Repository : ssh://git@open-mesh.org/batman-adv

On branch : master

commit d90c79bea9a624b9a6c8ae151fd5ef8fce08bdc3 Author: Linus Lüssing linus.luessing@c0d3.blue Date: Tue May 7 06:08:26 2019 +0200

batman-adv: mcast: shorten multicast tt/tvlv worker spinlock section

It is not necessary to hold the mla_lock spinlock during the whole multicast tt/tvlv worker callback. Just holding it during the checks and updates of the bat_priv stored multicast flags and mla_list is enough.

Therefore this patch splits batadv_mcast_mla_tvlv_update() in two: batadv_mcast_mla_flags_get() at the beginning of the worker to gather and calculate the new multicast flags, which does not need any locking as it neither reads from nor writes to bat_priv->mcast.

And batadv_mcast_mla_flags_update() at the end of the worker which commits the newly calculated flags and lists to bat_priv->mcast and therefore needs the lock.

Signed-off-by: Linus Lüssing linus.luessing@c0d3.blue Signed-off-by: Sven Eckelmann sven@narfation.org

d90c79bea9a624b9a6c8ae151fd5ef8fce08bdc3 net/batman-adv/multicast.c | 272 +++++++++++++++++++++------------------- net/batman-adv/soft-interface.c | 5 - net/batman-adv/types.h | 38 +++--- 3 files changed, 164 insertions(+), 151 deletions(-)

diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index ec54e236..af0e2ce8 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -72,6 +72,80 @@ static void batadv_mcast_start_timer(struct batadv_priv *bat_priv) }

/** + * batadv_mcast_has_bridge() - check whether the soft-iface is bridged + * @bat_priv: the bat priv with all the soft interface information + * + * Checks whether there is a bridge on top of our soft interface. + * + * Return: true if there is a bridge, false otherwise. + */ +static bool batadv_mcast_has_bridge(struct batadv_priv *bat_priv) +{ + struct net_device *upper = bat_priv->soft_iface; + + rcu_read_lock(); + do { + upper = netdev_master_upper_dev_get_rcu(upper); + } while (upper && !(upper->priv_flags & IFF_EBRIDGE)); + rcu_read_unlock(); + + return upper; +} + +/** + * batadv_mcast_mla_flags_get() - get the new multicast flags + * @bat_priv: the bat priv with all the soft interface information + * + * Return: A set of flags for the current/next TVLV, querier and + * bridge state. + */ +static struct batadv_mcast_mla_flags +batadv_mcast_mla_flags_get(struct batadv_priv *bat_priv) +{ + struct net_device *dev = bat_priv->soft_iface; + struct batadv_mcast_querier_state *qr4, *qr6; + struct batadv_mcast_mla_flags mla_flags; + + memset(&mla_flags, 0, sizeof(mla_flags)); + mla_flags.enabled = 1; + + if (!batadv_mcast_has_bridge(bat_priv)) + return mla_flags; + + mla_flags.bridged = 1; + qr4 = &mla_flags.querier_ipv4; + qr6 = &mla_flags.querier_ipv6; + + if (!IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING)) + pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n"); + + qr4->exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP); + qr4->shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP); + + qr6->exists = br_multicast_has_querier_anywhere(dev, ETH_P_IPV6); + qr6->shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IPV6); + + mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_UNSNOOPABLES; + + /* 1) If no querier exists at all, then multicast listeners on + * our local TT clients behind the bridge will keep silent. + * 2) If the selected querier is on one of our local TT clients, + * behind the bridge, then this querier might shadow multicast + * listeners on our local TT clients, behind this bridge. + * + * In both cases, we will signalize other batman nodes that + * we need all multicast traffic of the according protocol. + */ + if (!qr4->exists || qr4->shadowing) + mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_IPV4; + + if (!qr6->exists || qr6->shadowing) + mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_IPV6; + + return mla_flags; +} + +/** * batadv_mcast_get_bridge() - get the bridge on top of the softif if it exists * @soft_iface: netdev struct of the mesh interface * @@ -127,9 +201,9 @@ static bool batadv_mcast_addr_is_ipv6(const u8 *addr)

/** * batadv_mcast_mla_softif_get() - get softif multicast listeners - * @bat_priv: the bat priv with all the soft interface information * @dev: the device to collect multicast addresses from * @mcast_list: a list to put found addresses into + * @flags: flags indicating the new multicast state * * Collects multicast addresses of multicast listeners residing * on this kernel on the given soft interface, dev, in @@ -144,12 +218,13 @@ static bool batadv_mcast_addr_is_ipv6(const u8 *addr) * Return: -ENOMEM on memory allocation error or the number of * items added to the mcast_list otherwise. */ -static int batadv_mcast_mla_softif_get(struct batadv_priv *bat_priv, - struct net_device *dev, - struct hlist_head *mcast_list) +static int +batadv_mcast_mla_softif_get(struct net_device *dev, + struct hlist_head *mcast_list, + struct batadv_mcast_mla_flags *flags) { - bool all_ipv4 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV4; - bool all_ipv6 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV6; + bool all_ipv4 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4; + bool all_ipv6 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6; struct net_device *bridge = batadv_mcast_get_bridge(dev); struct netdev_hw_addr *mc_list_entry; struct batadv_hw_addr *new; @@ -227,9 +302,9 @@ static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src)

/** * batadv_mcast_mla_bridge_get() - get bridged-in multicast listeners - * @bat_priv: the bat priv with all the soft interface information * @dev: a bridge slave whose bridge to collect multicast addresses from * @mcast_list: a list to put found addresses into + * @flags: flags indicating the new multicast state * * Collects multicast addresses of multicast listeners residing * on foreign, non-mesh devices which we gave access to our mesh via @@ -239,13 +314,13 @@ static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src) * Return: -ENOMEM on memory allocation error or the number of * items added to the mcast_list otherwise. */ -static int batadv_mcast_mla_bridge_get(struct batadv_priv *bat_priv, - struct net_device *dev, - struct hlist_head *mcast_list) +static int batadv_mcast_mla_bridge_get(struct net_device *dev, + struct hlist_head *mcast_list, + struct batadv_mcast_mla_flags *flags) { struct list_head bridge_mcast_list = LIST_HEAD_INIT(bridge_mcast_list); - bool all_ipv4 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV4; - bool all_ipv6 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV6; + bool all_ipv4 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4; + bool all_ipv6 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6; struct br_ip_list *br_ip_entry, *tmp; struct batadv_hw_addr *new; u8 mcast_addr[ETH_ALEN]; @@ -370,27 +445,6 @@ static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv, }

/** - * batadv_mcast_has_bridge() - check whether the soft-iface is bridged - * @bat_priv: the bat priv with all the soft interface information - * - * Checks whether there is a bridge on top of our soft interface. - * - * Return: true if there is a bridge, false otherwise. - */ -static bool batadv_mcast_has_bridge(struct batadv_priv *bat_priv) -{ - struct net_device *upper = bat_priv->soft_iface; - - rcu_read_lock(); - do { - upper = netdev_master_upper_dev_get_rcu(upper); - } while (upper && !(upper->priv_flags & IFF_EBRIDGE)); - rcu_read_unlock(); - - return upper; -} - -/** * batadv_mcast_querier_log() - debug output regarding the querier status on * link * @bat_priv: the bat priv with all the soft interface information @@ -424,7 +478,7 @@ batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto, batadv_info(bat_priv->soft_iface, "%s Querier disappeared - multicast optimizations disabled\n", str_proto); - else if (!bat_priv->mcast.bridged && !new_state->exists) + else if (!bat_priv->mcast.mla_flags.bridged && !new_state->exists) batadv_info(bat_priv->soft_iface, "No %s Querier present - multicast optimizations disabled\n", str_proto); @@ -446,9 +500,7 @@ batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto, * batadv_mcast_bridge_log() - debug output for topology changes in bridged * setups * @bat_priv: the bat priv with all the soft interface information - * @bridged: a flag about whether the soft interface is currently bridged or not - * @querier_ipv4: (maybe) new status of a potential, selected IGMP querier - * @querier_ipv6: (maybe) new status of a potential, selected MLD querier + * @new_flags: flags indicating the new multicast state * * If no bridges are ever used on this node, then this function does nothing. * @@ -461,38 +513,40 @@ batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto, * multicast flags this node is going to set. */ static void -batadv_mcast_bridge_log(struct batadv_priv *bat_priv, bool bridged, - struct batadv_mcast_querier_state *querier_ipv4, - struct batadv_mcast_querier_state *querier_ipv6) +batadv_mcast_bridge_log(struct batadv_priv *bat_priv, + struct batadv_mcast_mla_flags *new_flags) { - if (!bat_priv->mcast.bridged && bridged) + struct batadv_mcast_mla_flags *old_flags = &bat_priv->mcast.mla_flags; + + if (!old_flags->bridged && new_flags->bridged) batadv_dbg(BATADV_DBG_MCAST, bat_priv, "Bridge added: Setting Unsnoopables(U)-flag\n"); - else if (bat_priv->mcast.bridged && !bridged) + else if (old_flags->bridged && !new_flags->bridged) batadv_dbg(BATADV_DBG_MCAST, bat_priv, "Bridge removed: Unsetting Unsnoopables(U)-flag\n");

