1 files changed, 66 insertions, 0 deletions
diff --git a/libdiskfs/dev-open.c b/libdiskfs/dev-open.c
new file mode 100644
index 00000000..5b45c30e
--- /dev/null
+++ b/libdiskfs/dev-open.c
@@ -0,0 +1,66 @@
+/* Standard device opening
+
+   Copyright (C) 1995 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include <diskfs.h>
+
+/* Uses the values of DISKFS_DEVICE_ARG and DISKFS_USE_MACH_DEVICE, and
+   attempts to open the device and set the values of DISKFS_DEVICE,
+   DISKFS_DEVICE_NAME, DISKFS_DEVICE_START, DISKFS_DEVICE_SIZE, and
+   DISKFS_DEVICE_BLOCK_SIZE.  */
+error_t
+diskfs_device_open ()
+{
+  error_t err;
+  if (diskfs_use_mach_device)
+    {
+      diskfs_device_name = diskfs_device_arg;
+      err = 
+	diskfs_get_mach_device (diskfs_device_name, &diskfs_device,
+				&diskfs_device_start, &diskfs_device_size,
+				&diskfs_device_block_size);
+    }
+  else
+    err =
+      diskfs_get_file_device (diskfs_device_arg,
+			      &diskfs_device_name, &diskfs_device,
+			      &diskfs_device_start, &diskfs_device_size,
+			      &diskfs_device_block_size);
+
+  if (! err)
+    {
+      diskfs_log2_device_block_size = 0;
+      while ((1 << diskfs_log2_device_block_size) < diskfs_device_block_size)
+	diskfs_log2_device_block_size++;
+      while ((1 << diskfs_log2_device_block_size) != diskfs_device_block_size)
+	diskfs_log2_device_block_size = 0;
+
+      diskfs_log2_device_blocks_per_page = 0;
+      while ((diskfs_device_block_size << diskfs_log2_device_blocks_per_page)
+	     < vm_page_size)
+	diskfs_log2_device_blocks_per_page++;
+      if ((diskfs_device_block_size << diskfs_log2_device_blocks_per_page)
+	  != vm_page_size)
+	diskfs_log2_device_blocks_per_page = 0;
+    }
+
+  return err;
+}