Changeset 32195 in vbox for trunk/src/VBox

Timestamp:

Sep 2, 2010 1:18:14 PM (14 years ago)

Author:

vboxsync

Message:

VMDK/StreamOptimized: Truncate the file only if the size changed. Fixes horrible export performance if xfs is used on the target volume

File:

• trunk/src/VBox/Devices/Storage/VmdkHDDCore.cpp (modified) (1 diff)

trunk/src/VBox/Devices/Storage/VmdkHDDCore.cpp

@@ -1021 +1021 @@
              * guarantees that data gets only appended. */
             Assert(DeflateState.uFileOffset > uCompOffset);
-            rc = vmdkFileSetSize(pVmdkFile, DeflateState.uFileOffset);
+
+            /*
+             * Change the file size only if the size really changed,
+             * because this is very expensive on some filesystems
+             * like XFS.
+             */
+            uint64_t cbOld;
+            rc = vmdkFileGetSize(pVmdkFile, &cbOld);
+            if (RT_FAILURE(rc))
+                return rc;
+
+            if (cbOld != DeflateState.uFileOffset)
+                rc = vmdkFileSetSize(pVmdkFile, DeflateState.uFileOffset);
 
             if (uMarker == VMDK_MARKER_IGNORE)