From: Jens Axboe <axboe@fb.com>
Date: Tue, 10 Nov 2015 17:14:38 +0000 (-0700)
Subject: direct-io: be sure to assign dio->bio_bdev for both paths
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c1c534609fe8a859f9c8108a5591e6e8a97e34d1;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

direct-io: be sure to assign dio->bio_bdev for both paths

btrfs sets ->submit_io(), and we failed to set the block dev for
that path. That resulted in a potential NULL dereference when
we later wait for IO in dio_await_one().

Reported-by: kernel test robot <ying.huang@linux.intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---

diff --git a/fs/direct-io.c b/fs/direct-io.c
index 7025029c666f..15381c474a11 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -399,14 +399,14 @@ static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
 	if (dio->is_async && dio->rw == READ && dio->should_dirty)
 		bio_set_pages_dirty(bio);
 
+	dio->bio_bdev = bio->bi_bdev;
+
 	if (sdio->submit_io) {
 		sdio->submit_io(dio->rw, bio, dio->inode,
 			       sdio->logical_offset_in_bio);
 		dio->bio_cookie = BLK_QC_T_NONE;
-	} else {
+	} else
 		dio->bio_cookie = submit_bio(dio->rw, bio);
-		dio->bio_bdev = bio->bi_bdev;
-	}
 
 	sdio->bio = NULL;
 	sdio->boundary = 0;