Device lock should be held when releasing a device, and specifically when calling vhost_dev_cleanup(). Otherwise, RCU complains about it: [ 2025.642835] =============================== [ 2025.643838] [ INFO: suspicious RCU usage. ] [ 2025.645182] ------------------------------- [ 2025.645927] drivers/vhost/vhost.c:475 suspicious rcu_dereference_protected() usage! [ 2025.647329] [ 2025.647330] other info that might help us debug this: [ 2025.647331] [ 2025.649042] [ 2025.649043] rcu_scheduler_active = 1, debug_locks = 1 [ 2025.650235] no locks held by trinity/21042. [ 2025.650971] [ 2025.650972] stack backtrace: [ 2025.651789] Pid: 21042, comm: trinity Not tainted 3.2.0-rc2-sasha-00057-ga9098b3 #5 [ 2025.653342] Call Trace: [ 2025.653792] [<ffffffff810b4a6a>] lockdep_rcu_suspicious+0xaf/0xb9 [ 2025.654916] [<ffffffff818d4c2c>] vhost_dev_cleanup+0x342/0x3ac [ 2025.655985] [<ffffffff818d4f18>] vhost_net_release+0x48/0x7f [ 2025.657247] [<ffffffff811416e3>] fput+0x11e/0x1dc [ 2025.658091] [<ffffffff8113f1ec>] filp_close+0x6e/0x79 [ 2025.658964] [<ffffffff81089ed7>] put_files_struct+0xcc/0x196 [ 2025.659971] [<ffffffff8108a034>] exit_files+0x46/0x4f [ 2025.660865] [<ffffffff8108a716>] do_exit+0x264/0x75c [ 2025.662201] [<ffffffff8113f490>] ? fsnotify_modify+0x60/0x68 [ 2025.663260] [<ffffffff81bbdbca>] ? sysret_check+0x2e/0x69 [ 2025.664269] [<ffffffff8108acc1>] do_group_exit+0x83/0xb1 [ 2025.665448] [<ffffffff8108ad01>] sys_exit_group+0x12/0x16 [ 2025.666396] [<ffffffff81bbdb92>] system_call_fastpath+0x16/0x1b Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Cc: kvm@xxxxxxxxxxxxxxx Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: netdev@xxxxxxxxxxxxxxx Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx> --- drivers/vhost/net.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 882a51f..c9be601 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -586,6 +586,7 @@ static int vhost_net_release(struct inode *inode, struct file *f) struct socket *tx_sock; struct socket *rx_sock; + mutex_lock(&n->dev.mutex); vhost_net_stop(n, &tx_sock, &rx_sock); vhost_net_flush(n); vhost_dev_cleanup(&n->dev); @@ -596,6 +597,7 @@ static int vhost_net_release(struct inode *inode, struct file *f) /* We do an extra flush before freeing memory, * since jobs can re-queue themselves. */ vhost_net_flush(n); + mutex_unlock(&n->dev.mutex); kfree(n); return 0; } -- 1.7.8.rc1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
