1/*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/ 5 * Authors: Doug Rabson <dfr@rabson.org> 6 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org> 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30#include <sys/param.h> 31#include <sys/fcntl.h> 32#include <sys/jail.h> 33#include <sys/kernel.h> 34#include <sys/limits.h> 35#include <sys/lock.h> 36#include <sys/lockf.h> 37#include <sys/malloc.h> 38#include <sys/mbuf.h> 39#include <sys/mount.h> 40#include <sys/mutex.h> 41#include <sys/proc.h> 42#include <sys/socket.h> 43#include <sys/syslog.h> 44#include <sys/systm.h> 45#include <sys/unistd.h> 46#include <sys/vnode.h> 47 48#include <nfs/nfsproto.h> 49#include <nfsclient/nfs.h> 50#include <nfsclient/nfsmount.h> 51 52#include <nlm/nlm_prot.h> 53#include <nlm/nlm.h> 54 55/* 56 * We need to keep track of the svid values used for F_FLOCK locks. 57 */ 58struct nlm_file_svid { 59 int ns_refs; /* thread count + 1 if active */ 60 int ns_svid; /* on-the-wire SVID for this file */ 61 struct ucred *ns_ucred; /* creds to use for lock recovery */ 62 void *ns_id; /* local struct file pointer */ 63 bool_t ns_active; /* TRUE if we own a lock */ 64 LIST_ENTRY(nlm_file_svid) ns_link; 65}; 66LIST_HEAD(nlm_file_svid_list, nlm_file_svid); 67 68#define NLM_SVID_HASH_SIZE 256 69struct nlm_file_svid_list nlm_file_svids[NLM_SVID_HASH_SIZE]; 70 71struct mtx nlm_svid_lock; 72static struct unrhdr *nlm_svid_allocator; 73static volatile u_int nlm_xid = 1; 74 75static int nlm_setlock(struct nlm_host *host, struct rpc_callextra *ext, 76 rpcvers_t vers, struct timeval *timo, int retries, 77 struct vnode *vp, int op, struct flock *fl, int flags, 78 int svid, size_t fhlen, void *fh, off_t size, bool_t reclaim); 79static int nlm_clearlock(struct nlm_host *host, struct rpc_callextra *ext, 80 rpcvers_t vers, struct timeval *timo, int retries, 81 struct vnode *vp, int op, struct flock *fl, int flags, 82 int svid, size_t fhlen, void *fh, off_t size); 83static int nlm_getlock(struct nlm_host *host, struct rpc_callextra *ext, 84 rpcvers_t vers, struct timeval *timo, int retries, 85 struct vnode *vp, int op, struct flock *fl, int flags, 86 int svid, size_t fhlen, void *fh, off_t size); 87static int nlm_map_status(nlm4_stats stat); 88static struct nlm_file_svid *nlm_find_svid(void *id); 89static void nlm_free_svid(struct nlm_file_svid *nf); 90static int nlm_init_lock(struct flock *fl, int flags, int svid, 91 rpcvers_t vers, size_t fhlen, void *fh, off_t size, 92 struct nlm4_lock *lock, char oh_space[32]); 93 94static void 95nlm_client_init(void *dummy) 96{ 97 int i; 98 99 mtx_init(&nlm_svid_lock, "NLM svid lock", NULL, MTX_DEF); 100 /* pid_max cannot be greater than PID_MAX */ 101 nlm_svid_allocator = new_unrhdr(PID_MAX + 2, INT_MAX, &nlm_svid_lock); 102 for (i = 0; i < NLM_SVID_HASH_SIZE; i++) 103 LIST_INIT(&nlm_file_svids[i]); 104} 105SYSINIT(nlm_client_init, SI_SUB_LOCK, SI_ORDER_FIRST, nlm_client_init, NULL); 106 107static int 108nlm_msg(struct thread *td, const char *server, const char *msg, int error) 109{ 110 struct proc *p; 111 112 p = td ? td->td_proc : NULL; 113 if (error) { 114 tprintf(p, LOG_INFO, "nfs server %s: %s, error %d\n", server, 115 msg, error); 116 } else { 117 tprintf(p, LOG_INFO, "nfs server %s: %s\n", server, msg); 118 } 119 return (0); 120} 121 122struct nlm_feedback_arg { 123 bool_t nf_printed; 124 struct nfsmount *nf_nmp; 125}; 126 127static void 128nlm_down(struct nlm_feedback_arg *nf, struct thread *td, 129 const char *msg, int error) 130{ 131 struct nfsmount *nmp = nf->nf_nmp; 132 133 if (nmp == NULL) 134 return; 135 mtx_lock(&nmp->nm_mtx); 136 if (!