vfs_lockf.c revision 1.15
1/*	$NetBSD: vfs_lockf.c,v 1.15 2000/03/30 09:27:14 augustss Exp $	*/
2
3/*
4 * Copyright (c) 1982, 1986, 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Scooter Morris at Genentech Inc.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 *	@(#)ufs_lockf.c	8.4 (Berkeley) 10/26/94
39 */
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/kernel.h>
44#include <sys/file.h>
45#include <sys/proc.h>
46#include <sys/vnode.h>
47#include <sys/malloc.h>
48#include <sys/fcntl.h>
49#include <sys/lockf.h>
50
51/*
52 * This variable controls the maximum number of processes that will
53 * be checked in doing deadlock detection.
54 */
55int maxlockdepth = MAXDEPTH;
56
57#ifdef LOCKF_DEBUG
58int	lockf_debug = 0;
59#endif
60
61#define NOLOCKF (struct lockf *)0
62#define SELF	0x1
63#define OTHERS	0x2
64
65/*
66 * Do an advisory lock operation.
67 */
68int
69lf_advlock(head, size, id, op, fl, flags)
70	struct lockf **head;
71	off_t size;
72	caddr_t id;
73	int op;
74	struct flock *fl;
75	int flags;
76{
77	struct lockf *lock;
78	off_t start, end;
79	int error;
80
81	/*
82	 * Convert the flock structure into a start and end.
83	 */
84	switch (fl->l_whence) {
85	case SEEK_SET:
86	case SEEK_CUR:
87		/*
88		 * Caller is responsible for adding any necessary offset
89		 * when SEEK_CUR is used.
90		 */
91		start = fl->l_start;
92		break;
93
94	case SEEK_END:
95		start = size + fl->l_start;
96		break;
97
98	default:
99		return (EINVAL);
100	}
101	if (start < 0)
102		return (EINVAL);
103
104	/*
105	 * Avoid the common case of unlocking when inode has no locks.
106	 */
107	if (*head == (struct lockf *)0) {
108		if (op != F_SETLK) {
109			fl->l_type = F_UNLCK;
110			return (0);
111		}
112	}
113
114	if (fl->l_len == 0)
115		end = -1;
116	else
117		end = start + fl->l_len - 1;
118	/*
119	 * Create the lockf structure.
120	 */
121	MALLOC(lock, struct lockf *, sizeof(*lock), M_LOCKF, M_WAITOK);
122	lock->lf_start = start;
123	lock->lf_end = end;
124	lock->lf_id = id;
125	lock->lf_head = head;
126	lock->lf_type = fl->l_type;
127	lock->lf_next = (struct lockf *)0;
128	TAILQ_INIT(&lock->lf_blkhd);
129	lock->lf_flags = flags;
130	/*
131	 * Do the requested operation.
132	 */
133	switch (op) {
134
135	case F_SETLK:
136		return (lf_setlock(lock));
137
138	case F_UNLCK:
139		error = lf_clearlock(lock);
140		FREE(lock, M_LOCKF);
141		return (error);
142
143	case F_GETLK:
144		error = lf_getlock(lock, fl);
145		FREE(lock, M_LOCKF);
146		return (error);
147
148	default:
149		FREE(lock, M_LOCKF);
150		return (EINVAL);
151	}
152	/* NOTREACHED */
153}
154
155/*
156 * Set a byte-range lock.
157 */
158int
159lf_setlock(lock)
160	struct lockf *lock;
161{
162	struct lockf *block;
163	struct lockf **head = lock->lf_head;
164	struct lockf **prev, *overlap, *ltmp;
165	static char lockstr[] = "lockf";
166	int ovcase, priority, needtolink, error;
167
168#ifdef LOCKF_DEBUG
169	if (lockf_debug & 1)
170		lf_print("lf_setlock", lock);
171#endif /* LOCKF_DEBUG */
172
173	/*
174	 * Set the priority
175	 */
176	priority = PLOCK;
177	if (lock->lf_type == F_WRLCK)
178		priority += 4;
179	priority |= PCATCH;
180	/*
181	 * Scan lock list for this file looking for locks that would block us.
