Signed-off-by: Jan Klötzke <[email protected]>
---
util-linux/mdev.c | 44 +++++++++++++++++++++++++++-----------------
1 file changed, 27 insertions(+), 17 deletions(-)
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 4e3299d22..cfc1a38bc 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -1172,6 +1172,29 @@ static void initial_scan(char *temp)
# define RCVBUF (128 * 1024 * 1024)
# define MAX_ENV 32
+static int daemon_init(char *temp)
+{
+ int fd;
+
+ /* Subscribe for UEVENT kernel messages */
+ /* Without a sufficiently big RCVBUF, a ton of simultaneous events
+ * can trigger ENOBUFS on read, which is unrecoverable.
+ * Reproducer:
+ * mdev -d
+ * find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
+ */
+ fd = create_and_bind_to_netlink(NETLINK_KOBJECT_UEVENT, 1 << 0, RCVBUF);
+
+ /*
+ * Make inital scan after the uevent socket is alive and
+ * _before_ we fork away. Already open mdev.log because we work
+ * in daemon mode.
+ */
+ initial_scan(temp);
+
+ return fd;
+}
+
static void daemon_loop(char *temp, int fd)
{
for (;;) {
@@ -1241,24 +1264,11 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
#if ENABLE_FEATURE_MDEV_DAEMON
if (opt & MDEV_OPT_DAEMON) {
/*
- * Daemon mode listening on uevent netlink socket.
- */
- int fd;
-
- /* Subscribe for UEVENT kernel messages */
- /* Without a sufficiently big RCVBUF, a ton of simultaneous
events
- * can trigger ENOBUFS on read, which is unrecoverable.
- * Reproducer:
- * mdev -d
- * find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
- */
- fd = create_and_bind_to_netlink(NETLINK_KOBJECT_UEVENT, 1 << 0,
RCVBUF);
-
- /*
- * Make inital scan after the uevent socket is alive and
- * _before_ we fork away.
+ * Daemon mode listening on uevent netlink socket. Fork away
+ * after initial scan so that caller can be sure everything
+ * is up-to-date when mdev process returns.
*/
- initial_scan(temp);
+ int fd = daemon_init(temp);
if (!(opt & MDEV_OPT_FOREGROUND))
bb_daemonize_or_rexec(0, argv);
--
2.20.1
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