/* EXT4 delalloc reservation leakage testcase
 * To make that leackage more verbose please apply following patch
 * http://download.openvz.org/~dmonakhov/junk/ext4-sanity-check.patch
 */
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>

int main(int argc, char **argv)
{
	loff_t len, offset;
	int fd, ret;
	char buf[81920];
	if (argc != 2) {
		printf("Usage: %s <fname>\n", argv[0]);
		return 1;
	}
	fd = open(argv[1], O_CREAT|O_RDWR, 0777);
	ftruncate(fd, 40960);
	fsync(fd);
	ret = pwrite(fd, buf, 4096, 0);
	if (ret != 4096) {
		perror("write failed");
		return 1;
	}
	/* Leve one page gap between dirty pages */
	ret = pwrite(fd, buf, 8192, 8192);
	if (ret != 8192) {
		perror("write failed");
		return 1;
	}
	/* Create uninitialized extent */
	ret = fallocate(fd, 0x1, 0, 4096*5);
	if (ret) {
		perror("fallocate failed");
		return 1;
	}
	/* Force block allocation.
	 * Uninitialized extent will be converted to initialized one
	 * during ext4_map_blocks() on writing first pages set.
	 * Later second pages set will discover what blocks are already
	 * initialized, so reservation for that pages will leak.
	 */
	fsync(fd);
	return 0;
}