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/*
* Copyright (c) 2020, Sergey Bugaev <bugaevc@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Atomic.h>
#include <Kernel/FileSystem/FileBackedFileSystem.h>
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/FileSystem/Plan9FS/Definitions.h>
#include <Kernel/FileSystem/Plan9FS/Message.h>
#include <Kernel/KBufferBuilder.h>
namespace Kernel {
class Plan9FSInode;
class Plan9FS final : public FileBackedFileSystem {
friend class Plan9FSInode;
public:
virtual ~Plan9FS() override;
static ErrorOr<NonnullLockRefPtr<FileSystem>> try_create(OpenFileDescription&);
virtual bool supports_watchers() const override { return false; }
virtual Inode& root_inode() override;
u16 allocate_tag() { return m_next_tag++; }
u32 allocate_fid() { return m_next_fid++; }
enum class ProtocolVersion {
v9P2000,
v9P2000u,
v9P2000L
};
private:
Plan9FS(OpenFileDescription&);
virtual ErrorOr<void> prepare_to_clear_last_mount() override;
virtual bool is_initialized_while_locked() override;
virtual ErrorOr<void> initialize_while_locked() override;
class Blocker;
class Plan9FSBlockerSet final : public Thread::BlockerSet {
public:
Plan9FSBlockerSet(Plan9FS& fs)
: m_fs(fs)
{
}
void unblock_completed(u16);
void unblock_all();
void try_unblock(Blocker&);
protected:
virtual bool should_add_blocker(Thread::Blocker&, void*) override;
private:
Plan9FS& m_fs;
mutable Spinlock<LockRank::None> m_lock {};
};
struct ReceiveCompletion final : public AtomicRefCounted<ReceiveCompletion> {
mutable Spinlock<LockRank::None> lock {};
bool completed { false };
const u16 tag;
OwnPtr<Plan9FSMessage> message;
ErrorOr<void> result;
ReceiveCompletion(u16 tag);
~ReceiveCompletion();
};
class Blocker final : public Thread::Blocker {
public:
Blocker(Plan9FS& fs, Plan9FSMessage& message, NonnullLockRefPtr<ReceiveCompletion> completion)
: m_fs(fs)
, m_message(message)
, m_completion(move(completion))
{
}
virtual bool setup_blocker() override;
virtual StringView state_string() const override { return "Waiting"sv; }
virtual Type blocker_type() const override { return Type::Plan9FS; }
virtual void will_unblock_immediately_without_blocking(UnblockImmediatelyReason) override;
NonnullLockRefPtr<ReceiveCompletion> const& completion() const { return m_completion; }
u16 tag() const { return m_completion->tag; }
bool is_completed() const;
bool unblock()
{
unblock_from_blocker();
return true;
}
bool unblock(u16 tag);
private:
Plan9FS& m_fs;
Plan9FSMessage& m_message;
NonnullLockRefPtr<ReceiveCompletion> m_completion;
bool m_did_unblock { false };
};
friend class Blocker;
virtual StringView class_name() const override { return "Plan9FS"sv; }
bool is_complete(ReceiveCompletion const&);
ErrorOr<void> post_message(Plan9FSMessage&, LockRefPtr<ReceiveCompletion>);
ErrorOr<void> do_read(u8* buffer, size_t);
ErrorOr<void> read_and_dispatch_one_message();
ErrorOr<void> post_message_and_wait_for_a_reply(Plan9FSMessage&);
ErrorOr<void> post_message_and_explicitly_ignore_reply(Plan9FSMessage&);
ProtocolVersion parse_protocol_version(StringView) const;
size_t adjust_buffer_size(size_t size) const;
void thread_main();
void ensure_thread();
RefPtr<Plan9FSInode> m_root_inode;
Atomic<u16> m_next_tag { (u16)-1 };
Atomic<u32> m_next_fid { 1 };
ProtocolVersion m_remote_protocol_version { ProtocolVersion::v9P2000 };
size_t m_max_message_size { 4 * KiB };
Mutex m_send_lock { "Plan9FS send"sv };
Plan9FSBlockerSet m_completion_blocker;
HashMap<u16, NonnullLockRefPtr<ReceiveCompletion>> m_completions;
Spinlock<LockRank::None> m_thread_lock {};
LockRefPtr<Thread> m_thread;
Atomic<bool> m_thread_running { false };
Atomic<bool, AK::MemoryOrder::memory_order_relaxed> m_thread_shutdown { false };
};
}
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