#include <Filesystem.h>

Inheritance diagram for Filesystem:

Collaboration diagram for Filesystem:

Public Types
enum class	SyncStatus { Success , Unsupported , NoMemory , IoError }

typedef Filesystem (	ProbeCallback) (Disk *)

Public Member Functions
	Filesystem ()

virtual	~Filesystem ()

virtual bool	initialise (Disk *pDisk)=0

virtual File *	find (const StringView &path)

virtual File *	find (const String &path)

virtual File *	find (const StringView &path, File *pStartNode)

virtual File *	find (const String &path, File *pStartNode)

File *	findRetained (const StringView &path, Directory::ChildLease &result, File *pStartNode=nullptr)

virtual File *	getRoot () const =0

virtual const String &	getVolumeLabel () const =0

virtual bool	getUuid (String &uuid) const

virtual FileHandleStatus	encodeFileHandle (File &file, FileHandle &handle)

virtual FileHandleStatus	decodeFileHandle (const FileHandle &handle, RetainedFile &file)

virtual FileHandleStatus	fileHandleFsid (FileSystemId &id)

virtual SyncStatus	sync ()

virtual SyncStatus	shutdown ()

virtual bool	deviceRemoved (bool deviceAvailable=false)

bool	tryAcquireOperation (OperationBarrier::Lease &operation) const

bool	isDeviceRemoved () const

virtual QuotaStatus	quotaControl (const QuotaRequest &, QuotaResponse &, File *quotaFile=nullptr)

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

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

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

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

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

bool	remove (const StringView &path, File pStartNode, File expected)

bool	rename (const StringView &oldPath, File oldStart, const StringView &newPath, File newStart, bool noReplace=false)

Disk *	getDisk ()

bool	isReadOnly ()

virtual bool	isCaseSensitive ()

bool	remove (File parent, File file)

Protected Member Functions
virtual bool	createFile (File *parent, const String &filename, uint32_t mask)=0

virtual bool	createDirectory (File *parent, const String &filename, uint32_t mask)=0

virtual bool	createSymlink (File *parent, const String &filename, const String &value)=0

virtual bool	createLink (File parent, const String &filename, File target)

virtual bool	removeNode (File parent, const String &filename, File file)=0

virtual bool	renameNode (Directory oldParent, const String &oldName, File source, Directory newParent, const String &newName, File replaced)

bool	beginDeviceRemoval (bool deviceAvailable)

Protected Attributes
bool	m_bReadOnly

Disk *	m_pDisk

DiskUse	m_DiskUse

OperationBarrier	m_Operations

Private Member Functions
bool	removeChild (File parent, const String &filename, File expected, const FilesystemPathRef *parentPath=nullptr)

bool	renameChildren (File oldParent, const String &oldName, File newParent, const String &newName, bool noReplace, bool sourceMustBeDirectory, const FilesystemPathRef oldPath=nullptr, const FilesystemPathRef newPath=nullptr)

File *	findNode (File *pNode, StringView path)

File *	findNode (File pNode, StringView path, File stableStart, File trueRoot, File *retainedResult)

File *	findParent (StringView path, File pStartNode, String &filename, File *retainedParent=nullptr)

	Filesystem (const Filesystem &)

void	operator= (const Filesystem &)

Private Attributes
Atomic< Thread * >	m_RemovalOwner = nullptr

Static Private Attributes
static Mutex	m_StructureLock

Friends
class	Directory

class	VFS

class	VfsMountView

Detailed Description

This class provides the abstract skeleton that all filesystems must implement.

Thanks to gr00ber at osdev for the inspiration for the caching algorithms.

Definition at line 44 of file Filesystem.h.

Member Typedef Documentation

◆ ProbeCallback

typedef Filesystem *(* Filesystem::ProbeCallback) (Disk *)

Type of the probing callback given to the VFS. Probe function - if this filesystem is found on the given Disk device, create a new instance of it and return that. Else return 0.

Definition at line 70 of file Filesystem.h.

Member Enumeration Documentation

◆ SyncStatus

enum class Filesystem::SyncStatus

strong

Definition at line 52 of file Filesystem.h.

Constructor & Destructor Documentation

◆ Filesystem() [1/2]

Filesystem::Filesystem ( )

Constructor - creates a blank object.

Definition at line 39 of file Filesystem.cc.

◆ ~Filesystem()

Filesystem::~Filesystem ( )

virtual

Destructor

Definition at line 43 of file Filesystem.cc.

References OperationBarrier::closeAndWait().

