---

yaml
---
r: 287900
b: refs/heads/master
c: a6b0d5c
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: fe66a05a06795bd3b788404d69ea7709f46a1609
+refs/heads/master: a6b0d5c8dbfd428717fc4db4c36757783f391c7b

trunk/fs/btrfs/disk-io.c

@@ -2305,6 +2305,12 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
 	btrfs_close_extra_devices(fs_devices);
 
+	if (!fs_devices->latest_bdev) {
+		printk(KERN_CRIT "btrfs: failed to read devices on %s\n",
+		       sb->s_id);
+		goto fail_tree_roots;
+	}
+
 retry_root_backup:
 	blocksize = btrfs_level_size(tree_root,
 				     btrfs_super_root_level(disk_super));

trunk/fs/btrfs/volumes.c

@@ -459,12 +459,23 @@ int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
 {
 	struct btrfs_device *device, *next;
 
+	struct block_device *latest_bdev = NULL;
+	u64 latest_devid = 0;
+	u64 latest_transid = 0;
+
 	mutex_lock(&uuid_mutex);
 again:
 	/* This is the initialized path, it is safe to release the devices. */
 	list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
-		if (device->in_fs_metadata)
+		if (device->in_fs_metadata) {
+			if (!latest_transid ||
+			    device->generation > latest_transid) {
+				latest_devid = device->devid;
+				latest_transid = device->generation;
+				latest_bdev = device->bdev;
+			}
 			continue;
+		}
 
 		if (device->bdev) {
 			blkdev_put(device->bdev, device->mode);
@@ -487,6 +498,10 @@ int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices)
 		goto again;
 	}
 
+	fs_devices->latest_bdev = latest_bdev;
+	fs_devices->latest_devid = latest_devid;
+	fs_devices->latest_trans = latest_transid;
+
 	mutex_unlock(&uuid_mutex);
 	return 0;
 }