// _VerifyHashFunction
bool
Volume::_VerifyHashFunction(hash_function_t function)
{
bool result = true;
// iterate over the entries in the root dir until we find an entry, that
// doesn't falsify the hash function
DirEntryIterator iterator(fTree, fRootVNode->GetDirID(),
fRootVNode->GetObjectID(), DOT_DOT_OFFSET + 1);
DirItem item;
int32 index = 0;
while (iterator.GetNext(&item, &index) == B_OK) {
DirEntry *entry = item.EntryAt(index);
uint64 offset = entry->GetOffset();
// try the hash function
size_t nameLen = 0;
if (const char *name = item.EntryNameAt(index, &nameLen)) {
uint64 testOffset = key_offset_for_name(function, name, nameLen);
if (offset_hash_value(offset) != offset_hash_value(testOffset)) {
result = false;
break;
}
} // else: bad data
}
return result;
}
// FindDirEntry
status_t
Tree::FindDirEntry(uint32 dirID, uint32 objectID, const char *name,
size_t nameLen, DirItem *foundItem, int32 *entryIndex)
{
status_t error = (name && foundItem && entryIndex ? InitCheck()
: B_BAD_VALUE);
if (error == B_OK) {
uint64 offset = 0;
if (fVolume->GetKeyOffsetForName(name, nameLen, &offset) == B_OK) {
//PRINT(("Tree::FindDirEntry(): hash function: offset: %Lu (`%.*s', %lu)\n",
//offset, (int)nameLen, name, nameLen));
// offset computed -- we can directly iterate only over entries
// with that offset
DirEntryIterator iterator(this, dirID, objectID, offset, true);
DirItem dirItem;
int32 index = 0;
error = B_ENTRY_NOT_FOUND;
while (iterator.GetPrevious(&dirItem, &index) == B_OK) {
size_t itemNameLen = 0;
if (const char *itemName
= dirItem.EntryNameAt(index, &itemNameLen)) {
if (itemNameLen == nameLen
&& !strncmp(name, itemName, nameLen)) {
// item found
*foundItem = dirItem;
*entryIndex = index;
error = B_OK;
break;
}
}
}
} else {
//PRINT(("Tree::FindDirEntry(): no hash function\n"));
// no offset (no hash function) -- do it the slow way
ObjectItemIterator iterator(this, dirID, objectID);
DirItem dirItem;
error = B_ENTRY_NOT_FOUND;
while (iterator.GetNext(&dirItem, TYPE_DIRENTRY) == B_OK) {
if (dirItem.Check() != B_OK) // bad data: skip item
continue;
int32 index = dirItem.IndexOfName(name);
if (index >= 0) {
// item found
*foundItem = dirItem;
*entryIndex = index;
error = B_OK;
//PRINT((" offset: %lu\n", dirItem.EntryAt(index)->GetOffset()));
break;
}
}
}
}
return error;
}
// _DetectHashFunction
uint32
Volume::_DetectHashFunction()
{
// iterate over the entries in the root dir until we find an entry, that
// let us draw an unambiguous conclusion
DirEntryIterator iterator(fTree, fRootVNode->GetDirID(),
fRootVNode->GetObjectID(), DOT_DOT_OFFSET + 1);
uint32 foundCode = UNSET_HASH;
DirItem item;
int32 index = 0;
while (foundCode == UNSET_HASH
&& iterator.GetNext(&item, &index) == B_OK) {
DirEntry *entry = item.EntryAt(index);
uint64 offset = entry->GetOffset();
uint32 hashCodes[] = { TEA_HASH, YURA_HASH, R5_HASH };
int32 hashCodeCount = sizeof(hashCodes) / sizeof(uint32);
size_t nameLen = 0;
const char *name = item.EntryNameAt(index, &nameLen);
if (!name) // bad data!
