Swap per_peer_state lock order

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index a2a3f912fe5e386fddb75711489819bec6c94209..78d77f121348bccfd8874584d86de06630b763c6 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -577,13 +577,13 @@ pub type SimpleRefChannelManager<'a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, M, T, F, L> = C
 //  |   |
 //  |   |__`pending_intercepted_htlcs`
 //  |
-//  |__`pending_inbound_payments`
+//  |__`per_peer_state`
 //  |   |
-//  |   |__`claimable_payments`
-//  |   |
-//  |   |__`pending_outbound_payments` // This field's struct contains a map of pending outbounds
+//  |   |__`pending_inbound_payments`
+//  |       |
+//  |       |__`claimable_payments`
 //  |       |
-//  |       |__`per_peer_state`
+//  |       |__`pending_outbound_payments` // This field's struct contains a map of pending outbounds
 //  |           |
 //  |           |__`peer_state`
 //  |               |
@@ -3570,9 +3570,12 @@ where
                        // Ensure that no peer state channel storage lock is not held when calling this
                        // function.
                        // This ensures that future code doesn't introduce a lock_order requirement for
-                       // `forward_htlcs` to be locked after the `per_peer_state` locks, which calling this
-                       // function with the `per_peer_state` aquired would.
-                       assert!(self.per_peer_state.try_write().is_ok());
+                       // `forward_htlcs` to be locked after the `per_peer_state` peer locks, which calling
+                       // this function with any `per_peer_state` peer lock aquired would.
+                       let per_peer_state = self.per_peer_state.read().unwrap();
+                       for (_, peer) in per_peer_state.iter() {
+                               assert!(peer.try_lock().is_ok());
+                       }
                }
 
                //TODO: There is a timing attack here where if a node fails an HTLC back to us they can
@@ -6739,6 +6742,8 @@ where
                        }
                }
 
+               let per_peer_state = self.per_peer_state.write().unwrap();
+
                let pending_inbound_payments = self.pending_inbound_payments.lock().unwrap();
                let claimable_payments = self.claimable_payments.lock().unwrap();
                let pending_outbound_payments = self.pending_outbound_payments.pending_outbound_payments.lock().unwrap();
@@ -6754,7 +6759,6 @@ where
                        htlc_purposes.push(purpose);
                }
 
-               let per_peer_state = self.per_peer_state.write().unwrap();
                (per_peer_state.len() as u64).write(writer)?;
                for (peer_pubkey, peer_state_mutex) in per_peer_state.iter() {
                        peer_pubkey.write(writer)?;