dm raid: handle failed devices during start up
[~shefty/rdma-dev.git] / drivers / md / dm-raid.c
index c5a875d7b8827833b70eb76a818ee9bf55073f53..b0ba52459ed7381d4a802acb94e69df02f979149 100644 (file)
@@ -604,7 +604,9 @@ static int read_disk_sb(struct md_rdev *rdev, int size)
                return 0;
 
        if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
-               DMERR("Failed to read device superblock");
+               DMERR("Failed to read superblock of device at position %d",
+                     rdev->raid_disk);
+               set_bit(Faulty, &rdev->flags);
                return -EINVAL;
        }
 
@@ -855,9 +857,25 @@ static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
 {
        int ret;
+       unsigned redundancy = 0;
+       struct raid_dev *dev;
        struct md_rdev *rdev, *freshest;
        struct mddev *mddev = &rs->md;
 
+       switch (rs->raid_type->level) {
+       case 1:
+               redundancy = rs->md.raid_disks - 1;
+               break;
+       case 4:
+       case 5:
+       case 6:
+               redundancy = rs->raid_type->parity_devs;
+               break;
+       default:
+               ti->error = "Unknown RAID type";
+               return -EINVAL;
+       }
+
        freshest = NULL;
        rdev_for_each(rdev, mddev) {
                if (!rdev->meta_bdev)
@@ -872,6 +890,37 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
                case 0:
                        break;
                default:
+                       dev = container_of(rdev, struct raid_dev, rdev);
+                       if (redundancy--) {
+                               if (dev->meta_dev)
+                                       dm_put_device(ti, dev->meta_dev);
+
+                               dev->meta_dev = NULL;
+                               rdev->meta_bdev = NULL;
+
+                               if (rdev->sb_page)
+                                       put_page(rdev->sb_page);
+
+                               rdev->sb_page = NULL;
+
+                               rdev->sb_loaded = 0;
+
+                               /*
+                                * We might be able to salvage the data device
+                                * even though the meta device has failed.  For
+                                * now, we behave as though '- -' had been
+                                * set for this device in the table.
+                                */
+                               if (dev->data_dev)
+                                       dm_put_device(ti, dev->data_dev);
+
+                               dev->data_dev = NULL;
+                               rdev->bdev = NULL;
+
+                               list_del(&rdev->same_set);
+
+                               continue;
+                       }
                        ti->error = "Failed to load superblock";
                        return ret;
                }
@@ -1214,7 +1263,7 @@ static void raid_resume(struct dm_target *ti)
 
 static struct target_type raid_target = {
        .name = "raid",
-       .version = {1, 1, 0},
+       .version = {1, 2, 0},
        .module = THIS_MODULE,
        .ctr = raid_ctr,
        .dtr = raid_dtr,