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 A3859C71156 for ; Wed, 2 Dec 2020 06:49:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F3DC20DD4 for ; Wed, 2 Dec 2020 06:49:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728699AbgLBGtv (ORCPT ); Wed, 2 Dec 2020 01:49:51 -0500 Received: from mx2.suse.de ([195.135.220.15]:53474 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728623AbgLBGtu (ORCPT ); Wed, 2 Dec 2020 01:49:50 -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=1606891715; 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=3BLNgJuooQugIyc5magaI5yoL/H+svhmP1oQvBidNBY=; b=tJNtgJsnDd6YJXTq8+xwe+nYvvlsr7ESNWRKeThUAidKwQXTYgWRbibtGM9Cu7MhJbDeyO wuBoxXi9Dz5rCT662wNSYL14i3gzLBMq8FP7moovLgTECnqpXwvhXmr7Z9aMc5raB7GGif 23DshYLo7GcF1VJaNJ7RKFczAKoi3g4= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 8FF96AEC3 for ; Wed, 2 Dec 2020 06:48:35 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v3 06/15] btrfs: extent_io: don't allow tree block to cross page boundary for subpage support Date: Wed, 2 Dec 2020 14:48:02 +0800 Message-Id: <20201202064811.100688-7-wqu@suse.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201202064811.100688-1-wqu@suse.com> References: <20201202064811.100688-1-wqu@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org As a preparation for subpage sector size support (allowing filesystem with sector size smaller than page size to be mounted) if the sector size is smaller than page size, we don't allow tree block to be read if it crosses 64K(*) boundary. The 64K is selected because: - We are only going to support 64K page size for subpage for now - 64K is also the max node size btrfs supports This ensures that, tree blocks are always contained in one page for a system with 64K page size, which can greatly simplify the handling. Or we need to do complex multi-page handling for tree blocks. Currently there is no way to create such tree blocks. Kernel has avoided such tree blocks allocation even on 4K page size, as it can lead to RAID56 stripe scrubing. While btrfs-progs has fixed its chunk allocator since 2016 for convert, and has extra checks to do the same behavior as the kernel. Just add such graceful checks for ancient btrfs. Signed-off-by: Qu Wenruo --- fs/btrfs/extent_io.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 2bab66b42395..8cbd6d43b154 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -5272,6 +5272,13 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info, btrfs_err(fs_info, "bad tree block start %llu", start); return ERR_PTR(-EINVAL); } + if (fs_info->sectorsize < PAGE_SIZE && + offset_in_page(start) + len > PAGE_SIZE) { + btrfs_err(fs_info, + "tree block crosses page boundary, start %llu nodesize %lu", + start, len); + return ERR_PTR(-EINVAL); + } eb = find_extent_buffer(fs_info, start); if (eb) -- 2.29.2