Re: [patch net-next 01/15] net: introduce upper device lists

[Jiri Pirko <jiri@resnulli.us>]

Sun, Dec 30, 2012 at 12:31:01AM CET, davem@davemloft.net wrote:
>From: Jiri Pirko <jiri@resnulli.us>
>Date: Sat, 29 Dec 2012 11:38:28 +0100
>
>> +	/*
>> +	 * To prevent loops, check if dev is not upper device to upper_dev.
>> +	 */
>
>Please use:
>
>	/* To prevent loops, check if dev is not upper device to upper_dev.  */

fixed

>
>> +/**
>> + * netdev_upper_free_rcu - Frees a upper device list item via the RCU pointer
>> + * @entry: the entry's RCU field
>> + *
>> + * This function is designed to be used as a callback to the call_rcu()
>> + * function so that the memory allocated to the netdev upper device list item
>> + * can be released safely.
>> + */
>> +static void netdev_upper_free_rcu(struct rcu_head *entry)
>> +{
>> +	struct netdev_upper *upper;
>> +
>> +	upper = container_of(entry, struct netdev_upper, rcu);
>> +	kfree(upper);
>> +}
>
>Please use kfree_rcu().

fixed

>
>Also, since __netdev_has_upper_dev() modifies &search_list inside
>of the list traversal loop, I think you really need to use
>list_for_each_entry_safe() even though you always append to the
>tail of &search_list.

Hmm, I do not believe that list_for_each_entry_safe() would work correctly
here. In case that the current iterator is at the very end of
the list and now other items are added, list_for_each_entry_safe() would
remember that next is head and the newly added items would not be
processed. list_for_each_entry() works just fine in any case I can
imagine. Note that no items are removed during the iteration.
Am I missing something?

Thanks!

Jiri