diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 58d0678dfcba78ddbd41efb4f56539977914d315..b801d29f3f10ca6f21234ae8ece69765dcbb7438 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 cd040bf3fd87134bd36c76e40b29d7d0eab46b1d..7eefdef8a14c76b1d62e64fb18b36fcbba44e6d4 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 @@ 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; }