/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #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){	errno = Eio;	if(nret < 0){		chat("%s errstr=\"%r\"...", name);		close(xf->dev);		xf->dev = -1;		return -1;	}	fprint(2, "dev %d sector %ld, %s: %ld, should be %ld\n", xf->dev, addr, name, nret, n);	return -1;} intdevread(Xfs *xf, long addr, void *buf, long n){	long nread; 	if(xf->dev < 0)		return -1;	nread = pread(xf->dev, buf, n, xf->offset+(vlong)addr*Sectorsize);	if (nread == n)		return 0;	return deverror("read", xf, addr, n, nread);} intdevwrite(Xfs *xf, long addr, void *buf, long n){	long nwrite; 	if(xf->omode==OREAD)		return -1; 	if(xf->dev < 0)		return -1;	nwrite = pwrite(xf->dev, buf, n, xf->offset+(vlong)addr*Sectorsize);	if (nwrite == n)		return 0;	return deverror("write", xf, addr, n, nwrite);} intdevcheck(Xfs *xf){	char buf[Sectorsize]; 	if(xf->dev < 0)		return -1;	if(pread(xf->dev, buf, Sectorsize, 0) != Sectorsize){		close(xf->dev);		xf->dev = -1;		return -1;	}	return 0;}