2 * Copyright (c) 2000 Manuel Bouyer.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. All advertising materials mentioning features or use of this software
13 * must display the following acknowledgement:
14 * This product includes software developed by the University of
15 * California, Berkeley and its contributors.
16 * 4. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * $NetBSD: lockd_lock.c,v 1.5 2000/11/21 03:47:41 enami Exp $
33 * $FreeBSD: src/usr.sbin/rpc.lockd/lockd_lock.c,v 1.1 2001/03/19 12:50:09 alfred Exp $
45 #include <sys/types.h>
47 #include <sys/socket.h>
48 #include <sys/queue.h>
49 #include <sys/param.h>
50 #include <sys/mount.h>
52 #include <rpcsvc/sm_inter.h>
53 #include <rpcsvc/nlm_prot.h>
54 #include "lockd_lock.h"
57 /* A set of utilities for managing file locking */
58 LIST_HEAD(lcklst_head, file_lock);
59 struct lcklst_head lcklst_head = LIST_HEAD_INITIALIZER(lcklst_head);
61 /* struct describing a lock */
63 LIST_ENTRY(file_lock) lcklst;
64 fhandle_t filehandle; /* NFS filehandle */
65 struct sockaddr *addr;
66 struct nlm4_holder client; /* lock holder */
67 netobj client_cookie; /* cookie sent by the client */
68 char client_name[128];
69 int nsm_status; /* status from the remote lock manager */
70 int status; /* lock status, see below */
71 int flags; /* lock flags, see lockd_lock.h */
72 pid_t locker; /* pid of the child process trying to get the lock */
73 int fd; /* file descriptor for this lock */
77 #define LKST_LOCKED 1 /* lock is locked */
78 #define LKST_WAITING 2 /* file is already locked by another host */
79 #define LKST_PROCESSING 3 /* child is trying to aquire the lock */
80 #define LKST_DYING 4 /* must dies when we get news from the child */
82 void lfree(struct file_lock *);
83 enum nlm_stats do_lock(struct file_lock *, int);
84 enum nlm_stats do_unlock(struct file_lock *);
85 void send_granted(struct file_lock *, int);
89 /* list of hosts we monitor */
90 LIST_HEAD(hostlst_head, host);
91 struct hostlst_head hostlst_head = LIST_HEAD_INITIALIZER(hostlst_head);
93 /* struct describing a lock */
95 LIST_ENTRY(host) hostlst;
96 char name[SM_MAXSTRLEN];
103 * testlock(): inform the caller if the requested lock would be granted or not
104 * returns NULL if lock would granted, or pointer to the current nlm4_holder
109 testlock(struct nlm4_lock *lock, int flags)
111 struct file_lock *fl;
112 fhandle_t filehandle;
114 /* convert lock to a local filehandle */
115 memcpy(&filehandle, lock->fh.n_bytes, sizeof(filehandle));
118 /* search through the list for lock holder */
119 for (fl = LIST_FIRST(&lcklst_head); fl != NULL;
120 fl = LIST_NEXT(fl, lcklst)) {
121 if (fl->status != LKST_LOCKED)
123 if (memcmp(&fl->filehandle, &filehandle, sizeof(filehandle)))
126 syslog(LOG_DEBUG, "test for %s: found lock held by %s",
127 lock->caller_name, fl->client_name);
129 return (&fl->client);
133 syslog(LOG_DEBUG, "test for %s: no lock found", lock->caller_name);
138 * getlock: try to aquire the lock.
139 * If file is already locked and we can sleep, put the lock in the list with
140 * status LKST_WAITING; it'll be processed later.
141 * Otherwise try to lock. If we're allowed to block, fork a child which
142 * will do the blocking lock.
145 getlock(nlm4_lockargs *lckarg, struct svc_req *rqstp, int flags)
147 struct file_lock *fl, *newfl;
148 enum nlm_stats retval;
150 if (grace_expired == 0 && lckarg->reclaim == 0)
151 return (flags & LOCK_V4) ?
152 nlm4_denied_grace_period : nlm_denied_grace_period;
154 /* allocate new file_lock for this request */
155 newfl = malloc(sizeof(struct file_lock));
157 syslog(LOG_NOTICE, "malloc failed: %s", strerror(errno));
159 return (flags & LOCK_V4) ?
