Preserve channel files until checked metadata deletion commits

src/chat/chat_channel.c

@@ -330,6 +330,9 @@ void chat_core_delete_channel(struct UTUN_INSTANCE* inst, const char* ch_id) {
         return;
     }
     if (!ch_id || !ch_id[0]) { DEBUG_ERROR(DEBUG_CATEGORY_CHAT_SYNC, "%s: delete_channel — empty ch_id", CC_ID); return; }
+    if (!sqlite3_get_autocommit(cc->db)) {
+        DEBUG_ERROR(DEBUG_CATEGORY_CHAT_SYNC, "%s: delete_channel rejected inside external transaction ch=%s", CC_ID, ch_id); return;
+    }
     if (chat_media_defer_channel_delete(inst, ch_id)) return;
 
     DEBUG_INFO(DEBUG_CATEGORY_CHAT_SYNC, "%s: delete_channel BEGIN ch=%s", CC_ID, ch_id);
@@ -337,7 +340,6 @@ void chat_core_delete_channel(struct UTUN_INSTANCE* inst, const char* ch_id) {
 
     /* 1. отмена медиа-загрузок/релэев/суперузлов канала (держат conn_mgr handle группы) */
     media_delivery_cancel_channel(inst, gid);
-    chat_attachment_delete_channel(inst, ch_id);
     member_files_cancel_group(inst, gid);
     group_avatar_cancel_group(inst, gid);
 
@@ -357,16 +359,22 @@ void chat_core_delete_channel(struct UTUN_INSTANCE* inst, const char* ch_id) {
     /* 5. немедленно убрать канал из кеша chat_sync */
     chat_sync_on_channel_deleted(inst, ch_id);
 
-    /* 6. удалить медиафайлы канала на диске + строки media_files */
-    char media_base[MEDIA_BASE_MAX];
-    int media_error = media_index_get_base(cc->db, media_base) || media_index_delete_channel(cc->db, ch_id, media_base);
-    if (media_error) DEBUG_ERROR(DEBUG_CATEGORY_MEDIA, "channel=%s removed with incomplete media cleanup; retry required", ch_id);
-
-    /* 7. удалить таблицы и метаданные канала */
+    /* 6. удалить таблицы, метаданные и attachment-записи одной SQL-транзакцией до файловой очистки */
     if (topo_node_sqlite_channel_delete(cc->db, ch_id)) {
-        DEBUG_ERROR(DEBUG_CATEGORY_CHAT_SYNC, "channel metadata deletion failed ch=%s", ch_id); return;
+        DEBUG_ERROR(DEBUG_CATEGORY_CHAT_SYNC, "channel metadata deletion failed ch=%s; files preserved, retry required", ch_id);
+        if (!sqlite3_get_autocommit(cc->db)) {
+            DEBUG_ERROR(DEBUG_CATEGORY_CHAT_SYNC, "channel delete left transaction open ch=%s; requesting owner stop", ch_id);
+            chat_attachment_quiesce(inst); utun_instance_stop(inst);
+        }
+        return;
     }
 
+    /* 7. удалить файлы только после commit; I/O-отказ не восстанавливает удалённый канал */
+    int media_error = chat_attachment_delete_channel(inst, ch_id);
+    char media_base[MEDIA_BASE_MAX];
+    if (media_index_get_base(cc->db, media_base) || media_index_delete_channel(cc->db, ch_id, media_base)) media_error = 1;
+    if (media_error) DEBUG_ERROR(DEBUG_CATEGORY_MEDIA, "channel=%s removed with incomplete media cleanup; retry required", ch_id);
+
     /* 8. уведомить GUI */
     {
         uint8_t evt[65]; uint8_t cl = (uint8_t)strlen(ch_id);

src/routing_layer/topo_node_sqlite.c

@@ -623,19 +623,29 @@ int topo_node_sqlite_channel_delete(sqlite3* db, const char* channel_id) {
     if (rc == SQLITE_OK) rc = sqlite3_bind_text(st, 1, channel_id, -1, SQLITE_STATIC);
     if (rc == SQLITE_OK) rc = sqlite3_step(st);
     if (rc != SQLITE_DONE) goto fail;
-    sqlite3_finalize(st); st = NULL;
+    rc = sqlite3_finalize(st); st = NULL;
+    if (rc != SQLITE_OK) goto fail;
+    /* IGNORE может вернуть DONE, сохранив канал: это не успешное удаление. */
+    rc = sqlite3_prepare_v2(db, "SELECT 1 FROM channels WHERE channel_id=?", -1, &st, NULL);
+    if (rc == SQLITE_OK) rc = sqlite3_bind_text(st, 1, channel_id, -1, SQLITE_STATIC);
+    if (rc == SQLITE_OK) rc = sqlite3_step(st);
+    if (rc != SQLITE_DONE) goto fail;
+    rc = sqlite3_finalize(st); st = NULL;
+    if (rc != SQLITE_OK) goto fail;
     rc = sqlite3_prepare_v2(db, "SELECT 1 FROM sqlite_master WHERE type='table' AND name='merkle_tree_hash'", -1, &st, NULL);
     if (rc != SQLITE_OK) goto fail;
     rc = sqlite3_step(st);
     if (rc != SQLITE_ROW && rc != SQLITE_DONE) goto fail;
     int has_merkle = rc == SQLITE_ROW;
-    sqlite3_finalize(st); st = NULL;
+    rc = sqlite3_finalize(st); st = NULL;
+    if (rc != SQLITE_OK) goto fail;
     if (has_merkle) {
         rc = sqlite3_prepare_v2(db, "DELETE FROM merkle_tree_hash WHERE substr(namespace,instr(namespace,':')+1)=?", -1, &st, NULL);
         if (rc == SQLITE_OK) rc = sqlite3_bind_text(st, 1, channel_id, -1, SQLITE_STATIC);
         if (rc == SQLITE_OK) rc = sqlite3_step(st);
         if (rc != SQLITE_DONE) goto fail;
-        sqlite3_finalize(st); st = NULL;
+        rc = sqlite3_finalize(st); st = NULL;
+        if (rc != SQLITE_OK) goto fail;
     }
     if ((rc = sqlite3_exec(db, "RELEASE delete_topo_channel", NULL, NULL, NULL)) != SQLITE_OK) goto fail;
     DEBUG_INFO(DEBUG_CATEGORY_BGP, "channel deleted: channel=%s tables=peers/msg/feedback merkle=%d", channel_id, has_merkle);