| Message ID | 152228634995.16370.12793320017578882447.stgit@noble |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | rhashtable_walk fixes | expand |
On Thu, Mar 29, 2018 at 12:19:09PM +1100, NeilBrown wrote: > When rhltable_insert() finds an entry with the same key, > it splices the new entry at the start of a list of entries with the > same key. > It stores the address of the new object in *pprev, but in general this > is *not* the location where the match was found (though in a common > case where the hash chain has one element, it will be). > To fix this, pprev should be updated every time we find an object that > doesn't match. > > This patch changes the behaviour for non-slow insertion in that now > insertion happens at the end of a chain rather than at the head. > I don't think this is an important change. > > Signed-off-by: NeilBrown <neilb@suse.com> Thanks. But Paul Blakey beat you to it :) https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=d3dcf8eb615537526bd42ff27a081d46d337816e
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index c9df2527e0cd..668a21f04b09 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -766,8 +766,10 @@ static inline void *__rhashtable_insert_fast( if (!key || (params.obj_cmpfn ? params.obj_cmpfn(&arg, rht_obj(ht, head)) : - rhashtable_compare(&arg, rht_obj(ht, head)))) + rhashtable_compare(&arg, rht_obj(ht, head)))) { + pprev = &head->next; continue; + } data = rht_obj(ht, head); diff --git a/lib/rhashtable.c b/lib/rhashtable.c index 394de09a162c..72e56f89e20c 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -506,8 +506,10 @@ static void *rhashtable_lookup_one(struct rhashtable *ht, if (!key || (ht->p.obj_cmpfn ? ht->p.obj_cmpfn(&arg, rht_obj(ht, head)) : - rhashtable_compare(&arg, rht_obj(ht, head)))) + rhashtable_compare(&arg, rht_obj(ht, head)))) { + pprev = &head->next; continue; + } if (!ht->rhlist) return rht_obj(ht, head);
When rhltable_insert() finds an entry with the same key, it splices the new entry at the start of a list of entries with the same key. It stores the address of the new object in *pprev, but in general this is *not* the location where the match was found (though in a common case where the hash chain has one element, it will be). To fix this, pprev should be updated every time we find an object that doesn't match. This patch changes the behaviour for non-slow insertion in that now insertion happens at the end of a chain rather than at the head. I don't think this is an important change. Signed-off-by: NeilBrown <neilb@suse.com> --- include/linux/rhashtable.h | 4 +++- lib/rhashtable.c | 4 +++- 2 files changed, 6 insertions(+), 2 deletions(-)