#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <sys/ioctl.h>#include <sys/fcntl.h>#include <sys/stat.h>#include <sys/types.h>#include <linux/fs.h>extern void *xmalloc (size_t size);extern void *xrealloc (void *ptr, size_t size);extern char *boot_dev;extern int verbose;static dev_t boot_dev_nr = -1;dev_t get_dev (const char *path){	struct stat statbuf;	if (stat (path, &statbuf) < 0)	{		perror ("stat");		return -1;	}	if (S_ISBLK(statbuf.st_mode))		return statbuf.st_rdev;	else		return statbuf.st_dev;}dev_t get_boot_dev (void){	if (boot_dev_nr == (dev_t)-1)		boot_dev_nr = get_dev (boot_dev);	return boot_dev_nr;}/* * get the block map for a file, checking that it is on the root partition */int map_file(const char *path, unsigned long **bmap){	int fild;	struct stat statbuf;	unsigned long *buffer, blksize, fblocks;	unsigned int blw, curblkindex, blk;	if (get_boot_dev() == (dev_t)-1)		return -1;	if (boot_dev_nr != get_dev (path)) {		fprintf(stderr, "Kernel '%s' is not on the boot device '%s' "			"- ignored\n", path, boot_dev);		return -1;	}	fild = open(path, O_RDONLY, 0);	if (fild < 0) {		perror("open");		return -1;	}	if (ioctl(fild, FIGETBSZ, &blksize) < 0) {		perror("ioctl FIGETBSZ");		close(fild);		return -1;	}	if (fstat(fild, &statbuf) < 0) {		perror("fstat");		close(fild);		return -1;	}	fblocks = (statbuf.st_size + blksize - 1) / blksize;	if (verbose)		printf("map_file(%s, %ld blocks): ", path, fblocks);	curblkindex = 0;	blw = 64;	blk = 0;	buffer = xmalloc (blw * 4);	buffer[0] = 0xC53A4B2D;	buffer[1] = blksize;	for (blk = 0; blk < fblocks; blk++) {		volatile unsigned long fibmap_blk;		fibmap_blk = blk;		if (ioctl(fild, FIBMAP, &fibmap_blk) < 0) {			perror("ioctl FIBMAP");			close(fild);			return -1;		}		if (verbose)			printf("[%05lX] ", fibmap_blk);		if (fibmap_blk == 0) {			fprintf(stderr, "Unable to map file '%s' (has holes).\n", path);			close(fild);			return -1;		}		if (curblkindex >= 2 && buffer[curblkindex] + buffer[curblkindex + 1] == fibmap_blk)			buffer[curblkindex + 1] += 1;		else {			curblkindex += 2;			if (curblkindex >= blw)				buffer = xrealloc (buffer, (blw *= 2) * 4);			buffer[curblkindex] = fibmap_blk;			buffer[curblkindex + 1] = 1;		}	}	curblkindex += 2;	buffer[curblkindex] = 0;	buffer[curblkindex+1] = 0;	curblkindex += 2;	if (verbose)		printf("\n");	if (buffer[0] != 0)		*bmap = buffer;	return curblkindex * sizeof (unsigned long);}