Re: [PATCH 17/30] xfs: factor out a xfs_attr_match helper

[Chandan Rajendra <chandan@linux.ibm.com>]

On Wednesday, January 29, 2020 10:32 PM Christoph Hellwig wrote: 
> Factor out a helper that compares an on-disk attr vs the name, length and
> flags specified in struct xfs_da_args.
>

The newly introduced changes logically match with the code flow that existed
earlier.

Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>

> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
>  fs/xfs/libxfs/xfs_attr_leaf.c | 80 +++++++++++++----------------------
>  1 file changed, 30 insertions(+), 50 deletions(-)
> 
> diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
> index b0658eb8fbcc..8852754153ba 100644
> --- a/fs/xfs/libxfs/xfs_attr_leaf.c
> +++ b/fs/xfs/libxfs/xfs_attr_leaf.c
> @@ -445,14 +445,21 @@ xfs_attr3_leaf_read(
>   * Namespace helper routines
>   *========================================================================*/
> 
> -/*
> - * If namespace bits don't match return 0.
> - * If all match then return 1.
> - */
> -STATIC int
> -xfs_attr_namesp_match(int arg_flags, int ondisk_flags)
> +static bool
> +xfs_attr_match(
> +	struct xfs_da_args	*args,
> +	uint8_t			namelen,
> +	unsigned char		*name,
> +	int			flags)
>  {
> -	return XFS_ATTR_NSP_ONDISK(ondisk_flags) == XFS_ATTR_NSP_ARGS_TO_ONDISK(arg_flags);
> +	if (args->namelen != namelen)
> +		return false;
> +	if (memcmp(args->name, name, namelen) != 0)
> +		return false;
> +	if (XFS_ATTR_NSP_ARGS_TO_ONDISK(args->flags) !=
> +	    XFS_ATTR_NSP_ONDISK(flags))
> +		return false;
> +	return true;
>  }
> 
>  static int
> @@ -678,15 +685,8 @@ xfs_attr_shortform_add(xfs_da_args_t *args, int forkoff)
>  	sf = (xfs_attr_shortform_t *)ifp->if_u1.if_data;
>  	sfe = &sf->list[0];
>  	for (i = 0; i < sf->hdr.count; sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
> -#ifdef DEBUG
> -		if (sfe->namelen != args->namelen)
> -			continue;
> -		if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
> -			continue;
> -		if (!xfs_attr_namesp_match(args->flags, sfe->flags))
> -			continue;
> -		ASSERT(0);
> -#endif
> +		ASSERT(!xfs_attr_match(args, sfe->namelen, sfe->nameval,
> +			sfe->flags));
>  	}
> 
>  	offset = (char *)sfe - (char *)sf;
> @@ -749,13 +749,9 @@ xfs_attr_shortform_remove(xfs_da_args_t *args)
>  	for (i = 0; i < end; sfe = XFS_ATTR_SF_NEXTENTRY(sfe),
>  					base += size, i++) {
>  		size = XFS_ATTR_SF_ENTSIZE(sfe);
> -		if (sfe->namelen != args->namelen)
> -			continue;
> -		if (memcmp(sfe->nameval, args->name, args->namelen) != 0)
> -			continue;
> -		if (!xfs_attr_namesp_match(args->flags, sfe->flags))
> -			continue;
> -		break;
> +		if (xfs_attr_match(args, sfe->namelen, sfe->nameval,
> +				sfe->flags))
> +			break;
>  	}
>  	if (i == end)
>  		return -ENOATTR;
> @@ -816,13 +812,9 @@ xfs_attr_shortform_lookup(xfs_da_args_t *args)
>  	sfe = &sf->list[0];
>  	for (i = 0; i < sf->hdr.count;
>  				sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
> -		if (sfe->namelen != args->namelen)
> -			continue;
> -		if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
> -			continue;
> -		if (!xfs_attr_namesp_match(args->flags, sfe->flags))
> -			continue;
> -		return -EEXIST;
> +		if (xfs_attr_match(args, sfe->namelen, sfe->nameval,
> +				sfe->flags))
> +			return -EEXIST;
>  	}
>  	return -ENOATTR;
>  }
> @@ -847,14 +839,10 @@ xfs_attr_shortform_getvalue(
>  	sfe = &sf->list[0];
>  	for (i = 0; i < sf->hdr.count;
>  				sfe = XFS_ATTR_SF_NEXTENTRY(sfe), i++) {
> -		if (sfe->namelen != args->namelen)
> -			continue;
> -		if (memcmp(args->name, sfe->nameval, args->namelen) != 0)
> -			continue;
> -		if (!xfs_attr_namesp_match(args->flags, sfe->flags))
> -			continue;
> -		return xfs_attr_copy_value(args, &sfe->nameval[args->namelen],
> -						sfe->valuelen);
> +		if (xfs_attr_match(args, sfe->namelen, sfe->nameval,
> +				sfe->flags))
> +			return xfs_attr_copy_value(args,
> +				&sfe->nameval[args->namelen], sfe->valuelen);
>  	}
>  	return -ENOATTR;
>  }
> @@ -2409,23 +2397,15 @@ xfs_attr3_leaf_lookup_int(
>  		}
>  		if (entry->flags & XFS_ATTR_LOCAL) {
>  			name_loc = xfs_attr3_leaf_name_local(leaf, probe);
> -			if (name_loc->namelen != args->namelen)
> -				continue;
> -			if (memcmp(args->name, name_loc->nameval,
> -							args->namelen) != 0)
> -				continue;
> -			if (!xfs_attr_namesp_match(args->flags, entry->flags))
> +			if (!xfs_attr_match(args, name_loc->namelen,
> +					name_loc->nameval, entry->flags))
>  				continue;
>  			args->index = probe;
>  			return -EEXIST;
>  		} else {
>  			name_rmt = xfs_attr3_leaf_name_remote(leaf, probe);
> -			if (name_rmt->namelen != args->namelen)
> -				continue;
> -			if (memcmp(args->name, name_rmt->name,
> -							args->namelen) != 0)
> -				continue;
> -			if (!xfs_attr_namesp_match(args->flags, entry->flags))
> +			if (!xfs_attr_match(args, name_rmt->namelen,
> +					name_rmt->name, entry->flags))
>  				continue;
>  			args->index = probe;
>  			args->rmtvaluelen = be32_to_cpu(name_rmt->valuelen);
> 


-- 
chandan