@@ -29,3 +29,3 @@
 - [Design](./design/index.md)
   - [Related Work](./design/related_work.md)
-  - [Internals](./design/internals.md)
+  - [Design draft](./design/design_draft.md)

@@ -255,0 +267,4 @@
+			// so in all cases we add the block here to the todo list
+			// to check later that it arrived correctly, and if not
+			// we will fecth it from someone.
+			self.put_to_resync(hash, 2 * BLOCK_RW_TIMEOUT)?;

@@ -271,0 +279,4 @@
+			.update_and_fetch(&hash, |old| RcEntry::parse_opt(old).decrement().serialize())?;
+		let new_rc = RcEntry::parse_opt(new_rc);
+		if let RcEntry::Deletable { .. } = new_rc {
+			self.put_to_resync(hash, BLOCK_GC_DELAY + Duration::from_secs(10))?;

@@ -301,3 +323,3 @@
 			Err(e) => {
 				// Not found but maybe we should have had it ??
-				self.put_to_resync(hash, Duration::from_millis(0))?;
+				self.put_to_resync(hash, 2 * BLOCK_RW_TIMEOUT)?;

@@ -681,1 +709,3 @@
-	u64::from_be_bytes(x8)
+/// Describes the state of the reference counter for a block
+#[derive(Clone, Copy, Debug)]
+enum RcEntry {

@@ -682,0 +721,4 @@
+	/// This is stored as [0u8; 8] followed by u64::to_be_bytes(at_time),
+	/// (this allows for the data format to be backwards compatible with
+	/// previous Garage versions that didn't have this intermediate state)
+	Deletable { at_time: u64 },

@@ -55,3 +56,3 @@
 
 		let gc_todo = db
-			.open_tree(&format!("{}:gc_todo", name))
+			.open_tree(&format!("{}:gc_todo_v2", name))

@@ -100,3 +125,3 @@
 			let vhash = Hash::try_from(&vhash[..]).unwrap();
 
-			let v_opt = self
+			// Check if the tombstone is still the current value of the entry.

@@ -172,3 +222,4 @@
 	) -> Result<(), Error> {
 		let n_items = items.len();
 
+		// Strategy: we first send all of the values to the remote nodes,

@@ -251,0 +324,4 @@
+/// such entry in Sled
+///
+/// Format of an entry:
+/// - key =    8 bytes: timestamp of tombstone