Kernel/LibC: Implement fsync

kernel/kernel/FS/Ext2/FileSystem.cpp

@@ -346,6 +346,17 @@ namespace Kernel
 		return {};
 	}
 
+	BAN::ErrorOr<void> Ext2FS::sync_block(uint32_t block)
+	{
+		LockGuard _(m_mutex);
+
+		const uint32_t sector_size = m_block_device->blksize();
+		const uint32_t block_size = this->block_size();
+		const uint32_t sectors_per_block = block_size / sector_size;
+
+		return m_block_device->sync_blocks(block * sectors_per_block, sectors_per_block);
+	}
+
 	Ext2FS::BlockBufferWrapper Ext2FS::get_block_buffer()
 	{
 		LockGuard _(m_mutex);

kernel/kernel/FS/Ext2/Inode.cpp

@@ -259,6 +259,14 @@ namespace Kernel
 		return {};
 	}
 
+	BAN::ErrorOr<void> Ext2Inode::fsync_impl()
+	{
+		for (size_t i = 0; i < max_used_data_block_count(); i++)
+			if (const auto fs_block = TRY(fs_block_of_data_block_index(i)); fs_block.has_value())
+				TRY(m_fs.sync_block(fs_block.value()));
+		return {};
+	}
+
 	BAN::ErrorOr<void> Ext2Inode::cleanup_indirect_block(uint32_t block, uint32_t depth)
 	{
 		ASSERT(block);

kernel/kernel/FS/Inode.cpp

@@ -1,5 +1,6 @@
 #include <kernel/FS/Inode.h>
 #include <kernel/Lock/LockGuard.h>
+#include <kernel/Memory/FileBackedRegion.h>
 
 #include <fcntl.h>
 
@@ -203,6 +204,15 @@ namespace Kernel
 		return chown_impl(uid, gid);
 	}
 
+	BAN::ErrorOr<void> Inode::fsync()
+	{
+		LockGuard _(m_mutex);
+		if (auto shared = m_shared_region.lock())
+			for (size_t i = 0; i < shared->pages.size(); i++)
+				shared->sync(i);
+		return fsync_impl();
+	}
+
 	bool Inode::can_read() const
 	{
 		LockGuard _(m_mutex);