From patchwork Tue Sep 15 05:35:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qu Wenruo X-Patchwork-Id: 11775567 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id EF213159A for ; Tue, 15 Sep 2020 05:36:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E147E20771 for ; Tue, 15 Sep 2020 05:36:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726145AbgIOFgH (ORCPT ); Tue, 15 Sep 2020 01:36:07 -0400 Received: from mx2.suse.de ([195.135.220.15]:43248 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726122AbgIOFgC (ORCPT ); Tue, 15 Sep 2020 01:36:02 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 509CEAD52; Tue, 15 Sep 2020 05:36:17 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: Nikolay Borisov Subject: [PATCH v2 10/19] btrfs: add assert_spin_locked() for attach_extent_buffer_page() Date: Tue, 15 Sep 2020 13:35:23 +0800 Message-Id: <20200915053532.63279-11-wqu@suse.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200915053532.63279-1-wqu@suse.com> References: <20200915053532.63279-1-wqu@suse.com> MIME-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org When calling attach_extent_buffer_page(), either we're attaching anonymous pages, called from btrfs_clone_extent_buffer(). Or we're attaching btree_inode pages, called from alloc_extent_buffer(). For the later case, we should have page->mapping->private_lock hold to avoid race modifying page->private. Add assert_spin_locked() if we're calling from alloc_extent_buffer(). Signed-off-by: Qu Wenruo Reviewed-by: Nikolay Borisov Reviewed-by: Johannes Thumshirn --- fs/btrfs/extent_io.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index ba9cc864d9c0..9d4a81997738 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3096,6 +3096,15 @@ static int submit_extent_page(unsigned int opf, static void attach_extent_buffer_page(struct extent_buffer *eb, struct page *page) { + /* + * If the page is mapped to btree inode, we should hold the private + * lock to prevent race. + * For cloned or dummy extent buffers, their pages are not mapped and + * will not race with any other ebs. + */ + if (page->mapping) + assert_spin_locked(&page->mapping->private_lock); + if (!PagePrivate(page)) attach_page_private(page, eb); else