mm/failslab.c

   1 #include <linux/fault-inject.h>
   2 #include <linux/slab.h>
   3 #include <linux/mm.h>
   4 #include "slab.h"
   5
   6 static struct {
   7         struct fault_attr attr;
   8         bool ignore_gfp_reclaim;
   9         bool cache_filter;
  10 } failslab = {
  11         .attr = FAULT_ATTR_INITIALIZER,
  12         .ignore_gfp_reclaim = true,
  13         .cache_filter = false,
  14 };
  15
  16 bool should_failslab(struct kmem_cache *s, gfp_t gfpflags)
  17 {
  18         /* No fault-injection for bootstrap cache */
  19         if (unlikely(s == kmem_cache))
  20                 return false;
  21
  22         if (gfpflags & __GFP_NOFAIL)
  23                 return false;
  24
  25         if (failslab.ignore_gfp_reclaim && (gfpflags & __GFP_RECLAIM))
  26                 return false;
  27
  28         if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))
  29                 return false;
  30
  31         return should_fail(&failslab.attr, s->object_size);
  32 }
  33
  34 static int __init setup_failslab(char *str)
  35 {
  36         return setup_fault_attr(&failslab.attr, str);
  37 }
  38 __setup("failslab=", setup_failslab);
  39
  40 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
  41 static int __init failslab_debugfs_init(void)
  42 {
  43         struct dentry *dir;
  44         umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
  45
  46         dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
  47         if (IS_ERR(dir))
  48                 return PTR_ERR(dir);
  49
  50         if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
  51                                 &failslab.ignore_gfp_reclaim))
  52                 goto fail;
  53         if (!debugfs_create_bool("cache-filter", mode, dir,
  54                                 &failslab.cache_filter))
  55                 goto fail;
  56
  57         return 0;
  58 fail:
  59         debugfs_remove_recursive(dir);
  60
  61         return -ENOMEM;
  62 }
  63
  64 late_initcall(failslab_debugfs_init);
  65
  66 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */