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

#include "fs/ext2/ext2_driver.h"

#include <glacier/string/string.h>
#include <mammoth/debug.h>

glcr::ErrorOr<Ext2Driver> Ext2Driver::Init(ScopedDenaliClient&& denali) {
  ASSIGN_OR_RETURN(glcr::SharedPtr<Ext2BlockReader> reader,
                   Ext2BlockReader::Init(glcr::Move(denali)));

  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::ErrorCode Ext2Driver::ProbeDirectory(Inode* inode) {
  if (!(inode->mode & 0x4000)) {
    dbgln("Probing 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;
  }

  for (uint64_t i = 0; i < real_block_cnt; i++) {
    dbgln("Getting block %lx", 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);
      glcr::String name(entry->name, entry->name_len);
      switch (entry->file_type) {
        case kExt2FtFile:
          dbgln("FILE (0x%x): %s", entry->inode, name.cstr());
          break;
        case kExt2FtDirectory:
          dbgln("DIR  (0x%x): %s", entry->inode, name.cstr());
          break;
        default:
          dbgln("UNK  (0x%x): %s", entry->inode, name.cstr());
      }
      addr += entry->record_length;
    }
  }
  return glcr::OK;
}