continue;
// try each hash function -- if there's a single winner, we're done,
// otherwise the next entry must help
for (int32 i = 0; i < hashCodeCount; i++) {
hash_function_t function = hash_function_for_code(hashCodes[i]);
uint64 testOffset = key_offset_for_name(function, name, nameLen);
if (offset_hash_value(offset) == offset_hash_value(testOffset)) {
if (foundCode != UNSET_HASH) {
// ambiguous
foundCode = UNSET_HASH;
break;
} else
foundCode = hashCodes[i];
}
}
}
return foundCode;
}
// reiserfs_read_dir
static status_t
reiserfs_read_dir(fs_volume *fs, fs_vnode *_node, void *cookie,
struct dirent *buffer, size_t bufferSize, uint32 *count)
{
// FUNCTION_START();
Volume *volume = (Volume*)fs->private_volume;
VNode *node = (VNode*)_node->private_node;
FUNCTION(("node: (%Ld: %lu, %lu)\n", node->GetID(), node->GetDirID(),
node->GetObjectID()));
DirectoryCookie *iterator = (DirectoryCookie*)cookie;
status_t error = iterator->Resume();
if (error == B_OK) {
// read one entry
DirItem item;
int32 index = 0;
DirEntry *entry = NULL;
bool done = false;
while (error == B_OK && !done
&& (error = iterator->GetNext(&item, &index, &entry)) == B_OK) {
uint32 dirID = entry->GetDirID();
uint32 objectID = entry->GetObjectID();
// skip hidden entries and entries the user specified to be hidden
if (entry->IsHidden() || volume->IsNegativeEntry(dirID, objectID))
continue;
// skip entry, if we can't get the stat data, or it is neither a
// file, a dir nor a symlink and the user desired to hide those.
StatData statData;
StatItem statItem;
if (volume->GetTree()->FindStatItem(dirID, objectID, &statItem)
!= B_OK
|| statItem.GetStatData(&statData) != B_OK
|| (statData.IsEsoteric() && volume->GetHideEsoteric())) {
continue;
}
if (error == B_OK) {
// get the name
size_t nameLen = 0;
const char *name = item.EntryNameAt(index, &nameLen);
if (!name || nameLen == 0) // bad data: skip it gracefully
continue;
// fill in the entry name -- checks whether the
// entry fits into the buffer
error = set_dirent_name(buffer, bufferSize, name,
nameLen);
if (error == B_OK) {
// fill in the other data
buffer->d_dev = volume->GetID();
buffer->d_ino = VNode::GetIDFor(dirID, objectID);
*count = 1;
PRINT(("Successfully read entry: dir: (%Ld: %ld, %ld), name: `%s', "
"id: (%Ld, %ld, %ld), reclen: %hu\n", node->GetID(), node->GetDirID(),
node->GetObjectID(), buffer->d_name, buffer->d_ino, dirID, objectID,
buffer->d_reclen));
if (!strcmp("..", buffer->d_name))
iterator->SetEncounteredDotDot(true);
done = true;
}
}
}
if (error == B_ENTRY_NOT_FOUND) {
if (iterator->EncounteredDotDot()) {
error = B_OK;
*count = 0;
} else {
// this is necessary for the root directory
// it usually has no ".." entry, so we simulate one
// get the name
const char *name = "..";
size_t nameLen = strlen(name);
// fill in the entry name -- checks whether the
// entry fits into the buffer
error = set_dirent_name(buffer, bufferSize, name,
nameLen);
if (error == B_OK) {
// fill in the other data
buffer->d_dev = volume->GetID();
buffer->d_ino = node->GetID();
// < That's not correct!
*count = 1;
PRINT(("faking `..' entry: dir: (%Ld: %ld, %ld), name: `%s', "
"id: (%Ld, %ld, %ld), reclen: %hu\n", node->GetID(), node->GetDirID(),
node->GetObjectID(), buffer->d_name, buffer->d_ino, node->GetDirID(),
node->GetObjectID(), buffer->d_reclen));
iterator->SetEncounteredDotDot(true);
}
}
}
iterator->Suspend();
}
PRINT(("returning %ld entries\n", *count));
RETURN_ERROR(error);
}
