Re: [PATCH 1/4] sas: add flag for locally attached PHYs

Douglas Gilbert
2005-10-21T03:24:45Z

Jeff Garzik wrote:
> Douglas Gilbert wrote:
>
>> Just a suggestion if you want to bring /dev/sg into
>> the picture for a SMP (and even a STP) passthrough.
>
>
> Yep. That's another possibility, that falls into the 'block driver'
> category [see list of categories in my 'ioctl' email], since it is
> translated into a 'special' block request, and then sent to a normal
> request_queue.
>
> Jens Axboe's bsg[1] has also been mentioned in the context of SMP.

Jeff,
Yes, I like the bsg model: one well known device (/dev/bsg),
get a file descriptor and then bind to a "target". It
reminded me of a network interface.

As presented, it only bound to a block (or char?) device
node (e.g. /dev/sda). I asked some questions about widening
the variety of things it could bind to but Peter Jones
suggested that binding was a necessary evil that should
not be encouraged.

So perhaps we could bind to a SAS host ... (and a SCSI device
for those pesky things like safte, ses and wluns).

Doug Gilbert