gve: fix gve_get_stats()

[ Upstream commit 2f57d4975fa027eabd35fdf23a49f8222ef3abf2 ]

gve_get_stats() can report wrong numbers if/when u64_stats_fetch_retry()
returns true.

What is needed here is to sample values in temporary variables,
and only use them after each loop is ended.

Fixes: f5cedc84a3 ("gve: Add transmit and receive support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Catherine Sullivan <csully@google.com>
Cc: Sagi Shahar <sagis@google.com>
Cc: Jon Olson <jonolson@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Luigi Rizzo <lrizzo@google.com>
Cc: Jeroen de Borst <jeroendb@google.com>
Cc: Tao Liu <xliutaox@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Eric Dumazet 2021-10-05 17:30:30 -07:00 committed by Greg Kroah-Hartman
parent d83787c26d
commit d6c0668119

View File

@ -30,6 +30,7 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s)
{
struct gve_priv *priv = netdev_priv(dev);
unsigned int start;
u64 packets, bytes;
int ring;
if (priv->rx) {
@ -37,10 +38,12 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s)
do {
start =
u64_stats_fetch_begin(&priv->rx[ring].statss);
s->rx_packets += priv->rx[ring].rpackets;
s->rx_bytes += priv->rx[ring].rbytes;
packets = priv->rx[ring].rpackets;
bytes = priv->rx[ring].rbytes;
} while (u64_stats_fetch_retry(&priv->rx[ring].statss,
start));
s->rx_packets += packets;
s->rx_bytes += bytes;
}
}
if (priv->tx) {
@ -48,10 +51,12 @@ static void gve_get_stats(struct net_device *dev, struct rtnl_link_stats64 *s)
do {
start =
u64_stats_fetch_begin(&priv->tx[ring].statss);
s->tx_packets += priv->tx[ring].pkt_done;
s->tx_bytes += priv->tx[ring].bytes_done;
packets = priv->tx[ring].pkt_done;
bytes = priv->tx[ring].bytes_done;
} while (u64_stats_fetch_retry(&priv->tx[ring].statss,
start));
s->tx_packets += packets;
s->tx_bytes += bytes;
}
}
}