staging: zsmalloc: fix memory leak

This patch fixes a memory leak in zsmalloc where the first
subpage of each zspage is leaked when the zspage is freed.

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 18 insertions, 12 deletions

diff --git a/drivers/staging/zsmalloc/zsmalloc-main.c b/drivers/staging/zsmalloc/zsmalloc-main.c
index 09caa4f2687e..917461c66014 100644
--- a/drivers/staging/zsmalloc/zsmalloc-main.c
+++ b/drivers/staging/zsmalloc/zsmalloc-main.c
@@ -267,33 +267,39 @@ static unsigned long obj_idx_to_offset(struct page *page,
         return off + obj_idx * class_size;
 }
 
+static void reset_page(struct page *page)
+{
+        clear_bit(PG_private, &page->flags);
+        clear_bit(PG_private_2, &page->flags);
+        set_page_private(page, 0);
+        page->mapping = NULL;
+        page->freelist = NULL;
+        reset_page_mapcount(page);
+}
+
 static void free_zspage(struct page *first_page)
 {
-        struct page *nextp, *tmp;
+        struct page *nextp, *tmp, *head_extra;
 
         BUG_ON(!is_first_page(first_page));
         BUG_ON(first_page->inuse);
 
-        nextp = (struct page *)page_private(first_page);
+        head_extra = (struct page *)page_private(first_page);
 
-        clear_bit(PG_private, &first_page->flags);
-        clear_bit(PG_private_2, &first_page->flags);
-        set_page_private(first_page, 0);
-        first_page->mapping = NULL;
-        first_page->freelist = NULL;
-        reset_page_mapcount(first_page);
+        reset_page(first_page);
         __free_page(first_page);
 
         /* zspage with only 1 system page */
-        if (!nextp)
+        if (!head_extra)
                 return;
 
-        list_for_each_entry_safe(nextp, tmp, &nextp->lru, lru) {
+        list_for_each_entry_safe(nextp, tmp, &head_extra->lru, lru) {
                 list_del(&nextp->lru);
-                clear_bit(PG_private_2, &nextp->flags);
-                nextp->index = 0;
+                reset_page(nextp);
                 __free_page(nextp);
         }
+        reset_page(head_extra);
+        __free_page(head_extra);
 }
 
 /* Initialize a newly allocated zspage */