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

Eric Sandeen
2025-04-15T18:44:27Z

On 4/15/25 1:23 PM, Bill O'Donnell wrote:
> 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!

This is related to, but independent of, your patch (see my self-reply).
Please continue to fix your case, so that all entries do not end up in
lost+found when the header is bad.

Thanks,
-Eric

> 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
>>
>
>