nfsd4: do not throw away 4.1 lock state on last unlock

This reverts commit eb2099f31b0f090684a64ef8df44a30ff7c45fc2 "nfsd4:
release lockowners on last unlock in 4.1 case".  Trond identified
language in rfc 5661 section 8.2.4 which forbids this behavior:

	Stateids associated with byte-range locks are an exception.
	They remain valid even if a LOCKU frees all remaining locks, so
	long as the open file with which they are associated remains
	open, unless the client frees the stateids via the FREE_STATEID
	operation.

And bakeathon 2013 testing found a 4.1 freebsd client was getting an
incorrect BAD_STATEID return from a FREE_STATEID in the above situation
and then failing.

The spec language honestly was probably a mistake but at this point with
implementations already following it we're probably stuck with that.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 1 insertions, 8 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index fcc0610fe308..a7d8a11943ee 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4514,7 +4514,6 @@ __be32
 nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
             struct nfsd4_locku *locku)
 {
-        struct nfs4_lockowner *lo;
         struct nfs4_ol_stateid *stp;
         struct file *filp = NULL;
         struct file_lock *file_lock = NULL;
@@ -4547,10 +4546,9 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                 status = nfserr_jukebox;
                 goto out;
         }
-        lo = lockowner(stp->st_stateowner);
         locks_init_lock(file_lock);
         file_lock->fl_type = F_UNLCK;
-        file_lock->fl_owner = (fl_owner_t)lo;
+        file_lock->fl_owner = (fl_owner_t)lockowner(stp->st_stateowner);
         file_lock->fl_pid = current->tgid;
         file_lock->fl_file = filp;
         file_lock->fl_flags = FL_POSIX;
@@ -4569,11 +4567,6 @@ nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         update_stateid(&stp->st_stid.sc_stateid);
         memcpy(&locku->lu_stateid, &stp->st_stid.sc_stateid, sizeof(stateid_t));
 
-        if (nfsd4_has_session(cstate) && !check_for_locks(stp->st_file, lo)) {
-                WARN_ON_ONCE(cstate->replay_owner);
-                release_lockowner(lo);
-        }
-
 out:
         nfsd4_bump_seqid(cstate, status);
         if (!cstate->replay_owner)