[PATCH] nvme: translate zns errors to blk_status_t

[Keith Busch]

On Sat, Sep 12, 2020 at 08:41:04AM +0200, Christoph Hellwig wrote:
> On Fri, Sep 11, 2020 at 09:35:31AM +0000, Damien Le Moal wrote:
> > On 2020/09/11 15:10, Christoph Hellwig wrote:
> > > On Thu, Sep 10, 2020 at 10:25:24PM +0000, Damien Le Moal wrote:
> > >>> I'm not sure this is the best idea, we probably need specific error codes
> > >>> if we want file systems to be aware of the limit.
> > >>
> > >> Do you mean something else than -EBUSY being returned to the user by the block
> > >> layer ? Or a different/specific BLK_STS_XXX code which translates into -EBUSY in
> > >> blk_status_to_errno() ?
> > > 
> > > My primary aim is a different BLK_STS_ code.  But given that I think
> > > that we should not map different BLK_STS_ codes to the same errno if
> > > we can avoid it, we should probably also use a different errno.
> > > 
> > 
> > Hmm. Beside EBUSY, I do not see a nice existing errno that we can reuse. May be
> > ENOSR (out of stream resources) ? Or do we define a new one ? EZBUSY ?
> > 
> > And indeed if we define a new BLK_STS_ZONE_RESOURCE and map that to EBUSY,
> > errno_to_blkstatus() will get confused.
> 
> Yes, you need to pick a new error.  I don't really care which one,
> most of the mappings are pretty odd anyway.

Selecting an existing unused errno feels a bit arbitrary for a status
that is currently specific to NVMe ZNS. Could you provide a little more
guidance on what you're looking for?