Kernel: Remove the big inode lock

This moves locking to the inodes themselves which allows reducing lock
times significantly. Main inodes (ext2 and tmpfs) still do contain a
single big mutex that gets locked during operations but now we have the
architecture to optimize these.

kernel/kernel/FS/Pipe.cpp

@@ -73,6 +73,8 @@ namespace Kernel
 
 	BAN::ErrorOr<size_t> Pipe::read_impl(off_t, BAN::ByteSpan buffer)
 	{
+		LockGuard _(m_mutex);
+
 		while (m_buffer->empty())
 		{
 			if (m_writing_count == 0)
@@ -95,6 +97,8 @@ namespace Kernel
 
 	BAN::ErrorOr<size_t> Pipe::write_impl(off_t, BAN::ConstByteSpan buffer)
 	{
+		LockGuard _(m_mutex);
+
 		while (m_buffer->full())
 		{
 			if (m_reading_count == 0)