Re: [PATCH-v3 00/10] target: se_node_acl + se_lun RCU conversions

["Nicholas A. Bellinger" <nab@linux-iscsi.org>]

Please ignore this resend..

On Tue, 2015-05-26 at 06:40 +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> Hi all,
> 
> Here is -v3 series for converting LIO target se_node_acl + se_lun
> mapping tables from fixed size arrays to dynamic RCU hlist_heads.
> 
> This turns fast-path I/O into a lock-less RCU reader using existing
> percpu based se_lun->lun_ref logic, and converts the RCU updater
> path to allow for an arbitrary number of LUNs for both types of
> mappings within target-core.
> 
> As per this afternoon's email thread, the se_dev_entry->pr_comp
> has been left in place for se_dev_entry shutdown within patch #1.
> This completion is still required in order to prevent the configfs
> se_lun_acl->se_lun_group from being removed from out below the
> core_scsi3_lunacl_depend_item() caller during the special-case PR
> ALL_TG_PT=1 registration handling.
> 
> The changes based on -v2 series feedback from HCH & Co include:
> 
>   - Remove unused se_dev_entry->se_node_acl
>   - Drop unnecessary check in lunacl_undepend_item
>   - target: Drop bogus mutex_unlock in core_disable_device_list_for_node
>   - Drop left-over se_lun->lun_status
>   - target: Rename ->pr_regs to ->deve_flags + add bit definitions
>   - target: Convert se_dev_entry stats to atomic_long_t
>   - Avoid unnecessary PR target_nacl_find_deve() lookup in registration
>   - Add se_lun->lun_index for RCU dev->dev_index usage in stat.c
>   - Add various rcu_dereference and lockless_dereference RCU notation
> 
> Please review.
> 
> --nab
> 
> Christoph Hellwig (1):
>   target/pr: cleanup core_scsi3_pr_seq_non_holder
> 
> Nicholas Bellinger (9):
>   target: Convert se_node_acl->device_list[] to RCU hlist
>   target/pr: Use atomic bitop for se_dev_entry->deve_flags reservation
>     check
>   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
>   target: Only reset specific dynamic entries during lun_group creation
>   target: Drop left-over se_lun->lun_status
> 
>  drivers/target/iscsi/iscsi_target_tpg.c      |   2 -
>  drivers/target/sbp/sbp_target.c              |  97 +++---
>  drivers/target/sbp/sbp_target.h              |   2 +-
>  drivers/target/target_core_alua.c            |   2 +-
>  drivers/target/target_core_configfs.c        |   6 +-
>  drivers/target/target_core_device.c          | 477 +++++++++++----------------
>  drivers/target/target_core_fabric_configfs.c |  75 ++---
>  drivers/target/target_core_internal.h        |  17 +-
>  drivers/target/target_core_pr.c              | 221 +++++++------
>  drivers/target/target_core_pscsi.c           |   7 +-
>  drivers/target/target_core_spc.c             |  18 +-
>  drivers/target/target_core_stat.c            | 197 +++++------
>  drivers/target/target_core_tpg.c             | 271 ++++-----------
>  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_backend.h         |   2 +-
>  include/target/target_core_base.h            |  53 ++-
>  include/target/target_core_fabric.h          |   1 -
>  20 files changed, 665 insertions(+), 885 deletions(-)
>