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>
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index c41e210..904b419 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -487,6 +487,9 @@
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 @@
else if (ht->p.shrink_decision && ht->p.shrink_decision(ht, tbl->size))
rhashtable_shrink(ht);
+unlock:
mutex_unlock(&ht->mutex);
}