vhost-net-extend-device-allocation-to-vmalloc.patch

   1 vhost-net: extend device allocation to vmalloc
   2
   3 Backport upstream commit 23cc5a991c7a9fb7e6d6550e65cee4f4173111c5 to
   4 3.10 kernel.
   5 In upstream, this code is modified later in patch
   6 d04257b07f2362d4eb550952d5bf5f4241a8046d, but it's unapplicable in 3.10
   7 because there's still no open-coded kvfree() function (appeared in
   8 v3.15-rc5).
   9
  10 Should fix bug reported in forum
  11 http://forum.proxmox.com/threads/19194-VM-start-problem-with-virtio-net
  12
  13 diff -r -U 3 -p a/drivers/vhost/net.c b/drivers/vhost/net.c
  14 --- a/drivers/vhost/net.c       2014-07-16 22:25:31.000000000 +0400
  15 +++ b/drivers/vhost/net.c       2014-09-04 13:56:20.101952635 +0400
  16 @@ -18,6 +18,7 @@
  17  #include <linux/rcupdate.h>
  18  #include <linux/file.h>
  19  #include <linux/slab.h>
  20 +#include <linux/vmalloc.h>
  21
  22  #include <linux/net.h>
  23  #include <linux/if_packet.h>
  24 @@ -706,18 +707,30 @@ static void handle_rx_net(struct vhost_w
  25         handle_rx(net);
  26  }
  27
  28 +static void vhost_net_free(void *addr)
  29 +{
  30 +   if (is_vmalloc_addr(addr))
  31 +       vfree(addr);
  32 +   else
  33 +       kfree(addr);
  34 +}
  35 +
  36  static int vhost_net_open(struct inode *inode, struct file *f)
  37  {
  38 -       struct vhost_net *n = kmalloc(sizeof *n, GFP_KERNEL);
  39 +       struct vhost_net *n;
  40         struct vhost_dev *dev;
  41         struct vhost_virtqueue **vqs;
  42         int r, i;
  43
  44 -       if (!n)
  45 -               return -ENOMEM;
  46 +    n = kmalloc(sizeof *n, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
  47 +    if (!n) {
  48 +        n = vmalloc(sizeof *n);
  49 +        if (!n)
  50 +            return -ENOMEM;
  51 +   }
  52         vqs = kmalloc(VHOST_NET_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
  53         if (!vqs) {
  54 -               kfree(n);
  55 +               vhost_net_free(n);
  56                 return -ENOMEM;
  57         }
  58
  59 @@ -736,7 +749,7 @@ static int vhost_net_open(struct inode *
  60         }
  61         r = vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX);
  62         if (r < 0) {
  63 -               kfree(n);
  64 +               vhost_net_free(n);
  65                 kfree(vqs);
  66                 return r;
  67         }
  68 @@ -841,7 +854,7 @@ static int vhost_net_release(struct inod
  69          * since jobs can re-queue themselves. */
  70         vhost_net_flush(n);
  71         kfree(n->dev.vqs);
  72 -       kfree(n);
  73 +       vhost_net_free(n);
  74         return 0;
  75  }
  76