1 files changed, 209 insertions, 115 deletions

diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 6f3ace7e792f..1cb8f7643258 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -19,28 +19,27 @@
 enum blkio_policy_id {
 	BLKIO_POLICY_PROP = 0,		/* Proportional Bandwidth division */
 	BLKIO_POLICY_THROTL,		/* Throttling */
+
+	BLKIO_NR_POLICIES,
 };
 
 /* 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
+#ifdef CONFIG_BLK_CGROUP
 
 enum stat_type {
+	/* Number of IOs merged */
+	BLKIO_STAT_MERGED,
 	/* 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,
+	BLKIO_STAT_SERVICE_TIME,
 	/* 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
@@ -54,6 +53,9 @@ enum stat_type {
 #endif
 };
 
+/* Types lower than this live in stat_arr and have subtypes */
+#define BLKIO_STAT_ARR_NR	(BLKIO_STAT_QUEUED + 1)
+
 /* Per cpu stats */
 enum stat_type_cpu {
 	BLKIO_STAT_CPU_SECTORS,
@@ -61,8 +63,6 @@ enum stat_type_cpu {
 	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
 };
 
@@ -116,13 +116,16 @@ struct blkio_cgroup {
 	unsigned int weight;
 	spinlock_t lock;
 	struct hlist_head blkg_list;
-	struct list_head policy_list; /* list of blkio_policy_node */
+
+	/* for policies to test whether associated blkcg has changed */
+	uint64_t id;
 };
 
 struct blkio_group_stats {
+	struct u64_stats_sync syncp;
 	/* total disk time and nr sectors dispatched by this group */
 	uint64_t time;
-	uint64_t stat_arr[BLKIO_STAT_QUEUED + 1][BLKIO_STAT_TOTAL];
+	uint64_t stat_arr[BLKIO_STAT_ARR_NR][BLKIO_STAT_TOTAL];
 #ifdef CONFIG_DEBUG_BLK_CGROUP
 	/* Time not charged to this cgroup */
 	uint64_t unaccounted_time;
@@ -136,21 +139,31 @@ struct blkio_group_stats {
 
 	/* 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;
+
+	/* fields after this shouldn't be cleared on stat reset */
+	uint64_t start_group_wait_time;
+	uint64_t start_idle_time;
 	uint64_t start_empty_time;
 	uint16_t flags;
 #endif
 };
 
+#ifdef CONFIG_DEBUG_BLK_CGROUP
+#define BLKG_STATS_DEBUG_CLEAR_START	\
+	offsetof(struct blkio_group_stats, unaccounted_time)
+#define BLKG_STATS_DEBUG_CLEAR_SIZE	\
+	(offsetof(struct blkio_group_stats, start_group_wait_time) - \
+	 BLKG_STATS_DEBUG_CLEAR_START)
+#endif
+
 /* Per cpu blkio group stats */
 struct blkio_group_stats_cpu {
 	uint64_t sectors;
@@ -158,71 +171,60 @@ struct blkio_group_stats_cpu {
 	struct u64_stats_sync syncp;
 };
 
-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;
+struct blkio_group_conf {
+	unsigned int weight;
+	unsigned int iops[2];
+	u64 bps[2];
+};
+
+/* per-blkg per-policy data */
+struct blkg_policy_data {
+	/* the blkg this per-policy data belongs to */
+	struct blkio_group *blkg;
+
+	/* Configuration */
+	struct blkio_group_conf conf;
 
-	/* 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 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;
+	/* pol->pdata_size bytes of private data used by policy impl */
+	char pdata[] __aligned(__alignof__(unsigned long long));
 };
 
-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);
+struct blkio_group {
+	/* Pointer to the associated request_queue */
+	struct request_queue *q;
+	struct list_head q_node;
+	struct hlist_node blkcg_node;
+	struct blkio_cgroup *blkcg;
+	/* Store cgroup path */
+	char path[128];
+	/* reference count */
+	int refcnt;
 
-typedef void (blkio_unlink_group_fn) (void *key, struct blkio_group *blkg);
+	struct blkg_policy_data *pd[BLKIO_NR_POLICIES];
+
+	/* List of blkg waiting for per cpu stats memory to be allocated */
+	struct list_head alloc_node;
+	struct rcu_head rcu_head;
+};
 
-typedef void (blkio_update_group_weight_fn) (void *key,
+typedef void (blkio_init_group_fn)(struct blkio_group *blkg);
+typedef void (blkio_update_group_weight_fn)(struct request_queue *q,
 			struct blkio_group *blkg, unsigned int weight);
-typedef void (blkio_update_group_read_bps_fn) (void * key,
+typedef void (blkio_update_group_read_bps_fn)(struct request_queue *q,
 			struct blkio_group *blkg, u64 read_bps);
-typedef void (blkio_update_group_write_bps_fn) (void *key,
+typedef void (blkio_update_group_write_bps_fn)(struct request_queue *q,
 			struct blkio_group *blkg, u64 write_bps);
-typedef void (blkio_update_group_read_iops_fn) (void *key,
+typedef void (blkio_update_group_read_iops_fn)(struct request_queue *q,
 			struct blkio_group *blkg, unsigned int read_iops);
-typedef void (blkio_update_group_write_iops_fn) (void *key,
+typedef void (blkio_update_group_write_iops_fn)(struct request_queue *q,
 			struct blkio_group *blkg, unsigned int write_iops);
 
 struct blkio_policy_ops {
-	blkio_unlink_group_fn *blkio_unlink_group_fn;
+	blkio_init_group_fn *blkio_init_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;
@@ -234,17 +236,86 @@ struct blkio_policy_type {
 	struct list_head list;
 	struct blkio_policy_ops ops;
 	enum blkio_policy_id plid;
+	size_t pdata_size;		/* policy specific private data size */
 };
 
+extern int blkcg_init_queue(struct request_queue *q);
+extern void blkcg_drain_queue(struct request_queue *q);
+extern 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 *);
+extern void blkg_destroy_all(struct request_queue *q, bool destroy_root);
+extern void update_root_blkg_pd(struct request_queue *q,
+				enum blkio_policy_id plid);
+
+/**
+ * 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 void *blkg_to_pdata(struct blkio_group *blkg,
+			      struct blkio_policy_type *pol)
+{
+	return blkg ? blkg->pd[pol->plid]->pdata : NULL;
+}
+
+/**
+ * pdata_to_blkg - get blkg associated with policy private data
+ * @pdata: policy private data of interest
+ * @pol: policy @pdata is for
+ *
+ * @pdata is policy private data for @pol.  Determine the blkg it's
+ * associated with.
+ */
+static inline struct blkio_group *pdata_to_blkg(void *pdata,
+						struct blkio_policy_type *pol)
+{
+	if (pdata) {
+		struct blkg_policy_data *pd =
+			container_of(pdata, struct blkg_policy_data, pdata);
+		return pd->blkg;
+	}
+	return NULL;
+}
 
 static inline char *blkg_path(struct blkio_group *blkg)
 {
 	return blkg->path;
 }
 
+/**
+ * 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 blkio_group *blkg)
+{
+	lockdep_assert_held(blkg->q->queue_lock);
+	WARN_ON_ONCE(!blkg->refcnt);
+	blkg->refcnt++;
+}
+
+void __blkg_release(struct blkio_group *blkg);
+
+/**
+ * blkg_put - put a blkg reference
+ * @blkg: blkg to put
+ *
+ * The caller should be holding queue_lock.
+ */
+static inline void blkg_put(struct blkio_group *blkg)
+{
+	lockdep_assert_held(blkg->q->queue_lock);
+	WARN_ON_ONCE(blkg->refcnt <= 0);
+	if (!--blkg->refcnt)
+		__blkg_release(blkg);
+}
+
 #else
 
 struct blkio_group {
@@ -253,10 +324,23 @@ struct blkio_group {
 struct blkio_policy_type {
 };
 
