nfsd4: shut down more of delegation earlier
J. Bruce Fields [Thu, 21 Mar 2013 15:21:50 +0000 (11:21 -0400)]
Once we've unhashed the delegation, it's only hanging around for the
benefit of an oustanding recall, which only needs the encoded
filehandle, stateid, and dl_retries counter.  No point keeping the file
around any longer, or keeping it hashed.

This also fixes a race: calls to idr_remove should really be serialized
by the caller, but the nfs4_put_delegation call from the callback code
isn't taking the state lock.

(Better might be to cancel the callback before destroying the
delegation, and remove any need for reference counting--but I don't see
an easy way to cancel an rpc call.)

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

fs/nfsd/nfs4state.c

index 7293e29..26a03fa 100644 (file)
@@ -417,21 +417,18 @@ alloc_init_deleg(struct nfs4_client *clp, struct nfs4_ol_stateid *stp, struct sv
        return dp;
 }
 
-static void free_stid(struct nfs4_stid *s, struct kmem_cache *slab)
+static void remove_stid(struct nfs4_stid *s)
 {
        struct idr *stateids = &s->sc_client->cl_stateids;
 
        idr_remove(stateids, s->sc_stateid.si_opaque.so_id);
-       kmem_cache_free(slab, s);
 }
 
 void
 nfs4_put_delegation(struct nfs4_delegation *dp)
 {
        if (atomic_dec_and_test(&dp->dl_count)) {
-               dprintk("NFSD: freeing dp %p\n",dp);
-               put_nfs4_file(dp->dl_file);
-               free_stid(&dp->dl_stid, deleg_slab);
+               kmem_cache_free(deleg_slab, dp);
                num_delegations--;
        }
 }
@@ -462,6 +459,9 @@ unhash_delegation(struct nfs4_delegation *dp)
        list_del_init(&dp->dl_recall_lru);
        spin_unlock(&recall_lock);
        nfs4_put_deleg_lease(dp->dl_file);
+       put_nfs4_file(dp->dl_file);
+       dp->dl_file = NULL;
+       remove_stid(&dp->dl_stid);
        nfs4_put_delegation(dp);
 }
 
@@ -605,7 +605,8 @@ static void close_generic_stateid(struct nfs4_ol_stateid *stp)
 
 static void free_generic_stateid(struct nfs4_ol_stateid *stp)
 {
-       free_stid(&stp->st_stid, stateid_slab);
+       remove_stid(&stp->st_stid);
+       kmem_cache_free(stateid_slab, stp);
 }
 
 static void release_lock_stateid(struct nfs4_ol_stateid *stp)