1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
|
/*
* 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/KBufferBuilder.h>
namespace Kernel {
class Plan9FSInode;
class Plan9FS final : public FileBackedFileSystem {
friend class Plan9FSInode;
public:
virtual ~Plan9FS() override;
static NonnullRefPtr<Plan9FS> create(FileDescription&);
virtual KResult initialize() override;
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
};
struct qid {
u8 type;
u32 version;
u64 path;
};
class Message;
private:
Plan9FS(FileDescription&);
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<u8> m_lock;
};
struct ReceiveCompletion : public RefCounted<ReceiveCompletion> {
mutable Spinlock<u8> lock;
bool completed { false };
const u16 tag;
OwnPtr<Message> message;
KResult result { KSuccess };
ReceiveCompletion(u16 tag);
~ReceiveCompletion();
};
class Blocker final : public Thread::Blocker {
public:
Blocker(Plan9FS& fs, Message& message, NonnullRefPtr<ReceiveCompletion> completion)
: m_fs(fs)
, m_message(message)
, m_completion(move(completion))
{
add_to_blocker_set(fs.m_completion_blocker);
}
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;
const NonnullRefPtr<ReceiveCompletion>& 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;
Message& m_message;
NonnullRefPtr<ReceiveCompletion> m_completion;
bool m_did_unblock { false };
};
friend class Blocker;
virtual StringView class_name() const override { return "Plan9FS"sv; }
bool is_complete(const ReceiveCompletion&);
KResult post_message(Message&, RefPtr<ReceiveCompletion>);
KResult do_read(u8* buffer, size_t);
KResult read_and_dispatch_one_message();
KResult post_message_and_wait_for_a_reply(Message&);
KResult post_message_and_explicitly_ignore_reply(Message&);
ProtocolVersion parse_protocol_version(const 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" };
Plan9FSBlockerSet m_completion_blocker;
HashMap<u16, NonnullRefPtr<ReceiveCompletion>> m_completions;
Spinlock<u8> m_thread_lock;
RefPtr<Thread> m_thread;
Atomic<bool> m_thread_running { false };
Atomic<bool, AK::MemoryOrder::memory_order_relaxed> m_thread_shutdown { false };
};
class Plan9FSInode final : public Inode {
friend class Plan9FS;
public:
virtual ~Plan9FSInode() override;
u32 fid() const { return index().value(); }
// ^Inode
virtual InodeMetadata metadata() const override;
virtual void flush_metadata() override;
virtual KResultOr<size_t> read_bytes(off_t, size_t, UserOrKernelBuffer& buffer, FileDescription*) const override;
virtual KResultOr<size_t> write_bytes(off_t, size_t, const UserOrKernelBuffer& data, FileDescription*) override;
virtual KResult traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const override;
virtual KResultOr<NonnullRefPtr<Inode>> lookup(StringView name) override;
virtual KResultOr<NonnullRefPtr<Inode>> create_child(StringView name, mode_t, dev_t, uid_t, gid_t) override;
virtual KResult add_child(Inode&, const StringView& name, mode_t) override;
virtual KResult remove_child(const StringView& name) override;
virtual KResult chmod(mode_t) override;
virtual KResult chown(uid_t, gid_t) override;
virtual KResult truncate(u64) override;
private:
Plan9FSInode(Plan9FS&, u32 fid);
static NonnullRefPtr<Plan9FSInode> create(Plan9FS&, u32 fid);
enum class GetAttrMask : u64 {
Mode = 0x1,
NLink = 0x2,
UID = 0x4,
GID = 0x8,
RDev = 0x10,
ATime = 0x20,
MTime = 0x40,
CTime = 0x80,
Ino = 0x100,
Size = 0x200,
Blocks = 0x400,
BTime = 0x800,
Gen = 0x1000,
DataVersion = 0x2000,
Basic = 0x7ff,
All = 0x3fff
};
enum class SetAttrMask : u64 {
Mode = 0x1,
UID = 0x2,
GID = 0x4,
Size = 0x8,
ATime = 0x10,
MTime = 0x20,
CTime = 0x40,
ATimeSet = 0x80,
MTimeSet = 0x100
};
// Mode in which the file is already open, using SerenityOS constants.
int m_open_mode { 0 };
KResult ensure_open_for_mode(int mode);
Plan9FS& fs() { return reinterpret_cast<Plan9FS&>(Inode::fs()); }
Plan9FS& fs() const
{
return const_cast<Plan9FS&>(reinterpret_cast<const Plan9FS&>(Inode::fs()));
}
};
}
|
