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>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dadaaa8..f31c331 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1337,11 +1337,11 @@
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 @@
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;
}
/*