On Tue, Feb 01, 2022 at 10:35:14AM -0800, Maciej Żenczykowski wrote: > From: Maciej Żenczykowski <maze@xxxxxxxxxx> > > by resuming from the bucket the key would be in if it still existed > > Note: AFAICT this an API change that would require some sort of guard... > > bpf map iteration was added all the way back in v3.18-rc4-939-g0f8e4bd8a1fc > but behaviour of find first key with NULL was only done in v4.11-rc7-2042-g8fe45924387b > (before that you'd get EFAULT) > > this means previously find first key was done by calling with a non existing key > (AFAICT this was hoping to get lucky, since if your non existing key actually existed, > it wouldn't actually iterate right, since you couldn't guarantee your magic value was > the first one) > > ie. do we need a BPF_MAP_GET_NEXT_KEY2 or a sysctl? some other approach? BPF_MAP_LOOKUP_BATCH has already been added to lookup in batches of buckets, so the next bpf_map_lookup_batch will start from the beginning of the next bucket. Here is the details: https://lore.kernel.org/bpf/20200115184308.162644-6-brianvv@xxxxxxxxxx/#t
