Re: BUG: cannot acquire lock twice with NFSv4

[Trond Myklebust <trond.myklebust@fys.uio.no>]

On Sat, 2010-04-10 at 10:46 +0200, Arnaud Giersch wrote:=20
> Vendredi 09 avril 2010, vers 15:05:14 (+0200), j'ai =C3=A9crit :
>=20
> >   1. opens a first file, and acquires read lock on it ;
> >   2. opens a second file, and acquires read lock on it ;
> >   3. releases locks, and closes files.
> >
> > Both opened files are of course on the NFS mount.  On the first run=
, all
> > seems to be fine.  On the second (and subsequent) runs, the lock is
> > refused at step 2 with errno=3D37 (ENOLCK, No locks available).
>=20
> I noticed that things appear to work as expected if commit
> 8e469ebd6dc32cbaf620e134d79f740bf0ebab79 (NFSv4: Don't allow posix
> locking against servers that don't support it) is reverted.
>=20
> From what I can see, the client is granted a read delegation for the
> second file.  On the second run, the client fetches some cached state
> for this file.
>=20
> On this second run, state->flags (as in _nfs4_do_open, or in
> nfs4_proc_lock) only contains NFS_DELEGATED_STATE, while on the first
> run, it also contained NFS_O_RDONLY_STATE and NFS_STATE_POSIX_LOCKS.

Ah. Nice catch! That does indeed need to be fixed... I'll draft up a
patch tomorrow, and send you a copy.

Cheers
  Trond