#include <linux/fault-inject.h>

  #include <linux/slab.h>

  
  static struct {
  	struct fault_attr attr;
  	u32 ignore_gfp_wait;

  	int cache_filter;

  #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
  	struct dentry *ignore_gfp_wait_file;

  	struct dentry *cache_filter_file;

  #endif
  } 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;
  	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);

  	failslab.cache_filter_file =
  		debugfs_create_bool("cache-filter", mode, dir,
  				      &failslab.cache_filter);
  
  	if (!failslab.ignore_gfp_wait_file ||
  	    !failslab.cache_filter_file) {

  		err = -ENOMEM;

  		debugfs_remove(failslab.cache_filter_file);

  		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 */