summaryrefslogtreecommitdiff
path: root/Kernel/FileSystem.h
blob: 21a64decbb2f481bca7dba10eb2e3dcedee905e8 (plain)
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
#pragma once

#include "DiskDevice.h"
#include "InodeIdentifier.h"
#include "InodeMetadata.h"
#include "Limits.h"
#include "UnixTypes.h"
#include <AK/ByteBuffer.h>
#include <AK/HashMap.h>
#include <AK/OwnPtr.h>
#include <AK/Retainable.h>
#include <AK/RetainPtr.h>
#include <AK/AKString.h>
#include <AK/Function.h>
#include <AK/kstdio.h>

static const dword mepoch = 476763780;

class Inode;
class FileDescriptor;
class VMObject;

class FS : public Retainable<FS> {
public:
    static void initialize_globals();
    virtual ~FS();

    dword id() const { return m_fsid; }
    static FS* from_fsid(dword);
    static void sync();

    virtual bool initialize() = 0;
    virtual const char* class_name() const = 0;
    virtual InodeIdentifier root_inode() const = 0;

    bool is_readonly() const { return m_readonly; }

    struct DirectoryEntry {
        DirectoryEntry(const char* name, InodeIdentifier, byte fileType);
        DirectoryEntry(const char* name, size_t name_length, InodeIdentifier, byte fileType);
        char name[256];
        size_t name_length { 0 };
        InodeIdentifier inode;
        byte fileType { 0 };
    };

    virtual RetainPtr<Inode> create_inode(InodeIdentifier parentInode, const String& name, Unix::mode_t, unsigned size, int& error) = 0;
    virtual RetainPtr<Inode> create_directory(InodeIdentifier parentInode, const String& name, Unix::mode_t, int& error) = 0;

    virtual RetainPtr<Inode> get_inode(InodeIdentifier) const = 0;

protected:
    FS();

private:
    dword m_fsid { 0 };
    bool m_readonly { false };
};

class Inode : public Retainable<Inode> {
    friend class VFS;
public:
    virtual ~Inode();

    virtual void one_retain_left() { }

    FS& fs() { return m_fs; }
    const FS& fs() const { return m_fs; }
    unsigned fsid() const;
    unsigned index() const { return m_index; }

    size_t size() const { return metadata().size; }
    bool is_symlink() const { return metadata().isSymbolicLink(); }
    bool is_directory() const { return metadata().isDirectory(); }
    bool is_character_device() const { return metadata().isCharacterDevice(); }

    InodeIdentifier identifier() const { return { fsid(), index() }; }
    virtual InodeMetadata metadata() const = 0;

    ByteBuffer read_entire(FileDescriptor* = nullptr);

    virtual ssize_t read_bytes(Unix::off_t, size_t, byte* buffer, FileDescriptor*) = 0;
    virtual bool traverse_as_directory(Function<bool(const FS::DirectoryEntry&)>) = 0;
    virtual InodeIdentifier lookup(const String& name) = 0;
    virtual String reverse_lookup(InodeIdentifier) = 0;
    virtual ssize_t write_bytes(Unix::off_t, size_t, const byte* data, FileDescriptor*) = 0;
    virtual bool add_child(InodeIdentifier child_id, const String& name, byte file_type, int& error) = 0;
    virtual bool remove_child(const String& name, int& error) = 0;
    virtual RetainPtr<Inode> parent() const = 0;

    bool is_metadata_dirty() const { return m_metadata_dirty; }

    virtual int set_atime(Unix::time_t);
    virtual int set_ctime(Unix::time_t);
    virtual int set_mtime(Unix::time_t);
    virtual int increment_link_count();
    virtual int decrement_link_count();

    virtual void flush_metadata() = 0;

    void will_be_destroyed();

    void set_vmo(RetainPtr<VMObject>&&);
    VMObject* vmo() { return m_vmo.ptr(); }
    const VMObject* vmo() const { return m_vmo.ptr(); }

protected:
    Inode(FS& fs, unsigned index);

    void set_metadata_dirty(bool b) { m_metadata_dirty = b; }
private:
    FS& m_fs;
    unsigned m_index { 0 };
    RetainPtr<VMObject> m_vmo;
    bool m_metadata_dirty { false };
};

inline FS* InodeIdentifier::fs()
{
    return FS::from_fsid(m_fsid);
}

inline const FS* InodeIdentifier::fs() const
{
    return FS::from_fsid(m_fsid);
}

inline bool InodeIdentifier::is_root_inode() const
{
    return (*this) == fs()->root_inode();
}

inline unsigned Inode::fsid() const
{
    return m_fs.id();
}

namespace AK {

template<>
struct Traits<InodeIdentifier> {
    // FIXME: This is a shitty hash.
    static unsigned hash(const InodeIdentifier& inode) { return Traits<unsigned>::hash(inode.fsid()) + Traits<unsigned>::hash(inode.index()); }
    static void dump(const InodeIdentifier& inode) { kprintf("%02u:%08u", inode.fsid(), inode.index()); }
};

}