Re: [PATCH 2/2] nfsd: only set file_lock.fl_lmops in nfsd4_lockt if a stateowner is found

J. Bruce Fields
2009-01-27T22:33:25Z

On Thu, Jan 22, 2009 at 02:16:04PM -0500, Jeff Layton wrote:
> nfsd4_lockt does a search for a lockstateowner when building the lock
> struct to test. If one is found, it'll set fl_owner to it. Regardless of
> whether that happens, it'll also set fl_lmops. Given that this lock is
> basically a "lightweight" lock that's just used for checking conflicts,
> setting fl_lmops is probably not appropriate for it.
>
> This behavior exposed a bug in DLM's GETLK implementation where it
> wasn't clearing out the fields in the file_lock before filling in
> conflicting lock info. While we were able to fix this in DLM, it
> still seems pointless and dangerous to set the fl_lmops this way
> when we may have a NULL lockstateowner.
>
> Signed-off-by: Jeff Layton <jlayton@redhat.com>

Thanks, applied.--b.

> ---
> fs/nfsd/nfs4state.c | 1 -
> 1 files changed, 0 insertions(+), 1 deletions(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 88db7d3..b6f60f4 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -2871,7 +2871,6 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> file_lock.fl_owner = (fl_owner_t)lockt->lt_stateowner;
> file_lock.fl_pid = current->tgid;
> file_lock.fl_flags = FL_POSIX;
> - file_lock.fl_lmops = &nfsd_posix_mng_ops;
>
> file_lock.fl_start = lockt->lt_offset;
> file_lock.fl_end = last_byte_offset(lockt->lt_offset, lockt->lt_length);
> --
> 1.5.5.6
>