lib, ipcpd: Fix bad locking

Some locks were taken at an inappropriate time, causing the
shim-eth-llc to block indefinitely upon shutdown and causing flow
allocation to halt since a response could never be given.

2 files changed, 4 insertions, 7 deletions

diff --git a/src/ipcpd/shim-eth-llc/main.c b/src/ipcpd/shim-eth-llc/main.c
index 2cf46e51..7a64b9e1 100644
--- a/src/ipcpd/shim-eth-llc/main.c
+++ b/src/ipcpd/shim-eth-llc/main.c
@@ -575,14 +575,11 @@ static void * eth_llc_ipcp_sdu_writer(void * o)
                 uint8_t dsap;
                 uint8_t r_addr[MAC_SIZE];
 
-                pthread_rwlock_rdlock(&ipcpi.state_lock);
-
                 fd = ipcp_flow_read(&sdb);
-                if (fd < 0) {
-                        pthread_rwlock_unlock(&ipcpi.state_lock);
+                if (fd < 0)
                         continue;
-                }
 
+                pthread_rwlock_rdlock(&ipcpi.state_lock);
                 pthread_rwlock_rdlock(&eth_llc_data.flows_lock);
 
                 ssap = reverse_bits(eth_llc_data.fd_to_ef[fd].sap);
diff --git a/src/lib/dev.c b/src/lib/dev.c
index 178ee287..8e1ee342 100644
--- a/src/lib/dev.c
+++ b/src/lib/dev.c
@@ -889,11 +889,11 @@ int np1_flow_resp(pid_t n_api, int port_id)
         int fd;
         struct shm_ap_rbuff * rb;
 
+        port_wait_assign(&ai.ports[port_id]);
+
         pthread_rwlock_rdlock(&ai.data_lock);
         pthread_rwlock_wrlock(&ai.flows_lock);
 
-        port_wait_assign(&ai.ports[port_id]);
-
         fd = ai.ports[port_id].fd;
         if (fd < 0) {
                 pthread_rwlock_unlock(&ai.flows_lock);