From 585fc0d2871c9318c949fbf45b1f081edd489e96 Mon Sep 17 00:00:00 2001
From: Muchun Song <songmuchun@bytedance.com>
Date: Thu Feb 4 18:32:03 2021 -0800
Subject: [PATCH] mm: hugetlbfs: fix cannot migrate the fallocated HugeTLB page
Git-commit: 585fc0d2871c9318c949fbf45b1f081edd489e96
References: git-fixes
Patch-mainline: v5.11-rc7
If a new hugetlb page is allocated during fallocate it will not be
marked as active (set_page_huge_active) which will result in a later
isolate_huge_page failure when the page migration code would like to
move that page. Such a failure would be unexpected and wrong.
Only export set_page_huge_active, just leave clear_page_huge_active as
static. Because there are no external users.
Link: https://lkml.kernel.org/r/20210115124942.46403-3-songmuchun@bytedance.com
Fixes: 70c3547e36f5 (hugetlbfs: add hugetlbfs_fallocate())
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index b5c1097..21c20fd 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -735,9 +735,10 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
+ set_page_huge_active(page);
/*
* unlock_page because locked by add_to_page_cache()
- * page_put due to reference from alloc_huge_page()
+ * put_page() due to reference from alloc_huge_page()
*/
unlock_page(page);
put_page(page);
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index ebca2ef..b5807f2 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -770,6 +770,8 @@ static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
}
#endif
+void set_page_huge_active(struct page *page);
+
#else /* CONFIG_HUGETLB_PAGE */
struct hstate {};
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 18f6ee3..6f0e242 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1349,7 +1349,7 @@ bool page_huge_active(struct page *page)
}
/* never called for tail page */
-static void set_page_huge_active(struct page *page)
+void set_page_huge_active(struct page *page)
{
VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
SetPagePrivate(&page[1]);