1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/fs/nfs/super.c 4 * 5 * Copyright (C) 1992 Rick Sladkey 6 * 7 * nfs superblock handling functions 8 * 9 * Modularised by Alan Cox <alan@lxorguk.ukuu.org.uk>, while hacking some 10 * experimental NFS changes. Modularisation taken straight from SYS5 fs. 11 * 12 * Change to nfs_read_super() to permit NFS mounts to multi-homed hosts. 13 * J.S.Peatfield@damtp.cam.ac.uk 14 * 15 * Split from inode.c by David Howells <dhowells@redhat.com> 16 * 17 * - superblocks are indexed on server only - all inodes, dentries, etc. associated with a 18 * particular server are held in the same superblock 19 * - NFS superblocks can have several effective roots to the dentry tree 20 * - directory type roots are spliced into the tree when a path from one root reaches the root 21 * of another (see nfs_lookup()) 22 */ 23 24 #include <linux/module.h> 25 #include <linux/init.h> 26 27 #include <linux/time.h> 28 #include <linux/kernel.h> 29 #include <linux/mm.h> 30 #include <linux/string.h> 31 #include <linux/stat.h> 32 #include <linux/errno.h> 33 #include <linux/unistd.h> 34 #include <linux/sunrpc/clnt.h> 35 #include <linux/sunrpc/addr.h> 36 #include <linux/sunrpc/stats.h> 37 #include <linux/sunrpc/metrics.h> 38 #include <linux/sunrpc/xprtsock.h> 39 #include <linux/sunrpc/xprtrdma.h> 40 #include <linux/nfs_fs.h> 41 #include <linux/nfs_mount.h> 42 #include <linux/nfs4_mount.h> 43 #include <linux/lockd/bind.h> 44 #include <linux/seq_file.h> 45 #include <linux/mount.h> 46 #include <linux/namei.h> 47 #include <linux/vfs.h> 48 #include <linux/inet.h> 49 #include <linux/in6.h> 50 #include <linux/sched.h> 51 #include <linux/slab.h> 52 #include <net/ipv6.h> 53 #include <linux/netdevice.h> 54 #include <linux/nfs_xdr.h> 55 #include <linux/magic.h> 56 #include <linux/parser.h> 57 #include <linux/nsproxy.h> 58 #include <linux/rcupdate.h> 59 60 #include <linux/uaccess.h> 61 #include <linux/nfs_ssc.h> 62 63 #include <uapi/linux/tls.h> 64 65 #include "nfs4_fs.h" 66 #include "callback.h" 67 #include "delegation.h" 68 #include "iostat.h" 69 #include "internal.h" 70 #include "fscache.h" 71 #include "nfs4session.h" 72 #include "pnfs.h" 73 #include "nfs.h" 74 #include "netns.h" 75 #include "sysfs.h" 76 #include "nfs4idmap.h" 77 78 #define NFSDBG_FACILITY NFSDBG_VFS 79 80 const struct super_operations nfs_sops = { 81 .alloc_inode = nfs_alloc_inode, 82 .free_inode = nfs_free_inode, 83 .write_inode = nfs_write_inode, 84 .drop_inode = nfs_drop_inode, 85 .statfs = nfs_statfs, 86 .evict_inode = nfs_evict_inode, 87 .umount_begin = nfs_umount_begin, 88 .show_options = nfs_show_options, 89 .show_devname = nfs_show_devname, 90 .show_path = nfs_show_path, 91 .show_stats = nfs_show_stats, 92 }; 93 EXPORT_SYMBOL_GPL(nfs_sops); 94 95 #ifdef CONFIG_NFS_V4_2 96 static const struct nfs_ssc_client_ops nfs_ssc_clnt_ops_tbl = { 97 .sco_sb_deactive = nfs_sb_deactive, 98 }; 99 #endif 100 101 #if IS_ENABLED(CONFIG_NFS_V4) 102 static int __init register_nfs4_fs(void) 103 { 104 return register_filesystem(&nfs4_fs_type); 105 } 106 107 static void unregister_nfs4_fs(void) 108 { 109 unregister_filesystem(&nfs4_fs_type); 110 } 111 #else 112 static int __init register_nfs4_fs(void) 113 { 114 return 0; 115 } 116 117 static void unregister_nfs4_fs(void) 118 { 119 } 120 #endif 121 122 #ifdef CONFIG_NFS_V4_2 123 static void nfs_ssc_register_ops(void) 124 { 125 nfs_ssc_register(&nfs_ssc_clnt_ops_tbl); 126 } 127 128 static void nfs_ssc_unregister_ops(void) 129 { 130 nfs_ssc_unregister(&nfs_ssc_clnt_ops_tbl); 131 } 132 #endif /* CONFIG_NFS_V4_2 */ 133 134 static struct shrinker *acl_shrinker; 135 136 /* 137 * Register the NFS filesystems 138 */ 139 int __init register_nfs_fs(void) 140 { 141 int ret; 142 143 ret = register_filesystem(&nfs_fs_type); 144 if (ret < 0) 145 goto error_0; 146 147 ret = register_nfs4_fs(); 148 if (ret < 0) 149 goto error_1; 150 151 ret = nfs_register_sysctl(); 152 if (ret < 0) 153 goto error_2; 154 155 acl_shrinker = shrinker_alloc(0, "nfs-acl"); 156 if (!acl_shrinker) { 157 ret = -ENOMEM; 158 goto error_3; 159 } 160 161 acl_shrinker->count_objects = nfs_access_cache_count; 162 acl_shrinker->scan_objects = nfs_access_cache_scan; 163 164 shrinker_register(acl_shrinker); 165 166 #ifdef CONFIG_NFS_V4_2 167 nfs_ssc_register_ops(); 168 #endif 169 return 0; 170 error_3: 171 nfs_unregister_sysctl(); 172 error_2: 173 unregister_nfs4_fs(); 174 error_1: 175 unregister_filesystem(&nfs_fs_type); 176 error_0: 177 return ret; 178 } 179 180 /* 181 * Unregister the NFS filesystems 182 */ 183 void __exit unregister_nfs_fs(void) 184 { 185 shrinker_free(acl_shrinker); 186 nfs_unregister_sysctl(); 187 unregister_nfs4_fs(); 188 #ifdef CONFIG_NFS_V4_2 189 nfs_ssc_unregister_ops(); 190 #endif 191 unregister_filesystem(&nfs_fs_type); 192 } 193 194 bool nfs_sb_active(struct super_block *sb) 195 { 196 struct nfs_server *server = NFS_SB(sb); 197 198 if (!atomic_inc_not_zero(&sb->s_active)) 199 return false; 200 if (atomic_inc_return(&server->active) != 1) 201 atomic_dec(&sb->s_active); 202 return true; 203 } 204 EXPORT_SYMBOL_GPL(nfs_sb_active); 205 206 void nfs_sb_deactive(struct super_block *sb) 207 { 208 struct nfs_server *server = NFS_SB(sb); 209 210 if (atomic_dec_and_test(&server->active)) 211 deactivate_super(sb); 212 } 213 EXPORT_SYMBOL_GPL(nfs_sb_deactive); 214 215 static int __nfs_list_for_each_server(struct list_head *head, 216 int (*fn)(struct nfs_server *, void *), 217 void *data) 218 { 219 struct nfs_server *server, *last = NULL; 220 int ret = 0; 221 222 rcu_read_lock(); 223 list_for_each_entry_rcu(server, head, client_link) { 224 if (!(server->super && nfs_sb_active(server->super))) 225 continue; 226 rcu_read_unlock(); 227 if (last) 228 nfs_sb_deactive(last->super); 229 last = server; 230 ret = fn(server, data); 231 if (ret) 232 goto out; 233 cond_resched(); 234 rcu_read_lock(); 235 } 236 rcu_read_unlock(); 237 out: 238 if (last) 239 nfs_sb_deactive(last->super); 240 return ret; 241 } 242 243 int nfs_client_for_each_server(struct nfs_client *clp, 244 int (*fn)(struct nfs_server *, void *), 245 void *data) 246 { 247 return __nfs_list_for_each_server(&clp->cl_superblocks, fn, data); 248 } 249 EXPORT_SYMBOL_GPL(nfs_client_for_each_server); 250 251 /* 252 * Deliver file system statistics to userspace 253 */ 254 int nfs_statfs(struct dentry *dentry, struct kstatfs *buf) 255 { 256 struct nfs_server *server = NFS_SB(dentry->d_sb); 257 unsigned char blockbits; 258 unsigned long blockres; 259 struct nfs_fh *fh = NFS_FH(d_inode(dentry)); 260 struct nfs_fsstat res; 261 int error = -ENOMEM; 262 263 res.fattr = nfs_alloc_fattr(); 264 if (res.fattr == NULL) 265 goto out_err; 266 267 error = server->nfs_client->rpc_ops->statfs(server, fh, &res); 268 if (unlikely(error == -ESTALE)) { 269 struct dentry *pd_dentry; 270 271 pd_dentry = dget_parent(dentry); 272 nfs_zap_caches(d_inode(pd_dentry)); 273 dput(pd_dentry); 274 } 275 nfs_free_fattr(res.fattr); 276 if (error < 0) 277 goto out_err; 278 279 buf->f_type = NFS_SUPER_MAGIC; 280 281 /* 282 * Current versions of glibc do not correctly handle the 283 * case where f_frsize != f_bsize. Eventually we want to 284 * report the value of wtmult in this field. 285 */ 286 buf->f_frsize = dentry->d_sb->s_blocksize; 287 288 /* 289 * On most *nix systems, f_blocks, f_bfree, and f_bavail 290 * are reported in units of f_frsize. Linux hasn't had 291 * an f_frsize field in its statfs struct until recently, 292 * thus historically Linux's sys_statfs reports these 293 * fields in units of f_bsize. 294 */ 295 buf->f_bsize = dentry->d_sb->s_blocksize; 296 blockbits = dentry->d_sb->s_blocksize_bits; 297 blockres = (1 << blockbits) - 1; 298 buf->f_blocks = (res.tbytes + blockres) >> blockbits; 299 buf->f_bfree = (res.fbytes + blockres) >> blockbits; 300 buf->f_bavail = (res.abytes + blockres) >> blockbits; 301 302 buf->f_files = res.tfiles; 303 buf->f_ffree = res.afiles; 304 305 buf->f_namelen = server->namelen; 306 307 return 0; 308 309 out_err: 310 dprintk("%s: statfs error = %d\n", __func__, -error); 311 return error; 312 } 313 EXPORT_SYMBOL_GPL(nfs_statfs); 314 315 /* 316 * Map the security flavour number to a name 317 */ 318 static const char *nfs_pseudoflavour_to_name(rpc_authflavor_t flavour) 319 { 320 static const struct { 321 rpc_authflavor_t flavour; 322 const char *str; 323 } sec_flavours[NFS_AUTH_INFO_MAX_FLAVORS] = { 324 /* update NFS_AUTH_INFO_MAX_FLAVORS when this list changes! */ 325 { RPC_AUTH_NULL, "null" }, 326 { RPC_AUTH_UNIX, "sys" }, 327 { RPC_AUTH_GSS_KRB5, "krb5" }, 328 { RPC_AUTH_GSS_KRB5I, "krb5i" }, 329 { RPC_AUTH_GSS_KRB5P, "krb5p" }, 330 { RPC_AUTH_GSS_LKEY, "lkey" }, 331 { RPC_AUTH_GSS_LKEYI, "lkeyi" }, 332 { RPC_AUTH_GSS_LKEYP, "lkeyp" }, 333 { RPC_AUTH_GSS_SPKM, "spkm" }, 334 { RPC_AUTH_GSS_SPKMI, "spkmi" }, 335 { RPC_AUTH_GSS_SPKMP, "spkmp" }, 336 { UINT_MAX, "unknown" } 337 }; 338 int i; 339 340 for (i = 0; sec_flavours[i].flavour != UINT_MAX; i++) { 341 if (sec_flavours[i].flavour == flavour) 342 break; 343 } 344 return sec_flavours[i].str; 345 } 346 347 static void nfs_show_mountd_netid(struct seq_file *m, struct nfs_server *nfss, 348 int showdefaults) 349 { 350 struct sockaddr *sap = (struct sockaddr *) &nfss->mountd_address; 351 char *proto = NULL; 352 353 switch (sap->sa_family) { 354 case AF_INET: 355 switch (nfss->mountd_protocol) { 356 case IPPROTO_UDP: 357 proto = RPCBIND_NETID_UDP; 358 break; 359 case IPPROTO_TCP: 360 proto = RPCBIND_NETID_TCP; 361 break; 362 } 363 break; 364 case AF_INET6: 365 switch (nfss->mountd_protocol) { 366 case IPPROTO_UDP: 367 proto = RPCBIND_NETID_UDP6; 368 break; 369 case IPPROTO_TCP: 370 proto = RPCBIND_NETID_TCP6; 371 break; 372 } 373 break; 374 } 375 if (proto || showdefaults) 376 seq_printf(m, ",mountproto=%s", proto ?: "auto"); 377 } 378 379 static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss, 380 int showdefaults) 381 { 382 struct sockaddr *sap = (struct sockaddr *)&nfss->mountd_address; 383 384 if (nfss->flags & NFS_MOUNT_LEGACY_INTERFACE) 385 return; 386 387 switch (sap->sa_family) { 388 case AF_INET: { 389 struct sockaddr_in *sin = (struct sockaddr_in *)sap; 390 seq_printf(m, ",mountaddr=%pI4", &sin->sin_addr.s_addr); 391 break; 392 } 393 case AF_INET6: { 394 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap; 395 seq_printf(m, ",mountaddr=%pI6c", &sin6->sin6_addr); 396 break; 397 } 398 default: 399 if (showdefaults) 400 seq_puts(m, ",mountaddr=unspecified"); 401 } 402 403 if (nfss->mountd_version || showdefaults) 404 seq_printf(m, ",mountvers=%u", nfss->mountd_version); 405 if ((nfss->mountd_port && 406 nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) || 407 showdefaults) 408 seq_printf(m, ",mountport=%u", nfss->mountd_port); 409 410 nfs_show_mountd_netid(m, nfss, showdefaults); 411 } 412 413 #if IS_ENABLED(CONFIG_NFS_V4) 414 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss, 415 int showdefaults) 416 { 417 struct nfs_client *clp = nfss->nfs_client; 418 419 seq_printf(m, ",clientaddr=%s", clp->cl_ipaddr); 420 } 421 #else 422 static void nfs_show_nfsv4_options(struct seq_file *m, struct nfs_server *nfss, 423 int showdefaults) 424 { 425 } 426 #endif 427 428 static void nfs_show_nfs_version(struct seq_file *m, 429 unsigned int version, 430 unsigned int minorversion) 431 { 432 seq_printf(m, ",vers=%u", version); 433 if (version == 4) 434 seq_printf(m, ".