From: Sven Eckelmann sven@narfation.org

If a temporary error happened in the evaluation of the neighbor throughput information, then the invalid throughput result should not be stored in the throughtput EWMA.

Cc: stable@vger.kernel.org Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de --- net/batman-adv/bat_v_elp.c | 50 ++++++++++++++++++++++++++------------ 1 file changed, 34 insertions(+), 16 deletions(-)

diff --git a/net/batman-adv/bat_v_elp.c b/net/batman-adv/bat_v_elp.c index fbf499bcc671..65e52de52bcd 100644 --- a/net/batman-adv/bat_v_elp.c +++ b/net/batman-adv/bat_v_elp.c @@ -59,11 +59,13 @@ static void batadv_v_elp_start_timer(struct batadv_hard_iface *hard_iface) /** * batadv_v_elp_get_throughput() - get the throughput towards a neighbour * @neigh: the neighbour for which the throughput has to be obtained + * @pthroughput: calculated throughput towards the given neighbour in multiples + * of 100kpbs (a value of '1' equals 0.1Mbps, '10' equals 1Mbps, etc). * - * Return: The throughput towards the given neighbour in multiples of 100kpbs - * (a value of '1' equals 0.1Mbps, '10' equals 1Mbps, etc). + * Return: true when value behind @pthroughput was set */ -static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh) +static bool batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh, + u32 *pthroughput) { struct batadv_hard_iface *hard_iface = neigh->if_incoming; struct net_device *soft_iface = hard_iface->soft_iface; @@ -77,14 +79,16 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh) * batman-adv interface */ if (!soft_iface) - return BATADV_THROUGHPUT_DEFAULT_VALUE; + return false;

/* if the user specified a customised value for this interface, then * return it directly */ throughput = atomic_read(&hard_iface->bat_v.throughput_override); - if (throughput != 0) - return throughput; + if (throughput != 0) { + *pthroughput = throughput; + return true; + }

/* if this is a wireless device, then ask its throughput through * cfg80211 API @@ -111,19 +115,24 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh) * possible to delete this neighbor. For now set * the throughput metric to 0. */ - return 0; + *pthroughput = 0; + return true; } if (ret) goto default_throughput;

- if (sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)) - return sinfo.expected_throughput / 100; + if (sinfo.filled & BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT)) { + *pthroughput = sinfo.expected_throughput / 100; + return true; + }

/* try to estimate the expected throughput based on reported tx * rates */ - if (sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE)) - return cfg80211_calculate_bitrate(&sinfo.txrate) / 3; + if (sinfo.filled & BIT(NL80211_STA_INFO_TX_BITRATE)) { + *pthroughput = cfg80211_calculate_bitrate(&sinfo.txrate) / 3; + return true; + }

goto default_throughput; } @@ -142,8 +151,10 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh) hard_iface->bat_v.flags &= ~BATADV_FULL_DUPLEX;

throughput = link_settings.base.speed; - if (throughput && throughput != SPEED_UNKNOWN) - return throughput * 10; + if (throughput && throughput != SPEED_UNKNOWN) { + *pthroughput = throughput * 10; + return true; + } }

default_throughput: @@ -157,7 +168,8 @@ static u32 batadv_v_elp_get_throughput(struct batadv_hardif_neigh_node *neigh) }

/* if none of the above cases apply, return the base_throughput */ - return BATADV_THROUGHPUT_DEFAULT_VALUE; + *pthroughput = BATADV_THROUGHPUT_DEFAULT_VALUE; + return true; }

/** @@ -169,15 +181,21 @@ void batadv_v_elp_throughput_metric_update(struct work_struct *work) { struct batadv_hardif_neigh_node_bat_v *neigh_bat_v; struct batadv_hardif_neigh_node *neigh; + u32 throughput; + bool valid;

neigh_bat_v = container_of(work, struct batadv_hardif_neigh_node_bat_v, metric_work); neigh = container_of(neigh_bat_v, struct batadv_hardif_neigh_node, bat_v);

- ewma_throughput_add(&neigh->bat_v.throughput, - batadv_v_elp_get_throughput(neigh)); + valid = batadv_v_elp_get_throughput(neigh, &throughput); + if (!valid) + goto put_neigh; + + ewma_throughput_add(&neigh->bat_v.throughput, throughput);

+put_neigh: /* decrement refcounter to balance increment performed before scheduling * this task */