summaryrefslogtreecommitdiffstats
path: root/io_uring/notif.c
blob: 977736e82c1aab5c5870619b7bc18c70bfa94448 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
#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"
#include "rsrc.h"

static void __io_notif_complete_tw(struct io_kiocb *notif, bool *locked)
{
	struct io_notif_data *nd = io_notif_to_data(notif);
	struct io_ring_ctx *ctx = notif->ctx;

	if (nd->account_pages && ctx->user) {
		__io_unaccount_mem(ctx->user, nd->account_pages);
		nd->account_pages = 0;
	}
	io_req_task_complete(notif, locked);
}

static inline void io_notif_complete(struct io_kiocb *notif)
	__must_hold(&notif->ctx->uring_lock)
{
	bool locked = true;

	__io_notif_complete_tw(notif, &locked);
}

static void io_uring_tx_zerocopy_callback(struct sk_buff *skb,
					  struct ubuf_info *uarg,
					  bool success)
{
	struct io_notif_data *nd = container_of(uarg, struct io_notif_data, uarg);
	struct io_kiocb *notif = cmd_to_io_kiocb(nd);

	if (refcount_dec_and_test(&uarg->refcnt)) {
		notif->io_task_work.func = __io_notif_complete_tw;
		io_req_task_work_add(notif);
	}
}

struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx,
				struct io_notif_slot *slot)
	__must_hold(&ctx->uring_lock)
{
	struct io_kiocb *notif;
	struct io_notif_data *nd;

	if (unlikely(!io_alloc_req_refill(ctx)))
		return NULL;
	notif = io_alloc_req(ctx);
	notif->opcode = IORING_OP_NOP;
	notif->flags = 0;
	notif->file = NULL;
	notif->task = current;
	io_get_task_refs(1);
	notif->rsrc_node = NULL;
	io_req_set_rsrc_node(notif, ctx, 0);
	notif->cqe.user_data = slot->tag;
	notif->cqe.flags = slot->seq++;
	notif->cqe.res = 0;

	nd = io_notif_to_data(notif);
	nd->account_pages = 0;
	nd->uarg.flags = SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN;
	nd->uarg.callback = io_uring_tx_zerocopy_callback;
	/* master ref owned by io_notif_slot, will be dropped on flush */
	refcount_set(&nd->uarg.refcnt, 1);
	return notif;
}

void io_notif_slot_flush(struct io_notif_slot *slot)
	__must_hold(&ctx->uring_lock)
{
	struct io_kiocb *notif = slot->notif;
	struct io_notif_data *nd = io_notif_to_data(notif);

	slot->notif = NULL;

	/* drop slot's master ref */
	if (refcount_dec_and_test(&nd->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];
		struct io_kiocb *notif = slot->notif;
		struct io_notif_data *nd;

		if (!notif)
			continue;
		nd = io_notif_to_data(notif);
		slot->notif = NULL;
		if (!refcount_dec_and_test(&nd->uarg.refcnt))
			continue;
		notif->io_task_work.func = __io_notif_complete_tw;
		io_req_task_work_add(notif);
	}

	kvfree(ctx->notif_slots);
	ctx->notif_slots = NULL;
	ctx->nr_notif_slots = 0;
	return 0;
}

__cold int io_notif_register(struct io_ring_ctx *ctx,
			     void __user *arg, unsigned int size)
	__must_hold(&ctx->uring_lock)
{
	struct io_uring_notification_slot __user *slots;
	struct io_uring_notification_slot slot;
	struct io_uring_notification_register reg;
	unsigned i;

	if (ctx->nr_notif_slots)
		return -EBUSY;
	if (size != sizeof(reg))
		return -EINVAL;
	if (copy_from_user(&reg, arg, sizeof(reg)))
		return -EFAULT;
	if (!reg.nr_slots || reg.nr_slots > IORING_MAX_NOTIF_SLOTS)
		return -EINVAL;
	if (reg.resv || reg.resv2 || reg.resv3)
		return -EINVAL;

	slots = u64_to_user_ptr(reg.data);
	ctx->notif_slots = kvcalloc(reg.nr_slots, sizeof(ctx->notif_slots[0]),
				GFP_KERNEL_ACCOUNT);
	if (!ctx->notif_slots)
		return -ENOMEM;

	for (i = 0; i < reg.nr_slots; i++, ctx->nr_notif_slots++) {
		struct io_notif_slot *notif_slot = &ctx->notif_slots[i];

		if (copy_from_user(&slot, &slots[i], sizeof(slot))) {
			io_notif_unregister(ctx);
			return -EFAULT;
		}
		if (slot.resv[0] | slot.resv[1] | slot.resv[2]) {
			io_notif_unregister(ctx);
			return -EINVAL;
		}
		notif_slot->tag = slot.tag;
	}
	return 0;
}