Correct path-remaining with Reparse Points

When returning STATUS_REPARSE we are to calculate
how much of the path remains unused, and did so using
strlen(). This will break with non-ASCII characters
(umlauts etc). Now we use RtlUTF8ToUnicodeN() to
get the number of characters remaining (instead of bytes).

Also started work allowing fastio_query_open() to assign
vp, but currently not active.

Signed-off-by: Jorgen Lundman <lundman@lundman.net>

include/os/windows/zfs/sys/zfs_windows.h

@@ -206,7 +206,7 @@ extern NTSTATUS file_ea_information(PDEVICE_OBJECT, PIRP, PIO_STACK_LOCATION,
 extern NTSTATUS file_alignment_information(PDEVICE_OBJECT, PIRP,
     PIO_STACK_LOCATION, FILE_ALIGNMENT_INFORMATION *);
 extern void file_network_open_information_impl(PDEVICE_OBJECT, PFILE_OBJECT,
-    FILE_NETWORK_OPEN_INFORMATION *, PIO_STATUS_BLOCK);
+    struct vnode *, FILE_NETWORK_OPEN_INFORMATION *, PIO_STATUS_BLOCK);
 extern NTSTATUS file_network_open_information(PDEVICE_OBJECT, PIRP,
     PIO_STACK_LOCATION,	FILE_NETWORK_OPEN_INFORMATION *);
 extern NTSTATUS file_standard_link_information(PDEVICE_OBJECT, PIRP,

module/os/windows/zfs/zfs_vnops_windows.c

@@ -1138,11 +1138,16 @@ zfs_vnop_lookup_impl(PIRP Irp, PIO_STACK_LOCATION IrpSp, mount_t *zmo,
 			 * Should include the leading "/", when finalname
 			 * here would be "lower".
 			 */
-			rpb->Reserved = strlen(finalname) * sizeof (WCHAR);
-			if (rpb->Reserved != 0)
-				rpb->Reserved += sizeof (WCHAR); // the slash
+			ULONG len = 0;
+			if (finalname && *finalname) {
+				RtlUTF8ToUnicodeN(NULL, 0, &len,
+				    finalname, strlen(finalname));
+				len += sizeof (WCHAR);
+			}
+			rpb->Reserved = len;
 
-			dprintf("%s: returning REPARSE\n", __func__);
+			dprintf("%s: returning REPARSE (remainder %d)\n",
+			    __func__, rpb->Reserved);
 			Irp->IoStatus.Information = rpb->ReparseTag;
 			Irp->Tail.Overlay.AuxiliaryBuffer = (void *)rpb;
 
@@ -7994,7 +7999,8 @@ fastio_query_network_open_info(PFILE_OBJECT FileObject,
 		return (FALSE);
 	}
 
-	file_network_open_information_impl(DeviceObject, FileObject, fnoi,
+	file_network_open_information_impl(DeviceObject, FileObject, vp,
+	    fnoi,
 	    IoStatus);
 
 	ExReleaseResourceLite(vp->FileHeader.Resource);
@@ -8197,13 +8203,9 @@ fastio_query_open(PIRP Irp,
 			/* call sets the IoStatus */
 			dprintf("%s: open OK stat()ing.\n", __func__);
 
-//			if (IrpSp->FileObject->FsContext == NULL)
-//				zfs_couplefileobject(dvp, vp,
-//				    IrpSp->FileObject->FsContext, 0ULL, &zccb,
-//				    NULL, 0, NULL);
-
 			file_network_open_information_impl(DeviceObject,
-			    IrpSp->FileObject, NetworkInformation,
+			    IrpSp->FileObject, vp ? vp : dvp,
+			    NetworkInformation,
 			    &Irp->IoStatus);
 			if (vp)
 				VN_RELE(vp);

module/os/windows/zfs/zfs_vnops_windows_lib.c

@@ -2319,6 +2319,9 @@ zfs_send_notify_stream(zfsvfs_t *zfsvfs, char *name, int nameoffset,
 	if (name == NULL)
 		return;
 
+	if (nameoffset > strlen(name))
+		return;
+
 	AsciiStringToUnicodeString(name, &ustr);
 
 	dprintf("%s: '%wZ' part '%S' %lu %u\n", __func__, &ustr,
@@ -4596,12 +4599,11 @@ file_alignment_information(PDEVICE_OBJECT DeviceObject, PIRP Irp,
 
 void
 file_network_open_information_impl(PDEVICE_OBJECT DeviceObject,
-    PFILE_OBJECT FileObject, FILE_NETWORK_OPEN_INFORMATION *netopen,
+    PFILE_OBJECT FileObject, vnode_t *vp,
+    FILE_NETWORK_OPEN_INFORMATION *netopen,
     PIO_STATUS_BLOCK IoStatus)
 {
 	dprintf("   %s\n", __func__);
-	struct vnode *vp = FileObject->FsContext;
-	zfs_ccb_t *zccb = FileObject->FsContext2;
 	znode_t *zp = VTOZ(vp);
 	mount_t *zmo = DeviceObject->DeviceExtension;
 	zfsvfs_t *zfsvfs = vfs_fsprivate(zmo);
@@ -4662,7 +4664,7 @@ file_network_open_information(PDEVICE_OBJECT DeviceObject, PIRP Irp,
 
 	// This function relies on VN_HOLD in dispatcher.
 	file_network_open_information_impl(DeviceObject, IrpSp->FileObject,
-	    netopen, &Irp->IoStatus);
+	    IrpSp->FileObject->FsContext, netopen, &Irp->IoStatus);
 
 	return (Irp->IoStatus.Status);
 }