linux-stable.git/include/scsi, branch v6.5

ata,scsi: do not issue START STOP UNIT on resume

2023-08-02T08:01:12+00:00

During system resume, ata_port_pm_resume() triggers ata EH to
1) Resume the controller
2) Reset and rescan the ports
3) Revalidate devices
This EH execution is started asynchronously from ata_port_pm_resume(),
which means that when sd_resume() is executed, none or only part of the
above processing may have been executed. However, sd_resume() issues a
START STOP UNIT to wake up the drive from sleep mode. This command is
translated to ATA with ata_scsi_start_stop_xlat() and issued to the
device. However, depending on the state of execution of the EH process
and revalidation triggerred by ata_port_pm_resume(), two things may
happen:
1) The START STOP UNIT fails if it is received before the controller has
   been reenabled at the beginning of the EH execution. This is visible
   with error messages like:

ata10.00: device reported invalid CHS sector 0
sd 9:0:0:0: [sdc] Start/Stop Unit failed: Result: hostbyte=DID_OK driverbyte=DRIVER_OK
sd 9:0:0:0: [sdc] Sense Key : Illegal Request [current]
sd 9:0:0:0: [sdc] Add. Sense: Unaligned write command
sd 9:0:0:0: PM: dpm_run_callback(): scsi_bus_resume+0x0/0x90 returns -5
sd 9:0:0:0: PM: failed to resume async: error -5

2) The START STOP UNIT command is received while the EH process is
   on-going, which mean that it is stopped and must wait for its
   completion, at which point the command is rather useless as the drive
   is already fully spun up already. This case results also in a
   significant delay in sd_resume() which is observable by users as
   the entire system resume completion is delayed.

Given that ATA devices will be woken up by libata activity on resume,
sd_resume() has no need to issue a START STOP UNIT command, which solves
the above mentioned problems. Do not issue this command by introducing
the new scsi_device flag no_start_on_resume and setting this flag to 1
in ata_scsi_dev_config(). sd_resume() is modified to issue a START STOP
UNIT command only if this flag is not set.

Reported-by: Paul Ausbeck 
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=215880
Fixes: a19a93e4c6a9 ("scsi: core: pm: Rely on the device driver core for async power management")
Signed-off-by: Damien Le Moal 
Tested-by: Tanner Watkins 
Tested-by: Paul Ausbeck 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Bart Van Assche

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2023-06-30T18:57:07+00:00

Pull SCSI updates from James Bottomley:
 "Updates to the usual drivers (ufs, pm80xx, libata-scsi, smartpqi,
  lpfc, qla2xxx).

  We have a couple of major core changes impacting other systems:

   - Command Duration Limits, which spills into block and ATA

   - block level Persistent Reservation Operations, which touches block,
     nvme, target and dm

  Both of these are added with merge commits containing a cover letter
  explaining what's going on"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (187 commits)
  scsi: core: Improve warning message in scsi_device_block()
  scsi: core: Replace scsi_target_block() with scsi_block_targets()
  scsi: core: Don't wait for quiesce in scsi_device_block()
  scsi: core: Don't wait for quiesce in scsi_stop_queue()
  scsi: core: Merge scsi_internal_device_block() and device_block()
  scsi: sg: Increase number of devices
  scsi: bsg: Increase number of devices
  scsi: qla2xxx: Remove unused nvme_ls_waitq wait queue
  scsi: ufs: ufs-pci: Add support for Intel Arrow Lake
  scsi: sd: sd_zbc: Use PAGE_SECTORS_SHIFT
  scsi: ufs: wb: Add explicit flush_threshold sysfs attribute
  scsi: ufs: ufs-qcom: Switch to the new ICE API
  scsi: ufs: dt-bindings: qcom: Add ICE phandle
  scsi: ufs: ufs-mediatek: Set UFSHCD_QUIRK_MCQ_BROKEN_RTC quirk
  scsi: ufs: ufs-mediatek: Set UFSHCD_QUIRK_MCQ_BROKEN_INTR quirk
  scsi: ufs: core: Add host quirk UFSHCD_QUIRK_MCQ_BROKEN_RTC
  scsi: ufs: core: Add host quirk UFSHCD_QUIRK_MCQ_BROKEN_INTR
  scsi: ufs: core: Remove dedicated hwq for dev command
  scsi: ufs: core: mcq: Fix the incorrect OCS value for the device command
  scsi: ufs: dt-bindings: samsung,exynos: Drop unneeded quotes
  ...

Merge patch series "scsi: fixes for targets with many LUNs, and scsi_target_block rework"

2023-06-16T16:21:04+00:00

Martin Wilck  says:

This patch series addresses some issues we saw in a test setup with a
large number of SCSI LUNs. The first two patches simply increase the
number of available sg and bsg devices. 3-5 fix a large delay we
encountered between blocking a Fibre Channel remote port and the
dev_loss_tmo. 6 renames scsi_target_block() to scsi_block_targets(),
and makes additional changes to this API, as suggested in the review
of the v2 series. 7 improves a warning message.

Link: https://lore.kernel.org/r/20230614103616.31857-1-mwilck@suse.com
Signed-off-by: Martin K. Petersen

scsi: core: Replace scsi_target_block() with scsi_block_targets()

2023-06-16T16:19:59+00:00

All callers (fc_remote_port_delete(), __iscsi_block_session(),
__srp_start_tl_fail_timers(), srp_reconnect_rport(), snic_tgt_del()) pass
parent devices of scsi_target devices to scsi_target_block().

Rename the function to scsi_block_targets(), and simplify it by assuming
that it is always passed a parent device. Also, have callers pass the
Scsi_Host pointer to scsi_block_targets(), as every caller has this pointer
readily available.

Suggested-by: Christoph Hellwig 
Suggested-by: Bart Van Assche 
Signed-off-by: Martin Wilck 
Link: https://lore.kernel.org/r/20230614103616.31857-7-mwilck@suse.com
Cc: Karan Tilak Kumar 
Cc: Sesidhar Baddela 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen

scsi: replace the fmode_t argument to scsi_ioctl with a simple bool

2023-06-12T14:04:04+00:00

Instead of passing a fmode_t and only checking it for FMODE_WRITE, pass
a bool open_for_write to prepare for callers that won't have the fmode_t.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke 
Acked-by: Christian Brauner 
Link: https://lore.kernel.org/r/20230608110258.189493-20-hch@lst.de
Signed-off-by: Jens Axboe

scsi: replace the fmode_t argument to scsi_cmd_allowed with a simple bool

2023-06-12T14:04:04+00:00

Instead of passing a fmode_t and only checking it for FMODE_WRITE, pass
a bool open_for_write to prepare for callers that won't have the fmode_t.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Martin K. Petersen 
Reviewed-by: Hannes Reinecke 
Acked-by: Christian Brauner 
Link: https://lore.kernel.org/r/20230608110258.189493-19-hch@lst.de
Signed-off-by: Jens Axboe

Merge patch series "ufs: Do not requeue while ungating the clock"

2023-05-31T15:45:16+00:00

Bart Van Assche  says:

In the traces we recorded while testing zoned storage we noticed that UFS
commands are requeued while the clock is being ungated. Command requeueing
makes it harder than necessary to preserve the command order. Hence this
patch series that modifies the SCSI core and also the UFS driver such that
clock ungating does not trigger command requeueing.

