1  /*
       2   * ioctl based topology -- gathers topology information
       3   *
       4   * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
       5   *
       6   * This file may be redistributed under the terms of the
       7   * GNU Lesser General Public License.
       8   *
       9   */
      10  #include <stdio.h>
      11  #include <string.h>
      12  #include <stdlib.h>
      13  #include <stdint.h>
      14  #include <sys/types.h>
      15  #include <sys/stat.h>
      16  #include <unistd.h>
      17  #include <errno.h>
      18  
      19  #include "topology.h"
      20  
      21  /*
      22   * ioctl topology values
      23   */
      24  static const struct topology_val {
      25  
      26  	long  ioc;
      27  
      28  	/* functions to set probing result */
      29  	int (*set_ulong)(blkid_probe, unsigned long);
      30  	int (*set_int)(blkid_probe, int);
      31  	int (*set_u64)(blkid_probe, uint64_t);
      32  
      33  } topology_vals[] = {
      34  	{ BLKALIGNOFF, NULL, blkid_topology_set_alignment_offset },
      35  	{ BLKIOMIN, blkid_topology_set_minimum_io_size },
      36  	{ BLKIOOPT, blkid_topology_set_optimal_io_size },
      37  	{ BLKPBSZGET, blkid_topology_set_physical_sector_size },
      38  	{ BLKGETDISKSEQ, .set_u64 = blkid_topology_set_diskseq },
      39  	/* we read BLKSSZGET in topology.c */
      40  };
      41  
      42  static int probe_ioctl_tp(blkid_probe pr,
      43  		const struct blkid_idmag *mag __attribute__((__unused__)))
      44  {
      45  	size_t i;
      46  
      47  	for (i = 0; i < ARRAY_SIZE(topology_vals); i++) {
      48  		const struct topology_val *val = &topology_vals[i];
      49  		int rc = 1;
      50  		union {
      51  			unsigned long ul;
      52  			int i;
      53  			uint64_t u64;
      54  		} data;
      55  
      56  		if (ioctl(pr->fd, val->ioc, &data) == -1)
      57  			goto nothing;
      58  
      59  		if (val->set_int)
      60  			rc = val->set_int(pr, data.i);
      61  		else if (val->set_ulong)
      62  			rc = val->set_ulong(pr, data.ul);
      63  		else
      64  			rc = val->set_u64(pr, data.u64);
      65  
      66  		if (rc)
      67  			goto err;
      68  	}
      69  
      70  	return 0;
      71  nothing:
      72  	return 1;
      73  err:
      74  	return -1;
      75  }
      76  
      77  const struct blkid_idinfo ioctl_tp_idinfo =
      78  {
      79  	.name		= "ioctl",
      80  	.probefunc	= probe_ioctl_tp,
      81  	.magics		= BLKID_NONE_MAGIC
      82  };
      83