2 * Copyright (c) 2010 The FreeBSD Foundation
5 * This software was developed by Pawel Jakub Dawidek under sponsorship from
6 * the FreeBSD Foundation.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include <sys/queue.h>
41 #include "rangelock.h"
45 #define PJDLOG_ASSERT(...) assert(__VA_ARGS__)
48 #define RANGELOCKS_MAGIC 0x94310c
50 int rls_magic; /* Magic value. */
51 TAILQ_HEAD(, rlock) rls_locks; /* List of locked ranges. */
57 TAILQ_ENTRY(rlock) rl_next;
61 rangelock_init(struct rangelocks **rlsp)
63 struct rangelocks *rls;
65 PJDLOG_ASSERT(rlsp != NULL);
67 rls = malloc(sizeof(*rls));
71 TAILQ_INIT(&rls->rls_locks);
73 rls->rls_magic = RANGELOCKS_MAGIC;
80 rangelock_free(struct rangelocks *rls)
84 PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
88 while ((rl = TAILQ_FIRST(&rls->rls_locks)) != NULL) {
89 TAILQ_REMOVE(&rls->rls_locks, rl, rl_next);
96 rangelock_add(struct rangelocks *rls, off_t offset, off_t length)
100 PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
102 rl = malloc(sizeof(*rl));
105 rl->rl_start = offset;
106 rl->rl_end = offset + length;
107 TAILQ_INSERT_TAIL(&rls->rls_locks, rl, rl_next);
112 rangelock_del(struct rangelocks *rls, off_t offset, off_t length)
116 PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
118 TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) {
119 if (rl->rl_start == offset && rl->rl_end == offset + length)
122 PJDLOG_ASSERT(rl != NULL);
123 TAILQ_REMOVE(&rls->rls_locks, rl, rl_next);
128 rangelock_islocked(struct rangelocks *rls, off_t offset, off_t length)
133 PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
135 end = offset + length;
136 TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) {
137 if (rl->rl_start < end && rl->rl_end > offset)