160 nlm4_denied_nolock : nlm_denied_nolocks;
162 if (lckarg->alock.fh.n_len != sizeof(fhandle_t)) {
163 syslog(LOG_DEBUG, "received fhandle size %d, local size %d",
164 lckarg->alock.fh.n_len, (int)sizeof(fhandle_t));
166 memcpy(&newfl->filehandle, lckarg->alock.fh.n_bytes, sizeof(fhandle_t));
167 newfl->addr = (struct sockaddr *)svc_getrpccaller(rqstp->rq_xprt)->buf;
168 newfl->client.exclusive = lckarg->exclusive;
169 newfl->client.svid = lckarg->alock.svid;
170 newfl->client.oh.n_bytes = malloc(lckarg->alock.oh.n_len);
171 if (newfl->client.oh.n_bytes == NULL) {
172 syslog(LOG_NOTICE, "malloc failed: %s", strerror(errno));
174 return (flags & LOCK_V4) ?
175 nlm4_denied_nolock : nlm_denied_nolocks;
177 newfl->client.oh.n_len = lckarg->alock.oh.n_len;
178 memcpy(newfl->client.oh.n_bytes, lckarg->alock.oh.n_bytes,
179 lckarg->alock.oh.n_len);
180 newfl->client.l_offset = lckarg->alock.l_offset;
181 newfl->client.l_len = lckarg->alock.l_len;
182 newfl->client_cookie.n_len = lckarg->cookie.n_len;
183 newfl->client_cookie.n_bytes = malloc(lckarg->cookie.n_len);
184 if (newfl->client_cookie.n_bytes == NULL) {
185 syslog(LOG_NOTICE, "malloc failed: %s", strerror(errno));
186 free(newfl->client.oh.n_bytes);
188 return (flags & LOCK_V4) ?
189 nlm4_denied_nolock : nlm_denied_nolocks;
191 memcpy(newfl->client_cookie.n_bytes, lckarg->cookie.n_bytes,
192 lckarg->cookie.n_len);
193 strncpy(newfl->client_name, lckarg->alock.caller_name, 128);
194 newfl->nsm_status = lckarg->state;
196 newfl->flags = flags;
198 /* look for a lock rq from this host for this fh */
199 for (fl = LIST_FIRST(&lcklst_head); fl != NULL;
200 fl = LIST_NEXT(fl, lcklst)) {
201 if (memcmp(&newfl->filehandle, &fl->filehandle,
202 sizeof(fhandle_t)) == 0) {
203 if (strcmp(newfl->client_name, fl->client_name) == 0 &&
204 newfl->client.svid == fl->client.svid) {
205 /* already locked by this host ??? */
207 syslog(LOG_NOTICE, "duplicate lock from %s",
212 return (flags & LOCK_V4) ?
213 nlm4_granted : nlm_granted;
215 case LKST_PROCESSING:
216 return (flags & LOCK_V4) ?
217 nlm4_blocked : nlm_blocked;
219 return (flags & LOCK_V4) ?
220 nlm4_denied : nlm_denied;
222 syslog(LOG_NOTICE, "bad status %d",
224 return (flags & LOCK_V4) ?
225 nlm4_failed : nlm_denied;
229 * We already have a lock for this file. Put this one
230 * in waiting state if allowed to block
233 syslog(LOG_DEBUG, "lock from %s: already "
235 lckarg->alock.caller_name);
236 newfl->status = LKST_WAITING;
237 LIST_INSERT_HEAD(&lcklst_head, newfl, lcklst);
238 do_mon(lckarg->alock.caller_name);
240 return (flags & LOCK_V4) ?
241 nlm4_blocked : nlm_blocked;
244 syslog(LOG_DEBUG, "lock from %s: already "
246 lckarg->alock.caller_name);
248 return (flags & LOCK_V4) ?