182	 */
183	while ((block = lf_getblock(lock)) != NULL) {
184		/*
185		 * Free the structure and return if nonblocking.
186		 */
187		if ((lock->lf_flags & F_WAIT) == 0) {
188			FREE(lock, M_LOCKF);
189			return (EAGAIN);
190		}
191		/*
192		 * We are blocked. Since flock style locks cover
193		 * the whole file, there is no chance for deadlock.
194		 * For byte-range locks we must check for deadlock.
195		 *
196		 * Deadlock detection is done by looking through the
197		 * wait channels to see if there are any cycles that
198		 * involve us. MAXDEPTH is set just to make sure we
199		 * do not go off into neverland.
200		 */
201		if ((lock->lf_flags & F_POSIX) &&
202		    (block->lf_flags & F_POSIX)) {
203			struct proc *wproc;
204			struct lockf *waitblock;
205			int i = 0;
206
207			/* The block is waiting on something */
208			wproc = (struct proc *)block->lf_id;
209			while (wproc->p_wchan &&
210			       (wproc->p_wmesg == lockstr) &&
211			       (i++ < maxlockdepth)) {
212				waitblock = (struct lockf *)wproc->p_wchan;
213				/* Get the owner of the blocking lock */
214				waitblock = waitblock->lf_next;
215				if ((waitblock->lf_flags & F_POSIX) == 0)
216					break;
217				wproc = (struct proc *)waitblock->lf_id;
218				if (wproc == (struct proc *)lock->lf_id) {
219					free(lock, M_LOCKF);
220					return (EDEADLK);
221				}
222			}
223		}
224		/*
225		 * For flock type locks, we must first remove
226		 * any shared locks that we hold before we sleep
227		 * waiting for an exclusive lock.
228		 */
229		if ((lock->lf_flags & F_FLOCK) &&
230		    lock->lf_type == F_WRLCK) {
231			lock->lf_type = F_UNLCK;
232			(void) lf_clearlock(lock);
233			lock->lf_type = F_WRLCK;
234		}
235		/*
236		 * Add our lock to the blocked list and sleep until we're free.
237		 * Remember who blocked us (for deadlock detection).
238		 */
239		lock->lf_next = block;
240		TAILQ_INSERT_TAIL(&block->lf_blkhd, lock, lf_block);
241#ifdef LOCKF_DEBUG
242		if (lockf_debug & 1) {
243			lf_print("lf_setlock: blocking on", block);
244			lf_printlist("lf_setlock", block);
245		}
246#endif /* LOCKF_DEBUG */
247		error = tsleep((caddr_t)lock, priority, lockstr, 0);
248		if (error) {
249			/*
250			 * We may have been awakened by a signal (in
251			 * which case we must remove ourselves from the
252			 * blocked list) and/or by another process
253			 * releasing a lock (in which case we have already
254			 * been removed from the blocked list and our
255			 * lf_next field set to NOLOCKF).
256			 */
257			if (lock->lf_next)
258				TAILQ_REMOVE(&lock->lf_next->lf_blkhd, lock,
259				    lf_block);
260			free(lock, M_LOCKF);
261			return (error);
262		}
263	}
264	/*
265	 * No blocks!!  Add the lock.  Note that we will
266	 * downgrade or upgrade any overlapping locks this
267	 * process already owns.
268	 *
269	 * Skip over locks owned by other processes.
270	 * Handle any locks that overlap and are owned by ourselves.
271	 */
272	prev = head;
273	block = *head;
274	needtolink = 1;
275	for (;;) {
276		ovcase = lf_findoverlap(block, lock, SELF, &prev, &overlap);
277		if (ovcase)
278			block = overlap->lf_next;
279		/*
280		 * Six cases:
281		 *	0) no overlap
282		 *	1) overlap == lock
283		 *	2) overlap contains lock
284		 *	3) lock contains overlap
285		 *	4) overlap starts before lock
286		 *	5) overlap ends after lock
287		 */
288		switch (ovcase) {
289		case 0: /* no overlap */
290			if (needtolink) {
291				*prev = lock;
292				lock->lf_next = overlap;
293			}
294			break;
295
296		case 1: /* overlap == lock */
297			/*
298			 * If downgrading lock, others may be
299			 * able to acquire it.
