Bartlomiej Zolnierkiewicz wrote:
On Tuesday 14 April 2009 00:24:57 Jeff Garzik wrote:
Bartlomiej Zolnierkiewicz wrote:
I've started reading it and immediately noticed a thing which made by day. :-)
Sorry if it will sound off-topic or undiplomatic but it is the best occasion
to straighten up some facts:
"Discussion then moved on to the current status of getting libata out of
SCSI: we have had several successes, notably timer handling and pieces of
error handling have moved up to block. Unfortunately, the current progress
has reached the point where it's being impeded by the legacy IDE subsystem
Heh, you can also blame the lack of world peace on the legacy IDE subsystem.
I wonder who came up with this ridiculous excuse (I'm sure it wasn't James!).
It was you!? :)
The thing is that during last _five_ years almost nothing was done in this
direction. Despite the fact that it was #1 condition under which the whole
code has been merged. Sorry to say it but it seems like the whole merge
strategy was to over-promise things now and worry about delivery later.
Yet, shockingly, users have been happily using libata despite all these
horrors.
That was not the issue raised:
If you think that you can take a "I will deliver later" credit from the
developers community and later cover it up by "this is still my goal, I
just need to find some suckers to do it for me" and think that you won by
fooling people you're sadly mistaken and will most likely have a reality
check one day (not from me, I really don't care that much to waste my
precious time on proving you wrong).
The project you refer to -- move libata out of SCSI -- is far less
important than another project: keep libata going amidst new SAS and
SATA hardware.
Choosing to use the SCSI driver infrastructure was a solid technical
decision in the beginning, and time has proven that true: since we were
inside SCSI, ATAPI and SAT support came naturally. Support for SAS+SATA
controllers came naturally.
So it was absolutely the right thing to do for Linux users, to
de-prioritize the libata-out-of-SCSI project.
The users were not, and are not, asking for it. It will even introduce
some breakage if you're not careful.
The only people who even mention it are a few key IDE and block layer
developers - me, you, Tejun, Jens, sometimes James B. Linus has
probably forgotten, but for I occasionally mention it at kernel summits.
I think Linux users are happy that they were delivered a working ATA
driver of a much more clean design. That is the delivery that matters.
Even with the benefit of hindsight, I don't see that libata development
should have happened any other way.
Moving libata out of SCSI is now a long term, far off goal. A goal that
implies many intermediate steps, cleanups to block, libata, IDE, SCSI
and other block drivers.
I am highly confident we will reach this goal eventually, but there is
no rush. If it takes ten years, fine. THIS IS THE PROCESS. The end
result will be that all storage drivers in the kernel are improved.
We steer this ship by having a general idea of where we want to go, not
a specific roadmap. Interesting, unexpected things happen during the
journey, perhaps taking you down a different course. Open source...
it's all very zen. :)
Jeff
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