- if (bridged) { + if (new_flags->bridged) { batadv_mcast_querier_log(bat_priv, "IGMP", - &bat_priv->mcast.querier_ipv4, - querier_ipv4); + &old_flags->querier_ipv4, + &new_flags->querier_ipv4); batadv_mcast_querier_log(bat_priv, "MLD", - &bat_priv->mcast.querier_ipv6, - querier_ipv6); + &old_flags->querier_ipv6, + &new_flags->querier_ipv6); } }

/** * batadv_mcast_flags_logs() - output debug information about mcast flag changes * @bat_priv: the bat priv with all the soft interface information - * @flags: flags indicating the new multicast state + * @flags: TVLV flags indicating the new multicast state * - * Whenever the multicast flags this nodes announces changes (@mcast_flags vs. - * bat_priv->mcast.flags), this notifies userspace via the 'mcast' log level. + * Whenever the multicast TVLV flags this nodes announces change this notifies + * userspace via the 'mcast' log level. */ static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, u8 flags) { - u8 old_flags = bat_priv->mcast.flags; + bool old_enabled = bat_priv->mcast.mla_flags.enabled; + u8 old_flags = bat_priv->mcast.mla_flags.tvlv_flags; char str_old_flags[] = "[...]";

sprintf(str_old_flags, "[%c%c%c]", @@ -502,85 +556,39 @@ static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, u8 flags)

batadv_dbg(BATADV_DBG_MCAST, bat_priv, "Changing multicast flags from '%s' to '[%c%c%c]'\n", - bat_priv->mcast.enabled ? str_old_flags : "<undefined>", + old_enabled ? str_old_flags : "<undefined>", (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.', (flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.', (flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.'); }

/** - * batadv_mcast_mla_tvlv_update() - update multicast tvlv + * batadv_mcast_mla_flags_update() - update multicast flags * @bat_priv: the bat priv with all the soft interface information + * @flags: flags indicating the new multicast state * * Updates the own multicast tvlv with our current multicast related settings, * capabilities and inabilities. - * - * Return: false if we want all IPv4 && IPv6 multicast traffic and true - * otherwise. */ -static bool batadv_mcast_mla_tvlv_update(struct batadv_priv *bat_priv) +static void +batadv_mcast_mla_flags_update(struct batadv_priv *bat_priv, + struct batadv_mcast_mla_flags *flags) { struct batadv_tvlv_mcast_data mcast_data; - struct batadv_mcast_querier_state querier4 = {false, false}; - struct batadv_mcast_querier_state querier6 = {false, false}; - struct net_device *dev = bat_priv->soft_iface; - bool bridged; - - mcast_data.flags = BATADV_NO_FLAGS; - memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved)); - - bridged = batadv_mcast_has_bridge(bat_priv); - if (!bridged) - goto update; - - if (!IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING)) - pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n"); - - querier4.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP); - querier4.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP); - - querier6.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IPV6); - querier6.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IPV6); - - mcast_data.flags |= BATADV_MCAST_WANT_ALL_UNSNOOPABLES; - - /* 1) If no querier exists at all, then multicast listeners on - * our local TT clients behind the bridge will keep silent. - * 2) If the selected querier is on one of our local TT clients, - * behind the bridge, then this querier might shadow multicast - * listeners on our local TT clients, behind this bridge. - * - * In both cases, we will signalize other batman nodes that - * we need all multicast traffic of the according protocol. - */ - if (!querier4.exists || querier4.shadowing) - mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV4;

