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=-7.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 EB462C282DE for ; Wed, 5 Jun 2019 09:15:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C18B12075B for ; Wed, 5 Jun 2019 09:15:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="I7vrGwZZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726881AbfFEJPH (ORCPT ); Wed, 5 Jun 2019 05:15:07 -0400 Received: from mout.gmx.net ([212.227.15.19]:49849 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726831AbfFEJPH (ORCPT ); Wed, 5 Jun 2019 05:15:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1559726101; bh=oeBmMHN5/J667KE6bWMCWcy+QzOLDz93LHatOTAzjS8=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=I7vrGwZZir/JlFZ57ECtgqlv4B/TN6KrtDD5sC5mTasTgDhSd4ExG+abwK1suYbqv wNhd/uXQnc9eWkbCAcl4ELAcZkqRNKX59AvmKfsMq0L6zjgQ1ihQHhj/Y0CeUiETdu dcGrIBarB+iXBwNoV+ozzRMRC9p1CT7e1G0q1tQ4= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([54.250.245.166]) by mail.gmx.com (mrgmx004 [212.227.17.184]) with ESMTPSA (Nemesis) id 1M2f9h-1hYizb2Iil-004Amz; Wed, 05 Jun 2019 11:15:01 +0200 Subject: Re: [PATCH 3/4] btrfs: Skip first megabyte on device when trimming To: Nikolay Borisov , linux-btrfs@vger.kernel.org References: <20190603100602.19362-1-nborisov@suse.com> <20190603100602.19362-4-nborisov@suse.com> From: Qu Wenruo Openpgp: preference=signencrypt Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0IlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT6JAVQEEwEIAD4CGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCWdWCnQUJCWYC bgAKCRDCPZHzoSX+qAR8B/94VAsSNygx1C6dhb1u1Wp1Jr/lfO7QIOK/nf1PF0VpYjTQ2au8 ihf/RApTna31sVjBx3jzlmpy+lDoPdXwbI3Czx1PwDbdhAAjdRbvBmwM6cUWyqD+zjVm4RTG rFTPi3E7828YJ71Vpda2qghOYdnC45xCcjmHh8FwReLzsV2A6FtXsvd87bq6Iw2axOHVUax2 FGSbardMsHrya1dC2jF2R6n0uxaIc1bWGweYsq0LXvLcvjWH+zDgzYCUB0cfb+6Ib/ipSCYp 3i8BevMsTs62MOBmKz7til6Zdz0kkqDdSNOq8LgWGLOwUTqBh71+lqN2XBpTDu1eLZaNbxSI ilaVuQENBFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcga CbPEwhLj1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj /IrRUUka68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fN GSsRb+pKEKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0 q1eW4Jrv0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEv ABEBAAGJATwEGAEIACYWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCWdWBrwIbDAUJA8JnAAAK CRDCPZHzoSX+qA3xB/4zS8zYh3Cbm3FllKz7+RKBw/ETBibFSKedQkbJzRlZhBc+XRwF61mi f0SXSdqKMbM1a98fEg8H5kV6GTo62BzvynVrf/FyT+zWbIVEuuZttMk2gWLIvbmWNyrQnzPl mnjK4AEvZGIt1pk+3+N/CMEfAZH5Aqnp0PaoytRZ/1vtMXNgMxlfNnb96giC3KMR6U0E+siA 4V7biIoyNoaN33t8m5FwEwd2FQDG9dAXWhG13zcm9gnk63BN3wyCQR+X5+jsfBaS4dvNzvQv h8Uq/YGjCoV1ofKYh3WKMY8avjq25nlrhzD/Nto9jHp8niwr21K//pXVA81R2qaXqGbql+zo Message-ID: <91bf1d48-dea5-45a9-4c0f-7a2fa0b22c98@gmx.com> Date: Wed, 5 Jun 2019 17:14:56 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190603100602.19362-4-nborisov@suse.