eliott/serenity
1
0
Fork 0
mirror of https://github.com/SerenityOS/serenity synced 2026-05-03 04:42:19 +02:00
Code Issues Packages Projects Releases Wiki Activity

Kernel: Move most of VirtualFileSystem code to be in a namespace

Browse Source 
There's no point in constructing an object just for the sake of keeping
a state that can be touched by anything in the kernel code.

Let's reduce everything to be in a C++ namespace called with the
previous name "VirtualFileSystem" and keep a smaller textual-footprint
struct called "VirtualFileSystemDetails".

This change also cleans up old "friend class" statements that were no
longer needed, and move methods from the VirtualFileSystem code to more
appropriate places as well.
Please note that the method of locking all filesystems during shutdown
is removed, as in that place there's no meaning to actually locking all
filesystems because of running in kernel mode entirely.
This commit is contained in:
Liav A.
2024-07-12 09:21:07 +03:00
committed by Tim Schumacher
parent 4370bbb3ad
commit 3692af528e
45 changed files with 230 additions and 268 deletions
Download Patch File Download Diff File Expand all files Collapse all files

124
Kernel/FileSystem/VirtualFileSystem.h
View File

@@ -46,101 +46,53 @@ enum class AccessFlags {
AK_ENUM_BITWISE_OPERATORS(AccessFlags);
class VirtualFileSystem {
friend class StorageManagement;
namespace VirtualFileSystem {
public:
// Required to be at least 8 by POSIX
// https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html
static constexpr int symlink_recursion_limit = 8;
// Required to be at least 8 by POSIX
// https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html
static constexpr int symlink_recursion_limit = 8;
static void initialize();
static VirtualFileSystem& the();
bool check_matching_absolute_path_hierarchy(Custody const& first_custody, Custody const& second_custody);
static bool check_matching_absolute_path_hierarchy(Custody const& first_custody, Custody const& second_custody);
ErrorOr<FileSystemInitializer const*> find_filesystem_type_initializer(StringView fs_type);
static ErrorOr<FileSystemInitializer const*> find_filesystem_type_initializer(StringView fs_type);
ErrorOr<void> mount(VFSRootContext&, MountFile&, OpenFileDescription*, Custody& mount_point, int flags);
ErrorOr<void> pivot_root_by_copying_mounted_fs_instance(VFSRootContext&, FileSystem& fs, int root_mount_flags);
VirtualFileSystem();
~VirtualFileSystem();
ErrorOr<void> bind_mount(VFSRootContext&, Custody& source, Custody& mount_point, int flags);
ErrorOr<void> copy_mount(Custody& source, VFSRootContext& destination, Custody& mount_point, int flags);
ErrorOr<void> remount(VFSRootContext&, Custody& mount_point, int new_flags);
ErrorOr<void> unmount(VFSRootContext&, Custody& mount_point);
ErrorOr<void> unmount(VFSRootContext&, Inode& guest_inode, StringView custody_path);
SpinlockProtected<IntrusiveList<&FileSystem::m_file_system_node>, LockRank::FileSystem>& all_file_systems_list(Badge<VFSRootContext>) { return m_file_systems_list; }
SpinlockProtected<IntrusiveList<&VFSRootContext::m_list_node>, LockRank::FileSystem>& all_root_contexts_list(Badge<PowerStateSwitchTask>) { return m_root_contexts; }
SpinlockProtected<IntrusiveList<&VFSRootContext::m_list_node>, LockRank::FileSystem>& all_root_contexts_list(Badge<VFSRootContext>) { return m_root_contexts; }
SpinlockProtected<IntrusiveList<&VFSRootContext::m_list_node>, LockRank::FileSystem>& all_root_contexts_list(Badge<Process>) { return m_root_contexts; }
ErrorOr<NonnullRefPtr<OpenFileDescription>> open(VFSRootContext const&, Credentials const&, StringView path, int options, mode_t mode, CustodyBase const& base, Optional<UidAndGid> = {});
ErrorOr<NonnullRefPtr<OpenFileDescription>> open(Process const&, VFSRootContext const&, Credentials const&, StringView path, int options, mode_t mode, CustodyBase const& base, Optional<UidAndGid> = {});
ErrorOr<NonnullRefPtr<OpenFileDescription>> create(Credentials const&, StringView path, int options, mode_t mode, Custody& parent_custody, Optional<UidAndGid> = {});
ErrorOr<NonnullRefPtr<OpenFileDescription>> create(Process const&, Credentials const&, StringView path, int options, mode_t mode, Custody& parent_custody, Optional<UidAndGid> = {});
