From e1e94543d1a2a930e11603609b9da61742f5c261 Mon Sep 17 00:00:00 2001
From: "Jun'ichi \"Nick\" Nomura" <j-nomura@ce.jp.nec.com>
Date: Wed, 1 Feb 2006 03:04:53 -0800
Subject: [PATCH] --- yaml --- r: 19329 b: refs/heads/master c:
 3eaf840e0b0046f56602c524c7ba58a82f5526c5 h: refs/heads/master i:   19327:
 c0045610c8f820f73f739975e3b0864827cb5897 v: v3

---
 [refs]                  |  2 +-
 trunk/block/ll_rw_blk.c |  2 ++
 trunk/drivers/md/dm.c   | 35 +++++++++++++++++++++++++++++++++--
 3 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index cb243a495c6c..748d28926ffb 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 12f03a49cf0ab5e8511911142d28699499a572c4
+refs/heads/master: 3eaf840e0b0046f56602c524c7ba58a82f5526c5
diff --git a/trunk/block/ll_rw_blk.c b/trunk/block/ll_rw_blk.c
index d38b4afa37ef..f9fc07efd2da 100644
--- a/trunk/block/ll_rw_blk.c
+++ b/trunk/block/ll_rw_blk.c
@@ -2579,6 +2579,8 @@ void disk_round_stats(struct gendisk *disk)
 	disk->stamp = now;
 }
 
+EXPORT_SYMBOL_GPL(disk_round_stats);
+
 /*
  * queue lock must be held
  */
diff --git a/trunk/drivers/md/dm.c b/trunk/drivers/md/dm.c
index c47518386c91..e9adeb9d172f 100644
--- a/trunk/drivers/md/dm.c
+++ b/trunk/drivers/md/dm.c
@@ -31,6 +31,7 @@ struct dm_io {
 	int error;
 	struct bio *bio;
 	atomic_t io_count;
+	unsigned long start_time;
 };
 
 /*
@@ -244,6 +245,36 @@ static inline void free_tio(struct mapped_device *md, struct target_io *tio)
 	mempool_free(tio, md->tio_pool);
 }
 
+static void start_io_acct(struct dm_io *io)
+{
+	struct mapped_device *md = io->md;
+
+	io->start_time = jiffies;
+
+	preempt_disable();
+	disk_round_stats(dm_disk(md));
+	preempt_enable();
+	dm_disk(md)->in_flight = atomic_inc_return(&md->pending);
+}
+
+static int end_io_acct(struct dm_io *io)
+{
+	struct mapped_device *md = io->md;
+	struct bio *bio = io->bio;
+	unsigned long duration = jiffies - io->start_time;
+	int pending;
+	int rw = bio_data_dir(bio);
+
+	preempt_disable();
+	disk_round_stats(dm_disk(md));
+	preempt_enable();
+	dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending);
+
+	disk_stat_add(dm_disk(md), ticks[rw], duration);
+
+	return !pending;
+}
+
 /*
  * Add the bio to the list of deferred io.
  */
@@ -299,7 +330,7 @@ static void dec_pending(struct dm_io *io, int error)
 		io->error = error;
 
 	if (atomic_dec_and_test(&io->io_count)) {
-		if (atomic_dec_and_test(&io->md->pending))
+		if (end_io_acct(io))
 			/* nudge anyone waiting on suspend queue */
 			wake_up(&io->md->wait);
 
@@ -554,7 +585,7 @@ static void __split_bio(struct mapped_device *md, struct bio *bio)
 	ci.sector_count = bio_sectors(bio);
 	ci.idx = bio->bi_idx;
 
-	atomic_inc(&md->pending);
+	start_io_acct(ci.io);
 	while (ci.sector_count)
 		__clone_and_map(&ci);