Re: SCSI commands order when using scsi_do_req

[Vladislav Bolkhovitin <vst@vlnb.net>]

James Bottomley wrote:
> On Thu, 2005-06-02 at 20:31 +0300, Liran Schour wrote:
> 
>>I am developing a new SCSI upper layer driver. (Object based SCSI device)
>>I noticed that scsi_do_req execute commands in LIFO order (add new commands
>>to the head of the Q).
>>This behavior can cause a starvation of commands (or at least long delays).
>>What is the proper solution to this?
> 
> 
> Well, to use the proper interfaces.
> 
> scsi_do_req is deprecated, so don't use it.  scsi_wait_req is its
> replacement.  Note: they're only really intended to allow ULDs to
> execute commands that are necessary for controlling the device (that's
> why they go at the head of the queue).  Block commands are executed in
> order using ULD init_command() (or REQ_BLOCK_PC).

Hm, st/osst/sg use scsi_do_req(), so should we consider those drivers 
broken in async mode? Apparently, a user in this mode could write not 
what he/she intented, the order could be wrong. Or do I miss something?

Vlad