Re: [PATCH 03/11] ext4: split _ext4_fiemap

[Ritesh Harjani <riteshh@xxxxxxxxxxxxx>]

On 4/27/20 11:49 PM, Christoph Hellwig wrote:
> The fiemap and EXT4_IOC_GET_ES_CACHE cases share almost no code, so split
> them into entirely separate functions.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Looks fine. Feel free to add
Reviewed-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxx>

> ---
>   fs/ext4/extents.c | 72 +++++++++++++++++++++++------------------------
>   1 file changed, 35 insertions(+), 37 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index 2b4b94542e34d..d2a2a3ba5c44a 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -4854,11 +4854,9 @@ static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len)
>   	return 0;
>   }
>   
> -static int _ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> -			__u64 start, __u64 len, bool from_es_cache)
> +int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> +		u64 start, u64 len)
>   {
> -	ext4_lblk_t start_blk;
> -	u32 ext4_fiemap_flags = FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR;
>   	int error = 0;
>   
>   	if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
> @@ -4868,10 +4866,7 @@ static int _ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
>   		fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
>   	}
>   
> -	if (from_es_cache)
> -		ext4_fiemap_flags &= FIEMAP_FLAG_XATTR;
> -
> -	if (fiemap_check_flags(fieinfo, ext4_fiemap_flags))
> +	if (fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR))
>   		return -EBADR;
>   
>   	/*
> @@ -4885,40 +4880,20 @@ static int _ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
>   
>   	if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
>   		fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
> -		error = iomap_fiemap(inode, fieinfo, start, len,
> -				     &ext4_iomap_xattr_ops);
> -	} else if (!from_es_cache) {
> -		error = iomap_fiemap(inode, fieinfo, start, len,
> -				     &ext4_iomap_report_ops);
> -	} else {
> -		ext4_lblk_t len_blks;
> -		__u64 last_blk;
> -
> -		start_blk = start >> inode->i_sb->s_blocksize_bits;
> -		last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
> -		if (last_blk >= EXT_MAX_BLOCKS)
> -			last_blk = EXT_MAX_BLOCKS-1;
> -		len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
> -
> -		/*
> -		 * Walk the extent tree gathering extent information
> -		 * and pushing extents back to the user.
> -		 */
> -		error = ext4_fill_es_cache_info(inode, start_blk, len_blks,
> -						fieinfo);
> +		return iomap_fiemap(inode, fieinfo, start, len,
> +				    &ext4_iomap_xattr_ops);
>   	}
> -	return error;
> -}
>   
> -int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> -		__u64 start, __u64 len)
> -{
> -	return _ext4_fiemap(inode, fieinfo, start, len, false);
> +	return iomap_fiemap(inode, fieinfo, start, len, &ext4_iomap_report_ops);
>   }
>   
>   int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo,
>   		      __u64 start, __u64 len)
>   {
> +	ext4_lblk_t start_blk, len_blks;
> +	__u64 last_blk;
> +	int error = 0;
> +
>   	if (ext4_has_inline_data(inode)) {
>   		int has_inline;
>   
> @@ -4929,9 +4904,32 @@ int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo,
>   			return 0;
>   	}
>   
> -	return _ext4_fiemap(inode, fieinfo, start, len, true);
> -}
> +	if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
> +		error = ext4_ext_precache(inode);
> +		if (error)
> +			return error;
> +		fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
> +	}
> +
> +	if (fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC))
> +		return -EBADR;
>   
> +	error = ext4_fiemap_check_ranges(inode, start, &len);
> +	if (error)
> +		return error;
> +
> +	start_blk = start >> inode->i_sb->s_blocksize_bits;
> +	last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
> +	if (last_blk >= EXT_MAX_BLOCKS)
> +		last_blk = EXT_MAX_BLOCKS-1;
> +	len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
> +
> +	/*
> +	 * Walk the extent tree gathering extent information
> +	 * and pushing extents back to the user.
> +	 */
> +	return ext4_fill_es_cache_info(inode, start_blk, len_blks, fieinfo);
> +}
>   
>   /*
>    * ext4_access_path: