nfsd: Ensure that nfs4_open_delegation() references the delegation stateid

Ensure that nfs4_open_delegation() keeps a reference to the delegation
stateid until it is done working with it. Necessary step toward
client_mutex removal.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 4f191456d73784865a6754fe414eccf8f46ce077..2df6af93120e0289f0c3e911b16dd5ce0b6c383d 100644 (file)
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -674,6 +674,7 @@ hash_delegation_locked(struct nfs4_delegation *dp, struct nfs4_file *fp)
        lockdep_assert_held(&state_lock);
        lockdep_assert_held(&fp->fi_lock);
 
+       atomic_inc(&dp->dl_stid.sc_count);
        dp->dl_stid.sc_type = NFS4_DELEG_STID;
        list_add(&dp->dl_perfile, &fp->fi_delegations);
        list_add(&dp->dl_perclnt, &dp->dl_stid.sc_client->cl_delegations);
@@ -3704,6 +3705,7 @@ nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open,
        dprintk("NFSD: delegation stateid=" STATEID_FMT "\n",
                STATEID_VAL(&dp->dl_stid.sc_stateid));
        open->op_delegate_type = NFS4_OPEN_DELEGATE_READ;
+       nfs4_put_stid(&dp->dl_stid);
        return;
 out_no_deleg:
        open->op_delegate_type = NFS4_OPEN_DELEGATE_NONE;