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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY 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 05D15C433DF for ; Tue, 2 Jun 2020 00:24:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCEC92073B for ; Tue, 2 Jun 2020 00:24:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="afauOMum" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725841AbgFBAYG (ORCPT ); Mon, 1 Jun 2020 20:24:06 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:44854 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725446AbgFBAYF (ORCPT ); Mon, 1 Jun 2020 20:24:05 -0400 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0520GtRw134409; Tue, 2 Jun 2020 00:23:59 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=fu7DEnipL6gIAuPcbbsuXTE4pi17dU/DALvhSVsoY9s=; b=afauOMum1JqpaRv/qMYmR28S61q/fhKNlfPPhvdlTREanbUmcQMNkkHcR3DgbdWmp16V 4gNcAkhbERqdqJtlHhj5F+qsEox6yVLwsvlMma8kYjC7PlzAOi2L3JMR3U+h5/OagyaN qJj56Z5s0CC3EMZlYP6T7Ph9xDqTtpa8a5fbjgTr9HjNPKtsu5oGc0Bnxzx4gqF5Em/W 7eV2CSPK6rW5wdEhrnfSBHwmuQf/F2zxtSDOtYhAnz919t1lLRqCOBsPjbL03bCuVbxx Y6PAbu/P8AxLy5rRTXyzKxJ8FOzwUwdkEWf1ioPJHk+kmr9KFSS4wB6JnE23jjPxIy35 +g== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by aserp2120.oracle.com with ESMTP id 31bfem1aka-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 02 Jun 2020 00:23:59 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0520DsSD145916; Tue, 2 Jun 2020 00:21:58 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3020.oracle.com with ESMTP id 31c25m5mef-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 02 Jun 2020 00:21:58 +0000 Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 0520Lvfl019281; Tue, 2 Jun 2020 00:21:58 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 01 Jun 2020 17:21:57 -0700 Date: Mon, 1 Jun 2020 17:21:56 -0700 From: "Darrick J. Wong" To: Brian Foster Cc: sandeen@sandeen.net, linux-xfs@vger.kernel.org Subject: Re: [PATCH 4/9] xfs_repair: rebuild free space btrees with bulk loader Message-ID: <20200602002156.GH2162697@magnolia> References: <158993944270.983175.4120094597556662259.stgit@magnolia> <158993946854.983175.10392092867098415197.stgit@magnolia> <20200528151044.GC17794@bfoster> <20200529213937.GT8230@magnolia> <20200601120525.GB2012@bfoster> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200601120525.GB2012@bfoster> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9639 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 suspectscore=5 spamscore=0 malwarescore=0 bulkscore=0 mlxscore=0 phishscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006020000 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9639 signatures=668686 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 suspectscore=5 mlxlogscore=999 priorityscore=1501 bulkscore=0 phishscore=0 clxscore=1015 impostorscore=0 adultscore=0 spamscore=0 mlxscore=0 lowpriorityscore=0 cotscore=-2147483648 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006020000 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Mon, Jun 01, 2020 at 08:05:25AM -0400, Brian Foster wrote: > On Fri, May 29, 2020 at 02:39:37PM -0700, Darrick J. Wong wrote: > > On Thu, May 28, 2020 at 11:10:44AM -0400, Brian Foster wrote: > > > On Tue, May 19, 2020 at 06:51:08PM -0700, Darrick J. Wong wrote: > > > > From: Darrick J. Wong > > > > > > > > Use the btree bulk loading functions to rebuild the free space btrees > > > > and drop the open-coded implementation. > > > > > > > > Signed-off-by: Darrick J. Wong > > > > --- > > > > libxfs/libxfs_api_defs.h | 3 > > > > repair/phase5.c | 870 +++++++++++++--------------------------------- > > > > 2 files changed, 254 insertions(+), 619 deletions(-) > > > > > > > > > > > ... > > > > diff --git a/repair/phase5.c b/repair/phase5.c > > > > index 8f5e5f59..e69b042c 100644 > > > > --- a/repair/phase5.c > > > > +++ b/repair/phase5.c > > > ... > > > > @@ -837,268 +567,202 @@ btnum_to_ops( > ... > > > > + > > > > + /* Ok, now how many free space records do we have? */ > > > > + *nr_extents = count_bno_extents_blocks(agno, &num_freeblocks); > > > > + } while (1); > > > > + > > > > + *extra_blocks = (bno_blocks - btr_bno->bload.nr_blocks) + > > > > + (cnt_blocks - btr_cnt->bload.nr_blocks); > > > > +} > > > > + > > > > +static void > > > > +get_freesp_data( > > > > + struct xfs_btree_cur *cur, > > > > + struct extent_tree_node *bno_rec, > > > > + xfs_agblock_t *freeblks) > > > > +{ > > > > + struct xfs_alloc_rec_incore *arec = &cur->bc_rec.a; > > > > + > > > > + arec->ar_startblock = bno_rec->ex_startblock; > > > > + arec->ar_blockcount = bno_rec->ex_blockcount; > > > > + if (freeblks) > > > > + *freeblks += bno_rec->ex_blockcount; > > > > +} > > > > + > > > > +/* Grab one bnobt record. */ > > > > +static int > > > > +get_bnobt_record( > > > > + struct xfs_btree_cur *cur, > > > > + void *priv) > > > > +{ > > > > + struct bt_rebuild *btr = priv; > > > > + > > > > + get_freesp_data(cur, btr->bno_rec, btr->freeblks); > > > > + btr->bno_rec = findnext_bno_extent(btr->bno_rec); > > > > > > We should probably check for NULL here even if we don't expect it to > > > happen. > > > > > > Also, this logic where we load the current pointer and get the next had > > > my eyes crossed for a bit. Can we just check the pointer state here to > > > determine whether to find the first record or the next? > > > > Hm, I did that, and the logic ends up more cluttered looking: > > > > if (cur->bc_btnum == XFS_BTNUM_BNO) { > > if (btr->bno_rec == NULL) > > btr->bno_rec = findfirst_bno_extent(agno); > > else > > btr->bno_rec = findnext_bno_extent(btr->bno_rec); > > } else { > > if (btr->bno_rec == NULL) > > btr->bno_rec = findfirst_bcnt_extent(agno); > > else > > btr->bno_rec = findnext_bcnt_extent(cur->bc_ag.agno, > > btr->bno_rec); > > } > > > > Yeah, I figured this approach would boil down to something like this in > the record feeding code. For one, I'd stick that in a function with a > brief comment. Otherwise, despite the cluttered look, the logic itself > is simple and much easier to read IMO. I had to stare at the current > code for a few minutes before I recognized what was going on, then read > through the iteration thing again to make sure I had it correct. This > eliminates that confusion entirely and thus simplifies the broader > implementation. I think it also facilitates reducing the amount of code > even more if we can generalize the build_*() functions a bit more.. > > OTOH I think you do have a good point that splitting the code that sets > > bno_rec across three functions is not easy to understand. > > > > Exactly. > > > > Finally, I notice we duplicate the build_[bno|cnt]bt() functions for > > > what amounts to a different get_record() callback specific to the tree > > > type. If we also generalize get_record() to use the tree type (it > > > already has the cursor), it seems that much of the duplication can be > > > reduced and the logic simplified. > > > > Ok, done. > > > > > > + return 0; > > > > +} > > > > + > > > > +/* Rebuild a free space by block number btree. */ > > > > +static void > > > > +build_bnobt( > > > > + struct repair_ctx *sc, > > > > + xfs_agnumber_t agno, > > > > + struct bt_rebuild *btr_bno, > > > > + xfs_agblock_t *freeblks) > > > > +{ > > > > + int error; > > > > + > > > > + *freeblks = 0; > > > > + btr_bno->bload.get_record = get_bnobt_record; > > > > + btr_bno->bload.claim_block = rebuild_claim_block; > > > > > > Note that one of these callbacks is introduced in this patch and the > > > other in the previous. I've no issue with splitting the patches as noted > > > in the previous patch, but these should probably be consistent one way > > > or the other. > > > > All the btree types set ->claim_block to rebuild_claim_block, whereas > > ->get_record is specific to the particular type of btree. > > > > Ok, seems more reasonable in hindsight. FWIW I also put the new code in its own file to declutter phase5.c further. --D > Brian > > > > > + btr_bno->bno_rec = findfirst_bno_extent(agno); > > > > + btr_bno->freeblks = freeblks; > > > > + > > > > + error = -libxfs_trans_alloc_empty(sc->mp, &sc->tp); > > > > + if (error) > > > > + do_error( > > > > +_("Insufficient memory to construct bnobt rebuild transaction.\n")); > > > > + > > > > + /* Add all observed bnobt records. */ > > > > + error = -libxfs_btree_bload(btr_bno->cur, &btr_bno->bload, btr_bno); > > > > + if (error) > > > > + do_error( > > > > +_("Error %d while creating bnobt btree for AG %u.