From: Lars Ellenberg Date: Wed, 1 Sep 2010 07:50:23 +0000 (+0200) Subject: drbd: fix race between deconfiguring and reconfiguring network X-Git-Tag: upstream/snapshot3+hdmi~12709^2~36 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c518d04fdec3d8b9d6f8b2228040934de9ee6708;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git drbd: fix race between deconfiguring and reconfiguring network If a drbd_nl_net_conf hits the small window between the state change to C_STANDALONE and the corresponding cleanup in after_state_ch, that cleanup would throw away stuff we now need again, and later trigger BUG_ON()s. Fixed by properly serializing the new config request with any pending cleanup. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 6742652..d066190 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -750,14 +750,16 @@ void drbd_setup_queue_param(struct drbd_conf *mdev, unsigned int max_seg_s) __mu /* serialize deconfig (worker exiting, doing cleanup) * and reconfig (drbdsetup disk, drbdsetup net) * - * wait for a potentially exiting worker, then restart it, - * or start a new one. + * Wait for a potentially exiting worker, then restart it, + * or start a new one. Flush any pending work, there may still be an + * after_state_change queued. */ static void drbd_reconfig_start(struct drbd_conf *mdev) { wait_event(mdev->state_wait, !test_and_set_bit(CONFIG_PENDING, &mdev->flags)); wait_event(mdev->state_wait, !test_bit(DEVICE_DYING, &mdev->flags)); drbd_thread_start(&mdev->worker); + drbd_flush_workqueue(mdev); } /* if still unconfigured, stops worker again.