(#533) Add print fn to print branch BTrees under trunk node.

- Introduce trunk_print_branch_btrees() to walk the root-addresses
  of branch BTree nodes for a given trunk node, and to invoke the
  BTree print methods on each such branch. The top-level BTree
  root node is being printed right, but upon recursing down, we
  are running into an unallocated page error.
  allocator_page_valid() is consistently failing for all sub-trees
  under root branch BTree.

src/trunk.c

@@ -2981,7 +2981,10 @@ trunk_get_memtable(trunk_handle *spl, uint64 generation)
 {
    uint64    memtable_idx = generation % TRUNK_NUM_MEMTABLES;
    memtable *mt           = &spl->mt_ctxt->mt[memtable_idx];
-   platform_assert(mt->generation == generation);
+   platform_assert((mt->generation == generation),
+                   "mt->generation=%lu, generation=%lu\n",
+                   mt->generation,
+                   generation);
    return mt;
 }
 
@@ -9007,6 +9010,41 @@ trunk_print_branches(platform_log_handle *log_handle, trunk_handle *spl)
    trunk_for_each_node(spl, trunk_node_print_branches, log_handle);
 }
 
+/*
+ * Print all the branch BTrees hanging off of input trunk node 'addr'.
+ */
+void
+trunk_print_branch_btrees(trunk_handle *spl, uint64 addr, void *arg)
+{
+   platform_log_handle *log_handle = (platform_log_handle *)arg;
+   trunk_node           node;
+   trunk_node_get(spl->cc, addr, &node);
+
+   uint16 start_branch = trunk_start_branch(spl, &node);
+   uint16 end_branch   = trunk_end_branch(spl, &node);
+
+   platform_log(log_handle,
+                "\n**** Print all BTree branches under "
+                "Trunk node addr=%lu ****\n{\n\n",
+                addr);
+   for (uint16 branch_no = start_branch; branch_no != end_branch;
+        branch_no        = trunk_add_branch_number(spl, branch_no, 1))
+   {
+      uint64 bt_addr = trunk_get_branch(spl, &node, branch_no)->root_addr;
+      platform_log(log_handle,
+                   "Trunk node addr=%lu, Branch number %u"
+                   ", BTree root addr=%lu\n{\n",
+                   addr,
+                   branch_no,
+                   bt_addr);
+      btree_print_tree(log_handle, spl->cc, trunk_btree_config(spl), bt_addr);
+      platform_log(log_handle, "\n}\n");
+   }
+
+   trunk_node_unget(spl->cc, &node);
+   platform_log(log_handle, "\n}\n");
+}
+
 // bool
 // trunk_node_print_extent_count(trunk_handle *spl,
 //                                 uint64           addr,

src/trunk.h

@@ -406,10 +406,16 @@ trunk_print_lookup(trunk_handle        *spl,
                    platform_log_handle *log_handle);
 void
 trunk_print_branches(platform_log_handle *log_handle, trunk_handle *spl);
+
 void
 trunk_print_extent_counts(platform_log_handle *log_handle, trunk_handle *spl);
+
+void
+trunk_print_branch_btrees(trunk_handle *spl, uint64 addr, void *arg);
+
 void
 trunk_print_space_use(platform_log_handle *log_handle, trunk_handle *spl);
+
 bool
 trunk_verify_tree(trunk_handle *spl);
 

tests/unit/splinter_test.c

@@ -663,6 +663,9 @@ CTEST2(splinter, test_splinter_print_diags)
    CTEST_LOG_INFO("\n** trunk_print() **\n");
    trunk_print(Platform_default_log_handle, spl);
 
+   CTEST_LOG_INFO("\n** trunk_print_branch_btrees() on Trunk root node **\n");
+   trunk_print_branch_btrees(spl, spl->root_addr, Platform_default_log_handle);
+
    CTEST_LOG_INFO("\n** Allocator stats **\n");
    allocator_print_stats(alp);
    allocator_print_allocated(alp);