On Wed, Mar 25, 2009 at 03:47:56PM -0400, Bill Nottingham wrote: > Matthew Wilcox (matthew@xxxxxx) said: > > On Wed, Mar 25, 2009 at 03:03:21PM -0400, Bill Nottingham wrote: > > > Then where is a better place to put this, as scsi_wait_scan.ko is > > > a ridiculous interface for userspace? > > > > It would be nice if people would comment on "ridiculous interface"s when > > they're asked for feedback, instead of waiting more than two years. > > Sure, but asking all people who might eventually have to use it > to always watch any possible interface addition isn't practical. Right. I asked several people at Red Hat about the interface and I got a "yeah, OK, whatever" kind of response. Clearly you need to educate your colleagues to pass these kinds of interface questions along to you. > I would have hoped that the fact that the interface required loading > a module and immediately removing it by hand is suboptimal enough > that it wouldn't have gotten in in the first place. It seems pretty elegant to me, actually. There's no overhead after you're done (unlike having a sysfs file, or even including a new ability in a procfs file). > > I think you're misunderstanding how to use scsi_wait_scan. The idea was > > that the bit of userspace that probes all the device drivers would do: > > > > modprobe fusion.ko > > modprobe aic79xx.ko > > modprobe sym53c8xx.ko > > modprobe scsi_wait_scan > > rmmod scsi_wait_scan > > > > et voila, you're done. It seems like you want random other bits of > > userspace to wait for scsi scanning to be done, and that wasn't the > > original intent. > > Well, in the case I'm looking at, udev is what's loading the host > controllers, and there needs to be some sort of synchronization point > between that and LVM invocations, fsck, mount, etc. Since scans > aren't sent over as events for udev to catch, 'udevadm settle' > isn't enough. So ... if we sent a udev event when the scan list was empty, you'd be OK? > Removing, loading, and removing scsi_wait_scan works > here, but it just seems like a kludge. I don't quite understand why it was loaded, and not unloaded immediately. > I can trigger a load of scsi_wait_scan when hosts are registered > in udev, but that's still ugly, and sort of overkill. That would rather miss the point, yes. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- 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
