From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:60566 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727450AbfBATAz (ORCPT ); Fri, 1 Feb 2019 14:00:55 -0500 Date: Fri, 1 Feb 2019 14:00:52 -0500 From: Brian Foster Subject: Re: [PATCH 4/8] xfs: strengthen AGI unlinked inode bucket pointer checks Message-ID: <20190201190052.GC31203@bfoster> References: <154897667054.26065.13164381203002725289.stgit@magnolia> <154897669539.26065.18123748779523685840.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <154897669539.26065.18123748779523685840.stgit@magnolia> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org On Thu, Jan 31, 2019 at 03:18:15PM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong > > Strengthen our checking of the AGI unlinked pointers when we start to > use them for updating the metadata. > > Signed-off-by: Darrick J. Wong > --- Reviewed-by: Brian Foster > fs/xfs/xfs_inode.c | 28 +++++++++++++++++----------- > 1 file changed, 17 insertions(+), 11 deletions(-) > > > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c > index 3c33136b21ef..4ddda3f3255f 100644 > --- a/fs/xfs/xfs_inode.c > +++ b/fs/xfs/xfs_inode.c > @@ -1942,6 +1942,7 @@ xfs_iunlink( > struct xfs_buf *ibp; > struct xfs_perag *pag; > xfs_agnumber_t agno; > + xfs_agino_t next_agino; > xfs_agino_t agino; > short bucket_index; > int offset; > @@ -1966,13 +1967,19 @@ xfs_iunlink( > agi = XFS_BUF_TO_AGI(agibp); > > /* > - * Get the index into the agi hash table for the > - * list this inode will go on. > + * Get the index into the agi hash table for the list this inode will > + * go on. Make sure the pointer isn't garbage and that this inode > + * isn't already on the list. > */ > - ASSERT(agi->agi_unlinked[bucket_index]); > - ASSERT(be32_to_cpu(agi->agi_unlinked[bucket_index]) != agino); > + next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]); > + if (next_agino == agino || > + (next_agino != NULLAGINO && > + !xfs_verify_agino(mp, agno, next_agino))) { > + error = -EFSCORRUPTED; > + goto out_unlock; > + } > > - if (agi->agi_unlinked[bucket_index] != cpu_to_be32(NULLAGINO)) { > + if (next_agino != NULLAGINO) { > /* > * There is already another inode in the bucket we need > * to add ourselves to. Add us at the front of the list. > @@ -2054,18 +2061,18 @@ xfs_iunlink_remove( > agi = XFS_BUF_TO_AGI(agibp); > > /* > - * Get the index into the agi hash table for the > - * list this inode will go on. > + * Get the index into the agi hash table for the list this inode will > + * go on. Make sure the head pointer isn't garbage. > */ > - if (!xfs_verify_agino(mp, agno, > - be32_to_cpu(agi->agi_unlinked[bucket_index]))) { > + next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]); > + if (!xfs_verify_agino(mp, agno, next_agino)) { > XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, > agi, sizeof(*agi)); > error = -EFSCORRUPTED; > goto out_unlock; > } > > - if (be32_to_cpu(agi->agi_unlinked[bucket_index]) == agino) { > + if (next_agino == agino) { > /* > * We're at the head of the list. Get the inode's on-disk > * buffer to see if there is anyone after us on the list. > @@ -2107,7 +2114,6 @@ xfs_iunlink_remove( > /* > * We need to search the list for the inode being freed. > */ > - next_agino = be32_to_cpu(agi->agi_unlinked[bucket_index]); > last_ibp = NULL; > while (next_agino != agino) { > struct xfs_imap imap; >