From: Willy Tarreau <w@1wt.eu>
Date: Fri, 21 Feb 2020 08:44:39 +0000 (+0100)
Subject: BUG/MINOR: mux: do not call conn_xprt_stop_recv() on buffer shortage
X-Git-Tag: v2.2-dev3~47
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d57e34978db7482ebdb0557f2908a033c40394c2;p=thirdparty%2Fhaproxy.git

BUG/MINOR: mux: do not call conn_xprt_stop_recv() on buffer shortage

In H1/H2/FCGI, the *_get_buf() functions try to disable receipt of data
when there's no buffer available. But they do so at the lowest possible
level, which is unrelated to the upper transport layers which may still
be trying to feed data based on subscription. The correct approach here
would theorically be to only disable subscription, though when we get
there, the subscription will already have been dropped, so we can safely
just remove that call.

It's unlikely that this could have had any practical impact, as the upper
xprt layer would call this callback which would fail an not resubscribe.
Having the lowest layer disabled would just be temporary since when
re-enabling reading, a subscribe at the end of data would re-enable it.

Backport should not harm but seems useless at this point.
---

diff --git a/src/mux_fcgi.c b/src/mux_fcgi.c
index 27f5edce0c..bfe44017ef 100644
--- a/src/mux_fcgi.c
+++ b/src/mux_fcgi.c
@@ -608,7 +608,6 @@ static inline struct buffer *fcgi_get_buf(struct fcgi_conn *fconn, struct buffer
 		HA_SPIN_LOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 		LIST_ADDQ(&buffer_wq, &fconn->buf_wait.list);
 		HA_SPIN_UNLOCK(BUF_WQ_LOCK, &buffer_wq_lock);
-		__conn_xprt_stop_recv(fconn->conn);
 	}
 	return buf;
 }
diff --git a/src/mux_h1.c b/src/mux_h1.c
index dcba3dfb8b..f175ac9bce 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -422,7 +422,6 @@ static inline struct buffer *h1_get_buf(struct h1c *h1c, struct buffer *bptr)
 		HA_SPIN_LOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 		LIST_ADDQ(&buffer_wq, &h1c->buf_wait.list);
 		HA_SPIN_UNLOCK(BUF_WQ_LOCK, &buffer_wq_lock);
-		__conn_xprt_stop_recv(h1c->conn);
 	}
 	return buf;
 }
diff --git a/src/mux_h2.c b/src/mux_h2.c
index d726944a32..a73ab0538a 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -686,7 +686,6 @@ static inline struct buffer *h2_get_buf(struct h2c *h2c, struct buffer *bptr)
 		HA_SPIN_LOCK(BUF_WQ_LOCK, &buffer_wq_lock);
 		LIST_ADDQ(&buffer_wq, &h2c->buf_wait.list);
 		HA_SPIN_UNLOCK(BUF_WQ_LOCK, &buffer_wq_lock);
-		__conn_xprt_stop_recv(h2c->conn);
 	}
 	return buf;
 }