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-rw-r--r--block/blk-cgroup.h647
1 files changed, 334 insertions, 313 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 6f3ace7e792f..8ac457ce7783 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -15,350 +15,371 @@
#include <linux/cgroup.h>
#include <linux/u64_stats_sync.h>
-
-enum blkio_policy_id {
- BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */
- BLKIO_POLICY_THROTL, /* Throttling */
-};
+#include <linux/seq_file.h>
+#include <linux/radix-tree.h>
/* Max limits for throttle policy */
#define THROTL_IOPS_MAX UINT_MAX
-#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
-
-#ifndef CONFIG_BLK_CGROUP
-/* When blk-cgroup is a module, its subsys_id isn't a compile-time constant */
-extern struct cgroup_subsys blkio_subsys;
-#define blkio_subsys_id blkio_subsys.subsys_id
-#endif
-
-enum stat_type {
- /* Total time spent (in ns) between request dispatch to the driver and
- * request completion for IOs doen by this cgroup. This may not be
- * accurate when NCQ is turned on. */
- BLKIO_STAT_SERVICE_TIME = 0,
- /* Total time spent waiting in scheduler queue in ns */
- BLKIO_STAT_WAIT_TIME,
- /* Number of IOs queued up */
- BLKIO_STAT_QUEUED,
- /* All the single valued stats go below this */
- BLKIO_STAT_TIME,
-#ifdef CONFIG_DEBUG_BLK_CGROUP
- /* Time not charged to this cgroup */
- BLKIO_STAT_UNACCOUNTED_TIME,
- BLKIO_STAT_AVG_QUEUE_SIZE,
- BLKIO_STAT_IDLE_TIME,
- BLKIO_STAT_EMPTY_TIME,
- BLKIO_STAT_GROUP_WAIT_TIME,
- BLKIO_STAT_DEQUEUE
-#endif
-};
+/* CFQ specific, out here for blkcg->cfq_weight */
+#define CFQ_WEIGHT_MIN 10
+#define CFQ_WEIGHT_MAX 1000
+#define CFQ_WEIGHT_DEFAULT 500
-/* Per cpu stats */
-enum stat_type_cpu {
- BLKIO_STAT_CPU_SECTORS,
- /* Total bytes transferred */
- BLKIO_STAT_CPU_SERVICE_BYTES,
- /* Total IOs serviced, post merge */
- BLKIO_STAT_CPU_SERVICED,
- /* Number of IOs merged */
- BLKIO_STAT_CPU_MERGED,
- BLKIO_STAT_CPU_NR
-};
+#ifdef CONFIG_BLK_CGROUP
-enum stat_sub_type {
- BLKIO_STAT_READ = 0,
- BLKIO_STAT_WRITE,
- BLKIO_STAT_SYNC,
- BLKIO_STAT_ASYNC,
- BLKIO_STAT_TOTAL
-};
+enum blkg_rwstat_type {
+ BLKG_RWSTAT_READ,
+ BLKG_RWSTAT_WRITE,
+ BLKG_RWSTAT_SYNC,
+ BLKG_RWSTAT_ASYNC,
-/* blkg state flags */
-enum blkg_state_flags {
- BLKG_waiting = 0,
- BLKG_idling,
- BLKG_empty,
+ BLKG_RWSTAT_NR,
+ BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR,
};
-/* cgroup files owned by proportional weight policy */
-enum blkcg_file_name_prop {
- BLKIO_PROP_weight = 1,
- BLKIO_PROP_weight_device,
- BLKIO_PROP_io_service_bytes,
- BLKIO_PROP_io_serviced,
- BLKIO_PROP_time,
- BLKIO_PROP_sectors,
- BLKIO_PROP_unaccounted_time,
- BLKIO_PROP_io_service_time,
- BLKIO_PROP_io_wait_time,
- BLKIO_PROP_io_merged,
- BLKIO_PROP_io_queued,
- BLKIO_PROP_avg_queue_size,
- BLKIO_PROP_group_wait_time,
- BLKIO_PROP_idle_time,
- BLKIO_PROP_empty_time,
- BLKIO_PROP_dequeue,
-};
+struct blkcg_gq;
-/* cgroup files owned by throttle policy */
-enum blkcg_file_name_throtl {
- BLKIO_THROTL_read_bps_device,
- BLKIO_THROTL_write_bps_device,
- BLKIO_THROTL_read_iops_device,
- BLKIO_THROTL_write_iops_device,
- BLKIO_THROTL_io_service_bytes,
- BLKIO_THROTL_io_serviced,
-};
+struct blkcg {
+ struct cgroup_subsys_state css;
+ spinlock_t lock;
-struct blkio_cgroup {
- struct cgroup_subsys_state css;
- unsigned int weight;
- spinlock_t lock;
- struct hlist_head blkg_list;
- struct list_head policy_list; /* list of blkio_policy_node */
-};
+ struct radix_tree_root blkg_tree;
+ struct blkcg_gq *blkg_hint;
+ struct hlist_head blkg_list;
+
+ /* for policies to test whether associated blkcg has changed */
+ uint64_t id;
-struct blkio_group_stats {
- /* total disk time and nr sectors dispatched by this group */
- uint64_t time;
- uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
-#ifdef CONFIG_DEBUG_BLK_CGROUP
- /* Time not charged to this cgroup */
- uint64_t unaccounted_time;
-
- /* Sum of number of IOs queued across all samples */
- uint64_t avg_queue_size_sum;
- /* Count of samples taken for average */
- uint64_t avg_queue_size_samples;
- /* How many times this group has been removed from service tree */
- unsigned long dequeue;
-
- /* Total time spent waiting for it to be assigned a timeslice. */
- uint64_t group_wait_time;
- uint64_t start_group_wait_time;
-
- /* Time spent idling for this blkio_group */
- uint64_t idle_time;
- uint64_t start_idle_time;
- /*
- * Total time when we have requests queued and do not contain the
- * current active queue.
- */
- uint64_t empty_time;
- uint64_t start_empty_time;
- uint16_t flags;
-#endif
+ /* TODO: per-policy storage in blkcg */
+ unsigned int cfq_weight; /* belongs to cfq */
};
-/* Per cpu blkio group stats */
-struct blkio_group_stats_cpu {
- uint64_t sectors;
- uint64_t stat_arr_cpu[BLKIO_STAT_CPU_NR][BLKIO_STAT_TOTAL];
- struct u64_stats_sync syncp;
+struct blkg_stat {
+ struct u64_stats_sync syncp;
+ uint64_t cnt;
};
-struct blkio_group {
- /* An rcu protected unique identifier for the group */
- void *key;
- struct hlist_node blkcg_node;
- unsigned short blkcg_id;
- /* Store cgroup path */
- char path[128];
- /* The device MKDEV(major, minor), this group has been created for */
- dev_t dev;
- /* policy which owns this blk group */
- enum blkio_policy_id plid;
-
- /* Need to serialize the stats in the case of reset/update */
- spinlock_t stats_lock;
- struct blkio_group_stats stats;
- /* Per cpu stats pointer */
- struct blkio_group_stats_cpu __percpu *stats_cpu;
+struct blkg_rwstat {
+ struct u64_stats_sync syncp;
+ uint64_t cnt[BLKG_RWSTAT_NR];
};
-struct blkio_policy_node {
- struct list_head node;
- dev_t dev;
- /* This node belongs to max bw policy or porportional weight policy */
- enum blkio_policy_id plid;
- /* cgroup file to which this rule belongs to */
- int fileid;
-
- union {
- unsigned int weight;
- /*
- * Rate read/write in terms of bytes per second
- * Whether this rate represents read or write is determined
- * by file type "fileid".
- */
- u64 bps;
- unsigned int iops;
- } val;
+/*
+ * A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a
+ * request_queue (q). This is used by blkcg policies which need to track
+ * information per blkcg - q pair.
+ *
+ * There can be multiple active blkcg policies and each has its private
+ * data on each blkg, the size of which is determined by
+ * blkcg_policy->pd_size. blkcg core allocates and frees such areas
+ * together with blkg and invokes pd_init/exit_fn() methods.
+ *
+ * Such private data must embed struct blkg_policy_data (pd) at the
+ * beginning and pd_size can't be smaller than pd.
+ */
+struct blkg_policy_data {
+ /* the blkg this per-policy data belongs to */
+ struct blkcg_gq *blkg;
+
+ /* used during policy activation */
+ struct list_head alloc_node;
};
-extern unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
- dev_t dev);
-extern uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg,
- dev_t dev);
-extern uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg,
- dev_t dev);
-extern unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg,
- dev_t dev);
-extern unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg,
- dev_t dev);
-
-typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
-
-typedef void (blkio_update_group_weight_fn) (void *key,
- struct blkio_group *blkg, unsigned int weight);
-typedef void (blkio_update_group_read_bps_fn) (void * key,
- struct blkio_group *blkg, u64 read_bps);
-typedef void (blkio_update_group_write_bps_fn) (void *key,
- struct blkio_group *blkg, u64 write_bps);
-typedef void (blkio_update_group_read_iops_fn) (void *key,
- struct blkio_group *blkg, unsigned int read_iops);
-typedef void (blkio_update_group_write_iops_fn) (void *key,
- struct blkio_group *blkg, unsigned int write_iops);
-
-struct blkio_policy_ops {
- blkio_unlink_group_fn *blkio_unlink_group_fn;
- blkio_update_group_weight_fn *blkio_update_group_weight_fn;
- blkio_update_group_read_bps_fn *blkio_update_group_read_bps_fn;
- blkio_update_group_write_bps_fn *blkio_update_group_write_bps_fn;
- blkio_update_group_read_iops_fn *blkio_update_group_read_iops_fn;
- blkio_update_group_write_iops_fn *blkio_update_group_write_iops_fn;
+/* association between a blk cgroup and a request queue */
+struct blkcg_gq {
+ /* Pointer to the associated request_queue */
+ struct request_queue *q;
+ struct list_head q_node;
+ struct hlist_node blkcg_node;
+ struct blkcg *blkcg;
+ /* reference count */
+ int refcnt;
+
+ struct blkg_policy_data *pd[BLKCG_MAX_POLS];
+
+ struct rcu_head rcu_head;
};
-struct blkio_policy_type {
- struct list_head list;
- struct blkio_policy_ops ops;
- enum blkio_policy_id plid;
+typedef void (blkcg_pol_init_pd_fn)(struct blkcg_gq *blkg);
+typedef void (blkcg_pol_exit_pd_fn)(struct blkcg_gq *blkg);
+typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkcg_gq *blkg);
+
+struct blkcg_policy {
+ int plid;
+ /* policy specific private data size */
+ size_t pd_size;
+ /* cgroup files for the policy */
+ struct cftype *cftypes;
+
+ /* operations */
+ blkcg_pol_init_pd_fn *pd_init_fn;
+ blkcg_pol_exit_pd_fn *pd_exit_fn;
+ blkcg_pol_reset_pd_stats_fn *pd_reset_stats_fn;
};
+extern struct blkcg blkcg_root;
+
+struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup);
+struct blkcg *bio_blkcg(struct bio *bio);
+struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, struct request_queue *q);
+struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
+ struct request_queue *q);
+int blkcg_init_queue(struct request_queue *q);
+void blkcg_drain_queue(struct request_queue *q);
+void blkcg_exit_queue(struct request_queue *q);
+
/* Blkio controller policy registration */
-extern void blkio_policy_register(struct blkio_policy_type *);
-extern void blkio_policy_unregister(struct blkio_policy_type *);
+int blkcg_policy_register(struct blkcg_policy *pol);
+void blkcg_policy_unregister(struct blkcg_policy *pol);
+int blkcg_activate_policy(struct request_queue *q,
+ const struct blkcg_policy *pol);
+void blkcg_deactivate_policy(struct request_queue *q,
+ const struct blkcg_policy *pol);
+
+void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
+ u64 (*prfill)(struct seq_file *,
+ struct blkg_policy_data *, int),
+ const struct blkcg_policy *pol, int data,
+ bool show_total);
+u64 __blkg_prfill_u64(struct seq_file *sf, struct blkg_policy_data *pd, u64 v);
+u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
+ const struct blkg_rwstat *rwstat);
+u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off);
+u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
+ int off);
+
+struct blkg_conf_ctx {
+ struct gendisk *disk;
+ struct blkcg_gq *blkg;
+ u64 v;
+};
+
+int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
+ const char *input, struct blkg_conf_ctx *ctx);
+void blkg_conf_finish(struct blkg_conf_ctx *ctx);
+
+
+/**
+ * blkg_to_pdata - get policy private data
+ * @blkg: blkg of interest
+ * @pol: policy of interest
+ *
+ * Return pointer to private data associated with the @blkg-@pol pair.
+ */
+static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
+ struct blkcg_policy *pol)
+{
+ return blkg ? blkg->pd[pol->plid] : NULL;
+}
+
+/**
+ * pdata_to_blkg - get blkg associated with policy private data
+ * @pd: policy private data of interest
+ *
+ * @pd is policy private data. Determine the blkg it's associated with.
+ */
+static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd)
+{
+ return pd ? pd->blkg : NULL;
+}
+
+/**
+ * blkg_path - format cgroup path of blkg
+ * @blkg: blkg of interest
+ * @buf: target buffer
+ * @buflen: target buffer length
+ *
+ * Format the path of the cgroup of @blkg into @buf.
+ */
+static inline int blkg_path(struct blkcg_gq *blkg, char *buf, int buflen)
+{
+ int ret;
+
+ rcu_read_lock();
+ ret = cgroup_path(blkg->blkcg->css.cgroup, buf, buflen);
+ rcu_read_unlock();
+ if (ret)
+ strncpy(buf, "<unavailable>", buflen);
+ return ret;
+}
-static inline char *blkg_path(struct blkio_group *blkg)
+/**
+ * blkg_get - get a blkg reference
+ * @blkg: blkg to get
+ *
+ * The caller should be holding queue_lock and an existing reference.
+ */
+static inline void blkg_get(struct blkcg_gq *blkg)
{
- return blkg->path;
+ lockdep_assert_held(blkg->q->queue_lock);
+ WARN_ON_ONCE(!blkg->refcnt);
+ blkg->refcnt++;
}
-#else
+void __blkg_release(struct blkcg_gq *blkg);
-struct blkio_group {
+/**
+ * blkg_put - put a blkg reference
+ * @blkg: blkg to put
+ *
+ * The caller should be holding queue_lock.
+ */
+static inline void blkg_put(struct blkcg_gq *blkg)
+{
+ lockdep_assert_held(blkg->q->queue_lock);
+ WARN_ON_ONCE(blkg->refcnt <= 0);
+ if (!--blkg->refcnt)
+ __blkg_release(blkg);
+}
+
+/**
+ * blkg_stat_add - add a value to a blkg_stat
+ * @stat: target blkg_stat
+ * @val: value to add
+ *
+ * Add @val to @stat. The caller is responsible for synchronizing calls to
+ * this function.
+ */
+static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val)
+{
+ u64_stats_update_begin(&stat->syncp);
+ stat->cnt += val;
+ u64_stats_update_end(&stat->syncp);
+}
+
+/**
+ * blkg_stat_read - read the current value of a blkg_stat
+ * @stat: blkg_stat to read
+ *
+ * Read the current value of @stat. This function can be called without
+ * synchroniztion and takes care of u64 atomicity.
+ */
+static inline uint64_t blkg_stat_read(struct blkg_stat *stat)
+{
+ unsigned int start;
+ uint64_t v;
+
+ do {
+ start = u64_stats_fetch_begin(&stat->syncp);
+ v = stat->cnt;
+ } while (u64_stats_fetch_retry(&stat->syncp, start));
+
+ return v;
+}
+
+/**
+ * blkg_stat_reset - reset a blkg_stat
+ * @stat: blkg_stat to reset
+ */
+static inline void blkg_stat_reset(struct blkg_stat *stat)
+{
+ stat->cnt = 0;
+}
+
+/**
+ * blkg_rwstat_add - add a value to a blkg_rwstat
+ * @rwstat: target blkg_rwstat
+ * @rw: mask of REQ_{WRITE|SYNC}
+ * @val: value to add
+ *
+ * Add @val to @rwstat. The counters are chosen according to @rw. The
+ * caller is responsible for synchronizing calls to this function.
+ */
+static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat,
+ int rw, uint64_t val)
+{
+ u64_stats_update_begin(&rwstat->syncp);
+
+ if (rw & REQ_WRITE)
+ rwstat->cnt[BLKG_RWSTAT_WRITE] += val;
+ else
+ rwstat->cnt[BLKG_RWSTAT_READ] += val;
+ if (rw & REQ_SYNC)
+ rwstat->cnt[BLKG_RWSTAT_SYNC] += val;
+ else
+ rwstat->cnt[BLKG_RWSTAT_ASYNC] += val;
+
+ u64_stats_update_end(&rwstat->syncp);
+}
+
+/**
+ * blkg_rwstat_read - read the current values of a blkg_rwstat
+ * @rwstat: blkg_rwstat to read
+ *
+ * Read the current snapshot of @rwstat and return it as the return value.
+ * This function can be called without synchronization and takes care of
+ * u64 atomicity.
+ */
+static inline struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat)
+{
+ unsigned int start;
+ struct blkg_rwstat tmp;
+
+ do {
+ start = u64_stats_fetch_begin(&rwstat->syncp);
+ tmp = *rwstat;
+ } while (u64_stats_fetch_retry(&rwstat->syncp, start));
+
+ return tmp;
+}
+
+/**
+ * blkg_rwstat_sum - read the total count of a blkg_rwstat
+ * @rwstat: blkg_rwstat to read
+ *
+ * Return the total count of @rwstat regardless of the IO direction. This
+ * function can be called without synchronization and takes care of u64
+ * atomicity.
+ */
+static inline uint64_t blkg_rwstat_sum(struct blkg_rwstat *rwstat)
+{
+ struct blkg_rwstat tmp = blkg_rwstat_read(rwstat);
+
+ return tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE];
+}
+
+/**
+ * blkg_rwstat_reset - reset a blkg_rwstat
+ * @rwstat: blkg_rwstat to reset
+ */
+static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat)
+{
+ memset(rwstat->cnt, 0, sizeof(rwstat->cnt));
+}
+
+#else /* CONFIG_BLK_CGROUP */
+
+struct cgroup;
+
+struct blkg_policy_data {
};
-struct blkio_policy_type {
+struct blkcg_gq {
};
-static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
-static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
-
-static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
-
-#endif
-
-#define BLKIO_WEIGHT_MIN 10
-#define BLKIO_WEIGHT_MAX 1000
-#define BLKIO_WEIGHT_DEFAULT 500
-
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
-void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
- unsigned long dequeue);
-void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg);
-void blkiocg_update_idle_time_stats(struct blkio_group *blkg);
-void blkiocg_set_start_empty_time(struct blkio_group *blkg);
-
-#define BLKG_FLAG_FNS(name) \
-static inline void blkio_mark_blkg_##name( \
- struct blkio_group_stats *stats) \
-{ \
- stats->flags |= (1 << BLKG_##name); \
-} \
-static inline void blkio_clear_blkg_##name( \
- struct blkio_group_stats *stats) \
-{ \
- stats->flags &= ~(1 << BLKG_##name); \
-} \
-static inline int blkio_blkg_##name(struct blkio_group_stats *stats) \
-{ \
- return (stats->flags & (1 << BLKG_##name)) != 0; \
-} \
-
-BLKG_FLAG_FNS(waiting)
-BLKG_FLAG_FNS(idling)
-BLKG_FLAG_FNS(empty)
-#undef BLKG_FLAG_FNS
-#else
-static inline void blkiocg_update_avg_queue_size_stats(
- struct blkio_group *blkg) {}
-static inline void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
- unsigned long dequeue) {}
-static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg)
-{}
-static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg) {}
-static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg) {}
-#endif
-
-#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
-extern struct blkio_cgroup blkio_root_cgroup;
-extern struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup);
-extern struct blkio_cgroup *task_blkio_cgroup(struct task_struct *tsk);
-extern void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
- struct blkio_group *blkg, void *key, dev_t dev,
- enum blkio_policy_id plid);
-extern int blkio_alloc_blkg_stats(struct blkio_group *blkg);
-extern int blkiocg_del_blkio_group(struct blkio_group *blkg);
-extern struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg,
- void *key);
-void blkiocg_update_timeslice_used(struct blkio_group *blkg,
- unsigned long time,
- unsigned long unaccounted_time);
-void blkiocg_update_dispatch_stats(struct blkio_group *blkg, uint64_t bytes,
- bool direction, bool sync);
-void blkiocg_update_completion_stats(struct blkio_group *blkg,
- uint64_t start_time, uint64_t io_start_time, bool direction, bool sync);
-void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
- bool sync);
-void blkiocg_update_io_add_stats(struct blkio_group *blkg,
- struct blkio_group *curr_blkg, bool direction, bool sync);
-void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
- bool direction, bool sync);
-#else
-struct cgroup;
-static inline struct blkio_cgroup *
-cgroup_to_blkio_cgroup(struct cgroup *cgroup) { return NULL; }
-static inline struct blkio_cgroup *
-task_blkio_cgroup(struct task_struct *tsk) { return NULL; }
-
-static inline void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
- struct blkio_group *blkg, void *key, dev_t dev,
- enum blkio_policy_id plid) {}
-
-static inline int blkio_alloc_blkg_stats(struct blkio_group *blkg) { return 0; }
-
-static inline int
-blkiocg_del_blkio_group(struct blkio_group *blkg) { return 0; }
-
-static inline struct blkio_group *
-blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
-static inline void blkiocg_update_timeslice_used(struct blkio_group *blkg,
- unsigned long time,
- unsigned long unaccounted_time)
-{}
-static inline void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
- uint64_t bytes, bool direction, bool sync) {}
-static inline void blkiocg_update_completion_stats(struct blkio_group *blkg,
- uint64_t start_time, uint64_t io_start_time, bool direction,
- bool sync) {}
-static inline void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
- bool direction, bool sync) {}
-static inline void blkiocg_update_io_add_stats(struct blkio_group *blkg,
- struct blkio_group *curr_blkg, bool direction, bool sync) {}
-static inline void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
- bool direction, bool sync) {}
-#endif
-#endif /* _BLK_CGROUP_H */
+struct blkcg_policy {
+};
+
+static inline struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup) { return NULL; }
+static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; }
+static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; }
+static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
+static inline void blkcg_drain_queue(struct request_queue *q) { }
+static inline void blkcg_exit_queue(struct request_queue *q) { }
+static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; }
+static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { }
+static inline int blkcg_activate_policy(struct request_queue *q,
+ const struct blkcg_policy *pol) { return 0; }
+static inline void blkcg_deactivate_policy(struct request_queue *q,
+ const struct blkcg_policy *pol) { }
+
+static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
+ struct blkcg_policy *pol) { return NULL; }
+static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; }
+static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; }
+static inline void blkg_get(struct blkcg_gq *blkg) { }
+static inline void blkg_put(struct blkcg_gq *blkg) { }
+
+#endif /* CONFIG_BLK_CGROUP */
+#endif /* _BLK_CGROUP_H */