Make DiskFile, CompositeDisk Debug

Making DiskFile Debug allows placing it inside the QcowFile.

TEST=Compiles
BUG=b:140069322
Change-Id: Idf20b7909146b0c2a60d864da386e362e8be97a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1982828
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Cody Schuffelen <schuffelen@google.com>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>

disk/src/composite.rs

@@ -49,6 +49,7 @@ impl Display for Error {
 
 pub type Result<T> = std::result::Result<T, Error>;
 
+#[derive(Debug)]
 struct ComponentDiskPart {
     file: Box<dyn DiskFile>,
     offset: u64,
@@ -65,6 +66,7 @@ impl ComponentDiskPart {
 /// disk by a protocol buffer file that lists out the component file locations and their offsets
 /// and lengths on the virtual disk. The spaces covered by the component disks must be contiguous
 /// and not overlapping.
+#[derive(Debug)]
 pub struct CompositeDiskFile {
     component_disks: Vec<ComponentDiskPart>,
 }

disk/src/disk.rs

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 use std::cmp::min;
-use std::fmt::{self, Display};
+use std::fmt::{self, Debug, Display};
 use std::fs::File;
 use std::io::{self, Read, Seek, SeekFrom, Write};
 
@@ -66,6 +66,7 @@ pub trait DiskFile:
     + WriteZeroesAt
     + Send
     + AsRawFds
+    + Debug
 {
 }
 impl<
@@ -76,7 +77,8 @@ impl<
             + FileReadWriteAtVolatile
             + WriteZeroesAt
             + Send
-            + AsRawFds,
+            + AsRawFds
+            + Debug,
     > DiskFile for D
 {
 }