mm/failslab.c

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