Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754366AbaBTIzI (ORCPT ); Thu, 20 Feb 2014 03:55:08 -0500 Received: from [115.239.196.105] ([115.239.196.105]:46951 "EHLO mail.ucloud.cn" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754302AbaBTIzF (ORCPT ); Thu, 20 Feb 2014 03:55:05 -0500 X-Greylist: delayed 578 seconds by postgrey-1.27 at vger.kernel.org; Thu, 20 Feb 2014 03:55:05 EST From: Minfei Huang To: linux-kernel@vger.kernel.org Cc: Minfei Huang , Joern Engel , Johannes Berg Subject: [PATCH] btree: Fix the bug to release whole btree nodes Date: Thu, 20 Feb 2014 16:45:03 +0800 Message-Id: <1392885903-2831-1-git-send-email-huangminfei@ucloud.cn> X-Mailer: git-send-email 1.8.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I use the btree which pickes up the latest version of kernel source 3.14-rc2 in my own module. When the btree module is removed, a warning arised: kmem_cache_destroy btree_node: Slab cache still has objects CPU: 13 PID: 9150 Comm: rmmod Tainted: GF O 3.14.0-rc2 #1 Hardware name: Inspur NF5270M3/NF5270M3, BIOS CHEETAH_2.1.3 09/10/2013 ffff881ff8643b18 ffff881ffdc23ea8 ffffffff815a4ecc 0000000000000000 ffff881ff8643ac0 ffff881ffdc23ec8 ffffffff811610df 0000000000000880 ffffffffa057da60 ffff881ffdc23ed8 ffffffffa057d57c ffff881ffdc23f78 Call Trace: [] dump_stack+0x49/0x5d [] kmem_cache_destroy+0xcf/0xe0 [] btree_module_exit+0x10/0x12 [btree] [] SyS_delete_module+0x198/0x1f0 [] ? retint_swapgs+0xe/0x13 [] ? trace_hardirqs_on_caller+0xfd/0x1c0 [] ? trace_hardirqs_on_thunk+0x3a/0x3f [] system_call_fastpath+0x16/0x1b The cause is that it doesn't release the last btree node, when height = 1 and fill = 1. Signed-off-by: Minfei Huang CC: Joern Engel CC: Johannes Berg --- lib/btree.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) diff --git a/lib/btree.c b/lib/btree.c index f9a4846..fd17d26 100644 --- a/lib/btree.c +++ b/lib/btree.c @@ -444,6 +444,16 @@ static void btree_shrink(struct btree_head *head, struct btree_geo *geo) mempool_free(node, head->mempool); } +static void btree_shrink_head(struct btree_head *head) +{ + if (head->height != 1) + return; + + mempool_free(head->node, head->mempool); + head->node = NULL; + head->height--; +} + static int btree_insert_level(struct btree_head *head, struct btree_geo *geo, unsigned long *key, void *val, int level, gfp_t gfp) @@ -620,6 +630,8 @@ static void *btree_remove_level(struct btree_head *head, struct btree_geo *geo, rebalance(head, geo, key, level, node, fill - 1); else if (fill - 1 == 1) btree_shrink(head, geo); + else if (fill - 1 == 0) + btree_shrink_head(head); } return ret; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/