From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=earthlink.net header.i=@earthlink.net header.b="P0+UqP9Q" X-Greylist: delayed 335 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 12 Dec 2023 09:21:15 PST Received: from mta-102a.earthlink-vadesecure.net (mta-102a.earthlink-vadesecure.net [51.81.61.66]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 95F57A0; Tue, 12 Dec 2023 09:21:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; bh=QLgKdeI1YofNbiS/FOWwaRkB1buWzAVPYqmRcM eNmgk=; c=relaxed/relaxed; d=earthlink.net; h=from:reply-to:subject: date:to:cc:resent-date:resent-from:resent-to:resent-cc:in-reply-to: references:list-id:list-help:list-unsubscribe:list-subscribe:list-post: list-owner:list-archive; q=dns/txt; s=dk12062016; t=1702401331; x=1703006131; b=P0+UqP9Q7efKX8QFIRYo4b1UjSvBp8kD/qsqoNx4RPIB3dsFvpSY7nV lzFqEyCkw5eNdspzxtXs9tfAKllEEx5sStOx5YdAk5z88/N3ycDG8AbQx1PRSCCI2EBJ3Dc WPr7JU0O4uBqYfDcWbIpdK9seqAdRlAYTpM9uv0wkwQ+cPdlBqGA+I+Op6LDQ8+z7EYfbh5 nk5oP/gnGIjQPbtVJZcuXmnLvHHOAOHq+e7wGGl6FmHBsiSpCH29EuXl69MDkJqkPSyT2e1 jW9M/ikV++GKX8k/97teNIBlIr7/f5WV+R/uZnu+qV+/637f3XIlOSLeWVXFpvjy36DGCOs aPg== Received: from FRANKSTHINKPAD ([174.174.49.201]) by vsel1nmtao02p.internal.vadesecure.com with ngmta id 48a1b7b4-17a024fd67e3209c; Tue, 12 Dec 2023 17:15:30 +0000 From: "Frank Filz" To: "'Theodore Ts'o'" , "'Donald Buczek'" Cc: "'Dave Chinner'" , "'NeilBrown'" , "'Kent Overstreet'" , , "'Stefan Krueger'" , "'David Howells'" , References: <20231208024919.yjmyasgc76gxjnda@moria.home.lan> <630fcb48-1e1e-43df-8b27-a396a06c9f37@molgen.mpg.de> <20231208200247.we3zrwmnkwy5ibbz@moria.home.lan> <170233460764.12910.276163802059260666@noble.neil.brown.name> <20231211233231.oiazgkqs7yahruuw@moria.home.lan> <170233878712.12910.112528191448334241@noble.neil.brown.name> <20231212000515.4fesfyobdlzjlwra@moria.home.lan> <170234279139.12910.809452786055101337@noble.neil.brown.name> <20231212152016.GB142380@mit.edu> In-Reply-To: <20231212152016.GB142380@mit.edu> Subject: RE: file handle in statx Date: Tue, 12 Dec 2023 09:15:29 -0800 Message-ID: <0b4c01da2d1e$cf65b930$6e312b90$@mindspring.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 15.0 Content-Language: en-us Thread-Index: AQI2jiBebf/oJPBNRzSpvij1RIkwjAJNcH/PAj0PmP4Bx04wjwGrb0drAjE7wAEBipc+KAKTzaQNAUh2UVECn5o3SAFneCXlr1A9N2A= Authentication-Results: earthlink-vadesecure.net; auth=pass smtp.auth=ffilzlnx@mindspring.com smtp.mailfrom=ffilzlnx@mindspring.com; X-Spam-Level: * > On Tue, Dec 12, 2023 at 10:10:23AM +0100, Donald Buczek wrote: > > On 12/12/23 06:53, Dave Chinner wrote: > > > > > So can someone please explain to me why we need to try to re-invent > > > a generic filehandle concept in statx when we already have a have > > > working and widely supported user API that provides exactly this > > > functionality? > > > > name_to_handle_at() is fine, but userspace could profit from being > > able to retrieve the filehandle together with the other metadata in a > > single system call. > > Can you say more? What, specifically is the application that would want to do > that, and is it really in such a hot path that it would be a user-visible > improveable, let aloine something that can be actually be measured? A user space NFS server like Ganesha could benefit from getting attributes and file handle in a single system call. Potentially it could also avoid some of the challenges of using name_to_handle_at that is a privileged operation. Frank