From: Jerome Marchand <jmarchand@redhat.com>
Date: Tue, 15 Jul 2008 15:55:43 +0200
Subject: [block] Enhanced Partition Statistics: update statistics
Message-id: 20080715135910.089113350@redhat.com
O-Subject: [Patch RHEL5.3 2/9] Enhanced Partition Statistics: update partition statitics
Bugzilla: 224322
RH-Acked-by: Anton Arapov <aarapov@redhat.com>

bz224322

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

commit: 6f2576af5ba5913538fda7dfb7c6a17771025477

diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 26220de..66da02a 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -2655,10 +2655,15 @@ static void drive_stat_acct(struct request *rq, int nr_sectors, 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);
+			get_partstats(part)->in_flight++;
+		}
 	}
 }
 
@@ -2713,6 +2718,22 @@ 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;
+	struct partstats *ps = get_partstats(part);
+
+	if (now == ps->stamp)
+		return;
+
+	if (ps->in_flight) {
+		part_stat_add(part, time_in_queue,
+			ps->in_flight * (now - ps->stamp));
+		part_stat_add(part, io_ticks, (now - ps->stamp));
+	}
+	ps->stamp = now;
+}
+
 /*
  * queue lock must be held
  */
@@ -2854,8 +2875,14 @@ static int attempt_merge(request_queue_t *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);
+			get_partstats(part)->in_flight--;
+		}
 	}
 
 	req->ioprio = ioprio_best(req->ioprio, next->ioprio);
@@ -3327,7 +3354,8 @@ static int __end_that_request_first(struct request *req, int uptodate,
 	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;
@@ -3554,11 +3582,16 @@ void end_that_request_last(struct request *req, int uptodate)
 	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);
+			get_partstats(part)->in_flight--;
+		}
 	}
 	if (req->end_io)
 		req->end_io(req, error);
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index c6b362f..075a221 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"
 
@@ -290,6 +291,7 @@ extern struct subsystem block_subsys;
 static void part_release(struct kobject *kobj)
 {
 	struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
+	free_partstats(p);
 	kfree(p);
 }
 
@@ -330,6 +332,7 @@ 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_reset(p);
 	sysfs_remove_link(&p->kobj, "subsystem");
 	if (p->holder_dir)
 		kobject_unregister(p->holder_dir);
@@ -347,6 +350,10 @@ void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len)
 		return;
 	
 	memset(p, 0, sizeof(*p));
+	if (!init_partstats(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 845e9ab..5f1478e 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -385,6 +385,7 @@ static inline void free_part_stats(struct partstats *ps)
 
 /* 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);