Merge tag 'for-6.2/io_uring-next-2022-12-08' of git://git.kernel.dk/linux

Pull io_uring updates part two from Jens Axboe:

 - Misc fixes (me, Lin)

 - Series from Pavel extending the single task exclusive ring mode,
   yielding nice improvements for the common case of having a single
   ring per thread (Pavel)

 - Cleanup for MSG_RING, removing our IOPOLL hack (Pavel)

 - Further poll cleanups and fixes (Pavel)

 - Misc cleanups and fixes (Pavel)

* tag 'for-6.2/io_uring-next-2022-12-08' of git://git.kernel.dk/linux: (22 commits)
  io_uring/msg_ring: flag target ring as having task_work, if needed
  io_uring: skip spinlocking for ->task_complete
  io_uring: do msg_ring in target task via tw
  io_uring: extract a io_msg_install_complete helper
  io_uring: get rid of double locking
  io_uring: never run tw and fallback in parallel
  io_uring: use tw for putting rsrc
  io_uring: force multishot CQEs into task context
  io_uring: complete all requests in task context
  io_uring: don't check overflow flush failures
  io_uring: skip overflow CQE posting for dying ring
  io_uring: improve io_double_lock_ctx fail handling
  io_uring: dont remove file from msg_ring reqs
  io_uring: reshuffle issue_flags
  io_uring: don't reinstall quiesce node for each tw
  io_uring: improve rsrc quiesce refs checks
  io_uring: don't raw spin unlock to match cq_lock
  io_uring: combine poll tw handlers
  io_uring: improve poll warning handling
  io_uring: remove ctx variable in io_poll_check_events
  ...

Author: torvalds

include/linux/io_uring.h

@@ -9,16 +9,17 @@
 enum io_uring_cmd_flags {
 	IO_URING_F_COMPLETE_DEFER	= 1,
 	IO_URING_F_UNLOCKED		= 2,
+	/* the request is executed from poll, it should not be freed */
+	IO_URING_F_MULTISHOT		= 4,
+	/* executed by io-wq */
+	IO_URING_F_IOWQ			= 8,
 	/* int's last bit, sign checks are usually faster than a bit test */
 	IO_URING_F_NONBLOCK		= INT_MIN,
 
 	/* ctx state flags, for URING_CMD */
-	IO_URING_F_SQE128		= 4,
-	IO_URING_F_CQE32		= 8,
-	IO_URING_F_IOPOLL		= 16,
-
-	/* the request is executed from poll, it should not be freed */
-	IO_URING_F_MULTISHOT		= 32,
+	IO_URING_F_SQE128		= (1 << 8),
+	IO_URING_F_CQE32		= (1 << 9),
+	IO_URING_F_IOPOLL		= (1 << 10),
 };
 
 struct io_uring_cmd {

include/linux/io_uring_types.h

@@ -208,6 +208,8 @@ struct io_ring_ctx {
 		unsigned int		drain_disabled: 1;
 		unsigned int		has_evfd: 1;
 		unsigned int		syscall_iopoll: 1;
+		/* all CQEs should be posted only by the submitter task */
+		unsigned int		task_complete: 1;
 	} ____cacheline_aligned_in_smp;
 
 	/* submission data */
@@ -326,6 +328,7 @@ struct io_ring_ctx {
 	struct io_rsrc_data		*buf_data;
 
 	struct delayed_work		rsrc_put_work;
+	struct callback_head		rsrc_put_tw;
 	struct llist_head		rsrc_put_llist;
 	struct list_head		rsrc_ref_list;
 	spinlock_t			rsrc_ref_lock;