[PATCH v3 8/8] hugetlb: add lockdep_assert_held() calls for hugetlb_lock

[Mike Kravetz]

After making hugetlb lock irq safe and separating some functionality
done under the lock, add some lockdep_assert_held to help verify
locking.

Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Reviewed-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
 mm/hugetlb.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 0bd4dc04df0f..c22111f3da20 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1068,6 +1068,8 @@ static void __enqueue_huge_page(struct list_head *list, struct page *page)
 static void enqueue_huge_page(struct hstate *h, struct page *page)
 {
 	int nid = page_to_nid(page);
+
+	lockdep_assert_held(&hugetlb_lock);
 	__enqueue_huge_page(&h->hugepage_freelists[nid], page);
 	h->free_huge_pages++;
 	h->free_huge_pages_node[nid]++;
@@ -1078,6 +1080,7 @@ static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid)
 	struct page *page;
 	bool pin = !!(current->flags & PF_MEMALLOC_PIN);
 
+	lockdep_assert_held(&hugetlb_lock);
 	list_for_each_entry(page, &h->hugepage_freelists[nid], lru) {
 		if (pin && !is_pinnable_page(page))
 			continue;
@@ -1346,6 +1349,7 @@ static void remove_hugetlb_page(struct hstate *h, struct page *page,
 {
 	int nid = page_to_nid(page);
 
+	lockdep_assert_held(&hugetlb_lock);
 	if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
 		return;
 
@@ -1701,6 +1705,7 @@ static struct page *remove_pool_huge_page(struct hstate *h,
 	int nr_nodes, node;
 	struct page *page = NULL;
 
+	lockdep_assert_held(&hugetlb_lock);
 	for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) {
 		/*
 		 * If we're returning unused surplus pages, only examine
@@ -1950,6 +1955,7 @@ static int gather_surplus_pages(struct hstate *h, long delta)
 	long needed, allocated;
 	bool alloc_ok = true;
 
+	lockdep_assert_held(&hugetlb_lock);
 	needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
 	if (needed <= 0) {
 		h->resv_huge_pages += delta;
@@ -2043,6 +2049,7 @@ static void return_unused_surplus_pages(struct hstate *h,
 	struct page *page;
 	LIST_HEAD(page_list);
 
+	lockdep_assert_held(&hugetlb_lock);
 	/* Uncommit the reservation */
 	h->resv_huge_pages -= unused_resv_pages;
 
@@ -2641,6 +2648,7 @@ static void try_to_free_low(struct hstate *h, unsigned long count,
 	int i;
 	LIST_HEAD(page_list);
 
+	lockdep_assert_held(&hugetlb_lock);
 	if (hstate_is_gigantic(h))
 		return;
 
@@ -2682,6 +2690,7 @@ static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
 {
 	int nr_nodes, node;
 
+	lockdep_assert_held(&hugetlb_lock);
 	VM_BUG_ON(delta != -1 && delta != 1);
 
 	if (delta < 0) {
-- 
2.30.2