[PATCH 2/2] md/raid5: initialize ->recovery_offset when growing raid_disks

[Dan Williams <dan.j.williams@intel.com>]

We mark the disk in-sync, and also need to init ->recovery_offset lest
we confuse older versions of mdadm that don't consider this case at
assembly (i.e. that when growing we assume the disk is insync).

mdadm: /dev/md0 assembled from 3 drives and  1 rebuilding - not enough to start the array.

Cc: <stable@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/md/raid5.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 9e8ecd5..f8a27d4 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5580,6 +5580,7 @@ static int raid5_start_reshape(mddev_t *mddev)
 			if (raid5_add_disk(mddev, rdev) == 0) {
 				char nm[20];
 				if (rdev->raid_disk >= conf->previous_raid_disks) {
+					rdev->recovery_offset = MaxSector;
 					set_bit(In_sync, &rdev->flags);
 					added_devices++;
 				} else