[SCSI] scsi_transport_iscsi: Add host statistics support

Add transport_iscsi hooks to get aggregate host statistics.
The statistics include MAC, TCP/IP & iSCSI statistics.

Signed-off-by: Lalit Chandivade <lalit.chandivade@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 9477f84c83a6..4cf918a9fc6f 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -3416,6 +3416,73 @@ exit_logout_sid:
 }
 
 static int
+iscsi_get_host_stats(struct iscsi_transport *transport, struct nlmsghdr *nlh)
+{
+	struct iscsi_uevent *ev = nlmsg_data(nlh);
+	struct Scsi_Host *shost = NULL;
+	struct iscsi_internal *priv;
+	struct sk_buff *skbhost_stats;
+	struct nlmsghdr *nlhhost_stats;
+	struct iscsi_uevent *evhost_stats;
+	int host_stats_size = 0;
+	int len, err = 0;
+	char *buf;
+
+	if (!transport->get_host_stats)
+		return -EINVAL;
+
+	priv = iscsi_if_transport_lookup(transport);
+	if (!priv)
+		return -EINVAL;
+
+	host_stats_size = sizeof(struct iscsi_offload_host_stats);
+	len = nlmsg_total_size(sizeof(*ev) + host_stats_size);
+
+	shost = scsi_host_lookup(ev->u.get_host_stats.host_no);
+	if (!shost) {
+		pr_err("%s: failed. Cound not find host no %u\n",
+		       __func__, ev->u.get_host_stats.host_no);
+		return -ENODEV;
+	}
+
+	do {
+		int actual_size;
+
+		skbhost_stats = alloc_skb(len, GFP_KERNEL);
+		if (!skbhost_stats) {
+			pr_err("cannot deliver host stats: OOM\n");
+			err = -ENOMEM;
+			goto exit_host_stats;
+		}
+
+		nlhhost_stats = __nlmsg_put(skbhost_stats, 0, 0, 0,
+				      (len - sizeof(*nlhhost_stats)), 0);
+		evhost_stats = nlmsg_data(nlhhost_stats);
+		memset(evhost_stats, 0, sizeof(*evhost_stats));
+		evhost_stats->transport_handle = iscsi_handle(transport);
+		evhost_stats->type = nlh->nlmsg_type;
+		evhost_stats->u.get_host_stats.host_no =
+					ev->u.get_host_stats.host_no;
+		buf = (char *)((char *)evhost_stats + sizeof(*evhost_stats));
+		memset(buf, 0, host_stats_size);
+
+		err = transport->get_host_stats(shost, buf, host_stats_size);
+
+		actual_size = nlmsg_total_size(sizeof(*ev) + host_stats_size);
+		skb_trim(skbhost_stats, NLMSG_ALIGN(actual_size));
+		nlhhost_stats->nlmsg_len = actual_size;
+
+		err = iscsi_multicast_skb(skbhost_stats, ISCSI_NL_GRP_ISCSID,
+					  GFP_KERNEL);
+	} while (err < 0 && err != -ECONNREFUSED);
+
+exit_host_stats:
+	scsi_host_put(shost);
+	return err;
+}
+
+
+static int
 iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
 {
 	int err = 0;
@@ -3594,6 +3661,9 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
 		err = iscsi_set_chap(transport, ev,
 				     nlmsg_attrlen(nlh, sizeof(*ev)));
 		break;
+	case ISCSI_UEVENT_GET_HOST_STATS:
+		err = iscsi_get_host_stats(transport, nlh);
+		break;
 	default:
 		err = -ENOSYS;
 		break;