On Sat, Jun 25, 2005 at 04:13:20PM +0200, Philip Paeps wrote: > On 2005-06-23 16:21:17 (+0200), Jeremie Le Hen <jeremie_at_le-hen.org> wrote: > > > > Could you show us the locked vnodes for these two cases please ? > > > > > > Is there any way I can either try to unmount the filesystem manually from > > > the debugger or make the unmounting code more chatting about what it's > > > waiting for? > > > > I don't think that having a snapshot of locked vnode when union_unmount() is > > called would inform us further. However, I you want to try, you just have > > to drop to DDB, set a breakpoint on union_unmount() (typing "break > > union_unmount") and then try the unmount (you can delete the breakpoint by > > simply using "delete union_unmount"). > > Note that the problem is not in unmounting the union filesystem, that works > fine, it's unmounting the top layer. Unmounting the bottom layer is not a > problem either. Ah, I misread. This is the expected behaviour : the top layer is obviously busy while the unionfs mount is active. Here is the same setup that you first described : %%% /dev/md0 on /root/tests/mnt0 (ufs, local) /dev/md1 on /root/tests/mnt1 (ufs, local) <above>:/root/tests/mnt1 on /root/tests/mnt0 (unionfs, local, noclusterw) %%% Imagine what would happen to the unionfs mount if /root/tests/mnt1 was unmounted. This is nonsense. > %%% > vflush: busy vnode > 0xc2578bb0: tag ufs, type VDIR > usecount 1, writecount 0, refcount 4 mountedhere 0 > flags (VV_ROOT) > VI_LOCKed v_object 0xc256c630 ref 0 pages 1 > lock type ufs: EXCL (count 1) by thread 0xc2547900 (pid 687) > ino 2, on dev md1 > %%% This is a bug, I can reproduce it here. I am not enough skilled to correct this filesystem. It has been known to be broken for a long time and I expect things goes bader with time, as the second thermothynamics principle states :-). Regards, PS: I'm willing to try to foreport FiST [1] to FreeBSD 6, it is known to have, among others, a very good union filesystem implementation, very well tested with POSIX test suite [2] (you may want to have a look to the whole thread, it's quite interesting IIRC). It only works on FreeBSD 4 and FreeBSD 5 ATM and it needs to include phk's changes to the VFS to be compiled on CURRENT. [1] http://www.filesystems.org/ [2] http://lists.freebsd.org/pipermail/freebsd-fs/2005-March/000959.html -- Jeremie Le Hen < jeremie at le-hen dot org >< ttz at chchile dot org >Received on Mon Jun 27 2005 - 11:45:06 UTC
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