[PATCH 3/4] btrfs: zoned: fail mount if the device does not support zone append

[Christoph Hellwig]

On Fri, Apr 16, 2021 at 06:17:21PM +0200, David Sterba wrote:
> On Fri, Apr 16, 2021 at 12:05:27PM +0900, Damien Le Moal wrote:
> > From: Johannes Thumshirn <johannes.thumshirn at wdc.com>
> > 
> > For zoned btrfs, zone append is mandatory to write to a sequential write
> > only zone, otherwise parallel writes to the same zone could result in
> > unaligned write errors.
> > 
> > If a zoned block device does not support zone append (e.g. a dm-crypt
> > zoned device using a non-NULL IV cypher), fail to mount.
> > 
> > Signed-off-by: Johannes Thumshirn <johannes.thumshirn at wdc.com>
> > Signed-off-by: Damien Le Moal <damien.lemoal at wdc.com>
> 
> Added to misc-next, thanks. I'll queue it for 5.13, it's not an urgent
> fix for 5.12 release but i'll tag it as stable so it'll apear in 5.12.x
> later.

Please don't.  Zone append is a strict requirement for zoned devices,
no need to add cargo cult code like this everywhere.