth_info_match(&ctx->auth_info, nfss->client->cl_auth->au_flavor) ||
970	    ctx->acregmin != nfss->acregmin / HZ ||
971	    ctx->acregmax != nfss->acregmax / HZ ||
972	    ctx->acdirmin != nfss->acdirmin / HZ ||
973	    ctx->acdirmax != nfss->acdirmax / HZ ||
974	    ctx->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
975	    (ctx->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
976	    ctx->nfs_server.port != nfss->port ||
977	    ctx->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
978	    !rpc_cmp_addr((struct sockaddr *)&ctx->nfs_server.address,
979			  (struct sockaddr *)&nfss->nfs_client->cl_addr))
980		return -EINVAL;
981
982	return 0;
983}
984
985int nfs_reconfigure(struct fs_context *fc)
986{
987	struct nfs_fs_context *ctx = nfs_fc2context(fc);
988	struct super_block *sb = fc->root->d_sb;
989	struct nfs_server *nfss = sb->s_fs_info;
990
991	sync_filesystem(sb);
992
993	/*
994	 * Userspace mount programs that send binary options generally send
995	 * them populated with default values. We have no way to know which
996	 * ones were explicitly specified. Fall back to legacy behavior and
997	 * just return success.
998	 */
999	if (ctx->skip_reconfig_option_check)
1000		return 0;
1001
1002	/*
1003	 * noac is a special case. It implies -o sync, but that's not
1004	 * necessarily reflected in the mtab options. reconfigure_super
1005	 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
1006	 * remount options, so we have to explicitly reset it.
1007	 */
1008	if (ctx->flags & NFS_MOUNT_NOAC) {
1009		fc->sb_flags |= SB_SYNCHRONOUS;
1010		fc->sb_flags_mask |= SB_SYNCHRONOUS;
1011	}
1012
1013	/* compare new mount options with old ones */
1014	return nfs_compare_remount_data(nfss, ctx);
1015}
1016EXPORT_SYMBOL_GPL(nfs_reconfigure);
1017
1018/*
1019 * Finish setting up an NFS superblock
1020 */
1021static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx)
1022{
1023	struct nfs_server *server = NFS_SB(sb);
1024
1025	sb->s_blocksize_bits = 0;
1026	sb->s_blocksize = 0;
1027	sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
1028	sb->s_op = server->nfs_client->cl_nfs_mod->sops;
1029	if (ctx && ctx->bsize)
1030		sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits);
1031
1032	switch (server->nfs_client->rpc_ops->version) {
1033	case 2:
1034		sb->s_time_gran = 1000;
1035		sb->s_time_min = 0;
1036		sb->s_time_max = U32_MAX;
1037		break;
1038	case 3:
1039		/*
1040		 * The VFS shouldn't apply the umask to mode bits.
1041		 * We will do so ourselves when necessary.
1042		 */
1043		sb->s_flags |= SB_POSIXACL;
1044		sb->s_time_gran = 1;
1045		sb->s_time_min = 0;
1046		sb->s_time_max = U32_MAX;
1047		sb->s_export_op = &nfs_export_ops;
1048		break;
1049	case 4:
1050		sb->s_flags |= SB_POSIXACL;
1051		sb->s_time_gran = 1;
1052		sb->s_time_min = S64_MIN;
1053		sb->s_time_max = S64_MAX;
1054		if (server->caps & NFS_CAP_ATOMIC_OPEN_V1)
1055			sb->s_export_op = &nfs_export_ops;
1056		break;
1057	}
1058
1059	sb->s_magic = NFS_SUPER_MAGIC;
1060
1061	/* We probably want something more informative here */
1062	snprintf(sb->s_id, sizeof(sb->s_id),
1063		 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1064
1065	if (sb->s_blocksize == 0)
1066		sb->s_blocksize = nfs_block_bits(server->wsize,
1067						 &sb->s_blocksize_bits);
1068
1069	nfs_super_set_maxbytes(sb, server->maxfilesize);
1070}
1071
1072static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b,
1073				     const struct fs_context *fc)
1074{
1075	const struct nfs_server *a = s->s_fs_info;
1076	const struct rpc_clnt *clnt_a = a->client;
1077	const struct rpc_clnt *clnt_b = b->client;
1078
1079	if ((s->s_flags & NFS_SB_MASK) != (fc->sb_flags & NFS_SB_MASK))
1080		goto Ebusy;
1081	if (a->nfs_client != b->nfs_client)
1082		goto Ebusy;
1083	if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
1084		goto Ebusy;
1085	if (a->wsize != b->wsize)
1086		goto Ebusy;
1087	if (a->rsize != b->rsize)
1088		goto Ebusy;
1089	if (a->acregmin != b->acregmin)
1090		goto Ebusy;
1091	if (a->acregmax != b->acregmax)
1092		goto Ebusy;
1093	if (a->acdirmin != b->acdirmin)
1094		goto Ebusy;
1095	if (a->acdirmax != b->acdirmax)
1096		goto Ebusy;
1097	if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1098		goto Ebusy;
1099	return 1;
1100Ebusy:
1101	return 0;
1102}
1103
1104static int nfs_set_super(struct super_block *s, struct fs_context *fc)
1105{
1106	struct nfs_server *server = fc->s_fs_info;
1107	int ret;
1108
1109	s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
1110	ret = set_anon_super(s, server);
1111	if (ret == 0)
1112		server->s_dev = s->s_dev;
1113	return ret;
1114}
1115
1116static int nfs_compare_super_address(struct nfs_server *server1,
1117				     struct nfs_server *server2)
1118{
1119	struct sockaddr *sap1, *sap2;
1120	struct rpc_xprt *xprt1 = server1->client->cl_xprt;
1121	struct rpc_xprt *xprt2 = server2->client->cl_xprt;
1122
1123	if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
1124		return 0;
1125
1126	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1127	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1128
1129	if (sap1->sa_family != sap2->sa_family)
1130		return 0;
1131
1132	switch (sap1->sa_family) {
1133	case AF_INET: {
1134		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1135		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1136		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1137			return 0;
1138		if (sin1->sin_port != sin2->sin_port)
1139			return 0;
1140		break;
1141	}
1142	case AF_INET6: {
1143		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1144		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1145		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1146			return 0;
1147		if (sin1->sin6_port != sin2->sin6_port)
1148			return 0;
1149		break;
1150	}
1151	default:
1152		return 0;
1153	}
1154
1155	return 1;
1156}
1157
1158static int nfs_compare_userns(const struct nfs_server *old,
1159		const struct nfs_server *new)
1160{
1161	const struct user_namespace *oldns = &init_user_ns;
1162	const struct user_namespace *newns = &init_user_ns;
1163
1164	if (old->client && old->client->cl_cred)
1165		oldns = old->client->cl_cred->user_ns;
1166	if (new->client && new->client->cl_cred)
1167		newns = new->client->cl_cred->user_ns;
1168	if (oldns != newns)
1169		return 0;
1170	return 1;
1171}
1172
1173static int nfs_compare_super(struct super_block *sb, struct fs_context *fc)
1174{
1175	struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb);
1176
1177	if (!nfs_compare_super_address(old, server))
1178		return 0;
1179	/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1180	if (old->flags & NFS_MOUNT_UNSHARED)
1181		return 0;
1182	if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1183		return 0;
1184	if (!nfs_compare_userns(old, server))
1185		return 0;
1186	return nfs_compare_mount_options(sb, server, fc);
1187}
1188
1189#ifdef CONFIG_NFS_FSCACHE
1190static void nfs_get_cache_cookie(struct super_block *sb,
1191				 struct nfs_fs_context *ctx)
1192{
1193	struct nfs_server *nfss = NFS_SB(sb);
1194	char *uniq = NULL;
1195	int ulen = 0;
1196
1197	nfss->fscache_key = NULL;
1198	nfss->fscache = NULL;
1199
1200	if (!ctx)
1201		return;
1202
1203	if (ctx->clone_data.sb) {
1204		struct nfs_server *mnt_s = NFS_SB(ctx->clone_data.sb);
1205		if (!(mnt_s->options & NFS_OPTION_FSCACHE))
1206			return;
1207		if (mnt_s->fscache_key) {
1208			uniq = mnt_s->fscache_key->key.uniquifier;
1209			ulen = mnt_s->fscache_key->key.uniq_len;
1210		}
1211	} else {
1212		if (!(ctx->options & NFS_OPTION_FSCACHE))
1213			return;
1214		if (ctx->fscache_uniq) {
1215			uniq = ctx->fscache_uniq;
1216			ulen = strlen(ctx->fscache_uniq);
1217		}
1218	}
1219
1220	nfs_fscache_get_super_cookie(sb, uniq, ulen);
1221}
1222#else
1223static void nfs_get_cache_cookie(struct super_block *sb,
1224				 struct nfs_fs_context *ctx)
1225{
1226}
1227#endif
1228
1229int nfs_get_tree_common(struct fs_context *fc)
1230{
1231	struct nfs_fs_context *ctx = nfs_fc2context(fc);
1232	struct super_block *s;
1233	int (*compare_super)(struct super_block *, struct fs_context *) = nfs_compare_super;
1234	struct nfs_server *server = ctx->server;
1235	int error;
1236
1237	ctx->server = NULL;
1238	if (IS_ERR(server))
1239		return PTR_ERR(server);
1240
1241	if (server->flags & NFS_MOUNT_UNSHARED)
1242		compare_super = NULL;
1243
1244	/* -o noac implies -o sync */
1245	if (server->flags & NFS_MOUNT_NOAC)
1246		fc->sb_flags |= SB_SYNCHRONOUS;
1247
1248	if (ctx->clone_data.sb)
1249		if (ctx->clone_data.sb->s_flags & SB_SYNCHRONOUS)
1250			fc->sb_flags |= SB_SYNCHRONOUS;
1251
1252	if (server->caps & NFS_CAP_SECURITY_LABEL)
1253		fc->lsm_flags |= SECURITY_LSM_NATIVE_LABELS;
1254
1255	/* Get a superblock - note that we may end up sharing one that already exists */
1256	fc->s_fs_info = server;
1257	s = sget_fc(fc, compare_super, nfs_set_super);
1258	fc->s_fs_info = NULL;
1259	if (IS_ERR(s)) {
1260		error = PTR_ERR(s);
1261		nfs_errorf(fc, "NFS: Couldn't get superblock");
1262		goto out_err_nosb;
1263	}
