int
fwormwrite(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);
}
int
fwormread(Device *d, Off b, void *c)
{
Iobuf *p;
Device *fdev;
Devsize l;
if(chatty > 1)
fprint(2, "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);
fprint(2, "fworm: read %lld\n", (Wideoff)b);
return 1;
}
putbuf(p);
return devread(fdev, b, c);
}
void
fwormream(Device *d)
{
Iobuf *p;
Device *fdev;
Off a, b;
if(chatty)
print("fworm ream\n");
devinit(d);
fdev = FDEV(d);
a = fwormsize(d);
b = devsize(fdev);
if(chatty){
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);
}
}
Devsize
fwormsize(Device *d)
{
Devsize l;
l = devsize(FDEV(d));
l -= l/(BUFSIZE*8) + 1;
return l;
}
void
fworminit(Device *d)
{
print("fworm init\n");
devinit(FDEV(d));
}
