Re: 2.7 block ramblings (was Re: DMA for ide-scsi?)

Jens Axboe
2003-09-21T09:23:50Z

On Sat, Sep 20 2003, Jeff Garzik wrote:
> Jens Axboe wrote:
> >On Tue, Sep 16 2003, Jeff Garzik wrote:
>
> >>And we should deprecate them with a solution that aligns what with Linus
> >>described in Dec 2001 on lkml: a chrdev where userland write(2)s cdbs
> >>and taskfiles, and read(2)s the results. This is where my thinking
> >>picked up: if we are creating a chrdev to send "packets" and receive
> >>responses to those packets............ <insert conclusion here>
> >
> >
> >== bsg, block sg. Did you read what I wrote? :). I started implementing
> >this and have something that barely works. You just bind a block device
> >to a /dev/sg* char device and use read/write on that. Aka sg.
>
> sg needs some modifications -- for example it errors out instead of
> sleeps on queue full -- but sounds good to me.

Definitely. bsg will be a new implementation from scratch, also dumping
a lot of really (imo) useless "features" that clutter up the code. And
yes, of course it should honor the typical write(2) model :)

--
Jens Axboe