On Mon, Mar 04, 2013 at 06:02:58PM +0100, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@xxxxxxxxx>
>
> Make the TX bytes/packets counters race-free by keeping
> them per AC so concurrent TX on queues can't cause lost
> or wrong updates. This works since each station belongs
> to a single interface. While at it also make the bytes
> counters 64-bit.
>
> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
> ---
> net/mac80211/cfg.c | 22 ++++++++++++++--------
> net/mac80211/sta_info.h | 9 +++++----
> net/mac80211/tx.c | 5 +++--
> 3 files changed, 22 insertions(+), 14 deletions(-)
>
> diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
> index 8259a5b..1ff629a 100644
> --- a/net/mac80211/cfg.c
> +++ b/net/mac80211/cfg.c
> @@ -445,12 +445,13 @@ static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
> struct ieee80211_sub_if_data *sdata = sta->sdata;
> struct ieee80211_local *local = sdata->local;
> struct timespec uptime;
> + int ac;
>
> sinfo->generation = sdata->local->sta_generation;
>
> sinfo->filled = STATION_INFO_INACTIVE_TIME |
> - STATION_INFO_RX_BYTES |
> - STATION_INFO_TX_BYTES |
> + STATION_INFO_RX_BYTES64 |
> + STATION_INFO_TX_BYTES64 |
> STATION_INFO_RX_PACKETS |
> STATION_INFO_TX_PACKETS |
> STATION_INFO_TX_RETRIES |
> @@ -467,10 +468,14 @@ static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
> sinfo->connected_time = uptime.tv_sec - sta->last_connected;
>
> sinfo->inactive_time = jiffies_to_msecs(jiffies - sta->last_rx);
> + sinfo->tx_bytes = 0;
> + sinfo->tx_packets = 0;
> + for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
> + sinfo->tx_bytes += sta->tx_bytes[ac];
> + sinfo->tx_packets += sta->tx_packets[ac];
> + }
> sinfo->rx_bytes = sta->rx_bytes;
> - sinfo->tx_bytes = sta->tx_bytes;
> sinfo->rx_packets = sta->rx_packets;
> - sinfo->tx_packets = sta->tx_packets;
> sinfo->tx_retries = sta->tx_retry_count;
> sinfo->tx_failed = sta->tx_retry_failed;
> sinfo->rx_dropped_misc = sta->rx_dropped;
> @@ -598,8 +603,8 @@ static void ieee80211_get_et_stats(struct wiphy *wiphy,
> data[i++] += sta->rx_fragments; \
> data[i++] += sta->rx_dropped; \
> \
> - data[i++] += sta->tx_packets; \
> - data[i++] += sta->tx_bytes; \
> + data[i++] += sinfo.tx_packets; \
> + data[i++] += sinfo.tx_bytes; \
> data[i++] += sta->tx_fragments; \
> data[i++] += sta->tx_filtered_count; \
> data[i++] += sta->tx_retry_failed; \
> @@ -621,13 +626,14 @@ static void ieee80211_get_et_stats(struct wiphy *wiphy,
> if (!(sta && !WARN_ON(sta->sdata->dev != dev)))
> goto do_survey;
>
> + sinfo.filled = 0;
> + sta_set_sinfo(sta, &sinfo);
> +
> i = 0;
> ADD_STA_STATS(sta);
>
> data[i++] = sta->sta_state;
>
> - sinfo.filled = 0;
> - sta_set_sinfo(sta, &sinfo);
>
> if (sinfo.filled & STATION_INFO_TX_BITRATE)
> data[i] = 100000 *
> diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
> index e5868c3..0d4fec3 100644
> --- a/net/mac80211/sta_info.h
> +++ b/net/mac80211/sta_info.h
> @@ -333,7 +333,8 @@ struct sta_info {
> unsigned long driver_buffered_tids;
>
> /* Updated from RX path only, no locking requirements */
> - unsigned long rx_packets, rx_bytes;
> + unsigned long rx_packets;
> + u64 rx_bytes;
> unsigned long wep_weak_iv_count;
> unsigned long last_rx;
> long last_connected;
> @@ -353,9 +354,9 @@ struct sta_info {
> unsigned int fail_avg;
>
> /* Updated from TX path only, no locking requirements */
> - unsigned long tx_packets;
> - unsigned long tx_bytes;
> - unsigned long tx_fragments;
> + u32 tx_packets[IEEE80211_NUM_ACS];
> + u32 tx_fragments;
> + u64 tx_bytes[IEEE80211_NUM_ACS];
> struct ieee80211_tx_rate last_tx_rate;
> int last_rx_rate_idx;
> u32 last_rx_rate_flag;
> diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
> index c79860f..6af7f60 100644
> --- a/net/mac80211/tx.c
> +++ b/net/mac80211/tx.c
> @@ -991,14 +991,15 @@ static ieee80211_tx_result debug_noinline
> ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
> {
> struct sk_buff *skb;
> + int ac = skb_get_queue_mapping(tx->skb);
>
Here, ieee80211_tx_h_fragmentm has set tx->skb to NULL and this oopses.
Karl
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