status_t
DirEntryTree::FreeTree(Transaction& transaction)
{
status_t error = _InitReadOnly();
if (error != B_OK)
RETURN_ERROR(error);
int32 depth = _Depth();
if (depth == 0)
return B_OK;
LevelInfo* infos = new(std::nothrow) LevelInfo[
kCheckSumFSMaxDirEntryTreeDepth + 1];
if (infos == NULL)
RETURN_ERROR(B_NO_MEMORY);
ArrayDeleter<LevelInfo> infosDeleter(infos);
infos[0].entryBlock.SetTo(fRootEntryBlock, fRootEntryBlockSize);
infos[0].index = 0;
// Iterate through the tree in post order. We don't touch the content of
// any block, we only free the blocks.
int32 level = 0;
while (true) {
LevelInfo& info = infos[level];
if (level == depth || info.index >= info.entryBlock.EntryCount()) {
// we're through with the block
if (level == 0)
break;
// free it
error = fDirectory->GetVolume()->GetBlockAllocator()->Free(
info.block.Index(), 1, transaction);
// continue with the next sibling branch
infos[--level].index++;
}
// descend to next level
uint64 nextBlockIndex = info.entryBlock.BlockIndexAt(info.index);
LevelInfo& nextInfo = infos[++level];
if (!nextInfo.block.GetReadable(fDirectory->GetVolume(),
nextBlockIndex)) {
RETURN_ERROR(B_ERROR);
}
nextInfo.entryBlock.SetTo(
(checksumfs_dir_entry_block*)nextInfo.block.Data(),
B_PAGE_SIZE);
}
return B_OK;
}
status_t
DirEntryTree::_InsertEntryIncrementDepth(LevelInfo* infos,
Transaction& transaction)
{
FUNCTION("depth: %u -> %u\n", _Depth(), _Depth() + 1);
if (_Depth() >= kCheckSumFSMaxDirEntryTreeDepth)
RETURN_ERROR(B_DEVICE_FULL);
// allocate a new block
AllocatedBlock allocatedBlock(
fDirectory->GetVolume()->GetBlockAllocator(), transaction);
status_t error = allocatedBlock.Allocate(fDirectory->BlockIndex());
if (error != B_OK)
RETURN_ERROR(error);
fDirectory->SetSize(fDirectory->Size() + B_PAGE_SIZE);
LevelInfo& newInfo = infos[1];
if (!newInfo.block.GetZero(fDirectory->GetVolume(),
allocatedBlock.Index(), transaction)) {
RETURN_ERROR(B_ERROR);
}
allocatedBlock.Detach();
newInfo.entryBlock.SetTo(
(checksumfs_dir_entry_block*)newInfo.block.Data(), B_PAGE_SIZE);
ASSERT(newInfo.entryBlock.Check());
// move the old root block contents to the new block
LevelInfo& rootInfo = infos[0];
rootInfo.entryBlock.SplitBlock(0, newInfo.entryBlock);
// add an entry for the new block to the root block
size_t nameLength;
const char* name = newInfo.entryBlock.NameAt(0, nameLength);
rootInfo.entryBlock.InsertEntry(0, name, nameLength,
newInfo.block.Index());
PRINT(" -> new block: %" B_PRIu64 "\n", newInfo.block.Index());
newInfo.index = rootInfo.index;
rootInfo.index = 0;
fTree->depth++;
return B_OK;
}
status_t
DirEntryTree::_InitWritable(Transaction& transaction)
{
if (!fRootBlock.GetWritable(fDirectory->GetVolume(),
fDirectory->BlockIndex(), transaction)) {
RETURN_ERROR(B_ERROR);
}
return _InitCommon();
}
status_t
DirEntryTree::_InitReadOnly()
{
if (!fRootBlock.GetReadable(fDirectory->GetVolume(),
fDirectory->BlockIndex())) {
RETURN_ERROR(B_ERROR);
}
return _InitCommon();
}
status_t
DirEntryTree::_InsertEntrySplitBlock(int32 level, LevelInfo& info,
size_t needed, Transaction& transaction, Block& newBlock,
int32& _splitIndex)
{
int32 splitIndex = info.entryBlock.FindSplitIndex(info.index,
needed);
FUNCTION("level: %" B_PRId32 ", size needed: %" B_PRIuSIZE ", split index: "
"%" B_PRId32 "/%" B_PRId32 "\n", level, needed, splitIndex,
info.entryBlock.EntryCount());
// allocate a new block
AllocatedBlock allocatedBlock(
fDirectory->GetVolume()->GetBlockAllocator(), transaction);
status_t error = allocatedBlock.Allocate(fDirectory->BlockIndex());
if (error != B_OK)
RETURN_ERROR(error);
fDirectory->SetSize(fDirectory->Size() + B_PAGE_SIZE);
if (!newBlock.GetZero(fDirectory->GetVolume(), allocatedBlock.Index(),
transaction)) {
RETURN_ERROR(B_ERROR);
}
allocatedBlock.Detach();
// split the old block
DirEntryBlock newEntryBlock(
(checksumfs_dir_entry_block*)newBlock.Data(), B_PAGE_SIZE);
ASSERT(newEntryBlock.Check());
info.entryBlock.SplitBlock(splitIndex, newEntryBlock);
PRINT(" -> new block: %" B_PRIu64 "\n", newBlock.Index());
_splitIndex = splitIndex;
return B_OK;
}
status_t ReadNextEntry(struct dirent* buffer, size_t size,
uint32& _countRead)
{
const char* name;
uint64 blockIndex;
int nextIterationState = OTHERS;
switch (iterationState) {
case DOT:
name = ".";
blockIndex = directory->BlockIndex();
nextIterationState = DOT_DOT;
break;
case DOT_DOT:
name = "..";
blockIndex = directory->ParentDirectory();
break;
default:
// TODO: Implement!
_countRead = 0;
return B_OK;
}
size_t entrySize = sizeof(dirent) + strlen(name);
if (entrySize > size)
return B_BUFFER_OVERFLOW;
buffer->d_dev = directory->GetVolume()->ID();
buffer->d_ino = blockIndex;
buffer->d_reclen = entrySize;
strcpy(buffer->d_name, name);
iterationState = nextIterationState;
_countRead = 1;
return B_OK;
}
status_t
DirEntryTree::RemoveEntry(const char* name, Transaction& transaction)
{
FUNCTION("name: \"%s\"\n", name);
status_t error = _InitWritable(transaction);
if (error != B_OK)
RETURN_ERROR(error);
size_t nameLength = strlen(name);
if (nameLength == 0)
RETURN_ERROR(B_BAD_VALUE);
if (nameLength > kCheckSumFSNameLength)
RETURN_ERROR(B_ENTRY_NOT_FOUND);
int32 depth = _Depth();
LevelInfo* infos = new(std::nothrow) LevelInfo[
kCheckSumFSMaxDirEntryTreeDepth + 1];
if (infos == NULL)
RETURN_ERROR(B_NO_MEMORY);
ArrayDeleter<LevelInfo> infosDeleter(infos);
infos[0].entryBlock.SetTo(fRootEntryBlock, fRootEntryBlockSize);
for (int32 level = 0; level <= depth; level++) {
LevelInfo& info = infos[level];
if (info.entryBlock.EntryCount() == 0) {
if (level == 0) {
// directory is empty
PRINT(" directory is empty\n");
RETURN_ERROR(B_ENTRY_NOT_FOUND);
}
RETURN_ERROR(B_BAD_DATA);
}
info.index = info.entryBlock.FindInsertionIndex(name, nameLength,
info.exactMatch);
PRINT(" level %" B_PRId32 ", block %" B_PRIu64 " -> index: %" B_PRId32
" %sexact\n", level,
level == 0 ? fDirectory->BlockIndex() : info.block.Index(),
info.index, info.exactMatch ? "" : " not ");
if (level == depth) {
// final level -- here the entry should be found
if (!info.exactMatch)
RETURN_ERROR(B_ENTRY_NOT_FOUND);
break;
}
// If we haven't found an exact match, the index points to the first
// entry that is greater or after the last entry.
if (!info.exactMatch) {
if (info.index == 0) {
// The first entry is already greater, so the branch doesn't
// contain the entry we're looking for.
RETURN_ERROR(B_ENTRY_NOT_FOUND);
}
info.index--;
}
uint64 nextBlockIndex = info.entryBlock.BlockIndexAt(info.index);
// not the final level -- load the block and descend to the next
// level
LevelInfo& nextInfo = infos[level + 1];
if (!nextInfo.block.GetReadable(fDirectory->GetVolume(),
nextBlockIndex)) {
RETURN_ERROR(B_ERROR);
}
nextInfo.entryBlock.SetTo(
(checksumfs_dir_entry_block*)nextInfo.block.Data(),
B_PAGE_SIZE);
ASSERT(nextInfo.entryBlock.Check());
}
// We've found the entry. Insert the key and iterate backwards to perform
// the potentially necessary updates. Removal at index 0 of the block
// changes the block's key, requiring an update in the parent block.
// Removal of the last entry will require removal of the block from its
// parent. Key update can cause the block to be split (if there's not
// enough space left in it), requiring an insertion in the parent block.
// We start with a pending removal in the leaf block and work our way
// upwards as long as the blocks become empty. As soon as a key update is
// required, we delegate the remaining to the update/insert backwards loop.
for (int32 level = depth; level >= 0; level--) {
LevelInfo& info = infos[level];
// make the block writable
if (level > 0) {
error = info.block.MakeWritable(transaction);
if (error != B_OK)
RETURN_ERROR(error);
}
PRINT(" level: %" B_PRId32 ", index: %" B_PRId32 ": removing key "
"\"%.*s\" (%" B_PRIuSIZE ")\n", level, info.index, (int)nameLength,
name, nameLength);
if (info.entryBlock.EntryCount() == 1) {
// That's the last key in the block. Unless that's the root level,
// we remove the block completely.
PRINT(" -> block is empty\n");
if (level == 0) {
info.entryBlock.RemoveEntry(info.index);
return B_OK;
}
error = fDirectory->GetVolume()->GetBlockAllocator()->Free(
info.block.Index(), 1, transaction);
if (error != B_OK)
RETURN_ERROR(error);
fDirectory->SetSize(fDirectory->Size() - B_PAGE_SIZE);
// remove the key (the same one) from the parent block
continue;
}
// There are more entries, so just remove the entry in question. If it
// is not the first one, we're done, otherwise we have to update the
// block's key in the parent block.
info.entryBlock.RemoveEntry(info.index);
if (info.index > 0 || level == 0)
return B_OK;
name = info.entryBlock.NameAt(0, nameLength);
return _UpdateOrInsertKey(infos, level - 1, name, nameLength, 0, false,
transaction);
}
return B_OK;
}
status_t
DirEntryTree::InsertEntry(const char* name, uint64 blockIndex,
Transaction& transaction)
{
FUNCTION("name: \"%s\", blockIndex: %" B_PRIu64 "\n", name, blockIndex);
status_t error = _InitWritable(transaction);
if (error != B_OK)
RETURN_ERROR(error);
size_t nameLength = strlen(name);
if (nameLength == 0)
RETURN_ERROR(B_BAD_VALUE);
if (nameLength > kCheckSumFSNameLength)
RETURN_ERROR(B_NAME_TOO_LONG);
int32 depth = _Depth();
LevelInfo* infos = new(std::nothrow) LevelInfo[
kCheckSumFSMaxDirEntryTreeDepth + 1];
if (infos == NULL)
RETURN_ERROR(B_NO_MEMORY);
ArrayDeleter<LevelInfo> infosDeleter(infos);
infos[0].entryBlock.SetTo(fRootEntryBlock, fRootEntryBlockSize);
for (int32 level = 0; level <= depth; level++) {
LevelInfo& info = infos[level];
if (info.entryBlock.EntryCount() == 0) {
if (level == 0) {
PRINT(" directory is empty\n");
// directory is empty
info.index = 0;
break;
}
RETURN_ERROR(B_BAD_DATA);
}
info.index = info.entryBlock.FindInsertionIndex(name, nameLength,
info.exactMatch);
PRINT(" level %" B_PRId32 ", block %" B_PRIu64 " -> index: %" B_PRId32
" %sexact\n", level,
level == 0 ? fDirectory->BlockIndex() : info.block.Index(),
info.index, info.exactMatch ? "" : " not ");
// Finding an exact match -- even in the non-final level -- means
// that there's an entry with that name.
if (info.exactMatch)
RETURN_ERROR(B_FILE_EXISTS);
if (level == depth) {
// final level -- here we need to insert the entry
break;
}
// Since we haven't found an exact match, the index points to the
// first entry that is greater or after the last entry.
info.index--;
uint64 nextBlockIndex = info.entryBlock.BlockIndexAt(info.index);
// not the final level -- load the block and descend to the next
// level
LevelInfo& nextInfo = infos[level + 1];
if (!nextInfo.block.GetReadable(fDirectory->GetVolume(),
nextBlockIndex)) {
RETURN_ERROR(B_ERROR);
}
nextInfo.entryBlock.SetTo(
(checksumfs_dir_entry_block*)nextInfo.block.Data(),
B_PAGE_SIZE);
ASSERT(nextInfo.entryBlock.Check());
}
// We've found the insertion point. Insert the key and iterate backwards
// to perform the potentially necessary updates. Insertion at index 0 of
// the block changes the block's key, requiring an update in the parent
// block. Insertion or key update can cause the block to be split (if
// there's not enough space left in it), requiring an insertion in the
// parent block. So we start with a pending insertion in the leaf block
// and work our way upwards, performing key updates and insertions as
// necessary.
return _UpdateOrInsertKey(infos, depth, name, nameLength, blockIndex, true,
transaction);
}
status_t
DirEntryTree::LookupNextEntry(const char* name, char* foundName,
size_t& _foundNameLength, uint64& _blockIndex)
{
FUNCTION("name: \"%s\"\n", name);
status_t error = _InitReadOnly();
if (error != B_OK)
RETURN_ERROR(error);
size_t nameLength = strlen(name);
if (nameLength > kCheckSumFSNameLength)
RETURN_ERROR(B_ENTRY_NOT_FOUND);
int32 depth = _Depth();
LevelInfo* infos = new(std::nothrow) LevelInfo[
kCheckSumFSMaxDirEntryTreeDepth + 1];
if (infos == NULL)
RETURN_ERROR(B_NO_MEMORY);
ArrayDeleter<LevelInfo> infosDeleter(infos);
infos[0].entryBlock.SetTo(fRootEntryBlock, fRootEntryBlockSize);
ASSERT(infos[0].entryBlock.Check());
// descend the tree
for (int32 level = 0; level <= depth; level++) {
LevelInfo& info = infos[level];
if (info.entryBlock.EntryCount() == 0) {
if (level == 0) {
// directory is empty
return B_ENTRY_NOT_FOUND;
}
RETURN_ERROR(B_BAD_DATA);
}
info.index = info.entryBlock.FindInsertionIndex(name, nameLength,
info.exactMatch);
PRINT(" level %" B_PRId32 " -> index: %" B_PRId32 " %sexact\n", level,
info.index, info.exactMatch ? "" : " not ");
if (level == depth)
break;
// If we haven't found an exact match, the index points to the first
// entry that is greater or after the last entry.
if (!info.exactMatch && info.index > 0)
info.index--;
uint64 nextBlockIndex = info.entryBlock.BlockIndexAt(info.index);
// not the final level -- load the block and descend to the next
// level
LevelInfo& nextInfo = infos[level + 1];
if (!nextInfo.block.GetReadable(fDirectory->GetVolume(),
nextBlockIndex)) {
RETURN_ERROR(B_ERROR);
}
nextInfo.entryBlock.SetTo(
(checksumfs_dir_entry_block*)nextInfo.block.Data(),
B_PAGE_SIZE);
ASSERT(nextInfo.entryBlock.Check());
}
if (infos[depth].exactMatch)
infos[depth].index++;
if (infos[depth].index >= infos[depth].entryBlock.EntryCount()) {
// We're at the end of the last block -- we need to track back to find a
// greater branch.
PRINT(" searching for greater branch\n");
int32 level;
for (level = depth - 1; level >= 0; level--) {
LevelInfo& info = infos[level];
if (++info.index < info.entryBlock.EntryCount()) {
PRINT(" found greater branch: level: %" B_PRId32 " -> index: %"
B_PRId32 "\n", level, info.index);
break;
}
}
if (level < 0)
return B_ENTRY_NOT_FOUND;
// We've found a greater branch -- get the first entry in that branch.
