cache.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

/*
 * COPYRIGHT:        See COPYING in the top level directory
 * PROJECT:          ReactOS kernel
 * FILE:             services/fs/minix/cache.c
 * PURPOSE:          Minix FSD
 * PROGRAMMER:       David Welch ([e-mail])
 * UPDATE HISTORY:
 */

/* INCLUDES *****************************************************************/

#include <ntddk.h>
#include <ntifs.h>

//#define NDEBUG
#include <debug.h>

#include "minix.h"

/* FUNCTIONS ****************************************************************/

NTSTATUS MinixRequestCacheBlock(PDEVICE_OBJECT DeviceObject,
				PBCB Bcb,
				ULONG FileOffset,
				PVOID* BaseAddress,
				PCACHE_SEGMENT* CacheSeg)
{
   BOOLEAN UptoDate;

   CcRosRequestCacheSegment(Bcb,
		      FileOffset,
		      BaseAddress,
		      &UptoDate,
		      CacheSeg);
   if (!UptoDate)
     {
	MinixReadPage(DeviceObject,
		      PAGE_ROUND_DOWN(FileOffset),
		      BaseAddress);
     }
   BaseAddress = BaseAddress + (FileOffset % PAGE_SIZE);

   return(STATUS_SUCCESS);
}