sys: IRP_MJ_DIRECTORY_CONTROL: properly support asynchronous I/O

src/sys/dirctl.c

@@ -61,6 +61,9 @@ enum
     RequestAddress                      = 2,
     RequestProcess                      = 3,
 
+    /* QueryDirectoryRetry */
+    RequestSystemBufferLength           = 0,
+
     /* DirectoryControlComplete retry */
     RequestDirInfoChangeNumber          = 0,
 };
@@ -331,6 +334,31 @@ static NTSTATUS FspFsvolQueryDirectoryCopyInPlace(
     return Result;
 }
 
+static inline NTSTATUS FspFsvolQueryDirectoryBufferUserBuffer(
+    FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension, PIRP Irp, PULONG PLength)
+{
+    if (0 != Irp->AssociatedIrp.SystemBuffer)
+        return STATUS_SUCCESS;
+
+    NTSTATUS Result;
+    ULONG Length = *PLength;
+
+    if (Length > FspFsvolDeviceDirInfoCacheItemSizeMax)
+        Length = FspFsvolDeviceDirInfoCacheItemSizeMax;
+    else if (Length < sizeof(FSP_FSCTL_DIR_INFO) +
+        FsvolDeviceExtension->VolumeParams.MaxComponentLength * sizeof(WCHAR))
+        Length = sizeof(FSP_FSCTL_DIR_INFO) +
+            FsvolDeviceExtension->VolumeParams.MaxComponentLength * sizeof(WCHAR);
+
+    Result = FspBufferUserBuffer(Irp, FSP_FSCTL_ALIGN_UP(Length, PAGE_SIZE), IoWriteAccess);
+    if (!NT_SUCCESS(Result))
+        return Result;
+
+    *PLength = Length;
+
+    return STATUS_SUCCESS;
+}
+
 static NTSTATUS FspFsvolQueryDirectoryRetry(
     PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp,
     BOOLEAN CanWait)
@@ -354,16 +382,47 @@ static NTSTATUS FspFsvolQueryDirectoryRetry(
     ULONG SystemBufferLength;
     PVOID DirInfoBuffer;
     ULONG DirInfoSize;
-    FSP_FSCTL_TRANSACT_REQ *Request;
+    FSP_FSCTL_TRANSACT_REQ *Request = FspIrpRequest(Irp);
     BOOLEAN Success;
 
     ASSERT(FileNode == FileDesc->FileNode);
 
+    SystemBufferLength = 0 != Request ?
+        (ULONG)(UINT_PTR)FspIopRequestContext(Request, RequestSystemBufferLength) : 0;
+
     /* try to acquire the FileNode exclusive; Full because we may need to send a Request */
     Success = DEBUGTEST(90, TRUE) &&
         FspFileNodeTryAcquireExclusiveF(FileNode, FspFileNodeAcquireFull, CanWait);
     if (!Success)
-        return FspWqRepostIrpWorkItem(Irp, FspFsvolQueryDirectoryRetry, 0);
+    {
+        if (0 == SystemBufferLength)
+            SystemBufferLength = 0 != FsvolDeviceExtension->VolumeParams.FileInfoTimeout ?
+                FspFsvolDeviceDirInfoCacheItemSizeMax : Length; /* best guess! */
+
+        Result = FspFsvolQueryDirectoryBufferUserBuffer(
+            FsvolDeviceExtension, Irp, &SystemBufferLength);
+        if (!NT_SUCCESS(Result))
+            return Result;
+
+        Result = FspWqCreateIrpWorkItem(Irp, FspFsvolQueryDirectoryRetry, 0);
+        if (!NT_SUCCESS(Result))
+            return Result;
+
+        Request = FspIrpRequest(Irp);
+        FspIopRequestContext(Request, RequestSystemBufferLength) =
+            (PVOID)(UINT_PTR)SystemBufferLength;
+
+        FspWqPostIrpWorkItem(Irp);
+
+        return STATUS_PENDING;
+    }
+
+    /* if we have been retried reset our work item now! */
+    if (0 != Request)
+    {
+        FspWqDeleteIrpWorkItem(Irp);
+        Request = 0;
+    }
 
     /* set the DirectoryPattern in the FileDesc */
     Result = FspFileDescResetDirectoryPattern(FileDesc, FileName, RestartScan);
@@ -388,6 +447,7 @@ static NTSTATUS FspFsvolQueryDirectoryRetry(
     /* see if the required information is still in the cache and valid! */
     if (FspFileNodeReferenceDirInfo(FileNode, &DirInfoBuffer, &DirInfoSize))
     {
+        if (0 == SystemBufferLength)
             SystemBufferLength = Length;
 
