Re: [PATCH v2] erofs: fix wrong address in erofs_get_block

[Chao Yu <yuchao0@huawei.com>]

On 2020/12/8 17:31, Huang Jianan wrote:
> iblock indicates the number of i_blkbits-sized blocks rather than
> sectors, fix it.
> 
> If the data has a disk mapping, map_bh should be used to read the
> correct data from the device.

Thanks for the fix, I was misled by sector_t type...

What about avoiding using generic_block_bmap() which uses buffer_head
structure, it limits mapped size to 32-bits:

https://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs.git/commit/?h=dev-test&id=b876f4c94c3d1688edea021d45a528571499e0b9

Thanks,

> 
> Fixes: 9da681e017a3 ("staging: erofs: support bmap")
> Signed-off-by: Huang Jianan <huangjianan@oppo.com>
> Signed-off-by: Guo Weichao <guoweichao@oppo.com>
> ---
>   fs/erofs/data.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/erofs/data.c b/fs/erofs/data.c
> index 347be146884c..aad3fb68d6c8 100644
> --- a/fs/erofs/data.c
> +++ b/fs/erofs/data.c
> @@ -316,7 +316,7 @@ static int erofs_get_block(struct inode *inode, sector_t iblock,
>   			   struct buffer_head *bh, int create)
>   {
>   	struct erofs_map_blocks map = {
> -		.m_la = iblock << 9,
> +		.m_la = blknr_to_addr(iblock),
>   	};
>   	int err;
>   
> @@ -325,7 +325,7 @@ static int erofs_get_block(struct inode *inode, sector_t iblock,
>   		return err;
>   
>   	if (map.m_flags & EROFS_MAP_MAPPED)
> -		bh->b_blocknr = erofs_blknr(map.m_pa);
> +		map_bh(bh, inode->i_sb, erofs_blknr(map.m_pa));
>   
>   	return err;
>   }
>