1 | /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ |
2 | #ifndef _LINUX_CACHEFILES_H |
3 | #define _LINUX_CACHEFILES_H |
4 | |
5 | #include <linux/types.h> |
6 | #include <linux/ioctl.h> |
7 | |
8 | /* |
9 | * Fscache ensures that the maximum length of cookie key is 255. The volume key |
10 | * is controlled by netfs, and generally no bigger than 255. |
11 | */ |
12 | #define CACHEFILES_MSG_MAX_SIZE 1024 |
13 | |
14 | enum cachefiles_opcode { |
15 | CACHEFILES_OP_OPEN, |
16 | CACHEFILES_OP_CLOSE, |
17 | CACHEFILES_OP_READ, |
18 | }; |
19 | |
20 | /* |
21 | * Message Header |
22 | * |
23 | * @msg_id a unique ID identifying this message |
24 | * @opcode message type, CACHEFILE_OP_* |
25 | * @len message length, including message header and following data |
26 | * @object_id a unique ID identifying a cache file |
27 | * @data message type specific payload |
28 | */ |
29 | struct cachefiles_msg { |
30 | __u32 msg_id; |
31 | __u32 opcode; |
32 | __u32 len; |
33 | __u32 object_id; |
34 | __u8 data[]; |
35 | }; |
36 | |
37 | /* |
38 | * @data contains the volume_key followed directly by the cookie_key. volume_key |
39 | * is a NUL-terminated string; @volume_key_size indicates the size of the volume |
40 | * key in bytes. cookie_key is binary data, which is netfs specific; |
41 | * @cookie_key_size indicates the size of the cookie key in bytes. |
42 | * |
43 | * @fd identifies an anon_fd referring to the cache file. |
44 | */ |
45 | struct cachefiles_open { |
46 | __u32 volume_key_size; |
47 | __u32 cookie_key_size; |
48 | __u32 fd; |
49 | __u32 flags; |
50 | __u8 data[]; |
51 | }; |
52 | |
53 | /* |
54 | * @off indicates the starting offset of the requested file range |
55 | * @len indicates the length of the requested file range |
56 | */ |
57 | struct cachefiles_read { |
58 | __u64 off; |
59 | __u64 len; |
60 | }; |
61 | |
62 | /* |
63 | * Reply for READ request |
64 | * @arg for this ioctl is the @id field of READ request. |
65 | */ |
66 | #define CACHEFILES_IOC_READ_COMPLETE _IOW(0x98, 1, int) |
67 | |
68 | #endif |
69 | |