From patchwork Mon Jun 20 01:18:52 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Xiaoguang Wang X-Patchwork-Id: 9186403 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 73D906075E for ; Mon, 20 Jun 2016 01:33:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5783A20748 for ; Mon, 20 Jun 2016 01:33:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4BA4D22230; Mon, 20 Jun 2016 01:33:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C7F6B20748 for ; Mon, 20 Jun 2016 01:33:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752128AbcFTBdJ (ORCPT ); Sun, 19 Jun 2016 21:33:09 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:45023 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752092AbcFTBdH (ORCPT ); Sun, 19 Jun 2016 21:33:07 -0400 X-Greylist: delayed 498 seconds by postgrey-1.27 at vger.kernel.org; Sun, 19 Jun 2016 21:33:07 EDT X-IronPort-AV: E=Sophos;i="5.20,367,1444665600"; d="scan'208";a="638998" Received: from unknown (HELO cn.fujitsu.com) ([10.167.250.3]) by song.cn.fujitsu.com with ESMTP; 20 Jun 2016 09:20:44 +0800 Received: from localhost.localdomain (unknown [10.167.226.107]) by cn.fujitsu.com (Postfix) with ESMTP id 74F194056401; Mon, 20 Jun 2016 09:20:41 +0800 (CST) From: Wang Xiaoguang To: linux-btrfs@vger.kernel.org Cc: fdmanana@kernel.org Subject: [PATCH] btrfs: fix WARNING in btrfs_select_ref_head() Date: Mon, 20 Jun 2016 09:18:52 +0800 Message-Id: <1466385532-6005-1-git-send-email-wangxg.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.5.0 MIME-Version: 1.0 X-yoursite-MailScanner-ID: 74F194056401.AEEBD X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: wangxg.fnst@cn.fujitsu.com Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This issue was found when testing in-band dedupe enospc behaviour, sometimes run_one_delayed_ref() may fail for enospc reason, then __btrfs_run_delayed_refs（）will return, but forget to add num_heads_read back, which will trigger "WARN_ON(delayed_refs->num_heads_ready == 0)" in btrfs_select_ref_head(). Signed-off-by: Wang Xiaoguang --- fs/btrfs/extent-tree.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 6146729..eeedff3 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2665,7 +2665,10 @@ static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, btrfs_free_delayed_extent_op(extent_op); if (ret) { + spin_lock(&delayed_refs->lock); locked_ref->processing = 0; + delayed_refs->num_heads_ready++; + spin_unlock(&delayed_refs->lock); btrfs_delayed_ref_unlock(locked_ref); btrfs_put_delayed_ref(ref); btrfs_debug(fs_info, "run_one_delayed_ref returned %d", ret);