nlm_advlock.c revision 302209
1/*- 2 * Copyright (c) 2008 Isilon Inc http://www.isilon.com/ 3 * Authors: Doug Rabson <dfr@rabson.org> 4 * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: stable/10/sys/nlm/nlm_advlock.c 302209 2016-06-26 13:18:03Z kib $"); 30 31#include <sys/param.h> 32#include <sys/fcntl.h> 33#include <sys/jail.h> 34#include <sys/kernel.h> 35#include <sys/limits.h> 36#include <sys/lock.h> 37#include <sys/lockf.h> 38#include <sys/malloc.h> 39#include <sys/mbuf.h> 40#include <sys/mount.h> 41#include <sys/mutex.h> 42#include <sys/proc.h> 43#include <sys/socket.h> 44#include <sys/syslog.h> 45#include <sys/systm.h> 46#include <sys/unistd.h> 47#include <sys/vnode.h> 48 49#include <nfs/nfsproto.h> 50#include <nfsclient/nfs.h> 51#include <nfsclient/nfsmount.h> 52 53#include <nlm/nlm_prot.h> 54#include <nlm/nlm.h> 55 56/* 57 * We need to keep track of the svid values used for F_FLOCK locks. 58 */ 59struct nlm_file_svid { 60 int ns_refs; /* thread count + 1 if active */ 61 int ns_svid; /* on-the-wire SVID for this file */ 62 struct ucred *ns_ucred; /* creds to use for lock recovery */ 63 void *ns_id; /* local struct file pointer */ 64 bool_t ns_active; /* TRUE if we own a lock */ 65 LIST_ENTRY(nlm_file_svid) ns_link; 66}; 67LIST_HEAD(nlm_file_svid_list, nlm_file_svid); 68 69#define NLM_SVID_HASH_SIZE 256 70struct nlm_file_svid_list nlm_file_svids[NLM_SVID_HASH_SIZE]; 71 72struct mtx nlm_svid_lock; 73static struct unrhdr *nlm_svid_allocator; 74static volatile u_int nlm_xid = 1; 75 76static int nlm_setlock(struct nlm_host *host, struct rpc_callextra *ext, 77 rpcvers_t vers, struct timeval *timo, int retries, 78 struct vnode *vp, int op, struct flock *fl, int flags, 79 int svid, size_t fhlen, void *fh, off_t size, bool_t reclaim); 80static int nlm_clearlock(struct nlm_host *host, struct rpc_callextra *ext, 81 rpcvers_t vers, struct timeval *timo, int retries, 82 struct vnode *vp, int op, struct flock *fl, int flags, 83 int svid, size_t fhlen, void *fh, off_t size); 84static int nlm_getlock(struct nlm_host *host, struct rpc_callextra *ext, 85 rpcvers_t vers, struct timeval *timo, int retries, 86 struct vnode *vp, int op, struct flock *fl, int flags, 87 int svid, size_t fhlen, void *fh, off_t size); 88static int nlm_map_status(nlm4_stats stat); 89static struct nlm_file_svid *nlm_find_svid(void *id); 90static void nlm_free_svid(struct nlm_file_svid *nf); 91static int nlm_init_lock(struct flock *fl, int flags, int svid, 92 rpcvers_t vers, size_t fhlen, void *fh, off_t size, 93 struct nlm4_lock *lock, char oh_space[32]); 94 95static void 96nlm_client_init(void *dummy) 97{ 98 int i; 99 100 mtx_init(&nlm_svid_lock, "NLM svid lock", NULL, MTX_DEF); 101 /* pid_max cannot be greater than PID_MAX */ 102 nlm_svid_allocator = new_unrhdr(PID_MAX + 2, INT_MAX, &nlm_svid_lock); 103 for (i = 0; i < NLM_SVID_HASH_SIZE; i++) 104 LIST_INIT(&nlm_file_svids[i]); 105} 106SYSINIT(nlm_client_init, SI_SUB_LOCK, SI_ORDER_FIRST, nlm_client_init, NULL); 107 108static int 109nlm_msg(struct thread *td, const char *server, const char *msg, int error) 110{ 111 struct proc *p; 112 113 p = td ? td->td_proc : NULL; 114 if (error) { 115 tprintf(p, LOG_INFO, "nfs server %s: %s, error %d\n", server, 116 msg, error); 117 } else { 118 tprintf(p, LOG_INFO, "nfs server %s: %s\n", server, msg); 119 } 120 return (0); 121} 122 123struct nlm_feedback_arg { 124 bool_t nf_printed; 125 struct nfsmount *nf_nmp; 126}; 127 128static void 129nlm_down(struct nlm_feedback_arg *nf, struct thread *td, 130 const char *msg, int error) 131{ 132 struct nfsmount *nmp = nf->nf_nmp; 133 134 if (nmp == NULL) 135 return; 136 mtx_lock(&nmp->nm_mtx); 137 if (!