On Wed, Oct 23, 2019 at 03:04:47PM +0800, Qu Wenruo wrote: > This member is not used by any one, just remove it. What's the patch that removed the last use? This should be in patches that remove struct members. Otherwise good, every byte removed counts. I've briefly checked 'void *private', but looks like it can be removed as well, it's holds bi_private of the first_bio (btrfs_map_bio) and it's read in btrfs_end_bbio, but bbio is accessible and so bbio->private is bbio->orig_bio->bi_private.
