Merge pull request #3563 from mulkieran/metadata-to-vec

Do not construct a String from metadata when saving

src/engine/strat_engine/pool.rs

@@ -324,8 +324,8 @@ impl StratPool {
     /// Write current metadata to pool members.
     #[pool_mutating_action("NoPoolChanges")]
     pub fn write_metadata(&mut self, name: &str) -> StratisResult<()> {
-        let data = serde_json::to_string(&self.record(name))?;
-        self.backstore.save_state(data.as_bytes())
+        let data = serde_json::to_vec(&self.record(name))?;
+        self.backstore.save_state(&data)
     }
 
     /// Teardown a pool.
@@ -433,10 +433,8 @@ impl StratPool {
         self.thin_pool.teardown(pool_uuid)?;
         let mut data = self.record(pool_name);
         data.started = Some(false);
-        let json = serde_json::to_string(&data).map_err(|e| (StratisError::from(e), false))?;
-        self.backstore
-            .save_state(json.as_bytes())
-            .map_err(|e| (e, false))?;
+        let json = serde_json::to_vec(&data).map_err(|e| (StratisError::from(e), false))?;
+        self.backstore.save_state(&json).map_err(|e| (e, false))?;
         self.backstore.teardown(pool_uuid).map_err(|e| (e, false))?;
         let bds = self.backstore.drain_bds();
         Ok(DeviceSet::from(bds))

src/engine/strat_engine/thinpool/mdv.rs

@@ -110,7 +110,7 @@ impl MetadataVol {
         uuid: FilesystemUuid,
         fs: &StratFilesystem,
     ) -> StratisResult<()> {
-        let data = serde_json::to_string(&fs.record(name, uuid))?;
+        let data = serde_json::to_vec(&fs.record(name, uuid))?;
         let path = self
             .mount_pt
             .join(FILESYSTEM_DIR)
@@ -125,7 +125,7 @@ impl MetadataVol {
                 .create(true)
                 .open(&temp_path)?;
 
-            mdv_record_file.write_all(data.as_bytes())?;
+            mdv_record_file.write_all(&data)?;
             // This ultimately results in an fsync() on the file.
             mdv_record_file.sync_all()?;
         }