1. 29 11月, 2010 39 次提交
  2. 28 11月, 2010 1 次提交
    • T
      rtnl: make link af-specific updates atomic · cf7afbfe
      Thomas Graf 提交于
      As David pointed out correctly, updates to af-specific attributes
      are currently not atomic. If multiple changes are requested and
      one of them fails, previous updates may have been applied already
      leaving the link behind in a undefined state.
      
      This patch splits the function parse_link_af() into two functions
      validate_link_af() and set_link_at(). validate_link_af() is placed
      to validate_linkmsg() check for errors as early as possible before
      any changes to the link have been made. set_link_af() is called to
      commit the changes later.
      
      This method is not fail proof, while it is currently sufficient
      to make set_link_af() inerrable and thus 100% atomic, the
      validation function method will not be able to detect all error
      scenarios in the future, there will likely always be errors
      depending on states which are f.e. not protected by rtnl_mutex
      and thus may change between validation and setting.
      
      Also, instead of silently ignoring unknown address families and
      config blocks for address families which did not register a set
      function the errors EAFNOSUPPORT respectively EOPNOSUPPORT are
      returned to avoid comitting 4 out of 5 update requests without
      notifying the user.
      Signed-off-by: NThomas Graf <tgraf@infradead.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      cf7afbfe