Filesystem: Wait for unmount() to finish

1 files changed, 41 insertions, 8 deletions

diff --git a/cpukit/libcsupport/src/unmount.c b/cpukit/libcsupport/src/unmount.c
index b58955d33c..ad45220fd5 100644
--- a/cpukit/libcsupport/src/unmount.c
+++ b/cpukit/libcsupport/src/unmount.c
@@ -22,6 +22,18 @@
 
 #include <rtems/libio_.h>
 
+static bool contains_root_or_current_directory(
+  const rtems_filesystem_mount_table_entry_t *mt_entry
+)
+{
+  const rtems_filesystem_location_info_t *root =
+    &rtems_filesystem_root->location;
+  const rtems_filesystem_location_info_t *current =
+    &rtems_filesystem_current->location;
+
+  return mt_entry == root->mt_entry || mt_entry == current->mt_entry;
+}
+
 int unmount( const char *path )
 {
   int rv = 0;
@@ -32,16 +44,23 @@ int unmount( const char *path )
   rtems_filesystem_mount_table_entry_t *mt_entry = currentloc->mt_entry;
 
   if ( rtems_filesystem_location_is_root( currentloc ) ) {
-    const rtems_filesystem_operations_table *mt_point_ops =
-      mt_entry->mt_point_node->location.mt_entry->ops;
+    if ( !contains_root_or_current_directory( mt_entry ) ) {
+      const rtems_filesystem_operations_table *mt_point_ops =
+        mt_entry->mt_point_node->location.mt_entry->ops;
 
-    rv = (*mt_point_ops->unmount_h)( mt_entry );
-    if ( rv == 0 ) {
-      rtems_filesystem_mt_entry_declare_lock_context( lock_context );
+      rv = (*mt_point_ops->unmount_h)( mt_entry );
+      if ( rv == 0 ) {
+        rtems_id self_task_id = rtems_task_self();
+        rtems_filesystem_mt_entry_declare_lock_context( lock_context );
 
-      rtems_filesystem_mt_entry_lock( lock_context );
-      mt_entry->mounted = false;
-      rtems_filesystem_mt_entry_unlock( lock_context );
+        rtems_filesystem_mt_entry_lock( lock_context );
+        mt_entry->unmount_task = self_task_id;
+        mt_entry->mounted = false;
+        rtems_filesystem_mt_entry_unlock( lock_context );
+      }
+    } else {
+      errno = EBUSY;
+      rv = -1;
     }
   } else {
     errno = EACCES;
@@ -50,5 +69,19 @@ int unmount( const char *path )
 
   rtems_filesystem_eval_path_cleanup( &ctx );
 
+  if ( rv == 0 ) {
+    rtems_event_set out;
+    rtems_status_code sc = rtems_event_receive(
+      RTEMS_FILESYSTEM_UNMOUNT_EVENT,
+      RTEMS_EVENT_ALL | RTEMS_WAIT,
+      RTEMS_NO_TIMEOUT,
+      &out
+    );
+
+    if ( sc != RTEMS_SUCCESSFUL ) {
+      rtems_fatal_error_occurred( 0xdeadbeef );
+    }
+  }
+
   return rv;
 }