Disk Class Reference

#include <Disk.h>

Inheritance diagram for Disk:

Collaboration diagram for Disk:

Public Types
enum	SubType { ATA = 0, ATAPI }
Public Types inherited from Device
enum	Type {   Generic, Root, Disk, Bus,   Display, Network, Sound, Console,   Mouse, Controller, UsbController, UsbGeneric,   UsbContainer }
typedef Device *(*	Callback) (Device *)

Public Member Functions
	Disk (Device *p)
virtual Type	getType ()
virtual SubType	getSubType ()
virtual void	getName (String &str)
virtual void	dump (String &str)
virtual uintptr_t	read (uint64_t location)
virtual void	write (uint64_t location)
virtual void	align (uint64_t location)
	Sets the page boundary alignment after a specific location on the disk. More...
virtual size_t	getSize () const
	Gets the size of the disk. More...
virtual size_t	getBlockSize () const
	Gets the block size of the disk. More...
virtual void	pin (uint64_t location)
	Pins a cache page. More...
virtual void	unpin (uint64_t location)
virtual bool	cacheIsCritical ()
	Whether or not the cache is critical and cannot be flushed or deleted. More...
virtual void	flush (uint64_t location)
	Flush a cached page to disk. More...
Public Member Functions inherited from Device
	Device (Device *p)
Device *	getParent () const
void	setParent (Device *p)
virtual String	getSpecificType ()
virtual void	setSpecificType (String str)
void	setPciPosition (uint32_t bus, uint32_t device, uint32_t func)
void	setPciIdentifiers (uint8_t classCode, uint8_t subclassCode, uint16_t vendorId, uint16_t deviceId, uint8_t progIf)
void	setPciConfigHeader (const PciBus::ConfigSpace &space)
PciBus::ConfigSpace	getPciConfigHeader () const
uint8_t	getPciClassCode ()
uint8_t	getPciSubclassCode ()
uint16_t	getPciVendorId ()
uint16_t	getPciDeviceId ()
uint8_t	getPciProgInterface ()
uint32_t	getPciBusPosition ()
uint32_t	getPciDevicePosition ()
uint32_t	getPciFunctionNumber ()
virtual Vector< Address * > &	addresses ()
virtual uintptr_t	getInterruptNumber ()
virtual void	setInterruptNumber (uintptr_t n)
void	addChild (Device *pDevice)
Device *	getChild (size_t n)
size_t	getNumChildren ()
void	removeChild (size_t n)
void	removeChild (Device *d)
void	replaceChild (Device *src, Device *dest)

Additional Inherited Members
Static Public Member Functions inherited from Device
static void	foreach (Callback callback, Device *root=0)
template<class F , class... Args>
static void	foreach (pedigree_std::Callable< F > &callback, Device *root, Args...args)
static void	addToRoot (Device *device)
static void	searchByVendorId (uint16_t vendorId, void(*callback)(Device *), Device *root=0)
static void	searchByVendorIdAndDeviceId (uint16_t vendorId, uint16_t deviceId, void(*callback)(Device *), Device *root=0)
static void	searchByClass (uint16_t classCode, void(*callback)(Device *), Device *root=0)
static void	searchByClassAndSubclass (uint16_t classCode, uint16_t subclassCode, void(*callback)(Device *), Device *root=0)
static void	searchByClassSubclassAndProgInterface (uint16_t classCode, uint16_t subclassCode, uint8_t progInterface, void(*callback)(Device *), Device *root=0)
Protected Member Functions inherited from Device
	NOT_COPYABLE_OR_ASSIGNABLE (Device)
Static Protected Member Functions inherited from Device
static Device &	root ()
Protected Attributes inherited from Device
Vector< Address * >	m_Addresses
Vector< Device * >	m_Children
Device *	m_pParent
uintptr_t	m_InterruptNumber
String	m_SpecificType
PciBus::ConfigSpace	m_ConfigHeader
uint8_t	m_ClassCode
uint8_t	m_SubclassCode
uint16_t	m_VendorId
uint16_t	m_DeviceId
uint8_t	m_ProgInterface
uint32_t	m_PciBusPos
uint32_t	m_PciDevicePos
uint32_t	m_PciFunctionNum
Static Protected Attributes inherited from Device
static Device	m_Root
static Mutex	m_TreeLock

Detailed Description

A disk is a random access fixed size block device.

Definition at line 32 of file Disk.h.

Member Function Documentation

void Disk::align ( uint64_t  location )

virtual

Sets the page boundary alignment after a specific location on the disk.

For example, if one has a partition starting on byte 512, one will probably want 4096-byte reads to be aligned with this (so reading 4096 bytes from byte 0 on the partition will create one page of cache and not span two). Without an align point a read of the first sector of a partition starting at byte 512 will have to have a location of 512 rather than 0.

Use this function to allow reads to fit into the 4096 byte buffers manipulated in read() or write() even when location isn't aligned on a 4096 byte boundary.

Reimplemented in ScsiDisk, and FileDisk.

Definition at line 65 of file Disk.cc.

