From: Qu Wenruo <wqu@xxxxxxxx> commit 2d974619a77f106f3d1341686dea95c0eaad601f upstream. The old code goes: offset = logical - em->start; length = min_t(u64, em->len - offset, length); Where @length calculation is dependent on offset, it can take reader several more seconds to find it's just the same code as: offset = logical - em->start; length = min_t(u64, em->start + em->len - logical, length); Use above code to make the length calculate independent from other variable, thus slightly increase the readability. Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx> Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> Signed-off-by: Qu Wenruo <wqu@xxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/volumes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5714,7 +5714,7 @@ static int __btrfs_map_block_for_discard } offset = logical - em->start; - length = min_t(u64, em->len - offset, length); + length = min_t(u64, em->start + em->len - logical, length); stripe_len = map->stripe_len; /*
