scsi: core: Query the Block Limits Extension VPD page

Parse the Reduced Stream Control Supported (RSCS) bit from the block limits
extension VPD page. The RSCS bit is defined in SBC-5 r05
(https://www.t10.org/cgi-bin/ac.pl?t=f&f=sbc5r05.pdf).

Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240130214911.1863909-10-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Allow passthrough to request midlayer retries

For passthrough we don't retry any error which we get a check condition
for. This results in a lot of callers driving their own retries for all
UAs, specific UAs, NOT_READY, specific sense values or any type of failure.

This adds the core code to allow passthrough users to specify what errors
they want the SCSI midlayer to retry for them. We can then convert users to
drop a lot of their sense parsing and retry handling.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Link: https://lore.kernel.org/r/20240123002220.129141-2-michael.christie@oracle.com
Reviewed-by: John Garry <john.g.garry@oracle.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Consult supported VPD page list prior to fetching page

Commit c92a6b5d6335 ("scsi: core: Query VPD size before getting full
page") removed the logic which checks whether a VPD page is present on
the supported pages list before asking for the page itself. That was
done because SPC helpfully states "The Supported VPD Pages VPD page
list may or may not include all the VPD pages that are able to be
returned by the device server". Testing had revealed a few devices
that supported some of the 0xBn pages but didn't actually list them in
page 0.

Julian Sikorski bisected a problem with his drive resetting during
discovery to the commit above. As it turns out, this particular drive
firmware will crash if we attempt to fetch page 0xB9.

Various approaches were attempted to work around this. In the end,
reinstating the logic that consults VPD page 0 before fetching any
other page was the path of least resistance. A firmware update for the
devices which originally compelled us to remove the check has since
been released.

Link: https://lore.kernel.org/r/20240214221411.2888112-1-martin.petersen@oracle.com
Fixes: c92a6b5d6335 ("scsi: core: Query VPD size before getting full page")
Cc: stable@vger.kernel.org
Cc: Bart Van Assche <bvanassche@acm.org>
Reported-by: Julian Sikorski <belegdol@gmail.com>
Tested-by: Julian Sikorski <belegdol@gmail.com>
Reviewed-by: Lee Duncan <lee.duncan@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: sd: usb_storage: uas: Access media prior to querying device properties

It has been observed that some USB/UAS devices return generic properties
hardcoded in firmware for mode pages for a period of time after a device
has been discovered. The reported properties are either garbage or they do
not accurately reflect the characteristics of the physical storage device
attached in the case of a bridge.

Prior to commit 1e029397d12f ("scsi: sd: Reorganize DIF/DIX code to
avoid calling revalidate twice") we would call revalidate several
times during device discovery. As a result, incorrect values would
eventually get replaced with ones accurately describing the attached
storage. When we did away with the redundant revalidate pass, several
cases were reported where devices reported nonsensical values or would
end up in write-protected state.

An initial attempt at addressing this issue involved introducing a
delayed second revalidate invocation. However, this approach still
left some devices reporting incorrect characteristics.

Tasos Sahanidis debugged the problem further and identified that
introducing a READ operation prior to MODE SENSE fixed the problem and that
it wasn't a timing issue. Issuing a READ appears to cause the devices to
update their state to reflect the actual properties of the storage
media. Device properties like vendor, model, and storage capacity appear to
be correctly reported from the get-go. It is unclear why these devices
defer populating the remaining characteristics.

Match the behavior of a well known commercial operating system and
trigger a READ operation prior to querying device characteristics to
force the device to populate the mode pages.

The additional READ is triggered by a flag set in the USB storage and
UAS drivers. We avoid issuing the READ for other transport classes
since some storage devices identify Linux through our particular
discovery command sequence.

Link: https://lore.kernel.org/r/20240213143306.2194237-1-martin.petersen@oracle.com
Fixes: 1e029397d12f ("scsi: sd: Reorganize DIF/DIX code to avoid calling revalidate twice")
Cc: stable@vger.kernel.org
Reported-by: Tasos Sahanidis <tasos@tasossah.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Tasos Sahanidis <tasos@tasossah.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: sd: Fix system start for ATA devices

It is not always possible to keep a device in the runtime suspended state
when a system level suspend/resume cycle is executed. E.g. for ATA devices
connected to AHCI adapters, system resume resets the ATA ports, which
causes connected devices to spin up. In such case, a runtime suspended disk
will incorrectly be seen with a suspended runtime state because the device
is not resumed by sd_resume_system(). The power state seen by the user is
different than the actual device physical power state.

Fix this issue by introducing the struct scsi_device flag
force_runtime_start_on_system_start. When set, this flag causes
sd_resume_system() to request a runtime resume operation for runtime
suspended devices. This results in the user seeing the device runtime_state
as active after a system resume, thus correctly reflecting the device
physical power state.

Fixes: 9131bff6a9f1 ("scsi: core: pm: Only runtime resume if necessary")
Cc: <stable@vger.kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20231120225631.37938-3-dlemoal@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Change SCSI device boolean fields to single bit flags

Commit 3cc2ffe5c16d ("scsi: sd: Differentiate system and runtime start/stop
management") changed the single bit manage_start_stop flag into 2 boolean
fields of the SCSI device structure. Commit 24eca2dce0f8 ("scsi: sd:
Introduce manage_shutdown device flag") introduced the manage_shutdown
boolean field for the same structure. Together, these 2 commits increase
the size of struct scsi_device by 8 bytes by using booleans instead of
defining the manage_xxx fields as single bit flags, similarly to other
flags of this structure.

Avoid this unnecessary structure size increase and be consistent with the
definition of other flags by reverting the definitions of the manage_xxx
fields as single bit flags.

Fixes: 3cc2ffe5c16d ("scsi: sd: Differentiate system and runtime start/stop management")
Fixes: 24eca2dce0f8 ("scsi: sd: Introduce manage_shutdown device flag")
Cc: <stable@vger.kernel.org>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20231120225631.37938-2-dlemoal@kernel.org
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Remove scsi device no_start_on_resume flag

The scsi device flag no_start_on_resume is not set by any scsi low
level driver. Remove it. This reverts the changes introduced by commit
0a8589055936 ("ata,scsi: do not issue START STOP UNIT on resume").

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: sd: Introduce manage_shutdown device flag

Commit aa3998dbeb3a ("ata: libata-scsi: Disable scsi device
manage_system_start_stop") change setting the manage_system_start_stop
flag to false for libata managed disks to enable libata internal
management of disk suspend/resume. However, a side effect of this change
is that on system shutdown, disks are no longer being stopped (set to
standby mode with the heads unloaded). While this is not a critical
issue, this unclean shutdown is not recommended and shows up with
increased smart counters (e.g. the unexpected power loss counter
"Unexpect_Power_Loss_Ct").

Instead of defining a shutdown driver method for all ATA adapter
drivers (not all of them define that operation), this patch resolves
this issue by further refining the sd driver start/stop control of disks
using the new flag manage_shutdown. If this new flag is set to true by
a low level driver, the function sd_shutdown() will issue a
START STOP UNIT command with the start argument set to 0 when a disk
needs to be powered off (suspended) on system power off, that is, when
system_state is equal to SYSTEM_POWER_OFF.

Similarly to the other manage_xxx flags, the new manage_shutdown flag is
exposed through sysfs as a read-write device attribute.

To avoid any confusion between manage_shutdown and
manage_system_start_stop, the comments describing these flags in
include/scsi/scsi.h are also improved.

Fixes: aa3998dbeb3a ("ata: libata-scsi: Disable scsi device manage_system_start_stop")
Cc: stable@vger.kernel.org
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218038
Link: https://lore.kernel.org/all/cd397c88-bf53-4768-9ab8-9d107df9e613@gmail.com/
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: sd: Differentiate system and runtime start/stop management

The underlying device and driver of a SCSI disk may have different
system and runtime power mode control requirements. This is because
runtime power management affects only the SCSI disk, while system level
power management affects all devices, including the controller for the
SCSI disk.

For instance, issuing a START STOP UNIT command when a SCSI disk is
runtime suspended and resumed is fine: the command is translated to a
STANDBY IMMEDIATE command to spin down the ATA disk and to a VERIFY
command to wake it up. The SCSI disk runtime operations have no effect
on the ata port device used to connect the ATA disk. However, for
system suspend/resume operations, the ATA port used to connect the
device will also be suspended and resumed, with the resume operation
requiring re-validating the device link and the device itself. In this
case, issuing a VERIFY command to spinup the disk must be done before
starting to revalidate the device, when the ata port is being resumed.
In such case, we must not allow the SCSI disk driver to issue START STOP
UNIT commands.

Allow a low level driver to refine the SCSI disk start/stop management
by differentiating system and runtime cases with two new SCSI device
flags: manage_system_start_stop and manage_runtime_start_stop. These new
flags replace the current manage_start_stop flag. Drivers setting the
manage_start_stop are modifed to set both new flags, thus preserving the
existing start/stop management behavior. For backward compatibility, the
old manage_start_stop sysfs device attribute is kept as a read-only
attribute showing a value of 1 for devices enabling both new flags and 0
otherwise.

Fixes: 0a8589055936 ("ata,scsi: do not issue START STOP UNIT on resume")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

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

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 <paula@soe.ucsc.edu>
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 <dlemoal@kernel.org>
Tested-by: Tanner Watkins <dalzot@gmail.com>
Tested-by: Paul Ausbeck <paula@soe.ucsc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>

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

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 <hch@lst.de>
Suggested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Link: https://lore.kernel.org/r/20230614103616.31857-7-mwilck@suse.com
Cc: Karan Tilak Kumar <kartilak@cisco.com>
Cc: Sesidhar Baddela <sebaddel@cisco.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Allow enabling and disabling command duration limits

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 <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-10-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Detect support for command duration limits

Introduce the function scsi_cdl_check() to detect if a device supports
command duration limits (CDL). Support for the READ 16, WRITE 16, READ 32
and WRITE 32 commands are checked using the function scsi_report_opcode()
to probe the rwcdlp and cdlp bits as they indicate the mode page defining
the command duration limits descriptors that apply to the command being
tested.

If any of these commands support CDL, the field cdl_supported of struct
scsi_device is set to 1 to indicate that the device supports CDL.

Support for CDL for a device is advertizes through sysfs using the new
cdl_supported device attribute. This attribute value is 1 for a device
supporting CDL and 0 otherwise.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Co-developed-by: Niklas Cassel <niklas.cassel@wdc.com>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-9-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Support Service Action in scsi_report_opcode()

The REPORT_SUPPORTED_OPERATION_CODES command allows checking for support of
commands that have the same opcode but different service actions, such as
READ 32 and WRITE 32. However, the current implementation of
scsi_report_opcode() only allows checking an operation code without a
service action differentiation.

Add the "sa" argument to scsi_report_opcode() to allow passing a service
action. If a non-zero service action is specified, the reporting options
field value is set to 3 to have the service action field taken into account
by the device. If no service action field is specified (zero), the
reporting options field is set to 1 as before.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-8-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Support retrieving sub-pages of mode pages

Allow scsi_mode_sense() to retrieve sub-pages of mode pages by adding the
subpage argument. Change all the current caller sites to specify the
subpage 0.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20230511011356.227789-7-nks@flawful.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Add BLIST_NO_VPD_SIZE for some VDASD

Some storage, such as AIX VDASD (virtual storage) and IBM 2076 (front
end), fail as a result of commit c92a6b5d6335 ("scsi: core: Query VPD
size before getting full page").

That commit changed getting SCSI VPD pages so that we now read just
enough of the page to get the actual page size, then read the whole
page in a second read. The problem is that the above mentioned
hardware returns zero for the page size, because of a firmware
error. In such cases, until the firmware is fixed, this new blacklist
flag says to revert to the original method of reading the VPD pages,
i.e. try to read a whole buffer's worth on the first try.

[mkp: reworked somewhat]

Fixes: c92a6b5d6335 ("scsi: core: Query VPD size before getting full page")
Reported-by: Martin Wilck <mwilck@suse.com>
Suggested-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Lee Duncan <lduncan@suse.com>
Link: https://lore.kernel.org/r/20220928181350.9948-1-leeman.duncan@gmail.com
Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Extend struct scsi_exec_args

Allow SCSI LLDs to specify SCMD_* flags.

