On Wed, Sep 14, 2016 at 2:49 AM, Thomas Graf <tg...@suug.ch> wrote:
> On 09/09/16 at 04:19pm, Tom Herbert wrote:
>> diff --git a/net/core/resolver.c b/net/core/resolver.c
>> new file mode 100644
>> index 0000000..61b36c5
>> --- /dev/null
>> +++ b/net/core/resolver.c
>> @@ -0,0 +1,267 @@
>> +#include <linux/errno.h>
>> +#include <linux/ip.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/netlink.h>
>> +#include <linux/skbuff.h>
>> +#include <linux/socket.h>
>> +#include <linux/types.h>
>> +#include <linux/vmalloc.h>
>> +#include <net/checksum.h>
>> +#include <net/ip.h>
>> +#include <net/ip6_fib.h>
>> +#include <net/lwtunnel.h>
>> +#include <net/protocol.h>
>> +#include <net/resolver.h>
>> +#include <uapi/linux/ila.h>
>
> This include list could be stripped down a bit. ila, lwt, fib, ...
>
>> +
>> +static struct net_rslv_ent *net_rslv_new_ent(struct net_rslv *nrslv,
>> + void *key)
>
> Comment above that net_rslv_get_lock() must be held?
>
>> +{
>> + struct net_rslv_ent *nrent;
>> + int err;
>> +
>> + nrent = kzalloc(sizeof(*nrent) + nrslv->obj_size, GFP_KERNEL);
>
> GFP_ATOMIC since you typically hold net_rslv_get_lock() spinlock?
>
>> + if (!nrent)
>> + return ERR_PTR(-EAGAIN);
>> +
>> + /* Key is always at beginning of object data */
>> + memcpy(nrent->object, key, nrslv->params.key_len);
>> +
>> + /* Initialize user data */
>> + if (nrslv->rslv_init)
>> + nrslv->rslv_init(nrslv, nrent);
>> +
>> + /* Put in hash table */
>> + err = rhashtable_lookup_insert_fast(&nrslv->rhash_table,
>> + &nrent->node, nrslv->params);
>> + if (err)
>> + return ERR_PTR(err);
>> +
>> + if (nrslv->timeout) {
>> + /* Schedule timeout for resolver */
>> + INIT_DELAYED_WORK(&nrent->timeout_work, net_rslv_delayed_work);
>
> Should this be done before inserting into rhashtable?
>
Adding to the table and setting delayed work are done under a lock so
I think it should be okay. I'll add a comment to the function that the
lock is held.
>> + schedule_delayed_work(&nrent->timeout_work, nrslv->timeout);
>> + }
>> +
>> + nrent->nrslv = nrslv;
>
> Same here. net_rslv_cancel_all_delayed_work() walking the rhashtable could
> see ->nrslv as NULL.
I'll move it up, but net_rslv_cancel_all_delayed_work is only called
when we're destroying the table so it would be a bug in the higher
layer if it is both destroying the table and adding entries at the
same time.
Thanks,
Tom
>
