QIOChannelSocket: Fix zero-copy send so socket flush works

Somewhere between v6 and v7 the of the zero-copy-send patchset a crucial
part of the flushing mechanism got missing: incrementing zero_copy_queued.

Without that, the flushing interface becomes a no-op, and there is no
guarantee the buffer is really sent.

This can go as bad as causing a corruption in RAM during migration.

Fixes: 2bc58ffc2926 ("QIOChannelSocket: Implement io_writev zero copy flag & io_flush for CONFIG_LINUX")
Reported-by: 徐闯 <[email protected]>
Signed-off-by: Leonardo Bras <[email protected]>
Reviewed-by: Daniel P. Berrangé <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Reviewed-by: Juan Quintela <[email protected]>
Signed-off-by: Juan Quintela <[email protected]>
Signed-off-by: Dr. David Alan Gilbert <[email protected]>

diff --git a/io/channel-socket.c b/io/channel-socket.c
index b8c13dba7c8aa85e350e8174c73727f6f4dbc2d6..4466bb1cd45e05b0807d88e20558c2335dbef737 100644 (file)
--- a/io/channel-socket.c
+++ b/io/channel-socket.c
@@ -611,6 +611,11 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc,
                          "Unable to write to socket");
         return -1;
     }
+
+    if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) {
+        sioc->zero_copy_queued++;
+    }
+
     return ret;
 }
 #else /* WIN32 */