net: fix 64 bit counters on 32 bit arches

There is a small possibility that a reader gets incorrect values on 32
bit arches. SNMP applications could catch incorrect counters when a
32bit high part is changed by another stats consumer/provider.

One way to solve this is to add a rtnl_link_stats64 param to all
ndo_get_stats64() methods, and also add such a parameter to
dev_get_stats().

Rule is that we are not allowed to use dev->stats64 as a temporary
storage for 64bit stats, but a caller provided area (usually on stack)

Old drivers (only providing get_stats() method) need no changes.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 44a07593de56..1a429ed6da9d 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -2653,6 +2653,7 @@ static void fcoe_get_lesb(struct fc_lport *lport,
         u32 lfc, vlfc, mdac;
         struct fcoe_dev_stats *devst;
         struct fcoe_fc_els_lesb *lesb;
+        struct rtnl_link_stats64 temp;
         struct net_device *netdev = fcoe_netdev(lport);
 
         lfc = 0;
@@ -2669,7 +2670,7 @@ static void fcoe_get_lesb(struct fc_lport *lport,
         lesb->lesb_link_fail = htonl(lfc);
         lesb->lesb_vlink_fail = htonl(vlfc);
         lesb->lesb_miss_fka = htonl(mdac);
-        lesb->lesb_fcs_error = htonl(dev_get_stats(netdev)->rx_crc_errors);
+        lesb->lesb_fcs_error = htonl(dev_get_stats(netdev, &temp)->rx_crc_errors);
 }
 
 /**