Merge pull request lightningdevkit#2591 from TheBlueMatt/2023-09-2562-followups

Doc and comment followups to lightningdevkit#2562

Author: tnull

lightning-persister/src/fs_store.rs

@@ -436,7 +436,7 @@ mod tests {
 	}
 
 	// Test that if the store's path to channel data is read-only, writing a
-	// monitor to it results in the store returning an InProgress.
+	// monitor to it results in the store returning an UnrecoverableError.
 	// Windows ignores the read-only flag for folders, so this test is Unix-only.
 	#[cfg(not(target_os = "windows"))]
 	#[test]
@@ -458,7 +458,7 @@ mod tests {
 		let update_id = update_map.get(&added_monitors[0].0.to_channel_id()).unwrap();
 
 		// Set the store's directory to read-only, which should result in
-		// returning a permanent failure when we then attempt to persist a
+		// returning an unrecoverable failure when we then attempt to persist a
 		// channel update.
 		let path = &store.get_data_dir();
 		let mut perms = fs::metadata(path).unwrap().permissions();

lightning/src/chain/chainmonitor.rs

@@ -98,7 +98,7 @@ impl MonitorUpdateId {
 ///    If at some point no further progress can be made towards persisting the pending updates, the
 ///    node should simply shut down.
 ///
-///  * If the persistence has failed and cannot be retried further (e.g. because of some timeout),
+///  * If the persistence has failed and cannot be retried further (e.g. because of an outage),
 ///    [`ChannelMonitorUpdateStatus::UnrecoverableError`] can be used, though this will result in
 ///    an immediate panic and future operations in LDK generally failing.
 ///
@@ -113,7 +113,10 @@ impl MonitorUpdateId {
 ///  [`ChainMonitor::channel_monitor_updated`] must be called once for *each* update which occurs.
 ///
 ///  If at some point no further progress can be made towards persisting a pending update, the node
-///  should simply shut down.
+///  should simply shut down. Until then, the background task should either loop indefinitely, or
+///  persistence should be regularly retried with [`ChainMonitor::list_pending_monitor_updates`]
+///  and [`ChainMonitor::get_monitor`] (note that if a full monitor is persisted all pending
+///  monitor updates may be marked completed).
 ///
 /// # Using remote watchtowers
 ///

lightning/src/ln/channelmanager.rs

@@ -3471,9 +3471,8 @@ where
 	/// In general, a path may raise:
 	///  * [`APIError::InvalidRoute`] when an invalid route or forwarding parameter (cltv_delta, fee,
 	///    node public key) is specified.
-	///  * [`APIError::ChannelUnavailable`] if the next-hop channel is not available for updates
-	///    (including due to previous monitor update failure or new permanent monitor update
-	///    failure).
+	///  * [`APIError::ChannelUnavailable`] if the next-hop channel is not available as it has been
+	///    closed, doesn't exist, or the peer is currently disconnected.
 	///  * [`APIError::MonitorUpdateInProgress`] if a new monitor update failure prevented sending the
 	///    relevant updates.
 	///

lightning/src/ln/shutdown_tests.rs

@@ -264,7 +264,7 @@ fn shutdown_on_unfunded_channel() {
 	nodes[0].node.create_channel(nodes[1].node.get_our_node_id(), 1_000_000, 100_000, 0, None).unwrap();
 	let open_chan = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
 
-	// P2WSH
+	// Create a dummy P2WPKH script
 	let script = Builder::new().push_int(0)
 		.push_slice(&[0; 20])
 		.into_script();