From: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx> Subject: Re: Open for adoption: orphan sbp2_target Date: Thu, 24 Aug 2006 14:19:54 +0200 > Hani Mustafa wrote to linux1394-devel on 2006-08-14: > > I had finished writing an sbp2_target implementation in the linux > > kernel a year or so ago and was hoping I could get the time to polish > > it, but it got stuck in a vicious procrastination loop. > > > > The implementation worked fine with a usb-storage device (as it > > appears as a SCSI device) against windows/linux/mac, but otherwise > > panics the kernel when it is a real SCSI controller. Probably > > something wrong with the way I acquire and post CDB's to the SCSI > > device. > > > > In anycase, if anyone has the motivation to toss this project from the > > ears into a working module, you are more than welcome to contact me > > directly. > > Perhaps you are aware of Manish Singh's SBP-2 target implementation > called Endpoint, http://oss.oracle.com/projects/endpoint/. I haven't > tested it myself yet. AFAIU it runs completely in userspace on top of > libraw1394 and implements (only?) RBC. It is available under GPL. > > An alternative in-kernel implementation might be interesting > nevertheless because /a/ performance optimization might be easier and > /b/ it could perhaps be adapted to the upcoming generic SCSI target > framework, > http://kernel.org/git/?p=linux/kernel/git/jejb/scsi-target-2.6.git . > This framework pushes parts of the required functionality into userspace > though. I didn't look into the particular goals and features of this > framework yet. Maybe I am wrong and the SBP-2 specific parts to add to > the SCSI target framework would rather end up in userspace, I don't know. > > Could someone of the SCSI target folks give a rough outline of a SCSI > target's building blocks when using this framework? Our OLS's paper and slides have good pictures. http://stgt.berlios.de/ I guess that SBP target stuff works well with the target framework. All you need to do is to take care of SBP protocol. The framework does the rest, that is, SCSI protocol processing, I/O, logical unit management, configuration, etc. For example, your driver receives a SCSI command from an initiator, tell the framework to perform it. Then the framework sends back the result and buffer containing data you send to the initiator if necessary. I don't know where your driver is implemented, in kernel space or user space. The framework was designed for the former, however, it works with both models now. You can find an example of the latter (though it's just experiment): svn co http://svn.berlios.de/svnroot/repos/stgt/branches/user-iscsi BTW, we've prepared a new git tree: http://www.kernel.org/git/?p=linux/kernel/git/mnc/linux-2.6-target.git;a=summary - 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