1264
1265	if (s->s_fs_info != server) {
1266		nfs_free_server(server);
1267		server = NULL;
1268	} else {
1269		error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
1270					     MINOR(server->s_dev));
1271		if (error)
1272			goto error_splat_super;
1273		s->s_bdi->io_pages = server->rpages;
1274		server->super = s;
1275	}
1276
1277	if (!s->s_root) {
1278		unsigned bsize = ctx->clone_data.inherited_bsize;
1279		/* initial superblock/root creation */
1280		nfs_fill_super(s, ctx);
1281		if (bsize) {
1282			s->s_blocksize_bits = bsize;
1283			s->s_blocksize = 1U << bsize;
1284		}
1285		nfs_get_cache_cookie(s, ctx);
1286	}
1287
1288	error = nfs_get_root(s, fc);
1289	if (error < 0) {
1290		nfs_errorf(fc, "NFS: Couldn't get root dentry");
1291		goto error_splat_super;
1292	}
1293
1294	s->s_flags |= SB_ACTIVE;
1295	error = 0;
1296
1297out:
1298	return error;
1299
1300out_err_nosb:
1301	nfs_free_server(server);
1302	goto out;
1303error_splat_super:
1304	deactivate_locked_super(s);
1305	goto out;
1306}
1307
1308/*
1309 * Destroy an NFS2/3 superblock
1310 */
1311void nfs_kill_super(struct super_block *s)
1312{
1313	struct nfs_server *server = NFS_SB(s);
1314	dev_t dev = s->s_dev;
1315
1316	generic_shutdown_super(s);
1317
1318	nfs_fscache_release_super_cookie(s);
1319
1320	nfs_free_server(server);
1321	free_anon_bdev(dev);
1322}
1323EXPORT_SYMBOL_GPL(nfs_kill_super);
1324
1325#if IS_ENABLED(CONFIG_NFS_V4)
1326
1327/*
1328 * NFS v4 module parameters need to stay in the
1329 * NFS client for backwards compatibility
1330 */
1331unsigned int nfs_callback_set_tcpport;
1332unsigned short nfs_callback_nr_threads;
1333/* Default cache timeout is 10 minutes */
1334unsigned int nfs_idmap_cache_timeout = 600;
1335/* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
1336bool nfs4_disable_idmapping = true;
1337unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
1338unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
1339unsigned short send_implementation_id = 1;
1340char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
1341bool recover_lost_locks = false;
1342
1343EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
1344EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
1345EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
1346EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
1347EXPORT_SYMBOL_GPL(max_session_slots);
1348EXPORT_SYMBOL_GPL(max_session_cb_slots);
1349EXPORT_SYMBOL_GPL(send_implementation_id);
1350EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
1351EXPORT_SYMBOL_GPL(recover_lost_locks);
1352
1353#define NFS_CALLBACK_MAXPORTNR (65535U)
1354
1355static int param_set_portnr(const char *val, const struct kernel_param *kp)
1356{
1357	unsigned long num;
1358	int ret;
1359
1360	if (!val)
1361		return -EINVAL;
1362	ret = kstrtoul(val, 0, &num);
1363	if (ret || num > NFS_CALLBACK_MAXPORTNR)
1364		return -EINVAL;
1365	*((unsigned int *)kp->arg) = num;
1366	return 0;
1367}
1368static const struct kernel_param_ops param_ops_portnr = {
1369	.set = param_set_portnr,
1370	.get = param_get_uint,
1371};
1372#define param_check_portnr(name, p) __param_check(name, p, unsigned int);
1373
1374module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
1375module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
1376MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
1377		"assigned to the NFSv4 callback channels.");
1378module_param(nfs_idmap_cache_timeout, int, 0644);
1379module_param(nfs4_disable_idmapping, bool, 0644);
1380module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
1381			NFS4_CLIENT_ID_UNIQ_LEN, 0600);
1382MODULE_PARM_DESC(nfs4_disable_idmapping,
1383		"Turn off NFSv4 idmapping when using 'sec=sys'");
1384module_param(max_session_slots, ushort, 0644);
1385MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
1386		"requests the client will negotiate");
1387module_param(max_session_cb_slots, ushort, 0644);
1388MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
1389		"callbacks the client will process for a given server");
1390module_param(send_implementation_id, ushort, 0644);
1391MODULE_PARM_DESC(send_implementation_id,
1392		"Send implementation ID with NFSv4.1 exchange_id");
1393MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
1394
1395module_param(recover_lost_locks, bool, 0644);
1396MODULE_PARM_DESC(recover_lost_locks,
1397		 "If the server reports that a lock might be lost, "
1398		 "try to recover it risking data corruption.");
1399
1400
1401#endif /* CONFIG_NFS_V4 */
1402