ErrorOr<void> mkdir(VFSRootContext const&, Credentials const&, StringView path, mode_t mode, CustodyBase const& base);
ErrorOr<void> link(VFSRootContext const&, Credentials const&, StringView old_path, StringView new_path, CustodyBase const& base);
ErrorOr<void> unlink(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base);
ErrorOr<void> symlink(VFSRootContext const&, Credentials const&, StringView target, StringView linkpath, CustodyBase const& base);
ErrorOr<void> rmdir(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base);
ErrorOr<void> chmod(VFSRootContext const&, Credentials const&, StringView path, mode_t, CustodyBase const& base, int options = 0);
ErrorOr<void> chmod(Credentials const&, Custody&, mode_t);
ErrorOr<void> chown(VFSRootContext const&, Credentials const&, StringView path, UserID, GroupID, CustodyBase const& base, int options);
ErrorOr<void> chown(Credentials const&, Custody&, UserID, GroupID);
ErrorOr<void> access(VFSRootContext const&, Credentials const&, StringView path, int mode, CustodyBase const& base, AccessFlags);
ErrorOr<InodeMetadata> lookup_metadata(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base, int options = 0);
ErrorOr<void> utime(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base, time_t atime, time_t mtime);
ErrorOr<void> utimensat(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base, timespec const& atime, timespec const& mtime, int options = 0);
ErrorOr<void> do_utimens(Credentials const&, Custody& custody, timespec const& atime, timespec const& mtime);
ErrorOr<void> rename(VFSRootContext const&, Credentials const&, CustodyBase const& old_base, StringView oldpath, CustodyBase const& new_base, StringView newpath);
ErrorOr<void> mknod(VFSRootContext const&, Credentials const&, StringView path, mode_t, dev_t, CustodyBase const& base);
ErrorOr<NonnullRefPtr<Custody>> open_directory(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base);
ErrorOr<void> mount(VFSRootContext&, MountFile&, OpenFileDescription*, Custody& mount_point, int flags);
ErrorOr<void> pivot_root_by_copying_mounted_fs_instance(VFSRootContext&, FileSystem& fs, int root_mount_flags);
ErrorOr<NonnullRefPtr<Custody>> resolve_path(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0);
ErrorOr<NonnullRefPtr<Custody>> resolve_path(Process const&, VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0);
ErrorOr<NonnullRefPtr<Custody>> resolve_path_without_veil(VFSRootContext const&, Credentials const&, StringView path, NonnullRefPtr<Custody> base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0);
ErrorOr<void> bind_mount(VFSRootContext&, Custody& source, Custody& mount_point, int flags);
ErrorOr<void> copy_mount(Custody& source, VFSRootContext& destination, Custody& mount_point, int flags);
ErrorOr<void> remount(VFSRootContext&, Custody& mount_point, int new_flags);
ErrorOr<void> unmount(VFSRootContext&, Custody& mount_point);
ErrorOr<void> unmount(VFSRootContext&, Inode& guest_inode, StringView custody_path);
void sync_filesystems();
ErrorOr<NonnullRefPtr<OpenFileDescription>> open(VFSRootContext const&, Credentials const&, StringView path, int options, mode_t mode, CustodyBase const& base, Optional<UidAndGid> = {});
ErrorOr<NonnullRefPtr<OpenFileDescription>> open(Process const&, VFSRootContext const&, Credentials const&, StringView path, int options, mode_t mode, CustodyBase const& base, Optional<UidAndGid> = {});
ErrorOr<NonnullRefPtr<OpenFileDescription>> create(Credentials const&, StringView path, int options, mode_t mode, Custody& parent_custody, Optional<UidAndGid> = {});
ErrorOr<NonnullRefPtr<OpenFileDescription>> create(Process const&, Credentials const&, StringView path, int options, mode_t mode, Custody& parent_custody, Optional<UidAndGid> = {});
ErrorOr<void> mkdir(VFSRootContext const&, Credentials const&, StringView path, mode_t mode, CustodyBase const& base);
ErrorOr<void> link(VFSRootContext const&, Credentials const&, StringView old_path, StringView new_path, CustodyBase const& base);
ErrorOr<void> unlink(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base);
ErrorOr<void> symlink(VFSRootContext const&, Credentials const&, StringView target, StringView linkpath, CustodyBase const& base);
ErrorOr<void> rmdir(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base);
