Re: [PATCH v2 10/24] ext4: add EXT4_LBLK_TO_PG and EXT4_PG_TO_LBLK for block/page conversion

From: Jan Kara
Date: Mon Nov 10 2025 - 04:39:21 EST


On Fri 07-11-25 22:42:35, libaokun@xxxxxxxxxxxxxxx wrote:
> From: Baokun Li <libaokun1@xxxxxxxxxx>
>
> As BS > PS support is coming, all block number to page index (and
> vice-versa) conversions must now go via bytes. Added EXT4_LBLK_TO_PG()
> and EXT4_PG_TO_LBLK() macros to simplify these conversions and handle
> both BS <= PS and BS > PS scenarios cleanly.
>
> Suggested-by: Jan Kara <jack@xxxxxxx>
> Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
> Reviewed-by: Zhang Yi <yi.zhang@xxxxxxxxxx>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> fs/ext4/ext4.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index c00ce6db69f0..4bc0b2b7288a 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -370,6 +370,12 @@ struct ext4_io_submit {
> (round_up((offset), i_blocksize(inode)) >> (inode)->i_blkbits)
> #define EXT4_LBLK_TO_B(inode, lblk) ((loff_t)(lblk) << (inode)->i_blkbits)
>
> +/* Translate a block number to a page index */
> +#define EXT4_LBLK_TO_PG(inode, lblk) (EXT4_LBLK_TO_B((inode), (lblk)) >> \
> + PAGE_SHIFT)
> +/* Translate a page index to a block number */
> +#define EXT4_PG_TO_LBLK(inode, pnum) (((loff_t)(pnum) << PAGE_SHIFT) >> \
> + (inode)->i_blkbits)
> /* Translate a block number to a cluster number */
> #define EXT4_B2C(sbi, blk) ((blk) >> (sbi)->s_cluster_bits)
> /* Translate a cluster number to a block number */
> --
> 2.46.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR