hulk inclusion
category: bugfix
bugzilla: 27600
CVE: NA
---------------------------

dio_bio_complete will set page dirty without consider is there still
buffer_head valid with this page. This will trigger some problem while
ext4 try to writeback this page. For ext4, we fix it by skip writeback
the page without buffer_head.

[1] https://lwn.net/Articles/774411/ : "DMA and get_user_pages()"
[2] https://lwn.net/Articles/753027/ : "The Trouble with get_user_pages()"
[3] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=fc1d8e7cca2daa18Signed-off-by: Nyangerkun <yangerkun@huawei.com>
Reviewed-by: Nzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NXie XiuQi <xiexiuqi@huawei.com>