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: releng/7.3/sys/nlm/nlm_advlock.c 181328 2008-08-05 10:35:51Z dfr $");
30
31 #include <sys/param.h>
32 #include <sys/fcntl.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/mount.h>
39 #include <sys/mutex.h>
40 #include <sys/proc.h>
41 #include <sys/syslog.h>
42 #include <sys/systm.h>
43 #include <sys/unistd.h>
44 #include <sys/vnode.h>
45
46 #include <rpc/rpcclnt.h>
47 #include <nfs/nfsproto.h>
48 #include <nfsclient/nfs.h>
49 #include <nfsclient/nfsnode.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 */
58 struct 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 };
66 LIST_HEAD(nlm_file_svid_list, nlm_file_svid);
67
68 #define NLM_SVID_HASH_SIZE 256
69 struct nlm_file_svid_list nlm_file_svids[NLM_SVID_HASH_SIZE];
70
71 struct mtx nlm_svid_lock;
72 static struct unrhdr *nlm_svid_allocator;
73 static volatile u_int nlm_xid = 1;
74
75 static 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);
79 static 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);
83 static 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);
87 static int nlm_map_status(nlm4_stats stat);
88 static struct nlm_file_svid *nlm_find_svid(void *id);
89 static void nlm_free_svid(struct nlm_file_svid *nf);
90 static 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
94 static void
95 nlm_client_init(void *dummy)
96 {
97 int i;
98
99 mtx_init(&nlm_svid_lock, "NLM svid lock", NULL, MTX_DEF);
100 nlm_svid_allocator = new_unrhdr(PID_MAX + 2, INT_MAX, &nlm_svid_lock);
101 for (i = 0; i < NLM_SVID_HASH_SIZE; i++)
102 LIST_INIT(&nlm_file_svids[i]);
103 }
104 SYSINIT(nlm_client_init, SI_SUB_LOCK, SI_ORDER_FIRST, nlm_client_init, NULL);
105
106 static int
107 nlm_msg(struct thread *td, const char *server, const char *msg, int error)
108 {
109 struct proc *p;
110
111 p = td ? td->td_proc : NULL;
112 if (error) {
113 tprintf(p, LOG_INFO, "nfs server %s: %s, error %d\n", server,
114 msg, error);
115 } else {
116 tprintf(p, LOG_INFO, "nfs server %s: %s\n", server, msg);
117 }
118 return (0);
119 }
120
121 struct nlm_feedback_arg {
122 bool_t nf_printed;
123 struct nfsmount *nf_nmp;
124 };
125
126 static void
127 nlm_down(struct nlm_feedback_arg *nf, struct thread *td,
128 const char *msg, int error)
129 {
130 struct nfsmount *nmp = nf->nf_nmp;
131
132 if (nmp == NULL)
133 return;
134 mtx_lock(&nmp->nm_mtx);
135 if (!(nmp->nm_state & NFSSTA_LOCKTIMEO)) {
136 nmp->nm_state |= NFSSTA_LOCKTIMEO;
137 mtx_unlock(&nmp->nm_mtx);
138 vfs_event_signal(&nmp->nm_mountp->mnt_stat.f_fsid,
139 VQ_NOTRESPLOCK, 0);
140 } else {
141 mtx_unlock(&nmp->nm_mtx);
142 }
143
144 nf->nf_printed = TRUE;
145 nlm_msg(td, nmp->nm_mountp->mnt_stat.f_mntfromname, msg, error);
146 }
147
148 static void
149 nlm_up(struct nlm_feedback_arg *nf, struct thread *td,
150 const char *msg)
151 {
152 struct nfsmount *nmp = nf->nf_nmp;
153
154 if (!nf->nf_printed)
155 return;
156
157 nlm_msg(td, nmp->nm_mountp->mnt_stat.f_mntfromname, msg, 0);
158
159 mtx_lock(&nmp->nm_mtx);
160 if (nmp->nm_state & NFSSTA_LOCKTIMEO) {
161 nmp->nm_state &= ~NFSSTA_LOCKTIMEO;
162 mtx_unlock(&nmp->nm_mtx);
163 vfs_event_signal(&nmp->nm_mountp->mnt_stat.f_fsid,
164 VQ_NOTRESPLOCK, 1);
165 } else {
166 mtx_unlock(&nmp->nm_mtx);
167 }
168 }
169
170 static void
171 nlm_feedback(int type, int proc, void *arg)
172 {
173 struct thread *td = curthread;
174 struct nlm_feedback_arg *nf = (struct nlm_feedback_arg *) arg;
175
176 switch (type) {
177 case FEEDBACK_REXMIT2:
178 case FEEDBACK_RECONNECT:
179 nlm_down(nf, td, "lockd not responding", 0);
180 break;
181
182 case FEEDBACK_OK:
183 nlm_up(nf, td, "lockd is alive again");
184 break;
185 }
186 }
187
188 /*
189 * nlm_advlock --
190 * NFS advisory byte-level locks.
191 */
192 static int
193 nlm_advlock_internal(struct vnode *vp, void *id, int op, struct flock *fl,
194 int flags, bool_t reclaim, bool_t unlock_vp)
195 {
196 struct thread *td = curthread;
197 struct nfsmount *nmp;
198 struct nfsnode *np;
199 off_t size;
200 size_t fhlen;
201 union nfsfh fh;
202 struct sockaddr *sa;
203 struct sockaddr_storage ss;
204 char servername[MNAMELEN];
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;
213 struct nlm_file_svid *ns;
214 int svid;
215 int error;
216
217 ASSERT_VOP_LOCKED(vp, "nlm_advlock_1");
218
219 /*
220 * Push any pending writes to the server and flush our cache
221 * so that if we are contending with another machine for a
222 * file, we get whatever they wrote and vice-versa.
223 */
224 if (op == F_SETLK || op == F_UNLCK)
225 nfs_vinvalbuf(vp, V_SAVE, td, 1);
226
227 np = VTONFS(vp);
228 nmp = VFSTONFS(vp->v_mount);
229 size = np->n_size;
230 sa = nmp->nm_nam;
231 memcpy(&ss, sa, sa->sa_len);
232 sa = (struct sockaddr *) &ss;
233 strcpy(servername, nmp->nm_hostname);
234 fhlen = np->n_fhsize;
235 memcpy(&fh.fh_bytes, np->n_fhp, fhlen);
236 timo.tv_sec = nmp->nm_timeo / NFS_HZ;
237 timo.tv_usec = (nmp->nm_timeo % NFS_HZ) * (1000000 / NFS_HZ);
238 if (NFS_ISV3(vp))
239 vers = NLM_VERS4;
240 else
241 vers = NLM_VERS;
242
243 if (nmp->nm_flag & NFSMNT_SOFT)
244 retries = nmp->nm_retry;
245 else
246 retries = INT_MAX;
247
248 if (unlock_vp)
249 VOP_UNLOCK(vp, 0, td);
250
251 /*
252 * We need to switch to mount-point creds so that we can send
253 * packets from a privileged port.
254 */
255 cred = td->td_ucred;
256 td->td_ucred = vp->v_mount->mnt_cred;
257
258 host = nlm_find_host_by_name(servername, sa, vers);
259 auth = authunix_create(cred);
260 memset(&ext, 0, sizeof(ext));
261
262 nf.nf_printed = FALSE;
263 nf.nf_nmp = nmp;
264 ext.rc_auth = auth;
265
266 ext.rc_feedback = nlm_feedback;
267 ext.rc_feedback_arg = &nf;
268
269 ns = NULL;
270 if (flags & F_FLOCK) {
271 ns = nlm_find_svid(id);
272 KASSERT(fl->l_start == 0 && fl->l_len == 0,
273 ("F_FLOCK lock requests must be whole-file locks"));
274 if (!ns->ns_ucred) {
275 /*
276 * Remember the creds used for locking in case
277 * we need to recover the lock later.
278 */
279 ns->ns_ucred = crdup(cred);
280 }
281 svid = ns->ns_svid;
282 } else if (flags & F_REMOTE) {
283 /*
284 * If we are recovering after a server restart or
285 * trashing locks on a force unmount, use the same
286 * svid as last time.
287 */
288 svid = fl->l_pid;
289 } else {
290 svid = ((struct proc *) id)->p_pid;
291 }
292
293 switch(op) {
294 case F_SETLK:
295 if ((flags & (F_FLOCK|F_WAIT)) == (F_FLOCK|F_WAIT)
296 && fl->l_type == F_WRLCK) {
297 /*
298 * The semantics for flock(2) require that any
299 * shared lock on the file must be released
300 * before an exclusive lock is granted. The
301 * local locking code interprets this by
302 * unlocking the file before sleeping on a
303 * blocked exclusive lock request. We
304 * approximate this by first attempting
305 * non-blocking and if that fails, we unlock
306 * the file and block.
307 */
308 error = nlm_setlock(host, &ext, vers, &timo, retries,
309 vp, F_SETLK, fl, flags & ~F_WAIT,
310 svid, fhlen, &fh.fh_bytes, size, reclaim);
311 if (error == EAGAIN) {
312 fl->l_type = F_UNLCK;
313 error = nlm_clearlock(host, &ext, vers, &timo,
314 retries, vp, F_UNLCK, fl, flags,
315 svid, fhlen, &fh.fh_bytes, size);
316 fl->l_type = F_WRLCK;
317 if (!error) {
318 mtx_lock(&nlm_svid_lock);
319 if (ns->ns_active) {
320 ns->ns_refs--;
321 ns->ns_active = FALSE;
322 }
323 mtx_unlock(&nlm_svid_lock);
324 flags |= F_WAIT;
325 error = nlm_setlock(host, &ext, vers,
326 &timo, retries, vp, F_SETLK, fl,
327 flags, svid, fhlen, &fh.fh_bytes,
328 size, reclaim);
329 }
330 }
331 } else {
332 error = nlm_setlock(host, &ext, vers, &timo, retries,
333 vp, op, fl, flags, svid, fhlen, &fh.fh_bytes,
334 size, reclaim);
335 }
336 if (!error && ns) {
337 mtx_lock(&nlm_svid_lock);
338 if (!ns->ns_active) {
339 /*
340 * Add one to the reference count to
341 * hold onto the SVID for the lifetime
342 * of the lock. Note that since
343 * F_FLOCK only supports whole-file
344 * locks, there can only be one active
345 * lock for this SVID.
346 */
347 ns->ns_refs++;
348 ns->ns_active = TRUE;
349 }
350 mtx_unlock(&nlm_svid_lock);
351 }
352 break;
353
354 case F_UNLCK:
355 error = nlm_clearlock(host, &ext, vers, &timo, retries,
356 vp, op, fl, flags, svid, fhlen, &fh.fh_bytes, size);
357 if (!error && ns) {
358 mtx_lock(&nlm_svid_lock);
359 if (ns->ns_active) {
360 ns->ns_refs--;
361 ns->ns_active = FALSE;
362 }
363 mtx_unlock(&nlm_svid_lock);
364 }
365 break;
366
367 case F_GETLK:
368 error = nlm_getlock(host, &ext, vers, &timo, retries,
369 vp, op, fl, flags, svid, fhlen, &fh.fh_bytes, size);
370 break;
371
372 default:
373 error = EINVAL;
374 break;
375 }
376
377 if (ns)
378 nlm_free_svid(ns);
379
380 td->td_ucred = cred;
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, td);
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 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 error = lf_advlockasync(&a, &vp->v_lockf, size);
717 KASSERT(error == 0, ("Failed to register NFS lock locally - error=%d",
718 error));
719 }
720
721 static int
722 nlm_setlock(struct nlm_host *host, struct rpc_callextra *ext,
723 rpcvers_t vers, struct timeval *timo, int retries,
724 struct vnode *vp, int op, struct flock *fl, int flags,
725 int svid, size_t fhlen, void *fh, off_t size, bool_t reclaim)
726 {
727 struct nlm4_lockargs args;
728 char oh_space[32];
729 struct nlm4_res res;
730 u_int xid;
731 CLIENT *client;
732 enum clnt_stat stat;
733 int retry, block, exclusive;
734 void *wait_handle = NULL;
735 int error;
736
737 memset(&args, 0, sizeof(args));
738 memset(&res, 0, sizeof(res));
739
740 block = (flags & F_WAIT) ? TRUE : FALSE;
741 exclusive = (fl->l_type == F_WRLCK);
742
743 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
744 &args.alock, oh_space);
745 if (error)
746 return (error);
747 args.block = block;
748 args.exclusive = exclusive;
749 args.reclaim = reclaim;
750 args.state = nlm_nsm_state;
751
752 retry = 5*hz;
753 for (;;) {
754 client = nlm_host_get_rpc(host);
755 if (!client)
756 return (ENOLCK); /* XXX retry? */
757
758 if (block)
759 wait_handle = nlm_register_wait_lock(&args.alock, vp);
760
761 xid = atomic_fetchadd_int(&nlm_xid, 1);
762 args.cookie.n_len = sizeof(xid);
763 args.cookie.n_bytes = (char*) &xid;
764
765 stat = nlm_lock_rpc(vers, &args, &res, client, ext, *timo);
766
767 CLNT_RELEASE(client);
768
769 if (stat != RPC_SUCCESS) {
770 if (block)
771 nlm_deregister_wait_lock(wait_handle);
772 if (retries) {
773 retries--;
774 continue;
775 }
776 return (EINVAL);
777 }
778
779 /*
780 * Free res.cookie.
781 */
782 xdr_free((xdrproc_t) xdr_nlm4_res, &res);
783
784 if (block && res.stat.stat != nlm4_blocked)
785 nlm_deregister_wait_lock(wait_handle);
786
787 if (res.stat.stat == nlm4_denied_grace_period) {
788 /*
789 * The server has recently rebooted and is
790 * giving old clients a change to reclaim
791 * their locks. Wait for a few seconds and try
792 * again.
793 */
794 error = tsleep(&args, PCATCH, "nlmgrace", retry);
795 if (error && error != EWOULDBLOCK)
796 return (error);
797 retry = 2*retry;
798 if (retry > 30*hz)
799 retry = 30*hz;
800 continue;
801 }
802
803 if (block && res.stat.stat == nlm4_blocked) {
804 /*
805 * The server should call us back with a
806 * granted message when the lock succeeds. In
807 * order to deal with broken servers, lost
808 * granted messages and server reboots, we
809 * will also re-try every few seconds.
810 */
811 error = nlm_wait_lock(wait_handle, retry);
812 if (error == EWOULDBLOCK) {
813 retry = 2*retry;
814 if (retry > 30*hz)
815 retry = 30*hz;
816 continue;
817 }
818 if (error) {
819 /*
820 * We need to call the server to
821 * cancel our lock request.
822 */
823 nlm4_cancargs cancel;
824
825 memset(&cancel, 0, sizeof(cancel));
826
827 xid = atomic_fetchadd_int(&nlm_xid, 1);
828 cancel.cookie.n_len = sizeof(xid);
829 cancel.cookie.n_bytes = (char*) &xid;
830 cancel.block = block;
831 cancel.exclusive = exclusive;
832 cancel.alock = args.alock;
833
834 do {
835 client = nlm_host_get_rpc(host);
836 if (!client)
837 /* XXX retry? */
838 return (ENOLCK);
839
840 stat = nlm_cancel_rpc(vers, &cancel,
841 &res, client, ext, *timo);
842
843 CLNT_RELEASE(client);
844
845 if (stat != RPC_SUCCESS) {
846 /*
847 * We need to cope
848 * with temporary
849 * network partitions
850 * as well as server
851 * reboots. This means
852 * we have to keep
853 * trying to cancel
854 * until the server
855 * wakes up again.
