From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: [PATCH 00/26] Userspace-RCU for config accesses Date: Mon, 20 Jun 2016 10:08:47 +0200 Message-ID: <1466410153-23896-1-git-send-email-hare@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Christophe Varoqui Cc: dm-devel@redhat.com List-Id: dm-devel.ids 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. The patchset can be found at github.com:/hreinecke/multipath-tools.git branch rcu 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 | 121 +++++++------ 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, 1063 insertions(+), 734 deletions(-) -- 2.6.6