From 33138900de506f3c71803b084272d0422c75ae43 Mon Sep 17 00:00:00 2001
From: Itamar <itamar8910@gmail.com>
Date: Sat, 29 Aug 2020 21:25:01 +0300
Subject: [PATCH] FileSystem: Convert file types to DT_* types at a later stage

A change introduced in 5e01234 made it the resposibility of each
filesystem to have the file types returned from
'traverse_as_directory' match up with the DT_* types.
However, this caused corruption of the Ext2FS file format because
the Ext2FS uses 'traverse_as_directory' internally when manipulating
 the file system. The result was a mixture between EXT2_FT_* and DT_*
file types in the internal Ext2FS structures.

Starting with this commit, the conversion from internal filesystem file
types to the user facing DT_* types happens at a later stage,
in the 'FileDescription::get_dir_entries' function which is directly
used by sys$get_dir_entries.
---
 Kernel/FileSystem/Ext2FileSystem.cpp  | 6 +++---
 Kernel/FileSystem/Ext2FileSystem.h    | 2 ++
 Kernel/FileSystem/FileDescription.cpp | 4 ++--
 Kernel/FileSystem/FileSystem.h        | 5 ++++-
 4 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/Kernel/FileSystem/Ext2FileSystem.cpp b/Kernel/FileSystem/Ext2FileSystem.cpp
index e18e8049c7..2d93e734fe 100644
--- a/Kernel/FileSystem/Ext2FileSystem.cpp
+++ b/Kernel/FileSystem/Ext2FileSystem.cpp
@@ -855,7 +855,7 @@ ssize_t Ext2FSInode::write_bytes(off_t offset, ssize_t count, const u8* data, Fi
     return nwritten;
 }
 
-u8 Ext2FSInode::file_type_for_directory_entry(const ext2_dir_entry_2& entry)
+u8 Ext2FS::internal_file_type_to_directory_entry_type(const DirectoryEntryView& entry) const
 {
     switch (entry.file_type) {
     case EXT2_FT_REG_FILE:
@@ -869,7 +869,7 @@ u8 Ext2FSInode::file_type_for_directory_entry(const ext2_dir_entry_2& entry)
     case EXT2_FT_FIFO:
         return DT_FIFO;
     case EXT2_FT_SOCK:
-        return EXT2_FT_SOCK;
+        return DT_SOCK;
     case EXT2_FT_SYMLINK:
         return DT_LNK;
     default:
@@ -899,7 +899,7 @@ KResult Ext2FSInode::traverse_as_directory(Function<bool(const FS::DirectoryEntr
 #ifdef EXT2_DEBUG
             dbg() << "Ext2Inode::traverse_as_directory: " << entry->inode << ", name_len: " << entry->name_len << ", rec_len: " << entry->rec_len << ", file_type: " << entry->file_type << ", name: " << String(entry->name, entry->name_len);
 #endif
-            if (!callback({ { entry->name, entry->name_len }, { fsid(), entry->inode }, file_type_for_directory_entry(*entry) }))
+            if (!callback({ { entry->name, entry->name_len }, { fsid(), entry->inode }, entry->file_type }))
                 break;
         }
         entry = (ext2_dir_entry_2*)((char*)entry + entry->rec_len);
diff --git a/Kernel/FileSystem/Ext2FileSystem.h b/Kernel/FileSystem/Ext2FileSystem.h
index dee084813a..bdaa3255ca 100644
--- a/Kernel/FileSystem/Ext2FileSystem.h
+++ b/Kernel/FileSystem/Ext2FileSystem.h
@@ -110,6 +110,8 @@ public:
 
     virtual bool supports_watchers() const override { return true; }
 
+    virtual u8 internal_file_type_to_directory_entry_type(const DirectoryEntryView& entry) const override;
+
 private:
     typedef unsigned BlockIndex;
     typedef unsigned GroupIndex;
diff --git a/Kernel/FileSystem/FileDescription.cpp b/Kernel/FileSystem/FileDescription.cpp
index ce0ddd0715..09a286b215 100644
--- a/Kernel/FileSystem/FileDescription.cpp
+++ b/Kernel/FileSystem/FileDescription.cpp
@@ -188,9 +188,9 @@ ssize_t FileDescription::get_dir_entries(u8* buffer, ssize_t size)
 
     auto temp_buffer = ByteBuffer::create_uninitialized(size_to_allocate);
     BufferStream stream(temp_buffer);
-    KResult result = VFS::the().traverse_directory_inode(*m_inode, [&stream](auto& entry) {
+    KResult result = VFS::the().traverse_directory_inode(*m_inode, [&stream, this](auto& entry) {
         stream << (u32)entry.inode.index();
-        stream << (u8)entry.file_type;
+        stream << m_inode->fs().internal_file_type_to_directory_entry_type(entry);
         stream << (u32)entry.name.length();
         stream << entry.name;
         return true;
diff --git a/Kernel/FileSystem/FileSystem.h b/Kernel/FileSystem/FileSystem.h
index 0cdd6d2b5c..19fea4bafd 100644
--- a/Kernel/FileSystem/FileSystem.h
+++ b/Kernel/FileSystem/FileSystem.h
@@ -77,12 +77,15 @@ public:
         u8 file_type { 0 };
     };
 
-    virtual void flush_writes() { }
+    virtual void flush_writes() {}
 
     size_t block_size() const { return m_block_size; }
 
     virtual bool is_file_backed() const { return false; }
 
+    // Converts file types that are used internally by the filesystem to DT_* types
+    virtual u8 internal_file_type_to_directory_entry_type(const DirectoryEntryView& entry) const { return entry.file_type; }
+
 protected:
     FS();