%u", minorversion); 435 } 436 437 /* 438 * Describe the mount options in force on this server representation 439 */ 440 static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss, 441 int showdefaults) 442 { 443 static const struct proc_nfs_info { 444 int flag; 445 const char *str; 446 const char *nostr; 447 } nfs_info[] = { 448 { NFS_MOUNT_SOFT, ",soft", "" }, 449 { NFS_MOUNT_SOFTERR, ",softerr", "" }, 450 { NFS_MOUNT_SOFTREVAL, ",softreval", "" }, 451 { NFS_MOUNT_POSIX, ",posix", "" }, 452 { NFS_MOUNT_NOCTO, ",nocto", "" }, 453 { NFS_MOUNT_NOAC, ",noac", "" }, 454 { NFS_MOUNT_NONLM, ",nolock", "" }, 455 { NFS_MOUNT_NOACL, ",noacl", "" }, 456 { NFS_MOUNT_NORDIRPLUS, ",nordirplus", "" }, 457 { NFS_MOUNT_FORCE_RDIRPLUS, ",rdirplus=force", "" }, 458 { NFS_MOUNT_UNSHARED, ",nosharecache", "" }, 459 { NFS_MOUNT_NORESVPORT, ",noresvport", "" }, 460 { NFS_MOUNT_NETUNREACH_FATAL, 461 ",fatal_neterrors=ENETDOWN:ENETUNREACH", 462 ",fatal_neterrors=none" }, 463 { 0, NULL, NULL } 464 }; 465 const struct proc_nfs_info *nfs_infop; 466 struct nfs_client *clp = nfss->nfs_client; 467 u32 version = clp->rpc_ops->version; 468 int local_flock, local_fcntl; 469 470 nfs_show_nfs_version(m, version, clp->cl_minorversion); 471 seq_printf(m, ",rsize=%u", nfss->rsize); 472 seq_printf(m, ",wsize=%u", nfss->wsize); 473 if (nfss->bsize != 0) 474 seq_printf(m, ",bsize=%u", nfss->bsize); 475 seq_printf(m, ",namlen=%u", nfss->namelen); 476 if (nfss->acregmin != NFS_DEF_ACREGMIN*HZ || showdefaults) 477 seq_printf(m, ",acregmin=%u", nfss->acregmin/HZ); 478 if (nfss->acregmax != NFS_DEF_ACREGMAX*HZ || showdefaults) 479 seq_printf(m, ",acregmax=%u", nfss->acregmax/HZ); 480 if (nfss->acdirmin != NFS_DEF_ACDIRMIN*HZ || showdefaults) 481 seq_printf(m, ",acdirmin=%u", nfss->acdirmin/HZ); 482 if (nfss->acdirmax != NFS_DEF_ACDIRMAX*HZ || showdefaults) 483 seq_printf(m, ",acdirmax=%u", nfss->acdirmax/HZ); 484 if (!(nfss->flags & (NFS_MOUNT_SOFT|NFS_MOUNT_SOFTERR))) 485 seq_puts(m, ",hard"); 486 for (nfs_infop = nfs_info; nfs_infop->flag; nfs_infop++) { 487 if (nfss->flags & nfs_infop->flag) 488 seq_puts(m, nfs_infop->str); 489 else 490 seq_puts(m, nfs_infop->nostr); 491 } 492 rcu_read_lock(); 493 seq_printf(m, ",proto=%s", 494 rpc_peeraddr2str(nfss->client, RPC_DISPLAY_NETID)); 495 rcu_read_unlock(); 496 if (clp->cl_nconnect > 0) 497 seq_printf(m, ",nconnect=%u", clp->cl_nconnect); 498 if (version == 4) { 499 if (clp->cl_max_connect > 1) 500 seq_printf(m, ",max_connect=%u", clp->cl_max_connect); 501 if (nfss->port != NFS_PORT) 502 seq_printf(m, ",port=%u", nfss->port); 503 } else 504 if (nfss->port) 505 seq_printf(m, ",port=%u", nfss->port); 506 507 seq_printf(m, ",timeo=%lu", 10U * nfss->client->cl_timeout->to_initval / HZ); 508 seq_printf(m, ",retrans=%u", nfss->client->cl_timeout->to_retries); 509 seq_printf(m, ",sec=%s", nfs_pseudoflavour_to_name(nfss->client->cl_auth->au_flavor)); 510 switch (clp->cl_xprtsec.policy) { 511 case RPC_XPRTSEC_TLS_ANON: 512 seq_puts(m, ",xprtsec=tls"); 513 break; 514 case RPC_XPRTSEC_TLS_X509: 515 seq_puts(m, ",xprtsec=mtls"); 516 break; 517 default: 518 break; 519 } 520 521 if (version != 4) 522 nfs_show_mountd_options(m, nfss, showdefaults); 523 else 524 nfs_show_nfsv4_options(m, nfss, showdefaults); 525 526 if (nfss->options & NFS_OPTION_FSCACHE) { 527 #ifdef CONFIG_NFS_FSCACHE 528 if (nfss->fscache_uniq) 529 seq_printf(m, ",fsc=%s", nfss->fscache_uniq); 530 else 531 seq_puts(m, ",fsc"); 532 #else 533 seq_puts(m, ",fsc"); 534 #endif 535 } 536 537 if (nfss->options & NFS_OPTION_MIGRATION) 538 seq_puts(m, ",migration"); 539 540 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) { 541 if (nfss->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) 542 seq_puts(m, ",lookupcache=none"); 543 else 544 seq_puts(m, ",lookupcache=pos"); 545 } 546 547 local_flock = nfss->flags & NFS_MOUNT_LOCAL_FLOCK; 548 local_fcntl = nfss->flags & NFS_MOUNT_LOCAL_FCNTL; 549 550 if (!local_flock && !local_fcntl) 551 seq_puts(m, ",local_lock=none"); 552 else if (local_flock && local_fcntl) 553 seq_puts(m, ",local_lock=all"); 554 else if (local_flock) 555 seq_puts(m, ",local_lock=flock"); 556 else 557 seq_puts(m, ",local_lock=posix"); 558 559 if (nfss->flags & NFS_MOUNT_NO_ALIGNWRITE) 560 seq_puts(m, ",noalignwrite"); 561 562 if (nfss->flags & NFS_MOUNT_WRITE_EAGER) { 563 if (nfss->flags & NFS_MOUNT_WRITE_WAIT) 564 seq_puts(m, ",write=wait"); 565 else 566 seq_puts(m, ",write=eager"); 567 } 568 } 569 570 /* 571 * Describe the mount options on this VFS mountpoint 572 */ 573 int nfs_show_options(struct seq_file *m, struct dentry *root) 574 { 575 struct nfs_server *nfss = NFS_SB(root->d_sb); 576 577 nfs_show_mount_options(m, nfss, 0); 578 579 rcu_read_lock(); 580 seq_printf(m, ",addr=%s", 581 rpc_peeraddr2str(nfss->nfs_client->cl_rpcclient, 582 RPC_DISPLAY_ADDR)); 583 rcu_read_unlock(); 584 585 return 0; 586 } 587 EXPORT_SYMBOL_GPL(nfs_show_options); 588 589 #if IS_ENABLED(CONFIG_NFS_V4) 590 static void show_lease(struct seq_file *m, struct nfs_server *server) 591 { 592 struct nfs_client *clp = server->nfs_client; 593 unsigned long expire; 594 595 seq_printf(m, ",lease_time=%ld", clp->cl_lease_time / HZ); 596 expire = clp->cl_last_renewal + clp->cl_lease_time; 597 seq_printf(m, ",lease_expired=%ld", 598 time_after(expire, jiffies) ? 