Re: ceph: fix hanging __ceph_get_caps() with stale `mds_wanted`

Hi Max,

> >   1. [minor] fs/ceph/caps.c:3093: Timeout constant should be a #define
>
> Why?

Because Slava explicitly asked for this in his review. A named constant like

#define CEPH_GET_CAPS_WAIT_TIMEOUT (5 * HZ)

keeps the arbitrary recovery timeout discoverable and documents the intent at
the callsite.

> >   3. [nit] commit message: Missing Fixes: tag
>
> What should it say?

I think the relevant commit is:

Fixes: 0a454bdd501a ("ceph: reorganize __send_cap for less spinlock abuse")

That is where __prep_cap() started updating mds_wanted before the cap message
is queued.

The split-out request for the CEPH_FILE_MODE_MASK change still stands, but you
already agreed to separate that in v2.

Thanks,
Alex