Link: https://lore.kernel.org/r/20230210193258.4004923-2-bvanassche@acm.org
Cc: Mike Christie <michael.christie@oracle.com>
Cc: John Garry <john.g.garry@oracle.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Remove scsi_execute_req()/scsi_execute() functions

scsi_execute() and scsi_execute_req() are no longer used so remove them.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Add struct for args to execution functions

Move the SCSI execution functions to use a struct for passing in optional
args. This commit adds the new struct, temporarily converts scsi_execute()
and scsi_execute_req() ands a new helper, scsi_execute_cmd(), which takes
the scsi_exec_args struct.

There should be no change in behavior. We no longer allow users to pass in
any request->rq_flags value, but they were only passing in RQF_PM which we
do support by allowing users to pass in the BLK_MQ_REQ flags used by
blk_mq_alloc_request().

Subsequent commits will convert scsi_execute() and scsi_execute_req() users
to the new helpers then remove scsi_execute() and scsi_execute_req().

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: sd: Use 16-byte SYNCHRONIZE CACHE on ZBC devices

ZBC Zoned Block Commands specification mandates SYNCHRONIZE CACHE(16) for
host-managed zoned block devices, but does not mandate SYNCHRONIZE
CACHE(10). Call SYNCHRONIZE CACHE(16) in place of SYNCHRONIZE CACHE(10) to
ensure that the command is always supported. For this purpose, add
use_16_for_sync flag to struct scsi_device in same manner as use_16_for_rw
flag.

To be precise, ZBC does not mandate SYNCHRONIZE CACHE(16) for host-aware
zoned block devices. However, modern devices should support 16-byte
commands. Hence, call SYNCHRONIZE CACHE (16) on both types of ZBC devices,
host-aware and host-managed. Of note is that READ(16) and WRITE(16) have
same story and they are already called for both types of ZBC devices.

Another note is that this patch depends on the fix commit ea045fd344cb
("ata: libata-scsi: fix SYNCHRONIZE CACHE (16) command failure").

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20221115002905.1709006-1-shinichiro.kawasaki@wdc.com
Reviewed-by: Damien Le Moal <damien.lemoal@opendource.wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Release SCSI devices synchronously

All upstream scsi_device_put() calls happen from thread context. Hence
simplify scsi_device_put() by always calling the release function
synchronously. This commit prepares for constifying the SCSI host template
by removing an assignment that clears the module pointer in the SCSI host
template.

scsi_device_dev_release_usercontext() was introduced in 2006 via
commit 65110b216895 ("[SCSI] fix wrong context bugs in SCSI").

Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.garry@huawei.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20221015002418.30955-9-bvanassche@acm.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Add I/O timeout count for SCSI device

Currently struct scsi_device maintains counters for requests, completions,
and errors but is missing a counter for timeouts.

For better tracking of timeouts, add a suitable counter.

Link: https://lore.kernel.org/r/1663666339-17560-1-git-send-email-wubo40@huawei.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Wu Bo <wubo40@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Revert "Make sure that targets outlive devices"

Revert the patch series "Call blk_mq_free_tag_set() earlier" because it
introduces a deadlock if the scsi_remove_host() caller holds a reference on
a device, target or host.

Link: https://lore.kernel.org/r/20220821220502.13685-5-bvanassche@acm.org
Fixes: fe442604199e ("scsi: core: Make sure that targets outlive devices")
Reported-by: syzbot+bafeb834708b1bb750bc@syzkaller.appspotmail.com
Tested-by: Kenneth R. Crudup <kenny@panix.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Make sure that targets outlive devices

This commit prevents that the following sequence triggers a kernel crash:

- Deletion of a SCSI device is requested via sysfs. Device removal takes
some time because blk_cleanup_queue() is waiting for the SCSI error
handler.

- The SCSI target associated with that SCSI device is removed.

- scsi_remove_target() returns and its caller frees the resources
associated with the SCSI target.

- The error handler makes progress and invokes an LLD callback that
dereferences the SCSI target pointer.

Link: https://lore.kernel.org/r/20220728221851.1822295-2-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.garry@huawei.com>
Cc: Li Zhijian <lizhijian@fujitsu.com>
Reported-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi/core: Use the new blk_opf_t type

Use the new blk_opf_t type for arguments and variables that represent
request flags. Use the !! operator in scsi_noretry_cmd() to convert the
blk_opf_t type into a boolean. This patch does not change any functionality.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: John Garry <john.garry@huawei.com>
Cc: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-42-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: core: Cache VPD pages b0, b1, b2

The SCSI disk driver consults VPD pages b0 (Block Limits), b1 (Block Device
Characteristics), and b2 (Logical Block Provisioning). Instead of having
sd.c request these pages every revalidate cycle, cache them along with the
other commonly used VPDs.

Link: https://lore.kernel.org/r/20220302053559.32147-6-martin.petersen@oracle.com
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Query VPD size before getting full page

We currently default to 255 bytes when fetching VPD pages during discovery.
However, we have had a few devices that are known to wedge if the requested
buffer exceeds a certain size. See commit af73623f5f10 ("[SCSI] sd: Reduce
buffer size for vpd request") which works around one example of this
problem in the SCSI disk driver.

With commit d188b0675b21 ("scsi: core: Add sysfs attributes for VPD pages
0h and 89h") we now risk triggering the same issue in the generic midlayer
code.

The problem with the ATA VPD page in particular is that the SCSI portion of
the page is trailed by 512 bytes of verbatim ATA Identify Device
information. However, not all controllers actually provide the additional
512 bytes and will lock up if one asks for more than the 64 bytes
containing the SCSI protocol fields.

Instead of picking a new, somewhat arbitrary, number of bytes for the VPD
buffer size, start fetching the 4-byte header for each page. The header
contains the size of the page as far as the device is concerned. We can use
the reported size to specify the correct allocation length when
subsequently fetching the full page.

The header validation is done by a new helper function scsi_get_vpd_size()
and both scsi_get_vpd_page() and scsi_get_vpd_buf() now rely on this to
query the page size.

In addition, scsi_get_vpd_page() is simplified to mirror the logic in
scsi_get_vpd_page(). This involves removing the Supported VPD Pages lookup
prior to attempting to query a page. There does not appear any evidence,
even in the oldest SCSI specs, that this step is required. We already rely
on scsi_get_vpd_page() throughout the stack and this function never
consulted the Supported VPD Pages. Since this has not caused any problems
it should be safe to remove the precondition from scsi_get_vpd_page().

Instrumented runs also revealed that the Supported VPD Pages lookup had
little effect since the device page index often was larger than the
supplied buffer size. As a result, inquiries frequently bypassed the index
check and went through the "If we ran off the end of the buffer, give us
the benefit of the doubt" code path which assumed the page was present
despite not being listed. The revised code takes both the page size
reported by the device as well as the size of the buffer provided by the
scsi_get_vpd_page() caller into account.

Link: https://lore.kernel.org/r/20220302053559.32147-3-martin.petersen@oracle.com
Fixes: d188b0675b21 ("scsi: core: Add sysfs attributes for VPD pages 0h and 89h")
Reported-by: Maciej W. Rozycki <macro@orcam.me.uk>
Tested-by: Maciej W. Rozycki <macro@orcam.me.uk>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: sd: Add silence_suspend flag to suppress some PM messages

Kernel messages produced during runtime PM can cause a never-ending cycle
because user space utilities (e.g. journald or rsyslog) write the messages
back to storage, causing runtime resume, more messages, and so on.

Messages that tell of things that are expected to happen are arguably
unnecessary, so add a flag to suppress them. This flag is used by the UFS
driver.

Link: https://lore.kernel.org/r/20220228113652.970857-2-adrian.hunter@intel.com
Cc: stable@vger.kernel.org
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Fix scsi_mode_select() interface

The modepage argument is unused. Remove it.

Link: https://lore.kernel.org/r/20210929091744.706003-3-damien.lemoal@wdc.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: remove the ->rq_disk field in struct request

Just use the disk attached to the request_queue instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20211126121802.2090656-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: core: Fix early registration of sysfs attributes for scsi_device

v4.17 commit 86b87cde0b55 ("scsi: core: host template attribute groups")
introduced explicit sysfs_create_groups() in scsi_sysfs_add_sdev()
and sysfs_remove_groups() in __scsi_remove_device(), both for sdev_gendev,
based on a new field const struct attribute_group **sdev_groups
of struct scsi_host_template.

Commit 92c4b58b15c5 ("scsi: core: Register sysfs attributes earlier")
removed above explicit (de)registration of scsi_device attribute groups.
It also converted all scsi_device attributes and attribute_groups to
end up in a new field const struct attribute_group *gendev_attr_groups[6]
of struct scsi_device. However, that new field was not used anywhere.

Surprisingly, this only caused missing LLDD specific scsi_device sysfs
attributes. Whereas, scsi core attributes from scsi_sdev_attr_groups
did continue to exist because of scsi_dev_type.groups.

We separate scsi core attibutes from LLDD specific attributes.
Hence, we keep the initializing assignment scsi_dev_type =
{ .groups = scsi_sdev_attr_groups, } as this takes care of core
attributes. Without the separation, it would cause attribute double
registration due to scsi_dev_type.groups and sdev_gendev.groups.

Julian suggested to assign the sdev_groups pointer of the
scsi_host_template directly to the groups pointer of sdev_gendev.
This way we can delete the container scsi_device.gendev_attr_groups
and the loop copying each entry from hostt->sdev_groups to
sdev->gendev_attr_groups.

Alternative approaches ruled out:
Assigning gendev_attr_groups to sdev_dev has no visible effect.
Assigning sdev->gendev_attr_groups to scsi_dev_type.groups
caused scsi_device of all scsi host types to get LLDD specific
attributes of the LLDD for which the last sdev alloc happened to occur,
as that overwrote scsi_dev_type.groups,
e.g. scsi_debug had zfcp-specific scsi_device attributes.

Link: https://lore.kernel.org/r/20211026014240.4098365-1-maier@linux.ibm.com
Fixes: 92c4b58b15c5 ("scsi: core: Register sysfs attributes earlier")
Suggested-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: make sure that request queue queiesce and unquiesce balanced

For fixing queue quiesce race between driver and block layer(elevator
switch, update nr_requests, ...), we need to support concurrent quiesce
and unquiesce, which requires the two call balanced.

It isn't easy to audit that in all scsi drivers, especially the two may
be called from different contexts, so do it in scsi core with one
per-device atomic variable to balance quiesce and unquiesce.

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Fixes: e70feb8b3e68 ("blk-mq: support concurrent queue quiesce/unquiesce")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20211109071144.181581-4-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: core: Remove two host template members that are no longer used

All SCSI drivers have been converted to use shost_groups and sdev_groups
instead of shost_attrs or sdev_attrs. Hence remove shost_attrs and
sdev_attrs. Additionally, remove the 'lld_attr_group' members and also
the scsi_convert_dev_attrs() function.

Link: https://lore.kernel.org/r/20211012233558.4066756-47-bvanassche@acm.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Register sysfs attributes earlier

A quote from Documentation/driver-api/driver-model/device.rst:
"Word of warning: While the kernel allows device_create_file() and
device_remove_file() to be called on a device at any time, userspace has
strict expectations on when attributes get created. When a new device is
registered in the kernel, a uevent is generated to notify userspace (like
udev) that a new device is available. If attributes are added after the
device is registered, then userspace won't get notified and userspace will
not know about the new attributes."

Hence register SCSI host sysfs attributes before the SCSI host shost_dev
uevent is emitted instead of after that event has been emitted.

Link: https://lore.kernel.org/r/20211012233558.4066756-2-bvanassche@acm.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: move struct request to blk-mq.h

struct request is only used by blk-mq drivers, so move it and all
related declarations to blk-mq.h.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-18-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: core: Remove 'current_tag'

The 'current_tag' field in struct scsi_device is unused now; remove it.

Link: https://lore.kernel.org/r/1631696835-136198-4-git-send-email-john.garry@huawei.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Use scsi_cmd_to_rq() instead of scsi_cmnd.request

Prepare for removal of the request pointer by using scsi_cmd_to_rq()
instead. Cast away constness where necessary when passing a SCSI command
pointer to scsi_cmd_to_rq(). This patch does not change any functionality.

Link: https://lore.kernel.org/r/20210809230355.8186-3-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: block: Remove the remaining SG_IO-related fields from struct request_queue

Move the sg_timeout and sg_reserved_size fields into the bsg_device and
scsi_device structures as they have nothing to do with generic block I/O.
Note that these values are now separate for bsg vs. SCSI device node
access, but that just matches how /dev/sg vs the other nodes has always
behaved.

Link: https://lore.kernel.org/r/20210729064845.1044147-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: bsg: Simplify device registration

Use the per-device cdev_device_interface to store the bsg data in the char
device inode, and thus remove the need to embedd the bsg_class_device
structure in the request_queue.

Link: https://lore.kernel.org/r/20210729064845.1044147-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Add new flag BLIST_IGN_MEDIA_CHANGE

Add a new flag for devices that erroneously establish MEDIUM MAY HAVE
CHANGED unit attentions. Drivers can set this flag to make the SCSI
layer ignore media change events during resume.

[mkp: add "ignore" and add corresponding flag to struct scsi_device]

Link: https://lore.kernel.org/r/20210704075403.147114-2-martin.kepplinger@puri.sm
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Remove an incorrect comment

scsi_device.sdev_target is used in more code than the single_lun code,
hence remove the comment next to the definition of the sdev_target member.

Link: https://lore.kernel.org/r/20210415220826.29438-3-bvanassche@acm.org
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Replace sdev->device_busy with sbitmap

SCSI currently uses an atomic variable to track queue depth for each
attached device. The queue depth depends on many factors such as transport
type and device implementation. In addition, the SCSI device queue depth is
not a static entity but changes over time as a result of congestion
management.

While blk-mq currently tracks queue depth for each hctx, it can't easily be
changed to accommodate the SCSI per-device requirement.

The current approach of using an atomic variable doesn't scale well when
there are lots of CPU cores and the disk is very fast. IOPS can be
substantially impacted by the atomic in the hot path.

Replace the atomic variable sdev->device_busy with an sbitmap for tracking
the SCSI device queue depth.

It has been observed that IOPS is improved ~30% by this patchset in the
following test:

1) test machine(32 logical CPU cores)
Thread(s) per core: 2
Core(s) per socket: 8
Socket(s): 2
NUMA node(s): 2
Model name: Intel(R) Xeon(R) Silver 4110 CPU @ 2.10GHz

2) setup scsi_debug:
modprobe scsi_debug virtual_gb=128 max_luns=1 submit_queues=32 delay=0 max_queue=256

3) fio script:
fio --rw=randread --size=128G --direct=1 --ioengine=libaio --iodepth=2048 \
--numjobs=32 --bs=4k --group_reporting=1 --group_reporting=1 --runtime=60 \
--loops=10000 --name=job1 --filename=/dev/sdN

[mkp: fix device_busy reference in mpt3sas]

Link: https://lore.kernel.org/r/20210122023317.687987-14-ming.lei@redhat.com
Link: https://lore.kernel.org/linux-block/20200119071432.18558-6-ming.lei@redhat.com/
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Add scsi_device_busy() wrapper

Add scsi_device_busy() helper to prepare drivers for tracking device queue
depth via sbitmap_queue.

Link: https://lore.kernel.org/r/20210122023317.687987-12-ming.lei@redhat.com
Cc: Omar Sandoval <osandov@fb.com>
Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Cc: Ewan D. Milne <emilne@redhat.com>
Tested-by: Sumanesh Samanta <sumanesh.samanta@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Only re-run queue in scsi_end_request() if device queue is busy

The request queue is currently run unconditionally in scsi_end_request() if
both target queue and host queue are ready.

Recently Long Li reported that cost of a queue run can be very heavy in
case of high queue depth. Improve this situation by only running the
request queue when this LUN is busy.

Link: https://lore.kernel.org/r/20200910075056.36509-1-ming.lei@redhat.com
Reported-by: Long Li <longli@microsoft.com>
Tested-by: Long Li <longli@microsoft.com>
Tested-by: Kashyap Desai <kashyap.desai@broadcom.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: move dma drain handling to scsi

Don't burden the common block code with with specifics of the libata DMA
draining mechanism. Instead move most of the code to the scsi midlayer.

That also means the nr_phys_segments adjustments in the blk-mq fast path
can go away entirely, given that SCSI never looks at nr_phys_segments
after mapping the request to a scatterlist.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: core: avoid repetitive logging of device offline messages

Large queues of I/O to offline devices that are eventually submitted when
devices are unblocked result in a many repeated "rejecting I/O to offline
device" messages. These messages can fill up the dmesg buffer in crash
dumps so no useful prior messages remain. In addition, if a serial console
is used, the flood of messages can cause a hard lockup in the console code.

Introduce a flag indicating the message has already been logged for the
device, and reset the flag when scsi_device_set_state() changes the device
state.

Link: https://lore.kernel.org/r/20200311143930.20674-1-emilne@redhat.com
Reviewed-by: Bart van Assche <bvanassche@acm.org>
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Replace zero-length array with flexible-array member

The current codebase makes use of the zero-length array language extension
to the C90 standard, but the preferred mechanism to declare variable-length
types such as these ones is a flexible array member[1][2], introduced in
C99:

struct foo {
int stuff;
struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning in
case the flexible array does not occur last in the structure, which will
help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by this
change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Link: https://lore.kernel.org/r/20200224161406.GA21454@embeddedor
Reviewed-by: Lee Duncan <lduncan@suse.com>
Reviewed-by: Satish Kharat <satishkh@cisco.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Remove cmd_list functionality

Remove cmd_list functionality; no users left. With that the
scsi_put_command() becomes empty, so remove that one, too.

Link: https://lore.kernel.org/r/20200228075318.91255-14-hare@suse.de
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart van Assche <bvanassche@acm.org>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Adjust DBD setting in MODE SENSE for caching mode page per LLD

UFS JEDEC standards require DBD field to be set to 1 in mode sense
command. This patch allows LLD to define the setting of DBD, if
required.

Link: https://lore.kernel.org/r/0101016ed3d643f9-ffd45d6c-c593-4a13-a18f-a32da3d3bb97-000000@us-west-2.amazonses.com
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: Add sysfs attributes for VPD pages 0h and 89h

Add sysfs attributes for the ATA information page and Supported VPD Pages
page.

Link: https://lore.kernel.org/r/20190926162216.56591-1-ryanattard@ryanattard.info
Signed-off-by: Ryan Attard <ryanattard@ryanattard.info>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: core: allow auto suspend override by low-level driver

Rework from previous work by:
Sujit Reddy Thumma <sthumma@codeaurora.org>

Until now the scsi mid-layer forbids runtime suspend till userspace enables
it. This is mainly to quarantine some disks with broken runtime power
management or have high latencies executing suspend resume callbacks. If
the userspace doesn't enable the runtime suspend the underlying hardware
will be always on even when it is not doing any useful work and thus
wasting power.

Some low-level drivers for the controllers can efficiently use runtime
power management to reduce power consumption and improve battery life.
Allow runtime suspend parameters override within the LLD itself instead of
waiting for userspace to control the power management.

Link: https://lore.kernel.org/r/1568649411-5127-2-git-send-email-stanley.chu@mediatek.com
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Check sense buffer size at build time

To avoid introducing problems like those fixed in commit f7068114d45e
("sr: pass down correctly sized SCSI sense buffer"), this creates a macro
wrapper for scsi_execute() that verifies the size of the sense buffer
similar to what was done for command string sizes in commit 3756f6401c30
("exec: avoid gcc-8 warning for get_task_comm").

Another solution could be to add a length argument to scsi_execute(),
but this function already takes a lot of arguments and Jens was not fond
of that approach.

Additionally, this moves the SCSI_SENSE_BUFFERSIZE definition into
scsi_device.h, and removes a redundant include for scsi_device.h from
scsi_cmnd.h.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

scsi: devinfo: change blist_flag_t to 64bit

Space for SCSI blist flags is gradually running out. Change the type to
__u64 and fix a checkpatch complaint about symbolic mode flags in
scsi_devinfo.c.

Make checkpatch happy by replacing simple_strtoul() with kstrtoull().

Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Use 'blist_flags_t' for scsi_devinfo flags

As per recommendation from Linus we should be using a distinct type for
blacklist flags.

[mkp: was cut against an older kernel, applied by hand]

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block, scsi: Make SCSI quiesce and resume work reliably

The contexts from which a SCSI device can be quiesced or resumed are:
* Writing into /sys/class/scsi_device/*/device/state.
* SCSI parallel (SPI) domain validation.
* The SCSI device power management methods. See also scsi_bus_pm_ops.

It is essential during suspend and resume that neither the filesystem
state nor the filesystem metadata in RAM changes. This is why while
the hibernation image is being written or restored that SCSI devices
are quiesced. The SCSI core quiesces devices through scsi_device_quiesce()
and scsi_device_resume(). In the SDEV_QUIESCE state execution of
non-preempt requests is deferred. This is realized by returning
BLKPREP_DEFER from inside scsi_prep_state_check() for quiesced SCSI
devices. Avoid that a full queue prevents power management requests
to be submitted by deferring allocation of non-preempt requests for
devices in the quiesced state. This patch has been tested by running
the following commands and by verifying that after each resume the
fio job was still running:

for ((i=0; i<10; i++)); do
(
cd /sys/block/md0/md &&
while true; do
[ "$(<sync_action)" = "idle" ] && echo check > sync_action
sleep 1
done
) &
pids=($!)
for d in /sys/class/block/sd*[a-z]; do
bdev=${d#/sys/class/block/}
hcil=$(readlink "$d/device")
hcil=${hcil#../../../}
echo 4 > "$d/queue/nr_requests"
echo 1 > "/sys/class/scsi_device/$hcil/device/queue_depth"
fio --name="$bdev" --filename="/dev/$bdev" --buffered=0 --bs=512 \
--rw=randread --ioengine=libaio --numjobs=4 --iodepth=16 \
--iodepth_batch=1 --thread --loops=$((2**31)) &
pids+=($!)
done
sleep 1
echo "$(date) Hibernating ..." >>hibernate-test-log.txt
systemctl hibernate
sleep 10
kill "${pids[@]}"
echo idle > /sys/block/md0/md/sync_action
wait
echo "$(date) Done." >>hibernate-test-log.txt
done

Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
References: "I/O hangs after resuming from suspend-to-ram" (https://marc.info/?l=linux-block&m=150340235201348).
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Martin Steigerwald <martin@lichtvoll.de>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: scsi_error: Handle power-on reset unit attention

As per SAM there is a status precedence, with any sense code 29/XX
taking second place just after an ACA ACTIVE status. Additionally, each
target might prefer to not queue any unit attention conditions, but just
report one. Due to the above, this will be that one with the highest
precedence. This results in the sense code 29/XX effectively
overwriting any other unit attention. Hence we should report the
power-on reset to userland so that it can take appropriate action.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: sd: Implement blacklist option for WRITE SAME w/ UNMAP

SBC-4 states:

"A MAXIMUM UNMAP LBA COUNT field set to a non-zero value indicates the
maximum number of LBAs that may be unmapped by an UNMAP command"

"A MAXIMUM WRITE SAME LENGTH field set to a non-zero value indicates
the maximum number of contiguous logical blocks that the device server
allows to be unmapped or written in a single WRITE SAME command."

Despite the spec being clear on the topic, some devices incorrectly
expect WRITE SAME commands with the UNMAP bit set to be limited to the
value reported in MAXIMUM UNMAP LBA COUNT in the Block Limits VPD.

Implement a blacklist option that can be used to accommodate devices
with this behavior.

Cc: <stable@vger.kernel.org>
Reported-by: Bill Kuzeja <William.Kuzeja@stratus.com>
Reported-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Rework handling of scsi_device.vpd_pg8[03]

Introduce struct scsi_vpd for the VPD page length, data and the RCU head
that will be used to free the VPD data. Use kfree_rcu() instead of
kfree() to free VPD data. Move the VPD buffer pointer check inside the
RCU read lock in the sysfs code. Only annotate pointers that are shared
across threads with __rcu. Use rcu_dereference() when dereferencing an
RCU pointer. This patch suppresses about twenty sparse complaints about
the vpd_pg8[03] pointers. This patch also fixes a race condition, namely
that updating of the VPD pointers and length variables in struct
scsi_device was not atomic with reference to the code reading these
variables. See also "Does the update code tolerate concurrent accesses?"
in Documentation/RCU/checklist.txt.

Fixes: commit 09e2b0b14690 ("scsi: rescan VPD attributes")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Shane Seymour <shane.seymour@hpe.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Shane Seymour <shane.seymour@hpe.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Avoid sign extension of scsi_device.type

This patch avoids that smatch reports the following:

drivers/scsi/scsi_sysfs.c:506 scsi_bus_uevent() warn: argument 3 to %02x specifier has type 'char'
drivers/scsi/scsi_sysfs.c:872 sdev_show_modalias() warn: argument 4 to %02x specifier has type 'char'

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Add STARGET_CREATED_REMOVE state to scsi_target_state

The addition of the STARGET_REMOVE state had the side effect of
introducing a race condition that can cause a crash.

scsi_target_reap_ref_release() checks the starget->state to
see if it still in STARGET_CREATED, and if so, skips calling
transport_remove_device() and device_del(), because the starget->state
is only set to STARGET_RUNNING after scsi_target_add() has called
device_add() and transport_add_device().

