1  /*
       2   * Evms topology
       3   * -- this is fallback for old systems where the topology information is not
       4   *    exported by sysfs
       5   *
       6   * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
       7   *
       8   * This file may be redistributed under the terms of the
       9   * GNU Lesser General Public License.
      10   *
      11   */
      12  #include <errno.h>
      13  #include <fcntl.h>
      14  #include <stdint.h>
      15  #include <stdio.h>
      16  #include <stdlib.h>
      17  #include <string.h>
      18  #include <sys/ioctl.h>
      19  #include <sys/stat.h>
      20  #include <sys/types.h>
      21  #include <unistd.h>
      22  
      23  #include "topology.h"
      24  
      25  #define EVMS_MAJOR		117
      26  
      27  #ifndef _IOT__IOTBASE_u_int32_t
      28  #define _IOT__IOTBASE_u_int32_t IOT_SIMPLE(uint32_t)
      29  #endif
      30  #define _IOT_evms_stripe_info _IOT (_IOTS(uint32_t), 2, 0, 0, 0, 0)
      31  #define EVMS_GET_STRIPE_INFO	_IOR(EVMS_MAJOR, 0xF0, struct evms_stripe_info)
      32  
      33  struct evms_stripe_info {
      34  	uint32_t	size;		/* stripe unit 512-byte blocks */
      35  	uint32_t	width;		/* the number of stripe members or RAID data disks */
      36  };
      37  
      38  static int is_evms_device(dev_t devno)
      39  {
      40  	if (major(devno) == EVMS_MAJOR)
      41  		return 1;
      42  	return blkid_driver_has_major("evms", major(devno));
      43  }
      44  
      45  static int probe_evms_tp(blkid_probe pr,
      46  		const struct blkid_idmag *mag __attribute__((__unused__)))
      47  {
      48  	struct evms_stripe_info evms;
      49  	dev_t devno = blkid_probe_get_devno(pr);
      50  
      51  	if (!devno)
      52  		goto nothing;		/* probably not a block device */
      53  
      54  	if (!is_evms_device(devno))
      55  		goto nothing;
      56  
      57  	memset(&evms, 0, sizeof(evms));
      58  
      59  	if (ioctl(pr->fd, EVMS_GET_STRIPE_INFO, &evms))
      60  		goto nothing;
      61  
      62  	blkid_topology_set_minimum_io_size(pr, evms.size << 9);
      63  	blkid_topology_set_optimal_io_size(pr, (evms.size * evms.width) << 9);
      64  
      65  	return 0;
      66  
      67  nothing:
      68  	return 1;
      69  }
      70  
      71  const struct blkid_idinfo evms_tp_idinfo =
      72  {
      73  	.name		= "evms",
      74  	.probefunc	= probe_evms_tp,
      75  	.magics		= BLKID_NONE_MAGIC
      76  };
      77