On Sun, 01 Dec 2013 05:14:41 -0800 Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > This series tries to get rid of the damage created by sprinkling the > network namespace cat poo all over rpc_pipefs and users. > > Instead of getting lost in a maze of notifiers and infrastructure build > around it a cargo cult manner we revert to a slightly nicer version of > the pre-namespace API. > > To do this we just have to create an in-kernel instance of rpc_pipefs > that is mounted at network namespace creation so that all functions can > operated on it. > > As-is this has one major downside: because the initial mount already grabs > a reference to the network namespace we'll create a cyclic reference and > will never free the network namespace. To get around this we'd need > some way to only grab it once user mounts show up / disapear in the VFS. > > Given that the namespace kraken has infected various internal filesystem > and will get more soon I suspect this problem is or will become generic > and will need a proper solution anyway. Al, any good ideas how to deal > with this? Most straight forward way would be to add a counter of > user vfsmount to the superblock and methods when it goes to 1 and 0, > but that seems a bit ugly. I see what you mean here...hrm... One possibility (though it may have holes that I don't see right offhand): Don't call get_ns in rpc_fill_super. Do it in rpc_mount instead, and only take the reference if MS_KERNMOUNT isn't set? -- Jeff Layton <jlayton@xxxxxxxxxx> -- 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
