From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 814C53E16B9 for ; Mon, 13 Jul 2026 09:29:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783934957; cv=none; b=RK0/G6FgFmheIaz5EMWg7nwHbq2ftFtPPc8r4YP3cp42G/klE0AY+2Bnz+o6IKgCHz6Qiv+tITqYIqJqkW5m+XtvwOC5uOo6pLG1qeXfAlZtslyhZvj+csHjZFQBSYE3jxRWjnAjaztp1Xnqq54ktVGk+y73maHR32Ish9Otcfs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783934957; c=relaxed/simple; bh=0nA11BXnZhy6beyXpGTVp/GXCqhu2s5d2WRd/Cwo5Ng=; h=From:In-Reply-To:References:To:Cc:Subject:MIME-Version: Content-Type:Date:Message-ID; b=qxmP+oMv0cmFVtJj9mmc7dAH5buN0oSJ/t4koVJvQGO+EoZHXVni0+Itc+pt5RguxRJZ5qgDQZrGTJwqpz3zkTAev5/L7o9M6J0LEVbOJq4U6ch+6sK/TpcNA8U6gEzgVmyB3Iqe6paDGMp+YnQObDBxZ0bd4v/YCOKt3BXjrGg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=GN3RInUZ; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GN3RInUZ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1783934952; 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=2PxznJxxcUHJSFe/GCh1hYyXPLmFNfjYwV+riV2lLZg=; b=GN3RInUZabOnPl3JAU9I9E9FPn8igOUBeckA3pILudnic8Y5TAFp0NHjxVdPOs9fmiw8am XRk9zfW46XGEnMU+cfED7jjrC4DYPVqai1nLMFntIEtrcGg30WRWIgbrfe2n/h2vW236PT TiCQjQtoLAGa83fXK5V3fe8HN6YPLPs= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-493-5eqAlzAFMpOB6iUZCkVQuQ-1; Mon, 13 Jul 2026 05:29:09 -0400 X-MC-Unique: 5eqAlzAFMpOB6iUZCkVQuQ-1 X-Mimecast-MFC-AGG-ID: 5eqAlzAFMpOB6iUZCkVQuQ_1783934947 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (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 mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CD42E1955DD1; Mon, 13 Jul 2026 09:29:06 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.44.33.159]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id D3144195604B; Mon, 13 Jul 2026 09:29:03 +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: <20260702090941.1298188-1-brho@google.com> To: Dominique Martinet Cc: dhowells@redhat.com, Barret Rhoden , Eric Van Hensbergen , Latchesar Ionkov , Christian Schoenebeck , v9fs@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] 9p: treat read return values of 0 as EOF Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <2237819.1783934942.1@warthog.procyon.org.uk> Date: Mon, 13 Jul 2026 10:29:02 +0100 Message-ID: <2237820.1783934942@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 This is kind of a weird situation. We're caching locally the content of files aren't really regular files and probably shouldn't be cached. I'm not sure what the best way to deal with that is. I wonder if there's some way to detect that and mark then non-cacheable. (Assuming the server can be told not to even serve them). Can we detect that the EOF length doesn't match i_size and set a flag to say "don't cache" in netfs_inode::flags? David