blkcg: add blkcg_{init|drain|exit}_queue()

Currently block core calls directly into blk-throttle for init, drain and exit. This patch adds blkcg_{init|drain|exit}_queue() which wraps the blk-throttle functions. This is to give more control and visiblity to blkcg core layer for proper layering. Further patches will add logic common to blkcg policies to the functions. While at it, collapse blk_throtl_release() into blk_throtl_exit(). There's no reason to keep them separate. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>

blkcg: add blkcg_{init|drain|exit}_queue()
Currently block core calls directly into blk-throttle for init, drain and exit. This patch adds blkcg_{init|drain|exit}_queue() which wraps the blk-throttle functions. This is to give more control and visiblity to blkcg core layer for proper layering. Further patches will add logic common to blkcg policies to the functions. While at it, collapse blk_throtl_release() into blk_throtl_exit(). There's no reason to keep them separate. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Tejun Heo · Jens Axboe
1 parent 7ee9c56205
Showing 6 changed files with 55 additions and 10 deletions Side-by-side Diff
block/blk-cgroup.c
block/blk-cgroup.h
block/blk-core.c
block/blk-sysfs.c
block/blk-throttle.c
block/blk.h
@@ -20,6 +20,7 @@
 #include <linux/genhd.h>
 #include <linux/delay.h>
 #include "blk-cgroup.h"
+#include "blk.h"
  
 #define MAX_KEY_LEN 100
  
@@ -1457,6 +1458,47 @@
 	INIT_HLIST_HEAD(&blkcg->blkg_list);
  
 	return &blkcg->css;
+}
+
+/**
+ * blkcg_init_queue - initialize blkcg part of request queue
+ * @q: request_queue to initialize
+ *
+ * Called from blk_alloc_queue_node(). Responsible for initializing blkcg
+ * part of new request_queue @q.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int blkcg_init_queue(struct request_queue *q)
+{
+	might_sleep();
+
+	return blk_throtl_init(q);
+}
+
+/**
+ * blkcg_drain_queue - drain blkcg part of request_queue
+ * @q: request_queue to drain
+ *
+ * Called from blk_drain_queue().  Responsible for draining blkcg part.
+ */
+void blkcg_drain_queue(struct request_queue *q)
+{
+	lockdep_assert_held(q->queue_lock);
+
+	blk_throtl_drain(q);
+}
+
+/**
+ * blkcg_exit_queue - exit and release blkcg part of request_queue
+ * @q: request_queue being released
+ *
+ * Called from blk_release_queue().  Responsible for exiting blkcg part.
+ */
+void blkcg_exit_queue(struct request_queue *q)
+{
+	blk_throtl_exit(q);
 }
  
 /*
@@ -215,6 +215,10 @@
 	enum blkio_policy_id plid;
 };
  
+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 *);
@@ -233,6 +237,9 @@
 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) { }
@@ -34,6 +34,7 @@
 #include <trace/events/block.h>
  
 #include "blk.h"
+#include "blk-cgroup.h"
  
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
 EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
@@ -280,7 +281,7 @@
  *
  *     This function does not cancel any asynchronous activity arising
  *     out of elevator or throttling code. That would require elevaotor_exit()
- *     and blk_throtl_exit() to be called with queue lock initialized.
+ *     and blkcg_exit_queue() to be called with queue lock initialized.
  *
  */
 void blk_sync_queue(struct request_queue *q)
@@ -372,7 +373,7 @@
 		if (q->elevator)
 			elv_drain_elevator(q);
  
-		blk_throtl_drain(q);
+		blkcg_drain_queue(q);
  
 		/*
 		 * This function might be called on a queue which failed
@@ -562,7 +563,7 @@
 	 */
 	q->queue_lock = &q->__queue_lock;
  
-	if (blk_throtl_init(q))
+	if (blkcg_init_queue(q))
 		goto fail_id;
  
 	return q;
@@ -9,6 +9,7 @@
 #include <linux/blktrace_api.h>
  
 #include "blk.h"
+#include "blk-cgroup.h"
  
 struct queue_sysfs_entry {
 	struct attribute attr;
@@ -486,7 +487,7 @@
 		elevator_exit(q->elevator);
 	}
  
