From: Jeff Layton 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 13:59:30 -0500 Message-ID: <20090122135930.1779562c@barsoom.rdu.redhat.com> References: <1232555691-29859-1-git-send-email-jlayton@redhat.com> <1232555691-29859-3-git-send-email-jlayton@redhat.com> <20090122185232.GC15279@fieldses.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: linux-fsdevel@vger.kernel.org, cluster-devel@redhat.com, linux-nfs@vger.kernel.org, nfsv4@linux-nfs.org To: "J. Bruce Fields" Return-path: In-Reply-To: <20090122185232.GC15279@fieldses.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: cluster-devel-bounces@redhat.com Errors-To: cluster-devel-bounces@redhat.com List-ID: On Thu, 22 Jan 2009 13:52:32 -0500 "J. Bruce Fields" wrote: > 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. > Do we even need to worry about the lockstateowner at all then? If fl_lmops isn't set then I think the fl_owner will be basically ignored by nfs4_set_lock_denied anyway. > > + } > > + > > 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 -- Jeff Layton