sys_util: don't implement File*Volatile for SharedMemory

The implementations of FileReadWriteVolatile and FileReadWriteAtVolatile
for SharedMemory are never used; SharedMemory is typically accessed as a
memory mapping, not as a writable/readable file-like object.  Remove the
implementation of these traits for SharedMemory to simplify porting to
other platforms where SharedMemory may not necessarily be backed by a
file-like object.

BUG=None
TEST=./build_test.py

Change-Id: I9c1e46ad2d3299b8676fad33151cde7c4b1c7b8e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1937555
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>

1 files changed, 0 insertions, 4 deletions

diff --git a/sys_util/src/file_traits.rs b/sys_util/src/file_traits.rs
index 60ba050..7e615d6 100644
--- a/sys_util/src/file_traits.rs
+++ b/sys_util/src/file_traits.rs
@@ -8,8 +8,6 @@ use std::os::unix::io::{AsRawFd, RawFd};
 
 use data_model::VolatileSlice;
 
-use crate::SharedMemory;
-
 /// A trait for flushing the contents of a file to disk.
 /// This is equivalent to File's `sync_all` method, but
 /// wrapped in a trait so that it can be implemented for
@@ -489,8 +487,6 @@ macro_rules! volatile_at_impl {
 
 volatile_impl!(File);
 volatile_at_impl!(File);
-volatile_impl!(SharedMemory);
-volatile_at_impl!(SharedMemory);
 
 /// A trait similar to `AsRawFd` but supports an arbitrary number of file descriptors.
 pub trait AsRawFds {