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