block: vhd: Remove legacy async_io::DiskFile impl from FixedVhdDiskSync

No remaining consumers after switching to DiskBackend::Next.

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

Author: weltling

block/src/fixed_vhd_sync.rs

@@ -7,9 +7,7 @@ use std::os::unix::io::{AsRawFd, RawFd};
 
 use vmm_sys_util::eventfd::EventFd;
 
-use crate::async_io::{
-    AsyncIo, AsyncIoError, AsyncIoResult, BorrowedDiskFd, DiskFile, DiskFileError, DiskFileResult,
-};
+use crate::async_io::{AsyncIo, AsyncIoError, AsyncIoResult, BorrowedDiskFd, DiskFileError};
 use crate::error::{BlockError, BlockErrorKind, BlockResult, ErrorOp};
 use crate::fixed_vhd::FixedVhd;
 use crate::raw_sync::RawFileSync;
@@ -26,33 +24,6 @@ impl FixedVhdDiskSync {
     }
 }
 
-impl DiskFile for FixedVhdDiskSync {
-    fn logical_size(&mut self) -> DiskFileResult<u64> {
-        Ok(self.0.logical_size().unwrap())
-    }
-
-    fn physical_size(&mut self) -> DiskFileResult<u64> {
-        self.0.physical_size().map_err(|e| {
-            let io_inner = match e {
-                crate::Error::GetFileMetadata(e) => e,
-                _ => unreachable!(),
-            };
-            DiskFileError::Size(io_inner)
-        })
-    }
-
-    fn new_async_io(&self, _ring_depth: u32) -> DiskFileResult<Box<dyn AsyncIo>> {
-        Ok(Box::new(
-            FixedVhdSync::new(self.0.as_raw_fd(), self.0.logical_size().unwrap())
-                .map_err(DiskFileError::NewAsyncIo)?,
-        ) as Box<dyn AsyncIo>)
-    }
-
-    fn fd(&mut self) -> BorrowedDiskFd<'_> {
-        BorrowedDiskFd::new(self.0.as_raw_fd())
-    }
-}
-
 impl disk_file::DiskSize for FixedVhdDiskSync {
     fn logical_size(&self) -> BlockResult<u64> {
         Ok(self.0.logical_size().unwrap())