mirror of
https://github.com/RGBCube/serenity
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23a7ccf607
This is a preparation before we can create a usable mechanism to use filesystem-specific mount flags. To keep some compatibility with userland code, LibC and LibCore mount functions are kept being usable, but now instead of doing an "atomic" syscall, they do multiple syscalls to perform the complete procedure of mounting a filesystem. The FileBackedFileSystem IntrusiveList in the VFS code is now changed to be protected by a Mutex, because when we mount a new filesystem, we need to check if a filesystem is already created for a given source_fd so we do a scan for that OpenFileDescription in that list. If we fail to find an already-created filesystem we create a new one and register it in the list if we successfully mounted it. We use a Mutex because we might need to initiate disk access during the filesystem creation, which will take other mutexes in other parts of the kernel, therefore making it not possible to take a spinlock while doing this.
53 lines
1.6 KiB
C++
53 lines
1.6 KiB
C++
/*
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* Copyright (c) 2022, Undefine <undefine@undefine.pl>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#pragma once
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#include <AK/OwnPtr.h>
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#include <AK/RefPtr.h>
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#include <AK/Types.h>
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#include <Kernel/FileSystem/BlockBasedFileSystem.h>
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#include <Kernel/FileSystem/FATFS/Definitions.h>
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#include <Kernel/FileSystem/Inode.h>
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#include <Kernel/Forward.h>
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#include <Kernel/Library/KBuffer.h>
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namespace Kernel {
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class FATFS final : public BlockBasedFileSystem {
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friend FATInode;
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public:
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static ErrorOr<NonnullRefPtr<FileSystem>> try_create(OpenFileDescription&, ReadonlyBytes);
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virtual ~FATFS() override = default;
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virtual StringView class_name() const override { return "FATFS"sv; }
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virtual Inode& root_inode() override;
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private:
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virtual ErrorOr<void> initialize_while_locked() override;
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virtual bool is_initialized_while_locked() override;
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// FIXME: This is not a proper way to clear last mount of a FAT filesystem,
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// but for now we simply have no other way to properly do it.
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virtual ErrorOr<void> prepare_to_clear_last_mount() override { return {}; }
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FATFS(OpenFileDescription&);
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static constexpr u8 signature_1 = 0x28;
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static constexpr u8 signature_2 = 0x29;
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static constexpr u32 first_data_cluster = 2;
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FAT32BootRecord const* boot_record() const { return reinterpret_cast<FAT32BootRecord const*>(m_boot_record->data()); };
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BlockBasedFileSystem::BlockIndex first_block_of_cluster(u32 cluster) const;
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OwnPtr<KBuffer> m_boot_record {};
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RefPtr<FATInode> m_root_inode;
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u32 m_first_data_sector { 0 };
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};
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}
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