◆ Filesystem() [2/2]

Filesystem::Filesystem ( const Filesystem & )

private

Copy constructor.

Note: NOT implemented.

Member Function Documentation

◆ beginDeviceRemoval()

bool Filesystem::beginDeviceRemoval ( bool deviceAvailable )

protected

Definition at line 71 of file Filesystem.cc.

◆ createDirectory() [1/2]

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

Creates a directory on the filesystem. Fails if the dir's parent directory does not exist.

Definition at line 262 of file Filesystem.cc.

References VFS::checkAccess(), createDirectory(), and findParent().

Referenced by VFS::createDirectory(), and createDirectory().

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◆ createDirectory() [2/2]

virtual bool Filesystem::createDirectory	(	File *	parent,
		const String &	filename,
		uint32_t	mask
	)

protectedpure virtual

createDirectory calls this after it has parsed the string path.

Implemented in SysFs, DevFs, ProcFs, UnixFilesystem, ConsoleManager, Ext2Filesystem, Iso9660Filesystem, RawFs, FatFilesystem, and RamFs.

◆ createFile() [1/2]

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

Creates a file on the filesystem - fails if the file's parent directory does not exist.

Definition at line 223 of file Filesystem.cc.

References VFS::checkAccess(), createFile(), and findParent().

Referenced by VFS::createFile(), and createFile().

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◆ createFile() [2/2]

virtual bool Filesystem::createFile	(	File *	parent,
		const String &	filename,
		uint32_t	mask
	)

protectedpure virtual

createFile calls this after it has parsed the string path.

Implemented in SysFs, DevFs, ProcFs, UnixFilesystem, ConsoleManager, Ext2Filesystem, Iso9660Filesystem, RawFs, FatFilesystem, and RamFs.

◆ createLink() [1/2]

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

Creates a hard link on the filesystem to the given target.

Definition at line 340 of file Filesystem.cc.

References VFS::checkAccess(), createLink(), and findParent().

Referenced by VFS::createLink(), and createLink().

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◆ createLink() [2/2]

bool Filesystem::createLink	(	File *	parent,
		const String &	filename,
		File *	target
	)

protectedvirtual

createLink calls this after it has parsed the string path.

Reimplemented in Ext2Filesystem, and RamFs.

Definition at line 988 of file Filesystem.cc.

◆ createSymlink() [1/2]

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

Creates a symlink on the filesystem, with the given value.

Definition at line 301 of file Filesystem.cc.

References VFS::checkAccess(), createSymlink(), and findParent().

Referenced by VFS::createSymlink(), and createSymlink().

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◆ createSymlink() [2/2]

virtual bool Filesystem::createSymlink	(	File *	parent,
		const String &	filename,
		const String &	value
	)

protectedpure virtual

createSymlink calls this after it has parsed the string path.

Implemented in SysFs, DevFs, ProcFs, UnixFilesystem, ConsoleManager, Ext2Filesystem, Iso9660Filesystem, RawFs, FatFilesystem, and RamFs.

◆ decodeFileHandle()

FileHandleStatus Filesystem::decodeFileHandle	(	const FileHandle &	handle,
		RetainedFile &	file
	)

virtual

Definition at line 115 of file Filesystem.cc.

◆ deviceRemoved()

bool Filesystem::deviceRemoved ( bool deviceAvailable = false )

virtual

Rejects backend operations and releases a removed device's ownership.

Reimplemented in Ext2Filesystem, and FatFilesystem.

Definition at line 92 of file Filesystem.cc.

References m_pDisk.

Referenced by Ext2Filesystem::deviceRemoved(), FatFilesystem::deviceRemoved(), and VFS::removeDiskFilesystem().

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◆ encodeFileHandle()

FileHandleStatus Filesystem::encodeFileHandle	(	File &	file,
		FileHandle &	handle
	)

virtual

Caller holds a VFS mount operation through handle access and publication.

Reimplemented in Ext2Filesystem.

Definition at line 110 of file Filesystem.cc.

◆ fileHandleFsid()

FileHandleStatus Filesystem::fileHandleFsid ( FileSystemId & id )

virtual

Definition at line 120 of file Filesystem.cc.

◆ find() [1/4]

File * Filesystem::find ( const String & path )

virtual

Definition at line 187 of file Filesystem.cc.

◆ find() [2/4]

File * Filesystem::find	(	const String &	path,
		File *	pStartNode
	)

virtual

Definition at line 197 of file Filesystem.cc.

