add mut version marker trait

Signed-off-by: Yuchen Liang <yuchen@neon.tech>

pageserver/src/virtual_file.rs

@@ -52,6 +52,7 @@ pub(crate) mod owned_buffers_io {
     //! but for the time being we're proving out the primitives in the neon.git repo
     //! for faster iteration.
 
+    pub(crate) mod io_buf_aligned;
     pub(crate) mod io_buf_ext;
     pub(crate) mod slice;
     pub(crate) mod write;

pageserver/src/virtual_file/owned_buffers_io/io_buf_aligned.rs

@@ -0,0 +1,7 @@
+use tokio_epoll_uring::IoBufMut;
+
+use crate::virtual_file::dio::IoBufferMut;
+
+pub(crate) trait IoBufAlignedMut: IoBufMut {}
+
+impl IoBufAlignedMut for IoBufferMut {}