\n"), error, agno); > > > > + > > > > + /* Since we're not writing the AGF yet, no need to commit the cursor */ > > > > + libxfs_btree_del_cursor(btr_bno->cur, 0); > > > > + error = -libxfs_trans_commit(sc->tp); > > > > + if (error) > > > > + do_error( > > > > +_("Error %d while writing bnobt btree for AG %u.\n"), error, agno); > > > > + sc->tp = NULL; > > > > +} > > > > + > > > ... > > > > @@ -2354,48 +2041,14 @@ build_agf_agfl( > > > > freelist[i] = cpu_to_be32(NULLAGBLOCK); > > > > } > > > > > > > > - /* > > > > - * do we have left-over blocks in the btree cursors that should > > > > - * be used to fill the AGFL? > > > > - */ > > > > - if (bno_bt->num_free_blocks > 0 || bcnt_bt->num_free_blocks > 0) { > > > > - /* > > > > - * yes, now grab as many blocks as we can > > > > - */ > > > > - i = 0; > > > > - while (bno_bt->num_free_blocks > 0 && i < libxfs_agfl_size(mp)) > > > > - { > > > > - freelist[i] = cpu_to_be32( > > > > - get_next_blockaddr(agno, 0, bno_bt)); > > > > - i++; > > > > - } > > > > - > > > > - while (bcnt_bt->num_free_blocks > 0 && i < libxfs_agfl_size(mp)) > > > > - { > > > > - freelist[i] = cpu_to_be32( > > > > - get_next_blockaddr(agno, 0, bcnt_bt)); > > > > - i++; > > > > - } > > > > - /* > > > > - * now throw the rest of the blocks away and complain > > > > - */ > > > > - while (bno_bt->num_free_blocks > 0) { > > > > - fsb = XFS_AGB_TO_FSB(mp, agno, > > > > - get_next_blockaddr(agno, 0, bno_bt)); > > > > - error = slab_add(lost_fsb, &fsb); > > > > - if (error) > > > > - do_error( > > > > -_("Insufficient memory saving lost blocks.\n")); > > > > - } > > > > - while (bcnt_bt->num_free_blocks > 0) { > > > > - fsb = XFS_AGB_TO_FSB(mp, agno, > > > > - get_next_blockaddr(agno, 0, bcnt_bt)); > > > > - error = slab_add(lost_fsb, &fsb); > > > > - if (error) > > > > - do_error( > > > > -_("Insufficient memory saving lost blocks.\n")); > > > > - } > > > > + /* Fill the AGFL with leftover blocks or save them for later. */ > > > > + i = 0; > > > > > > How about agfl_idx or something since this variable is passed down into > > > a function? > > > > The 'i' variable existed before this patch. I can add a new cleanup to > > fix the name... > > > > > > + freelist = xfs_buf_to_agfl_bno(agfl_buf); > > > > + fill_agfl(btr_bno, freelist, &i); > > > > + fill_agfl(btr_cnt, freelist, &i); > > > > > > > > + /* Set the AGF counters for the AGFL. */ > > > > + if (i > 0) { > > > > agf->agf_flfirst = 0; > > > > agf->agf_fllast = cpu_to_be32(i - 1); > > > > agf->agf_flcount = cpu_to_be32(i); > > > ... > > > > @@ -2650,9 +2283,9 @@ _("unable to rebuild AG %u. Not enough free space in on-disk AG.\n"), > > > > /* > > > > * set up agf and agfl > > > > */ > > > > - build_agf_agfl(mp, agno, &bno_btree_curs, > > > > - &bcnt_btree_curs, freeblks1, extra_blocks, > > > > - &rmap_btree_curs, &refcnt_btree_curs, lost_fsb); > > > > + build_agf_agfl(mp, agno, &btr_bno, &btr_cnt, freeblks1, extra_blocks, > > > > + &rmap_btree_curs, &refcnt_btree_curs, lost_fsb); > > > > + > > > > > > I was trying to figure out what extra_blocks was used for and noticed > > > that it's not even used by this function. Perhaps a preceding cleanup > > > patch to drop it? > > > > Ok. > > > > > > /* > > > > * build inode allocation tree. > > > > */ > > > > @@ -2674,15 +2307,14 @@ _("unable to rebuild AG %u. Not enough free space in on-disk AG.\n"), > > > > /* > > > > * tear down cursors > > > > */ > > > > - finish_cursor(&bno_btree_curs); > > > > - finish_cursor(&ino_btree_curs); > > > > > > Looks like this one shouldn't be going away here. > > > > Oops, good catch. > > > > --D > > > > > Brian > > > > > > > + finish_rebuild(mp, &btr_bno, lost_fsb); > > > > + finish_rebuild(mp, &btr_cnt, lost_fsb); > > > > if (xfs_sb_version_hasrmapbt(&mp->m_sb)) > > > > finish_cursor(&rmap_btree_curs); > > > > if (xfs_sb_version_hasreflink(&mp->m_sb)) > > > > finish_cursor(&refcnt_btree_curs); > > > > if (xfs_sb_version_hasfinobt(&mp->m_sb)) > > > > finish_cursor(&fino_btree_curs); > > > > - finish_cursor(&bcnt_btree_curs); > > > > > > > > /* > > > > * release the incore per-AG bno/bcnt trees so the extent nodes > > > > > > > > > >