◆ find() [3/4]

File * Filesystem::find ( const StringView & path )

virtual

Attempt to find a file or directory in this filesystem.

Parameters

path	The path to the file, in UTF-8 format, without filesystem identifier (e.g. not "root:/file", but "/file").
pStartNode	The node to start parsing 'path' from - defaults to / but is expected to contain the current working directory.

Returns: The file if one was found, or 0 otherwise or if there was an error.

Definition at line 183 of file Filesystem.cc.

References findNode().

Referenced by VFS::find().

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◆ find() [4/4]

File * Filesystem::find	(	const StringView &	path,
		File *	pStartNode
	)

virtual

Definition at line 191 of file Filesystem.cc.

◆ findNode() [1/2]

File * Filesystem::findNode	(	File *	pNode,
		StringView	path
	)

private

Internal function to find a node - Returns 0 on failure or the node.

Parameters

pNode	The node to start parsing 'path' from.
path	The path from pNode to the destination node.

Definition at line 790 of file Filesystem.cc.

References findNode().

Referenced by find(), findNode(), findNode(), findParent(), and findRetained().

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◆ findNode() [2/2]

File * Filesystem::findNode	(	File *	pNode,
		StringView	path,
		File *	stableStart,
		File *	trueRoot,
		File **	retainedResult
	)

private

Traverse while retaining the terminal tracked node for a mutation.

Todo:: do we need to do permissions checks at each intermediate step?

Definition at line 799 of file Filesystem.cc.

References Directory::cacheResolvedChildren(), VFS::checkAccess(), findNode(), Symlink::followLinkRetained(), Directory::fromFile(), Symlink::fromFile(), File::getFullPath(), File::getNamespace(), Directory::getReparsePoint(), VFS::instance(), File::isDirectory(), File::isSymlink(), Directory::lookupChild(), StringView::substring(), and UNLIKELY.

◆ findParent()

File * Filesystem::findParent	(	StringView	path,
		File *	pStartNode,
		String &	filename,
		File **	retainedParent = `nullptr`
	)

private

Internal function to find a node's parent directory.

Parameters

	path	The path from pStartNode to the original file.
	pStartNode	The node to start parsing 'path' from.
[out]	filename	The child file's name.

Definition at line 921 of file Filesystem.cc.

References findNode(), Directory::fromFile(), Directory::getReparsePoint(), VFS::instance(), File::isDirectory(), VFS::retainTrackedFile(), StringView::substring(), and VFS::untrackFile().

Referenced by createDirectory(), createFile(), createLink(), createSymlink(), remove(), and rename().

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◆ findRetained()

File * Filesystem::findRetained	(	const StringView &	path,
		Directory::ChildLease &	result,
		File *	pStartNode = `nullptr`
	)

Find a node and retain its VFS lifetime for the lexical lifetime of result. Filesystem-owned roots are returned without a lease.

Definition at line 201 of file Filesystem.cc.

References findNode().

Referenced by VFS::findRetained(), and Symlink::followLinkRetained().

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◆ getDisk()

Disk * Filesystem::getDisk ( )

inline

Returns the disk in use

Definition at line 145 of file Filesystem.h.

Referenced by MountService::serve().

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◆ getRoot()

virtual File * Filesystem::getRoot ( ) const

pure virtual

Returns the root filesystem node.

Implemented in DevFs, ProcFs, UnixFilesystem, ConsoleManager, Ext2Filesystem, Iso9660Filesystem, RawFs, SysFs, FatFilesystem, and RamFs.

Referenced by File::isStableVfsRoot(), VFS::removeEphemeralFiles(), and File::retainDetachedParent().

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◆ getUuid()

virtual bool Filesystem::getUuid ( String & uuid ) const

inlinevirtual

Returns the canonical filesystem UUID when this filesystem has one.

Reimplemented in FatFilesystem, and Ext2Filesystem.

Definition at line 98 of file Filesystem.h.

◆ getVolumeLabel()

virtual const String & Filesystem::getVolumeLabel ( ) const

pure virtual

Returns a string identifying the volume label.

Implemented in DevFs, ProcFs, UnixFilesystem, ConsoleManager, Ext2Filesystem, Iso9660Filesystem, RawFs, SysFs, FatFilesystem, and RamFs.

Referenced by File::getFilesystemLabel(), VFS::mount(), MountService::serve(), VFS::setRootFilesystem(), and VFS::unregisterFilesystem().

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◆ initialise()

virtual bool Filesystem::initialise ( Disk * pDisk )

pure virtual

Populates this filesystem with data from the given Disk device.

