From: "J. Bruce Fields" Subject: Re: [PATCH 2/2] nfsd: only set file_lock.fl_lmops in nfsd4_lockt if a stateowner is found Date: Thu, 22 Jan 2009 13:52:32 -0500 Message-ID: <20090122185232.GC15279@fieldses.org> References: <1232555691-29859-1-git-send-email-jlayton@redhat.com> <1232555691-29859-3-git-send-email-jlayton@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: lkml@vger.kernel.org, linux-fsdevel@vger.kernel.org, cluster-devel@redhat.com, linux-nfs@vger.kernel.org, nfsv4@linux-nfs.org To: Jeff Layton Return-path: In-Reply-To: <1232555691-29859-3-git-send-email-jlayton@redhat.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Wed, Jan 21, 2009 at 11:34:51AM -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. > > If a lockstateowner is not found, then we'll have fl_owner set to NULL > and fl_lmops set pointing to nfsd_posix_mng_ops. Other parts of the > NFSv4 server code assume that fl_owner will point to a valid > nfs4_stateowner if fl_lmops is set this way. > > 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 have a NULL lockstateowner. > > Signed-off-by: Jeff Layton > --- > fs/nfsd/nfs4state.c | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index 88db7d3..07d196a 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -2867,11 +2867,13 @@ nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, > > lockt->lt_stateowner = find_lockstateowner_str(inode, > &lockt->lt_clientid, &lockt->lt_owner); > - if (lockt->lt_stateowner) > + if (lockt->lt_stateowner) { > file_lock.fl_owner = (fl_owner_t)lockt->lt_stateowner; > + file_lock.fl_lmops = &nfsd_posix_mng_ops; So I think we just shouldn't need this second assignment at all. --b. > + } > + > 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 > > _______________________________________________ > NFSv4 mailing list > NFSv4@linux-nfs.org > http://linux-nfs.org/cgi-bin/mailman/listinfo/nfsv4