Alistair Popple wrote: > Currently to map a DAX page the DAX driver calls vmf_insert_pfn. This > creates a special devmap PTE entry for the pfn but does not take a > reference on the underlying struct page for the mapping. This is > because DAX page refcounts are treated specially, as indicated by the > presence of a devmap entry. > > To allow DAX page refcounts to be managed the same as normal page > refcounts introduce vmf_insert_page_mkwrite(). This will take a > reference on the underlying page much the same as vmf_insert_page, > except it also permits upgrading an existing mapping to be writable if > requested/possible. > > Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx> > > --- > > Updates from v2: > > - Rename function to make not DAX specific > > - Split the insert_page_into_pte_locked() change into a separate > patch. > > Updates from v1: > > - Re-arrange code in insert_page_into_pte_locked() based on comments > from Jan Kara. > > - Call mkdrity/mkyoung for the mkwrite case, also suggested by Jan. > --- > include/linux/mm.h | 2 ++ > mm/memory.c | 36 ++++++++++++++++++++++++++++++++++++ > 2 files changed, 38 insertions(+) Looks good to me, you can add: Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>
