BugLink: https://bugs.launchpad.net/bugs/1818797

commit 0833721e upstream.

This patch check blkaddr more accuratly before issue a
write or read bio.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
[bwh: Backported to 4.4:
 - CoW is not implemented so check f2fs_io_info::blk_addr instead of
   f2fs_io_info::{old,new}_blkaddr
 - Operation code is f2fs_io_info::rw instead of f2fs_io_info::op
 - Adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>