From: Dominick L. <dom...@gm...> - 2007-07-13 23:59:35
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Miklos Szeredi wrote: > OK. And you need your filesystem to be aware of the leases on the > file? Isn't it enough if the kernel is aware of them? Well, my goal was to be able to propagate the leases across a distributed filesystem. However, on further investigation, it now looks like that's not going to be sufficient to achieve what I want, anyway. The problem is that Samba keeps both a private lock database, *and* takes out leases in the underlying filesystem. Propagating the leases (while a potentially useful capability for a distributed filesystem) is not sufficient to make multiple Samba instances behave like a distributed Samba server. To achieve that goal, I need to monitor Samba's locking database on node A for changes, and then insert locks into Samba's database on node B. That's a big headache. Happily, it turns out that there is already a distributed Samba project (CTDB) that does exactly this. There are a lot of aspects of CTDB that don't work the way I would like, but it is clear that this is going to be the most useful starting-point. > Strangely it looks like the kernel is not forwarding the lease > information to filesystems at the moment. This means that currently > only local filesystems can correctly support leases. You mean, leases don't currently work at all on *any* FUSE-based filesystems? Or just that the leases are not being passed to fuse_operations.lock(), and consequently no lease propagation across a distributed filesystem is possible? -- Dominick |