Re: bidi, varlen, bsg success report

[Boaz Harrosh <bharrosh@panasas.com>]

On Sat, Dec 22 2007 at 22:15 +0200, Pete Wyckoff <pw@osc.edu> wrote:
> I spent the last couple of days rebasing my working set of kernel
> patches from 2.6.22-rc5 to 2.6.24-rc6.  I want to use the BSG
> interface from userspace to submit variable-length bidirectional
> SCSI commands to targets via iSCSI TCP.
> 
> Many thanks to all the work with scsi data accessors and iscsi that
> makes this much easier, and to Boaz for continuing to maintain
> patches.  Here's what I needed to do to make it work.
> 
> Start with linus-2.6.24-rc6.
> Merge scsi-misc.
> Apply the following outstanding patches from Boaz:
> 
> bidi
>     scsi: scsi_data_buffer
>     http://marc.info/?l=linux-scsi&m=119754650614813&w=2
> 
>     scsi: bidi support
>     http://marc.info/?l=linux-scsi&m=119754667915055&w=2
> 
> varlen
>     [PATCH 1/3] Let scsi_cmnd->cmnd use request->cmd buffer
>     http://marc.info/?l=linux-scsi&m=119798523823750&w=2
> 
>     [PATCH 2/2] block layer varlen-cdb
>     http://marc.info/?l=linux-scsi&m=119798548624218&w=2
> 
>     [PATCH 3/3] scsi: varlen extended and vendor-specific cdbs
>     http://marc.info/?l=linux-scsi&m=119798563924476&w=2
> 
> Then a few more, two modified from earlier Boaz patches, and three
> new ones by me, mainly to make bsg work.  They follow.
> 
> 1. iscsi: extended cdb support
> Adapted from Boaz
> http://marc.info/?l=linux-scsi&m=119394074127857&w=2
> 
> 2. iscsi: bidi support
> Adapted from two old Boaz patches that can be found in this git:
> http://www.bhalevy.com/git/gitweb.cgi?p=open-osd/.git;a=commitdiff;h=b5a97649eadb9434acbc4170a8aebd962af6d960
> http://www.bhalevy.com/git/gitweb.cgi?p=open-osd/.git;a=commitdiff;h=cf3d4684a22bde6787f2eccee66d7b0ee9c9182c
> 
> 3. bsg: accept varlen commands
> 
> 4. bsg: bidi fix
> 
> 5. iscsi tcp: bidi capable
> 
> Suggestions:  Boaz is probably the best qualified to shepherd his
> outstanding five patches plus the two others I mention above (#1,
> #2).  The first bsg patch (#3) won't apply without the varlen
> patches.  The last two (#4, #5) are harmless and can go in now, but
> won't matter until the bidi patches are in.  Comments on these
> welcome.
> 
> Hope this is helpful.  I'm definitely looking forward to seeing
> all this merged into mainline eventually.
> 
> 		-- Pete
> -
Dear peter.

This is grate to know. I know from passed experience that code
might work well for your own set of tests, but otherwise hide bugs.

Please forgive me about the iSCSI patches, I have an updated set
here in my trees, but I have not posted them, because I thought
that no one cares, but me.

I did not yet get any principle OK about the varlen API. that
is - scsi_cmnd->cmnd changes to a pointer that points to either
a static buffer at request or a dynamic buffer at ULD - Because
if this principle is accepted, than please Note that the patch
"iscsi: extended cdb support" can be applied now, before the actual
cleanups and implementation are applied.
I attributed the complete silence treatment from both block and scsi 
maintainers, to the holiday session. I hope they come with renewed 
strength next year ;)

I will compare our iscsi patches and put a freshen set at:
git://git.bhalevy.com/open-osd osd_dev
or on the web
http://git.bhalevy.com/git/gitweb.cgi?p=open-osd/.git;a=summary
(give me until the end of today)

I have inspected your other patches, and they all look good.
I will include them in above git.

Happy holidays
Boaz