fs/ceph/metric.c - linux/kernel/git/bpf/bpf - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/ceph/ceph_debug.h>

 #include <linux/types.h>
 #include <linux/percpu_counter.h>
 #include <linux/math64.h>

 #include "metric.h"
 #include "mds_client.h"

 static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
 				   struct ceph_mds_session *s)
 {
 	struct ceph_metric_head *head;
 	struct ceph_metric_cap *cap;
 	struct ceph_metric_read_latency *read;
 	struct ceph_metric_write_latency *write;
 	struct ceph_metric_metadata_latency *meta;
 	struct ceph_metric_dlease *dlease;
 	struct ceph_opened_files *files;
 	struct ceph_pinned_icaps *icaps;
 	struct ceph_opened_inodes *inodes;
 	struct ceph_client_metric *m = &mdsc->metric;
 	u64 nr_caps = atomic64_read(&m->total_caps);
 	struct ceph_msg *msg;
 	struct timespec64 ts;
 	s64 sum;
 	s32 items = 0;
 	s32 len;

 	len = sizeof(*head) + sizeof(*cap) + sizeof(*read) + sizeof(*write)
 	      + sizeof(*meta) + sizeof(*dlease) + sizeof(*files)
 	      + sizeof(*icaps) + sizeof(*inodes);

 	msg = ceph_msg_new(CEPH_MSG_CLIENT_METRICS, len, GFP_NOFS, true);
 	if (!msg) {
 		pr_err("send metrics to mds%d, failed to allocate message\n",
 		       s->s_mds);
 		return false;
 	}

 	head = msg->front.iov_base;

 	/* encode the cap metric */
 	cap = (struct ceph_metric_cap *)(head + 1);
 	cap->type = cpu_to_le32(CLIENT_METRIC_TYPE_CAP_INFO);
 	cap->ver = 1;
 	cap->compat = 1;
 	cap->data_len = cpu_to_le32(sizeof(*cap) - 10);
 	cap->hit = cpu_to_le64(percpu_counter_sum(&m->i_caps_hit));
 	cap->mis = cpu_to_le64(percpu_counter_sum(&m->i_caps_mis));
 	cap->total = cpu_to_le64(nr_caps);
 	items++;

 	/* encode the read latency metric */
 	read = (struct ceph_metric_read_latency *)(cap + 1);
 	read->type = cpu_to_le32(CLIENT_METRIC_TYPE_READ_LATENCY);
 	read->ver = 1;
 	read->compat = 1;
 	read->data_len = cpu_to_le32(sizeof(*read) - 10);
 	sum = m->read_latency_sum;
 	jiffies_to_timespec64(sum, &ts);
 	read->sec = cpu_to_le32(ts.tv_sec);
 	read->nsec = cpu_to_le32(ts.tv_nsec);
 	items++;

 	/* encode the write latency metric */
 	write = (struct ceph_metric_write_latency *)(read + 1);
 	write->type = cpu_to_le32(CLIENT_METRIC_TYPE_WRITE_LATENCY);
 	write->ver = 1;
 	write->compat = 1;
 	write->data_len = cpu_to_le32(sizeof(*write) - 10);
 	sum = m->write_latency_sum;
 	jiffies_to_timespec64(sum, &ts);
 	write->sec = cpu_to_le32(ts.tv_sec);
 	write->nsec = cpu_to_le32(ts.tv_nsec);
 	items++;

 	/* encode the metadata latency metric */
 	meta = (struct ceph_metric_metadata_latency *)(write + 1);
 	meta->type = cpu_to_le32(CLIENT_METRIC_TYPE_METADATA_LATENCY);
 	meta->ver = 1;
 	meta->compat = 1;
 	meta->data_len = cpu_to_le32(sizeof(*meta) - 10);
 	sum = m->metadata_latency_sum;
 	jiffies_to_timespec64(sum, &ts);
 	meta->sec = cpu_to_le32(ts.tv_sec);
 	meta->nsec = cpu_to_le32(ts.tv_nsec);
 	items++;

 	/* encode the dentry lease metric */
 	dlease = (struct ceph_metric_dlease *)(meta + 1);
 	dlease->type = cpu_to_le32(CLIENT_METRIC_TYPE_DENTRY_LEASE);
 	dlease->ver = 1;
 	dlease->compat = 1;
 	dlease->data_len = cpu_to_le32(sizeof(*dlease) - 10);
 	dlease->hit = cpu_to_le64(percpu_counter_sum(&m->d_lease_hit));
 	dlease->mis = cpu_to_le64(percpu_counter_sum(&m->d_lease_mis));
 	dlease->total = cpu_to_le64(atomic64_read(&m->total_dentries));
 	items++;

 	sum = percpu_counter_sum(&m->total_inodes);

 	/* encode the opened files metric */
 	files = (struct ceph_opened_files *)(dlease + 1);
 	files->type = cpu_to_le32(CLIENT_METRIC_TYPE_OPENED_FILES);
 	files->ver = 1;
 	files->compat = 1;
 	files->data_len = cpu_to_le32(sizeof(*files) - 10);
 	files->opened_files = cpu_to_le64(atomic64_read(&m->opened_files));
 	files->total = cpu_to_le64(sum);
 	items++;

 	/* encode the pinned icaps metric */
 	icaps = (struct ceph_pinned_icaps *)(files + 1);
 	icaps->type = cpu_to_le32(CLIENT_METRIC_TYPE_PINNED_ICAPS);
 	icaps->ver = 1;
 	icaps->compat = 1;
 	icaps->data_len = cpu_to_le32(sizeof(*icaps) - 10);
 	icaps->pinned_icaps = cpu_to_le64(nr_caps);
 	icaps->total = cpu_to_le64(sum);
 	items++;

 	/* encode the opened inodes metric */
 	inodes = (struct ceph_opened_inodes *)(icaps + 1);
 	inodes->type = cpu_to_le32(CLIENT_METRIC_TYPE_OPENED_INODES);
 	inodes->ver = 1;
 	inodes->compat = 1;
 	inodes->data_len = cpu_to_le32(sizeof(*inodes) - 10);
 	inodes->opened_inodes = cpu_to_le64(percpu_counter_sum(&m->opened_inodes));
 	inodes->total = cpu_to_le64(sum);
 	items++;

 	put_unaligned_le32(items, &head->num);
 	msg->front.iov_len = len;
 	msg->hdr.version = cpu_to_le16(1);
 	msg->hdr.compat_version = cpu_to_le16(1);
 	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
 	dout("client%llu send metrics to mds%d\n",
 	     ceph_client_gid(mdsc->fsc->client), s->s_mds);
 	ceph_con_send(&s->s_con, msg);

 	return true;
 }


 static void metric_get_session(struct ceph_mds_client *mdsc)
 {
 	struct ceph_mds_session *s;
 	int i;

 	mutex_lock(&mdsc->mutex);
 	for (i = 0; i < mdsc->max_sessions; i++) {
 		s = __ceph_lookup_mds_session(mdsc, i);
 		if (!s)
 			continue;

 		/*
 		 * Skip it if MDS doesn't support the metric collection,
 		 * or the MDS will close the session's socket connection
 		 * directly when it get this message.
 		 */
 		if (check_session_state(s) &&
 		    test_bit(CEPHFS_FEATURE_METRIC_COLLECT, &s->s_features)) {
 			mdsc->metric.session = s;
 			break;
 		}

 		ceph_put_mds_session(s);
 	}
 	mutex_unlock(&mdsc->mutex);
 }

 static void metric_delayed_work(struct work_struct *work)
 {
 	struct ceph_client_metric *m =
 		container_of(work, struct ceph_client_metric, delayed_work.work);
 	struct ceph_mds_client *mdsc =
 		container_of(m, struct ceph_mds_client, metric);

 	if (mdsc->stopping)
 		return;

 	if (!m->session || !check_session_state(m->session)) {
 		if (m->session) {
 			ceph_put_mds_session(m->session);
 			m->session = NULL;
 		}
 		metric_get_session(mdsc);
 	}
 	if (m->session) {
 		ceph_mdsc_send_metrics(mdsc, m->session);
 		metric_schedule_delayed(m);
 	}
 }

 int ceph_metric_init(struct ceph_client_metric *m)
 {
 	int ret;

 	if (!m)
 		return -EINVAL;

 	atomic64_set(&m->total_dentries, 0);
 	ret = percpu_counter_init(&m->d_lease_hit, 0, GFP_KERNEL);
 	if (ret)
 		return ret;

 	ret = percpu_counter_init(&m->d_lease_mis, 0, GFP_KERNEL);
 	if (ret)
 		goto err_d_lease_mis;

 	atomic64_set(&m->total_caps, 0);
 	ret = percpu_counter_init(&m->i_caps_hit, 0, GFP_KERNEL);
 	if (ret)
 		goto err_i_caps_hit;

 	ret = percpu_counter_init(&m->i_caps_mis, 0, GFP_KERNEL);
 	if (ret)
 		goto err_i_caps_mis;

 	spin_lock_init(&m->read_metric_lock);
 	m->read_latency_sq_sum = 0;
 	m->read_latency_min = KTIME_MAX;
 	m->read_latency_max = 0;
 	m->total_reads = 0;
 	m->read_latency_sum = 0;

 	spin_lock_init(&m->write_metric_lock);
 	m->write_latency_sq_sum = 0;
 	m->write_latency_min = KTIME_MAX;
 	m->write_latency_max = 0;
 	m->total_writes = 0;
 	m->write_latency_sum = 0;

 	spin_lock_init(&m->metadata_metric_lock);
 	m->metadata_latency_sq_sum = 0;
 	m->metadata_latency_min = KTIME_MAX;
 	m->metadata_latency_max = 0;
 	m->total_metadatas = 0;
 	m->metadata_latency_sum = 0;

 	atomic64_set(&m->opened_files, 0);
 	ret = percpu_counter_init(&m->opened_inodes, 0, GFP_KERNEL);
 	if (ret)
 		goto err_opened_inodes;
 	ret = percpu_counter_init(&m->total_inodes, 0, GFP_KERNEL);
 	if (ret)
 		goto err_total_inodes;

 	m->session = NULL;
 	INIT_DELAYED_WORK(&m->delayed_work, metric_delayed_work);

 	return 0;

 err_total_inodes:
 	percpu_counter_destroy(&m->opened_inodes);
 err_opened_inodes:
 	percpu_counter_destroy(&m->i_caps_mis);
 err_i_caps_mis:
 	percpu_counter_destroy(&m->i_caps_hit);
 err_i_caps_hit:
 	percpu_counter_destroy(&m->d_lease_mis);
 err_d_lease_mis:
 	percpu_counter_destroy(&m->d_lease_hit);

 	return ret;
 }

 void ceph_metric_destroy(struct ceph_client_metric *m)
 {
 	if (!m)
 		return;

 	percpu_counter_destroy(&m->total_inodes);
 	percpu_counter_destroy(&m->opened_inodes);
 	percpu_counter_destroy(&m->i_caps_mis);
 	percpu_counter_destroy(&m->i_caps_hit);
 	percpu_counter_destroy(&m->d_lease_mis);
 	percpu_counter_destroy(&m->d_lease_hit);

 	cancel_delayed_work_sync(&m->delayed_work);

 	if (m->session)
 		ceph_put_mds_session(m->session);
 }

 static inline void __update_latency(ktime_t *totalp, ktime_t *lsump,
 				    ktime_t *min, ktime_t *max,
 				    ktime_t *sq_sump, ktime_t lat)
 {
 	ktime_t total, avg, sq, lsum;

 	total = ++(*totalp);
 	lsum = (*lsump += lat);

 	if (unlikely(lat < *min))
 		*min = lat;
 	if (unlikely(lat > *max))
 		*max = lat;

 	if (unlikely(total == 1))
 		return;

 	/* the sq is (lat - old_avg) * (lat - new_avg) */
 	avg = DIV64_U64_ROUND_CLOSEST((lsum - lat), (total - 1));
 	sq = lat - avg;
 	avg = DIV64_U64_ROUND_CLOSEST(lsum, total);
 	sq = sq * (lat - avg);
 	*sq_sump += sq;
 }

 void ceph_update_read_metrics(struct ceph_client_metric *m,
 			      ktime_t r_start, ktime_t r_end,
 			      int rc)
 {
 	ktime_t lat = ktime_sub(r_end, r_start);

 	if (unlikely(rc < 0 && rc != -ENOENT && rc != -ETIMEDOUT))
 		return;

 	spin_lock(&m->read_metric_lock);
 	__update_latency(&m->total_reads, &m->read_latency_sum,
 			 &m->read_latency_min, &m->read_latency_max,
 			 &m->read_latency_sq_sum, lat);
 	spin_unlock(&m->read_metric_lock);
 }

 void ceph_update_write_metrics(struct ceph_client_metric *m,
 			       ktime_t r_start, ktime_t r_end,
 			       int rc)
 {
 	ktime_t lat = ktime_sub(r_end, r_start);

 	if (unlikely(rc && rc != -ETIMEDOUT))
 		return;

 	spin_lock(&m->write_metric_lock);
 	__update_latency(&m->total_writes, &m->write_latency_sum,
 			 &m->write_latency_min, &m->write_latency_max,
 			 &m->write_latency_sq_sum, lat);
 	spin_unlock(&m->write_metric_lock);
 }

 void ceph_update_metadata_metrics(struct ceph_client_metric *m,
 				  ktime_t r_start, ktime_t r_end,
 				  int rc)
 {
 	ktime_t lat = ktime_sub(r_end, r_start);

 	if (unlikely(rc && rc != -ENOENT))
 		return;

 	spin_lock(&m->metadata_metric_lock);
 	__update_latency(&m->total_metadatas, &m->metadata_latency_sum,
 			 &m->metadata_latency_min, &m->metadata_latency_max,
 			 &m->metadata_latency_sq_sum, lat);
 	spin_unlock(&m->metadata_metric_lock);
 }
	/* SPDX-License-Identifier: GPL-2.0 */
	#include <linux/ceph/ceph_debug.h>

	#include <linux/types.h>
	#include <linux/percpu_counter.h>
	#include <linux/math64.h>

	#include "metric.h"
	#include "mds_client.h"

	static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
	struct ceph_mds_session *s)
	{
	struct ceph_metric_head *head;
	struct ceph_metric_cap *cap;
	struct ceph_metric_read_latency *read;
	struct ceph_metric_write_latency *write;
	struct ceph_metric_metadata_latency *meta;
	struct ceph_metric_dlease *dlease;
	struct ceph_opened_files *files;
	struct ceph_pinned_icaps *icaps;
	struct ceph_opened_inodes *inodes;
	struct ceph_client_metric *m = &mdsc->metric;
	u64 nr_caps = atomic64_read(&m->total_caps);
	struct ceph_msg *msg;
	struct timespec64 ts;
	s64 sum;
	s32 items = 0;
	s32 len;

	len = sizeof(head) + sizeof(cap) + sizeof(read) + sizeof(write)
	+ sizeof(meta) + sizeof(dlease) + sizeof(*files)
	+ sizeof(icaps) + sizeof(inodes);

	msg = ceph_msg_new(CEPH_MSG_CLIENT_METRICS, len, GFP_NOFS, true);
	if (!msg) {
	pr_err("send metrics to mds%d, failed to allocate message\n",
	s->s_mds);
	return false;
	}

	head = msg->front.iov_base;

