From patchwork Fri Feb 23 02:00:15 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 10236779 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4AD05602A0 for ; Fri, 23 Feb 2018 02:00:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 44D0129177 for ; Fri, 23 Feb 2018 02:00:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 42BD82918C; Fri, 23 Feb 2018 02:00:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BB65229174 for ; Fri, 23 Feb 2018 02:00:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751440AbeBWCAT (ORCPT ); Thu, 22 Feb 2018 21:00:19 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:54200 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750916AbeBWCAS (ORCPT ); Thu, 22 Feb 2018 21:00:18 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w1N1xDsL148137 for ; Fri, 23 Feb 2018 02:00:17 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : from : to : cc : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=corp-2017-10-26; bh=0VJzkTFiUqYxkrxE2aOJMYSLk19To+FtEIprfltYZ9c=; b=Bm7TeMPqAGksm5GYOW0JDd7VYJiv2lhFPQDyC3jyIsDEk/Qq9mRGO+LkCAuowdnkTewm 2O9+UBQbeLzekvbhxzzdL5GnmNYMPAVN036rK7Vx9eprm4BSsTOLjGas+aaTGviv+3Vs OCR9KtJKH1mMDyHplcCTCQkKMarUcpoyC+XOncxkY+YPHPZcfRPww1y7c1S4fNBRzdfd 4HD/IHIaHt+RELd6yW3ofBL8FhAx3hZiUm9H37OnEsGJIwYcKDOCg9NBYf/mFj/WoMJo 6SMWuGhi1Srif5LL41H4FLUxfJe6XkPpNdQDIt0Gtrv5263FlBwyc3gr+zOA/lrFgbpb iA== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by aserp2120.oracle.com with ESMTP id 2ga9bpg1xh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 23 Feb 2018 02:00:17 +0000 Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w1N20Ht4008458 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Fri, 23 Feb 2018 02:00:17 GMT Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w1N20HIW015165 for ; Fri, 23 Feb 2018 02:00:17 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 22 Feb 2018 18:00:16 -0800 Subject: [PATCH 5/5] xfs: fix agfl wrapping From: "Darrick J. Wong" To: darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org Date: Thu, 22 Feb 2018 18:00:15 -0800 Message-ID: <151935121574.21654.7158330354778549108.stgit@magnolia> In-Reply-To: <151935118240.21654.10146641674018880885.stgit@magnolia> References: <151935118240.21654.10146641674018880885.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8812 signatures=668677 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=3 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802230020 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/Makefile | 1 fs/xfs/xfs_fixups.c | 310 +++++++++++++++++++++++++++++++++++++++++++++++++++ fs/xfs/xfs_fixups.h | 26 ++++ fs/xfs/xfs_mount.c | 21 +++ fs/xfs/xfs_super.c | 10 ++ 5 files changed, 367 insertions(+), 1 deletion(-) create mode 100644 fs/xfs/xfs_fixups.c create mode 100644 fs/xfs/xfs_fixups.h -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index b03c77e..f88368a 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -86,6 +86,7 @@ xfs-y += xfs_aops.o \ xfs_extent_busy.o \ xfs_file.o \ xfs_filestream.o \ + xfs_fixups.o \ xfs_fsmap.o \ xfs_fsops.o \ xfs_globals.o \ diff --git a/fs/xfs/xfs_fixups.c b/fs/xfs/xfs_fixups.c new file mode 100644 index 0000000..0cad7bb --- /dev/null +++ b/fs/xfs/xfs_fixups.c @@ -0,0 +1,310 @@ +/* + * Copyright (C) 2018 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_shared.h" +#include "xfs_format.h" +#include "xfs_log_format.h" +#include "xfs_trans_resv.h" +#include "xfs_sb.h" +#include "xfs_mount.h" +#include "xfs_alloc.h" +#include "xfs_trans.h" +#include "xfs_fixups.h" + +/* + * v5 AGFL padding defects + * + * When the v5 format was first introduced, there was a defect in the struct + * xfs_agfl definition that resulted in XFS_AGFL_SIZE returning different + * values depending on the compiler padding. On