sys: FspFsvolCreateTryFlushImage

inc/winfsp/fsctl.h

@@ -48,7 +48,7 @@ extern const __declspec(selectany) GUID FspFsvrtDeviceClassGuid =
 #pragma warning(disable:4200)           /* zero-sized array in struct/union */
 enum
 {
-    FspFsctlTransactUnknownKind = 0,
+    FspFsctlTransactReservedKind = 0,
     FspFsctlTransactCreateKind,
     FspFsctlTransactOverwriteKind,
     FspFsctlTransactCleanupKind,

src/sys/create.c

@@ -15,7 +15,10 @@ static NTSTATUS FspFsvolCreate(
 FSP_IOPREP_DISPATCH FspFsvolCreatePrepare;
 FSP_IOCMPL_DISPATCH FspFsvolCreateComplete;
 static VOID FspFsvolCreatePostClose(FSP_FILE_DESC *FileDesc);
+static NTSTATUS FspFsvolCreateTryFlushImage(PIRP Irp, FSP_FSCTL_TRANSACT_REQ *Request,
+    FSP_FILE_NODE *FileNode, FSP_FILE_DESC *FileDesc, PFILE_OBJECT FileObject);
 static FSP_IOP_REQUEST_FINI FspFsvolCreateRequestFini;
+static FSP_IOP_REQUEST_FINI FspFsvolCreateReservedRequestFini;
 static FSP_IOP_REQUEST_FINI FspFsvolCreateOverwriteRequestFini;
 FSP_DRIVER_DISPATCH FspCreate;
 
@@ -26,7 +29,9 @@ FSP_DRIVER_DISPATCH FspCreate;
 #pragma alloc_text(PAGE, FspFsvolCreatePrepare)
 #pragma alloc_text(PAGE, FspFsvolCreateComplete)
 #pragma alloc_text(PAGE, FspFsvolCreatePostClose)
+#pragma alloc_text(PAGE, FspFsvolCreateTryFlushImage)
 #pragma alloc_text(PAGE, FspFsvolCreateRequestFini)
+#pragma alloc_text(PAGE, FspFsvolCreateReservedRequestFini)
 #pragma alloc_text(PAGE, FspFsvolCreateOverwriteRequestFini)
 #pragma alloc_text(PAGE, FspCreate)
 #endif
@@ -41,7 +46,7 @@ enum
     RequestAccessToken                  = 1,
     RequestProcess                      = 2,
 
-    /* OverwriteRequest */
+    /* Reserved/OverwriteRequest */
     //RequestFileDesc                   = 0,
     RequestFileObject                   = 1,
     RequestState                        = 2,
@@ -347,7 +352,37 @@ NTSTATUS FspFsvolCreatePrepare(
     FSP_FILE_DESC *FileDesc;
     PFILE_OBJECT FileObject;
 
-    if (FspFsctlTransactCreateKind == Request->Kind)
+    if (FspFsctlTransactReservedKind == Request->Kind)
+    {
+        /*
+         * This branch is not taken during IRP preparation, but rather during IRP completion
+         * when FlushImageSection needs to be retried.
+         */
+        FileDesc = FspIopRequestContext(Request, RequestFileDesc);
+        FileNode = FileDesc->FileNode;
+        FileObject = FspIopRequestContext(Request, RequestFileObject);
+
+        Result = FspFsvolCreateTryFlushImage(Irp, Request, FileNode, FileDesc, FileObject);
+        if (STATUS_PENDING == Result)
+            return Result;
+        else
+        {
+            if (NT_SUCCESS(Result))
+            {
+                /* SUCCESS! */
+                FspIopRequestContext(Request, RequestFileDesc) = 0;
+                Irp->IoStatus.Information = FILE_OPENED;
+                Result = STATUS_SUCCESS;
+            }
+
+            DEBUGLOGIRP(Irp, Result);
+
+            FspIopCompleteIrp(Irp, Result);
+
+            return FSP_STATUS_COMPLETED;
+        }
+    }
+    else if (FspFsctlTransactCreateKind == Request->Kind)
     {
         SecuritySubjectContext = &IrpSp->Parameters.Create.SecurityContext->
             AccessState->SubjectSecurityContext;
@@ -558,15 +593,9 @@ VOID FspFsvolCreateComplete(
             if (FlagOn(Response->Rsp.Create.Opened.GrantedAccess, FILE_WRITE_DATA) ||
                 DeleteOnClose)
             {
-                if (!MmFlushImageSection(&FileNode->NonPaged->SectionObjectPointers,
+                Result = FspFsvolCreateTryFlushImage(Irp, 0, FileNode, FileDesc, FileObject);
-                    MmFlushForWrite))
+                if (STATUS_PENDING == Result || !NT_SUCCESS(Result))
-                {
-                    FspFsvolCreatePostClose(FileDesc);
-                    FspFileNodeClose(FileNode, FileObject, 0);
-
-                    Result = DeleteOnClose ? STATUS_CANNOT_DELETE : STATUS_SHARING_VIOLATION;
                     FSP_RETURN();
-                }
             }
 
