#include <u.h>#include <libc.h> char	*block;char	*zb;int	bs;int	fd; intisure(void){	char ebuf[ERRMAX]; 	rerrstr(ebuf, sizeof ebuf);	return strstr(ebuf, "i/o error") != nil;} voidchkblk(uvlong lba){	int r; 	r = pread(fd, block, bs, lba*bs);	if(r == -1){		if(!isure())			sysfatal("pread: %ulld %r", lba);		r = pwrite(fd, zb, bs, lba*bs);		if(r == -1)			sysfatal("uncorrectable: %ulld %r", lba);		fprint(2, "%ulld\n", lba);		/* fruitless to reread here.  can't fua */	}} voidusage(void){	fprint(2, "usage: scrubure file\n");	exits("usage");} voidmain(int argc, char **argv){	uvlong max, i;	Dir *d; 	bs = 512; 	ARGBEGIN{	default:		usage();	}ARGEND	if(argc != 1)		usage(); 	fd = open(*argv, ORDWR);	if(fd == -1)		sysfatal("open: %r");	d = dirfstat(fd);	if(d == nil)		sysfatal("dirfstat: %r");	max = d->length;	free(d); 	if(max % bs)		fprint(2, "warning: size not multiple of bs %ulld", max % bs);	max /= bs;	block = malloc(bs);	zb = malloc(bs); 	if(block == nil || zb == nil)		sysfatal("malloc: %r");	memset(zb, 0, bs); 	for(i = 0; i < max; i++)		chkblk(i);	close(fd);	exits("");}