src/patches/suse-2.6.27.39/patches.xen/764-netback-foreign-pages.patch

   1 From: http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/618fc299e2f1
   2 # HG changeset 764 patch
   3 # User Keir Fraser <keir.fraser@citrix.com>
   4 # Date 1229601096 0
   5 # Node ID 618fc299e2f1e222686bc234c48ac70e1104e18d
   6 # Parent  ff9683032b76f533509191bb9532df10cbb9830b
   7 Subject: netback: handle non-netback foreign pages
   8 Patch-mainline: obsolete
   9
  10 An SKB can contain pages which are foreign but not tracked by netback,
  11 such as those created by gnttab_copy_grant_page when in
  12 NETBK_DELAYED_COPY_SKB mode. These pages do not have a mapping field
  13 which points to a valid offset in the pending_tx_info array.
  14
  15 Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
  16 Acked-by: jbeulich@novell.com
  17
  18 --- head-2008-12-23.orig/drivers/xen/netback/netback.c  2008-12-01 11:25:57.000000000 +0100
  19 +++ head-2008-12-23/drivers/xen/netback/netback.c       2008-12-23 09:31:07.000000000 +0100
  20 @@ -40,9 +40,6 @@
  21
  22  /*define NETBE_DEBUG_INTERRUPT*/
  23
  24 -/* extra field used in struct page */
  25 -#define netif_page_index(pg) (*(long *)&(pg)->mapping)
  26 -
  27  struct netbk_rx_meta {
  28         skb_frag_t frag;
  29         int id;
  30 @@ -89,6 +86,25 @@ static inline unsigned long idx_to_kaddr
  31         return (unsigned long)pfn_to_kaddr(idx_to_pfn(idx));
  32  }
  33
  34 +/* extra field used in struct page */
  35 +static inline void netif_set_page_index(struct page *pg, unsigned int index)
  36 +{
  37 +       *(unsigned long *)&pg->mapping = index;
  38 +}
  39 +
  40 +static inline int netif_page_index(struct page *pg)
  41 +{
  42 +       unsigned long idx = (unsigned long)pg->mapping;
  43 +
  44 +       if (!PageForeign(pg))
  45 +               return -1;
  46 +
  47 +       if ((idx >= MAX_PENDING_REQS) || (mmap_pages[idx] != pg))
  48 +               return -1;
  49 +
  50 +       return idx;
  51 +}
  52 +
  53  #define PKT_PROT_LEN 64
  54
  55  static struct pending_tx_info {
  56 @@ -370,6 +386,7 @@ static u16 netbk_gop_frag(netif_t *netif
  57         multicall_entry_t *mcl;
  58         netif_rx_request_t *req;
  59         unsigned long old_mfn, new_mfn;
  60 +       int idx = netif_page_index(page);
  61
  62         old_mfn = virt_to_mfn(page_address(page));
  63
  64 @@ -380,9 +397,8 @@ static u16 netbk_gop_frag(netif_t *netif
  65                 meta->copy = 1;
  66                 copy_gop = npo->copy + npo->copy_prod++;
  67                 copy_gop->flags = GNTCOPY_dest_gref;
  68 -               if (PageForeign(page)) {
  69 -                       struct pending_tx_info *src_pend =
  70 -                               &pending_tx_info[netif_page_index(page)];
  71 +               if (idx > -1) {
  72 +                       struct pending_tx_info *src_pend = &pending_tx_info[idx];
  73                         copy_gop->source.domid = src_pend->netif->domid;
  74                         copy_gop->source.u.ref = src_pend->req.gref;
  75                         copy_gop->flags |= GNTCOPY_source_gref;
  76 @@ -1437,8 +1453,10 @@ static void netif_idx_release(u16 pendin
  77
  78  static void netif_page_release(struct page *page, unsigned int order)
  79  {
  80 +       int idx = netif_page_index(page);
  81         BUG_ON(order);
  82 -       netif_idx_release(netif_page_index(page));
  83 +       BUG_ON(idx < 0);
  84 +       netif_idx_release(idx);
  85  }
  86
  87  irqreturn_t netif_be_int(int irq, void *dev_id, struct pt_regs *regs)
  88 @@ -1572,7 +1590,7 @@ static int __init netback_init(void)
  89         for (i = 0; i < MAX_PENDING_REQS; i++) {
  90                 page = mmap_pages[i];
  91                 SetPageForeign(page, netif_page_release);
  92 -               netif_page_index(page) = i;
  93 +               netif_set_page_index(page, i);
  94                 INIT_LIST_HEAD(&pending_inuse[i].list);
  95         }
  96