libdm: add help func _get_last_load_segment

Share code for same functionality.

diff --git a/libdm/libdm-deptree.c b/libdm/libdm-deptree.c
index 1ef1700fe4479e993929c685876a377b285810d2..ef5da59e0ece1ebf6b99d93b2cf7f0376e77d21a 100644 (file)
--- a/libdm/libdm-deptree.c
+++ b/libdm/libdm-deptree.c
@@ -1485,6 +1485,16 @@ out:
        return r;
 }
 
+static struct load_segment *_get_last_load_segment(struct dm_tree_node *node)
+{
+       if (dm_list_empty(&node->props.segs)) {
+               log_error("Node %s is missing a segment.", _node_name(node));
+               return NULL;
+       }
+
+       return dm_list_item(dm_list_last(&node->props.segs), struct load_segment);
+}
+
 /* For preload pass only validate pool's transaction_id */
 static int _node_send_messages(struct dm_tree_node *dnode,
                               const char *uuid_prefix,
@@ -1497,10 +1507,12 @@ static int _node_send_messages(struct dm_tree_node *dnode,
        const char *uuid;
        int have_messages;
 
-       if (!dnode->info.exists || (dm_list_size(&dnode->props.segs) != 1))
+       if (!dnode->info.exists)
                return 1;
 
-       seg = dm_list_item(dm_list_last(&dnode->props.segs), struct load_segment);
+       if (!(seg = _get_last_load_segment(dnode)))
+               return_0;
+
        if (seg->type != SEG_THIN_POOL)
                return 1;
 
@@ -3146,12 +3158,8 @@ int dm_tree_node_add_mirror_target_log(struct dm_tree_node *node,
        struct dm_tree_node *log_node = NULL;
        struct load_segment *seg;
 
-       if (!node->props.segment_count) {
-               log_error(INTERNAL_ERROR "Attempt to add target area to missing segment.");
-               return 0;
-       }
-
-       seg = dm_list_item(dm_list_last(&node->props.segs), struct load_segment);
+       if (!(seg = _get_last_load_segment(node)))
+               return_0;
 
        if (log_uuid) {
                if (!(seg->uuid = dm_pool_strdup(node->dtree->mem, log_uuid))) {
@@ -3429,13 +3437,16 @@ static struct load_segment *_get_single_load_segment(struct dm_tree_node *node,
 {
        struct load_segment *seg;
 
+       if (!(seg = _get_last_load_segment(node)))
+               return_NULL;
+
+       /* Never used past _load_node(), so can test segment_count */
        if (node->props.segment_count != 1) {
                log_error("Node %s must have only one segment.",
                          _dm_segtypes[type].target);
                return NULL;
        }
 
-       seg = dm_list_item(dm_list_last(&node->props.segs), struct load_segment);
        if (seg->type != type) {
                log_error("Node %s has segment type %s.",
                          _dm_segtypes[type].target,
@@ -3741,12 +3752,8 @@ int dm_tree_node_add_target_area(struct dm_tree_node *node,
                        return_0;
        }
 
-       if (!node->props.segment_count) {
-               log_error(INTERNAL_ERROR "Attempt to add target area to missing segment.");
-               return 0;
-       }
-
-       seg = dm_list_item(dm_list_last(&node->props.segs), struct load_segment);
+       if (!(seg = _get_last_load_segment(node)))
+               return_0;
 
        if (!_add_area(node, seg, dev_node, offset))
                return_0;
@@ -3758,7 +3765,8 @@ int dm_tree_node_add_null_area(struct dm_tree_node *node, uint64_t offset)
 {
        struct load_segment *seg;
 
-       seg = dm_list_item(dm_list_last(&node->props.segs), struct load_segment);
+       if (!(seg = _get_last_load_segment(node)))
+               return_0;
 
        switch (seg->type) {
        case SEG_RAID0: