From 17a93f3007c13003c739a19d0814cb5c2d21daba Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Wed, 24 Nov 2010 10:37:35 +0100 Subject: [PATCH] drbd: remove /proc/drbd before unregistering from netlink There still exists a (theoretical) race on module unload, where /proc/drbd may still exist, but the netlink callback has been unregistered already, allowing drbdsetup to shout without listeners, and get no reply. Reorder remove_proc_entry and unregister of netlink callback. drbdsetup first checks for existence of the proc entry, and if that is missing, won't even try to contact the module. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_main.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 8b8a38dc6492..150ed16d26ef 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -3174,11 +3174,20 @@ static void drbd_cleanup(void) unregister_reboot_notifier(&drbd_notifier); + /* first remove proc, + * drbdsetup uses it's presence to detect + * whether DRBD is loaded. + * If we would get stuck in proc removal, + * but have netlink already deregistered, + * some drbdsetup commands may wait forever + * for an answer. + */ + if (drbd_proc) + remove_proc_entry("drbd", NULL); + drbd_nl_cleanup(); if (minor_table) { - if (drbd_proc) - remove_proc_entry("drbd", NULL); i = minor_count; while (i--) drbd_delete_device(i); -- 2.20.1