Is sector no. related to partitions in scsi drivers?

Is sector no. related to partitions in scsi drivers?

[Jianyong Zhang]

Hi,

  Now I want to write a io trace collect tool in the scsi driver layer. I
use aix7xxx driver, and collect io trace in the end of the funcion
ahc_linux_run_device_queue() in the file
drivers/scsi/aic7xxx/aic7xxx_linux.c .  According to my understanding,
here cmd->request.sector is related to the begining of the partition, not
to the whole disk (suppose one disk has several partitions), is it right?

  I'm wonder where this request's sector number will be converted to one
related to the whole disk. Is it done by the firmware of controller?

Re: Is sector no. related to partitions in scsi drivers?

[Doug Ledford]

On Wed, Aug 28, 2002 at 09:06:38PM -0400, Jianyong Zhang wrote:
> 
>   I'm wonder where this request's sector number will be converted to one
> related to the whole disk. Is it done by the firmware of controller?

No.  The aic7xxx driver couldn't care less what the sector number in the 
request item is.  The sd.c code handles converting request struct items to 
physical sectors on the disk and then encodes the physical sector number 
directly into the actual scsi command that it builds.  The scsi command is 
then sent to the device by the aic7xxx driver and the aic7xxx driver never 
even bothers to look and see what sector the command is going to (it 
doesn't need to).

-- 
  Doug Ledford <dledford@redhat.com>     919-754-3700 x44233
         Red Hat, Inc. 
         1801 Varsity Dr.
         Raleigh, NC 27606