From: Jeffrey Altman <jaltman@your-file-system.com>
Date: Fri, 18 May 2012 20:31:19 +0000 (-0400)
Subject: Windows: avoid deadlock TreeLock vs Fcb Resource
X-Git-Tag: upstream/1.8.0_pre1^2~2401
X-Git-Url: https://git.michaelhowe.org/gitweb/?a=commitdiff_plain;h=3a7dbe331580e418d1bdd5d75769512bb5e38cee;p=packages%2Fo%2Fopenafs.git

Windows: avoid deadlock TreeLock vs Fcb Resource

Cannot call AFSPerformObjectInvalidate directly because
ObjectInfoCB->Specific.Directory.DirectoryNodeHdr.TreeLock is
held during the sequence

  AFSVerifyEntry->AFSValidateDirectoryCache->AFSVerifyDirectoryContent

and AFSPerformObjectInvalidate requires the Fcb->NPFcb->Resource
which must be held prior to the TreeLock.

Change-Id: I337f52e2927c8e5ae2d218867987625c3240a792
Reviewed-on: http://gerrit.openafs.org/7423
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@secure-endpoints.com>
Tested-by: Jeffrey Altman <jaltman@secure-endpoints.com>
---

diff --git a/src/WINNT/afsrdr/kernel/lib/AFSCommSupport.cpp b/src/WINNT/afsrdr/kernel/lib/AFSCommSupport.cpp
index 763c45d6b..771041b0e 100644
--- a/src/WINNT/afsrdr/kernel/lib/AFSCommSupport.cpp
+++ b/src/WINNT/afsrdr/kernel/lib/AFSCommSupport.cpp
@@ -1070,12 +1070,22 @@ AFSVerifyDirectoryContent( IN AFSObjectInfoCB *ObjectInfoCB,
 
                             //
                             // The ObjectReferenceCount will be freed by AFSPerformObjectInvalidate
+                            // if successfully queued.  Cannot call AFSPerformObjectInvalidate directly
+                            // because ObjectInfoCB->Specific.Directory.DirectoryNodeHdr.TreeLock is
+                            // held during the sequence AFSVerifyEntry->AFSValidateDirectoryCache->
+                            // AFSVerifyDirectoryContent and AFSPerformObjectInvalidate requires the
+                            // Fcb->NPFcb->Resource which must be held prior to the TreeLock in the
+                            // lock hierarchy.
                             //
 
                             lCount = InterlockedIncrement( &pObjectInfo->ObjectReferenceCount);
 
-                            AFSPerformObjectInvalidate( pObjectInfo,
-                                                        AFS_INVALIDATE_DATA_VERSION);
+                            if ( !NT_SUCCESS( AFSQueueInvalidateObject( pObjectInfo,
+                                                                        AFS_INVALIDATE_DATA_VERSION)))
+                            {
+
+                                lCount = InterlockedDecrement( &pObjectInfo->ObjectReferenceCount);
+                            }
                         }
                         else
                         {