             /* SUCCESS! */
@@ -690,6 +719,70 @@ static VOID FspFsvolCreatePostClose(FSP_FILE_DESC *FileDesc)
      */
 }
 
+static NTSTATUS FspFsvolCreateTryFlushImage(PIRP Irp, FSP_FSCTL_TRANSACT_REQ *Request,
+    FSP_FILE_NODE *FileNode, FSP_FILE_DESC *FileDesc, PFILE_OBJECT FileObject)
+{
+    PAGED_CODE();
+
+    ASSERT(0 == Request || FspFsctlTransactReservedKind == Request->Kind);
+
+    BOOLEAN Success;
+
+    Success = FspFileNodeTryAcquireExclusive(FileNode, Main);
+    if (!Success)
+    {
+        /* repost the IRP to retry later */
+        NTSTATUS Result;
+        PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation(Irp);
+        FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension =
+            FspFsvolDeviceExtension(IrpSp->DeviceObject);
+
+        if (0 == Request)
+        {
+            /* delete the old request */
+            Request = FspIrpRequest(Irp);
+            FspIrpRequest(Irp) = 0;
+            FspIopRequestContext(Request, RequestFileDesc) = 0;
+                /* disassociate the FileDesc from the old Request as we want to keep it around! */
+            FspIopDeleteRequest(Request);
+
+            /* create the special Reserved request */
+            FspIopCreateRequestFunnel(Irp, 0, 0,
+                FspFsvolCreateReservedRequestFini, TRUE,
+                &Request);
+
+            /* associate the FileDesc and FileObject with the Reserved request */
+            FspIopRequestContext(Request, RequestFileDesc) = FileDesc;
+            FspIopRequestContext(Request, RequestFileObject) = FileObject;
+
+            Request->Kind = FspFsctlTransactReservedKind;
+        }
+
+        FspIoqPostIrpBestEffort(FsvolDeviceExtension->Ioq, Irp, &Result);
+
+        return Result;
+    }
+
+    Success = MmFlushImageSection(&FileNode->NonPaged->SectionObjectPointers,
+        MmFlushForWrite);
+    FspFileNodeRelease(FileNode, Main);
+    if (!Success)
+    {
+        PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation(Irp);
+        BOOLEAN DeleteOnClose = BooleanFlagOn(IrpSp->Parameters.Create.Options, FILE_DELETE_ON_CLOSE);
+
+        if (0 == Request)
+        {
+            FspFsvolCreatePostClose(FileDesc);
+            FspFileNodeClose(FileNode, FileObject, 0);
+        }
+        
+        return DeleteOnClose ? STATUS_CANNOT_DELETE : STATUS_SHARING_VIOLATION;
+    }
+
+    return STATUS_SUCCESS;
+}
+
 static VOID FspFsvolCreateRequestFini(PVOID Context[3])
 {
     PAGED_CODE();
@@ -731,6 +824,26 @@ static VOID FspFsvolCreateRequestFini(PVOID Context[3])
     Context[RequestFileDesc] = Context[RequestAccessToken] = Context[RequestProcess] = 0;
 }
 
