Merge branch 'for-6.10/io_uring' into net-accept-more

* for-6.10/io_uring: (97 commits)
  io_uring: support to inject result for NOP
  io_uring: fail NOP if non-zero op flags is passed in
  io_uring/net: add IORING_ACCEPT_POLL_FIRST flag
  io_uring/net: add IORING_ACCEPT_DONTWAIT flag
  io_uring/filetable: don't unnecessarily clear/reset bitmap
  io_uring/io-wq: Use set_bit() and test_bit() at worker->flags
  io_uring/msg_ring: cleanup posting to IOPOLL vs !IOPOLL ring
  io_uring: Require zeroed sqe->len on provided-buffers send
  io_uring/notif: disable LAZY_WAKE for linked notifs
  io_uring/net: fix sendzc lazy wake polling
  io_uring/msg_ring: reuse ctx->submitter_task read using READ_ONCE instead of re-reading it
  io_uring/rw: reinstate thread check for retries
  io_uring/notif: implement notification stacking
  io_uring/notif: simplify io_notif_flush()
  net: add callback for setting a ubuf_info to skb
  net: extend ubuf_info callback to ops structure
  io_uring/net: support bundles for recv
  io_uring/net: support bundles for send
  io_uring/kbuf: add helpers for getting/peeking multiple buffers
  io_uring/net: add provided buffer support for IORING_OP_SEND
  ...

Author: axboe

drivers/net/tap.c

@@ -754,7 +754,7 @@ static ssize_t tap_get_user(struct tap_queue *q, void *msg_control,
 		skb_zcopy_init(skb, msg_control);
 	} else if (msg_control) {
 		struct ubuf_info *uarg = msg_control;
-		uarg->callback(NULL, uarg, false);
+		uarg->ops->complete(NULL, uarg, false);
 	}
 
 	dev_queue_xmit(skb);

drivers/net/tun.c

@@ -1906,7 +1906,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 		skb_zcopy_init(skb, msg_control);
 	} else if (msg_control) {
 		struct ubuf_info *uarg = msg_control;
-		uarg->callback(NULL, uarg, false);
+		uarg->ops->complete(NULL, uarg, false);
 	}
 
 	skb_reset_network_header(skb);

drivers/net/xen-netback/common.h

@@ -390,9 +390,8 @@ bool xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb);
 
 void xenvif_carrier_on(struct xenvif *vif);
 
-/* Callback from stack when TX packet can be released */
-void xenvif_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *ubuf,
-			      bool zerocopy_success);
+/* Callbacks from stack when TX packet can be released */
+extern const struct ubuf_info_ops xenvif_ubuf_ops;
 
 static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue)
 {

drivers/net/xen-netback/interface.c

@@ -593,7 +593,7 @@ int xenvif_init_queue(struct xenvif_queue *queue)
 
 	for (i = 0; i < MAX_PENDING_REQS; i++) {
 		queue->pending_tx_info[i].callback_struct = (struct ubuf_info_msgzc)
-			{ { .callback = xenvif_zerocopy_callback },
+			{ { .ops = &xenvif_ubuf_ops },
 			  { { .ctx = NULL,
 			      .desc = i } } };
 		queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;

drivers/net/xen-netback/netback.c

@@ -1156,7 +1156,7 @@ static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *s
 	uarg = skb_shinfo(skb)->destructor_arg;
 	/* increase inflight counter to offset decrement in callback */
 	atomic_inc(&queue->inflight_packets);
-	uarg->callback(NULL, uarg, true);
+	uarg->ops->complete(NULL, uarg, true);
 	skb_shinfo(skb)->destructor_arg = NULL;
 
 	/* Fill the skb with the new (local) frags. */
@@ -1278,8 +1278,9 @@ static int xenvif_tx_submit(struct xenvif_queue *queue)
 	return work_done;
 }
 
-void xenvif_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *ubuf_base,
-			      bool zerocopy_success)
+static void xenvif_zerocopy_callback(struct sk_buff *skb,
+				     struct ubuf_info *ubuf_base,
+				     bool zerocopy_success)
 {
 	unsigned long flags;
 	pending_ring_idx_t index;
@@ -1312,6 +1313,10 @@ void xenvif_zerocopy_callback(struct sk_buff *skb, struct ubuf_info *ubuf_base,
 	xenvif_skb_zerocopy_complete(queue);
 }
 
+const struct ubuf_info_ops xenvif_ubuf_ops = {
+	.complete = xenvif_zerocopy_callback,
+};
+
 static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
 {
 	struct gnttab_unmap_grant_ref *gop;

drivers/nvme/host/ioctl.c

@@ -423,13 +423,20 @@ static enum rq_end_io_ret nvme_uring_cmd_end_io(struct request *req,
 	pdu->result = le64_to_cpu(nvme_req(req)->result.u64);
 
