[PATCH v4 00/10] Fix a deadlock in the UFS driver

[Bart Van Assche <bvanassche@acm.org>]

Hi Martin,

This patch series fixes a deadlock in the UFS driver between the suspend/resume
code and the SCSI error handler. Please consider this patch series for the next
merge window.

Thanks,

Bart.

Changes compared to v3:
* Added two patches: one patch to reduce the START STOP UNIT timeout and another
  patch that introduces the ufshcd_execute_start_stop() function.
* Modified patch 3 such that it introduces a new flag (SCMD_FAIL_IF_RECOVERING)
  instead of modifying the behavior for the REQ_FAILFAST flags.

Changes compared to v2:
* Replaced the custom error handling code in ufshcd_eh_timed_out() with a call
  to ufshcd_link_recovery().

Changes compared to v1:
* Added support in the SCSI core for failing SCSI commands quickly during host
  recovery.
* Removed the patch that splits the ufshcd_err_handler() function.
* Fixed the code in ufshcd_eh_timed_out() for handling command timeouts.
* Removed the power management notifier again.

Bart Van Assche (10):
  scsi: core: Fix a race between scsi_done() and scsi_timeout()
  scsi: core: Change the return type of .eh_timed_out()
  scsi: core: Support failing requests while recovering
  scsi: ufs: Remove an outdated comment
  scsi: ufs: Use 'else' in ufshcd_set_dev_pwr_mode()
  scsi: ufs: Reduce the START STOP UNIT timeout
  scsi: ufs: Try harder to change the power mode
  scsi: ufs: Track system suspend / resume activity
  scsi: ufs: Introduce the function ufshcd_execute_start_stop()
  scsi: ufs: Fix a deadlock between PM and the SCSI error handler

 Documentation/scsi/scsi_eh.rst            |  7 +-
 drivers/message/fusion/mptsas.c           |  8 +--
 drivers/scsi/libiscsi.c                   | 26 +++----
 drivers/scsi/megaraid/megaraid_sas_base.c |  7 +-
 drivers/scsi/mvumi.c                      |  4 +-
 drivers/scsi/qla4xxx/ql4_os.c             |  8 +--
 drivers/scsi/scsi_error.c                 | 41 +++++------
 drivers/scsi/scsi_lib.c                   |  8 ++-
 drivers/scsi/scsi_transport_fc.c          |  7 +-
 drivers/scsi/scsi_transport_srp.c         |  8 +--
 drivers/scsi/storvsc_drv.c                |  4 +-
 drivers/scsi/virtio_scsi.c                |  4 +-
 drivers/ufs/core/ufshcd.c                 | 86 ++++++++++++++++++-----
 include/scsi/libiscsi.h                   |  2 +-
 include/scsi/scsi_cmnd.h                  |  3 +-
 include/scsi/scsi_host.h                  | 14 +++-
 include/scsi/scsi_transport_fc.h          |  2 +-
 include/scsi/scsi_transport_srp.h         |  2 +-
 include/ufs/ufshcd.h                      |  5 +-
 19 files changed, 155 insertions(+), 91 deletions(-)