(nmp->nm_state & NFSSTA_LOCKTIMEO)) { 137 nmp->nm_state |= NFSSTA_LOCKTIMEO; 138 mtx_unlock(&nmp->nm_mtx); 139 vfs_event_signal(&nmp->nm_mountp->mnt_stat.f_fsid, 140 VQ_NOTRESPLOCK, 0); 141 } else { 142 mtx_unlock(&nmp->nm_mtx); 143 } 144 145 nf->nf_printed = TRUE; 146 nlm_msg(td, nmp->nm_mountp->mnt_stat.f_mntfromname, msg, error); 147} 148 149static void 150nlm_up(struct nlm_feedback_arg *nf, struct thread *td, 151 const char *msg) 152{ 153 struct nfsmount *nmp = nf->nf_nmp; 154 155 if (!nf->nf_printed) 156 return; 157 158 nlm_msg(td, nmp->nm_mountp->mnt_stat.f_mntfromname, msg, 0); 159 160 mtx_lock(&nmp->nm_mtx); 161 if (nmp->nm_state & NFSSTA_LOCKTIMEO) { 162 nmp->nm_state &= ~NFSSTA_LOCKTIMEO; 163 mtx_unlock(&nmp->nm_mtx); 164 vfs_event_signal(&nmp->nm_mountp->mnt_stat.f_fsid, 165 VQ_NOTRESPLOCK, 1); 166 } else { 167 mtx_unlock(&nmp->nm_mtx); 168 } 169} 170 171static void 172nlm_feedback(int type, int proc, void *arg) 173{ 174 struct thread *td = curthread; 175 struct nlm_feedback_arg *nf = (struct nlm_feedback_arg *) arg; 176 177 switch (type) { 178 case FEEDBACK_REXMIT2: 179 case FEEDBACK_RECONNECT: 180 nlm_down(nf, td, "lockd not responding", 0); 181 break; 182 183 case FEEDBACK_OK: 184 nlm_up(nf, td, "lockd is alive again"); 185 break; 186 } 187} 188 189/* 190 * nlm_advlock -- 191 * NFS advisory byte-level locks. 192 */ 193static int 194nlm_advlock_internal(struct vnode *vp, void *id, int op, struct flock *fl, 195 int flags, bool_t reclaim, bool_t unlock_vp) 196{ 197 struct thread *td = curthread; 198 struct nfsmount *nmp; 199 off_t size; 200 size_t fhlen; 201 union nfsfh fh; 202 struct sockaddr *sa; 203 struct sockaddr_storage ss; 204 char *servername; 205 struct timeval timo; 206 int retries; 207 rpcvers_t vers; 208 struct nlm_host *host; 209 struct rpc_callextra ext; 210 struct nlm_feedback_arg nf; 211 AUTH *auth; 212 struct ucred *cred, *cred1; 213 struct nlm_file_svid *ns; 214 int svid; 215 int error; 216 int is_v3; 217 218 ASSERT_VOP_LOCKED(vp, "nlm_advlock_1"); 219 220 servername = malloc(MNAMELEN, M_TEMP, M_WAITOK); /* XXXKIB vp locked */ 221 nmp = VFSTONFS(vp->v_mount); 222 /* 223 * Push any pending writes to the server and flush our cache 224 * so that if we are contending with another machine for a 225 * file, we get whatever they wrote and vice-versa. 226 */ 227 if (op == F_SETLK || op == F_UNLCK) 228 nmp->nm_vinvalbuf(vp, V_SAVE, td, 1); 229 230 strcpy(servername, nmp->nm_hostname); 231 nmp->nm_getinfo(vp, fh.fh_bytes, &fhlen, &ss, &is_v3, &size, &timo); 232 sa = (struct sockaddr *) &ss; 233 if (is_v3 != 0) 234 vers = NLM_VERS4; 235 else 236 vers = NLM_VERS; 237 238 if (nmp->nm_flag & NFSMNT_SOFT) 239 retries = nmp->nm_retry; 240 else 241 retries = INT_MAX; 242 243 /* 244 * We need to switch to mount-point creds so that we can send 245 * packets from a privileged port. Reference mnt_cred and 246 * switch to them before unlocking the vnode, since mount 247 * point could be unmounted right after unlock. 248 */ 249 cred = td->td_ucred; 250 td->td_ucred = vp->v_mount->mnt_cred; 251 crhold(td->td_ucred); 252 if (unlock_vp) 253 VOP_UNLOCK(vp); 254 255 host = nlm_find_host_by_name(servername, sa, vers); 256 auth = authunix_create(cred); 257 memset(&ext, 0, sizeof(ext)); 258 259 nf.nf_printed = FALSE; 260 nf.nf_nmp = nmp; 261 ext.rc_auth = auth; 262 263 ext.rc_feedback = nlm_feedback; 264 ext.rc_feedback_arg = &nf; 265 ext.rc_timers = NULL; 266 267 ns = NULL; 268 if (flags & F_FLOCK) { 269 ns = nlm_find_svid(id); 270 KASSERT(fl->l_start == 0 && fl->l_len == 0, 271 ("F_FLOCK lock requests must be whole-file locks")); 272 if (!ns->ns_ucred) { 273 /* 274 * Remember the creds used for locking in case 275 * we need to recover the lock later. 276 */ 277 ns->ns_ucred = crdup(cred); 278 } 279 svid = ns->ns_svid; 280 } else if (flags & F_REMOTE) { 281 /* 282 * If we are recovering after a server restart or 283 * trashing locks on a force unmount, use the same 284 * svid as last time. 285 */ 286 svid = fl->l_pid; 287 } else { 288 svid = ((struct proc *) id)->p_pid; 289 } 290 291 switch(op) { 292 case F_SETLK: 293 if ((flags & (F_FLOCK|F_WAIT)) == (F_FLOCK|F_WAIT) 294 && fl->l_type == F_WRLCK) { 295 /* 296 * The semantics for flock(2) require that any 297 * shared lock on the file must be released 298 * before an exclusive lock is granted. The 299 * local locking code interprets this by 300 * unlocking the file before sleeping on a 301 * blocked exclusive lock request. We 302 * approximate this by first attempting 303 * non-blocking and if that fails, we unlock 304 * the file and block. 