mm/failslab.c

   1 #include <linux/fault-inject.h>
   2 #include <linux/slab.h>
   3
   4 static struct {
   5         struct fault_attr attr;
   6         u32 ignore_gfp_wait;
   7         int cache_filter;
   8 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
   9         struct dentry *ignore_gfp_wait_file;
  10         struct dentry *cache_filter_file;
  11 #endif
  12 } failslab = {
  13         .attr = FAULT_ATTR_INITIALIZER,
  14         .ignore_gfp_wait = 1,
  15         .cache_filter = 0,
  16 };
  17
  18 bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags)
  19 {
  20         if (gfpflags & __GFP_NOFAIL)
  21                 return false;
  22
  23         if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT))
  24                 return false;
  25
  26         if (failslab.cache_filter && !(cache_flags & SLAB_FAILSLAB))
  27                 return false;
  28
  29         return should_fail(&failslab.attr, size);
  30 }
  31
  32 static int __init setup_failslab(char *str)
  33 {
  34         return setup_fault_attr(&failslab.attr, str);
  35 }
  36 __setup("failslab=", setup_failslab);
  37
  38 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
  39 static int __init failslab_debugfs_init(void)
  40 {
  41         mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
  42         struct dentry *dir;
  43         int err;
  44
  45         err = init_fault_attr_dentries(&failslab.attr, "failslab");
  46         if (err)
  47                 return err;
  48         dir = failslab.attr.dentries.dir;
  49
  50         failslab.ignore_gfp_wait_file =
  51                 debugfs_create_bool("ignore-gfp-wait", mode, dir,
  52                                       &failslab.ignore_gfp_wait);
  53
  54         failslab.cache_filter_file =
  55                 debugfs_create_bool("cache-filter", mode, dir,
  56                                       &failslab.cache_filter);
  57
  58         if (!failslab.ignore_gfp_wait_file ||
  59             !failslab.cache_filter_file) {
  60                 err = -ENOMEM;
  61                 debugfs_remove(failslab.cache_filter_file);
  62                 debugfs_remove(failslab.ignore_gfp_wait_file);
  63                 cleanup_fault_attr_dentries(&failslab.attr);
  64         }
  65
  66         return err;
  67 }
  68
  69 late_initcall(failslab_debugfs_init);
  70
  71 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */