Re: [v3] ceph: add 'lazyio' mount option to kclient

Hi Alex,

Good catch. You are right, let me fix it and respin as v4.

Thanks
- Xiubo

On Thu, 20 Aug 2026 at 11:43, Alex Markuze <[email protected]> wrote:
>
> Hi Xiubo,
>
> One issue in caps.c:1014: ceph_adjust_caps_used_for_lazyio() maps
> CACHE/BUFFER onto LAZYIO only while LAZYIO is in issued. The grant path
> in handle_cap_grant() is fine — the writeback/invalidate wait fires
> there. But after the revoke, ceph_check_caps() sees used as BUFFER/CACHE
> with revoking as LAZYIO, (revoking & cap_used)==0, and ACKs immediately.
> The MDS can then hand the cap to another client while dirty or stale
> pages are still present.
>
> Fix: extend the mapping to cover implemented, not just issued, so the
> LAZYIO-revoking case holds until writeback and invalidation actually
> complete. Also worth queuing writeback when revoking LAZYIO with
> i_wrbuffer_ref set, matching the existing BUFFER path.
>
> Minor: the commit message still says CEPH_FILE_MODE_LAZY is set in
> ceph_init_file_info(); since v2 it's set in ceph_open()/ceph_atomic_open().
>
> Could you respin?
>
> --
> Alex Markuze
>