From d560030548cb237f9ef09a82fd6f372836655306 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jan=20Kl=C3=B6tzke?= Date: Mon, 16 Dec 2019 22:56:52 +0100 Subject: [PATCH] mdev: re-initialize if uevent messages were lost MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If the netlink read() failed with ENOBUFS we know that we have missed at least one message due to a socket receive buffer overrun. The only way how to recover is to drop the old socket, open a fresh one and make a cold-plug scan of the current system state. Signed-off-by: Jan Klötzke Signed-off-by: Denys Vlasenko --- util-linux/mdev.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/util-linux/mdev.c b/util-linux/mdev.c index 4c00a2d7e..d4f06c128 100644 --- a/util-linux/mdev.c +++ b/util-linux/mdev.c @@ -1199,6 +1199,16 @@ static void daemon_loop(char *temp, int fd) len = safe_read(fd, netbuf, sizeof(netbuf) - 1); if (len < 0) { + if (errno == ENOBUFS) { + /* + * We ran out of socket receive buffer space. + * Start from scratch. + */ + dbg1s("uevent overrun, rescanning"); + close(fd); + fd = daemon_init(temp); + continue; + } bb_simple_perror_msg_and_die("read"); } end = netbuf + len;