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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_2 autolearn=no 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 7EE90C54FCB for ; Wed, 22 Apr 2020 18:52:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A8652076E for ; Wed, 22 Apr 2020 18:52:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=nic.cz header.i=@nic.cz header.b="R8hBWsm+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726847AbgDVSwM (ORCPT ); Wed, 22 Apr 2020 14:52:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58350 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726833AbgDVSwM (ORCPT ); Wed, 22 Apr 2020 14:52:12 -0400 Received: from mail.nic.cz (mail.nic.cz [IPv6:2001:1488:800:400::400]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 00F2CC03C1A9 for ; Wed, 22 Apr 2020 11:52:11 -0700 (PDT) Received: from localhost (unknown [172.20.6.135]) by mail.nic.cz (Postfix) with ESMTPSA id AA8D2140BC2 for ; Wed, 22 Apr 2020 20:52:09 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nic.cz; s=default; t=1587581529; bh=UrsPs8jNrsz7Px784nikxDT36F/VadRKL4cR/cg8sxo=; h=Date:From:To; b=R8hBWsm+pEkxyuMMipr/JdAM1I2tcW+YQW3vDflBpVAhSGya7DF2cNcGI/Uh3qZdN dBGQhSMcBpzvlQx/dXP/cY/NMp5go4vYkna7/ioq0vAWLEKmnCHCl0vGBfmlcChXyU bAhMV5z85+1g+IYSVIqwVF2yERefD58HF9o1OGJs= Date: Wed, 22 Apr 2020 20:52:09 +0200 From: Marek Behun To: linux-btrfs@vger.kernel.org Subject: when does btrfs create sparse extents? Message-ID: <20200422205209.0e2efd53@nic.cz> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamav-milter 0.101.4 at mail X-Virus-Status: Clean Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hello, there was a bug fixed recently in U-Boot's btrfs driver - the driver failed to read files with sparse extents. This causes that sometimes device failes to boot Linux, since the kernel fails to load from storage. So when does kernel's btrfs driver write sparse extents? Is it always when it finds a PAGE_SIZEd and aligned all-zeros block? Or is it more complicated? Thanks. Marek