Returns: true on success, false on failure.

Implemented in SysFs, DevFs, ProcFs, UnixFilesystem, ConsoleManager, Ext2Filesystem, Iso9660Filesystem, RawFs, FatFilesystem, and RamFs.

◆ isCaseSensitive()

virtual bool Filesystem::isCaseSensitive ( )

inlinevirtual

Does the filesystem care about case sensitivity?

Definition at line 155 of file Filesystem.h.

◆ isDeviceRemoved()

bool Filesystem::isDeviceRemoved ( ) const

Definition at line 59 of file Filesystem.cc.

◆ isReadOnly()

bool Filesystem::isReadOnly ( )

inline

Is the filesystem readonly?

Definition at line 150 of file Filesystem.h.

Referenced by File::allocateRange(), UnixSocketSyscalls::bind(), Ext2File::prepareSharedMapping(), and File::resize().

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◆ operator=()

void Filesystem::operator= ( const Filesystem & )

private

Assignment operator.

Note: NOT implemented.

◆ quotaControl()

QuotaStatus Filesystem::quotaControl	(	const QuotaRequest &	,
		QuotaResponse &	,
		File *	quotaFile = `nullptr`
	)

virtual

Definition at line 7 of file Quota.cc.

◆ remove() [1/3]

bool Filesystem::remove	(	const StringView &	path,
		File *	pStartNode,
		File *	expected
	)

Remove a path only if its terminal entry still has the expected identity.

Definition at line 393 of file Filesystem.cc.

References VFS::checkAccess(), findParent(), and removeChild().

◆ remove() [2/3]

bool Filesystem::remove	(	const StringView &	path,
		File *	pStartNode = `0`
	)

Removes a file, directory or symlink.

Note: Will fail if it is a directory and is not empty. The failure mode is unspecified.

Definition at line 385 of file Filesystem.cc.

References remove().

Referenced by Ext2Filesystem::releaseInode(), VFS::remove(), and remove().

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◆ remove() [3/3]

bool Filesystem::remove	(	File *	parent,
		File *	file
	)

Remove the file only if it is still the given child of parent.

Definition at line 435 of file Filesystem.cc.

References File::getName(), and removeChild().

◆ removeChild()

bool Filesystem::removeChild	(	File *	parent,
		const String &	filename,
		File *	expected,
		const FilesystemPathRef *	parentPath = `nullptr`
	)

private

Resolve and remove one child at a namespace-locked linearization point.

Definition at line 696 of file Filesystem.cc.

References Directory::fromFile(), VFS::instance(), File::isDirectory(), Directory::isEmpty(), Directory::lookupChild(), m_StructureLock, Directory::namespaceMutationLock(), File::publishEvent(), removeNode(), and String::view().

Referenced by remove(), and remove().

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◆ removeNode()

virtual bool Filesystem::removeNode	(	File *	parent,
		const String &	filename,
		File *	file
	)

protectedpure virtual

Remove a backing node while the VFS holds the parent's namespace lock. A successful implementation must retire the parent's cached entry before returning and must recheck directory emptiness while holding the child's namespace lock.

Implemented in DevFs, ProcFs, ConsoleManager, RawFs, SysFs, UnixFilesystem, Ext2Filesystem, Iso9660Filesystem, FatFilesystem, and RamFs.

Referenced by removeChild().

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◆ rename()

bool Filesystem::rename	(	const StringView &	oldPath,
		File *	oldStart,
		const StringView &	newPath,
		File *	newStart,
		bool	noReplace = `false`
	)

Move one terminal namespace entry without following its symlink target.

Definition at line 447 of file Filesystem.cc.

References findParent().

◆ renameChildren()

bool Filesystem::renameChildren	(	File *	oldParent,
		const String &	oldName,
		File *	newParent,
		const String &	newName,
		bool	noReplace,
		bool	sourceMustBeDirectory,
		const FilesystemPathRef *	oldPath = `nullptr`,
		const FilesystemPathRef *	newPath = `nullptr`
	)

private

Definition at line 490 of file Filesystem.cc.

◆ renameNode()

bool Filesystem::renameNode	(	Directory *	oldParent,
		const String &	oldName,
		File *	source,
		Directory *	newParent,
		const String &	newName,
		File *	replaced
	)

protectedvirtual

Change backing entries while the VFS reserves both names and owns their namespace locks. Do not call ordinary lookup/add/remove APIs here. Failure must leave both names unchanged; the VFS publishes cache changes on success.

Reimplemented in UnixFilesystem, Ext2Filesystem, FatFilesystem, and RamFs.

Definition at line 691 of file Filesystem.cc.

◆ shutdown()

Filesystem::SyncStatus Filesystem::shutdown ( )

virtual

After all users drain, finish teardown writes before backend destruction.

Reimplemented in Ext2Filesystem, RawFs, and FatFilesystem.

Definition at line 105 of file Filesystem.cc.

References m_bReadOnly, m_pDisk, and sync().

Referenced by VFS::unregisterFilesystem().

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◆ sync()

Filesystem::SyncStatus Filesystem::sync ( )

virtual

Completes data, metadata and device writeback for changes made before entry.

Reimplemented in Ext2Filesystem, RawFs, DevFs, ProcFs, SysFs, UnixFilesystem, FatFilesystem, and RamFs.

Definition at line 101 of file Filesystem.cc.

References m_bReadOnly.

Referenced by shutdown().

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◆ tryAcquireOperation()

bool Filesystem::tryAcquireOperation ( OperationBarrier::Lease & operation ) const

Definition at line 47 of file Filesystem.cc.

Friends And Related Symbol Documentation

◆ Directory

friend class Directory

friend

Definition at line 45 of file Filesystem.h.

◆ VFS

friend class VFS

friend

VFS can access nAliases

Definition at line 48 of file Filesystem.h.

◆ VfsMountView

friend class VfsMountView

friend

Definition at line 49 of file Filesystem.h.

Member Data Documentation

◆ m_bReadOnly

bool Filesystem::m_bReadOnly

protected

is this entire filesystem read-only?

Definition at line 186 of file Filesystem.h.

Referenced by FatFilesystem::createDirectory(), FatFilesystem::createFile(), FatFilesystem::createSymlink(), Ext2Filesystem::deviceRemoved(), Ext2Filesystem::initialise(), Iso9660Filesystem::initialise(), FatFilesystem::removeNode(), Ext2Filesystem::shutdown(), shutdown(), Ext2Filesystem::sync(), and sync().

◆ m_DiskUse

DiskUse Filesystem::m_DiskUse

protected

Definition at line 189 of file Filesystem.h.

◆ m_Operations

OperationBarrier Filesystem::m_Operations

mutableprotected

Definition at line 190 of file Filesystem.h.

◆ m_pDisk

Disk* Filesystem::m_pDisk

protected

◆ m_RemovalOwner

Atomic<Thread*> Filesystem::m_RemovalOwner = nullptr

private

Definition at line 194 of file Filesystem.h.

◆ m_StructureLock

Mutex Filesystem::m_StructureLock

staticprivate

Serializes changes to directory ancestry against removal.

Definition at line 199 of file Filesystem.h.

Referenced by removeChild().

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

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Private Attributes

Static Private Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ ProbeCallback

Member Enumeration Documentation

◆ SyncStatus

Constructor & Destructor Documentation

◆ Filesystem() [1/2]

◆ ~Filesystem()

◆ Filesystem() [2/2]

Member Function Documentation

◆ beginDeviceRemoval()

◆ createDirectory() [1/2]

◆ createDirectory() [2/2]

◆ createFile() [1/2]

◆ createFile() [2/2]

◆ createLink() [1/2]

◆ createLink() [2/2]

◆ createSymlink() [1/2]

◆ createSymlink() [2/2]

◆ decodeFileHandle()

◆ deviceRemoved()

◆ encodeFileHandle()

◆ fileHandleFsid()

◆ find() [1/4]

◆ find() [2/4]

◆ find() [3/4]

◆ find() [4/4]

◆ findNode() [1/2]

◆ findNode() [2/2]

◆ findParent()

◆ findRetained()

◆ getDisk()

◆ getRoot()

◆ getUuid()

◆ getVolumeLabel()

◆ initialise()

◆ isCaseSensitive()

◆ isDeviceRemoved()

◆ isReadOnly()

◆ operator=()

◆ quotaControl()

◆ remove() [1/3]

◆ remove() [2/3]

◆ remove() [3/3]

◆ removeChild()

◆ removeNode()

◆ rename()

◆ renameChildren()

◆ renameNode()

◆ shutdown()

◆ sync()

◆ tryAcquireOperation()

Friends And Related Symbol Documentation

◆ Directory

◆ VFS

◆ VfsMountView

Member Data Documentation

◆ m_bReadOnly

◆ m_DiskUse

◆ m_Operations

◆ m_pDisk

◆ m_RemovalOwner

◆ m_StructureLock