Btrfs: cast bio->bi_sector to a u64 before shifting

On 32 bit machines without CONFIG_LBD, the bi_sector field is only 32 bits.
Btrfs needs to cast it before shifting up, or we end up doing IO into
the wrong place.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f63cf7621a01..2eed7f91f51a 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2187,7 +2187,7 @@ int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
         struct btrfs_mapping_tree *map_tree;
         struct btrfs_device *dev;
         struct bio *first_bio = bio;
-        u64 logical = bio->bi_sector << 9;
+        u64 logical = (u64)bio->bi_sector << 9;
         u64 length = 0;
         u64 map_length;
         struct btrfs_multi_bio *multi = NULL;