add descriptions, some refactoring

1 files changed, 10 insertions, 2 deletions

diff --git a/kernel/src/filesystem/ext2/filesystem.cpp b/kernel/src/filesystem/ext2/filesystem.cpp
index d7c989c..7ee1072 100644
--- a/kernel/src/filesystem/ext2/filesystem.cpp
+++ b/kernel/src/filesystem/ext2/filesystem.cpp
@@ -36,6 +36,10 @@ namespace kernel::filesystem::ext2
     constexpr uint16_t S_IFREG = 0x8000;
     constexpr uint16_t S_IFDIR = 0x4000;
 
+    // Error codes
+    constexpr int INVALID_MAGIC_NUMBER = -1;
+    constexpr int INVALID_ROOT_INODE = -2;
+
     auto S_ISREG(uint16_t mode) -> bool
     {
       return (mode & S_IFMT) == S_IFREG;
@@ -55,7 +59,7 @@ namespace kernel::filesystem::ext2
 
     if (m_superblock.magic != MAGIC_NUMBER)
     {
-      return -1;
+      return INVALID_MAGIC_NUMBER;
     }
 
     auto const block_size = get_block_size();
@@ -70,7 +74,11 @@ namespace kernel::filesystem::ext2
                                               num_block_groups * sizeof(block_group_descriptor));
 
     m_root_inode = read_inode(ROOT_INODE_NUMBER);
-    // TODO BA-FS26 check if root inode is valid and is a directory ??
+
+    if (!m_root_inode || !m_root_inode->is_directory())
+    {
+      return INVALID_ROOT_INODE;
+    }
     return 0;
   }