Re: [PATCH 3/4] xfs: check owner of dir3 data blocks

Allison Collins
2020-03-02T18:12:21Z

On 2/28/20 6:48 PM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> Check the owner field of dir3 data block headers.
"Check the owner field of dir3 data block headers, and release the
buffer on error." ?

It's a bit of an api change though isnt it? Do we need to go find all
the callers and make sure there's not going to be a double release if
error == -EFSCORRUPTED ?

Allison

>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> fs/xfs/libxfs/xfs_dir2_data.c | 32 +++++++++++++++++++++++++++++++-
> 1 file changed, 31 insertions(+), 1 deletion(-)
>
>
> diff --git a/fs/xfs/libxfs/xfs_dir2_data.c b/fs/xfs/libxfs/xfs_dir2_data.c
> index b9eba8213180..e5910bc9ab83 100644
> --- a/fs/xfs/libxfs/xfs_dir2_data.c
> +++ b/fs/xfs/libxfs/xfs_dir2_data.c
> @@ -394,6 +394,22 @@ static const struct xfs_buf_ops xfs_dir3_data_reada_buf_ops = {
> .verify_write = xfs_dir3_data_write_verify,
> };
>
> +static xfs_failaddr_t
> +xfs_dir3_data_header_check(
> + struct xfs_inode *dp,
> + struct xfs_buf *bp)
> +{
> + struct xfs_mount *mp = dp->i_mount;
> +
> + if (xfs_sb_version_hascrc(&mp->m_sb)) {
> + struct xfs_dir3_data_hdr *hdr3 = bp->b_addr;
> +
> + if (be64_to_cpu(hdr3->hdr.owner) != dp->i_ino)
> + return __this_address;
> + }
> +
> + return NULL;
> +}
>
> int
> xfs_dir3_data_read(
> @@ -403,11 +419,25 @@ xfs_dir3_data_read(
> unsigned int flags,
> struct xfs_buf **bpp)
> {
> + xfs_failaddr_t fa;
> int err;
>
> err = xfs_da_read_buf(tp, dp, bno, flags, bpp, XFS_DATA_FORK,
> &xfs_dir3_data_buf_ops);
> - if (!err && tp && *bpp)
> + if (err || !*bpp)
> + return err;
> +
> + /* Check things that we can't do in the verifier. */
> + fa = xfs_dir3_data_header_check(dp, *bpp);
> + if (fa) {
> + xfs_verifier_error(*bpp, -EFSCORRUPTED, fa);
> + (*bpp)->b_flags &= ~XBF_DONE;
> + xfs_trans_brelse(tp, *bpp);
> + *bpp = NULL;
> + return -EFSCORRUPTED;
> + }
> +
> + if (tp)
> xfs_trans_buf_set_type(tp, *bpp, XFS_BLFT_DIR_DATA_BUF);
> return err;
> }
>