300			 */
301			if (lock->lf_type == F_RDLCK &&
302			    overlap->lf_type == F_WRLCK)
303				lf_wakelock(overlap);
304			overlap->lf_type = lock->lf_type;
305			FREE(lock, M_LOCKF);
306			lock = overlap; /* for debug output below */
307			break;
308
309		case 2: /* overlap contains lock */
310			/*
311			 * Check for common starting point and different types.
312			 */
313			if (overlap->lf_type == lock->lf_type) {
314				free(lock, M_LOCKF);
315				lock = overlap; /* for debug output below */
316				break;
317			}
318			if (overlap->lf_start == lock->lf_start) {
319				*prev = lock;
320				lock->lf_next = overlap;
321				overlap->lf_start = lock->lf_end + 1;
322			} else
323				lf_split(overlap, lock);
324			lf_wakelock(overlap);
325			break;
326
327		case 3: /* lock contains overlap */
328			/*
329			 * If downgrading lock, others may be able to
330			 * acquire it, otherwise take the list.
331			 */
332			if (lock->lf_type == F_RDLCK &&
333			    overlap->lf_type == F_WRLCK) {
334				lf_wakelock(overlap);
335			} else {
336				while ((ltmp = overlap->lf_blkhd.tqh_first)) {
337					TAILQ_REMOVE(&overlap->lf_blkhd, ltmp,
338					    lf_block);
339					TAILQ_INSERT_TAIL(&lock->lf_blkhd,
340					    ltmp, lf_block);
341				}
342			}
343			/*
344			 * Add the new lock if necessary and delete the overlap.
345			 */
346			if (needtolink) {
347				*prev = lock;
348				lock->lf_next = overlap->lf_next;
349				prev = &lock->lf_next;
350				needtolink = 0;
351			} else
352				*prev = overlap->lf_next;
353			free(overlap, M_LOCKF);
354			continue;
355
356		case 4: /* overlap starts before lock */
357			/*
358			 * Add lock after overlap on the list.
359			 */
360			lock->lf_next = overlap->lf_next;
361			overlap->lf_next = lock;
362			overlap->lf_end = lock->lf_start - 1;
363			prev = &lock->lf_next;
364			lf_wakelock(overlap);
365			needtolink = 0;
366			continue;
367
368		case 5: /* overlap ends after lock */
369			/*
370			 * Add the new lock before overlap.
371			 */
372			if (needtolink) {
373				*prev = lock;
374				lock->lf_next = overlap;
375			}
376			overlap->lf_start = lock->lf_end + 1;
377			lf_wakelock(overlap);
378			break;
379		}
380		break;
381	}
382#ifdef LOCKF_DEBUG
383	if (lockf_debug & 1) {
384		lf_print("lf_setlock: got the lock", lock);
385		lf_printlist("lf_setlock", lock);
386	}
387#endif /* LOCKF_DEBUG */
388	return (0);
389}
390
391/*
392 * Remove a byte-range lock on an inode.
393 *
394 * Generally, find the lock (or an overlap to that lock)
395 * and remove it (or shrink it), then wakeup anyone we can.
396 */
397int
398lf_clearlock(unlock)
399	struct lockf *unlock;
400{
401	struct lockf **head = unlock->lf_head;
402	struct lockf *lf = *head;
403	struct lockf *overlap, **prev;
404	int ovcase;
405
406	if (lf == NOLOCKF)
407		return (0);
408#ifdef LOCKF_DEBUG
409	if (unlock->lf_type != F_UNLCK)
410		panic("lf_clearlock: bad type");
411	if (lockf_debug & 1)
412		lf_print("lf_clearlock", unlock);
413#endif /* LOCKF_DEBUG */
414	prev = head;
415	while ((ovcase = lf_findoverlap(lf, unlock, SELF,
416					&prev, &overlap)) != 0) {
417		/*
418		 * Wakeup the list of locks to be retried.
