#include <linux/freezer.h>
#include <linux/ptrace.h>
#include <linux/uaccess.h>
-#include <linux/cgroup.h>
#include <trace/events/sched.h>
static DEFINE_SPINLOCK(kthread_create_lock);
void *data;
struct completion parked;
struct completion exited;
+#ifdef CONFIG_BLK_CGROUP
+ struct cgroup_subsys_state *blkcg_css;
+#endif
};
enum KTHREAD_BITS {
KTHREAD_IS_PER_CPU = 0,
KTHREAD_SHOULD_STOP,
KTHREAD_SHOULD_PARK,
- KTHREAD_IS_PARKED,
};
static inline void set_kthread_struct(void *kthread)
void free_kthread_struct(struct task_struct *k)
{
+ struct kthread *kthread;
+
/*
* Can be NULL if this kthread was created by kernel_thread()
* or if kmalloc() in kthread() failed.
*/
- kfree(to_kthread(k));
+ kthread = to_kthread(k);
+#ifdef CONFIG_BLK_CGROUP
+ WARN_ON_ONCE(kthread && kthread->blkcg_css);
+#endif
+ kfree(kthread);
}
/**
static void __kthread_parkme(struct kthread *self)
{
- __set_current_state(TASK_PARKED);
- while (test_bit(KTHREAD_SHOULD_PARK, &self->flags)) {
- if (!test_and_set_bit(KTHREAD_IS_PARKED, &self->flags))
- complete(&self->parked);
+ for (;;) {
+ set_current_state(TASK_PARKED);
+ if (!test_bit(KTHREAD_SHOULD_PARK, &self->flags))
+ break;
schedule();
- __set_current_state(TASK_PARKED);
}
- clear_bit(KTHREAD_IS_PARKED, &self->flags);
__set_current_state(TASK_RUNNING);
}
}
EXPORT_SYMBOL_GPL(kthread_parkme);
+void kthread_park_complete(struct task_struct *k)
+{
+ complete(&to_kthread(k)->parked);
+}
+
static int kthread(void *_create)
{
/* Copy data: it's on kthread's stack */
struct kthread *self;
int ret;
- self = kmalloc(sizeof(*self), GFP_KERNEL);
+ self = kzalloc(sizeof(*self), GFP_KERNEL);
set_kthread_struct(self);
/* If user was SIGKILLed, I release the structure. */
do_exit(-ENOMEM);
}
- self->flags = 0;
self->data = data;
init_completion(&self->exited);
init_completion(&self->parked);
* new kernel thread.
*/
if (unlikely(wait_for_completion_killable(&done))) {
+ int i = 0;
+
+ /*
+ * I got SIGKILL, but wait for 10 more seconds for completion
+ * unless chosen by the OOM killer. This delay is there as a
+ * workaround for boot failure caused by SIGKILL upon device
+ * driver initialization timeout.
+ */
+ while (i++ < 10 && !test_tsk_thread_flag(current, TIF_MEMDIE))
+ if (wait_for_completion_timeout(&done, HZ))
+ goto ready;
/*
* If I was SIGKILLed before kthreadd (or new kernel thread)
* calls complete(), leave the cleanup of this structure to
*/
wait_for_completion(&done);
}
+ready:
task = create->result;
if (!IS_ERR(task)) {
static const struct sched_param param = { .sched_priority = 0 };
{
struct kthread *kthread = to_kthread(k);
- clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
/*
- * We clear the IS_PARKED bit here as we don't wait
- * until the task has left the park code. So if we'd
- * park before that happens we'd see the IS_PARKED bit
- * which might be about to be cleared.
+ * Newly created kthread was parked when the CPU was offline.
+ * The binding was lost and we need to set it again.
*/
- if (test_and_clear_bit(KTHREAD_IS_PARKED, &kthread->flags)) {
- /*
- * Newly created kthread was parked when the CPU was offline.
- * The binding was lost and we need to set it again.
- */
- if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags))
- __kthread_bind(k, kthread->cpu, TASK_PARKED);
- wake_up_state(k, TASK_PARKED);
- }
+ if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags))
+ __kthread_bind(k, kthread->cpu, TASK_PARKED);
+
+ clear_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
+ wake_up_state(k, TASK_PARKED);
}
EXPORT_SYMBOL_GPL(kthread_unpark);
if (WARN_ON(k->flags & PF_EXITING))
return -ENOSYS;
- if (!test_bit(KTHREAD_IS_PARKED, &kthread->flags)) {
- set_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
- if (k != current) {
- wake_up_process(k);
- wait_for_completion(&kthread->parked);
- }
+ if (WARN_ON_ONCE(test_bit(KTHREAD_SHOULD_PARK, &kthread->flags)))
+ return -EBUSY;
+
+ set_bit(KTHREAD_SHOULD_PARK, &kthread->flags);
+ if (k != current) {
+ wake_up_process(k);
+ wait_for_completion(&kthread->parked);
}
return 0;
struct timer_list *timer = &dwork->timer;
struct kthread_work *work = &dwork->work;
- WARN_ON_ONCE(timer->function != (TIMER_FUNC_TYPE)kthread_delayed_work_timer_fn);
+ WARN_ON_ONCE(timer->function != kthread_delayed_work_timer_fn);
/*
* If @delay is 0, queue @dwork->work immediately. This is for
kfree(worker);
}
EXPORT_SYMBOL(kthread_destroy_worker);
+
+#ifdef CONFIG_BLK_CGROUP
+/**
+ * kthread_associate_blkcg - associate blkcg to current kthread
+ * @css: the cgroup info
+ *
+ * Current thread must be a kthread. The thread is running jobs on behalf of
+ * other threads. In some cases, we expect the jobs attach cgroup info of
+ * original threads instead of that of current thread. This function stores
+ * original thread's cgroup info in current kthread context for later
+ * retrieval.
+ */
+void kthread_associate_blkcg(struct cgroup_subsys_state *css)
+{
+ struct kthread *kthread;
+
+ if (!(current->flags & PF_KTHREAD))
+ return;
+ kthread = to_kthread(current);
+ if (!kthread)
+ return;
+
+ if (kthread->blkcg_css) {
+ css_put(kthread->blkcg_css);
+ kthread->blkcg_css = NULL;
+ }
+ if (css) {
+ css_get(css);
+ kthread->blkcg_css = css;
+ }
+}
+EXPORT_SYMBOL(kthread_associate_blkcg);
+
+/**
+ * kthread_blkcg - get associated blkcg css of current kthread
+ *
+ * Current thread must be a kthread.
+ */
+struct cgroup_subsys_state *kthread_blkcg(void)
+{
+ struct kthread *kthread;
+
+ if (current->flags & PF_KTHREAD) {
+ kthread = to_kthread(current);
+ if (kthread)
+ return kthread->blkcg_css;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(kthread_blkcg);
+#endif
projects / mirror_ubuntu-bionic-kernel.git / blobdiff