 	/*
-	 * For iopoll, complete it directly.
+	 * For iopoll, complete it directly. Note that using the uring_cmd
+	 * helper for this is safe only because we check blk_rq_is_poll().
+	 * As that returns false if we're NOT on a polled queue, then it's
+	 * safe to use the polled completion helper.
+	 *
 	 * Otherwise, move the completion to task work.
 	 */
-	if (blk_rq_is_poll(req))
-		nvme_uring_task_cb(ioucmd, IO_URING_F_UNLOCKED);
-	else
+	if (blk_rq_is_poll(req)) {
+		if (pdu->bio)
+			blk_rq_unmap_user(pdu->bio);
+		io_uring_cmd_iopoll_done(ioucmd, pdu->result, pdu->status);
+	} else {
 		io_uring_cmd_do_in_task_lazy(ioucmd, nvme_uring_task_cb);
+	}
 
 	return RQ_END_IO_FREE;
 }

drivers/vhost/net.c

@@ -380,7 +380,7 @@ static void vhost_zerocopy_signal_used(struct vhost_net *net,
 	}
 }
 
-static void vhost_zerocopy_callback(struct sk_buff *skb,
+static void vhost_zerocopy_complete(struct sk_buff *skb,
 				    struct ubuf_info *ubuf_base, bool success)
 {
 	struct ubuf_info_msgzc *ubuf = uarg_to_msgzc(ubuf_base);
@@ -408,6 +408,10 @@ static void vhost_zerocopy_callback(struct sk_buff *skb,
 	rcu_read_unlock_bh();
 }
 
+static const struct ubuf_info_ops vhost_ubuf_ops = {
+	.complete = vhost_zerocopy_complete,
+};
+
 static inline unsigned long busy_clock(void)
 {
 	return local_clock() >> 10;
@@ -879,7 +883,7 @@ static void handle_tx_zerocopy(struct vhost_net *net, struct socket *sock)
 			vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
 			ubuf->ctx = nvq->ubufs;
 			ubuf->desc = nvq->upend_idx;
-			ubuf->ubuf.callback = vhost_zerocopy_callback;
+			ubuf->ubuf.ops = &vhost_ubuf_ops;
 			ubuf->ubuf.flags = SKBFL_ZEROCOPY_FRAG;
 			refcount_set(&ubuf->ubuf.refcnt, 1);
 			msg.msg_control = &ctl;

include/linux/io_uring.h

@@ -11,7 +11,6 @@ void __io_uring_cancel(bool cancel_all);
 void __io_uring_free(struct task_struct *tsk);
 void io_uring_unreg_ringfd(void);
 const char *io_uring_get_opcode(u8 opcode);
-int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags);
 bool io_is_uring_fops(struct file *file);
 
 static inline void io_uring_files_cancel(void)
@@ -45,11 +44,6 @@ static inline const char *io_uring_get_opcode(u8 opcode)
 {
 	return "";
 }
-static inline int io_uring_cmd_sock(struct io_uring_cmd *cmd,
-				    unsigned int issue_flags)
-{
-	return -EOPNOTSUPP;
-}
 static inline bool io_is_uring_fops(struct file *file)
 {
 	return false;

include/linux/io_uring/cmd.h

@@ -26,12 +26,25 @@ static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe)
 #if defined(CONFIG_IO_URING)
 int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
 			      struct iov_iter *iter, void *ioucmd);
+
+/*
+ * Completes the request, i.e. posts an io_uring CQE and deallocates @ioucmd
+ * and the corresponding io_uring request.
+ *
+ * Note: the caller should never hard code @issue_flags and is only allowed
+ * to pass the mask provided by the core io_uring code.
+ */
 void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, ssize_t res2,
 			unsigned issue_flags);
+
 void __io_uring_cmd_do_in_task(struct io_uring_cmd *ioucmd,
 			    void (*task_work_cb)(struct io_uring_cmd *, unsigned),
 			    unsigned flags);
 
+/*
+ * Note: the caller should never hard code @issue_flags and only use the
+ * mask provided by the core io_uring code.
+ */
 void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
 		unsigned int issue_flags);
 
@@ -56,6 +69,17 @@ static inline void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
 }
 #endif
 
+/*
+ * Polled completions must ensure they are coming from a poll queue, and
+ * hence are completed inside the usual poll handling loops.
+ */
+static inline void io_uring_cmd_iopoll_done(struct io_uring_cmd *ioucmd,
+					    ssize_t ret, ssize_t res2)
+{
+	lockdep_assert(in_task());
+	io_uring_cmd_done(ioucmd, ret, res2, 0);
+}
+
 /* users must follow the IOU_F_TWQ_LAZY_WAKE semantics */
 static inline void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
 			void (*task_work_cb)(struct io_uring_cmd *, unsigned))

include/linux/io_uring/net.h

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _LINUX_IO_URING_NET_H
+#define _LINUX_IO_URING_NET_H
+
+struct io_uring_cmd;
+
+#if defined(CONFIG_IO_URING)
+int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags);
+
+#else
+static inline int io_uring_cmd_sock(struct io_uring_cmd *cmd,
+				    unsigned int issue_flags)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+#endif