From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793208027; b=ntY+9sbBNNJYN159h1bmtgCr6ThpJwnajhTDE80COO22AbsqCsx/TR1sBSNxK0Ql2uSO SBKr2uSWlB+8EyZ0TeVjhjtJxt2Fp5vwuJ/2zyqSHbE/yYCoZ2VhJ2OzCoufDEcadPs2I 42rNlq+fhXT6qwcQSA8qeRsBahgdB8L5GFgcAyARWPB9yD0xFrLbi/Oz5epxCGmfSAl4t T56pCTMeYb/aAsR0MI28lGGZU2dHQzkPFiz1cs3L17s+zqhbDBFXtJdDT8Xv/RP8FnAJl epO+e1XQID+A7cLqplJMU9qXVpvhSaJhvYgymSXd7W6mgAnFB0/sol1NT2LZ7OE9dAw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793208027; h=Received:DKIM-Signature:Message-ID:Subject:From:To:Cc:Date: In-Reply-To:References:Autocrypt:Content-Type: Content-Transfer-Encoding:User-Agent:MIME-Version; bh=Jyz5jeE6e0Lc2tu2mEkLEw3LQE0FMfSOeYQ4TiqqUfs=; b=S/UFAIoltdE1XpSroNdAODwUnZ9PeQn7/1BzpL7gdneGV8gAxwshK2Kw2HuAR3hVFbys 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header.b=awnqYfeg Received: by smtp.kernel.org (Postfix) with ESMTPSA id 138C41F01825; Wed, 28 Oct 2026 17:20:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793208027; bh=Jyz5jeE6e0Lc2tu2mEkLEw3LQE0FMfSOeYQ4TiqqUfs=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=awnqYfeg56pS3qYA2Tk/wS2m4fmsDvbTM8CHEEXl2LlrFxu1Zps1jedbb4E1si18B rZbJY15Qr4yqMPgIRpME9FAvSW7oUi9JYSZ4fzwQ7rg2E5P8isTbFhtge6SU2ly0wt nNaL5LHrVFUsGw0PEXvwxK6Ublj+ZiE1DSvaAEVlJgyz3dwFk1PW695WrGCgm4gcX/ GCGpYyOGcO4poinoCN+eD59c+I9nkqPYT6DfzmlsHCbqZaEvyAkMEauMqNTAyPcQ0v HQUoStaLGtfhzobLY1r/e9Vx0L41TTjyv4Rtl6IkqoOfQjg28N9Dxc5RpwGxMgy9pk 4ddeuBHqcOwJg== Message-ID: <3a5b0778c77df7cce94bf9fce974b1bf1dfb6324.camel@kernel.org> Subject: Re: [PATCH RFC fstests] generic: add a test for multigrain timestamps From: Jeff Layton To: Christoph Hellwig Cc: Zorro Lang , fstests@vger.kernel.org, linux-fsdevel@vger.kernel.org Date: Wed, 28 Oct 2026 13:20:24 -0400 In-Reply-To: References: 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f8lfK1XVNbRq/R7GZ9zHESlsa35ha60yd/j3pu5hT2xyy8krV8vGhHvnJ1XRMJBAB/UYb6FyC7S+m QZIQXVeAA+smfTT0tDrisj1U5x6ZB9b3nBg65kc= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 (3.60.2-2.fc44) X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 On Wed, 2026-10-28 at 08:54 -0700, Christoph Hellwig wrote: > On Tue, Oct 27, 2026 at 09:58:50AM -0400, Jeff Layton wrote: > > Ensure that the mtime and ctime apparently change, even when there are > > multiple writes in quick succession. Since this is opt-in for in-kernel > > filesystems and there is no way to test for this feature in userland, > > limit it to just ext4, f2fs, btrfs, tmpfs and xfs for now. > >=20 > > Signed-off-by: Jeff Layton > > --- > > I'd like to start testing this to make sure it doesn't break, but it's > > not universally supported on all filesystems. Is an explicit allowlist > > like this the right approach? >=20 > Can we please expose the fact that multi-grain timestamp are supported > from the kernel? This seems like it would be just one bit we'd need > in sttx or something similar. I'd been resisting that, but maybe it's a good idea. I'll see what I can come up with. We can probably just add a flag to stx_attributes? --=20 Jeff Layton