blob: b57bf56a5eef1cdf420b3e8c60a65215db1a7530 [file] [log] [blame]
/*
* getsectsize.c --- get the sector size of a device.
*
* Copyright (C) 1995, 1995 Theodore Ts'o.
* Copyright (C) 2003 VMware, Inc.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Library
* General Public License, version 2.
* %End-Header%
*/
#ifndef _LARGEFILE_SOURCE
#define _LARGEFILE_SOURCE
#endif
#ifndef _LARGEFILE64_SOURCE
#define _LARGEFILE64_SOURCE
#endif
#include "config.h"
#include <stdio.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_ERRNO_H
#include <errno.h>
#endif
#include <fcntl.h>
#ifdef HAVE_LINUX_FD_H
#include <sys/ioctl.h>
#include <linux/fd.h>
#endif
#if defined(__linux__) && defined(_IO)
#if !defined(BLKSSZGET)
#define BLKSSZGET _IO(0x12,104)/* get block device sector size */
#endif
#if !defined(BLKPBSZGET)
#define BLKPBSZGET _IO(0x12,123)/* get block physical sector size */
#endif
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
/*
* Returns the logical sector size of a device
*/
errcode_t ext2fs_get_device_sectsize(const char *file, int *sectsize)
{
int fd;
fd = ext2fs_open_file(file, O_RDONLY, 0);
if (fd < 0)
return errno;
#ifdef BLKSSZGET
if (ioctl(fd, BLKSSZGET, sectsize) >= 0) {
close(fd);
return 0;
}
#endif
*sectsize = 0;
close(fd);
return 0;
}
/*
* Return desired alignment for direct I/O
*/
int ext2fs_get_dio_alignment(int fd)
{
int align = 0;
#ifdef BLKSSZGET
if (ioctl(fd, BLKSSZGET, &align) < 0)
align = 0;
#endif
#ifdef _SC_PAGESIZE
if (align <= 0)
align = sysconf(_SC_PAGESIZE);
#endif
#ifdef HAVE_GETPAGESIZE
if (align <= 0)
align = getpagesize();
#endif
if (align <= 0)
align = 4096;
return align;
}
/*
* Returns the physical sector size of a device
*/
errcode_t ext2fs_get_device_phys_sectsize(const char *file, int *sectsize)
{
int fd;
fd = ext2fs_open_file(file, O_RDONLY, 0);
if (fd < 0)
return errno;
#ifdef BLKPBSZGET
if (ioctl(fd, BLKPBSZGET, sectsize) >= 0) {
close(fd);
return 0;
}
#endif
*sectsize = 0;
close(fd);
return 0;
}