| Message ID | 1444932148-15633-1-git-send-email-wuninsu@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, Oct 15, 2015 at 02:02:47PM -0400, Insu Yun wrote: > I changed patch with valid format. > > On Thu, Oct 15, 2015 at 2:02 PM, Insu Yun <wuninsu@gmail.com> wrote: > > > Since vzalloc can be failed in memory pressure, > > writes -ENOMEM to xenstore to indicate error. > > > > Signed-off-by: Insu Yun <wuninsu@gmail.com> > > --- > > drivers/net/xen-netback/xenbus.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/drivers/net/xen-netback/xenbus.c > > b/drivers/net/xen-netback/xenbus.c > > index 929a6e7..56ebd82 100644 > > --- a/drivers/net/xen-netback/xenbus.c > > +++ b/drivers/net/xen-netback/xenbus.c > > @@ -788,6 +788,12 @@ static void connect(struct backend_info *be) > > /* Use the number of queues requested by the frontend */ > > be->vif->queues = vzalloc(requested_num_queues * > > sizeof(struct xenvif_queue)); > > + if (!be->vif->queues) { > > + xenbus_dev_fatal(dev, -ENOMEM, > > + "allocating queues"); > > + return; > > > > I didn't use goto err, because another error handling is not required > It's recommended in kernel coding style to use "goto" style error handling. I personally prefer that to arbitrary return in function body, too. It's not a matter of whether another error handling is required or not, it's about cleaner code that is easy to reason about and consistent coding style. The existing code is not perfect, but that doesn't mean we should follow bad example. Wei. > > > + } > > + > > be->vif->num_queues = requested_num_queues; > > be->vif->stalled_queues = requested_num_queues; > > > > -- > > 1.9.1 > > > > > > > -- > Regards > Insu Yun -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Oct 16, 2015 at 10:05:21AM +0100, Wei Liu wrote: > On Thu, Oct 15, 2015 at 02:02:47PM -0400, Insu Yun wrote: > > I changed patch with valid format. > > > > On Thu, Oct 15, 2015 at 2:02 PM, Insu Yun <wuninsu@gmail.com> wrote: > > > > > Since vzalloc can be failed in memory pressure, > > > writes -ENOMEM to xenstore to indicate error. > > > > > > Signed-off-by: Insu Yun <wuninsu@gmail.com> > > > --- > > > drivers/net/xen-netback/xenbus.c | 6 ++++++ > > > 1 file changed, 6 insertions(+) > > > > > > diff --git a/drivers/net/xen-netback/xenbus.c > > > b/drivers/net/xen-netback/xenbus.c > > > index 929a6e7..56ebd82 100644 > > > --- a/drivers/net/xen-netback/xenbus.c > > > +++ b/drivers/net/xen-netback/xenbus.c > > > @@ -788,6 +788,12 @@ static void connect(struct backend_info *be) > > > /* Use the number of queues requested by the frontend */ > > > be->vif->queues = vzalloc(requested_num_queues * > > > sizeof(struct xenvif_queue)); > > > + if (!be->vif->queues) { > > > + xenbus_dev_fatal(dev, -ENOMEM, > > > + "allocating queues"); > > > + return; > > > > > > > I didn't use goto err, because another error handling is not required > > > > It's recommended in kernel coding style to use "goto" style error > handling. I personally prefer that to arbitrary return in function body, > too. > > It's not a matter of whether another error handling is required or not, > it's about cleaner code that is easy to reason about and consistent > coding style. > > The existing code is not perfect, but that doesn't mean we should follow > bad example. And to be clear, I don't want to block this patch just because of this coding style thing. It's still an improvement and fix a real problem. So: Acked-by: Wei Liu <wei.liu2@citrix.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 16/10/15 10:05, Wei Liu wrote: > On Thu, Oct 15, 2015 at 02:02:47PM -0400, Insu Yun wrote: >> I changed patch with valid format. >> >> On Thu, Oct 15, 2015 at 2:02 PM, Insu Yun <wuninsu@gmail.com> wrote: >> >>> Since vzalloc can be failed in memory pressure, >>> writes -ENOMEM to xenstore to indicate error. >>> >>> Signed-off-by: Insu Yun <wuninsu@gmail.com> >>> --- >>> drivers/net/xen-netback/xenbus.c | 6 ++++++ >>> 1 file changed, 6 insertions(+) >>> >>> diff --git a/drivers/net/xen-netback/xenbus.c >>> b/drivers/net/xen-netback/xenbus.c >>> index 929a6e7..56ebd82 100644 >>> --- a/drivers/net/xen-netback/xenbus.c >>> +++ b/drivers/net/xen-netback/xenbus.c >>> @@ -788,6 +788,12 @@ static void connect(struct backend_info *be) >>> /* Use the number of queues requested by the frontend */ >>> be->vif->queues = vzalloc(requested_num_queues * >>> sizeof(struct xenvif_queue)); >>> + if (!be->vif->queues) { >>> + xenbus_dev_fatal(dev, -ENOMEM, >>> + "allocating queues"); >>> + return; >>> >> >> I didn't use goto err, because another error handling is not required >> > > It's recommended in kernel coding style to use "goto" style error > handling. I personally prefer that to arbitrary return in function body, > too. > > It's not a matter of whether another error handling is required or not, > it's about cleaner code that is easy to reason about and consistent > coding style. Using xenbus_dev_fatal(); return; throughout would be consistent and easy to reason about. Also, the goto err path should raise a fatal error (instead of disconnecting). I also note that failures in the xen_net_read_rate(), xen_register_watchers() and read_xenbus_vif_flags() are also not handled. David -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Insu Yun <wuninsu@gmail.com> Date: Thu, 15 Oct 2015 18:02:28 +0000 > Since vzalloc can be failed in memory pressure, > writes -ENOMEM to xenstore to indicate error. > > Signed-off-by: Insu Yun <wuninsu@gmail.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 929a6e7..56ebd82 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -788,6 +788,12 @@ static void connect(struct backend_info *be) /* Use the number of queues requested by the frontend */ be->vif->queues = vzalloc(requested_num_queues * sizeof(struct xenvif_queue)); + if (!be->vif->queues) { + xenbus_dev_fatal(dev, -ENOMEM, + "allocating queues"); + return; + } + be->vif->num_queues = requested_num_queues; be->vif->stalled_queues = requested_num_queues;
Since vzalloc can be failed in memory pressure, writes -ENOMEM to xenstore to indicate error. Signed-off-by: Insu Yun <wuninsu@gmail.com> --- drivers/net/xen-netback/xenbus.c | 6 ++++++ 1 file changed, 6 insertions(+)