ErrorOr<void> chmod(VFSRootContext const&, Credentials const&, StringView path, mode_t, CustodyBase const& base, int options = 0);
ErrorOr<void> chmod(Credentials const&, Custody&, mode_t);
ErrorOr<void> chown(VFSRootContext const&, Credentials const&, StringView path, UserID, GroupID, CustodyBase const& base, int options);
ErrorOr<void> chown(Credentials const&, Custody&, UserID, GroupID);
ErrorOr<void> access(VFSRootContext const&, Credentials const&, StringView path, int mode, CustodyBase const& base, AccessFlags);
ErrorOr<InodeMetadata> lookup_metadata(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base, int options = 0);
ErrorOr<void> utime(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base, time_t atime, time_t mtime);
ErrorOr<void> utimensat(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base, timespec const& atime, timespec const& mtime, int options = 0);
ErrorOr<void> do_utimens(Credentials const&, Custody& custody, timespec const& atime, timespec const& mtime);
ErrorOr<void> rename(VFSRootContext const&, Credentials const&, CustodyBase const& old_base, StringView oldpath, CustodyBase const& new_base, StringView newpath);
ErrorOr<void> mknod(VFSRootContext const&, Credentials const&, StringView path, mode_t, dev_t, CustodyBase const& base);
ErrorOr<NonnullRefPtr<Custody>> open_directory(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base);
ErrorOr<void> for_each_mount(VFSRootContext& context, Function<ErrorOr<void>(Mount const&)>) const;
void sync_filesystems();
void lock_all_filesystems();
static void sync();
ErrorOr<NonnullRefPtr<Custody>> resolve_path(VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0);
ErrorOr<NonnullRefPtr<Custody>> resolve_path(Process const&, VFSRootContext const&, Credentials const&, StringView path, CustodyBase const& base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0);
ErrorOr<NonnullRefPtr<Custody>> resolve_path_without_veil(VFSRootContext const&, Credentials const&, StringView path, NonnullRefPtr<Custody> base, RefPtr<Custody>* out_parent = nullptr, int options = 0, int symlink_recursion_level = 0);
private:
friend class OpenFileDescription;
UnveilNode const& find_matching_unveiled_path(Process const&, StringView path);
ErrorOr<void> validate_path_against_process_veil(Process const&, StringView path, int options);
ErrorOr<void> validate_path_against_process_veil(Process const& process, Custody const& custody, int options);
ErrorOr<void> validate_path_against_process_veil(Custody const& path, int options);
ErrorOr<void> validate_path_against_process_veil(StringView path, int options);
static void delete_mount_from_list(Mount& mount);
ErrorOr<void> remove_mount(Mount& mount, IntrusiveList<&FileBackedFileSystem::m_file_backed_file_system_node>& file_backed_fs_list);
static ErrorOr<NonnullRefPtr<FileSystem>> create_and_initialize_filesystem_from_mount_file(MountFile& mount_file);
static ErrorOr<NonnullRefPtr<FileSystem>> create_and_initialize_filesystem_from_mount_file_and_description(IntrusiveList<&FileBackedFileSystem::m_file_backed_file_system_node>& file_backed_fs_list, MountFile& mount_file, OpenFileDescription& source_description);
static ErrorOr<void> verify_mount_file_and_description_requirements(MountFile& mount_file, OpenFileDescription& source_description);
ErrorOr<void> traverse_directory_inode(Inode&, Function<ErrorOr<void>(FileSystem::DirectoryEntryView const&)>);
ErrorOr<void> apply_to_mount_for_host_custody(VFSRootContext&, Custody const& current_custody, Function<void(Mount&)>);
// NOTE: The FileBackedFileSystem list is protected by a mutex because we need to scan it
// to search for existing filesystems for already used block devices and therefore when doing
// that we could fail to find a filesystem so we need to create a new filesystem which might
// need to do disk access (i.e. taking Mutexes in other places) and then register that new filesystem
// in this list, to avoid TOCTOU bugs.
MutexProtected<IntrusiveList<&FileBackedFileSystem::m_file_backed_file_system_node>> m_file_backed_file_systems_list {};
SpinlockProtected<IntrusiveList<&FileSystem::m_file_system_node>, LockRank::FileSystem> m_file_systems_list {};
SpinlockProtected<IntrusiveList<&VFSRootContext::m_list_node>, LockRank::FileSystem> m_root_contexts {};
};
}