#include <u.h>#include <libc.h>#include "iotrack.h"#include "dat.h"#include "fns.h" int readonly; static intdeverror(char *name, Xfs *xf, long addr, long n, long nret){	char errbuf[ERRLEN]; 	errno = Eio;	if(nret < 0){		errstr(errbuf);		chat("%s errstr=\"%s\"...", name, errbuf);		close(xf->dev);		xf->dev = -1;		/*if(strcmp(errbuf, "disk changed") == 0)*/			return -1;	}	fprint(2, "dev %d sector %ld, %s: %ld, should be %ld\n",		xf->dev, addr, name, nret, n);//	panic(name);	return -1;} intdevread(Xfs *xf, long addr, void *buf, long n){	long nread;/* *	chat("devread %d,%d...", dev, addr); */	if(xf->dev < 0)		return -1;	seek(xf->dev, xf->offset+(vlong)addr*Sectorsize, 0);	nread = read(xf->dev, buf, n);	if (nread == n)		return 0;	return deverror("read", xf, addr, n, nread);} intdevwrite(Xfs *xf, long addr, void *buf, long n){	long nwrite;/* *	chat("devwrite %d,%d...", p->dev, p->addr); */	if(readonly)		return -1; 	if(xf->dev < 0)		return -1;	seek(xf->dev, xf->offset+(vlong)addr*Sectorsize, 0);	nwrite = write(xf->dev, buf, n);	if (nwrite == n)		return 0;	return deverror("write", xf, addr, n, nwrite);} intdevcheck(Xfs *xf){	char buf[Sectorsize]; 	if(xf->dev < 0)		return -1;	seek(xf->dev, 0, 0);	if(read(xf->dev, buf, Sectorsize) != Sectorsize){		close(xf->dev);		xf->dev = -1;		return -1;	}	return 0;}