a fs with 512-byte sectors, + * this meant that XFS_AGFL_SIZE was 119 on i386, but 118 on x64. Commit + * 96f859d52bcb1 ("libxfs: pack the agfl header structure so XFS_AGFL_SIZE is + * correct") changed the definition to disable padding the end of the + * structure, and was accepted into Linux 4.5. Since then, the AGFL has + * always used the larger size (e.g. 119 entries on a 512b sector fs). + * + * Unfortunately, pre-4.5 kernels can produce filesystems with AGFLs that wrap + * at the smaller size, and those kernels are not prepared to handle the + * longer size. This typically manifests itself as an AGF verifier corruption + * error followed by a filesystem shutdown. While we encourage admins to stay + * current with software, we would like to avoid this intermittent breakage. + * + * Any v5 filesystem which has a feature bit set for a feature that was + * introduced after Linux 4.5 will not have this problem, as such kernels + * cannot be mounted on older kernels. v4 filesystems are also unaffected. + * + * Therefore, we add two fixup functions -- the first runs at mount time to + * detect a short-wrapped AGFL and fix it; the second runs at unmount, freeze, + * or remount-ro time to move a wrapped AGFL to the beginning of the list. + * This reduces the likelihood of a screwup to the scenario where you have (a) + * a filesystem with no post-4.5 features (reflink, rmap), (b) the AGFL wraps, + * (c) the filesystem goes down leaving a dirty log, and (d) the dirty + * filesystem is mounted on an old kernel. + */ + +/* + * Decide if we need to have the agfl wrapping fixes applied. This only + * affects v5 filesystems that do not have any features enabled that did not + * exist when the agfl padding fix went in. + * + * Features already present when the fix went in were finobt, ftype, spinodes. + * If we see something new (e.g. reflink) then don't bother. + */ +#define XFS_SB_FEAT_RO_COMPAT_AGFL_WRAP_ALREADY_FIXED \ + (~(XFS_SB_FEAT_RO_COMPAT_FINOBT)) +#define XFS_SB_FEAT_INCOMPAT_AGFL_WRAP_ALREADY_FIXED \ + (~(XFS_SB_FEAT_INCOMPAT_FTYPE | \ + XFS_SB_FEAT_INCOMPAT_SPINODES)) +#define XFS_SB_FEAT_INCOMPAT_LOG_AGFL_WRAP_ALREADY_FIXED \ + (~0) +static inline bool xfs_sb_version_needs_agfl_wrap_fixes(struct xfs_sb *sbp) +{ + return xfs_sb_version_hascrc(sbp) && + !xfs_sb_has_incompat_feature(sbp, + XFS_SB_FEAT_INCOMPAT_AGFL_WRAP_ALREADY_FIXED) && + !xfs_sb_has_ro_compat_feature(sbp, + XFS_SB_FEAT_RO_COMPAT_AGFL_WRAP_ALREADY_FIXED) && + !xfs_sb_has_incompat_log_feature(sbp, + XFS_SB_FEAT_INCOMPAT_LOG_AGFL_WRAP_ALREADY_FIXED); +} + +/* + * Fix an AGFL wrapping that falls short of the end of the block by filling the + * gap at the end of the block. + */ +STATIC int +xfs_fixup_freelist_wrap_mount( + struct xfs_trans *tp, + struct xfs_buf *agfbp, + struct xfs_perag *pag) +{ + struct xfs_mount *mp = tp->t_mountp; + struct xfs_agf *agf; + struct xfs_buf *agflbp; + __be32 *agfl_bno; + xfs_agnumber_t agno; + uint32_t agfl_size; + uint32_t flfirst; + uint32_t fllast; + int32_t active; + int offset; + int len; + int error; + + if (pag->pagf_flcount == 0) + return 0; + + agfl_size = xfs_agfl_size(mp); + agf = XFS_BUF_TO_AGF(agfbp); + agno = be32_to_cpu(agf->agf_seqno); + flfirst = be32_to_cpu(agf->agf_flfirst); + fllast = be32_to_cpu(agf->agf_fllast); + + /* Make sure we're either spot on or off by 1. */ + active = fllast - flfirst + 1; + if (active <= 0) + active += agfl_size; + if (active == pag->pagf_flcount) + return 0; + else if (active != pag->pagf_flcount + 1) + return -EFSCORRUPTED; + + /* Would this have even passed muster on an old system? */ + if (flfirst >= agfl_size - 1 || fllast >= agfl_size - 1 || + pag->pagf_flcount > agfl_size - 1) + return -EFSCORRUPTED; + + /* + * Convert a 40-byte-padded agfl into a 36-byte-padded AGFL. + * Therefore, we need to move the AGFL blocks + * bno[flfirst..agfl_size - 2] to bno[flfirst + 1...agfl_size - 1]. + * + * Reusing the example above, if we had flfirst == 116, we need + * to move bno[116] and bno[117] into bno[117] and bno[118], + * respectively, and then increment flfirst. + */ + error = xfs_alloc_read_agfl(mp, tp, agno, &agflbp); + if (error) + return error; + agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp); + + len = (agfl_size - flfirst - 1) * sizeof(xfs_agblock_t); + memmove(&agfl_bno[flfirst + 1], &agfl_bno[flfirst], len); + offset = (char *)&agfl_bno[flfirst + 1] - (char *)agflbp->b_addr; + be32_add_cpu(&agf->agf_flfirst, 1); + + xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF); + xfs_trans_log_buf(tp, agflbp, offset, offset + len - 1); + xfs_trans_brelse(tp, agflbp); + agflbp = NULL; + xfs_alloc_log_agf(tp, agfbp, XFS_AGF_FLFIRST); + + return 0; +} + +/* + * Fix an AGFL that touches the end of the block by moving the first or last + * part of the list elsewhere in the AGFL so that old kernels don't trip over + * wrapping issues. + */ +STATIC int +xfs_fixup_freelist_wrap_unmount( + struct xfs_trans *tp, + struct xfs_buf *agfbp, + struct xfs_perag *pag) +{ + struct xfs_mount *mp = tp->t_mountp; + struct xfs_agf *agf; + struct xfs_buf *agflbp; + __be32 *agfl_bno; + xfs_agnumber_t agno; + uint32_t agfl_size; + uint32_t flfirst; + uint32_t fllast; + int offset; + int len; + int error; + + agfl_size = xfs_agfl_size(mp); + agf = XFS_BUF_TO_AGF(agfbp); + agno = be32_to_cpu(agf->agf_seqno); + flfirst = be32_to_cpu(agf->agf_flfirst); + fllast = be32_to_cpu(agf->agf_fllast); + + /* Empty AGFL? Make sure we aren't pointing at the end. */ + if (pag->pagf_flcount == 0) { + if (flfirst >= agfl_size || fllast >= agfl_size) { + agf->agf_flfirst = cpu_to_be32(1); + agf->agf_fllast = 0; + xfs_alloc_log_agf(tp, agfbp, + XFS_AGF_FLFIRST | XFS_AGF_FLLAST); + } + return 0; + } + + /* If we don't hit the end, we're done. */ + if (flfirst < fllast && fllast != agfl_size - 1) + return 0; + + /* + * Move a start of a wrapped list towards the start of the agfl block. + * Therefore, we need to move the AGFL blocks + * bno[flfirst..agfl_size - 1] to bno[fllast + 1...agfl_size - flfirst]. + * Then we reset flfirst and fllast appropriately. + * + * Reusing the example above, if we had flfirst == 117 and fllast == 4, + * we need to move bno[117] and bno[118] into bno[5] and bno[6], + * respectively, and then reset flfirst and fllast. + * + * If it's just the last block that touches the end, only move that. + */ + error = xfs_alloc_read_agfl(mp, tp, agno, &agflbp); + if (error) + return error; + agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp); + + if (fllast == agfl_size - 1) { + /* Back the AGFL off from the end of the block. */ + len = sizeof(xfs_agblock_t); + agfl_bno[flfirst - 1] = agfl_bno[agfl_size - 1]; + offset = (char *)&agfl_bno[flfirst - 1] - (char *)agflbp->b_addr; + be32_add_cpu(&agf->agf_fllast, -1); + be32_add_cpu(&agf->agf_flfirst, -1); + } else { + /* Move the first part of the AGFL towards the front. */ + len = (agfl_size - flfirst) * sizeof(xfs_agblock_t); + memcpy(&agfl_bno[fllast + 1], &agfl_bno[flfirst], len); + offset = (char *)&agfl_bno[fllast + 1] - (char *)agflbp->b_addr; + agf->agf_flfirst = 0; + agf->agf_fllast = cpu_to_be32(pag->pagf_flcount - 1); + } + + xfs_trans_buf_set_type(tp, agflbp, XFS_BLFT_AGFL_BUF); + xfs_trans_log_buf(tp, agflbp, offset, offset + len - 1); + xfs_trans_brelse(tp, agflbp); + agflbp = NULL; + xfs_alloc_log_agf(tp, agfbp, XFS_AGF_FLFIRST | XFS_AGF_FLLAST); + + return 0; +} + +typedef int (*xfs_agf_apply_fn_t)(struct xfs_trans *tp, struct xfs_buf *agfbp, + struct xfs_perag *pag); + +/* Apply something