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.

Reviewed-by: David Hildenbrand <da...@redhat.com>
Signed-off-by: Miaohe Lin <linmia...@huawei.com>
Cc: Mike Kravetz <mike.krav...@oracle.com>
---
 fs/hugetlbfs/inode.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 4bbfd78a7ccb..14df2f73b8ef 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -680,7 +680,6 @@ static long hugetlbfs_fallocate(struct file *file, int 
mode, loff_t offset,
                 */
                struct page *page;
                unsigned long addr;
-               int avoid_reserve = 0;
 
                cond_resched();
 
@@ -716,8 +715,15 @@ static long hugetlbfs_fallocate(struct file *file, int 
mode, loff_t offset,
                        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]);
-- 
2.19.1

Reply via email to