+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 void blkio_policy_register(struct blkio_policy_type *blkiop) { }
 static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
-
+static inline void blkg_destroy_all(struct request_queue *q,
+				    bool destory_root) { }
+static inline void update_root_blkg_pd(struct request_queue *q,
+				       enum blkio_policy_id plid) { }
+
+static inline void *blkg_to_pdata(struct blkio_group *blkg,
+				struct blkio_policy_type *pol) { return NULL; }
+static inline struct blkio_group *pdata_to_blkg(void *pdata,
+				struct blkio_policy_type *pol) { return NULL; }
 static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
+static inline void blkg_get(struct blkio_group *blkg) { }
+static inline void blkg_put(struct blkio_group *blkg) { }
 
 #endif
 
@@ -265,12 +349,17 @@ static inline char *blkg_path(struct blkio_group *blkg) { return NULL; }
 #define BLKIO_WEIGHT_DEFAULT	500
 
 #ifdef CONFIG_DEBUG_BLK_CGROUP
-void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg);
+void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg,
+					 struct blkio_policy_type *pol);
 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);
+				  struct blkio_policy_type *pol,
+				  unsigned long dequeue);
+void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg,
+					struct blkio_policy_type *pol);
+void blkiocg_update_idle_time_stats(struct blkio_group *blkg,
+				    struct blkio_policy_type *pol);
+void blkiocg_set_start_empty_time(struct blkio_group *blkg,
+				  struct blkio_policy_type *pol);
 
 #define BLKG_FLAG_FNS(name)						\
 static inline void blkio_mark_blkg_##name(				\
@@ -293,72 +382,77 @@ 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_avg_queue_size_stats(struct blkio_group *blkg,
+			struct blkio_policy_type *pol) { }
 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) {}
+			struct blkio_policy_type *pol, unsigned long dequeue) { }
+static inline void blkiocg_update_set_idle_time_stats(struct blkio_group *blkg,
+			struct blkio_policy_type *pol) { }
+static inline void blkiocg_update_idle_time_stats(struct blkio_group *blkg,
+			struct blkio_policy_type *pol) { }
+static inline void blkiocg_set_start_empty_time(struct blkio_group *blkg,
+			struct blkio_policy_type *pol) { }
 #endif
 
-#if defined(CONFIG_BLK_CGROUP) || defined(CONFIG_BLK_CGROUP_MODULE)
+#ifdef CONFIG_BLK_CGROUP
 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);
+extern struct blkio_cgroup *bio_blkio_cgroup(struct bio *bio);
+extern struct blkio_group *blkg_lookup(struct blkio_cgroup *blkcg,
+				       struct request_queue *q);
+struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg,
+				       struct request_queue *q,
+				       enum blkio_policy_id plid,
+				       bool for_root);
 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);
+				   struct blkio_policy_type *pol,
+				   unsigned long time,
+				   unsigned long unaccounted_time);
+void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
+				   struct blkio_policy_type *pol,
+				   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);
+				     struct blkio_policy_type *pol,
+				     uint64_t start_time,
+				     uint64_t io_start_time, bool direction,
+				     bool sync);
+void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
+				    struct blkio_policy_type *pol,
+				    bool direction, bool sync);
 void blkiocg_update_io_add_stats(struct blkio_group *blkg,
-		struct blkio_group *curr_blkg, bool direction, bool sync);
+				 struct blkio_policy_type *pol,
+				 struct blkio_group *curr_blkg, bool direction,
+				 bool sync);
 void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
-					bool direction, bool sync);
+				    struct blkio_policy_type *pol,
+				    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; }
+bio_blkio_cgroup(struct bio *bio) { return NULL; }
 
-static inline struct blkio_group *
-blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key) { return NULL; }
+static inline struct blkio_group *blkg_lookup(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)
-{}
+			struct blkio_policy_type *pol, 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) {}
+			struct blkio_policy_type *pol, 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) {}
+			struct blkio_policy_type *pol, 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) {}
+			struct blkio_policy_type *pol, 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) {}
+			struct blkio_policy_type *pol,
+			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) {}
+			struct blkio_policy_type *pol, bool direction,
+			bool sync) { }
 #endif
 #endif /* _BLK_CGROUP_H */