From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 991D9C3815B for ; Mon, 20 Apr 2020 07:48:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C1E622247 for ; Mon, 20 Apr 2020 07:48:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726100AbgDTHs0 (ORCPT ); Mon, 20 Apr 2020 03:48:26 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:47458 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725930AbgDTHs0 (ORCPT ); Mon, 20 Apr 2020 03:48:26 -0400 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 9753B57C67BC89FC2A2A; Mon, 20 Apr 2020 15:48:12 +0800 (CST) Received: from [127.0.0.1] (10.166.215.235) by DGGEMS409-HUB.china.huawei.com (10.3.19.209) with Microsoft SMTP Server id 14.3.487.0; Mon, 20 Apr 2020 15:48:03 +0800 Subject: Re: bcache: unlock new_nodes[i]->write_lock in btree_gc_coalesce To: Coly Li CC: , , , "wubo (T)" , Mingfangsen , Yanxiaodan , linfeilong References: <94f5343a-66c6-713c-4ce9-78c12ae5fd7a@suse.de> From: Zhiqiang Liu Message-ID: Date: Mon, 20 Apr 2020 15:48:01 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <94f5343a-66c6-713c-4ce9-78c12ae5fd7a@suse.de> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.166.215.235] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/4/20 15:10, Coly Li wrote: > On 2020/4/20 14:55, Zhiqiang Liu wrote: >> friendly ping... >> > > The patch is good. Just it would be better if the commit log can be more > accurate and understandable for other readers who are not very familiar > with bcache code. > > Thanks. > > > Coly Li Thanks for your reply. I will try my best to rewrite the commit log. Regards. Zhiqiang Liu. > > >> On 2020/4/15 19:42, Zhiqiang Liu wrote: >>> From: Zhiqiang Liu >>> >>> coccicheck reports: >>> drivers/md//bcache/btree.c:1538:1-7: preceding lock on line 1417 >>> >>> After obtaining new_nodes[i]->write_lock, we may go to out_nocoalesce >>> tag without releasing lock. Here, we add a new tag >>> 'out_unlock_nocoalesce' before out_nocoalesce tag to release >>> new_nodes[i]->write_lock. >>> >>> Fixes: 2a285686c1 ("bcache: btree locking rework") >>> Signed-off-by: Zhiqiang Liu >>> --- >>> drivers/md/bcache/btree.c | 8 ++++++-- >>> 1 file changed, 6 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c >>> index fa872df4e770..cad8b0b97e33 100644 >>> --- a/drivers/md/bcache/btree.c >>> +++ b/drivers/md/bcache/btree.c >>> @@ -1447,7 +1447,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op, >>> if (__set_blocks(n1, n1->keys + n2->keys, >>> block_bytes(b->c)) > >>> btree_blocks(new_nodes[i])) >>> - goto out_nocoalesce; >>> + goto out_unlock_nocoalesce; >>> >>> keys = n2->keys; >>> /* Take the key of the node we're getting rid of */ >>> @@ -1476,7 +1476,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op, >>> >>> if (__bch_keylist_realloc(&keylist, >>> bkey_u64s(&new_nodes[i]->key))) >>> - goto out_nocoalesce; >>> + goto out_unlock_nocoalesce; >>> >>> bch_btree_node_write(new_nodes[i], &cl); >>> bch_keylist_add(&keylist, &new_nodes[i]->key); >>> @@ -1522,6 +1522,10 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op, >>> /* Invalidated our iterator */ >>> return -EINTR; >>> >>> +out_unlock_nocoalesce: >>> + for (i = 0; i < nodes; i++) >>> + mutex_unlock(&new_nodes[i]->write_lock); >>> + >>> out_nocoalesce: >>> closure_sync(&cl); >>> >> > >