0 : (jiffies - expire) / HZ); 599 } 600 #ifdef CONFIG_NFS_V4_1 601 static void show_sessions(struct seq_file *m, struct nfs_server *server) 602 { 603 if (nfs4_has_session(server->nfs_client)) 604 seq_puts(m, ",sessions"); 605 } 606 #else 607 static void show_sessions(struct seq_file *m, struct nfs_server *server) {} 608 #endif 609 #endif 610 611 #ifdef CONFIG_NFS_V4_1 612 static void show_pnfs(struct seq_file *m, struct nfs_server *server) 613 { 614 seq_printf(m, ",pnfs="); 615 if (server->pnfs_curr_ld) 616 seq_printf(m, "%s", server->pnfs_curr_ld->name); 617 else 618 seq_printf(m, "not configured"); 619 } 620 621 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss) 622 { 623 if (nfss->nfs_client && nfss->nfs_client->cl_implid) { 624 struct nfs41_impl_id *impl_id = nfss->nfs_client->cl_implid; 625 seq_printf(m, "\n\timpl_id:\tname='%s',domain='%s'," 626 "date='%llu,%u'", 627 impl_id->name, impl_id->domain, 628 impl_id->date.seconds, impl_id->date.nseconds); 629 } 630 } 631 #else 632 #if IS_ENABLED(CONFIG_NFS_V4) 633 static void show_pnfs(struct seq_file *m, struct nfs_server *server) 634 { 635 } 636 #endif 637 static void show_implementation_id(struct seq_file *m, struct nfs_server *nfss) 638 { 639 } 640 #endif 641 642 int nfs_show_devname(struct seq_file *m, struct dentry *root) 643 { 644 char *page = (char *) __get_free_page(GFP_KERNEL); 645 char *devname, *dummy; 646 int err = 0; 647 if (!page) 648 return -ENOMEM; 649 devname = nfs_path(&dummy, root, page, PAGE_SIZE, 0); 650 if (IS_ERR(devname)) 651 err = PTR_ERR(devname); 652 else 653 seq_escape(m, devname, " \t\n\\"); 654 free_page((unsigned long)page); 655 return err; 656 } 657 EXPORT_SYMBOL_GPL(nfs_show_devname); 658 659 int nfs_show_path(struct seq_file *m, struct dentry *dentry) 660 { 661 seq_puts(m, "/"); 662 return 0; 663 } 664 EXPORT_SYMBOL_GPL(nfs_show_path); 665 666 /* 667 * Present statistical information for this VFS mountpoint 668 */ 669 int nfs_show_stats(struct seq_file *m, struct dentry *root) 670 { 671 int i, cpu; 672 struct nfs_server *nfss = NFS_SB(root->d_sb); 673 struct rpc_auth *auth = nfss->client->cl_auth; 674 struct nfs_iostats totals = { }; 675 676 seq_printf(m, "statvers=%s", NFS_IOSTAT_VERS); 677 678 /* 679 * Display all mount option settings 680 */ 681 seq_puts(m, "\n\topts:\t"); 682 seq_puts(m, sb_rdonly(root->d_sb) ? "ro" : "rw"); 683 seq_puts(m, root->d_sb->s_flags & SB_SYNCHRONOUS ? ",sync" : ""); 684 seq_puts(m, root->d_sb->s_flags & SB_NOATIME ? ",noatime" : ""); 685 seq_puts(m, root->d_sb->s_flags & SB_NODIRATIME ? ",nodiratime" : ""); 686 nfs_show_mount_options(m, nfss, 1); 687 688 seq_printf(m, "\n\tage:\t%lu", (jiffies - nfss->mount_time) / HZ); 689 690 show_implementation_id(m, nfss); 691 692 seq_puts(m, "\n\tcaps:\t"); 693 seq_printf(m, "caps=0x%x", nfss->caps); 694 seq_printf(m, ",wtmult=%u", nfss->wtmult); 695 seq_printf(m, ",dtsize=%u", nfss->dtsize); 696 seq_printf(m, ",bsize=%u", nfss->bsize); 697 seq_printf(m, ",namlen=%u", nfss->namelen); 698 699 #if IS_ENABLED(CONFIG_NFS_V4) 700 if (nfss->nfs_client->rpc_ops->version == 4) { 701 seq_puts(m, "\n\tnfsv4:\t"); 702 seq_printf(m, "bm0=0x%x", nfss->attr_bitmask[0]); 703 seq_printf(m, ",bm1=0x%x", nfss->attr_bitmask[1]); 704 seq_printf(m, ",bm2=0x%x", nfss->attr_bitmask[2]); 705 seq_printf(m, ",acl=0x%x", nfss->acl_bitmask); 706 show_sessions(m, nfss); 707 show_pnfs(m, nfss); 708 show_lease(m, nfss); 709 } 710 #endif 711 712 /* 713 * Display security flavor in effect for this mount 714 */ 715 seq_printf(m, "\n\tsec:\tflavor=%u", auth->au_ops->au_flavor); 716 if (auth->au_flavor) 717 seq_printf(m, ",pseudoflavor=%u", auth->au_flavor); 718 719 /* 720 * Display superblock I/O counters 721 */ 722 for_each_possible_cpu(cpu) { 723 struct nfs_iostats *stats; 724 725 preempt_disable(); 726 stats = per_cpu_ptr(nfss->io_stats, cpu); 727 728 for (i = 0; i < __NFSIOS_COUNTSMAX; i++) 729 totals.events[i] += stats->events[i]; 730 for (i = 0; i < __NFSIOS_BYTESMAX; i++) 731 totals.bytes[i] += stats->bytes[i]; 732 733 preempt_enable(); 734 } 735 736 seq_puts(m, "\n\tevents:\t"); 737 for (i = 0; i < __NFSIOS_COUNTSMAX; i++) 738 seq_printf(m, "%lu ", totals.events[i]); 739 seq_puts(m, "\n\tbytes:\t"); 740 for (i = 0; i < __NFSIOS_BYTESMAX; i++) 741 seq_printf(m, "%Lu ", totals.bytes[i]); 742 seq_putc(m, '\n'); 743 744 rpc_clnt_show_stats(m, nfss->client); 745 746 return 0; 747 } 748 EXPORT_SYMBOL_GPL(nfs_show_stats); 749 750 /* 751 * Begin unmount by attempting to remove all automounted mountpoints we added 752 * in response to xdev traversals and referrals 753 */ 754 void nfs_umount_begin(struct super_block *sb) 755 { 756 struct nfs_server *server; 757 struct rpc_clnt *rpc; 758 759 server = NFS_SB(sb); 760 /* -EIO all pending I/O */ 761 rpc = server->client_acl; 762 if (!IS_ERR(rpc)) 763 rpc_killall_tasks(rpc); 764 rpc = server->client; 765 if (!IS_ERR(rpc)) 766 rpc_killall_tasks(rpc); 767 } 768 EXPORT_SYMBOL_GPL(nfs_umount_begin); 769 770 /* 771 * Return true if 'match' is in auth_info or auth_info is empty. 772 * Return false otherwise. 773 */ 774 bool nfs_auth_info_match(const struct nfs_auth_info *auth_info, 775 rpc_authflavor_t match) 776 { 777 int i; 778 779 if (!auth_info->flavor_len) 780 return true; 781 782 for (i = 0; i < auth_info->flavor_len; i++) { 783 if (auth_info->flavors[i] == match) 784 return true; 785 } 786 return false; 787 } 788 EXPORT_SYMBOL_GPL(nfs_auth_info_match); 789 790 /* 791 * Ensure that a specified authtype in ctx->auth_info is supported by 792 * the server. Returns 0 and sets ctx->selected_flavor if it's ok, and 793 * -EACCES if not. 794 */ 795 static int nfs_verify_authflavors(struct nfs_fs_context *ctx, 796 rpc_authflavor_t *server_authlist, 797 unsigned int count) 798 { 799 rpc_authflavor_t flavor = RPC_AUTH_MAXFLAVOR; 800 bool found_auth_null = false; 801 unsigned int i; 802 803 /* 804 * If the sec= mount option is used, the specified flavor or AUTH_NULL 805 * must be in the list returned by the server. 