On Fri, 31 Oct 2008, Nigel Cunningham wrote: > Hi. > > On Fri, 2008-10-31 at 09:49 +0100, Miklos Szeredi wrote: > > On Fri, 31 Oct 2008, Nigel Cunningham wrote: > > > I'm not sure that's true. You see, I'm thinking of this as not that > > > different to the problem of unmounting filesystems. There, too, we need > > > to unmount in a particular order, and let transactions on each > > > filesystem stop cleanly before we can unmount them. Even if there are > > > differences, perhaps looking at how we handle unmounting will help with > > > handling freezing. > > > > There's nothing magic about umount, it just uses a refcount on the fs. > > > > But umount changes the namespace, that's the big difference. For > > example if a process is accessing path P which has a component inside > > the mount, it _will_ get different results before and after the > > umount. This is not acceptable for freezing. > > > > For freezing to work with such a refcounting scheme, we'd have to > > count _future_ uses of the fs as well, not just current ones, which is > > obviously impossible. > > I must be missing something. If you're freezing future users of the > filesystem before they can start anything new, doesn't that deal with > this problem? How do you determine which are the future users? Miklos _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
