block: rename DiskFile::size() -> DiskFile::logical_size()

This better reflects the actual usage.

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com

block/src/qcow/mod.rs

@@ -1808,7 +1808,7 @@ impl SeekHole for QcowFile {
 }
 
 impl BlockBackend for QcowFile {
-    fn size(&self) -> std::result::Result<u64, crate::Error> {
+    fn logical_size(&self) -> std::result::Result<u64, crate::Error> {
         Ok(self.virtual_size())
     }
 }

block/src/qcow/raw_file.rs

@@ -354,7 +354,7 @@ impl SeekHole for RawFile {
 }
 
 impl BlockBackend for RawFile {
-    fn size(&self) -> std::result::Result<u64, crate::Error> {
+    fn logical_size(&self) -> std::result::Result<u64, crate::Error> {
         Ok(self.metadata().map_err(crate::Error::RawFileError)?.len())
     }
 }