(nmp->nm_state & NFSSTA_LOCKTIMEO)) { 138 nmp->nm_state |= NFSSTA_LOCKTIMEO; 139 mtx_unlock(&nmp->nm_mtx); 140 vfs_event_signal(&nmp->nm_mountp->mnt_stat.f_fsid, 141 VQ_NOTRESPLOCK, 0); 142 } else { 143 mtx_unlock(&nmp->nm_mtx); 144 } 145 146 nf->nf_printed = TRUE; 147 nlm_msg(td, nmp->nm_mountp->mnt_stat.f_mntfromname, msg, error); 148} 149 150static void 151nlm_up(struct nlm_feedback_arg *nf, struct thread *td, 152 const char *msg) 153{ 154 struct nfsmount *nmp = nf->nf_nmp; 155 156 if (!nf->nf_printed) 157 return; 158 159 nlm_msg(td, nmp->nm_mountp->mnt_stat.f_mntfromname, msg, 0); 160 161 mtx_lock(&nmp->nm_mtx); 162 if (nmp->nm_state & NFSSTA_LOCKTIMEO) { 163 nmp->nm_state &= ~NFSSTA_LOCKTIMEO; 164 mtx_unlock(&nmp->nm_mtx); 165 vfs_event_signal(&nmp->nm_mountp->mnt_stat.f_fsid, 166 VQ_NOTRESPLOCK, 1); 167 } else { 168 mtx_unlock(&nmp->nm_mtx); 169 } 170} 171 172static void 173nlm_feedback(int type, int proc, void *arg) 174{ 175 struct thread *td = curthread; 176 struct nlm_feedback_arg *nf = (struct nlm_feedback_arg *) arg; 177 178 switch (type) { 179 case FEEDBACK_REXMIT2: 180 case FEEDBACK_RECONNECT: 181 nlm_down(nf, td, "lockd not responding", 0); 182 break; 183 184 case FEEDBACK_OK: 185 nlm_up(nf, td, "lockd is alive again"); 186 break; 187 } 188} 189 190/* 191 * nlm_advlock -- 192 * NFS advisory byte-level locks. 193 */ 194static int 195nlm_advlock_internal(struct vnode *vp, void *id, int op, struct flock *fl, 196 int flags, bool_t reclaim, bool_t unlock_vp) 197{ 198 struct thread *td = curthread; 199 struct nfsmount *nmp; 200 off_t size; 201 size_t fhlen; 202 union nfsfh fh; 203 struct sockaddr *sa; 204 struct sockaddr_storage ss; 205 char servername[MNAMELEN]; 206 struct timeval timo; 207 int retries; 208 rpcvers_t vers; 209 struct nlm_host *host; 210 struct rpc_callextra ext; 211 struct nlm_feedback_arg nf; 212 AUTH *auth; 213 struct ucred *cred, *cred1; 214 struct nlm_file_svid *ns; 215 int svid; 216 int error; 217 int is_v3; 218 219 ASSERT_VOP_LOCKED(vp, "nlm_advlock_1"); 220 221 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, 0); 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); 384 385 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 int error; 701 702 a.a_vp = vp; 703 a.a_id = NULL; 704 a.a_op = op; 705 a.a_fl = &newfl; 706 a.a_flags = F_REMOTE|F_WAIT|F_NOINTR; 707 a.a_task = NULL; 708 a.a_cookiep = NULL; 709 newfl.l_start = fl->l_start; 710 newfl.l_len = fl->l_len; 711 newfl.l_type = fl->l_type; 712 newfl.l_whence = fl->l_whence; 713 newfl.l_pid = svid; 714 newfl.l_sysid = NLM_SYSID_CLIENT | sysid; 715 716 for (;;) { 717 error = lf_advlockasync(&a, &vp->v_lockf, size); 718 if (error == EDEADLK) { 719 /* 720 * Locks are associated with the processes and 721 * not with threads. Suppose we have two 722 * threads A1 A2 in one process, A1 locked 723 * file f1, A2 is locking file f2, and A1 is 724 * unlocking f1. Then remote server may 725 * already unlocked f1, while local still not 726 * yet scheduled A1 to make the call to local 727 * advlock manager. The process B owns lock on 728 * f2 and issued the lock on f1. Remote would 729 * grant B the request on f1, but local would 730 * return EDEADLK. 731 */ 732 pause("nlmdlk", 1); 733 /* XXXKIB allow suspend */ 734 } else if (error == EINTR) { 735 /* 736 * lf_purgelocks() might wake up the lock 737 * waiter and removed our lock graph edges. 738 * There is no sense in re-trying recording 739 * the lock to the local manager after 740 * reclaim. 741 */ 742 error = 0; 743 break; 744 } else 745 break; 746 } 747 KASSERT(error == 0 || error == ENOENT, 748 ("Failed to register NFS lock locally - error=%d", error)); 749} 750 751static int 752nlm_setlock(struct nlm_host *host, struct rpc_callextra *ext, 753 rpcvers_t vers, struct timeval *timo, int retries, 754 struct vnode *vp, int op, struct flock *fl, int flags, 755 int svid, size_t fhlen, void *fh, off_t size, bool_t reclaim) 756{ 757 struct nlm4_lockargs args; 758 char oh_space[32]; 759 struct nlm4_res res; 760 u_int xid; 761 CLIENT *client; 762 enum clnt_stat stat; 763 int retry, block, exclusive; 764 void *wait_handle = NULL; 765 int error; 766 767 memset(&args, 0, sizeof(args)); 768 memset(&res, 0, sizeof(res)); 769 770 block = (flags & F_WAIT) ? TRUE : FALSE; 771 exclusive = (fl->l_type == F_WRLCK); 772 773 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size, 774 &args.alock, oh_space); 775 if (error) 776 return (error); 777 args.block = block; 778 args.exclusive = exclusive; 779 args.reclaim = reclaim; 780 args.state = nlm_nsm_state; 781 782 retry = 5*hz; 783 for (;;) { 784 client = nlm_host_get_rpc(host, FALSE); 785 if (!client) 786 return (ENOLCK); /* XXX retry? */ 787 788 if (block) 789 wait_handle = nlm_register_wait_lock(&args.alock, vp); 790 791 xid = atomic_fetchadd_int(&nlm_xid, 1); 792 args.cookie.n_len = sizeof(xid); 793 args.cookie.n_bytes = (char*) &xid; 794 795 stat = nlm_lock_rpc(vers, &args, &res, client, ext, *timo); 796 797 CLNT_RELEASE(client); 798 799 if (stat != RPC_SUCCESS) { 800 if (block) 801 nlm_deregister_wait_lock(wait_handle); 802 if (retries) { 803 retries--; 804 continue; 805 } 806 return (EINVAL); 807 } 808 809 /* 810 * Free res.cookie. 811 */ 812 xdr_free((xdrproc_t) xdr_nlm4_res, &res); 813 814 if (block && res.stat.stat != nlm4_blocked) 815 nlm_deregister_wait_lock(wait_handle); 816 817 if (res.stat.stat == nlm4_denied_grace_period) { 818 /* 819 * The server has recently rebooted and is 820 * giving old clients a change to reclaim 821 * their locks. Wait for a few seconds and try 822 * again. 823 */ 824 error = tsleep(&args, PCATCH, "nlmgrace", retry); 825 if (error && error != EWOULDBLOCK) 826 return (error); 827 retry = 2*retry; 828 if (retry > 30*hz) 829 retry = 30*hz; 830 continue; 831 } 832 833 if (block && res.stat.stat == nlm4_blocked) { 834 /* 835 * The server should call us back with a 836 * granted message when the lock succeeds. In 837 * order to deal with broken servers, lost 838 * granted messages and server reboots, we 839 * will also re-try every few seconds. 840 */ 841 error = nlm_wait_lock(wait_handle, retry); 842 if (error == EWOULDBLOCK) { 843 retry = 2*retry; 844 if (retry > 30*hz) 845 retry = 30*hz; 846 continue; 847 } 848 if (error) { 849 /* 850 * We need to call the server to 851 * cancel our lock request. 852 */ 853 nlm4_cancargs cancel; 854 855 memset(&cancel, 0, sizeof(cancel)); 856 857 xid = atomic_fetchadd_int(&nlm_xid, 1); 858 cancel.cookie.n_len = sizeof(xid); 859 cancel.cookie.n_bytes = (char*) &xid; 860 cancel.block = block; 861 cancel.exclusive = exclusive; 862 cancel.alock = args.alock; 863 864 do { 865 client = nlm_host_get_rpc(host, FALSE); 866 if (!client) 867 /* XXX retry? */ 868 return (ENOLCK); 869 870 stat = nlm_cancel_rpc(vers, &cancel, 871 &res, client, ext, *timo); 872 873 CLNT_RELEASE(client); 874 875 if (stat != RPC_SUCCESS) { 876 /* 877 * We need to cope 878 * with temporary 879 * network partitions 880 * as well as server 881 * reboots. This means 882 * we have to keep 883 * trying to cancel 884 * until the server 885 * wakes up again. 886 */ 887 pause("nlmcancel", 10*hz); 888 } 889 } while (stat != RPC_SUCCESS); 890 891 /* 892 * Free res.cookie. 893 */ 894 xdr_free((xdrproc_t) xdr_nlm4_res, &res); 895 896 switch (res.stat.stat) { 897 case nlm_denied: 898 /* 899 * There was nothing 900 * to cancel. We are 901 * going to go ahead 902 * and assume we got 903 * the lock. 904 */ 905 error = 0; 906 break; 907 908 case nlm4_denied_grace_period: 909 /* 910 * The server has 911 * recently rebooted - 912 * treat this as a 913 * successful 914 * cancellation. 915 */ 916 break; 917 918 case nlm4_granted: 919 /* 920 * We managed to 921 * cancel. 922 */ 923 break; 924 925 default: 926 /* 927 * Broken server 928 * implementation - 929 * can't really do 930 * anything here. 931 */ 932 break; 933 } 934 935 } 936 } else { 937 error = nlm_map_status(res.stat.stat); 938 } 939 940 if (!error && !reclaim) { 941 nlm_record_lock(vp, op, fl, args.alock.svid, 942 nlm_host_get_sysid(host), size); 943 nlm_host_monitor(host, 0); 944 } 945 946 return (error); 947 } 948} 949 950static int 951nlm_clearlock(struct nlm_host *host, struct rpc_callextra *ext, 952 rpcvers_t vers, struct timeval *timo, int retries, 953 struct vnode *vp, int op, struct flock *fl, int flags, 954 int svid, size_t fhlen, void *fh, off_t size) 955{ 956 struct nlm4_unlockargs args; 957 char oh_space[32]; 958 struct nlm4_res res; 959 u_int xid; 960 CLIENT *client; 961 enum clnt_stat stat; 962 int error; 963 964 memset(&args, 0, sizeof(args)); 965 memset(&res, 0, sizeof(res)); 966 967 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size, 968 &args.alock, oh_space); 969 if (error) 970 return (error); 971 972 for (;;) { 973 client = nlm_host_get_rpc(host, FALSE); 974 if (!client) 975 return (ENOLCK); /* XXX retry? */ 976 977 xid = atomic_fetchadd_int(&nlm_xid, 1); 978 args.cookie.n_len = sizeof(xid); 979 args.cookie.n_bytes = (char*) &xid; 980 981 stat = nlm_unlock_rpc(vers, &args, &res, client, ext, *timo); 982 983 CLNT_RELEASE(client); 984 985 if (stat != RPC_SUCCESS) { 986 if (retries) { 987 retries--; 988 continue; 989 } 990 return (EINVAL); 991 } 992 993 /* 994 * Free res.cookie. 