1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 1992 Rick Sladkey
7 * nfs superblock handling functions
9 * Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some
10 * experimental NFS changes. Modularisation taken straight from SYS5 fs.
12 * Change to nfs_read_super() to permit NFS mounts to multi-homed hosts.
13 * J.S.Peatfield@damtp.cam.ac.uk
15 * Split from inode.c by David Howells <dhowells@redhat.com>
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())
24 #include <linux/module.h>
25 #include <linux/init.h>
27 #include <linux/time.h>
28 #include <linux/kernel.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>
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>
59 #include <linux/uaccess.h>
60 #include <linux/nfs_ssc.h>
64 #include "delegation.h"
68 #include "nfs4session.h"
72 #define NFSDBG_FACILITY NFSDBG_VFS
74 const struct super_operations nfs_sops = {
75 .alloc_inode = nfs_alloc_inode,
76 .free_inode = nfs_free_inode,
77 .write_inode = nfs_write_inode,
78 .drop_inode = nfs_drop_inode,
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,
87 EXPORT_SYMBOL_GPL(nfs_sops);
89 #ifdef CONFIG_NFS_V4_2
90 static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = {
91 .sco_sb_deactive = nfs_sb_deactive,
95 #if IS_ENABLED(CONFIG_NFS_V4)
96 static int __init register_nfs4_fs(void)
98 return register_filesystem(&nfs4_fs_type);
101 static void unregister_nfs4_fs(void)
103 unregister_filesystem(&nfs4_fs_type);
106 static int __init register_nfs4_fs(void)
111 static void unregister_nfs4_fs(void)
116 #ifdef CONFIG_NFS_V4_2
117 static void nfs_ssc_register_ops(void)
119 #ifdef CONFIG_NFSD_V4
120 nfs_ssc_register(&nfs_ssc_clnt_ops_tbl);
124 static void nfs_ssc_unregister_ops(void)
126 #ifdef CONFIG_NFSD_V4
127 nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl);
130 #endif /* CONFIG_NFS_V4_2 */
132 static struct shrinker acl_shrinker = {
133 .count_objects = nfs_access_cache_count,
134 .scan_objects = nfs_access_cache_scan,
135 .seeks = DEFAULT_SEEKS,
139 * Register the NFS filesystems
141 int __init register_nfs_fs(void)
145 ret = register_filesystem(&nfs_fs_type);
149 ret = register_nfs4_fs();
153 ret = nfs_register_sysctl();
156 ret = register_shrinker(&acl_shrinker);
159 #ifdef CONFIG_NFS_V4_2
160 nfs_ssc_register_ops();
164 nfs_unregister_sysctl();
166 unregister_nfs4_fs();
168 unregister_filesystem(&nfs_fs_type);
174 * Unregister the NFS filesystems
176 void __exit unregister_nfs_fs(void)
178 unregister_shrinker(&acl_shrinker);
179 nfs_unregister_sysctl();
180 unregister_nfs4_fs();
181 #ifdef CONFIG_NFS_V4_2
182 nfs_ssc_unregister_ops();
184 unregister_filesystem(&nfs_fs_type);
187 bool nfs_sb_active(struct super_block *sb)
189 struct nfs_server *server = NFS_SB(sb);
191 if (!atomic_inc_not_zero(&sb->s_active))
193 if (atomic_inc_return(&server->active) != 1)
194 atomic_dec(&sb->s_active);
197 EXPORT_SYMBOL_GPL(nfs_sb_active);
199 void nfs_sb_deactive(struct super_block *sb)
201 struct nfs_server *server = NFS_SB(sb);
203 if (atomic_dec_and_test(&server->active))
204 deactivate_super(sb);
206 EXPORT_SYMBOL_GPL(nfs_sb_deactive);
208 static int __nfs_list_for_each_server(struct list_head *head,
209 int (*fn)(struct nfs_server *, void *),
212 struct nfs_server *server, *last = NULL;
216 list_for_each_entry_rcu(server, head, client_link) {
217 if (!(server->super && nfs_sb_active(server->super)))
221 nfs_sb_deactive(last->super);
223 ret = fn(server, data);
231 nfs_sb_deactive(last->super);
235 int nfs_client_for_each_server(struct nfs_client *clp,
236 int (*fn)(struct nfs_server *, void *),
239 return __nfs_list_for_each_server(&clp->cl_superblocks, fn, data);
241 EXPORT_SYMBOL_GPL(nfs_client_for_each_server);
244 * Deliver file system statistics to userspace
246 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf)
248 struct nfs_server *server = NFS_SB(dentry->d_sb);
249 unsigned char blockbits;
250 unsigned long blockres;
251 struct nfs_fh *fh = NFS_FH(d_inode(dentry));
252 struct nfs_fsstat res;
255 res.fattr = nfs_alloc_fattr();
256 if (res.fattr == NULL)
259 error = server->nfs_client->rpc_ops->statfs(server, fh, &res);
260 if (unlikely(error == -ESTALE)) {
261 struct dentry *pd_dentry;
263 pd_dentry = dget_parent(dentry);
264 nfs_zap_caches(d_inode(pd_dentry));
267 nfs_free_fattr(res.fattr);
271 buf->f_type = NFS_SUPER_MAGIC;
274 * Current versions of glibc do not correctly handle the
275 * case where f_frsize != f_bsize. Eventually we want to
276 * report the value of wtmult in this field.