305 */ 306 error = nlm_setlock(host, &ext, vers, &timo, retries, 307 vp, F_SETLK, fl, flags & ~F_WAIT, 308 svid, fhlen, &fh.fh_bytes, size, reclaim); 309 if (error == EAGAIN) { 310 fl->l_type = F_UNLCK; 311 error = nlm_clearlock(host, &ext, vers, &timo, 312 retries, vp, F_UNLCK, fl, flags, 313 svid, fhlen, &fh.fh_bytes, size); 314 fl->l_type = F_WRLCK; 315 if (!error) { 316 mtx_lock(&nlm_svid_lock); 317 if (ns->ns_active) { 318 ns->ns_refs--; 319 ns->ns_active = FALSE; 320 } 321 mtx_unlock(&nlm_svid_lock); 322 flags |= F_WAIT; 323 error = nlm_setlock(host, &ext, vers, 324 &timo, retries, vp, F_SETLK, fl, 325 flags, svid, fhlen, &fh.fh_bytes, 326 size, reclaim); 327 } 328 } 329 } else { 330 error = nlm_setlock(host, &ext, vers, &timo, retries, 331 vp, op, fl, flags, svid, fhlen, &fh.fh_bytes, 332 size, reclaim); 333 } 334 if (!error && ns) { 335 mtx_lock(&nlm_svid_lock); 336 if (!ns->ns_active) { 337 /* 338 * Add one to the reference count to 339 * hold onto the SVID for the lifetime 340 * of the lock. Note that since 341 * F_FLOCK only supports whole-file 342 * locks, there can only be one active 343 * lock for this SVID. 344 */ 345 ns->ns_refs++; 346 ns->ns_active = TRUE; 347 } 348 mtx_unlock(&nlm_svid_lock); 349 } 350 break; 351 352 case F_UNLCK: 353 error = nlm_clearlock(host, &ext, vers, &timo, retries, 354 vp, op, fl, flags, svid, fhlen, &fh.fh_bytes, size); 355 if (!error && ns) { 356 mtx_lock(&nlm_svid_lock); 357 if (ns->ns_active) { 358 ns->ns_refs--; 359 ns->ns_active = FALSE; 360 } 361 mtx_unlock(&nlm_svid_lock); 362 } 363 break; 364 365 case F_GETLK: 366 error = nlm_getlock(host, &ext, vers, &timo, retries, 367 vp, op, fl, flags, svid, fhlen, &fh.fh_bytes, size); 368 break; 369 370 default: 371 error = EINVAL; 372 break; 373 } 374 375 if (ns) 376 nlm_free_svid(ns); 377 378 cred1 = td->td_ucred; 379 td->td_ucred = cred; 380 crfree(cred1); 381 AUTH_DESTROY(auth); 382 383 nlm_host_release(host); 384 free(servername, M_TEMP); 385 return (error); 386} 387 388int 389nlm_advlock(struct vop_advlock_args *ap) 390{ 391 392 return (nlm_advlock_internal(ap->a_vp, ap->a_id, ap->a_op, ap->a_fl, 393 ap->a_flags, FALSE, TRUE)); 394} 395 396/* 397 * Set the creds of td to the creds of the given lock's owner. The new 398 * creds reference count will be incremented via crhold. The caller is 399 * responsible for calling crfree and restoring td's original creds. 400 */ 401static void 402nlm_set_creds_for_lock(struct thread *td, struct flock *fl) 403{ 404 int i; 405 struct nlm_file_svid *ns; 406 struct proc *p; 407 struct ucred *cred; 408 409 cred = NULL; 410 if (fl->l_pid > PID_MAX) { 411 /* 412 * If this was originally a F_FLOCK-style lock, we 413 * recorded the creds used when it was originally 414 * locked in the nlm_file_svid structure. 415 */ 416 mtx_lock(&nlm_svid_lock); 417 for (i = 0; i < NLM_SVID_HASH_SIZE; i++) { 418 for (ns = LIST_FIRST(&nlm_file_svids[i]); ns; 419 ns = LIST_NEXT(ns, ns_link)) { 420 if (ns->ns_svid == fl->l_pid) { 421 cred = crhold(ns->ns_ucred); 422 break; 423 } 424 } 425 } 426 mtx_unlock(&nlm_svid_lock); 427 } else { 428 /* 429 * This lock is owned by a process. Get a reference to 430 * the process creds. 431 */ 432 p = pfind(fl->l_pid); 433 if (p) { 434 cred = crhold(p->p_ucred); 435 PROC_UNLOCK(p); 436 } 437 } 438 439 /* 440 * If we can't find a cred, fall back on the recovery 441 * thread's cred. 442 */ 443 if (!cred) { 444 cred = crhold(td->td_ucred); 445 } 446 447 td->td_ucred = cred; 448} 449 450static int 451nlm_reclaim_free_lock(struct vnode *vp, struct flock *fl, void *arg) 452{ 453 struct flock newfl; 454 struct thread *td = curthread; 455 struct ucred *oldcred; 456 int error; 457 458 newfl = *fl; 459 newfl.l_type = F_UNLCK; 460 461 oldcred = td->td_ucred; 462 nlm_set_creds_for_lock(td, &newfl); 463 464 error = nlm_advlock_internal(vp, NULL, F_UNLCK, &newfl, F_REMOTE, 465 FALSE, FALSE); 466 467 crfree(td->td_ucred); 468 td->td_ucred = oldcred; 469 470 return (error); 471} 472 473int 474nlm_reclaim(struct vop_reclaim_args *ap) 475{ 476 477 nlm_cancel_wait(ap->a_vp); 478 lf_iteratelocks_vnode(ap->a_vp, nlm_reclaim_free_lock, NULL); 479 return (0); 480} 481 482struct nlm_recovery_context { 483 struct nlm_host *nr_host; /* host we are recovering */ 484 int nr_state; /* remote NSM state for recovery */ 485}; 486 487static int 488nlm_client_recover_lock(struct vnode *vp, struct flock *fl, void *arg) 489{ 490 struct nlm_recovery_context *nr = (struct nlm_recovery_context *) arg; 491 struct thread *td = curthread; 492 struct ucred *oldcred; 493 int state, error; 494 495 /* 496 * If the remote NSM state changes during recovery, the host 497 * must have rebooted a second time. In that case, we must 498 * restart the recovery. 499 */ 500 state = nlm_host_get_state(nr->nr_host); 501 if (nr->nr_state != state) 502 return (ERESTART); 503 504 error = vn_lock(vp, LK_SHARED); 505 if (error) 506 return (error); 507 508 oldcred = td->td_ucred; 509 nlm_set_creds_for_lock(td, fl); 510 511 error = nlm_advlock_internal(vp, NULL, F_SETLK, fl, F_REMOTE, 512 TRUE, TRUE); 513 514 crfree(td->td_ucred); 515 td->td_ucred = oldcred; 516 517 return (error); 518} 519 520void 521nlm_client_recovery(struct nlm_host *host) 522{ 523 struct nlm_recovery_context nr; 524 int sysid, error; 525 526 sysid = NLM_SYSID_CLIENT | nlm_host_get_sysid(host); 527 do { 528 nr.nr_host = host; 529 nr.nr_state = nlm_host_get_state(host); 530 error = lf_iteratelocks_sysid(sysid, 531 nlm_client_recover_lock, &nr); 532 } while (error == ERESTART); 533} 534 535static void 536nlm_convert_to_nlm_lock(struct nlm_lock *dst, struct nlm4_lock *src) 537{ 538 539 dst->caller_name = src->caller_name; 540 dst->fh = src->fh; 541 dst->oh = src->oh; 542 dst->svid = src->svid; 543 dst->l_offset = src->l_offset; 544 dst->l_len = src->l_len; 545} 546 547static void 548nlm_convert_to_nlm4_holder(struct nlm4_holder *dst, struct nlm_holder *src) 549{ 550 551 dst->exclusive = src->exclusive; 552 dst->svid = src->svid; 553 dst->oh = src->oh; 554 dst->l_offset = src->l_offset; 555 dst->l_len = src->l_len; 556} 557 558static void 559nlm_convert_to_nlm4_res(struct nlm4_res *dst, struct nlm_res *src) 560{ 561 dst->cookie = src->cookie; 562 dst->stat.stat = (enum nlm4_stats) src->stat.stat; 563} 564 565static enum clnt_stat 566nlm_test_rpc(rpcvers_t vers, nlm4_testargs *args, nlm4_testres *res, CLIENT *client, 567 struct rpc_callextra *ext, struct timeval timo) 568{ 569 if (vers == NLM_VERS4) { 570 return nlm4_test_4(args, res, client, ext, timo); 571 } else { 572 nlm_testargs args1; 573 nlm_testres res1; 574 enum clnt_stat stat; 575 576 args1.cookie = args->cookie; 577 args1.exclusive = args->exclusive; 578 nlm_convert_to_nlm_lock(&args1.alock, &args->alock); 579 memset(&res1, 0, sizeof(res1)); 580 581 stat = nlm_test_1(&args1, &res1, client, ext, timo); 582 583 if (stat == RPC_SUCCESS) { 584 res->cookie = res1.cookie; 585 res->stat.stat = (enum nlm4_stats) res1.stat.stat; 586 if (res1.stat.stat == nlm_denied) 587 nlm_convert_to_nlm4_holder( 588 &res->stat.nlm4_testrply_u.holder, 589 &res1.stat.nlm_testrply_u.holder); 590 } 591 592 return (stat); 593 } 594} 595 596static enum clnt_stat 597nlm_lock_rpc(rpcvers_t vers, nlm4_lockargs *args, nlm4_res *res, CLIENT *client, 598 struct rpc_callextra *ext, struct timeval timo) 599{ 600 if (vers == NLM_VERS4) { 601 return nlm4_lock_4(args, res, client, ext, timo); 602 } else { 603 nlm_lockargs args1; 604 nlm_res res1; 605 enum clnt_stat stat; 606 607 args1.cookie = args->cookie; 608 args1.block = args->block; 609 args1.exclusive = args->exclusive; 610 nlm_convert_to_nlm_lock(&args1.alock, &args->alock); 611 args1.reclaim = args->reclaim; 612 args1.state = args->state; 613 memset(&res1, 0, sizeof(res1)); 614 615 stat = nlm_lock_1(&args1, &res1, client, ext, timo); 616 617 if (stat == RPC_SUCCESS) { 618 nlm_convert_to_nlm4_res(res, &res1); 619 } 620 621 return (stat); 622 } 623} 624 625static enum clnt_stat 626nlm_cancel_rpc(rpcvers_t