BUG/MEDIUM: mux-fcgi: Fix locking of idle_conns lock in the FCGI I/O callback

When the commit e388f2fbc ("MEDIUM: muxes: mark idle conns tasklets with
TASK_F_USR1") was backported (commit id b360bb88 on the 2.3), a call to
HA_SPIN_UNLOCK() was missed and not moved in the right code block. Thus it
is possible to unlock the idle_conns lock while it was never acquired.

This patch should fix the issue #1191. It is 2.3 specific, thus there is no
upstream commid id. No backport is needed except if commit b360bb88 is
backported.

diff --git a/src/mux_fcgi.c b/src/mux_fcgi.c
index 08dde23..5f3989a 100644 (file)
--- a/src/mux_fcgi.c
+++ b/src/mux_fcgi.c
@@ -2957,13 +2957,14 @@ struct task *fcgi_io_cb(struct task *t, void *ctx, unsigned short status)
                conn_in_list = conn->flags & CO_FL_LIST_MASK;
                if (conn_in_list)
                        MT_LIST_DEL(&conn->list);
+
+               HA_SPIN_UNLOCK(OTHER_LOCK, &idle_conns[tid].takeover_lock);
        } else {
                /* we're certain the connection was not in an idle list */
                conn = fconn->conn;
                TRACE_ENTER(FCGI_EV_FCONN_WAKE, conn);
                conn_in_list = 0;
        }
-       HA_SPIN_UNLOCK(OTHER_LOCK, &idle_conns[tid].takeover_lock);
 
        if (!(fconn->wait_event.events & SUB_RETRY_SEND))
                ret = fcgi_send(fconn);