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Date: Fri, 23 Oct 2009 11:01:34 -0400
From: Mike Snitzer <snitzer@redhat.com>
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Cc: Mikulas Patocka <mpatocka@redhat.com>, Alasdair G Kergon <agk@redhat.com>
Subject: [dm-devel] Re: [PATCH v2 04/17] dm snapshot: exception handover
	improvements
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diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index fca2479..e0330e3 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -982,13 +982,13 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		}
 
 		/* cross reference snapshots that will do handover */
+		down_write(&dup->lock);
 		dup->handover_snap = s;
+		up_write(&dup->lock);
 		s->handover_snap = dup;
+
 		/* this new snapshot will accept the handover */
 		s->handover = 1;
-	} else if (is_merge(ti)) {
-		ti->error = "Unable to find snapshot that is to be merged";
-		goto bad_load_and_register;
 	}
 
 	/* Metadata must only be loaded into one table at once */