07/07: [NTOSKRNL] Start making our MMPAGING_FILE struct look like the real one

[Pierre Schweitzer]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=19318dcc1deb97ea8aa017...

commit 19318dcc1deb97ea8aa017df4a5b0f8ea02a1c0f
Author:     Pierre Schweitzer [e-mail]
AuthorDate: Thu Aug 16 14:04:27 2018 +0200
Commit:     Pierre Schweitzer [e-mail]
CommitDate: Thu Aug 16 14:04:27 2018 +0200

[NTOSKRNL] Start making our MMPAGING_FILE struct look like the real one
---
 ntoskrnl/include/internal/mm.h |  8 ++++----
 ntoskrnl/mm/pagefile.c         | 40 ++++++++++++++++++++++------------------
 2 files changed, 26 insertions(+), 22 deletions(-)

diff --git a/ntoskrnl/include/internal/mm.h b/ntoskrnl/include/internal/mm.h
index ca82fd87d9..cf9e5069ac 100644
--- a/ntoskrnl/include/internal/mm.h
+++ b/ntoskrnl/include/internal/mm.h
@@ -426,14 +426,14 @@ extern MM_MEMORY_CONSUMER MiMemoryConsumers[MC_MAXIMUM];
 /* Page file information */
 typedef struct _MMPAGING_FILE
 {
-    PFN_NUMBER CurrentSize;
+    PFN_NUMBER Size;
     PFN_NUMBER MaximumSize;
     PFN_NUMBER MinimumSize;
-    PFN_NUMBER FreePages;
-    PFN_NUMBER UsedPages;
+    PFN_NUMBER FreeSpace;
+    PFN_NUMBER CurrentUsage;
     PFILE_OBJECT FileObject;
     UNICODE_STRING PageFileName;
-    PRTL_BITMAP AllocMap;
+    PRTL_BITMAP Bitmap;
     HANDLE FileHandle;
 }
 MMPAGING_FILE, *PMMPAGING_FILE;
diff --git a/ntoskrnl/mm/pagefile.c b/ntoskrnl/mm/pagefile.c
index dd24fe7d5b..9019beef90 100644
--- a/ntoskrnl/mm/pagefile.c
+++ b/ntoskrnl/mm/pagefile.c
@@ -290,10 +290,10 @@ MmFreeSwapPage(SWAPENTRY Entry)
         KeBugCheck(MEMORY_MANAGEMENT);
     }

-    RtlClearBit(PagingFile->AllocMap, off >> 5);
+    RtlClearBit(PagingFile->Bitmap, off >> 5);

-    PagingFile->FreePages++;
-    PagingFile->UsedPages--;
+    PagingFile->FreeSpace++;
+    PagingFile->CurrentUsage--;

MiFreeSwapPages++;
     MiUsedSwapPages--;
@@ -320,9 +320,9 @@ MmAllocSwapPage(VOID)
     for (i = 0; i < MAX_PAGING_FILES; i++)
     {
         if (MmPagingFile[i] != NULL &&
-                MmPagingFile[i]->FreePages >= 1)
+                MmPagingFile[i]->FreeSpace >= 1)
         {
-            off = RtlFindClearBitsAndSet(MmPagingFile[i]->AllocMap, 1, 0);
+            off = RtlFindClearBitsAndSet(MmPagingFile[i]->Bitmap, 1, 0);
             if (off == 0xFFFFFFFF)
             {
                 KeBugCheck(MEMORY_MANAGEMENT);
@@ -741,17 +741,21 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
     PagingFile->FileHandle = FileHandle;
     PagingFile->FileObject = FileObject;
     PagingFile->MaximumSize = (SafeMaximumSize.QuadPart >> PAGE_SHIFT);
-    PagingFile->CurrentSize = (SafeMinimumSize.QuadPart >> PAGE_SHIFT);
+    PagingFile->Size = (SafeMinimumSize.QuadPart >> PAGE_SHIFT);
     PagingFile->MinimumSize = (SafeMinimumSize.QuadPart >> PAGE_SHIFT);
-    PagingFile->FreePages = (ULONG)(SafeMinimumSize.QuadPart / PAGE_SIZE);
-    PagingFile->UsedPages = 0;
+    /* First page is never used: it's the header
+     * TODO: write it
+     */
+    PagingFile->FreeSpace = (ULONG)(SafeMinimumSize.QuadPart / PAGE_SIZE) - 1;
+    PagingFile->CurrentUsage = 0;
     PagingFile->PageFileName = PageFileName;
+    ASSERT(PagingFile->Size == PagingFile->FreeSpace + PagingFile->CurrentUsage + 1);

-    AllocMapSize = sizeof(RTL_BITMAP) + (((PagingFile->FreePages + 31) / 32) * sizeof(ULONG));
-    PagingFile->AllocMap = ExAllocatePoolWithTag(NonPagedPool,
-                                                 AllocMapSize,
-                                                 TAG_MM);
-    if (PagingFile->AllocMap == NULL)
+    AllocMapSize = sizeof(RTL_BITMAP) + (((PagingFile->MaximumSize + 31) / 32) * sizeof(ULONG));
+    PagingFile->Bitmap = ExAllocatePoolWithTag(NonPagedPool,
+                                               AllocMapSize,
+                                               TAG_MM);
+    if (PagingFile->Bitmap == NULL)
     {
         ExFreePoolWithTag(PagingFile, TAG_MM);
         ObDereferenceObject(FileObject);
@@ -760,10 +764,10 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
         return STATUS_INSUFFICIENT_RESOURCES;
     }

-    RtlInitializeBitMap(PagingFile->AllocMap,
-                        (PULONG)(PagingFile->AllocMap + 1),
-                        (ULONG)(PagingFile->FreePages));
-    RtlClearAllBits(PagingFile->AllocMap);
+    RtlInitializeBitMap(PagingFile->Bitmap,
+                        (PULONG)(PagingFile->Bitmap + 1),
+                        (ULONG)(PagingFile->MaximumSize));
+    RtlClearAllBits(PagingFile->Bitmap);

/* FIXME: should be calling unsafe instead,
      * we should already be in a guarded region
@@ -772,7 +776,7 @@ NtCreatePagingFile(IN PUNICODE_STRING FileName,
     ASSERT(MmPagingFile[MmNumberOfPagingFiles] == NULL);
     MmPagingFile[MmNumberOfPagingFiles] = PagingFile;
     MmNumberOfPagingFiles++;
-    MiFreeSwapPages = MiFreeSwapPages + PagingFile->FreePages;
+    MiFreeSwapPages = MiFreeSwapPages + PagingFile->FreeSpace;
     KeReleaseGuardedMutex(&MmPageFileCreationLock);

MmSwapSpaceMessage = FALSE;