[PATCH 0/3] ceph: support for sparse read in msgr2 crc path

[Jeff Layton <jlayton@kernel.org>]

This patchset is a revised version of the one I sent a couple of weeks
ago. This adds support for sparse reads to libceph, and changes cephfs
over to use instead of non-sparse reads. The sparse read codepath is a
drop in replacement for regular reads, so the upper layers should be
able to use it interchangeibly.

This is necessary for the (ongoing) fscrypt work. We need to know which
regions in a file are actually sparse so that we can avoid decrypting
them.

The next step is to add the same support to the msgr2 secure codepath.
Currently that code sets up a scatterlist with the final destination
data pages in it and passes that to the decrypt routine so that the
decrypted data is written directly to the destination.

My thinking here is to change that to decrypt the data in-place for
sparse reads, and then we'll just parse the decrypted buffer via
calling sparse_read and copy the data into the right places.

Ilya, does that sound sane? Is it OK to pass gcm_crypt two different
scatterlists with a region that overlaps?

Jeff Layton (3):
  libceph: add sparse read support to msgr2 crc state machine
  libceph: add sparse read support to OSD client
  ceph: convert to sparse reads

 fs/ceph/addr.c                  |   2 +-
 fs/ceph/file.c                  |   4 +-
 include/linux/ceph/messenger.h  |  31 +++++
 include/linux/ceph/osd_client.h |  38 ++++++
 net/ceph/messenger.c            |   1 +
 net/ceph/messenger_v2.c         | 215 ++++++++++++++++++++++++++++++--
 net/ceph/osd_client.c           | 163 ++++++++++++++++++++++--
 7 files changed, 435 insertions(+), 19 deletions(-)

-- 
2.35.1