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:5lsx7HkETZ79A/ZotR+bC9eDN1fwMNBzbESXIVUk665ckdiMyYw Cb0JJrufoFaGWQqnWBpHGbfC1TGYcDTLN9YoGGJfzsExfC1pqCmhFkpaQEY4b5xlNyTL6Oy sgxBKbx9HeGl72usETf07vwXovz9RckPJjDm4HxQFAxEIKdUbMicXFvWrFGgfDXx4sw/AuH FG1Nx2wJ3ZGVeF2VP8ajg== X-UI-Out-Filterresults: notjunk:1;V03:K0:8zWxpF0lhgU=:pX3crKiNMQLXA9L57h2IYY auSBjs57eCI75vp4O9A00woHCcGd6cntZidqIwUvjquxauT/fTBLspEYvS1G8BbV/ABUql3RS QwlKwKRHJvmrpUXMS3I+FpWDEaEuYzuRAi0ugA6oXgwD/+o/xqYvtOijfbiGhIeqGujAtiygz XdFtNugltpkyVTA9Q1/EwPJQiIp+ryX4HpYM//Z8oUPFd+De3fsx1ey2V3/nX/8WAuSboxHrz B+RGm8bkWmGIFFdlZNJzJNjWnSmUEBNflLb3XYy6tl17gUWjOINm2vkAmH3lx0cC0teEughGK KPa2O6F053jjDp6uViJBwrMOQPsFgNbwFwish5ZbK0IXoZYtiD9y22/EirADTd2Jo4KdNhy0d 3WPertzGGAaffhn5jTRWpfbmCHJeFlpAvivcc7tfSrNy2oF/8zYLgRE120SHDZ7sGyKMHgvYN YPn4jv1rPGutizpgp8NR12OdttR5UNa4m82qr8AwTt7NscoyHaMMdToOqq6VZRcueK0UpYdDC Ljh5Bx2x6J6/+HAhDmVNJqPTetLS0AmsyfRvgYWaBsZUF+K1Itgv0ynuhW0B8L0pCqTyub1e3 akWh7Fn3r25B1fsYoEli26f6RLIUZ3U9gYwHUhf8PvRQ3ltH4dylhpI2gMO/xSzWjma9OKExO N70qxsmU9YzO/rdEqEVG6JwSHfAOGsGsed08+xYEB5nPTtRPNxGaNvUuSeynIMvDfAL8rDCMf HprvZ5RQK+vb7pRMn9LnNDRQNvql3XnIYs0yXhJAse4XlVBBDzcC0C6tlgwXWyWuAyi0GIfqn r/5XWrzG8vXZgatCuIxb5KTl2PiSmkuILxPOsGtspz8TGHLYIuF6JMDbYBpt6X0TTMcSKeXZp CSuezcsk/1aUTXkFXlP9R+LWKYSPUbu5OYSbYj4/pY4mK8NVWdBLPYfRrTKiapKuLlqwRJhIn miojiG94e8aZtw/WlvEmVYD2G3WQKz+utPuUUPe27iqTRCKpixNET Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2019/6/3 =E4=B8=8B=E5=8D=886:06, Nikolay Borisov wrote: > Currently the first megabyte on a device housing a btrfs filesystem is > exempt from allocation and trimming. Currently this is not a problem > since 'start' is set to 1m at the beginning of btrfs_trim_free_extents > and find_first_clear_extent_bit always returns a range that is >=3D star= t. > However, in a follow up patch find_first_clear_extent_bit will be > changed such that it will return a range containing 'start' and this > range may very well be 0...>=3D1M so 'start'. > > Future proof the sole user of find_first_clear_extent_bit by setting > 'start' after the function is called. No functional changes. > > Signed-off-by: Nikolay Borisov Doesn't that previous patch already address this by: + u64 start =3D SZ_1M, len =3D 0, end =3D 0; Thanks, Qu > --- > fs/btrfs/extent-tree.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index d8c5febf7636..5a11e4988243 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -11183,6 +11183,10 @@ static int btrfs_trim_free_extents(struct btrfs= _device *device, u64 *trimmed) > * to the caller to trim the value to the size of the device. > */ > end =3D min(end, device->total_bytes - 1); > + > + /* Ensure we skip first mb in case we have a bootloader there */ > + start =3D max_t(u64, start, SZ_1M); > + > len =3D end - start + 1; > > /* We didn't find any extents */ >