Add back the previously removed cgroup function to support the kthread
The biggest change for this part is in vhost_attach_cgroups() and
vhost_worker_cgroups_kthread(). This is because of the change in
struct dev->worker_xa.
The old function was remove in
commit 6e890c5d5021 ("vhost: use vhost_tasks for worker threads")
Signed-off-by: Cindy Lu <lulu@xxxxxxxxxx>
---
drivers/vhost/vhost.c | 52 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 65fda810b96e..e40cef3a1fa5 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -22,6 +22,7 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/kthread.h>
+#include <linux/cgroup.h>
#include <linux/module.h>
#include <linux/sort.h>
#include <linux/sched/mm.h>
@@ -621,6 +622,57 @@ long vhost_dev_check_owner(struct vhost_dev *dev)
}
EXPORT_SYMBOL_GPL(vhost_dev_check_owner);
+struct vhost_attach_cgroups_struct {
+ struct vhost_work work;
+ struct task_struct *owner;
+ int ret;
+};
+
+static void vhost_attach_cgroups_work(struct vhost_work *work)
+{
+ struct vhost_attach_cgroups_struct *s;
+
+ s = container_of(work, struct vhost_attach_cgroups_struct, work);
+ s->ret = cgroup_attach_task_all(s->owner, current);
+}
+
+static int vhost_worker_cgroups_kthread(struct vhost_worker *worker)
+{
+ struct vhost_flush_struct flush;
+ struct vhost_attach_cgroups_struct attach;
+
+ attach.owner = current;
+
+ vhost_work_init(&attach.work, vhost_attach_cgroups_work);
+ vhost_worker_queue(worker, &attach.work);
+
+ init_completion(&flush.wait_event);
+ vhost_work_init(&flush.work, vhost_flush_work);
+ vhost_worker_queue(worker, &flush.work);
+ wait_for_completion(&flush.wait_event);
+
+ return attach.ret;
+}
+
+static int vhost_attach_cgroups(struct vhost_dev *dev)
+{
+ struct vhost_worker *worker;
+ unsigned long i;
+ int ret;
+
+ /*
+ * Free the default worker we created and cleanup workers userspace
+ * created but couldn't clean up (it forgot or crashed).
+ */
+
+ xa_for_each(&dev->worker_xa, i, worker) {
+ ret = vhost_worker_cgroups_kthread(worker);
+ if (ret)
+ return ret;
+ }
+ return ret;
+}
+
/* Caller should have device mutex */
bool vhost_dev_has_owner(struct vhost_dev *dev)
{
--
2.45.0
