/*  * 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 "all.h" #define	FDEV(d)		((d)->fw.fw) enum { DEBUG = 0 }; Devsizefwormsize(Device *d){	Devsize l; 	l = devsize(FDEV(d));	l -= l/(BUFSIZE*8) + 1;	return l;} voidfwormream(Device *d){	Iobuf *p;	Device *fdev;	Off a, b; 	print("fworm ream\n");	devinit(d);	fdev = FDEV(d);	a = fwormsize(d);	b = devsize(fdev);	print("\tfwsize = %lld\n", (Wideoff)a);	print("\tbwsize = %lld\n", (Wideoff)b-a);	for(; a < b; a++) {		p = getbuf(fdev, a, Bmod|Bres);		if(!p)			panic("fworm: init");		memset(p->iobuf, 0, RBUFSIZE);		settag(p, Tvirgo, a);		putbuf(p);	}} voidfworminit(Device *d){	print("fworm init\n");	devinit(FDEV(d));} intfwormread(Device *d, Off b, void *c){	Iobuf *p;	Device *fdev;	Devsize l; 	if(DEBUG)		print("fworm read  %lld\n", (Wideoff)b);	fdev = FDEV(d);	l = devsize(fdev);	l -= l/(BUFSIZE*8) + 1;	if(b >= l)		panic("fworm: rbounds %lld", (Wideoff)b);	l += b/(BUFSIZE*8); 	p = getbuf(fdev, l, Brd|Bres);	if(!p || checktag(p, Tvirgo, l))		panic("fworm: checktag %lld", (Wideoff)l);	l = b % (BUFSIZE*8);	if(!(p->iobuf[l/8] & (1<<(l%8)))) {		putbuf(p);		print("fworm: read %lld\n", (Wideoff)b);		return 1;	}	putbuf(p);	return devread(fdev, b, c);} intfwormwrite(Device *d, Off b, void *c){	Iobuf *p;	Device *fdev;	Devsize l; 	if(DEBUG)		print("fworm write %lld\n", (Wideoff)b);	fdev = FDEV(d);	l = devsize(fdev);	l -= l/(BUFSIZE*8) + 1;	if(b >= l)		panic("fworm: wbounds %lld", (Wideoff)b);	l += b/(BUFSIZE*8); 	p = getbuf(fdev, l, Brd|Bmod|Bres);	if(!p || checktag(p, Tvirgo, l))		panic("fworm: checktag %lld", (Wideoff)l);	l = b % (BUFSIZE*8);	if((p->iobuf[l/8] & (1<<(l%8)))) {		putbuf(p);		print("fworm: write %lld\n", (Wideoff)b);		return 1;	}	p->iobuf[l/8] |= 1<<(l%8);	putbuf(p);	return devwrite(fdev, b, c);}