as promised here is now the second part of my ALUA device handler update.
This contains a major rework of the ALUA device handler as execution is
moved onto a workqueue. This has the advantage that we avoid having to
do multiple calls to the same LUN (as happens frequently when failing
over a LUN with several paths) and finally retries are handled correctly.
As some arrays are only capable of handling one STPG at a time I've added
a blacklist flag which then uses a singlethreaded workqueue, thereby
effectively synchronize STPG handling.
Thanks to Bart for this suggestion.
As usual, comments and reviews are welcome.
Changes to v5:
- Fixup lock imbalance noticed by Bart
- use #define instead of enum for access_state as suggested by Ewan
- Updated patch description as suggested by Ewan
- Changed occurrences to 'SET TARGET PORT GROUP' as suggested by Bart
Changes to v4:
- use kfree_rcu() as suggested by hch
- Use 'IS_ERR' instead of 'PTR_ERR' when checking for validity
of a pointer
- Simplify pg assignment as suggested by hch
- Use separate WARN_ON statements a suggested by hch
- Fixes to avoid I/O stall on failover
Changes to v3:
- Use scsi_device flag for blacklisting as suggested by hch
- Add Arrays for synchronous ALUA handling
- Move synchronize_rcu() into release_port_group()
- Add remaining reviewed tags
Changes to v2:
- Use a SCSI blacklist flag instead of a hardware handler parameter
for switching to synchronous ALUA handling
- Move scsi_get_device_flags{,_keyed} to scsi_devinfo.h
- Move flush_delayed_work() into release_port_group()
- Rename alua_lookup_pg() into alua_find_get_pg()
- Add __rcu annotations to keep sparse happy
Changes to v1:
- Include reviews from hch
- Switch to hardware handler parameter instead of module option
Hannes Reinecke (23):
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: allocate RTPG buffer separately
scsi_dh_alua: Use separate alua_port_group structure
scsi_dh_alua: use unique device id
scsi_dh_alua: simplify alua_initialize()
revert commit a8e5a2d593cb ("[SCSI] scsi_dh_alua: ALUA handler attach
should succeed while TPG is transitioning")
scsi_dh_alua: move optimize_stpg evaluation
scsi_dh_alua: remove 'rel_port' from alua_dh_data structure
scsi_dh_alua: Use workqueue for RTPG
scsi_dh_alua: Allow workqueue to run synchronously
scsi_dh_alua: Add new blacklist flag 'BLIST_SYNC_ALUA'
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_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 | 990 ++++++++++++++++++++---------
drivers/scsi/scsi_devinfo.c | 2 +
drivers/scsi/scsi_lib.c | 1 +
drivers/scsi/scsi_scan.c | 12 +-
drivers/scsi/scsi_sysfs.c | 49 ++
include/scsi/scsi_device.h | 2 +
include/scsi/scsi_devinfo.h | 1 +
include/scsi/scsi_dh.h | 2 +
include/scsi/scsi_proto.h | 12 +
9 files changed, 764 insertions(+), 307 deletions(-)
--
1.8.5.6
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