[PATCH] export clear_queue_congested and set_queue_congested

Export the clear_queue_congested() and set_queue_congested() functions
located in ll_rw_blk.c

The functions are renamed to blk_clear_queue_congested() and
blk_set_queue_congested().

(needed in the pktcdvd driver's bio write congestion control)

Signed-off-by: Thomas Maier <balagi@justmail.de>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

block/ll_rw_blk.c

@@ -117,7 +117,7 @@ static void blk_queue_congestion_threshold(struct request_queue *q)
  * congested queues, and wake up anyone who was waiting for requests to be
  * put back.
  */
-static void clear_queue_congested(request_queue_t *q, int rw)
+void blk_clear_queue_congested(request_queue_t *q, int rw)
 {
 	enum bdi_state bit;
 	wait_queue_head_t *wqh = &congestion_wqh[rw];
@@ -128,18 +128,20 @@ static void clear_queue_congested(request_queue_t *q, int rw)
 	if (waitqueue_active(wqh))
 		wake_up(wqh);
 }
+EXPORT_SYMBOL(blk_clear_queue_congested);
 
 /*
  * A queue has just entered congestion.  Flag that in the queue's VM-visible
  * state flags and increment the global gounter of congested queues.
  */
-static void set_queue_congested(request_queue_t *q, int rw)
+void blk_set_queue_congested(request_queue_t *q, int rw)
 {
 	enum bdi_state bit;
 
 	bit = (rw == WRITE) ? BDI_write_congested : BDI_read_congested;
 	set_bit(bit, &q->backing_dev_info.state);
 }
+EXPORT_SYMBOL(blk_set_queue_congested);
 
 /**
  * blk_get_backing_dev_info - get the address of a queue's backing_dev_info
@@ -159,15 +161,13 @@ struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev)
 		ret = &q->backing_dev_info;
 	return ret;
 }
-
 EXPORT_SYMBOL(blk_get_backing_dev_info);
 
 void blk_queue_activity_fn(request_queue_t *q, activity_fn *fn, void *data)
 {
 	q->activity_fn = fn;
 	q->activity_data = data;
 }
-
 EXPORT_SYMBOL(blk_queue_activity_fn);
 
 /**
@@ -2067,7 +2067,7 @@ static void __freed_request(request_queue_t *q, int rw)
 	struct request_list *rl = &q->rq;
 
 	if (rl->count[rw] < queue_congestion_off_threshold(q))
-		clear_queue_congested(q, rw);
+		blk_clear_queue_congested(q, rw);
 
 	if (rl->count[rw] + 1 <= q->nr_requests) {
 		if (waitqueue_active(&rl->wait[rw]))
@@ -2137,7 +2137,7 @@ static struct request *get_request(request_queue_t *q, int rw, struct bio *bio,
 				}
 			}
 		}
-		set_queue_congested(q, rw);
+		blk_set_queue_congested(q, rw);
 	}
 
 	/*
@@ -3765,14 +3765,14 @@ queue_requests_store(struct request_queue *q, const char *page, size_t count)
 	blk_queue_congestion_threshold(q);
 
 	if (rl->count[READ] >= queue_congestion_on_threshold(q))
-		set_queue_congested(q, READ);
+		blk_set_queue_congested(q, READ);
 	else if (rl->count[READ] < queue_congestion_off_threshold(q))
-		clear_queue_congested(q, READ);
+		blk_clear_queue_congested(q, READ);
 
 	if (rl->count[WRITE] >= queue_congestion_on_threshold(q))
-		set_queue_congested(q, WRITE);
+		blk_set_queue_congested(q, WRITE);
 	else if (rl->count[WRITE] < queue_congestion_off_threshold(q))
-		clear_queue_congested(q, WRITE);
+		blk_clear_queue_congested(q, WRITE);
 
 	if (rl->count[READ] >= q->nr_requests) {
 		blk_set_queue_full(q, READ);

include/linux/blkdev.h

@@ -651,6 +651,8 @@ extern void blk_recount_segments(request_queue_t *, struct bio *);
 extern int scsi_cmd_ioctl(struct file *, struct gendisk *, unsigned int, void __user *);
 extern int sg_scsi_ioctl(struct file *, struct request_queue *,
 		struct gendisk *, struct scsi_ioctl_command __user *);
+extern void blk_clear_queue_congested(request_queue_t *q, int rw);
+extern void blk_set_queue_congested(request_queue_t *q, int rw);
 extern void blk_start_queue(request_queue_t *q);
 extern void blk_stop_queue(request_queue_t *q);
 extern void blk_sync_queue(struct request_queue *q);