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/* 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;
}
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