         Result = FspFsvolQueryDirectoryCopyCache(FileDesc,
@@ -405,20 +465,17 @@ static NTSTATUS FspFsvolQueryDirectoryRetry(
         }
     }
     else
+    {
+        if (0 == SystemBufferLength)
             SystemBufferLength = 0 != FsvolDeviceExtension->VolumeParams.FileInfoTimeout ?
                 FspFsvolDeviceDirInfoCacheItemSizeMax : Length;
+    }
 
     FspFileNodeConvertExclusiveToShared(FileNode, Full);
 
     /* buffer the user buffer! */
-    if (SystemBufferLength > FspFsvolDeviceDirInfoCacheItemSizeMax)
-        SystemBufferLength = FspFsvolDeviceDirInfoCacheItemSizeMax;
-    else if (SystemBufferLength < sizeof(FSP_FSCTL_DIR_INFO) +
-        FsvolDeviceExtension->VolumeParams.MaxComponentLength * sizeof(WCHAR))
-        SystemBufferLength = sizeof(FSP_FSCTL_DIR_INFO) +
-            FsvolDeviceExtension->VolumeParams.MaxComponentLength * sizeof(WCHAR);
-    Result = FspBufferUserBuffer(Irp,
-        FSP_FSCTL_ALIGN_UP(SystemBufferLength, PAGE_SIZE), IoWriteAccess);
+    Result = FspFsvolQueryDirectoryBufferUserBuffer(
+        FsvolDeviceExtension, Irp, &SystemBufferLength);
     if (!NT_SUCCESS(Result))
     {
         FspFileNodeRelease(FileNode, Full);
@@ -462,6 +519,13 @@ static NTSTATUS FspFsvolQueryDirectory(
     ULONG Length = IrpSp->Parameters.QueryDirectory.Length;
     ULONG BaseInfoLen;
 
+    /* SystemBuffer must be NULL as we are going to be using it! */
+    if (0 != Irp->AssociatedIrp.SystemBuffer)
+    {
+        ASSERT(0);
+        return STATUS_INVALID_PARAMETER;
+    }
+
     /* only directory files can be queried */
     if (!FileNode->IsDirectory)
         return STATUS_INVALID_PARAMETER;

src/sys/driver.h

@@ -613,6 +613,7 @@ typedef NTSTATUS FSP_WQ_REQUEST_WORK(
 NTSTATUS FspWqCreateAndPostIrpWorkItem(PIRP Irp,
     FSP_WQ_REQUEST_WORK *WorkRoutine, FSP_IOP_REQUEST_FINI *RequestFini,
     BOOLEAN CreateAndPost);
+VOID FspWqDeleteIrpWorkItem(PIRP Irp);
 VOID FspWqPostIrpWorkItem(PIRP Irp);
 #define FspWqCreateIrpWorkItem(I, RW, RF)\
     FspWqCreateAndPostIrpWorkItem(I, RW, RF, FALSE)

src/sys/wq.c

@@ -30,13 +30,6 @@ NTSTATUS FspWqCreateAndPostIrpWorkItem(PIRP Irp,
             if (!NT_SUCCESS(Result))
                 return Result;
         }
-        else if (IRP_MJ_DIRECTORY_CONTROL == IrpSp->MajorFunction &&
-            IRP_MN_QUERY_DIRECTORY == IrpSp->MinorFunction)
-        {
-            Result = FspBufferUserBuffer(Irp, IrpSp->Parameters.QueryDirectory.Length, IoWriteAccess);
-            if (!NT_SUCCESS(Result))
-                return Result;
-        }
 
         Result = FspIopCreateRequestWorkItem(Irp, sizeof(WORK_QUEUE_ITEM),
             RequestFini, &RequestWorkItem);
@@ -57,6 +50,18 @@ NTSTATUS FspWqCreateAndPostIrpWorkItem(PIRP Irp,
     return STATUS_PENDING;
 }
 
+VOID FspWqDeleteIrpWorkItem(PIRP Irp)
+{
+    FSP_FSCTL_TRANSACT_REQ *RequestWorkItem = FspIrpRequest(Irp);
+
+    ASSERT(RequestWorkItem->Kind == FspFsctlTransactReservedKind);
+    ASSERT(RequestWorkItem->Size == sizeof *RequestWorkItem + sizeof(WORK_QUEUE_ITEM));
+    ASSERT(RequestWorkItem->Hint == (UINT_PTR)Irp);
+
+    FspIopDeleteRequest(RequestWorkItem);
+    FspIrpSetRequest(Irp, 0);
+}
+
 VOID FspWqPostIrpWorkItem(PIRP Irp)
 {
     FSP_FSCTL_TRANSACT_REQ *RequestWorkItem = FspIrpRequest(Irp);