However, if an rport loss occurs while a target is being scanned,
it can happen that scsi_remove_target() will be called while the
starget is still in the STARGET_CREATED state. In this case, the
starget->state will be set to STARGET_REMOVE, and as a result,
scsi_target_reap_ref_release() will take the wrong path. The end
result is a panic:

[ 1255.356653] Oops: 0000 [#1] SMP
[ 1255.360154] Modules linked in: x86_pkg_temp_thermal kvm_intel kvm irqbypass crc32c_intel ghash_clmulni_i
[ 1255.393234] CPU: 5 PID: 149 Comm: kworker/u96:4 Tainted: G W 4.11.0+ #8
[ 1255.401879] Hardware name: Dell Inc. PowerEdge R320/08VT7V, BIOS 2.0.22 11/19/2013
[ 1255.410327] Workqueue: scsi_wq_6 fc_scsi_scan_rport [scsi_transport_fc]
[ 1255.417720] task: ffff88060ca8c8c0 task.stack: ffffc900048a8000
[ 1255.424331] RIP: 0010:kernfs_find_ns+0x13/0xc0
[ 1255.429287] RSP: 0018:ffffc900048abbf0 EFLAGS: 00010246
[ 1255.435123] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
[ 1255.443083] RDX: 0000000000000000 RSI: ffffffff8188d659 RDI: 0000000000000000
[ 1255.451043] RBP: ffffc900048abc10 R08: 0000000000000000 R09: 0000012433fe0025
[ 1255.459005] R10: 0000000025e5a4b5 R11: 0000000025e5a4b5 R12: ffffffff8188d659
[ 1255.466972] R13: 0000000000000000 R14: ffff8805f55e5088 R15: 0000000000000000
[ 1255.474931] FS: 0000000000000000(0000) GS:ffff880616b40000(0000) knlGS:0000000000000000
[ 1255.483959] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1255.490370] CR2: 0000000000000068 CR3: 0000000001c09000 CR4: 00000000000406e0
[ 1255.498332] Call Trace:
[ 1255.501058] kernfs_find_and_get_ns+0x31/0x60
[ 1255.505916] sysfs_unmerge_group+0x1d/0x60
[ 1255.510498] dpm_sysfs_remove+0x22/0x60
[ 1255.514783] device_del+0xf4/0x2e0
[ 1255.518577] ? device_remove_file+0x19/0x20
[ 1255.523241] attribute_container_class_device_del+0x1a/0x20
[ 1255.529457] transport_remove_classdev+0x4e/0x60
[ 1255.534607] ? transport_add_class_device+0x40/0x40
[ 1255.540046] attribute_container_device_trigger+0xb0/0xc0
[ 1255.546069] transport_remove_device+0x15/0x20
[ 1255.551025] scsi_target_reap_ref_release+0x25/0x40
[ 1255.556467] scsi_target_reap+0x2e/0x40
[ 1255.560744] __scsi_scan_target+0xaa/0x5b0
[ 1255.565312] scsi_scan_target+0xec/0x100
[ 1255.569689] fc_scsi_scan_rport+0xb1/0xc0 [scsi_transport_fc]
[ 1255.576099] process_one_work+0x14b/0x390
[ 1255.580569] worker_thread+0x4b/0x390
[ 1255.584651] kthread+0x109/0x140
[ 1255.588251] ? rescuer_thread+0x330/0x330
[ 1255.592730] ? kthread_park+0x60/0x60
[ 1255.596815] ret_from_fork+0x29/0x40
[ 1255.600801] Code: 24 08 48 83 42 40 01 5b 41 5c 5d c3 66 66 66 2e 0f 1f 84 00 00 00 00 00 66 66 66 66 90
[ 1255.621876] RIP: kernfs_find_ns+0x13/0xc0 RSP: ffffc900048abbf0
[ 1255.628479] CR2: 0000000000000068
[ 1255.632756] ---[ end trace 34a69ba0477d036f ]---

Fix this by adding another scsi_target state STARGET_CREATED_REMOVE
to distinguish this case.

Fixes: f05795d3d771 ("scsi: Add intermediate STARGET_REMOVE state to scsi_target_state")
Reported-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Laurence Oberman <loberman@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

sd: add support for TCG OPAL self encrypting disks

Just wire up the generic TCG OPAL infrastructure to the SCSI disk driver
and the Security In/Out commands.

Note that I don't know of any actual SCSI disks that do support TCG OPAL,
but this is required to support ATA disks through libata.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

scsi: scsi_dh_alua: remove synchronous STPG support

Since 9c58b395 ("scsi: scsi_devinfo: remove synchronous ALUA for NETAPP
devices") this code is unused.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Protect SCSI device state changes with a mutex

Serializing SCSI device state changes avoids that two state changes can
occur concurrently, e.g. the state changes in scsi_target_block() and
__scsi_remove_device(). This serialization is essential to make patch
"Make __scsi_remove_device go straight from BLOCKED to DEL" work
reliably.

Enable this mechanism for all scsi_target_*block() callers but not for
the scsi_internal_device_unblock() calls from the mpt3sas driver because
that driver can call scsi_internal_device_unblock() from atomic context.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Create two versions of scsi_internal_device_unblock()

This will make it easier to serialize SCSI device state changes through
a mutex.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Split scsi_internal_device_block()

Instead of passing a "wait" argument to scsi_internal_device_block(),
split this function into a function that waits and a function that
doesn't wait. This will make it easier to serialize SCSI device state
changes through a mutex.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Make checking the scsi_device_get() return value mandatory

Now that all scsi_device_get() callers check the return value of this
function, make checking that return value mandatory.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: mpt3sas: Avoid sleeping in interrupt context

Commit 669f044170d8 ("scsi: srp_transport: Move queuecommand() wait code
to SCSI core") can make scsi_internal_device_block() sleep. However,
the mpt3sas driver can call this function from an interrupt
handler. Hence add a second argument to scsi_internal_device_block()
that restores the old behavior of this function for the mpt3sas handler.

The call chain that triggered an "IRQ handler enabled interrupts"
complaint is as follows:

_base_interrupt()
-> _base_async_event()
-> mpt3sas_scsih_event_callback()
-> _scsih_check_topo_delete_events()
-> _scsih_block_io_to_children_attached_directly()
-> _scsih_block_io_device()
-> _scsih_internal_device_block()
-> scsi_internal_device_block()

Reported-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Omar Sandoval <osandov@osandov.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sathya Prakash <sathya.prakash@broadcom.com>
Cc: Chaitra P B <chaitra.basappa@broadcom.com>
Cc: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
Cc: Sreekanth Reddy <Sreekanth.Reddy@broadcom.com>
Cc: <stable@vger.kernel.org> # v4.10+
Tested-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: remove scsi_execute_req_flags

And switch all callers to use scsi_execute instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: merge __scsi_execute into scsi_execute

All but one caller want the decoded sense header, so offer the existing
__scsi_execute helper as the public scsi_execute API to simply the
callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: use 'scsi_device_from_queue()' for scsi_dh

The device handler needs to check if a given queue belongs to a scsi
device; only then does it make sense to attach a device handler.

[mkp: dropped flags]

Cc: <stable@vger.kernel.org>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

block: split out request-only flags into a new namespace

A lot of the REQ_* flags are only used on struct requests, and only of
use to the block layer and a few drivers that dig into struct request
internals.

This patch adds a new req_flags_t rq_flags field to struct request for
them, and thus dramatically shrinks the number of common requests. It
also removes the unfortunate situation where we have to fit the fields
from the same enum into 32 bits for struct bio and 64 bits for
struct request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

scsi: remove current_cmnd field from struct scsi_device

The field is only used by the 53c700 driver, so move it into the
driver-private device data instead of having it in the common structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: vpd pages are mandatory for SPC-2

VPD pages 0x0 and 0x83 are mandatory even for SPC-2, so we should be
lowering the restriction to avoid having to whitelist every SPC-2
compliant device.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Add intermediate STARGET_REMOVE state to scsi_target_state

Add intermediate STARGET_REMOVE state to scsi_target_state to avoid
running into the BUG_ON() in scsi_target_reap(). The STARGET_REMOVE
state is only valid in the path from scsi_remove_target() to
scsi_target_destroy() indicating this target is going to be removed.

This re-fixes the problem introduced in commits bc3f02a795d3 ("[SCSI]
scsi_remove_target: fix softlockup regression on hot remove") and
40998193560d ("scsi: restart list search after unlock in
scsi_remove_target") in a more comprehensive way.

[mkp: Included James' fix for scsi_target_destroy()]

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Fixes: 40998193560dab6c3ce8d25f4fa58a23e252ef38
Cc: stable@vger.kernel.org
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: James Bottomley <jejb@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: disable automatic target scan

On larger installations it is useful to disable automatic LUN scanning,
and only add the required LUNs via udev rules. This can speed up bootup
dramatically.

This patch introduces a new scan module parameter value 'manual', which
works like 'none', but can be overridden by setting the 'rescan' value
from scsi_scan_target to 'SCSI_SCAN_MANUAL'. And it updates all
relevant callers to set the 'rescan' value to 'SCSI_SCAN_MANUAL' if
invoked via the 'scan' option in sysfs.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Tested-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Do not attach VPD to devices that don't support it

The patch "scsi: rescan VPD attributes" introduced a regression in which
devices that don't support VPD were being scanned for VPD attributes
anyway. This could cause issues for some devices and should be avoided
so the check for scsi_level has been moved out of scsi_add_lun and into
scsi_attach_vpd so that all callers will not scan VPD for devices that
don't support it.

[mkp: Merge fix]

Fixes: 09e2b0b14690 ("scsi: rescan VPD attributes")
Cc: <stable@vger.kernel.org> #v4.5+
Suggested-by: Alexander Duyck <aduyck@mirantis.com>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Add 'access_state' and 'preferred_path' attribute

Add an 'access_state' field to struct scsi_device and display them in
sysfs as 'access_state' and 'preferred_path' attribute.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh_alua: Add new blacklist flag 'BLIST_SYNC_ALUA'

Add a new blacklist flag BLIST_SYNC_ALUA to instruct the
alua device handler to use synchronous command submission
for ALUA commands.

Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Export function scsi_scan.c:sanitize_inquiry_string

The hpsa driver uses this function to cleanup inquiry data. Our new pqi
driver will also use this function. This function was copied into both
drivers.

This patch exports sanitize_inquiry_string so the hpsa and the pqi
drivers can use this function directly.

Suggested-by: Hannes Reinecke <hare@suse.de>
Suggested-by: Matthew R. Ochs mrochs@linux.vnet.ibm.com
Reviewed-by: Kevin Barnett <kevin.barnett@pmcs.com>
Reviewed-by: Justin Lindley <justin.lindley@pmcs.com>
Reviewed-by: Scott Teel <scott.teel@pmcs.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Don Brace <don.brace@pmcs.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Add scsi_vpd_tpg_id()

Implement scsi_vpd_tpg_id() to extract the target
port group id and the relative port id from
SCSI VPD page 0x83.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: Add scsi_vpd_lun_id()

Add a function scsi_vpd_lun_id() to return a unique device
identifcation based on the designation descriptors of
VPD page 0x83.

As devices might implement several descriptors the order
of preference is:
- NAA IEE Registered Extended
- EUI-64 based 16-byte
- EUI-64 based 12-byte
- NAA IEEE Registered
- NAA IEEE Extended
A SCSI name string descriptor is preferred to all of them
if the identification is longer than 16 bytes.

The returned unique device identification will be formatted
as a SCSI Name string to avoid clashes between different
designator types.

[mkp: Fixed up kernel doc comment from Johannes]

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: rescan VPD attributes

The VPD page information might change, so we need to be able to update
it. This patch implements a VPD page rescan whenever the 'rescan' sysfs
attribute is triggered.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Shane Seymour <shane.seymour@hpe.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi_dh: kill struct scsi_dh_data

Add a ->handler and a ->handler_data field to struct scsi_device and kill
this indirection. Also move struct scsi_device_handler to scsi_dh.h so that
changes to it don't require rebuilding every SCSI LLDD.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi_dh: move device matching to the core code

Add a single list of devices that need non-ALUA device handlers to the core
scsi_dh code so that we can autoload the modules for them at probe time.

While this is a little ugly in terms of architecture it actually
significantly simplifies the code in addition to the new autoloading
functionality.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

dm-mpath, scsi_dh: don't let dm detach device handlers

While allowing dm-mpath to attach device handlers is a functionality we need
for backwards compatibility reason there is no reason to reference count
them and detach them if dm-mpath stops using the device for some reason.

If the device handler works for the given device it can just stay attached,
and we can take the retain_hw_handler codepath.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Hannes Reinecke <hare@Suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi: Add ALUA state change UA handling

Log the ALUA state change unit attention correctly with
the message log and emit an event to allow user-space
tools to react to it.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

Move code that is used both by initiator and target drivers

Move the functions that are used by both the initiator and target
subsystems into scsi_common.c/.h. This change will allow to remove
the initiator SCSI header include directives from most SCSI target
source files in a later patch.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

scsi_logging: return void for dev_printk() functions

dev_printk() is now a void function, so the related functions
scmd_printk() and sdev_prefix_printk() should be made void, too.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

scsi: annotate sdev_prefix_printk and scmd_printk as printf-like

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Bottomley <JBottomley@Parallels.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: Implement per-cpu logging buffer

Implement a per-cpu buffer for formatting messages to avoid line breaks
up under high load. This patch implements scmd_printk() and
sdev_prefix_printk() using the per-cpu buffer and makes sdev_printk() a
wrapper for sdev_prefix_printk().

Tested-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

SCSI / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM

After commit b2b49ccbdd54 (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so #ifdef blocks
depending on CONFIG_PM_RUNTIME may now be changed to depend on
CONFIG_PM.

Replace CONFIG_PM_RUNTIME with CONFIG_PM everywhere under
drivers/scsi/ and in include/scsi/scsi_device.h.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Christoph Hellwig <hch@lst.de>

scsi: drop reason argument from ->change_queue_depth

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: don't set tagging state from scsi_adjust_queue_depth

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth. For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway. The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: remove ordered_tags scsi_device field

Remove the ordered_tags field, we haven't been issuing ordered tags based
on it since the big barrier rework in 2010.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: handle more device handler setup/teardown in common code

Move all code to set up and tear down sdev->scsi_dh_data to common code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: remove struct scsi_dh_devlist

All drivers now do their own matching, so there is no more need to expose
a device list as part of the interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: use container_of to get at device handler private data

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

scsi: introduce sdev_prefix_printk()

Like scmd_printk(), but the device name is passed in as
a string. Can be used by eg ULDs which do not have access
to the scsi_cmnd structure.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: don't store LUN bits in CDB[1] for USB mass-storage devices

The SCSI specification requires that the second Command Data Byte
should contain the LUN value in its high-order bits if the recipient
device reports SCSI level 2 or below. Nevertheless, some USB
mass-storage devices use those bits for other purposes in
vendor-specific commands. Currently Linux has no way to send such
commands, because the SCSI stack always overwrites the LUN bits.

Testing shows that Windows 7 and XP do not store the LUN bits in the
CDB when sending commands to a USB device. This doesn't matter if the
device uses the Bulk-Only or UAS transports (which virtually all
modern USB mass-storage devices do), as these have a separate
mechanism for sending the LUN value.

Therefore this patch introduces a flag in the Scsi_Host structure to
inform the SCSI midlayer that a transport does not require the LUN
bits to be stored in the CDB, and it makes usb-storage set this flag
for all devices using the Bulk-Only transport. (UAS is handled by a
separate driver, but it doesn't really matter because no SCSI-2 or
lower device is at all likely to use UAS.)

The patch also cleans up the code responsible for storing the LUN
value by adding a bitflag to the scsi_device structure. The test for
whether to stick the LUN value in the CDB can be made when the device
is probed, and stored for future use rather than being made over and
over in the fast path.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Tiziano Bacocco <tiziano.bacocco@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: add a blacklist flag which enables VPD page inquiries

Despite supporting modern SCSI features some storage devices continue to
claim conformance to an older version of the SPC spec. This is done for
compatibility with legacy operating systems.

Linux by default will not attempt to read VPD pages on devices that
claim SPC-2 or older. Introduce a blacklist flag that can be used to
trigger VPD page inquiries on devices that are known to support them.

Reported-by: KY Srinivasan <kys@microsoft.com>
Tested-by: KY Srinivasan <kys@microsoft.com>
Reviewed-by: KY Srinivasan <kys@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

scsi: move the writeable field from struct scsi_device to struct scsi_cd

We currently set the field in common code based on the device type,
but then only use it in the cdrom driver which also overrides the
value previously set in the generic code.

Just leave this entirely to the CDROM driver to make everyones life
simpler.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: fix the {host,target,device}_blocked counter mess

Seems like these counters are missing any sort of synchronization for
updates, as a over 10 year old comment from me noted. Fix this by
using atomic counters, and while we're at it also make sure they are
in the same cacheline as the _busy counters and not needlessly stored
to in every I/O completion.

With the new model the _busy counters can temporarily go negative,
so all the readers are updated to check for > 0 values. Longer
term every successful I/O completion will reset the counters to zero,
so the temporarily negative values will not cause any harm.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>

scsi: convert device_busy to atomic_t

Avoid taking the queue_lock to check the per-device queue limit. Instead
we do an atomic_inc_return early on to grab our slot in the queue,
and if necessary decrement it after finishing all checks.

Unlike the host and target busy counters this doesn't allow us to avoid the
queue_lock in the request_fn due to the way the interface works, but it'll
allow us to prepare for using the blk-mq code, which doesn't use the
queue_lock at all, and it at least avoids a queue_lock round trip in
scsi_device_unbusy, which is still important given how busy the queue_lock
is.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>

scsi: convert target_busy to an atomic_t

Avoid taking the host-wide host_lock to check the per-target queue limit.
Instead we do an atomic_inc_return early on to grab our slot in the queue,
and if necessary decrement it after finishing all checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>

scsi: use 64-bit LUNs

The SCSI standard defines 64-bit values for LUNs, and large arrays
employing large or hierarchical LUN numbers become more and more
common.

So update the linux SCSI stack to use 64-bit LUN numbers.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

usb-storage/SCSI: Add broken_fua blacklist flag

Some buggy JMicron USB-ATA bridges don't know how to translate the FUA
bit in READs or WRITEs. This patch adds an entry in unusual_devs.h
and a blacklist flag to tell the sd driver not to use FUA.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Michael Büsch <m@bues.ch>
Tested-by: Michael Büsch <m@bues.ch>
Acked-by: James Bottomley <James.Bottomley@HansenPartnership.com>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scsi: Make sure cmd_flags are 64-bit

cmd_flags in struct request is now 64 bits wide but the scsi_execute
functions truncated arguments passed to int leading to errors. Make sure
the flags parameters are u64.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Jens Axboe <axboe@fb.com>
CC: Jan Kara <jack@suse.cz>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

[SCSI] Add EVPD page 0x83 and 0x80 to sysfs

EVPD page 0x83 is used to uniquely identify the device.
So instead of having each and every program issue a separate
SG_IO call to retrieve this information it does make far more
sense to display it in sysfs.

Some older devices (most notably tapes) will only report reliable
information in page 0x80 (Unit Serial Number). So export this
in the sysfs attribute 'vpd_pg80'.

[jejb: checkpatch fix]
[hare: attach after transport configure]
[fengguang.wu@intel.com: spotted problems with the original now fixed]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] fix our current target reap infrastructure

This patch eliminates the reap_ref and replaces it with a proper kref.
On last put of this kref, the target is removed from visibility in
sysfs. The final call to scsi_target_reap() for the device is done from
__scsi_remove_device() and only if the device was made visible. This
ensures that the target disappears as soon as the last device is gone
rather than waiting until final release of the device (which is often
too long).

Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org # delay backport by 2 months for field testing
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] libsas: introduce scmd_dbg() to quiet false positive "timeout" messages

libsas sometimes short circuits timeouts to force commands into error
recovery. It is misleading to log that the command timed-out in
sas_scsi_timed_out() when in fact it was just queued for error handling.
It's also redundant in the case of a true timeout as libata eh will
detect and report timeouts via it's AC_ERR_TIMEOUT facility.

Given that some environments consider "timeout" errors to be indicative
of impending device failure demote the sas_scsi_timed_out() timeout
message to be disabled by default. This parallels ata_scsi_timed_out().

[jejb: checkpatch fix]
Reported-by: Xun Ni <xun.ni@intel.com>
Tested-by: Nelson Cheng <nelson.cheng@intel.com>
Acked-by: Lukasz Dorau <lukasz.dorau@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Generate uevents on certain unit attention codes

Generate a uevent when the following Unit Attention ASC/ASCQ
codes are received:

2A/01 MODE PARAMETERS CHANGED
2A/09 CAPACITY DATA HAS CHANGED
38/07 THIN PROVISIONING SOFT THRESHOLD REACHED
3F/03 INQUIRY DATA HAS CHANGED
3F/0E REPORTED LUNS DATA HAS CHANGED

Log kernel messages when the following Unit Attention ASC/ASCQ
codes are received that are not as specific as those above:

2A/xx PARAMETERS CHANGED
3F/xx TARGET OPERATING CONDITIONS HAVE CHANGED

Added logic to set expecting_lun_change for other LUNs on the target
after REPORTED LUNS DATA HAS CHANGED is received, so that duplicate
uevents are not generated, and clear expecting_lun_change when a
REPORT LUNS command completes, in accordance with the SPC-3
specification regarding reporting of the 3F 0E ASC/ASCQ UA.

[jejb: remove SPC3 test in scsi_report_lun_change and some docbook fixes and
unused variable fix, both reported by Fengguang Wu]
Signed-off-by: Ewan D. Milne <emilne@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Allow error handling timeout to be specified

Introduce eh_timeout which can be used for error handling purposes. This
was previously hardcoded to 10 seconds in the SCSI error handling
code. However, for some fast-fail scenarios it is necessary to be able
to tune this as it can take several iterations (bus device, target, bus,
controller) before we give up.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] sd: use REQ_PM in sd's runtime suspend operation

With the introduction of REQ_PM, modify sd's runtime suspend operation
functions to use that flag so that the operations to put the device into
runtime suspended state(i.e. sync cache and stop device) will not affect
its runtime PM status.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] remove can_power_off flag from scsi_device

Commit 166a2967b45ede2e2e56f3ede3cd32053dc17812 "libata: tell scsi layer
device supports runtime power off" introduced the can_power_off flag for
scsi_device and is used to support ZPODD implementation in SCSI layer.
Since ZPODD is now implemented in ATA layer, that flag is no longer
needed, so remove it.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[libata] scsi: no poll when ODD is powered off

When the ODD is powered off, any action the user did to the ODD that
would generate a media event will trigger an ACPI interrupt, so the
poll for media event is no longer necessary. And the poll will also
cause a runtime status change, which will stop the ODD from staying in
powered off state, so the poll should better be stopped.

But since we don't have access to the gendisk structure in LLDs, here
comes the disk_events_disable_depth for scsi device. This field is a
hint set by LLDs to convey information to upper layer drivers. A value
of 0 means media poll is necessary for the device, while values above 0
means media poll is not needed and should better be skipped. So we can
increase its value when we are to power off the ODD in ATA layer and
decrease its value when the ODD is powered on, effectively silence the
media events poll.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[SCSI] sd: Use SCSI read/write(16) with > 32-bit LBA drives

Force large capacity (> 0xFFFFFFFF blocks) drives to use READ/WRITE(16) instead
of READ/WRITE(10). Some(most/all?) USB enclosures do not like READ(10) commands
when a large capacity drive is installed. This issue was reported and discussed
here: http://marc.info/?l=linux-usb&m=135247705222324

Signed-off-by: Jason J. Herne <hernejj@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] sd: Implement support for WRITE SAME

Implement support for WRITE SAME(10) and WRITE SAME(16) in the SCSI disk
driver.

- We set the default maximum to 0xFFFF because there are several
devices out there that only support two-byte block counts even with
WRITE SAME(16). We only enable transfers bigger than 0xFFFF if the
device explicitly reports MAXIMUM WRITE SAME LENGTH in the BLOCK
LIMITS VPD.

- max_write_same_blocks can be overriden per-device basis in sysfs.

- The UNMAP discovery heuristics remain unchanged but the discard
limits are tweaked to match the "real" WRITE SAME commands.

