From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64F74C433E1 for ; Thu, 16 Jul 2020 13:05:21 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2FF4B2065F for ; Thu, 16 Jul 2020 13:05:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fYZRw1uT" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2FF4B2065F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jw3ZJ-0003tg-Jl; Thu, 16 Jul 2020 13:04:57 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jw3ZJ-0003tb-0q for xen-devel@lists.xenproject.org; Thu, 16 Jul 2020 13:04:57 +0000 X-Inumbo-ID: f1503728-c764-11ea-bca7-bc764e2007e4 Received: from us-smtp-delivery-1.mimecast.com (unknown [207.211.31.81]) by us1-rack-iad1.inumbo.com (Halon) with ESMTP id f1503728-c764-11ea-bca7-bc764e2007e4; Thu, 16 Jul 2020 13:04:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594904694; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=az+FmhN9pIiPX+LZPos7raST+pyWDt55nirXChkVUsk=; b=fYZRw1uTWVebuDFBB7Wgt42/fQ8ZYH6ftBBY4EOrMiDqmKan6D7JJws4OxtDguqM9hgJzd Che/A6edVbJurCconjDuXvK32+BxHiDoYtTYhsaeJrrPhVsAw7M2DJRWAXlWWv4dKCpvjf /vJzXlwL6UHt0+hq0oN29BP7DzxBjUc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-319-wJh8r9ASND-BW_uZ_7uN3Q-1; Thu, 16 Jul 2020 09:04:49 -0400 X-MC-Unique: wJh8r9ASND-BW_uZ_7uN3Q-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9AB15107ACCA; Thu, 16 Jul 2020 13:04:47 +0000 (UTC) Received: from redhat.com (unknown [10.36.110.42]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 99B3D6FEF4; Thu, 16 Jul 2020 13:04:43 +0000 (UTC) Date: Thu, 16 Jul 2020 14:04:40 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Subject: Re: [RFC PATCH-for-5.2 v2 2/2] block/block-backend: Let blk_attach_dev() provide helpful error Message-ID: <20200716130440.GT227735@redhat.com> References: <20200716123704.6557-1-f4bug@amsat.org> <20200716123704.6557-3-f4bug@amsat.org> MIME-Version: 1.0 In-Reply-To: <20200716123704.6557-3-f4bug@amsat.org> User-Agent: Mutt/1.14.5 (2020-06-23) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Disposition: inline X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Fam Zheng , Kevin Wolf , Stefano Stabellini , Eduardo Habkost , qemu-block@nongnu.org, Paul Durrant , Markus Armbruster , qemu-devel@nongnu.org, Paolo Bonzini , Anthony Perard , xen-devel@lists.xenproject.org, Max Reitz , John Snow , Laurent Vivier Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On Thu, Jul 16, 2020 at 02:37:04PM +0200, Philippe Mathieu-Daudé wrote: > Let blk_attach_dev() take an Error* object to return helpful > information. Adapt the callers. > > $ qemu-system-arm -M n800 > qemu-system-arm: sd_init failed: cannot attach blk 'sd0' to device 'sd-card' > blk 'sd0' is already attached by device 'omap2-mmc' > Drive 'sd0' is already in use because it has been automatically connected to another device > (do you need 'if=none' in the drive options?) > > Signed-off-by: Philippe Mathieu-Daudé > --- > v2: Rebased after 668f62ec62 ("error: Eliminate error_propagate()") > --- > include/sysemu/block-backend.h | 2 +- > block/block-backend.c | 11 ++++++++++- > hw/block/fdc.c | 4 +--- > hw/block/swim.c | 4 +--- > hw/block/xen-block.c | 5 +++-- > hw/core/qdev-properties-system.c | 16 +++++++++------- > hw/ide/qdev.c | 4 +--- > hw/scsi/scsi-disk.c | 4 +--- > 8 files changed, 27 insertions(+), 23 deletions(-) > > diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h > index 8203d7f6f9..118fbad0b4 100644 > --- a/include/sysemu/block-backend.h > +++ b/include/sysemu/block-backend.h > @@ -113,7 +113,7 @@ BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk); > void blk_iostatus_disable(BlockBackend *blk); > void blk_iostatus_reset(BlockBackend *blk); > void blk_iostatus_set_err(BlockBackend *blk, int error); > -int blk_attach_dev(BlockBackend *blk, DeviceState *dev); > +int blk_attach_dev(BlockBackend *blk, DeviceState *dev, Error **errp); > void blk_detach_dev(BlockBackend *blk, DeviceState *dev); > DeviceState *blk_get_attached_dev(BlockBackend *blk); > char *blk_get_attached_dev_id(BlockBackend *blk); > diff --git a/block/block-backend.c b/block/block-backend.c > index 63ff940ef9..b7be0a4619 100644 > --- a/block/block-backend.c > +++ b/block/block-backend.c > @@ -884,12 +884,21 @@ void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm) > > /* > * Attach device model @dev to @blk. > + * > + * @blk: Block backend > + * @dev: Device to attach the block backend to > + * @errp: pointer to NULL initialized error object > + * > * Return 0 on success, -EBUSY when a device model is attached already. > */ > -int blk_attach_dev(BlockBackend *blk, DeviceState *dev) > +int blk_attach_dev(BlockBackend *blk, DeviceState *dev, Error **errp) > { > trace_blk_attach_dev(blk_name(blk), object_get_typename(OBJECT(dev))); > if (blk->dev) { > + error_setg(errp, "cannot attach blk '%s' to device '%s'", > + blk_name(blk), object_get_typename(OBJECT(dev))); > + error_append_hint(errp, "blk '%s' is already attached by device '%s'\n", > + blk_name(blk), object_get_typename(OBJECT(blk->dev))); I would have a preference for expanding the main error message and not using a hint. Any hint is completely thrown away when using QMP :-( Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|