278 buf->f_frsize = dentry->d_sb->s_blocksize;
281 * On most *nix systems, f_blocks, f_bfree, and f_bavail
282 * are reported in units of f_frsize. Linux hasn't had
283 * an f_frsize field in its statfs struct until recently,
284 * thus historically Linux's sys_statfs reports these
285 * fields in units of f_bsize.
287 buf->f_bsize = dentry->d_sb->s_blocksize;
288 blockbits = dentry->d_sb->s_blocksize_bits;
289 blockres = (1 << blockbits) - 1;
290 buf->f_blocks = (res.tbytes + blockres) >> blockbits;
291 buf->f_bfree = (res.fbytes + blockres) >> blockbits;
292 buf->f_bavail = (res.abytes + blockres) >> blockbits;
294 buf->f_files = res.tfiles;
295 buf->f_ffree = res.afiles;
297 buf->f_namelen = server->namelen;
302 dprintk("%s: statfs error = %d\n", __func__, -error);
305 EXPORT_SYMBOL_GPL(nfs_statfs);
308 * Map the security flavour number to a name
310 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour)
312 static const struct {
313 rpc_authflavor_t flavour;
315 } sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = {
316 /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */
317 { RPC_AUTH_NULL, "null" },
318 { RPC_AUTH_UNIX, "sys" },
319 { RPC_AUTH_GSS_KRB5, "krb5" },
320 { RPC_AUTH_GSS_KRB5I, "krb5i" },
321 { RPC_AUTH_GSS_KRB5P, "krb5p" },
322 { RPC_AUTH_GSS_LKEY, "lkey" },
323 { RPC_AUTH_GSS_LKEYI, "lkeyi" },
324 { RPC_AUTH_GSS_LKEYP, "lkeyp" },
325 { RPC_AUTH_GSS_SPKM, "spkm" },
326 { RPC_AUTH_GSS_SPKMI, "spkmi" },
327 { RPC_AUTH_GSS_SPKMP, "spkmp" },
328 { UINT_MAX, "unknown" }
332 for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) {
333 if (sec_flavours[i].flavour == flavour)
336 return sec_flavours[i].str;
339 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss,
342 struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address;
345 switch (sap->sa_family) {
347 switch (nfss->mountd_protocol) {
349 proto = RPCBIND_NETID_UDP;
352 proto = RPCBIND_NETID_TCP;
357 switch (nfss->mountd_protocol) {
359 proto = RPCBIND_NETID_UDP6;
362 proto = RPCBIND_NETID_TCP6;
367 if (proto || showdefaults)
368 seq_printf(m, ",mountproto=%s", proto ?: "auto");
371 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,
374 struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address;
376 if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE)
379 switch (sap->sa_family) {
381 struct sockaddr_in *sin = (struct sockaddr_in *)sap;
382 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr);
386 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
387 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr);
392 seq_puts(m, ",mountaddr=unspecified");
395 if (nfss->mountd_version || showdefaults)
396 seq_printf(m, ",mountvers=%u", nfss->mountd_version);
397 if ((nfss->mountd_port &&
398 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) ||
400 seq_printf(m, ",mountport=%u", nfss->mountd_port);
402 nfs_show_mountd_netid(m, nfss, showdefaults);
405 #if IS_ENABLED(CONFIG_NFS_V4)
406 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
409 struct nfs_client *clp = nfss->nfs_client;
411 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr);
414 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss,
420 static void nfs_show_nfs_version(struct seq_file *m,
421 unsigned int version,
422 unsigned int minorversion)
424 seq_printf(m, ",vers=%u", version);
426 seq_printf(m, ".%u", minorversion);
430 * Describe the mount options in force on this server representation
432 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
435 static const struct proc_nfs_info {
440 { NFS_MOUNT_SOFT, ",soft", "" },
441 { NFS_MOUNT_SOFTERR, ",softerr", "" },
442 { NFS_MOUNT_SOFTREVAL, ",softreval", "" },
443 { NFS_MOUNT_POSIX, ",posix", "" },
444 { NFS_MOUNT_NOCTO, ",nocto", "" },
445 { NFS_MOUNT_NOAC, ",noac", "" },
446 { NFS_MOUNT_NONLM, ",nolock", "" },
447 { NFS_MOUNT_NOACL, ",noacl", "" },
448 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" },
449 { NFS_MOUNT_UNSHARED, ",nosharecache", "" },
450 { NFS_MOUNT_NORESVPORT, ",noresvport", "" },
453 const struct proc_nfs_info *nfs_infop;
454 struct nfs_client *clp = nfss->nfs_client;
455 u32 version = clp->rpc_ops->version;
456 int local_flock, local_fcntl;
458 nfs_show_nfs_version(m, version, clp->cl_minorversion);
459 seq_printf(m, ",rsize=%u", nfss->rsize);
460 seq_printf(m, ",wsize=%u", nfss->wsize);
461 if (nfss->bsize != 0)
462 seq_printf(m, ",bsize=%u", nfss->bsize);
463 seq_printf(m, ",namlen=%u", nfss->namelen);
464 if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults)
465 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ);
466 if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults)
467 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ);
468 if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults)
469 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ);
470 if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults)
471 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ);
472 if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR)))
473 seq_puts(m, ",hard");
474 for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) {
475 if (nfss->flags & nfs_infop->flag)
476 seq_puts(m, nfs_infop->str);
478 seq_puts(m, nfs_infop->nostr);
481 seq_printf(m, ",proto=%s",
482 rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID));
484 if (clp->cl_nconnect > 0)
485 seq_printf(m, ",nconnect=%u", clp->cl_nconnect);
487 if (nfss->port != NFS_PORT)
488 seq_printf(m, ",port=%u", nfss->port);
491 seq_printf(m, ",port=%u", nfss->port);
493 seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ);
494 seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries);
495 seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor));
498 nfs_show_mountd_options(m, nfss, showdefaults);
500 nfs_show_nfsv4_options(m, nfss, showdefaults);
502 if (nfss->options & NFS_OPTION_FSCACHE)
505 if (nfss->options & NFS_OPTION_MIGRATION)
506 seq_puts(m, ",migration");
508 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) {
509 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
510 seq_puts(m, ",lookupcache=none");
512 seq_puts(m, ",lookupcache=pos");
515 local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK;
516 local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL;
518 if (!local_flock && !local_fcntl)
519 seq_puts(m, ",local_lock=none");
520 else if (local_flock && local_fcntl)
521 seq_puts(m, ",local_lock=all");
522 else if (local_flock)
523 seq_puts(m, ",local_lock=flock");
525 seq_puts(m, ",local_lock=posix");
529 * Describe the mount options on this VFS mountpoint
531 int nfs_show_options(struct seq_file *m, struct dentry *root)
533 struct nfs_server *nfss = NFS_SB(root->d_sb);
535 nfs_show_mount_options(m, nfss, 0);
538 seq_printf(m, ",addr=%s",
539 rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient,
545 EXPORT_SYMBOL_GPL(nfs_show_options);
547 #if IS_ENABLED(CONFIG_NFS_V4)
548 static void show_lease(struct seq_file *m, struct nfs_server *server)
550 struct nfs_client *clp = server->nfs_client;
551 unsigned long expire;
553 seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ);
554 expire = clp->cl_last_renewal + clp->cl_lease_time;
555 seq_printf(m, ",lease_expired=%ld",
556 time_after(expire, jiffies) ? 0 : (jiffies - expire) / HZ);
558 #ifdef CONFIG_NFS_V4_1
559 static void show_sessions(struct seq_file *m, struct nfs_server *server)
561 if (nfs4_has_session(server->nfs_client))
562 seq_puts(m, ",sessions");
565 static void show_sessions(struct seq_file *m, struct nfs_server *server) {}
569 #ifdef CONFIG_NFS_V4_1
570 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
572 seq_printf(m, ",pnfs=");
573 if (server->pnfs_curr_ld)
574 seq_printf(m, "%s", server->pnfs_curr_ld->name);
576 seq_printf(m, "not configured");
579 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
581 if (nfss->nfs_client && nfss->nfs_client->cl_implid) {
582 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid;
583 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s',"
585 impl_id->name, impl_id->domain,
586 impl_id->date.seconds, impl_id->date.nseconds);
590 #if IS_ENABLED(CONFIG_NFS_V4)
591 static void show_pnfs(struct seq_file *m, struct nfs_server *server)
595 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss)
600 int nfs_show_devname(struct seq_file *m, struct dentry *root)
602 char *page = (char *) __get_free_page(GFP_KERNEL);
603 char *devname, *dummy;
607 devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0);
609 err = PTR_ERR(devname);
611 seq_escape(m, devname, " \t\n\\");
612 free_page((unsigned long)page);
615 EXPORT_SYMBOL_GPL(nfs_show_devname);
617 int nfs_show_path(struct seq_file *m, struct dentry *dentry)
622 EXPORT_SYMBOL_GPL(nfs_show_path);
625 * Present statistical information for this VFS mountpoint
627 int nfs_show_stats(struct seq_file *m, struct dentry *root)
630 struct nfs_server *nfss = NFS_SB(root->d_sb);
631 struct rpc_auth *auth = nfss->client->cl_auth;
632 struct nfs_iostats totals = { };
634 seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS);
637 * Display all mount option settings
639 seq_puts(m, "\n\topts:\t");
640 seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw");
641 seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : "");
642 seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : "");
643 seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : "");
644 nfs_show_mount_options(m, nfss, 1);
646 seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ);
648 show_implementation_id(m, nfss);
650 seq_puts(m, "\n\tcaps:\t");
651 seq_printf(m, "caps=0x%x", nfss->caps);
652 seq_printf(m, ",wtmult=%u", nfss->wtmult);
653 seq_printf(m, ",dtsize=%u", nfss->dtsize);
654 seq_printf(m, ",bsize=%u", nfss->bsize);
655 seq_printf(m, ",namlen=%u", nfss->namelen);
657 #if IS_ENABLED(CONFIG_NFS_V4)
658 if (nfss->nfs_client->rpc_ops->version == 4) {
659 seq_puts(m, "\n\tnfsv4:\t");
660 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]);
661 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]);
662 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]);
663 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask);
664 show_sessions(m, nfss);
671 * Display security flavor in effect for this mount
673 seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor);
675 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor);
678 * Display superblock I/O counters
680 for_each_possible_cpu(cpu) {
681 struct nfs_iostats *stats;
684 stats = per_cpu_ptr(nfss->io_stats, cpu);
686 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
687 totals.events[i] += stats->events[i];
688 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
689 totals.bytes[i] += stats->bytes[i];
690 #ifdef CONFIG_NFS_FSCACHE
691 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
692 totals.fscache[i] += stats->fscache[i];
698 seq_puts(m, "\n\tevents:\t");
699 for (i = 0; i < __NFSIOS_COUNTSMAX; i++)
700 seq_printf(m, "%lu ", totals.events[i]);
701 seq_puts(m, "\n\tbytes:\t");
702 for (i = 0; i < __NFSIOS_BYTESMAX; i++)
703 seq_printf(m, "%Lu ", totals.bytes[i]);
704 #ifdef CONFIG_NFS_FSCACHE
705 if (nfss->options & NFS_OPTION_FSCACHE) {
706 seq_puts(m, "\n\tfsc:\t");
707 for (i = 0; i < __NFSIOS_FSCACHEMAX; i++)
708 seq_printf(m, "%Lu ", totals.fscache[i]);
713 rpc_clnt_show_stats(m, nfss->client);
717 EXPORT_SYMBOL_GPL(nfs_show_stats);
720 * Begin unmount by attempting to remove all automounted mountpoints we added
721 * in response to xdev traversals and referrals
723 void nfs_umount_begin(struct super_block *sb)
725 struct nfs_server *server;
726 struct rpc_clnt *rpc;
729 /* -EIO all pending I/O */
730 rpc = server->client_acl;
732 rpc_killall_tasks(rpc);
733 rpc = server->client;
735 rpc_killall_tasks(rpc);
737 EXPORT_SYMBOL_GPL(nfs_umount_begin);
740 * Return true if 'match' is in auth_info or auth_info is empty.
741 * Return false otherwise.
743 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info,
744 rpc_authflavor_t match)
748 if (!auth_info->flavor_len)
751 for (i = 0; i < auth_info->flavor_len; i++) {
752 if (auth_info->flavors[i] == match)
757 EXPORT_SYMBOL_GPL(nfs_auth_info_match);
760 * Ensure that a specified authtype in ctx->auth_info is supported by
761 * the server. Returns 0 and sets ctx->selected_flavor if it's ok, and
764 static int nfs_verify_authflavors(struct nfs_fs_context *ctx,
765 rpc_authflavor_t *server_authlist,
768 rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR;
769 bool found_auth_null = false;
773 * If the sec= mount option is used, the specified flavor or AUTH_NULL
774 * must be in the list returned by the server.
