Re: [PATCH 3/5] xfs_repair: fix dir refcount when '.' missing and dir is rebuilt

Brian Foster
2014-09-08T13:45:28Z

On Sun, Sep 07, 2014 at 11:41:03AM -0500, Eric Sandeen wrote:
> In phase 6's longform_dir2_entry_check, if we never
> find a '.' entry we never add a reference to that entry;
> if we subsequently rebuild it, '.' gets added, but
> no ref to it is ever made. This leads to Phase 7 doing
> i.e.:
>
> Phase 7 - verify and correct link counts...
> resetting inode 5184 nlinks from 2 to 1
>
> and the next run will do:
>
> Phase 7 - verify and correct link counts...
> resetting inode 5184 nlinks from 1 to 2
>
> So if '.' was never found, but the directory got
> rebuilt, manually add the ref for it.
>
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
> repair/phase6.c | 6 ++++++
> 1 files changed, 6 insertions(+), 0 deletions(-)
>
> diff --git a/repair/phase6.c b/repair/phase6.c
> index f13069f..cc36a9c 100644
> --- a/repair/phase6.c
> +++ b/repair/phase6.c
> @@ -2288,6 +2288,12 @@ out_fix:
> if (bplist[i])
> libxfs_putbuf(bplist[i]);
> longform_dir2_rebuild(mp, ino, ip, irec, ino_offset, hashtab);
> + /*
> + * If we didn't find a dot, we never added a ref for it;
> + * it's there now after the rebuild, so mark it as reached.
> + */
> + if (*need_dot)
> + add_inode_ref(irec, ino_offset);

So if I follow this correctly, we iterate through the dir, add each name
to the hashtable and handle the inode reference count in the first
longform_dir2_entry_check() loop. If something is wrong, we call
longform_dir2_rebuild() to rebuild the dir from the hashtable of
names/inodes. We may or may not have added a reference for dot at that
point, and need_dot is set appropriately.

This seems Ok, but where is the dot entry actually added? Hmm, I see
that we handle dot in the longform_dir2_rebuild() loop by just skipping
over it...

Brian

> *num_illegal = 0;
> *need_dot = 0;
> } else {
> --
> 1.7.1
>
> _______________________________________________
> xfs mailing list
> xfs@oss.sgi.com
> http://oss.sgi.com/mailman/listinfo/xfs