Sindbad~EG File Manager

/**
@file
@brief    Process (aka task) info storage
@details  Copyright (c) 2017-2021 Acronis International GmbH
@author   Ivan Matveev (ivan.matveev@acronis.com)
@since    $Id: $
*/

#pragma once

#include "transport_protocol.h" // task_status_t

#include <linux/path.h>
#include <linux/rbtree.h>
#include <linux/spinlock.h>
#include <linux/types.h>  // bool

typedef struct {
	struct rb_node rb_node;
	pid_t pid;

	atomic_t ref_cnt;
	spinlock_t spinlock;

	task_status_t status;
	struct path exe_path;

	struct list_head exited_list_item;
    struct list_head clear_list_item;
    bool is_exe_path_changed;
} task_info_t;

typedef struct task_info_map_s {
    bool is_acquired;
	spinlock_t spinlock;
	struct rb_root root;

	spinlock_t exited_list_spinlock;
	struct list_head exited_list;
} task_info_map_t;

#define MAX_TASK_INFO_MAP_SIZE 4

const char *task_status_to_string(task_status_t status);

// on success return 0
int task_info_map_del_by_map_id(unsigned char map_id, pid_t pid);
// =========================  useful wrappers  ========================= //

// create task_info struct if needed
// errors:
// 1. ENOMEM - alloc failed
// 2. ENOENT - no such pid or task_struct without executable file
// 3. EINVAL - task_info with sutch pid already exist - synchronisation broken
int task_info_status_set_by_map_id(unsigned char map_id, pid_t pid, task_status_t status);

void task_info_map_clear_exited_list_by_map_id(unsigned char map_id);
void task_info_map_on_exit_event(pid_t tgid, pid_t pid);
typedef void (*for_each_task_info_with_pid)(task_info_t *task_info, void *arg);
unsigned char acquire_task_info_map(void);
void release_task_info_map(unsigned char id);
int check_exec_with_task_info(pid_t tgid, struct path exe_path);
void task_info_maps_init(void);
void task_info_maps_clear(void);
bool sys_call_fs_events_should_skip(pid_t pid, uint64_t events_mask);
void get_should_send_task_info_map_ids(bool *should_send_map_ids, msg_type_img_t msg_type);