status_t
DirEntryTree::_InitCommon()
{
fTree = (checksumfs_dir_entry_tree*)
((uint8*)fRootBlock.Data() + sizeof(checksumfs_node));
fRootEntryBlock = (checksumfs_dir_entry_block*)(fTree + 1);
fRootEntryBlockSize = B_PAGE_SIZE
- ((addr_t)fRootEntryBlock - (addr_t)fRootBlock.Data());
if (_Depth() > kCheckSumFSMaxDirEntryTreeDepth)
RETURN_ERROR(B_BAD_DATA);
return B_OK;
}
status_t
SymLink::WriteSymLink(const char* buffer, size_t toWrite,
Transaction& transaction)
{
uint64 size = Size();
if (size > kMaxSymLinkSize)
RETURN_ERROR(B_BAD_DATA);
if (toWrite > kMaxSymLinkSize)
RETURN_ERROR(B_NAME_TOO_LONG);
if (toWrite == 0) {
SetSize(0);
return B_OK;
}
Block block;
if (!block.GetWritable(GetVolume(), BlockIndex(), transaction))
return B_ERROR;
char* data = (char*)block.Data() + kSymLinkDataOffset;
memcpy(data, buffer, toWrite);
SetSize(toWrite);
return B_OK;
}
status_t
SymLink::ReadSymLink(char* buffer, size_t toRead, size_t& _bytesRead)
{
uint64 size = Size();
if (size > kMaxSymLinkSize)
RETURN_ERROR(B_BAD_DATA);
if (toRead > size)
toRead = size;
if (toRead == 0) {
_bytesRead = 0;
return B_OK;
}
// get the block
Block block;
if (!block.GetReadable(GetVolume(), BlockIndex()))
RETURN_ERROR(B_ERROR);
const char* data = (char*)block.Data() + kSymLinkDataOffset;
memcpy(buffer, data, toRead);
_bytesRead = toRead;
return B_OK;
}
status_t
Volume::ReadNode(uint64 blockIndex, Node*& _node)
{
if (blockIndex == 0 || blockIndex >= fTotalBlocks)
return B_BAD_VALUE;
// load the node's block
Block block;
if (!block.GetReadable(this, blockIndex))
return B_ERROR;
checksumfs_node* nodeData = (checksumfs_node*)block.Data();
// create the Node object
Node* node;
switch (nodeData->mode & S_IFMT) {
// TODO: Don't directly access mode!
case S_IFDIR:
node = new(std::nothrow) Directory(this, blockIndex, *nodeData);
break;
default:
node = new(std::nothrow) Node(this, blockIndex, *nodeData);
break;
}
if (node == NULL)
return B_NO_MEMORY;
// TODO: Sanity check the node!
_node = node;
return B_OK;
}
status_t
Volume::Initialize(const char* name)
{
fName = strdup(name);
if (fName == NULL)
return B_NO_MEMORY;
status_t error = fBlockAllocator->Initialize();
if (error != B_OK)
return error;
// create the root directory
error = CreateDirectory(S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH,
fRootDirectory);
if (error != B_OK)
return error;
error = fRootDirectory->Flush();
if (error != B_OK)
return error;
// write the super block
Block block;
if (!block.GetZero(this, kCheckSumFSSuperBlockOffset / B_PAGE_SIZE))
return B_ERROR;
SuperBlock* superBlock = (SuperBlock*)block.Data();
superBlock->Initialize(this);
block.Put();
return block_cache_sync(fBlockCache);
}
status_t
Node::Flush()
{
if (!fNodeDataDirty)
return B_OK;
Block block;
if (!block.GetWritable(fVolume, fBlockIndex))
return B_ERROR;
memcpy(block.Data(), &fNode, sizeof(fNode));
fNodeDataDirty = false;
return B_OK;
}
status_t
Volume::Mount(fs_volume* fsVolume)
{
fFSVolume = fsVolume;
// load the superblock
Block block;
if (!block.GetReadable(this, kCheckSumFSSuperBlockOffset / B_PAGE_SIZE))
RETURN_ERROR(B_ERROR);
SuperBlock* superBlock = (SuperBlock*)block.Data();
if (!superBlock->Check(fTotalBlocks))
RETURN_ERROR(B_BAD_DATA);
// copy the volume name
fName = strdup(superBlock->Name());
if (fName == NULL)
RETURN_ERROR(B_NO_MEMORY);
// init the block allocator
status_t error = fBlockAllocator->Init(superBlock->BlockBitmap(),