- if (!querier6.exists || querier6.shadowing) - mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV6; - -update: - batadv_mcast_bridge_log(bat_priv, bridged, &querier4, &querier6); - - bat_priv->mcast.querier_ipv4.exists = querier4.exists; - bat_priv->mcast.querier_ipv4.shadowing = querier4.shadowing; + if (!memcmp(flags, &bat_priv->mcast.mla_flags, sizeof(*flags))) + return;

- bat_priv->mcast.querier_ipv6.exists = querier6.exists; - bat_priv->mcast.querier_ipv6.shadowing = querier6.shadowing; + batadv_mcast_bridge_log(bat_priv, flags); + batadv_mcast_flags_log(bat_priv, flags->tvlv_flags);

- bat_priv->mcast.bridged = bridged; + mcast_data.flags = flags->tvlv_flags; + memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved));

- if (!bat_priv->mcast.enabled || - mcast_data.flags != bat_priv->mcast.flags) { - batadv_mcast_flags_log(bat_priv, mcast_data.flags); - batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 2, - &mcast_data, sizeof(mcast_data)); - bat_priv->mcast.flags = mcast_data.flags; - bat_priv->mcast.enabled = true; - } + batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 2, + &mcast_data, sizeof(mcast_data));

- return !(mcast_data.flags & BATADV_MCAST_WANT_ALL_IPV4 && - mcast_data.flags & BATADV_MCAST_WANT_ALL_IPV6); + bat_priv->mcast.mla_flags = *flags; }

/** @@ -599,22 +607,24 @@ static void __batadv_mcast_mla_update(struct batadv_priv *bat_priv) { struct net_device *soft_iface = bat_priv->soft_iface; struct hlist_head mcast_list = HLIST_HEAD_INIT; + struct batadv_mcast_mla_flags flags; int ret;

- if (!batadv_mcast_mla_tvlv_update(bat_priv)) - goto update; + flags = batadv_mcast_mla_flags_get(bat_priv);

- ret = batadv_mcast_mla_softif_get(bat_priv, soft_iface, &mcast_list); + ret = batadv_mcast_mla_softif_get(soft_iface, &mcast_list, &flags); if (ret < 0) goto out;

- ret = batadv_mcast_mla_bridge_get(bat_priv, soft_iface, &mcast_list); + ret = batadv_mcast_mla_bridge_get(soft_iface, &mcast_list, &flags); if (ret < 0) goto out;

-update: + spin_lock(&bat_priv->mcast.mla_lock); batadv_mcast_mla_tt_retract(bat_priv, &mcast_list); batadv_mcast_mla_tt_add(bat_priv, &mcast_list); + batadv_mcast_mla_flags_update(bat_priv, &flags); + spin_unlock(&bat_priv->mcast.mla_lock);

out: batadv_mcast_mla_list_free(&mcast_list); @@ -639,10 +649,7 @@ static void batadv_mcast_mla_update(struct work_struct *work) priv_mcast = container_of(delayed_work, struct batadv_priv_mcast, work); bat_priv = container_of(priv_mcast, struct batadv_priv, mcast);

- spin_lock(&bat_priv->mcast.mla_lock); __batadv_mcast_mla_update(bat_priv); - spin_unlock(&bat_priv->mcast.mla_lock); - batadv_mcast_start_timer(bat_priv); }

@@ -1417,15 +1424,16 @@ void batadv_mcast_init(struct batadv_priv *bat_priv) static void batadv_mcast_flags_print_header(struct batadv_priv *bat_priv, struct seq_file *seq) { - u8 flags = bat_priv->mcast.flags; + struct batadv_mcast_mla_flags *mla_flags = &bat_priv->mcast.mla_flags; char querier4, querier6, shadowing4, shadowing6; - bool bridged = bat_priv->mcast.bridged; + bool bridged = mla_flags->bridged; + u8 flags = mla_flags->tvlv_flags;

