Added dm_tree_node_set_callback() for preload and deactivation hooks

Run users hook after preload for the node is finished,
or after the node has been deactivated.

diff --git a/WHATS_NEW_DM b/WHATS_NEW_DM
index c3e8e159447444f5133993196b3c766895d36857..f8e7e7bdfa64460fed8cf6e6538103718bcb3e65 100644 (file)
--- a/WHATS_NEW_DM
+++ b/WHATS_NEW_DM
@@ -1,5 +1,6 @@
 Version 1.02.73 - 
 ====================================
+  Added dm_tree_node_set_callback() for preload and deactivation hooks.
   Drop unsupported TRIM message for thin pool.
   Improve logging for fifo startup in dmeventd.
   Add few pointer validation in dmsetup.

diff --git a/libdm/libdevmapper.h b/libdm/libdevmapper.h
index dfbadaa27476df6c2a22ffa05c0d2d41055e0dcb..7df4db8a601984b9119015755c18e9e9c821d67c 100644 (file)
--- a/libdm/libdevmapper.h
+++ b/libdm/libdevmapper.h
@@ -688,6 +688,20 @@ void dm_tree_node_set_read_ahead(struct dm_tree_node *dnode,
                                 uint32_t read_ahead,
                                 uint32_t read_ahead_flags);
 
+/*
+ * Set node callback hook before de/activation.
+ * Callback is called before 'activation' of node for activation tree,
+ * or 'deactivation' of node for deactivation tree.
+ */
+typedef enum {
+       DM_NODE_CALLBACK_PRELOADED,   /* Node has preload deps */
+       DM_NODE_CALLBACK_DEACTIVATED, /* Node is deactivated */
+} dm_node_callback_t;
+typedef int (*dm_node_callback_fn) (struct dm_tree_node *node,
+                                   dm_node_callback_t type, void *cb_data);
+void dm_tree_node_set_callback(struct dm_tree_node *node,
+                              dm_node_callback_fn cb, void *cb_data);
+
 void dm_tree_set_cookie(struct dm_tree_node *node, uint32_t cookie);
 uint32_t dm_tree_get_cookie(struct dm_tree_node *node);
 

diff --git a/libdm/libdm-deptree.c b/libdm/libdm-deptree.c
index e80db2fee0ebbe53ab469ad11c4e8ed61e808f73..582a14a66732168925b6defafd687addf4879bac 100644 (file)
--- a/libdm/libdm-deptree.c
+++ b/libdm/libdm-deptree.c
@@ -263,6 +263,10 @@ struct dm_tree_node {
         * Note: only direct child is allowed
         */
        struct dm_tree_node *presuspend_node;
+
+       /* Callback */
+       dm_node_callback_fn callback;
+       void *callback_data;
 };
 
 struct dm_tree {
@@ -1588,6 +1592,14 @@ static int _dm_tree_deactivate_children(struct dm_tree_node *dnode,
                } else if (info.suspended)
                        dec_suspended();
 
+               if (child->callback &&
+                   !child->callback(child, DM_NODE_CALLBACK_DEACTIVATED,
+                                    child->callback_data)) {
+                       r = 0;
+                       // FIXME: break tree shutdown or continue?
+                       // hmm what about _node_clear_table()?
+               }
+
                if (dm_tree_node_num_children(child, 0)) {
                        if (!_dm_tree_deactivate_children(child, uuid_prefix, uuid_prefix_len, level + 1))
                                return_0;
@@ -2445,10 +2457,16 @@ int dm_tree_preload_children(struct dm_tree_node *dnode,
                        update_devs_flag = 1;
        }
 
-       if (update_devs_flag) {
+       if (update_devs_flag ||
+           (!dnode->info.exists && dnode->callback)) {
                if (!dm_udev_wait(dm_tree_get_cookie(dnode)))
                        stack;
                dm_tree_set_cookie(dnode, 0);
+
+               if (!dnode->info.exists && dnode->callback &&
+                   !dnode->callback(child, DM_NODE_CALLBACK_PRELOADED,
+                                    dnode->callback_data))
+                       return_0;
        }
 
        return r;
@@ -3245,3 +3263,10 @@ int dm_tree_node_add_null_area(struct dm_tree_node *node, uint64_t offset)
 
        return 1;
 }
+
+void dm_tree_node_set_callback(struct dm_tree_node *dnode,
+                              dm_node_callback_fn cb, void *data)
+{
+       dnode->callback = cb;
+       dnode->callback_data = data;
+}