From 6f2576af5ba5913538fda7dfb7c6a17771025477 Mon Sep 17 00:00:00 2001
From: Jerome Marchand <jmarchan@redhat.com>
Date: Fri, 8 Feb 2008 11:04:35 +0100
Subject: [PATCH] Enhanced partition statistics: update partition statitics

Updates the enhanced partition statistics in generic block layer
besides the disk statistics.

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
 block/blk-core.c      | 34 ++++++++++++++++++++++++++++++----
 block/blk-merge.c     |  6 ++++++
 fs/partitions/check.c |  7 +++++++
 include/linux/genhd.h |  1 +
 4 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index fba4ca7c6086..2358fc5de5a4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -60,10 +60,15 @@ static void drive_stat_acct(struct request *rq, int new_io)
 		return;
 
 	if (!new_io) {
-		__disk_stat_inc(rq->rq_disk, merges[rw]);
+		__all_stat_inc(rq->rq_disk, merges[rw], rq->sector);
 	} else {
+		struct hd_struct *part = get_part(rq->rq_disk, rq->sector);
 		disk_round_stats(rq->rq_disk);
 		rq->rq_disk->in_flight++;
+		if (part) {
+			part_round_stats(part);
+			part->in_flight++;
+		}
 	}
 }
 
@@ -997,6 +1002,21 @@ void disk_round_stats(struct gendisk *disk)
 }
 EXPORT_SYMBOL_GPL(disk_round_stats);
 
+void part_round_stats(struct hd_struct *part)
+{
+	unsigned long now = jiffies;
+
+	if (now == part->stamp)
+		return;
+
+	if (part->in_flight) {
+		__part_stat_add(part, time_in_queue,
+				part->in_flight * (now - part->stamp));
+		__part_stat_add(part, io_ticks, (now - part->stamp));
+	}
+	part->stamp = now;
+}
+
 /*
  * queue lock must be held
  */
@@ -1530,7 +1550,8 @@ static int __end_that_request_first(struct request *req, int error,
 	if (blk_fs_request(req) && req->rq_disk) {
 		const int rw = rq_data_dir(req);
 
-		disk_stat_add(req->rq_disk, sectors[rw], nr_bytes >> 9);
+		all_stat_add(req->rq_disk, sectors[rw],
+			     nr_bytes >> 9, req->sector);
 	}
 
 	total_bytes = bio_nbytes = 0;
@@ -1715,11 +1736,16 @@ static void end_that_request_last(struct request *req, int error)
 	if (disk && blk_fs_request(req) && req != &req->q->bar_rq) {
 		unsigned long duration = jiffies - req->start_time;
 		const int rw = rq_data_dir(req);
+		struct hd_struct *part = get_part(disk, req->sector);
 
-		__disk_stat_inc(disk, ios[rw]);
-		__disk_stat_add(disk, ticks[rw], duration);
+		__all_stat_inc(disk, ios[rw], req->sector);
+		__all_stat_add(disk, ticks[rw], duration, req->sector);
 		disk_round_stats(disk);
 		disk->in_flight--;
+		if (part) {
+			part_round_stats(part);
+			part->in_flight--;
+		}
 	}
 
 	if (req->end_io)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 845ef8131108..d3b84bbb776a 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -454,8 +454,14 @@ static int attempt_merge(struct request_queue *q, struct request *req,
 	elv_merge_requests(q, req, next);
 
 	if (req->rq_disk) {
+		struct hd_struct *part
+			= get_part(req->rq_disk, req->sector);
 		disk_round_stats(req->rq_disk);
 		req->rq_disk->in_flight--;
+		if (part) {
+			part_round_stats(part);
+			part->in_flight--;
+		}
 	}
 
 	req->ioprio = ioprio_best(req->ioprio, next->ioprio);
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 9a64045ff845..f2ec7f1b0ec5 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -18,6 +18,7 @@
 #include <linux/fs.h>
 #include <linux/kmod.h>
 #include <linux/ctype.h>
+#include <linux/genhd.h>
 
 #include "check.h"
 
@@ -273,6 +274,7 @@ static struct attribute_group *part_attr_groups[] = {
 static void part_release(struct device *dev)
 {
 	struct hd_struct *p = dev_to_part(dev);
+	free_part_stats(p);
 	kfree(p);
 }
 
@@ -314,6 +316,7 @@ void delete_partition(struct gendisk *disk, int part)
 	p->nr_sects = 0;
 	p->ios[0] = p->ios[1] = 0;
 	p->sectors[0] = p->sectors[1] = 0;
+	part_stat_set_all(p, 0);
 	kobject_put(p->holder_dir);
 	device_del(&p->dev);
 	put_device(&p->dev);
@@ -336,6 +339,10 @@ void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len,
 	if (!p)
 		return;
 
+	if (!init_part_stats(p)) {
+		kfree(p);
+		return;
+	}
 	p->start_sect = start;
 	p->nr_sects = len;
 	p->partno = part;
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 589830aca99d..4cf25a5f4159 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -365,6 +365,7 @@ static inline void free_part_stats(struct hd_struct *part)
 
 /* drivers/block/ll_rw_blk.c */
 extern void disk_round_stats(struct gendisk *disk);
+extern void part_round_stats(struct hd_struct *part);
 
 /* drivers/block/genhd.c */
 extern int get_blkdev_list(char *, int);
-- 
2.20.1