Re: [PATCH] btrfs: split discard handling out of btrfs_map_block

[David Sterba <dsterba@suse.cz>]

On Fri, Jun 03, 2022 at 08:57:25AM +0200, Christoph Hellwig wrote:
> Mapping block for discard doesn't really share any code with the regular
> block mapping case.  Split it out into an entirely separate helper
> that just returns an array of btrfs_discard_stripe structures and the
> number of stripes.
> 
> This removes the need for the length field in the btrfs_io_context
> structure, so remove tht.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Added to misc-next, thanks.

>  	/* we don't discard raid56 yet */
> -	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
> -		ret = -EOPNOTSUPP;
> -		goto out;
> -	}
> +	ret = -EOPNOTSUPP;
> +	if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
> +		goto out_free_map;

Please don't use this error value pattern in btrfs code, the preferred
style is

	if (condition()) {
		ret = ERROR;
		goto label;
	}