From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 1C57122083 for ; Mon, 14 Jul 2025 05:58:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752472686; cv=none; b=VbWCOaXSHCxQL+2u4dNcBm0RWLi9jzrTsZL1Pwq07BbDJrq3p/qlJRMz2x2twDoyGaWOfxEFqjQVronX0bI87Oat8f71W9JdM4wLRfpu5ogPZ9jUMQNmMiEpeyibMGk4fTzdPLyMvDlL5mButSnCSwP0dKKWhCYVC5DNwmlx2R8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752472686; c=relaxed/simple; bh=4/4+X4Z5aKLBuS0lQXSjnxJ++a8A/6vNHZ0Dx1FfTsI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qdeUjw8fV3tXNiRpXM8kRSnloCbEsTpPLoTEN2MmIGrjgJVwLakg17KQ5GVENUwSBThg18IYk7156sA8ixwZPf3Y6Zv1JDBOEROfWxRomavayHGMbvnjP/IiJkJbOemWYhSrh4zCiCYwIb9Y8s+Ir/QW0fmnKGNBm5W/WhphSXA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=hkntMo7O; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="hkntMo7O" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Transfer-Encoding :Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=pT/MT5FN3YmzQaCGDd+lQ2wzTibCgtBStaYy8DwITic=; b=hkntMo7OYu4d81GFRr6/hUcaGd yGfpRPviujtNi2Zpid39Ri9d3I4b/FeX4QH1XWYxGTa2yRYwP27KZGqY3qCvZxDXb1yelIjxCoWX+ LsLvb8ca+iiEQJ0hVvRNYGRU1Ta41shOWadUKsXun1m06XH3NdBVfZvtl/Mj0BPhFHl1OM9lVooG4 7vCSF7qNVcl8rWwUcHbeaQVlmI9SN1pa+SBK2MchSPy7Rirewgfp92n3WOaM5788G8vsVdbN+QKwW 6WAj44r0D92qQxXs4ZPSz/KTWlvVIgJ11sSH835FNWT6VNzQ0gt6efVdPiIUddnjdnqWXbcgkrkNS wBgRwfBw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1ubCCS-00000001GDr-1zoX; Mon, 14 Jul 2025 05:58:04 +0000 Date: Sun, 13 Jul 2025 22:58:04 -0700 From: Christoph Hellwig To: Priya PM Cc: linux-xfs@vger.kernel.org Subject: Re: Query: XFS reflink unique block measurement / snapshot accounting Message-ID: References: Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Sat, Jul 12, 2025 at 01:19:19PM +0530, Priya PM wrote: > Hi, > > I was using reflinks to create snapshots of an XFS filesystem; > however, I’m looking for ways to determine the unique snapshot usage > or perform snapshot accounting. Can you explain what you are trying to measure? How many blocks in a given file are refcounted blocks with other users? Or the difference between i_blocks for all files combined vs actual space usage? There isn't really such a thing as snapshot accouting in XFS.