Subject: [PATCH] Exported dm_put() to be used by parse_hw_handler()
of dm-mpath.  Changed parse_hw_handler() and
hw_handler interface to pass ptr to the hardware
handler's mapped device to enhance event logging.

Signed-off-by: Edward Goggin <egoggin@lcld0081.lss.emc.com>

---

 drivers/md/dm-hw-handler.h |    2 +-
 drivers/md/dm-mpath.c      |   10 +++++++++-
 drivers/md/dm.c            |    1 +
 3 files changed, 11 insertions(+), 2 deletions(-)

applies-to: 8bb04a9fe67f844e84691e53829813ca65b981b4
7e5d4b23929dd889b34c0d9c9ccbc62e970c5863
diff --git a/drivers/md/dm-hw-handler.h b/drivers/md/dm-hw-handler.h
index 15f5629..53be8aa 100644
--- a/drivers/md/dm-hw-handler.h
+++ b/drivers/md/dm-hw-handler.h
@@ -28,7 +28,7 @@ struct hw_handler_type {
 	struct module *module;
 
 	int (*create) (struct hw_handler *handler, unsigned int argc,
-		       char **argv);
+		       char **argv, struct mapped_device *md);
 	void (*destroy) (struct hw_handler *hwh);
 
 	void (*pg_init) (struct hw_handler *hwh, unsigned bypassed,
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index d754e0b..be87a4f 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -627,6 +627,7 @@ static int parse_hw_handler(struct arg_s
 	struct hw_handler_type *hwht;
 	unsigned hw_argc;
 	struct dm_target *ti = m->ti;
+	struct mapped_device *md;
 
 	static struct param _params[] = {
 		{0, 1024, "invalid number of hardware handler args"},
@@ -645,7 +646,14 @@ static int parse_hw_handler(struct arg_s
 		return -EINVAL;
 	}
 
-	r = hwht->create(&m->hw_handler, hw_argc - 1, as->argv);
+	/*
+	 * No need to hold a reference on the mapped device here
+	 * since one is already held for the duration of the
+	 * mapped device open.
+	 */
+	md = dm_table_get_md(ti->table);
+	r = hwht->create(&m->hw_handler, hw_argc - 1, as->argv, md);
+	dm_put(md);
 	if (r) {
 		dm_put_hw_handler(hwht);
 		ti->error = "hardware handler constructor failed";
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index fc4f743..163a7a3 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1196,6 +1196,7 @@ void dm_put(struct mapped_device *md)
 		free_dev(md);
 	}
 }
+EXPORT_SYMBOL_GPL(dm_put);
 
 /*
  * Process the deferred bios
---
0.99.9i