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="HPZDKqWv" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2AEFCDC for ; Tue, 12 Dec 2023 01:46:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702374417; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=esvxw69kt9HBv0/olNC0BlWzgDrZkwrB0IdPpNeWzPE=; b=HPZDKqWvFRFG77KnfYS4sDqdaGQL1ir6sTD3VLmGKoiiR4w9BBDK61M9QjBSAAAXtxY5wK 4ALurNNvmHhN0erVcS0wBAbzWbkh/2EKk+UIeFN2BEPMblO4kW343ZqQ5yMc0CmSJHJpUQ n/8wPhBC3P17xIJS4qPjgI2/s/Wtxzk= 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-607-SCyH3tE6PLuxiN5U41ameg-1; Tue, 12 Dec 2023 04:46:54 -0500 X-MC-Unique: SCyH3tE6PLuxiN5U41ameg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (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 8FAE8835389; Tue, 12 Dec 2023 09:46:53 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id F118F40C6EB9; Tue, 12 Dec 2023 09:46:51 +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: <20231212-ablauf-achtbar-ae6e5b15b057@brauner> References: <20231212-ablauf-achtbar-ae6e5b15b057@brauner> <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> <2810685.1702372247@warthog.procyon.org.uk> To: Christian Brauner Cc: dhowells@redhat.com, Amir Goldstein , Dave Chinner , NeilBrown , Kent Overstreet , Donald Buczek , linux-bcachefs@vger.kernel.org, Stefan Krueger , linux-fsdevel@vger.kernel.org, Josef Bacik , linux-btrfs@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: <2812078.1702374411.1@warthog.procyon.org.uk> Content-Transfer-Encoding: quoted-printable Date: Tue, 12 Dec 2023 09:46:51 +0000 Message-ID: <2812079.1702374411@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 Christian Brauner wrote: > > There is a upcoming potential problem where even the 64-bit field I pl= aced > > in statx() may be insufficient. The Auristor AFS server, for example,= has > > a 96-bit vnode ID, but I can't properly represent this in stx_ino. > > Currently, I > = > Is that vnode ID akin to a volume? Because if so you could just > piggy-back on a subvolume id field in statx() and expose it there. No. The volume ID is the ID of the volume. The vnode is the equivalent o= f an inode. > > just truncate the value to fit and hope that the discarded part will b= e all > > zero, but that's not really a good thing to do - especially when stx_i= no is > > used programmatically to check for hardlinks. > > = > > Would it be better to add an 'stx_ino_2' field and corresponding flag? > = > Would this be meaningfully different from using a file handle? There's also the matter of presenting the "inode number" to the user - "ls= -i" for example. David