Changeset 51749 in vbox for trunk/src/VBox/Devices/Storage

Timestamp:

Jun 27, 2014 8:38:04 PM (10 years ago)

Author:

vboxsync

Message:

Storage/DiskIntegrity: Add an option to record the write before it was actually written to disk, useful when debugging issues with filters enabled in VD because they might modify data in the I/O buffer in place which would result in wrong data written into the ramdisk when the write completes

File:

• trunk/src/VBox/Devices/Storage/DrvDiskIntegrity.cpp (modified) (9 diffs)

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

@@ -196 +196 @@
     /** Flag whether to do a immediate read after write for verification. */
     bool                    fReadAfterWrite;
+    /** Flag whether to record the data to write before the write completed successfully.
+     * Useful in case the data is modified in place later on (encryption for instance). */
+    bool                    fRecordWriteBeforeCompletion;
 
     /** I/O logger to use if enabled. */
@@ -819 +822 @@
     }
 
+    if (pThis->fRecordWriteBeforeCompletion)
+    {
+        RTSGSEG Seg;
+        Seg.cbSeg = cbWrite;
+        Seg.pvSeg = (void *)pvBuf;
+
+        rc = drvdiskintWriteRecord(pThis, &Seg, 1, off, cbWrite);
+        if (RT_FAILURE(rc))
+            return rc;
+    }
+
     rc = pThis->pDrvMedia->pfnWrite(pThis->pDrvMedia, off, pvBuf, cbWrite);
 
@@ -830 +844 @@
         return rc;
 
-    if (pThis->fCheckConsistency)
+    if (   pThis->fCheckConsistency
+        && !pThis->fRecordWriteBeforeCompletion)
     {
         /* Record the write. */
@@ -918 +933 @@
     }
 
+    if (pThis->fRecordWriteBeforeCompletion)
+    {
+        int rc2 = drvdiskintWriteRecord(pThis, paSeg, cSeg, uOffset, cbWrite);
+        AssertRC(rc2);
+    }
+
     int rc = pThis->pDrvMediaAsync->pfnStartWrite(pThis->pDrvMediaAsync, uOffset, paSeg, cSeg,
                                                   cbWrite, pIoReq);
@@ -923 +944 @@
     {
         /* Record the write. */
-        if  (pThis->fCheckConsistency)
+        if  (   pThis->fCheckConsistency
+             && !pThis->fRecordWriteBeforeCompletion)
         {
             int rc2 = drvdiskintWriteRecord(pThis, paSeg, cSeg, uOffset, cbWrite);
@@ -1153 +1175 @@
         if (pIoReq->enmTxDir == DRVDISKAIOTXDIR_READ)
             rc = drvdiskintReadVerify(pThis, pIoReq->paSeg, pIoReq->cSeg, pIoReq->off, pIoReq->cbTransfer);
-        else if (pIoReq->enmTxDir == DRVDISKAIOTXDIR_WRITE)
+        else if (   pIoReq->enmTxDir == DRVDISKAIOTXDIR_WRITE
+                 && !pThis->fRecordWriteBeforeCompletion)
             rc = drvdiskintWriteRecord(pThis, pIoReq->paSeg, pIoReq->cSeg, pIoReq->off, pIoReq->cbTransfer);
         else if (pIoReq->enmTxDir == DRVDISKAIOTXDIR_DISCARD)
@@ -1160 +1183 @@
             rc = drvdiskintReadAfterWriteVerify(pThis, pIoReq);
         else
-            AssertMsg(pIoReq->enmTxDir == DRVDISKAIOTXDIR_FLUSH, ("Huh?\n"));
+            AssertMsg(   pIoReq->enmTxDir == DRVDISKAIOTXDIR_FLUSH
+                      || (   pIoReq->enmTxDir == DRVDISKAIOTXDIR_WRITE
+                          && pThis->fRecordWriteBeforeCompletion), ("Huh?\n"));
 
         AssertRC(rc);
@@ -1316 +1341 @@
                                     "IoLog\0"
                                     "PrepopulateRamDisk\0"
-                                    "ReadAfterWrite\0"))
+                                    "ReadAfterWrite\0"
+                                    "RecordWriteBeforeCompletion\0"))
         return VERR_PDM_DRVINS_UNKNOWN_CFG_VALUES;
 
@@ -1334 +1360 @@
     AssertRC(rc);
     rc = CFGMR3QueryBoolDef(pCfg, "ReadAfterWrite", &pThis->fReadAfterWrite, false);
+    AssertRC(rc);
+    rc = CFGMR3QueryBoolDef(pCfg, "RecordWriteBeforeCompletion", &pThis->fRecordWriteBeforeCompletion, false);
     AssertRC(rc);