[Buildroot] [RFC PATCH 1/2] support/scripts/genimage.sh: support creating a bmap image

[Gero Schwäricke]

Hi Quentin,

On Tue, Apr 23, 2024 at 02:55:57PM +0200, Quentin Schulz via buildroot wrote:
> Hi Gero,
> 
> On 4/23/24 13:33, Gero Schwäricke via buildroot wrote:
> > Hi Dario,
> > 
> > I tried your patch, but it didn't work for me. bmaptool failed with an
> > error. The issue was that my home directory is encrypted using ecryptfs.
> > This does not implement all ioctl options that are needed for bmaptool
> > to read the block allocation of the image file. There also seem to be
> > issues with ZFS, so I would recommend to not enable this by default for
> > defconfigs.
> > 
> 
> Is this something you could report to the upstream project?
> 
> https://github.com/yoctoproject/bmaptool/

I reported my finding upstream in

https://github.com/yoctoproject/bmaptool/issues/22

though I don't expect a fix. Iiuc the issue is that ecryptfs does not
support the ioctl FIEMAP, which bmaptool needs to find the holes in
a file. So it would require implementing this for the ecryptfs kernel
module (if even possible) and then it'll take a while for that to hit
the mayor Linux distributions. But maybe a new command to bmaptool
could help in the midterm, like `bmaptool verify --check-fs`, so this
case could be detected and handled gracefully in scripts.

> 
> The ZFS issue seems to be documented, c.f.
> https://github.com/yoctoproject/bmaptool/?tab=readme-ov-file#known-issues

Yes, and it's fixable for ZFS. But I expect mailtraffic might increase
if bmaptool would be used by default in buildroot. That's why I would
recommend not to apply this to buildroot provided defconfigs
(PATCH 2/2). But I'm much in favor of supporting bmaptool in general
(PATCH 1/2).

Best,
Gero

> 
> Cheers,
> Quentin
> _______________________________________________
> buildroot mailing list
> buildroot at buildroot.org
> https://lists.buildroot.org/mailman/listinfo/buildroot

-- 



–––


grandcentrix GmbH | A Vodafone Company · Holzmarkt 1 · 50676 
*Cologne* | Phoenixseestrasse 18 · 44263 *Dortmund* · Germany
| in 
<https://www.linkedin.com/company/grandcentrix> | phone: +49-221-677-860-0 
| email: hello at grandcentrix.net <mailto:hello at grandcentrix.net>


grandcentrix cares about privacy 
<https://grandcentrix.net/de/pages/privacymail/>

Amtsgericht Köln | HRB  
70119 | Geschäftsführer: M. Krömer,  R. Hänel | USt.-IdNr.: DE266333969