[Linux-cachefs] [RFC PATCH 4/4] netfs: Add a function to extract an iterator into a scatterlist

[David Howells]

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