filesystem.cpp revision c1c9242f0046150566414e1f222cb667e03e605e
2N/A/* $Id$ */
2N/A/** @file
2N/A * IPRT Filesystem API (Filesystem) - generic code.
2N/A */
2N/A
2N/A/*
2N/A * Copyright (C) 2012 Oracle Corporation
2N/A *
2N/A * This file is part of VirtualBox Open Source Edition (OSE), as
2N/A * available from http://www.virtualbox.org. This file is free software;
2N/A * you can redistribute it and/or modify it under the terms of the GNU
2N/A * General Public License (GPL) as published by the Free Software
2N/A * Foundation, in version 2 as it comes in the "COPYING" file of the
2N/A * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
2N/A * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
2N/A *
2N/A * The contents of this file may alternatively be used under the terms
2N/A * of the Common Development and Distribution License Version 1.0
2N/A * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
2N/A * VirtualBox OSE distribution, in which case the provisions of the
2N/A * CDDL are applicable instead of those of the GPL.
2N/A *
2N/A * You may elect to license modified versions of this file under the
2N/A * terms and conditions of either the GPL or the CDDL or both.
2N/A */
2N/A
2N/A
2N/A/*******************************************************************************
2N/A* Header Files *
2N/A*******************************************************************************/
2N/A#define LOG_GROUP LOG_GROUP_DEFAULT
2N/A#include <iprt/types.h>
2N/A#include <iprt/assert.h>
2N/A#include <iprt/mem.h>
2N/A#include <iprt/filesystem.h>
2N/A#include <iprt/err.h>
2N/A#include <iprt/asm.h>
2N/A#include <iprt/string.h>
2N/A#include <iprt/list.h>
2N/A#include "internal/filesystem.h"
2N/A
2N/A/*******************************************************************************
2N/A* Structures and Typedefs *
2N/A*******************************************************************************/
2N/A
2N/A/**
2N/A * Medium descriptor.
2N/A */
2N/Atypedef struct RTFILESYSTEMMEDIUMINT
2N/A{
2N/A /** Size of the medium in bytes. */
2N/A uint64_t cbMedium;
2N/A /** Sector size. */
2N/A uint64_t cbSector;
2N/A /** Read callback */
2N/A PFNRTFILESYSTEMREAD pfnRead;
2N/A /** Write callback. */
2N/A PFNRTFILESYSTEMWRITE pfnWrite;
2N/A /** Opaque user data. */
2N/A void *pvUser;
2N/A} RTFILESYSTEMMEDIUMINT;
2N/A/** Pointer to a disk descriptor. */
2N/Atypedef RTFILESYSTEMMEDIUMINT *PRTFILESYSTEMMEDIUMINT;
2N/A/** Pointer to a const descriptor. */
2N/Atypedef const RTFILESYSTEMMEDIUMINT *PCRTFILESYSTEMMEDIUMINT;
2N/A
2N/A/**
2N/A * The internal filesystem object structure.
2N/A */
2N/Atypedef struct RTFILESYSTEMINT
2N/A{
2N/A /** The filesytem object magic (RTFILESYSTEM_MAGIC). */
2N/A uint32_t u32Magic;
2N/A /** Medium descriptor. */
2N/A RTFILESYSTEMMEDIUMINT Medium;
2N/A /** Filesystem format operations */
2N/A PCRTFILESYSTEMFMTOPS pcFsFmtOps;
2N/A /** Filesystem format handle. */
2N/A RTFILESYSTEMFMT hFsFmt;
2N/A /** Reference counter. */
2N/A uint32_t volatile cRefs;
2N/A} RTFILESYSTEMINT;
2N/A/** Pointer to an internal volume manager. */
2N/Atypedef RTFILESYSTEMINT *PRTFILESYSTEMINT;
2N/A
2N/A/*******************************************************************************
2N/A* Global variables *
2N/A*******************************************************************************/
2N/Aextern RTFILESYSTEMFMTOPS g_rtFilesystemFmtExt;
2N/A
2N/A/**
2N/A * Supported volume formats.
2N/A */
2N/Astatic PCRTFILESYSTEMFMTOPS g_aFilesystemFmts[] =
2N/A{
2N/A &g_rtFilesystemFmtExt
2N/A};
2N/A
DECLHIDDEN(uint64_t) rtFilesystemMediumGetSize(RTFILESYSTEMMEDIUM hMedium)
{
PRTFILESYSTEMMEDIUMINT pMedInt = hMedium;
AssertPtrReturn(pMedInt, 0);
return pMedInt->cbMedium;
}
DECLHIDDEN(int) rtFilesystemMediumRead(RTFILESYSTEMMEDIUM hMedium, uint64_t off,
void *pvBuf, size_t cbRead)
{
PRTFILESYSTEMMEDIUMINT pMedInt = hMedium;
AssertPtrReturn(pMedInt, VERR_INVALID_HANDLE);
return pMedInt->pfnRead(pMedInt->pvUser, off, pvBuf, cbRead);
}
DECLHIDDEN(int) rtFilesystemMediumWrite(RTFILESYSTEMMEDIUM hMedium, uint64_t off,
const void *pvBuf, size_t cbWrite)
{
PRTFILESYSTEMMEDIUMINT pMedInt = hMedium;
AssertPtrReturn(pMedInt, VERR_INVALID_HANDLE);
return pMedInt->pfnWrite(pMedInt->pvUser, off, pvBuf, cbWrite);
}
RTDECL(uint32_t) RTFilesystemRetain(RTFILESYSTEM hFs)
{
PRTFILESYSTEMINT pThis = hFs;
AssertPtrReturn(pThis, UINT32_MAX);
AssertReturn(pThis->u32Magic == RTFILESYSTEM_MAGIC, UINT32_MAX);
uint32_t cRefs = ASMAtomicIncU32(&pThis->cRefs);
AssertMsg(cRefs > 1 && cRefs < _1M, ("%#x %p\n", cRefs, pThis));
return cRefs;
}
/**
* Destroys a volume manager handle.
