FreeBSD/Linux Kernel Cross Reference
sys/nlm/nlm_advlock.c
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("$FreeBSD$");
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 */
59 struct 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 };
67 LIST_HEAD(nlm_file_svid_list, nlm_file_svid);
68
69 #define NLM_SVID_HASH_SIZE 256
70 struct nlm_file_svid_list nlm_file_svids[NLM_SVID_HASH_SIZE];
71
72 struct mtx nlm_svid_lock;
73 static struct unrhdr *nlm_svid_allocator;
74 static volatile u_int nlm_xid = 1;
75
76 static 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);
80 static 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);
84 static 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);
88 static int nlm_map_status(nlm4_stats stat);
89 static struct nlm_file_svid *nlm_find_svid(void *id);
90 static void nlm_free_svid(struct nlm_file_svid *nf);
91 static 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
95 static void
96 nlm_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 }
106 SYSINIT(nlm_client_init, SI_SUB_LOCK, SI_ORDER_FIRST, nlm_client_init, NULL);
107
108 static int
109 nlm_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
123 struct nlm_feedback_arg {
124 bool_t nf_printed;
125 struct nfsmount *nf_nmp;
126 };
127
128 static void
129 nlm_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
150 static void
151 nlm_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
172 static void
173 nlm_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 */
194 static int
195 nlm_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
388 int
389 nlm_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 */
401 static void
402 nlm_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
450 static int
451 nlm_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
473 int
474 nlm_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
482 struct nlm_recovery_context {
483 struct nlm_host *nr_host; /* host we are recovering */
484 int nr_state; /* remote NSM state for recovery */
485 };
486
487 static int
488 nlm_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
520 void
521 nlm_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
535 static void
536 nlm_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
547 static void
548 nlm_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
558 static void
559 nlm_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
565 static enum clnt_stat
566 nlm_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
596 static enum clnt_stat
597 nlm_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
625 static enum clnt_stat
626 nlm_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
652 static enum clnt_stat
653 nlm_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 */
694 static void
695 nlm_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
757 static int
758 nlm_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 }
942 } else {
943 error = nlm_map_status(res.stat.stat);
944 }
945
946 if (!error && !reclaim) {
947 nlm_record_lock(vp, op, fl, args.alock.svid,
948 nlm_host_get_sysid(host), size);
949 nlm_host_monitor(host, 0);
950 }
951
952 return (error);
953 }
954 }
955
956 static int
957 nlm_clearlock(struct nlm_host *host, struct rpc_callextra *ext,
958 rpcvers_t vers, struct timeval *timo, int retries,
959 struct vnode *vp, int op, struct flock *fl, int flags,
960 int svid, size_t fhlen, void *fh, off_t size)
961 {
962 struct nlm4_unlockargs args;
963 char oh_space[32];
964 struct nlm4_res res;
965 u_int xid;
966 CLIENT *client;
967 enum clnt_stat stat;
968 int error;
969
970 memset(&args, 0, sizeof(args));
971 memset(&res, 0, sizeof(res));
972
973 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
974 &args.alock, oh_space);
975 if (error)
976 return (error);
977
978 for (;;) {
979 client = nlm_host_get_rpc(host, FALSE);
980 if (!client)
981 return (ENOLCK); /* XXX retry? */
982
983 xid = atomic_fetchadd_int(&nlm_xid, 1);
984 args.cookie.n_len = sizeof(xid);
985 args.cookie.n_bytes = (char*) &xid;
986
987 stat = nlm_unlock_rpc(vers, &args, &res, client, ext, *timo);
988
989 CLNT_RELEASE(client);
990
991 if (stat != RPC_SUCCESS) {
992 if (retries) {
993 retries--;
994 continue;
995 }
996 return (EINVAL);
997 }
998
999 /*
1000 * Free res.cookie.
1001 */
1002 xdr_free((xdrproc_t) xdr_nlm4_res, &res);
1003
1004 if (res.stat.stat == nlm4_denied_grace_period) {
1005 /*
1006 * The server has recently rebooted and is
1007 * giving old clients a change to reclaim
1008 * their locks. Wait for a few seconds and try
1009 * again.
1010 */
1011 error = tsleep(&args, PCATCH, "nlmgrace", 5*hz);
1012 if (error && error != EWOULDBLOCK)
1013 return (error);
1014 continue;
1015 }
1016
1017 /*
1018 * If we are being called via nlm_reclaim (which will
1019 * use the F_REMOTE flag), don't record the lock
1020 * operation in the local lock manager since the vnode
1021 * is going away.
1022 */
1023 if (!(flags & F_REMOTE))
1024 nlm_record_lock(vp, op, fl, args.alock.svid,
1025 nlm_host_get_sysid(host), size);
1026
1027 return (0);
1028 }
1029 }
1030
1031 static int
1032 nlm_getlock(struct nlm_host *host, struct rpc_callextra *ext,
1033 rpcvers_t vers, struct timeval *timo, int retries,
1034 struct vnode *vp, int op, struct flock *fl, int flags,
1035 int svid, size_t fhlen, void *fh, off_t size)
1036 {
1037 struct nlm4_testargs args;
1038 char oh_space[32];
1039 struct nlm4_testres res;
1040 u_int xid;
1041 CLIENT *client;
1042 enum clnt_stat stat;
1043 int exclusive;
1044 int error;
1045
1046 KASSERT(!(flags & F_FLOCK), ("unexpected F_FLOCK for F_GETLK"));
1047
1048 memset(&args, 0, sizeof(args));
1049 memset(&res, 0, sizeof(res));
1050
1051 exclusive = (fl->l_type == F_WRLCK);
1052
1053 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
1054 &args.alock, oh_space);
1055 if (error)
1056 return (error);
1057 args.exclusive = exclusive;
1058
1059 for (;;) {
1060 client = nlm_host_get_rpc(host, FALSE);
1061 if (!client)
1062 return (ENOLCK); /* XXX retry? */
1063
1064 xid = atomic_fetchadd_int(&nlm_xid, 1);
1065 args.cookie.n_len = sizeof(xid);
1066 args.cookie.n_bytes = (char*) &xid;
1067
1068 stat = nlm_test_rpc(vers, &args, &res, client, ext, *timo);
1069
1070 CLNT_RELEASE(client);
1071
1072 if (stat != RPC_SUCCESS) {
1073 if (retries) {
1074 retries--;
1075 continue;
1076 }
1077 return (EINVAL);
1078 }
1079
1080 if (res.stat.stat == nlm4_denied_grace_period) {
1081 /*
1082 * The server has recently rebooted and is
1083 * giving old clients a change to reclaim
1084 * their locks. Wait for a few seconds and try
1085 * again.
1086 */
1087 xdr_free((xdrproc_t) xdr_nlm4_testres, &res);
1088 error = tsleep(&args, PCATCH, "nlmgrace", 5*hz);
1089 if (error && error != EWOULDBLOCK)
1090 return (error);
1091 continue;
1092 }
1093
1094 if (res.stat.stat == nlm4_denied) {
1095 struct nlm4_holder *h =
1096 &res.stat.nlm4_testrply_u.holder;
1097 fl->l_start = h->l_offset;
1098 fl->l_len = h->l_len;
1099 fl->l_pid = h->svid;
1100 if (h->exclusive)
1101 fl->l_type = F_WRLCK;
1102 else
1103 fl->l_type = F_RDLCK;
1104 fl->l_whence = SEEK_SET;
1105 fl->l_sysid = 0;
1106 } else {
1107 fl->l_type = F_UNLCK;
1108 }
1109
1110 xdr_free((xdrproc_t) xdr_nlm4_testres, &res);
1111
1112 return (0);
1113 }
1114 }
1115
1116 static int
1117 nlm_map_status(nlm4_stats stat)
1118 {
1119 switch (stat) {
1120 case nlm4_granted:
1121 return (0);
1122
1123 case nlm4_denied:
1124 return (EAGAIN);
1125
1126 case nlm4_denied_nolocks:
1127 return (ENOLCK);
1128
1129 case nlm4_deadlck:
1130 return (EDEADLK);
1131
1132 case nlm4_rofs:
1133 return (EROFS);
1134
1135 case nlm4_stale_fh:
1136 return (ESTALE);
1137
1138 case nlm4_fbig:
1139 return (EFBIG);
1140
1141 case nlm4_failed:
1142 return (EACCES);
1143
1144 default:
1145 return (EINVAL);
1146 }
1147 }
1148
1149 static struct nlm_file_svid *
1150 nlm_find_svid(void *id)
1151 {
1152 struct nlm_file_svid *ns, *newns;
1153 int h;
1154
1155 h = (((uintptr_t) id) >> 7) % NLM_SVID_HASH_SIZE;
1156
1157 mtx_lock(&nlm_svid_lock);
1158 LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) {
1159 if (ns->ns_id == id) {
1160 ns->ns_refs++;
1161 break;
1162 }
1163 }
1164 mtx_unlock(&nlm_svid_lock);
1165 if (!ns) {
1166 int svid = alloc_unr(nlm_svid_allocator);
1167 newns = malloc(sizeof(struct nlm_file_svid), M_NLM,
1168 M_WAITOK);
1169 newns->ns_refs = 1;
1170 newns->ns_id = id;
1171 newns->ns_svid = svid;
1172 newns->ns_ucred = NULL;
1173 newns->ns_active = FALSE;
1174
1175 /*
1176 * We need to check for a race with some other
1177 * thread allocating a svid for this file.
1178 */
1179 mtx_lock(&nlm_svid_lock);
1180 LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) {
1181 if (ns->ns_id == id) {
1182 ns->ns_refs++;
1183 break;
1184 }
1185 }
1186 if (ns) {
1187 mtx_unlock(&nlm_svid_lock);
1188 free_unr(nlm_svid_allocator, newns->ns_svid);
1189 free(newns, M_NLM);
1190 } else {
1191 LIST_INSERT_HEAD(&nlm_file_svids[h], newns,
1192 ns_link);
1193 ns = newns;
1194 mtx_unlock(&nlm_svid_lock);
1195 }
1196 }
1197
1198 return (ns);
1199 }
1200
1201 static void
1202 nlm_free_svid(struct nlm_file_svid *ns)
1203 {
1204
1205 mtx_lock(&nlm_svid_lock);
1206 ns->ns_refs--;
1207 if (!ns->ns_refs) {
1208 KASSERT(!ns->ns_active, ("Freeing active SVID"));
1209 LIST_REMOVE(ns, ns_link);
1210 mtx_unlock(&nlm_svid_lock);
1211 free_unr(nlm_svid_allocator, ns->ns_svid);
1212 if (ns->ns_ucred)
1213 crfree(ns->ns_ucred);
1214 free(ns, M_NLM);
1215 } else {
1216 mtx_unlock(&nlm_svid_lock);
1217 }
1218 }
1219
1220 static int
1221 nlm_init_lock(struct flock *fl, int flags, int svid,
1222 rpcvers_t vers, size_t fhlen, void *fh, off_t size,
1223 struct nlm4_lock *lock, char oh_space[32])
1224 {
1225 size_t oh_len;
1226 off_t start, len;
1227
1228 if (fl->l_whence == SEEK_END) {
1229 if (size > OFF_MAX
1230 || (fl->l_start > 0 && size > OFF_MAX - fl->l_start))
1231 return (EOVERFLOW);
1232 start = size + fl->l_start;
1233 } else if (fl->l_whence == SEEK_SET || fl->l_whence == SEEK_CUR) {
1234 start = fl->l_start;
1235 } else {
1236 return (EINVAL);
1237 }
1238 if (start < 0)
1239 return (EINVAL);
1240 if (fl->l_len < 0) {
1241 len = -fl->l_len;
1242 start -= len;
1243 if (start < 0)
1244 return (EINVAL);
1245 } else {
1246 len = fl->l_len;
1247 }
1248
1249 if (vers == NLM_VERS) {
1250 /*
1251 * Enforce range limits on V1 locks
1252 */
1253 if (start > 0xffffffffLL || len > 0xffffffffLL)
1254 return (EOVERFLOW);
1255 }
1256
1257 snprintf(oh_space, 32, "%d@", svid);
1258 oh_len = strlen(oh_space);
1259 getcredhostname(NULL, oh_space + oh_len, 32 - oh_len);
1260 oh_len = strlen(oh_space);
1261
1262 memset(lock, 0, sizeof(*lock));
1263 lock->caller_name = prison0.pr_hostname;
1264 lock->fh.n_len = fhlen;
1265 lock->fh.n_bytes = fh;
1266 lock->oh.n_len = oh_len;
1267 lock->oh.n_bytes = oh_space;
1268 lock->svid = svid;
1269 lock->l_offset = start;
1270 lock->l_len = len;
1271
1272 return (0);
1273 }
Cache object: 40b7f404d4b8425b993fe7c4493b3a21
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