Re: [PATCH RFC] bonding: rate-limit bonding driver inspect messages

[Hangbin Liu <liuhangbin@gmail.com>]

On Thu, Feb 15, 2024 at 10:55:54PM +0530, Praveen Kumar Kannoju wrote:
> Rate limit bond driver log messages, to prevent a log flood in a run-away
> situation, e.g couldn't get rtnl lock. Message flood leads to instability
> of system and loss of other crucial messages.

Hi Praveen,

The patch looks good to me. But would you please help explain why these
slave_info() are chosen under net_ratelimit?

Thanks
Hangbin
> 
> v2: Use exising net_ratelimit() instead of introducing new rate-limit
> parameter.
> 
> Signed-off-by: Praveen Kumar Kannoju <praveen.kannoju@oracle.com>
> ---
>  drivers/net/bonding/bond_main.c | 36 ++++++++++++++++++++----------------
>  1 file changed, 20 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
> index 4e0600c..e92eba1 100644
> --- a/drivers/net/bonding/bond_main.c
> +++ b/drivers/net/bonding/bond_main.c
> @@ -2610,12 +2610,13 @@ static int bond_miimon_inspect(struct bonding *bond)
>  			commit++;
>  			slave->delay = bond->params.downdelay;
>  			if (slave->delay) {
> -				slave_info(bond->dev, slave->dev, "link status down for %sinterface, disabling it in %d ms\n",
> -					   (BOND_MODE(bond) ==
> -					    BOND_MODE_ACTIVEBACKUP) ?
> -					    (bond_is_active_slave(slave) ?
> -					     "active " : "backup ") : "",
> -					   bond->params.downdelay * bond->params.miimon);
> +				if (net_ratelimit())
> +					slave_info(bond->dev, slave->dev, "link status down for %sinterface, disabling it in %d ms\n",
> +						   (BOND_MODE(bond) ==
> +						   BOND_MODE_ACTIVEBACKUP) ?
> +						   (bond_is_active_slave(slave) ?
> +						   "active " : "backup ") : "",
> +						   bond->params.downdelay * bond->params.miimon);
>  			}
>  			fallthrough;
>  		case BOND_LINK_FAIL:
> @@ -2623,9 +2624,10 @@ static int bond_miimon_inspect(struct bonding *bond)
>  				/* recovered before downdelay expired */
>  				bond_propose_link_state(slave, BOND_LINK_UP);
>  				slave->last_link_up = jiffies;
> -				slave_info(bond->dev, slave->dev, "link status up again after %d ms\n",
> -					   (bond->params.downdelay - slave->delay) *
> -					   bond->params.miimon);
> +				if (net_ratelimit())
> +					slave_info(bond->dev, slave->dev, "link status up again after %d ms\n",
> +						   (bond->params.downdelay - slave->delay) *
> +						   bond->params.miimon);
>  				commit++;
>  				continue;
>  			}
> @@ -2648,18 +2650,20 @@ static int bond_miimon_inspect(struct bonding *bond)
>  			slave->delay = bond->params.updelay;
>  
>  			if (slave->delay) {
> -				slave_info(bond->dev, slave->dev, "link status up, enabling it in %d ms\n",
> -					   ignore_updelay ? 0 :
> -					   bond->params.updelay *
> -					   bond->params.miimon);
> +				if (net_ratelimit())
> +					slave_info(bond->dev, slave->dev, "link status up, enabling it in %d ms\n",
> +						   ignore_updelay ? 0 :
> +						   bond->params.updelay *
> +						   bond->params.miimon);
>  			}
>  			fallthrough;
>  		case BOND_LINK_BACK:
>  			if (!link_state) {
>  				bond_propose_link_state(slave, BOND_LINK_DOWN);
> -				slave_info(bond->dev, slave->dev, "link status down again after %d ms\n",
> -					   (bond->params.updelay - slave->delay) *
> -					   bond->params.miimon);
> +				if (net_ratelimit())
> +					slave_info(bond->dev, slave->dev, "link status down again after %d ms\n",
> +						   (bond->params.updelay - slave->delay) *
> +						   bond->params.miimon);
>  				commit++;
>  				continue;
>  			}
> -- 
> 1.8.3.1
>