+static VOID FspFsvolCreateReservedRequestFini(PVOID Context[3])
+{
+    PAGED_CODE();
+
+    FSP_FILE_DESC *FileDesc = Context[RequestFileDesc];
+    PFILE_OBJECT FileObject = Context[RequestFileObject];
+
+    if (0 != FileDesc)
+    {
+        ASSERT(0 != FileObject);
+
+        FspFsvolCreatePostClose(FileDesc);
+        FspFileNodeClose(FileDesc->FileNode, FileObject, 0);
+        FspFileNodeDereference(FileDesc->FileNode);
+        FspFileDescDelete(FileDesc);
+    }
+
+    Context[RequestFileDesc] = Context[RequestFileObject] = 0;
+}
+
 static VOID FspFsvolCreateOverwriteRequestFini(PVOID Context[3])
 {
     PAGED_CODE();

src/sys/driver.h

@@ -29,6 +29,7 @@
 #define FSP_STATUS_PRIVATE_BIT          (0x20000000)
 #define FSP_STATUS_IOQ_POST             (FSP_STATUS_PRIVATE_BIT | 0x0000)
 #define FSP_STATUS_IOQ_POST_BEST_EFFORT (FSP_STATUS_PRIVATE_BIT | 0x0001)
+#define FSP_STATUS_COMPLETED            (FSP_STATUS_PRIVATE_BIT | 0x0002)
 
 /* misc macros */
 #define FSP_ALLOC_INTERNAL_TAG          'IpsF'
@@ -43,6 +44,13 @@
 #define DEBUGLOG(fmt, ...)              ((void)0)
 #endif
 
+/* DEBUGLOGIRP */
+#if DBG
+#define DEBUGLOGIRP(Irp, Result)        FspDebugLogIrp(Irp, Result)
+#else
+#define DEBUGLOGIRP(Irp, Result)        ((void)0)
+#endif
+
 /* DEBUGBREAK */
 #if DBG
 extern __declspec(selectany) int fsp_bp = 1;
@@ -590,6 +598,19 @@ const char *NtStatusSym(NTSTATUS Status);
 const char *IrpMajorFunctionSym(UCHAR MajorFunction);
 const char *IrpMinorFunctionSym(UCHAR MajorFunction, UCHAR MinorFunction);
 const char *IoctlCodeSym(ULONG ControlCode);
+static inline
+VOID FspDebugLogIrp(PIRP Irp, NTSTATUS Result)
+{
+    PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation(Irp);
+    DEBUGLOG("IRP=%p, %s%c, %s%s, IoStatus=%s[%lld]",
+        Irp,
+        (const char *)&FspDeviceExtension(IrpSp->DeviceObject)->Kind,
+        Irp->RequestorMode == KernelMode ? 'K' : 'U',
+        IrpMajorFunctionSym(IrpSp->MajorFunction),
+        IrpMinorFunctionSym(IrpSp->MajorFunction, IrpSp->MinorFunction),
+        NtStatusSym(Result),
+        (LONGLONG)Irp->IoStatus.Information);
+}
 #endif
 
 /* extern */

src/sys/iop.c

@@ -238,15 +238,7 @@ VOID FspIopCompleteCanceledIrp(PIRP Irp)
 {
     PAGED_CODE();
 
-#if DBG
+    DEBUGLOGIRP(Irp, STATUS_CANCELLED);
-    PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation(Irp);
-    DEBUGLOG("IRP=%p, %s%c, %s%s",
-        Irp,
-        (const char *)&FspDeviceExtension(IrpSp->DeviceObject)->Kind,
-        Irp->RequestorMode == KernelMode ? 'K' : 'U',
-        IrpMajorFunctionSym(IrpSp->MajorFunction),
-        IrpMinorFunctionSym(IrpSp->MajorFunction, IrpSp->MinorFunction));
-#endif
 
     FspIopCompleteIrpEx(Irp, STATUS_CANCELLED, TRUE);
 }

src/sys/volume.c

@@ -565,7 +565,9 @@ NTSTATUS FspVolumeTransact(
         PendingIrpRequest = FspIrpRequest(PendingIrp);
 
         Result = FspIopDispatchPrepare(PendingIrp, PendingIrpRequest);
-        if (STATUS_PENDING == Result)
+        if (FSP_STATUS_COMPLETED == Result)
+            ;
+        else if (STATUS_PENDING == Result)
         {
             /*
              * The IRP has been reposted to our Ioq. Remember the first such IRP,