From 99d03c141b40914b67d63c9d23b8da4386422ed7 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Thu, 13 Jan 2011 20:00:02 +0000
Subject: [PATCH] dm: per target unplug callback support

Add per-target unplug callback support.

Cc: linux-raid@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
---
 drivers/md/dm-table.c         | 5 +++++
 include/linux/device-mapper.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 7e2ec3c055502..dffa0ac7c4f0e 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1278,6 +1278,7 @@ void dm_table_unplug_all(struct dm_table *t)
 {
 	struct dm_dev_internal *dd;
 	struct list_head *devices = dm_table_get_devices(t);
+	struct dm_target_callbacks *cb;
 
 	list_for_each_entry(dd, devices, list) {
 		struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
@@ -1290,6 +1291,10 @@ void dm_table_unplug_all(struct dm_table *t)
 				     dm_device_name(t->md),
 				     bdevname(dd->dm_dev.bdev, b));
 	}
+
+	list_for_each_entry(cb, &t->target_callbacks, list)
+		if (cb->unplug_fn)
+			cb->unplug_fn(cb);
 }
 
 struct mapped_device *dm_table_get_md(struct dm_table *t)
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 4b1c63d478ab9..272496d1fae41 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -197,6 +197,7 @@ struct dm_target {
 struct dm_target_callbacks {
 	struct list_head list;
 	int (*congested_fn) (struct dm_target_callbacks *, int);
+	void (*unplug_fn)(struct dm_target_callbacks *);
 };
 
 int dm_register_target(struct target_type *t);
-- 
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