4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
commit 899f0429c7d3eed886406cd72182bee3b96aa1f9 upstream.
In the code added to function submit_page_section by commit b1058b981,
sdio->bio can currently be NULL when calling dio_bio_submit. This then
leads to a NULL pointer access in dio_bio_submit, so check for a NULL
bio in submit_page_section before trying to submit it instead.
Fixes xfstest generic/250 on gfs2.
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/direct-io.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -823,7 +823,8 @@ out:
*/
if (sdio->boundary) {
ret = dio_send_cur_page(dio, sdio, map_bh);
- dio_bio_submit(dio, sdio);
+ if (sdio->bio)
+ dio_bio_submit(dio, sdio);
page_cache_release(sdio->cur_page);
sdio->cur_page = NULL;
}