#include <VFS.h>

Collaboration diagram for VFS:

Public Types
typedef void(*	MountCallback) ()

typedef HashTable< String, Filesystem *, HashedStringView >	AliasTable

Public Member Functions
	VFS ()

	~VFS ()

bool	mount (Disk *pDisk, String &alias)

void	addAlias (Filesystem *pFs, const String &alias)

void	addAlias (const String &oldAlias, const String &newAlias)

String	getUniqueAlias (const String &alias)

bool	aliasExists (const String &alias)

AliasTable &	getAliases ()

Tree< Filesystem , List< String > * > &	getMounts ()

void	removeAlias (const String &alias)

void	removeAllAliases (Filesystem *pFs, bool canDelete=true)

Filesystem *	lookupFilesystem (const String &alias)

Filesystem *	lookupFilesystem (const HashedStringView &alias)

File *	find (const String &path, File *pStartNode=0)

bool	createFile (const String &path, uint32_t mask, File *pStartNode=0)

bool	createDirectory (const String &path, uint32_t mask, File *pStartNode=0)

bool	createSymlink (const String &path, const String &value, File *pStartNode=0)

bool	createLink (const String &path, File target, File pStartNode=0)

bool	remove (const String &path, File *pStartNode=0)

void	addProbeCallback (Filesystem::ProbeCallback callback)

void	addMountCallback (MountCallback callback)

Static Public Member Functions
static VFS &	instance ()

static bool	checkAccess (File *pFile, bool bRead, bool bWrite, bool bExecute)

static constexpr const char *	mountSeparator ()

Private Member Functions
ssize_t	findColon (const String &path)

Private Attributes
AliasTable	m_Aliases

Tree< Filesystem , List< String > * >	m_Mounts

List< Filesystem::ProbeCallback * >	m_ProbeCallbacks

List< MountCallback * >	m_MountCallbacks

LruCache< String, Filesystem * >	m_AliasCache

LruCache< String, File * >	m_FindCache

Static Private Attributes
static VFS	m_Instance

static File *	m_EmptyFile

Detailed Description

This class implements a virtual file system.

The pedigree VFS is structured in a similar way to windows' - every filesystem is identified by a unique name and accessed thus:

myfs:/mydir/myfile

No UNIX-style mounting of filesystems inside filesystems is possible. A filesystem may be referred to by multiple names - a reference count is maintained by the filesystem - when no aliases point to it, it is unmounted totally.

The 'root' filesystem - that is the FS with system data on, is visible by the alias 'root', thus; 'root:/System/Boot/kernel' could be used to access the kernel image.

Definition at line 57 of file VFS.h.

Member Typedef Documentation

typedef HashTable<String, Filesystem *, HashedStringView> VFS::AliasTable

Type of the alias lookup table.

Definition at line 64 of file VFS.h.

typedef void(* VFS::MountCallback) ()

Callback type, called when a disk is mounted or unmounted.

Definition at line 61 of file VFS.h.

Constructor & Destructor Documentation

VFS::VFS ( )

Constructor

Definition at line 61 of file VFS.cc.

VFS::~VFS ( )

Destructor

Definition at line 65 of file VFS.cc.

References List< T, nodePoolSize >::begin(), Tree< K, E >::begin(), List< T, nodePoolSize >::end(), and Tree< K, E >::end().

Member Function Documentation

void VFS::addAlias	(	Filesystem *	pFs,
		const String &	alias
	)

Adds an alias to an existing filesystem.

Parameters

pFs	The filesystem to add an alias for.
pAlias	The alias to add.

Definition at line 123 of file VFS.cc.

References Tree< K, E >::insert(), HashTable< K, V, SiblingK, InitialBuckets, QuadraticProbe, GrowthFactor >::insert(), Tree< K, E >::lookup(), HashTable< K, V, SiblingK, InitialBuckets, QuadraticProbe, GrowthFactor >::lookup(), and Filesystem::m_nAliases.

Referenced by RawFs::getRoot(), and mount().

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void VFS::addMountCallback ( MountCallback callback )

Adds a mount callback - the function is called when a disk is mounted or unmounted.

Definition at line 305 of file VFS.cc.

References List< T, nodePoolSize >::pushBack().

Referenced by RawFs::getRoot().

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void VFS::addProbeCallback ( Filesystem::ProbeCallback callback )

Adds a filesystem probe callback - this is called when a device is mounted.

Definition at line 298 of file VFS.cc.

References List< T, nodePoolSize >::pushBack().

Referenced by Ext2Filesystem::releaseInode(), Iso9660Filesystem::remove(), and FatFilesystem::remove().

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bool VFS::aliasExists ( const String & alias )

Does a given alias exist?

Definition at line 174 of file VFS.cc.

References HashTable< K, V, SiblingK, InitialBuckets, QuadraticProbe, GrowthFactor >::contains().

Referenced by getUniqueAlias().

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bool VFS::checkAccess	(	File *	pFile,
		bool	bRead,
		bool	bWrite,
		bool	bExecute
	)

static

Checks if the current user can access the given file.

Definition at line 448 of file VFS.cc.

References Process::getUserId(), Processor::information(), NOTICE, and Oct.

Referenced by Filesystem::createDirectory(), Filesystem::createFile(), Filesystem::createLink(), Filesystem::createSymlink(), Filesystem::findNode(), PosixSubsystem::invoke(), Filesystem::remove(), and PosixSubsystem::threadRemoved().

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bool VFS::createDirectory	(	const String &	path,
		uint32_t	mask,
		File *	pStartNode = `0`
	)

Attempts to create a directory.

Definition at line 338 of file VFS.cc.

References Filesystem::createDirectory(), and lookupFilesystem().

Referenced by Filesystem::isCaseSensitive().