995 */ 996 xdr_free((xdrproc_t) xdr_nlm4_res, &res); 997 998 if (res.stat.stat == nlm4_denied_grace_period) { 999 /* 1000 * The server has recently rebooted and is 1001 * giving old clients a change to reclaim 1002 * their locks. Wait for a few seconds and try 1003 * again. 1004 */ 1005 error = tsleep(&args, PCATCH, "nlmgrace", 5*hz); 1006 if (error && error != EWOULDBLOCK) 1007 return (error); 1008 continue; 1009 } 1010 1011 /* 1012 * If we are being called via nlm_reclaim (which will 1013 * use the F_REMOTE flag), don't record the lock 1014 * operation in the local lock manager since the vnode 1015 * is going away. 1016 */ 1017 if (!(flags & F_REMOTE)) 1018 nlm_record_lock(vp, op, fl, args.alock.svid, 1019 nlm_host_get_sysid(host), size); 1020 1021 return (0); 1022 } 1023} 1024 1025static int 1026nlm_getlock(struct nlm_host *host, struct rpc_callextra *ext, 1027 rpcvers_t vers, struct timeval *timo, int retries, 1028 struct vnode *vp, int op, struct flock *fl, int flags, 1029 int svid, size_t fhlen, void *fh, off_t size) 1030{ 1031 struct nlm4_testargs args; 1032 char oh_space[32]; 1033 struct nlm4_testres res; 1034 u_int xid; 1035 CLIENT *client; 1036 enum clnt_stat stat; 1037 int exclusive; 1038 int error; 1039 1040 KASSERT(!(flags & F_FLOCK), ("unexpected F_FLOCK for F_GETLK")); 1041 1042 memset(&args, 0, sizeof(args)); 1043 memset(&res, 0, sizeof(res)); 1044 1045 exclusive = (fl->l_type == F_WRLCK); 1046 1047 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size, 1048 &args.alock, oh_space); 1049 if (error) 1050 return (error); 1051 args.exclusive = exclusive; 1052 1053 for (;;) { 1054 client = nlm_host_get_rpc(host, FALSE); 1055 if (!client) 1056 return (ENOLCK); /* XXX retry? */ 1057 1058 xid = atomic_fetchadd_int(&nlm_xid, 1); 1059 args.cookie.n_len = sizeof(xid); 1060 args.cookie.n_bytes = (char*) &xid; 1061 1062 stat = nlm_test_rpc(vers, &args, &res, client, ext, *timo); 1063 1064 CLNT_RELEASE(client); 1065 1066 if (stat != RPC_SUCCESS) { 1067 if (retries) { 1068 retries--; 1069 continue; 1070 } 1071 return (EINVAL); 1072 } 1073 1074 if (res.stat.stat == nlm4_denied_grace_period) { 1075 /* 1076 * The server has recently rebooted and is 1077 * giving old clients a change to reclaim 1078 * their locks. Wait for a few seconds and try 1079 * again. 1080 */ 1081 xdr_free((xdrproc_t) xdr_nlm4_testres, &res); 1082 error = tsleep(&args, PCATCH, "nlmgrace", 5*hz); 1083 if (error && error != EWOULDBLOCK) 1084 return (error); 1085 continue; 1086 } 1087 1088 if (res.stat.stat == nlm4_denied) { 1089 struct nlm4_holder *h = 1090 &res.stat.nlm4_testrply_u.holder; 1091 fl->l_start = h->l_offset; 1092 fl->l_len = h->l_len; 1093 fl->l_pid = h->svid; 1094 if (h->exclusive) 1095 fl->l_type = F_WRLCK; 1096 else 1097 fl->l_type = F_RDLCK; 1098 fl->l_whence = SEEK_SET; 1099 fl->l_sysid = 0; 1100 } else { 1101 fl->l_type = F_UNLCK; 1102 } 1103 1104 xdr_free((xdrproc_t) xdr_nlm4_testres, &res); 1105 1106 return (0); 1107 } 1108} 1109 1110static int 1111nlm_map_status(nlm4_stats stat) 1112{ 1113 switch (stat) { 1114 case nlm4_granted: 1115 return (0); 1116 1117 case nlm4_denied: 1118 return (EAGAIN); 1119 1120 case nlm4_denied_nolocks: 1121 return (ENOLCK); 1122 1123 case nlm4_deadlck: 1124 return (EDEADLK); 1125 1126 case nlm4_rofs: 1127 return (EROFS); 1128 1129 case nlm4_stale_fh: 1130 return (ESTALE); 1131 1132 