SLUB: failslab support

Currently fault-injection capability for SLAB allocator is only
available to SLAB. This patch makes it available to SLUB, too.

[penberg@cs.helsinki.fi: unify slab and slub implementations]
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
diff --git a/mm/slab.c b/mm/slab.c
index 0918751..c347dd8 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3106,79 +3106,14 @@
 #define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
 #endif
 
-#ifdef CONFIG_FAILSLAB
-
-static struct failslab_attr {
-
-	struct fault_attr attr;
-
-	u32 ignore_gfp_wait;
-#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
-	struct dentry *ignore_gfp_wait_file;
-#endif
-
-} failslab = {
-	.attr = FAULT_ATTR_INITIALIZER,
-	.ignore_gfp_wait = 1,
-};
-
-static int __init setup_failslab(char *str)
-{
-	return setup_fault_attr(&failslab.attr, str);
-}
-__setup("failslab=", setup_failslab);
-
-static int should_failslab(struct kmem_cache *cachep, gfp_t flags)
+static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags)
 {
 	if (cachep == &cache_cache)
-		return 0;
-	if (flags & __GFP_NOFAIL)
-		return 0;
-	if (failslab.ignore_gfp_wait && (flags & __GFP_WAIT))
-		return 0;
+		return false;
 
-	return should_fail(&failslab.attr, obj_size(cachep));
+	return should_failslab(obj_size(cachep), flags);
 }
 
-#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
-
-static int __init failslab_debugfs(void)
-{
-	mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
-	struct dentry *dir;
-	int err;
-
-	err = init_fault_attr_dentries(&failslab.attr, "failslab");
-	if (err)
-		return err;
-	dir = failslab.attr.dentries.dir;
-
-	failslab.ignore_gfp_wait_file =
-		debugfs_create_bool("ignore-gfp-wait", mode, dir,
-				      &failslab.ignore_gfp_wait);
-
-	if (!failslab.ignore_gfp_wait_file) {
-		err = -ENOMEM;
-		debugfs_remove(failslab.ignore_gfp_wait_file);
-		cleanup_fault_attr_dentries(&failslab.attr);
-	}
-
-	return err;
-}
-
-late_initcall(failslab_debugfs);
-
-#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
-
-#else /* CONFIG_FAILSLAB */
-
-static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags)
-{
-	return 0;
-}
-
-#endif /* CONFIG_FAILSLAB */
-
 static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
 {
 	void *objp;
@@ -3381,7 +3316,7 @@
 	unsigned long save_flags;
 	void *ptr;
 
-	if (should_failslab(cachep, flags))
+	if (slab_should_failslab(cachep, flags))
 		return NULL;
 
 	cache_alloc_debugcheck_before(cachep, flags);
@@ -3457,7 +3392,7 @@
 	unsigned long save_flags;
 	void *objp;
 
-	if (should_failslab(cachep, flags))
+	if (slab_should_failslab(cachep, flags))
 		return NULL;
 
 	cache_alloc_debugcheck_before(cachep, flags);