[v5,0/8] Rework runtime suspend and SPI domain validation

Message

Bart Van Assche Dec. 9, 2020, 5:29 a.m. UTC

Hi Martin,

The SCSI runtime suspend and SPI domain validation mechanisms both use
scsi_device_quiesce(). scsi_device_quiesce() restricts blk_queue_enter() to
BLK_MQ_REQ_PREEMPT requests. There is a conflict between the requirements
of runtime suspend and SCSI domain validation: no requests must be sent to
runtime suspended devices that are in the state RPM_SUSPENDED while
BLK_MQ_REQ_PREEMPT requests must be processed during SCSI domain
validation. This conflict is resolved by reworking the SCSI domain
validation implementation.

Hybernation, runtime suspend and SCSI domain validation have been retested.

Please consider this patch series for kernel v5.11.

Thanks,

Bart.

Changes between v4 and v5:
- Fixed the CONFIG_PM=n build.
- Left out patch "scsi: Do not wait for a request in scsi_eh_lock_door()".

Changes between v3 and v4:
- Instead of creating a second request queue for SPI DV, set RQF_PM.

Changes between v2 and v3:
- Inlined scsi_mq_alloc_queue() into scsi_alloc_sdev() as requested by
  Christoph.

Changes between v1 and v2:
- Rebased this patch series on top of kernel v5.10-rc1.

Alan Stern (1):
  block: Do not accept any requests while suspended

Bart Van Assche (7):
  block: Fix a race in the runtime power management code
  block: Introduce BLK_MQ_REQ_PM
  ide: Do not set the RQF_PREEMPT flag for sense requests
  ide: Mark power management requests with RQF_PM instead of RQF_PREEMPT
  scsi_transport_spi: Set RQF_PM for domain validation commands
  scsi: Only process PM requests if rpm_status != RPM_ACTIVE
  block: Remove RQF_PREEMPT and BLK_MQ_REQ_PREEMPT

 block/blk-core.c                  | 13 +++++++------
 block/blk-mq-debugfs.c            |  1 -
 block/blk-mq.c                    |  4 ++--
 block/blk-pm.c                    | 15 +++++++++------
 block/blk-pm.h                    | 14 +++++++++-----
 drivers/ide/ide-atapi.c           |  1 -
 drivers/ide/ide-io.c              |  7 +------
 drivers/ide/ide-pm.c              |  2 +-
 drivers/scsi/scsi_lib.c           | 27 ++++++++++++++-------------
 drivers/scsi/scsi_transport_spi.c | 27 +++++++++++++++++++--------
 include/linux/blk-mq.h            |  4 ++--
 include/linux/blkdev.h            | 18 +++++++++++++-----
 12 files changed, 77 insertions(+), 56 deletions(-)

Comments

Martin K. Petersen Dec. 9, 2020, 4:44 p.m. UTC | #1

Bart,

> The SCSI runtime suspend and SPI domain validation mechanisms both use
> scsi_device_quiesce(). scsi_device_quiesce() restricts
> blk_queue_enter() to BLK_MQ_REQ_PREEMPT requests. There is a conflict
> between the requirements of runtime suspend and SCSI domain
> validation: no requests must be sent to runtime suspended devices that
> are in the state RPM_SUSPENDED while BLK_MQ_REQ_PREEMPT requests must
> be processed during SCSI domain validation. This conflict is resolved
> by reworking the SCSI domain validation implementation.

Applied to 5.11/scsi-staging. Thanks for fixing up the -next issue!