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 762E32BEC41 for ; Tue, 13 May 2025 16:30:01 +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=1747153803; cv=none; b=Cn+b7/gHIJweFQ3al/8Cfg2/5rfGTvJ7aWCEsJw965DtC4JwOUOdOyqALibPLm8NkjXDbrG08u8zbs58RFWCCnRiG2XMBwQlQRwn1BVrK3JotQoaatf78zyROjA4s7GYJR5FlgmxofMM1slyTHAzmbgpgmTygs0lR5Lo9YdR48M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747153803; c=relaxed/simple; bh=Jy2ZClgn9VEZaW82iC3qPWb7i5tVsDKsNOqhIwl2Ywk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qNVi6g7LQzZdewEFyt2tYyR0ooJAJnr/yWmZuZ1oqRtgz9mg2WOjaEYUphdoULy4T4XBA6t2ykBcY04nQDeK80oV/+wDUBbd3rt3O2iOdu6qnzkqQw/3kotTOUuqsH6TZpi+3CV+Ue0eNSZNbf+9W0HutrlpYcRtMB5grDz+1ek= 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=VJ//vUwr; 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="VJ//vUwr" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1747153800; 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=hcoqX5R2MqgY9J6AEcj0986EY9xMkUtFOKieofckVl0=; b=VJ//vUwruMuAi6iPhNqABCBrIOMt8DNmZxeAo+sponcy9bs5C867v6jmA4MqZ3SQX4HZes GdKWXAQVAN5zc6J0ypLLdBM6JCGPYgAaoLwkf40JsKLOMkLuv79LNdN2dslmJnSutcufQA M/XQxN8Text34gLvdxF/SFa6WfJxB5U= Received: from mx-prod-mc-02.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-635-laBsb9sjMnaB-jyEDSvZkA-1; Tue, 13 May 2025 12:29:57 -0400 X-MC-Unique: laBsb9sjMnaB-jyEDSvZkA-1 X-Mimecast-MFC-AGG-ID: laBsb9sjMnaB-jyEDSvZkA_1747153795 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (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-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 77F7D1956087; Tue, 13 May 2025 16:29:55 +0000 (UTC) Received: from bmarzins-01.fast.eng.rdu2.dc.redhat.com (unknown [10.6.23.247]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id EBBAA19560A3; Tue, 13 May 2025 16:29:54 +0000 (UTC) Received: from bmarzins-01.fast.eng.rdu2.dc.redhat.com (localhost [127.0.0.1]) by bmarzins-01.fast.eng.rdu2.dc.redhat.com (8.18.1/8.17.1) with ESMTPS id 54DGTrpd3643051 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 13 May 2025 12:29:53 -0400 Received: (from bmarzins@localhost) by bmarzins-01.fast.eng.rdu2.dc.redhat.com (8.18.1/8.18.1/Submit) id 54DGTpwa3643050; Tue, 13 May 2025 12:29:51 -0400 Date: Tue, 13 May 2025 12:29:51 -0400 From: Benjamin Marzinski To: Christoph Hellwig Cc: Hannes Reinecke , Kevin Wolf , Martin Wilck , dm-devel@lists.linux.dev, hreitz@redhat.com, mpatocka@redhat.com, snitzer@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] dm mpath: Interface for explicit probing of active paths Message-ID: References: <20250429165018.112999-1-kwolf@redhat.com> <47dd225b433b0df585a25084a2e793344eeda239.camel@suse.com> <0340c51e-6f89-4799-b2f1-19c785a19ff2@suse.de> 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-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 On Mon, May 12, 2025 at 11:49:19PM -0700, Christoph Hellwig wrote: > On Tue, May 13, 2025 at 08:32:12AM +0200, Hannes Reinecke wrote: > > Reservations and stuff. > > They should use the kernel persistent reservation API. Currently QEMU isn't sending Persistent Reservation requests to multipath devices at all. It's sending those directly to the underlying scsi devices. The issue here is with all the other SCSI commands that users want to send to their SCSI passthrough device that is actually a multipath device on top of a number of SCSI paths. They expect to get back the actual sense and status information, so QEMU needs to send them via SG_IOs. Without reading that sense and status information in kernel, the multipath target can't know if it needs to fail a path and retry the ioctl down a different path. QEMU can read this information, but it doesn't know what path the multipath device send the ioctl down. This patch just gives users a way to check the paths in the active pathgroup (which all should be able to handle IO) and fail those that can't. While QEMU is the driver of this, it's completely general functionality. -Ben > > > There are customer who use GPFS ... > > Supporting illegal binary only modules that is already enough of a > reason to NAK this.