DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 614MppZ9721455
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org A34984BA2E08
MIME-Version: 1.0
References: <CAAvCNcC0z2pOi92UezFxR-_o53P7dq2fNt+9js6WQAbqwWZTAQ@mail.gmail.com>
 <9e2c81eb-03ea-46ca-83e3-8adf5aa31934@SystematicSW.ab.ca>
In-Reply-To: <9e2c81eb-03ea-46ca-83e3-8adf5aa31934@SystematicSW.ab.ca>
Date: Wed, 4 Feb 2026 23:50:22 +0100
Message-ID: <CAAvCNcBSozq08ASWx6c-M8QB7aPz6tRx+Cqk8wz-1x=y0u_e5g@mail.gmail.com>
Subject: Re: Why does Cygwin always use absolute paths instead of
 OBJECT_ATTRIBUTES.RootDirectory?
To: cygwin@cygwin.com
From: Dan Shelton via Cygwin <cygwin@cygwin.com>
Reply-To: Dan Shelton <dan.f.shelton@gmail.com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie.com@cygwin.com>

On Wed, 4 Feb 2026 at 22:37, Brian Inglis via Cygwin <cygwin@cygwin.com> wrote:
>
> On 2026-02-04 14:17, Dan Shelton via Cygwin wrote:
> > Why does Cygwin always use absolute paths instead of
> > OBJECT_ATTRIBUTES.RootDirectory in NtOpenFile(),
> > NtSetInformationFile() for rename and hardlinks
> >
> > This slows down Cygwin path lookups a lot, and with lots of path
> > elements each lookup with a relative RootDirectory might be a lot
> > faster, e.g. for openat(), linkat(), renameat().
>
> Because volunteers' spare time is limited, and performance is good enough for
> those who might do the work:

Please do not slap me. That hurt.

My question is about whether there are any technical issues which
prevent OBJECT_ATTRIBUTES.RootDirectory from being used in Cygwin for
openat().

2nd question: Is OBJECT_ATTRIBUTES.RootDirectory really a root, and
you cannot do cd ..?

Dan
-- 
Dan Shelton - Cluster Specialist Win/Lin/Bsd

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple