[PATCH] hugetlbfs: release subpool on fill_super failure

[Yichong Chen]

hugetlbfs_fill_super() allocates a hugepage subpool when size or
min_size mount options are specified.  hugepage_new_subpool() may also
reserve huge pages for min_size.

If root dentry creation fails after the subpool is created, the failure
path frees the subpool with kfree().  This bypasses
hugepage_put_subpool() and can leave min_size reservations charged.

Use hugepage_put_subpool() on the failure path, matching the normal
put_super path.

Fixes: 7ca02d0ae586 ("hugetlbfs: accept subpool min_size mount option and setup accordingly")
Signed-off-by: Yichong Chen <chenyichong@xxxxxxxxxxxxx>
---
 fs/hugetlbfs/inode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 216e1a0dd0b2..6a1d7e778cb0 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -1419,7 +1419,8 @@ hugetlbfs_fill_super(struct super_block *sb, struct fs_context *fc)
 		goto out_free;
 	return 0;
 out_free:
-	kfree(sbinfo->spool);
+	if (sbinfo->spool)
+		hugepage_put_subpool(sbinfo->spool);
 	kfree(sbinfo);
 	return -ENOMEM;
 }
-- 
2.51.0