1204076Spjd/*- 2330449Seadler * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3330449Seadler * 4204076Spjd * Copyright (c) 2010 The FreeBSD Foundation 5204076Spjd * All rights reserved. 6204076Spjd * 7204076Spjd * This software was developed by Pawel Jakub Dawidek under sponsorship from 8204076Spjd * the FreeBSD Foundation. 9204076Spjd * 10204076Spjd * Redistribution and use in source and binary forms, with or without 11204076Spjd * modification, are permitted provided that the following conditions 12204076Spjd * are met: 13204076Spjd * 1. Redistributions of source code must retain the above copyright 14204076Spjd * notice, this list of conditions and the following disclaimer. 15204076Spjd * 2. Redistributions in binary form must reproduce the above copyright 16204076Spjd * notice, this list of conditions and the following disclaimer in the 17204076Spjd * documentation and/or other materials provided with the distribution. 18204076Spjd * 19204076Spjd * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 20204076Spjd * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21204076Spjd * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22204076Spjd * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 23204076Spjd * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24204076Spjd * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25204076Spjd * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26204076Spjd * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27204076Spjd * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28204076Spjd * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29204076Spjd * SUCH DAMAGE. 30204076Spjd */ 31204076Spjd 32204076Spjd#include <sys/cdefs.h> 33204076Spjd__FBSDID("$FreeBSD: stable/11/sbin/hastd/rangelock.c 330449 2018-03-05 07:26:05Z eadler $"); 34204076Spjd 35204076Spjd#include <sys/queue.h> 36204076Spjd 37204076Spjd#include <stdbool.h> 38204076Spjd#include <stdlib.h> 39204076Spjd#include <unistd.h> 40204076Spjd 41225787Spjd#include <pjdlog.h> 42225787Spjd 43204076Spjd#include "rangelock.h" 44204076Spjd 45225787Spjd#ifndef PJDLOG_ASSERT 46225787Spjd#include <assert.h> 47225787Spjd#define PJDLOG_ASSERT(...) assert(__VA_ARGS__) 48225787Spjd#endif 49225787Spjd 50204076Spjd#define RANGELOCKS_MAGIC 0x94310c 51204076Spjdstruct rangelocks { 52204076Spjd int rls_magic; /* Magic value. */ 53204076Spjd TAILQ_HEAD(, rlock) rls_locks; /* List of locked ranges. */ 54204076Spjd}; 55204076Spjd 56204076Spjdstruct rlock { 57204076Spjd off_t rl_start; 58204076Spjd off_t rl_end; 59204076Spjd TAILQ_ENTRY(rlock) rl_next; 60204076Spjd}; 61204076Spjd 62204076Spjdint 63204076Spjdrangelock_init(struct rangelocks **rlsp) 64204076Spjd{ 65204076Spjd struct rangelocks *rls; 66204076Spjd 67225787Spjd PJDLOG_ASSERT(rlsp != NULL); 68204076Spjd 69204076Spjd rls = malloc(sizeof(*rls)); 70204076Spjd if (rls == NULL) 71204076Spjd return (-1); 72204076Spjd 73204076Spjd TAILQ_INIT(&rls->rls_locks); 74204076Spjd 75204076Spjd rls->rls_magic = RANGELOCKS_MAGIC; 76204076Spjd *rlsp = rls; 77204076Spjd 78204076Spjd return (0); 79204076Spjd} 80204076Spjd 81204076Spjdvoid 82204076Spjdrangelock_free(struct rangelocks *rls) 83204076Spjd{ 84204076Spjd struct rlock *rl; 85204076Spjd 86225787Spjd PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC); 87204076Spjd 88204076Spjd rls->rls_magic = 0; 89204076Spjd 90204076Spjd while ((rl = TAILQ_FIRST(&rls->rls_locks)) != NULL) { 91204076Spjd TAILQ_REMOVE(&rls->rls_locks, rl, rl_next); 92204076Spjd free(rl); 93204076Spjd } 94204076Spjd free(rls); 95204076Spjd} 96204076Spjd 97204076Spjdint 98204076Spjdrangelock_add(struct rangelocks *rls, off_t offset, off_t length) 99204076Spjd{ 100204076Spjd struct rlock *rl; 101204076Spjd 102225787Spjd PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC); 103204076Spjd 104204076Spjd rl = malloc(sizeof(*rl)); 105204076Spjd if (rl == NULL) 106204076Spjd return (-1); 107204076Spjd rl->rl_start = offset; 108204076Spjd rl->rl_end = offset + length; 109204076Spjd TAILQ_INSERT_TAIL(&rls->rls_locks, rl, rl_next); 110204076Spjd return (0); 111204076Spjd} 112204076Spjd 113204076Spjdvoid 114204076Spjdrangelock_del(struct rangelocks *rls, off_t offset, off_t length) 115204076Spjd{ 116204076Spjd struct rlock *rl; 117204076Spjd 118225787Spjd PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC); 119204076Spjd 120204076Spjd TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) { 121204076Spjd if (rl->rl_start == offset && rl->rl_end == offset + length) 122204076Spjd break; 123204076Spjd } 124225787Spjd PJDLOG_ASSERT(rl != NULL); 125204076Spjd TAILQ_REMOVE(&rls->rls_locks, rl, rl_next); 126204076Spjd free(rl); 127204076Spjd} 128204076Spjd 129204076Spjdbool 130204076Spjdrangelock_islocked(struct rangelocks *rls, off_t offset, off_t length) 131204076Spjd{ 132204076Spjd struct rlock *rl; 133231525Spjd off_t end; 134204076Spjd 135225787Spjd PJDLOG_ASSERT(rls->rls_magic == RANGELOCKS_MAGIC); 136204076Spjd 137231525Spjd end = offset + length; 138204076Spjd TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) { 139231525Spjd if (rl->rl_start < end && rl->rl_end > offset) 140204076Spjd break; 141204076Spjd } 142204076Spjd return (rl != NULL); 143204076Spjd} 144