1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/errno.h>
4 #include <linux/fs.h>
5 #include <linux/file.h>
6 #include <linux/mm.h>
7 #include <linux/slab.h>
8 #include <linux/namei.h>
9 #include <linux/io_uring.h>
10 #include <linux/splice.h>
11
12 #include <uapi/linux/io_uring.h>
13
14 #include "io_uring.h"
15 #include "splice.h"
16
17 struct io_splice {
18 struct file *file_out;
19 loff_t off_out;
20 loff_t off_in;
21 u64 len;
22 int splice_fd_in;
23 unsigned int flags;
24 struct io_rsrc_node *rsrc_node;
25 };
26
__io_splice_prep(struct io_kiocb * req,const struct io_uring_sqe * sqe)27 static int __io_splice_prep(struct io_kiocb *req,
28 const struct io_uring_sqe *sqe)
29 {
30 struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
31 unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
32
33 sp->len = READ_ONCE(sqe->len);
34 sp->flags = READ_ONCE(sqe->splice_flags);
35 if (unlikely(sp->flags & ~valid_flags))
36 return -EINVAL;
37 sp->splice_fd_in = READ_ONCE(sqe->splice_fd_in);
38 sp->rsrc_node = NULL;
39 req->flags |= REQ_F_FORCE_ASYNC;
40 return 0;
41 }
42
io_tee_prep(struct io_kiocb * req,const struct io_uring_sqe * sqe)43 int io_tee_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
44 {
45 if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
46 return -EINVAL;
47 return __io_splice_prep(req, sqe);
48 }
49
io_splice_cleanup(struct io_kiocb * req)50 void io_splice_cleanup(struct io_kiocb *req)
51 {
52 struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
53
54 if (sp->rsrc_node)
55 io_put_rsrc_node(req->ctx, sp->rsrc_node);
56 }
57
io_splice_get_file(struct io_kiocb * req,unsigned int issue_flags)58 static struct file *io_splice_get_file(struct io_kiocb *req,
59 unsigned int issue_flags)
60 {
61 struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
62 struct io_ring_ctx *ctx = req->ctx;
63 struct io_rsrc_node *node;
64 struct file *file = NULL;
65
66 if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
67 return io_file_get_normal(req, sp->splice_fd_in);
68
69 io_ring_submit_lock(ctx, issue_flags);
70 node = io_rsrc_node_lookup(&ctx->file_table.data, sp->splice_fd_in);
71 if (node) {
72 node->refs++;
73 sp->rsrc_node = node;
74 file = io_slot_file(node);
75 req->flags |= REQ_F_NEED_CLEANUP;
76 }
77 io_ring_submit_unlock(ctx, issue_flags);
78 return file;
79 }
80
io_tee(struct io_kiocb * req,unsigned int issue_flags)81 int io_tee(struct io_kiocb *req, unsigned int issue_flags)
82 {
83 struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
84 struct file *out = sp->file_out;
85 unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
86 struct file *in;
87 ssize_t ret = 0;
88
89 WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
90
91 in = io_splice_get_file(req, issue_flags);
92 if (!in) {
93 ret = -EBADF;
94 goto done;
95 }
96
97 if (sp->len)
98 ret = do_tee(in, out, sp->len, flags);
99
100 if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
101 fput(in);
102 done:
103 if (ret != sp->len)
104 req_set_fail(req);
105 io_req_set_res(req, ret, 0);
106 return IOU_OK;
107 }
108
io_splice_prep(struct io_kiocb * req,const struct io_uring_sqe * sqe)109 int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
110 {
111 struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
112
113 sp->off_in = READ_ONCE(sqe->splice_off_in);
114 sp->off_out = READ_ONCE(sqe->off);
115 return __io_splice_prep(req, sqe);
116 }
117
io_splice(struct io_kiocb * req,unsigned int issue_flags)118 int io_splice(struct io_kiocb *req, unsigned int issue_flags)
119 {
120 struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
121 struct file *out = sp->file_out;
122 unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
123 loff_t *poff_in, *poff_out;
124 struct file *in;
125 ssize_t ret = 0;
126
127 WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
128
129 in = io_splice_get_file(req, issue_flags);
130 if (!in) {
131 ret = -EBADF;
132 goto done;
133 }
134
135 poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
136 poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
137
138 if (sp->len)
139 ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
140
141 if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
142 fput(in);
143 done:
144 if (ret != sp->len)
145 req_set_fail(req);
146 io_req_set_res(req, ret, 0);
147 return IOU_OK;
148 }
149