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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 Received-SPF: pass client-ip=207.211.31.81; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/16 04:55:15 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: 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: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-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 :|