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bool VFS::createFile	(	const String &	path,
		uint32_t	mask,
		File *	pStartNode = `0`
	)

Attempts to create a file.

Definition at line 312 of file VFS.cc.

References Filesystem::createFile(), and lookupFilesystem().

Referenced by Filesystem::isCaseSensitive().

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bool VFS::createLink	(	const String &	path,
		File *	target,
		File *	pStartNode = `0`
	)

Attempts to create a hard link.

Definition at line 397 of file VFS.cc.

References Filesystem::createLink(), and lookupFilesystem().

Referenced by Filesystem::isCaseSensitive().

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bool VFS::createSymlink	(	const String &	path,
		const String &	value,
		File *	pStartNode = `0`
	)

Attempts to create a symlink.

Definition at line 370 of file VFS.cc.

References Filesystem::createSymlink(), and lookupFilesystem().

Referenced by Filesystem::isCaseSensitive().

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File * VFS::find	(	const String &	path,
		File *	pStartNode = `0`
	)

Attempts to obtain a File for a specific path.

Definition at line 243 of file VFS.cc.

References Filesystem::find(), LruCache< K, T, Slots >::get(), lookupFilesystem(), LruCache< K, T, Slots >::store(), and String::view().

Referenced by UnixSocketSyscalls::bind(), UnixSocketSyscalls::connect(), PosixSubsystem::findFile(), ProcFs::initialise(), DynamicLinker::loadObject(), DynamicLinker::loadProgram(), and UnixSocketSyscalls::sendto_msg().

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AliasTable& VFS::getAliases ( )

inline

Obtains a list of all filesystem aliases

Definition at line 92 of file VFS.h.

Tree<Filesystem *, List<String *> *>& VFS::getMounts ( )

inline

Obtains a list of all mounted filesystems

Definition at line 98 of file VFS.h.

String VFS::getUniqueAlias ( const String & alias )

Gets a unique alias for a filesystem.

Definition at line 153 of file VFS.cc.

References aliasExists().

Referenced by mount().

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VFS & VFS::instance ( )

static

Returns the singleton VFS instance.

Definition at line 56 of file VFS.cc.

References m_Instance.

Referenced by UnixSocketSyscalls::bind(), UnixSocketSyscalls::connect(), PosixSubsystem::findFile(), RawFs::getRoot(), PosixProcess::getType(), ProcFs::initialise(), DynamicLinker::loadObject(), DynamicLinker::loadProgram(), Ext2Filesystem::releaseInode(), Iso9660Filesystem::remove(), FatFilesystem::remove(), and UnixSocketSyscalls::sendto_msg().

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Filesystem * VFS::lookupFilesystem ( const String & alias )

Looks up the Filesystem from a given alias.

Parameters

pAlias The alias to search for.

Returns: The filesystem aliased by pAlias or 0 if none found.

Definition at line 221 of file VFS.cc.

References LruCache< K, T, Slots >::get(), HashTable< K, V, SiblingK, InitialBuckets, QuadraticProbe, GrowthFactor >::lookup(), LruCache< K, T, Slots >::store(), and String::view().

Referenced by createDirectory(), createFile(), createLink(), createSymlink(), find(), PosixSubsystem::findFile(), PosixProcess::getType(), and remove().

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bool VFS::mount	(	Disk *	pDisk,
		String &	alias
	)

Mounts a Disk device as the alias "alias". If alias is zero-length, the Filesystem is asked for its preferred name (usually a volume name of some sort), and returned in "alias"

Definition at line 88 of file VFS.cc.

References addAlias(), List< T, nodePoolSize >::begin(), List< T, nodePoolSize >::end(), getUniqueAlias(), Filesystem::getVolumeLabel(), Tree< K, E >::insert(), and Tree< K, E >::lookup().

static constexpr const char* VFS::mountSeparator ( )

inlinestatic

Separator between mount point and filesystem path.

Definition at line 152 of file VFS.h.

bool VFS::remove	(	const String &	path,
		File *	pStartNode = `0`
	)

Attempts to remove a file/directory/symlink. WILL FAIL IF DIRECTORY NOT EMPTY

Definition at line 423 of file VFS.cc.

References lookupFilesystem(), and Filesystem::remove().

void VFS::removeAlias ( const String & alias )

Removes an alias from a filesystem. If no aliases remain for that filesystem, the filesystem is destroyed.

Parameters

pAlias The alias to remove.

Todo:: Remove from m_Mounts

Definition at line 179 of file VFS.cc.

References HashTable< K, V, SiblingK, InitialBuckets, QuadraticProbe, GrowthFactor >::remove().

void VFS::removeAllAliases	(	Filesystem *	pFs,
		bool	canDelete = `true`
	)

Removes all aliases from a filesystem - the filesystem is destroyed.

Parameters

pFs	The filesystem to destroy.

Todo:: Locking.

Definition at line 185 of file VFS.cc.

References List< T, nodePoolSize >::begin(), List< T, nodePoolSize >::end(), HashTable< K, V, SiblingK, InitialBuckets, QuadraticProbe, GrowthFactor >::erase(), Tree< K, E >::lookup(), and Tree< K, E >::remove().

Member Data Documentation

File* VFS::m_EmptyFile

staticprivate

A static File object representing an invalid file

Definition at line 164 of file VFS.h.

VFS VFS::m_Instance

staticprivate

The static instance object.

Todo:: Figure out a way to clean up files after deletion. Directory::remove() is not the right place to do this. There needs to be a way to add a File to some sort of queue that cleans it up once it hits refcount zero or something like that.

Definition at line 161 of file VFS.h.

Referenced by instance().

The documentation for this class was generated from the following files:

VFS.h
VFS.cc

Public Types

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation