block/blk-cgroup.h

   1 #ifndef _BLK_CGROUP_H
   2 #define _BLK_CGROUP_H
   3 /*
   4  * Common Block IO controller cgroup interface
   5  *
   6  * Based on ideas and code from CFQ, CFS and BFQ:
   7  * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk>
   8  *
   9  * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it>
  10  *                    Paolo Valente <paolo.valente@unimore.it>
  11  *
  12  * Copyright (C) 2009 Vivek Goyal <vgoyal@redhat.com>
  13  *                    Nauman Rafique <nauman@google.com>
  14  */
  15
  16 #include <linux/cgroup.h>
  17
  18 #ifdef CONFIG_BLK_CGROUP
  19
  20 struct blkio_cgroup {
  21         struct cgroup_subsys_state css;
  22         unsigned int weight;
  23         spinlock_t lock;
  24         struct hlist_head blkg_list;
  25 };
  26
  27 struct blkio_group {
  28         /* An rcu protected unique identifier for the group */
  29         void *key;
  30         struct hlist_node blkcg_node;
  31         unsigned short blkcg_id;
  32 #ifdef CONFIG_DEBUG_BLK_CGROUP
  33         /* Store cgroup path */
  34         char path[128];
  35         /* How many times this group has been removed from service tree */
  36         unsigned long dequeue;
  37 #endif
  38         /* The device MKDEV(major, minor), this group has been created for */
  39         dev_t   dev;
  40
  41         /* total disk time and nr sectors dispatched by this group */
  42         unsigned long time;
  43         unsigned long sectors;
  44 };
  45
  46 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
  47 typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg,
  48                                                 unsigned int weight);
  49
  50 struct blkio_policy_ops {
  51         blkio_unlink_group_fn *blkio_unlink_group_fn;
  52         blkio_update_group_weight_fn *blkio_update_group_weight_fn;
  53 };
  54
  55 struct blkio_policy_type {
  56         struct list_head list;
  57         struct blkio_policy_ops ops;
  58 };
  59
  60 /* Blkio controller policy registration */
  61 extern void blkio_policy_register(struct blkio_policy_type *);
  62 extern void blkio_policy_unregister(struct blkio_policy_type *);
  63
  64 #else
  65
  66 struct blkio_group {
  67 };
  68
  69 struct blkio_policy_type {
  70 };
  71
  72 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
  73 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
  74
  75 #endif
  76
  77 #define BLKIO_WEIGHT_MIN        100
  78 #define BLKIO_WEIGHT_MAX        1000
  79 #define BLKIO_WEIGHT_DEFAULT    500
  80
  81 #ifdef CONFIG_DEBUG_BLK_CGROUP
  82 static inline char *blkg_path(struct blkio_group *blkg)
  83 {
  84         return blkg->path;
  85 }
  86 void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg,
  87                                 unsigned long dequeue);
  88 #else
  89 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
  90 static inline void blkiocg_update_blkio_group_dequeue_stats(
  91                         struct blkio_group *blkg, unsigned long dequeue) {}
  92 #endif
  93
  94 #ifdef CONFIG_BLK_CGROUP
  95 extern struct blkio_cgroup blkio_root_cgroup;
  96 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
  97 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
  98                         struct blkio_group *blkg, void *key, dev_t dev);
  99 extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
 100 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
 101                                                 void *key);
 102 void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
 103                         unsigned long time, unsigned long sectors);
 104 #else
 105 struct cgroup;
 106 static inline struct blkio_cgroup *
 107 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
 108
 109 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 110                         struct blkio_group *blkg, void *key, dev_t dev)
 111 {
 112 }
 113
 114 static inline int
 115 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
 116
 117 static inline struct blkio_group *
 118 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
 119 static inline void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
 120                         unsigned long time, unsigned long sectors)
 121 {
 122 }
 123 #endif
 124 #endif /* _BLK_CGROUP_H */