776 * AUTH_NULL has a special meaning when it's in the server list - it
777 * means that the server will ignore the rpc creds, so any flavor
778 * can be used but still use the sec= that was specified.
780 * Note also that the MNT procedure in MNTv1 does not return a list
781 * of supported security flavors. In this case, nfs_mount() fabricates
782 * a security flavor list containing just AUTH_NULL.
784 for (i = 0; i < count; i++) {
785 flavor = server_authlist[i];
787 if (nfs_auth_info_match(&ctx->auth_info, flavor))
790 if (flavor == RPC_AUTH_NULL)
791 found_auth_null = true;
794 if (found_auth_null) {
795 flavor = ctx->auth_info.flavors[0];
800 "NFS: specified auth flavors not supported by server\n");
804 ctx->selected_flavor = flavor;
805 dfprintk(MOUNT, "NFS: using auth flavor %u\n", ctx->selected_flavor);
810 * Use the remote server's MOUNT service to request the NFS file handle
811 * corresponding to the provided path.
813 static int nfs_request_mount(struct fs_context *fc,
814 struct nfs_fh *root_fh,
815 rpc_authflavor_t *server_authlist,
816 unsigned int *server_authlist_len)
818 struct nfs_fs_context *ctx = nfs_fc2context(fc);
819 struct nfs_mount_request request = {
820 .sap = (struct sockaddr *)
821 &ctx->mount_server.address,
822 .dirpath = ctx->nfs_server.export_path,
823 .protocol = ctx->mount_server.protocol,
825 .noresvport = ctx->flags & NFS_MOUNT_NORESVPORT,
826 .auth_flav_len = server_authlist_len,
827 .auth_flavs = server_authlist,
832 if (ctx->mount_server.version == 0) {
833 switch (ctx->version) {
835 ctx->mount_server.version = NFS_MNT3_VERSION;
838 ctx->mount_server.version = NFS_MNT_VERSION;
841 request.version = ctx->mount_server.version;
843 if (ctx->mount_server.hostname)
844 request.hostname = ctx->mount_server.hostname;
846 request.hostname = ctx->nfs_server.hostname;
849 * Construct the mount server's address.
851 if (ctx->mount_server.address.sa_family == AF_UNSPEC) {
852 memcpy(request.sap, &ctx->nfs_server.address,
853 ctx->nfs_server.addrlen);
854 ctx->mount_server.addrlen = ctx->nfs_server.addrlen;
856 request.salen = ctx->mount_server.addrlen;
857 nfs_set_port(request.sap, &ctx->mount_server.port, 0);
860 * Now ask the mount server to map our export path
863 status = nfs_mount(&request);
865 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n",
866 request.hostname, status);
873 static struct nfs_server *nfs_try_mount_request(struct fs_context *fc)
875 struct nfs_fs_context *ctx = nfs_fc2context(fc);
878 bool tried_auth_unix = false;
879 bool auth_null_in_list = false;
880 struct nfs_server *server = ERR_PTR(-EACCES);
881 rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS];
882 unsigned int authlist_len = ARRAY_SIZE(authlist);
884 status = nfs_request_mount(fc, ctx->mntfh, authlist, &authlist_len);
886 return ERR_PTR(status);
889 * Was a sec= authflavor specified in the options? First, verify
890 * whether the server supports it, and then just try to use it if so.
892 if (ctx->auth_info.flavor_len > 0) {
893 status = nfs_verify_authflavors(ctx, authlist, authlist_len);
894 dfprintk(MOUNT, "NFS: using auth flavor %u\n",
895 ctx->selected_flavor);
897 return ERR_PTR(status);
898 return ctx->nfs_mod->rpc_ops->create_server(fc);
902 * No sec= option was provided. RFC 2623, section 2.7 suggests we
903 * SHOULD prefer the flavor listed first. However, some servers list
904 * AUTH_NULL first. Avoid ever choosing AUTH_NULL.
