From 3cfde79c6c7c8002375c4a8e5be7f602fbb9675d Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Fri, 9 Jul 2010 09:11:52 +0000 Subject: net: Get rid of rtnl_link_stats64 / net_device_stats union In commit be1f3c2c027cc5ad735df6a45a542ed1db7ec48b "net: Enable 64-bit net device statistics on 32-bit architectures" I redefined struct net_device_stats so that it could be used in a union with struct rtnl_link_stats64, avoiding the need for explicit copying or conversion between the two. However, this is unsafe because there is no locking required and no lock consistently held around calls to dev_get_stats() and use of the statistics structure it returns. In commit 28172739f0a276eb8d6ca917b3974c2edb036da3 "net: fix 64 bit counters on 32 bit arches" Eric Dumazet dealt with that problem by requiring callers of dev_get_stats() to provide storage for the result. This means that the net_device::stats64 field and the padding in struct net_device_stats are now redundant, so remove them. Update the comment on net_device_ops::ndo_get_stats64 to reflect its new usage. Change dev_txq_stats_fold() to use struct rtnl_link_stats64, since that is what all its callers are really using and it is no longer going to be compatible with struct net_device_stats. Eric Dumazet suggested the separate function for the structure conversion. Signed-off-by: Ben Hutchings Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- include/linux/netdevice.h | 70 +++++++++++++++++++---------------------------- 1 file changed, 28 insertions(+), 42 deletions(-) (limited to 'include') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 8018f6bf305..17e95e37aed 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -162,42 +162,32 @@ static inline bool dev_xmit_complete(int rc) /* * Old network device statistics. Fields are native words * (unsigned long) so they can be read and written atomically. - * Each field is padded to 64 bits for compatibility with - * rtnl_link_stats64. */ -#if BITS_PER_LONG == 64 -#define NET_DEVICE_STATS_DEFINE(name) unsigned long name -#elif defined(__LITTLE_ENDIAN) -#define NET_DEVICE_STATS_DEFINE(name) unsigned long name, pad_ ## name -#else -#define NET_DEVICE_STATS_DEFINE(name) unsigned long pad_ ## name, name -#endif - struct net_device_stats { - NET_DEVICE_STATS_DEFINE(rx_packets); - NET_DEVICE_STATS_DEFINE(tx_packets); - NET_DEVICE_STATS_DEFINE(rx_bytes); - NET_DEVICE_STATS_DEFINE(tx_bytes); - NET_DEVICE_STATS_DEFINE(rx_errors); - NET_DEVICE_STATS_DEFINE(tx_errors); - NET_DEVICE_STATS_DEFINE(rx_dropped); - NET_DEVICE_STATS_DEFINE(tx_dropped); - NET_DEVICE_STATS_DEFINE(multicast); - NET_DEVICE_STATS_DEFINE(collisions); - NET_DEVICE_STATS_DEFINE(rx_length_errors); - NET_DEVICE_STATS_DEFINE(rx_over_errors); - NET_DEVICE_STATS_DEFINE(rx_crc_errors); - NET_DEVICE_STATS_DEFINE(rx_frame_errors); - NET_DEVICE_STATS_DEFINE(rx_fifo_errors); - NET_DEVICE_STATS_DEFINE(rx_missed_errors); - NET_DEVICE_STATS_DEFINE(tx_aborted_errors); - NET_DEVICE_STATS_DEFINE(tx_carrier_errors); - NET_DEVICE_STATS_DEFINE(tx_fifo_errors); - NET_DEVICE_STATS_DEFINE(tx_heartbeat_errors); - NET_DEVICE_STATS_DEFINE(tx_window_errors); - NET_DEVICE_STATS_DEFINE(rx_compressed); - NET_DEVICE_STATS_DEFINE(tx_compressed); + unsigned long rx_packets; + unsigned long tx_packets; + unsigned long rx_bytes; + unsigned long tx_bytes; + unsigned long rx_errors; + unsigned long tx_errors; + unsigned long rx_dropped; + unsigned long tx_dropped; + unsigned long multicast; + unsigned long collisions; + unsigned long rx_length_errors; + unsigned long rx_over_errors; + unsigned long rx_crc_errors; + unsigned long rx_frame_errors; + unsigned long rx_fifo_errors; + unsigned long rx_missed_errors; + unsigned long tx_aborted_errors; + unsigned long tx_carrier_errors; + unsigned long tx_fifo_errors; + unsigned long tx_heartbeat_errors; + unsigned long tx_window_errors; + unsigned long rx_compressed; + unsigned long tx_compressed; }; #endif /* __KERNEL__ */ @@ -666,14 +656,13 @@ struct netdev_rx_queue { * Callback uses when the transmitter has not made any progress * for dev->watchdog ticks. * - * struct rtnl_link_stats64* (*ndo_get_stats64)(struct net_device *dev + * struct rtnl_link_stats64* (*ndo_get_stats64)(struct net_device *dev, * struct rtnl_link_stats64 *storage); * struct net_device_stats* (*ndo_get_stats)(struct net_device *dev); * Called when a user wants to get the network device usage * statistics. Drivers must do one of the following: - * 1. Define @ndo_get_stats64 to update a rtnl_link_stats64 structure - * (which should normally be dev->stats64) and return a ponter to - * it. The structure must not be changed asynchronously. + * 1. Define @ndo_get_stats64 to fill in a zero-initialised + * rtnl_link_stats64 structure passed by the caller. * 2. Define @ndo_get_stats to update a net_device_stats structure * (which should normally be dev->stats) and return a pointer to * it. The structure may be changed asynchronously only if each @@ -888,10 +877,7 @@ struct net_device { int ifindex; int iflink; - union { - struct rtnl_link_stats64 stats64; - struct net_device_stats stats; - }; + struct net_device_stats stats; #ifdef CONFIG_WIRELESS_EXT /* List of functions to handle Wireless Extensions (instead of ioctl). @@ -2147,7 +2133,7 @@ extern void dev_mcast_init(void); extern const struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev, struct rtnl_link_stats64 *storage); extern void dev_txq_stats_fold(const struct net_device *dev, - struct net_device_stats *stats); + struct rtnl_link_stats64 *stats); extern int netdev_max_backlog; extern int netdev_tstamp_prequeue; -- cgit v1.2.3-70-g09d2