	/* encode the cap metric */
	cap = (struct ceph_metric_cap *)(head + 1);
	cap->type = cpu_to_le32(CLIENT_METRIC_TYPE_CAP_INFO);
	cap->ver = 1;
	cap->compat = 1;
	cap->data_len = cpu_to_le32(sizeof(*cap) - 10);
	cap->hit = cpu_to_le64(percpu_counter_sum(&m->i_caps_hit));
	cap->mis = cpu_to_le64(percpu_counter_sum(&m->i_caps_mis));
	cap->total = cpu_to_le64(nr_caps);
	items++;

	/* encode the read latency metric */
	read = (struct ceph_metric_read_latency *)(cap + 1);
	read->type = cpu_to_le32(CLIENT_METRIC_TYPE_READ_LATENCY);
	read->ver = 1;
	read->compat = 1;
	read->data_len = cpu_to_le32(sizeof(*read) - 10);
	sum = m->read_latency_sum;
	jiffies_to_timespec64(sum, &ts);
	read->sec = cpu_to_le32(ts.tv_sec);
	read->nsec = cpu_to_le32(ts.tv_nsec);
	items++;

	/* encode the write latency metric */
	write = (struct ceph_metric_write_latency *)(read + 1);
	write->type = cpu_to_le32(CLIENT_METRIC_TYPE_WRITE_LATENCY);
	write->ver = 1;
	write->compat = 1;
	write->data_len = cpu_to_le32(sizeof(*write) - 10);
	sum = m->write_latency_sum;
	jiffies_to_timespec64(sum, &ts);
	write->sec = cpu_to_le32(ts.tv_sec);
	write->nsec = cpu_to_le32(ts.tv_nsec);
	items++;

	/* encode the metadata latency metric */
	meta = (struct ceph_metric_metadata_latency *)(write + 1);
	meta->type = cpu_to_le32(CLIENT_METRIC_TYPE_METADATA_LATENCY);
	meta->ver = 1;
	meta->compat = 1;
	meta->data_len = cpu_to_le32(sizeof(*meta) - 10);
	sum = m->metadata_latency_sum;
	jiffies_to_timespec64(sum, &ts);
	meta->sec = cpu_to_le32(ts.tv_sec);
	meta->nsec = cpu_to_le32(ts.tv_nsec);
	items++;

	/* encode the dentry lease metric */
	dlease = (struct ceph_metric_dlease *)(meta + 1);
	dlease->type = cpu_to_le32(CLIENT_METRIC_TYPE_DENTRY_LEASE);
	dlease->ver = 1;
	dlease->compat = 1;
	dlease->data_len = cpu_to_le32(sizeof(*dlease) - 10);
	dlease->hit = cpu_to_le64(percpu_counter_sum(&m->d_lease_hit));
	dlease->mis = cpu_to_le64(percpu_counter_sum(&m->d_lease_mis));
	dlease->total = cpu_to_le64(atomic64_read(&m->total_dentries));
	items++;

	sum = percpu_counter_sum(&m->total_inodes);

	/* encode the opened files metric */
	files = (struct ceph_opened_files *)(dlease + 1);
	files->type = cpu_to_le32(CLIENT_METRIC_TYPE_OPENED_FILES);
	files->ver = 1;
	files->compat = 1;
	files->data_len = cpu_to_le32(sizeof(*files) - 10);
	files->opened_files = cpu_to_le64(atomic64_read(&m->opened_files));
	files->total = cpu_to_le64(sum);
	items++;

	/* encode the pinned icaps metric */
	icaps = (struct ceph_pinned_icaps *)(files + 1);
	icaps->type = cpu_to_le32(CLIENT_METRIC_TYPE_PINNED_ICAPS);
	icaps->ver = 1;
	icaps->compat = 1;
	icaps->data_len = cpu_to_le32(sizeof(*icaps) - 10);
	icaps->pinned_icaps = cpu_to_le64(nr_caps);
	icaps->total = cpu_to_le64(sum);
	items++;