Link: https://lore.kernel.org/r/20230529202640.11883-1-bvanassche@acm.org
Signed-off-by: Martin K. Petersen

scsi: core: Support setting BLK_MQ_F_BLOCKING

2023-05-31T15:42:46+00:00

Prepare for adding code in ufshcd_queuecommand() that may sleep. This patch
is similar to a patch posted last year by Mike Christie. See also
https://lore.kernel.org/all/20220308003957.123312-2-michael.christie@oracle.com/

Cc: Mike Christie 
Signed-off-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20230529202640.11883-3-bvanassche@acm.org
Signed-off-by: Martin K. Petersen

Merge patch series "Add Command Duration Limits support"

2023-05-22T21:09:51+00:00

Niklas Cassel  says:

This series adds support for Command Duration Limits.
The series is based on linux tag: v6.4-rc1
The series can also be found in git: https://github.com/floatious/linux/commits/cdl-v7

=================
CDL in ATA / SCSI
=================
Command Duration Limits is defined in:
T13 ATA Command Set - 5 (ACS-5) and
T10 SCSI Primary Commands - 6 (SPC-6) respectively
(a simpler version of CDL is defined in T10 SPC-5).

CDL defines Duration Limits Descriptors (DLD).
7 DLDs for read commands and 7 DLDs for write commands.
Simply put, a DLD contains a limit and a policy.

A command can specify that a certain limit should be applied by setting
the DLD index field (3 bits, so 0-7) in the command itself.

The DLD index points to one of the 7 DLDs.
DLD index 0 means no descriptor, so no limit.
DLD index 1-7 means DLD 1-7.

A DLD can have a few different policies, but the two major ones are:
-Policy 0xF (abort), command will be completed with command aborted error
(ATA) or status CHECK CONDITION (SCSI), with sense data indicating that
the command timed out.
-Policy 0xD (complete-unavailable), command will be completed without
error (ATA) or status GOOD (SCSI), with sense data indicating that the
command timed out. Note that the command will not have transferred any
data to/from the device when the command timed out, even though the
command returned success.

Regardless of the CDL policy, in case of a CDL timeout, the I/O will
result in a -ETIME error to user-space.

The DLDs are defined in the CDL log page(s) and are readable and writable.
Reading and writing the CDL DLDs are outside the scope of the kernel.
If a user wants to read or write the descriptors, they can do so using a
user-space application that sends passthrough commands, such as cdl-tools:
https://github.com/westerndigitalcorporation/cdl-tools

================================
The introduction of ioprio hints
================================
What the kernel does provide, is a method to let I/O use one of the CDL DLDs
defined in the device. Note that the kernel will simply forward the DLD index
to the device, so the kernel currently does not know, nor does it need to know,
how the DLDs are defined inside the device.

The way that the CDL DLD index is supplied to the kernel is by introducing a
new 10 bit "ioprio hint" field within the existing 16 bit ioprio definition.

Currently, only 6 out of the 16 ioprio bits are in use, the remaining 10 bits
are unused, and are currently explicitly disallowed to be set by the kernel.

For now, we only add ioprio hints representing CDL DLD index 1-7. Additional
ioprio hints for other QoS features could be defined in the future.

A theoretical future work could be to make an I/O scheduler aware of these
hints. E.g. for CDL, an I/O scheduler could make use of the duration limit
in each descriptor, and take that information into account while scheduling
commands. Right now, the ioprio hints will be ignored by the I/O schedulers.

==============================
How to use CDL from user-space
==============================
Since CDL is mutually exclusive with NCQ priority
(see ncq_prio_enable and sas_ncq_prio_enable in
Documentation/ABI/testing/sysfs-block-device),
CDL has to be explicitly enabled using:
echo 1 > /sys/block/$bdev/device/cdl_enable

Since the ioprio hints are supplied through the existing I/O priority API,
it should be simple for an application to make use of the ioprio hints.

It simply has to reuse one of the new macros defined in
include/uapi/linux/ioprio.h: IOPRIO_PRIO_HINT() or IOPRIO_PRIO_VALUE_HINT(),
and supply one of the new hints defined in include/uapi/linux/ioprio.h:
IOPRIO_HINT_DEV_DURATION_LIMIT_[1-7], which indicates that the I/O should
use the corresponding CDL DLD index 1-7.

