On Mon, Aug 05, 2019 at 10:14:15PM +0800, Qu Wenruo wrote: > > > On 2019/8/5 下午9:19, Josef Bacik wrote: > > In testing block group removal it's sometimes handy to be able to create > > block groups on demand. Add an ioctl to allow us to force allocation > > from userspace. > > > > Signed-off-by: Josef Bacik <jo...@toxicpanda.com> > > --- > > v1->v2: > > - I noticed last week when backporting this that btrfs_chunk_alloc doesn't > > figure out the rest of the flags needed for the type. Use > > btrfs_force_chunk_alloc instead so that we get the raid settings for the > > alloc > > type we're using. > > Still not sure if it's worthy to add a debug only ioctl. > > If sysfs is not good enough, maybe modify btrfs_force_chunk_alloc() to > do extra chunk allocation depending on a internal return value > overridable function? > > At least for the later case, we can trigger empty chunk allocation with > BPF while without messing any interface.
I hadn't thought of the sysfs route, I actually like that a lot better. Once I figure out why our debugfs stuff is broken I'll add this in there, that'll save us a btrfs-progs command as well. Thanks, Josef
