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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#pragma once
28
29#include <AK/Function.h>
30#include <AK/HashTable.h>
31#include <AK/InlineLinkedList.h>
32#include <AK/RefCounted.h>
33#include <AK/String.h>
34#include <AK/WeakPtr.h>
35#include <Kernel/FileSystem/FileSystem.h>
36#include <Kernel/FileSystem/InodeIdentifier.h>
37#include <Kernel/FileSystem/InodeMetadata.h>
38#include <Kernel/Forward.h>
39#include <Kernel/KResult.h>
40#include <Kernel/Lock.h>
41
42namespace Kernel {
43
44class Inode : public RefCounted<Inode>
45 , public Weakable<Inode>
46 , public InlineLinkedListNode<Inode> {
47 friend class VFS;
48 friend class FS;
49
50public:
51 virtual ~Inode();
52
53 virtual void one_ref_left() {}
54
55 FS& fs() { return m_fs; }
56 const FS& fs() const { return m_fs; }
57 unsigned fsid() const;
58 unsigned index() const { return m_index; }
59
60 size_t size() const { return metadata().size; }
61 bool is_symlink() const { return metadata().is_symlink(); }
62 bool is_directory() const { return metadata().is_directory(); }
63 bool is_character_device() const { return metadata().is_character_device(); }
64 mode_t mode() const { return metadata().mode; }
65
66 InodeIdentifier identifier() const { return { fsid(), index() }; }
67 virtual InodeMetadata metadata() const = 0;
68
69 ByteBuffer read_entire(FileDescription* = nullptr) const;
70
71 virtual ssize_t read_bytes(off_t, ssize_t, u8* buffer, FileDescription*) const = 0;
72 virtual bool traverse_as_directory(Function<bool(const FS::DirectoryEntry&)>) const = 0;
73 virtual RefPtr<Inode> lookup(StringView name) = 0;
74 virtual ssize_t write_bytes(off_t, ssize_t, const u8* data, FileDescription*) = 0;
75 virtual KResult add_child(InodeIdentifier child_id, const StringView& name, mode_t) = 0;
76 virtual KResult remove_child(const StringView& name) = 0;
77 virtual size_t directory_entry_count() const = 0;
78 virtual KResult chmod(mode_t) = 0;
79 virtual KResult chown(uid_t, gid_t) = 0;
80 virtual KResult truncate(u64) { return KSuccess; }
81 virtual KResultOr<NonnullRefPtr<Custody>> resolve_as_link(Custody& base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0) const;
82
83 LocalSocket* socket() { return m_socket.ptr(); }
84 const LocalSocket* socket() const { return m_socket.ptr(); }
85 bool bind_socket(LocalSocket&);
86 bool unbind_socket();
87
88 virtual FileDescription* preopen_fd() { return nullptr; };
89
90 bool is_metadata_dirty() const { return m_metadata_dirty; }
91
92 virtual int set_atime(time_t);
93 virtual int set_ctime(time_t);
94 virtual int set_mtime(time_t);
95 virtual KResult increment_link_count();
96 virtual KResult decrement_link_count();
97
98 virtual void flush_metadata() = 0;
99
100 void will_be_destroyed();
101
102 void set_shared_vmobject(SharedInodeVMObject&);
103 SharedInodeVMObject* shared_vmobject() { return m_shared_vmobject.ptr(); }
104 const SharedInodeVMObject* shared_vmobject() const { return m_shared_vmobject.ptr(); }
105
106 static void sync();
107
108 bool has_watchers() const { return !m_watchers.is_empty(); }
109
110 void register_watcher(Badge<InodeWatcher>, InodeWatcher&);
111 void unregister_watcher(Badge<InodeWatcher>, InodeWatcher&);
112
113 // For InlineLinkedListNode.
114 Inode* m_next { nullptr };
115 Inode* m_prev { nullptr };
116
117protected:
118 Inode(FS& fs, unsigned index);
119 void set_metadata_dirty(bool);
120 void inode_contents_changed(off_t, ssize_t, const u8*);
121 void inode_size_changed(size_t old_size, size_t new_size);
122 KResult prepare_to_write_data();
123
124 mutable Lock m_lock { "Inode" };
125
126private:
127 FS& m_fs;
128 unsigned m_index { 0 };
129 WeakPtr<SharedInodeVMObject> m_shared_vmobject;
130 RefPtr<LocalSocket> m_socket;
131 HashTable<InodeWatcher*> m_watchers;
132 bool m_metadata_dirty { false };
133};
134
135}