mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-10-04 16:15:11 +00:00
Code Issues Releases Wiki Activity

drbd: fix race between deconfiguring and reconfiguring network

Browse source 
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 <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This commit is contained in:
Lars Ellenberg 2010-09-01 09:50:23 +02:00 committed by Philipp Reisner
parent 0778286a13
commit c518d04fde
1 changed files with 4 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
drivers/block/drbd/drbd_nl.c
View file

@ -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) /* serialize deconfig (worker exiting, doing cleanup)
* and reconfig (drbdsetup disk, drbdsetup net) * and reconfig (drbdsetup disk, drbdsetup net)
* *
* wait for a potentially exiting worker, then restart it, * Wait for a potentially exiting worker, then restart it,
* or start a new one. * 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) 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_and_set_bit(CONFIG_PENDING, &mdev->flags));
wait_event(mdev->state_wait, !test_bit(DEVICE_DYING, &mdev->flags)); wait_event(mdev->state_wait, !test_bit(DEVICE_DYING, &mdev->flags));
drbd_thread_start(&mdev->worker); drbd_thread_start(&mdev->worker);
drbd_flush_workqueue(mdev);
} }
/* if still unconfigured, stops worker again. /* if still unconfigured, stops worker again.