On Mon, 10 Aug 2015 05:10:35 -0700 Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > On Mon, Aug 10, 2015 at 07:23:51AM -0400, Jeff Layton wrote: > > I did consider a shrinker and LRU list for this. The problem there is > > that shrinkers are triggered on memory pressure. Keeping these files > > open after they've been idle for a long period of time would prevent > > the kernel from handing out leases on them, so closing them after a > > reasonable idle period seemed like the right thing to do. > > True. > > > I suppose however we could use a shrinker/LRU _and_ add a mechanism > > that would cause the kernel to close idle nfsd_files for an inode when > > there is an attempt to do a F_SETLEASE. That would probably work, > > unless I'm missing other reasons that keeping unused files open might > > be problematic. Are there any? > > That seems reasonable. Keepign the file open also will prevent > unmounting the file system, although currently any NFS export already > causes that as well. Yes, though that's the reason for the new ->flush hook in the sunrpc cache code. On any export table change, we'll clean out the nfsd_file cache to help ensure that you'll be able to unmount soon after unexporting a filesystem. In any case, I'll look at the shrinker/lru thing for the next respin and see whether adding a hook into the setlease code might be reasonable. Thanks for the review so far, -- Jeff Layton <jlayton@xxxxxxxxxxxxxxx> -- 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