806 * 807 * AUTH_NULL has a special meaning when it's in the server list - it 808 * means that the server will ignore the rpc creds, so any flavor 809 * can be used but still use the sec= that was specified. 810 * 811 * Note also that the MNT procedure in MNTv1 does not return a list 812 * of supported security flavors. In this case, nfs_mount() fabricates 813 * a security flavor list containing just AUTH_NULL. 814 */ 815 for (i = 0; i < count; i++) { 816 flavor = server_authlist[i]; 817 818 if (nfs_auth_info_match(&ctx->auth_info, flavor)) 819 goto out; 820 821 if (flavor == RPC_AUTH_NULL) 822 found_auth_null = true; 823 } 824 825 if (found_auth_null) { 826 flavor = ctx->auth_info.flavors[0]; 827 goto out; 828 } 829 830 dfprintk(MOUNT, 831 "NFS: specified auth flavors not supported by server\n"); 832 return -EACCES; 833 834 out: 835 ctx->selected_flavor = flavor; 836 dfprintk(MOUNT, "NFS: using auth flavor %u\n", ctx->selected_flavor); 837 return 0; 838 } 839 840 /* 841 * Use the remote server's MOUNT service to request the NFS file handle 842 * corresponding to the provided path. 843 */ 844 static int nfs_request_mount(struct fs_context *fc, 845 struct nfs_fh *root_fh, 846 rpc_authflavor_t *server_authlist, 847 unsigned int *server_authlist_len) 848 { 849 struct nfs_fs_context *ctx = nfs_fc2context(fc); 850 struct nfs_mount_request request = { 851 .sap = &ctx->mount_server._address, 852 .dirpath = ctx->nfs_server.export_path, 853 .protocol = ctx->mount_server.protocol, 854 .fh = root_fh, 855 .noresvport = ctx->flags & NFS_MOUNT_NORESVPORT, 856 .auth_flav_len = server_authlist_len, 857 .auth_flavs = server_authlist, 858 .net = fc->net_ns, 859 }; 860 int status; 861 862 if (ctx->mount_server.version == 0) { 863 switch (ctx->version) { 864 default: 865 ctx->mount_server.version = NFS_MNT3_VERSION; 866 break; 867 case 2: 868 ctx->mount_server.version = NFS_MNT_VERSION; 869 } 870 } 871 request.version = ctx->mount_server.version; 872 873 if (ctx->mount_server.hostname) 874 request.hostname = ctx->mount_server.hostname; 875 else 876 request.hostname = ctx->nfs_server.hostname; 877 878 /* 879 * Construct the mount server's address. 880 */ 881 if (ctx->mount_server.address.sa_family == AF_UNSPEC) { 882 memcpy(request.sap, &ctx->nfs_server._address, 883 ctx->nfs_server.addrlen); 884 ctx->mount_server.addrlen = ctx->nfs_server.addrlen; 885 } 886 request.salen = ctx->mount_server.addrlen; 887 nfs_set_port(request.sap, &ctx->mount_server.port, 0); 888 889 /* 890 * Now ask the mount server to map our export path 891 * to a file handle. 892 */ 893 if ((request.protocol == XPRT_TRANSPORT_UDP) == 894 !(ctx->flags & NFS_MOUNT_TCP)) 895 /* 896 * NFS protocol and mount protocol are both UDP or neither UDP 897 * so timeouts are compatible. Use NFS timeouts for MOUNT 898 */ 899 status = nfs_mount(&request, ctx->timeo, ctx->retrans); 900 else 901 status = nfs_mount(&request, NFS_UNSPEC_TIMEO, NFS_UNSPEC_RETRANS); 902 if (status != 0) { 903 dfprintk(MOUNT, "NFS: unable to mount server %s, error %d\n", 904 request.hostname, status); 905 return status; 906 } 907 908 return 0; 909 } 910 911 static struct nfs_server *nfs_try_mount_request(struct fs_context *fc) 912 { 913 struct nfs_fs_context *ctx = nfs_fc2context(fc); 914 int status; 915 unsigned int i; 916 bool tried_auth_unix = false; 917 bool auth_null_in_list = false; 918 struct nfs_server *server = ERR_PTR(-EACCES); 919 rpc_authflavor_t authlist[NFS_MAX_SECFLAVORS]; 920 unsigned int authlist_len = ARRAY_SIZE(authlist); 921 922 /* make sure 'nolock'/'lock' override the 'local_lock' mount option */ 923 if (ctx->lock_status) { 924 if (ctx->lock_status == NFS_LOCK_NOLOCK) { 925 ctx->flags |= NFS_MOUNT_NONLM; 926 ctx->flags |= (NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL); 927 } else { 928 ctx->flags &= ~NFS_MOUNT_NONLM; 929 ctx->flags &= ~(NFS_MOUNT_LOCAL_FLOCK | NFS_MOUNT_LOCAL_FCNTL); 930 } 931 } 932 status = nfs_request_mount(fc, ctx->mntfh, authlist, &authlist_len); 933 if (status) 934 return ERR_PTR(status); 935 936 /* 937 * Was a sec= authflavor specified in the options? First, verify 938 * whether the server supports it, and then just try to use it if so. 939 */ 940 if (ctx->auth_info.flavor_len > 0) { 941 status = nfs_verify_authflavors(ctx, authlist, authlist_len); 942 dfprintk(MOUNT, "NFS: using auth flavor %u\n", 943 ctx->selected_flavor); 944 if (status) 945 return ERR_PTR(status); 946 return ctx->nfs_mod->rpc_ops->create_server(fc); 947 } 948 949 /* 950 * No sec= option was provided. RFC 2623, section 2.7 suggests we 951 * SHOULD prefer the flavor listed first. However, some servers list 952 * AUTH_NULL first. Avoid ever choosing AUTH_NULL. 953 */ 954 for (i = 0; i < authlist_len; ++i) { 955 rpc_authflavor_t flavor; 956 struct rpcsec_gss_info info; 957 958 flavor = authlist[i]; 959 switch (flavor) { 960 case RPC_AUTH_UNIX: 961 tried_auth_unix = true; 962 break; 963 case RPC_AUTH_NULL: 964 auth_null_in_list = true; 965 continue; 966 default: 967 if (rpcauth_get_gssinfo(flavor, &info) != 0) 968 continue; 969 break; 970 } 971 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", flavor); 972 ctx->selected_flavor = flavor; 973 server = ctx->nfs_mod->rpc_ops->create_server(fc); 974 if (!IS_ERR(server)) 975 return