-	blk_throtl_exit(q);
+	blkcg_exit_queue(q);
  
 	if (rl->rq_pool)
 		mempool_destroy(rl->rq_pool);
@@ -494,7 +495,6 @@
 	if (q->queue_tags)
 		__blk_queue_free_tags(q);
  
-	blk_throtl_release(q);
 	blk_trace_shutdown(q);
  
 	bdi_destroy(&q->backing_dev_info);
@@ -1226,10 +1226,7 @@
 	 * it.
 	 */
 	throtl_shutdown_wq(q);
-}
  
-void blk_throtl_release(struct request_queue *q)
-{
 	kfree(q->td);
 }
  
@@ -236,7 +236,6 @@
 extern void blk_throtl_drain(struct request_queue *q);
 extern int blk_throtl_init(struct request_queue *q);
 extern void blk_throtl_exit(struct request_queue *q);
-extern void blk_throtl_release(struct request_queue *q);
 #else /* CONFIG_BLK_DEV_THROTTLING */
 static inline bool blk_throtl_bio(struct request_queue *q, struct bio *bio)
 {
@@ -245,7 +244,6 @@
 static inline void blk_throtl_drain(struct request_queue *q) { }
 static inline int blk_throtl_init(struct request_queue *q) { return 0; }
 static inline void blk_throtl_exit(struct request_queue *q) { }
-static inline void blk_throtl_release(struct request_queue *q) { }
 #endif /* CONFIG_BLK_DEV_THROTTLING */
  
