acadia/sys/victoriafalls/fs/ext2/ext2_driver.cpp

130 lines
4.1 KiB
C++

#include "fs/ext2/ext2_driver.h"
#include <glacier/string/string.h>
#include <mammoth/debug.h>
glcr::ErrorOr<Ext2Driver> Ext2Driver::Init(const DenaliInfo& denali_info) {
ASSIGN_OR_RETURN(glcr::SharedPtr<Ext2BlockReader> reader,
Ext2BlockReader::Init(glcr::Move(denali_info)));
ASSIGN_OR_RETURN(
MappedMemoryRegion bgdt,
reader->ReadBlocks(reader->BgdtBlockNum(), reader->BgdtBlockSize()));
BlockGroupDescriptor* bgds =
reinterpret_cast<BlockGroupDescriptor*>(bgdt.vaddr());
glcr::UniquePtr<InodeTable> inode_table(new InodeTable(reader, bgds));
return Ext2Driver(reader, glcr::Move(inode_table));
}
glcr::ErrorCode Ext2Driver::ProbePartition() {
Superblock* superblock = ext2_reader_->GetSuperblock();
if (superblock->magic != 0xEF53) {
dbgln("Invalid EXT2 magic code: {x}");
return glcr::INVALID_ARGUMENT;
}
dbgln("Block size: 0x{x}", 1024 << superblock->log_block_size);
dbgln("Blocks: 0x{x} (0x{x} per group)", superblock->blocks_count,
superblock->blocks_per_group);
dbgln("Inodes: 0x{x} (0x{x} per group)", superblock->inodes_count,
superblock->inodes_per_group);
dbgln("Inode size: 0x{x}", superblock->inode_size);
dbgln("Mounts: 0x{x} out of 0x{x}", superblock->mnt_count,
superblock->max_mnt_count);
dbgln("State: {x}", superblock->state);
dbgln("Created by: {x}", superblock->creator_os);
return glcr::OK;
}
glcr::ErrorOr<Inode*> Ext2Driver::GetInode(uint32_t inode_number) {
return inode_table_->GetInode(inode_number);
}
glcr::ErrorOr<glcr::Vector<DirEntry>> Ext2Driver::ReadDirectory(
uint32_t inode_number) {
ASSIGN_OR_RETURN(Inode * inode, inode_table_->GetInode(inode_number));
if (!(inode->mode & 0x4000)) {
dbgln("Reading non directory.");
return glcr::INVALID_ARGUMENT;
}
// This calculation is cursed.
uint64_t real_block_cnt =
(inode->blocks - 1) / (ext2_reader_->BlockSize() / 512) + 1;
if (real_block_cnt > 12) {
dbgln("Cant handle indirect blocks yet");
return glcr::FAILED_PRECONDITION;
}
glcr::Vector<DirEntry> directory;
for (uint64_t i = 0; i < real_block_cnt; i++) {
dbgln("Getting block {x}", inode->block[i]);
ASSIGN_OR_RETURN(MappedMemoryRegion block,
ext2_reader_->ReadBlock(inode->block[i]));
uint64_t addr = block.vaddr();
while (addr < block.vaddr() + ext2_reader_->BlockSize()) {
DirEntry* entry = reinterpret_cast<DirEntry*>(addr);
directory.PushBack(*entry);
glcr::StringView name(entry->name, entry->name_len);
switch (entry->file_type) {
case kExt2FtFile:
dbgln("FILE (0x{x}): {}", entry->inode, name);
break;
case kExt2FtDirectory:
dbgln("DIR (0x{x}): {}", entry->inode, name);
break;
default:
dbgln("UNK (0x{x}): {}", entry->inode, name);
}
addr += entry->record_length;
}
}
return directory;
}
glcr::ErrorOr<MappedMemoryRegion> Ext2Driver::ReadFile(uint64_t inode_number) {
ASSIGN_OR_RETURN(Inode * inode, inode_table_->GetInode(inode_number));
if (!(inode->mode & 0x8000)) {
dbgln("Reading non file.");
return glcr::INVALID_ARGUMENT;
}
// This calculation is cursed.
uint64_t real_block_cnt =
(inode->blocks - 1) / (ext2_reader_->BlockSize() / 512) + 1;
if (inode->block[14]) {
dbgln("Can't handle triply-indirect blocks yet.");
return glcr::UNIMPLEMENTED;
}
if (inode->block[13]) {
dbgln("Can't handle doubly-indirect blocks yet.");
return glcr::UNIMPLEMENTED;
}
MappedMemoryRegion indirect_block;
if (inode->block[12]) {
ASSIGN_OR_RETURN(indirect_block, ext2_reader_->ReadBlock(inode->block[12]));
}
glcr::Vector<uint64_t> blocks_to_read;
for (uint64_t i = 0; i < 12 && i < real_block_cnt; i++) {
blocks_to_read.PushBack(inode->block[i]);
}
for (uint64_t i = 12; i < 268 && i < real_block_cnt; i++) {
uint32_t* block_array = reinterpret_cast<uint32_t*>(indirect_block.vaddr());
uint64_t offset = i - 12;
blocks_to_read.PushBack(block_array[offset]);
}
return ext2_reader_->ReadBlocks(blocks_to_read);
}