Files
serenity/Kernel/FileSystem/FUSE/FileSystem.cpp
implicitfield 0e94887b2c Kernel/VFS: Make filesystem implementations responsible for renames
Previously, the VFS layer would try to handle renames more-or-less by
itself, which really only worked for ext2, and even that was only due to
the replace_child kludge existing specifically for this purpose. This
never worked properly for FATFS, since the VFS layer effectively
depended on filesystems having some kind of reference-counting for
inodes, which is something that simply doesn't exist on any FAT variant
we support.

To resolve various issues with the existing scheme, this commit makes
filesystem implementations themselves responsible for the actual rename
operation, while keeping all the existing validation inside the VFS
layer. The only intended behavior change here is that rename operations
should actually properly work on FATFS.
2024-12-17 19:02:15 -05:00

84 lines
2.5 KiB
C++

/*
* Copyright (c) 2024, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/IntegralMath.h>
#include <Kernel/Devices/Device.h>
#include <Kernel/FileSystem/FUSE/FileSystem.h>
#include <Kernel/FileSystem/FUSE/Inode.h>
#include <Kernel/Tasks/Process.h>
#include <Kernel/Time/TimeManagement.h>
namespace Kernel {
static constexpr StringView rootmode_flag = "rootmode"sv;
static constexpr StringView gid_flag = "gid"sv;
static constexpr StringView uid_flag = "uid"sv;
static constexpr StringView fd_flag = "fd"sv;
ErrorOr<NonnullRefPtr<FileSystem>> FUSE::try_create(FileSystemSpecificOptions const& filesystem_specific_options)
{
int device_inode = parse_unsigned_filesystem_specific_option(filesystem_specific_options, fd_flag).value_or(-1);
auto description = TRY(Process::current().open_file_description(device_inode));
auto connection = TRY(FUSEConnection::try_create(description));
u64 rootmode = parse_unsigned_filesystem_specific_option(filesystem_specific_options, rootmode_flag).value_or(0);
u64 gid = parse_unsigned_filesystem_specific_option(filesystem_specific_options, gid_flag).value_or(0);
u64 uid = parse_unsigned_filesystem_specific_option(filesystem_specific_options, uid_flag).value_or(0);
return TRY(adopt_nonnull_ref_or_enomem(new (nothrow) FUSE(connection, rootmode, uid, gid)));
}
ErrorOr<void> FUSE::validate_mount_unsigned_integer_flag(StringView flag_name, u64)
{
if (flag_name == rootmode_flag)
return {};
if (flag_name == gid_flag)
return {};
if (flag_name == uid_flag)
return {};
if (flag_name == fd_flag)
return {};
return EINVAL;
}
FUSE::FUSE(NonnullRefPtr<FUSEConnection> connection, u64 rootmode, u64 gid, u64 uid)
: m_connection(connection)
, m_rootmode(rootmode)
, m_gid(gid)
, m_uid(uid)
{
}
FUSE::~FUSE() = default;
ErrorOr<void> FUSE::initialize()
{
m_root_inode = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) FUSEInode(*this)));
m_root_inode->m_metadata.mode = m_rootmode;
m_root_inode->m_metadata.uid = m_gid;
m_root_inode->m_metadata.gid = m_uid;
m_root_inode->m_metadata.size = 0;
m_root_inode->m_metadata.mtime = TimeManagement::boot_time();
return {};
}
Inode& FUSE::root_inode()
{
return *m_root_inode;
}
ErrorOr<void> FUSE::rename(Inode&, StringView, Inode&, StringView)
{
return ENOTIMPL;
}
u8 FUSE::internal_file_type_to_directory_entry_type(DirectoryEntryView const& entry) const
{
return ram_backed_file_type_to_directory_entry_type(entry);
}
}