I updated the patch description to mention that pinning may be used instead of getting a ref: netfs: Add a function to extract an iterator into a scatterlist Provide a function for filling in a scatterlist from the list of pages contained in an iterator. If the iterator is UBUF- or IOBUF-type, the pages have a ref (WRITE) or a pin (READ) taken on them. If the iterator is BVEC-, KVEC- or XARRAY-type, no ref is taken on the pages and it is left to the caller to manage their lifetime. It cannot be assumed that a ref can be validly taken, particularly in the case of a KVEC iterator. David