vers, nlm4_cancargs *args, nlm4_res *res, CLIENT *client, 627 struct rpc_callextra *ext, struct timeval timo) 628{ 629 if (vers == NLM_VERS4) { 630 return nlm4_cancel_4(args, res, client, ext, timo); 631 } else { 632 nlm_cancargs args1; 633 nlm_res res1; 634 enum clnt_stat stat; 635 636 args1.cookie = args->cookie; 637 args1.block = args->block; 638 args1.exclusive = args->exclusive; 639 nlm_convert_to_nlm_lock(&args1.alock, &args->alock); 640 memset(&res1, 0, sizeof(res1)); 641 642 stat = nlm_cancel_1(&args1, &res1, client, ext, timo); 643 644 if (stat == RPC_SUCCESS) { 645 nlm_convert_to_nlm4_res(res, &res1); 646 } 647 648 return (stat); 649 } 650} 651 652static enum clnt_stat 653nlm_unlock_rpc(rpcvers_t vers, nlm4_unlockargs *args, nlm4_res *res, CLIENT *client, 654 struct rpc_callextra *ext, struct timeval timo) 655{ 656 if (vers == NLM_VERS4) { 657 return nlm4_unlock_4(args, res, client, ext, timo); 658 } else { 659 nlm_unlockargs args1; 660 nlm_res res1; 661 enum clnt_stat stat; 662 663 args1.cookie = args->cookie; 664 nlm_convert_to_nlm_lock(&args1.alock, &args->alock); 665 memset(&res1, 0, sizeof(res1)); 666 667 stat = nlm_unlock_1(&args1, &res1, client, ext, timo); 668 669 if (stat == RPC_SUCCESS) { 670 nlm_convert_to_nlm4_res(res, &res1); 671 } 672 673 return (stat); 674 } 675} 676 677/* 678 * Called after a lock request (set or clear) succeeded. We record the 679 * details in the local lock manager. Note that since the remote 680 * server has granted the lock, we can be sure that it doesn't 681 * conflict with any other locks we have in the local lock manager. 682 * 683 * Since it is possible that host may also make NLM client requests to 684 * our NLM server, we use a different sysid value to record our own 685 * client locks. 686 * 687 * Note that since it is possible for us to receive replies from the 688 * server in a different order than the locks were granted (e.g. if 689 * many local threads are contending for the same lock), we must use a 690 * blocking operation when registering with the local lock manager. 691 * We expect that any actual wait will be rare and short hence we 692 * ignore signals for this. 693 */ 694static void 695nlm_record_lock(struct vnode *vp, int op, struct flock *fl, 696 int svid, int sysid, off_t size) 697{ 698 struct vop_advlockasync_args a; 699 struct flock newfl; 700 struct proc *p; 701 int error, stops_deferred; 702 703 a.a_vp = vp; 704 a.a_id = NULL; 705 a.a_op = op; 706 a.a_fl = &newfl; 707 a.a_flags = F_REMOTE|F_WAIT|F_NOINTR; 708 a.a_task = NULL; 709 a.a_cookiep = NULL; 710 newfl.l_start = fl->l_start; 711 newfl.l_len = fl->l_len; 712 newfl.l_type = fl->l_type; 713 newfl.l_whence = fl->l_whence; 714 newfl.l_pid = svid; 715 newfl.l_sysid = NLM_SYSID_CLIENT | sysid; 716 717 for (;;) { 718 error = lf_advlockasync(&a, &vp->v_lockf, size); 719 if (error == EDEADLK) { 720 /* 721 * Locks are associated with the processes and 722 * not with threads. Suppose we have two 723 * threads A1 A2 in one process, A1 locked 724 * file f1, A2 is locking file f2, and A1 is 725 * unlocking f1. Then remote server may 726 * already unlocked f1, while local still not 727 * yet scheduled A1 to make the call to local 728 * advlock manager. The process B owns lock on 729 * f2 and issued the lock on f1. Remote would 730 * grant B the request on f1, but local would 731 * return EDEADLK. 732 */ 733 pause("nlmdlk", 1); 734 p = curproc; 735 stops_deferred = sigdeferstop(SIGDEFERSTOP_OFF); 736 PROC_LOCK(p); 737 thread_suspend_check(0); 738 PROC_UNLOCK(p); 739 sigallowstop(stops_deferred); 740 } else if (error == EINTR) { 741 /* 742 * lf_purgelocks() might wake up the lock 743 * waiter and removed our lock graph edges. 744 * There is no sense in re-trying recording 745 * the lock to the local manager after 746 * reclaim. 