Commit aa4cc28e authored by NeilBrown's avatar NeilBrown Committed by Greg Kroah-Hartman
Browse files

staging: lustre: tidy up ldlm_resource_putref() 



1/ the return value of ldlm_resource_putref() is never
  used, so change it to return 'void'.
2/ Move all of the code to run on the last putref to
   __ldlm_resource_putref_final().  This means a lock
   is taken in one function and dropped in another, but
   that isn't too uncommon, and will disappear in a future
   patch.
   Now that the code it together, it becomes apparent that
   we are dropping a ref on the namespace *before* the last
   use.  So keep the ref until after.

Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Reviewed-by: default avatarJames Simmons <jsimmons@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 14cfbd21

drivers/staging/lustre/lustre/include/lustre_dlm.h

+1 −1
Original line number Diff line number Diff line
@@ -1190,7 +1190,7 @@ struct ldlm_resource *ldlm_resource_get(struct ldlm_namespace *ns, 
					struct ldlm_resource *parent,

					const struct ldlm_res_id *,

					enum ldlm_type type, int create);

int ldlm_resource_putref(struct ldlm_resource *res);

void ldlm_resource_putref(struct ldlm_resource *res);

void ldlm_resource_add_lock(struct ldlm_resource *res,

			    struct list_head *head,

			    struct ldlm_lock *lock);

drivers/staging/lustre/lustre/ldlm/ldlm_resource.c

+9 −12
Original line number Diff line number Diff line
@@ -1195,6 +1195,7 @@ static void __ldlm_resource_putref_final(struct cfs_hash_bd *bd, 
					 struct ldlm_resource *res)

{

	struct ldlm_ns_bucket *nsb = res->lr_ns_bucket;

	struct ldlm_namespace *ns = nsb->nsb_namespace;



	if (!list_empty(&res->lr_granted)) {

		ldlm_resource_dump(D_ERROR, res);
@@ -1206,15 +1207,18 @@ static void __ldlm_resource_putref_final(struct cfs_hash_bd *bd, 
		LBUG();

	}



	cfs_hash_bd_del_locked(nsb->nsb_namespace->ns_rs_hash,

	cfs_hash_bd_del_locked(ns->ns_rs_hash,

			       bd, &res->lr_hash);

	lu_ref_fini(&res->lr_reference);

	cfs_hash_bd_unlock(ns->ns_rs_hash, bd, 1);

	if (ns->ns_lvbo && ns->ns_lvbo->lvbo_free)

		ns->ns_lvbo->lvbo_free(res);

	if (cfs_hash_bd_count_get(bd) == 0)

		ldlm_namespace_put(nsb->nsb_namespace);

		ldlm_namespace_put(ns);

	kmem_cache_free(ldlm_resource_slab, res);

}



/* Returns 1 if the resource was freed, 0 if it remains. */

int ldlm_resource_putref(struct ldlm_resource *res)

void ldlm_resource_putref(struct ldlm_resource *res)

{

	struct ldlm_namespace *ns = ldlm_res_to_ns(res);

	struct cfs_hash_bd   bd;
@@ -1224,15 +1228,8 @@ int ldlm_resource_putref(struct ldlm_resource *res) 
	       res, atomic_read(&res->lr_refcount) - 1);



	cfs_hash_bd_get(ns->ns_rs_hash, &res->lr_name, &bd);

	if (cfs_hash_bd_dec_and_lock(ns->ns_rs_hash, &bd, &res->lr_refcount)) {

	if (cfs_hash_bd_dec_and_lock(ns->ns_rs_hash, &bd, &res->lr_refcount))

		__ldlm_resource_putref_final(&bd, res);

		cfs_hash_bd_unlock(ns->ns_rs_hash, &bd, 1);

		if (ns->ns_lvbo && ns->ns_lvbo->lvbo_free)

			ns->ns_lvbo->lvbo_free(res);

		kmem_cache_free(ldlm_resource_slab, res);

		return 1;

	}

	return 0;

}

EXPORT_SYMBOL(ldlm_resource_putref);

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