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>

1 files changed, 59 insertions, 0 deletions

diff --git a/mm/failslab.c b/mm/failslab.c
new file mode 100644
index 0000000..7c6ea64
--- /dev/null
+++ b/mm/failslab.c
@@ -0,0 +1,59 @@
+#include <linux/fault-inject.h>
+
+static struct {
+	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,
+};
+
+bool should_failslab(size_t size, gfp_t gfpflags)
+{
+	if (gfpflags & __GFP_NOFAIL)
+		return false;
+
+        if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
+		return false;
+
+	return should_fail(&failslab.attr, size);
+}
+
+static int __init setup_failslab(char *str)
+{
+	return setup_fault_attr(&failslab.attr, str);
+}
+__setup("failslab=", setup_failslab);
+
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+
+static int __init failslab_debugfs_init(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_init);
+
+#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */