ladybird/Kernel/FileSystem/DevTmpFS.cpp
Ben Wiederhake 9a4e125468 Kernel: Remove misleading FIXME in DevTmpFS
This FIXME does not seem to apply anymore. Yes, symbolic links in all
filesystems appear to be slightly broken, but that has nothing to do
with File::absolute_path. Let's remove the wrong FIXME instead of adding
to the confusion.
2021-10-31 12:06:28 +01:00

347 lines
9.2 KiB
C++

/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/StringView.h>
#include <Kernel/Devices/DeviceManagement.h>
#include <Kernel/FileSystem/DevTmpFS.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
namespace Kernel {
KResultOr<NonnullRefPtr<DevTmpFS>> DevTmpFS::try_create()
{
return adopt_nonnull_ref_or_enomem(new (nothrow) DevTmpFS);
}
DevTmpFS::DevTmpFS()
{
}
size_t DevTmpFS::allocate_inode_index()
{
MutexLocker locker(m_lock);
m_next_inode_index = m_next_inode_index.value() + 1;
VERIFY(m_next_inode_index > 0);
return 1 + m_next_inode_index.value();
}
DevTmpFS::~DevTmpFS()
{
}
KResult DevTmpFS::initialize()
{
m_root_inode = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) DevTmpFSRootDirectoryInode(*this)));
return KSuccess;
}
Inode& DevTmpFS::root_inode()
{
return *m_root_inode;
}
DevTmpFSInode::DevTmpFSInode(DevTmpFS& fs)
: Inode(fs, fs.allocate_inode_index())
{
}
DevTmpFSInode::DevTmpFSInode(DevTmpFS& fs, unsigned major_number, unsigned minor_number)
: Inode(fs, fs.allocate_inode_index())
, m_major_number(major_number)
, m_minor_number(minor_number)
{
}
KResultOr<size_t> DevTmpFSInode::read_bytes(off_t, size_t, UserOrKernelBuffer&, OpenFileDescription*) const
{
VERIFY_NOT_REACHED();
}
KResult DevTmpFSInode::traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const
{
VERIFY_NOT_REACHED();
}
KResultOr<NonnullRefPtr<Inode>> DevTmpFSInode::lookup(StringView)
{
VERIFY_NOT_REACHED();
}
KResult DevTmpFSInode::flush_metadata()
{
return KSuccess;
}
KResultOr<size_t> DevTmpFSInode::write_bytes(off_t, size_t, const UserOrKernelBuffer&, OpenFileDescription*)
{
VERIFY_NOT_REACHED();
}
KResultOr<NonnullRefPtr<Inode>> DevTmpFSInode::create_child(StringView, mode_t, dev_t, UserID, GroupID)
{
VERIFY_NOT_REACHED();
}
KResult DevTmpFSInode::add_child(Inode&, const StringView&, mode_t)
{
VERIFY_NOT_REACHED();
}
InodeMetadata DevTmpFSInode::metadata() const
{
MutexLocker locker(m_inode_lock);
VERIFY((m_mode & 0777) == m_mode);
InodeMetadata metadata;
metadata.uid = m_uid;
metadata.gid = m_gid;
metadata.size = 0;
metadata.mtime = mepoch;
switch (node_type()) {
case Type::RootDirectory:
metadata.inode = { fsid(), 1 };
metadata.mode = 0040555;
metadata.uid = 0;
metadata.gid = 0;
metadata.size = 0;
metadata.mtime = mepoch;
break;
case Type::Directory:
metadata.inode = { fsid(), index() };
metadata.mode = S_IFDIR | m_mode;
break;
case Type::BlockDevice:
metadata.inode = { fsid(), index() };
metadata.mode = S_IFBLK | m_mode;
metadata.major_device = m_major_number;
metadata.minor_device = m_minor_number;
break;
case Type::CharacterDevice:
metadata.inode = { fsid(), index() };
metadata.mode = S_IFCHR | m_mode;
metadata.major_device = m_major_number;
metadata.minor_device = m_minor_number;
break;
case Type::Link:
metadata.inode = { fsid(), index() };
metadata.mode = S_IFLNK | m_mode;
break;
default:
VERIFY_NOT_REACHED();
}
return metadata;
}
KResult DevTmpFSInode::remove_child(const StringView&)
{
VERIFY_NOT_REACHED();
}
KResult DevTmpFSInode::chmod(mode_t mode)
{
MutexLocker locker(m_inode_lock);
mode &= 0777;
if (m_mode == mode)
return KSuccess;
m_mode = mode;
return KSuccess;
}
KResult DevTmpFSInode::chown(UserID uid, GroupID gid)
{
MutexLocker locker(m_inode_lock);
m_uid = uid;
m_gid = gid;
return KSuccess;
}
KResult DevTmpFSInode::truncate(u64)
{
return EPERM;
}
StringView DevTmpFSLinkInode::name() const
{
return m_name->view();
}
DevTmpFSLinkInode::~DevTmpFSLinkInode()
{
}
DevTmpFSLinkInode::DevTmpFSLinkInode(DevTmpFS& fs, NonnullOwnPtr<KString> name)
: DevTmpFSInode(fs)
, m_name(move(name))
{
}
KResultOr<size_t> DevTmpFSLinkInode::read_bytes(off_t offset, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) const
{
MutexLocker locker(m_inode_lock);
VERIFY(offset == 0);
VERIFY(m_link);
TRY(buffer.write(m_link->characters() + offset, m_link->length()));
return m_link->length();
}
KResultOr<size_t> DevTmpFSLinkInode::write_bytes(off_t offset, size_t count, UserOrKernelBuffer const& buffer, OpenFileDescription*)
{
auto new_string = TRY(buffer.try_copy_into_kstring(count));
MutexLocker locker(m_inode_lock);
VERIFY(offset == 0);
VERIFY(buffer.is_kernel_buffer());
m_link = move(new_string);
return count;
}
DevTmpFSDirectoryInode::DevTmpFSDirectoryInode(DevTmpFS& fs)
: DevTmpFSInode(fs)
{
}
DevTmpFSDirectoryInode::DevTmpFSDirectoryInode(DevTmpFS& fs, NonnullOwnPtr<KString> name)
: DevTmpFSInode(fs)
, m_name(move(name))
{
}
DevTmpFSDirectoryInode::~DevTmpFSDirectoryInode()
{
}
KResult DevTmpFSDirectoryInode::traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)> callback) const
{
MutexLocker locker(m_inode_lock);
callback({ ".", identifier(), 0 });
callback({ "..", identifier(), 0 });
for (auto& node : m_nodes) {
InodeIdentifier identifier = { fsid(), node.index() };
callback({ node.name(), identifier, 0 });
}
return KSuccess;
}
KResultOr<NonnullRefPtr<Inode>> DevTmpFSDirectoryInode::lookup(StringView name)
{
MutexLocker locker(m_inode_lock);
for (auto& node : m_nodes) {
if (node.name() == name) {
return node;
}
}
return KResult(ENOENT);
}
KResult DevTmpFSDirectoryInode::remove_child(const StringView& name)
{
MutexLocker locker(m_inode_lock);
for (auto& node : m_nodes) {
if (node.name() == name) {
m_nodes.remove(node);
return KSuccess;
}
}
return KResult(ENOENT);
}
KResultOr<NonnullRefPtr<Inode>> DevTmpFSDirectoryInode::create_child(StringView name, mode_t mode, dev_t device_mode, UserID, GroupID)
{
MutexLocker locker(m_inode_lock);
for (auto& node : m_nodes) {
if (node.name() == name)
return KResult(EEXIST);
}
InodeMetadata metadata;
metadata.mode = mode;
if (metadata.is_directory()) {
auto name_kstring = TRY(KString::try_create(name));
auto new_directory_inode = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) DevTmpFSDirectoryInode(fs(), move(name_kstring))));
m_nodes.append(*new_directory_inode);
return new_directory_inode;
}
if (metadata.is_device()) {
auto name_kstring = TRY(KString::try_create(name));
unsigned major = major_from_encoded_device(device_mode);
unsigned minor = minor_from_encoded_device(device_mode);
auto new_device_inode = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) DevTmpFSDeviceInode(fs(), major, minor, is_block_device(mode), move(name_kstring))));
TRY(new_device_inode->chmod(mode));
m_nodes.append(*new_device_inode);
return new_device_inode;
}
if (metadata.is_symlink()) {
auto name_kstring = TRY(KString::try_create(name));
auto new_link_inode = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) DevTmpFSLinkInode(fs(), move(name_kstring))));
TRY(new_link_inode->chmod(mode));
m_nodes.append(*new_link_inode);
return new_link_inode;
}
return EROFS;
}
DevTmpFSRootDirectoryInode::DevTmpFSRootDirectoryInode(DevTmpFS& fs)
: DevTmpFSDirectoryInode(fs)
{
m_mode = 0555;
}
DevTmpFSRootDirectoryInode::~DevTmpFSRootDirectoryInode()
{
}
KResult DevTmpFSRootDirectoryInode::chmod(mode_t)
{
return EPERM;
}
KResult DevTmpFSRootDirectoryInode::chown(UserID, GroupID)
{
return EPERM;
}
DevTmpFSDeviceInode::DevTmpFSDeviceInode(DevTmpFS& fs, unsigned major_number, unsigned minor_number, bool block_device, NonnullOwnPtr<KString> name)
: DevTmpFSInode(fs, major_number, minor_number)
, m_name(move(name))
, m_block_device(block_device)
{
}
DevTmpFSDeviceInode::~DevTmpFSDeviceInode()
{
}
StringView DevTmpFSDeviceInode::name() const
{
return m_name->view();
}
KResultOr<size_t> DevTmpFSDeviceInode::read_bytes(off_t offset, size_t count, UserOrKernelBuffer& buffer, OpenFileDescription* description) const
{
MutexLocker locker(m_inode_lock);
VERIFY(!!description);
RefPtr<Device> device = DeviceManagement::the().get_device(m_major_number, m_minor_number);
if (!device)
return KResult(ENODEV);
if (!device->can_read(*description, offset))
return KResult(ENOTIMPL);
auto result = const_cast<Device&>(*device).read(*description, offset, buffer, count);
if (result.is_error())
return result;
return result.value();
}
KResultOr<size_t> DevTmpFSDeviceInode::write_bytes(off_t offset, size_t count, const UserOrKernelBuffer& buffer, OpenFileDescription* description)
{
MutexLocker locker(m_inode_lock);
VERIFY(!!description);
RefPtr<Device> device = DeviceManagement::the().get_device(m_major_number, m_minor_number);
if (!device)
return KResult(ENODEV);
if (!device->can_write(*description, offset))
return KResult(ENOTIMPL);
auto result = const_cast<Device&>(*device).write(*description, offset, buffer, count);
if (result.is_error())
return result;
return result.value();
}
}