From patchwork Mon Feb 9 09:31:45 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Forrest Liu X-Patchwork-Id: 5800251 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id C78D19F336 for ; Mon, 9 Feb 2015 09:32:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E77A12011D for ; Mon, 9 Feb 2015 09:32:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0370520117 for ; Mon, 9 Feb 2015 09:32:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760031AbbBIJb5 (ORCPT ); Mon, 9 Feb 2015 04:31:57 -0500 Received: from mail.synology.com ([59.124.41.242]:48062 "EHLO mail.synology.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759523AbbBIJbz (ORCPT ); Mon, 9 Feb 2015 04:31:55 -0500 Received: from localhost.localdomain (unknown [192.168.0.152]) (Authenticated sender: forrestl@synology.com) by mail.synology.com (Postfix) with ESMTPSA id 74B1299C329; Mon, 9 Feb 2015 17:31:52 +0800 (CST) From: Forrest Liu To: linux-btrfs@vger.kernel.org Cc: Forrest Liu , Chien-Kuan Yeh Subject: [PATCH v3] Btrfs: btrfs_release_extent_buffer_page didn't free pages of dummy extent Date: Mon, 9 Feb 2015 17:31:45 +0800 Message-Id: <1423474305-26751-1-git-send-email-forrestl@synology.com> X-Mailer: git-send-email 1.9.1 X-MailScanner-ID: 74B1299C329.AD58F X-MailScanner: Found to be clean X-MailScanner-SpamCheck: not spam (whitelisted), SpamAssassin (not cached, score=0.735, required 8, ALL_TRUSTED -1.00, AWL 0.94, BAYES_00 -1.90, DNS_FROM_AHBL_RHSBL 2.70) X-MailScanner-From: forrestl@synology.com X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP btrfs_release_extent_buffer_page() can't handle dummy extent that allocated by btrfs_clone_extent_buffer() properly. That is because reference count of pages that allocated by btrfs_clone_extent_buffer() was 2, 1 by alloc_page(), and another by attach_extent_buffer_page(). Running following command repeatly can check this memory leak problem btrfs inspect-internal inode-resolve 256 /mnt/btrfs Signed-off-by: Chien-Kuan Yeh Signed-off-by: Forrest Liu Reviewed-by: Filipe Manana Tested-by: Filipe Manana --- V2: do not call PagePrivate if page is NULL V3: add reproducing step in commit message fs/btrfs/extent_io.c | 51 ++++++++++++++++++++++++++------------------------- 1 file changed, 26 insertions(+), 25 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 790dbae..9de93ee 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4554,36 +4554,37 @@ static void btrfs_release_extent_buffer_page(struct extent_buffer *eb) do { index--; page = eb->pages[index]; - if (page && mapped) { + if (!page) + continue; + if (mapped) spin_lock(&page->mapping->private_lock); + /* + * We do this since we'll remove the pages after we've + * removed the eb from the radix tree, so we could race + * and have this page now attached to the new eb. So + * only clear page_private if it's still connected to + * this eb. + */ + if (PagePrivate(page) && + page->private == (unsigned long)eb) { + BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); + BUG_ON(PageDirty(page)); + BUG_ON(PageWriteback(page)); /* - * We do this since we'll remove the pages after we've - * removed the eb from the radix tree, so we could race - * and have this page now attached to the new eb. So - * only clear page_private if it's still connected to - * this eb. + * We need to make sure we haven't be attached + * to a new eb. */ - if (PagePrivate(page) && - page->private == (unsigned long)eb) { - BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); - BUG_ON(PageDirty(page)); - BUG_ON(PageWriteback(page)); - /* - * We need to make sure we haven't be attached - * to a new eb. - */ - ClearPagePrivate(page); - set_page_private(page, 0); - /* One for the page private */ - page_cache_release(page); - } - spin_unlock(&page->mapping->private_lock); - - } - if (page) { - /* One for when we alloced the page */ + ClearPagePrivate(page); + set_page_private(page, 0); + /* One for the page private */ page_cache_release(page); } + + if (mapped) + spin_unlock(&page->mapping->private_lock); + + /* One for when we alloced the page */ + page_cache_release(page); } while (index != 0); }