Merge tag 'io_uring-5.8-2020-07-01' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "One fix in here, for a regression in 5.7 where a task is waiting in
  the kernel for a condition, but that condition won't become true until
  task_work is run. And the task_work can't be run exactly because the
  task is waiting in the kernel, so we'll never make any progress.

  One example of that is registering an eventfd and queueing io_uring
  work, and then the task goes and waits in eventfd read with the
  expectation that it'll get woken (and read an event) when the io_uring
  request completes. The io_uring request is finished through task_work,
  which won't get run while the task is looping in eventfd read"

* tag 'io_uring-5.8-2020-07-01' of git://git.kernel.dk/linux-block:
  io_uring: use signal based task_work running
  task_work: teach task_work_add() to do signal_wake_up()

1 files changed, 4 insertions, 1 deletions

diff --git a/include/linux/task_work.h b/include/linux/task_work.h
index bd9a6a91c097..0fb93aafa478 100644
--- a/include/linux/task_work.h
+++ b/include/linux/task_work.h
@@ -13,7 +13,10 @@ init_task_work(struct callback_head *twork, task_work_func_t func)
 	twork->func = func;
 }
 
-int task_work_add(struct task_struct *task, struct callback_head *twork, bool);
+#define TWA_RESUME	1
+#define TWA_SIGNAL	2
+int task_work_add(struct task_struct *task, struct callback_head *twork, int);
+
 struct callback_head *task_work_cancel(struct task_struct *, task_work_func_t);
 void task_work_run(void);