Changeset 34347 in vbox for trunk

Timestamp:

Nov 24, 2010 10:34:21 PM (14 years ago)

Author:

vboxsync

Message:

BlkCache: Suspend the VM if an error occurs during a write

Location:

trunk/src/VBox/VMM

Files:

• PDM.cpp (modified) (1 diff)
• PDMBlkCache.cpp (modified) (5 diffs)
• PDMBlkCacheInternal.h (modified) (1 diff)
• PDMInternal.h (modified) (1 diff)

trunk/src/VBox/VMM/PDM.cpp

@@ -1625 +1625 @@
 
     /*
+     * Resume the block cache.
+     */
+    if (RT_SUCCESS(rc))
+        pdmR3BlkCacheResume(pVM);
+
+    /*
      * On failure, clean up via PDMR3Suspend.
      */

trunk/src/VBox/VMM/PDMBlkCache.cpp

@@ -724 +724 @@
  * @returns Flag whether the amount of dirty bytes in the cache exceeds the threshold
  * @param   pBlkCache    The endpoint cache the entry belongs to.
- * @param   pEntry            The entry to add.
+ * @param   pEntry       The entry to add.
  */
 static bool pdmBlkCacheAddDirtyEntry(PPDMBLKCACHE pBlkCache, PPDMBLKCACHEENTRY pEntry)
@@ -748 +748 @@
         uint32_t cbDirty = ASMAtomicAddU32(&pCache->cbDirty, pEntry->cbData);
 
-        fDirtyBytesExceeded = (cbDirty >= pCache->cbCommitDirtyThreshold);
+        /* Prevent committing if the VM was suspended. */
+        if (RT_LIKELY(!ASMAtomicReadBool(&pCache->fIoErrorVmSuspended)))
+            fDirtyBytesExceeded = (cbDirty >= pCache->cbCommitDirtyThreshold);
     }
 
@@ -763 +765 @@
     LogFlowFunc(("Commit interval expired, commiting dirty entries\n"));
 
-    if (ASMAtomicReadU32(&pCache->cbDirty) > 0)
+    if (   ASMAtomicReadU32(&pCache->cbDirty) > 0
+        && !ASMAtomicReadBool(&pCache->fIoErrorVmSuspended))
         pdmBlkCacheCommitDirtyEntries(pCache);
 
@@ -946 +949 @@
 }
 
+int pdmR3BlkCacheResume(PVM pVM)
+{
+    PPDMBLKCACHEGLOBAL pBlkCacheGlobal = pVM->pUVM->pdm.s.pBlkCacheGlobal;
+
+    LogFlowFunc(("pVM=%#p\n", pVM));
+
+    if (   pBlkCacheGlobal
+        && ASMAtomicXchgBool(&pBlkCacheGlobal->fIoErrorVmSuspended, false))
+    {
+        /* The VM was suspended because of an I/O error, commit all dirty entries. */
+        pdmBlkCacheCommitDirtyEntries(pBlkCacheGlobal);
+    }
+
+    return VINF_SUCCESS;
+}
+
 static int pdmR3BlkCacheRetain(PVM pVM, PPPDMBLKCACHE ppBlkCache, const char *pcszId)
 {
@@ -2270 +2289 @@
                     pEntry->Core.Key, pEntry->cbData, pBlkCache->pszId));
 
-            int rc = VMSetRuntimeError(pCache->pVM, VMSETRTERR_FLAGS_SUSPEND | VMSETRTERR_FLAGS_NO_WAIT, "BLKCACHE_IOERR",
-                                       N_("The I/O cache encountered an error while updating data in medium \"%s\" (rc=%Rrc)."
-                                          "Make sure there is enough free space on the disk and that the disk is working properly."
-                                          "Operation can be resumed afterwards."),
-                                       pBlkCache->pszId, rcIoXfer);
-            AssertRC(rc);
+            if (!ASMAtomicXchgBool(&pCache->fIoErrorVmSuspended, true))
+            {
+                int rc = VMSetRuntimeError(pCache->pVM, VMSETRTERR_FLAGS_SUSPEND | VMSETRTERR_FLAGS_NO_WAIT, "BLKCACHE_IOERR",
+                                           N_("The I/O cache encountered an error while updating data in medium \"%s\" (rc=%Rrc). "
+                                              "Make sure there is enough free space on the disk and that the disk is working properly. "
+                                              "Operation can be resumed afterwards"),
+                                           pBlkCache->pszId, rcIoXfer);
+                AssertRC(rc);
+            }
+
+            /*
+             * The entry is still marked as dirty which prevents eviction.
+             * Add the waiters to the list again.
+             */
+            fDirty = true;
+
+            if (pComplete)
+            {
+                pEntry->pWaitingHead = pComplete;
+                while (pComplete->pNext)
+                    pComplete = pComplete->pNext;
+                pEntry->pWaitingTail = pComplete;
+                pComplete = NULL;
+            }
         }
         else

trunk/src/VBox/VMM/PDMBlkCacheInternal.h

@@ -154 +154 @@
     STAMCOUNTER       StatBuffersReused;
 #endif
+    /** Flag whether the VM was suspended becaus of an I/O error. */
+    volatile bool     fIoErrorVmSuspended;
 } PDMBLKCACHEGLOBAL;
 #ifdef VBOX_WITH_STATISTICS

trunk/src/VBox/VMM/PDMInternal.h

@@ -1178 +1178 @@
 int         pdmR3BlkCacheInit(PVM pVM);
 void        pdmR3BlkCacheTerm(PVM pVM);
+int         pdmR3BlkCacheResume(PVM pVM);
 
 #endif /* IN_RING3 */