On Sun, Aug 11, 2019 at 12:15:08PM -0400, Theodore Y. Ts'o wrote: > > Nak. No weird fs specific fiemap flags that aren't even in the uapi > > header. Please provide your own debug only interface. > > I can understand why you don't like this from the principle of the > thing. I think mixing up in-kernel temporary state with the on-disk layout is a bad idea, yes. I think it is an even worse idea to try to sneak it in without API review in an undocumented fashion. > > I'll create my own ioctl, and make a copy of ioctl_fiemap() into ext4 > and modify it for my needs. I was trying to avoid needing to do that, > since there is plenty of space in the fiemap flags to carve out space > for file-specific specific flags, and avoiding making extra copies of > code for the purposes of reuse weighed more heavily than "no > fs-specific fiemap flags". I think dumping your internal state is a candidate for debugs, not a copy of ioctl_fiemap.