Received-SPF: pass (google.com: domain of linux-kernel+bounces-78364-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Date: Fri, 23 Feb 2024 10:16:17 -0300
From: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
To: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	Gwendal Grignou <gwendal@chromium.org>, dlunev@chromium.org
Subject: Re: [PATCH] fat: ignore .. subdir and always add a link to dirs
Message-ID: <ZdiaoVT8ZqGkH6oQ@quatroqueijos.cascardo.eti.br>
References: <20240222203013.2649457-1-cascardo@igalia.com>
 <87bk88oskz.fsf@mail.parknet.co.jp>
 <Zdf8qPN5h74MzCQh@quatroqueijos.cascardo.eti.br>
 <874jdzpov7.fsf@mail.parknet.co.jp>
 <87zfvroa1c.fsf@mail.parknet.co.jp>
 <ZdhsYAUCe9GVMnYE@quatroqueijos.cascardo.eti.br>
 <87v86fnz2o.fsf@mail.parknet.co.jp>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <87v86fnz2o.fsf@mail.parknet.co.jp>

On Fri, Feb 23, 2024 at 09:29:35PM +0900, OGAWA Hirofumi wrote:
> Thadeu Lima de Souza Cascardo <cascardo@igalia.com> writes:
> 
> > So far, I have only seen expected correct behavior here: mkdir/rmdir inside the
> > "bogus" directory works. rmdir of the "bogus" directory works.
> >
> > The only idiosyncrasies I can think of is that if neither "." or ".." are
> > present, the directory will have a link of 1, instead of 2. And when listing
> > the directory, those entries will not show up.
> >
> > Do you expect any of these to be corrected? It will require a more convoluted
> > change.
> >
> > Right now, I think accepting the idiosyncratic behavior for the bogus
> > filesystems is fine, as long as the correct filesystems continue to behave as
> > before. Which seems to be the case here as far as my testing has shown.
> 
> There are many corrupted images, and attacks. Allowing too wide is
> danger for fs.
> 
> BTW, this image works and pass fsck on windows? When I quickly tested
> ev3fs.zip (https://github.com/microsoft/pxt-ev3/issues/980) on windows
> on qemu, it didn't seem recognized as FAT. I can wrongly tested though.
> 
> Thanks.
> -- 
> OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>

That image was further corrupted by mounting it on linux, as is mentioned
in one of the github issues. Let me see if I can arrange the Windows
testing of images I was able to test with. I can later attach them too, as
they should compress very well.

Cascardo.