From: Pavel Begunkov <asml.silence@xxxxxxxxx>
commit fd30d1cdcc4ff405fc54765edf2e11b03f2ed4f3 upstream.
We increase cache->nr_cached when we free into the cache but don't
decrease when we take from it, so in some time we'll get an empty
cache with cache->nr_cached larger than IO_ALLOC_CACHE_MAX, that fails
io_alloc_cache_put() and effectively disables caching.
Fixes: 9b797a37c4bd8 ("io_uring: add abstraction around apoll cache")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
io_uring/alloc_cache.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/io_uring/alloc_cache.h b/io_uring/alloc_cache.h
index 729793ae9712..c2cde88aeed5 100644
--- a/io_uring/alloc_cache.h
+++ b/io_uring/alloc_cache.h
@@ -27,6 +27,7 @@ static inline struct io_cache_entry *io_alloc_cache_get(struct io_alloc_cache *c
struct hlist_node *node = cache->list.first;
hlist_del(node);
+ cache->nr_cached--;
return container_of(node, struct io_cache_entry, node);
}
--
2.40.0
