xref: /openbmc/linux/io_uring/advise.c (revision f5c27da4)
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 
11 #include <uapi/linux/fadvise.h>
12 #include <uapi/linux/io_uring.h>
13 
14 #include "io_uring.h"
15 #include "advise.h"
16 
17 struct io_fadvise {
18 	struct file			*file;
19 	u64				offset;
20 	u32				len;
21 	u32				advice;
22 };
23 
24 struct io_madvise {
25 	struct file			*file;
26 	u64				addr;
27 	u32				len;
28 	u32				advice;
29 };
30 
31 int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
32 {
33 #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
34 	struct io_madvise *ma = io_kiocb_to_cmd(req, struct io_madvise);
35 
36 	if (sqe->buf_index || sqe->off || sqe->splice_fd_in)
37 		return -EINVAL;
38 
39 	ma->addr = READ_ONCE(sqe->addr);
40 	ma->len = READ_ONCE(sqe->len);
41 	ma->advice = READ_ONCE(sqe->fadvise_advice);
42 	return 0;
43 #else
44 	return -EOPNOTSUPP;
45 #endif
46 }
47 
48 int io_madvise(struct io_kiocb *req, unsigned int issue_flags)
49 {
50 #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
51 	struct io_madvise *ma = io_kiocb_to_cmd(req, struct io_madvise);
52 	int ret;
53 
54 	if (issue_flags & IO_URING_F_NONBLOCK)
55 		return -EAGAIN;
56 
57 	ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice);
58 	io_req_set_res(req, ret, 0);
59 	return IOU_OK;
60 #else
61 	return -EOPNOTSUPP;
62 #endif
63 }
64 
65 int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
66 {
67 	struct io_fadvise *fa = io_kiocb_to_cmd(req, struct io_fadvise);
68 
69 	if (sqe->buf_index || sqe->addr || sqe->splice_fd_in)
70 		return -EINVAL;
71 
72 	fa->offset = READ_ONCE(sqe->off);
73 	fa->len = READ_ONCE(sqe->len);
74 	fa->advice = READ_ONCE(sqe->fadvise_advice);
75 	return 0;
76 }
77 
78 int io_fadvise(struct io_kiocb *req, unsigned int issue_flags)
79 {
80 	struct io_fadvise *fa = io_kiocb_to_cmd(req, struct io_fadvise);
81 	int ret;
82 
83 	if (issue_flags & IO_URING_F_NONBLOCK) {
84 		switch (fa->advice) {
85 		case POSIX_FADV_NORMAL:
86 		case POSIX_FADV_RANDOM:
87 		case POSIX_FADV_SEQUENTIAL:
88 			break;
89 		default:
90 			return -EAGAIN;
91 		}
92 	}
93 
94 	ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
95 	if (ret < 0)
96 		req_set_fail(req);
97 	io_req_set_res(req, ret, 0);
98 	return IOU_OK;
99 }
100