[Backport for 5.10.y PATCH 2/7] mm,hwpoison: return -EBUSY when migration fails

[Hanjun Guo]

From: Oscar Salvador <osalvador@xxxxxxx>

commit 3f4b815a439adfb8f238335612c4b28bc10084d8

Currently, we return -EIO when we fail to migrate the page.

Migrations' failures are rather transient as they can happen due to
several reasons, e.g: high page refcount bump, mapping->migrate_page
failing etc.  All meaning that at that time the page could not be
migrated, but that has nothing to do with an EIO error.

Let us return -EBUSY instead, as we do in case we failed to isolate the
page.

While are it, let us remove the "ret" print as its value does not change.

Link: https://lkml.kernel.org/r/20201209092818.30417-1-osalvador@xxxxxxx
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Acked-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Hanjun Guo <guohanjun@xxxxxxxxxx>
---
 mm/memory-failure.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 25fb82320..01445dd 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1856,11 +1856,11 @@ static int __soft_offline_page(struct page *page)
 			pr_info("soft offline: %#lx: %s migration failed %d, type %lx (%pGp)\n",
 				pfn, msg_page[huge], ret, page->flags, &page->flags);
 			if (ret > 0)
-				ret = -EIO;
+				ret = -EBUSY;
 		}
 	} else {
-		pr_info("soft offline: %#lx: %s isolation failed: %d, page count %d, type %lx (%pGp)\n",
-			pfn, msg_page[huge], ret, page_count(page), page->flags, &page->flags);
+		pr_info("soft offline: %#lx: %s isolation failed, page count %d, type %lx (%pGp)\n",
+			pfn, msg_page[huge], page_count(page), page->flags, &page->flags);
 		ret = -EBUSY;
 	}
 	return ret;
-- 
1.7.12.4