[PATCH v4 2/3] io_uring: add wrapper type for io_req_tw_func_t arg

[Caleb Sander Mateos <csander@purestorage.com>]

In preparation for uring_cmd implementations to implement functions
with the io_req_tw_func_t signature, introduce a wrapper struct
io_tw_req to hide the struct io_kiocb * argument. The intention is for
only the io_uring core to access the inner struct io_kiocb *. uring_cmd
implementations should instead call a helper from io_uring/cmd.h to
convert struct io_tw_req to struct io_uring_cmd *.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 include/linux/io_uring_types.h |  6 +++++-
 io_uring/futex.c               | 16 +++++++++-------
 io_uring/io_uring.c            | 21 ++++++++++++---------
 io_uring/io_uring.h            |  4 ++--
 io_uring/msg_ring.c            |  3 ++-
 io_uring/notif.c               |  5 +++--
 io_uring/poll.c                | 11 ++++++-----
 io_uring/poll.h                |  2 +-
 io_uring/rw.c                  |  5 +++--
 io_uring/rw.h                  |  2 +-
 io_uring/timeout.c             | 18 +++++++++++-------
 io_uring/uring_cmd.c           |  3 ++-
 io_uring/waitid.c              |  7 ++++---
 13 files changed, 61 insertions(+), 42 deletions(-)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 25ee982eb435..f064a438ce43 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -613,11 +613,15 @@ enum {
 	REQ_F_IMPORT_BUFFER	= IO_REQ_FLAG(REQ_F_IMPORT_BUFFER_BIT),
 	/* ->sqe_copy() has been called, if necessary */
 	REQ_F_SQE_COPIED	= IO_REQ_FLAG(REQ_F_SQE_COPIED_BIT),
 };
 
-typedef void (*io_req_tw_func_t)(struct io_kiocb *req, io_tw_token_t tw);
+struct io_tw_req {
+	struct io_kiocb *req;
+};
+
+typedef void (*io_req_tw_func_t)(struct io_tw_req tw_req, io_tw_token_t tw);
 
 struct io_task_work {
 	struct llist_node		node;
 	io_req_tw_func_t		func;
 };
diff --git a/io_uring/futex.c b/io_uring/futex.c
index 64f3bd51c84c..4e022c76236d 100644
--- a/io_uring/futex.c
+++ b/io_uring/futex.c
@@ -39,28 +39,30 @@ bool io_futex_cache_init(struct io_ring_ctx *ctx)
 void io_futex_cache_free(struct io_ring_ctx *ctx)
 {
 	io_alloc_cache_free(&ctx->futex_cache, kfree);
 }
 
-static void __io_futex_complete(struct io_kiocb *req, io_tw_token_t tw)
+static void __io_futex_complete(struct io_tw_req tw_req, io_tw_token_t tw)
 {
-	hlist_del_init(&req->hash_node);
-	io_req_task_complete(req, tw);
+	hlist_del_init(&tw_req.req->hash_node);
+	io_req_task_complete(tw_req, tw);
 }
 
-static void io_futex_complete(struct io_kiocb *req, io_tw_token_t tw)
+static void io_futex_complete(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	struct io_ring_ctx *ctx = req->ctx;
 
 	io_tw_lock(ctx, tw);
 	io_cache_free(&ctx->futex_cache, req->async_data);
 	io_req_async_data_clear(req, 0);
-	__io_futex_complete(req, tw);
+	__io_futex_complete(tw_req, tw);
 }
 
-static void io_futexv_complete(struct io_kiocb *req, io_tw_token_t tw)
+static void io_futexv_complete(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex);
 	struct futex_vector *futexv = req->async_data;
 
 	io_tw_lock(req->ctx, tw);
 
@@ -71,11 +73,11 @@ static void io_futexv_complete(struct io_kiocb *req, io_tw_token_t tw)
 		if (res != -1)
 			io_req_set_res(req, res, 0);
 	}
 
 	io_req_async_data_free(req);
-	__io_futex_complete(req, tw);
+	__io_futex_complete(tw_req, tw);
 }
 
 static bool io_futexv_claim(struct io_futex *iof)
 {
 	if (test_bit(0, &iof->futexv_owned) ||
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 4e6676ac4662..01631b6ff442 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -289,11 +289,11 @@ static __cold void io_fallback_req_func(struct work_struct *work)
 
 	percpu_ref_get(&ctx->refs);
 	mutex_lock(&ctx->uring_lock);
 	ts.cancel = io_should_terminate_tw(ctx);
 	llist_for_each_entry_safe(req, tmp, node, io_task_work.node)
-		req->io_task_work.func(req, ts);
+		req->io_task_work.func((struct io_tw_req){req}, ts);
 	io_submit_flush_completions(ctx);
 	mutex_unlock(&ctx->uring_lock);
 	percpu_ref_put(&ctx->refs);
 }
 
@@ -537,13 +537,13 @@ static void io_queue_iowq(struct io_kiocb *req)
 
 	trace_io_uring_queue_async_work(req, io_wq_is_hashed(&req->work));
 	io_wq_enqueue(tctx->io_wq, &req->work);
 }
 
-static void io_req_queue_iowq_tw(struct io_kiocb *req, io_tw_token_t tw)
+static void io_req_queue_iowq_tw(struct io_tw_req tw_req, io_tw_token_t tw)
 {
-	io_queue_iowq(req);
+	io_queue_iowq(tw_req.req);
 }
 
 void io_req_queue_iowq(struct io_kiocb *req)
 {
 	req->io_task_work.func = io_req_queue_iowq_tw;
@@ -1164,11 +1164,11 @@ struct llist_node *io_handle_tw_list(struct llist_node *node,
 			percpu_ref_get(&ctx->refs);
 			ts.cancel = io_should_terminate_tw(ctx);
 		}
 		INDIRECT_CALL_2(req->io_task_work.func,
 				io_poll_task_func, io_req_rw_complete,
-				req, ts);
+				(struct io_tw_req){req}, ts);
 		node = next;
 		(*count)++;
 		if (unlikely(need_resched())) {
 			ctx_flush_and_put(ctx, ts);
 			ctx = NULL;
@@ -1387,11 +1387,11 @@ static int __io_run_local_work_loop(struct llist_node **node,
 		struct llist_node *next = (*node)->next;
 		struct io_kiocb *req = container_of(*node, struct io_kiocb,
 						    io_task_work.node);
 		INDIRECT_CALL_2(req->io_task_work.func,
 				io_poll_task_func, io_req_rw_complete,
-				req, tw);
+				(struct io_tw_req){req}, tw);
 		*node = next;
 		if (++ret >= events)
 			break;
 	}
 
@@ -1457,18 +1457,21 @@ static int io_run_local_work(struct io_ring_ctx *ctx, int min_events,
 	ret = __io_run_local_work(ctx, ts, min_events, max_events);
 	mutex_unlock(&ctx->uring_lock);
 	return ret;
 }
 
-static void io_req_task_cancel(struct io_kiocb *req, io_tw_token_t tw)
+static void io_req_task_cancel(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
+
 	io_tw_lock(req->ctx, tw);
 	io_req_defer_failed(req, req->cqe.res);
 }
 
-void io_req_task_submit(struct io_kiocb *req, io_tw_token_t tw)
+void io_req_task_submit(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	struct io_ring_ctx *ctx = req->ctx;
 
 	io_tw_lock(ctx, tw);
 	if (unlikely(tw.cancel))
 		io_req_defer_failed(req, -EFAULT);
@@ -1700,13 +1703,13 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned int min_events)
 	} while (nr_events < min_events);
 
 	return 0;
 }
 
-void io_req_task_complete(struct io_kiocb *req, io_tw_token_t tw)
+void io_req_task_complete(struct io_tw_req tw_req, io_tw_token_t tw)
 {
-	io_req_complete_defer(req);
+	io_req_complete_defer(tw_req.req);
 }
 
 /*
  * After the iocb has been issued, it's safe to be found on the poll list.
  * Adding the kiocb to the list AFTER submission ensures that we don't
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 44b8091c7fcd..f97356ce29d0 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -147,13 +147,13 @@ struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
 			       unsigned issue_flags);
 
 void __io_req_task_work_add(struct io_kiocb *req, unsigned flags);
 void io_req_task_work_add_remote(struct io_kiocb *req, unsigned flags);
 void io_req_task_queue(struct io_kiocb *req);
-void io_req_task_complete(struct io_kiocb *req, io_tw_token_t tw);
+void io_req_task_complete(struct io_tw_req tw_req, io_tw_token_t tw);
 void io_req_task_queue_fail(struct io_kiocb *req, int ret);
-void io_req_task_submit(struct io_kiocb *req, io_tw_token_t tw);
+void io_req_task_submit(struct io_tw_req tw_req, io_tw_token_t tw);
 struct llist_node *io_handle_tw_list(struct llist_node *node, unsigned int *count, unsigned int max_entries);
 struct llist_node *tctx_task_work_run(struct io_uring_task *tctx, unsigned int max_entries, unsigned int *count);
 void tctx_task_work(struct callback_head *cb);
 __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
 
