rhashtable: Fix potential crash on destroy in rhashtable_shrink

The current being_destroyed check in rhashtable_expand is not
enough since if we start a shrinking process after freeing all
elements in the table that's also going to crash.

This patch adds a being_destroyed check to the deferred worker
thread so that we bail out as soon as we take the lock.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2015-02-04 07:33:22 +11:00 committed by David S. Miller
parent 9b55669c14
commit 28134a53d6

View File

@ -487,6 +487,9 @@ static void rht_deferred_worker(struct work_struct *work)
ht = container_of(work, struct rhashtable, run_work);
mutex_lock(&ht->mutex);
if (ht->being_destroyed)
goto unlock;
tbl = rht_dereference(ht->tbl, ht);
if (ht->p.grow_decision && ht->p.grow_decision(ht, tbl->size))
@ -494,6 +497,7 @@ static void rht_deferred_worker(struct work_struct *work)
else if (ht->p.shrink_decision && ht->p.shrink_decision(ht, tbl->size))
rhashtable_shrink(ht);
unlock:
mutex_unlock(&ht->mutex);
}