On Thu, Jun 09, 2011 at 08:51:05AM +0930, Rusty Russell wrote: > On Wed, 08 Jun 2011 09:08:29 -0400, Mark Wu <dwu@xxxxxxxxxx> wrote: > > Hi Rusty, > > Yes, I can't figure out an instance of disk probing in parallel either, but as > > per the following commit, I think we still need use lock for safety. What's your opinion? > > > > commit 4034cc68157bfa0b6622efe368488d3d3e20f4e6 > > Author: Tejun Heo <tj@xxxxxxxxxx> > > Date: Sat Feb 21 11:04:45 2009 +0900 > > > > [SCSI] sd: revive sd_index_lock > > > > Commit f27bac2761cab5a2e212dea602d22457a9aa6943 which converted sd to > > use ida instead of idr incorrectly removed sd_index_lock around id > > allocation and free. idr/ida do have internal locks but they protect > > their free object lists not the allocation itself. The caller is > > responsible for that. This missing synchronization led to the same id > > being assigned to multiple devices leading to oops. > > I'm confused. Tejun, Greg, anyone can probes happen in parallel? > > If so, I'll have to review all my drivers. I know we've tried it in the past, at the PCI device level, and ran into some issues, but I don't remember if that code ever made it into the mainline kernel or not. greg k-h -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
