Re: [PATCH v2] xfsrestore: suggest -x rather than assert for false roots

Darrick J. Wong
2023-08-22T18:34:06Z

On Mon, Aug 07, 2023 at 02:53:57PM +1000, Donald Douwsma wrote:
> If we're going to have a fix for false root problems its a good idea to
> let people know that there's a way to recover, error out with a useful
> message that mentions the `-x` option rather than just assert.
>
> Before
>
> xfsrestore: searching media for directory dump
> xfsrestore: reading directories
> xfsrestore: tree.c:757: tree_begindir: Assertion `ino != persp->p_rootino || hardh == persp->p_rooth' failed.
> Aborted
>
> After
>
> xfsrestore: ERROR: tree.c:791: tree_begindir: Assertion `ino != persp->p_rootino || hardh == persp->p_rooth` failed.
> xfsrestore: ERROR: False root detected. Recovery may be possible using the `-x` option
> Aborted
>
> Fixes: d7cba7410710 ("xfsrestore: fix rootdir due to xfsdump bulkstat misuse")
> Signed-off-by: Donald Douwsma <ddouwsma@redhat.com>
>
> ---
> Changes for v2
> - Use xfsprogs style for conditional
> - Remove trailing white-space
> - Place printf format all on one line for grepability
> - use __func__ instead of gcc specific __FUNCTION__
> ---
> restore/tree.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/restore/tree.c b/restore/tree.c
> index bfa07fe..e959aa1 100644
> --- a/restore/tree.c
> +++ b/restore/tree.c
> @@ -783,8 +783,15 @@ tree_begindir(filehdr_t *fhdrp, dah_t *dahp)
> /* lookup head of hardlink list
> */
> hardh = link_hardh(ino, gen);
> - if (need_fixrootdir == BOOL_FALSE)
> - assert(ino != persp->p_rootino || hardh == persp->p_rooth);
> + if (need_fixrootdir == BOOL_FALSE &&
> + !(ino != persp->p_rootino || hardh == persp->p_rooth)) {
> + mlog(MLOG_ERROR | MLOG_TREE,

Nit: Second line of the if test has the same level of indentation as the
if body.

With that fixed,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> +"%s:%d: %s: Assertion `ino != persp->p_rootino || hardh == persp->p_rooth` failed.\n",
> + __FILE__, __LINE__, __func__);
> + mlog(MLOG_ERROR | MLOG_TREE, _(
> +"False root detected. Recovery may be possible using the `-x` option\n"));
> + return NH_NULL;
> + }
>
> /* already present
> */
> --
> 2.39.3
>