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=-8.3 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,URIBL_BLOCKED, USER_AGENT_SANE_1 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 832A2C341B9 for ; Fri, 13 Dec 2019 20:36:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFA2B246A2 for ; Fri, 13 Dec 2019 20:36:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Ig9FJaYb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726851AbfLMMSs (ORCPT ); Fri, 13 Dec 2019 07:18:48 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:24313 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726421AbfLMMSs (ORCPT ); Fri, 13 Dec 2019 07:18:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576239526; 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=BeHxcq8vgVrPG5H4U0PoCORmJH9h5plmqWxS0CUlUwA=; b=Ig9FJaYbsBtnO/Hc/igFW6PfBTi0itiYA2sTZPMgVkB/wiP5iJajgJ8puXaUoSco/GsCN6 NRV369FnUJ5caFfe5SyQ9VwsedWXbrHwqvlUeqPlMUspuLl/mvdob8uh/f80sBPZU2EIrA IcdfSMPryemH9aKIn5c7Aq0Cphb4YTI= 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-360-kFkcj4k7NsSpioT5cSDZMw-1; Fri, 13 Dec 2019 07:18:42 -0500 X-MC-Unique: kFkcj4k7NsSpioT5cSDZMw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B1D2B107ACC9; Fri, 13 Dec 2019 12:18:41 +0000 (UTC) Received: from bfoster (dhcp-41-2.bos.redhat.com [10.18.41.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 21A2C10013A1; Fri, 13 Dec 2019 12:18:40 +0000 (UTC) Date: Fri, 13 Dec 2019 07:18:40 -0500 From: Brian Foster To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org, Omar Sandoval , Dave Chinner Subject: Re: [PATCH] xfs: fix log reservation overflows when allocating large rt extents Message-ID: <20191213121840.GA43376@bfoster> References: <20191204163809.GP7335@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191204163809.GP7335@magnolia> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Wed, Dec 04, 2019 at 08:38:09AM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong > > Omar Sandoval reported that a 4G fallocate on the realtime device causes > filesystem shutdowns due to a log reservation overflow that happens when > we log the rtbitmap updates. Factor rtbitmap/rtsummary updates into the > the tr_write and tr_itruncate log reservation calculation. > > "The following reproducer results in a transaction log overrun warning > for me: > > mkfs.xfs -f -r rtdev=/dev/vdc -d rtinherit=1 -m reflink=0 /dev/vdb > mount -o rtdev=/dev/vdc /dev/vdb /mnt > fallocate -l 4G /mnt/foo > > Reported-by: Omar Sandoval > Signed-off-by: Darrick J. Wong > --- Looks reasonable enough given my limited knowledge on the rt bits. One question.. > fs/xfs/libxfs/xfs_trans_resv.c | 96 ++++++++++++++++++++++++++++++++-------- > 1 file changed, 77 insertions(+), 19 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_trans_resv.c b/fs/xfs/libxfs/xfs_trans_resv.c > index c55cd9a3dec9..824073a839ac 100644 > --- a/fs/xfs/libxfs/xfs_trans_resv.c > +++ b/fs/xfs/libxfs/xfs_trans_resv.c > @@ -196,6 +196,24 @@ xfs_calc_inode_chunk_res( > return res; > } > > +/* > + * Per-extent log reservation for the btree changes involved in freeing or > + * allocating a realtime extent. We have to be able to log as many rtbitmap > + * blocks as needed to mark inuse MAXEXTLEN blocks' worth of realtime extents, > + * as well as the realtime summary block. > + */ > +unsigned int > +xfs_rtalloc_log_count( > + struct xfs_mount *mp, > + unsigned int num_ops) > +{ > + unsigned int blksz = XFS_FSB_TO_B(mp, 1); > + unsigned int rtbmp_bytes; > + > + rtbmp_bytes = (MAXEXTLEN / mp->m_sb.sb_rextsize) / NBBY; > + return (howmany(rtbmp_bytes, blksz) + 1) * num_ops; > +} > + > /* > * Various log reservation values. > * > @@ -218,13 +236,21 @@ xfs_calc_inode_chunk_res( > > /* > * In a write transaction we can allocate a maximum of 2 > - * extents. This gives: > + * extents. This gives (t1): > * the inode getting the new extents: inode size > * the inode's bmap btree: max depth * block size > * the agfs of the ags from which the extents are allocated: 2 * sector > * the superblock free block counter: sector size > * the allocation btrees: 2 exts * 2 trees * (2 * max depth - 1) * block size > - * And the bmap_finish transaction can free bmap blocks in a join: > + * Or, if we're writing to a realtime file (t2): > + * the