From: Pavel Begunkov asml.silence@gmail.com
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@vger.kernel.org Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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); }