LU-4524 ldlm: improve ldlm_lock_create() return value

[fs/lustre-release.git] / lustre / ldlm / ldlm_resource.c

diff --git a/lustre/ldlm/ldlm_resource.c b/lustre/ldlm/ldlm_resource.c
index 11937d2..ae70626 100644 (file)
--- a/lustre/ldlm/ldlm_resource.c
+++ b/lustre/ldlm/ldlm_resource.c
@@ -1072,11 +1072,11 @@ struct ldlm_resource *
 ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
                   const struct ldlm_res_id *name, ldlm_type_t type, int create)
 {
-        cfs_hlist_node_t     *hnode;
-        struct ldlm_resource *res;
-        cfs_hash_bd_t         bd;
-        __u64                 version;
-       int                   ns_refcount = 0;
+       struct hlist_node       *hnode;
+       struct ldlm_resource    *res = NULL;
+       cfs_hash_bd_t           bd;
+       __u64                   version;
+       int                     ns_refcount = 0;
 
         LASSERT(ns != NULL);
         LASSERT(parent == NULL);
@@ -1087,42 +1087,31 @@ ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
         hnode = cfs_hash_bd_lookup_locked(ns->ns_rs_hash, &bd, (void *)name);
         if (hnode != NULL) {
                 cfs_hash_bd_unlock(ns->ns_rs_hash, &bd, 0);
-                res = cfs_hlist_entry(hnode, struct ldlm_resource, lr_hash);
-               /* Synchronize with regard to resource creation. */
-                if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
-                       mutex_lock(&res->lr_lvb_mutex);
-                       mutex_unlock(&res->lr_lvb_mutex);
-                }
-
-               if (unlikely(res->lr_lvb_len < 0)) {
-                       ldlm_resource_putref(res);
-                       res = NULL;
-               }
-                return res;
-        }
+               GOTO(lvbo_init, res);
+       }
 
-        version = cfs_hash_bd_version_get(&bd);
-        cfs_hash_bd_unlock(ns->ns_rs_hash, &bd, 0);
+       version = cfs_hash_bd_version_get(&bd);
+       cfs_hash_bd_unlock(ns->ns_rs_hash, &bd, 0);
 
-        if (create == 0)
-                return NULL;
+       if (create == 0)
+               return ERR_PTR(-ENOENT);
 
-        LASSERTF(type >= LDLM_MIN_TYPE && type < LDLM_MAX_TYPE,
-                 "type: %d\n", type);
-        res = ldlm_resource_new();
-        if (!res)
-                return NULL;
+       LASSERTF(type >= LDLM_MIN_TYPE && type < LDLM_MAX_TYPE,
+                "type: %d\n", type);
+       res = ldlm_resource_new();
+       if (res == NULL)
+               return ERR_PTR(-ENOMEM);
 
-        res->lr_ns_bucket  = cfs_hash_bd_extra_get(ns->ns_rs_hash, &bd);
-        res->lr_name       = *name;
-        res->lr_type       = type;
-        res->lr_most_restr = LCK_NL;
+       res->lr_ns_bucket  = cfs_hash_bd_extra_get(ns->ns_rs_hash, &bd);
+       res->lr_name       = *name;
+       res->lr_type       = type;
+       res->lr_most_restr = LCK_NL;
 
-        cfs_hash_bd_lock(ns->ns_rs_hash, &bd, 1);
-        hnode = (version == cfs_hash_bd_version_get(&bd)) ?  NULL :
-                cfs_hash_bd_lookup_locked(ns->ns_rs_hash, &bd, (void *)name);
+       cfs_hash_bd_lock(ns->ns_rs_hash, &bd, 1);
+       hnode = (version == cfs_hash_bd_version_get(&bd)) ? NULL :
+               cfs_hash_bd_lookup_locked(ns->ns_rs_hash, &bd, (void *)name);
 
-        if (hnode != NULL) {
+       if (hnode != NULL) {
                /* Someone won the race and already added the resource. */
                cfs_hash_bd_unlock(ns->ns_rs_hash, &bd, 1);
                /* Clean lu_ref for failed resource. */
@@ -1130,8 +1119,8 @@ ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
                /* We have taken lr_lvb_mutex. Drop it. */
                mutex_unlock(&res->lr_lvb_mutex);
                OBD_SLAB_FREE(res, ldlm_resource_slab, sizeof *res);
-
-               res = cfs_hlist_entry(hnode, struct ldlm_resource, lr_hash);
+lvbo_init:
+               res = hlist_entry(hnode, struct ldlm_resource, lr_hash);
                /* Synchronize with regard to resource creation. */
                if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init) {
                        mutex_lock(&res->lr_lvb_mutex);
@@ -1140,7 +1129,7 @@ ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
 
                if (unlikely(res->lr_lvb_len < 0)) {
                        ldlm_resource_putref(res);
-                       res = NULL;
+                       res = ERR_PTR(res->lr_lvb_len);
                }
                return res;
        }
@@ -1166,7 +1155,7 @@ ldlm_resource_get(struct ldlm_namespace *ns, struct ldlm_resource *parent,
                        res->lr_lvb_len = rc;
                        mutex_unlock(&res->lr_lvb_mutex);
                        ldlm_resource_putref(res);
-                       return NULL;
+                       return ERR_PTR(rc);
                }
        }