419		 */
420		lf_wakelock(overlap);
421
422		switch (ovcase) {
423
424		case 1: /* overlap == lock */
425			*prev = overlap->lf_next;
426			FREE(overlap, M_LOCKF);
427			break;
428
429		case 2: /* overlap contains lock: split it */
430			if (overlap->lf_start == unlock->lf_start) {
431				overlap->lf_start = unlock->lf_end + 1;
432				break;
433			}
434			lf_split(overlap, unlock);
435			overlap->lf_next = unlock->lf_next;
436			break;
437
438		case 3: /* lock contains overlap */
439			*prev = overlap->lf_next;
440			lf = overlap->lf_next;
441			free(overlap, M_LOCKF);
442			continue;
443
444		case 4: /* overlap starts before lock */
445			overlap->lf_end = unlock->lf_start - 1;
446			prev = &overlap->lf_next;
447			lf = overlap->lf_next;
448			continue;
449
450		case 5: /* overlap ends after lock */
451			overlap->lf_start = unlock->lf_end + 1;
452			break;
453		}
454		break;
455	}
456#ifdef LOCKF_DEBUG
457	if (lockf_debug & 1)
458		lf_printlist("lf_clearlock", unlock);
459#endif /* LOCKF_DEBUG */
460	return (0);
461}
462
463/*
464 * Check whether there is a blocking lock,
465 * and if so return its process identifier.
466 */
467int
468lf_getlock(lock, fl)
469	struct lockf *lock;
470	struct flock *fl;
471{
472	struct lockf *block;
473
474#ifdef LOCKF_DEBUG
475	if (lockf_debug & 1)
476		lf_print("lf_getlock", lock);
477#endif /* LOCKF_DEBUG */
478
479	if ((block = lf_getblock(lock)) != NULL) {
480		fl->l_type = block->lf_type;
481		fl->l_whence = SEEK_SET;
482		fl->l_start = block->lf_start;
483		if (block->lf_end == -1)
484			fl->l_len = 0;
485		else
486			fl->l_len = block->lf_end - block->lf_start + 1;
487		if (block->lf_flags & F_POSIX)
488			fl->l_pid = ((struct proc *)(block->lf_id))->p_pid;
489		else
490			fl->l_pid = -1;
491	} else {
492		fl->l_type = F_UNLCK;
493	}
494	return (0);
495}
496
497/*
498 * Walk the list of locks for an inode and
499 * return the first blocking lock.
500 */
501struct lockf *
502lf_getblock(lock)
503	struct lockf *lock;
504{
505	struct lockf **prev, *overlap, *lf = *(lock->lf_head);
506	int ovcase;
507
508	prev = lock->lf_head;
509	while ((ovcase = lf_findoverlap(lf, lock, OTHERS,
510					&prev, &overlap)) != 0) {
511		/*
512		 * We've found an overlap, see if it blocks us
513		 */
514		if ((lock->lf_type == F_WRLCK || overlap->lf_type == F_WRLCK))
515			return (overlap);
516		/*
517		 * Nope, point to the next one on the list and
518		 * see if it blocks us
519		 */
520		lf = overlap->lf_next;
521	}
522	return (NOLOCKF);
523}
524
525/*
526 * Walk the list of locks for an inode to
527 * find an overlapping lock (if any).
528 *
529 * NOTE: this returns only the FIRST overlapping lock.  There
530 *	 may be more than one.