856 */
857 pause("nlmcancel", 10*hz);
858 }
859 } while (stat != RPC_SUCCESS);
860
861 /*
862 * Free res.cookie.
863 */
864 xdr_free((xdrproc_t) xdr_nlm4_res, &res);
865
866 switch (res.stat.stat) {
867 case nlm_denied:
868 /*
869 * There was nothing
870 * to cancel. We are
871 * going to go ahead
872 * and assume we got
873 * the lock.
874 */
875 error = 0;
876 break;
877
878 case nlm4_denied_grace_period:
879 /*
880 * The server has
881 * recently rebooted -
882 * treat this as a
883 * successful
884 * cancellation.
885 */
886 break;
887
888 case nlm4_granted:
889 /*
890 * We managed to
891 * cancel.
892 */
893 break;
894
895 default:
896 /*
897 * Broken server
898 * implementation -
899 * can't really do
900 * anything here.
901 */
902 break;
903 }
904
905 }
906 } else {
907 error = nlm_map_status(res.stat.stat);
908 }
909
910 if (!error && !reclaim) {
911 nlm_record_lock(vp, op, fl, args.alock.svid,
912 nlm_host_get_sysid(host), size);
913 nlm_host_monitor(host, 0);
914 }
915
916 return (error);
917 }
918 }
919
920 static int
921 nlm_clearlock(struct nlm_host *host, struct rpc_callextra *ext,
922 rpcvers_t vers, struct timeval *timo, int retries,
923 struct vnode *vp, int op, struct flock *fl, int flags,
924 int svid, size_t fhlen, void *fh, off_t size)
925 {
926 struct nlm4_unlockargs args;
927 char oh_space[32];
928 struct nlm4_res res;
929 u_int xid;
930 CLIENT *client;
931 enum clnt_stat stat;
932 int error;
933
934 memset(&args, 0, sizeof(args));
935 memset(&res, 0, sizeof(res));
936
937 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
938 &args.alock, oh_space);
939 if (error)
940 return (error);
941
942 for (;;) {
943 client = nlm_host_get_rpc(host);
944 if (!client)
945 return (ENOLCK); /* XXX retry? */
946
947 xid = atomic_fetchadd_int(&nlm_xid, 1);
948 args.cookie.n_len = sizeof(xid);
949 args.cookie.n_bytes = (char*) &xid;
950
951 stat = nlm_unlock_rpc(vers, &args, &res, client, ext, *timo);
952
953 CLNT_RELEASE(client);
954
955 if (stat != RPC_SUCCESS) {
956 if (retries) {
957 retries--;
958 continue;
959 }
960 return (EINVAL);
961 }
962
963 /*
964 * Free res.cookie.
965 */
966 xdr_free((xdrproc_t) xdr_nlm4_res, &res);
967
968 if (res.stat.stat == nlm4_denied_grace_period) {
969 /*
970 * The server has recently rebooted and is
971 * giving old clients a change to reclaim
972 * their locks. Wait for a few seconds and try
973 * again.
974 */
975 error = tsleep(&args, PCATCH, "nlmgrace", 5*hz);
976 if (error && error != EWOULDBLOCK)
977 return (error);
978 continue;
979 }
980
981 /*
982 * If we are being called via nlm_reclaim (which will
983 * use the F_REMOTE flag), don't record the lock
984 * operation in the local lock manager since the vnode
985 * is going away.
