From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60321) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VCTDb-0006Qo-48 for qemu-devel@nongnu.org; Thu, 22 Aug 2013 07:38:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VCTDS-0005jO-Lg for qemu-devel@nongnu.org; Thu, 22 Aug 2013 07:38:23 -0400 Received: from mail-ea0-x22e.google.com ([2a00:1450:4013:c01::22e]:43608) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VCTDS-0005jH-F0 for qemu-devel@nongnu.org; Thu, 22 Aug 2013 07:38:14 -0400 Received: by mail-ea0-f174.google.com with SMTP id z15so843851ead.5 for ; Thu, 22 Aug 2013 04:38:13 -0700 (PDT) Date: Thu, 22 Aug 2013 13:38:10 +0200 From: Stefan Hajnoczi Message-ID: <20130822113810.GA27613@stefanha-thinkpad.redhat.com> References: <1376042521-12293-1-git-send-email-famz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1376042521-12293-1-git-send-email-famz@redhat.com> Subject: Re: [Qemu-devel] [PATCH v5 0/8] Implement reference count for BlockDriverState [resend] List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: kwolf@redhat.com, jcody@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, pbonzini@redhat.com, xiawenc@linux.vnet.ibm.com On Fri, Aug 09, 2013 at 06:01:53PM +0800, Fam Zheng wrote: > [resend to the correct list] > > BlockDriverState lifecycle management is needed by future features such as > image fleecing and blockdev-add. This series adds reference count to > BlockDriverState. > > The first two patches clean up two odd BlockDriverState use cases, so all code > uses bdrv_new() to create BlockDriverState instance. > > Then implemented bdrv_ref() and bdrv_unref() to operate on refcnt: Initially, > refcnt is 1, which means bdrv_unref is effectively a bdrv_delete() here. So > patch 04 has a search and replace to convert bdrv_delete to bdrv_unref, before > bdrv_ref is used anywhere. 05~08 patches calls bdrv_ref for device attach, > block-migration and nbd. > > The rule is: Either bdrv_ref() or bdrv_new() must have a matching > bdrv_unref() call, and the last matching bdrv_unref deletes the bs. > > v4: > 08: Added, let block job use BDS reference. > 02: Fix leak of bs.opaque > > v3: > 03: Removed unnecessary bdrv_close() call. > > v2: > 05: Removed: "block: use BlockDriverState refcnt for device attach/detach" > 07: Fix xen_disk blk_disconnect() as it depended on device attach refcnt. Sorry, can't merge this because it breaks qemu-iotests 041 and 055: $ ./check -qcow2 055 041 Please always run qemu-iotests before submitting patches. Stefan