Referenced by FileDisk::getName(), Partition::read(), and Partition::write().

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bool Disk::cacheIsCritical ( )

virtual

Whether or not the cache is critical and cannot be flushed or deleted.

Some implementations of this class may provide a Disk that does not actually back onto a writable media, or perhaps sit only in RAM and have no correlation to physical hardware. If cache pages are deleted for these implementations, data may be lost.

Note that cache should only be marked "critical" if it is possible to write via an implementation. There is no need to worry about cache pages being deleted on a read-only disk as they will be re-created on the next read (and no written data is lost).

This function allows callers that want to delete cache pages to verify that the cache is not critical to the performance of the implementation.

Returns

True if the cache is critical and must not be removed or flushed. False otherwise.

Reimplemented in FileDisk, and CdiDisk.

Definition at line 87 of file Disk.cc.

void Disk::dump ( String &  str )

virtual

Dumps a textual representation of the device into the given string.

Reimplemented from Device.

Reimplemented in Partition, and DiskImage.

Definition at line 51 of file Disk.cc.

void Disk::flush ( uint64_t  location )

virtual

Flush a cached page to disk.

Essentially a no-op if the given location is not actually in cache. Called either by filesystem drivers (on removable disks) or from a central cache manager which handles flushing caches back to the disk on a regular basis.

Will not remove the page from cache, that must be done by the caller.

Reimplemented in ScsiDisk, and CdiDisk.

Definition at line 92 of file Disk.cc.

size_t Disk::getBlockSize ( ) const

virtual

Gets the block size of the disk.

This is the native block size with which all reads and writes are performed, regardless of how much data is available to be read/written.

Reimplemented in ScsiDisk, Partition, AtaDisk, and DiskImage.

Definition at line 74 of file Disk.cc.

Referenced by RawFsFile::getBlockSize(), and Partition::getBlockSize().

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void Disk::getName ( String &  str )

virtual

Stores the device's name in str.

Reimplemented from Device.

Reimplemented in ScsiDisk, AtaDisk, FileDisk, DiskImage, CdiDisk, and Partition.

Definition at line 46 of file Disk.cc.

Referenced by Ext2Filesystem::initialise(), FatFilesystem::initialise(), and msdosProbeDisk().

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size_t Disk::getSize ( ) const

virtual

Gets the size of the disk.

This is the size in bytes of the disk. Reads or writes beyond this size will fail.

Reimplemented in ScsiDisk, Partition, AtaDisk, and DiskImage.

Definition at line 69 of file Disk.cc.

Referenced by RawFsFile::RawFsFile().

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Device::Type Disk::getType ( )

virtual

Returns the (abstract) type of the device.

Reimplemented from Device.

Definition at line 36 of file Disk.cc.

References Device::Disk.

void Disk::pin ( uint64_t  location )

virtual

Pins a cache page.

This allows an upstream user of Disk pages to 'pin' cache pages, causing them to only be freed once all consumers have done an 'unpin'. The pin and unpin semantics allow for memory mappings to be made in a reasonably safe manner, as it can be assumed that the physical page for a particular cache block will not be freed.

Reimplemented in ScsiDisk, and DiskImage.

Definition at line 79 of file Disk.cc.

uintptr_t Disk::read ( uint64_t  location )

virtual

Read from location on disk and return a pointer to it. location must be 512 byte aligned. The pointer returned is within a page of cache that maps to 4096 bytes of disk area.

Note

If the Disk is backed by a Cache, the buffer returned should have its refcount incremented by one by a successful run of read(). Use unpin() to indicate you no longer care about the buffer.

Parameters

location

The offset from the start of the device, in bytes, to start the read, must be multiple of 512.

Returns

Pointer to writable area of memory containing the data. If the data is written, the page is marked as dirty and may be written back to disk at any time (or forced with write() or flush() ).

Reimplemented in ScsiDisk, FileDisk, Partition, CdiDisk, and DiskImage.

Definition at line 56 of file Disk.cc.

Referenced by Iso9660Directory::cacheDirectoryContents(), FileDisk::getName(), FatFilesystem::initialise(), msdosProbeDisk(), msdosReadTable(), Partition::read(), RawFsFile::readBlock(), FatFilesystem::readSectorBlock(), and FatFilesystem::writeSectorBlock().

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void Disk::unpin ( uint64_t  location )

virtual

Unpins a cache page (see pin() for more information and rationale).

Reimplemented in ScsiDisk, and DiskImage.

Definition at line 83 of file Disk.cc.

void Disk::write ( uint64_t  location )

virtual

This function schedules a cache writeback of the given location. The data to be written back is fetched from the cache (pointer returned by read() ).

Parameters

location

The offset from the start of the device, in bytes, to start the write. Must be 512byte aligned.

Reimplemented in ScsiDisk, Partition, FileDisk, and CdiDisk.

Definition at line 61 of file Disk.cc.

Referenced by FileDisk::getName(), Partition::write(), and FatFilesystem::writeSectorBlock().

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

• Disk.h
• Disk.cc