server; 976 } 977 978 /* 979 * Nothing we tried so far worked. At this point, give up if we've 980 * already tried AUTH_UNIX or if the server's list doesn't contain 981 * AUTH_NULL 982 */ 983 if (tried_auth_unix || !auth_null_in_list) 984 return server; 985 986 /* Last chance! Try AUTH_UNIX */ 987 dfprintk(MOUNT, "NFS: attempting to use auth flavor %u\n", RPC_AUTH_UNIX); 988 ctx->selected_flavor = RPC_AUTH_UNIX; 989 return ctx->nfs_mod->rpc_ops->create_server(fc); 990 } 991 992 int nfs_try_get_tree(struct fs_context *fc) 993 { 994 struct nfs_fs_context *ctx = nfs_fc2context(fc); 995 996 if (ctx->need_mount) 997 ctx->server = nfs_try_mount_request(fc); 998 else 999 ctx->server = ctx->nfs_mod->rpc_ops->create_server(fc); 1000 1001 return nfs_get_tree_common(fc); 1002 } 1003 EXPORT_SYMBOL_GPL(nfs_try_get_tree); 1004 1005 1006 #define NFS_REMOUNT_CMP_FLAGMASK ~(NFS_MOUNT_INTR \ 1007 | NFS_MOUNT_SECURE \ 1008 | NFS_MOUNT_TCP \ 1009 | NFS_MOUNT_VER3 \ 1010 | NFS_MOUNT_KERBEROS \ 1011 | NFS_MOUNT_NONLM \ 1012 | NFS_MOUNT_BROKEN_SUID \ 1013 | NFS_MOUNT_STRICTLOCK \ 1014 | NFS_MOUNT_LEGACY_INTERFACE) 1015 1016 #define NFS_MOUNT_CMP_FLAGMASK (NFS_REMOUNT_CMP_FLAGMASK & \ 1017 ~(NFS_MOUNT_UNSHARED | NFS_MOUNT_NORESVPORT)) 1018 1019 static int 1020 nfs_compare_remount_data(struct nfs_server *nfss, 1021 struct nfs_fs_context *ctx) 1022 { 1023 if ((ctx->flags ^ nfss->flags) & NFS_REMOUNT_CMP_FLAGMASK || 1024 ctx->rsize != nfss->rsize || 1025 ctx->wsize != nfss->wsize || 1026 ctx->version != nfss->nfs_client->rpc_ops->version || 1027 ctx->minorversion != nfss->nfs_client->cl_minorversion || 1028 ctx->retrans != nfss->client->cl_timeout->to_retries || 1029 !nfs_auth_info_match(&ctx->auth_info, nfss->client->cl_auth->au_flavor) || 1030 ctx->acregmin != nfss->acregmin / HZ || 1031 ctx->acregmax != nfss->acregmax / HZ || 1032 ctx->acdirmin != nfss->acdirmin / HZ || 1033 ctx->acdirmax != nfss->acdirmax / HZ || 1034 ctx->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) || 1035 (ctx->options & NFS_OPTION_FSCACHE) != (nfss->options & NFS_OPTION_FSCACHE) || 1036 ctx->nfs_server.port != nfss->port || 1037 ctx->nfs_server.addrlen != nfss->nfs_client->cl_addrlen || 1038 !rpc_cmp_addr((struct sockaddr *)&ctx->nfs_server.address, 1039 (struct sockaddr *)&nfss->nfs_client->cl_addr)) 1040 return -EINVAL; 1041 1042 return 0; 1043 } 1044 1045 int nfs_reconfigure(struct fs_context *fc) 1046 { 1047 struct nfs_fs_context *ctx = nfs_fc2context(fc); 1048 struct super_block *sb = fc->root->d_sb; 1049 struct nfs_server *nfss = sb->s_fs_info; 1050 int ret; 1051 1052 sync_filesystem(sb); 1053 1054 /* 1055 * The SB_RDONLY flag has been removed from the superblock during 1056 * mounts to prevent interference between different filesystems. 1057 * Similarly, it is also necessary to ignore the SB_RDONLY flag 1058 * during reconfiguration; otherwise, it may also result in the 1059 * creation of redundant superblocks when mounting a directory with 1060 * different rw and ro flags multiple times. 1061 */ 1062 fc->sb_flags_mask &= ~SB_RDONLY; 1063 1064 /* 1065 * Userspace mount programs that send binary options generally send 1066 * them populated with default values. We have no way to know which 1067 * ones were explicitly specified. Fall back to legacy behavior and 1068 * just return success. 1069 */ 1070 if (ctx->skip_reconfig_option_check) 1071 return 0; 1072 1073 /* 1074 * noac is a special case. It implies -o sync, but that's not 1075 * necessarily reflected in the mtab options. reconfigure_super 1076 * will clear SB_SYNCHRONOUS if -o sync wasn't specified in the 1077 * remount options, so we have to explicitly reset it. 1078 */ 1079 if (ctx->flags & NFS_MOUNT_NOAC) { 1080 fc->sb_flags |= SB_SYNCHRONOUS; 1081 fc->sb_flags_mask |= SB_SYNCHRONOUS; 1082 } 1083 1084 /* compare new mount options with old ones */ 1085 ret = nfs_compare_remount_data(nfss, ctx); 1086 if (ret) 1087 return ret; 1088 1089 return nfs_probe_server(nfss, NFS_FH(d_inode(fc->root))); 1090 } 1091 EXPORT_SYMBOL_GPL(nfs_reconfigure); 1092 1093 /* 1094 * Finish setting up an NFS superblock 1095 */ 1096 static void nfs_fill_super(struct super_block *sb, struct nfs_fs_context *ctx) 1097 { 1098 struct nfs_server *server = NFS_SB(sb); 1099 1100 sb->s_blocksize_bits = 0; 1101 sb->s_blocksize = 0; 1102 sb->s_xattr = server->nfs_client->cl_nfs_mod->xattr; 1103 sb->s_op = server->nfs_client->cl_nfs_mod->sops; 1104 if (ctx->bsize) 1105 sb->s_blocksize = nfs_block_size(ctx->bsize, &sb->s_blocksize_bits); 1106 1107 switch (server->nfs_client->rpc_ops->version) { 1108 case 2: 1109 sb->s_time_gran = 1000; 1110 sb->s_time_min = 0; 1111 sb->s_time_max = U32_MAX; 1112 break; 1113 case 3: 1114 /* 1115 * The VFS shouldn't apply the umask to mode bits. 1116 * We will do so ourselves when necessary. 