Re: [PATCH v4 0/5] ceph/libceph: add support for sparse reads to msgr2 crc codepath

[Jeff Layton <jlayton@kernel.org>]

On Mon, 2022-03-21 at 14:26 -0400, Jeff Layton wrote:
> This is a revised version of the sparse read code I posted a week or so
> ago. Sparse read support is required for fscrypt integration work, but
> may be useful on its own.
> 
> The main differences from the v3 set are a couple of small bugfixes, and
> the addition of a new "sparseread" mount option to force the cephfs
> client to use sparse reads. I also renamed the sparse_ext_len field to
> be sparse_ext_cnt (as suggested by Xiubo).
> 
> Ilya, at this point I'm mostly looking for feedback from you. Does this
> approach seem sound? If so, I'll plan to work on implementing the v2-secure
> and v1 codepaths next.
> 
> These patches are currently available in the 'ceph-sparse-read-v4' tag
> in my kernel tree here:
> 
>     https://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux.git/
> 
> Jeff Layton (5):
>   libceph: add spinlock around osd->o_requests
>   libceph: define struct ceph_sparse_extent and add some helpers
>   libceph: add sparse read support to msgr2 crc state machine
>   libceph: add sparse read support to OSD client
>   ceph: add new mount option to enable sparse reads
> 
>  fs/ceph/addr.c                  |  18 ++-
>  fs/ceph/file.c                  |  51 ++++++-
>  fs/ceph/super.c                 |  16 +-
>  fs/ceph/super.h                 |   8 +
>  include/linux/ceph/messenger.h  |  29 ++++
>  include/linux/ceph/osd_client.h |  71 ++++++++-
>  net/ceph/messenger.c            |   1 +
>  net/ceph/messenger_v2.c         | 170 +++++++++++++++++++--
>  net/ceph/osd_client.c           | 255 +++++++++++++++++++++++++++++++-
>  9 files changed, 593 insertions(+), 26 deletions(-)
> 

I've pushed this series into a new branch in the ceph tree called
"wip-sparseread", if anyone wants to test it. Note that ms_mode=secure
and ms_mode=legacy settings do not work properly with sparse reads yet.

-- 
Jeff Layton <jlayton@kernel.org>