249 nlm4_denied : nlm_denied;
253 /* no entry for this file yet; add to list */
254 LIST_INSERT_HEAD(&lcklst_head, newfl, lcklst);
256 retval = do_lock(newfl, lckarg->block);
259 /* case nlm_granted: is the same as nlm4_granted */
261 /* case nlm_blocked: is the same as nlm4_blocked */
262 do_mon(lckarg->alock.caller_name);
272 /* unlock a filehandle */
274 unlock(nlm4_lock *lck, int flags)
276 struct file_lock *fl;
277 fhandle_t filehandle;
278 int err = (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
280 memcpy(&filehandle, lck->fh.n_bytes, sizeof(fhandle_t));
282 for (fl = LIST_FIRST(&lcklst_head); fl != NULL;
283 fl = LIST_NEXT(fl, lcklst)) {
284 if (strcmp(fl->client_name, lck->caller_name) ||
285 memcmp(&filehandle, &fl->filehandle, sizeof(fhandle_t)) ||
286 fl->client.oh.n_len != lck->oh.n_len ||
287 memcmp(fl->client.oh.n_bytes, lck->oh.n_bytes,
288 fl->client.oh.n_len) != 0 ||
289 fl->client.svid != lck->svid)
291 /* Got it, unlock and remove from the queue */
292 syslog(LOG_DEBUG, "unlock from %s: found struct, status %d",
293 lck->caller_name, fl->status);
294 switch (fl->status) {
299 /* remove from the list */
300 LIST_REMOVE(fl, lcklst);
303 case LKST_PROCESSING:
305 * being handled by a child; will clean up
306 * when the child exits
308 fl->status = LKST_DYING;
314 syslog(LOG_NOTICE, "unknow status %d for %s",
315 fl->status, fl->client_name);
321 /* didn't find a matching entry; log anyway */
322 syslog(LOG_NOTICE, "no matching entry for %s",
324 return (flags & LOCK_V4) ? nlm4_granted : nlm_granted;
328 lfree(struct file_lock *fl)
330 free(fl->client.oh.n_bytes);
331 free(fl->client_cookie.n_bytes);
336 sigchild_handler(int sig)
340 struct file_lock *fl;
343 pid = wait4(-1, &status, WNOHANG, NULL);
346 syslog(LOG_NOTICE, "wait failed: %s",
349 syslog(LOG_DEBUG, "wait failed: %s",
354 /* no more child to handle yet */
358 * if we're here we have a child that exited
359 * Find the associated file_lock.
361 for (fl = LIST_FIRST(&lcklst_head); fl != NULL;
362 fl = LIST_NEXT(fl, lcklst)) {
363 if (pid == fl->locker)
366 if (pid != fl->locker) {
367 syslog(LOG_NOTICE, "unknow child %d", pid);
369 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
370 syslog(LOG_NOTICE, "child %d failed", pid);
372 * can't do much here; we can't reply
373 * anything but OK for blocked locks
374 * Eventually the client will time out
381 /* check lock status */
382 syslog(LOG_DEBUG, "processing child %d, status %d",
385 case LKST_PROCESSING:
386 fl->status = LKST_LOCKED;
387 send_granted(fl, (fl->flags & LOCK_V4) ?
388 nlm4_granted : nlm_granted);
394 syslog(LOG_NOTICE, "bad lock status (%d) for"
395 " child %d", fl->status, pid);
403 * try to aquire the lock described by fl. Eventually fock a child to do a
404 * blocking lock if allowed and required.
408 do_lock(struct file_lock *fl, int block)
413 fl->fd = fhopen(&fl->filehandle, O_RDWR);
417 error = nlm4_stale_fh;
425 if ((fl->flags & LOCK_V4) == 0)
427 syslog(LOG_NOTICE, "fhopen failed (from %s): %s",
428 fl->client_name, strerror(errno));
429 LIST_REMOVE(fl, lcklst);
432 if (fstat(fl->fd, &st) < 0) {
433 syslog(LOG_NOTICE, "fstat failed (from %s): %s",
434 fl->client_name, strerror(errno));
436 syslog(LOG_DEBUG, "lock from %s for file%s%s: dev %d ino %d (uid %d), "
438 fl->client_name, fl->client.exclusive ? " (exclusive)":"",
439 block ? " (block)":"",
440 st.st_dev, st.st_ino, st.st_uid, fl->flags);
442 if (fl->client.exclusive == 0)
446 error = flock(fl->fd, lflags);
447 if (error != 0 && errno == EAGAIN && block) {
448 switch (fl->locker = fork()) {
449 case -1: /* fork failed */
450 syslog(LOG_NOTICE, "fork failed: %s", strerror(errno));
451 LIST_REMOVE(fl, lcklst);
453 return (fl->flags & LOCK_V4) ?
