Pull ceph updates from Sage Weil:
 "The big item here is support for inline data for CephFS and for
  message signatures from Zheng.  There are also several bug fixes,
  including interrupted flock request handling, 0-length xattrs, mksnap,
  cached readdir results, and a message version compat field.  Finally
  there are several cleanups from Ilya, Dan, and Markus.

  Note that there is another series coming soon that fixes some bugs in
  the RBD 'lingering' requests, but it isn't quite ready yet"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (27 commits)
  ceph: fix setting empty extended attribute
  ceph: fix mksnap crash
  ceph: do_sync is never initialized
  libceph: fixup includes in pagelist.h
  ceph: support inline data feature
  ceph: flush inline version
  ceph: convert inline data to normal data before data write
  ceph: sync read inline data
  ceph: fetch inline data when getting Fcr cap refs
  ceph: use getattr request to fetch inline data
  ceph: add inline data to pagecache
  ceph: parse inline data in MClientReply and MClientCaps
  libceph: specify position of extent operation
  libceph: add CREATE osd operation support
  libceph: add SETXATTR/CMPXATTR osd operations support
  rbd: don't treat CEPH_OSD_OP_DELETE as extent op
  ceph: remove unused stringification macros
  libceph: require cephx message signature by default
  ceph: introduce global empty snap context
  ceph: message versioning fixes
  ...

Before any data write, convert inline data to normal data and set
i_inline_version to CEPH_INLINE_NONE. The OSD request that saves
inline data to object contains 3 operations (CMPXATTR, WRITE and
SETXATTR). It compares a xattr named 'inline_version' to prevent
old data overwrites newer data.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

we can't use getattr to fetch inline data while holding Fr cap,
because it can cause deadlock. If we need to sync read inline data,
drop cap refs first, then use getattr to fetch inline data.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

we can't use getattr to fetch inline data after getting Fcr caps,
because it can cause deadlock. The solution is try bringing inline
data to page cache when not holding any cap, and hope the inline
data page is still there after getting the Fcr caps. If the page
is still there, pin it in page cache for later IO.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

allow specifying position of extent operation in multi-operations
osd request. This is required for cephfs to convert inline data to
normal data (compare xattr, then write object).

Signed-off-by: Yan, Zheng <zyan@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@redhat.com>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Current code set new file/directory's initial ACL in a non-atomic
manner.
Client first sends request to MDS to create new file/directory, then set
the initial ACL after the new file/directory is successfully created.

The fix is include the initial ACL in create/mkdir/mknod MDS requests.
So MDS can handle creating file/directory and setting the initial ACL in
one request.

Signed-off-by: Yan, Zheng <zyan@redhat.com>
Reviewed-by: Sage Weil <sage@redhat.com>

ceph_sync_read and generic_file_read_iter() have already advanced the
IO iterator.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

Following sequence of events can happen.
  - Client releases an inode, queues cap release message.
  - A 'lookup' reply brings the same inode back, but the reply
    doesn't contain xattrs because MDS didn't receive the cap release
    message and thought client already has up-to-data xattrs.

The fix is force sending a getattr request to MDS if xattrs_version
is 0. The getattr mask is set to CEPH_STAT_CAP_XATTR, so MDS knows client
does not have xattr.

Signed-off-by: Yan, Zheng <zyan@redhat.com>