/* SPDX-License-Identifier: GPL-2.0 */
  #ifndef _FS_CEPH_MDS_METRIC_H
  #define _FS_CEPH_MDS_METRIC_H
  
  #include <linux/types.h>
  #include <linux/percpu_counter.h>

  #include <linux/ktime.h>

  extern bool disable_send_metrics;
  
  enum ceph_metric_type {
  	CLIENT_METRIC_TYPE_CAP_INFO,
  	CLIENT_METRIC_TYPE_READ_LATENCY,
  	CLIENT_METRIC_TYPE_WRITE_LATENCY,
  	CLIENT_METRIC_TYPE_METADATA_LATENCY,
  	CLIENT_METRIC_TYPE_DENTRY_LEASE,
  
  	CLIENT_METRIC_TYPE_MAX = CLIENT_METRIC_TYPE_DENTRY_LEASE,
  };

  /*
   * This will always have the highest metric bit value
   * as the last element of the array.
   */
  #define CEPHFS_METRIC_SPEC_CLIENT_SUPPORTED {	\
  	CLIENT_METRIC_TYPE_CAP_INFO,		\
  	CLIENT_METRIC_TYPE_READ_LATENCY,	\
  	CLIENT_METRIC_TYPE_WRITE_LATENCY,	\
  	CLIENT_METRIC_TYPE_METADATA_LATENCY,	\
  						\
  	CLIENT_METRIC_TYPE_MAX,			\
  }

  /* metric caps header */
  struct ceph_metric_cap {
  	__le32 type;     /* ceph metric type */
  
  	__u8  ver;
  	__u8  compat;
  
  	__le32 data_len; /* length of sizeof(hit + mis + total) */
  	__le64 hit;
  	__le64 mis;
  	__le64 total;
  } __packed;
  
  /* metric read latency header */
  struct ceph_metric_read_latency {
  	__le32 type;     /* ceph metric type */
  
  	__u8  ver;
  	__u8  compat;
  
  	__le32 data_len; /* length of sizeof(sec + nsec) */
  	__le32 sec;
  	__le32 nsec;
  } __packed;
  
  /* metric write latency header */
  struct ceph_metric_write_latency {
  	__le32 type;     /* ceph metric type */
  
  	__u8  ver;
  	__u8  compat;
  
  	__le32 data_len; /* length of sizeof(sec + nsec) */
  	__le32 sec;
  	__le32 nsec;
  } __packed;
  
  /* metric metadata latency header */
  struct ceph_metric_metadata_latency {
  	__le32 type;     /* ceph metric type */
  
  	__u8  ver;
  	__u8  compat;
  
  	__le32 data_len; /* length of sizeof(sec + nsec) */
  	__le32 sec;
  	__le32 nsec;
  } __packed;
  
  struct ceph_metric_head {
  	__le32 num;	/* the number of metrics that will be sent */
  } __packed;

  /* This is the global metrics */
  struct ceph_client_metric {
  	atomic64_t            total_dentries;
  	struct percpu_counter d_lease_hit;
  	struct percpu_counter d_lease_mis;

  	atomic64_t            total_caps;

  	struct percpu_counter i_caps_hit;
  	struct percpu_counter i_caps_mis;

  
  	spinlock_t read_latency_lock;
  	u64 total_reads;
  	ktime_t read_latency_sum;
  	ktime_t read_latency_sq_sum;
  	ktime_t read_latency_min;
  	ktime_t read_latency_max;
  
  	spinlock_t write_latency_lock;
  	u64 total_writes;
  	ktime_t write_latency_sum;
  	ktime_t write_latency_sq_sum;
  	ktime_t write_latency_min;
  	ktime_t write_latency_max;

  
  	spinlock_t metadata_latency_lock;
  	u64 total_metadatas;
  	ktime_t metadata_latency_sum;
  	ktime_t metadata_latency_sq_sum;
  	ktime_t metadata_latency_min;
  	ktime_t metadata_latency_max;

  	/* The total number of directories and files that are opened */
  	atomic64_t opened_files;
  
  	/* The total number of inodes that have opened files or directories */
  	struct percpu_counter opened_inodes;
  	struct percpu_counter total_inodes;

  	struct ceph_mds_session *session;
  	struct delayed_work delayed_work;  /* delayed work */

  };

  static inline void metric_schedule_delayed(struct ceph_client_metric *m)
  {
  	if (disable_send_metrics)
  		return;
  
  	/* per second */
  	schedule_delayed_work(&m->delayed_work, round_jiffies_relative(HZ));
  }

  extern int ceph_metric_init(struct ceph_client_metric *m);
  extern void ceph_metric_destroy(struct ceph_client_metric *m);

  
  static inline void ceph_update_cap_hit(struct ceph_client_metric *m)
  {
  	percpu_counter_inc(&m->i_caps_hit);
  }
  
  static inline void ceph_update_cap_mis(struct ceph_client_metric *m)
  {
  	percpu_counter_inc(&m->i_caps_mis);
  }

  
  extern void ceph_update_read_latency(struct ceph_client_metric *m,
  				     ktime_t r_start, ktime_t r_end,
  				     int rc);
  extern void ceph_update_write_latency(struct ceph_client_metric *m,
  				      ktime_t r_start, ktime_t r_end,
  				      int rc);

  extern void ceph_update_metadata_latency(struct ceph_client_metric *m,
  				         ktime_t r_start, ktime_t r_end,
  					 int rc);

  #endif /* _FS_CEPH_MDS_METRIC_H */