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/inode.c b/fs/btrfs/inode.c
index e5c9261dcbaa..ff0c35976657 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -386,7 +386,7 @@ int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
 {
         struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
         struct btrfs_mapping_tree *map_tree;
-        u64 logical = bio->bi_sector << 9;
+        u64 logical = (u64)bio->bi_sector << 9;
         u64 length = 0;
         u64 map_length;
         int ret;