| From hch@lst.de Tue Jan 10 11:30:37 2017 |
| From: Christoph Hellwig <hch@lst.de> |
| Date: Mon, 9 Jan 2017 16:38:58 +0100 |
| Subject: xfs: ignore leaf attr ichdr.count in verifier during log replay |
| To: stable@vger.kernel.org |
| Cc: linux-xfs@vger.kernel.org, Eric Sandeen <sandeen@redhat.com>, Dave Chinner <david@fromorbit.com> |
| Message-ID: <1483976343-661-28-git-send-email-hch@lst.de> |
| |
| |
| From: Eric Sandeen <sandeen@redhat.com> |
| |
| commit 2e1d23370e75d7d89350d41b4ab58c7f6a0e26b2 upstream. |
| |
| When we create a new attribute, we first create a shortform |
| attribute, and try to fit the new attribute into it. |
| If that fails, we copy the (empty) attribute into a leaf attribute, |
| and do the copy again. Thus there can be a transient state where |
| we have an empty leaf attribute. |
| |
| If we encounter this during log replay, the verifier will fail. |
| So add a test to ignore this part of the leaf attr verification |
| during log replay. |
| |
| Thanks as usual to dchinner for spotting the problem. |
| |
| Signed-off-by: Eric Sandeen <sandeen@redhat.com> |
| Reviewed-by: Christoph Hellwig <hch@lst.de> |
| Signed-off-by: Dave Chinner <david@fromorbit.com> |
| Cc: Christoph Hellwig <hch@lst.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| fs/xfs/libxfs/xfs_attr_leaf.c | 8 +++++++- |
| 1 file changed, 7 insertions(+), 1 deletion(-) |
| |
| --- a/fs/xfs/libxfs/xfs_attr_leaf.c |
| +++ b/fs/xfs/libxfs/xfs_attr_leaf.c |
| @@ -253,6 +253,7 @@ xfs_attr3_leaf_verify( |
| { |
| struct xfs_mount *mp = bp->b_target->bt_mount; |
| struct xfs_attr_leafblock *leaf = bp->b_addr; |
| + struct xfs_perag *pag = bp->b_pag; |
| struct xfs_attr3_icleaf_hdr ichdr; |
| |
| xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf); |
| @@ -273,7 +274,12 @@ xfs_attr3_leaf_verify( |
| if (ichdr.magic != XFS_ATTR_LEAF_MAGIC) |
| return false; |
| } |
| - if (ichdr.count == 0) |
| + /* |
| + * In recovery there is a transient state where count == 0 is valid |
| + * because we may have transitioned an empty shortform attr to a leaf |
| + * if the attr didn't fit in shortform. |
| + */ |
| + if (pag && pag->pagf_init && ichdr.count == 0) |
| return false; |
| |
| /* XXX: need to range check rest of attr header values */ |
