From 8ef10e5992d85be1df537e0099534817a7a3c1fc Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Mon, 4 Apr 2016 16:13:04 -0700
Subject: [PATCH] sys: IRP_MJ_FLUSH_BUFFERS: fix deadlock when flushing volume

---
 src/sys/flush.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/sys/flush.c b/src/sys/flush.c
index 407110c4..90255991 100644
--- a/src/sys/flush.c
+++ b/src/sys/flush.c
@@ -37,6 +37,7 @@ static NTSTATUS FspFsvolFlushBuffers(
     FSP_FILE_DESC *FileDesc = FileObject->FsContext2;
     FSP_FILE_NODE **FileNodes;
     ULONG FileNodeCount, Index;
+    PIRP TopLevelIrp;
     IO_STATUS_BLOCK IoStatus;
     FSP_FSCTL_TRANSACT_REQ *Request;
 
@@ -50,6 +51,10 @@ static NTSTATUS FspFsvolFlushBuffers(
         if (!NT_SUCCESS(Result))
             return Result;
 
+        /* reset the top-level IRP to avoid deadlock on the FileNodes' resources */
+        TopLevelIrp = IoGetTopLevelIrp();
+        IoSetTopLevelIrp(0);
+
         /*
          * Enumerate in reverse order so that files are flushed before containing directories.
          * This would be useful if we ever started flushing directories, but since we do not
@@ -65,6 +70,8 @@ static NTSTATUS FspFsvolFlushBuffers(
                     FlushResult = Result;
             }
 
+        IoSetTopLevelIrp(TopLevelIrp);
+
         FspFileNodeDeleteList(FileNodes, FileNodeCount);
 
         Result = FspIopCreateRequest(Irp, 0, 0, &Request);