if (bridged) { - querier4 = bat_priv->mcast.querier_ipv4.exists ? '.' : '4'; - querier6 = bat_priv->mcast.querier_ipv6.exists ? '.' : '6'; - shadowing4 = bat_priv->mcast.querier_ipv4.shadowing ? '4' : '.'; - shadowing6 = bat_priv->mcast.querier_ipv6.shadowing ? '6' : '.'; + querier4 = mla_flags->querier_ipv4.exists ? '.' : '4'; + querier6 = mla_flags->querier_ipv6.exists ? '.' : '6'; + shadowing4 = mla_flags->querier_ipv4.shadowing ? '4' : '.'; + shadowing6 = mla_flags->querier_ipv6.shadowing ? '6' : '.'; } else { querier4 = '?'; querier6 = '?'; @@ -1517,19 +1525,19 @@ int batadv_mcast_flags_seq_print_text(struct seq_file *seq, void *offset) int batadv_mcast_mesh_info_put(struct sk_buff *msg, struct batadv_priv *bat_priv) { - u32 flags = bat_priv->mcast.flags; + u32 flags = bat_priv->mcast.mla_flags.tvlv_flags; u32 flags_priv = BATADV_NO_FLAGS;

- if (bat_priv->mcast.bridged) { + if (bat_priv->mcast.mla_flags.bridged) { flags_priv |= BATADV_MCAST_FLAGS_BRIDGED;

- if (bat_priv->mcast.querier_ipv4.exists) + if (bat_priv->mcast.mla_flags.querier_ipv4.exists) flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV4_EXISTS; - if (bat_priv->mcast.querier_ipv6.exists) + if (bat_priv->mcast.mla_flags.querier_ipv6.exists) flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV6_EXISTS; - if (bat_priv->mcast.querier_ipv4.shadowing) + if (bat_priv->mcast.mla_flags.querier_ipv4.shadowing) flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV4_SHADOWING; - if (bat_priv->mcast.querier_ipv6.shadowing) + if (bat_priv->mcast.mla_flags.querier_ipv6.shadowing) flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV6_SHADOWING; }

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 499afbce..c7a2e77c 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -804,11 +804,6 @@ static int batadv_softif_init_late(struct net_device *dev) atomic_set(&bat_priv->distributed_arp_table, 1); #endif #ifdef CONFIG_BATMAN_ADV_MCAST - bat_priv->mcast.querier_ipv4.exists = false; - bat_priv->mcast.querier_ipv4.shadowing = false; - bat_priv->mcast.querier_ipv6.exists = false; - bat_priv->mcast.querier_ipv6.shadowing = false; - bat_priv->mcast.flags = BATADV_NO_FLAGS; atomic_set(&bat_priv->multicast_mode, 1); atomic_set(&bat_priv->multicast_fanout, 16); atomic_set(&bat_priv->mcast.num_want_all_unsnoopables, 0); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 581f93c0..72f65b37 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1171,6 +1171,26 @@ struct batadv_mcast_querier_state { };

/** + * struct batadv_mcast_mla_flags - flags for the querier, bridge and tvlv state + */ +struct batadv_mcast_mla_flags { + /** @querier_ipv4: the current state of an IGMP querier in the mesh */ + struct batadv_mcast_querier_state querier_ipv4; + + /** @querier_ipv6: the current state of an MLD querier in the mesh */ + struct batadv_mcast_querier_state querier_ipv6; + + /** @enabled: whether the multicast tvlv is currently enabled */ + unsigned char enabled:1; + + /** @bridged: whether the soft interface has a bridge on top */ + unsigned char bridged:1; + + /** @tvlv_flags: the flags we have last sent in our mcast tvlv */ + u8 tvlv_flags; +}; + +/** * struct batadv_priv_mcast - per mesh interface mcast data */ struct batadv_priv_mcast { @@ -1198,20 +1218,10 @@ struct batadv_priv_mcast { */ struct hlist_head want_all_ipv6_list;

- /** @querier_ipv4: the current state of an IGMP querier in the mesh */ - struct batadv_mcast_querier_state querier_ipv4; - - /** @querier_ipv6: the current state of an MLD querier in the mesh */ - struct batadv_mcast_querier_state querier_ipv6; - - /** @flags: the flags we have last sent in our mcast tvlv */ - u8 flags; - - /** @enabled: whether the multicast tvlv is currently enabled */ - unsigned char enabled:1; - - /** @bridged: whether the soft interface has a bridge on top */ - unsigned char bridged:1; + /** + * @mla_flags: flags for the querier, bridge and tvlv state + */ + struct batadv_mcast_mla_flags mla_flags;

/** * @mla_lock: a lock protecting mla_list and mla_flags