case nlm4_fbig: 1133 return (EFBIG); 1134 1135 case nlm4_failed: 1136 return (EACCES); 1137 1138 default: 1139 return (EINVAL); 1140 } 1141} 1142 1143static struct nlm_file_svid * 1144nlm_find_svid(void *id) 1145{ 1146 struct nlm_file_svid *ns, *newns; 1147 int h; 1148 1149 h = (((uintptr_t) id) >> 7) % NLM_SVID_HASH_SIZE; 1150 1151 mtx_lock(&nlm_svid_lock); 1152 LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) { 1153 if (ns->ns_id == id) { 1154 ns->ns_refs++; 1155 break; 1156 } 1157 } 1158 mtx_unlock(&nlm_svid_lock); 1159 if (!ns) { 1160 int svid = alloc_unr(nlm_svid_allocator); 1161 newns = malloc(sizeof(struct nlm_file_svid), M_NLM, 1162 M_WAITOK); 1163 newns->ns_refs = 1; 1164 newns->ns_id = id; 1165 newns->ns_svid = svid; 1166 newns->ns_ucred = NULL; 1167 newns->ns_active = FALSE; 1168 1169 /* 1170 * We need to check for a race with some other 1171 * thread allocating a svid for this file. 1172 */ 1173 mtx_lock(&nlm_svid_lock); 1174 LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) { 1175 if (ns->ns_id == id) { 1176 ns->ns_refs++; 1177 break; 1178 } 1179 } 1180 if (ns) { 1181 mtx_unlock(&nlm_svid_lock); 1182 free_unr(nlm_svid_allocator, newns->ns_svid); 1183 free(newns, M_NLM); 1184 } else { 1185 LIST_INSERT_HEAD(&nlm_file_svids[h], newns, 1186 ns_link); 1187 ns = newns; 1188 mtx_unlock(&nlm_svid_lock); 1189 } 1190 } 1191 1192 return (ns); 1193} 1194 1195static void 1196nlm_free_svid(struct nlm_file_svid *ns) 1197{ 1198 1199 mtx_lock(&nlm_svid_lock); 1200 ns->ns_refs--; 1201 if (!ns->ns_refs) { 1202 KASSERT(!ns->ns_active, ("Freeing active SVID")); 1203 LIST_REMOVE(ns, ns_link); 1204 mtx_unlock(&nlm_svid_lock); 1205 free_unr(nlm_svid_allocator, ns->ns_svid); 1206 if (ns->ns_ucred) 1207 crfree(ns->ns_ucred); 1208 free(ns, M_NLM); 1209 } else { 1210 mtx_unlock(&nlm_svid_lock); 1211 } 1212} 1213 1214static int 1215nlm_init_lock(struct flock *fl, int flags, int svid, 1216 rpcvers_t vers, size_t fhlen, void *fh, off_t size, 1217 struct nlm4_lock *lock, char oh_space[32]) 1218{ 1219 size_t oh_len; 1220 off_t start, len; 1221 1222 if (fl->l_whence == SEEK_END) { 1223 if (size > OFF_MAX 1224 || (fl->l_start > 0 && size > OFF_MAX - fl->l_start)) 1225 return (EOVERFLOW); 1226 start = size + fl->l_start; 1227 } else if (fl->l_whence == SEEK_SET || fl->l_whence == SEEK_CUR) { 1228 start = fl->l_start; 1229 } else { 1230 return (EINVAL); 1231 } 1232 if (start < 0) 1233 return (EINVAL); 1234 if (fl->l_len < 0) { 1235 len = -fl->l_len; 1236 start -= len; 1237 if (start < 0) 1238 return (EINVAL); 1239 } else { 1240 len = fl->l_len; 1241 } 1242 1243 if (vers == NLM_VERS) { 1244 /* 1245 * Enforce range limits on V1 locks 1246 */ 1247 if (start > 0xffffffffLL || len > 0xffffffffLL) 1248 return (EOVERFLOW); 1249 } 1250 1251 snprintf(oh_space, 32, "%d@", svid); 1252 oh_len = strlen(oh_space); 1253 getcredhostname(NULL, oh_space + oh_len, 32 - oh_len); 1254 oh_len = strlen(oh_space); 1255 1256 memset(lock, 0, sizeof(*lock)); 1257 lock->caller_name = prison0.pr_hostname; 1258 lock->fh.n_len = fhlen; 1259 lock->fh.n_bytes = fh; 1260 lock->oh.n_len = oh_len; 1261 lock->oh.n_bytes = oh_space; 1262 lock->svid = svid; 1263 lock->l_offset = start; 1264 lock->l_len = len; 1265 1266 return (0); 1267} 1268