Once MD_BROKEN is set on an array, no further writes can be
performed to it.
The user must be informed that the array cannot continue operation.

Signed-off-by: Kenta Akagi <k@mgml.me>
---
 drivers/md/raid1.c  | 5 +++++
 drivers/md/raid10.c | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 8a61fd93b3ff..547635bcfdb9 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1770,7 +1770,12 @@ static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
 				mdname(mddev), rdev->bdev);
 			return;
 		}
+
 		set_bit(MD_BROKEN, &mddev->flags);
+		pr_crit("md/raid1:%s: Disk failure on %pg, this is the last device.\n"
+			"md/raid1:%s: Cannot continue operation (%d/%d failed).\n",
+			mdname(mddev), rdev->bdev,
+			mdname(mddev), mddev->degraded + 1, conf->raid_disks);
 
 		if (!mddev->fail_last_dev) {
 			conf->recovery_disabled = mddev->recovery_disabled;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 530ad6503189..b940ab4f6618 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2018,7 +2018,12 @@ static void raid10_error(struct mddev *mddev, struct md_rdev *rdev)
 				mdname(mddev), rdev->bdev);
 			return;
 		}
+
 		set_bit(MD_BROKEN, &mddev->flags);
+		pr_crit("md/raid10:%s: Disk failure on %pg, this is the last device.\n"
+			"md/raid10:%s: Cannot continue operation (%d/%d failed).\n",
+			mdname(mddev), rdev->bdev,
+			mdname(mddev), mddev->degraded + 1, conf->geo.raid_disks);
 
 		if (!mddev->fail_last_dev) {
 			spin_unlock_irqrestore(&conf->device_lock, flags);
-- 
2.50.1