[RFC PATCH v2 00/10] ceph: asynchronous file create support

From: Jeff Layton <jlayton@kernel.org>
To: ceph-devel@vger.kernel.org
Cc: zyan@redhat.com, sage@redhat.com, idryomov@gmail.com,
	pdonnell@redhat.com, xiubli@redhat.com
Subject: [RFC PATCH v2 00/10] ceph: asynchronous file create support
Date: Wed, 15 Jan 2020 15:59:02 -0500	[thread overview]
Message-ID: <20200115205912.38688-1-jlayton@kernel.org> (raw)

v2:
- move cached layout to dedicated field in inode
- protect cached layout with i_ceph_lock
- wipe cached layout in __check_cap_issue
- set max_size of file to layout.stripe_unit
- set truncate_size to (u64)-1
- use dedicated CephFS feature bit instead of CEPHFS_FEATURE_OCTOPUS
- set cap_id to 1 in async created inode
- allocate inode number before submitting request
- rework the prep for an async create to be more efficient
- don't allow MDS or cap messages involving an inode until we get async
  create reply

A lot of changes in this set, mostly based on Zheng and Xiubo's
comments. Performance is pretty similar to the previous set:

Untarring a kernel tarball into a cephfs takes about 98s with
async dirops disabled. With them enabled, it takes around 78s,
which is about a 25% improvement.

This is not quite ready for merge. Error handling could still be
improved. With xfstest generic/531, I see some messages like this pop
up in the ring buffer:

    [ 7331.393110] ceph: ceph_async_create_cb: inode number mismatch! err=0 deleg_ino=0x100001232d9 target=0x100001232b9

Basically, we went to do an async create and got a different inode
number back than expected. That still needs investigation, but I
didn't see any test failures due to it.

Jeff Layton (10):
  libceph: export ceph_file_layout_is_valid
  ceph: make ceph_fill_inode non-static
  ceph: make dentry_lease_is_valid non-static
  ceph: make __take_cap_refs a public function
  ceph: decode interval_sets for delegated inos
  ceph: add flag to designate that a request is asynchronous
  ceph: add infrastructure for waiting for async create to complete
  ceph: add new MDS req field to hold delegated inode number
  ceph: cache layout in parent dir on first sync create
  ceph: attempt to do async create when possible

 fs/ceph/caps.c               |  34 ++++--
 fs/ceph/dir.c                |  13 ++-
 fs/ceph/file.c               | 218 +++++++++++++++++++++++++++++++++--
 fs/ceph/inode.c              |  50 ++++----
 fs/ceph/mds_client.c         | 126 ++++++++++++++++++--
 fs/ceph/mds_client.h         |   9 +-
 fs/ceph/super.h              |  16 ++-
 include/linux/ceph/ceph_fs.h |   8 +-
 net/ceph/ceph_fs.c           |   1 +
 9 files changed, 410 insertions(+), 65 deletions(-)

-- 
2.24.1