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authorJan Klötzke2020-11-22 14:17:56 +0100
committerDenys Vlasenko2020-11-22 14:33:58 +0100
commite3f4759019544673d654ad8a1ea256ed481fa5e3 (patch)
treed07dc3c6bc79bdd81d0a085c02bbab8d5941311b /util-linux/mdev.c
parenta569fd37fec970d8aeebca1c34a964502072d817 (diff)
downloadbusybox-e3f4759019544673d654ad8a1ea256ed481fa5e3.zip
busybox-e3f4759019544673d654ad8a1ea256ed481fa5e3.tar.gz
mdev: move daemon setup to dedicated function
Signed-off-by: Jan Klötzke <jan@kloetzke.net> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'util-linux/mdev.c')
-rw-r--r--util-linux/mdev.c44
1 files changed, 27 insertions, 17 deletions
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 8b06d34..4c00a2d 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -1165,6 +1165,29 @@ static void initial_scan(char *temp)
# define KERN_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, KERN_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 (;;) {
@@ -1234,24 +1257,11 @@ 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, KERN_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);