From e046fb449947a48e013bf25d806ecb60e5a88319 Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Fri, 12 Feb 2016 14:46:50 +0000 Subject: [PATCH] char: fix handling of QIO_CHANNEL_ERR_BLOCK If io_channel_send_full gets QIO_CHANNEL_ERR_BLOCK it and has already sent some of the data, it should return that amount of data, not EAGAIN, as that would cause the caller to re-try already sent data. Unfortunately due to a previous rebase conflict resolution error, the code for dealing with this was in the wrong part of the conditional, and so mistakenly ran on other I/O errors. This be seen running qemu-system-x86_64 -monitor stdio and entering 'info mtree', when running on a slow console (eg a slow remote ssh session). The monitor would get into an indefinite loop writing the same data until it managed to send it all without getting EAGAIN. Reported-by: Igor Mammedov Signed-off-by: Daniel P. Berrange Message-Id: <1455288410-27046-1-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini --- qemu-char.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/qemu-char.c b/qemu-char.c index 00caf659c2..ad11b75e3d 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -896,13 +896,13 @@ static int io_channel_send_full(QIOChannel *ioc, ioc, &iov, 1, fds, nfds, NULL); if (ret == QIO_CHANNEL_ERR_BLOCK) { - errno = EAGAIN; - return -1; - } else if (ret < 0) { if (offset) { return offset; } + errno = EAGAIN; + return -1; + } else if (ret < 0) { errno = EINVAL; return -1; }