986 */
987 if (!(flags & F_REMOTE))
988 nlm_record_lock(vp, op, fl, args.alock.svid,
989 nlm_host_get_sysid(host), size);
990
991 return (0);
992 }
993 }
994
995 static int
996 nlm_getlock(struct nlm_host *host, struct rpc_callextra *ext,
997 rpcvers_t vers, struct timeval *timo, int retries,
998 struct vnode *vp, int op, struct flock *fl, int flags,
999 int svid, size_t fhlen, void *fh, off_t size)
1000 {
1001 struct nlm4_testargs args;
1002 char oh_space[32];
1003 struct nlm4_testres res;
1004 u_int xid;
1005 CLIENT *client;
1006 enum clnt_stat stat;
1007 int exclusive;
1008 int error;
1009
1010 KASSERT(!(flags & F_FLOCK), ("unexpected F_FLOCK for F_GETLK"));
1011
1012 memset(&args, 0, sizeof(args));
1013 memset(&res, 0, sizeof(res));
1014
1015 exclusive = (fl->l_type == F_WRLCK);
1016
1017 error = nlm_init_lock(fl, flags, svid, vers, fhlen, fh, size,
1018 &args.alock, oh_space);
1019 if (error)
1020 return (error);
1021 args.exclusive = exclusive;
1022
1023 for (;;) {
1024 client = nlm_host_get_rpc(host);
1025 if (!client)
1026 return (ENOLCK); /* XXX retry? */
1027
1028 xid = atomic_fetchadd_int(&nlm_xid, 1);
1029 args.cookie.n_len = sizeof(xid);
1030 args.cookie.n_bytes = (char*) &xid;
1031
1032 stat = nlm_test_rpc(vers, &args, &res, client, ext, *timo);
1033
1034 CLNT_RELEASE(client);
1035
1036 if (stat != RPC_SUCCESS) {
1037 if (retries) {
1038 retries--;
1039 continue;
1040 }
1041 return (EINVAL);
1042 }
1043
1044 if (res.stat.stat == nlm4_denied_grace_period) {
1045 /*
1046 * The server has recently rebooted and is
1047 * giving old clients a change to reclaim
1048 * their locks. Wait for a few seconds and try
1049 * again.
1050 */
1051 xdr_free((xdrproc_t) xdr_nlm4_testres, &res);
1052 error = tsleep(&args, PCATCH, "nlmgrace", 5*hz);
1053 if (error && error != EWOULDBLOCK)
1054 return (error);
1055 continue;
1056 }
1057
1058 if (res.stat.stat == nlm4_denied) {
1059 struct nlm4_holder *h =
1060 &res.stat.nlm4_testrply_u.holder;
1061 fl->l_start = h->l_offset;
1062 fl->l_len = h->l_len;
1063 fl->l_pid = h->svid;
1064 if (h->exclusive)
1065 fl->l_type = F_WRLCK;
1066 else
1067 fl->l_type = F_RDLCK;
1068 fl->l_whence = SEEK_SET;
1069 fl->l_sysid = 0;
1070 } else {
1071 fl->l_type = F_UNLCK;
1072 }
1073
1074 xdr_free((xdrproc_t) xdr_nlm4_testres, &res);
1075
1076 return (0);
1077 }
1078 }
1079
1080 static int
1081 nlm_map_status(nlm4_stats stat)
1082 {
1083 switch (stat) {
1084 case nlm4_granted:
1085 return (0);
1086
1087 case nlm4_denied:
1088 return (EAGAIN);
1089
1090 case nlm4_denied_nolocks:
1091 return (ENOLCK);
1092
1093 case nlm4_deadlck:
1094 return (EDEADLK);
1095
1096 case nlm4_rofs:
1097 return (EROFS);
1098
1099 case nlm4_stale_fh:
1100 return (ESTALE);
1101
1102 case nlm4_fbig:
1103 return (EFBIG);
1104
1105 case nlm4_failed:
1106 return (EACCES);
1107
1108 default:
1109 return (EINVAL);
1110 }
1111 }
1112
1113 static struct nlm_file_svid *
1114 nlm_find_svid(void *id)
1115 {
1116 struct nlm_file_svid *ns, *newns;
1117 int h;
1118
1119 h = (((uintptr_t) id) >> 7) % NLM_SVID_HASH_SIZE;
1120
1121 mtx_lock(&nlm_svid_lock);
1122 LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) {
1123 if (ns->ns_id == id) {
1124 ns->ns_refs++;
1125 break;
1126 }
1127 }
1128 mtx_unlock(&nlm_svid_lock);
1129 if (!ns) {
1130 int svid = alloc_unr(nlm_svid_allocator);
1131 newns = malloc(sizeof(struct nlm_file_svid), M_NLM,
1132 M_WAITOK);
1133 newns->ns_refs = 1;
1134 newns->ns_id = id;
1135 newns->ns_svid = svid;
1136 newns->ns_ucred = NULL;
1137 newns->ns_active = FALSE;
1138
1139 /*
1140 * We need to check for a race with some other
1141 * thread allocating a svid for this file.
