2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2010 The FreeBSD Foundation
7 * This software was developed by Pawel Jakub Dawidek under sponsorship from
8 * the FreeBSD Foundation.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include <sys/queue.h>
43 #include "rangelock.h"
47 #define PJDLOG_ASSERT(...) assert(__VA_ARGS__)
50 #define RANGELOCKS_MAGIC 0x94310c
52 int rls_magic; /* Magic value. */
53 TAILQ_HEAD(, rlock) rls_locks; /* List of locked ranges. */
59 TAILQ_ENTRY(rlock) rl_next;
63 rangelock_init(struct rangelocks **rlsp)
65 struct rangelocks *rls;
67 PJDLOG_ASSERT(rlsp != NULL);
69 rls = malloc(sizeof(*rls));
73 TAILQ_INIT(&rls->rls_locks);
75 rls->rls_magic = RANGELOCKS_MAGIC;
82 rangelock_free(struct rangelocks *rls)
86 PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
90 while ((rl = TAILQ_FIRST(&rls->rls_locks)) != NULL) {
91 TAILQ_REMOVE(&rls->rls_locks, rl, rl_next);
98 rangelock_add(struct rangelocks *rls, off_t offset, off_t length)
102 PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
104 rl = malloc(sizeof(*rl));
107 rl->rl_start = offset;
108 rl->rl_end = offset + length;
109 TAILQ_INSERT_TAIL(&rls->rls_locks, rl, rl_next);
114 rangelock_del(struct rangelocks *rls, off_t offset, off_t length)
118 PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
120 TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) {
121 if (rl->rl_start == offset && rl->rl_end == offset + length)
124 PJDLOG_ASSERT(rl != NULL);
125 TAILQ_REMOVE(&rls->rls_locks, rl, rl_next);
130 rangelock_islocked(struct rangelocks *rls, off_t offset, off_t length)
135 PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC);
137 end = offset + length;
138 TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) {
139 if (rl->rl_start < end && rl->rl_end > offset)