Re: [PATCH 00/13] scsi: Support LUN/target based error handle

["haowenchao (C)" <haowenchao2@huawei.com>]

On 2023/7/24 7:44, Wenchao Hao wrote:
> The origin error handle would set host to recovery state and perform
> error recovery operations, and makes all LUNs which share a same host
> can not handle IOs. This phenomenon is unbearable for systems which
> deploy many LUNs in one HBA.
> 
> This patchset introduce support for LUN/target based error handle,
> drivers can chose if to implement it. They can implement LUN, target or
> both of LUN and target based error handle by their own error handle
> strategy. The first patch defined this framework, it abstract three
> key operations which are: add error command, wake up error handle, block
> ios when error command is added and recoverying. Drivers should
> implement these three function callbacks and setup to SCSI middle level.
> 

Ping...

Is anyone reviewing these changes?

> Besides the basic framework, this patchset also add a basic LUN/target
> based error handle strategy.
> 
> For LUN based eh, it would try check sense, start unit and reset LUN,
> if all above steps can not recovery all error commands, fallback to
> further recovery like tartget based (if implemented) or host based error
> handle.
> 
> It's same for tartget based eh, it would try check sense, start unit,
> reset LUN and reset target. If all above steps can not recovery all error
> commands, fallback to further recovery which is host based error handle.
> 
> This patchset is tested by scsi_debug which support single LUN error
> injection, the scsi_debug patches is here:
> 
> https://lore.kernel.org/linux-scsi/20230723234105.1628982-1-haowenchao2@huawei.com/T/#t
> 
> Wenchao Hao (13):
>    scsi: Define basic framework for driver LUN/target based error handle
>    scsi:scsi_error: Move complete variable eh_action from shost to sdevice
>    scsi:scsi_error: Check if to do reset in scsi_try_xxx_reset
>    scsi:scsi_error: Add helper scsi_eh_sdev_stu to do START_UNIT
>    scsi:scsi_error: Add helper scsi_eh_sdev_reset to do lun reset
>    scsi:scsi_error: Add flags to mark error handle steps has done
>    scsi:scsi_error: Define helper to perform LUN based error handle
>    scsi:scsi_error: Add LUN based error handler based previous helper
>    scsi:core: increase/decrease target_busy without check can_queue
>    scsi:scsi_error: Define helper to perform target based error handle
>    scsi:scsi_error: Add target based error handler based previous helper
>    scsi:scsi_debug: Add param to control if setup LUN based error handle
>    scsi:scsi_debug: Add param to control if setup target based error handle
> 
>   drivers/scsi/scsi_debug.c  |  19 +
>   drivers/scsi/scsi_error.c  | 705 ++++++++++++++++++++++++++++++++++---
>   drivers/scsi/scsi_lib.c    |  23 +-
>   drivers/scsi/scsi_priv.h   |  20 ++
>   include/scsi/scsi_device.h |  97 +++++
>   include/scsi/scsi_eh.h     |   4 +
>   include/scsi/scsi_host.h   |   2 -
>   7 files changed, 813 insertions(+), 57 deletions(-)
>