454 nlm4_denied_nolock : nlm_denied_nolocks;
457 * Attempt a blocking lock. Will have to call
460 setproctitle("%s", fl->client_name);
462 if(flock(fl->fd, lflags) != 0) {
463 syslog(LOG_NOTICE, "flock failed: %s",
470 syslog(LOG_DEBUG, "lock request from %s: forked %d",
471 fl->client_name, fl->locker);
472 fl->status = LKST_PROCESSING;
473 return (fl->flags & LOCK_V4) ?
474 nlm4_blocked : nlm_blocked;
484 error = nlm4_stale_fh;
492 if ((fl->flags & LOCK_V4) == 0)
495 syslog(LOG_NOTICE, "flock for %s failed: %s",
496 fl->client_name, strerror(errno));
497 else syslog(LOG_DEBUG, "flock for %s failed: %s",
498 fl->client_name, strerror(errno));
499 LIST_REMOVE(fl, lcklst);
503 fl->status = LKST_LOCKED;
504 return (fl->flags & LOCK_V4) ? nlm4_granted : nlm_granted;
508 send_granted(struct file_lock *fl, int opcode)
512 struct timeval timeo;
514 static struct nlm_res retval;
515 static struct nlm4_res retval4;
517 cli = get_client(fl->addr,
518 (fl->flags & LOCK_V4) ? NLM_VERS4 : NLM_VERS);
520 syslog(LOG_NOTICE, "failed to get CLIENT for %s",
523 * We fail to notify remote that the lock has been granted.
524 * The client will timeout and retry, the lock will be
525 * granted at this time.
530 timeo.tv_usec = (fl->flags & LOCK_ASYNC) ? 0 : 500000; /* 0.5s */
532 if (fl->flags & LOCK_V4) {
533 static nlm4_testargs res;
534 res.cookie = fl->client_cookie;
535 res.exclusive = fl->client.exclusive;
536 res.alock.caller_name = fl->client_name;
537 res.alock.fh.n_len = sizeof(fhandle_t);
538 res.alock.fh.n_bytes = (char*)&fl->filehandle;
539 res.alock.oh = fl->client.oh;
540 res.alock.svid = fl->client.svid;
541 res.alock.l_offset = fl->client.l_offset;
542 res.alock.l_len = fl->client.l_len;
543 syslog(LOG_DEBUG, "sending v4 reply%s",
544 (fl->flags & LOCK_ASYNC) ? " (async)":"");
545 if (fl->flags & LOCK_ASYNC) {
546 success = clnt_call(cli, NLM4_GRANTED_MSG,
547 xdr_nlm4_testargs, &res, xdr_void, &dummy, timeo);
549 success = clnt_call(cli, NLM4_GRANTED,
550 xdr_nlm4_testargs, &res, xdr_nlm4_res,
554 static nlm_testargs res;
556 res.cookie = fl->client_cookie;
557 res.exclusive = fl->client.exclusive;
558 res.alock.caller_name = fl->client_name;
559 res.alock.fh.n_len = sizeof(fhandle_t);
560 res.alock.fh.n_bytes = (char*)&fl->filehandle;
561 res.alock.oh = fl->client.oh;
562 res.alock.svid = fl->client.svid;
563 res.alock.l_offset = fl->client.l_offset;
564 res.alock.l_len = fl->client.l_len;
565 syslog(LOG_DEBUG, "sending v1 reply%s",
566 (fl->flags & LOCK_ASYNC) ? " (async)":"");
567 if (fl->flags & LOCK_ASYNC) {
568 success = clnt_call(cli, NLM_GRANTED_MSG,
569 xdr_nlm_testargs, &res, xdr_void, &dummy, timeo);
571 success = clnt_call(cli, NLM_GRANTED,
572 xdr_nlm_testargs, &res, xdr_nlm_res,
577 syslog(LOG_DEBUG, "clnt_call returns %d(%s) for granted",
578 success, clnt_sperrno(success));
583 do_unlock(struct file_lock *rfl)
585 struct file_lock *fl;
589 /* unlock the file: closing is enouth ! */
590 if (close(rfl->fd) < 0) {
592 error = nlm4_stale_fh;
595 if ((fl->flags & LOCK_V4) == 0)
598 "close failed (from %s): %s",
599 rfl->client_name, strerror(errno));
601 error = (fl->flags & LOCK_V4) ?
