md: clear CHANGE_PENDING in readonly array

If faulty disks of an array are more than allowed degraded number, the
array enters error handling. It will be marked as read-only with
MD_CHANGE_PENDING/RECOVERY_NEEDED set. But currently recovery doesn't
clear CHANGE_PENDING bit for read-only array.  If MD_CHANGE_PENDING is
set for a raid5 array, all returned IO will be hold on a list till the
bit is clear. But recovery nevery clears this bit, the IO is always in
pending state and nevery finish. This has bad effects like upper layer
can't get an IO error and the array can't be stopped.

Fixes: c3cce6cda162 ("md/raid5: ensure device failure recorded before write request returns.")
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index b8247bc32cf6f6ae198f96b09851fd605d7526de..c702de18207ae76ab56f1235ed5c98a9095ed050 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8164,6 +8164,7 @@ void md_check_recovery(struct mddev *mddev)
                        md_reap_sync_thread(mddev);
                        clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                        clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+                       clear_bit(MD_CHANGE_PENDING, &mddev->flags);
                        goto unlock;
                }