[PATCH] hugetlb: make hugepage_put_subpool() tolerate NULL

[Yichong Chen <chenyichong@uniontech.com>]

Both callers of hugepage_put_subpool() check whether the subpool pointer
is NULL before calling it.  Move the NULL check into
hugepage_put_subpool() so callers can use the helper unconditionally.

This is a follow-up cleanup after using hugepage_put_subpool() from the
hugetlbfs_fill_super() failure path.

Signed-off-by: Yichong Chen <chenyichong@uniontech.com>
---
 fs/hugetlbfs/inode.c | 6 ++----
 mm/hugetlb.c         | 3 +++
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 6a1d7e778cb0..0c125eda16fd 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -1129,8 +1129,7 @@ static void hugetlbfs_put_super(struct super_block *sb)
 	if (sbi) {
 		sb->s_fs_info = NULL;
 
-		if (sbi->spool)
-			hugepage_put_subpool(sbi->spool);
+		hugepage_put_subpool(sbi->spool);
 
 		kfree(sbi);
 	}
@@ -1419,8 +1418,7 @@ hugetlbfs_fill_super(struct super_block *sb, struct fs_context *fc)
 		goto out_free;
 	return 0;
 out_free:
-	if (sbinfo->spool)
-		hugepage_put_subpool(sbinfo->spool);
+	hugepage_put_subpool(sbinfo->spool);
 	kfree(sbinfo);
 	return -ENOMEM;
 }
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 571212b80835..e319c6a00555 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -181,6 +181,9 @@ void hugepage_put_subpool(struct hugepage_subpool *spool)
 {
 	unsigned long flags;
 
+	if (!spool)
+		return;
+
 	spin_lock_irqsave(&spool->lock, flags);
 	BUG_ON(!spool->count);
 	spool->count--;
-- 
2.51.0