ladybird/Kernel/FileSystem/DevFS.cpp
2021-09-05 19:02:57 +02:00

409 lines
10 KiB
C++

/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/StringView.h>
#include <Kernel/FileSystem/DevFS.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
namespace Kernel {
NonnullRefPtr<DevFS> DevFS::create()
{
return adopt_ref(*new DevFS);
}
DevFS::DevFS()
: m_root_inode(adopt_ref(*new DevFSRootDirectoryInode(*this)))
{
MutexLocker locker(m_lock);
Device::for_each([&](Device& device) {
// FIXME: Find a better way to not add MasterPTYs or SlavePTYs!
if (device.is_master_pty() || (device.is_character_device() && device.major() == 201))
return;
notify_new_device(device);
});
}
void DevFS::notify_new_device(Device& device)
{
auto name = KString::try_create(device.device_name());
VERIFY(name);
MutexLocker locker(m_lock);
auto new_device_inode = adopt_ref(*new DevFSDeviceInode(*this, device, name.release_nonnull()));
m_nodes.append(new_device_inode);
m_root_inode->m_devices.append(new_device_inode);
}
size_t DevFS::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();
}
void DevFS::notify_device_removal(Device&)
{
TODO();
}
DevFS::~DevFS()
{
}
KResult DevFS::initialize()
{
return KSuccess;
}
Inode& DevFS::root_inode()
{
return *m_root_inode;
}
KResultOr<NonnullRefPtr<Inode>> DevFS::get_inode(InodeIdentifier inode_id) const
{
MutexLocker locker(m_lock);
if (inode_id.index() == 1)
return m_root_inode;
for (auto& node : m_nodes) {
if (inode_id.index() == node.index())
return node;
}
return ENOENT;
}
DevFSInode::DevFSInode(DevFS& fs)
: Inode(fs, fs.allocate_inode_index())
{
}
KResultOr<size_t> DevFSInode::read_bytes(off_t, size_t, UserOrKernelBuffer&, FileDescription*) const
{
VERIFY_NOT_REACHED();
}
KResult DevFSInode::traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)>) const
{
VERIFY_NOT_REACHED();
}
KResultOr<NonnullRefPtr<Inode>> DevFSInode::lookup(StringView)
{
VERIFY_NOT_REACHED();
}
void DevFSInode::flush_metadata()
{
}
KResultOr<size_t> DevFSInode::write_bytes(off_t, size_t, const UserOrKernelBuffer&, FileDescription*)
{
VERIFY_NOT_REACHED();
}
KResultOr<NonnullRefPtr<Inode>> DevFSInode::create_child(StringView, mode_t, dev_t, UserID, GroupID)
{
return EROFS;
}
KResult DevFSInode::add_child(Inode&, const StringView&, mode_t)
{
return EROFS;
}
KResult DevFSInode::remove_child(const StringView&)
{
return EROFS;
}
KResult DevFSInode::chmod(mode_t)
{
return EPERM;
}
KResult DevFSInode::chown(UserID, GroupID)
{
return EPERM;
}
KResult DevFSInode::truncate(u64)
{
return EPERM;
}
StringView DevFSLinkInode::name() const
{
return m_name->view();
}
DevFSLinkInode::~DevFSLinkInode()
{
}
DevFSLinkInode::DevFSLinkInode(DevFS& fs, NonnullOwnPtr<KString> name)
: DevFSInode(fs)
, m_name(move(name))
{
}
KResultOr<size_t> DevFSLinkInode::read_bytes(off_t offset, size_t, UserOrKernelBuffer& buffer, FileDescription*) const
{
MutexLocker locker(m_inode_lock);
VERIFY(offset == 0);
VERIFY(m_link);
if (!buffer.write(m_link->characters() + offset, m_link->length()))
return EFAULT;
return m_link->length();
}
InodeMetadata DevFSLinkInode::metadata() const
{
InodeMetadata metadata;
metadata.inode = { fsid(), index() };
metadata.mode = S_IFLNK | 0555;
metadata.uid = 0;
metadata.gid = 0;
metadata.size = 0;
metadata.mtime = mepoch;
return metadata;
}
KResultOr<size_t> DevFSLinkInode::write_bytes(off_t offset, size_t count, UserOrKernelBuffer const& buffer, FileDescription*)
{
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;
}
DevFSDirectoryInode::DevFSDirectoryInode(DevFS& fs)
: DevFSInode(fs)
{
}
DevFSDirectoryInode::~DevFSDirectoryInode()
{
}
InodeMetadata DevFSDirectoryInode::metadata() const
{
InodeMetadata metadata;
metadata.inode = { fsid(), 1 };
metadata.mode = 0040555;
metadata.uid = 0;
metadata.gid = 0;
metadata.size = 0;
metadata.mtime = mepoch;
return metadata;
}
DevFSRootDirectoryInode::DevFSRootDirectoryInode(DevFS& fs)
: DevFSDirectoryInode(fs)
{
}
KResult DevFSRootDirectoryInode::traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)> callback) const
{
MutexLocker locker(fs().m_lock);
callback({ ".", identifier(), 0 });
callback({ "..", identifier(), 0 });
for (auto& directory : m_subdirectories) {
InodeIdentifier identifier = { fsid(), directory.index() };
callback({ directory.name(), identifier, 0 });
}
for (auto& link : m_links) {
InodeIdentifier identifier = { fsid(), link.index() };
callback({ link.name(), identifier, 0 });
}
for (auto& device_node : m_devices) {
InodeIdentifier identifier = { fsid(), device_node.index() };
callback({ device_node.name(), identifier, 0 });
}