747 */ 748 error = 0; 749 break; 750 } else 751 break; 752 } 753 KASSERT(error == 0 || error == ENOENT, 754 ("Failed to register NFS lock locally - error=%d", error)); 755} 756 757static int 758nlm_setlock(struct nlm_host *host, struct rpc_callextra *ext, 759 rpcvers_t vers, struct timeval *timo, int retries, 760 struct vnode *vp, int op, struct flock *fl, int flags, 761 int svid, size_t fhlen, void *fh, off_t size, bool_t reclaim) 762{ 763 struct nlm4_lockargs args; 764 char oh_space[32]; 765 struct nlm4_res res; 766 u_int xid; 767 CLIENT *client; 768 enum clnt_stat stat; 769 int retry, block, exclusive; 770 void *wait_handle = NULL; 771 int error; 772 773 memset(&args, 0, sizeof(args)); 774 memset(&res, 0, sizeof(res)); 775 776 block = (flags & F_WAIT) ? TRUE : FALSE; 777 exclusive = (fl->l_type == F_WRLCK); 778 779 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size, 780 &args.alock, oh_space); 781 if (error) 782 return (error); 783 args.block = block; 784 args.exclusive = exclusive; 785 args.reclaim = reclaim; 786 args.state = nlm_nsm_state; 787 788 retry = 5*hz; 789 for (;;) { 790 client = nlm_host_get_rpc(host, FALSE); 791 if (!client) 792 return (ENOLCK); /* XXX retry? */ 793 794 if (block) 795 wait_handle = nlm_register_wait_lock(&args.alock, vp); 796 797 xid = atomic_fetchadd_int(&nlm_xid, 1); 798 args.cookie.n_len = sizeof(xid); 799 args.cookie.n_bytes = (char*) &xid; 800 801 stat = nlm_lock_rpc(vers, &args, &res, client, ext, *timo); 802 803 CLNT_RELEASE(client); 804 805 if (stat != RPC_SUCCESS) { 806 if (block) 807 nlm_deregister_wait_lock(wait_handle); 808 if (retries) { 809 retries--; 810 continue; 811 } 812 return (EINVAL); 813 } 814 815 /* 816 * Free res.cookie. 817 */ 818 xdr_free((xdrproc_t) xdr_nlm4_res, &res); 819 820 if (block && res.stat.stat != nlm4_blocked) 821 nlm_deregister_wait_lock(wait_handle); 822 823 if (res.stat.stat == nlm4_denied_grace_period) { 824 /* 825 * The server has recently rebooted and is 826 * giving old clients a change to reclaim 827 * their locks. Wait for a few seconds and try 828 * again. 829 */ 830 error = tsleep(&args, PCATCH, "nlmgrace", retry); 831 if (error && error != EWOULDBLOCK) 832 return (error); 833 retry = 2*retry; 834 if (retry > 30*hz) 835 retry = 30*hz; 836 continue; 837 } 838 839 if (block && res.stat.stat == nlm4_blocked) { 840 /* 841 * The server should call us back with a 842 * granted message when the lock succeeds. In 843 * order to deal with broken servers, lost 844 * granted messages and server reboots, we 845 * will also re-try every few seconds. 846 */ 847 error = nlm_wait_lock(wait_handle, retry); 848 if (error == EWOULDBLOCK) { 849 retry = 2*retry; 850 if (retry > 30*hz) 851 retry = 30*hz; 852 continue; 853 } 854 if (error) { 855 /* 856 * We need to call the server to 857 * cancel our lock request. 858 */ 859 nlm4_cancargs cancel; 860 861 memset(&cancel, 0, sizeof(cancel)); 862 863 xid = atomic_fetchadd_int(&nlm_xid, 1); 864 cancel.cookie.n_len = sizeof(xid); 865 cancel.cookie.n_bytes = (char*) &xid; 866 cancel.block = block; 867 cancel.exclusive = exclusive; 868 cancel.alock = args.alock; 869 870 do { 871 client = nlm_host_get_rpc(host, FALSE); 872 if (!client) 873 /* XXX retry? */ 874 return (ENOLCK); 875 876 stat = nlm_cancel_rpc(vers, &cancel, 877 &res, client, ext, *timo); 878 879 CLNT_RELEASE(client); 880 881 if (stat != RPC_SUCCESS) { 882 /* 883 * We need to cope 884 * with temporary 885 * network partitions 886 * as well as server 887 * reboots. This means 888 * we have to keep 889 * trying to cancel 890 * until the server 891 * wakes up again. 892 */ 893 pause("nlmcancel", 10*hz); 894 } 895 } while (stat != RPC_SUCCESS); 896 897 /* 898 * Free res.cookie. 899 */ 900 xdr_free((xdrproc_t) xdr_nlm4_res, &res); 901 902 switch (res.stat.stat) { 903 case nlm_denied: 904 /* 905 * There was nothing 906 * to cancel. We are 907 * going to go ahead 908 * and assume we got 909 * the lock. 910 */ 911 error = 0; 912 break; 913 914 case nlm4_denied_grace_period: 915 /* 916 * The server has 917 * recently rebooted - 918 * treat this as a 919 * successful 920 * cancellation. 921 */ 922 break; 923 924 case nlm4_granted: 925 /* 926 * We managed to 927 * cancel. 