From bedadf5d39bf6a3bd878ade0df9559f32095e0c8 Mon Sep 17 00:00:00 2001
From: NeilBrown <neilb@suse.de>
Date: Fri, 23 Dec 2011 10:17:55 +1100
Subject: [PATCH] --- yaml --- r: 280518 b: refs/heads/master c:
 56a2559bb654ae2555b2ae3b29c837615d0c45c9 h: refs/heads/master v: v3

---
 [refs]                    |  2 +-
 trunk/drivers/md/raid10.c | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 8db56ecbdae5..edb4e85b6845 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4ca40c2ce099e4f1ce35445994f49836662596c8
+refs/heads/master: 56a2559bb654ae2555b2ae3b29c837615d0c45c9
diff --git a/trunk/drivers/md/raid10.c b/trunk/drivers/md/raid10.c
index 90e951730a23..011827d0df25 100644
--- a/trunk/drivers/md/raid10.c
+++ b/trunk/drivers/md/raid10.c
@@ -3201,6 +3201,16 @@ static int run(struct mddev *mddev)
 			continue;
 		disk = conf->mirrors + disk_idx;
 
+		if (test_bit(Replacement, &rdev->flags)) {
+			if (disk->replacement)
+				goto out_free_conf;
+			disk->replacement = rdev;
+		} else {
+			if (disk->rdev)
+				goto out_free_conf;
+			disk->rdev = rdev;
+		}
+
 		disk->rdev = rdev;
 		disk_stack_limits(mddev->gendisk, rdev->bdev,
 				  rdev->data_offset << 9);
@@ -3228,6 +3238,13 @@ static int run(struct mddev *mddev)
 
 		disk = conf->mirrors + i;
 
+		if (!disk->rdev && disk->replacement) {
+			/* The replacement is all we have - use it */
+			disk->rdev = disk->replacement;
+			disk->replacement = NULL;
+			clear_bit(Replacement, &disk->rdev->flags);
+		}
+
 		if (!disk->rdev ||
 		    !test_bit(In_sync, &disk->rdev->flags)) {
 			disk->head_position = 0;