Re: [PATCH v3 4/6] ext4: convert to use i_blockmask()

[Al Viro]

On Thu, Mar 09, 2023 at 11:21:25PM +0800, Yangtao Li wrote:
> Use i_blockmask() to simplify code.
> 
> Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
> ---
> v3:
> -none
> v2:
> -convert to i_blockmask()
>  fs/ext4/inode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index d251d705c276..eec36520e5e9 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -2218,7 +2218,7 @@ static int mpage_process_page_bufs(struct mpage_da_data *mpd,
>  {
>  	struct inode *inode = mpd->inode;
>  	int err;
> -	ext4_lblk_t blocks = (i_size_read(inode) + i_blocksize(inode) - 1)
> +	ext4_lblk_t blocks = (i_size_read(inode) + i_blockmask(inode))
>  							>> inode->i_blkbits;

Umm...  That actually asks for DIV_ROUND_UP(i_size_read_inode(), i_blocksize(inode)) -
compiler should bloody well be able to figure out that division by (1 << n) is
shift down by n and it's easier to follow that way...