Hi. Miklos Szeredi wrote: >>>> On Tue 2008-01-08 12:35:09, Miklos Szeredi wrote: >>>>> From: Miklos Szeredi <mszeredi@xxxxxxx> >>>>> >>>>> Use FS_SAFE for "fuse" fs type, but not for "fuseblk". >>>>> >>>>> FUSE was designed from the beginning to be safe for unprivileged users. This >>>>> has also been verified in practice over many years. In addition unprivileged >>>> Eh? So 'kill -9 no longer works' and 'suspend no longer works' is not >>>> considered important enough to even mention? >>> No. Because in practice they don't seem to matter. Also because >>> there's no way in which fuse could be done differently to address >>> these issues. >> Could you clarify, please? I hope I'm getting the wrong end of the stick >> - it sounds to me like you and Pavel are saying that this patch breaks >> suspending to ram (and hibernating?) but you want to push it anyway >> because you haven't been able to produce an instance, don't think >> suspending or hibernating matter and couldn't fix fuse anyway? > > This patch has nothing to do with suspend or hibernate. What this > patchset does, is help get rid of fusermount, a suid-root mount > helper. It also opens up new possibilities, which are not fuse > related. That's what I thought. So what was Pavel talking about with "kill -9 no longer works" and "suspend no longer works" above? I couldn't understand it from the context. > Fuse has bad interactions with the freezer, theoretically. In > practice, I remember just one bug report (that sparked off this whole > "do we need freezer, or don't we" flamefest), that actually got fixed > fairly quickly, ...maybe. Rafael probably remembers better. I think they just gave up and considered it unsolvable. I'm not sure it is. >>> The 'kill -9' thing is basically due to VFS level locking not being >>> interruptible. It could be changed, but I'm not sure it's worth it. >>> >>> For the suspend issue, there are also no easy solutions. >> What are the non-easy solutions? > > The ability to freeze tasks in uninterruptible sleep, or more > generally at any preempt point (except when drivers are poking > hardware). Couldn't some sort of scheduler based solution deal with the uninterruptible sleeping case? > I know this doesn't play well with userspace hibernate, and I don't > think it can be resolved without going the kexec way. I can see the desirability of kexec when it comes to avoiding the freezer, but comes with its own problems too - having the original context usable is handy, not having to set aside a large amount of space for a second kernel is also desirable and there are still greater issues of transferring information backwards and forwards between the two kernels. Regards, Nigel - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
