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="dQ4i/4To" 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 0517DCD for ; Mon, 11 Dec 2023 15:40:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702338022; 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=obt9erShmifbxfTVwB/4/79H5BqitQ1XmDr9oZuepQo=; b=dQ4i/4ToEx6h1PlgjpuEKI6YSaSy3zd/esyPmm89oWtLvyEuB+dvDjMeIfdkcz8hbfyrGe cUMZoERQGhNeS9FGW+2N0GZHwlo5KZCppcnjHNyea+ltibycz4C+FILgbf8jNuEKJaXRq7 cGGC75Qhsl6hM69NLZQSa9GrsEIImLM= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-391-QWupS-0EPHKHCPioHCt1xw-1; Mon, 11 Dec 2023 18:40:18 -0500 X-MC-Unique: QWupS-0EPHKHCPioHCt1xw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (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 6BFFA3C36AE6; Mon, 11 Dec 2023 23:40:18 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2A50F2166B32; Mon, 11 Dec 2023 23:40:17 +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: <20231211233231.oiazgkqs7yahruuw@moria.home.lan> References: <20231211233231.oiazgkqs7yahruuw@moria.home.lan> <12f711f9-70a2-408e-8588-2839e599b668@molgen.mpg.de> <170181366042.7109.5045075782421670339@noble.neil.brown.name> <97375d00-4bf7-4c4f-96ec-47f4078abb3d@molgen.mpg.de> <170199821328.12910.289120389882559143@noble.neil.brown.name> <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> To: Kent Overstreet Cc: dhowells@redhat.com, NeilBrown , 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: <2799306.1702338016.1@warthog.procyon.org.uk> Date: Mon, 11 Dec 2023 23:40:16 +0000 Message-ID: <2799307.1702338016@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.6 Kent Overstreet wrote: > I was chatting a bit with David Howells on IRC about this, and floated > adding the file handle to statx. It looks like there's enough space > reserved to make this feasible - probably going with a fixed maximum > size of 128-256 bits. We can always save the last bit to indicate extension space/extension record, so we're not that strapped for space. David