superBlock->FreeBlocks());
if (error != B_OK)
RETURN_ERROR(error);
// load the root directory
Node* rootNode;
error = ReadNode(superBlock->RootDirectory(), rootNode);
if (error != B_OK)
RETURN_ERROR(error);
fRootDirectory = dynamic_cast<Directory*>(rootNode);
if (fRootDirectory == NULL) {
delete rootNode;
RETURN_ERROR(B_BAD_DATA);
}
error = PublishNode(fRootDirectory, 0);
if (error != B_OK) {
delete fRootDirectory;
fRootDirectory = NULL;
return error;
}
return B_OK;
}
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
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;
}
status_t
DirEntryTree::_UpdateOrInsertKey(LevelInfo* infos, int32 level,
const char* name, size_t nameLength, uint64 blockIndex, bool insertKey,
Transaction& transaction)
{
FUNCTION("level: %" B_PRId32 ": %s name: \"%.*s\" (%" B_PRIuSIZE "), "
"blockIndex: %" B_PRIu64 "\n", level, insertKey ? "insert" : "update",
(int)nameLength, name, nameLength, blockIndex);
// Some temporary blocks: newBlock is used when a block is split. The
// other three are used when a key update respectively insertion in the
// parent block becomes necessary. We only need them, since the name
// we update/insert is potentially from a block and instead of cloning
// the name, we simple postpone putting the block until we don't need
// the name anymore.
Block newBlock;
Block tempBlockUpdate;
Block tempBlockUpdateInsert;
Block tempBlockInsert;
int32 depth = _Depth();
status_t error;
bool updateNextKey = !insertKey;
bool insertNextKey = insertKey;
const char* nameToUpdate = name;
size_t nameToUpdateLength = nameLength;
const char* nextNameToInsert = name;
size_t nextNameToInsertLength = nameLength;
uint64 nextBlockIndexToInsert = blockIndex;
for (; level >= 0; level--) {
LevelInfo& info = infos[level];
bool updateThisKey = updateNextKey;
bool insertThisKey = insertNextKey;
if (!updateThisKey && !insertThisKey)
return B_OK;
updateNextKey = false;
insertNextKey = false;
blockIndex = nextBlockIndexToInsert;
name = nextNameToInsert;
nameLength = nextNameToInsertLength;
// make the block writable
if (level > 0) {
error = info.block.MakeWritable(transaction);
if (error != B_OK)
RETURN_ERROR(error);
}
if (updateThisKey) {
PRINT(" level: %" B_PRId32 ", index: %" B_PRId32 ": updating key "
"to \"%.*s\" (%" B_PRIuSIZE ")\n", level, info.index,
(int)nameToUpdateLength, nameToUpdate, nameToUpdateLength);
size_t oldNameLength;
info.entryBlock.NameAt(info.index, oldNameLength);
size_t spaceNeeded = oldNameLength < nameToUpdateLength
? nameToUpdateLength - oldNameLength : 0;
if (spaceNeeded <= info.entryBlock.FreeSpace()) {
info.entryBlock.ReplaceEntryName(info.index, nameToUpdate,
nameToUpdateLength);
if (info.index == 0) {
// we updated at index 0, so we need to update this
// block's key in the parent block
updateNextKey = true;
nameToUpdate = info.entryBlock.NameAt(0,
nameToUpdateLength);
// make sure the new block is kept until we no longer
// use the name in the next iteration
tempBlockUpdate.TransferFrom(info.block);
}
} else if (level == 0) {
// We need to split the root block -- clone it first.
error = _InsertEntryIncrementDepth(infos, transaction);
if (error != B_OK)
RETURN_ERROR(error);
level = 2;
// _InsertEntryIncrementDepth() moved the root block
// content to level 1, where we want to continue.
updateNextKey = true;
insertNextKey = insertThisKey;
continue;
} else {
// We need to split this non-root block.
