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