[dm-devel] [PATCH 1/4] block: add a hard-readonly flag to struct gendisk

[Christoph Hellwig]

On Wed, Dec 02, 2020 at 11:04:33PM -0500, Martin K. Petersen wrote:
> 
> Hi Christoph!
> 
> >  - If BLKROSET is used to set a whole-disk device read-only, any
> >    partitions will end up in a read-only state until the user
> >    explicitly clears the flag.
> 
> This no longer appears to be the case with your tweak.

True.

> 
> It's very common for database folks to twiddle the read-only state of
> block devices and partitions. I know that our users will find it very
> counter-intuitive that setting /dev/sda read-only won't prevent writes
> to /dev/sda1.

What I'm worried about it is that this would be a huge change from the
historic behavior.