Re: [PATCH] btrfs-progs: add options to sync filesystem after subvol delete

[David Sterba <dsterba@suse.cz>]

On Mon, Dec 02, 2013 at 05:02:49PM +0800, Wang Shilong wrote:
> >So an enahced interface could look like this:
> >
> >subvol delete:
> >--commit-each - run the ioc sync/wait ioctl after each delete ioctl
> >--commit-after - dtto but sync/wait after all are deleted
> >--wait-for-cleanup - wait until all given subvols are cleaned
> >
> >'filesystem sync' exteded to wait for subvol cleanup has following
> >cases:
> >- wait for a specific subvolume to be cleaned
> >- wait for all currently deleted, do not care if more subvols are
> >   deleted in the meantime
> >- wait until there are no subvolumes left to clean
> I think it is unnecessary to add such options for 'filesystem sync'.
> we may wait a long time until all subvolume deletion are finished as
> async subvolume deletion is implemented in cleaner thread.:-)

I mean that 'filesystem sync' will stay as it is now, but will be
enhanced with a few options to further specify what else should be
synced.

The difference is that the wait/sync is not tied to the 'subvol delete'
operation. I start to think that a new 'filesystem' subcommand would be
suitable for that, instead of 'fi sync'.

> Miao also pointed out that only if we are running out of space, waiting
> subvolume deletion finished will make sense, our opinion is not to disturb
> 'filesystem sync' .
> 
> What do you think ? :-)

I agree with that.