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Message-ID: <51C33BD7.4090508@redhat.com>
Date: Thu, 20 Jun 2013 19:28:55 +0200
From: Nikolay Aleksandrov <nikolay@...hat.com>
To: Veaceslav Falico <vfalico@...hat.com>
CC: netdev@...r.kernel.org, fubar@...ibm.com, andy@...yhouse.net,
davem@...emloft.net, linux@...2.net, nicolas.2p.debian@...e.fr,
rick.jones2@...com
Subject: Re: [PATCH v2 net-next 6/6] bonding: add an option to fail when any
of arp_ip_target is inaccessible
On 20/06/13 18:35, Veaceslav Falico wrote:
> Currently, we fail only when all of the ips in arp_ip_target are gone.
> However, in some situations we might need to fail if even one host from
> arp_ip_target becomes unavailable.
>
> All situations, obviously, rely on the idea that we need *completely*
> functional network, with all interfaces/addresses working correctly.
>
> One real world example might be:
> vlans on top on bond (hybrid port). If bond and vlans have ips assigned
> and we have their peers monitored via arp_ip_target - in case of switch
> misconfiguration (trunk/access port), slave driver malfunction or
> tagged/untagged traffic dropped on the way - we will be able to switch
> to another slave.
>
> Though any other configuration needs that if we need to have access to all
> arp_ip_targets.
>
> This patch adds this possibility by adding a new parameter -
> arp_all_targets (both as a module parameter and as a sysfs knob). It can be
> set to:
>
> 0 or any (the default) - which works exactly as it's working now -
> the slave is up if any of the arp_ip_targets are up.
>
> 1 or all - the slave is up if all of the arp_ip_targets are up.
>
> This parameter can be changed on the fly (via sysfs), and requires the mode
> to be active-backup and arp_validate to be enabled (it obeys the
> arp_validate config on which slaves to validate).
>
> Internally it's done through:
>
> 1) Add target_last_arp_rx[BOND_MAX_ARP_TARGETS] array to slave struct. It's
> an array of jiffies, meaning that slave->target_last_arp_rx[i] is the
> last time we've received arp from bond->params.arp_targets[i] on this
> slave.
>
> 2) If we successfully validate an arp from bond->params.arp_targets[i] in
> bond_validate_arp() - update the slave->target_last_arp_rx[i] with the
> current jiffies value.
>
> 3) When getting slave's last_rx via slave_last_rx(), we return the oldest
> time when we've received an arp from any address in
> bond->params.arp_targets[].
>
> If the value of arp_all_targets == 0 - we still work the same way as
> before.
>
> Also, update the documentation to reflect the new parameter.
>
> v1->v2:
> Correctly handle adding/removing hosts in arp_ip_target - we need to
> shift/initialize all slave's target_last_arp_rx. Also, don't fail module
> loading on arp_all_targets misconfiguration, just disable it, and some
> minor style fixes.
>
> Signed-off-by: Veaceslav Falico <vfalico@...hat.com>
> ---
> Documentation/networking/bonding.txt | 17 ++++++
> drivers/net/bonding/bond_main.c | 36 +++++++++++++-
> drivers/net/bonding/bond_sysfs.c | 91 ++++++++++++++++++++++++++++++----
> drivers/net/bonding/bonding.h | 30 ++++++++++-
> 4 files changed, 160 insertions(+), 14 deletions(-)
>
> diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
> index adee3b4..d04f1f5 100644
> --- a/Documentation/networking/bonding.txt
> +++ b/Documentation/networking/bonding.txt
> @@ -321,6 +321,23 @@ arp_validate
>
> This option was added in bonding version 3.1.0.
>
> +arp_all_targets
> +
> + Specifies whether, in active-backup mode with arp validation,
> + any of the arp_ip_targets should be up to keep the slave up
> + (default) or it should go down if at least one of
> + arp_ip_targets doesn't reply to arp requests.
