Re: [PATCH v3 10/21] xfs: Update xfs_is_falloc_aligned() mask for forcealign

[John Garry]

On 01/05/2024 00:35, Dave Chinner wrote:
> >   	return !((pos | len) & mask);
> I think this whole function needs to be rewritten so that
> non-power-of-2 extent sizes are supported on both devices properly.
>
> 	xfs_extlen_t	fsbs = 1;
> 	u64		bytes;
> 	u32		mod;
>
> 	if (xfs_inode_has_forcealign(ip))
> 		fsbs = ip->i_extsize;
> 	else if (XFS_IS_REALTIME_INODE(ip))
> 		fsbs = mp->m_sb.sb_rextsize;
>
> 	bytes = XFS_FSB_TO_B(mp, fsbs);
> 	if (is_power_of_2(fsbs))
> 		return !((pos | len) & (bytes - 1));
>
> 	div_u64_rem(pos, bytes, &mod);
> 	if (mod)
> 		return false;
> 	div_u64_rem(len, bytes, &mod);
> 	return mod == 0;

ok, but I still have a doubt about non-power-of-2 forcealign extsize 
support.

Thanks,
John