602 nlm4_granted : nlm_granted;
604 LIST_REMOVE(rfl, lcklst);
606 /* process the next LKST_WAITING lock request for this fh */
607 for (fl = LIST_FIRST(&lcklst_head); fl != NULL;
608 fl = LIST_NEXT(fl, lcklst)) {
609 if (fl->status != LKST_WAITING ||
610 memcmp(&rfl->filehandle, &fl->filehandle,
611 sizeof(fhandle_t)) != 0)
614 lockst = do_lock(fl, 1); /* If it's LKST_WAITING we can block */
617 /* case nlm_granted: same as nlm4_granted */
618 send_granted(fl, (fl->flags & LOCK_V4) ?
619 nlm4_granted : nlm_granted);
622 /* case nlm_blocked: same as nlm4_blocked */
639 sigaddset(&block, SIGCHLD);
641 if (sigprocmask(SIG_BLOCK, &block, NULL) < 0) {
642 syslog(LOG_WARNING, "siglock failed: %s", strerror(errno));
652 sigaddset(&block, SIGCHLD);
654 if (sigprocmask(SIG_UNBLOCK, &block, NULL) < 0) {
655 syslog(LOG_WARNING, "sigunlock failed: %s", strerror(errno));
659 /* monitor a host through rpc.statd, and keep a ref count */
661 do_mon(char *hostname)
665 struct sm_stat_res res;
668 for (hp = LIST_FIRST(&hostlst_head); hp != NULL;
669 hp = LIST_NEXT(hp, hostlst)) {
670 if (strcmp(hostname, hp->name) == 0) {
671 /* already monitored, just bump refcnt */
676 /* not found, have to create an entry for it */
677 hp = malloc(sizeof(struct host));
678 strncpy(hp->name, hostname, SM_MAXSTRLEN);
680 syslog(LOG_DEBUG, "monitoring host %s",
682 memset(&my_mon, 0, sizeof(my_mon));
683 my_mon.mon_id.mon_name = hp->name;
684 my_mon.mon_id.my_id.my_name = "localhost";
685 my_mon.mon_id.my_id.my_prog = NLM_PROG;
686 my_mon.mon_id.my_id.my_vers = NLM_SM;
687 my_mon.mon_id.my_id.my_proc = NLM_SM_NOTIFY;
689 callrpc("localhost", SM_PROG, SM_VERS, SM_MON, xdr_mon,
690 (char*)&my_mon, xdr_sm_stat_res, (char*)&res)) != 0) {
691 syslog(LOG_WARNING, "rpc to statd failed: %s",
692 clnt_sperrno((enum clnt_stat)retval));
696 if (res.res_stat == stat_fail) {
697 syslog(LOG_WARNING, "statd failed");
701 LIST_INSERT_HEAD(&hostlst_head, hp, hostlst);
705 notify(const char *hostname, int state)
707 struct file_lock *fl, *next_fl;
709 syslog(LOG_DEBUG, "notify from %s, new state %d", hostname, state);
710 /* search all lock for this host; if status changed, release the lock */
712 for (fl = LIST_FIRST(&lcklst_head); fl != NULL; fl = next_fl) {
713 next_fl = LIST_NEXT(fl, lcklst);
714 if (strcmp(hostname, fl->client_name) == 0 &&
715 fl->nsm_status != state) {
716 syslog(LOG_DEBUG, "state %d, nsm_state %d, unlocking",
717 fl->status, fl->nsm_status);
721 if (err != nlm_granted)
723 "notify: unlock failed for %s (%d)",
727 LIST_REMOVE(fl, lcklst);
730 case LKST_PROCESSING:
731 fl->status = LKST_DYING;
736 syslog(LOG_NOTICE, "unknown status %d for %s",
737 fl->status, fl->client_name);