#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <stdint.h>
#include <inttypes.h>
#include <string.h>

#include "fiemap.h"

#define FS_IOC_FIEMAP	_IOWR('f', 11, struct fiemap)

static unsigned int num_extents	= 1024;
static unsigned int estimate_extents = 1;

static unsigned long long map_start = 0ULL;
static unsigned long long map_len = FIEMAP_MAX_OFFSET;
static char *fname;
static unsigned int blocksize = 4096;

static void usage(void)
{
	printf("Usage: fiemap filename\n");
	exit(1);
}

static void print_extent(struct fiemap_extent *extent)
{
	__u64 val;

	printf("Logical: ###[%8"PRIu64"]\t", extent->fe_logical);
	printf("Ext length: ###[%8"PRIu64"]\t", extent->fe_length);
	printf("Physical: ###[%8"PRIu64"]\t", extent->fe_physical);
	printf("flags: %u\t", extent->fe_flags);

	if (extent->fe_flags & FIEMAP_EXTENT_SHARED)
		printf("Yeah, found an shared extent\n");
	if (extent->fe_flags & FIEMAP_EXTENT_UNWRITTEN)
		printf("Yeah, you are hole?\n");

	printf("\n");
}

static void show_results(struct fiemap *fiemap)
{
	int i;

	printf("Extents returned: %u\n", fiemap->fm_mapped_extents);
	if (fiemap->fm_extent_count == 0 || fiemap->fm_mapped_extents == 0)
		return;

	for (i = 0; i < fiemap->fm_mapped_extents; i++)
		print_extent(&fiemap->fm_extents[i]);

}

static int
figure_extents(int fd, unsigned int *num)
{
	int ret;
	struct fiemap fiemap = { 0, };

	fiemap.fm_start = map_start;
	fiemap.fm_length = map_len;
	fiemap.fm_flags = 0;

	ret = ioctl(fd, FS_IOC_FIEMAP, &fiemap);
	if (ret == -1) {
		fprintf(stderr, "fiemap get count error %d: \"%s\"\n", errno,
			strerror(errno));
		return -1;
	}

	*num = fiemap.fm_mapped_extents;

	return 0;
}

int
main(int argc, char **argv)
{
	int ret, fd;
	struct fiemap *fiemap;

	fd = open(argv[1], O_RDONLY);
	if (fd == -1) {
		fprintf(stderr, "open error %d: \"%s\"\n", errno,
			strerror(errno));
		return -1;
	}

	if (figure_extents(fd, &num_extents))
		return -1;

	printf("Extents in file \"%s\":    %u\n", argv[1], num_extents);

	fiemap = malloc(sizeof(fiemap) +
			num_extents * sizeof(struct fiemap_extent));
	if (fiemap == NULL) {
		fprintf(stderr, "malloc error %d: \"%s\"\n", errno,
			strerror(errno));
		return -1;
	}

	fiemap->fm_start = map_start;
	fiemap->fm_length = map_len;
	fiemap->fm_extent_count = num_extents;

	ret = ioctl(fd, FS_IOC_FIEMAP, fiemap);
	if (ret == -1) {
		if (errno == EBADR) {
			fprintf(stderr, "Kernel does not support the flags: 0x%x\n",
				fiemap->fm_flags);
			return -1;
		}
		fprintf(stderr, "fiemap error %d: \"%s\"\n", errno,
			strerror(errno));
		return -1;
	}

	show_results(fiemap);

	close(fd);

	return 0;
}