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LU-5092 nodemap: save nodemaps to targets for caching
[fs/lustre-release.git] / lustre / ptlrpc / nodemap_handler.c
index a416c90..59b1734 100644 (file)
@@ -1399,9 +1399,13 @@ void nodemap_config_dealloc(struct nodemap_config *config)
 }
 EXPORT_SYMBOL(nodemap_config_dealloc);
 
-static int nm_hash_list_cb(struct cfs_hash *hs, struct cfs_hash_bd *bd,
-                          struct hlist_node *hnode,
-                          void *nodemap_list_head)
+/*
+ * callback for cfs_hash_for_each_safe used to convert a nodemap hash to a
+ * nodemap list, generally for locking purposes as a hash cb can't sleep.
+ */
+int nm_hash_list_cb(struct cfs_hash *hs, struct cfs_hash_bd *bd,
+                   struct hlist_node *hnode,
+                   void *nodemap_list_head)
 {
        struct lu_nodemap *nodemap;
 
@@ -1415,6 +1419,7 @@ void nodemap_config_set_active(struct nodemap_config *config)
        struct nodemap_config   *old_config = active_config;
        struct lu_nodemap       *nodemap;
        struct lu_nodemap       *tmp;
+       bool revoke_locks;
        LIST_HEAD(nodemap_list_head);
 
        ENTRY;
@@ -1445,6 +1450,14 @@ void nodemap_config_set_active(struct nodemap_config *config)
                }
        }
 
+       /*
+        * We only need to revoke locks if old nodemap was active, and new
+        * config is now nodemap inactive. nodemap_config_dealloc will
+        * reclassify exports, triggering a lock revoke if and only if new
+        * nodemap is active.
+        */
+       revoke_locks = !config->nmc_nodemap_is_active && nodemap_active;
+
        /* if new config is inactive, deactivate live config before switching */
        if (!config->nmc_nodemap_is_active)
                nodemap_active = false;
@@ -1457,7 +1470,8 @@ void nodemap_config_set_active(struct nodemap_config *config)
        if (old_config != NULL)
                nodemap_config_dealloc(old_config);
 
-       nm_member_revoke_all();
+       if (revoke_locks)
+               nm_member_revoke_all();
 
        EXIT;
 }
@@ -1519,7 +1533,7 @@ void nm_member_revoke_all(void)
 
        /* revoke_locks sleeps, so can't call in cfs hash cb */
        list_for_each_entry_safe(nodemap, tmp, &nodemap_list_head, nm_list)
-               nm_member_revoke_locks(nodemap);
+               nm_member_revoke_locks_always(nodemap);
        mutex_unlock(&active_config_lock);
 }