block: remove per-queue plugging

Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

8 files changed, 9 insertions, 66 deletions

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index 4ce34fa..96f4094 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -66,8 +66,6 @@ struct backing_dev_info {
 	unsigned int capabilities; /* Device capabilities */
 	congested_fn *congested_fn; /* Function pointer if device is md/dm */
 	void *congested_data;	/* Pointer to aux data for congested func */
-	void (*unplug_io_fn)(struct backing_dev_info *, struct page *);
-	void *unplug_io_data;
 
 	char *name;
 
@@ -251,7 +249,6 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
 
 extern struct backing_dev_info default_backing_dev_info;
 extern struct backing_dev_info noop_backing_dev_info;
-void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page);
 
 int writeback_in_progress(struct backing_dev_info *bdi);
 
@@ -336,17 +333,4 @@ static inline int bdi_sched_wait(void *word)
 	return 0;
 }
 
-static inline void blk_run_backing_dev(struct backing_dev_info *bdi,
-				       struct page *page)
-{
-	if (bdi && bdi->unplug_io_fn)
-		bdi->unplug_io_fn(bdi, page);
-}
-
-static inline void blk_run_address_space(struct address_space *mapping)
-{
-	if (mapping)
-		blk_run_backing_dev(mapping->backing_dev_info, NULL);
-}
-
 #endif		/* _LINUX_BACKING_DEV_H */
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5873037..64ab2a1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -196,7 +196,6 @@ typedef void (request_fn_proc) (struct request_queue *q);
 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
 typedef void (unprep_rq_fn) (struct request_queue *, struct request *);
-typedef void (unplug_fn) (struct request_queue *);
 
 struct bio_vec;
 struct bvec_merge_data {
@@ -279,7 +278,6 @@ struct request_queue
 	make_request_fn		*make_request_fn;
 	prep_rq_fn		*prep_rq_fn;
 	unprep_rq_fn		*unprep_rq_fn;
-	unplug_fn		*unplug_fn;
 	merge_bvec_fn		*merge_bvec_fn;
 	softirq_done_fn		*softirq_done_fn;
 	rq_timed_out_fn		*rq_timed_out_fn;
@@ -293,14 +291,6 @@ struct request_queue
 	struct request		*boundary_rq;
 
 	/*
-	 * Auto-unplugging state
-	 */
-	struct timer_list	unplug_timer;
-	int			unplug_thresh;	/* After this many requests */
-	unsigned long		unplug_delay;	/* After this many jiffies */
-	struct work_struct	unplug_work;
-
-	/*
 	 * Delayed queue handling
 	 */
 	struct delayed_work	delay_work;
@@ -399,14 +389,13 @@ struct request_queue
 #define QUEUE_FLAG_ASYNCFULL	4	/* write queue has been filled */
 #define QUEUE_FLAG_DEAD		5	/* queue being torn down */
 #define QUEUE_FLAG_REENTER	6	/* Re-entrancy avoidance */
-#define QUEUE_FLAG_PLUGGED	7	/* queue is plugged */
-#define QUEUE_FLAG_ELVSWITCH	8	/* don't use elevator, just do FIFO */
-#define QUEUE_FLAG_BIDI		9	/* queue supports bidi requests */
-#define QUEUE_FLAG_NOMERGES    10	/* disable merge attempts */
-#define QUEUE_FLAG_SAME_COMP   11	/* force complete on same CPU */
-#define QUEUE_FLAG_FAIL_IO     12	/* fake timeout */
-#define QUEUE_FLAG_STACKABLE   13	/* supports request stacking */
-#define QUEUE_FLAG_NONROT      14	/* non-rotational device (SSD) */
+#define QUEUE_FLAG_ELVSWITCH	7	/* don't use elevator, just do FIFO */
+#define QUEUE_FLAG_BIDI		8	/* queue supports bidi requests */
+#define QUEUE_FLAG_NOMERGES     9	/* disable merge attempts */
+#define QUEUE_FLAG_SAME_COMP   10	/* force complete on same CPU */
+#define QUEUE_FLAG_FAIL_IO     11	/* fake timeout */
+#define QUEUE_FLAG_STACKABLE   12	/* supports request stacking */
+#define QUEUE_FLAG_NONROT      13	/* non-rotational device (SSD) */
 #define QUEUE_FLAG_VIRT        QUEUE_FLAG_NONROT /* paravirt device */
 #define QUEUE_FLAG_IO_STAT     15	/* do IO stats */
 #define QUEUE_FLAG_DISCARD     16	/* supports DISCARD */
@@ -484,7 +473,6 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q)
 	__clear_bit(flag, &q->queue_flags);
 }
 
-#define blk_queue_plugged(q)	test_bit(QUEUE_FLAG_PLUGGED, &(q)->queue_flags)
 #define blk_queue_tagged(q)	test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
@@ -679,9 +667,6 @@ extern int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
 extern void blk_rq_unprep_clone(struct request *rq);
 extern int blk_insert_cloned_request(struct request_queue *q,
 				     struct request *rq);
-extern void blk_plug_device(struct request_queue *);
-extern void blk_plug_device_unlocked(struct request_queue *);
-extern int blk_remove_plug(struct request_queue *);
 extern void blk_delay_queue(struct request_queue *, unsigned long);
 extern void blk_recount_segments(struct request_queue *, struct bio *);
 extern int scsi_cmd_ioctl(struct request_queue *, struct gendisk *, fmode_t,
@@ -726,7 +711,6 @@ extern int blk_execute_rq(struct request_queue *, struct gendisk *,
 			  struct request *, int);
 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 				  struct request *, int, rq_end_io_fn *);
-extern void blk_unplug(struct request_queue *q);
 
