root/include/linux/pr.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef LINUX_PR_H
#define LINUX_PR_H

#include <uapi/linux/pr.h>

struct pr_keys {
        u32     generation;
        u32     num_keys;
        u64     keys[];
};

struct pr_held_reservation {
        u64             key;
        u32             generation;
        enum pr_type    type;
};

struct pr_ops {
        int (*pr_register)(struct block_device *bdev, u64 old_key, u64 new_key,
                        u32 flags);
        int (*pr_reserve)(struct block_device *bdev, u64 key,
                        enum pr_type type, u32 flags);
        int (*pr_release)(struct block_device *bdev, u64 key,
                        enum pr_type type);
        int (*pr_preempt)(struct block_device *bdev, u64 old_key, u64 new_key,
                        enum pr_type type, bool abort);
        int (*pr_clear)(struct block_device *bdev, u64 key);
        /*
         * pr_read_keys - Read the registered keys and return them in the
         * pr_keys->keys array. The keys array will have been allocated at the
         * end of the pr_keys struct, and pr_keys->num_keys must be set to the
         * number of keys the array can hold. If there are more than can fit
         * in the array, success will still be returned and pr_keys->num_keys
         * will reflect the total number of keys the device contains, so the
         * caller can retry with a larger array.
         */
        int (*pr_read_keys)(struct block_device *bdev,
                        struct pr_keys *keys_info);
        int (*pr_read_reservation)(struct block_device *bdev,
                        struct pr_held_reservation *rsv);
};

#endif /* LINUX_PR_H */