Hi! > > > > > This is from a work queue, so in fact from a process context, but from > > > > > a process that is running with PF_NOFREEZE. > > > > > > > > Why not simply &~ PF_NOFREEZE on that particular process? Filesystems > > > > are free to use threads/work queues/whatever, but refrigerator should > > > > mean "no writes to filesystem" for them... > > > > > > But how we differentiate worker_threads used by filesystems from the > > > other ones? > > > > I'd expect filesystems to do &~ PF_NOFREEZE by hand. > > > > > BTW, I think that worker_threads run with PF_NOFREEZE for a reason, > > > but what exactly is it? > > > > I do not think we had particulary good reasons... > > Well, it looks like quite a lot of drivers depend on them, including libata. > > I think we can add a flag to __create_workqueue() that will indicate if > this one is to be running with PF_NOFREEZE and a corresponding macro like > create_freezable_workqueue() to be used wherever we want the worker thread > to freeze (in which case it should be calling try_to_freeze() somewhere). > Then, we can teach filesystems to use this macro instead of > create_workqueue(). Works for me. > Having done that we'd be able to drop the freezing of bdevs patch and forget > about the dm-related complexity. yes. > [Still I wonder if the sys_sync() in freeze_processes() is actually safe if > there's a suspended dm device somewhere in the stack, because in the other > case the freezing of bdevs would be no more dangerous than the thing > that we're already doing.] ? Not sure if I quite understand, but if dm breaks sync... something is teribly wrong with dm. And we do simple sys_sync()... so I do not think we have a problem. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
