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Message-ID: <20090907125025.GB2914@psychotron.lab.eng.brq.redhat.com>
Date: Mon, 7 Sep 2009 14:50:26 +0200
From: Jiri Pirko <jpirko@...hat.com>
To: Nicolas de Pesloüan <nicolas.2p.debian@...e.fr>
Cc: netdev@...r.kernel.org, davem@...emloft.net, fubar@...ibm.com,
bonding-devel@...ts.sourceforge.net
Subject: Re: [PATCH net-next-2.6] bonding: introduce primary_passive option
Thu, Sep 03, 2009 at 09:56:21PM CEST, nicolas.2p.debian@...e.fr wrote:
> Jiri Pirko wrote:
>> (updated)
>>
>> In some cases there is not desirable to switch back to primary interface when
>> it's link recovers and rather stay with currently active one. We need to avoid
>> packetloss as much as we can in some cases. This is solved by introducing
>> primary_passive option. Note that enslaved primary slave is set as current
>> active no matter what.
>>
>> This patch depends on the following one:
>> [net-next-2.6] bonding: make ab_arp select active slaves as other modes
>> http://patchwork.ozlabs.org/patch/32684/
>>
>> Signed-off-by: Jiri Pirko <jpirko@...hat.com>
>>
>> diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
>> index d5181ce..e70fa8e 100644
>> --- a/Documentation/networking/bonding.txt
>> +++ b/Documentation/networking/bonding.txt
>> @@ -614,6 +614,17 @@ primary
>> The primary option is only valid for active-backup mode.
>> +primary_passive
>> +
>> + Specifies the behaviour of the primary slave in case of
>> + it's link recovery has been detected. By default (value 0) the
>> + primary slave is set as active slave immediately after the link
>> + recovery. If the value is 1 or 2 then current active slave doesn't
>> + change as long as it's link status doesn't change. This prevents
>> + the bonding device from flip-flopping. Plus if the value is 1 this
>> + behaviour happens only if the speed and duplex of primary slave is
>> + higher. It the value is 2 then it happens everytime.
>> +
>
> May I suggest the following option name and description instead ?
>
> -----
>
> primary_return
>
> Specifies the behavior of the current active slave when the primary was
> down and comes back up. This option is designed to prevent flip-flopping
> between the primary slave and other slaves. The possible values and
> their respective effects are:
>
> alway or 0 (default)
>
> The primary slave becomes the active slave whenever it comes
> back up.
>
> better or 1
>
> The primary slave becomes the active slave when it comes back
> up, if the speed and duplex of the primary slave is better
> than the speed and duplex of the current active slave.
>
> failure_only or 2
>
> The primary slave becomes the active slave only if the current
> active slave fails and the primary slave is up.
>
> When no slave are active, if the primary comes back up, it becomes the
> active slave, regardless of the value of primary_return.
>
> -----
>
> Then, to allow those logical names, I suggest you use the
> bond_parse_parm() function and the following constants and struct, to
> parse module params and sysfs configuration.
>
> enum {
> BOND_PRI_RETURN_ALWAYS = 0,
> BOND_PRI_RETURN_BETTER = 1,
> BOND_PRI_RETURN_FAILURE_ONLY = 2,
> };
>
> const struct bond_parm_tbl bond_pri_return_tbl[] = {
> { "always", BOND_PRI_RETURN_ALWAYS},
> { "better", BOND_PRI_RETURN_BETTER},
> { "failure_only", BOND_PRI_RETURN_FAILURE_ONLY},
> { NULL, -1},
> };
>
> Nicolas.
Ok, I like this, but I would stay rather with Jay's suggestion to call this
option primary_passive. Seems more accurate to me.
I'm going to repost soon.
