From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 54022172795; Tue, 11 Jun 2024 07:30:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718091046; cv=none; b=T0Kt9a7Kz9LJablClmHOQ7Fnl/BJlON3U5ysAbikS0KejBOwIqSa0XFZqHUOAr3IRTFqnUtuiiuHoiCyOsG0emo5OtiORv4DME9SOFHQzV/JNnvJ9/yxfEUdJty59zkOn2TpXAdMo1oxQ5GcLxSPuuPrkHgnkbEUES4dXq5JX5Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718091046; c=relaxed/simple; bh=mXwlDhzGw5x2p2Nr8gAFPISP2nDIAfZIJOaFJyvJXOI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=QvMlz1qoL0/mE667j99aP850Mfaz7WKBIa5XQ/7dkrMfYAXJKm5YKz9f+EkZ/kUvDEpVQbyEuR8WC62q0y8I1TD/5cl+DY4HMiiDqY0j4zKeKYHtJ41YEqBtaNMlplzxknt3FAnNLl8rWamWg9NKSVuTeTMP4HgguUdCJc+yR24= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VCI1eDgX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VCI1eDgX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEC6CC2BD10; Tue, 11 Jun 2024 07:30:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718091045; bh=mXwlDhzGw5x2p2Nr8gAFPISP2nDIAfZIJOaFJyvJXOI=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=VCI1eDgXTsePnpt155uEye/3wYDicIPNZJ3+S2Hq2BKZNkLNvV5I0fT+JdCzdUnSb yuXJ7xiSHP9TiSA6PVPXt+qO9Dn4e1NQaWtG0WZKRDKr7qk2obBVABl9+DPiAto15R ZY06Qeaqugg7VSWPCcJ0qkt9/u4FV8hF/W3PG2hU6Xg27Ev50hNdLuTn4EcUBYyJ8n S+KRGHhRfCxLhpogZoDRTutfmrs5hXd1HvW8FhrlCCZSHQ5haYJkZbrzON8/BzrfEH kcYMtKu/xYq8uguhHsXhgHJwfT/OivpjDtyI/mVqW6dF9WSlmB2m2KaCIH1Th4AQTt 8udJurnL3fqPA== Message-ID: Date: Tue, 11 Jun 2024 16:30:39 +0900 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 10/26] xen-blkfront: don't disable cache flushes when they fail To: Christoph Hellwig , Jens Axboe Cc: Geert Uytterhoeven , Richard Weinberger , Philipp Reisner , Lars Ellenberg , =?UTF-8?Q?Christoph_B=C3=B6hmwalder?= , Josef Bacik , Ming Lei , "Michael S. Tsirkin" , Jason Wang , =?UTF-8?Q?Roger_Pau_Monn=C3=A9?= , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Song Liu , Yu Kuai , Vineeth Vijayan , "Martin K. Petersen" , linux-m68k@lists.linux-m68k.org, linux-um@lists.infradead.org, drbd-dev@lists.linbit.com, nbd@other.debian.org, linuxppc-dev@lists.ozlabs.org, ceph-devel@vger.kernel.org, virtualization@lists.linux.dev, xen-devel@lists.xenproject.org, linux-bcache@vger.kernel.org, dm-devel@lists.linux.dev, linux-raid@vger.kernel.org, linux-mmc@vger.kernel.org, linux-mtd@lists.infradead.org, nvdimm@lists.linux.dev, linux-nvme@lists.infradead.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-block@vger.kernel.org References: <20240611051929.513387-1-hch@lst.de> <20240611051929.513387-11-hch@lst.de> Content-Language: en-US From: Damien Le Moal Organization: Western Digital Research In-Reply-To: <20240611051929.513387-11-hch@lst.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/11/24 2:19 PM, Christoph Hellwig wrote: > blkfront always had a robust negotiation protocol for detecting a write > cache. Stop simply disabling cache flushes when they fail as that is > a grave error. > > Signed-off-by: Christoph Hellwig Looks good to me but maybe mention that removal of xlvbd_flush() as well ? And it feels like the "stop disabling cache flushes when they fail" part should be a fix patch sent separately... Anyway, for both parts, feel free to add: Reviewed-by: Damien Le Moal > --- > drivers/block/xen-blkfront.c | 29 +++++++++-------------------- > 1 file changed, 9 insertions(+), 20 deletions(-) > > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c > index 9b4ec3e4908cce..9794ac2d3299d1 100644 > --- a/drivers/block/xen-blkfront.c > +++ b/drivers/block/xen-blkfront.c > @@ -982,18 +982,6 @@ static const char *flush_info(struct blkfront_info *info) > return "barrier or flush: disabled;"; > } > > -static void xlvbd_flush(struct blkfront_info *info) > -{ > - blk_queue_write_cache(info->rq, info->feature_flush ? true : false, > - info->feature_fua ? true : false); > - pr_info("blkfront: %s: %s %s %s %s %s %s %s\n", > - info->gd->disk_name, flush_info(info), > - "persistent grants:", info->feature_persistent ? > - "enabled;" : "disabled;", "indirect descriptors:", > - info->max_indirect_segments ? "enabled;" : "disabled;", > - "bounce buffer:", info->bounce ? "enabled" : "disabled;"); > -} > - > static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset) > { > int major; > @@ -1162,7 +1150,15 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity, > info->sector_size = sector_size; > info->physical_sector_size = physical_sector_size; > > - xlvbd_flush(info); > + blk_queue_write_cache(info->rq, info->feature_flush ? true : false, > + info->feature_fua ? true : false); > + > + pr_info("blkfront: %s: %s %s %s %s %s %s %s\n", > + info->gd->disk_name, flush_info(info), > + "persistent grants:", info->feature_persistent ? > + "enabled;" : "disabled;", "indirect descriptors:", > + info->max_indirect_segments ? "enabled;" : "disabled;", > + "bounce buffer:", info->bounce ? "enabled" : "disabled;"); > > if (info->vdisk_info & VDISK_READONLY) > set_disk_ro(gd, 1); > @@ -1622,13 +1618,6 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id) > info->gd->disk_name, op_name(bret.operation)); > blkif_req(req)->error = BLK_STS_NOTSUPP; > } > - if (unlikely(blkif_req(req)->error)) { > - if (blkif_req(req)->error == BLK_STS_NOTSUPP) > - blkif_req(req)->error = BLK_STS_OK; > - info->feature_fua = 0; > - info->feature_flush = 0; > - xlvbd_flush(info); > - } > fallthrough; > case BLKIF_OP_READ: > case BLKIF_OP_WRITE: -- Damien Le Moal Western Digital Research