Commit 3a5497a2 authored by Miaohe Lin's avatar Miaohe Lin Committed by Andrew Morton
Browse files

mm/hugetlb: fix missing call to restore_reserve_on_error() 

When huge_add_to_page_cache() fails, the page is freed directly without
calling restore_reserve_on_error() to restore reserve for newly allocated
pages not in page cache.  Fix this by calling restore_reserve_on_error()
when huge_add_to_page_cache fails.

[linmiaohe@huawei.com: remove err == -EEXIST check and retry logic]
  Link: https://lkml.kernel.org/r/20220823030209.57434-4-linmiaohe@huawei.com
Link: https://lkml.kernel.org/r/20220816130553.31406-4-linmiaohe@huawei.com


Signed-off-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Reviewed-by: default avatarMike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 3a6bdda0

mm/hugetlb.c

+8 −3
Original line number Diff line number Diff line
@@ -5563,7 +5563,6 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 
	if (idx >= size)

		goto out;



retry:

	new_page = false;

	page = find_lock_page(mapping, idx);

	if (!page) {
@@ -5603,9 +5602,15 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm, 
		if (vma->vm_flags & VM_MAYSHARE) {

			int err = huge_add_to_page_cache(page, mapping, idx);

			if (err) {

				/*

				 * err can't be -EEXIST which implies someone

				 * else consumed the reservation since hugetlb

				 * fault mutex is held when add a hugetlb page

				 * to the page cache. So it's safe to call

				 * restore_reserve_on_error() here.

				 */

				restore_reserve_on_error(h, vma, haddr, page);

				put_page(page);

				if (err == -EEXIST)

					goto retry;

				goto out;

			}

			new_pagecache_page = true;