Re: [PATCH] nfsd: Detect unhashed stids in nfsd4_verify_open_stid()

[bfields@fieldses.org (J. Bruce Fields)]

On Fri, Jan 12, 2018 at 09:15:46PM -0500, Chuck Lever wrote:
> 
> 
> > On Jan 12, 2018, at 5:42 PM, Trond Myklebust <trond.myklebust@primarydata.com> 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 <trond.myklebust@primarydata.com>
> 
> Three successful passes of the git regression suite on NFSv4.1
> Three successful passes of xfstests on NFSv4.1
> 
> Tested-by: Chuck Lever <chuck.lever@oracle.com>

Thanks!  Applying.

Then I think this makes a couple of "sc_type = NFS4_CLOSED_STID"'s
superfluous.

--b.

commit 17693d95b3d3
Author: J. Bruce Fields <bfields@redhat.com>
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 <bfields@redhat.com>

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);