- In the error handling logic we now distinguish between WRITE SAME
with and without UNMAP set.

The discovery process heuristics are:

- If the device reports a SCSI level of SPC-3 or greater we'll issue
READ SUPPORTED OPERATION CODES to find out whether WRITE SAME(16) is
supported. If that's the case we will use it.

- If the device supports the block limits VPD and reports a MAXIMUM
WRITE SAME LENGTH bigger than 0xFFFF we will use WRITE SAME(16).

- Otherwise we will use WRITE SAME(10) unless the target LBA is beyond
0xFFFFFFFF or the block count exceeds 0xFFFF.

- no_write_same is set for ATA, FireWire and USB.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Add a report opcode helper

The REPORT SUPPORTED OPERATION CODES command can be used to query
whether a given opcode is supported by a device. Add a helper function
that allows us to look up commands.

We only issue RSOC if the device reports compliance with SPC-3 or
later. But to err on the side of caution we disable the command for ATA,
FireWire and USB.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] Disable DIF on Hitachi Ultrastar 15K300

Hitachi Ultrastar 15K300 is quirky. Disable T10 PI (DIF).

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] set to WCE if usb cache quirk is present.

Make use of USB quirk method to identify such HDD while reading
the cache status in sd_probe(). If cache quirk is present for
the HDD, lets assume that cache is enabled and make WCE bit
equal to 1.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] core, classes, mpt2sas: have scsi_internal_device_unblock take new state

This has scsi_internal_device_unblock/scsi_target_unblock take
the new state to set the devices as an argument instead of
always setting to running. The patch also converts users of these
functions.

This allows the FC and iSCSI class to transition devices from blocked
to transport-offline, so that when fast_io_fail/replacement_timeout
has fired we do not set the devices back to running. Instead, we
set them to SDEV_TRANSPORT_OFFLINE.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] add new SDEV_TRANSPORT_OFFLINE state

This patch adds a new state SDEV_TRANSPORT_OFFLINE. It will
be used by transport classes to offline devices for cases like
when the fast_io_fail/recovery_tmo fires. In those cases we
want all IO to fail, and we have not yet escalated to dev_loss_tmo
behavior where we are removing the devices.

Currently to handle this state, transport classes are setting
the scsi_device's state to running, setting their internal
session/port structs state to something that indicates failed,
and then failing IO from some transport check in the queuecommand.

The reason for the new value is so that users can distinguish
between a device failure that is a result of a transport problem
vs the wide range of errors that devices get offlined for
when a scsi command times out and we offline the devices there.
It also fixes the confusion as to why the transport class is
failing IO, but has set the device state from blocked to running.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

scsi: set to WCE if usb cache quirk is present.

Make use of USB quirk method to identify such HDD while reading
the cache status in sd_probe(). If cache quirk is present for
the HDD, lets assume that cache is enabled and make WCE bit
equal to 1.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Pankaj Kumar <pankaj.km@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

libata: tell scsi layer device supports runtime power off

If ATA device supports "Device Attention", then tell scsi layer that
the device supports runtime power off.

Signed-off-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

SCSI & usb-storage: add try_rc_10_first flag

Several bug reports have been received recently for USB mass-storage
devices that don't handle READ CAPACITY(16) commands properly. They
report bogus sizes, in some cases becoming unusable as a result.

The bugs were triggered by commit
09b6b51b0b6c1b9bb61815baf205e4d74c89ff04 (SCSI & usb-storage: add
flags for VPD pages and REPORT LUNS), which caused usb-storage to stop
overriding the SCSI level reported by devices. By default, the sd
driver will try READ CAPACITY(16) first for any device whose level is
above SCSI_SPC_2.

It seems likely that any device large enough to require the use of
READ CAPACITY(16) (i.e., 2 TB or more) would be able to handle READ
CAPACITY(10) commands properly. Indeed, I don't know of any devices
that don't handle READ CAPACITY(10) properly.

Therefore this patch (as1559) adds a new flag telling the sd driver
to try READ CAPACITY(10) before READ CAPACITY(16), and sets this flag
for every USB mass-storage device. If a device really is larger than
2 TB, sd will fall back to READ CAPACITY(16) just as it used to.

This fixes Bugzilla #43391.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Hans de Goede <hdegoede@redhat.com>
CC: "James E.J. Bottomley" <JBottomley@parallels.com>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

device.h: audit and cleanup users in main include dir

The <linux/device.h> header includes a lot of stuff, and
it in turn gets a lot of use just for the basic "struct device"
which appears so often.

Clean up the users as follows:

1) For those headers only needing "struct device" as a pointer
in fcn args, replace the include with exactly that.

2) For headers not really using anything from device.h, simply
delete the include altogether.

3) For headers relying on getting device.h implicitly before
being included themselves, now explicitly include device.h

4) For files in which doing #1 or #2 uncovers an implicit
dependency on some other header, fix by explicitly adding
the required header(s).

Any C files that were implicitly relying on device.h to be
present have already been dealt with in advance.

Total removals from #1 and #2: 51. Total additions coming
from #3: 9. Total other implicit dependencies from #4: 7.

As of 3.3-rc1, there were 110, so a net removal of 42 gives
about a 38% reduction in device.h presence in include/*

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

SCSI & usb-storage: add flags for VPD pages and REPORT LUNS

This patch (as1507) adds a skip_vpd_pages flag to struct scsi_device
and a no_report_luns flag to struct scsi_target. The first is used to
control whether sd will look at VPD pages for information on block
provisioning, limits, and characteristics. The second prevents
scsi_report_lun_scan() from issuing a REPORT LUNS command.

The patch also modifies usb-storage to set the new flag bits for all
USB devices and targets, and to stop adjusting the scsi_level value.

Historically we have seen that USB mass-storage devices often don't
support VPD pages or REPORT LUNS properly. Until now we have avoided
these things by setting the scsi_level to SCSI_2 for all USB devices.
But this has the side effect of storing the LUN bits into the second
byte of each CDB, and now we have a report of a device which doesn't
like that. The best solution is to stop abusing scsi_level and
instead have separate flags for VPD pages and REPORT LUNS.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Perry Wagle <wagle@mac.com>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

SCSI: fix typo in definition of struct scsi_target

This patch (as1506) corrects a typo in the definition of the
scsi_target structure. pdt_1f_for_no_lun is supposed to be a
single-bit flag, not a full-sized integer.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[SCSI] scsi_dh: code cleanup and remove the references to scsi_dev_info

All the handlers have now implemented the match function so We don't need to
use scsi_dev_info any more for matching purposes.

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh: Implement match callback function

Some device handler types are not tied to the vendor/model
but rather to a specific capability. Eg ALUA is supported
if the 'TPGS' setting in the standard inquiry is set.
This patch implements a 'match' callback for device handler
which supersedes the original vendor/model lookup and
implements the callback for the ALUA handler.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

[SCSI] scsi_dh_alua: Evaluate TPGS setting from inquiry data

Instead of issuing a standard inquiry from within the
alua device handler we can evaluate the TPGS setting from
the existing inquiry data of the sdev and save us the I/O.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

atomic: use <linux/atomic.h>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scsi: remove performance regression due to async queue run

Commit c21e6beb removed our queue request_fn re-enter
protection, and defaulted to always running the queues from
kblockd to be safe. This was a known potential slow down,
but should be safe.

Unfortunately this is causing big performance regressions for
some, so we need to improve this logic. Looking into the details
of the re-enter, the real issue is on requeue of requests.

Requeue of requests upon seeing a BUSY condition from the device
ends up re-running the queue, causing traces like this:

scsi_request_fn()
scsi_dispatch_cmd()
scsi_queue_insert()
__scsi_queue_insert()
scsi_run_queue()
scsi_request_fn()
...

potentially causing the issue we want to avoid. So special
case the requeue re-run of the queue, but improve it to offload
the entire run of local queue and starved queue from a single
workqueue callback. This is a lot better than potentially
kicking off a workqueue run for each device seen.

This also fixes the issue of the local device going into recursion,
since the above mentioned commit never moved that queue run out
of line.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

[SCSI] ses: Avoid kernel panic when lun 0 is not mapped

During device discovery, scsi mid layer sends INQUIRY command to LUN
0. If the LUN 0 is not mapped to host, it creates a temporary
scsi_device with LUN id 0 and sends REPORT_LUNS command to it. After
the REPORT_LUNS succeeds, it walks through the LUN table and adds each
LUN found to sysfs. At the end of REPORT_LUNS lun table scan, it will
delete the temporary scsi_device of LUN 0.

When scsi devices are added to sysfs, it calls add_dev function of all
the registered class interfaces. If ses driver has been registered,
ses_intf_add() of ses module will be called. This function calls
scsi_device_enclosure() to check the inquiry data for EncServ
bit. Since inquiry was not allocated for temporary LUN 0 scsi_device,
it will cause NULL pointer exception.

To fix the problem, sdev->inquiry is checked for NULL before reading it.

Signed-off-by: Somasundaram Krishnasamy <Somasundaram.Krishnasamy@lsi.com>
Signed-off-by: Babu Moger <babu.moger@lsi.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh: Use scsi_devinfo functions to do matching of device_handler tables.

Previously we were using strncmp in order to avoid having to include
whitespace in the devlist, but this means "HSV1000" matches a device
list entry that says "HSV100", which is wrong. This patch changes
scsi_dh.c to use scsi_devinfo's matching functions instead, since they
handle these cases correctly.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>

scsi/sd: add a no_read_capacity_16 scsi_device flag

I seem to have a knack for digging up buggy usb devices which don't work
with Linux, and I'm crazy enough to try to make them work. So this time a
friend of mine asked me to get an mp4 player (an mp3 player which can play
videos on a small screen) to work with Linux.

It is based on the well known rockbox chipset for which we already have an
unusual devs entries to work around some of its bugs. But this model
comes with an additional twist.

This model chokes on read_capacity_16 calls. Now normally we don't make
those calls, but this model comes with an sdcard slot and when there is no
card in there (and shipped from the factory there is none), it reports a
size of 0. However this time the programmers actually got the
read_capacity_10 response right! So they substract one from the size as
stored internally in the mp3 player before reporting it back, resulting in
an answer of ... 0xffffffff sectors, causing sd.c to try a
read_capacity_16, on which the device crashes.

This patch adds a flag to scsi_device to indicate that a a device cannot
handle read_capacity_16, and when this flag is set if a device reports an
lba of 0xffffffff as answer to a read_capacity_10, assumes it tries to
report a size of 0.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

scsi/sr: add no_read_disc_info scsi_device flag

Some USB devices emulate a usb-mass-storage attached (scsi) cdrom device,
usually this fake cdrom contains the windows software for the device.
While working on supporting Appotech ax3003 based photoframes, which do
this I discovered that they will go of into lala land when ever they see a
READ_DISC_INFO scsi command.

Thus this patch adds a scsi_device flag (which can then be set by the
usb-storage driver through an unsual-devs entry), to indicate this, and
makes the sr driver honor this flag.

I know this sucks, but as discussed on linux-scsi list there is no other
way to make this device work properly.

Looking at usb traces made under windows, windows never sends a
READ_DISC_INFO during normal interactions with a usb cdrom device. So as
this cdrom emulation thingie becomes more common we might see more of this
problem.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[SCSI] implement runtime Power Management

This patch (as1398b) adds runtime PM support to the SCSI layer. Only
the machanism is provided; use of it is up to the various high-level
drivers, and the patch doesn't change any of them. Except for sg --
the patch expicitly prevents a device from being runtime-suspended
while its sg device file is open.

The implementation is simplistic. In general, hosts and targets are
automatically suspended when all their children are asleep, but for
them the runtime-suspend code doesn't actually do anything. (A host's
runtime PM status is propagated up the device tree, though, so a
runtime-PM-aware lower-level driver could power down the host adapter
hardware at the appropriate times.) There are comments indicating
where a transport class might be notified or some other hooks added.

LUNs are runtime-suspended by calling the drivers' existing suspend
handlers (and likewise for runtime-resume). Somewhat arbitrarily, the
implementation delays for 100 ms before suspending an eligible LUN.
This is because there typically are occasions during bootup when the
same device file is opened and closed several times in quick
succession.

The way this all works is that the SCSI core increments a device's
PM-usage count when it is registered. If a high-level driver does
nothing then the device will not be eligible for runtime-suspend
because of the elevated usage count. If a high-level driver wants to
use runtime PM then it can call scsi_autopm_put_device() in its probe
routine to decrement the usage count and scsi_autopm_get_device() in
its remove routine to restore the original count.