diff --git a/io_uring/msg_ring.c b/io_uring/msg_ring.c
index 5e5b94236d72..7063ea7964e7 100644
--- a/io_uring/msg_ring.c
+++ b/io_uring/msg_ring.c
@@ -68,12 +68,13 @@ void io_msg_ring_cleanup(struct io_kiocb *req)
 static inline bool io_msg_need_remote(struct io_ring_ctx *target_ctx)
 {
 	return target_ctx->task_complete;
 }
 
-static void io_msg_tw_complete(struct io_kiocb *req, io_tw_token_t tw)
+static void io_msg_tw_complete(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	struct io_ring_ctx *ctx = req->ctx;
 
 	io_add_aux_cqe(ctx, req->cqe.user_data, req->cqe.res, req->cqe.flags);
 	kfree_rcu(req, rcu_head);
 	percpu_ref_put(&ctx->refs);
diff --git a/io_uring/notif.c b/io_uring/notif.c
index d8ba1165c949..9960bb2a32d5 100644
--- a/io_uring/notif.c
+++ b/io_uring/notif.c
@@ -9,12 +9,13 @@
 #include "notif.h"
 #include "rsrc.h"
 
 static const struct ubuf_info_ops io_ubuf_ops;
 
-static void io_notif_tw_complete(struct io_kiocb *notif, io_tw_token_t tw)
+static void io_notif_tw_complete(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *notif = tw_req.req;
 	struct io_notif_data *nd = io_notif_to_data(notif);
 	struct io_ring_ctx *ctx = notif->ctx;
 
 	lockdep_assert_held(&ctx->uring_lock);
 
@@ -32,11 +33,11 @@ static void io_notif_tw_complete(struct io_kiocb *notif, io_tw_token_t tw)
 			__io_unaccount_mem(notif->ctx->user, nd->account_pages);
 			nd->account_pages = 0;
 		}
 
 		nd = nd->next;
-		io_req_task_complete(notif, tw);
+		io_req_task_complete((struct io_tw_req){notif}, tw);
 	} while (nd);
 }
 
 void io_tx_ubuf_complete(struct sk_buff *skb, struct ubuf_info *uarg,
 			 bool success)
diff --git a/io_uring/poll.c b/io_uring/poll.c
index c403e751841a..8aa4e3a31e73 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -308,12 +308,13 @@ static int io_poll_check_events(struct io_kiocb *req, io_tw_token_t tw)
 
 	io_napi_add(req);
 	return IOU_POLL_NO_ACTION;
 }
 
-void io_poll_task_func(struct io_kiocb *req, io_tw_token_t tw)
+void io_poll_task_func(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	int ret;
 
 	ret = io_poll_check_events(req, tw);
 	if (ret == IOU_POLL_NO_ACTION) {
 		return;
@@ -330,26 +331,26 @@ void io_poll_task_func(struct io_kiocb *req, io_tw_token_t tw)
 			struct io_poll *poll;
 
 			poll = io_kiocb_to_cmd(req, struct io_poll);
 			req->cqe.res = mangle_poll(req->cqe.res & poll->events);
 		} else if (ret == IOU_POLL_REISSUE) {
-			io_req_task_submit(req, tw);
+			io_req_task_submit(tw_req, tw);
 			return;
 		} else if (ret != IOU_POLL_REMOVE_POLL_USE_RES) {
 			req->cqe.res = ret;
 			req_set_fail(req);
 		}
 
 		io_req_set_res(req, req->cqe.res, 0);
-		io_req_task_complete(req, tw);
+		io_req_task_complete(tw_req, tw);
 	} else {
 		io_tw_lock(req->ctx, tw);
 
 		if (ret == IOU_POLL_REMOVE_POLL_USE_RES)
-			io_req_task_complete(req, tw);
+			io_req_task_complete(tw_req, tw);
 		else if (ret == IOU_POLL_DONE || ret == IOU_POLL_REISSUE)
-			io_req_task_submit(req, tw);
+			io_req_task_submit(tw_req, tw);
 		else
 			io_req_defer_failed(req, ret);
 	}
 }
 
