From 7d41fb3dc78576b2f3bef5f5afd458b614122fe7 Mon Sep 17 00:00:00 2001 From: Christopher Faulet Date: Thu, 23 Sep 2021 14:17:20 +0200 Subject: [PATCH] BUG/MEDIUM: stream-int: Notify stream that the mux wants more room to xfer data When the mux failed to transfer data to the upper layer because of a lack of room, it is important to wake the stream up to let it handle this event. Otherwise, if the stream is waiting for more data, both the stream and the mux reamin blocked waiting for each other. When this happens, the mux set the CS_FL_WANT_ROOM flag on the conn-stream. Thus, in si_cs_recv() we are able to detect this event. Today, the stream-interface is blocked. But, it is not enough to wake the stream up. To fix the bug, CF_READ_PARTIAL flag is extended to also handle cases where a read exception occurred. This flag should idealy be renamed. But for now, it is good enough. By setting this flag, we are sure the stream will be woken up. This patch is part of a series related to the issue #1362. It should be backported as far as 2.0, probably with some adaptations. So be careful during backports. (cherry picked from commit df99408e0d4e59cf54666772a4224a8665743fbd) Signed-off-by: Christopher Faulet (cherry picked from commit 47545caccaf4b429f4fd002062c66d2c2592abcd) Signed-off-by: Christopher Faulet --- include/haproxy/channel-t.h | 2 +- src/stream_interface.c | 7 ++++++- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/include/haproxy/channel-t.h b/include/haproxy/channel-t.h index 8bd06e1..0ac213a 100644 --- a/include/haproxy/channel-t.h +++ b/include/haproxy/channel-t.h @@ -52,7 +52,7 @@ */ #define CF_READ_NULL 0x00000001 /* last read detected on producer side */ -#define CF_READ_PARTIAL 0x00000002 /* some data were read from producer */ +#define CF_READ_PARTIAL 0x00000002 /* some data were read from producer or a read exception occurred */ #define CF_READ_TIMEOUT 0x00000004 /* timeout while waiting for producer */ #define CF_READ_ERROR 0x00000008 /* unrecoverable error on producer side */ #define CF_READ_ACTIVITY (CF_READ_NULL|CF_READ_PARTIAL|CF_READ_ERROR) diff --git a/src/stream_interface.c b/src/stream_interface.c index 69102f7..520d43d 100644 --- a/src/stream_interface.c +++ b/src/stream_interface.c @@ -1344,8 +1344,13 @@ int si_cs_recv(struct conn_stream *cs) flags |= ((!conn_is_back(conn) && (si_strm(si)->be->options & PR_O_ABRT_CLOSE)) ? CO_RFL_KEEP_RECV : 0); ret = cs->conn->mux->rcv_buf(cs, &ic->buf, max, flags | (co_data(ic) ? CO_RFL_BUF_WET : 0)); - if (cs->flags & CS_FL_WANT_ROOM) + if (cs->flags & CS_FL_WANT_ROOM) { si_rx_room_blk(si); + /* Add READ_PARTIAL because some data are pending but + * cannot be xferred to the channel + */ + ic->flags |= CF_READ_PARTIAL; + } if (cs->flags & CS_FL_READ_PARTIAL) { if (tick_isset(ic->rex)) -- 1.7.10.4