/*
* NAME: node->new()
* DESCRIPTION: allocate a new b*-tree node
*/
int n_new(node *np)
{
btree *bt = np->bt;
unsigned long num;
if (bt->hdr.bthFree == 0)
ERROR(EIO, "b*-tree full");
num = 0;
while (num < bt->hdr.bthNNodes && BMTST(bt->map, num))
++num;
if (num == bt->hdr.bthNNodes)
ERROR(EIO, "free b*-tree node not found");
np->nnum = num;
BMSET(bt->map, num);
--bt->hdr.bthFree;
bt->flags |= HFS_BT_UPDATE_HDR;
return 0;
fail:
return -1;
}
/*
* NAME: vol->allocblocks()
* DESCRIPTION: allocate a contiguous range of blocks
*/
int v_allocblocks(hfsvol *vol, ExtDescriptor *blocks)
{
unsigned int request, found, foundat, start, end;
register unsigned int pt;
const block *vbm;
int wrap = 0;
if (vol->mdb.drFreeBks == 0)
ERROR(ENOSPC, "volume full");
request = blocks->xdrNumABlks;
found = 0;
foundat = 0;
start = vol->mdb.drAllocPtr;
end = vol->mdb.drNmAlBlks;
vbm = vol->vbm;
# ifdef DEBUG
if (request == 0)
abort();
# endif
/* backtrack the start pointer to recover unused space */
if (! BMTST(vbm, start))
{
while (start > 0 && ! BMTST(vbm, start - 1))
--start;
}
/* find largest unused block which satisfies request */
pt = start;
while (1)
{
unsigned int mark;
/* skip blocks in use */
while (pt < end && BMTST(vbm, pt))
++pt;
if (wrap && pt >= start)
break;
/* count blocks not in use */
mark = pt;
while (pt < end && pt - mark < request && ! BMTST(vbm, pt))
++pt;
if (pt - mark > found)
{
found = pt - mark;
foundat = mark;
}
if (wrap && pt >= start)
break;
if (pt == end)
pt = 0, wrap = 1;
if (found == request)
break;
}
if (found == 0 || found > vol->mdb.drFreeBks)
ERROR(EIO, "bad volume bitmap or free block count");
blocks->xdrStABN = foundat;
blocks->xdrNumABlks = found;
vol->mdb.drAllocPtr = pt;
vol->mdb.drFreeBks -= found;
for (pt = foundat; pt < foundat + found; ++pt)
BMSET(vbm, pt);
vol->flags |= HFS_VOL_UPDATE_MDB | HFS_VOL_UPDATE_VBM;
return 0;
fail:
return -1;
}
/*
* NAME: vol->scavenge()
* DESCRIPTION: safeguard blocks in the volume bitmap
*/
int v_scavenge(hfsvol *vol)
{
const block *vbm = vol->vbm;
node n;
unsigned int pt, blks;
if (vbm == 0)
goto done;
markexts(vbm, &vol->mdb.drXTExtRec);
markexts(vbm, &vol->mdb.drCTExtRec);
vol->flags |= HFS_VOL_UPDATE_VBM;
/* scavenge the extents overflow file */
n.bt = &vol->ext;
n.nnum = vol->ext.hdr.bthFNode;
if (n.nnum > 0)
{
if (bt_getnode(&n) == -1)
goto fail;
n.rnum = 0;
while (1)
{
ExtDataRec data;
const byte *ptr;
while (n.rnum >= n.nd.ndNRecs)
{
n.nnum = n.nd.ndFLink;
if (n.nnum == 0)
break;
if (bt_getnode(&n) == -1)
goto fail;
n.rnum = 0;
}
if (n.nnum == 0)
break;
ptr = HFS_NODEREC(n, n.rnum);
r_unpackextdata(HFS_RECDATA(ptr), &data);
markexts(vbm, &data);
++n.rnum;
}
}
/* scavenge the catalog file */
n.bt = &vol->cat;
n.nnum = vol->cat.hdr.bthFNode;
if (n.nnum > 0)
{
if (bt_getnode(&n) == -1)
goto fail;
n.rnum = 0;
while (1)
{
CatDataRec data;
const byte *ptr;
while (n.rnum >= n.nd.ndNRecs)
{
n.nnum = n.nd.ndFLink;
if (n.nnum == 0)
break;
if (bt_getnode(&n) == -1)
goto fail;
n.rnum = 0;
}
if (n.nnum == 0)
break;
ptr = HFS_NODEREC(n, n.rnum);
r_unpackcatdata(HFS_RECDATA(ptr), &data);
if (data.cdrType == cdrFilRec)
{
markexts(vbm, &data.u.fil.filExtRec);
markexts(vbm, &data.u.fil.filRExtRec);
}
++n.rnum;
}
}
for (blks = 0, pt = vol->mdb.drNmAlBlks; pt--; )
{
if (! BMTST(vbm, pt))
++blks;
}
if (vol->mdb.drFreeBks != blks)
{
vol->mdb.drFreeBks = blks;
vol->flags |= HFS_VOL_UPDATE_MDB;
}
done:
return 0;
fail:
return -1;
}
/*
* NAME: vol->allocblocks()
* DESCRIPTION: allocate a contiguous range of blocks
*/
int v_allocblocks(hfsvol *vol, ExtDescriptor *blocks)
{
unsigned int request, found, foundat, start, end, pt;
block *vbm;
int wrap = 0;
if (vol->mdb.drFreeBks == 0)
{
ERROR(ENOSPC, "volume full");
return -1;
}
request = blocks->xdrNumABlks;
found = 0;
foundat = 0;
start = vol->mdb.drAllocPtr;
end = vol->mdb.drNmAlBlks;
pt = start;
vbm = vol->vbm;
if (request == 0)
abort();
while (1)
{
unsigned int mark;
/* skip blocks in use */
while (pt < end && BMTST(vbm, pt))
++pt;
if (wrap && pt >= start)
break;
/* count blocks not in use */
mark = pt;
while (pt < end && pt - mark < request && ! BMTST(vbm, pt))
++pt;
if (pt - mark > found)
{
found = pt - mark;
foundat = mark;
}
if (pt == end)
pt = 0, wrap = 1;
if (found == request)
break;
}
if (found == 0 || found > vol->mdb.drFreeBks)
{
ERROR(EIO, "bad volume bitmap or free block count");
return -1;
}
blocks->xdrStABN = foundat;
blocks->xdrNumABlks = found;
vol->mdb.drAllocPtr = pt;
vol->mdb.drFreeBks -= found;
for (pt = foundat; pt < foundat + found; ++pt)
BMSET(vbm, pt);
vol->flags |= HFS_UPDATE_MDB | HFS_UPDATE_VBM;
return 0;
}
