From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49315) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WzOFA-0000J3-TQ for qemu-devel@nongnu.org; Tue, 24 Jun 2014 06:46:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WzOF5-00068A-Gh for qemu-devel@nongnu.org; Tue, 24 Jun 2014 06:46:28 -0400 Date: Tue, 24 Jun 2014 12:46:14 +0200 From: Kevin Wolf Message-ID: <20140624104614.GD3458@noname.redhat.com> References: <53A84797.9040304@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <53A84797.9040304@gmail.com> Subject: Re: [Qemu-devel] [PATCH trivial v2] block.c: Add return value for bdrv_append_temp_snapshot() to avoid incorrect failure processing issue List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Chen Gang Cc: famz@redhat.com, qemu-trivial@nongnu.org, Michael Tokarev , qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com Am 23.06.2014 um 17:28 hat Chen Gang geschrieben: > When failure occurs, 'ret' need be set, or may return 0 to indicate success. > And error_propagate() also need be called only one time within a function. > > It is abnormal to prevent bdrv_append_temp_snapshot() return value but still > set errp when error occurs -- although it contents return value internally. > > So let bdrv_append_temp_snapshot() internal return value outside, and let > all things normal, then fix the issue too. > > Signed-off-by: Chen Gang What does this fix? Having both a return value and an Error* object is duplication and only a sign that a function hasn't been fully converted to the Error framework yet. We shouldn't introduce new instances of this without a very good reason. Kevin