[PATCH]netfront: need release all resources after adding and removing NICs time and again

[roger.pau at citrix.com]

On Fri, Nov 04, 2016 at 07:43:41AM +0000, Liuyingdong wrote:
> On xen,freebsd 10.2 virtual machines hang after adding and removing NICs time and again(more than 30 times).
> I found error log is as follows:
> "netfront can't alloc tx grant refs"

Hello,

Thanks for the patch, although I'm not able to import it, git complain with:

patch: **** malformed patch at line 7: }

Could you please resend it using git send-email?

I also have a couple of comments below regarding style.

> 
> Signed-off-by: Liudong Liu<Liuyingdong at huawei.com>
> 
> diff --git a/dev/xen/netfront/netfront.c b/dev/xen/netfront/netfront.c
> index 5497139..e96bbba 100644
> --- a/dev/xen/netfront/netfront.c
> +++ b/dev/xen/netfront/netfront.c
> @@ -790,6 +790,44 @@ netif_release_tx_bufs(struct netfront_info *np)
>        }
> }

Missing new line.

> +static void
netif_release_rx_bufs_copy(struct netfront_info *np)

This needs to be on a new line.

> +{
> +       struct mbuf *m;
> +       int i, ref;
> +       int busy = 0, inuse = 0;
> +
> +       XN_RX_LOCK(np);
> +
> +       for (i = 0; i < NET_RX_RING_SIZE; i++) {
> +                ref = np->grant_rx_ref[i];
> +
> +                if (ref == GRANT_REF_INVALID)
> +                          continue;
> +
> +                inuse++;
> +
> +                m = np->rx_mbufs[i];
> +
> +                if (!gnttab_end_foreign_access_ref(ref))
> +                {
> +                          busy++;
> +                          continue;
> +                }
> +
> +                gnttab_release_grant_reference(&np->gref_rx_head, ref);
> +                np->grant_rx_ref[i] = GRANT_REF_INVALID;
> +                add_id_to_freelist(np->rx_mbufs, i);
> +
> +                m_freem(m);
> +       }
> +
> +       if (busy)
> +                DPRINTK("%s: Unable to release %d of %d inuse grant references out of %ld total.\n",
> +                          __FUNCTION__, busy, inuse, NET_RX_RING_SIZE);

Please use device_printf for this instead of the function name. Also, could 
you align the string so it doesn't extend past 80 characters?

Roger.