Add ability to cleanup avirt

- Add reset all function for streams
- Add checks for empty /config dir, to avoid remount of configfs

Signed-off-by: Mark Farrugia <mark.farrugia@fiberdyne.com.au>

2 files changed, 102 insertions, 7 deletions

diff --git a/include/avirt/avirt.h b/include/avirt/avirt.h
index 9389f47..afd856f 100644
--- a/include/avirt/avirt.h
+++ b/include/avirt/avirt.h
@@ -112,6 +112,8 @@ int snd_avirt_audiopaths(struct snd_avirt_audiopath **audiopaths, int *count);
  */
 int snd_avirt_card_configure();
 
+int snd_avirt_card_unconfigure();
+
 /**
  * snd_avirt_pcm_info - Get PCM info for a given PCM name
  * @pcm_name: The PCM name of which to retrieve the PCM info
diff --git a/src/avirt-config.c b/src/avirt-config.c
index 6f1391c..a52ef0a 100644
--- a/src/avirt-config.c
+++ b/src/avirt-config.c
@@ -134,9 +134,29 @@ static bool configfs_mounted = false;
 static bool card_configured = false;
 static int card_index = -1;
 
+bool check_dir_empty(char *dirname)
+{
+  int n = 0;
+  struct dirent *d;
+
+  DIR *dir = opendir(dirname);
+  if (dir == NULL) // Not a directory or doesn't exist
+    return 1;
+  while ((d = readdir(dir)) != NULL) {
+    if (++n > 2) // Ignore the '.' and '..' directories
+      break;
+  }
+
+  closedir(dir);
+  if (n <= 2) // Directory Empty
+    return true;
+
+  return false;
+}
+
 static int mount_configfs()
 {
-  int err;
+  int err = 0;
   char fsline[100];
   bool configfs_supported = false;
   FILE *procfs;
@@ -164,14 +184,18 @@ static int mount_configfs()
   if (stat("/config", &st) == -1)
     mkdir("/config", S_IRWXU | S_IRWXG | S_IRWXO);
 
-  err = mount("none", "/config", "configfs", 0, NULL);
-  if (!err)
+  // Check whether configfs is mounted, if not, mount it
+  if (check_dir_empty("/config"))
   {
-    AVIRT_DEBUG("Successfully mounted configfs");
-    configfs_mounted = true;
+    err = mount("none", "/config", "configfs", 0, NULL);
+    if (!err)
+    {
+      AVIRT_DEBUG("Successfully mounted configfs");
+      configfs_mounted = true;
+    }
+    else
+      AVIRT_ERROR("Failed to mount configfs filesystem!");
   }
-  else
-    AVIRT_ERROR("Failed to mount configfs filesystem!");
 
   return err;
 }
@@ -409,6 +433,48 @@ close_handle:
   return retval;
 }
 
+static int snd_avirt_stream_reset_all()
+{
+  int err;
+  DIR *d;
+  struct dirent *dir;
+  char path[AVIRT_CONFIGFS_PATH_MAXLEN];
+
+  d = opendir(AVIRT_CONFIGFS_PATH_STREAMS);
+  if (d)
+  {
+    while ((dir = readdir(d)) != NULL)
+    {
+      // Ignore the directory . and ..
+      if ((!strcmp(dir->d_name, ".")) || (!strcmp(dir->d_name, "..")))
+        continue;
+
+      memset(path, 0, AVIRT_CONFIGFS_PATH_MAXLEN);
+      strcpy(path, AVIRT_CONFIGFS_PATH_STREAMS);
+      strcat(path, dir->d_name);
+
+      // If not a directory, continue
+      struct stat path_stat;
+      stat(path, &path_stat);
+      if (S_ISREG(path_stat.st_mode))
+        continue;
+
+      err = rmdir(path);
+      if (err < 0)
+      {
+        AVIRT_ERROR_V("Cannot remove config item '%s' at directory '%s'", dir->d_name, path);
+        return err;
+      }
+    }
+
+    AVIRT_DEBUG("Reset streams!");
+
+    return 0;
+  }
+
+  return -EPERM;
+}
+
 int snd_avirt_stream_new(const char *name, unsigned int channels, int direction,
                          const char *map, bool internal)
 {
@@ -526,6 +592,33 @@ int snd_avirt_card_configure()
     AVIRT_DEBUG_V("Running router: '%s'", cmd);
   }
 
+
+  return 0;
+}
+
+int snd_avirt_card_unconfigure()
+{
+  // Check if card is already configured
+  if (!card_configured)
+  {
+    AVIRT_ERROR("Card is already unconfigured!");
+    return -EPERM;
+  }
+
+  IS_CONFIGFS_MOUNTED();
+
+  snd_avirt_stream_reset_all();
+
+  WRITE_ATTR_TO_DIR(AVIRT_CONFIGFS_PATH_STREAMS, "configured", "%d", 0);
+
+  AVIRT_DEBUG("Card unconfigured!");
+  card_configured = false;
+
+  if (card_index < 0)
+    card_index = snd_avirt_card_index_get(0);
+  if (card_index < 0)
+    return card_index;
+
   return 0;
 }