Changeset 43861 in vbox

Timestamp:

Nov 13, 2012 10:35:55 AM (12 years ago)

Author:

vboxsync

Message:

Storage: Introduce new flag to skip unnecessary consistency checks in the VMDK backend while opening an image in readonly mode to speed up opening snapshots

Location:

trunk

Files:

• include/VBox/vd.h (modified) (3 diffs)
• src/VBox/Devices/Storage/DrvVD.cpp (modified) (6 diffs)
• src/VBox/Storage/VD.cpp (modified) (1 diff)
• src/VBox/Storage/VMDK.cpp (modified) (2 diffs)

trunk/include/VBox/vd.h

@@ -152 +152 @@
 
 /**
- * Auxiliary data structure for difference between GPT and MBR 
- * disks. 
- */
-enum PARTITIONING_TYPE 
+ * Auxiliary data structure for difference between GPT and MBR
+ * disks.
+ */
+enum PARTITIONING_TYPE
 {
     MBR,
@@ -179 +179 @@
     /** Pointer to the partition descriptor array. */
     PVBOXHDDRAWPARTDESC pPartDescs;
-    /**partitioning type of the disk */ 
+    /**partitioning type of the disk */
     PARTITIONING_TYPE uPartitioningType;
 
@@ -231 +231 @@
  */
 #define VD_OPEN_FLAGS_INFORM_ABOUT_ZERO_BLOCKS RT_BIT(9)
+/**
+ * Don't do unnecessary consistency checks when opening the image.
+ * Only valid when the image is opened in readonly because inconsistencies
+ * can lead to corrupted images in read-write mode.
+ */
+#define VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS  RT_BIT(10)
 /** Mask of valid flags. */
-#define VD_OPEN_FLAGS_MASK          (VD_OPEN_FLAGS_NORMAL | VD_OPEN_FLAGS_READONLY | VD_OPEN_FLAGS_HONOR_ZEROES | VD_OPEN_FLAGS_HONOR_SAME | VD_OPEN_FLAGS_INFO | VD_OPEN_FLAGS_ASYNC_IO | VD_OPEN_FLAGS_SHAREABLE | VD_OPEN_FLAGS_SEQUENTIAL | VD_OPEN_FLAGS_DISCARD | VD_OPEN_FLAGS_IGNORE_FLUSH | VD_OPEN_FLAGS_INFORM_ABOUT_ZERO_BLOCKS)
+#define VD_OPEN_FLAGS_MASK          (VD_OPEN_FLAGS_NORMAL | VD_OPEN_FLAGS_READONLY | VD_OPEN_FLAGS_HONOR_ZEROES | VD_OPEN_FLAGS_HONOR_SAME | VD_OPEN_FLAGS_INFO | VD_OPEN_FLAGS_ASYNC_IO | VD_OPEN_FLAGS_SHAREABLE | VD_OPEN_FLAGS_SEQUENTIAL | VD_OPEN_FLAGS_DISCARD | VD_OPEN_FLAGS_IGNORE_FLUSH | VD_OPEN_FLAGS_INFORM_ABOUT_ZERO_BLOCKS | VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS)
 /** @}*/
 

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

@@ -2142 +2142 @@
     bool        fDiscard = false;
     bool        fInformAboutZeroBlocks = false;
+    bool        fSkipConsistencyChecks = false;
     unsigned    iLevel = 0;
     PCFGMNODE   pCurNode = pCfg;
@@ -2159 +2160 @@
                                           "HostIPStack\0UseNewIo\0BootAcceleration\0BootAccelerationBuffer\0"
                                           "SetupMerge\0MergeSource\0MergeTarget\0BwGroup\0Type\0BlockCache\0"
-                                          "CachePath\0CacheFormat\0Discard\0InformAboutZeroBlocks\0");
+                                          "CachePath\0CacheFormat\0Discard\0InformAboutZeroBlocks\0"
+                                          "SkipConsistencyChecks\0");
         }
         else
@@ -2299 +2301 @@
                 rc = PDMDRV_SET_ERROR(pDrvIns, rc,
                                       N_("DrvVD: Configuration error: Querying \"InformAboutZeroBlocks\" as boolean failed"));
+                break;
+            }
+            rc = CFGMR3QueryBoolDef(pCurNode, "SkipConsistencyChecks", &fSkipConsistencyChecks, true);
+            if (RT_FAILURE(rc))
+            {
+                rc = PDMDRV_SET_ERROR(pDrvIns, rc,
+                                      N_("DrvVD: Configuration error: Querying \"SKipConsistencyChecks\" as boolean failed"));
                 break;
             }
@@ -2405 +2414 @@
     if (pThis->pDrvMediaAsyncPort && fUseNewIo)
         pThis->fAsyncIOSupported = true;
+
+    uint64_t tsStart = RTTimeNanoTS();
 
     unsigned iImageIdx = 0;
@@ -2603 +2614 @@
         if (fInformAboutZeroBlocks)
             uOpenFlags |= VD_OPEN_FLAGS_INFORM_ABOUT_ZERO_BLOCKS;
+        if (   (uOpenFlags & VD_OPEN_FLAGS_READONLY)
+            && fSkipConsistencyChecks)
+            uOpenFlags |= VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS;
 
         /* Try to open backend in async I/O mode first. */
@@ -2662 +2676 @@
         pCurNode = CFGMR3GetParent(pCurNode);
     }
+
+    LogRel(("VD: Opening the disk took %lld ns\n", RTTimeNanoTS() - tsStart));
 
     /* Open the cache image if set. */

trunk/src/VBox/Storage/VD.cpp

@@ -5357 +5357 @@
                            rc = VERR_INVALID_PARAMETER);
         AssertMsgBreakStmt((uOpenFlags & ~VD_OPEN_FLAGS_MASK) == 0,
+                           ("uOpenFlags=%#x\n", uOpenFlags),
+                           rc = VERR_INVALID_PARAMETER);
+        AssertMsgBreakStmt(   !(uOpenFlags & VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS)
+                           ||  (uOpenFlags & VD_OPEN_FLAGS_READONLY),
                            ("uOpenFlags=%#x\n", uOpenFlags),
                            rc = VERR_INVALID_PARAMETER);

trunk/src/VBox/Storage/VMDK.cpp

@@ -1086 +1086 @@
         *pGDTmp = RT_LE2H_U32(*pGDTmp);
 
-    if (pExtent->uSectorRGD)
+    if (   pExtent->uSectorRGD
+        && !(pImage->uOpenFlags & VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS))
     {
         /* The VMDK 1.1 spec seems to talk about compressed grain directories,
@@ -6548 +6549 @@
         else
             rc = VERR_INVALID_PARAMETER;
-        goto out;
-    }
-
-    /* Implement this operation via reopening the image. */
-    vmdkFreeImage(pImage, false);
-    rc = vmdkOpenImage(pImage, uOpenFlags);
+    }
+    else
+    {
+        /* Implement this operation via reopening the image. */
+        vmdkFreeImage(pImage, false);
+        rc = vmdkOpenImage(pImage, uOpenFlags);
+    }
 
 out: