> Thanks, it's been there since the first merge of scrub, but hard to hit.

Yeah, very hard to hit. Debated submitting a patch, but the fix seemed
simple enough, so figured I'd send one in.

Side note: I noticed most of the time ENOMEM is hit in fs/btrfs BUG or BUG_ON is
called. Would it be better (more in line with the fs/btrfs style) to call BUG or
BUG_ON e.g. BUG_ON(!sbio) instead of goto nomem at fs/btrfs/scrub.c:592?

Cheers,

Dan