From: Chas Williams <chas3@att.com>
Date: Thu, 6 Sep 2018 15:10:41 +0000 (-0400)
Subject: Fixes: Commit 86af955d02bb ("mm: numa: avoid waiting on freed migrated pages")
X-Git-Tag: v3.18.123~74
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dd6ff2938d7be1a4eecdd7ba9af466959c95df3b;p=linux

Fixes: Commit 86af955d02bb ("mm: numa: avoid waiting on freed migrated pages")

Commit 86af955d02bb ("mm: numa: avoid waiting on freed migrated pages")
was an incomplete backport of the upstream commit.  It is necessary to
always reset page_nid before attempting any early exit.

The original commit conflicted due to lack of commit 82b0f8c39a38
("mm: join struct fault_env and vm_fault") in 4.9 so it wasn't a clean
application, and the change must have just gotten lost in the noise.

Signed-off-by: Chas Williams <chas3@att.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 690d172436c4..bc402f39ac48 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1329,12 +1329,12 @@ int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
 
 	/* Migration could have started since the pmd_trans_migrating check */
 	if (!page_locked) {
+		page_nid = -1;
 		if (!get_page_unless_zero(page))
 			goto out_unlock;
 		spin_unlock(ptl);
 		wait_on_page_locked(page);
 		put_page(page);
-		page_nid = -1;
 		goto out;
 	}