531 */
532int
533lf_findoverlap(lf, lock, type, prev, overlap)
534	struct lockf *lf;
535	struct lockf *lock;
536	int type;
537	struct lockf ***prev;
538	struct lockf **overlap;
539{
540	off_t start, end;
541
542	*overlap = lf;
543	if (lf == NOLOCKF)
544		return (0);
545#ifdef LOCKF_DEBUG
546	if (lockf_debug & 2)
547		lf_print("lf_findoverlap: looking for overlap in", lock);
548#endif /* LOCKF_DEBUG */
549	start = lock->lf_start;
550	end = lock->lf_end;
551	while (lf != NOLOCKF) {
552		if (((type & SELF) && lf->lf_id != lock->lf_id) ||
553		    ((type & OTHERS) && lf->lf_id == lock->lf_id)) {
554			*prev = &lf->lf_next;
555			*overlap = lf = lf->lf_next;
556			continue;
557		}
558#ifdef LOCKF_DEBUG
559		if (lockf_debug & 2)
560			lf_print("\tchecking", lf);
561#endif /* LOCKF_DEBUG */
562		/*
563		 * OK, check for overlap
564		 *
565		 * Six cases:
566		 *	0) no overlap
567		 *	1) overlap == lock
568		 *	2) overlap contains lock
569		 *	3) lock contains overlap
570		 *	4) overlap starts before lock
571		 *	5) overlap ends after lock
572		 */
573		if ((lf->lf_end != -1 && start > lf->lf_end) ||
574		    (end != -1 && lf->lf_start > end)) {
575			/* Case 0 */
576#ifdef LOCKF_DEBUG
577			if (lockf_debug & 2)
578				printf("no overlap\n");
579#endif /* LOCKF_DEBUG */
580			if ((type & SELF) && end != -1 && lf->lf_start > end)
581				return (0);
582			*prev = &lf->lf_next;
583			*overlap = lf = lf->lf_next;
584			continue;
585		}
586		if ((lf->lf_start == start) && (lf->lf_end == end)) {
587			/* Case 1 */
588#ifdef LOCKF_DEBUG
589			if (lockf_debug & 2)
590				printf("overlap == lock\n");
591#endif /* LOCKF_DEBUG */
592			return (1);
593		}
594		if ((lf->lf_start <= start) &&
595		    (end != -1) &&
596		    ((lf->lf_end >= end) || (lf->lf_end == -1))) {
597			/* Case 2 */
598#ifdef LOCKF_DEBUG
599			if (lockf_debug & 2)
600				printf("overlap contains lock\n");
601#endif /* LOCKF_DEBUG */
602			return (2);
603		}
604		if (start <= lf->lf_start &&
605		           (end == -1 ||
606			   (lf->lf_end != -1 && end >= lf->lf_end))) {
607			/* Case 3 */
608#ifdef LOCKF_DEBUG
609			if (lockf_debug & 2)
610				printf("lock contains overlap\n");
611#endif /* LOCKF_DEBUG */
612			return (3);
613		}
614		if ((lf->lf_start < start) &&
615			((lf->lf_end >= start) || (lf->lf_end == -1))) {
616			/* Case 4 */
617#ifdef LOCKF_DEBUG
618			if (lockf_debug & 2)
619				printf("overlap starts before lock\n");
620#endif /* LOCKF_DEBUG */
621			return (4);
622		}
623		if ((lf->lf_start > start) &&
624			(end != -1) &&
625			((lf->lf_end > end) || (lf->lf_end == -1))) {
626			/* Case 5 */
627#ifdef LOCKF_DEBUG
628			if (lockf_debug & 2)
629				printf("overlap ends after lock\n");
630#endif /* LOCKF_DEBUG */
631			return (5);
632		}
633		panic("lf_findoverlap: default");
634	}
635	return (0);
636}
637
638/*
639 * Split a lock and a contained region into
640 * two or three locks as necessary.
641 */
642void
643lf_split(lock1, lock2)
644	struct lockf *lock1;
645	struct lockf *lock2;
646{
647	struct lockf *splitlock;
648
649#ifdef LOCKF_DEBUG
650	if (lockf_debug & 2) {
651		lf_print("lf_split", lock1);
652		lf_print("splitting from", lock2);
653	}
654#endif /* LOCKF_DEBUG */
655	/*
656	 * Check to see if spliting into only two pieces.
