From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="NIDk/5tt" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F638CB for ; Mon, 11 Dec 2023 23:04:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702364639; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=3ugA+dgRKXupJQ3FSbhSO+8qa+aTwoDRrWz+Rab04D0=; b=NIDk/5ttKi8DWQQx/yTqMB1PNy5uMVtujCBYgujPhMdqZwj5DE8BVeylS0pSxpAyJBXeqn 7DY78HyiFplaHyrrqCYCZNt29sAtgpK5tcDF03hXnAtZruYJLGemUtKX5NA6aBb82Obadb NaQhftQpSQnFUfK2eMbJtCZt6zWxHFQ= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-508-o0IAlGikPiKu9sS4Jxl-Kw-1; Tue, 12 Dec 2023 02:03:54 -0500 X-MC-Unique: o0IAlGikPiKu9sS4Jxl-Kw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 85D97101AA4D; Tue, 12 Dec 2023 07:03:53 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3DB983C25; Tue, 12 Dec 2023 07:03:52 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <20231208013739.frhvlisxut6hexnd@moria.home.lan> <170200162890.12910.9667703050904306180@noble.neil.brown.name> <20231208024919.yjmyasgc76gxjnda@moria.home.lan> <630fcb48-1e1e-43df-8b27-a396a06c9f37@molgen.mpg.de> <20231208200247.we3zrwmnkwy5ibbz@moria.home.lan> <170233460764.12910.276163802059260666@noble.neil.brown.name> <20231211233231.oiazgkqs7yahruuw@moria.home.lan> <170233878712.12910.112528191448334241@noble.neil.brown.name> <20231212000515.4fesfyobdlzjlwra@moria.home.lan> <170234279139.12910.809452786055101337@noble.neil.brown.name> To: Dave Chinner Cc: dhowells@redhat.com, NeilBrown , Kent Overstreet , Donald Buczek , linux-bcachefs@vger.kernel.org, Stefan Krueger , linux-fsdevel@vger.kernel.org Subject: Re: file handle in statx (was: Re: How to cope with subvolumes and snapshots on muti-user systems?) Precedence: bulk X-Mailing-List: linux-bcachefs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2805884.1702364631.1@warthog.procyon.org.uk> Date: Tue, 12 Dec 2023 07:03:51 +0000 Message-ID: <2805885.1702364631@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.1 Dave Chinner wrote: > I mean, we already have name_to_handle_at() for userspace to get a > unique, opaque, filesystem defined file handle for any given file. > It's the same filehandle that filesystems hand to the nfsd so nfs > clients can uniquely identify the file they are asking the nfsd to > operate on. That's the along lines I was thinking of when I suggested using a file handle to Kent. Question is, though, do we need to also expand stx_ino in some way for apps that present it to the user? David