 #endif /* BLK_INTERNAL_H */
...	...	@@ -20,6 +20,7 @@
20	20	#include <linux/genhd.h>
21	21	#include <linux/delay.h>
22	22	#include "blk-cgroup.h"
	23	+#include "blk.h"
23	24
24	25	#define MAX_KEY_LEN 100
25	26
...	...	@@ -1457,6 +1458,47 @@
1457	1458	INIT_HLIST_HEAD(&blkcg->blkg_list);
1458	1459
1459	1460	return &blkcg->css;
	1461	+}
	1462	+
	1463	+/**
	1464	+ * blkcg_init_queue - initialize blkcg part of request queue
	1465	+ * @q: request_queue to initialize
	1466	+ *
	1467	+ * Called from blk_alloc_queue_node(). Responsible for initializing blkcg
	1468	+ * part of new request_queue @q.
	1469	+ *
	1470	+ * RETURNS:
	1471	+ * 0 on success, -errno on failure.
	1472	+ */
	1473	+int blkcg_init_queue(struct request_queue *q)
	1474	+{
	1475	+ might_sleep();
	1476	+
	1477	+ return blk_throtl_init(q);
	1478	+}
	1479	+
	1480	+/**
	1481	+ * blkcg_drain_queue - drain blkcg part of request_queue
	1482	+ * @q: request_queue to drain
	1483	+ *
	1484	+ * Called from blk_drain_queue(). Responsible for draining blkcg part.
	1485	+ */
	1486	+void blkcg_drain_queue(struct request_queue *q)
	1487	+{
	1488	+ lockdep_assert_held(q->queue_lock);
	1489	+
	1490	+ blk_throtl_drain(q);
	1491	+}
	1492	+
	1493	+/**
	1494	+ * blkcg_exit_queue - exit and release blkcg part of request_queue
	1495	+ * @q: request_queue being released
	1496	+ *
	1497	+ * Called from blk_release_queue(). Responsible for exiting blkcg part.
	1498	+ */
	1499	+void blkcg_exit_queue(struct request_queue *q)
	1500	+{
	1501	+ blk_throtl_exit(q);
1460	1502	}
1461	1503
1462	1504	/*
...	...	@@ -215,6 +215,10 @@
215	215	enum blkio_policy_id plid;
216	216	};
217	217
	218	+extern int blkcg_init_queue(struct request_queue *q);
	219	+extern void blkcg_drain_queue(struct request_queue *q);
	220	+extern void blkcg_exit_queue(struct request_queue *q);
	221	+
218	222	/* Blkio controller policy registration */
219	223	extern void blkio_policy_register(struct blkio_policy_type *);
220	224	extern void blkio_policy_unregister(struct blkio_policy_type *);
...	...	@@ -233,6 +237,9 @@
233	237	struct blkio_policy_type {
234	238	};
235	239
	240	+static inline int blkcg_init_queue(struct request_queue *q) { return 0; }
	241	+static inline void blkcg_drain_queue(struct request_queue *q) { }
	242	+static inline void blkcg_exit_queue(struct request_queue *q) { }
236	243	static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { }
237	244	static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { }
238	245	static inline void blkg_destroy_all(struct request_queue *q) { }
...	...	@@ -34,6 +34,7 @@
34	34	#include <trace/events/block.h>
35	35
36	36	#include "blk.h"
	37	+#include "blk-cgroup.h"
37	38
38	39	EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
39	40	EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
...	...	@@ -280,7 +281,7 @@
280	281	*
281	282	* This function does not cancel any asynchronous activity arising
282	283	* out of elevator or throttling code. That would require elevaotor_exit()
283		- * and blk_throtl_exit() to be called with queue lock initialized.
	284	+ * and blkcg_exit_queue() to be called with queue lock initialized.
284	285	*
285	286	*/
286	287	void blk_sync_queue(struct request_queue *q)
...	...	@@ -372,7 +373,7 @@
372	373	if (q->elevator)
373	374	elv_drain_elevator(q);
374	375
375		- blk_throtl_drain(q);
	376	+ blkcg_drain_queue(q);
376	377
377	378	/*
378	379	* This function might be called on a queue which failed
...	...	@@ -562,7 +563,7 @@
562	563	*/
563	564	q->queue_lock = &q->__queue_lock;
564	565
565		- if (blk_throtl_init(q))
	566	+ if (blkcg_init_queue(q))
566	567	goto fail_id;
567	568
568	569	return q;
...	...	@@ -9,6 +9,7 @@
9	9	#include <linux/blktrace_api.h>
10	10
11	11	#include "blk.h"
	12	+#include "blk-cgroup.h"
12	13
13	14	struct queue_sysfs_entry {
14	15	struct attribute attr;
...	...	@@ -486,7 +487,7 @@
486	487	elevator_exit(q->elevator);
487	488	}
488	489
489		- blk_throtl_exit(q);
	490	+ blkcg_exit_queue(q);
490	491
491	492	if (rl->rq_pool)
492	493	mempool_destroy(rl->rq_pool);
...	...	@@ -494,7 +495,6 @@
494	495	if (q->queue_tags)
495	496	__blk_queue_free_tags(q);
496	497
497		- blk_throtl_release(q);
498	498	blk_trace_shutdown(q);
499	499
500	500	bdi_destroy(&q->backing_dev_info);
...	...	@@ -1226,10 +1226,7 @@
1226	1226	* it.
1227	1227	*/
1228	1228	throtl_shutdown_wq(q);
1229		-}
1230	1229
1231		-void blk_throtl_release(struct request_queue *q)
1232		-{
1233	1230	kfree(q->td);
1234	1231	}
1235	1232
...	...	@@ -236,7 +236,6 @@
236	236	extern void blk_throtl_drain(struct request_queue *q);
237	237	extern int blk_throtl_init(struct request_queue *q);
238	238	extern void blk_throtl_exit(struct request_queue *q);
239		-extern void blk_throtl_release(struct request_queue *q);
240	239	#else /* CONFIG_BLK_DEV_THROTTLING */
241	240	static inline bool blk_throtl_bio(struct request_queue q, struct bio bio)
242	241	{
...	...	@@ -245,7 +244,6 @@
245	244	static inline void blk_throtl_drain(struct request_queue *q) { }
246	245	static inline int blk_throtl_init(struct request_queue *q) { return 0; }
247	246	static inline void blk_throtl_exit(struct request_queue *q) { }
248		-static inline void blk_throtl_release(struct request_queue *q) { }
249	247	#endif /* CONFIG_BLK_DEV_THROTTLING */
250	248
251	249	#endif /* BLK_INTERNAL_H */