tuntap: add sanity checks about msg_controllen in sendmsg

[mirror_ubuntu-focal-kernel.git] / mm / page-writeback.c

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 50055d2e4ea85cf305e209f8a7dd3c84c8251721..bb1a57bdfff7d7c9f2b0ca3b1d9dbae4038d295e 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -201,11 +201,11 @@ static void wb_min_max_ratio(struct bdi_writeback *wb,
        if (this_bw < tot_bw) {
                if (min) {
                        min *= this_bw;
-                       do_div(min, tot_bw);
+                       min = div64_ul(min, tot_bw);
                }
                if (max < 100) {
                        max *= this_bw;
-                       do_div(max, tot_bw);
+                       max = div64_ul(max, tot_bw);
                }
        }
 
@@ -2764,7 +2764,7 @@ int test_clear_page_writeback(struct page *page)
 int __test_set_page_writeback(struct page *page, bool keep_write)
 {
        struct address_space *mapping = page_mapping(page);
-       int ret;
+       int ret, access_ret;
 
        lock_page_memcg(page);
        if (mapping && mapping_use_writeback_tags(mapping)) {
@@ -2807,6 +2807,13 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
                inc_zone_page_state(page, NR_ZONE_WRITE_PENDING);
        }
        unlock_page_memcg(page);
+       access_ret = arch_make_page_accessible(page);
+       /*
+        * If writeback has been triggered on a page that cannot be made
+        * accessible, it is too late to recover here.
+        */
+       VM_BUG_ON_PAGE(access_ret != 0, page);
+
        return ret;
 
 }