block: Move raw format files into formats/raw/

Move raw format implementation into a structured directory layout:

  raw_disk.rs        -> formats/raw/mod.rs                (RawDisk)
  raw_sync.rs        -> formats/raw/worker/sync.rs        (RawSync)
  raw_async.rs       -> formats/raw/worker/async_uring.rs (RawAsync)
  raw_async_aio.rs   -> formats/raw/worker/async_aio.rs   (RawAio)
  raw_async_io_tests.rs -> formats/raw/worker/tests.rs

Update imports in fixed_vhd_sync.rs and fixed_vhd_async.rs to use
the new paths. Re-export formats::raw as raw_disk in lib.rs to
preserve the external API.

Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>

block/src/factory.rs

@@ -21,8 +21,8 @@ use crate::block_io_uring_is_supported;
 use crate::disk_file::AsyncFullDiskFile;
 use crate::error::{BlockError, BlockErrorKind, BlockResult};
 use crate::fixed_vhd_disk::VhdDisk;
+use crate::formats::raw::{RawBackend, RawDisk};
 use crate::qcow_disk::QcowDisk;
-use crate::raw_disk::{RawBackend, RawDisk};
 use crate::vhdx_sync::VhdxDisk;
 use crate::{
     ImageType, block_aio_is_supported, detect_image_type, open_disk_image, preallocate_disk,

block/src/fixed_vhd_async.rs

@@ -10,7 +10,7 @@ use vmm_sys_util::eventfd::EventFd;
 
 use crate::async_io::{AsyncIo, AsyncIoCompletion, AsyncIoError, AsyncIoOperation, AsyncIoResult};
 use crate::error::BlockResult;
-use crate::raw_async::RawAsync;
+use crate::formats::raw::worker::async_uring::RawAsync;
 
 pub struct FixedVhdAsync {
     raw_file_async: RawAsync,

block/src/fixed_vhd_sync.rs

@@ -9,7 +9,7 @@ use std::os::unix::io::RawFd;
 use vmm_sys_util::eventfd::EventFd;
 
 use crate::async_io::{AsyncIo, AsyncIoCompletion, AsyncIoError, AsyncIoOperation, AsyncIoResult};
-use crate::raw_sync::RawSync;
+use crate::formats::raw::worker::sync::RawSync;
 
 pub struct FixedVhdSync {
     raw_file_sync: RawSync,

block/src/formats/mod.rs

@@ -0,0 +1,10 @@
+// Copyright 2026 The Cloud Hypervisor Authors. All rights reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+
+//! Disk format implementations.
+//!
+//! Each format lives in its own submodule with a `DiskFile` wrapper,
+//! format specific internals, and sync/async I/O workers.
+
+pub mod raw;

block/src/formats/raw/mod.rs

@@ -2,6 +2,11 @@
 //
 // SPDX-License-Identifier: Apache-2.0 AND BSD-3-Clause
 
+//! Raw disk image format.
+//!
+//! Provides [`RawDisk`], the `DiskFile` wrapper for flat disk images
+//! with no metadata or copy on write layer.
+
 use std::fs::File;
 use std::io;
 use std::os::unix::fs::FileTypeExt;
@@ -9,14 +14,16 @@ use std::os::unix::io::AsRawFd;
 
 use log::warn;
 
+use self::worker::async_aio::RawAio;
+#[cfg(feature = "io_uring")]
+use self::worker::async_uring::RawAsync;
+use self::worker::sync::RawSync;
 use crate::async_io::{AsyncIo, BorrowedDiskFd, DiskFileError};
 use crate::error::{BlockError, BlockErrorKind, BlockResult};
-#[cfg(feature = "io_uring")]
-use crate::raw_async::RawAsync;
-use crate::raw_async_aio::RawAio;
-use crate::raw_sync::RawSync;
 use crate::{DiskTopology, disk_file, probe_sparse_support, query_device_size};
 
+pub(crate) mod worker;
+
 /// Selects which async I/O backend a `RawDisk` uses.
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum RawBackend {

block/src/formats/raw/worker/async_aio.rs

@@ -107,14 +107,14 @@ mod unit_tests {
     use vmm_sys_util::tempfile::TempFile;
 
     use super::*;
-    use crate::raw_async_io_tests;
+    use crate::raw_disk::worker::tests;
 
     #[test]
     fn test_punch_hole() {
         let temp_file = TempFile::new().unwrap();
         let mut file = temp_file.into_file();
         let mut async_io = RawAio::new(file.as_raw_fd(), 128).unwrap();
-        raw_async_io_tests::test_punch_hole(&mut async_io, &mut file);
+        tests::test_punch_hole(&mut async_io, &mut file);
     }
 