inode getting the new extents: inode size > + * the inode's bmap btree: max depth * block size > + * the agfs of the ags from which the extents are allocated: 2 * sector > + * the superblock free block counter: sector size > + * the realtime bitmap: ((MAXEXTLEN / rtextsize) / NBBY) bytes > + * the realtime summary: 1 block > + * the allocation btrees: 2 trees * (2 * max depth - 1) * block size Why do we include the allocation btrees in the rt reservations? I thought that we'd either allocate (or free) out of one pool or the other. Do we operate on both sets of structures in the same transaction? Brian > + * And the bmap_finish transaction can free bmap blocks in a join (t3): > * the agfs of the ags containing the blocks: 2 * sector size > * the agfls of the ags containing the blocks: 2 * sector size > * the super block free block counter: sector size > @@ -234,40 +260,72 @@ STATIC uint > xfs_calc_write_reservation( > struct xfs_mount *mp) > { > - return XFS_DQUOT_LOGRES(mp) + > - max((xfs_calc_inode_res(mp, 1) + > + unsigned int t1, t2, t3; > + unsigned int blksz = XFS_FSB_TO_B(mp, 1); > + > + t1 = xfs_calc_inode_res(mp, 1) + > + xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK), blksz) + > + xfs_calc_buf_res(3, mp->m_sb.sb_sectsize) + > + xfs_calc_buf_res(xfs_allocfree_log_count(mp, 2), blksz); > + > + if (xfs_sb_version_hasrealtime(&mp->m_sb)) { > + t2 = xfs_calc_inode_res(mp, 1) + > xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK), > - XFS_FSB_TO_B(mp, 1)) + > + blksz) + > xfs_calc_buf_res(3, mp->m_sb.sb_sectsize) + > - xfs_calc_buf_res(xfs_allocfree_log_count(mp, 2), > - XFS_FSB_TO_B(mp, 1))), > - (xfs_calc_buf_res(5, mp->m_sb.sb_sectsize) + > - xfs_calc_buf_res(xfs_allocfree_log_count(mp, 2), > - XFS_FSB_TO_B(mp, 1)))); > + xfs_calc_buf_res(xfs_rtalloc_log_count(mp, 1), blksz) + > + xfs_calc_buf_res(xfs_allocfree_log_count(mp, 1), blksz); > + } else { > + t2 = 0; > + } > + > + t3 = xfs_calc_buf_res(5, mp->m_sb.sb_sectsize) + > + xfs_calc_buf_res(xfs_allocfree_log_count(mp, 2), blksz); > + > + return XFS_DQUOT_LOGRES(mp) + max3(t1, t2, t3); > } > > /* > - * In truncating a file we free up to two extents at once. We can modify: > + * In truncating a file we free up to two extents at once. We can modify (t1): > * the inode being truncated: inode size > * the inode's bmap btree: (max depth + 1) * block size > - * And the bmap_finish transaction can free the blocks and bmap blocks: > + * And the bmap_finish transaction can free the blocks and bmap blocks (t2): > * the agf for each of the ags: 4 * sector size > * the agfl for each of the ags: 4 * sector size > * the super block to reflect the freed blocks: sector size > * worst case split in allocation btrees per extent assuming 4 extents: > * 4 exts * 2 trees * (2 * max depth - 1) * block size > + * Or, if it's a realtime file (t3): > + * the agf for each of the ags: 2 * sector size > + * the agfl for each of the ags: 2 * sector size > + * the super block to reflect the freed blocks: sector size > + * the realtime bitmap: 2 exts * ((MAXEXTLEN / rtextsize) / NBBY) bytes > + * the realtime summary: 2 exts * 1 block > + * worst case split in allocation btrees per extent assuming 2 extents: > + * 2 exts * 2 trees * (2 * max depth - 1) * block size > */ > STATIC uint > xfs_calc_itruncate_reservation( > struct xfs_mount *mp) > { > - return XFS_DQUOT_LOGRES(mp) + > - max((xfs_calc_inode_res(mp, 1) + > - xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK) + 1, > - XFS_FSB_TO_B(mp, 1))), > - (xfs_calc_buf_res(9, mp->m_sb.sb_sectsize) + > - xfs_calc_buf_res(xfs_allocfree_log_count(mp, 4), > - XFS_FSB_TO_B(mp, 1)))); > + unsigned int t1, t2, t3; > + unsigned int blksz = XFS_FSB_TO_B(mp, 1); > + > + t1 = xfs_calc_inode_res(mp, 1) + > + xfs_calc_buf_res(XFS_BM_MAXLEVELS(mp, XFS_DATA_FORK) + 1, blksz); > + > + t2 = xfs_calc_buf_res(9, mp->m_sb.sb_sectsize) + > + xfs_calc_buf_res(xfs_allocfree_log_count(mp, 4), blksz); > + > + if (xfs_sb_version_hasrealtime(&mp->m_sb)) { > + t3 = xfs_calc_buf_res(5, mp->m_sb.sb_sectsize) + > + xfs_calc_buf_res(xfs_rtalloc_log_count(mp, 2), blksz) + > + xfs_calc_buf_res(xfs_allocfree_log_count(mp, 2), blksz); > + } else { > + t3 = 0; > + } > + > + return XFS_DQUOT_LOGRES(mp) + max3(t1, t2, t3); > } > > /* >