[dm-devel] [PATCH 0/5] multipath: alternative reservation_key method

[Benjamin Marzinski]

The scsi persistent reservation API doesn't force devices to implement any
method to display the mapping from a reservation key to an I_T Nexus (the
READ_FULL_STATUS action is an optional later addition, and a number of devices
don't support it). To allow multipathd to determine the correct reservation key
for a device without support from the device itself, it uses the
reservation_key configuration option. Unfortunately, using this option forces
the multipath configuration to be updated whenever a new scsi registration key
is used.  This isn't acceptable to some users, who want a static configuration
file. I've had multiple requests to allow persistent reservations without
needing to set the reservation_key paramter beforehand.

This patch set provides an alternative method of setting the reservation_key
for the multipath device. The reservation_key configuration option now also
accepts the keyword "file". If this is used, multpath will look in the new
prkeys file (by default "/etc/multipath/prkeys") for a line with the device
wwid and it's associated reservation_key. The patches allow users to manually
set reservation_key to multipath device mappings by using the multipathd
client commands, but mpathpersist will automatically detect when devices are
configured to use the prkeys file, and will set and clear the reservation
keys automatically.

Benjamin Marzinski (5):
  libmultipath: pull functions into util.c
  libmultipath: change reservation_key to a uint64_t
  libmpathpersist: fix update_prflag code
  multipath: add alternate reservation_key method
  mpathpersist: add support for prkeys file

 libmpathpersist/mpath_persist.c  |  70 ++++++++---------
 libmpathpersist/mpath_updatepr.c |  43 ++++++----
 libmpathpersist/mpathpr.h        |   3 +-
 libmultipath/Makefile            |   2 +-
 libmultipath/byteorder.h         |  36 +++++++++
 libmultipath/checkers/rbd.c      |  16 +---
 libmultipath/config.c            |   9 ++-
 libmultipath/config.h            |   9 ++-
 libmultipath/defaults.h          |   1 +
 libmultipath/dict.c              | 106 +++++++++++++------------
 libmultipath/dict.h              |   2 +-
 libmultipath/prkey.c             | 166 +++++++++++++++++++++++++++++++++++++++
 libmultipath/prkey.h             |  19 +++++
 libmultipath/propsel.c           |  35 +++++++--
 libmultipath/structs.h           |  12 ++-
 libmultipath/util.c              |  33 ++++++++
 libmultipath/util.h              |   4 +
 multipathd/cli.c                 |   8 ++
 multipathd/cli.h                 |   8 ++
 multipathd/cli_handlers.c        |  82 +++++++++++++++++++
 multipathd/cli_handlers.h        |   3 +
 multipathd/main.c                |  26 ++----
 22 files changed, 541 insertions(+), 152 deletions(-)
 create mode 100644 libmultipath/byteorder.h
 create mode 100644 libmultipath/prkey.c
 create mode 100644 libmultipath/prkey.h

-- 
2.7.4