     #[test]
@@ -122,7 +122,7 @@ mod unit_tests {
         let temp_file = TempFile::new().unwrap();
         let mut file = temp_file.into_file();
         let mut async_io = RawAio::new(file.as_raw_fd(), 128).unwrap();
-        raw_async_io_tests::test_write_zeroes(&mut async_io, &mut file);
+        tests::test_write_zeroes(&mut async_io, &mut file);
     }
 
     #[test]
@@ -130,6 +130,6 @@ mod unit_tests {
         let temp_file = TempFile::new().unwrap();
         let mut file = temp_file.into_file();
         let mut async_io = RawAio::new(file.as_raw_fd(), 128).unwrap();
-        raw_async_io_tests::test_punch_hole_multiple_operations(&mut async_io, &mut file);
+        tests::test_punch_hole_multiple_operations(&mut async_io, &mut file);
     }
 }

block/src/formats/raw/worker/mod.rs

@@ -0,0 +1,15 @@
+// Copyright 2026 The Cloud Hypervisor Authors. All rights reserved.
+//
+// SPDX-License-Identifier: Apache-2.0
+
+//! Sync/async I/O workers for raw images.
+//!
+//! Each backend implements the [`AsyncIo`](crate::async_io::AsyncIo)
+//! trait.
+
+pub(crate) mod async_aio;
+#[cfg(feature = "io_uring")]
+pub(crate) mod async_uring;
+pub(crate) mod sync;
+#[cfg(test)]
+pub(crate) mod tests;

block/src/formats/raw/worker/sync.rs

@@ -135,14 +135,14 @@ mod unit_tests {
     use vmm_sys_util::tempfile::TempFile;
 
     use super::*;
-    use crate::raw_async_io_tests;
+    use crate::raw_disk::worker::tests;
 
     #[test]
     fn test_punch_hole() {
         let temp_file = TempFile::new().unwrap();
         let mut file = temp_file.into_file();
         let mut async_io = RawSync::new(file.as_raw_fd());
-        raw_async_io_tests::test_punch_hole(&mut async_io, &mut file);
+        tests::test_punch_hole(&mut async_io, &mut file);
     }
 
     #[test]
@@ -150,7 +150,7 @@ mod unit_tests {
         let temp_file = TempFile::new().unwrap();
         let mut file = temp_file.into_file();
         let mut async_io = RawSync::new(file.as_raw_fd());
-        raw_async_io_tests::test_write_zeroes(&mut async_io, &mut file);
+        tests::test_write_zeroes(&mut async_io, &mut file);
     }
 
     #[test]
@@ -158,6 +158,6 @@ mod unit_tests {
         let temp_file = TempFile::new().unwrap();
         let mut file = temp_file.into_file();
         let mut async_io = RawSync::new(file.as_raw_fd());
-        raw_async_io_tests::test_punch_hole_multiple_operations(&mut async_io, &mut file);
+        tests::test_punch_hole_multiple_operations(&mut async_io, &mut file);
     }
 }

block/src/lib.rs

@@ -20,21 +20,15 @@ pub mod fixed_vhd;
 pub mod fixed_vhd_async;
 pub mod fixed_vhd_disk;
 pub mod fixed_vhd_sync;
+pub mod formats;
 pub mod qcow;
 #[cfg(feature = "io_uring")]
 pub(crate) mod qcow_async;
 pub(crate) mod qcow_common;
 pub mod qcow_disk;
 pub(crate) mod qcow_sync;
-#[cfg(feature = "io_uring")]
-pub(crate) mod raw_async;
-pub(crate) mod raw_async_aio;
-#[cfg(test)]
-mod raw_async_io_tests;
-pub mod raw_disk;
-pub(crate) mod raw_sync;
 mod sparse;
-pub use sparse::{BLKDISCARD, BLKZEROOUT};
+pub use formats::raw as raw_disk;
 pub mod vhd;
 pub mod vhdx;
 pub mod vhdx_sync;
@@ -58,6 +52,7 @@ use libc::{
 use log::{debug, info, warn};
 pub use request::{ExecuteAsync, MAX_DISCARD_WRITE_ZEROES_SEG, Request, RequestType};
 use serde::{Deserialize, Serialize};
+pub use sparse::{BLKDISCARD, BLKZEROOUT};
 use thiserror::Error;
 use virtio_bindings::virtio_blk::*;
 use vm_memory::bitmap::Bitmap;