[PATCH] md: avoid backward event updates in md superblock when degraded.

[uclinux-h8/linux.git] / drivers / md / md.c

diff --git a/drivers/md/md.c b/drivers/md/md.c
index b6d1602..8dbab2e 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1597,6 +1597,19 @@ void md_update_sb(mddev_t * mddev)
 
 repeat:
        spin_lock_irq(&mddev->write_lock);
+
+       if (mddev->degraded && mddev->sb_dirty == 3)
+               /* If the array is degraded, then skipping spares is both
+                * dangerous and fairly pointless.
+                * Dangerous because a device that was removed from the array
+                * might have a event_count that still looks up-to-date,
+                * so it can be re-added without a resync.
+                * Pointless because if there are any spares to skip,
+                * then a recovery will happen and soon that array won't
+                * be degraded any more and the spare can go back to sleep then.
+                */
+               mddev->sb_dirty = 1;
+
        sync_req = mddev->in_sync;
        mddev->utime = get_seconds();
        if (mddev->sb_dirty == 3)