log: Log a warning for each service that still has processes at shutdown

This makes it clearer which services are causing log process to hang, and
also which processes may have their logging discarded afterwards.

diff --git a/src/log/log-connection.c b/src/log/log-connection.c
index b300a87ee9d79867d333b1ac0c4aa38b72c944aa..e687705e5a1da95cdfe7a25e90800dcdf2762ce8 100644 (file)
--- a/src/log/log-connection.c
+++ b/src/log/log-connection.c
@@ -54,7 +54,8 @@ static ARRAY(struct log_connection *) logs_by_fd;
 static unsigned int global_pending_count;
 static struct log_connection *last_pending_log;
 
-static void log_connection_destroy(struct log_connection *log);
+static void
+log_connection_destroy(struct log_connection *log, bool shutting_down);
 
 static void log_refresh_proctitle(void)
 {
@@ -337,7 +338,7 @@ static void log_connection_input(struct log_connection *log)
 
        if (!log->handshaked) {
                if (log_connection_handshake(log) < 0) {
-                       log_connection_destroy(log);
+                       log_connection_destroy(log, FALSE);
                        return;
                }
                /* come back here even if we read something else besides a
@@ -364,7 +365,7 @@ static void log_connection_input(struct log_connection *log)
        if (log->input->eof) {
                if (log->input->stream_errno != 0)
                        i_error("read(log %s) failed: %m", log->default_prefix);
-               log_connection_destroy(log);
+               log_connection_destroy(log, FALSE);
        } else {
                i_assert(!log->input->closed);
                if (!too_much) {
@@ -410,22 +411,31 @@ void log_connection_create(struct log_error_buffer *errorbuf,
        log_connection_input(log);
 }
 
-static void log_connection_destroy(struct log_connection *log)
+static void
+log_connection_destroy(struct log_connection *log, bool shutting_down)
 {
        struct hash_iterate_context *iter;
        void *key;
        struct log_client *client;
+       unsigned int client_count = 0;
 
        array_idx_clear(&logs_by_fd, log->listen_fd);
 
        DLLIST_REMOVE(&log_connections, log);
 
        iter = hash_table_iterate_init(log->clients);
-       while (hash_table_iterate(iter, log->clients, &key, &client))
+       while (hash_table_iterate(iter, log->clients, &key, &client)) {
                i_free(client);
+               client_count++;
+       }
        hash_table_iterate_deinit(&iter);
        hash_table_destroy(&log->clients);
 
+       if (client_count > 0 && shutting_down) {
+               i_warning("Shutting down logging for '%s' with %u clients",
+                         log->default_prefix, client_count);
+       }
+
        i_stream_unref(&log->input);
        if (log->io != NULL)
                io_remove(&log->io);
@@ -447,6 +457,6 @@ void log_connections_deinit(void)
        /* normally we don't exit until all log connections are gone,
           but we could get here when we're being killed by a signal */
        while (log_connections != NULL)
-               log_connection_destroy(log_connections);
+               log_connection_destroy(log_connections, TRUE);
        array_free(&logs_by_fd);
 }