RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 05:38:11 +00:00
Code Issues Activity Actions

Kernel+SystemServer+Base: Introduce the RAMFS filesystem

Browse source 
This filesystem is based on the code of the long-lived TmpFS. It differs
from that filesystem in one keypoint - its root inode doesn't have a
sticky bit on it.

Therefore, we mount it on /dev, to ensure only root can modify files on
that directory. In addition to that, /tmp is mounted directly in the
SystemServer main (start) code, so it's no longer specified in the fstab
file. We ensure that /tmp has a sticky bit and has the value 0777 for
root directory permissions, which is certainly a special case when using
RAM-backed (and in general other) filesystems.

Because of these 2 changes, it's no longer needed to maintain the TmpFS
filesystem, hence it's removed (renamed to RAMFS), because the RAMFS
represents the purpose of this filesystem in a much better way - it
relies on being backed by RAM "storage", and therefore it's easy to
conclude it's temporary and volatile, so its content is gone on either
system shutdown or unmounting of the filesystem.
This commit is contained in:
Liav A 2023-01-28 19:00:54 +02:00 • committed by Andrew Kaster
parent fa637e29d2
commit ed67a877a3
12 changed files with 123 additions and 118 deletions
Download patch file Download diff file Expand all files Collapse all files

41
Kernel/FileSystem/TmpFS/FileSystem.h
View file

@ -1,41 +0,0 @@
/*
* Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
* Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <Kernel/FileSystem/FileSystem.h>
#include <Kernel/FileSystem/Inode.h>
#include <Kernel/Forward.h>
namespace Kernel {
class TmpFS final : public FileSystem {
friend class TmpFSInode;
public:
virtual ~TmpFS() override;
static ErrorOr<NonnullLockRefPtr<FileSystem>> try_create();
virtual ErrorOr<void> initialize() override;
virtual StringView class_name() const override { return "TmpFS"sv; }
virtual bool supports_watchers() const override { return true; }
virtual Inode& root_inode() override;
private:
TmpFS();
LockRefPtr<TmpFSInode> m_root_inode;
// NOTE: We start by assigning InodeIndex of 2, because 0 is invalid and 1
// is reserved for the root directory inode.
unsigned m_next_inode_index { 2 };
unsigned next_inode_index();
};
}