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 8E01D1C84A0 for ; Fri, 8 Aug 2025 17:25:50 +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=1754673952; cv=none; b=FTsHDUiD2ihrWkQ5C6ZBhTyT5jlT6pp5UjaymzjQ/DN6bvz9sZVWm9HGOMwiLI+uaZEcCWqYbe8NZYV40F/NFLcWbLz4/f4YDTpWa8yv1SLXa6YFOavbAiHuDWwwaptXz3U+8NJ07hzTY+MQJuiBWQEGFQdRyPU1UyE7UfIif2M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754673952; c=relaxed/simple; bh=cKWON+MNVCEnFy9/lmYI3igEZSr+GnOQq6Q+TJmTu14=; h=From:In-Reply-To:References:To:Cc:Subject:MIME-Version: Content-Type:Date:Message-ID; b=H+QRRCKjubnU2+pCG+h3g4PJXo2EPTlaAetSNcnmp6BMg9LzVmIlsG/TOAa32pslBfBjmXu59Nd6kiMsSQP75DvdnMYkOazyv0v7WlC00LpwoPC0znijyjRyYICAZg509DovgbQg2v3V/4BARVhduuuqkMZP6c/t2s2uDyDZb8U= 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=DWjcUnAE; 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="DWjcUnAE" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1754673949; 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=79lZqFsCw1oT9Q6mp5jk4aDocHiI3mHPJRRd8ro+mY8=; b=DWjcUnAEnkximLJOkJjFPWG+X3X6t5wD239XeyaOLhF9KBFtavXyf2lSJcKyGNYxSc7QD+ mhSxlNCb9ACy1Q7XCqF0ZjQ+6xh/VXorq15QhG1Mb+RO5Efx1dBnbagJyZd9Y44zxts9IK QkAVxOAA25Hct1VtiKUknsaGMH6AgUc= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-321-zLjUtnEaP0qG5uCumLZAPQ-1; Fri, 08 Aug 2025 13:25:44 -0400 X-MC-Unique: zLjUtnEaP0qG5uCumLZAPQ-1 X-Mimecast-MFC-AGG-ID: zLjUtnEaP0qG5uCumLZAPQ_1754673942 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (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-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id F0B601800342; Fri, 8 Aug 2025 17:25:41 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.17]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id A68783001455; Fri, 8 Aug 2025 17:25:38 +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: <20250806203705.2560493-1-dhowells@redhat.com> To: Enzo Matsumiya Cc: dhowells@redhat.com, Steve French , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Wang Zhaolong , Stefan Metzmacher , Mina Almasry , linux-cifs@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 00/31] netfs: [WIP] Allow the use of MSG_SPLICE_PAGES and use netmem allocator 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: <2938702.1754673937.1@warthog.procyon.org.uk> Date: Fri, 08 Aug 2025 18:25:37 +0100 Message-ID: <2938703.1754673937@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Hi Enzo, > > (d) Compression should be a matter of vmap()'ing these pages to form > > the source buffer, allocating a second buffer of pages to form a > > dest buffer, also in a bvecq, vmapping that and then doing the > > compression. The first buffer can then just be replaced by the > > second. > > OTOH, compression can't be in-place because SMB2 says that if > compression fails, the original uncompressed request must be sent (i.e. > src must be left untouched until smb_compress() finishes). I've got a change which should achieve this, but it seems I can't test it. None of ksmbd, samba and azure seem to support it:-/ David