fault injection: fix failslab with CONFIG_NUMA

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.

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 4 deletions

diff --git a/mm/slab.c b/mm/slab.c
index 583644f6ae11..2a3cbd6e675d 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3170,7 +3170,7 @@ 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;
@@ -3208,9 +3208,6 @@ static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
 
         check_irq_off();
 
-        if (should_failslab(cachep, flags))
-                return NULL;
-
         ac = cpu_cache_get(cachep);
         if (likely(ac->avail)) {
                 STATS_INC_ALLOCHIT(cachep);
@@ -3402,6 +3399,9 @@ __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
         unsigned long save_flags;
         void *ptr;
 
+        if (should_failslab(cachep, flags))
+                return NULL;
+
         cache_alloc_debugcheck_before(cachep, flags);
         local_irq_save(save_flags);
 
@@ -3472,6 +3472,9 @@ __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller)
         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);