hugetlbfs: fix quota leak

In the error path of both shared and private hugetlb page allocation,
the file system quota is never undone, leading to fs quota leak.  Fix
them up.

[akpm@linux-foundation.org: cleanup, micro-optimise]
Signed-off-by: Ken Chen <kenchen@google.com>
Acked-by: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 7224a4f071067c3d60a017d949daa2e97f0e8a5d..e0fda156f0212a1a44c0d27f13dc8ffd1cda1064 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -418,9 +418,14 @@ static struct page *alloc_huge_page_private(struct vm_area_struct *vma,
        if (free_huge_pages > resv_huge_pages)
                page = dequeue_huge_page(vma, addr);
        spin_unlock(&hugetlb_lock);
-       if (!page)
+       if (!page) {
                page = alloc_buddy_huge_page(vma, addr);
-       return page ? page : ERR_PTR(-VM_FAULT_OOM);
+               if (!page) {
+                       hugetlb_put_quota(vma->vm_file->f_mapping, 1);
+                       return ERR_PTR(-VM_FAULT_OOM);
+               }
+       }
+       return page;
 }
 
 static struct page *alloc_huge_page(struct vm_area_struct *vma,
@@ -1206,8 +1211,10 @@ int hugetlb_reserve_pages(struct inode *inode, long from, long to)
        if (hugetlb_get_quota(inode->i_mapping, chg))
                return -ENOSPC;
        ret = hugetlb_acct_memory(chg);
-       if (ret < 0)
+       if (ret < 0) {
+               hugetlb_put_quota(inode->i_mapping, chg);
                return ret;
+       }
        region_add(&inode->i_mapping->private_list, from, to);
        return 0;
 }