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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 84C15C433E1 for ; Mon, 22 Mar 2021 11:31:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58B6C619A0 for ; Mon, 22 Mar 2021 11:31:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229574AbhCVLbK (ORCPT ); Mon, 22 Mar 2021 07:31:10 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:25961 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230050AbhCVLau (ORCPT ); Mon, 22 Mar 2021 07:30:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616412649; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=q8xjjsvlA5bupUPYqMtM+Z8Wp88WAUw0BnReF1e7pbc=; b=IkcGMtIJL8TKHCTy6sKHXpWhaJD8ee+BuNM8TgZhEFXMUASsMjuYULUZYh/HEr2/Fyv45l esV5+ysOqoyp9OY1zhu7bv9578pBj1qiGpB1IaqkA1yArowEobAACHrX/ePmb3H0E3917o Xyq46GcZ1+o+wroDaL5/GYeL5AXTx88= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-273-ykJRpT0tPm2ZACR6RGguDQ-1; Mon, 22 Mar 2021 07:30:47 -0400 X-MC-Unique: ykJRpT0tPm2ZACR6RGguDQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 850EB87A82A; Mon, 22 Mar 2021 11:30:46 +0000 (UTC) Received: from bfoster (ovpn-112-29.rdu2.redhat.com [10.10.112.29]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 9B7F0709A9; Mon, 22 Mar 2021 11:30:42 +0000 (UTC) Date: Mon, 22 Mar 2021 07:30:40 -0400 From: Brian Foster To: Gao Xiang Cc: linux-xfs@vger.kernel.org, "Darrick J. Wong" , Dave Chinner , Christoph Hellwig , Eric Sandeen Subject: Re: [PATCH v8 4/5] xfs: support shrinking unused space in the last AG Message-ID: References: <20210305025703.3069469-1-hsiangkao@redhat.com> <20210305025703.3069469-5-hsiangkao@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210305025703.3069469-5-hsiangkao@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Mar 05, 2021 at 10:57:02AM +0800, Gao Xiang wrote: > As the first step of shrinking, this attempts to enable shrinking > unused space in the last allocation group by fixing up freespace > btree, agi, agf and adjusting super block and use a helper > xfs_ag_shrink_space() to fixup the last AG. > > This can be all done in one transaction for now, so I think no > additional protection is needed. > > Reviewed-by: Darrick J. Wong > Signed-off-by: Gao Xiang > --- > fs/xfs/xfs_fsops.c | 88 ++++++++++++++++++++++++++++------------------ > fs/xfs/xfs_trans.c | 1 - > 2 files changed, 53 insertions(+), 36 deletions(-) > > diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c > index fc9e799b2ae3..71cba61a451c 100644 > --- a/fs/xfs/xfs_fsops.c > +++ b/fs/xfs/xfs_fsops.c > @@ -91,23 +91,28 @@ xfs_growfs_data_private( > xfs_agnumber_t nagcount; > xfs_agnumber_t nagimax = 0; > xfs_rfsblock_t nb, nb_div, nb_mod; > - xfs_rfsblock_t delta; > + int64_t delta; > bool lastag_resetagres; > xfs_agnumber_t oagcount; > struct xfs_trans *tp; > struct aghdr_init_data id = {}; > > nb = in->newblocks; > - if (nb < mp->m_sb.sb_dblocks) > - return -EINVAL; > - if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb))) > + if (nb == mp->m_sb.sb_dblocks) > + return 0; It looks like the caller already does this check. > + > + error = xfs_sb_validate_fsb_count(&mp->m_sb, nb); > + if (error) > return error; > - error = xfs_buf_read_uncached(mp->m_ddev_targp, > + > + if (nb > mp->m_sb.sb_dblocks) { > + error = xfs_buf_read_uncached(mp->m_ddev_targp, > XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1), > XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL); > - if (error) > - return error; > - xfs_buf_relse(bp); > + if (error) > + return error; > + xfs_buf_relse(bp); > + } > > nb_div = nb; > nb_mod = do_div(nb_div, mp->m_sb.sb_agblocks); > @@ -115,10 +120,15 @@ xfs_growfs_data_private( > if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) { > nagcount--; > nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks; > - if (nb < mp->m_sb.sb_dblocks) > - return -EINVAL; > } > delta = nb - mp->m_sb.sb_dblocks; > + /* > + * XFS doesn't really support single-AG filesystems, so do not > + * permit callers to remove the filesystem's second and last AG. > + */ > + if (delta < 0 && nagcount < 2) > + return -EINVAL; > + What if the filesystem is already single AG? Unless I'm missing something, we already have a check a bit further down that prevents removal of AGs in the first place. Otherwise looks reasonable.. Brian > oagcount = mp->m_sb.sb_agcount; > > /* allocate the new per-ag structures */ > @@ -126,15 +136,22 @@ xfs_growfs_data_private( > error = xfs_initialize_perag(mp, nagcount, &nagimax); > if (error) > return error; > + } else if (nagcount < oagcount) { > + /* TODO: shrinking the entire AGs hasn't yet completed */ > + return -EINVAL; > } > > error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata, > - XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp); > + (delta > 0 ? XFS_GROWFS_SPACE_RES(mp) : -delta), 0, > + XFS_TRANS_RESERVE, &tp); > if (error) > return error; > > - error = xfs_resizefs_init_new_ags(tp, &id, oagcount, nagcount, > - delta, &lastag_resetagres); > + if (delta > 0) > + error = xfs_resizefs_init_new_ags(tp, &id, oagcount, nagcount, > + delta, &lastag_resetagres); > + else > + error = xfs_ag_shrink_space(mp, &tp, nagcount - 1, -delta); > if (error) > goto out_trans_cancel; > > @@ -145,7 +162,7 @@ xfs_growfs_data_private( > */ > if (nagcount > oagcount) > xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount); > - if (delta > 0) > + if (delta) > xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS, delta); > if (id.nfree) > xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, id.nfree); > @@ -169,28 +186,29 @@ xfs_growfs_data_private( > xfs_set_low_space_thresholds(mp); > mp->m_alloc_set_aside = xfs_alloc_set_aside(mp); > > - /* > - * If we expanded the last AG, free the per-AG reservation > - * so we can reinitialize it with the new size. > - */ > - if (lastag_resetagres) { > - struct xfs_perag *pag; > - > - pag = xfs_perag_get(mp, id.agno); > - error = xfs_ag_resv_free(pag); > - xfs_perag_put(pag); > - if (error) > - return error; > + if (delta > 0) { > + /* > + * If we expanded the last AG, free the per-AG reservation > + * so we can reinitialize it with the new size. > + */ > + if (lastag_resetagres) { > + struct xfs_perag *pag; > + > + pag = xfs_perag_get(mp, id.agno); > + error = xfs_ag_resv_free(pag); > + xfs_perag_put(pag); > + if (error) > + return error; > + } > + /* > + * Reserve AG metadata blocks. ENOSPC here does not mean there > + * was a growfs failure, just that there still isn't space for > + * new user data after the grow has been run. > + */ > + error = xfs_fs_reserve_ag_blocks(mp); > + if (error == -ENOSPC) > + error = 0; > } > - > - /* > - * Reserve AG metadata blocks. ENOSPC here does not mean there was a > - * growfs failure, just that there still isn't space for new user data > - * after the grow has been run. > - */ > - error = xfs_fs_reserve_ag_blocks(mp); > - if (error == -ENOSPC) > - error = 0; > return error; > > out_trans_cancel: > diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c > index 44f72c09c203..d047f5f26cc0 100644 > --- a/fs/xfs/xfs_trans.c > +++ b/fs/xfs/xfs_trans.c > @@ -434,7 +434,6 @@ xfs_trans_mod_sb( > tp->t_res_frextents_delta += delta; > break; > case XFS_TRANS_SB_DBLOCKS: > - ASSERT(delta > 0); > tp->t_dblocks_delta += delta; > break; > case XFS_TRANS_SB_AGCOUNT: > -- > 2.27.0 >