Re: rbd format check

[Josh Durgin <josh.durgin@dreamhost.com>]

On 11/16/2011 10:40 AM, Sage Weil wrote:
> On Tue, 15 Nov 2011, Josh Durgin wrote:
>> I added a simple check for the old version in the wip-rbd-layering branch of
>> ceph and ceph-client.git. If that looks good and you want to push it upstream,
>> maybe grab the rollback removal from wip-rollback as well.
>
> On the librbd side, let's add a dout(0 or 1) so that we can figure out why
> things are failing.  Ideally we could use a distinct error code too so
> that the tools can report an appropriate error message, altho looking at
> errno-base.h nothing looks like an obvious choice.

I looked through errno.h as well and didn't see anything that fit very 
well. Anyone have a suggestion? The ones that seem closest are EBADMSG 
or EMEDIUMTYPE.

Also, the dout(0) errors don't seem to be printed unless you add the 
--err-to-stderr (or stronger) flags. Shouldn't printing errors be the 
default?

> For the kernel code, a pr_info or pr_warn would be good so that something
> useful up on the console.  And again, a distinct error code would be nice
> so that 'rbd map ...' can print something helpful to stderr...
>
> sage