[POWERPC] spufs: Fix memory leak on SPU affinity

Reference count for the "neighbor" spu context was not
being correctly decremented after usage.
So, contexts used as reference during SPU affinity setup
were not being deallocated, leading to a memory leak.
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/cell/spufs/inode.c

@@ -322,7 +322,7 @@ static struct spu_context *
 spufs_assert_affinity(unsigned int flags, struct spu_gang *gang,
 						struct file *filp)
 {
-	struct spu_context *tmp, *neighbor;
+	struct spu_context *tmp, *neighbor, *err;
 	int count, node;
 	int aff_supp;
 
@@ -354,11 +354,15 @@ spufs_assert_affinity(unsigned int flags, struct spu_gang *gang,
 		if (!list_empty(&neighbor->aff_list) && !(neighbor->aff_head) &&
 		    !list_is_last(&neighbor->aff_list, &gang->aff_list_head) &&
 		    !list_entry(neighbor->aff_list.next, struct spu_context,
-		    aff_list)->aff_head)
-			return ERR_PTR(-EEXIST);
+		    aff_list)->aff_head) {
+			err = ERR_PTR(-EEXIST);
+			goto out_put_neighbor;
+		}
 
-		if (gang != neighbor->gang)
-			return ERR_PTR(-EINVAL);
+		if (gang != neighbor->gang) {
+			err = ERR_PTR(-EINVAL);
+			goto out_put_neighbor;
+		}
 
 		count = 1;
 		list_for_each_entry(tmp, &gang->aff_list_head, aff_list)
@@ -372,11 +376,17 @@ spufs_assert_affinity(unsigned int flags, struct spu_gang *gang,
 				break;
 		}
 
-		if (node == MAX_NUMNODES)
-			return ERR_PTR(-EEXIST);
+		if (node == MAX_NUMNODES) {
+			err = ERR_PTR(-EEXIST);
+			goto out_put_neighbor;
+		}
 	}
 
 	return neighbor;
+
+out_put_neighbor:
+	put_spu_context(neighbor);
+	return err;
 }
 
 static void
@@ -454,9 +464,12 @@ spufs_create_context(struct inode *inode, struct dentry *dentry,
 	if (ret)
 		goto out_aff_unlock;
 
-	if (affinity)
+	if (affinity) {
 		spufs_set_affinity(flags, SPUFS_I(dentry->d_inode)->i_ctx,
 								neighbor);
+		if (neighbor)
+			put_spu_context(neighbor);
+	}
 
 	/*
 	 * get references for dget and mntget, will be released