From 65dd9d5ad3024d843c47073175546a509e12b336 Mon Sep 17 00:00:00 2001
From: Liav A <liavalb@gmail.com>
Date: Mon, 6 Apr 2020 16:50:24 +0300
Subject: [PATCH] Kernel: Ensure we flush the entire ext2 superblock

---
 Kernel/FileSystem/Ext2FileSystem.cpp       |  6 ++++--
 Kernel/FileSystem/FileBackedFileSystem.cpp | 19 +++++++++++++++++++
 Kernel/FileSystem/FileBackedFileSystem.h   |  3 +++
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/Kernel/FileSystem/Ext2FileSystem.cpp b/Kernel/FileSystem/Ext2FileSystem.cpp
index 7b36144640..77a7d6bef9 100644
--- a/Kernel/FileSystem/Ext2FileSystem.cpp
+++ b/Kernel/FileSystem/Ext2FileSystem.cpp
@@ -81,7 +81,8 @@ Ext2FS::~Ext2FS()
 bool Ext2FS::flush_super_block()
 {
     LOCKER(m_lock);
-    bool success = raw_write(2, (const u8*)&m_super_block);
+    ASSERT((sizeof(ext2_super_block) % logical_block_size()) == 0);
+    bool success = raw_write_blocks(2, (sizeof(ext2_super_block) / logical_block_size()), (const u8*)&m_super_block);
     ASSERT(success);
     return true;
 }
@@ -96,7 +97,8 @@ const ext2_group_desc& Ext2FS::group_descriptor(GroupIndex group_index) const
 bool Ext2FS::initialize()
 {
     LOCKER(m_lock);
-    bool success = raw_read(2, (u8*)&m_super_block);
+    ASSERT((sizeof(ext2_super_block) % logical_block_size()) == 0);
+    bool success = raw_read_blocks(2, (sizeof(ext2_super_block) / logical_block_size()), (u8*)&m_super_block);
     ASSERT(success);
 
     auto& super_block = this->super_block();
diff --git a/Kernel/FileSystem/FileBackedFileSystem.cpp b/Kernel/FileSystem/FileBackedFileSystem.cpp
index a3d30b90c9..3ee5c09a51 100644
--- a/Kernel/FileSystem/FileBackedFileSystem.cpp
+++ b/Kernel/FileSystem/FileBackedFileSystem.cpp
@@ -168,6 +168,25 @@ bool FileBackedFS::raw_write(unsigned index, const u8* buffer)
     return true;
 }
 
+bool FileBackedFS::raw_read_blocks(unsigned index, size_t count, u8* buffer)
+{
+    for (unsigned block = index; block < (index + count); block++) {
+        if (!raw_read(block, buffer))
+            return false;
+        buffer += logical_block_size();
+    }
+    return true;
+}
+bool FileBackedFS::raw_write_blocks(unsigned index, size_t count, const u8* buffer)
+{
+    for (unsigned block = index; block < (index + count); block++) {
+        if (!raw_write(block, buffer))
+            return false;
+        buffer += logical_block_size();
+    }
+    return true;
+}
+
 bool FileBackedFS::write_blocks(unsigned index, unsigned count, const u8* data, FileDescription* description)
 {
     ASSERT(m_logical_block_size);
diff --git a/Kernel/FileSystem/FileBackedFileSystem.h b/Kernel/FileSystem/FileBackedFileSystem.h
index ac2fa9fca3..498a35595e 100644
--- a/Kernel/FileSystem/FileBackedFileSystem.h
+++ b/Kernel/FileSystem/FileBackedFileSystem.h
@@ -58,6 +58,9 @@ protected:
     bool raw_read(unsigned index, u8* buffer);
     bool raw_write(unsigned index, const u8* buffer);
 
+    bool raw_read_blocks(unsigned index, size_t count, u8* buffer);
+    bool raw_write_blocks(unsigned index, size_t count, const u8* buffer);
+
     bool write_block(unsigned index, const u8*, FileDescription* = nullptr);
     bool write_blocks(unsigned index, unsigned count, const u8*, FileDescription* = nullptr);