From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4609517DA39; Wed, 3 Jul 2024 19:55:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720036511; cv=none; b=H+L9ZMfcVl5VKAQkpDe1/EydvS2a9kYVTi4Sw+UnmV/1ZwDyx7C+YO1D89+Z0S2lQXHnNon6yu2sqEXlAJM9A1oIedIwm8iXHrO8dq/tSyyHgiy9yTVLal7m9sQcRzaZFaawxJB6yk1mYSwNCkwF5pBbGFarzRVHg2wcrCsG+Go= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720036511; c=relaxed/simple; bh=3+KFKcrbRO4keOpt+JOi00B7hn3XwKfZiZ7l4BeJAs0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ss9lhwRa6BsxWA69GuYmFg7R4rGPc6UvdBh+qgItvCDray8GYsdDF2eBYRnBkZusWTZYV/UdbFnRNBwe+o0/YpW41MUT44SpD6Ime51DDRTMA60KRtSdKlRFMgSgqxluF9sRJjgTgONPk6/lU+j5QvxUpn81mvuGpDlFNWSDKec= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=K5yCwFlP; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="K5yCwFlP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90EC7C2BD10; Wed, 3 Jul 2024 19:55:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720036510; bh=3+KFKcrbRO4keOpt+JOi00B7hn3XwKfZiZ7l4BeJAs0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=K5yCwFlP1evFYpDwXK3vVXxP/IgzwHvR2q7ZairTUXyPqRIGJwVdgOBMZFi+Kq+IY /fldO1PlBPChuRfQgILgfeTwFBKI6i0RDUUapFIsUi/RcA3KReuEsUe7TDZ98a4Tmc uf5FQK6xGcEcHy/G+oMB/KKSUpJv+o+Wv/zWSSaMkamf/nWndPExiIKMw4/aI1McN7 9Z75B2chyCgl28NM2JbATXCndxwD+PGu1B3q0fI6MVe8ND00RT7/Ke8Tk9V5G5clRv iCjKw0k9i655alQwxKCyQ57mRdH8dMLvD6La5xOmO8sG50oEU+2tlwE+mmivQgK3N6 JeTWutncFRupg== Date: Wed, 3 Jul 2024 21:55:00 +0200 From: Christian Brauner To: Arnd Bergmann Cc: Linus Torvalds , Xi Ruoyao , Xi Ruoyao , Andreas K Huettel , Huacai Chen , Mateusz Guzik , Alexander Viro , Jan Kara , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, io-uring@vger.kernel.org, Jens Axboe , loongarch@lists.linux.dev Subject: Re: [PATCH 2/2] vfs: support statx(..., NULL, AT_EMPTY_PATH, ...) Message-ID: <20240703-eckdaten-ganzheit-3b6ca8d71aed@brauner> References: <1b5d0840-766b-4c3b-8579-3c2c892c4d74@app.fastmail.com> <8f2d356d-9cd6-4b06-8e20-941e187cab43@app.fastmail.com> <20240703-bergwacht-sitzung-ef4f2e63cd70@brauner> <8b6d59ffc9baa57fee0f9fa97e72121fd88cf0e4.camel@xry111.site> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On Wed, Jul 03, 2024 at 08:44:50PM GMT, Arnd Bergmann wrote: > On Wed, Jul 3, 2024, at 19:40, Linus Torvalds wrote: > > On Wed, 3 Jul 2024 at 10:30, Xi Ruoyao wrote: > >> > >> struct stat64 { > >> > >> // ... > >> > >> int st_atime; /* Time of last access. */ > > > > Oh wow. Shows just *how* long ago that was - and how long ago I looked > > at 32-bit code. Because clearly, I was wrong. > > > > I guess it shows how nobody actually cares about 32-bit any more, at > > least in the 2037 sense. > > > > The point stands, though - statx isn't a replacement for existing binaries. > > We had long discussions about adding another stat()/fstat() > variant with 64-bit timestamps from 2012 to 2017, the result > was that we mandated that a libc implementation with 64-bit > time_t must only use statx() and not fall back to the time32 > syscalls on kernels that are new enough to have statx(). > This is both for architectures that were introduced after > time64 support was added (riscv32 and the glibc port for > arc), and for userspace builds that are explicitly using > time64 syscalls only. > > That may have been a mistake in hindsight, or it may have > been the right choice, but the thing is that if we now decide > that 32-bit userspace can not rely on statx() to be available, > then we need to introduce one or two new system calls. I'm not sure we need to now pull the rug out from everyone now and I don't think this was where the discussion was going. Any new architecture will implement statx(). And for 32bit I think that's entirely fine and we don't need to add even more variants just for this case. I don't think we need to add newnewstat_promiseitsthelastone().