Re: [PATCH] btrfs-progs: convert, warn if converting a fs which won't mount

[Roman Mamedov <rm@romanrm.net>]

On Fri, 28 Feb 2020 10:13:41 +0200
Nikolay Borisov <nborisov@suse.com> wrote:

> 
> 
> On 28.02.20 г. 10:03 ч., Anand Jain wrote:
> > On aarch64 with pagesize 64k, btrfs-convert of ext4 is successful,
> > but it won't mount because we don't yet support subpage blocksize/
> > sectorsize.
> > 
> >  BTRFS error (device vda): sectorsize 4096 not supported yet, only support 65536
> > 
> > So in this case during convert provide a warning and a 10s delay to
> > terminate the command.
> > 
> > For example:
> > 
> > WARNING: Blocksize 4096 is not equal to the pagesize 65536,
> >          converted filesystem won't mount on this system.
> >          The operation will start in 10 seconds. Use Ctrl-c to stop it.
> > 10 9 8 7 6 5 4^C
> 
> What's the point of the delay? Just refuse to start the operation and quit.

IMO there should be a way to proceed with convert, if the user knows what they
are doing; maybe refuse the operation, but provide an "-f" "--force" option to
proceed anyway?

As for these 10 second delays, they always seemed a bit odd and unusual among
Linux filesystem tools or Unix CLI software in general.

-- 
With respect,
Roman