*
* @param pThis The filesystem object to destroy.
*/
static void rtFilesystemDestroy(PRTFILESYSTEMINT pThis)
{
if (pThis->hFsFmt != NIL_RTFILESYSTEMFMT)
{
AssertPtr(pThis->pcFsFmtOps);
/* Let the backend do it's own cleanup first. */
pThis->pcFsFmtOps->pfnClose(pThis->hFsFmt);
pThis->hFsFmt = NIL_RTFILESYSTEMFMT;
}
pThis->Medium.cbMedium = 0;
pThis->Medium.pvUser = NULL;
pThis->Medium.pfnRead = NULL;
pThis->Medium.pfnWrite = NULL;
pThis->u32Magic = RTFILESYSTEM_MAGIC_DEAD;
RTMemFree(pThis);
}
RTDECL(uint32_t) RTFilesystemRelease(RTFILESYSTEM hFs)
{
PRTFILESYSTEMINT pThis = hFs;
if (pThis == NIL_RTFILESYSTEM)
return 0;
AssertPtrReturn(pThis, UINT32_MAX);
AssertReturn(pThis->u32Magic == RTFILESYSTEM_MAGIC, UINT32_MAX);
uint32_t cRefs = ASMAtomicDecU32(&pThis->cRefs);
AssertMsg(cRefs < _1M, ("%#x %p\n", cRefs, pThis));
if (cRefs == 0)
rtFilesystemDestroy(pThis);
return cRefs;
}
RTDECL(int) RTFilesystemOpen(PRTFILESYSTEM phFs, PFNRTFILESYSTEMREAD pfnRead,
PFNRTFILESYSTEMWRITE pfnWrite, uint64_t cbMedium,
uint64_t cbSector, void *pvUser, uint32_t fFlags)
{
int rc = VINF_SUCCESS;
uint32_t uScoreMax = RTFILESYSTEM_MATCH_SCORE_UNSUPPORTED;
PCRTFILESYSTEMFMTOPS pcFsFmtOpsMatch = NULL;
PRTFILESYSTEMINT pThis = NULL;
AssertPtrReturn(phFs, VERR_INVALID_POINTER);
AssertPtrReturn(pfnRead, VERR_INVALID_POINTER);
pThis = (PRTFILESYSTEMINT)RTMemAllocZ(sizeof(RTFILESYSTEMINT));
if (!pThis)
return VERR_NO_MEMORY;
pThis->u32Magic = RTFILESYSTEM_MAGIC;
pThis->Medium.cbMedium = cbMedium;
pThis->Medium.cbSector = cbSector;
pThis->Medium.pfnRead = pfnRead;
pThis->Medium.pfnWrite = pfnWrite;
pThis->Medium.pvUser = pvUser;
pThis->cRefs = 1;
for (unsigned i = 0; i < RT_ELEMENTS(g_aFilesystemFmts); i++)
{
uint32_t uScore;
PCRTFILESYSTEMFMTOPS pcFsFmtOps = g_aFilesystemFmts[i];
rc = pcFsFmtOps->pfnProbe(&pThis->Medium, &uScore);
if ( RT_SUCCESS(rc)
&& uScore > uScoreMax)
{
pcFsFmtOpsMatch = pcFsFmtOps;
uScoreMax = uScore;
}
else if (RT_FAILURE(rc))
break;
}
if (RT_SUCCESS(rc))
{
if (uScoreMax > RTFILESYSTEM_MATCH_SCORE_UNSUPPORTED)
{
AssertPtr(pcFsFmtOpsMatch);
/* Open the format. */
rc = pcFsFmtOpsMatch->pfnOpen(&pThis->Medium, &pThis->hFsFmt);
if (RT_SUCCESS(rc))
pThis->pcFsFmtOps = pcFsFmtOpsMatch;
}
else
rc = VERR_NOT_SUPPORTED;
}
if (RT_SUCCESS(rc))
*phFs = pThis;
else
RTMemFree(pThis);
return rc;
}
RTDECL(const char *) RTFilesystemGetFormat(RTFILESYSTEM hFs)
{
PRTFILESYSTEMINT pThis = hFs;
AssertPtrReturn(pThis, NULL);
AssertReturn(pThis->u32Magic == RTFILESYSTEM_MAGIC, NULL);
return pThis->pcFsFmtOps->pcszFmt;
}
RTDECL(uint64_t) RTFilesystemGetBlockSize(RTFILESYSTEM hFs)
{
PRTFILESYSTEMINT pThis = hFs;
AssertPtrReturn(pThis, 0);
AssertReturn(pThis->u32Magic == RTFILESYSTEM_MAGIC, 0);
return pThis->pcFsFmtOps->pfnGetBlockSize(pThis->hFsFmt);
}
RTDECL(int) RTFilesystemQueryRangeUse(RTFILESYSTEM hFs, uint64_t offStart, size_t cb,
bool *pfUsed)
{
PRTFILESYSTEMINT pThis = hFs;
AssertPtrReturn(pThis, VERR_INVALID_HANDLE);
AssertReturn(pThis->u32Magic == RTFILESYSTEM_MAGIC, VERR_INVALID_HANDLE);
AssertPtrReturn(pfUsed, VERR_INVALID_POINTER);
AssertReturn(offStart + cb <= pThis->Medium.cbMedium, VERR_OUT_OF_RANGE);
return pThis->pcFsFmtOps->pfnQueryRangeUse(pThis->hFsFmt, offStart, cb, pfUsed);
}