diff --git a/io_uring/poll.h b/io_uring/poll.h
index c8438286dfa0..5647c5138932 100644
--- a/io_uring/poll.h
+++ b/io_uring/poll.h
@@ -44,6 +44,6 @@ int io_poll_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd,
 int io_arm_apoll(struct io_kiocb *req, unsigned issue_flags, __poll_t mask);
 int io_arm_poll_handler(struct io_kiocb *req, unsigned issue_flags);
 bool io_poll_remove_all(struct io_ring_ctx *ctx, struct io_uring_task *tctx,
 			bool cancel_all);
 
-void io_poll_task_func(struct io_kiocb *req, io_tw_token_t tw);
+void io_poll_task_func(struct io_tw_req tw_req, io_tw_token_t tw);
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 5b2241a5813c..828ac4f902b4 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -562,12 +562,13 @@ static inline int io_fixup_rw_res(struct io_kiocb *req, long res)
 			res += io->bytes_done;
 	}
 	return res;
 }
 
-void io_req_rw_complete(struct io_kiocb *req, io_tw_token_t tw)
+void io_req_rw_complete(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
 	struct kiocb *kiocb = &rw->kiocb;
 
 	if ((kiocb->ki_flags & IOCB_DIO_CALLER_COMP) && kiocb->dio_complete) {
 		long res = kiocb->dio_complete(rw->kiocb.private);
@@ -579,11 +580,11 @@ void io_req_rw_complete(struct io_kiocb *req, io_tw_token_t tw)
 
 	if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING))
 		req->cqe.flags |= io_put_kbuf(req, req->cqe.res, NULL);
 
 	io_req_rw_cleanup(req, 0);
-	io_req_task_complete(req, tw);
+	io_req_task_complete(tw_req, tw);
 }
 
 static void io_complete_rw(struct kiocb *kiocb, long res)
 {
 	struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb);
diff --git a/io_uring/rw.h b/io_uring/rw.h
index 129a53fe5482..9bd7fbf70ea9 100644
--- a/io_uring/rw.h
+++ b/io_uring/rw.h
@@ -44,9 +44,9 @@ int io_read(struct io_kiocb *req, unsigned int issue_flags);
 int io_write(struct io_kiocb *req, unsigned int issue_flags);
 int io_read_fixed(struct io_kiocb *req, unsigned int issue_flags);
 int io_write_fixed(struct io_kiocb *req, unsigned int issue_flags);
 void io_readv_writev_cleanup(struct io_kiocb *req);
 void io_rw_fail(struct io_kiocb *req);
-void io_req_rw_complete(struct io_kiocb *req, io_tw_token_t tw);
+void io_req_rw_complete(struct io_tw_req tw_req, io_tw_token_t tw);
 int io_read_mshot_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
 int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags);
 void io_rw_cache_free(const void *entry);
diff --git a/io_uring/timeout.c b/io_uring/timeout.c
index 444142ba9d04..d8fbbaf31cf3 100644
--- a/io_uring/timeout.c
+++ b/io_uring/timeout.c
@@ -66,12 +66,13 @@ static inline bool io_timeout_finish(struct io_timeout *timeout,
 	return true;
 }
 
 static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer);
 
-static void io_timeout_complete(struct io_kiocb *req, io_tw_token_t tw)
+static void io_timeout_complete(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
 	struct io_timeout_data *data = req->async_data;
 	struct io_ring_ctx *ctx = req->ctx;
 
 	if (!io_timeout_finish(timeout, data)) {
@@ -83,11 +84,11 @@ static void io_timeout_complete(struct io_kiocb *req, io_tw_token_t tw)
 			raw_spin_unlock_irq(&ctx->timeout_lock);
 			return;
 		}
 	}
 
-	io_req_task_complete(req, tw);
+	io_req_task_complete(tw_req, tw);
 }
 
 static __cold bool io_flush_killed_timeouts(struct list_head *list, int err)
 {
 	if (list_empty(list))
@@ -155,22 +156,24 @@ __cold void io_flush_timeouts(struct io_ring_ctx *ctx)
 	ctx->cq_last_tm_flush = seq;
 	raw_spin_unlock_irq(&ctx->timeout_lock);
 	io_flush_killed_timeouts(&list, 0);
 }
 
