[PATCH 00/12] target: TPG/NodeACL LUN table conversion to RCU hlist

Nicholas A. Bellinger
2015-05-12T09:25:24Z

From: Nicholas Bellinger <nab@linux-iscsi.org>

Hi all,

This patch converts target-core from traditional fixed size arrays for
TPG LUN and NodeACL MappedLUNs tables to modern read-copy-update (RCU)
logic using hlist_head primitives.

This includes the changes necessary for performing se_dev_entry + se_lun
allocation + call_rcu() release within RCU updater path code, fast-path
conversion of transport_lookup_*_lun() to lock-less RCU reader using
existing percpu_ref, and a handful of fabric configfs and CDB emulation
related RCU reader changes.

It allows for an arbitrary number of entries per hlist_head, but for the
moment is still enforcing TRANSPORT_MAX_LUNS_PER_TPG following what
user-space expects. It also converts non-fast path RCU updater code to
use blocking struct mutex instead of spinlocks for both hlist_heads.

Note that sbp-target is broken atm due to the way it's using se_lun
directly, and will be fixed up soon.

Please review.

--nab

Nicholas Bellinger (12):
target: Convert se_node_acl->device_list[] to RCU hlist
target: Convert REPORT_LUN + MODE_SENSE to RCU reader
target/configfs: Convert mappedlun + SCSI MIBs to RCU reader
target: Convert UNIT_ATTENTION logic to RCU reader
target: Convert transport_lookup_*_lun to RCU reader
target/pr: Convert se_dev_entry to kref for RCU
target/pr: Convert registration check to RCU pointer
target/pr: Change alloc_registration to avoid pr_reg_tg_pt_lun
target: Convert se_portal_group->tpg_lun_list[] to RCU hlist
target: Convert se_tpg->acl_node_lock to ->acl_node_mutex
target: Convert core_tpg_deregister to use list splice
target: Drop unused se_lun->lun_acl_list

drivers/target/iscsi/iscsi_target_tpg.c | 2 -
drivers/target/sbp/sbp_target.c | 16 +-
drivers/target/target_core_configfs.c | 6 +-
drivers/target/target_core_device.c | 409 ++++++++++++---------------
drivers/target/target_core_fabric_configfs.c | 65 +++--
drivers/target/target_core_internal.h | 9 +-
drivers/target/target_core_pr.c | 210 ++++++++------
drivers/target/target_core_pscsi.c | 17 +-
drivers/target/target_core_spc.c | 27 +-
drivers/target/target_core_stat.c | 180 ++++++------
drivers/target/target_core_tpg.c | 249 +++++-----------
drivers/target/target_core_transport.c | 20 +-
drivers/target/target_core_ua.c | 51 ++--
drivers/target/tcm_fc/tfc_conf.c | 4 +-
drivers/xen/xen-scsiback.c | 27 +-
include/target/target_core_base.h | 31 +-
include/target/target_core_fabric.h | 1 -
17 files changed, 633 insertions(+), 691 deletions(-)

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1.9.1