928 */ 929 break; 930 931 default: 932 /* 933 * Broken server 934 * implementation - 935 * can't really do 936 * anything here. 937 */ 938 break; 939 } 940 } 941 } else { 942 error = nlm_map_status(res.stat.stat); 943 } 944 945 if (!error && !reclaim) { 946 nlm_record_lock(vp, op, fl, args.alock.svid, 947 nlm_host_get_sysid(host), size); 948 nlm_host_monitor(host, 0); 949 } 950 951 return (error); 952 } 953} 954 955static int 956nlm_clearlock(struct nlm_host *host, struct rpc_callextra *ext, 957 rpcvers_t vers, struct timeval *timo, int retries, 958 struct vnode *vp, int op, struct flock *fl, int flags, 959 int svid, size_t fhlen, void *fh, off_t size) 960{ 961 struct nlm4_unlockargs args; 962 char oh_space[32]; 963 struct nlm4_res res; 964 u_int xid; 965 CLIENT *client; 966 enum clnt_stat stat; 967 int error; 968 969 memset(&args, 0, sizeof(args)); 970 memset(&res, 0, sizeof(res)); 971 972 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size, 973 &args.alock, oh_space); 974 if (error) 975 return (error); 976 977 for (;;) { 978 client = nlm_host_get_rpc(host, FALSE); 979 if (!client) 980 return (ENOLCK); /* XXX retry? */ 981 982 xid = atomic_fetchadd_int(&nlm_xid, 1); 983 args.cookie.n_len = sizeof(xid); 984 args.cookie.n_bytes = (char*) &xid; 985 986 stat = nlm_unlock_rpc(vers, &args, &res, client, ext, *timo); 987 988 CLNT_RELEASE(client); 989 990 if (stat != RPC_SUCCESS) { 991 if (retries) { 992 retries--; 993 continue; 994 } 995 return (EINVAL); 996 } 997 998 /* 999 * Free res.cookie. 1000 */ 1001 xdr_free((xdrproc_t) xdr_nlm4_res, &res); 1002 1003 if (res.stat.stat == nlm4_denied_grace_period) { 1004 /* 1005 * The server has recently rebooted and is 1006 * giving old clients a change to reclaim 1007 * their locks. Wait for a few seconds and try 1008 * again. 1009 */ 1010 error = tsleep(&args, PCATCH, "nlmgrace", 5*hz); 1011 if (error && error != EWOULDBLOCK) 1012 return (error); 1013 continue; 1014 } 1015 1016 /* 1017 * If we are being called via nlm_reclaim (which will 1018 * use the F_REMOTE flag), don't record the lock 1019 * operation in the local lock manager since the vnode 1020 * is going away. 1021 */ 1022 if (!(flags & F_REMOTE)) 1023 nlm_record_lock(vp, op, fl, args.alock.svid, 1024 nlm_host_get_sysid(host), size); 1025 1026 return (0); 1027 } 1028} 1029 1030static int 1031nlm_getlock(struct nlm_host *host, struct rpc_callextra *ext, 1032 rpcvers_t vers, struct timeval *timo, int retries, 1033 struct vnode *vp, int op, struct flock *fl, int flags, 1034 int svid, size_t fhlen, void *fh, off_t size) 1035{ 1036 struct nlm4_testargs args; 1037 char oh_space[32]; 1038 struct nlm4_testres res; 1039 u_int xid; 1040 CLIENT *client; 1041 enum clnt_stat stat; 1042 int exclusive; 1043 int error; 1044 1045 KASSERT(!(flags & F_FLOCK), ("unexpected F_FLOCK for F_GETLK")); 1046 1047 memset(&args, 0, sizeof(args)); 1048 memset(&res, 0, sizeof(res)); 1049 1050 exclusive = (fl->l_type == F_WRLCK); 1051 1052 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size, 1053 &args.alock, oh_space); 1054 if (error) 1055 return (error); 1056 args.exclusive = exclusive; 1057 1058 for (;;) { 1059 client = nlm_host_get_rpc(host, FALSE); 1060 if (!client) 1061 return (ENOLCK); /* XXX retry? */ 1062 1063 xid = atomic_fetchadd_int(&nlm_xid, 1); 1064 args.cookie.n_len = sizeof(xid); 1065 args.cookie.n_bytes = (char*) &xid; 1066 1067 stat = nlm_test_rpc(vers, &args, &res, client, ext, *timo); 1068 1069 CLNT_RELEASE(client); 1070 1071 if (stat != RPC_SUCCESS) { 1072 if (retries) { 1073 retries--; 1074 continue; 1075 } 1076 return (EINVAL); 1077 } 1078 1079 if (res.stat.stat == nlm4_denied_grace_period) { 1080 /* 1081 * The server has recently rebooted and is 1082 * giving old clients a change to reclaim 1083 * their locks. Wait for a few seconds and try 1084 * again. 