Explicitly close the playlist files in the queue on storage unmount

src/tangara/audio/playlist.cpp

@@ -33,6 +33,10 @@ Playlist::Playlist(const std::string& playlistFilepath)
 auto Playlist::open() -> bool {
   std::unique_lock<std::mutex> lock(mutex_);
 
+  if (file_open_) {
+    return true;
+  }
+
   FRESULT res =
       f_open(&file_, filepath_.c_str(), FA_READ | FA_WRITE | FA_OPEN_ALWAYS);
   if (res != FR_OK) {
@@ -194,6 +198,14 @@ auto Playlist::deserialiseCache() -> bool {
   return true;
 }
 
+auto Playlist::close() -> void {
+  if (file_open_) {
+    f_close(&file_);
+    file_open_ = false;
+    file_error_ = false;
+  }
+}
+
 auto Playlist::skipToLocked(size_t position) -> void {
   if (!file_open_ || file_error_) {
     return;
@@ -307,6 +319,10 @@ MutablePlaylist::MutablePlaylist(const std::string& playlistFilepath)
 auto MutablePlaylist::open() -> bool {
   std::unique_lock<std::mutex> lock(mutex_);
 
+  if (file_open_) {
+    return true;
+  }
+  
   FRESULT res =
       f_open(&file_, filepath_.c_str(), FA_READ | FA_WRITE | FA_OPEN_ALWAYS);
   if (res != FR_OK) {

src/tangara/audio/playlist.hpp

@@ -47,6 +47,7 @@ class Playlist {
 
   auto serialiseCache() -> bool;
   auto deserialiseCache() -> bool;
+  auto close() -> void;
 
  protected:
   const std::string filepath_;

src/tangara/audio/track_queue.cpp

@@ -159,6 +159,13 @@ auto TrackQueue::open() -> bool {
   return playlist_.open();
 }
 
+auto TrackQueue::close() -> void {
+  playlist_.close();
+  if (opened_playlist_) {
+    opened_playlist_->close();
+  }
+}
+
 auto TrackQueue::openPlaylist(const std::string& playlist_file, bool notify)
     -> bool {
   opened_playlist_.emplace(playlist_file);

src/tangara/audio/track_queue.hpp

@@ -76,8 +76,9 @@ class TrackQueue {
   auto currentPosition(size_t position) -> bool;
   auto totalSize() const -> size_t;
   auto open() -> bool;
-  auto openPlaylist(const std::string& playlist_file, bool notify = true)
-      -> bool;
+  auto close() -> void;
+  auto openPlaylist(const std::string& playlist_file,
+                    bool notify = true) -> bool;
   auto playFromPosition(const std::string& filepath, uint32_t position) -> void;
 
   using Item =

src/tangara/system_fsm/running.cpp

@@ -214,6 +214,7 @@ void Running::react(const internal::Mount& ev) {
 
 auto Running::unmountStorage() -> void {
   ESP_LOGW(kTag, "unmounting storage");
+  sServices->track_queue().close();
   sServices->database({});
   sStorage.reset();
   updateSdState(drivers::SdState::kNotMounted);