xref: /openbmc/linux/io_uring/advise.c (revision 20a55463)
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 	req->flags |= REQ_F_FORCE_ASYNC;
43 	return 0;
44 #else
45 	return -EOPNOTSUPP;
46 #endif
47 }
48 
49 int io_madvise(struct io_kiocb *req, unsigned int issue_flags)
50 {
51 #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
52 	struct io_madvise *ma = io_kiocb_to_cmd(req, struct io_madvise);
53 	int ret;
54 
55 	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
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 static bool io_fadvise_force_async(struct io_fadvise *fa)
66 {
67 	switch (fa->advice) {
68 	case POSIX_FADV_NORMAL:
69 	case POSIX_FADV_RANDOM:
70 	case POSIX_FADV_SEQUENTIAL:
71 		return false;
72 	default:
73 		return true;
74 	}
75 }
76 
77 int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
78 {
79 	struct io_fadvise *fa = io_kiocb_to_cmd(req, struct io_fadvise);
80 
81 	if (sqe->buf_index || sqe->addr || sqe->splice_fd_in)
82 		return -EINVAL;
83 
84 	fa->offset = READ_ONCE(sqe->off);
85 	fa->len = READ_ONCE(sqe->len);
86 	fa->advice = READ_ONCE(sqe->fadvise_advice);
87 	if (io_fadvise_force_async(fa))
88 		req->flags |= REQ_F_FORCE_ASYNC;
89 	return 0;
90 }
91 
92 int io_fadvise(struct io_kiocb *req, unsigned int issue_flags)
93 {
94 	struct io_fadvise *fa = io_kiocb_to_cmd(req, struct io_fadvise);
95 	int ret;
96 
97 	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK && io_fadvise_force_async(fa));
98 
99 	ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
100 	if (ret < 0)
101 		req_set_fail(req);
102 	io_req_set_res(req, ret, 0);
103 	return IOU_OK;
104 }
105