mm/failslab.c

   1 #include <linux/fault-inject.h>
   2
   3 static struct {
   4         struct fault_attr attr;
   5         u32 ignore_gfp_wait;
   6 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
   7         struct dentry *ignore_gfp_wait_file;
   8 #endif
   9 } failslab = {
  10         .attr = FAULT_ATTR_INITIALIZER,
  11         .ignore_gfp_wait = 1,
  12 };
  13
  14 bool should_failslab(size_t size, gfp_t gfpflags)
  15 {
  16         if (gfpflags & __GFP_NOFAIL)
  17                 return false;
  18
  19         if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
  20                 return false;
  21
  22         return should_fail(&failslab.attr, size);
  23 }
  24
  25 static int __init setup_failslab(char *str)
  26 {
  27         return setup_fault_attr(&failslab.attr, str);
  28 }
  29 __setup("failslab=", setup_failslab);
  30
  31 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
  32
  33 static int __init failslab_debugfs_init(void)
  34 {
  35         mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
  36         struct dentry *dir;
  37         int err;
  38
  39         err = init_fault_attr_dentries(&failslab.attr, "failslab");
  40         if (err)
  41                 return err;
  42         dir = failslab.attr.dentries.dir;
  43
  44         failslab.ignore_gfp_wait_file =
  45                 debugfs_create_bool("ignore-gfp-wait", mode, dir,
  46                                       &failslab.ignore_gfp_wait);
  47
  48         if (!failslab.ignore_gfp_wait_file) {
  49                 err = -ENOMEM;
  50                 debugfs_remove(failslab.ignore_gfp_wait_file);
  51                 cleanup_fault_attr_dentries(&failslab.attr);
  52         }
  53
  54         return err;
  55 }
  56
  57 late_initcall(failslab_debugfs_init);
  58
  59 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */