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 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE) 19 20 #ifndef CONFIG_BLK_CGROUP 21 /* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */ 22 extern struct cgroup_subsys blkio_subsys; 23 #define blkio_subsys_id blkio_subsys.subsys_id 24 #endif 25 26 struct blkio_cgroup { 27 struct cgroup_subsys_state css; 28 unsigned int weight; 29 spinlock_t lock; 30 struct hlist_head blkg_list; 31 }; 32 33 struct blkio_group { 34 /* An rcu protected unique identifier for the group */ 35 void *key; 36 struct hlist_node blkcg_node; 37 unsigned short blkcg_id; 38 #ifdef CONFIG_DEBUG_BLK_CGROUP 39 /* Store cgroup path */ 40 char path[128]; 41 /* How many times this group has been removed from service tree */ 42 unsigned long dequeue; 43 #endif 44 /* The device MKDEV(major, minor), this group has been created for */ 45 dev_t dev; 46 47 /* total disk time and nr sectors dispatched by this group */ 48 unsigned long time; 49 unsigned long sectors; 50 }; 51 52 typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg); 53 typedef void (blkio_update_group_weight_fn) (struct blkio_group *blkg, 54 unsigned int weight); 55 56 struct blkio_policy_ops { 57 blkio_unlink_group_fn *blkio_unlink_group_fn; 58 blkio_update_group_weight_fn *blkio_update_group_weight_fn; 59 }; 60 61 struct blkio_policy_type { 62 struct list_head list; 63 struct blkio_policy_ops ops; 64 }; 65 66 /* Blkio controller policy registration */ 67 extern void blkio_policy_register(struct blkio_policy_type *); 68 extern void blkio_policy_unregister(struct blkio_policy_type *); 69 70 #else 71 72 struct blkio_group { 73 }; 74 75 struct blkio_policy_type { 76 }; 77 78 static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { } 79 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { } 80 81 #endif 82 83 #define BLKIO_WEIGHT_MIN 100 84 #define BLKIO_WEIGHT_MAX 1000 85 #define BLKIO_WEIGHT_DEFAULT 500 86 87 #ifdef CONFIG_DEBUG_BLK_CGROUP 88 static inline char *blkg_path(struct blkio_group *blkg) 89 { 90 return blkg->path; 91 } 92 void blkiocg_update_blkio_group_dequeue_stats(struct blkio_group *blkg, 93 unsigned long dequeue); 94 #else 95 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; } 96 static inline void blkiocg_update_blkio_group_dequeue_stats( 97 struct blkio_group *blkg, unsigned long dequeue) {} 98 #endif 99 100 #if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE) 101 extern struct blkio_cgroup blkio_root_cgroup; 102 extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup); 103 extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, 104 struct blkio_group *blkg, void *key, dev_t dev); 105 extern int blkiocg_del_blkio_group(struct blkio_group *blkg); 106 extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, 107 void *key); 108 void blkiocg_update_blkio_group_stats(struct blkio_group *blkg, 109 unsigned long time, unsigned long sectors); 110 #else 111 struct cgroup; 112 static inline struct blkio_cgroup * 113 cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; } 114 115 static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg, 116 struct blkio_group *blkg, void *key, dev_t dev) 117 { 118 } 119 120 static inline int 121 blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; } 122 123 static inline struct blkio_group * 124 blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; } 125 static inline void blkiocg_update_blkio_group_stats(struct blkio_group *blkg, 126 unsigned long time, unsigned long sectors) 127 { 128 } 129 #endif 130 #endif /* _BLK_CGROUP_H */ 131