Add blocks in errored state to `garage stats`

src/block/manager.rs

@@ -265,6 +265,11 @@ impl BlockManager {
 		self.resync_queue.len()
 	}
 
+	/// Get number of blocks that have an error
+	pub fn resync_errors_len(&self) -> usize {
+		self.resync_errors.len()
+	}
+
 	/// Get number of items in the refcount table
 	pub fn rc_len(&self) -> usize {
 		self.rc.rc.len()

src/garage/admin.rs

@@ -728,6 +728,12 @@ impl AdminRpcHandler {
 			self.garage.block_manager.resync_queue_len()
 		)
 		.unwrap();
+		writeln!(
+			&mut ret,
+			"  blocks with resync errors: {}",
+			self.garage.block_manager.resync_errors_len()
+		)
+		.unwrap();
 
 		ret
 	}