/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _LINUX_CACHEFILES_H
#define _LINUX_CACHEFILES_H
#include <linux/types.h>
#include <linux/ioctl.h>
/*
* Fscache ensures that the maximum length of cookie key is 255. The volume key
* is controlled by netfs, and generally no bigger than 255.
*/
#define CACHEFILES_MSG_MAX_SIZE 1024
enum cachefiles_opcode {
CACHEFILES_OP_OPEN,
CACHEFILES_OP_CLOSE,
CACHEFILES_OP_READ,
};
/*
* Message Header
*
* @msg_id a unique ID identifying this message
* @opcode message type, CACHEFILE_OP_*
* @len message length, including message header and following data
* @object_id a unique ID identifying a cache file
* @data message type specific payload
*/
struct cachefiles_msg {
__u32 msg_id;
__u32 opcode;
__u32 len;
__u32 object_id;
__u8 data[];
};
/*
* @data contains the volume_key followed directly by the cookie_key. volume_key
* is a NUL-terminated string; @volume_key_size indicates the size of the volume
* key in bytes. cookie_key is binary data, which is netfs specific;
* @cookie_key_size indicates the size of the cookie key in bytes.
*
* @fd identifies an anon_fd referring to the cache file.
*/
struct cachefiles_open {
__u32 volume_key_size;
__u32 cookie_key_size;
__u32 fd;
__u32 flags;
__u8 data[];
};
/*
* @off indicates the starting offset of the requested file range
* @len indicates the length of the requested file range
*/
struct cachefiles_read {
__u64 off;
__u64 len;
};
/*
* Reply for READ request
* @arg for this ioctl is the @id field of READ request.
*/
#define CACHEFILES_IOC_READ_COMPLETE _IOW(0x98, 1, int)
#endif
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