From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40770) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fM2Hk-0006Dj-J3 for qemu-devel@nongnu.org; Thu, 24 May 2018 22:16:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fM2Hj-0001NV-Ey for qemu-devel@nongnu.org; Thu, 24 May 2018 22:16:52 -0400 Date: Fri, 25 May 2018 10:16:41 +0800 From: Fam Zheng Message-ID: <20180525021641.GD12594@lemon.usersys.redhat.com> References: <20180521063516.5479-1-famz@redhat.com> <677208b5-586b-354a-5fd4-67468152510e@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <677208b5-586b-354a-5fd4-67468152510e@redhat.com> Subject: Re: [Qemu-devel] [PATCH] nvme: Make nvme_init error handling code more readable List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: qemu-devel@nongnu.org, Kevin Wolf , Max Reitz , qemu-block@nongnu.org On Thu, 05/24 19:16, Paolo Bonzini wrote: > On 21/05/2018 08:35, Fam Zheng wrote: > > Coverity doesn't like the tests under fail label (report CID 1385847). > > Reset the fields so the clean up order is more apparent. > > > > Signed-off-by: Fam Zheng > > --- > > block/nvme.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/block/nvme.c b/block/nvme.c > > index 6f71122bf5..8239b920c8 100644 > > --- a/block/nvme.c > > +++ b/block/nvme.c > > @@ -560,6 +560,13 @@ static int nvme_init(BlockDriverState *bs, const char *device, int namespace, > > qemu_co_queue_init(&s->dma_flush_queue); > > s->nsid = namespace; > > s->aio_context = bdrv_get_aio_context(bs); > > + > > + /* Fields we've not touched should be zero-initialized by block layer > > + * already, but reset them anyway to make the error handling code easier to > > + * reason. */ > > + s->regs = NULL; > > + s->vfio = NULL; > > + > > ret = event_notifier_init(&s->irq_notifier, 0); > > if (ret) { > > error_setg(errp, "Failed to init event notifier"); > > > > I think we should just mark it as a false positive or do something like > > fail_regs: > qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)s->regs, 0, NVME_BAR_SIZE); > fail_vfio: > qemu_vfio_close(s->vfio); > fail: > g_free(s->queues); > event_notifier_cleanup(&s->irq_notifier); > return ret; > > even though it's a larger patch. And that makes five labels in total, I'm not sure I like it: fail_handler: aio_set_event_notifier(bdrv_get_aio_context(bs), &s->irq_notifier, false, NULL, NULL); fail_queue: nvme_free_queue_pair(bs, s->queues[0]); fail_regs: qemu_vfio_pci_unmap_bar(s->vfio, 0, (void *)s->regs, 0, NVME_BAR_SIZE); fail_vfio: qemu_vfio_close(s->vfio); fail: g_free(s->queues); event_notifier_cleanup(&s->irq_notifier); return ret; Maybe we just mark it as false positive then? Fam