[dm-devel] [PATCHv2 00/26] Userspace-RCU for config accesses

[Hannes Reinecke]

Hi all,

as Benjamin Marzinski pointed out the 'config' structure is
not protected, but it will be re-allocated whenever we do a
reconfiguration.
This leads to inevitable race conditions, which ATM are only
imperfectly handled.
With this patchset accesses to the configuration are RCU-protected,
so we are guaranteed that the pointer to the configuration is always
valid.
To facilitate this the patchset moves the 'cmd', 'dev', and 'dev_type'
entries out of the configuration, and replaces them with local variables
in multipath.

Changes to the original version:
- Fixup arguments for get_mpe_wwid() and find_mpe() as
  found by Ben Marzinski
- Revert to original handling in get_state() as found
  by Ben Marzinski

The patchset can be found at

github.com:/hreinecke/multipath-tools.git
branch rcu.v2

As usual, comments and reviews are welcome.

Hannes Reinecke (26):
  Revert patch 'move filter_devnode() under vector lock'
  Use 'mptable' as argument for find_mpe() and get_mpe_wwid()
  config: set 'deferred_remove' defaults at correct call
  devmapper: explicit config settings
  dmparser: use 'is_daemon' as argument for disassemble_map()
  libmultipath: use 'is_daemon' as argument for domap() etc
  libmultipath: drop 'daemon' configuration setting
  libmultipath: Do not access 'conf->cmd' in domap()
  libmultipath: add 'cmd' as argument for get_refwwid()
  libmultipath: fallback to checking environment variable in
    get_udev_uid()
  multipath: make 'cmd' internal to multipath program
  multipath: make 'dev_type' internal to the multipath program
  multipath: make 'dev' internal to the multipath program
  libmultipath: separate out 'udev' config entry
  libmultipath: use 'checkint' as argument for sysfs_set_scsi_tmo()
  discovery: Pass in 'hwtable' for get_state() and
    scsi_sysfs_discovery()
  libmultipath: use 'struct config' as argument for pathinfo()
  checkers: use 'multipath_dir' as argument
  prio: use 'multipath_dir' as argument
  libmultipath: use 'timeout' as argument for getprio()
  libmultipath: use explicit 'config' argument for configuration file
    parsing
  libmultipath: use (get,put)_multipath_config() accessors
  multipathd: Fixup commandline argument handling
  multipath: make 'struct config' a local variable
  multipathd: use userspace RCU to access configuration
  libmultipath: Allocate keywords directly

 libmpathpersist/mpath_persist.c       |  28 +--
 libmpathpersist/mpath_persist.h       |   6 +-
 libmultipath/checkers.c               |  22 ++-
 libmultipath/checkers.h               |   6 +-
 libmultipath/config.c                 |  43 ++---
 libmultipath/config.h                 |  18 +-
 libmultipath/configure.c              | 163 +++++++++++------
 libmultipath/configure.h              |  10 +-
 libmultipath/debug.c                  |   3 +
 libmultipath/devmapper.c              |  21 +--
 libmultipath/devmapper.h              |   4 +-
 libmultipath/dict.c                   |  79 ++++----
 libmultipath/dict.h                   |   2 +-
 libmultipath/discovery.c              | 108 ++++++-----
 libmultipath/discovery.h              |  12 +-
 libmultipath/dmparser.c               |   6 +-
 libmultipath/dmparser.h               |   2 +-
 libmultipath/parser.c                 |  61 +++----
 libmultipath/parser.h                 |  27 +--
 libmultipath/print.c                  |  72 ++++----
 libmultipath/print.h                  |  16 +-
 libmultipath/prio.c                   |  40 +++--
 libmultipath/prio.h                   |  14 +-
 libmultipath/prioritizers/alua.c      |  12 +-
 libmultipath/prioritizers/alua_rtpg.c |  25 +--
 libmultipath/prioritizers/alua_rtpg.h |   6 +-
 libmultipath/prioritizers/emc.c       |   8 +-
 libmultipath/prioritizers/hds.c       |   8 +-
 libmultipath/prioritizers/hp_sw.c     |  46 ++---
 libmultipath/prioritizers/ontap.c     |  19 +-
 libmultipath/prioritizers/rdac.c      |   8 +-
 libmultipath/propsel.c                |  99 +++++-----
 libmultipath/propsel.h                |  48 ++---
 libmultipath/structs_vec.c            |  62 ++++---
 libmultipath/structs_vec.h            |  13 +-
 libmultipath/waiter.c                 |   4 +
 libmultipath/wwids.c                  |  22 ++-
 mpathpersist/main.c                   |  24 ++-
 multipath/main.c                      | 199 ++++++++++++---------
 multipathd/Makefile                   |   2 +-
 multipathd/cli_handlers.c             |  84 ++++++---
 multipathd/main.c                     | 327 +++++++++++++++++++++++-----------
 multipathd/uxlsnr.c                   |   5 -
 43 files changed, 1057 insertions(+), 727 deletions(-)

-- 
2.6.6