Merge tag 'io_uring-5.7-2020-04-09' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "Here's a set of fixes that either weren't quite ready for the first,
  or came about from some intensive testing on memcached with 350K+
  sockets.

  Summary:

   - Fixes for races or deadlocks around poll handling

   - Don't double account fixed files against RLIMIT_NOFILE

   - IORING_OP_OPENAT LFS fix

   - Poll retry handling (Bijan)

   - Missing finish_wait() for SQPOLL (Hillf)

   - Cleanup/split of io_kiocb alloc vs ctx references (Pavel)

   - Fixed file unregistration and init fixes (Xiaoguang)

   - Various little fixes (Xiaoguang, Pavel, Colin)"

* tag 'io_uring-5.7-2020-04-09' of git://git.kernel.dk/linux-block:
  io_uring: punt final io_ring_ctx wait-and-free to workqueue
  io_uring: fix fs cleanup on cqe overflow
  io_uring: don't read user-shared sqe flags twice
  io_uring: remove req init from io_get_req()
  io_uring: alloc req only after getting sqe
  io_uring: simplify io_get_sqring
  io_uring: do not always copy iovec in io_req_map_rw()
  io_uring: ensure openat sets O_LARGEFILE if needed
  io_uring: initialize fixed_file_data lock
  io_uring: remove redundant variable pointer nxt and io_wq_assign_next call
  io_uring: fix ctx refcounting in io_submit_sqes()
  io_uring: process requests completed with -EAGAIN on poll list
  io_uring: remove bogus RLIMIT_NOFILE check in file registration
  io_uring: use io-wq manager as backup task if task is exiting
  io_uring: grab task reference for poll requests
  io_uring: retry poll if we got woken with non-matching mask
  io_uring: add missing finish_wait() in io_sq_thread()
  io_uring: refactor file register/unregister/update handling

fs/io-wq.c

@@ -17,6 +17,7 @@
 #include <linux/kthread.h>
 #include <linux/rculist_nulls.h>
 #include <linux/fs_struct.h>
+#include <linux/task_work.h>
 
 #include "io-wq.h"
 
@@ -716,6 +717,9 @@ static int io_wq_manager(void *data)
 	complete(&wq->done);
 
 	while (!kthread_should_stop()) {
+		if (current->task_works)
+			task_work_run();
+
 		for_each_node(node) {
 			struct io_wqe *wqe = wq->wqes[node];
 			bool fork_worker[2] = { false, false };
@@ -738,6 +742,9 @@ static int io_wq_manager(void *data)
 		schedule_timeout(HZ);
 	}
 
+	if (current->task_works)
+		task_work_run();
+
 	return 0;
 err:
 	set_bit(IO_WQ_BIT_ERROR, &wq->state);
@@ -1124,3 +1131,8 @@ void io_wq_destroy(struct io_wq *wq)
 	if (refcount_dec_and_test(&wq->use_refs))
 		__io_wq_destroy(wq);
 }
+
+struct task_struct *io_wq_get_task(struct io_wq *wq)
+{
+	return wq->manager;
+}

fs/io-wq.h

@@ -136,6 +136,8 @@ typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
 enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
 					void *data);
 
+struct task_struct *io_wq_get_task(struct io_wq *wq);
+
 #if defined(CONFIG_IO_WQ)
 extern void io_wq_worker_sleeping(struct task_struct *);
 extern void io_wq_worker_running(struct task_struct *);