static int32_t
rel2abs(Fs *fs, Dentry *d, int32_t a)
{
int32_t addr;
if(a < NDBLOCK)
return d->dblock[a];
a -= NDBLOCK;
if(a < fs->kfs.INDPERBUF){
if(d->iblock == 0)
return 0;
addr = indfetch(fs, d->iblock, a, Tind1, d->qid.path);
if(addr == 0)
print("rel2abs indfetch 0 %s %ld\n", d->name, a);
return addr;
}
a -= fs->kfs.INDPERBUF;
if(a < fs->kfs.INDPERBUF2){
if(d->diblock == 0)
return 0;
addr = indfetch(fs, d->diblock, a/fs->kfs.INDPERBUF, Tind2, d->qid.path);
if(addr == 0){
print("rel2abs indfetch 0 %s %ld\n", d->name, a/fs->kfs.INDPERBUF);
return 0;
}
addr = indfetch(fs, addr, a%fs->kfs.INDPERBUF, Tind1, d->qid.path);
return addr;
}
print("rel2abs trip ind %s %ld\n", d->name, a);
return -1;
}
long
rel2abs(Iobuf *p, Dentry *d, long a, int tag, int putb)
{
long addr, qpath;
Device dev;
if(a < 0) {
print("dnodebuf: neg\n");
return 0;
}
qpath = d->qid.path;
dev = p->dev;
if(a < NDBLOCK) {
addr = d->dblock[a];
if(!addr && tag) {
addr = balloc(dev, tag, qpath);
d->dblock[a] = addr;
p->flags |= Bmod|Bimm;
}
if(putb)
putbuf(p);
return addr;
}
a -= NDBLOCK;
if(a < INDPERBUF) {
addr = d->iblock;
if(!addr && tag) {
addr = balloc(dev, Tind1, qpath);
d->iblock = addr;
p->flags |= Bmod|Bimm;
}
if(putb)
putbuf(p);
addr = indfetch(p, d, addr, a, Tind1, tag);
return addr;
}
a -= INDPERBUF;
if(a < INDPERBUF2) {
addr = d->diblock;
if(!addr && tag) {
addr = balloc(dev, Tind2, qpath);
d->diblock = addr;
p->flags |= Bmod|Bimm;
}
if(putb)
putbuf(p);
addr = indfetch(p, d, addr, a/INDPERBUF, Tind2, Tind1);
addr = indfetch(p, d, addr, a%INDPERBUF, Tind1, tag);
return addr;
}
if(putb)
putbuf(p);
print("dnodebuf: trip indirect\n");
return 0;
}
Off
rel2abs(Iobuf *p, Dentry *d, Off a, int tag, int putb, int uid)
{
int i;
Off addr, qpath, indaddrs = 1, div;
Device *dev;
if(a < 0) {
print("rel2abs: neg offset\n");
if(putb)
putbuf(p);
return 0;
}
dev = p->dev;
qpath = d->qid.path;
/* is `a' a direct block? */
if(a < NDBLOCK) {
addr = d->dblock[a];
if(!addr && tag) {
addr = bufalloc(dev, tag, qpath, uid);
d->dblock[a] = addr;
p->flags |= Bmod|Bimm;
}
if(putb)
putbuf(p);
return addr;
}
a -= NDBLOCK;
/*
* loop through indirect block depths.
*/
for (i = 0; i < NIBLOCK; i++) {
indaddrs *= INDPERBUF;
/* is a's disk addr in this indir block or one of its kids? */
if (a < indaddrs) {
addr = d->iblocks[i];
if(!addr && tag) {
addr = bufalloc(dev, Tind1+i, qpath, uid);
d->iblocks[i] = addr;
p->flags |= Bmod|Bimm;
}
if(putb)
putbuf(p);
div = indaddrs;
for (; i >= 0; i--) {
div /= INDPERBUF;
if (div <= 0)
panic("rel2abs: non-positive divisor");
addr = indfetch(dev, qpath, addr,
(a/div)%INDPERBUF, Tind1+i,
(i == 0? tag: Tind1+i-1), uid);
}
return addr;
}
a -= indaddrs;
}
if(putb)
putbuf(p);
/* quintuple-indirect blocks not implemented. */
print("rel2abs: no %d-deep indirect\n", NIBLOCK+1);
return 0;
}
