On Thu, Feb 18, 2021 at 08:20:18AM -0800, Darrick J. Wong wrote: > > I think a nested call like this is necessary. That's why I use the open > > code way. > > This might be a good place to implement an iomap_apply2() loop that > actually /does/ walk all the extents of file1 and file2. There's now > two users of this idiom. Why do we need a special helper for that? > (Possibly structured as a "get next mappings from both" generator > function like Matthew Wilcox keeps asking for. :)) OTOH this might be a good first use for that.