[PATCHv5 00/36] asynchronous ALUA device handler

[Hannes Reinecke <hare@suse.de>]

Hi all,

here the next round of my update to the ALUA device handler. The main
features are:

- Topology discovery: the device handler creates a separate
  port_group structure, which is used to update all paths to
  the same port group. With that we achieve a significant
  reduction of the number of RTPGs.
- Asynchronous state update: The ALUA state is now updated
  from a workqueue item, so all concurrent RTPG calls are
  coaleasced. The ALUA state update is also triggered by
  sense codes indicating an ALUA state change.
- Use the existing vpd page 0x83 to detect device IDs
- Add generic 'access_state' attribute to discover the
  current ALUA state from userspace.

The entire tree can be found at

kernel/hare/scsi-devel branch alua.v5

on git.kernel.org

As usual, reviews and comments are welcome.

Changes to v1:
  - Split off rtpg workqueue into separate items
  - User per-port workqueues
  - Incorporate review from Bart
  - Incorporate review from hch
Changes to v2:
  - Fixup patch descriptions
  - Split off 'Improve error handling' patch
Changes to v3:
  - Implement generic 'scsi_vpd_lun_id()' function to parse vpd page 0x83
Changes to v4:
  - Revert back to a single workqueue item
  - Implement generic 'scsi_vpd_tpg_id()' function
  - Add 'access_state' attribute to struct scsi_device
  - Incorporate review from Ewan Milne
  - Incorporate further reviews from hch
  - Reshuffle patches

Hannes Reinecke (36):
  scsi_dh: move 'dh_state' sysfs attribute to generic code
  scsi: ignore errors from scsi_dh_add_device()
  scsi_dh_alua: Disable ALUA handling for non-disk devices
  scsi_dh_alua: Use vpd_pg83 information
  scsi_dh_alua: improved logging
  scsi_dh_alua: sanitze sense code handling
  scsi_dh_alua: use standard logging functions
  scsi_dh_alua: return standard SCSI return codes in submit_rtpg
  scsi_dh_alua: fixup description of stpg_endio()
  scsi: remove scsi_show_sense_hdr()
  scsi_dh_alua: use flag for RTPG extended header
  scsi_dh_alua: use unaligned access macros
  scsi_dh_alua: Pass buffer as function argument
  scsi_dh_alua: separate out alua_stpg()
  scsi_dh_alua: Make stpg synchronous
  scsi_dh_alua: call alua_rtpg() if stpg fails
  scsi_dh_alua: switch to scsi_execute_req_flags()
  scsi_dh_alua: rework alua_check_tpgs() to return the tpgs mode
  scsi_dh_alua: Use separate alua_port_group structure
  scsi_dh_alua: allocate RTPG buffer separately
  scsi_dh_alua: simplify sense code handling
  scsi: Add scsi_vpd_lun_id()
  scsi_dh_alua: use unique device id
  scsi: Add scsi_vpd_tpg_id()
  scsi_dh_alua: simplify alua_initialize()
  revert "scsi_dh_alua: ALUA hander attach should succeed while TPG is
    transitioning"
  scsi_dh_alua: Use workqueue for RTPG
  scsi_dh_alua: Recheck state on unit attention
  scsi_dh_alua: update all port states
  scsi_dh_alua: Send TEST UNIT READY to poll for transitioning
  scsi: rescan VPD attributes
  scsi_dh: add 'rescan' callback
  scsi: Add 'access_state' attribute
  scsi_dh_alua: use common definitions for ALUA state
  scsi_dh_alua: update 'access_state' field
  scsi_dh_alua: Update version to 2.0

 drivers/scsi/device_handler/scsi_dh_alua.c | 1173 +++++++++++++++++-----------
 drivers/scsi/scsi.c                        |   20 +-
 drivers/scsi/scsi_dh.c                     |   68 +-
 drivers/scsi/scsi_lib.c                    |  184 +++++
 drivers/scsi/scsi_scan.c                   |   11 +
 drivers/scsi/scsi_sysfs.c                  |  122 ++-
 drivers/scsi/ses.c                         |   13 +-
 include/scsi/scsi_dbg.h                    |    2 -
 include/scsi/scsi_device.h                 |    4 +
 include/scsi/scsi_dh.h                     |    2 +
 include/scsi/scsi_proto.h                  |   13 +
 11 files changed, 1081 insertions(+), 531 deletions(-)

-- 
1.8.5.6