1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
/* map_shared.c -- memory-mapping routines.
*
* Copyright (c) 1994-2008 Carnegie Mellon University. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The name "Carnegie Mellon University" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For permission or any legal
* details, please contact
* Carnegie Mellon University
* Center for Technology Transfer and Enterprise Creation
* 4615 Forbes Avenue
* Suite 302
* Pittsburgh, PA 15213
* (412) 268-7393, fax: (412) 268-7395
* innovation@andrew.cmu.edu
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Computing Services
* at Carnegie Mellon University (http://www.cmu.edu/computing/)."
*
* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <config.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sysexits.h>
#include <syslog.h>
#include "map.h"
#include "slowio.h"
#include "xmalloc.h"
#define SLOP (8*1024)
EXPORTED const char map_method_desc[] = "shared";
/*
* Create/refresh mapping of file
*/
EXPORTED void map_refresh(int fd, int onceonly, const char **base,
size_t *len, size_t newlen,
const char *name, const char *mboxname)
{
struct stat sbuf;
char buf[256];
if (newlen == MAP_UNKNOWN_LEN) {
if (fstat(fd, &sbuf) == -1) {
syslog(LOG_ERR, "IOERROR: fstating %s file%s%s: %m", name,
mboxname ? " for " : "", mboxname ? mboxname : "");
snprintf(buf, sizeof(buf), "failed to fstat %s file", name);
fatal(buf, EX_IOERR);
}
newlen = sbuf.st_size;
}
/* Already mapped in */
if (*len >= newlen) return;
if (*len) {
int r = munmap((char *)*base, *len);
if (r) {
syslog(LOG_ERR, "IOERROR: unmapping %s file%s%s: %m", name,
mboxname ? " for " : "", mboxname ? mboxname : "");
snprintf(buf, sizeof(buf), "failed to munmap %s file", name);
fatal(buf, EX_IOERR);
}
}
/* always map one extra byte so there's a trailing NULL to protect
* us from overruns. This does NOT mean that we should treat this
* memory as a cstring */
if (!onceonly)
newlen = (newlen + 2*SLOP) & ~(SLOP-1);
*base = (char *)mmap((caddr_t)0, onceonly ? newlen + 1 : newlen, PROT_READ, MAP_SHARED
#ifdef MAP_FILE
| MAP_FILE
#endif
#ifdef MAP_VARIABLE
| MAP_VARIABLE
#endif
, fd, 0L);
if (*base == (char *)-1) {
syslog(LOG_ERR, "IOERROR: mapping %s file%s%s: %m", name,
mboxname ? " for " : "", mboxname ? mboxname : "");
snprintf(buf, sizeof(buf), "failed to mmap %s file", name);
fatal(buf, EX_IOERR);
}
*len = newlen;
slowio_maybe_delay_read(newlen);
}
/*
* Destroy mapping of file
*/
EXPORTED void map_free(const char **base, size_t *len)
{
if (*len) {
int r = munmap((char *)*base, *len);
if (r) {
syslog(LOG_ERR, "IOERROR: map_free");
fatal("Failed to map_free", EX_IOERR);
}
}
*base = 0;
*len = 0;
}
|
