xref: /openbmc/linux/io_uring/splice.c (revision 1edd0337)
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 };
25 
26 static int __io_splice_prep(struct io_kiocb *req,
27 			    const struct io_uring_sqe *sqe)
28 {
29 	struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
30 	unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
31 
32 	sp->len = READ_ONCE(sqe->len);
33 	sp->flags = READ_ONCE(sqe->splice_flags);
34 	if (unlikely(sp->flags & ~valid_flags))
35 		return -EINVAL;
36 	sp->splice_fd_in = READ_ONCE(sqe->splice_fd_in);
37 	req->flags |= REQ_F_FORCE_ASYNC;
38 	return 0;
39 }
40 
41 int io_tee_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
42 {
43 	if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
44 		return -EINVAL;
45 	return __io_splice_prep(req, sqe);
46 }
47 
48 int io_tee(struct io_kiocb *req, unsigned int issue_flags)
49 {
50 	struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
51 	struct file *out = sp->file_out;
52 	unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
53 	struct file *in;
54 	long ret = 0;
55 
56 	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
57 
58 	if (sp->flags & SPLICE_F_FD_IN_FIXED)
59 		in = io_file_get_fixed(req, sp->splice_fd_in, issue_flags);
60 	else
61 		in = io_file_get_normal(req, sp->splice_fd_in);
62 	if (!in) {
63 		ret = -EBADF;
64 		goto done;
65 	}
66 
67 	if (sp->len)
68 		ret = do_tee(in, out, sp->len, flags);
69 
70 	if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
71 		io_put_file(in);
72 done:
73 	if (ret != sp->len)
74 		req_set_fail(req);
75 	io_req_set_res(req, ret, 0);
76 	return IOU_OK;
77 }
78 
79 int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
80 {
81 	struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
82 
83 	sp->off_in = READ_ONCE(sqe->splice_off_in);
84 	sp->off_out = READ_ONCE(sqe->off);
85 	return __io_splice_prep(req, sqe);
86 }
87 
88 int io_splice(struct io_kiocb *req, unsigned int issue_flags)
89 {
90 	struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
91 	struct file *out = sp->file_out;
92 	unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
93 	loff_t *poff_in, *poff_out;
94 	struct file *in;
95 	long ret = 0;
96 
97 	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
98 
99 	if (sp->flags & SPLICE_F_FD_IN_FIXED)
100 		in = io_file_get_fixed(req, sp->splice_fd_in, issue_flags);
101 	else
102 		in = io_file_get_normal(req, sp->splice_fd_in);
103 	if (!in) {
104 		ret = -EBADF;
105 		goto done;
106 	}
107 
108 	poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
109 	poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
110 
111 	if (sp->len)
112 		ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
113 
114 	if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
115 		io_put_file(in);
116 done:
117 	if (ret != sp->len)
118 		req_set_fail(req);
119 	io_req_set_res(req, ret, 0);
120 	return IOU_OK;
121 }
122