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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 BA041C4167B for ; Thu, 10 Dec 2020 06:40:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6774523C44 for ; Thu, 10 Dec 2020 06:40:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387497AbgLJGkE (ORCPT ); Thu, 10 Dec 2020 01:40:04 -0500 Received: from mx2.suse.de ([195.135.220.15]:44282 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387496AbgLJGkE (ORCPT ); Thu, 10 Dec 2020 01:40:04 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1607582357; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3MYT7OdT61w2xAFuZTlre1acT7NXGekPZPGk/vnndeE=; b=f4o9k6zEZ7N/ob1jWV+IdMg3BVcCd4Gkmi4uhqjqG/Q3g9TEYhYNyt4e3ZBDJ+30CPfF/h no+XdMAVcz8tVtKJw2lrmv6jNcoQ6xkBNP/buLNwBe6qQh7MGNPhGF9NDEoJg+JJY0JAcd Vxhw6bgJlqDtriKXqYSXTR1GwYkPtaI= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 7DD0EACE1; Thu, 10 Dec 2020 06:39:17 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Cc: Johannes Thumshirn Subject: [PATCH v2 04/18] btrfs: extent_io: introduce a helper to grab an existing extent buffer from a page Date: Thu, 10 Dec 2020 14:38:51 +0800 Message-Id: <20201210063905.75727-5-wqu@suse.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201210063905.75727-1-wqu@suse.com> References: <20201210063905.75727-1-wqu@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This patch will extract the code to grab an extent buffer from a page into a helper, grab_extent_buffer_from_page(). This reduces one indent level, and provides the work place for later expansion for subapge support. Reviewed-by: Johannes Thumshirn Signed-off-by: Qu Wenruo --- fs/btrfs/extent_io.c | 52 +++++++++++++++++++++++++++----------------- 1 file changed, 32 insertions(+), 20 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 612fe60b367e..6350c2687c7e 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5251,6 +5251,32 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info, } #endif +static struct extent_buffer *grab_extent_buffer_from_page(struct page *page) +{ + struct extent_buffer *exists; + + /* Page not yet attached to an extent buffer */ + if (!PagePrivate(page)) + return NULL; + + /* + * We could have already allocated an eb for this page + * and attached one so lets see if we can get a ref on + * the existing eb, and if we can we know it's good and + * we can just return that one, else we know we can just + * overwrite page->private. + */ + exists = (struct extent_buffer *)page->private; + if (atomic_inc_not_zero(&exists->refs)) { + mark_extent_buffer_accessed(exists, page); + return exists; + } + + WARN_ON(PageDirty(page)); + detach_page_private(page); + return NULL; +} + struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, u64 start, u64 owner_root, int level) { @@ -5296,26 +5322,12 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, } spin_lock(&mapping->private_lock); - if (PagePrivate(p)) { - /* - * We could have already allocated an eb for this page - * and attached one so lets see if we can get a ref on - * the existing eb, and if we can we know it's good and - * we can just return that one, else we know we can just - * overwrite page->private. - */ - exists = (struct extent_buffer *)p->private; - if (atomic_inc_not_zero(&exists->refs)) { - spin_unlock(&mapping->private_lock); - unlock_page(p); - put_page(p); - mark_extent_buffer_accessed(exists, p); - goto free_eb; - } - exists = NULL; - - WARN_ON(PageDirty(p)); - detach_page_private(p); + exists = grab_extent_buffer_from_page(p); + if (exists) { + spin_unlock(&mapping->private_lock); + unlock_page(p); + put_page(p); + goto free_eb; } attach_extent_buffer_page(eb, p); spin_unlock(&mapping->private_lock); -- 2.29.2