staging: lustre: ptlrpc: Add OBD_CONNECT_MULTIMODRPCS flag

staging: lustre: ptlrpc: Add OBD_CONNECT_MULTIMODRPCS flag

The new OBD_CONNECT_MULTIMODRPCS connection flag indicates the support
of multiple modify RPCs in parallel. It can be specified by the client
within the connection request and by the server within the connection
reply. The new ocd_maxmodrpcs connection data specifies the maximum modify
RPCs in parallel supported by the server.

To allow the MDS to send the new ocd_maxmodrpcs field, it has been
required to modify RMF_CONNECT_DATA so that its size includes the new
field. This change leads to remove the ocd_connect_data_v1 structure.
Note that the client has been allocating an extra 16*sizeof(__u64) for
the obd_connect_data reply since 2.0 and even in later versions of 1.8)
so there is no problem for the MDS to just send the full reply size.

This patch fixes a bug in __req_capsule_get() since it wasn't checking
RMF_F_NO_SIZE_CHECK when receiving the message. This allows legacy
clients (with version lower that this commit) to send connection
request with ocd_connect_data structure size smaller (actually size is
ocd_connect_data_v1 structure size) than new server ocd_connect_data
structure size.

This patch also fixes a bug in the routine that displays the import's
connect data.

Signed-off-by: Gregoire Pichon <gregoire.pichon@bull.net>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5319
Reviewed-on: http://review.whamcloud.com/#/c/13960
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>