Merge branch 'master' of git://chlamydia.fs.ei.tum.de/dragonfly
[dragonfly.git] / sbin / fsck / memzone.c
blob0f556cf70f2cc458312370ba65d9e9113ef99564
1 /*
2 * Copyright (c) 2006 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
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
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
34 * $DragonFly: src/sbin/fsck/memzone.c,v 1.2 2007/11/25 01:28:23 swildner Exp $
37 #include <sys/types.h>
38 #include <sys/mman.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include <unistd.h>
43 #include "memzone.h"
46 * Efficiently allocate memory that will only be freed in bulk
48 void *
49 mzalloc(struct memzone *zone, int bytes)
51 struct memchunk *chunk;
52 void *ptr;
54 if ((chunk = zone->curr) != NULL) {
55 if (bytes > chunk->bytes - zone->index) {
56 chunk->next = zone->list;
57 zone->list = chunk;
58 zone->curr = NULL;
59 chunk = NULL;
62 if (chunk == NULL) {
63 chunk = malloc(sizeof(*chunk));
64 if (chunk == NULL)
65 return(NULL);
66 bzero(chunk, sizeof(*chunk));
67 chunk->base = mmap(NULL, MEMZONE_CHUNK, PROT_READ|PROT_WRITE,
68 MAP_ANON|MAP_PRIVATE, -1, 0);
69 if (chunk->base == MAP_FAILED) {
70 free(chunk);
71 return(NULL);
73 chunk->bytes = MEMZONE_CHUNK;
74 zone->curr = chunk;
75 zone->index = 0;
77 if (bytes > chunk->bytes)
78 pfatal("allocation to large for mzalloc!");
79 ptr = chunk->base + zone->index;
80 zone->index += (bytes + 7) & ~7;
81 return(ptr);
85 * Free memory in bulk
87 void *
88 mzpurge(struct memzone *zone)
90 struct memchunk *chunk;
92 if ((chunk = zone->curr) != NULL) {
93 chunk->next = zone->list;
94 zone->list = chunk;
95 zone->curr = NULL;
97 while ((chunk = zone->list) != NULL) {
98 zone->list = chunk->next;
99 munmap(chunk->base, chunk->bytes);
100 free(chunk);