906 for (i = 0; i < authlist_len; ++i) {
907 rpc_authflavor_t flavor;
908 struct rpcsec_gss_info info;
910 flavor = authlist[i];
913 tried_auth_unix = true;
916 auth_null_in_list = true;
919 if (rpcauth_get_gssinfo(flavor, &info) != 0)
923 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor);
924 ctx->selected_flavor = flavor;
925 server = ctx->nfs_mod->rpc_ops->create_server(fc);
931 * Nothing we tried so far worked. At this point, give up if we've
932 * already tried AUTH_UNIX or if the server's list doesn't contain
935 if (tried_auth_unix || !auth_null_in_list)
938 /* Last chance! Try AUTH_UNIX */
939 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX);
940 ctx->selected_flavor = RPC_AUTH_UNIX;
941 return ctx->nfs_mod->rpc_ops->create_server(fc);
944 int nfs_try_get_tree(struct fs_context *fc)
946 struct nfs_fs_context *ctx = nfs_fc2context(fc);
949 ctx->server = nfs_try_mount_request(fc);
951 ctx->server = ctx->nfs_mod->rpc_ops->create_server(fc);
953 return nfs_get_tree_common(fc);
955 EXPORT_SYMBOL_GPL(nfs_try_get_tree);
958 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \
962 | NFS_MOUNT_KERBEROS \
964 | NFS_MOUNT_BROKEN_SUID \
965 | NFS_MOUNT_STRICTLOCK \
966 | NFS_MOUNT_LEGACY_INTERFACE)
968 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \
969 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT))
972 nfs_compare_remount_data(struct nfs_server *nfss,
973 struct nfs_fs_context *ctx)
975 if ((ctx->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK ||
976 ctx->rsize != nfss->rsize ||
977 ctx->wsize != nfss->wsize ||
978 ctx->version != nfss->nfs_client->rpc_ops->version ||
979 ctx->minorversion != nfss->nfs_client->cl_minorversion ||
980 ctx->retrans != nfss->client->cl_timeout->to_retries ||
981 !nfs_auth_info_match(&ctx->auth_info, nfss->client->cl_auth->au_flavor) ||
982 ctx->acregmin != nfss->acregmin / HZ ||
983 ctx->acregmax != nfss->acregmax / HZ ||
984 ctx->acdirmin != nfss->acdirmin / HZ ||
985 ctx->acdirmax != nfss->acdirmax / HZ ||
986 ctx->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) ||
987 (ctx->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) ||
988 ctx->nfs_server.port != nfss->port ||
989 ctx->nfs_server.addrlen != nfss->nfs_client->cl_addrlen ||
990 !rpc_cmp_addr((struct sockaddr *)&ctx->nfs_server.address,
991 (struct sockaddr *)&nfss->nfs_client->cl_addr))
997 int nfs_reconfigure(struct fs_context *fc)
999 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1000 struct super_block *sb = fc->root->d_sb;
1001 struct nfs_server *nfss = sb->s_fs_info;
1003 sync_filesystem(sb);
1006 * Userspace mount programs that send binary options generally send
1007 * them populated with default values. We have no way to know which
1008 * ones were explicitly specified. Fall back to legacy behavior and
1009 * just return success.
1011 if (ctx->skip_reconfig_option_check)
1015 * noac is a special case. It implies -o sync, but that's not
1016 * necessarily reflected in the mtab options. reconfigure_super
1017 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the
1018 * remount options, so we have to explicitly reset it.
1020 if (ctx->flags & NFS_MOUNT_NOAC) {
1021 fc->sb_flags |= SB_SYNCHRONOUS;
1022 fc->sb_flags_mask |= SB_SYNCHRONOUS;
1025 /* compare new mount options with old ones */
1026 return nfs_compare_remount_data(nfss, ctx);
1028 EXPORT_SYMBOL_GPL(nfs_reconfigure);
1031 * Finish setting up an NFS superblock
1033 static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx)
1035 struct nfs_server *server = NFS_SB(sb);
1037 sb->s_blocksize_bits = 0;
1038 sb->s_blocksize = 0;
1039 sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr;
1040 sb->s_op = server->nfs_client->cl_nfs_mod->sops;
1041 if (ctx && ctx->bsize)
1042 sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits);
1044 if (server->nfs_client->rpc_ops->version != 2) {
1045 /* The VFS shouldn't apply the umask to mode bits. We will do
1046 * so ourselves when necessary.
