nfsd: only set file_lock.fl_lmops in nfsd4_lockt if a stateowner is found
On Thu, 22 Jan 2009 13:52:32 -0500
"J. Bruce Fields" <bfields@fieldses.org> 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 <jlayton@redhat.com>
> > ---
> > 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.
nfsd: only set file_lock.fl_lmops in nfsd4_lockt if a stateowner is found
On Thu, 22 Jan 2009 13:52:32 -0500
"J. Bruce Fields" <bfields@fieldses.org> 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 <jlayton@redhat.com>
> > ---
> > 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.
nfsd: only set file_lock.fl_lmops in nfsd4_lockt if a stateowner is found
On Thu, 22 Jan 2009 13:59:30 -0500
Jeff Layton <jlayton@redhat.com> wrote:
> On Thu, 22 Jan 2009 13:52:32 -0500
> "J. Bruce Fields" <bfields@fieldses.org> 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 <jlayton@redhat.com>
> > > ---
> > > 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.
>
Ahh, nm. I think we do need to set fl_owner so that posix_same_owner
does the right thing. I'll just get rid of the fl_lmops setting and I
think that'll be done.
nfsd: only set file_lock.fl_lmops in nfsd4_lockt if a stateowner is found
