Re: [Libguestfs] [PATCHv4 0/2] Introduce vfs_minimum_size API to get minimum filesystem size.

On 10/20/2015 08:58 PM, Richard W.M. Jones wrote: >On Tue, Oct 20, 2015 at 08:56:25PM +0300, Maxim Perevedentsev wrote: >>I have an issue with btrfs: >> >>There's an API >>>btrfs inspect-internal min-dev-size /sysroot/ >>But this API is available only in btrfs-progs >= 4.2. >>Before this, there's no reliable way to get minimum size (I could >>parse "btrfs filesystem show", but it is veeery inaccurate). >> >>Can we require btrfs-progs v4.2? Or how should I work-around this issue? >Well it's a new API, so we can just tell people they need new >btrfs-progs if they want to use the new API. > >It would be a problem if we were changing an old API, but that's not >the case here. > >Rich. OK. I have another question: The call for ext works on mounted and unmounted fs. for ntfs on read-only-mounted and unmounted. for btrfs on mounted (ro and rw). for xfs on mounted (ro and rw) (xfs does not support shrinking, so guestfs_xfs_info). Should we require the user to care about fs mount status / do mounts/unmounts ourselves (how to choose mountpoint?) / refuse to work if fs is not ro-mounted? I would vote for 1st option: include mount check into functions and politely report incompatible mount status to user.