From d67b3cdacac911958c6353f043fe98d42c84f5ad Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 30 Mar 2023 06:52:38 -0600 Subject: [PATCH] io_uring: fix poll/netmsg alloc caches 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 Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- 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); }