Hosts, targets, and LUNs are not suspended while they are being probed
or removed, or while the error handler is running. In fact, a fairly
large part of the patch consists of code to make sure that things
aren't suspended at such times.

[jejb: fix up compile issues in PM config variations]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] eliminate potential kmalloc failure in scsi_get_vpd_page()

The best way to fix this is to eliminate the intenal kmalloc() and
make the caller allocate the required amount of storage.

Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh: Change the scsidh_activate interface to be asynchronous

Make scsi_dh_activate() function asynchronous, by taking in two additional
parameters, one is the callback function and the other is the data to call
the callback function with.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] add queue_depth ramp up code

Current FC HBA queue_depth ramp up code depends on last queue
full time. The sdev already has last_queue_full_time field to
track last queue full time but stored value is truncated by
last four bits.

So this patch updates last_queue_full_time without truncating
last 4 bits to store full value and then updates its only
current usages in scsi_track_queue_full to ignore last four bits
to keep current usages same while also use this field
in added ramp up code.

Adds scsi_handle_queue_ramp_up to ramp up queue_depth on
successful completion of IO. The scsi_handle_queue_ramp_up will
do ramp up on all luns of a target, just same as ramp down done
on all luns on a target.

The ramp up is skipped in case the change_queue_depth is not
supported by LLD or already reached to added max_queue_depth.

Updates added max_queue_depth on every new update to default
queue_depth value.

The ramp up is also skipped if lapsed time since either last
queue ramp up or down is less than LLD specified
queue_ramp_up_period.

Adds queue_ramp_up_period to sysfs but only if change_queue_depth
is supported since ramp up and queue_ramp_up_period is needed only
in case change_queue_depth is supported first.

Initializes queue_ramp_up_period to 120HZ jiffies as initial
default value, it is same as used in existing lpfc and qla2xxx.

-v2
Combined all ramp code into this single patch.

-v3
Moves max_queue_depth initialization after slave_configure is
called from after slave_alloc calling done. Also adjusted
max_queue_depth check to skip ramp up if current queue_depth
is >= max_queue_depth.

-v4
Changes sdev->queue_ramp_up_period unit to ms when using sysfs i/f
to store or show its value.

Signed-off-by: Vasu Dev <vasu.dev@intel.com>
Tested-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Tested-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] fix async scan add/remove race resulting in an oops

Async scanning introduced a very wide window where the SCSI device is
up and running but has not yet been added to sysfs. We delay the
adding until all scans have completed to retain the same ordering as
sync scanning.

This delay in visibility causes an oops if a device is removed before
we make it visible because the SCSI removal routines have an inbuilt
assumption that if a device is in SDEV_RUNNING state, it must be
visible (which is not necessarily true in the async scanning case).

Fix this by introducing an additional is_visible flag which we can use
to condition the tear down so we do the right thing for running but
not yet made visible.

Reported-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh: add the interface scsi_dh_set_params()

When we moved the device handler functionality from dm layer to SCSI layer
we dropped the parameter functionality.

This path adds an interface to scsi dh layer to set device handler
parameters.

Basically, multipath layer need to create a string with all the parameters
and call scsi_dh_set_params() after it called scsi_dh_attach() on a
device.

If a device handler provides such an interface it will handle the parameters
as it expects them.

Reported-by: Eddie Williams <Eddie.Williams@steeleye.com>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Tested-by: Eddie Williams <Eddie.Williams@steeleye.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] scsi_dh: Reference count scsi_dh_attach

Problem reported: http://marc.info/?l=dm-devel&m=124585978305866&w=2

scsi_dh does not do a refernce count for attach/detach, and this affects
the way it is supposed to work with multipath when a device is not
in the dev_list of the hardware handler.

This patch adds a reference count that counts each attach.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] remove scsi_req_map_sg

No one uses scsi_execute_async with data transfer now. We can remove
scsi_req_map_sg.

Only scsi_eh_lock_door uses scsi_execute_async. scsi_eh_lock_door
doesn't handle sense and the callback. So we can remove
scsi_io_context too.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Check for deleted device in scsi_device_online()

scsi_device_online() is not just a negation of SDEV_OFFLINE,
also devices in state SDEV_DEL are actually offline.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Add VPD helper

Based on prior work by Martin Petersen and James Bottomley, this patch
adds a generic helper for retrieving VPD pages from SCSI devices.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] add residual argument to scsi_execute and scsi_execute_req

scsi_execute() and scsi_execute_req() discard the residual length
information. Some callers need it. This adds residual argument
(optional) to scsi_execute and scsi_execute_req.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] remove timeout from struct scsi_device

by removing the unused timeout parameter we ensure a compile failure if
anyone is accidentally still using it rather than the block timeout.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Add helper code so transport classes/driver can control queueing (v3)

SCSI-ml manages the queueing limits for the device and host, but
does not do so at the target level. However something something similar
can come in userful when a driver is transitioning a transport object to
the the blocked state, becuase at that time we do not want to queue
io and we do not want the queuecommand to be called again.

The patch adds code similar to the exisiting SCSI_ML_*BUSY handlers.
You can now return SCSI_MLQUEUE_TARGET_BUSY when we hit
a transport level queueing issue like the hw cannot allocate some
resource at the iscsi session/connection level, or the target has temporarily
closed or shrunk the queueing window, or if we are transitioning
to the blocked state.

bnx2i, when they rework their firmware according to netdev
developers requests, will also need to be able to limit queueing at this
level. bnx2i will hook into libiscsi, but will allocate a scsi host per
netdevice/hba, so unlike pure software iscsi/iser which is allocating
a host per session, it cannot set the scsi_host->can_queue and return
SCSI_MLQUEUE_HOST_BUSY to reflect queueing limits on the transport.

The iscsi class/driver can also set a scsi_target->can_queue value which
reflects the max commands the driver/class can support. For iscsi this
reflects the number of commands we can support for each session due to
session/connection hw limits, driver limits, and to also reflect the
session/targets's queueing window.

Changes:
v1 - initial patch.
v2 - Fix scsi_run_queue handling of multiple blocked targets.
Previously we would break from the main loop if a device was added back on
the starved list. We now run over the list and check if any target is
blocked.
v3 - Rediff for scsi-misc.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Update the SCSI state model to allow blocking in the created state

Brian King <brking@linux.vnet.ibm.com> reported that fibre channel
devices can oops during scanning if their ports block (because the
device goes from CREATED -> BLOCK -> RUNNING rather than CREATED ->
BLOCK -> CREATED).

Fix this by adding a new state: CREATED_BLOCK which can only transition
back to CREATED and disallow the CREATED -> BLOCK transition. Now both
the created and blocked states that the mid-layer recognises can include
CREATED_BLOCK.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] add inline functions for recognising created and blocked states

The created and blocked states are very shortly going to correspond to
mixed sdev_state states.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] sd: fix USB devices incorrectly reporting DIF support

Some USB devices set the protect bit in the INQUIRY data which
currently causes the DIF code in sd to assume (incorrectly) that they
support READ_CAPACITY(16). Fix this (only for the time being) by
making sure we only believe the protect bit in the inquiry data if the
device claims conformance to SCSI-3 or above.

Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

Re-introduce "[SCSI] extend the last_sector_bug flag to cover more sectors"

This re-introduces commit 2b142900784c6e38c8d39fa57d5f95ef08e735d8,
which was reverted due to the regression it caused by commit
fca082c9f1e11ec07efa8d2f9f13688521253f36.

That regression was not root-caused by the original commit, it was just
uncovered by it, and the real fix was done by Alan Stern in commit
580da34847488b404218d1d7f53b156f245f5555 ("Fix USB storage hang on
command abort").

We can thus re-introduce the change that was confirmed by Alan Jenkins
to be still required by his odd card reader.

Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Revert "[SCSI] extend the last_sector_bug flag to cover more sectors"

This reverts commit 2b142900784c6e38c8d39fa57d5f95ef08e735d8, since it
seems to break some other USB storage devices (at least a JMicron USB to
ATA bridge). As such, while it apparently fixes some cardreaders, it
would need to be made conditional on the exact reader it fixes in order
to avoid causing regressions.

Cc: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[SCSI] extend the last_sector_bug flag to cover more sectors

The last_sector_bug flag was added to work around a bug in certain usb
cardreaders, where they would crash if a multiple sector read included the
last sector. The original implementation avoids this by e.g. splitting an 8
sector read which includes the last sector into a 7 sector read, and a single
sector read for the last sector. The flag is enabled for all USB devices.

This revealed a second bug in other usb cardreaders, which crash when they
get a multiple sector read which stops 1 sector short of the last sector.
Affected hardware includes the Kingston "MobileLite" external USB cardreader
and the internal USB cardreader on the Asus EeePC.

Extend the last_sector_bug workaround to ensure that any access which touches
the last 8 hardware sectors of the device is a single sector long. Requests
are shrunk as necessary to meet this constraint.

This gives us a safety margin against potential unknown or future bugs
affecting multi-sector access to the end of the device. The two known bugs
only affect the last 2 sectors. However, they suggest that these devices
are prone to fencepost errors and that multi-sector access to the end of the
device is not well tested. Popular OS's use multi-sector accesses, but they
rarely read the last few sectors. Linux (with udev & vol_id) automatically
reads sectors from the end of the device on insertion. It is assumed that
single sector accesses are more thoroughly tested during development.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] Support devices with protection information

Implement support for DMA of protection information for devices that
are data integrity capable.

- Add support for mapping an extra scatter-gather list containing
the protection information.

- Allocate protection scsi_data_buffer if host is DIX (integrity DMA)
capable.

- Accessor function for checking whether a device has protection
enabled.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] scsi_dh: Implement common device table handling

Instead of having each and every driver implement its own
device table scanning code we should rather implement a common
routine and scan the device tables there.
This allows us also to implement a general notifier chain
callback for all device handler instead for one per handler.

[sekharan: Fix rejections caused by conflicting bug fix]
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

scsi: sd: optionally set power condition in START STOP UNIT

Adds a new scsi_device flag, start_stop_pwr_cond: If enabled, the sd
driver will not send plain START STOP UNIT commands but ones with the
power condition field set to 3 (standby) or 1 (active) respectively.

Some FireWire disk firmwares do not stop the motor if power condition is
zero. Or worse, they become unresponsive after a START STOP UNIT with
power condition = 0 and start = 0.

http://lkml.org/lkml/2008/4/29/704

This patch only adds the necessary code to sd_mod but doesn't activate
it. Follow-up patches to the FireWire drivers will add detection of
affected devices and enable the code for them.

I did not add power condition values to scsi_error.c::scsi_eh_try_stu()
for now. The three firmwares which suffer from above mentioned problems
do not need START STOP UNIT in the error handler, and they are not
adversely affected by START STOP UNIT with power condition = 0 and start
= 1 (like scsi_eh_try_stu() sends it if scsi_device.allow_restart is
enabled).

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: Tino Keitel <tino.keitel@gmx.de>

[SCSI] scsi_dh: add infrastructure for SCSI Device Handlers

Some of the storage devices (that can be accessed through multiple paths),
do need some special handling for
1. Activating the passive path of the storage access.
2. Decode and handle the special sense codes returned by the devices.
3. Handle the I/Os being sent to the passive path, especially
during the device probe time.
when accessed through multiple paths.

As of today this special device handling is done at the dm-multipath
layer using dm-handlers. That works well for (1); for (2) to be handled
at dm layer, scsi sense information need to be exported from SCSI to dm-layer,
which is not very attractive; (3) cannot be done at all at the dm layer.

Device handler has been moved to SCSI mainly to handle (2) and (3) properly.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] rework scsi_target allocation

The current target allocation code registeres each possible target
with sysfs; it will be deleted again if no useable LUN on this target
was found. This results in a string of 'target add/target remove' uevents.

Based on a patch by Hannes Reinecke <hare@suse.de> this patch reworks
the target allocation code so that only uevents for existing targets
are sent. The sysfs registration is split off from the existing
scsi_target_alloc() into a in a new scsi_add_target() function, which
should be called whenever an existing target is found. Only then a
uevent is sent, so we'll be generating events for existing targets
only.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

SCSI: convert struct class_device to struct device

It's big, but there doesn't seem to be a way to split it up smaller...

Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[SCSI] scsi.h: add macro for enclosure bit of inquiry data

The macro tells us whether the device is (or contains) an enclosure device.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] sd: add fix for devices with last sector access problems

This patch adds a new scsi_device flag (last_sector_bug) for devices
which contain a bug where the device crashes when the last sector is
read in a larger then 1 sector read.

