From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: hugetlbfs: remove meaningless variable avoid_reserve The variable avoid_reserve is meaningless because we never changed its value and just passed it to alloc_huge_page(). So remove it to make code more clear that in hugetlbfs_fallocate, we never avoid reserve when alloc hugepage yet. Also add a comment offered by Mike Kravetz to explain this. Link: https://lkml.kernel.org/r/20210120071508.9078-1-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/hugetlbfs/inode.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/fs/hugetlbfs/inode.c~hugetlbfs-remove-meaningless-variable-avoid_reserve +++ a/fs/hugetlbfs/inode.c @@ -680,7 +680,6 @@ static long hugetlbfs_fallocate(struct f */ struct page *page; unsigned long addr; - int avoid_reserve = 0; cond_resched(); @@ -716,8 +715,15 @@ static long hugetlbfs_fallocate(struct f continue; } - /* Allocate page and add to page cache */ - page = alloc_huge_page(&pseudo_vma, addr, avoid_reserve); + /* + * Allocate page without setting the avoid_reserve argument. + * There certainly are no reserves associated with the + * pseudo_vma. However, there could be shared mappings with + * reserves for the file at the inode level. If we fallocate + * pages in these areas, we need to consume the reserves + * to keep reservation accounting consistent. + */ + page = alloc_huge_page(&pseudo_vma, addr, 0); hugetlb_drop_vma_policy(&pseudo_vma); if (IS_ERR(page)) { mutex_unlock(&hugetlb_fault_mutex_table[hash]); _
