Hi,
`hdparm -t' uses HDIO_DRIVE_CMD(null) to flush the disk's buffer.
When using it on my own block device (the new PS3 disk storage driver), hdparm
gives the following error message:
| HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl
for device
When using it on an ATA or SCSI device, no such error message is printed.
According to the hdparm sources, hdparm expects the HDIO_DRIVE_CMD(null) ioctl
to either succeed, or to fail with errno EINVAL.
Apparently handling of ioctls is different for the different device types:
- ATA/SATA handle HDIO_DRIVE_CMD(null) (and a few other variants)
=> fine for hdparm
- SCSI doesn't handle HDIO_DRIVE_CMD(null), and returns EINVAL
=> fine for hdparm
- If a block device doesn't support the ioctl, blkdev_driver_ioctl() returns
ENOTTY
=> hdparm error message
Which one is correct?
- blkdev_ioctl()/blkdev_driver_ioctl() return -ENOTTY
- scsi_cmd_ioctl() returns -ENOTTY
- scsi_ioctl() returns -EINVAL
- cdrom_ioctl() returns -ENOSYS to mean not handled, continue
- some block layer routines return -ENOIOCTLCMD to mean not handled, continue
This causes constructs with different tests like e.g.:
sr_block_ioctl()
{
...
ret = cdrom_ioctl(...);
if (ret != -ENOSYS)
return ret;
...
return scsi_ioctl(...);
}
cdrom_ioctl()
{
...
ret = scsi_cmd_ioctl(...);
if (ret != -ENOTTY)
return ret;
...
return -ENOSYS;
}
blkdev_ioctl()
{
...
ret = blkdev_locked_ioctl(...);
...
if (ret != -ENOIOCTLCMD)
return ret;
return blkdev_driver_ioctl(...);
}
My questions:
1. Does any of these have to be fixed?
2. Shall I add a dummy HDIO_DRIVE_CMD(null) handler to my block device to
return -EINVAL?
3. Shall I just ignore the hdparm error message?
Thanks!
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- Sony Network and Software Technology Center Europe (NSCE)
[EMAIL PROTECTED] ------- The Corporate Village, Da Vincilaan 7-D1
Voice +32-2-7008453 Fax +32-2-7008622 ---------------- B-1935 Zaventem, Belgium
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