Jirka
>
>> updelay
>> Specifies the time, in milliseconds, to wait before enabling a
>> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
>> index 699bfdd..65066c1 100644
>> --- a/drivers/net/bonding/bond_main.c
>> +++ b/drivers/net/bonding/bond_main.c
>> @@ -94,6 +94,7 @@ static int downdelay;
>> static int use_carrier = 1;
>> static char *mode;
>> static char *primary;
>> +static int primary_passive;
>> static char *lacp_rate;
>> static char *ad_select;
>> static char *xmit_hash_policy;
>> @@ -126,6 +127,9 @@ MODULE_PARM_DESC(mode, "Mode of operation : 0 for balance-rr, "
>> "6 for balance-alb");
>> module_param(primary, charp, 0);
>> MODULE_PARM_DESC(primary, "Primary network device to use");
>> +module_param(primary_passive, int, 0);
>> +MODULE_PARM_DESC(primary_passive, "Do not set primary slave active once it comes up; "
>> + "0 for off (default), 1 for on only if speed of primary is not higher, 2 for on");
>> module_param(lacp_rate, charp, 0);
>> MODULE_PARM_DESC(lacp_rate, "LACPDU tx rate to request from 802.3ad partner "
>> "(slow/fast)");
>> @@ -1070,6 +1074,25 @@ out:
>> }
>> +static bool bond_should_loose_active(struct bonding *bond)
>> +{
>> + struct slave *prim = bond->primary_slave;
>> + struct slave *curr = bond->curr_active_slave;
>> +
>> + if (!prim || !curr || curr->link != BOND_LINK_UP)
>> + return true;
>> + if (bond->force_primary) {
>> + bond->force_primary = false;
>> + return true;
>> + }
>> + if (bond->params.primary_passive == 1 &&
>> + (prim->speed < curr->speed ||
>> + (prim->speed == curr->speed && prim->duplex <= curr->duplex)))
>> + return false;
>> + if (bond->params.primary_passive == 2)
>> + return false;
>> + return true;
>> +}
>> /**
>> * find_best_interface - select the best available slave to be the active one
>> @@ -1094,7 +1117,8 @@ static struct slave *bond_find_best_slave(struct bonding *bond)
>> }
>> if ((bond->primary_slave) &&
>> - bond->primary_slave->link == BOND_LINK_UP) {
>> + bond->primary_slave->link == BOND_LINK_UP &&
>> + bond_should_loose_active(bond)) {
>> new_active = bond->primary_slave;
>> }
>> @@ -1675,8 +1699,10 @@ int bond_enslave(struct net_device *bond_dev,
>> struct net_device *slave_dev)
>> if (USES_PRIMARY(bond->params.mode) && bond->params.primary[0]) {
>> /* if there is a primary slave, remember it */
>> - if (strcmp(bond->params.primary, new_slave->dev->name) == 0)
>> + if (strcmp(bond->params.primary, new_slave->dev->name) == 0) {
>> bond->primary_slave = new_slave;
>> + bond->force_primary = true;
>> + }
>> }
>> write_lock_bh(&bond->curr_slave_lock);
>> @@ -4942,6 +4968,18 @@ static int bond_check_params(struct bond_params *params)
>> primary = NULL;
>> }
>> + if (primary) {
>> + if ((primary_passive != 0) && (primary_passive != 1) &&
>> + (primary_passive != 2)) {
>> + pr_warning(DRV_NAME
>> + ": Warning: primary_passive module parameter "
>> + "(%d), not of valid value (0/1/2), so it was "
>> + "set to 0\n",
>> + primary_passive);
>> + primary_passive = 0;
>> + }
>> + }
>> +
>> if (fail_over_mac) {
>> fail_over_mac_value = bond_parse_parm(fail_over_mac,
>> fail_over_mac_tbl);
>> @@ -4973,6 +5011,7 @@ static int bond_check_params(struct bond_params *params)
>> params->use_carrier = use_carrier;
>> params->lacp_fast = lacp_fast;
>> params->primary[0] = 0;
>> + params->primary_passive = primary_passive;
>> params->fail_over_mac = fail_over_mac_value;
>> if (primary) {
>> diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
>> index 6044e12..e813d48 100644
>> --- a/drivers/net/bonding/bond_sysfs.c
>> +++ b/drivers/net/bonding/bond_sysfs.c
>> @@ -1212,6 +1212,59 @@ static DEVICE_ATTR(primary, S_IRUGO | S_IWUSR,
>> bonding_show_primary, bonding_store_primary);
>> /*
>> + * Show and set the primary_passive flag.
