Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block

* 'for-3.3/core' of git://git.kernel.dk/linux-block: (37 commits)
  Revert "block: recursive merge requests"
  block: Stop using macro stubs for the bio data integrity calls
  blockdev: convert some macros to static inlines
  fs: remove unneeded plug in mpage_readpages()
  block: Add BLKROTATIONAL ioctl
  block: Introduce blk_set_stacking_limits function
  block: remove WARN_ON_ONCE() in exit_io_context()
  block: an exiting task should be allowed to create io_context
  block: ioc_cgroup_changed() needs to be exported
  block: recursive merge requests
  block, cfq: fix empty queue crash caused by request merge
  block, cfq: move icq creation and rq->elv.icq association to block core
  block, cfq: restructure io_cq creation path for io_context interface cleanup
  block, cfq: move io_cq exit/release to blk-ioc.c
  block, cfq: move icq cache management to block core
  block, cfq: move io_cq lookup to blk-ioc.c
  block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq
  block, cfq: reorganize cfq_io_context into generic and cfq specific parts
  block: remove elevator_queue->ops
  block: reorder elevator switch sequence
  ...

Fix up conflicts in:
 - block/blk-cgroup.c
	Switch from can_attach_task to can_attach
 - block/cfq-iosched.c
	conflict with now removed cic index changes (we now use q->id instead)

1 files changed, 19 insertions, 22 deletions

diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 1d0f7a2ff73b..c24f3d7fbf1e 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -5,6 +5,8 @@
 
 #ifdef CONFIG_BLOCK
 
+struct io_cq;
+
 typedef int (elevator_merge_fn) (struct request_queue *, struct request **,
 				 struct bio *);
 
@@ -24,6 +26,8 @@ typedef struct request *(elevator_request_list_fn) (struct request_queue *, stru
 typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *);
 typedef int (elevator_may_queue_fn) (struct request_queue *, int);
 
+typedef void (elevator_init_icq_fn) (struct io_cq *);
+typedef void (elevator_exit_icq_fn) (struct io_cq *);
 typedef int (elevator_set_req_fn) (struct request_queue *, struct request *, gfp_t);
 typedef void (elevator_put_req_fn) (struct request *);
 typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *);
@@ -56,6 +60,9 @@ struct elevator_ops
 	elevator_request_list_fn *elevator_former_req_fn;
 	elevator_request_list_fn *elevator_latter_req_fn;
 
+	elevator_init_icq_fn *elevator_init_icq_fn;	/* see iocontext.h */
+	elevator_exit_icq_fn *elevator_exit_icq_fn;	/* ditto */
+
 	elevator_set_req_fn *elevator_set_req_fn;
 	elevator_put_req_fn *elevator_put_req_fn;
 
@@ -63,7 +70,6 @@ struct elevator_ops
 
 	elevator_init_fn *elevator_init_fn;
 	elevator_exit_fn *elevator_exit_fn;
-	void (*trim)(struct io_context *);
 };
 
 #define ELV_NAME_MAX	(16)
@@ -79,11 +85,20 @@ struct elv_fs_entry {
  */
 struct elevator_type
 {
-	struct list_head list;
+	/* managed by elevator core */
+	struct kmem_cache *icq_cache;
+
+	/* fields provided by elevator implementation */
 	struct elevator_ops ops;
+	size_t icq_size;	/* see iocontext.h */
+	size_t icq_align;	/* ditto */
 	struct elv_fs_entry *elevator_attrs;
 	char elevator_name[ELV_NAME_MAX];
 	struct module *elevator_owner;
+
+	/* managed by elevator core */
+	char icq_cache_name[ELV_NAME_MAX + 5];	/* elvname + "_io_cq" */
+	struct list_head list;
 };
 
 /*
@@ -91,10 +106,9 @@ struct elevator_type
  */
 struct elevator_queue
 {
-	struct elevator_ops *ops;
+	struct elevator_type *type;
 	void *elevator_data;
 	struct kobject kobj;
-	struct elevator_type *elevator_type;
 	struct mutex sysfs_lock;
 	struct hlist_head *hash;
 	unsigned int registered:1;
@@ -129,7 +143,7 @@ extern void elv_drain_elevator(struct request_queue *);
 /*
  * io scheduler registration
  */
-extern void elv_register(struct elevator_type *);
+extern int elv_register(struct elevator_type *);
 extern void elv_unregister(struct elevator_type *);
 
 /*
@@ -197,22 +211,5 @@ enum {
 	INIT_LIST_HEAD(&(rq)->csd.list);	\
 	} while (0)
 
-/*
- * io context count accounting
- */
-#define elv_ioc_count_mod(name, __val) this_cpu_add(name, __val)
-#define elv_ioc_count_inc(name)	this_cpu_inc(name)
-#define elv_ioc_count_dec(name)	this_cpu_dec(name)
-
-#define elv_ioc_count_read(name)				\
-({								\
-	unsigned long __val = 0;				\
-	int __cpu;						\
-	smp_wmb();						\
-	for_each_possible_cpu(__cpu)				\
-		__val += per_cpu(name, __cpu);			\
-	__val;							\
-})
-
 #endif /* CONFIG_BLOCK */
 #endif