batman-adv/patches/0002-batman-adv-Unmap-fragment-page-once-iterator-is-done.patch

   1 From 0d941e82ab5f92faf33bee6abdde519056f3ac2d Mon Sep 17 00:00:00 2001
   2 From: Simon Wunderlich <simon.wunderlich@s2003.tu-chemnitz.de>
   3 Date: Wed, 26 Jun 2013 11:37:51 +0200
   4 Subject: [PATCH 2/4] batman-adv: Unmap fragment page once iterator is done
   5
   6 Callers of skb_seq_read() are currently forced to call skb_abort_seq_read()
   7 even when consuming all the data because the last call to skb_seq_read (the
   8 one that returns 0 to indicate the end) fails to unmap the last fragment page.
   9
  10 With this patch callers will be allowed to traverse the SKB data by calling
  11 skb_prepare_seq_read() once and repeatedly calling skb_seq_read() as originally
  12 intended (and documented in the original commit 677e90eda), that is, only call
  13 skb_abort_seq_read() if the sequential read is actually aborted.
  14
  15 Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
  16 Signed-off-by: David S. Miller <davem@davemloft.net>
  17 Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
  18 Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
  19 ---
  20  compat.h | 8 ++++++++
  21  main.c   | 1 -
  22  2 files changed, 8 insertions(+), 1 deletion(-)
  23
  24 diff --git a/compat.h b/compat.h
  25 index 17ef089..346a824 100644
  26 --- a/compat.h
  27 +++ b/compat.h
  28 @@ -306,6 +306,14 @@ static int __batadv_interface_set_mac_addr(x, y)
  29
  30  #define netdev_notifier_info_to_dev(ptr) ptr
  31
  32 +/* older kernels still need to call skb_abort_seq_read() */
  33 +#define skb_seq_read(consumed, data, st) \
  34 +       ({ \
  35 +               int len = skb_seq_read(consumed, data, st); \
  36 +               if (len == 0) \
  37 +                       skb_abort_seq_read(st); \
  38 +               len; \
  39 +       })
  40  #endif /* < KERNEL_VERSION(3, 11, 0) */
  41
  42  #endif /* _NET_BATMAN_ADV_COMPAT_H_ */
  43 diff --git a/main.c b/main.c
  44 index 51aafd6..08125f3 100644
  45 --- a/main.c
  46 +++ b/main.c
  47 @@ -473,7 +473,6 @@ __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
  48                 crc = crc32c(crc, data, len);
  49                 consumed += len;
  50         }
  51 -       skb_abort_seq_read(&st);
  52
  53         return htonl(crc);
  54  }
  55 --
  56 1.8.4.rc3
  57