> +
> + Possible values are:
> +
> + any or 0
> +
> + consider the slave up if any of the arp_ip_targets is up
> +
> + all or 1
> +
> + consider the slave up if all of the arp_ip_targets are up
> +
> downdelay
>
> Specifies the time, in milliseconds, to wait before disabling
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index f51c379..e19ef34 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -104,6 +104,7 @@ static char *xmit_hash_policy;
> static int arp_interval = BOND_LINK_ARP_INTERV;
> static char *arp_ip_target[BOND_MAX_ARP_TARGETS];
> static char *arp_validate;
> +static char *arp_all_targets;
> static char *fail_over_mac;
> static int all_slaves_active = 0;
> static struct bond_params bonding_defaults;
> @@ -166,6 +167,8 @@ module_param(arp_validate, charp, 0);
> MODULE_PARM_DESC(arp_validate, "validate src/dst of ARP probes; "
> "0 for none (default), 1 for active, "
> "2 for backup, 3 for all");
> +module_param(arp_all_targets, charp, 0);
> +MODULE_PARM_DESC(arp_all_targets, "fail on any/all arp targets timeout; 0 for any (default), 1 for all");
> module_param(fail_over_mac, charp, 0);
> MODULE_PARM_DESC(fail_over_mac, "For active-backup, do not set all slaves to "
> "the same MAC; 0 for none (default), "
> @@ -216,6 +219,12 @@ const struct bond_parm_tbl xmit_hashtype_tbl[] = {
> { NULL, -1},
> };
>
> +const struct bond_parm_tbl arp_all_targets_tbl[] = {
> +{ "any", BOND_ARP_TARGETS_ANY},
> +{ "all", BOND_ARP_TARGETS_ALL},
> +{ NULL, -1},
> +};
> +
> const struct bond_parm_tbl arp_validate_tbl[] = {
> { "none", BOND_ARP_VALIDATE_NONE},
> { "active", BOND_ARP_VALIDATE_ACTIVE},
> @@ -1483,7 +1492,7 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
> struct slave *new_slave = NULL;
> struct sockaddr addr;
> int link_reporting;
> - int res = 0;
> + int res = 0, i;
>
> if (!bond->params.use_carrier &&
> slave_dev->ethtool_ops->get_link == NULL &&
> @@ -1712,6 +1721,8 @@ int bond_enslave(struct net_device *bond_dev, struct net_device *slave_dev)
>
> new_slave->last_arp_rx = jiffies -
> (msecs_to_jiffies(bond->params.arp_interval) + 1);
> + for (i = 0; i < BOND_MAX_ARP_TARGETS; i++)
> + new_slave->target_last_arp_rx[i] = jiffies;
>
> if (bond->params.miimon && !bond->params.use_carrier) {
> link_reporting = bond_check_dev_link(bond, slave_dev, 1);
> @@ -2610,16 +2621,20 @@ static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
>
> static void bond_validate_arp(struct bonding *bond, struct slave *slave, __be32 sip, __be32 tip)
> {
> + int i;
> +
> if (!sip || !bond_has_this_ip(bond, tip)) {
> pr_debug("bva: sip %pI4 tip %pI4 not found\n", &sip, &tip);
> return;
> }
>
> - if (bond_get_targets_ip(bond->params.arp_targets, sip) == -1) {
> + i = bond_get_targets_ip(bond->params.arp_targets, sip);
> + if (i == -1) {
> pr_debug("bva: sip %pI4 not found in targets\n", &sip);
> return;
> }
> slave->last_arp_rx = jiffies;
> + slave->target_last_arp_rx[i] = jiffies;
> }
>
> static int bond_arp_rcv(const struct sk_buff *skb, struct bonding *bond,
> @@ -4407,6 +4422,7 @@ int bond_parse_parm(const char *buf, const struct bond_parm_tbl *tbl)
> static int bond_check_params(struct bond_params *params)
> {
> int arp_validate_value, fail_over_mac_value, primary_reselect_value, i;
> + int arp_all_targets_value;
>
> /*
> * Convert string parameters.
> @@ -4632,6 +4648,21 @@ static int bond_check_params(struct bond_params *params)
> } else
> arp_validate_value = 0;
>
> + if (arp_all_targets && arp_validate_value) {
> + arp_all_targets_value = bond_parse_parm(arp_all_targets,
> + arp_all_targets_tbl);
> +
> + if (arp_all_targets_value == -1) {
> + pr_err("Error: invalid arp_all_targets_value \"%s\"\n",
> + arp_all_targets);
> + arp_all_targets_value = 0;
> + }
> + } else {
> + if (!arp_validate_value)
> + pr_err("arp_all_targets requires arp_validate\n");
This will print every time we don't have arp_validate_value (w/ or w/o
arp_all_targets). The check should probably be if (arp_all_targets &&
!arp_validate_value).
> + arp_all_targets_value = 0;
> + }
> +
> if (miimon) {
> pr_info("MII link monitoring set to %d ms\n", miimon);
> } else if (arp_interval) {
> @@ -4696,6 +4727,7 @@ static int bond_check_params(struct bond_params *params)
> params->num_peer_notif = num_peer_notif;
> params->arp_interval = arp_interval;
> params->arp_validate = arp_validate_value;
> + params->arp_all_targets = arp_all_targets_value;
> params->updelay = updelay;
> params->downdelay = downdelay;
> params->use_carrier = use_carrier;
> diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
> index ece57f1..7f8f119 100644
> --- a/drivers/net/bonding/bond_sysfs.c
> +++ b/drivers/net/bonding/bond_sysfs.c
> @@ -443,6 +443,49 @@ static ssize_t bonding_store_arp_validate(struct device *d,
>
> static DEVICE_ATTR(arp_validate, S_IRUGO | S_IWUSR, bonding_show_arp_validate,
> bonding_store_arp_validate);
> +/*
> + * Show and set arp_all_targets.