to every AGF. */ +STATIC int +xfs_fixup_agf_apply( + struct xfs_mount *mp, + xfs_agf_apply_fn_t fn) +{ + struct xfs_trans *tp; + struct xfs_perag *pag; + struct xfs_buf *agfbp; + xfs_agnumber_t agno; + int error; + + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata, 0, 0, 0, &tp); + if (error) + return error; + + for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) { + error = xfs_alloc_read_agf(mp, tp, agno, 0, &agfbp); + if (error) + goto cancel; + if (!agfbp) { + error = -ENOMEM; + goto cancel; + } + pag = xfs_perag_get(mp, agno); + error = fn(tp, agfbp, pag); + xfs_perag_put(pag); + xfs_trans_brelse(tp, agfbp); + if (error) + goto cancel; + } + + return xfs_trans_commit(tp); +cancel: + xfs_trans_cancel(tp); + return error; +} + +/* Fix AGFL wrapping so we can use the filesystem. */ +int +xfs_fixup_agfl_wrap_mount( + struct xfs_mount *mp) +{ + if (!xfs_sb_version_needs_agfl_wrap_fixes(&mp->m_sb)) + return 0; + + return xfs_fixup_agf_apply(mp, xfs_fixup_freelist_wrap_mount); +} + +/* Fix AGFL wrapping so old kernels can use this filesystem. */ +int +xfs_fixup_agfl_wrap_unmount( + struct xfs_mount *mp) +{ + if (!xfs_sb_version_needs_agfl_wrap_fixes(&mp->m_sb)) + return 0; + + return xfs_fixup_agf_apply(mp, xfs_fixup_freelist_wrap_unmount); +} diff --git a/fs/xfs/xfs_fixups.h b/fs/xfs/xfs_fixups.h new file mode 100644 index 0000000..fb52a96 --- /dev/null +++ b/fs/xfs/xfs_fixups.h @@ -0,0 +1,26 @@ +/* + * Copyright (C) 2018 Oracle. All Rights Reserved. + * + * Author: Darrick J. Wong + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. + */ +#ifndef __XFS_FIXUPS_H__ +#define __XFS_FIXUPS_H__ + +int xfs_fixup_agfl_wrap_mount(struct xfs_mount *mp); +int xfs_fixup_agfl_wrap_unmount(struct xfs_mount *mp); + +#endif /* __XFS_FIXUPS_H__ */ diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index 98fd41c..eb284aa 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -46,7 +46,7 @@ #include "xfs_refcount_btree.h" #include "xfs_reflink.h" #include "xfs_extent_busy.h" - +#include "xfs_fixups.h" static DEFINE_MUTEX(xfs_uuid_table_mutex); static int xfs_uuid_table_size; @@ -875,6 +875,16 @@ xfs_mountfs( } /* + * Make sure our AGFL counters do not wrap the end of the block + * in a troublesome manner. + */ + error = xfs_fixup_agfl_wrap_mount(mp); + if (error) { + xfs_warn(mp, "Failed to fix agfl wrapping. Run xfs_repair."); + goto out_log_dealloc; + } + + /* * Get and sanity-check the root inode. * Save the pointer to it in the mount structure. */ @@ -1128,6 +1138,15 @@ xfs_unmountfs( xfs_qm_unmount(mp); /* + * Make sure our AGFL counters do not wrap the end of the block + * in a troublesome manner for old kernels. + */ + error = xfs_fixup_agfl_wrap_unmount(mp); + if (error) + xfs_warn(mp, "Unable to fix agfl wrapping. " + "This may cause problems on next mount."); + + /* * Unreserve any blocks we have so that when we unmount we don't account * the reserved free space as used. This is really only necessary for * lazy superblock counting because it trusts the incore superblock diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 624a802..d9aa39a 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -50,6 +50,7 @@ #include "xfs_refcount_item.h" #include "xfs_bmap_item.h" #include "xfs_reflink.h" +#include "xfs_fixups.h" #include #include @@ -1206,6 +1207,15 @@ xfs_quiesce_attr( xfs_reclaim_inodes(mp, 0); xfs_reclaim_inodes(mp, SYNC_WAIT); + /* + * Make sure our AGFL counters do not wrap the end of the block + * in a troublesome manner for old kernels. + */ + error = xfs_fixup_agfl_wrap_unmount(mp); + if (error) + xfs_warn(mp, "Unable to fix agfl wrapping. " + "This may cause problems on next mount."); + /* Push the superblock and write an unmount record */ error = xfs_log_sbcount(mp); if (error)