base: delete PunchHoleMut trait

Was only needed for QcowFile, which can now use its internal mutex.

BUG=b:338274203

Change-Id: I995cf646a66909b9b146b9a7c0ff7d5a8348acd7
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/5507755
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Frederick Mayle <fmayle@google.com>

base/src/lib.rs

@@ -80,7 +80,6 @@ pub use wait_context::TriggeredEvent;
 pub use wait_context::WaitContext;
 pub use worker_thread::WorkerThread;
 pub use write_zeroes::PunchHole;
-pub use write_zeroes::PunchHoleMut;
 pub use write_zeroes::WriteZeroesAt;
 
 // TODO(b/233233301): reorganize platform specific exports under platform

base/src/write_zeroes.rs

@@ -19,18 +19,6 @@ impl PunchHole for File {
     }
 }
 
-/// A trait for deallocating space in a file of a mutable reference
-pub trait PunchHoleMut {
-    /// Replace a range of bytes with a hole.
-    fn punch_hole_mut(&mut self, offset: u64, length: u64) -> io::Result<()>;
-}
-
-impl<T: PunchHole> PunchHoleMut for T {
-    fn punch_hole_mut(&mut self, offset: u64, length: u64) -> io::Result<()> {
-        self.punch_hole(offset, length)
-    }
-}
-
 /// A trait for writing zeroes to an arbitrary position in a file.
 pub trait WriteZeroesAt {
     /// Write up to `length` bytes of zeroes starting at `offset`, returning how many bytes were

disk/src/asynchronous.rs

@@ -13,7 +13,7 @@ use base::AsRawDescriptors;
 use base::FileAllocate;
 use base::FileSetLen;
 use base::FileSync;
-use base::PunchHoleMut;
+use base::PunchHole;
 use base::RawDescriptor;
 use base::WriteZeroesAt;
 use cros_async::BackingMemory;
@@ -84,7 +84,7 @@ impl<
             + FileAllocate
             + FileSetLen
             + FileSync
-            + PunchHoleMut
+            + PunchHole
             + WriteZeroesAt,
     > AsyncDisk for AsyncDiskFileWrapper<T>
 {
@@ -186,9 +186,9 @@ impl<
         let inner_clone = self.inner.clone();
         self.blocking_pool
             .spawn(move || {
-                let mut disk_file = inner_clone.lock();
+                let disk_file = inner_clone.lock();
                 disk_file
-                    .punch_hole_mut(file_offset, length)
+                    .punch_hole(file_offset, length)
                     .map_err(Error::IoPunchHole)
             })
             .await

disk/src/qcow/mod.rs

@@ -27,7 +27,7 @@ use base::FileAllocate;
 use base::FileReadWriteAtVolatile;
 use base::FileSetLen;
 use base::FileSync;
-use base::PunchHoleMut;
+use base::PunchHole;
 use base::RawDescriptor;
 use base::VolatileMemory;
 use base::VolatileSlice;
@@ -1244,10 +1244,7 @@ impl QcowFileInner {
             // This cluster is no longer in use; deallocate the storage.
             // The underlying FS may not support FALLOC_FL_PUNCH_HOLE,
             // so don't treat an error as fatal.  Future reads will return zeros anyways.
-            let _ = self
-                .raw_file
-                .file_mut()
-                .punch_hole_mut(cluster_addr, cluster_size);
+            let _ = self.raw_file.file().punch_hole(cluster_addr, cluster_size);
             self.unref_clusters.push(cluster_addr);
         }
         Ok(())
@@ -1617,9 +1614,9 @@ impl FileAllocate for QcowFile {
     }
 }
 
-impl PunchHoleMut for QcowFile {
-    fn punch_hole_mut(&mut self, offset: u64, length: u64) -> std::io::Result<()> {
-        let inner = self.inner.get_mut();
+impl PunchHole for QcowFile {
+    fn punch_hole(&self, offset: u64, length: u64) -> std::io::Result<()> {
+        let mut inner = self.inner.lock();
         let mut remaining = length;
         let mut offset = offset;
         while remaining > 0 {
@@ -1634,7 +1631,7 @@ impl PunchHoleMut for QcowFile {
 
 impl WriteZeroesAt for QcowFile {
     fn write_zeroes_at(&mut self, offset: u64, length: usize) -> io::Result<usize> {
-        self.punch_hole_mut(offset, length as u64)?;
+        self.punch_hole(offset, length as u64)?;
         Ok(length)
     }
 }