ladybird/Kernel/FileSystem/FATFS/FileSystem.cpp
Andreas Kling 673592dea8 Kernel: Stop using *LockRefPtr for FileSystem pointers
There was only one permanent storage location for these: as a member
in the Mount class.

That member is never modified after Mount initialization, so we don't
need to worry about races there.
2023-04-04 10:33:42 +02:00

95 lines
3.6 KiB
C++

/*
* Copyright (c) 2022, Undefine <undefine@undefine.pl>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/FATFS/FileSystem.h>
#include <Kernel/FileSystem/FATFS/Inode.h>
namespace Kernel {
ErrorOr<NonnullRefPtr<FileSystem>> FATFS::try_create(OpenFileDescription& file_description)
{
return TRY(adopt_nonnull_ref_or_enomem(new (nothrow) FATFS(file_description)));
}
FATFS::FATFS(OpenFileDescription& file_description)
: BlockBasedFileSystem(file_description)
{
}
bool FATFS::is_initialized_while_locked()
{
VERIFY(m_lock.is_locked());
return !m_root_inode.is_null();
}
ErrorOr<void> FATFS::initialize_while_locked()
{
VERIFY(m_lock.is_locked());
VERIFY(!is_initialized_while_locked());
m_boot_record = TRY(KBuffer::try_create_with_size("FATFS: Boot Record"sv, m_logical_block_size));
auto boot_record_buffer = UserOrKernelBuffer::for_kernel_buffer(m_boot_record->data());
TRY(raw_read(0, boot_record_buffer));
if constexpr (FAT_DEBUG) {
dbgln("FATFS: oem_identifier: {}", boot_record()->oem_identifier);
dbgln("FATFS: bytes_per_sector: {}", boot_record()->bytes_per_sector);
dbgln("FATFS: sectors_per_cluster: {}", boot_record()->sectors_per_cluster);
dbgln("FATFS: reserved_sector_count: {}", boot_record()->reserved_sector_count);
dbgln("FATFS: fat_count: {}", boot_record()->fat_count);
dbgln("FATFS: root_directory_entry_count: {}", boot_record()->root_directory_entry_count);
dbgln("FATFS: media_descriptor_type: {}", boot_record()->media_descriptor_type);
dbgln("FATFS: sectors_per_track: {}", boot_record()->sectors_per_track);
dbgln("FATFS: head_count: {}", boot_record()->head_count);
dbgln("FATFS: hidden_sector_count: {}", boot_record()->hidden_sector_count);
dbgln("FATFS: sector_count: {}", boot_record()->sector_count);
dbgln("FATFS: sectors_per_fat: {}", boot_record()->sectors_per_fat);
dbgln("FATFS: flags: {}", boot_record()->flags);
dbgln("FATFS: fat_version: {}", boot_record()->fat_version);
dbgln("FATFS: root_directory_cluster: {}", boot_record()->root_directory_cluster);
dbgln("FATFS: fs_info_sector: {}", boot_record()->fs_info_sector);
dbgln("FATFS: backup_boot_sector: {}", boot_record()->backup_boot_sector);
dbgln("FATFS: drive_number: {}", boot_record()->drive_number);
dbgln("FATFS: volume_id: {}", boot_record()->volume_id);
}
if (boot_record()->signature != signature_1 && boot_record()->signature != signature_2) {
dbgln("FATFS: Invalid signature");
return EINVAL;
}
m_logical_block_size = boot_record()->bytes_per_sector;
set_block_size(m_logical_block_size);
u32 root_directory_sectors = ((boot_record()->root_directory_entry_count * sizeof(FATEntry)) + (m_logical_block_size - 1)) / m_logical_block_size;
m_first_data_sector = boot_record()->reserved_sector_count + (boot_record()->fat_count * boot_record()->sectors_per_fat) + root_directory_sectors;
TRY(BlockBasedFileSystem::initialize_while_locked());
FATEntry root_entry {};
root_entry.first_cluster_low = boot_record()->root_directory_cluster & 0xFFFF;
root_entry.first_cluster_high = boot_record()->root_directory_cluster >> 16;
root_entry.attributes = FATAttributes::Directory;
m_root_inode = TRY(FATInode::create(*this, root_entry));
return {};
}
Inode& FATFS::root_inode()
{
return *m_root_inode;
}
BlockBasedFileSystem::BlockIndex FATFS::first_block_of_cluster(u32 cluster) const
{
return ((cluster - first_data_cluster) * boot_record()->sectors_per_cluster) + m_first_data_sector;
}
}