	/* encode the opened inodes metric */
	inodes = (struct ceph_opened_inodes *)(icaps + 1);
	inodes->type = cpu_to_le32(CLIENT_METRIC_TYPE_OPENED_INODES);
	inodes->ver = 1;
	inodes->compat = 1;
	inodes->data_len = cpu_to_le32(sizeof(*inodes) - 10);
	inodes->opened_inodes = cpu_to_le64(percpu_counter_sum(&m->opened_inodes));
	inodes->total = cpu_to_le64(sum);
	items++;

	put_unaligned_le32(items, &head->num);
	msg->front.iov_len = len;
	msg->hdr.version = cpu_to_le16(1);
	msg->hdr.compat_version = cpu_to_le16(1);
	msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
	dout("client%llu send metrics to mds%d\n",
	ceph_client_gid(mdsc->fsc->client), s->s_mds);
	ceph_con_send(&s->s_con, msg);

	return true;
	}


	static void metric_get_session(struct ceph_mds_client *mdsc)
	{
	struct ceph_mds_session *s;
	int i;

	mutex_lock(&mdsc->mutex);
	for (i = 0; i < mdsc->max_sessions; i++) {
	s = __ceph_lookup_mds_session(mdsc, i);
	if (!s)
	continue;

	/*
	* Skip it if MDS doesn't support the metric collection,
	* or the MDS will close the session's socket connection
	* directly when it get this message.
	*/
	if (check_session_state(s) &&
	test_bit(CEPHFS_FEATURE_METRIC_COLLECT, &s->s_features)) {
	mdsc->metric.session = s;
	break;
	}

	ceph_put_mds_session(s);
	}
	mutex_unlock(&mdsc->mutex);
	}

	static void metric_delayed_work(struct work_struct *work)
	{
	struct ceph_client_metric *m =
	container_of(work, struct ceph_client_metric, delayed_work.work);
	struct ceph_mds_client *mdsc =
	container_of(m, struct ceph_mds_client, metric);

	if (mdsc->stopping)
	return;

	if (!m->session \|\| !check_session_state(m->session)) {
	if (m->session) {
	ceph_put_mds_session(m->session);
	m->session = NULL;
	}
	metric_get_session(mdsc);
	}
	if (m->session) {
	ceph_mdsc_send_metrics(mdsc, m->session);
	metric_schedule_delayed(m);
	}
	}

	int ceph_metric_init(struct ceph_client_metric *m)
	{
	int ret;

	if (!m)
	return -EINVAL;

	atomic64_set(&m->total_dentries, 0);
	ret = percpu_counter_init(&m->d_lease_hit, 0, GFP_KERNEL);
	if (ret)
	return ret;

	ret = percpu_counter_init(&m->d_lease_mis, 0, GFP_KERNEL);
	if (ret)
	goto err_d_lease_mis;

	atomic64_set(&m->total_caps, 0);
	ret = percpu_counter_init(&m->i_caps_hit, 0, GFP_KERNEL);
	if (ret)
	goto err_i_caps_hit;

	ret = percpu_counter_init(&m->i_caps_mis, 0, GFP_KERNEL);
	if (ret)
	goto err_i_caps_mis;

	spin_lock_init(&m->read_metric_lock);
	m->read_latency_sq_sum = 0;
	m->read_latency_min = KTIME_MAX;
	m->read_latency_max = 0;
	m->total_reads = 0;
	m->read_latency_sum = 0;

	spin_lock_init(&m->write_metric_lock);
	m->write_latency_sq_sum = 0;
	m->write_latency_min = KTIME_MAX;
	m->write_latency_max = 0;
	m->total_writes = 0;
	m->write_latency_sum = 0;

	spin_lock_init(&m->metadata_metric_lock);
	m->metadata_latency_sq_sum = 0;
	m->metadata_latency_min = KTIME_MAX;
	m->metadata_latency_max = 0;
	m->total_metadatas = 0;
	m->metadata_latency_sum = 0;

