projects/linux·blob master · refs

141 lines · 3.5 KiB

1// SPDX-License-Identifier: GPL-2.0
2#include <linux/kernel.h>
3#include <linux/errno.h>
4#include <linux/file.h>
5#include <linux/slab.h>
6#include <linux/net.h>
7#include <linux/io_uring.h>
8
9#include "io_uring.h"
10#include "notif.h"
11#include "rsrc.h"
12
13static const struct ubuf_info_ops io_ubuf_ops;
14
15static void io_notif_tw_complete(struct io_tw_req tw_req, io_tw_token_t tw)
16{
17 struct io_kiocb *notif = tw_req.req;
18 struct io_notif_data *nd = io_notif_to_data(notif);
19 struct io_ring_ctx *ctx = notif->ctx;
20
21 lockdep_assert_held(&ctx->uring_lock);
22
23 do {
24 notif = cmd_to_io_kiocb(nd);
25
26 if (WARN_ON_ONCE(ctx != notif->ctx))
27 return;
28 lockdep_assert(refcount_read(&nd->uarg.refcnt) == 0);
29
30 if (unlikely(nd->zc_report) && (nd->zc_copied || !nd->zc_used))
31 notif->cqe.res |= IORING_NOTIF_USAGE_ZC_COPIED;
32
33 if (nd->account_pages && notif->ctx->user) {
34 __io_unaccount_mem(notif->ctx->user, nd->account_pages);
35 nd->account_pages = 0;
36 }
37
38 nd = nd->next;
39 io_req_task_complete((struct io_tw_req){notif}, tw);
40 } while (nd);
41}
42
43void io_tx_ubuf_complete(struct sk_buff *skb, struct ubuf_info *uarg,
44 bool success)
45{
46 struct io_notif_data *nd = container_of(uarg, struct io_notif_data, uarg);
47 struct io_kiocb *notif = cmd_to_io_kiocb(nd);
48 unsigned tw_flags;
49
50 if (nd->zc_report) {
51 if (success && !nd->zc_used && skb)
52 WRITE_ONCE(nd->zc_used, true);
53 else if (!success && !nd->zc_copied)
54 WRITE_ONCE(nd->zc_copied, true);
55 }
56
57 if (!refcount_dec_and_test(&uarg->refcnt))
58 return;
59
60 if (nd->head != nd) {
61 io_tx_ubuf_complete(skb, &nd->head->uarg, success);
62 return;
63 }
64
65 tw_flags = nd->next ? 0 : IOU_F_TWQ_LAZY_WAKE;
66 notif->io_task_work.func = io_notif_tw_complete;
67 __io_req_task_work_add(notif, tw_flags);
68}
69
70static int io_link_skb(struct sk_buff *skb, struct ubuf_info *uarg)
71{
72 struct io_notif_data *nd, *prev_nd;
73 struct io_kiocb *prev_notif, *notif;
74 struct ubuf_info *prev_uarg = skb_zcopy(skb);
75
76 nd = container_of(uarg, struct io_notif_data, uarg);
77 notif = cmd_to_io_kiocb(nd);
78
79 if (!prev_uarg) {
80 net_zcopy_get(&nd->uarg);
81 skb_zcopy_init(skb, &nd->uarg);
82 return 0;
83 }
84 /* handle it separately as we can't link a notif to itself */
85 if (unlikely(prev_uarg == &nd->uarg))
86 return 0;
87 /* we can't join two links together, just request a fresh skb */
88 if (unlikely(nd->head != nd || nd->next))
89 return -EEXIST;
90 /* don't mix zc providers */
91 if (unlikely(prev_uarg->ops != &io_ubuf_ops))
92 return -EEXIST;
93
94 prev_nd = container_of(prev_uarg, struct io_notif_data, uarg);
95 prev_notif = cmd_to_io_kiocb(prev_nd);
96
97 /* make sure all notifications can be finished in the same task_work */
98 if (unlikely(notif->ctx != prev_notif->ctx ||
99 notif->tctx != prev_notif->tctx))
100 return -EEXIST;
101
102 nd->head = prev_nd->head;
103 nd->next = prev_nd->next;
104 prev_nd->next = nd;
105 net_zcopy_get(&nd->head->uarg);
106 return 0;
107}
108
109static const struct ubuf_info_ops io_ubuf_ops = {
110 .complete = io_tx_ubuf_complete,
111 .link_skb = io_link_skb,
112};
113
114struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx)
115 __must_hold(&ctx->uring_lock)
116{
117 struct io_kiocb *notif;
118 struct io_notif_data *nd;
119
120 if (unlikely(!io_alloc_req(ctx, &notif)))
121 return NULL;
122 notif->ctx = ctx;
123 notif->opcode = IORING_OP_NOP;
124 notif->flags = 0;
125 notif->file = NULL;
126 notif->tctx = current->io_uring;
127 io_get_task_refs(1);
128 notif->file_node = NULL;
129 notif->buf_node = NULL;
130
131 nd = io_notif_to_data(notif);
132 nd->zc_report = false;
133 nd->account_pages = 0;
134 nd->next = NULL;
135 nd->head = nd;
136
137 nd->uarg.flags = IO_NOTIF_UBUF_FLAGS;
138 nd->uarg.ops = &io_ubuf_ops;
139 refcount_set(&nd->uarg.refcnt, 1);
140 return notif;
141}