1085 */ 1086 xdr_free((xdrproc_t) xdr_nlm4_testres, &res); 1087 error = tsleep(&args, PCATCH, "nlmgrace", 5*hz); 1088 if (error && error != EWOULDBLOCK) 1089 return (error); 1090 continue; 1091 } 1092 1093 if (res.stat.stat == nlm4_denied) { 1094 struct nlm4_holder *h = 1095 &res.stat.nlm4_testrply_u.holder; 1096 fl->l_start = h->l_offset; 1097 fl->l_len = h->l_len; 1098 fl->l_pid = h->svid; 1099 if (h->exclusive) 1100 fl->l_type = F_WRLCK; 1101 else 1102 fl->l_type = F_RDLCK; 1103 fl->l_whence = SEEK_SET; 1104 fl->l_sysid = 0; 1105 } else { 1106 fl->l_type = F_UNLCK; 1107 } 1108 1109 xdr_free((xdrproc_t) xdr_nlm4_testres, &res); 1110 1111 return (0); 1112 } 1113} 1114 1115static int 1116nlm_map_status(nlm4_stats stat) 1117{ 1118 switch (stat) { 1119 case nlm4_granted: 1120 return (0); 1121 1122 case nlm4_denied: 1123 return (EAGAIN); 1124 1125 case nlm4_denied_nolocks: 1126 return (ENOLCK); 1127 1128 case nlm4_deadlck: 1129 return (EDEADLK); 1130 1131 case nlm4_rofs: 1132 return (EROFS); 1133 1134 case nlm4_stale_fh: 1135 return (ESTALE); 1136 1137 case nlm4_fbig: 1138 return (EFBIG); 1139 1140 case nlm4_failed: 1141 return (EACCES); 1142 1143 default: 1144 return (EINVAL); 1145 } 1146} 1147 1148static struct nlm_file_svid * 1149nlm_find_svid(void *id) 1150{ 1151 struct nlm_file_svid *ns, *newns; 1152 int h; 1153 1154 h = (((uintptr_t) id) >> 7) % NLM_SVID_HASH_SIZE; 1155 1156 mtx_lock(&nlm_svid_lock); 1157 LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) { 1158 if (ns->ns_id == id) { 1159 ns->ns_refs++; 1160 break; 1161 } 1162 } 1163 mtx_unlock(&nlm_svid_lock); 1164 if (!ns) { 1165 int svid = alloc_unr(nlm_svid_allocator); 1166 newns = malloc(sizeof(struct nlm_file_svid), M_NLM, 1167 M_WAITOK); 1168 newns->ns_refs = 1; 1169 newns->ns_id = id; 1170 newns->ns_svid = svid; 1171 newns->ns_ucred = NULL; 1172 newns->ns_active = FALSE; 1173 1174 /* 1175 * We need to check for a race with some other 1176 * thread allocating a svid for this file. 1177 */ 1178 mtx_lock(&nlm_svid_lock); 1179 LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) { 1180 if (ns->ns_id == id) { 1181 ns->ns_refs++; 1182 break; 1183 } 1184 } 1185 if (ns) { 1186 mtx_unlock(&nlm_svid_lock); 1187 free_unr(nlm_svid_allocator, newns->ns_svid); 1188 free(newns, M_NLM); 1189 } else { 1190 LIST_INSERT_HEAD(&nlm_file_svids[h], newns, 1191 ns_link); 1192 ns = newns; 1193 mtx_unlock(&nlm_svid_lock); 1194 } 1195 } 1196 1197 return (ns); 1198} 1199 1200static void 1201nlm_free_svid(struct nlm_file_svid *ns) 1202{ 1203 1204 mtx_lock(&nlm_svid_lock); 1205 ns->ns_refs--; 1206 if (!ns->ns_refs) { 1207 KASSERT(!ns->ns_active, ("Freeing active SVID")); 1208 LIST_REMOVE(ns, ns_link); 1209 mtx_unlock(&nlm_svid_lock); 1210 free_unr(nlm_svid_allocator, ns->ns_svid); 1211 if (ns->ns_ucred) 1212 crfree(ns->ns_ucred); 1213 free(ns, M_NLM); 1214 } else { 1215 mtx_unlock(&nlm_svid_lock); 1216 } 1217} 1218 1219static int 1220nlm_init_lock(struct flock *fl, int flags, int svid, 1221 rpcvers_t vers, size_t fhlen, void *fh, off_t size, 1222 struct nlm4_lock *lock, char oh_space[32]) 1223{ 1224 size_t oh_len; 1225 off_t start, len; 1226 1227 if (fl->l_whence == SEEK_END) { 1228 if (size > OFF_MAX 1229 || (fl->l_start > 0 && size > OFF_MAX - fl->l_start)) 1230 return (EOVERFLOW); 1231 start = size + fl->l_start; 1232 } else if (fl->l_whence == SEEK_SET || fl->l_whence == SEEK_CUR) { 1233 start = fl->l_start; 1234 } else { 1235 return (EINVAL); 1236 } 1237 if (start < 0) 1238 return (EINVAL); 1239 if (fl->l_len < 0) { 1240 len = -fl->l_len; 1241 start -= len; 1242 if (start < 0) 1243 return (EINVAL); 1244 } else { 1245 len = fl->l_len; 1246 } 1247 1248 if (vers == NLM_VERS) { 1249 /* 1250 * Enforce range limits on V1 locks 1251 */ 1252 if (start > 0xffffffffLL || len > 0xffffffffLL) 1253 return (EOVERFLOW); 1254 } 1255 1256 snprintf(oh_space, 32, "%d@", svid); 1257 oh_len = strlen(oh_space); 1258 getcredhostname(NULL, oh_space + oh_len, 32 - oh_len); 1259 oh_len = strlen(oh_space); 1260 1261 memset(lock, 0, sizeof(*lock)); 1262 lock->caller_name = prison0.pr_hostname; 1263 lock->fh.n_len = fhlen; 1264 lock->fh.n_bytes = fh; 1265 lock->oh.n_len = oh_len; 1266 lock->oh.n_bytes = oh_space; 1267 lock->svid = svid; 1268 lock->l_offset = start; 1269 lock->l_len = len; 1270 1271 return (0); 1272} 1273