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#include <sys/types.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include "blkdev.h"
#include "linux_version.h"
static long
blkdev_valid_offset (int fd, off_t offset) {
char ch;
if (lseek (fd, offset, 0) < 0)
return 0;
if (read (fd, &ch, 1) < 1)
return 0;
return 1;
}
off_t
blkdev_find_size (int fd) {
off_t high, low;
low = 0;
for (high = 1; high > 0 && blkdev_valid_offset (fd, high); high *= 2)
low = high;
while (low < high - 1)
{
const off_t mid = (low + high) / 2;
if (blkdev_valid_offset (fd, mid))
low = mid;
else
high = mid;
}
blkdev_valid_offset (fd, 0);
return (low + 1);
}
/* get size in bytes */
int
blkdev_get_size(int fd, unsigned long long *bytes)
{
/* TODO: use stat as well */
#ifdef BLKGETSIZE64
#ifdef __linux__
int ver = get_linux_version();
/* kernels 2.4.15-2.4.17, had a broken BLKGETSIZE64 */
if (ver >= KERNEL_VERSION (2,6,0) ||
(ver >= KERNEL_VERSION (2,4,18) && ver < KERNEL_VERSION (2,5,0)))
#endif
if (ioctl(fd, BLKGETSIZE64, bytes) >= 0)
return 0;
#endif /* BLKGETSIZE64 */
#ifdef BLKGETSIZE
{
unsigned long size;
if (ioctl(fd, BLKGETSIZE, &size) >= 0) {
*bytes = ((unsigned long long)size << 9);
return 0;
}
}
return -1;
#endif /* BLKGETSIZE */
*bytes = blkdev_find_size(fd);
return 0;
}
/* get 512-byte sector count */
int
blkdev_get_sectors(int fd, unsigned long long *sectors)
{
unsigned long long bytes;
if (blkdev_get_size(fd, &bytes) == 0) {
*sectors = (bytes >> 9);
return 0;
}
return -1;
}
/* get logical sector size (default is 512)
*
* This is the smallest unit the storage device can
* address. It is typically 512 bytes.
*/
int
blkdev_get_sector_size(int fd, int *sector_size)
{
#ifdef BLKSSZGET
#ifdef __linux__
if (get_linux_version() < KERNEL_VERSION(2,3,3)) {
*sector_size = DEFAULT_SECTOR_SIZE;
return 0;
}
#endif
if (ioctl(fd, BLKSSZGET, sector_size) >= 0)
return 0;
return -1;
#else
*sector_size = DEFAULT_SECTOR_SIZE;
return 0;
#endif
}
#ifdef TEST_PROGRAM
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <err.h>
int
main(int argc, char **argv)
{
unsigned long long bytes;
unsigned long long sectors;
int sector_size;
int fd;
if (argc != 2) {
fprintf(stderr, "usage: %s device\n", argv[0]);
exit(EXIT_FAILURE);
}
if ((fd = open(argv[1], O_RDONLY)) < 0)
err(EXIT_FAILURE, "open %s failed", argv[1]);
if (blkdev_get_size(fd, &bytes) < 0)
err(EXIT_FAILURE, "blkdev_get_size() failed");
if (blkdev_get_sectors(fd, §ors) < 0)
err(EXIT_FAILURE, "blkdev_get_sectors() failed");
if (blkdev_get_sector_size(fd, §or_size) < 0)
err(EXIT_FAILURE, "blkdev_get_sector_size() failed");
printf("bytes %llu\n", bytes);
printf("sectors %llu\n", sectors);
printf("sectorsize %d\n", sector_size);
return EXIT_SUCCESS;
}
#endif /* TEST_PROGRAM */
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