[PATCH v2 00/13] create sysfs files for changing IP address

[Olga Kornievskaia <olga.kornievskaia@gmail.com>]

From: Olga Kornievskaia <kolga@netapp.com>

This is the same patch series that was introduced by Anna Schumaker
and slightly redone with also including some elements of the proposed
additions by Dan Alohi.

The main motivation behind is a situation where an NFS server
goes down and then comes back up with a different IP. These patches
provide a way for administrators to handle this issue by providing
a new IP address for one ore more existing transports to connect to.

Sysfs structure has changed slightly. Everything is still off the
/sys/kernel/sunrpc which has 2 main subdirectories "rpc-clients" and
"xprt-switches".

"xprt-switches" contain one or more subdirectories
"switch-<uniqueid>" that represent a group of transports created
for a given NFS server. Under this directory is one or more directories
named "xprt-<uniqueid>-type" where type is "udp, tcp, rdma, local".
Under each transport directory are 2 files. "dstaddr" which can
be queried to see what's this transport is connected to and "dstaddr"
can be changed by providing a new IP for the server. The setting
of the new address is allowed only for "tcp" and "rdma" transport
types.

There is also "xprt_info" file which contains a list of possibly
useful information about the transport: xprt state, last time use,
etc (for the full list see an individual commit). At the
"switch-<uniqueid>" directory there is also "xprt_switch_info" which
contains the info about number of transports and active transports
and xprt_switch's queue len.

Going back to the "rpc-clients" directory, it contains a subdirectory
for each rpc client "clnt-<uniqueid>" and inside is a symlink to
the xprt_switch directory this rpc client is using.

Some of Anna's and Dan's patches were slightly modified to satisfy
checkpatch script.

v2: fixed kernel test robot issues.

Anna Schumaker (1):
  sunrpc: Prepare xs_connect() for taking NULL tasks

Dan Aloni (1):
  sunrpc: add xprt id

Olga Kornievskaia (11):
  sunrpc: Create a sunrpc directory under /sys/kernel/
  sunrpc: Create a client/ subdirectory in the sunrpc sysfs
  sunrpc: Create per-rpc_clnt sysfs kobjects
  sunrpc: add IDs to multipath
  sunrpc: keep track of the xprt_class in rpc_xprt structure
  sunrpc: add xprt_switch direcotry to sunrpc's sysfs
  sunrpc: add a symlink from rpc-client directory to the xprt_switch
  sunrpc: add add sysfs directory per xprt under each xprt_switch
  sunrpc: add dst_attr attributes to the sysfs xprt directory
  sunrpc: provide transport info in the sysfs directory
  sunrpc: provide multipath info in the sysfs directory

 include/linux/sunrpc/clnt.h          |   1 +
 include/linux/sunrpc/xprt.h          |   5 +
 include/linux/sunrpc/xprtmultipath.h |   5 +
 net/sunrpc/Makefile                  |   2 +-
 net/sunrpc/clnt.c                    |   5 +
 net/sunrpc/sunrpc_syms.c             |  10 +
 net/sunrpc/sysfs.c                   | 476 +++++++++++++++++++++++++++
 net/sunrpc/sysfs.h                   |  42 +++
 net/sunrpc/xprt.c                    |  26 ++
 net/sunrpc/xprtmultipath.c           |  32 ++
 net/sunrpc/xprtrdma/transport.c      |   2 +
 net/sunrpc/xprtsock.c                |  11 +-
 12 files changed, 615 insertions(+), 2 deletions(-)
 create mode 100644 net/sunrpc/sysfs.c
 create mode 100644 net/sunrpc/sysfs.h

-- 
2.27.0