xref: /linux/io_uring/splice.c (revision 43b46e6bc69c2aa4331cfd7fa4e2943a894339e5)
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 	return 0;
38 }
39 
40 int io_tee_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
41 {
42 	if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
43 		return -EINVAL;
44 	return __io_splice_prep(req, sqe);
45 }
46 
47 int io_tee(struct io_kiocb *req, unsigned int issue_flags)
48 {
49 	struct io_splice *sp = io_kiocb_to_cmd(req, struct io_splice);
50 	struct file *out = sp->file_out;
51 	unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
52 	struct file *in;
53 	long ret = 0;
54 
55 	if (issue_flags & IO_URING_F_NONBLOCK)
56 		return -EAGAIN;
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 	if (issue_flags & IO_URING_F_NONBLOCK)
98 		return -EAGAIN;
99 
100 	if (sp->flags & SPLICE_F_FD_IN_FIXED)
101 		in = io_file_get_fixed(req, sp->splice_fd_in, issue_flags);
102 	else
103 		in = io_file_get_normal(req, sp->splice_fd_in);
104 	if (!in) {
105 		ret = -EBADF;
106 		goto done;
107 	}
108 
109 	poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
110 	poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
111 
112 	if (sp->len)
113 		ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
114 
115 	if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
116 		io_put_file(in);
117 done:
118 	if (ret != sp->len)
119 		req_set_fail(req);
120 	io_req_set_res(req, ret, 0);
121 	return IOU_OK;
122 }
123