 static inline struct request_queue *bdev_get_queue(struct block_device *bdev)
 {
@@ -863,7 +847,6 @@ extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bd
 
 extern int blk_rq_map_sg(struct request_queue *, struct request *, struct scatterlist *);
 extern void blk_dump_rq_flags(struct request *, char *);
-extern void generic_unplug_device(struct request_queue *);
 extern long nr_blockdev_pages(void);
 
 int blk_get_queue(struct request_queue *);
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 68d1fe7..f5df235 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -219,7 +219,6 @@ int generic_cont_expand_simple(struct inode *inode, loff_t size);
 int block_commit_write(struct page *page, unsigned from, unsigned to);
 int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf,
 				get_block_t get_block);
-void block_sync_page(struct page *);
 sector_t generic_block_bmap(struct address_space *, sector_t, get_block_t *);
 int block_truncate_page(struct address_space *, loff_t, get_block_t *);
 int nobh_write_begin(struct address_space *, loff_t, unsigned, unsigned,
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 272496d..e276883 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -286,11 +286,6 @@ void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callback
 int dm_table_complete(struct dm_table *t);
 
 /*
- * Unplug all devices in a table.
- */
-void dm_table_unplug_all(struct dm_table *t);
-
-/*
  * Table reference counting.
  */
 struct dm_table *dm_get_live_table(struct mapped_device *md);
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 8857cf9..ec6f72b 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -20,7 +20,6 @@ typedef void (elevator_bio_merged_fn) (struct request_queue *,
 typedef int (elevator_dispatch_fn) (struct request_queue *, int);
 
 typedef void (elevator_add_req_fn) (struct request_queue *, struct request *);
-typedef int (elevator_queue_empty_fn) (struct request_queue *);
 typedef struct request *(elevator_request_list_fn) (struct request_queue *, struct request *);
 typedef void (elevator_completed_req_fn) (struct request_queue *, struct request *);
 typedef int (elevator_may_queue_fn) (struct request_queue *, int);
@@ -46,7 +45,6 @@ struct elevator_ops
 	elevator_activate_req_fn *elevator_activate_req_fn;
 	elevator_deactivate_req_fn *elevator_deactivate_req_fn;
 
-	elevator_queue_empty_fn *elevator_queue_empty_fn;
 	elevator_completed_req_fn *elevator_completed_req_fn;
 
 	elevator_request_list_fn *elevator_former_req_fn;
@@ -101,8 +99,8 @@ struct elevator_queue
  */
 extern void elv_dispatch_sort(struct request_queue *, struct request *);
 extern void elv_dispatch_add_tail(struct request_queue *, struct request *);
-extern void elv_add_request(struct request_queue *, struct request *, int, int);
-extern void __elv_add_request(struct request_queue *, struct request *, int, int);
+extern void elv_add_request(struct request_queue *, struct request *, int);
+extern void __elv_add_request(struct request_queue *, struct request *, int);
 extern void elv_insert(struct request_queue *, struct request *, int);
 extern int elv_merge(struct request_queue *, struct request **, struct bio *);
 extern int elv_try_merge(struct request *, struct bio *);
@@ -112,7 +110,6 @@ extern void elv_merged_request(struct request_queue *, struct request *, int);
 extern void elv_bio_merged(struct request_queue *q, struct request *,
 				struct bio *);
 extern void elv_requeue_request(struct request_queue *, struct request *);
-extern int elv_queue_empty(struct request_queue *);
 extern struct request *elv_former_request(struct request_queue *, struct request *);
 extern struct request *elv_latter_request(struct request_queue *, struct request *);
 extern int elv_register_queue(struct request_queue *q);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index bd32159..9f2cf69 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -583,7 +583,6 @@ typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
 struct address_space_operations {
 	int (*writepage)(struct page *page, struct writeback_control *wbc);
 	int (*readpage)(struct file *, struct page *);
-	void (*sync_page)(struct page *);
 
 	/* Write back some dirty pages from this mapping. */
 	int (*writepages)(struct address_space *, struct writeback_control *);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 9c66e99..e112b8d 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -298,7 +298,6 @@ static inline pgoff_t linear_page_index(struct vm_area_struct *vma,
 
 extern void __lock_page(struct page *page);
 extern int __lock_page_killable(struct page *page);
-extern void __lock_page_nosync(struct page *page);
 extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
 				unsigned int flags);
 extern void unlock_page(struct page *page);
@@ -342,17 +341,6 @@ static inline int lock_page_killable(struct page *page)
 }
 
 /*
- * lock_page_nosync should only be used if we can't pin the page's inode.
- * Doesn't play quite so well with block device plugging.
- */
-static inline void lock_page_nosync(struct page *page)
-{
-	might_sleep();
-	if (!trylock_page(page))
-		__lock_page_nosync(page);
-}
-	
-/*
  * lock_page_or_retry - Lock the page, unless this would block and the
  * caller indicated that it can handle a retry.
  */
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 4d55932..9ee3218 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -299,8 +299,6 @@ extern void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
 					struct page **pagep, swp_entry_t *ent);
 #endif
 
-extern void swap_unplug_io_fn(struct backing_dev_info *, struct page *);
-
 #ifdef CONFIG_SWAP
 /* linux/mm/page_io.c */
 extern int swap_readpage(struct page *);