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>

diff --git a/mm/slab.c b/mm/slab.c
index 583644f..2a3cbd6 100644 (file)
--- 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);