>> + */
>> +static ssize_t bonding_show_primary_passive(struct device *d,
>> + struct device_attribute *attr,
>> + char *buf)
>> +{
>> + struct bonding *bond = to_bond(d);
>> +
>> + return sprintf(buf, "%d\n", bond->params.primary_passive);
>> +}
>> +
>> +static ssize_t bonding_store_primary_passive(struct device *d,
>> + struct device_attribute *attr,
>> + const char *buf, size_t count)
>> +{
>> + int new_value, ret = count;
>> + struct bonding *bond = to_bond(d);
>> +
>> + if (!rtnl_trylock())
>> + return restart_syscall();
>> +
>> + if (sscanf(buf, "%d", &new_value) != 1) {
>> + pr_err(DRV_NAME
>> + ": %s: no primary_passive value specified.\n",
>> + bond->dev->name);
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> + if (new_value == 0 || new_value == 1 || new_value == 2) {
>> + bond->params.primary_passive = new_value;
>> + pr_info(DRV_NAME ": %s: Setting primary_passive to %d.\n",
>> + bond->dev->name, new_value);
>> + if (new_value == 0 || new_value == 1) {
>> + bond->force_primary = true;
>> + read_lock(&bond->lock);
>> + write_lock_bh(&bond->curr_slave_lock);
>> + bond_select_active_slave(bond);
>> + write_unlock_bh(&bond->curr_slave_lock);
>> + read_unlock(&bond->lock);
>> + }
>> + } else {
>> + pr_info(DRV_NAME
>> + ": %s: Ignoring invalid primary_passive value %d.\n",
>> + bond->dev->name, new_value);
>> + }
>> +out:
>> + rtnl_unlock();
>> + return count;
>> +}
>> +static DEVICE_ATTR(primary_passive, S_IRUGO | S_IWUSR,
>> + bonding_show_primary_passive, bonding_store_primary_passive);
>> +
>> +/*
>> * Show and set the use_carrier flag.
>> */
>> static ssize_t bonding_show_carrier(struct device *d,
>> @@ -1500,6 +1553,7 @@ static struct attribute *per_bond_attrs[] = {
>> &dev_attr_num_unsol_na.attr,
>> &dev_attr_miimon.attr,
>> &dev_attr_primary.attr,
>> + &dev_attr_primary_passive.attr,
>> &dev_attr_use_carrier.attr,
>> &dev_attr_active_slave.attr,
>> &dev_attr_mii_status.attr,
>> diff --git a/drivers/net/bonding/bonding.h b/drivers/net/bonding/bonding.h
>> index 6290a50..b6287e0 100644
>> --- a/drivers/net/bonding/bonding.h
>> +++ b/drivers/net/bonding/bonding.h
>> @@ -131,6 +131,7 @@ struct bond_params {
>> int lacp_fast;
>> int ad_select;
>> char primary[IFNAMSIZ];
>> + int primary_passive;
>> __be32 arp_targets[BOND_MAX_ARP_TARGETS];
>> };
>> @@ -190,6 +191,7 @@ struct bonding {
>> struct slave *curr_active_slave;
>> struct slave *current_arp_slave;
>> struct slave *primary_slave;
>> + bool force_primary;
>> s32 slave_cnt; /* never change this value outside the attach/detach wrappers */
>> rwlock_t lock;
>> rwlock_t curr_slave_lock;
>>
>
--
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