2 files changed, 22 insertions, 1 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 58d0678dfcba..b801d29f3f10 100644
--- a/fs/btrfs/disk-io.c
+++ b/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));
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index cd040bf3fd87..7eefdef8a14c 100644
--- a/fs/btrfs/volumes.c
+++ b/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 @@ again:
                 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;
 }