[RESEND PATCH] erofs: relax the constraint of non-empty device tag in flatdev mode

[Gao Xiang]

On 2023/9/15 16:27, Jingbo Xu wrote:
> The device tag is not required in flatdev mode, and thus relax this
> constraint in flatdev mode.
> 
> Signed-off-by: Jingbo Xu <jefflexu at linux.alibaba.com>

I tend to update the subject title and commit message as a fix:

erofs: allow empty device tags in flatdev mode

Device tags aren't actually required in flatdev mode, thus
fix mount failure due to empty device tags in flatdev mode.

Fixes: 8b465fecc35a ("erofs: support flattened block device for multi-blob images")
Reviewed-by: Gao Xiang <hsiangkao at linux.alibaba.com>

Thanks,
Gao Xiang