linux-sg2042/mm/failslab.c

#include <linux/fault-inject.h>
#include <linux/slab.h>

static struct {
	struct fault_attr attr;
	u32 ignore_gfp_wait;
	int cache_filter;
} failslab = {
	.attr = FAULT_ATTR_INITIALIZER,
	.ignore_gfp_wait = 1,
	.cache_filter = 0,
};

bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags)
{
	if (gfpflags & __GFP_NOFAIL)
		return false;

        if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
		return false;

	if (failslab.cache_filter && !(cache_flags & SLAB_FAILSLAB))
		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;
	int err;

	err = init_fault_attr_dentries(&failslab.attr, "failslab");
	if (err)
		return err;

	if (!debugfs_create_bool("ignore-gfp-wait", mode, failslab.attr.dir,
				&failslab.ignore_gfp_wait))
		goto fail;
	if (!debugfs_create_bool("cache-filter", mode, failslab.attr.dir,
				&failslab.cache_filter))
		goto fail;

	return 0;
fail:
	cleanup_fault_attr_dentries(&failslab.attr);

	return -ENOMEM;
}

late_initcall(failslab_debugfs_init);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */