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

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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>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
This commit is contained in:
Linus Lüssing 2019-05-07 06:08:26 +02:00 committed by Simon Wunderlich
parent 68a600de9a
commit 6bc4544021
3 changed files with 165 additions and 152 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

274
net/batman-adv/multicast.c
View File

@ -71,6 +71,80 @@ static void batadv_mcast_start_timer(struct batadv_priv *bat_priv)
msecs_to_jiffies(BATADV_MCAST_WORK_PERIOD));
}
/**
* 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];
@ -369,27 +444,6 @@ 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
@ -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;
if (!memcmp(flags, &bat_priv->mcast.mla_flags, sizeof(*flags)))
return;
batadv_mcast_bridge_log(bat_priv, flags);
batadv_mcast_flags_log(bat_priv, flags->tvlv_flags);
mcast_data.flags = flags->tvlv_flags;
memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved));
bridged = batadv_mcast_has_bridge(bat_priv);
if (!bridged)
goto update;
batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 2,
&mcast_data, sizeof(mcast_data));
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;
bat_priv->mcast.querier_ipv6.exists = querier6.exists;
bat_priv->mcast.querier_ipv6.shadowing = querier6.shadowing;
bat_priv->mcast.bridged = bridged;
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;
}
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;
}

5
net/batman-adv/soft-interface.c
View File

@ -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);

38
net/batman-adv/types.h
View File

@ -1170,6 +1170,26 @@ struct batadv_mcast_querier_state {
unsigned char shadowing:1;
};
/**
* 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
*/
@ -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