On Mon, 08 Jun 2009, Valerie Aurora wrote: > 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. As I don't need rw NFS, i didn't even try that :) > > 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. Thanks for clarification. > 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. I did just that, --union didn't change standard NFS behaviour. mount -t nfs server:/export/system /mnt mount --union -t nfs server:/export/profile /mnt mount.nfs: /mnt is busy or already mounted I did an experiment by using different IP of the server (same machine) when mounting the second fs, mount worked then, but 'ls -1 /mnt' oopsed. I can reproduce this and send you the oops next week. -- Jan Rekorajski | ALL SUSPECTS ARE GUILTY. PERIOD! baggins<at>mimuw.edu.pl | OTHERWISE THEY WOULDN'T BE SUSPECTS, WOULD THEY? BOFH, MANIAC | -- TROOPS by Kevin Rubio -- 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
