The state of the stid is guaranteed by 2 locks:
- The nfs4_client 'cl_lock' spinlock
- The nfs4_ol_stateid 'st_mutex' mutex
so it is quite possible for the stid to be unhashed after lookup,
but before calling nfsd4_lock_ol_stateid(). So we do need to check
for a zero value for 'sc_type' in nfsd4_verify_open_stid().
Signed-off-by: Trond Myklebust <[email protected]>
---
fs/nfsd/nfs4state.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 8d53d29161f5..b5bda115f6a9 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3591,6 +3591,7 @@ nfsd4_verify_open_stid(struct nfs4_stid *s)
switch (s->sc_type) {
default:
break;
+ case 0:
case NFS4_CLOSED_STID:
case NFS4_CLOSED_DELEG_STID:
ret = nfserr_bad_stateid;
--
2.14.3
> On Jan 12, 2018, at 5:42 PM, Trond Myklebust =
<[email protected]> wrote:
>=20
> The state of the stid is guaranteed by 2 locks:
> - The nfs4_client 'cl_lock' spinlock
> - The nfs4_ol_stateid 'st_mutex' mutex
>=20
> so it is quite possible for the stid to be unhashed after lookup,
> but before calling nfsd4_lock_ol_stateid(). So we do need to check
> for a zero value for 'sc_type' in nfsd4_verify_open_stid().
>=20
> Signed-off-by: Trond Myklebust <[email protected]>
Three successful passes of the git regression suite on NFSv4.1
Three successful passes of xfstests on NFSv4.1
Tested-by: Chuck Lever <[email protected]>
> ---
> fs/nfsd/nfs4state.c | 1 +
> 1 file changed, 1 insertion(+)
>=20
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 8d53d29161f5..b5bda115f6a9 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -3591,6 +3591,7 @@ nfsd4_verify_open_stid(struct nfs4_stid *s)
> switch (s->sc_type) {
> default:
> break;
> + case 0:
> case NFS4_CLOSED_STID:
> case NFS4_CLOSED_DELEG_STID:
> ret =3D nfserr_bad_stateid;
> --=20
> 2.14.3
>=20
--
Chuck Lever
On Fri, Jan 12, 2018 at 09:15:46PM -0500, Chuck Lever wrote:
>
>
> > On Jan 12, 2018, at 5:42 PM, Trond Myklebust <[email protected]> wrote:
> >
> > The state of the stid is guaranteed by 2 locks:
> > - The nfs4_client 'cl_lock' spinlock
> > - The nfs4_ol_stateid 'st_mutex' mutex
> >
> > so it is quite possible for the stid to be unhashed after lookup,
> > but before calling nfsd4_lock_ol_stateid(). So we do need to check
> > for a zero value for 'sc_type' in nfsd4_verify_open_stid().
> >
> > Signed-off-by: Trond Myklebust <[email protected]>
>
> Three successful passes of the git regression suite on NFSv4.1
> Three successful passes of xfstests on NFSv4.1
>
> Tested-by: Chuck Lever <[email protected]>
Thanks! Applying.
Then I think this makes a couple of "sc_type = NFS4_CLOSED_STID"'s
superfluous.
--b.
commit 17693d95b3d3
Author: J. Bruce Fields <[email protected]>
Date: Wed Jan 17 16:25:59 2018 -0500
nfsd4: don't set lock stateid's sc_type to CLOSED
There's no point I can see to
stp->st_stid.sc_type = NFS4_CLOSED_STID;
given release_lock_stateid immediately sets sc_type to 0.
That set of sc_type to 0 should be enough to prevent it being used where
we don't want it to be; NFS4_CLOSED_STID should only be needed for
actual open stateid's that are actually closed.
Signed-off-by: J. Bruce Fields <[email protected]>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 5a75135f5f53..150521c9671b 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -5183,7 +5183,6 @@ nfsd4_free_lock_stateid(stateid_t *stateid, struct nfs4_stid *s)
lockowner(stp->st_stateowner)))
goto out;
- stp->st_stid.sc_type = NFS4_CLOSED_STID;
release_lock_stateid(stp);
ret = nfs_ok;
@@ -6079,10 +6078,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
* If this is a new, never-before-used stateid, and we are
* returning an error, then just go ahead and release it.
*/
- if (status && new) {
- lock_stp->st_stid.sc_type = NFS4_CLOSED_STID;
+ if (status && new)
release_lock_stateid(lock_stp);
- }
mutex_unlock(&lock_stp->st_mutex);
On Wed, Jan 17, 2018 at 04:30:57PM -0500, bfields wrote:
> On Fri, Jan 12, 2018 at 09:15:46PM -0500, Chuck Lever wrote:
> >
> >
> > > On Jan 12, 2018, at 5:42 PM, Trond Myklebust <[email protected]> wrote:
> > >
> > > The state of the stid is guaranteed by 2 locks:
> > > - The nfs4_client 'cl_lock' spinlock
> > > - The nfs4_ol_stateid 'st_mutex' mutex
> > >
> > > so it is quite possible for the stid to be unhashed after lookup,
> > > but before calling nfsd4_lock_ol_stateid(). So we do need to check
> > > for a zero value for 'sc_type' in nfsd4_verify_open_stid().
> > >
> > > Signed-off-by: Trond Myklebust <[email protected]>
> >
> > Three successful passes of the git regression suite on NFSv4.1
> > Three successful passes of xfstests on NFSv4.1
> >
> > Tested-by: Chuck Lever <[email protected]>
>
> Thanks! Applying.
Though the changelog doesn't make sense to me. What does it mean for
the "state of the stid" to be "gauranteed by 2 locks"?
The following paragraph suggests that once we acquire st_mutex, sc_type
can no longer change, but that doesn't look right--e.g.
nfsd4_release_lockowner calls unhash-lock_stateid->nfs4_unhash_stid with
only the cl_lock held.
--b.
>
> Then I think this makes a couple of "sc_type = NFS4_CLOSED_STID"'s
> superfluous.
>
> --b.
>
> commit 17693d95b3d3
> Author: J. Bruce Fields <[email protected]>
> Date: Wed Jan 17 16:25:59 2018 -0500
>
> nfsd4: don't set lock stateid's sc_type to CLOSED
>
> There's no point I can see to
>
> stp->st_stid.sc_type = NFS4_CLOSED_STID;
>
> given release_lock_stateid immediately sets sc_type to 0.
>
> That set of sc_type to 0 should be enough to prevent it being used where
> we don't want it to be; NFS4_CLOSED_STID should only be needed for
> actual open stateid's that are actually closed.
>
> Signed-off-by: J. Bruce Fields <[email protected]>
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 5a75135f5f53..150521c9671b 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -5183,7 +5183,6 @@ nfsd4_free_lock_stateid(stateid_t *stateid, struct nfs4_stid *s)
> lockowner(stp->st_stateowner)))
> goto out;
>
> - stp->st_stid.sc_type = NFS4_CLOSED_STID;
> release_lock_stateid(stp);
> ret = nfs_ok;
>
> @@ -6079,10 +6078,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> * If this is a new, never-before-used stateid, and we are
> * returning an error, then just go ahead and release it.
> */
> - if (status && new) {
> - lock_stp->st_stid.sc_type = NFS4_CLOSED_STID;
> + if (status && new)
> release_lock_stateid(lock_stp);
> - }
>
> mutex_unlock(&lock_stp->st_mutex);
>