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Commit 4589d7f8 authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Philipp Reisner
Browse files

drbd_disconnect: grab meta.socket mutex as well 



Fixes a race and potential kernel panic if e.g. the worker was just
about to send a few P_RS_IS_IN_SYNC via the meta socket for checksum
based resync, while the receiver destroys the sockets in
drbd_disconnect.

To make sure no-one is using the meta socket,
it is not enough to stop the asender...
Grab the meta socket mutex before destroying it.

Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent 676396d5

drivers/block/drbd/drbd_main.c

+4 −0
Original line number Diff line number Diff line
@@ -3173,14 +3173,18 @@ void drbd_free_bc(struct drbd_backing_dev *ldev) 
void drbd_free_sock(struct drbd_conf *mdev)

{

	if (mdev->data.socket) {

		mutex_lock(&mdev->data.mutex);

		kernel_sock_shutdown(mdev->data.socket, SHUT_RDWR);

		sock_release(mdev->data.socket);

		mdev->data.socket = NULL;

		mutex_unlock(&mdev->data.mutex);

	}

	if (mdev->meta.socket) {

		mutex_lock(&mdev->meta.mutex);

		kernel_sock_shutdown(mdev->meta.socket, SHUT_RDWR);

		sock_release(mdev->meta.socket);

		mdev->meta.socket = NULL;

		mutex_unlock(&mdev->meta.mutex);

	}

}

drivers/block/drbd/drbd_receiver.c

+0 −3
Original line number Diff line number Diff line
@@ -3617,10 +3617,7 @@ static void drbd_disconnect(struct drbd_conf *mdev) 


	/* asender does not clean up anything. it must not interfere, either */

	drbd_thread_stop(&mdev->asender);



	mutex_lock(&mdev->data.mutex);

	drbd_free_sock(mdev);

	mutex_unlock(&mdev->data.mutex);



	spin_lock_irq(&mdev->req_lock);

	_drbd_wait_ee_list_empty(mdev, &mdev->active_ee);