By reusing the I/O priority API, the user can both define a DLD to use per
AIO (io_uring sqe->ioprio or libaio iocb->aio_reqprio) or per-thread
(ioprio_set()).

=======
Testing
=======
With the following fio patches:
https://github.com/floatious/fio/commits/cdl

fio adds support for ioprio hints, such that CDL can be tested using e.g.:
fio --ioengine=io_uring --cmdprio_percentage=10 --cmdprio_hint=DLD_index

A simple way to test is to use a DLD with a very short duration limit,
and send large reads. Regardless of the CDL policy, in case of a CDL
timeout, the I/O will result in a -ETIME error to user-space.

We also provide a CDL test suite located in the cdl-tools repo, see:
https://github.com/westerndigitalcorporation/cdl-tools#testing-a-system-command-duration-limits-support

We have tested this patch series using:
-real hardware
-the following QEMU implementation:
https://github.com/floatious/qemu/tree/cdl
(NOTE: the QEMU implementation requires you to define the CDL policy at compile
time, so you currently need to recompile QEMU when switching between policies.)

===================
Further information
===================
For further information about CDL, see Damien's slides:

Presented at SDC 2021:
https://www.snia.org/sites/default/files/SDC/2021/pdfs/SNIA-SDC21-LeMoal-Be-On-Time-command-duration-limits-Feature-Support-in%20Linux.pdf

Presented at Lund Linux Con 2022:
https://drive.google.com/file/d/1I6ChFc0h4JY9qZdO1bY5oCAdYCSZVqWw/view?usp=sharing

================
Changes since V6
================
-Rebased series on v6.4-rc1.
-Picked up Reviewed-by tags from Hannes (Thank you Hannes!)
-Picked up Reviewed-by tag from Christoph (Thank you Christoph!)
-Changed KernelVersion from 6.4 to 6.5 for new sysfs attributes.

For older change logs, see previous patch series versions:
https://lore.kernel.org/linux-scsi/20230406113252.41211-1-nks@flawful.org/
https://lore.kernel.org/linux-scsi/20230404182428.715140-1-nks@flawful.org/
https://lore.kernel.org/linux-scsi/20230309215516.3800571-1-niklas.cassel@wdc.com/
https://lore.kernel.org/linux-scsi/20230124190308.127318-1-niklas.cassel@wdc.com/
https://lore.kernel.org/linux-scsi/20230112140412.667308-1-niklas.cassel@wdc.com/
https://lore.kernel.org/linux-scsi/20221208105947.2399894-1-niklas.cassel@wdc.com/

Link: https://lore.kernel.org/r/20230511011356.227789-1-nks@flawful.org
Signed-off-by: Martin K. Petersen

scsi: core: Allow enabling and disabling command duration limits

2023-05-22T21:05:19+00:00

Add the sysfs scsi_device attribute cdl_enable to allow a user to enable or
disable a device command duration limits feature. CDL is disabled by
default. This feature must be explicitly enabled by a user by setting the
cdl_enable attribute to 1.

The new function scsi_cdl_enable() does not do anything beside setting the
cdl_enable field of struct scsi_device in the case of a (real) SCSI device
(e.g. a SAS HDD). For ATA devices, the command duration limits feature
needs to be enabled/disabled using the ATA feature sub-page of the control
mode page. To do so, the scsi_cdl_enable() function checks if this mode
page is supported using scsi_mode_sense(). If it is, scsi_mode_select() is
used to enable and disable CDL.

Signed-off-by: Damien Le Moal 
Reviewed-by: Hannes Reinecke 
Co-developed-by: Niklas Cassel 
Signed-off-by: Niklas Cassel 
Link: https://lore.kernel.org/r/20230511011356.227789-10-nks@flawful.org
Signed-off-by: Martin K. Petersen