hugetlbfs: call VM_BUG_ON_PAGE earlier in free_huge_page()
A stack trace was triggered by VM_BUG_ON_PAGE(page_mapcount(page), page)
in free_huge_page(). Unfortunately, the page->mapping field was set to
NULL before this test. This made it more difficult to determine the
root cause of the problem.
Move the VM_BUG_ON_PAGE tests earlier in the function so that if they do
trigger more information is present in the page struct.
Link: http://lkml.kernel.org/r/1543491843-23438-1-git-send-email-nic_w@163.com
Signed-off-by: Yongkai Wu <nic_w@163.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 705a3e9c..a808324 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1248,10 +1248,11 @@ void free_huge_page(struct page *page)
(struct hugepage_subpool *)page_private(page);
bool restore_reserve;
- set_page_private(page, 0);
- page->mapping = NULL;
VM_BUG_ON_PAGE(page_count(page), page);
VM_BUG_ON_PAGE(page_mapcount(page), page);
+
+ set_page_private(page, 0);
+ page->mapping = NULL;
restore_reserve = PagePrivate(page);
ClearPagePrivate(page);
