1/*-
2 * Copyright (c) 2010 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Pawel Jakub Dawidek under sponsorship from
6 * the FreeBSD Foundation.
7 *
8 * Redistribution and use in source and binary forms, with or without

--- 14 unchanged lines hidden (view full) ---

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
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: head/sbin/hastd/rangelock.c 204076 2010-02-18 23:16:19Z pjd $");
32
33#include <sys/queue.h>
34
35#include <assert.h>
36#include <stdbool.h>
37#include <stdlib.h>
38#include <unistd.h>
39
40#include "rangelock.h"
41
42#define RANGELOCKS_MAGIC 0x94310c
43struct rangelocks {
44 int rls_magic; /* Magic value. */
45 TAILQ_HEAD(, rlock) rls_locks; /* List of locked ranges. */
46};
47
48struct rlock {
49 off_t rl_start;
50 off_t rl_end;
51 TAILQ_ENTRY(rlock) rl_next;
52};
53
54int
55rangelock_init(struct rangelocks **rlsp)
56{
57 struct rangelocks *rls;
58
59 assert(rlsp != NULL);
60
61 rls = malloc(sizeof(*rls));
62 if (rls == NULL)
63 return (-1);
64
65 TAILQ_INIT(&rls->rls_locks);
66
67 rls->rls_magic = RANGELOCKS_MAGIC;
68 *rlsp = rls;
69
70 return (0);
71}
72
73void
74rangelock_free(struct rangelocks *rls)
75{
76 struct rlock *rl;
77
78 assert(rls->rls_magic == RANGELOCKS_MAGIC);
79
80 rls->rls_magic = 0;
81
82 while ((rl = TAILQ_FIRST(&rls->rls_locks)) != NULL) {
83 TAILQ_REMOVE(&rls->rls_locks, rl, rl_next);
84 free(rl);
85 }
86 free(rls);
87}
88
89int
90rangelock_add(struct rangelocks *rls, off_t offset, off_t length)
91{
92 struct rlock *rl;
93
94 assert(rls->rls_magic == RANGELOCKS_MAGIC);
95
96 rl = malloc(sizeof(*rl));
97 if (rl == NULL)
98 return (-1);
99 rl->rl_start = offset;
100 rl->rl_end = offset + length;
101 TAILQ_INSERT_TAIL(&rls->rls_locks, rl, rl_next);
102 return (0);
103}
104
105void
106rangelock_del(struct rangelocks *rls, off_t offset, off_t length)
107{
108 struct rlock *rl;
109
110 assert(rls->rls_magic == RANGELOCKS_MAGIC);
111
112 TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) {
113 if (rl->rl_start == offset && rl->rl_end == offset + length)
114 break;
115 }
116 assert(rl != NULL);
117 TAILQ_REMOVE(&rls->rls_locks, rl, rl_next);
118 free(rl);
119}
120
121bool
122rangelock_islocked(struct rangelocks *rls, off_t offset, off_t length)
123{
124 struct rlock *rl;
125
126 assert(rls->rls_magic == RANGELOCKS_MAGIC);
127
128 TAILQ_FOREACH(rl, &rls->rls_locks, rl_next) {
129 if (rl->rl_start >= offset && rl->rl_start < offset + length)
130 break;
131 else if (rl->rl_end > offset && rl->rl_end <= offset + length)
132 break;
133 else if (rl->rl_start < offset && rl->rl_end > offset + length)
134 break;
135 }
136 return (rl != NULL);
137}