for (level++; level <= depth; level++) {
LevelInfo& previousInfo = infos[level - 1];
LevelInfo& info = infos[level];
uint64 nextBlockIndex = previousInfo.entryBlock.BlockIndexAt(
previousInfo.index);
// load the block
if (!info.block.GetReadable(fDirectory->GetVolume(),
nextBlockIndex)) {
RETURN_ERROR(B_ERROR);
}
info.entryBlock.SetTo(
(checksumfs_dir_entry_block*)info.block.Data(), B_PAGE_SIZE);
ASSERT(info.entryBlock.Check());
info.index = 0;
if (info.entryBlock.EntryCount() == 0)
RETURN_ERROR(B_BAD_DATA);
}
}
// get and check the name
LevelInfo& info = infos[depth];
name = info.entryBlock.NameAt(info.index, nameLength);
if (nameLength > kCheckSumFSNameLength
|| strnlen(name, nameLength) != nameLength) {
RETURN_ERROR(B_BAD_DATA);
}
// set the return values
memcpy(foundName, name, nameLength);
foundName[nameLength] = '\0';
_foundNameLength = nameLength;
_blockIndex = info.entryBlock.BlockIndexAt(info.index);
PRINT(" found entry: \"%s\" -> %" B_PRIu64 "\n", foundName, _blockIndex);
return B_OK;
}
status_t
DirEntryTree::LookupEntry(const char* name, uint64& _blockIndex)
{
FUNCTION("name: \"%s\"\n", name);
status_t error = _InitReadOnly();
if (error != B_OK)
RETURN_ERROR(error);
size_t nameLength = strlen(name);
if (nameLength > kCheckSumFSNameLength)
RETURN_ERROR(B_ENTRY_NOT_FOUND);
uint32 depth = _Depth();
DirEntryBlock entryBlock(fRootEntryBlock, fRootEntryBlockSize);
ASSERT(entryBlock.Check());
Block block;
for (uint32 level = 0; level <= depth; level++) {
if (entryBlock.EntryCount() == 0)
RETURN_ERROR(level == 0 ? B_ENTRY_NOT_FOUND : B_BAD_DATA);
bool exactMatch;
int32 index = entryBlock.FindInsertionIndex(name, nameLength,
exactMatch);
// If we haven't found an exact match, the index points to the first
// entry that is greater or after the last entry.
if (!exactMatch) {
if (index == 0) {
// The first entry is already greater, so the branch doesn't
// contain the entry we're looking for.
RETURN_ERROR(B_ENTRY_NOT_FOUND);
}
index--;
}
PRINT(" level %" B_PRId32 " -> index: %" B_PRId32 " %sexact\n", level,
index, exactMatch ? "" : " not ");
uint64 blockIndex = entryBlock.BlockIndexAt(index);
if (level == depth) {
// final level -- here we should have an exact match
if (!exactMatch)
RETURN_ERROR(B_ENTRY_NOT_FOUND);
_blockIndex = blockIndex;
return B_OK;
}
// not the final level -- load the block and descend to the next
// level
if (!block.GetReadable(fDirectory->GetVolume(), blockIndex))
RETURN_ERROR(B_ERROR);
entryBlock.SetTo((checksumfs_dir_entry_block*)block.Data(),
B_PAGE_SIZE);
ASSERT(entryBlock.Check());
}
// cannot get here, but keep the compiler happy
RETURN_ERROR(B_ENTRY_NOT_FOUND);
}
bool
DirEntryTree::_Check(int32 level, uint64 blockIndex, const char* key,
size_t keyLength, DirEntryBlock& entryBlock)
{
// check block for validity
if (!entryBlock.Check()) {
ERROR("DirEntryTree::Check(): level %" B_PRIu32 ": block %"
B_PRIu64 " not valid!\n", level, blockIndex);
return false;
}
// The root block is allowed to be empty. For all other blocks that is an
// error.
uint32 entryCount = entryBlock.EntryCount();
if (entryCount == 0) {
if (level == 0)
return true;
ERROR("DirEntryTree::Check(): level %" B_PRIu32 ": block %"
B_PRIu64 " empty!\n", level, blockIndex);
return false;
}
// Verify that the block's first entry matches the key with which the
// parent block refers to it.
if (level > 0) {
size_t nameLength;
const char* name = entryBlock.NameAt(0, nameLength);
if (nameLength != keyLength || strncmp(name, key, keyLength) != 0) {
ERROR("DirEntryTree::Check(): level %" B_PRIu32 ": block %"
B_PRIu64 " key mismatch: is \"%.*s\", should be \"%.*s\"\n",
level, blockIndex, (int)keyLength, key, (int)nameLength, name);
return false;
}
}
if (level == _Depth())
return true;
// not the final level -- recurse
for (uint32 i = 0; i < entryCount; i++) {
size_t nameLength;
const char* name = entryBlock.NameAt(i, nameLength);
uint64 childBlockIndex = entryBlock.BlockIndexAt(i);
Block childBlock;
if (!childBlock.GetReadable(fDirectory->GetVolume(), childBlockIndex)) {
ERROR("DirEntryTree::Check(): level %" B_PRIu32 ": block %"
B_PRIu64 " failed to get child block %" B_PRIu64 " (entry %"
B_PRIu32 ")\n", level, blockIndex, childBlockIndex, i);
}
DirEntryBlock childEntryBlock(
(checksumfs_dir_entry_block*)childBlock.Data(), B_PAGE_SIZE);
if (!_Check(level + 1, childBlockIndex, name, nameLength,
childEntryBlock)) {
return false;
}
}
return true;
}