Merge branch 'improve-mount-reference-count' into 'develop-BA-FS26'

Increase reference count of source_mount when one of its files is mounted somewhere

See merge request teachos/kernel!42

1 files changed, 15 insertions, 1 deletions

diff --git a/kernel/src/filesystem/mount_table.cpp b/kernel/src/filesystem/mount_table.cpp
index 26828b4..af8434b 100644
--- a/kernel/src/filesystem/mount_table.cpp
+++ b/kernel/src/filesystem/mount_table.cpp
@@ -22,6 +22,11 @@ namespace kernel::filesystem
   {
     m_mounts.push_back(mount);
 
+    if (auto source_mount = mount->source_mount())
+    {
+      source_mount->increment_ref_count();
+    }
+
     if (auto mount_dentry = mount->mount_dentry())
     {
       mount_dentry->set_flag(dentry::dentry_flags::is_mount_point);
@@ -46,7 +51,16 @@ namespace kernel::filesystem
       return operation_result::has_child_mounts;
     }
 
-    mount->mount_dentry()->unset_flag(dentry::dentry_flags::is_mount_point);
+    if (auto source_mount = mount->source_mount())
+    {
+      source_mount->decrement_ref_count();
+    }
+
+    if (auto mount_dentry = mount->mount_dentry())
+    {
+      mount_dentry->unset_flag(dentry::dentry_flags::is_mount_point);
+    }
+
     m_mounts.erase(mount_it);
     return operation_result::removed;
   }