[PATCH] fault injection: fix failslab with CONFIG_NUMA

Akinobu Mita
2007-04-22T09:16:41Z

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);