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authorLeonardo Bras <leobras@redhat.com>2022-07-11 18:11:11 -0300
committerDr. David Alan Gilbert <dgilbert@redhat.com>2022-07-20 12:15:09 +0100
commit927f93e099c4f9184e60a1bc61624ac2d04d0223 (patch)
treefdc23458934876fe4fe162689be5004f2ee75981 /io
parent5f87072e9532a92e6270577665aa2fa659ec0b3f (diff)
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QIOChannelSocket: Fix zero-copy flush returning code 1 when nothing sent
If flush is called when no buffer was sent with MSG_ZEROCOPY, it currently returns 1. This return code should be used only when Linux fails to use MSG_ZEROCOPY on a lot of sendmsg(). Fix this by returning early from flush if no sendmsg(...,MSG_ZEROCOPY) was attempted. Fixes: 2bc58ffc2926 ("QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX") Signed-off-by: Leonardo Bras <leobras@redhat.com> Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Acked-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Message-Id: <20220711211112.18951-2-leobras@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Diffstat (limited to 'io')
-rw-r--r--io/channel-socket.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/io/channel-socket.c b/io/channel-socket.c
index 4466bb1..74a936c 100644
--- a/io/channel-socket.c
+++ b/io/channel-socket.c
@@ -716,12 +716,18 @@ static int qio_channel_socket_flush(QIOChannel *ioc,
struct cmsghdr *cm;
char control[CMSG_SPACE(sizeof(*serr))];
int received;
- int ret = 1;
+ int ret;
+
+ if (sioc->zero_copy_queued == sioc->zero_copy_sent) {
+ return 0;
+ }
msg.msg_control = control;
msg.msg_controllen = sizeof(control);
memset(control, 0, sizeof(control));
+ ret = 1;
+
while (sioc->zero_copy_sent < sioc->zero_copy_queued) {
received = recvmsg(sioc->fd, &msg, MSG_ERRQUEUE);
if (received < 0) {