> + */
> +static ssize_t bonding_show_arp_all_targets(struct device *d,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct bonding *bond = to_bond(d);
> + int value = bond->params.arp_all_targets;
> +
> + return sprintf(buf, "%s %d\n", arp_all_targets_tbl[value].modename,
> + value);
> +}
> +
> +static ssize_t bonding_store_arp_all_targets(struct device *d,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct bonding *bond = to_bond(d);
> + int new_value;
> +
> + new_value = bond_parse_parm(buf, arp_all_targets_tbl);
> + if (new_value < 0) {
> + pr_err("%s: Ignoring invalid arp_all_targets value %s\n",
> + bond->dev->name, buf);
> + return -EINVAL;
> + }
> + if (new_value && !bond->params.arp_validate) {
> + pr_err("%s: arp_all_targets requires arp_validate.\n",
> + bond->dev->name);
> + return -EINVAL;
> + }
> + pr_info("%s: setting arp_all_targets to %s (%d).\n",
> + bond->dev->name, arp_all_targets_tbl[new_value].modename,
> + new_value);
> +
> + bond->params.arp_all_targets = new_value;
> +
> + return count;
> +}
> +
> +static DEVICE_ATTR(arp_all_targets, S_IRUGO | S_IWUSR,
> + bonding_show_arp_all_targets, bonding_store_arp_all_targets);
>
> /*
> * Show and store fail_over_mac. User only allowed to change the
> @@ -590,10 +633,14 @@ static ssize_t bonding_store_arp_targets(struct device *d,
> struct device_attribute *attr,
> const char *buf, size_t count)
> {
> - __be32 newtarget;
> - int i = 0, ret = -EINVAL;
> struct bonding *bond = to_bond(d);
> - __be32 *targets;
> + struct slave *slave;
> + __be32 newtarget, *targets;
> + unsigned long *targets_rx;
> + int ind, i, j, ret = -EINVAL;
> +
> + if (!rtnl_trylock())
> + return restart_syscall();
Why do we need RTNL here, what can we race with ?
>
> targets = bond->params.arp_targets;
> newtarget = in_aton(buf + 1);
> @@ -611,8 +658,8 @@ static ssize_t bonding_store_arp_targets(struct device *d,
> goto out;
> }
>
> - i = bond_get_targets_ip(targets, 0); /* first free slot */
> - if (i == -1) {
> + ind = bond_get_targets_ip(targets, 0); /* first free slot */
> + if (ind == -1) {
> pr_err("%s: ARP target table is full!\n",
> bond->dev->name);
> goto out;
> @@ -620,7 +667,13 @@ static ssize_t bonding_store_arp_targets(struct device *d,
>
> pr_info("%s: adding ARP target %pI4.\n", bond->dev->name,
> &newtarget);
> - targets[i] = newtarget;
> + /* not to race with bond_arp_rcv */
> + write_lock(&bond->lock);
I think this should be _bh since we may get preempted and deadlock.
> + bond_for_each_slave(bond, slave, i)
> + slave->target_last_arp_rx[ind] = slave_last_rx(bond,
> + slave);
Why not simply jiffies ? The oldest one will still be the oldest one :-)
> + targets[ind] = newtarget;
> + write_unlock(&bond->lock);
> } else if (buf[0] == '-') {
> if ((newtarget == 0) || (newtarget == htonl(INADDR_BROADCAST))) {
> pr_err("%s: invalid ARP target %pI4 specified for removal\n",
> @@ -628,18 +681,34 @@ static ssize_t bonding_store_arp_targets(struct device *d,
> goto out;
> }
>
> - i = bond_get_targets_ip(targets, newtarget);
> - if (i == -1) {
> - pr_info("%s: unable to remove nonexistent ARP target %pI4.\n",
> + ind = bond_get_targets_ip(targets, newtarget);
> + if (ind == -1) {
> + pr_err("%s: unable to remove nonexistent ARP target %pI4.\n",
> bond->dev->name, &newtarget);
> goto out;
> }
>
> + if (ind == 0 && targets[1] == 0 && bond->params.arp_validate) {
> + pr_err("%s: can't remove last arp target if arp_validate is on\n",
> + bond->dev->name);
> + goto out;
> + }
Can't I turn arp_validate off, then delete the last target and then turn
it on again ? Are you fixing the 0 first entry with this ?
