[PATCH v4 8/9] md/raid1,raid10: Add error message when setting MD_BROKEN

[Kenta Akagi <k@mgml.me>]

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  | 4 ++++
 drivers/md/raid10.c | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 55213bcd82f4..febe2849a71a 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1786,6 +1786,10 @@ static void raid1_error(struct mddev *mddev, struct md_rdev *rdev)
 	if (test_bit(In_sync, &rdev->flags) &&
 	    (conf->raid_disks - mddev->degraded) == 1) {
 		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 86c0eacd37cb..be5fd77da3e1 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2039,6 +2039,10 @@ static void raid10_error(struct mddev *mddev, struct md_rdev *rdev)
 
 	if (test_bit(In_sync, &rdev->flags) && !enough(conf, rdev->raid_disk)) {
 		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