[git pull] skb_copy_{,and_csum_}datagram_msg() fixes

[Al Viro]

        Fixes rsync et.al. regression since 3.19...

The following changes since commit c02ed2e75ef4c74e41e421acb4ef1494671585e8:

  Linux 4.11-rc4 (2017-03-26 14:15:16 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git for-davem

for you to fetch changes up to 3278682123811dd8ef07de5eb701fc4548fcebf2:

  make skb_copy_datagram_msg() et.al. preserve ->msg_iter on error (2017-04-02 
12:10:57 -0400)

----------------------------------------------------------------
Al Viro (2):
      [iov_iter] new privimitive: iov_iter_revert()
      make skb_copy_datagram_msg() et.al. preserve ->msg_iter on error

 include/linux/uio.h |  6 ++++-
 lib/iov_iter.c      | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 net/core/datagram.c | 23 +++++++++++--------
 3 files changed, 82 insertions(+), 10 deletions(-)