Merge pull request #2868 from mulkieran/cache-used-value

Get cached used value for filesystem in check()

src/engine/strat_engine/thinpool/filesystem.rs

@@ -243,7 +243,7 @@ impl StratFilesystem {
         let mut needs_save = false;
         let original_state = self.cached(|fs| StratFilesystemState {
             size: fs.size(),
-            used: fs.used().ok(),
+            used: fs.used,
         });
         match self.thin_dev.status(get_dm(), DmOptions::default())? {
             ThinStatus::Working(_) => {