Subject: Re: [PATCH v3 15/18] ext4: switch to using the crc32c library

From: Eric Biggers <[email-masked]>
Date: Mon, 4 Nov 2024 17:48:39 +0000

On Mon, Nov 04, 2024 at 07:59:00AM -0800, Darrick J. Wong wrote:
> Hmm.  Looking at your git branch (which was quite helpful to link to!) I
> think for XFS we don't need to change the crc32c() calls, and the only
> porting work that needs to be done is mirroring this Kconfig change?
> And that doesn't even need to be done until someone wants to get rid of
> CONFIG_LIBCRC32C, right?

That's correct, no porting work is required now.  'select LIBCRC32C' should be
replaced with 'select CRC32', but that can be done later.

> > @@ -3278,15 +3263,11 @@ extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
> >  extern int ext4_register_li_request(struct super_block *sb,
> >  				    ext4_group_t first_not_zeroed);
> >  
> >  static inline int ext4_has_metadata_csum(struct super_block *sb)
> >  {
> > -	WARN_ON_ONCE(ext4_has_feature_metadata_csum(sb) &&
> > -		     !EXT4_SB(sb)->s_chksum_driver);
> > -
> > -	return ext4_has_feature_metadata_csum(sb) &&
> > -	       (EXT4_SB(sb)->s_chksum_driver != NULL);
> > +	return ext4_has_feature_metadata_csum(sb);
> >  }
> 
> Nit: Someone might want to
> s/ext4_has_metadata_csum/ext4_has_feature_metadata_csum/ here to get rid
> of the confusingly named trivial helper.
> 

Yes, that should be done as a follow-up patch.

> Otherwise this logic looks ok to me, so
> Reviewed-by: Darrick J. Wong <[email-masked]>
> 
> --D

Thanks,

- Eric