1142 */
1143 mtx_lock(&nlm_svid_lock);
1144 LIST_FOREACH(ns, &nlm_file_svids[h], ns_link) {
1145 if (ns->ns_id == id) {
1146 ns->ns_refs++;
1147 break;
1148 }
1149 }
1150 if (ns) {
1151 mtx_unlock(&nlm_svid_lock);
1152 free_unr(nlm_svid_allocator, newns->ns_svid);
1153 free(newns, M_NLM);
1154 } else {
1155 LIST_INSERT_HEAD(&nlm_file_svids[h], newns,
1156 ns_link);
1157 ns = newns;
1158 mtx_unlock(&nlm_svid_lock);
1159 }
1160 }
1161
1162 return (ns);
1163 }
1164
1165 static void
1166 nlm_free_svid(struct nlm_file_svid *ns)
1167 {
1168
1169 mtx_lock(&nlm_svid_lock);
1170 ns->ns_refs--;
1171 if (!ns->ns_refs) {
1172 KASSERT(!ns->ns_active, ("Freeing active SVID"));
1173 LIST_REMOVE(ns, ns_link);
1174 mtx_unlock(&nlm_svid_lock);
1175 free_unr(nlm_svid_allocator, ns->ns_svid);
1176 if (ns->ns_ucred)
1177 crfree(ns->ns_ucred);
1178 free(ns, M_NLM);
1179 } else {
1180 mtx_unlock(&nlm_svid_lock);
1181 }
1182 }
1183
1184 static int
1185 nlm_init_lock(struct flock *fl, int flags, int svid,
1186 rpcvers_t vers, size_t fhlen, void *fh, off_t size,
1187 struct nlm4_lock *lock, char oh_space[32])
1188 {
1189 size_t oh_len;
1190 off_t start, len;
1191
1192 if (fl->l_whence == SEEK_END) {
1193 if (size > OFF_MAX
1194 || (fl->l_start > 0 && size > OFF_MAX - fl->l_start))
1195 return (EOVERFLOW);
1196 start = size + fl->l_start;
1197 } else if (fl->l_whence == SEEK_SET || fl->l_whence == SEEK_CUR) {
1198 start = fl->l_start;
1199 } else {
1200 return (EINVAL);
1201 }
1202 if (start < 0)
1203 return (EINVAL);
1204 if (fl->l_len < 0) {
1205 len = -fl->l_len;
1206 start -= len;
1207 if (start < 0)
1208 return (EINVAL);
1209 } else {
1210 len = fl->l_len;
1211 }
1212
1213 if (vers == NLM_VERS) {
1214 /*
1215 * Enforce range limits on V1 locks
1216 */
1217 if (start > 0xffffffffLL || len > 0xffffffffLL)
1218 return (EOVERFLOW);
1219 }
1220
1221 snprintf(oh_space, 32, "%d@%s", svid, hostname);
1222 oh_len = strlen(oh_space);
1223
1224 memset(lock, 0, sizeof(*lock));
1225 lock->caller_name = hostname;
1226 lock->fh.n_len = fhlen;
1227 lock->fh.n_bytes = fh;
1228 lock->oh.n_len = oh_len;
1229 lock->oh.n_bytes = oh_space;
1230 lock->svid = svid;
1231 lock->l_offset = start;
1232 lock->l_len = len;
1233
1234 return (0);
1235 }
Cache object: 7f1051cc8d1289147536605866baf5d0
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