Re: [PATCH] xfs_repair: Bump link count if longform_dir2_rebuild yields shortform dir

[Bill O'Donnell <bodonnel@redhat.com>]

On Tue, Apr 15, 2025 at 01:09:23PM -0500, user.mail wrote:
> From: Eric Sandeen <sandeen@redhat.com>
> 
> If longform_dir2_rebuild() has so few entries in *hashtab that it results
> in a short form directory, bump the link count manually as shortform
> directories have no explicit "." entry.
> 
> Without this, repair will end with i.e.:
> 
> resetting inode 131 nlinks from 2 to 1
> 
> in this case, because it thinks this directory inode only has 1 link
> discovered, and then a 2nd repair will fix it:
> 
> resetting inode 131 nlinks from 1 to 2
> 
> because shortform_dir2_entry_check() explicitly adds the extra ref when
> the (newly-created)shortform directory is checked:
> 
>         /*
>          * no '.' entry in shortform dirs, just bump up ref count by 1
>          * '..' was already (or will be) accounted for and checked when
>          * the directory is reached or will be taken care of when the
>          * directory is moved to orphanage.
>          */
>         add_inode_ref(current_irec, current_ino_offset);
> 
> Avoid this by adding the extra ref if we convert from longform to
> shortform.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> Signed-off-by: user.mail <sandeen@redhat.com>
> ---

I was about to send a v3 of my patch to handle this (fix link counts
update...) based on djwong's review. This looks cleaner. Thanks!

Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>


>  repair/phase6.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/repair/phase6.c b/repair/phase6.c
> index dbc090a5..8804278a 100644
> --- a/repair/phase6.c
> +++ b/repair/phase6.c
> @@ -1392,6 +1392,13 @@ _("name create failed in ino %" PRIu64 " (%d)\n"), ino, error);
>  _("name create failed (%d) during rebuild\n"), error);
>  	}
>  
> +	/*
> +	 * If we added too few entries to retain longform, add the extra
> +	 * ref for . as this is now a shortform directory.
> +	 */
> +	if (ip->i_df.if_format == XFS_DINODE_FMT_LOCAL)
> +		add_inode_ref(irec, ino_offset);
> +
>  	return;
>  
>  out_bmap_cancel:
> -- 
> 2.49.0
>