[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;