Re: [PATCH] fat: fix parent link count when replacing a sibling directory

[OGAWA Hirofumi]

Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> writes:

> On Thu, 29 Oct 2026 14:57:43 +0900 OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> wrote:
>
>> Hungyu Lin <dennylin0707@xxxxxxxxx> writes:
>> 
>> > vfat_rename() and do_msdos_rename() adjust parent link counts only when
>> > updating the dotdot entry for a move between different parents. Replacing
>> > an existing empty directory in the same parent also removes a
>> > subdirectory, but leaves the parent's link count unchanged.
>> >
>> > For example, renaming one of two sibling directories over the other
>> > leaves the parent with four links instead of three. stat and ls report
>> > the stale count, and find -links 3 does not match the parent.
>> >
>> > Drop the parent's link count for this case after the source entry has
>> > been removed successfully. Leave cross-parent renames, regular files
>> > and the existing error paths unchanged.
>> >
>> > Signed-off-by: Hungyu Lin <dennylin0707@xxxxxxxxx>
>> 
>> Looks good. Thanks.
>> 
>> Acked-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
>
> Thanks.  Sashiko asked a thing:
> 	https://sashiko.dev/#/patchset/20261028211626.26103-1-dennylin0707@xxxxxxxxx

Hm, sure. It is possible what sashiko says. This patch itself should be
ok though.

Hungyu, can you add ->i_nlink check for corrupted dir?

Thanks.
-- 
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>