In ancient times, the messenger could both initiate and accept connections.
An artifact if that was data structures to store/process an incoming
ceph_msg_connect request and send an outgoing ceph_msg_connect_reply.
Sadly, the negotiation code was referencing those structures and ignoring
important information (like the peer's connect_seq) from the correct ones.

Among other things, this fixes tight reconnect loops where the server sends
RETRY_SESSION and we (the client) retries with the same connect_seq as last
time.  This bug pretty easily triggered by injecting socket failures on the
MDS and running some fs workload like workunits/direct_io/test_sync_io.

Signed-off-by: Sage Weil <sage@inktank.com>

Pull ceph updates from Sage Weil:
 "There are some updates and cleanups to the CRUSH placement code, a bug
  fix with incremental maps, several cleanups and fixes from Josh Durgin
  in the RBD block device code, a series of cleanups and bug fixes from
  Alex Elder in the messenger code, and some miscellaneous bounds
  checking and gfp cleanups/fixes."

Fix up trivial conflicts in net/ceph/{messenger.c,osdmap.c} due to the
networking people preferring "unsigned int" over just "unsigned".

* git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (45 commits)
  libceph: fix pg_temp updates
  libceph: avoid unregistering osd request when not registered
  ceph: add auth buf in prepare_write_connect()
  ceph: rename prepare_connect_authorizer()
  ceph: return pointer from prepare_connect_authorizer()
  ceph: use info returned by get_authorizer
  ceph: have get_authorizer methods return pointers
  ceph: ensure auth ops are defined before use
  ceph: messenger: reduce args to create_authorizer
  ceph: define ceph_auth_handshake type
  ceph: messenger: check return from get_authorizer
  ceph: messenger: rework prepare_connect_authorizer()
  ceph: messenger: check prepare_write_connect() result
  ceph: don't set WRITE_PENDING too early
  ceph: drop msgr argument from prepare_write_connect()
  ceph: messenger: send banner in process_connect()
  ceph: messenger: reset connection kvec caller
  libceph: don't reset kvec in prepare_write_banner()
  ceph: ignore preferred_osd field
  ceph: fully initialize new layout
  ...

Rather than passing a bunch of arguments to be filled in with the
content of the ceph_auth_handshake buffer now returned by the
get_authorizer method, just use the returned information in the
caller, and drop the unnecessary arguments.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

Have the get_authorizer auth_client method return a ceph_auth
pointer rather than an integer, pointer-encoding any returned
error value.  This is to pave the way for making use of the
returned value in an upcoming patch.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

Make use of the new ceph_auth_handshake structure in order to reduce
the number of arguments passed to the create_authorizor method in
ceph_auth_client_ops.  Use a local variable of that type as a
shorthand in the get_authorizer method definitions.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

The definitions for the ceph_mds_session and ceph_osd both contain
five fields related only to "authorizers."  Encapsulate those fields
into their own struct type, allowing for better isolation in some
upcoming patches.

Fix the #includes in "linux/ceph/osd_client.h" to lay out their more
complete canonical path.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

Given a large n, the bounds check (*p + n > end) can be bypassed due to
pointer wraparound.  A safer check is (n > end - *p).

[elder@dreamhost.com: inverted test and renamed ceph_has_room()]

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>

This was an ill-conceived feature that has been removed from Ceph.  Do
this gracefully:

 - reject attempts to specify a preferred_osd via the ioctl
 - stop exposing this information via virtual xattrs
 - always fill in -1 for requests, in case we talk to an older server
 - don't calculate preferred_osd placements/pgids

Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Sage Weil <sage@inktank.com>

Pull Ceph updates for 3.4-rc1 from Sage Weil:
 "Alex has been busy.  There are a range of rbd and libceph cleanups,
  especially surrounding device setup and teardown, and a few critical
  fixes in that code.  There are more cleanups in the messenger code,
  virtual xattrs, a fix for CRC calculation/checks, and lots of other
  miscellaneous stuff.

  There's a patch from Amon Ott to make inos behave a bit better on
  32-bit boxes, some decode check fixes from Xi Wang, and network
  throttling fix from Jim Schutt, and a couple RBD fixes from Josh
  Durgin.

  No new functionality, just a lot of cleanup and bug fixing."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (65 commits)
  rbd: move snap_rwsem to the device, rename to header_rwsem
  ceph: fix three bugs, two in ceph_vxattrcb_file_layout()
  libceph: isolate kmap() call in write_partial_msg_pages()
  libceph: rename "page_shift" variable to something sensible
  libceph: get rid of zero_page_address
  libceph: only call kernel_sendpage() via helper
  libceph: use kernel_sendpage() for sending zeroes
  libceph: fix inverted crc option logic
  libceph: some simple changes
  libceph: small refactor in write_partial_kvec()
  libceph: do crc calculations outside loop
  libceph: separate CRC calculation from byte swapping
  libceph: use "do" in CRC-related Boolean variables
  ceph: ensure Boolean options support both senses
  libceph: a few small changes
  libceph: make ceph_tcp_connect() return int
  libceph: encapsulate some messenger cleanup code
  libceph: make ceph_msgr_wq private
  libceph: encapsulate connection kvec operations
  libceph: move prepare_write_banner()
  ...

Change the name (and type) of a few CRC-related Boolean local
variables so they contain the word "do", to distingish their purpose
from variables used for holding an actual CRC value.

Note that in the process of doing this I identified a fairly serious
logic error in write_partial_msg_pages():  the value of "do_crc"
assigned appears to be the opposite of what it should be.  No
attempt to fix this is made here; this change preserves the
erroneous behavior.  The problem I found is documented here:
    http://tracker.newdream.net/issues/2064

Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>