Changeset 78584 in vbox for trunk/src

Timestamp:

May 18, 2019 9:07:57 PM (6 years ago)

Author:

vboxsync

Message:

winnt/vboxsf: Use CcCoherencyFlushAndPurgeCache before writes and reads to ensure mmap coherency. This makes the FsPerf mmap tests happy, however the KPI is only available on windows 7 and later, so we'll have to skip this mmap test aspect on older systems, I fear. bugref:9172

Location:

trunk/src/VBox/Additions/WINNT/SharedFolders/driver

Files:

• file.cpp (modified) (3 diffs)
• vbsf.cpp (modified) (2 diffs)
• vbsf.h (modified) (1 diff)

trunk/src/VBox/Additions/WINNT/SharedFolders/driver/file.cpp

@@ -114 +114 @@
                 pReq->PgLst.aPages[iPage] = (RTGCPHYS)paPfns[iPage] << PAGE_SHIFT;
             pReq->PgLst.offFirstPage = offPage;
+
+            /*
+             * Flush dirty cache content before we try read it from the host.  RDBSS calls
+             * CcFlushCache before it calls us, I think, but CcCoherencyFlushAndPurgeCache
+             * does the right thing whereas CcFlushCache clearly does (FsPerf mmap+read
+             * coherency test fails consistently on W10, XP, ++).
+             */
+            if (   g_pfnCcCoherencyFlushAndPurgeCache
+                && !(RxContext->CurrentIrp && (RxContext->CurrentIrp->Flags & IRP_PAGING_IO))
+                && RxContext->NonPagedFcb != NULL
+                && RxContext->NonPagedFcb->SectionObjectPointers.DataSectionObject != NULL)
+            {
+                LARGE_INTEGER offFlush;
+                offFlush.QuadPart = offFile;
+                g_pfnCcCoherencyFlushAndPurgeCache(&RxContext->NonPagedFcb->SectionObjectPointers, &offFlush, cbChunk,
+                                                   &RxContext->CurrentIrp->IoStatus, CC_FLUSH_AND_PURGE_NO_PURGE);
+            }
 
             /*
@@ -294 +311 @@
     AssertReturn(pBufferMdl,  STATUS_INTERNAL_ERROR);
 
-
     /*
      * We should never get a zero byte request (RDBSS checks), but in case we
@@ -358 +374 @@
 
             /*
+             * Flush and purge the cache range we're touching upon now, provided we can and
+             * really needs to.  The CcCoherencyFlushAndPurgeCache API seems to work better
+             * than the CcFlushCache + CcPurgeCacheSection that RDBSS does before calling us.
+             */
+            if (   g_pfnCcCoherencyFlushAndPurgeCache
+                && !(RxContext->CurrentIrp && (RxContext->CurrentIrp->Flags & IRP_PAGING_IO))
+                && RxContext->NonPagedFcb != NULL
+                && RxContext->NonPagedFcb->SectionObjectPointers.DataSectionObject != NULL)
+            {
+                /** @todo locking.   */
+                LARGE_INTEGER offFlush;
+                offFlush.QuadPart = offFile;
+                g_pfnCcCoherencyFlushAndPurgeCache(&RxContext->NonPagedFcb->SectionObjectPointers, &offFlush, cbChunk,
+                                                   &RxContext->CurrentIrp->IoStatus, 0 /*fFlags*/);
+            }
+
+            /*
              * Issue the request and unlock the pages.
              */

trunk/src/VBox/Additions/WINNT/SharedFolders/driver/vbsf.cpp

@@ -52 +52 @@
  */
 PRDBSS_DEVICE_OBJECT VBoxMRxDeviceObject;
+
+/** Pointer to CcCoherencyFlushAndPurgeCache if present in ntoskrnl. */
+PFNCCCOHERENCYFLUSHANDPURGECACHE g_pfnCcCoherencyFlushAndPurgeCache;
 
 /** The shared folder service client structure. */
@@ -659 +662 @@
     }
 
+    /* Resolve newer kernel APIs we might want to use: */
+    UNICODE_STRING RoutineName;
+    RtlInitUnicodeString(&RoutineName, L"CcCoherencyFlushAndPurgeCache");
+    g_pfnCcCoherencyFlushAndPurgeCache = (PFNCCCOHERENCYFLUSHANDPURGECACHE)MmGetSystemRoutineAddress(&RoutineName);
+
     /* Init the driver object. */
     DriverObject->DriverUnload = VBoxMRxUnload;

trunk/src/VBox/Additions/WINNT/SharedFolders/driver/vbsf.h

@@ -57 +57 @@
 extern PRDBSS_DEVICE_OBJECT VBoxMRxDeviceObject;
 extern uint32_t             g_uSfLastFunction;
+/** Pointer to the CcCoherencyFlushAndPurgeCache API (since win 7). */
+typedef VOID (NTAPI *PFNCCCOHERENCYFLUSHANDPURGECACHE)(PSECTION_OBJECT_POINTERS, PLARGE_INTEGER, ULONG, PIO_STATUS_BLOCK,ULONG);
+extern PFNCCCOHERENCYFLUSHANDPURGECACHE g_pfnCcCoherencyFlushAndPurgeCache;
+#ifndef CC_FLUSH_AND_PURGE_NO_PURGE
+# define CC_FLUSH_AND_PURGE_NO_PURGE 1
+#endif
+
 
 /**