Re: [PATCH] erofs: explicit cast blkaddr to u64 before shift operation

From: Gao Xiang
Date: Thu Apr 13 2023 - 00:38:30 EST




On 2023/4/13 11:57, Jia Zhu wrote:
We should explicitly cast @blkaddr from u32 to u64 before the shift
operation to return the larger type.

Fixes: b1c2d99b18ff ("erofs: avoid hardcoded blocksize for subpage block support")
Signed-off-by: Jia Zhu <zhujia.zj@xxxxxxxxxxxxx>

Reviewed-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>

Let's fold it into the original patch.

Thanks,
Gao Xiang

---
fs/erofs/data.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index aa7f9e4f86fb..6fe9a779fa91 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -35,7 +35,7 @@ void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr,
enum erofs_kmap_type type)
{
struct inode *inode = buf->inode;
- erofs_off_t offset = blkaddr << inode->i_blkbits;
+ erofs_off_t offset = (erofs_off_t)blkaddr << inode->i_blkbits;
pgoff_t index = offset >> PAGE_SHIFT;
struct page *page = buf->page;
struct folio *folio;