This is for example the case with sdcards in the HP PSC1350 printer
cardreader and in the HP PSC1610 printer cardreader.

Signed-off-by: Hans de Goede <j.w.r.degoede@hhs.nl>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] sd,sr: add early detection of medium not present

The current scsi_test_unit_ready() is updated to return sense code
information (in struct scsi_sense_hdr). The sd and sr drivers are
changed to interpret the sense code return asc 0x3a as no media and
adjust the device status accordingly.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

[SCSI] move single_lun flag from scsi_device to scsi_target

Some SCSI tape medium changers that need the BLIST_SINGLELUN flag have
the medium changer at one LUN and the tape drive at a different LUN.
The inquiry string of the tape drive may be different from that of the
medium changer. In order for single_lun to be effective, every
scsi_device under a given scsi_target must have it set. This means that
there needs to be a blacklist entry for BOTH the medium changer AND the
tape drive, which is impractical because some medium changers may be
paired with a variety of different tape drive models. It makes more
sense to put the single_lun flag in scsi_target instead of scsi_device,
which causes every device at a given target ID to inherit the single_lun
flag from one LUN. This makes it possible to blacklist just the medium
changer and not the tape drive.

Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

esp_scsi: fix reset cleanup spinlock recursion

The esp_reset_cleanup() function is called with the host lock held and
invokes starget_for_each_device() which wants to take it too. Here is a
fix along the lines of shost_for_each_device()/__shost_for_each_device()
adding a __starget_for_each_device() counterpart which assumes the lock
has already been taken.

Eventually, I think the driver should get modified so that more work is
done as a softirq rather than in the interrupt context, but for now it
fixes a bug that causes the spinlock debugger to fire.

While at it, it fixes a small number of cosmetic problems with
starget_for_each_device() too.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

SCSI: add asynchronous event notification API

Originally based on a patch by Kristen Carlson Accardi @ Intel.
Copious input from James Bottomley.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

[SCSI] Remove unused method scsi_device_cancel

Removes an obsolete method scsi_device_cancel which isn't being used
anywhere in the kernel.

Signed-off-by: Priyanka Gupta <priyankag@google.com>
Acked-by: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] zfcp: Report FCP LUN to SCSI midlayer

When reporting SCSI devices to the SCSI midlayer, use the FCP LUN as
LUN reported to the SCSI layer. With this approach, zfcp does not have
to create unique LUNS, and this code can be removed.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] modalias for scsi devices

The following patch adds support for sysfs/uevent modalias
attribute for scsi devices (like disks, tapes, cdroms etc),
based on whatever current sd.c, sr.c, st.c and osst.c drivers
supports.

The modalias format is like this:

scsi:type-0x04

(for TYPE_WORM, handled by sr.c now).

Several comments.

o This hexadecimal type value is because all TYPE_XXX constants
in include/scsi/scsi.h are given in hex, but __stringify() will
not convert them to decimal (so it will NOT be scsi:type-4).
Since it does not really matter in which format it is, while
both modalias in module and modalias attribute match each other,
I descided to go for that 0x%02x format (and added a comment in
include/scsi/scsi.h to keep them that way), instead of changing
them all to decimal.

o There was no .uevent routine for SCSI bus. It might be a good
idea to add some more ueven environment variables in there.

o osst.c driver handles tapes too, like st.c, but only SOME tapes.
With this setup, hotplug scripts (or whatever is used by the
user) will try to load both st and osst modules for all SCSI
tapes found, because both modules have scsi:type-0x01 alias).
It is not harmful, but one extra module is no good either.
It is possible to solve this, by exporting more info in
modalias attribute, including vendor and device identification
strings, so that modalias becomes something like
scsi:type-0x12:vendor-Adaptec LTD:device-OnStream Tape Drive
and having that, match for all 3 attributes, not only device
type. But oh well, vendor and device strings may be large,
and they do contain spaces and whatnot.
So I left them for now, awaiting for comments first.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] sd: implement START/STOP management

Implement SBC START/STOP management. sdev->mange_start_stop is added.
When it's set to one, sd STOPs the device on suspend and shutdown and
STARTs it on resume. sdev->manage_start_stop defaults is in sdev
instead of scsi_disk cdev to allow ->slave_config() override the
default configuration but is exported under scsi_disk sysfs node as
sdev->allow_restart is.

When manage_start_stop is zero (the default value), this patch doesn't
introduce any behavior change.

Signed-off-by: Tejun Heo <htejun@gmail.com>

Rejections fixed and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Make error printing more verbose

This patch enhances SCSI error printing by:

- Making use of scsi_print_result() in the completion functions.

- Having scmd_printk() output the disk name (when applicable).

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

USB Storage: indistinguishable devices with broken and unbroken firmware

there's a USB mass storage device which exists in two version. One
reports the correct size and the other does not. Apart from that they
are identical and cannot be told apart. Here's a heuristic based on the
empirical finding that drives have even sizes.


Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[SCSI] Add ability to scan scsi busses asynchronously

Since it often takes around 20-30 seconds to scan a scsi bus, it's
highly advantageous to do this in parallel with other things. The bulk
of this patch is ensuring that devices don't change numbering, and that
all devices are discovered prior to trying to start init. For those
who build SCSI as modules, there's a new scsi_wait_scan module that will
ensure all bus scans are finished.

This patch only handles drivers which call scsi_scan_host. Fibre Channel,
SAS, SATA, USB and Firewire all need additional work.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] scsi: device_reprobe() can fail

device_reprobe() should return an error code. When it does so,
scsi_device_reprobe() should propagate it back.

Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[SCSI] scsi: device_reprobe() can fail

device_reprobe() should return an error code. When it does so,
scsi_device_reprobe() should propagate it back.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] add scsi_mode_select to scsi_lib.c

This complements the scsi_mode_sense() function

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] add scsi_reprobe_device

Original from Christoph Hellwig and Eric Moore. This version exports
the scsi_reprobe_device() function as an inline.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix scsi process problems and clean up the target reap issues

In order to use the new execute_in_process_context() API, you have to
provide it with the work storage, which I do in SCSI in scsi_device and
scsi_target, but which also means that we can no longer queue up the
target reaps, so instead I moved the target to a state model which
allows target_alloc to detect if we've received a dying target and wait
for it to be gone. Hopefully, this should also solve the target
namespace race.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Recognize missing LUNs for non-standard devices

Some non-standard SCSI targets or protocols, such as USB UFI, report "no
LUN present" by setting the Peripheral Device Type to 0x1f and the
Peripheral Qualifier to 0 (not 3 as the standard requires) in the INQUIRY
response. This patch (as650b) adds a new target flag and code to
accomodate such targets.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Remove devfs support from the SCSI subsystem

As devfs has been disabled from the kernel tree for a number of months
now (5 to be exact), here's a patch against 2.6.16-rc1-git1 that removes
support for it from the SCSI subsystem.

The patch also removes the scsi_disk devfs_name field as it's no longer
needed.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Prevent scsi_execute_async from guessing cdb length

When the scsi_execute_async interface was added it ended up reducing
the flexibility of userspace to send arbitrary scsi commands through
sg using SG_IO. The SG_IO interface allows userspace to specify the
CDB length. This is now ignored in scsi_execute_async and it is
guessed using the COMMAND_SIZE macro, which is not always correct,
particularly for vendor specific commands. This patch adds a cmd_len
parameter to the scsi_execute_async interface to allow the caller
to specify the length of the CDB.

Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Convert SCSI mid-layer to scsi_execute_async

Add scsi helpers to create really-large-requests and convert
scsi-ml to scsi_execute_async().

Per Jens's previous comments, I placed this function in scsi_lib.c.
I made it follow all the queue's limits - I think I did at least :), so
I removed the warning on the function header.

I think the scsi_execute_* functions should eventually take a request_queue
and be placed some place where the dm-multipath hw_handler can use them
if that failover code is going to stay in the kernel. That conversion
patch will be sent in another mail though.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] correct some dropped const compiler warnings

Make the vendor, model and rev fields in scsi_device pointers to const
and update a few prototypes of functions using them.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] introduce sfoo_printk, sfoo_id, sfoo_channel helpers

New dev_printk wrappers, which allow us to shrink code, and
eliminate direct references to host/channel/id/lun members:
scmd_printk()

Introduce wrappers for highly common idioms, which may also help us
eliminate some ->{channel,id} references in the future:
{scmd,sdev}_id()
{scmd,sdev}_channel()

The scmd_* wrappers are present in scsi/scsi_device.h because they all
employ the dereference chain cmd->device->$member. We would prefer to
use static inline functions rather than macros, but that would have a

Rejections fixed up and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] move the mid-layer printk's over to shost/starget/sdev_printk

This should eliminate (at least in the mid layer) to make numeric
assumptions about any of the enumeration variables. As a side effect,
it will also make all the messages consistent and line us up nicely for
the error logging strategy (if it ever shows itself again).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] allow REPORT LUN scanning even for LUN 0 PQ of 3

Currently we just ignore the device, which means there are a few
arrays out there that we don't find.

This patch updates the scsi_report_lun_scan() to take a target instead
of a device so it can be called on a return of
SCSI_SCAN_TARGET_PRESENT, which is what a PQ 3 device returns.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Alter the scsi_add_device() API to conform to what users expect

The original API returned either an ERR_PTR() or a refcounted sdev.
Unfortunately, if it's successful, you need to do a scsi_device_put() on
the sdev otherwise the refcounting is wrong.

Everyone seems to expect that scsi_add_device() should be callable
without doing the ref put, so alter the API so it is (we still have
__scsi_add_device with the original behaviour).

The only actual caller that needs altering is the one in firewire ...
not because it gets this right, but because it acts on the error if one
is returned.

Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] convert sd to scsi_execute_req (and update the scsi_execute_req API)

This one removes struct scsi_request entirely from sd. In the process,
I noticed we have no callers of scsi_wait_req who don't immediately
normalise the sense, so I updated the API to make it take a struct
scsi_sense_hdr instead of simply a big sense buffer.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] convert SPI transport class to scsi_execute

This one's slightly more difficult. The transport class uses
REQ_FAILFAST, so another interface (scsi_execute) had to be invented to
take the extra flag. Also, the sense functions are shifted around to
allow spi_execute to place data directly into a struct scsi_sense_hdr.
With this change, there's probably a lot of unnecessary sense buffer
allocation going on which we can fix later.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] convert the remaining mid-layer pieces to scsi_execute_req

After this, we just have some drivers, all the ULDs and the SPI
transport class using scsi_wait_req().

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] fix function prototype warning

int_to_scsilun() takes a pointer to a struct scsi_lun in it's
prototype, so add this structure to scsi_device.h to avoid declaration
inside function prototype warnings.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] add int_to_scsilun() function

One of the issues we had was reverting the midlayers lun value
into the 8byte lun value that we wanted to send to the device.
Historically, there's been some combination of byte swapping,
setting high/low, etc. There's also been no common thread between
how our driver did it and others. I also got very confused as
to why byteswap routines were being used.

Anyway, this patch is a LLDD-callable function that reverts the
midlayer's lun value, stored in an int, to the 8-byte quantity
(note: this is not the real 8byte quantity, just the same amount
that scsilun_to_int() was able to convert and store originally).

This also solves the dilemma of the thread:
http://marc.theaimsgroup.com/?l=linux-kernel&m=112116767118981&w=2

A patch for the lpfc driver to use this function will be along
in a few days (batched with other patches).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[SCSI] Add target alloc/destroy callbacks to the host template

This gives the HBA driver notice when a target is created and
destroyed to allow it to manage its own target based allocations
accordingly.

This is a much reduced verson of the original patch sent in by
James.Smart@Emulex.com

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] scsi: remove volatile from scsi data

This patch removes volatile qualifier from scsi_device->device_busy,
Scsi_Host->host_busy and ->host_failed as the volatile qualifiers
don't serve any purpose now. While at it, convert those fields from
unsigned short to unsigned int as suggested by Christoph.


Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

updates for CFQ oops fix

- add a comment to the device structure that the device_busy field
is now protected by the request_queue->queue_lock
- null out sdev->request_queue after the queue is released to trap
any (and there shouldn't be any) use after the queue is freed.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] fix NMI lockup with CFQ scheduler

The current problem seen is that the queue lock is actually in the
SCSI device structure, so when that structure is freed on device
release, we go boom if the queue tries to access the lock again.

The fix here is to move the lock from the scsi_device to the queue.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!