1048 sb->s_flags |= SB_POSIXACL;
1049 sb->s_time_gran = 1;
1050 sb->s_export_op = &nfs_export_ops;
1052 sb->s_time_gran = 1000;
1054 if (server->nfs_client->rpc_ops->version != 4) {
1056 sb->s_time_max = U32_MAX;
1058 sb->s_time_min = S64_MIN;
1059 sb->s_time_max = S64_MAX;
1062 sb->s_magic = NFS_SUPER_MAGIC;
1064 /* We probably want something more informative here */
1065 snprintf(sb->s_id, sizeof(sb->s_id),
1066 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev));
1068 if (sb->s_blocksize == 0)
1069 sb->s_blocksize = nfs_block_bits(server->wsize,
1070 &sb->s_blocksize_bits);
1072 nfs_super_set_maxbytes(sb, server->maxfilesize);
1075 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b,
1076 const struct fs_context *fc)
1078 const struct nfs_server *a = s->s_fs_info;
1079 const struct rpc_clnt *clnt_a = a->client;
1080 const struct rpc_clnt *clnt_b = b->client;
1082 if ((s->s_flags & NFS_SB_MASK) != (fc->sb_flags & NFS_SB_MASK))
1084 if (a->nfs_client != b->nfs_client)
1086 if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK)
1088 if (a->wsize != b->wsize)
1090 if (a->rsize != b->rsize)
1092 if (a->acregmin != b->acregmin)
1094 if (a->acregmax != b->acregmax)
1096 if (a->acdirmin != b->acdirmin)
1098 if (a->acdirmax != b->acdirmax)
1100 if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor)
1107 static int nfs_set_super(struct super_block *s, struct fs_context *fc)
1109 struct nfs_server *server = fc->s_fs_info;
1112 s->s_d_op = server->nfs_client->rpc_ops->dentry_ops;
1113 ret = set_anon_super(s, server);
1115 server->s_dev = s->s_dev;
1119 static int nfs_compare_super_address(struct nfs_server *server1,
1120 struct nfs_server *server2)
1122 struct sockaddr *sap1, *sap2;
1123 struct rpc_xprt *xprt1 = server1->client->cl_xprt;
1124 struct rpc_xprt *xprt2 = server2->client->cl_xprt;
1126 if (!net_eq(xprt1->xprt_net, xprt2->xprt_net))
1129 sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
1130 sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
1132 if (sap1->sa_family != sap2->sa_family)
1135 switch (sap1->sa_family) {
1137 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
1138 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
1139 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
1141 if (sin1->sin_port != sin2->sin_port)
1146 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
1147 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
1148 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
1150 if (sin1->sin6_port != sin2->sin6_port)
1161 static int nfs_compare_userns(const struct nfs_server *old,
1162 const struct nfs_server *new)
1164 const struct user_namespace *oldns = &init_user_ns;
1165 const struct user_namespace *newns = &init_user_ns;
1167 if (old->client && old->client->cl_cred)
1168 oldns = old->client->cl_cred->user_ns;
1169 if (new->client && new->client->cl_cred)
1170 newns = new->client->cl_cred->user_ns;
1176 static int nfs_compare_super(struct super_block *sb, struct fs_context *fc)
1178 struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb);
1180 if (!nfs_compare_super_address(old, server))
1182 /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
1183 if (old->flags & NFS_MOUNT_UNSHARED)
1185 if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0)
1187 if (!nfs_compare_userns(old, server))
1189 return nfs_compare_mount_options(sb, server, fc);
1192 #ifdef CONFIG_NFS_FSCACHE
1193 static void nfs_get_cache_cookie(struct super_block *sb,
1194 struct nfs_fs_context *ctx)
1196 struct nfs_server *nfss = NFS_SB(sb);
1200 nfss->fscache_key = NULL;
1201 nfss->fscache = NULL;
1206 if (ctx->clone_data.sb) {
1207 struct nfs_server *mnt_s = NFS_SB(ctx->clone_data.sb);
1208 if (!(mnt_s->options & NFS_OPTION_FSCACHE))
1210 if (mnt_s->fscache_key) {
1211 uniq = mnt_s->fscache_key->key.uniquifier;
1212 ulen = mnt_s->fscache_key->key.uniq_len;
1215 if (!(ctx->options & NFS_OPTION_FSCACHE))
1217 if (ctx->fscache_uniq) {
1218 uniq = ctx->fscache_uniq;
1219 ulen = strlen(ctx->fscache_uniq);
1223 nfs_fscache_get_super_cookie(sb, uniq, ulen);
1226 static void nfs_get_cache_cookie(struct super_block *sb,
1227 struct nfs_fs_context *ctx)
1232 int nfs_get_tree_common(struct fs_context *fc)
1234 struct nfs_fs_context *ctx = nfs_fc2context(fc);
1235 struct super_block *s;
1236 int (*compare_super)(struct super_block *, struct fs_context *) = nfs_compare_super;
1237 struct nfs_server *server = ctx->server;
1242 return PTR_ERR(server);
1244 if (server->flags & NFS_MOUNT_UNSHARED)
1245 compare_super = NULL;
1247 /* -o noac implies -o sync */
1248 if (server->flags & NFS_MOUNT_NOAC)
1249 fc->sb_flags |= SB_SYNCHRONOUS;
1251 if (ctx->clone_data.sb)
1252 if (ctx->clone_data.sb->s_flags & SB_SYNCHRONOUS)
1253 fc->sb_flags |= SB_SYNCHRONOUS;
1255 if (server->caps & NFS_CAP_SECURITY_LABEL)
1256 fc->lsm_flags |= SECURITY_LSM_NATIVE_LABELS;
1258 /* Get a superblock - note that we may end up sharing one that already exists */
1259 fc->s_fs_info = server;
1260 s = sget_fc(fc, compare_super, nfs_set_super);
1261 fc->s_fs_info = NULL;
1264 nfs_errorf(fc, "NFS: Couldn't get superblock");
1268 if (s->s_fs_info != server) {
1269 nfs_free_server(server);
1272 error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev),
1273 MINOR(server->s_dev));
1275 goto error_splat_super;
1276 s->s_bdi->io_pages = server->rpages;
1281 unsigned bsize = ctx->clone_data.inherited_bsize;
1282 /* initial superblock/root creation */
1283 nfs_fill_super(s, ctx);
1285 s->s_blocksize_bits = bsize;
1286 s->s_blocksize = 1U << bsize;
1288 nfs_get_cache_cookie(s, ctx);
1291 error = nfs_get_root(s, fc);
1293 nfs_errorf(fc, "NFS: Couldn't get root dentry");
1294 goto error_splat_super;
1297 s->s_flags |= SB_ACTIVE;
1304 nfs_free_server(server);
1307 deactivate_locked_super(s);
1312 * Destroy an NFS2/3 superblock
1314 void nfs_kill_super(struct super_block *s)
1316 struct nfs_server *server = NFS_SB(s);
1317 dev_t dev = s->s_dev;
1319 generic_shutdown_super(s);
1321 nfs_fscache_release_super_cookie(s);
1323 nfs_free_server(server);
1324 free_anon_bdev(dev);
1326 EXPORT_SYMBOL_GPL(nfs_kill_super);
1328 #if IS_ENABLED(CONFIG_NFS_V4)
1331 * NFS v4 module parameters need to stay in the
1332 * NFS client for backwards compatibility
1334 unsigned int nfs_callback_set_tcpport;
1335 unsigned short nfs_callback_nr_threads;
1336 /* Default cache timeout is 10 minutes */
1337 unsigned int nfs_idmap_cache_timeout = 600;
1338 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */
1339 bool nfs4_disable_idmapping = true;
1340 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE;
1341 unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE;
1342 unsigned short send_implementation_id = 1;
1343 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = "";
1344 bool recover_lost_locks = false;
1346 EXPORT_SYMBOL_GPL(nfs_callback_nr_threads);
1347 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport);
1348 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout);
1349 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping);
1350 EXPORT_SYMBOL_GPL(max_session_slots);
1351 EXPORT_SYMBOL_GPL(max_session_cb_slots);
1352 EXPORT_SYMBOL_GPL(send_implementation_id);
1353 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier);
1354 EXPORT_SYMBOL_GPL(recover_lost_locks);
1356 #define NFS_CALLBACK_MAXPORTNR (65535U)
1358 static int param_set_portnr(const char *val, const struct kernel_param *kp)
1365 ret = kstrtoul(val, 0, &num);
1366 if (ret || num > NFS_CALLBACK_MAXPORTNR)
1368 *((unsigned int *)kp->arg) = num;
1371 static const struct kernel_param_ops param_ops_portnr = {
1372 .set = param_set_portnr,
1373 .get = param_get_uint,
1375 #define param_check_portnr(name, p) __param_check(name, p, unsigned int);
1377 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644);
1378 module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644);
1379 MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be "
1380 "assigned to the NFSv4 callback channels.");
1381 module_param(nfs_idmap_cache_timeout, int, 0644);
1382 module_param(nfs4_disable_idmapping, bool, 0644);
1383 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier,
1384 NFS4_CLIENT_ID_UNIQ_LEN, 0600);
1385 MODULE_PARM_DESC(nfs4_disable_idmapping,
1386 "Turn off NFSv4 idmapping when using 'sec=sys'");
1387 module_param(max_session_slots, ushort, 0644);
1388 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 "
1389 "requests the client will negotiate");
1390 module_param(max_session_cb_slots, ushort, 0644);
1391 MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 "
1392 "callbacks the client will process for a given server");
1393 module_param(send_implementation_id, ushort, 0644);
1394 MODULE_PARM_DESC(send_implementation_id,
1395 "Send implementation ID with NFSv4.1 exchange_id");
1396 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string");
1398 module_param(recover_lost_locks, bool, 0644);
1399 MODULE_PARM_DESC(recover_lost_locks,
1400 "If the server reports that a lock might be lost, "
1401 "try to recover it risking data corruption.");
1404 #endif /* CONFIG_NFS_V4 */