From c57c36adb222d90b3c46cf66280be8e8565a6d6c Mon Sep 17 00:00:00 2001
From: Thales Macedo Garitezi <thalesmg@gmail.com>
Date: Thu, 4 Apr 2024 14:05:12 -0300
Subject: [PATCH] feat(ds): clear all checkpoints when (re)starting storage
 layer

Fixes https://emqx.atlassian.net/browse/EMQX-12143
---
 .../src/emqx_ds_storage_layer.erl             | 26 +++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/apps/emqx_durable_storage/src/emqx_ds_storage_layer.erl b/apps/emqx_durable_storage/src/emqx_ds_storage_layer.erl
index 28ce1d943..4981c3fc1 100644
--- a/apps/emqx_durable_storage/src/emqx_ds_storage_layer.erl
+++ b/apps/emqx_durable_storage/src/emqx_ds_storage_layer.erl
@@ -500,6 +500,7 @@ init({ShardId, Options}) ->
     process_flag(trap_exit, true),
     logger:set_process_metadata(#{shard_id => ShardId, domain => [ds, storage_layer, shard]}),
     erase_schema_runtime(ShardId),
+    clear_all_checkpoints(ShardId),
     {ok, DB, CFRefs0} = rocksdb_open(ShardId, Options),
     {Schema, CFRefs} =
         case get_schema_persistent(DB) of
@@ -567,6 +568,23 @@ terminate(_Reason, #s{db = DB, shard_id = ShardId}) ->
 %% Internal functions
 %%================================================================================
 
+-spec clear_all_checkpoints(shard_id()) -> ok.
+clear_all_checkpoints(ShardId) ->
+    CheckpointBaseDir = checkpoints_dir(ShardId),
+    ok = filelib:ensure_path(CheckpointBaseDir),
+    {ok, AllFiles} = file:list_dir(CheckpointBaseDir),
+    CheckpointDirs = [Dir || Dir <- AllFiles, filelib:is_dir(Dir)],
+    lists:foreach(
+        fun(Dir) ->
+            logger:debug(#{
+                msg => "ds_storage_deleting_previous_checkpoint",
+                dir => Dir
+            }),
+            ok = file:del_dir_r(Dir)
+        end,
+        CheckpointDirs
+    ).
+
 -spec open_shard(shard_id(), rocksdb:db_handle(), cf_refs(), shard_schema()) ->
     shard().
 open_shard(ShardId, DB, CFRefs, ShardSchema) ->
@@ -777,9 +795,13 @@ rocksdb_open(Shard, Options) ->
 db_dir({DB, ShardId}) ->
     filename:join([emqx_ds:base_dir(), DB, binary_to_list(ShardId)]).
 
+-spec checkpoints_dir(shard_id()) -> file:filename().
+checkpoints_dir({DB, ShardId}) ->
+    filename:join([emqx_ds:base_dir(), DB, checkpoints, binary_to_list(ShardId)]).
+
 -spec checkpoint_dir(shard_id(), _Name :: file:name()) -> file:filename().
-checkpoint_dir({DB, ShardId}, Name) ->
-    filename:join([emqx_ds:base_dir(), DB, checkpoints, binary_to_list(ShardId), Name]).
+checkpoint_dir(ShardId, Name) ->
+    filename:join([checkpoints_dir(ShardId), Name]).
 
 -spec update_last_until(Schema, emqx_ds:time()) ->
     Schema | {error, exists | overlaps_existing_generations}