From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:35012 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751306AbdISTRb (ORCPT ); Tue, 19 Sep 2017 15:17:31 -0400 Subject: Re: [PATCH 4/7] xfs: Implement fallocate query support mode To: Christoph Hellwig , Theodore Ts'o Cc: Andreas Dilger , "Darrick J. Wong" , Lukas Czerner , linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org References: <1505749947-26360-1-git-send-email-lczerner@redhat.com> <1505749947-26360-5-git-send-email-lczerner@redhat.com> <20170918204838.GW6540@magnolia> <7B6B7C4C-7FEB-401F-B4EE-6E11E95FB246@dilger.ca> <20170919145520.c4y4w32lmsnqhhxp@thunk.org> <20170919155528.GA8907@infradead.org> From: Florian Weimer Message-ID: <563513ad-afb5-4c76-9f38-4b2e79e7af8a@redhat.com> Date: Tue, 19 Sep 2017 21:17:28 +0200 MIME-Version: 1.0 In-Reply-To: <20170919155528.GA8907@infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On 09/19/2017 05:55 PM, Christoph Hellwig wrote: > On Tue, Sep 19, 2017 at 10:55:20AM -0400, Theodore Ts'o wrote: >> Maybe the right answer is we should define a new pathconfat(2) system >> call which can be used as part of a C library's implementation of >> pathconf() and fpathconf()? glibc probably won't use it for years, of >> course. But we can at least provide the information via an interface >> which we can control, and which is capable of returning correct >> results? > > glibc is very fast at picking up new kernel interface these days > as long as they aren't too controversial. Implementing a syscall > that backs a function they implement should not be in the controversial > category I think. We have a significant backlog, but I don't expect opposition to patches implementing syscall wrappers which are just slightly generic (and pathconfat should really be fine). Technically, pathconfat might be tricky to maintain if it's expected to be a variadic dispatcher function, and the accompanying UAPI header isn't very clean. Thanks, Florian