On Sun, Dec 26, 2021 at 6:35 AM Shiyang Ruan <ruansy.fnst@xxxxxxxxxxx> wrote: > > The current dax_lock_page() locks dax entry by obtaining mapping and > index in page. To support 1-to-N RMAP in NVDIMM, we need a new function > to lock a specific dax entry corresponding to this file's mapping,index. > And output the page corresponding to the specific dax entry for caller > use. Is this necessary? The point of dax_lock_page() is to ensure that the fs does not destroy the address_space, or remap the pfn while memory_failure() is operating on the pfn. In the notify_failure case control is handed to the fs so I expect it can make those guarantees itself, no?
