[PATCH] fault injection: fix failslab with CONFIG_NUMA

[Akinobu Mita <akinobu.mita@gmail.com>]

Currently failslab injects failures into ____cache_alloc().
But with enabling CONFIG_NUMA it's not enough to let actual
slab allocator functions (kmalloc, kmem_cache_alloc, ...) return NULL.

This patch moves fault injection hook inside of __cache_alloc() and
__cache_alloc_node(). These are lower call path than ____cache_alloc()
and enable to inject faulures to slab allocators with CONFIG_NUMA.

Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>

---
 mm/slab.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

Index: 2.6-git/mm/slab.c
===================================================================
--- 2.6-git.orig/mm/slab.c
+++ 2.6-git/mm/slab.c
@@ -3142,7 +3142,7 @@ static int __init failslab_debugfs(void)
 	struct dentry *dir;
 	int err;
 
-       	err = init_fault_attr_dentries(&failslab.attr, "failslab");
+	err = init_fault_attr_dentries(&failslab.attr, "failslab");
 	if (err)
 		return err;
 	dir = failslab.attr.dentries.dir;
@@ -3180,9 +3180,6 @@ static inline void *____cache_alloc(stru
 
 	check_irq_off();
 
-	if (should_failslab(cachep, flags))
-		return NULL;
-
 	ac = cpu_cache_get(cachep);
 	if (likely(ac->avail)) {
 		STATS_INC_ALLOCHIT(cachep);
@@ -3374,6 +3371,9 @@ __cache_alloc_node(struct kmem_cache *ca
 	unsigned long save_flags;
 	void *ptr;
 
+	if (should_failslab(cachep, flags))
+		return NULL;
+
 	cache_alloc_debugcheck_before(cachep, flags);
 	local_irq_save(save_flags);
 
@@ -3444,6 +3444,9 @@ __cache_alloc(struct kmem_cache *cachep,
 	unsigned long save_flags;
 	void *objp;
 
+	if (should_failslab(cachep, flags))
+		return NULL;
+
 	cache_alloc_debugcheck_before(cachep, flags);
 	local_irq_save(save_flags);
 	objp = __do_cache_alloc(cachep, flags);