From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7BB2D35C69A; Tue, 21 Jul 2026 23:21:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784676080; cv=none; b=RnJn92UerIazQwiHRves8Aqgd5m+wM+ERcOg/ZYu7qWh9fLtifLq2bGh+4hmkKyOcaT2FYvaAfY4W/99QEDcTz3oenS99AifFxmK5ux/5j8ePJf++EcqQi1R6bd1C/R7Ux12EosUSYa3RsyrWA7fMvlQ1StYq5mWLALmTS/rWs0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784676080; c=relaxed/simple; bh=Epape1AZPmNPiDqSRRrDa6xUcdS+YMFPuT7Z66bYN5U=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pL1PevruiFQmcSQgB4zpbt9Q2Ny3Mu5xHWQr7g08TEMQq2uUxatzgKOSh7AGXH3xlCm+8AWK28WzuS2Km0R6u6ERo2iOeeLN+Q+l3WoC3grxr0h+cjjY/Mzu9cJCHuBtLkpr40DIJt8GVy5inFSmHjQHLVZ775PYhzAcpP5IahI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=If+xVjPS; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="If+xVjPS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 785C31F000E9; Tue, 21 Jul 2026 23:21:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784676079; bh=73WfWUSvjW6xW9PAg9sUSImOvdQUpt4d8xftqMCXXKw=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=If+xVjPSe8sYvTjtWw7yXmNRrFVTXLA1mqvOdcLJmbh6fRpE9UVxcw6BqYLQWpZFB zllcimaBn5wDsxVCAD6fAlhKO4ImnJUipNtNLYCV+tZ4Mt0igW5QB965d+n/4LbjI4 DZeMyqxya6Z+iBLHdpXRjyXWWX27PvjqFdT4NyREjCO/RfrdFe4crnMNOD8o89juLp YbOj2KaC1Qd95fGGwblRV8rNKYkmq/2I4pL9ksR/Cx+jxh6PeHIfzl/Eoq2SO3P7hi cOUVKALJ8rk6KklJGW4FIdid17qd0opO1oHEaFNKNByX4Gw+prQp2uJixt1vXeYR0x 1FZOGjx4515zA== Message-ID: <18d569b9-dbea-448c-8b3d-56de32c0d6ef@kernel.org> Date: Wed, 22 Jul 2026 07:21:15 +0800 Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7 06/11] fstests: verify f_fsid for cloned filesystems To: "Darrick J. Wong" Cc: fstests@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, zlang@redhat.com, hch@infradead.org References: <2ac5fb22fd6b51973d11082a1ee8fe354926c63c.1781694879.git.asj@kernel.org> <20260701173314.GH6517@frogsfrogsfrogs> <328de723-6f9c-4f09-a68a-da24d49300d5@kernel.org> <20260721225703.GZ7380@frogsfrogsfrogs> Content-Language: en-US From: Anand Suveer Jain In-Reply-To: <20260721225703.GZ7380@frogsfrogsfrogs> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit >>> just in case there *are* programs foolish enough to >>> use (fsid,ino) as a uniqueness check. >> >> On the other hand, if a program needs a unique ID, do we currently have >> any way to get one? > > I don't think there is a way to get a globally unique identifier for a > filesystem image except for the meta_uuid filesystems, and even then > only if the volume manager resets the user-visible uuid every time it > makes a clone and nobody runs a duplicator. Yeah, interesting problem to solve though. Do you have any further code review comments on this test case? Thanks.