	atomic64_set(&m->opened_files, 0);
	ret = percpu_counter_init(&m->opened_inodes, 0, GFP_KERNEL);
	if (ret)
	goto err_opened_inodes;
	ret = percpu_counter_init(&m->total_inodes, 0, GFP_KERNEL);
	if (ret)
	goto err_total_inodes;

	m->session = NULL;
	INIT_DELAYED_WORK(&m->delayed_work, metric_delayed_work);

	return 0;

	err_total_inodes:
	percpu_counter_destroy(&m->opened_inodes);
	err_opened_inodes:
	percpu_counter_destroy(&m->i_caps_mis);
	err_i_caps_mis:
	percpu_counter_destroy(&m->i_caps_hit);
	err_i_caps_hit:
	percpu_counter_destroy(&m->d_lease_mis);
	err_d_lease_mis:
	percpu_counter_destroy(&m->d_lease_hit);

	return ret;
	}

	void ceph_metric_destroy(struct ceph_client_metric *m)
	{
	if (!m)
	return;

	percpu_counter_destroy(&m->total_inodes);
	percpu_counter_destroy(&m->opened_inodes);
	percpu_counter_destroy(&m->i_caps_mis);
	percpu_counter_destroy(&m->i_caps_hit);
	percpu_counter_destroy(&m->d_lease_mis);
	percpu_counter_destroy(&m->d_lease_hit);

	cancel_delayed_work_sync(&m->delayed_work);

	if (m->session)
	ceph_put_mds_session(m->session);
	}

	static inline void __update_latency(ktime_t totalp, ktime_t lsump,
	ktime_t min, ktime_t max,
	ktime_t *sq_sump, ktime_t lat)
	{
	ktime_t total, avg, sq, lsum;

	total = ++(*totalp);
	lsum = (*lsump += lat);

	if (unlikely(lat < *min))
	*min = lat;
	if (unlikely(lat > *max))
	*max = lat;

	if (unlikely(total == 1))
	return;

	/* the sq is (lat - old_avg) * (lat - new_avg) */
	avg = DIV64_U64_ROUND_CLOSEST((lsum - lat), (total - 1));
	sq = lat - avg;
	avg = DIV64_U64_ROUND_CLOSEST(lsum, total);
	sq = sq * (lat - avg);
	*sq_sump += sq;
	}

	void ceph_update_read_metrics(struct ceph_client_metric *m,
	ktime_t r_start, ktime_t r_end,
	int rc)
	{
	ktime_t lat = ktime_sub(r_end, r_start);

	if (unlikely(rc < 0 && rc != -ENOENT && rc != -ETIMEDOUT))
	return;

	spin_lock(&m->read_metric_lock);
	__update_latency(&m->total_reads, &m->read_latency_sum,
	&m->read_latency_min, &m->read_latency_max,
	&m->read_latency_sq_sum, lat);
	spin_unlock(&m->read_metric_lock);
	}

	void ceph_update_write_metrics(struct ceph_client_metric *m,
	ktime_t r_start, ktime_t r_end,
	int rc)
	{
	ktime_t lat = ktime_sub(r_end, r_start);

	if (unlikely(rc && rc != -ETIMEDOUT))
	return;

	spin_lock(&m->write_metric_lock);
	__update_latency(&m->total_writes, &m->write_latency_sum,
	&m->write_latency_min, &m->write_latency_max,
	&m->write_latency_sq_sum, lat);
	spin_unlock(&m->write_metric_lock);
	}

	void ceph_update_metadata_metrics(struct ceph_client_metric *m,
	ktime_t r_start, ktime_t r_end,
	int rc)
	{
	ktime_t lat = ktime_sub(r_end, r_start);

	if (unlikely(rc && rc != -ENOENT))
	return;

	spin_lock(&m->metadata_metric_lock);
	__update_latency(&m->total_metadatas, &m->metadata_latency_sum,
	&m->metadata_latency_min, &m->metadata_latency_max,
	&m->metadata_latency_sq_sum, lat);
	spin_unlock(&m->metadata_metric_lock);
	}