From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44706) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XUsNg-00004v-Oa for qemu-devel@nongnu.org; Fri, 19 Sep 2014 03:13:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XUsNb-0005D5-C5 for qemu-devel@nongnu.org; Fri, 19 Sep 2014 03:13:24 -0400 Received: from mail-pd0-x236.google.com ([2607:f8b0:400e:c02::236]:35971) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XUsNb-0005Bt-54 for qemu-devel@nongnu.org; Fri, 19 Sep 2014 03:13:19 -0400 Received: by mail-pd0-f182.google.com with SMTP id w10so3096187pde.27 for ; Fri, 19 Sep 2014 00:13:12 -0700 (PDT) From: Zifei Tong Date: Fri, 19 Sep 2014 15:12:53 +0800 Message-Id: <1411110773-489-1-git-send-email-zifeitong@gmail.com> Subject: [Qemu-devel] [PATCH v3] qemu-char: Do not disconnect when there's data for reading List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kirill Batuzov , Anthony Liguori , Markus Armbruster , Nikolay Nikolaev , Zifei Tong After commit 812c1057f6175ac9a9829fa2920a2b5783814193 (Handle G_IO_HUP in tcp_chr_read for tcp chardev), connections are disconnected when in G_IO_HUP condition. However, it's possible that there is still data for reading in the channel. In that case, the remaining data is not handled. I saw a related bug when running socat in write-only mode, after $ echo "quit" | socat -u - UNIX-CONNECT:qemu-monitor the monitor won't not run the 'quit' command. Instead of GIOCondition, this patch uses the return value of tcp_chr_recv() to check the state of connection as suggested by Kirill. Cc: Kirill Batuzov Cc: Nikolay Nikolaev Cc: Markus Armbruster Cc: Anthony Liguori Signed-off-by: Zifei Tong --- Changes in v3: handle EWOULDBLOCK, remove inaccurate comment qemu-char.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/qemu-char.c b/qemu-char.c index 2a3cb9f..d1893a0 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -2692,12 +2692,6 @@ static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque) uint8_t buf[READ_BUF_LEN]; int len, size; - if (cond & G_IO_HUP) { - /* connection closed */ - tcp_chr_disconnect(chr); - return TRUE; - } - if (!s->connected || s->max_size <= 0) { return TRUE; } @@ -2705,8 +2699,8 @@ static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque) if (len > s->max_size) len = s->max_size; size = tcp_chr_recv(chr, (void *)buf, len); - if (size == 0) { - /* connection closed */ + if (size == 0 || + (size < 0 && !(errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR))) { tcp_chr_disconnect(chr); } else if (size > 0) { if (s->do_telnetopt) -- 2.1.0