mm/hwpoison: retry with shake_page() for unhandlable pages

HWPoisonHandlable() sometimes returns false for typical user pages due
to races with average memory events like transfers over LRU lists.  This
causes failures in hwpoison handling.

There's retry code for such a case but does not work because the retry
loop reaches the retry limit too quickly before the page settles down to
handlable state.  Let get_any_page() call shake_page() to fix it.

[[email protected]: get_any_page(): return -EIO when retry limit reached]
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 25182f05ffed ("mm,hwpoison: fix race with hugetlb page allocation")
Signed-off-by: Naoya Horiguchi <[email protected]>
Reported-by: Tony Luck <[email protected]>
Reviewed-by: Yang Shi <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: <[email protected]>		[5.13+]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index eefd823deb679ad0b9d84b5b374614aace672851..470400cc751363235c94fdd28cd1d6ad7ecf661d 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1146,7 +1146,7 @@ static int __get_hwpoison_page(struct page *page)
         * unexpected races caused by taking a page refcount.
         */
        if (!HWPoisonHandlable(head))
-               return 0;
+               return -EBUSY;
 
        if (PageTransHuge(head)) {
                /*
@@ -1199,9 +1199,15 @@ try_again:
                        }
                        goto out;
                } else if (ret == -EBUSY) {
-                       /* We raced with freeing huge page to buddy, retry. */
-                       if (pass++ < 3)
+                       /*
+                        * We raced with (possibly temporary) unhandlable
+                        * page, retry.
+                        */
+                       if (pass++ < 3) {
+                               shake_page(p, 1);
                                goto try_again;
+                       }
+                       ret = -EIO;
                        goto out;
                }
        }