Changeset 107671 in vbox

Timestamp:

Jan 10, 2025 3:38:26 PM (2 months ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

166763

Message:

Storage/VMDK.cpp: Fix unused variable assignment (VERR_NO_MEMORY would get lost when allocating memory for the zero buffer fails) and replace allocating the buffer with using the zero 4K data object, bugref:3409

File:

• trunk/src/VBox/Storage/VMDK.cpp (modified) (7 diffs)

trunk/src/VBox/Storage/VMDK.cpp

@@ -49 +49 @@
 #include <iprt/zip.h>
 #include <iprt/asm.h>
+#include <iprt/zero.h>
 #ifdef RT_OS_WINDOWS
 # include <iprt/utf16.h>
@@ -8653 +8654 @@
     * of the image.
     */
-    void *pvBuf = NULL, *pvZero = NULL;
+    void *pvBuf = NULL;
+    AssertCompile(sizeof(g_abRTZero4K) >= VMDK_GRAIN_TABLE_SIZE);
 
     do
@@ -8661 +8663 @@
         if (!pvBuf)
         {
-            rc = VERR_NO_MEMORY;
-            break;
-        }
-
-        /* Allocate buffer for overwriting with zeroes. */
-        pvZero = RTMemAllocZ(VMDK_GRAIN_TABLE_SIZE);
-        if (!pvZero)
-        {
-            RTMemFree(pvBuf);
-            pvBuf = NULL;
-
             rc = VERR_NO_MEMORY;
             break;
@@ -8782 +8773 @@
     }
 
-    if (pvZero)
-    {
-        RTMemFree(pvZero);
-        pvZero = NULL;
-    }
-
     pExtent->cGDEntries = cNewDirEntries;
-
-    /* Allocate buffer for overwriting with zeroes. */
-    pvZero = RTMemAllocZ(VMDK_GRAIN_TABLE_SIZE);
-    if (!pvZero)
-        return VERR_NO_MEMORY;
 
     // Allocate additional grain dir
@@ -8816 +8796 @@
 
         rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pExtent->pFile->pStorage,
-                                    VMDK_SECTOR2BYTE(uTmpDirVal), pvZero,
+                                    VMDK_SECTOR2BYTE(uTmpDirVal), &g_abRTZero4K[0],
                                     VMDK_GRAIN_TABLE_SIZE);
 
@@ -8831 +8811 @@
 
         rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pExtent->pFile->pStorage,
-                                    VMDK_SECTOR2BYTE(uRTmpDirVal), pvZero,
+                                    VMDK_SECTOR2BYTE(uRTmpDirVal), &g_abRTZero4K[0],
                                     VMDK_GRAIN_TABLE_SIZE);
 
@@ -8839 +8819 @@
         uRTmpDirVal += VMDK_GRAIN_DIR_ENTRY_SIZE;
     }
-
-    RTMemFree(pvZero);
-    pvZero = NULL;
 
     rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pExtent->pFile->pStorage,