On Thu, May 21, 2009 at 02:54:19PM +0200, Jan Rekorajski wrote: > On Mon, 18 May 2009, Jan Blunck wrote: > > > Here is another post of the VFS based union mount implementation. > > Is there any chance this will support NFS? I can union-mount tmpfs over NFS as the read-only layer ought to work. NFS as the read-write layer is still up in the air. > nfs mounted fs, but if I try to mount --union two NFS filesystems I > always get -EBUSY on second mount on the same mountpoint. > > Something along these lines: > > doesn't matter if I use --union on first mount, the result is always the > same. > > mount <--union> -t nfs server:/export/system /mnt > OK > mount --union -t nfs server:/export/profile /mnt > mount.nfs: /mnt is busy or already mounted > > I patched mount.nfs so it knows about MS_UNION, and strace shows me that > it passes that flag to kernel. FYI, using --union on the first mount will make it union with the local directory below it. The --union option is not needed when you mount the lower read-only layer. You'll get -EBUSY on the second mount of any NFS file system over another - try it again with the --union flag. Support for NFS on NFS union mount would have to change this. -VAL -- 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
