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 B872AC433E6 for ; Sat, 16 Jan 2021 07:17:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E30F23AF8 for ; Sat, 16 Jan 2021 07:17:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726714AbhAPHRO (ORCPT ); Sat, 16 Jan 2021 02:17:14 -0500 Received: from mx2.suse.de ([195.135.220.15]:56156 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726701AbhAPHRO (ORCPT ); Sat, 16 Jan 2021 02:17:14 -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=1610781358; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YUfWAyhbQG+1m6zDQGC63vBbQkN2NuPvOKVSpKvbno8=; b=H/xBxIQBADFqmgzkK1W6z33Ro1B5fA+L+n633IvZT5OJERLtkKFumS5MXY5p5sqOgKTr/f k/kv1wEPnIxTtnvcW8YbQUYHwQ4F3r5g47aNLsdqsp2IPgTm3/KODoBfOTbKufDOi3YPvL pU+x0vapHJcYE82Tu5x3Tg9iEaKU314= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D786DB8F2 for ; Sat, 16 Jan 2021 07:15:58 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v4 07/18] btrfs: attach private to dummy extent buffer pages Date: Sat, 16 Jan 2021 15:15:22 +0800 Message-Id: <20210116071533.105780-8-wqu@suse.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210116071533.105780-1-wqu@suse.com> References: <20210116071533.105780-1-wqu@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Even for regular btrfs, there are locations where we allocate dummy extent buffers for temporary usage. Like tree_mod_log_rewind() and get_old_root(). Those dummy extent buffers will be handled by the same eb accessors, and if they don't have page::private subpage eb accessors can fail. To address such problems, make __alloc_dummy_extent_buffer() to attach page private for dummy extent buffers too. Signed-off-by: Qu Wenruo --- fs/btrfs/extent_io.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index fb800f237099..7f94f00936d7 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5204,9 +5204,14 @@ struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, num_pages = num_extent_pages(eb); for (i = 0; i < num_pages; i++) { + int ret; + eb->pages[i] = alloc_page(GFP_NOFS); if (!eb->pages[i]) goto err; + ret = attach_extent_buffer_page(eb, eb->pages[i], NULL); + if (ret < 0) + goto err; } set_extent_buffer_uptodate(eb); btrfs_set_header_nritems(eb, 0); @@ -5214,8 +5219,10 @@ struct extent_buffer *__alloc_dummy_extent_buffer(struct btrfs_fs_info *fs_info, return eb; err: - for (; i > 0; i--) + for (; i > 0; i--) { + detach_extent_buffer_page(eb, eb->pages[i - 1]); __free_page(eb->pages[i - 1]); + } __free_extent_buffer(eb); return NULL; } -- 2.30.0