ceph: send dentry lease metrics to MDS daemon

For the old ceph version, if it received this one metric message
containing the dentry lease metric info, it will just ignore it.

URL: https://tracker.ceph.com/issues/43423Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/metric.c

@@ -16,6 +16,7 @@ static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
 	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_client_metric *m = &mdsc->metric;
 	u64 nr_caps = atomic64_read(&m->total_caps);
 	struct ceph_msg *msg;
@@ -25,7 +26,7 @@ static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
 	s32 len;
 
 	len = sizeof(*head) + sizeof(*cap) + sizeof(*read) + sizeof(*write)
-	      + sizeof(*meta);
+	      + sizeof(*meta) + sizeof(*dlease);
 
 	msg = ceph_msg_new(CEPH_MSG_CLIENT_METRICS, len, GFP_NOFS, true);
 	if (!msg) {
@@ -42,8 +43,8 @@ static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
 	cap->ver = 1;
 	cap->compat = 1;
 	cap->data_len = cpu_to_le32(sizeof(*cap) - 10);
-	cap->hit = cpu_to_le64(percpu_counter_sum(&mdsc->metric.i_caps_hit));
-	cap->mis = cpu_to_le64(percpu_counter_sum(&mdsc->metric.i_caps_mis));
+	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++;
 
@@ -83,6 +84,17 @@ static bool ceph_mdsc_send_metrics(struct ceph_mds_client *mdsc,
 	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++;
+
 	put_unaligned_le32(items, &head->num);
 	msg->front.iov_len = len;
 	msg->hdr.version = cpu_to_le16(1);

fs/ceph/metric.h

@@ -27,6 +27,7 @@ enum ceph_metric_type {
 	CLIENT_METRIC_TYPE_READ_LATENCY,	\
 	CLIENT_METRIC_TYPE_WRITE_LATENCY,	\
 	CLIENT_METRIC_TYPE_METADATA_LATENCY,	\
+	CLIENT_METRIC_TYPE_DENTRY_LEASE,	\
 						\
 	CLIENT_METRIC_TYPE_MAX,			\
 }
@@ -80,6 +81,19 @@ struct ceph_metric_metadata_latency {
 	__le32 nsec;
 } __packed;
 
+/* metric dentry lease header */
+struct ceph_metric_dlease {
+	__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;
+
 struct ceph_metric_head {
 	__le32 num;	/* the number of metrics that will be sent */
 } __packed;