> +
> pr_info("%s: removing ARP target %pI4.\n", bond->dev->name,
> &newtarget);
> - for (; (i < BOND_MAX_ARP_TARGETS-1) && targets[i+1]; i++)
> +
> + write_lock(&bond->lock);
_bh ditto
> + bond_for_each_slave(bond, slave, i) {
> + targets_rx = slave->target_last_arp_rx;
> + j = ind;
> + for (; (j < BOND_MAX_ARP_TARGETS-1) && targets[j+1]; j++)
> + targets_rx[j] = targets_rx[j+1];
> + targets_rx[j] = 0;
> + }
> + for (i = ind; (i < BOND_MAX_ARP_TARGETS-1) && targets[i+1]; i++)
> targets[i] = targets[i+1];
> targets[i] = 0;
> + write_unlock(&bond->lock);
> } else {
> pr_err("no command found in arp_ip_targets file for bond %s. Use +<addr> or -<addr>.\n",
> bond->dev->name);
> @@ -649,6 +718,7 @@ static ssize_t bonding_store_arp_targets(struct device *d,
>
> ret = count;
> out:
> + rtnl_unlock();
> return ret;
> }
> static DEVICE_ATTR(arp_ip_target, S_IRUGO | S_IWUSR , bonding_show_arp_targets, bonding_store_arp_targets);
> @@ -1623,6 +1693,7 @@ static struct attribute *per_bond_attrs[] = {
> &dev_attr_mode.attr,
> &dev_attr_fail_over_mac.attr,
> &dev_attr_arp_validate.attr,
> + &dev_attr_arp_all_targets.attr,
> &dev_attr_arp_interval.attr,
> &dev_attr_arp_ip_target.attr,
> &dev_attr_downdelay.attr,
> diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
> index 486e532..3fb73cc 100644
> --- a/drivers/net/bonding/bonding.h
> +++ b/drivers/net/bonding/bonding.h
> @@ -144,6 +144,7 @@ struct bond_params {
> u8 num_peer_notif;
> int arp_interval;
> int arp_validate;
> + int arp_all_targets;
> int use_carrier;
> int fail_over_mac;
> int updelay;
> @@ -179,6 +180,7 @@ struct slave {
> int delay;
> unsigned long jiffies;
> unsigned long last_arp_rx;
> + unsigned long target_last_arp_rx[BOND_MAX_ARP_TARGETS];
> s8 link; /* one of BOND_LINK_XXXX */
> s8 new_link;
> u8 backup:1, /* indicates backup slave. Value corresponds with
> @@ -322,6 +324,9 @@ static inline bool bond_is_active_slave(struct slave *slave)
> #define BOND_FOM_ACTIVE 1
> #define BOND_FOM_FOLLOW 2
>
> +#define BOND_ARP_TARGETS_ANY 0
> +#define BOND_ARP_TARGETS_ALL 1
> +
> #define BOND_ARP_VALIDATE_NONE 0
> #define BOND_ARP_VALIDATE_ACTIVE (1 << BOND_STATE_ACTIVE)
> #define BOND_ARP_VALIDATE_BACKUP (1 << BOND_STATE_BACKUP)
> @@ -334,11 +339,31 @@ static inline int slave_do_arp_validate(struct bonding *bond,
> return bond->params.arp_validate & (1 << bond_slave_state(slave));
> }
>
> +/* Get the oldest arp which we've received on this slave for bond's
> + * arp_targets.
> + */
> +static inline unsigned long slave_oldest_target_arp_rx(struct bonding *bond,
> + struct slave *slave)
> +{
> + int i = 1;
> + unsigned long ret = slave->target_last_arp_rx[0];
> +
> + for (; (i < BOND_MAX_ARP_TARGETS) && bond->params.arp_targets[i]; i++)
> + if (time_before(slave->target_last_arp_rx[i], ret))
> + ret = slave->target_last_arp_rx[i];
> +
> + return ret;
> +}
> +
> static inline unsigned long slave_last_rx(struct bonding *bond,
> struct slave *slave)
> {
> - if (slave_do_arp_validate(bond, slave))
> - return slave->last_arp_rx;
> + if (slave_do_arp_validate(bond, slave)) {
> + if (bond->params.arp_all_targets == BOND_ARP_TARGETS_ALL)
> + return slave_oldest_target_arp_rx(bond, slave);
> + else
> + return slave->last_arp_rx;
> + }
>
> return slave->dev->last_rx;
> }
> @@ -486,6 +511,7 @@ extern const struct bond_parm_tbl bond_lacp_tbl[];
> extern const struct bond_parm_tbl bond_mode_tbl[];
> extern const struct bond_parm_tbl xmit_hashtype_tbl[];
> extern const struct bond_parm_tbl arp_validate_tbl[];
> +extern const struct bond_parm_tbl arp_all_targets_tbl[];
> extern const struct bond_parm_tbl fail_over_mac_tbl[];
> extern const struct bond_parm_tbl pri_reselect_tbl[];
> extern struct bond_parm_tbl ad_select_tbl[];
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