hugetlb: fix dynamic pool resize failure case
When gather_surplus_pages() fails to allocate enough huge pages to satisfy
the requested reservation, it frees what it did allocate back to the buddy
allocator. put_page() should be called instead of update_and_free_page()
to ensure that pool counters are updated as appropriate and the page's
refcount is decremented.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Acked-by: Dave Hansen <haveblue@us.ibm.com>
Cc: David Gibson <hermes@gibson.dropbear.id.au>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Ken Chen <kenchen@google.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.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 82efecb..ae2959b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -302,8 +302,17 @@
list_del(&page->lru);
if ((--needed) >= 0)
enqueue_huge_page(page);
- else
- update_and_free_page(page);
+ else {
+ /*
+ * Decrement the refcount and free the page using its
+ * destructor. This must be done with hugetlb_lock
+ * unlocked which is safe because free_huge_page takes
+ * hugetlb_lock before deciding how to free the page.
+ */
+ spin_unlock(&hugetlb_lock);
+ put_page(page);
+ spin_lock(&hugetlb_lock);
+ }
}
return ret;