657	 */
658	if (lock1->lf_start == lock2->lf_start) {
659		lock1->lf_start = lock2->lf_end + 1;
660		lock2->lf_next = lock1;
661		return;
662	}
663	if (lock1->lf_end == lock2->lf_end) {
664		lock1->lf_end = lock2->lf_start - 1;
665		lock2->lf_next = lock1->lf_next;
666		lock1->lf_next = lock2;
667		return;
668	}
669	/*
670	 * Make a new lock consisting of the last part of
671	 * the encompassing lock
672	 */
673	MALLOC(splitlock, struct lockf *, sizeof(*splitlock), M_LOCKF, M_WAITOK);
674	memcpy((caddr_t)splitlock, (caddr_t)lock1, sizeof(*splitlock));
675	splitlock->lf_start = lock2->lf_end + 1;
676	TAILQ_INIT(&splitlock->lf_blkhd);
677	lock1->lf_end = lock2->lf_start - 1;
678	/*
679	 * OK, now link it in
680	 */
681	splitlock->lf_next = lock1->lf_next;
682	lock2->lf_next = splitlock;
683	lock1->lf_next = lock2;
684}
685
686/*
687 * Wakeup a blocklist
688 */
689void
690lf_wakelock(listhead)
691	struct lockf *listhead;
692{
693	struct lockf *wakelock;
694
695	while ((wakelock = listhead->lf_blkhd.tqh_first)) {
696		TAILQ_REMOVE(&listhead->lf_blkhd, wakelock, lf_block);
697		wakelock->lf_next = NOLOCKF;
698#ifdef LOCKF_DEBUG
699		if (lockf_debug & 2)
700			lf_print("lf_wakelock: awakening", wakelock);
701#endif
702		wakeup((caddr_t)wakelock);
703	}
704}
705
706#ifdef LOCKF_DEBUG
707/*
708 * Print out a lock.
709 */
710void
711lf_print(tag, lock)
712	char *tag;
713	struct lockf *lock;
714{
715
716	printf("%s: lock %p for ", tag, lock);
717	if (lock->lf_flags & F_POSIX)
718		printf("proc %d", ((struct proc *)(lock->lf_id))->p_pid);
719	else
720		printf("id 0x%p", lock->lf_id);
721	printf(" %s, start %qx, end %qx",
722		lock->lf_type == F_RDLCK ? "shared" :
723		lock->lf_type == F_WRLCK ? "exclusive" :
724		lock->lf_type == F_UNLCK ? "unlock" :
725		"unknown", lock->lf_start, lock->lf_end);
726	if (lock->lf_blkhd.tqh_first)
727		printf(" block %p\n", lock->lf_blkhd.tqh_first);
728	else
729		printf("\n");
730}
731
732void
733lf_printlist(tag, lock)
734	char *tag;
735	struct lockf *lock;
736{
737	struct lockf *lf, *blk;
738
739	printf("%s: Lock list:\n", tag);
740	for (lf = *lock->lf_head; lf; lf = lf->lf_next) {
741		printf("\tlock %p for ", lf);
742		if (lf->lf_flags & F_POSIX)
743			printf("proc %d", ((struct proc *)(lf->lf_id))->p_pid);
744		else
745			printf("id 0x%p", lf->lf_id);
746		printf(", %s, start %qx, end %qx",
747			lf->lf_type == F_RDLCK ? "shared" :
748			lf->lf_type == F_WRLCK ? "exclusive" :
749			lf->lf_type == F_UNLCK ? "unlock" :
750			"unknown", lf->lf_start, lf->lf_end);
751		for (blk = lf->lf_blkhd.tqh_first; blk;
752		     blk = blk->lf_block.tqe_next) {
753			if (blk->lf_flags & F_POSIX)
754				printf("proc %d",
755				    ((struct proc *)(blk->lf_id))->p_pid);
756			else
757				printf("id 0x%p", blk->lf_id);
758			printf(", %s, start %qx, end %qx",
759				blk->lf_type == F_RDLCK ? "shared" :
760				blk->lf_type == F_WRLCK ? "exclusive" :
761				blk->lf_type == F_UNLCK ? "unlock" :
762				"unknown", blk->lf_start, blk->lf_end);
763			if (blk->lf_blkhd.tqh_first)
764				 panic("lf_printlist: bad list");
765		}
766		printf("\n");
767	}
768}
769#endif /* LOCKF_DEBUG */
770