[v4,14/15] mm,hwpoison: Return 0 if the page is already poisoned in soft-offline
diff mbox series

Message ID 20200716123810.25292-15-osalvador@suse.de
State In Next
Commit 11164c514fb5642c25d6de1d6100a8ba185564e2
Headers show
  • Hwpoison soft-offline rework
Related show

Commit Message

Oscar Salvador July 16, 2020, 12:38 p.m. UTC
Currently, there is an inconsistency when calling soft-offline from
different paths on a page that is already poisoned.

1) madvise:

        madvise_inject_error skips any poisoned page and continues
        the loop.
        If that was the only page to madvise, it returns 0.

2) /sys/devices/system/memory/:

        When calling soft_offline_page_store()->soft_offline_page(),
        we return -EBUSY in case the page is already poisoned.
        This is inconsistent with a) the above example and b)
        memory_failure, where we return 0 if the page was poisoned.

Fix this by dropping the PageHWPoison() check in madvise_inject_error,
and let soft_offline_page return 0 if it finds the page already poisoned.

Please, note that this represents a user-api change, since now the
return error when calling soft_offline_page_store()->soft_offline_page()
will be different.

Signed-off-by: Oscar Salvador <osalvador@suse.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
 mm/madvise.c        | 3 ---
 mm/memory-failure.c | 4 ++--
 2 files changed, 2 insertions(+), 5 deletions(-)

diff mbox series

diff --git a/mm/madvise.c b/mm/madvise.c
index 226f0fcf0828..7b5ca96108cd 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -920,9 +920,6 @@  static int madvise_inject_error(int behavior,
-		if (PageHWPoison(page))
-			continue;
 		if (behavior == MADV_SOFT_OFFLINE) {
 			pr_info("Soft offlining pfn %#lx at process virtual address %#lx\n",
 				 pfn, start);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index c6c83337708a..2b2aa5a76b9b 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1781,7 +1781,7 @@  static int __soft_offline_page(struct page *page)
 		pr_info("soft offline: %#lx page already poisoned\n", pfn);
-		return -EBUSY;
+		return 0;
 	if (!PageHuge(page))
@@ -1881,7 +1881,7 @@  int soft_offline_page(unsigned long pfn)
 	if (PageHWPoison(page)) {
 		pr_info("soft offline: %#lx page already poisoned\n", pfn);
-		return -EBUSY;
+		return 0;