-static void io_req_tw_fail_links(struct io_kiocb *link, io_tw_token_t tw)
+static void io_req_tw_fail_links(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *link = tw_req.req;
+
 	io_tw_lock(link->ctx, tw);
 	while (link) {
 		struct io_kiocb *nxt = link->link;
 		long res = -ECANCELED;
 
 		if (link->flags & REQ_F_FAIL)
 			res = link->cqe.res;
 		link->link = NULL;
 		io_req_set_res(link, res, 0);
-		io_req_task_complete(link, tw);
+		io_req_task_complete((struct io_tw_req){link}, tw);
 		link = nxt;
 	}
 }
 
 static void io_fail_links(struct io_kiocb *req)
@@ -315,12 +318,13 @@ int io_timeout_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd)
 		return PTR_ERR(req);
 	io_req_task_queue_fail(req, -ECANCELED);
 	return 0;
 }
 
-static void io_req_task_link_timeout(struct io_kiocb *req, io_tw_token_t tw)
+static void io_req_task_link_timeout(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
 	struct io_kiocb *prev = timeout->prev;
 	int ret;
 
 	if (prev) {
@@ -333,15 +337,15 @@ static void io_req_task_link_timeout(struct io_kiocb *req, io_tw_token_t tw)
 			ret = io_try_cancel(req->tctx, &cd, 0);
 		} else {
 			ret = -ECANCELED;
 		}
 		io_req_set_res(req, ret ?: -ETIME, 0);
-		io_req_task_complete(req, tw);
+		io_req_task_complete(tw_req, tw);
 		io_put_req(prev);
 	} else {
 		io_req_set_res(req, -ETIME, 0);
-		io_req_task_complete(req, tw);
+		io_req_task_complete(tw_req, tw);
 	}
 }
 
 static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
 {
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 9d67a2a721aa..c09b99e91c86 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -111,12 +111,13 @@ void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
 		io_ring_submit_unlock(ctx, issue_flags);
 	}
 }
 EXPORT_SYMBOL_GPL(io_uring_cmd_mark_cancelable);
 
-static void io_uring_cmd_work(struct io_kiocb *req, io_tw_token_t tw)
+static void io_uring_cmd_work(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
 	unsigned int flags = IO_URING_F_COMPLETE_DEFER;
 
 	if (unlikely(tw.cancel))
 		flags |= IO_URING_F_TASK_DEAD;
diff --git a/io_uring/waitid.c b/io_uring/waitid.c
index c5e0d979903a..62f7f1f004a5 100644
--- a/io_uring/waitid.c
+++ b/io_uring/waitid.c
@@ -14,11 +14,11 @@
 #include "io_uring.h"
 #include "cancel.h"
 #include "waitid.h"
 #include "../kernel/exit.h"
 
-static void io_waitid_cb(struct io_kiocb *req, io_tw_token_t tw);
+static void io_waitid_cb(struct io_tw_req tw_req, io_tw_token_t tw);
 
 #define IO_WAITID_CANCEL_FLAG	BIT(31)
 #define IO_WAITID_REF_MASK	GENMASK(30, 0)
 
 struct io_waitid {
@@ -192,12 +192,13 @@ static inline bool io_waitid_drop_issue_ref(struct io_kiocb *req)
 	req->io_task_work.func = io_waitid_cb;
 	io_req_task_work_add(req);
 	return true;
 }
 
-static void io_waitid_cb(struct io_kiocb *req, io_tw_token_t tw)
+static void io_waitid_cb(struct io_tw_req tw_req, io_tw_token_t tw)
 {
+	struct io_kiocb *req = tw_req.req;
 	struct io_waitid_async *iwa = req->async_data;
 	struct io_ring_ctx *ctx = req->ctx;
 	int ret;
 
 	io_tw_lock(ctx, tw);
@@ -227,11 +228,11 @@ static void io_waitid_cb(struct io_kiocb *req, io_tw_token_t tw)
 			/* fall through to complete, will kill waitqueue */
 		}
 	}
 
 	io_waitid_complete(req, ret);
-	io_req_task_complete(req, tw);
+	io_req_task_complete(tw_req, tw);
 }
 
 static int io_waitid_wait(struct wait_queue_entry *wait, unsigned mode,
 			  int sync, void *key)
 {
-- 
2.45.2