From: Willy Tarreau <w@1wt.eu>
Date: Thu, 31 Oct 2019 14:36:30 +0000 (+0100)
Subject: BUG/MEDIUM: mux-h2: immediately remove a failed connection from the idle list
X-Git-Tag: v2.1-dev4~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4481e26e5dd2bc04df494c3f176aa5ceea3d63d5;p=thirdparty%2Fhaproxy.git

BUG/MEDIUM: mux-h2: immediately remove a failed connection from the idle list

If a connection faces an error or a timeout, it must be removed from its
idle list ASAP. We certainly don't want to risk sending new streams on
it.

This should be backported to 2.0 (replacing MT_LIST_DEL with LIST_DEL_LOCKED)
and 1.9 (there's no lock there, the idle lists are per-thread and per-server
however a LIST_DEL_INIT will be needed).
---

diff --git a/src/mux_h2.c b/src/mux_h2.c
index 22bf42919b..c9b805bb3c 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -3626,6 +3626,17 @@ static int h2_process(struct h2c *h2c)
 			TRACE_DEVEL("leaving after releasing the connection", H2_EV_H2C_WAKE);
 			return -1;
 		}
+
+		/* connections in error must be removed from the idle lists */
+		HA_SPIN_LOCK(OTHER_LOCK, &toremove_lock[tid]);
+		MT_LIST_DEL((struct mt_list *)&conn->list);
+		HA_SPIN_UNLOCK(OTHER_LOCK, &toremove_lock[tid]);
+	}
+	else if (h2c->st0 == H2_CS_ERROR) {
+		/* connections in error must be removed from the idle lists */
+		HA_SPIN_LOCK(OTHER_LOCK, &toremove_lock[tid]);
+		MT_LIST_DEL((struct mt_list *)&conn->list);
+		HA_SPIN_UNLOCK(OTHER_LOCK, &toremove_lock[tid]);
 	}
 
 	if (!b_data(&h2c->dbuf))
@@ -3733,6 +3744,11 @@ static struct task *h2_timeout_task(struct task *t, void *context, unsigned shor
 			offer_buffers(NULL, tasks_run_queue);
 	}
 
+	/* in any case this connection must not be considered idle anymore */
+	HA_SPIN_LOCK(OTHER_LOCK, &toremove_lock[tid]);
+	MT_LIST_DEL((struct mt_list *)&h2c->conn->list);
+	HA_SPIN_UNLOCK(OTHER_LOCK, &toremove_lock[tid]);
+
 	/* either we can release everything now or it will be done later once
 	 * the last stream closes.
 	 */