int32 splitIndex;
error = _InsertEntrySplitBlock(level, info, spaceNeeded,
transaction, newBlock, splitIndex);
if (error != B_OK)
RETURN_ERROR(error);
nextBlockIndexToInsert = newBlock.Index();
DirEntryBlock newEntryBlock(
(checksumfs_dir_entry_block*)newBlock.Data(),
B_PAGE_SIZE);
ASSERT(newEntryBlock.Check());
if (info.index < splitIndex) {
ASSERT(info.entryBlock.FreeSpace() >= spaceNeeded);
info.entryBlock.ReplaceEntryName(info.index,
nameToUpdate, nameToUpdateLength);
if (info.index == 0) {
// we updated at index 0, so we need to update this
// block's key in the parent block
updateNextKey = true;
nameToUpdate = info.entryBlock.NameAt(0,
nameToUpdateLength);
// make sure the new block is kept until we no
// longer use the name in the next iteration
tempBlockUpdate.TransferFrom(info.block);
}
} else {
ASSERT(newEntryBlock.FreeSpace() >= spaceNeeded);
// we need to transfer the block to the info, in case we
// also need to insert a key below
info.block.TransferFrom(newBlock);
info.entryBlock.SetTo(
(checksumfs_dir_entry_block*)info.block.Data(),
B_PAGE_SIZE);
ASSERT(info.entryBlock.Check());
info.index -= splitIndex;
info.entryBlock.ReplaceEntryName(info.index, nameToUpdate,
nameToUpdateLength);
}
// the newly created block needs to be inserted in the
// parent
insertNextKey = true;
nextNameToInsert = newEntryBlock.NameAt(0,
nextNameToInsertLength);
// make sure the new block is kept until we no longer use
// the name in the next iteration (might already have been
// transferred to entry.block)
tempBlockUpdateInsert.TransferFrom(newBlock);
}
}
if (insertThisKey) {
// insert after the block we descended
if (level < depth)
info.index++;
PRINT(" level: %" B_PRId32 ", index: %" B_PRId32 ": inserting key "
"\"%.*s\" (%" B_PRIuSIZE "), blockIndex: %" B_PRIu64 "\n",
level, info.index, (int)nameLength, name, nameLength,
blockIndex);
if (info.entryBlock.FreeSpace() >= nameLength + 10) {
info.entryBlock.InsertEntry(info.index, name,
nameLength, blockIndex);
if (info.index == 0) {
// we inserted at index 0, so we need to update this
// block's key in the parent block
updateNextKey = true;
nameToUpdate = info.entryBlock.NameAt(0,
nameToUpdateLength);
// make sure the new block is kept until we no longer
// use the name in the next iteration
tempBlockUpdate.TransferFrom(info.block);
}
continue;
}
// Not enough space left in the block -- we need to split it.
ASSERT(!insertNextKey);
// for level == 0 we need to clone the block first
if (level == 0) {
error = _InsertEntryIncrementDepth(infos, transaction);
if (error != B_OK)
RETURN_ERROR(error);
level = 2;
// _InsertEntryIncrementDepth() moved the root block
// content to level 1, where we want to continue.
updateNextKey = false;
insertNextKey = true;
continue;
}
int32 splitIndex;
error = _InsertEntrySplitBlock(level, info, nameLength + 10,
transaction, newBlock, splitIndex);
if (error != B_OK)
RETURN_ERROR(error);
DirEntryBlock newEntryBlock(
(checksumfs_dir_entry_block*)newBlock.Data(),
B_PAGE_SIZE);
ASSERT(newEntryBlock.Check());
if (info.index < splitIndex) {
ASSERT(info.entryBlock.FreeSpace() >= nameLength + 10);
info.entryBlock.InsertEntry(info.index, name,
nameLength, blockIndex);
if (info.index == 0) {
// we inserted at index 0, so we need to update this
// block's key in the parent block
updateNextKey = true;
nameToUpdate = info.entryBlock.NameAt(0,
nameToUpdateLength);
// make sure the new block is kept until we no longer
// use the name in the next iteration
tempBlockUpdate.TransferFrom(info.block);
}
} else {
ASSERT(newEntryBlock.FreeSpace() >= nameLength + 10);
info.index -= splitIndex;
newEntryBlock.InsertEntry(info.index, name, nameLength,
blockIndex);
}
// the newly created block needs to be inserted in the parent
insertNextKey = true;
nextNameToInsert = newEntryBlock.NameAt(0, nextNameToInsertLength);
nextBlockIndexToInsert = newBlock.Index();
// make sure the new block is kept until we no longer use
// the name in the next iteration
tempBlockInsert.TransferFrom(newBlock);
}
}
return B_OK;
}
