From: Lukáš Ondráček <lukas.ondracek@nic.cz>
Date: Wed, 20 Nov 2024 23:59:47 +0000 (+0100)
Subject: daemon/defer: fix closing session with deferred EOF
X-Git-Tag: v6.0.10~6^2~34
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a4cbb25f85d24242e556a5eb5b55df583534666e;p=thirdparty%2Fknot-resolver.git

daemon/defer: fix closing session with deferred EOF
---

diff --git a/daemon/defer.c b/daemon/defer.c
index 3835bceb6..e4456dfe3 100644
--- a/daemon/defer.c
+++ b/daemon/defer.c
@@ -286,23 +286,30 @@ static inline struct protolayer_iter_ctx *pop_query(void)
 static inline void break_query(struct protolayer_iter_ctx *ctx, int err)
 {
 	if (ctx->session->stream) {
+		struct session2 *s = ctx->session;
 		struct pl_defer_sess_data *sdata = protolayer_sess_data_get_current(ctx);
+		s->ref_count++; // keep session and sdata alive for a while
 		waiting_requests_size -= sdata->size;
 		if (!ctx->session->closing) {
-			session2_force_close(ctx->session); // session is not freed here as iter contexts exist
+			session2_force_close(ctx->session);
 		}
-		queue_pop(sdata->queue);
-		while (queue_len(sdata->queue) > 0) {
-			struct pl_defer_iter_data *idata = protolayer_iter_data_get_current(ctx);
-			waiting_requests_size -= idata->size;
-			protolayer_break(ctx, kr_error(err)); // session is not freed here as other contexts exist
-			ctx = queue_head(sdata->queue);
+		kr_assert(ctx == queue_head(sdata->queue));
+		while (true) {
 			queue_pop(sdata->queue);
+			if (ctx) {
+				struct pl_defer_iter_data *idata = protolayer_iter_data_get_current(ctx);
+				waiting_requests_size -= idata->size;
+				protolayer_break(ctx, kr_error(err));
+			}
+			if (queue_len(sdata->queue) == 0) break;
+			ctx = queue_head(sdata->queue);
 		}
+		session2_unhandle(s); // decrease ref_count
+	} else {
+		struct pl_defer_iter_data *idata = protolayer_iter_data_get_current(ctx);
+		waiting_requests_size -= idata->size;
+		protolayer_break(ctx, kr_error(err));
 	}
-	struct pl_defer_iter_data *idata = protolayer_iter_data_get_current(ctx);
-	waiting_requests_size -= idata->size;
-	protolayer_break(ctx, kr_error(err));
 	kr_assert(waiting_requests ? waiting_requests_size > 0 : waiting_requests_size == 0);
 }
 
@@ -366,7 +373,7 @@ static inline void process_single_deferred(void)
 
 	if (eof) {
 		// Keep session alive even if it is somehow force-closed during continuation.
-		// TODO Is it needed?
+		// TODO Is it possible?
 		session->ref_count++;
 	}