1117 */ 1118 sb->s_flags |= SB_POSIXACL; 1119 sb->s_time_gran = 1; 1120 sb->s_time_min = 0; 1121 sb->s_time_max = U32_MAX; 1122 sb->s_export_op = &nfs_export_ops; 1123 break; 1124 case 4: 1125 sb->s_iflags |= SB_I_NOUMASK; 1126 sb->s_time_gran = 1; 1127 sb->s_time_min = S64_MIN; 1128 sb->s_time_max = S64_MAX; 1129 if (server->caps & NFS_CAP_ATOMIC_OPEN_V1) 1130 sb->s_export_op = &nfs_export_ops; 1131 break; 1132 } 1133 1134 sb->s_magic = NFS_SUPER_MAGIC; 1135 1136 /* We probably want something more informative here */ 1137 snprintf(sb->s_id, sizeof(sb->s_id), 1138 "%u:%u", MAJOR(sb->s_dev), MINOR(sb->s_dev)); 1139 1140 if (sb->s_blocksize == 0) 1141 sb->s_blocksize = nfs_block_bits(server->wsize, 1142 &sb->s_blocksize_bits); 1143 1144 nfs_super_set_maxbytes(sb, server->maxfilesize); 1145 nfs_sysfs_move_server_to_sb(sb); 1146 server->has_sec_mnt_opts = ctx->has_sec_mnt_opts; 1147 } 1148 1149 static int nfs_compare_mount_options(const struct super_block *s, const struct nfs_server *b, 1150 const struct fs_context *fc) 1151 { 1152 const struct nfs_server *a = s->s_fs_info; 1153 const struct rpc_clnt *clnt_a = a->client; 1154 const struct rpc_clnt *clnt_b = b->client; 1155 1156 if ((s->s_flags & NFS_SB_MASK) != (fc->sb_flags & NFS_SB_MASK)) 1157 goto Ebusy; 1158 if (a->nfs_client != b->nfs_client) 1159 goto Ebusy; 1160 if ((a->flags ^ b->flags) & NFS_MOUNT_CMP_FLAGMASK) 1161 goto Ebusy; 1162 if (a->wsize != b->wsize) 1163 goto Ebusy; 1164 if (a->rsize != b->rsize) 1165 goto Ebusy; 1166 if (a->acregmin != b->acregmin) 1167 goto Ebusy; 1168 if (a->acregmax != b->acregmax) 1169 goto Ebusy; 1170 if (a->acdirmin != b->acdirmin) 1171 goto Ebusy; 1172 if (a->acdirmax != b->acdirmax) 1173 goto Ebusy; 1174 if (clnt_a->cl_auth->au_flavor != clnt_b->cl_auth->au_flavor) 1175 goto Ebusy; 1176 return 1; 1177 Ebusy: 1178 return 0; 1179 } 1180 1181 static int nfs_set_super(struct super_block *s, struct fs_context *fc) 1182 { 1183 struct nfs_server *server = fc->s_fs_info; 1184 int ret; 1185 1186 s->s_d_op = server->nfs_client->rpc_ops->dentry_ops; 1187 ret = set_anon_super(s, server); 1188 if (ret == 0) 1189 server->s_dev = s->s_dev; 1190 return ret; 1191 } 1192 1193 static int nfs_compare_super_address(struct nfs_server *server1, 1194 struct nfs_server *server2) 1195 { 1196 struct sockaddr *sap1, *sap2; 1197 struct rpc_xprt *xprt1 = server1->client->cl_xprt; 1198 struct rpc_xprt *xprt2 = server2->client->cl_xprt; 1199 1200 if (!net_eq(xprt1->xprt_net, xprt2->xprt_net)) 1201 return 0; 1202 1203 sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr; 1204 sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr; 1205 1206 if (sap1->sa_family != sap2->sa_family) 1207 return 0; 1208 1209 switch (sap1->sa_family) { 1210 case AF_INET: { 1211 struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1; 1212 struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2; 1213 if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr) 1214 return 0; 1215 if (sin1->sin_port != sin2->sin_port) 1216 return 0; 1217 break; 1218 } 1219 case AF_INET6: { 1220 struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1; 1221 struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2; 1222 if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr)) 1223 return 0; 1224 if (sin1->sin6_port != sin2->sin6_port) 1225 return 0; 1226 break; 1227 } 1228 default: 1229 return 0; 1230 } 1231 1232 return 1; 1233 } 1234 1235 static int nfs_compare_userns(const struct nfs_server *old, 1236 const struct nfs_server *new) 1237 { 1238 const struct user_namespace *oldns = &init_user_ns; 1239 const struct user_namespace *newns = &init_user_ns; 1240 1241 if (old->client && old->client->cl_cred) 1242 oldns = old->client->cl_cred->user_ns; 1243 if (new->client && new->client->cl_cred) 1244 newns = new->client->cl_cred->user_ns; 1245 if (oldns != newns) 1246 return 0; 1247 return 1; 1248 } 1249 1250 static int nfs_compare_super(struct super_block *sb, struct fs_context *fc) 1251 { 1252 struct nfs_server *server = fc->s_fs_info, *old = NFS_SB(sb); 1253 1254 if (!nfs_compare_super_address(old, server)) 1255 return 0; 1256 /* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */ 1257 if (old->flags & NFS_MOUNT_UNSHARED) 1258 return 0; 1259 if (memcmp(&old->fsid, &server->fsid, sizeof(old->fsid)) != 0) 1260 return 0; 1261 if (!nfs_compare_userns(old, server)) 1262 return 0; 1263 if ((old->has_sec_mnt_opts || fc->security) && 1264 security_sb_mnt_opts_compat(sb, fc->security)) 1265 return 0; 1266 return nfs_compare_mount_options(sb, server, fc); 1267 } 1268 1269 #ifdef CONFIG_NFS_FSCACHE 1270 static int nfs_get_cache_cookie(struct super_block *sb, 1271 struct nfs_fs_context *ctx) 1272 { 1273 struct nfs_server *nfss = NFS_SB(sb); 1274 char *uniq = NULL; 1275 int ulen = 0; 1276 1277 nfss->fscache = NULL; 1278 1279 if (!ctx) 1280 return 0; 1281 1282 if (ctx->clone_data.sb) { 1283 struct nfs_server *mnt_s = NFS_SB(ctx->clone_data.sb); 1284 if (!(mnt_s->options & NFS_OPTION_FSCACHE)) 1285 return 0; 1286 if (mnt_s->fscache_uniq) { 1287 uniq = mnt_s->fscache_uniq; 1288 ulen = strlen(uniq); 1289 } 1290 } else { 1291 if (!(ctx->options & NFS_OPTION_FSCACHE)) 1292 return 0; 1293 if (ctx->fscache_uniq) { 1294 uniq = ctx->fscache_uniq; 1295 ulen = strlen(ctx->fscache_uniq); 1296 } 1297 } 1298 1299 return nfs_fscache_get_super_cookie(sb, uniq, ulen); 1300 } 1301 #else 1302 static int nfs_get_cache_cookie(struct super_block *sb, 1303 struct nfs_fs_context *ctx) 1304 { 1305 return 0; 1306 } 1307 #endif 1308 1309 int nfs_get_tree_common(struct fs_context *fc) 1310 { 1311 struct nfs_fs_context *ctx = nfs_fc2context(fc); 1312 struct super_block *s; 1313 int (*compare_super)(struct super_block *, struct fs_context *) = nfs_compare_super; 1314 struct nfs_server *server = ctx->server; 1315 int error; 1316 1317 ctx->server = NULL; 1318 if (IS_ERR(server)) 1319 return PTR_ERR(server); 1320 1321 /* 1322 * When NFS_MOUNT_UNSHARED is not set, NFS forces the sharing of a 1323 * superblock among each filesystem that mounts sub-directories 1324 * belonging to a single exported root path. 1325 * To prevent interference between different filesystems, the 1326 * SB_RDONLY flag should be removed from the superblock. 