Commit 9b3517e9 authored Feb 15, 2011 by Ilya Dryomov Committed by Chris Mason Feb 16, 2011

Btrfs: make btrfs_rm_device() fail gracefully



If shrinking done as part of the online device removal fails add that
device back to the allocation list and increment the rw_devices counter.
This fixes two bugs:

1) we could have a perfectly good device out of alloc list for no good
reason;

2) in the btrfs consisting of two devices, failure in btrfs_rm_device()
could lead to a situation where it was impossible to remove any of the
devices because of the "unable to remove the only writeable device"
error.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

parent ca9b688c

fs/btrfs/volumes.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -1337,11 +1337,11 @@ int btrfs_rm_device(struct btrfs_root root, char device_path)

		ret = btrfs_shrink_device(device, 0);
		if (ret)
		goto error_brelse;
		goto error_undo;

		ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
		if (ret)
		goto error_brelse;
		goto error_undo;

		device->in_fs_metadata = 0;

		@@ -1415,6 +1415,13 @@ int btrfs_rm_device(struct btrfs_root root, char device_path)
		mutex_unlock(&root->fs_info->volume_mutex);
		mutex_unlock(&uuid_mutex);
		return ret;
		error_undo:
		if (device->writeable) {
		list_add(&device->dev_alloc_list,
		&root->fs_info->fs_devices->alloc_list);
		root->fs_info->fs_devices->rw_devices++;
		}
		goto error_brelse;
		}

		/*