From 4589d7f829951c1713ef5a4ad1a9bb563da329b5 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Wed, 3 Mar 2010 02:25:33 +0100 Subject: [PATCH] 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: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_main.c | 4 ++++ drivers/block/drbd/drbd_receiver.c | 3 --- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index b2d347d18c7d..67e0fc542249 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -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); } } diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 41f36a9cd407..d803e6c257e2 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -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); -- 2.20.1