/*! shrink directory to the size needed
errors here are neither likely nor problematic
w95 doesn't seem to do this, so it's possible to create a
really large directory that consumes all available space!
*/
status_t
compact_directory(nspace *vol, vnode *dir)
{
uint32 last = 0;
struct diri diri;
status_t error = B_ERROR; /* quiet warning */
DPRINTF(0, ("compacting directory with vnode id %Lx\n", dir->vnid));
// root directory can't shrink in fat12 and fat16
if (IS_FIXED_ROOT(dir->cluster))
return 0;
if (diri_init(vol, dir->cluster, 0, &diri) == NULL) {
dprintf("compact_directory: cannot open dir at cluster (%lx)\n",
dir->cluster);
return EIO;
}
while (diri.current_block) {
char filename[512];
struct _dirent_info_ info;
error = _next_dirent_(&diri, &info, filename, 512);
if (error == B_OK) {
// don't compact away volume labels in the root dir
if (!(info.mode & FAT_VOLUME) || (dir->vnid != vol->root_vnode.vnid))
last = diri.current_index;
} else if (error == ENOENT) {
uint32 clusters = (last + vol->bytes_per_sector / 0x20
* vol->sectors_per_cluster - 1) / (vol->bytes_per_sector / 0x20)
/ vol->sectors_per_cluster;
error = 0;
// special case for fat32 root directory; we don't want
// it to disappear
if (clusters == 0)
clusters = 1;
if (clusters * vol->bytes_per_sector * vol->sectors_per_cluster < dir->st_size) {
DPRINTF(0, ("shrinking directory to %lx clusters\n", clusters));
error = set_fat_chain_length(vol, dir, clusters);
dir->st_size = clusters*vol->bytes_per_sector*vol->sectors_per_cluster;
dir->iteration++;
}
break;
} else {
dprintf("compact_directory: unknown error from _next_dirent_ (%s)\n",
strerror(error));
break;
}
}
diri_free(&diri);
return error;
}
static off_t _csi_to_block_(struct csi *csi)
{
// presumes the caller has already called _validate_cs_ on the argument
ASSERT(_validate_cs_(csi->vol, csi->cluster, csi->sector) == 0);
if (_validate_cs_(csi->vol, csi->cluster, csi->sector) != 0)
return EINVAL;
if (IS_FIXED_ROOT(csi->cluster))
return csi->vol->root_start + csi->sector;
return csi->vol->data_start +
(off_t)(csi->cluster - 2)* csi->vol->sectors_per_cluster +
csi->sector;
}
static int _validate_cs_(nspace *vol, uint32 cluster, uint32 sector)
{
if (sector < 0) return -1;
if ((vol->fat_bits != 32) && IS_FIXED_ROOT(cluster)) { // fat12 or fat16 root
if (sector >= vol->root_sectors)
return -1;
return 0;
}
if (sector >= vol->sectors_per_cluster) return -1;
if (!IS_DATA_CLUSTER(cluster)) return -1;
return 0;
}
int iter_csi(struct csi *csi, int sectors)
{
if (csi->sector == 0xffff) // check if already at end of chain
return -1;
if (sectors < 0)
return EINVAL;
if (sectors == 0)
return 0;
if (IS_FIXED_ROOT(csi->cluster)) {
csi->sector += sectors;
if (csi->sector < csi->vol->root_sectors)
return 0;
} else {
csi->sector += sectors;
if (csi->sector < csi->vol->sectors_per_cluster)
return 0;
csi->cluster = get_nth_fat_entry(csi->vol, csi->cluster, csi->sector / csi->vol->sectors_per_cluster);
if ((int32)csi->cluster < 0) {
csi->sector = 0xffff;
return csi->cluster;
}
if (vIS_DATA_CLUSTER(csi->vol,csi->cluster)) {
csi->sector %= csi->vol->sectors_per_cluster;
return 0;
}
}
csi->sector = 0xffff;
return -1;
}