From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm: use find_get_incore_page in memcontrol The current code does not protect against swapoff of the underlying swap device, so this is a bug fix as well as a worthwhile reduction in code complexity. Link: https://lkml.kernel.org/r/20200910183318.20139-3-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Huang Ying <ying.huang@xxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Matthew Auld <matthew.auld@xxxxxxxxx> Cc: William Kucharski <william.kucharski@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 24 ++---------------------- 1 file changed, 2 insertions(+), 22 deletions(-) --- a/mm/memcontrol.c~mm-use-find_get_incore_page-in-memcontrol +++ a/mm/memcontrol.c @@ -5539,35 +5539,15 @@ static struct page *mc_handle_swap_pte(s static struct page *mc_handle_file_pte(struct vm_area_struct *vma, unsigned long addr, pte_t ptent, swp_entry_t *entry) { - struct page *page = NULL; - struct address_space *mapping; - pgoff_t pgoff; - if (!vma->vm_file) /* anonymous vma */ return NULL; if (!(mc.flags & MOVE_FILE)) return NULL; - mapping = vma->vm_file->f_mapping; - pgoff = linear_page_index(vma, addr); - /* page is moved even if it's not RSS of this task(page-faulted). */ -#ifdef CONFIG_SWAP /* shmem/tmpfs may report page out on swap: account for that too. */ - if (shmem_mapping(mapping)) { - page = find_get_entry(mapping, pgoff); - if (xa_is_value(page)) { - swp_entry_t swp = radix_to_swp_entry(page); - *entry = swp; - page = find_get_page(swap_address_space(swp), - swp_offset(swp)); - } - } else - page = find_get_page(mapping, pgoff); -#else - page = find_get_page(mapping, pgoff); -#endif - return page; + return find_get_incore_page(vma->vm_file->f_mapping, + linear_page_index(vma, addr)); } /** _