1327 */ 1328 if (server->flags & NFS_MOUNT_UNSHARED) 1329 compare_super = NULL; 1330 else 1331 fc->sb_flags &= ~SB_RDONLY; 1332 1333 /* -o noac implies -o sync */ 1334 if (server->flags & NFS_MOUNT_NOAC) 1335 fc->sb_flags |= SB_SYNCHRONOUS; 1336 1337 if (ctx->clone_data.sb) 1338 if (ctx->clone_data.sb->s_flags & SB_SYNCHRONOUS) 1339 fc->sb_flags |= SB_SYNCHRONOUS; 1340 1341 /* Get a superblock - note that we may end up sharing one that already exists */ 1342 fc->s_fs_info = server; 1343 s = sget_fc(fc, compare_super, nfs_set_super); 1344 fc->s_fs_info = NULL; 1345 if (IS_ERR(s)) { 1346 error = PTR_ERR(s); 1347 nfs_errorf(fc, "NFS: Couldn't get superblock"); 1348 goto out_err_nosb; 1349 } 1350 1351 if (s->s_fs_info != server) { 1352 nfs_free_server(server); 1353 server = NULL; 1354 } else { 1355 error = super_setup_bdi_name(s, "%u:%u", MAJOR(server->s_dev), 1356 MINOR(server->s_dev)); 1357 if (error) 1358 goto error_splat_super; 1359 s->s_bdi->io_pages = server->rpages; 1360 server->super = s; 1361 } 1362 1363 if (!s->s_root) { 1364 unsigned bsize = ctx->clone_data.inherited_bsize; 1365 /* initial superblock/root creation */ 1366 nfs_fill_super(s, ctx); 1367 if (bsize) { 1368 s->s_blocksize_bits = bsize; 1369 s->s_blocksize = 1U << bsize; 1370 } 1371 error = nfs_get_cache_cookie(s, ctx); 1372 if (error < 0) 1373 goto error_splat_super; 1374 } 1375 1376 error = nfs_get_root(s, fc); 1377 if (error < 0) { 1378 nfs_errorf(fc, "NFS: Couldn't get root dentry"); 1379 goto error_splat_super; 1380 } 1381 1382 s->s_flags |= SB_ACTIVE; 1383 error = 0; 1384 1385 out: 1386 return error; 1387 1388 out_err_nosb: 1389 nfs_free_server(server); 1390 goto out; 1391 error_splat_super: 1392 deactivate_locked_super(s); 1393 goto out; 1394 } 1395 1396 /* 1397 * Destroy an NFS superblock 1398 */ 1399 void nfs_kill_super(struct super_block *s) 1400 { 1401 struct nfs_server *server = NFS_SB(s); 1402 1403 nfs_sysfs_move_sb_to_server(server); 1404 kill_anon_super(s); 1405 1406 nfs_fscache_release_super_cookie(s); 1407 1408 nfs_free_server(server); 1409 } 1410 EXPORT_SYMBOL_GPL(nfs_kill_super); 1411 1412 #if IS_ENABLED(CONFIG_NFS_V4) 1413 1414 /* 1415 * NFS v4 module parameters need to stay in the 1416 * NFS client for backwards compatibility 1417 */ 1418 unsigned int nfs_callback_set_tcpport; 1419 unsigned short nfs_callback_nr_threads; 1420 /* Default cache timeout is 10 minutes */ 1421 unsigned int nfs_idmap_cache_timeout = 600; 1422 /* Turn off NFSv4 uid/gid mapping when using AUTH_SYS */ 1423 bool nfs4_disable_idmapping = true; 1424 unsigned short max_session_slots = NFS4_DEF_SLOT_TABLE_SIZE; 1425 unsigned short max_session_cb_slots = NFS4_DEF_CB_SLOT_TABLE_SIZE; 1426 unsigned short send_implementation_id = 1; 1427 char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN] = ""; 1428 bool recover_lost_locks = false; 1429 short nfs_delay_retrans = -1; 1430 1431 EXPORT_SYMBOL_GPL(nfs_callback_nr_threads); 1432 EXPORT_SYMBOL_GPL(nfs_callback_set_tcpport); 1433 EXPORT_SYMBOL_GPL(nfs_idmap_cache_timeout); 1434 EXPORT_SYMBOL_GPL(nfs4_disable_idmapping); 1435 EXPORT_SYMBOL_GPL(max_session_slots); 1436 EXPORT_SYMBOL_GPL(max_session_cb_slots); 1437 EXPORT_SYMBOL_GPL(send_implementation_id); 1438 EXPORT_SYMBOL_GPL(nfs4_client_id_uniquifier); 1439 EXPORT_SYMBOL_GPL(recover_lost_locks); 1440 EXPORT_SYMBOL_GPL(nfs_delay_retrans); 1441 1442 #define NFS_CALLBACK_MAXPORTNR (65535U) 1443 1444 static int param_set_portnr(const char *val, const struct kernel_param *kp) 1445 { 1446 unsigned long num; 1447 int ret; 1448 1449 if (!val) 1450 return -EINVAL; 1451 ret = kstrtoul(val, 0, &num); 1452 if (ret || num > NFS_CALLBACK_MAXPORTNR) 1453 return -EINVAL; 1454 *((unsigned int *)kp->arg) = num; 1455 return 0; 1456 } 1457 static const struct kernel_param_ops param_ops_portnr = { 1458 .set = param_set_portnr, 1459 .get = param_get_uint, 1460 }; 1461 #define param_check_portnr(name, p) __param_check(name, p, unsigned int) 1462 1463 module_param_named(callback_tcpport, nfs_callback_set_tcpport, portnr, 0644); 1464 module_param_named(callback_nr_threads, nfs_callback_nr_threads, ushort, 0644); 1465 MODULE_PARM_DESC(callback_nr_threads, "Number of threads that will be " 1466 "assigned to the NFSv4 callback channels."); 1467 module_param(nfs_idmap_cache_timeout, int, 0644); 1468 module_param(nfs4_disable_idmapping, bool, 0644); 1469 module_param_string(nfs4_unique_id, nfs4_client_id_uniquifier, 1470 NFS4_CLIENT_ID_UNIQ_LEN, 0600); 1471 MODULE_PARM_DESC(nfs4_disable_idmapping, 1472 "Turn off NFSv4 idmapping when using 'sec=sys'"); 1473 module_param(max_session_slots, ushort, 0644); 1474 MODULE_PARM_DESC(max_session_slots, "Maximum number of outstanding NFSv4.1 " 1475 "requests the client will negotiate"); 1476 module_param(max_session_cb_slots, ushort, 0644); 1477 MODULE_PARM_DESC(max_session_cb_slots, "Maximum number of parallel NFSv4.1 " 1478 "callbacks the client will process for a given server"); 1479 module_param(send_implementation_id, ushort, 0644); 1480 MODULE_PARM_DESC(send_implementation_id, 1481 "Send implementation ID with NFSv4.1 exchange_id"); 1482 MODULE_PARM_DESC(nfs4_unique_id, "nfs_client_id4 uniquifier string"); 1483 1484 module_param(recover_lost_locks, bool, 0644); 1485 MODULE_PARM_DESC(recover_lost_locks, 1486 "If the server reports that a lock might be lost, " 1487 "try to recover it risking data corruption."); 1488 1489 module_param_named(delay_retrans, nfs_delay_retrans, short, 0644); 1490 MODULE_PARM_DESC(delay_retrans, 1491 "Unless negative, specifies the number of times the NFSv4 " 1492 "client retries a request before returning an EAGAIN error, " 1493 "after a reply of NFS4ERR_DELAY from the server."); 1494 #endif /* CONFIG_NFS_V4 */ 1495