On Mon, Sep 10, 2012 at 10:40:51AM +0800, Guo Chao wrote: > On Fri, Sep 07, 2012 at 05:39:01PM -0400, J. Bruce Fields wrote: > > On Fri, Sep 07, 2012 at 10:27:05AM +0800, Guo Chao wrote: > > > One script ... > > > > > > #!/bin/bash > > > while true > > > do > > > mount -t sysfs nodev mnt && umount mnt > > > done > > > > > > > > > > > > The other ... > > > > > > #!/bin/bash > > > while true > > > do > > > mv mnt mnt2 && mv mnt2 mnt > > > done > > > > > > > > > > > > Run them simultaneously in two consoles. When mount keeps reporting > > > 'mount point mnt does not exist', stop them, then you will see the > > > familiar sysfs under mnt2. > > > > Oh, thanks, for some reason I assumed it would be more difficult to > > reproduce. > > > > I think we can do this--I don't think it even requires any care to the > > locking order of the renamed vs the victim directory, though I can't > > completely convince myself of that. > > > > Is it necessary to fix this, though? Does it cause any problems other > > than unexpected behavior? > > > > --b. > > -- > > Hard to say whether it's a bug or what's problems of being able to rename > mountpoint. > > Anyway, this patch closes this race when mountpoint is a file. Thus we get > different behaviour when deal with files and directories. It's apparently > not well-defined, but again, is it a problem? Not sure ... ... OK. I'm not seeing a strong argument to change the current behavior, so inclined to leave it alone for now. --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