return KSuccess;
}
KResultOr<NonnullRefPtr<Inode>> DevFSRootDirectoryInode::lookup(StringView name)
{
MutexLocker locker(fs().m_lock);
for (auto& subdirectory : m_subdirectories) {
if (subdirectory.name() == name)
return subdirectory;
}
for (auto& link : m_links) {
if (link.name() == name)
return link;
}
for (auto& device_node : m_devices) {
if (device_node.name() == name) {
return device_node;
}
}
return ENOENT;
}
KResultOr<NonnullRefPtr<Inode>> DevFSRootDirectoryInode::create_child(StringView name, mode_t mode, dev_t, UserID, GroupID)
{
MutexLocker locker(fs().m_lock);
InodeMetadata metadata;
metadata.mode = mode;
if (metadata.is_directory()) {
for (auto& directory : m_subdirectories) {
if (directory.name() == name)
return EEXIST;
}
if (name != "pts")
return EROFS;
auto new_directory_inode = adopt_ref_if_nonnull(new (nothrow) DevFSPtsDirectoryInode(fs()));
if (!new_directory_inode)
return ENOMEM;
if (!m_subdirectories.try_ensure_capacity(m_subdirectories.size() + 1))
return ENOMEM;
if (!fs().m_nodes.try_ensure_capacity(fs().m_nodes.size() + 1))
return ENOMEM;
m_subdirectories.append(*new_directory_inode);
fs().m_nodes.append(*new_directory_inode);
return KResult(KSuccess);
}
if (metadata.is_symlink()) {
for (auto& link : m_links) {
if (link.name() == name)
return EEXIST;
}
auto name_kstring = KString::try_create(name);
if (!name_kstring)
return ENOMEM;
auto new_link_inode = adopt_ref_if_nonnull(new (nothrow) DevFSLinkInode(fs(), name_kstring.release_nonnull()));
if (!new_link_inode)
return ENOMEM;
if (!m_links.try_ensure_capacity(m_links.size() + 1))
return ENOMEM;
if (!fs().m_nodes.try_ensure_capacity(fs().m_nodes.size() + 1))
return ENOMEM;
m_links.append(*new_link_inode);
fs().m_nodes.append(*new_link_inode);
return new_link_inode.release_nonnull();
}
return EROFS;
}
DevFSRootDirectoryInode::~DevFSRootDirectoryInode()
{
}
InodeMetadata DevFSRootDirectoryInode::metadata() const
{
InodeMetadata metadata;
metadata.inode = { fsid(), 1 };
metadata.mode = 0040555;
metadata.uid = 0;
metadata.gid = 0;
metadata.size = 0;
metadata.mtime = mepoch;
return metadata;
}
DevFSDeviceInode::DevFSDeviceInode(DevFS& fs, Device const& device, NonnullOwnPtr<KString> name)
: DevFSInode(fs)
, m_attached_device(device)
, m_name(move(name))
{
}
DevFSDeviceInode::~DevFSDeviceInode()
{
}
KResult DevFSDeviceInode::chown(UserID uid, GroupID gid)
{
MutexLocker locker(m_inode_lock);
m_uid = uid;
m_gid = gid;
return KSuccess;
}
StringView DevFSDeviceInode::name() const
{
return m_name->view();
}
KResultOr<size_t> DevFSDeviceInode::read_bytes(off_t offset, size_t count, UserOrKernelBuffer& buffer, FileDescription* description) const
{
MutexLocker locker(m_inode_lock);
VERIFY(!!description);
if (!m_attached_device->can_read(*description, offset))
return 0;
auto nread = const_cast<Device&>(*m_attached_device).read(*description, offset, buffer, count);
if (nread.is_error())
return EIO;
return nread.value();
}
InodeMetadata DevFSDeviceInode::metadata() const
{
MutexLocker locker(m_inode_lock);
InodeMetadata metadata;
metadata.inode = { fsid(), index() };
metadata.mode = (m_attached_device->is_block_device() ? S_IFBLK : S_IFCHR) | m_attached_device->required_mode();
metadata.uid = m_uid;
metadata.gid = m_gid;
metadata.size = 0;
metadata.mtime = mepoch;
metadata.major_device = m_attached_device->major();
metadata.minor_device = m_attached_device->minor();
return metadata;
}
KResultOr<size_t> DevFSDeviceInode::write_bytes(off_t offset, size_t count, const UserOrKernelBuffer& buffer, FileDescription* description)
{
MutexLocker locker(m_inode_lock);
VERIFY(!!description);
if (!m_attached_device->can_write(*description, offset))
return 0;
auto nread = const_cast<Device&>(*m_attached_device).write(*description, offset, buffer, count);
if (nread.is_error())
return EIO;
return nread.value();
}
DevFSPtsDirectoryInode::DevFSPtsDirectoryInode(DevFS& fs)
: DevFSDirectoryInode(fs)
{
}
KResult DevFSPtsDirectoryInode::traverse_as_directory(Function<bool(FileSystem::DirectoryEntryView const&)> callback) const
{
MutexLocker locker(m_inode_lock);
callback({ ".", identifier(), 0 });
callback({ "..", identifier(), 0 });
return KSuccess;
}
KResultOr<NonnullRefPtr<Inode>> DevFSPtsDirectoryInode::lookup(StringView)
{
return ENOENT;
}
DevFSPtsDirectoryInode::~DevFSPtsDirectoryInode()
{
}
InodeMetadata DevFSPtsDirectoryInode::metadata() const
{
InodeMetadata metadata;
metadata.inode = { fsid(), index() };
metadata.mode = 0040555;
metadata.uid = 0;
metadata.gid = 0;
metadata.size = 0;
metadata.mtime = mepoch;
return metadata;
}
}