I have a linux mapper device on the host, I would like to get the start offset.
I get this by the following ioctl . Although the call succeeds but it sets the hd_geometry_rec to "0"
I checked through gdb , the ioctl call suceeds ,but sets all the field of hd_geometry to "0"
(gdb) p hd_geometry_rec
$2 = {heads = 0 '\0', sectors = 0 '\0', cylinders = 0, start = 0}
The device configuration
===================
[root@localh trunk]# uname -a
Linux localh 2.6.18-164.el5 #1 SMP Tue Aug 18 15:51:48 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux
[root@localh trunk]# fdisk -l /dev/mapper/mpath4
Disk /dev/mapper/mpath4: 523 MB, 523960320 bytes
255 heads, 63 sectors/track, 63 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/mapper/mpath4p1 1 10 80293+ 83 Linux
/dev/mapper/mpath4p2 11 20 80325 83 Linux
/dev/mapper/mpath4p3 21 30 80325 83 Linux
/dev/mapper/mpath4p4 31 38 64260 83 Linux
[root@localh trunk]#
The Source code
============
struct hd_geometry hd_geometry_rec;
unsigned int offset;
// Here p_ppdevname is /dev/mapper/mpath4p4
if ((fd = open(p_ppdevname, O_RDONLY | O_NONBLOCK)) < 0)
{
//Error
}
if ((sts = ioctl(fd, HDIO_GETGEO, &hd_geometry_rec)) < 0)
{
// Error
}
else
{
offset = (unsigned int) hd_geometry_rec.start;
}
--
With best regards,
Santosh.
-- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
