On Fri, May 03, 2024 at 04:26:55PM +0100, Matthew Wilcox wrote: > I think this is wandering into a minefield. I'm pretty sure > it's considered valid to split the bio, and complete the two halves > independently. Each one will put the refcounts for the pages it touches, > and if we do this early putting of references, that's going to fail. That's now how bios work. The submitter always operates on the entire bio using the _all iterators. bios do get split and advances, but that only affects the bi_iter state. In a perfect world we'd split the memory containers aspect of the bio from the iterator, but that would be a lot of churn and we've got bigger fish to fry.
