1 /*
2 * getsectsize.c --- get the sector size of a device.
3 *
4 * Copyright (C) 1995, 1995 Theodore Ts'o.
5 * Copyright (C) 2003 VMware, Inc.
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the GNU Library
9 * General Public License, version 2.
10 * %End-Header%
11 */
12
13 #ifndef _LARGEFILE_SOURCE
14 #define _LARGEFILE_SOURCE
15 #endif
16 #ifndef _LARGEFILE64_SOURCE
17 #define _LARGEFILE64_SOURCE
18 #endif
19
20 #include "config.h"
21 #include <stdio.h>
22 #if HAVE_UNISTD_H
23 #include <unistd.h>
24 #endif
25 #if HAVE_ERRNO_H
26 #include <errno.h>
27 #endif
28 #include <fcntl.h>
29 #ifdef HAVE_SYS_DISK_H
30 #include <sys/disk.h>
31 #endif
32 #ifdef HAVE_LINUX_FD_H
33 #include <sys/ioctl.h>
34 #include <linux/fd.h>
35 #endif
36
37 #if defined(__linux__) && defined(_IO)
38 #if !defined(BLKSSZGET)
39 #define BLKSSZGET _IO(0x12,104)/* get block device sector size */
40 #endif
41 #if !defined(BLKPBSZGET)
42 #define BLKPBSZGET _IO(0x12,123)/* get block physical sector size */
43 #endif
44 #endif
45
46 #include "ext2_fs.h"
47 #include "ext2fs.h"
48
49 /*
50 * Returns the logical sector size of a device
51 */
ext2fs_get_device_sectsize(const char * file,int * sectsize)52 errcode_t ext2fs_get_device_sectsize(const char *file, int *sectsize)
53 {
54 int fd;
55
56 fd = ext2fs_open_file(file, O_RDONLY, 0);
57 if (fd < 0)
58 return errno;
59
60 #ifdef BLKSSZGET
61 if (ioctl(fd, BLKSSZGET, sectsize) >= 0) {
62 close(fd);
63 return 0;
64 }
65 #endif
66 #ifdef DIOCGSECTORSIZE
67 if (ioctl(fd, DIOCGSECTORSIZE, sectsize) >= 0) {
68 close(fd);
69 return 0;
70 }
71 #endif
72 *sectsize = 0;
73 close(fd);
74 return 0;
75 }
76
77 /*
78 * Return desired alignment for direct I/O
79 */
ext2fs_get_dio_alignment(int fd)80 int ext2fs_get_dio_alignment(int fd)
81 {
82 int align = 0;
83
84 #ifdef BLKSSZGET
85 if (ioctl(fd, BLKSSZGET, &align) < 0)
86 align = 0;
87 #endif
88 #ifdef DIOCGSECTORSIZE
89 if (align <= 0 &&
90 ioctl(fd, DIOCGSECTORSIZE, &align) < 0)
91 align = 0;
92 #endif
93
94 #ifdef _SC_PAGESIZE
95 if (align <= 0)
96 align = sysconf(_SC_PAGESIZE);
97 #endif
98 #ifdef HAVE_GETPAGESIZE
99 if (align <= 0)
100 align = getpagesize();
101 #endif
102 if (align <= 0)
103 align = 4096;
104
105 return align;
106 }
107
108 /*
109 * Returns the physical sector size of a device
110 */
ext2fs_get_device_phys_sectsize(const char * file,int * sectsize)111 errcode_t ext2fs_get_device_phys_sectsize(const char *file, int *sectsize)
112 {
113 int fd;
114
115 fd = ext2fs_open_file(file, O_RDONLY, 0);
116 if (fd < 0)
117 return errno;
118
119 #ifdef BLKPBSZGET
120 if (ioctl(fd, BLKPBSZGET, sectsize) >= 0) {
121 close(fd);
122 return 0;
123 }
124 #endif
125 #ifdef DIOCGSECTORSIZE
126 /* This isn't really the physical sector size, but FreeBSD
127 * doesn't seem to have this concept. */
128 if (ioctl(fd, DIOCGSECTORSIZE, sectsize) >= 0) {
129 close(fd);
130 return 0;
131 }
132 #endif
133 *sectsize = 0;
134 close(fd);
135 return 0;
136 }
137