fanotify: don't set FAN_ONDIR implicitly on a marks ignored mask

fanotify: don't set FAN_ONDIR implicitly on a marks ignored mask

Currently FAN_ONDIR is always set on a mark's ignored mask when the
event mask is extended without FAN_MARK_ONDIR being set.  This may
result in events for directories being ignored unexpectedly for call
sequences like

  fanotify_mark(fd, FAN_MARK_ADD, FAN_OPEN | FAN_ONDIR , AT_FDCWD, "dir");
  fanotify_mark(fd, FAN_MARK_ADD, FAN_CLOSE, AT_FDCWD, "dir");

Also FAN_MARK_ONDIR is only honored when adding events to a mark's mask,
but not for event removal.  Fix both issues by not setting FAN_ONDIR
implicitly on the ignore mask any more.  Instead treat FAN_ONDIR as any
other event flag and require FAN_MARK_ONDIR to be set by the user for
both event mask and ignore mask.  Furthermore take FAN_MARK_ONDIR into
account when set for event removal.

[[email protected]: coding-style fixes]
Signed-off-by: Lino Sanfilippo <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Cc: Eric Paris <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>