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rhashtable: Add more lock verification

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Catch hash miscalculations which result in hard to track down race
conditions.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Thomas Graf 2015-02-05 02:03:35 +01:00 committed by David S. Miller
parent a03eaec0df
commit 7cd10db8de
1 changed files with 8 additions and 2 deletions
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10
lib/rhashtable.c
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@ -348,9 +348,11 @@ static bool hashtable_chain_unzip(struct rhashtable *ht,
return !rht_is_a_nulls(p); return !rht_is_a_nulls(p);
} }
static void link_old_to_new(struct bucket_table *new_tbl, static void link_old_to_new(struct rhashtable *ht, struct bucket_table *new_tbl,
unsigned int new_hash, struct rhash_head *entry) unsigned int new_hash, struct rhash_head *entry)
{ {
ASSERT_BUCKET_LOCK(ht, new_tbl, new_hash);
rcu_assign_pointer(*bucket_tail(new_tbl, new_hash), entry); rcu_assign_pointer(*bucket_tail(new_tbl, new_hash), entry);
} }
@ -406,7 +408,7 @@ int rhashtable_expand(struct rhashtable *ht)
lock_buckets(new_tbl, old_tbl, new_hash); lock_buckets(new_tbl, old_tbl, new_hash);
rht_for_each(he, old_tbl, old_hash) { rht_for_each(he, old_tbl, old_hash) {
if (head_hashfn(ht, new_tbl, he) == new_hash) { if (head_hashfn(ht, new_tbl, he) == new_hash) {
link_old_to_new(new_tbl, new_hash, he); link_old_to_new(ht, new_tbl, new_hash, he);
break; break;
} }
} }
@ -492,6 +494,7 @@ int rhashtable_shrink(struct rhashtable *ht)
rcu_assign_pointer(*bucket_tail(new_tbl, new_hash), rcu_assign_pointer(*bucket_tail(new_tbl, new_hash),
tbl->buckets[new_hash]); tbl->buckets[new_hash]);
ASSERT_BUCKET_LOCK(ht, tbl, new_hash + new_tbl->size);
rcu_assign_pointer(*bucket_tail(new_tbl, new_hash), rcu_assign_pointer(*bucket_tail(new_tbl, new_hash),
tbl->buckets[new_hash + new_tbl->size]); tbl->buckets[new_hash + new_tbl->size]);
@ -557,6 +560,8 @@ static void __rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj,
struct rhash_head *head = rht_dereference_bucket(tbl->buckets[hash], struct rhash_head *head = rht_dereference_bucket(tbl->buckets[hash],
tbl, hash); tbl, hash);
ASSERT_BUCKET_LOCK(ht, tbl, hash);
if (rht_is_a_nulls(head)) if (rht_is_a_nulls(head))
INIT_RHT_NULLS_HEAD(obj->next, ht, hash); INIT_RHT_NULLS_HEAD(obj->next, ht, hash);
else else
@ -641,6 +646,7 @@ bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj)
continue; continue;
} }
ASSERT_BUCKET_LOCK(ht, tbl, hash);
rcu_assign_pointer(*pprev, obj->next); rcu_assign_pointer(*pprev, obj->next);
ret = true; ret = true;