[PATCH AUTOSEL 5.2 147/185] md/raid1: fail run raid1 array when active disk less than one

[Sasha Levin]

From: Yufen Yu <yuyu...@huawei.com>

[ Upstream commit 07f1a6850c5d5a65c917c3165692b5179ac4cb6b ]

When run test case:
  mdadm -CR /dev/md1 -l 1 -n 4 /dev/sd[a-d] --assume-clean --bitmap=internal
  mdadm -S /dev/md1
  mdadm -A /dev/md1 /dev/sd[b-c] --run --force

  mdadm --zero /dev/sda
  mdadm /dev/md1 -a /dev/sda

  echo offline > /sys/block/sdc/device/state
  echo offline > /sys/block/sdb/device/state
  sleep 5
  mdadm -S /dev/md1

  echo running > /sys/block/sdb/device/state
  echo running > /sys/block/sdc/device/state
  mdadm -A /dev/md1 /dev/sd[a-c] --run --force

mdadm run fail with kernel message as follow:
[  172.986064] md: kicking non-fresh sdb from array!
[  173.004210] md: kicking non-fresh sdc from array!
[  173.022383] md/raid1:md1: active with 0 out of 4 mirrors
[  173.022406] md1: failed to create bitmap (-5)

In fact, when active disk in raid1 array less than one, we
need to return fail in raid1_run().

Reviewed-by: NeilBrown <ne...@suse.de>
Signed-off-by: Yufen Yu <yuyu...@huawei.com>
Signed-off-by: Song Liu <songliubrav...@fb.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/md/raid1.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index a26731a9b38e7..f393f0dc042fc 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -3096,6 +3096,13 @@ static int raid1_run(struct mddev *mddev)
                    !test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
                    test_bit(Faulty, &conf->mirrors[i].rdev->flags))
                        mddev->degraded++;
+       /*
+        * RAID1 needs at least one disk in active
+        */
+       if (conf->raid_disks - mddev->degraded < 1) {
+               ret = -EINVAL;
+               goto abort;
+       }
 
        if (conf->raid_disks - mddev->degraded == 1)
                mddev->recovery_cp = MaxSector;
@@ -3129,8 +3136,12 @@ static int raid1_run(struct mddev *mddev)
        ret =  md_integrity_register(mddev);
        if (ret) {
                md_unregister_thread(&mddev->thread);
-               raid1_free(mddev, conf);
+               goto abort;
        }
+       return 0;
+
+abort:
+       raid1_free(mddev, conf);
        return ret;
 }
 
-- 
2.20.1