1 files changed, 102 insertions, 0 deletions

diff --git a/io_uring/notif.c b/io_uring/notif.c
new file mode 100644
index 000000000000..6ee948af6a49
--- /dev/null
+++ b/io_uring/notif.c
@@ -0,0 +1,102 @@
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/net.h>
+#include <linux/io_uring.h>
+
+#include "io_uring.h"
+#include "notif.h"
+
+static void __io_notif_complete_tw(struct callback_head *cb)
+{
+	struct io_notif *notif = container_of(cb, struct io_notif, task_work);
+	struct io_ring_ctx *ctx = notif->ctx;
+
+	io_cq_lock(ctx);
+	io_fill_cqe_aux(ctx, notif->tag, 0, notif->seq, true);
+	io_cq_unlock_post(ctx);
+
+	percpu_ref_put(&ctx->refs);
+	kfree(notif);
+}
+
+static inline void io_notif_complete(struct io_notif *notif)
+{
+	__io_notif_complete_tw(&notif->task_work);
+}
+
+static void io_notif_complete_wq(struct work_struct *work)
+{
+	struct io_notif *notif = container_of(work, struct io_notif, commit_work);
+
+	io_notif_complete(notif);
+}
+
+static void io_uring_tx_zerocopy_callback(struct sk_buff *skb,
+					  struct ubuf_info *uarg,
+					  bool success)
+{
+	struct io_notif *notif = container_of(uarg, struct io_notif, uarg);
+
+	if (!refcount_dec_and_test(&uarg->refcnt))
+		return;
+	INIT_WORK(&notif->commit_work, io_notif_complete_wq);
+	queue_work(system_unbound_wq, &notif->commit_work);
+}
+
+struct io_notif *io_alloc_notif(struct io_ring_ctx *ctx,
+				struct io_notif_slot *slot)
+	__must_hold(&ctx->uring_lock)
+{
+	struct io_notif *notif;
+
+	notif = kzalloc(sizeof(*notif), GFP_ATOMIC | __GFP_ACCOUNT);
+	if (!notif)
+		return NULL;
+
+	notif->seq = slot->seq++;
+	notif->tag = slot->tag;
+	notif->ctx = ctx;
+	notif->uarg.flags = SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN;
+	notif->uarg.callback = io_uring_tx_zerocopy_callback;
+	/* master ref owned by io_notif_slot, will be dropped on flush */
+	refcount_set(&notif->uarg.refcnt, 1);
+	percpu_ref_get(&ctx->refs);
+	return notif;
+}
+
+static void io_notif_slot_flush(struct io_notif_slot *slot)
+	__must_hold(&ctx->uring_lock)
+{
+	struct io_notif *notif = slot->notif;
+
+	slot->notif = NULL;
+
+	if (WARN_ON_ONCE(in_interrupt()))
+		return;
+	/* drop slot's master ref */
+	if (refcount_dec_and_test(&notif->uarg.refcnt))
+		io_notif_complete(notif);
+}
+
+__cold int io_notif_unregister(struct io_ring_ctx *ctx)
+	__must_hold(&ctx->uring_lock)
+{
+	int i;
+
+	if (!ctx->notif_slots)
+		return -ENXIO;
+
+	for (i = 0; i < ctx->nr_notif_slots; i++) {
+		struct io_notif_slot *slot = &ctx->notif_slots[i];
+
+		if (slot->notif)
+			io_notif_slot_flush(slot);
+	}
+
+	kvfree(ctx->notif_slots);
+	ctx->notif_slots = NULL;
+	ctx->nr_notif_slots = 0;
+	return 0;
+}
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