Drivers may override the WCE flag, in which case the DPOFUA flag in
MODE SENSE might differ from the check used to reject invalid FUA
bits in sbc_check_dpofua.  Also now that we reject invalid FUA
bits early there is no need to duplicate the same buggy check
down in the fileio code.

As the DPOFUA flag controls th support for FUA bits on read and
write commands as well as DPO key off all the checks off a single
helper, and deprecate the emulate_dpo and emulate_fua_read attributs.

This fixes various failures in the libiscsi testsuite.

Personally I'd prefer to also remove the emulate_fua_write attribute
as there is no good reason to disable it, but I'll leave that for
a separate discussion.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch updates standard INQUIRY, INQUIRY EVPD=0x86, READ_CAPACITY_16
and control mode pages to use se_sess->sess_prot_type when determing which
type of T10-PI related feature bits can be exposed.

This is required for fabric sessions supporting T10-PI metadata to
backend devices that don't have protection enabled.
Reviewed-by: NMartin Petersen <martin.petersen@oracle.com>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Doug Gilbert <dgilbert@interlog.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

A check that rejects a CDB with FUA bit set if no write cache is
emulated was added by the following commit:

  fde9f50f target: Add sanity checks for DPO/FUA bit usage

The condition is as follows:

  if (!dev->dev_attrib.emulate_fua_write ||
      !dev->dev_attrib.emulate_write_cache)

However, this check is wrong if the backend device supports WCE but
"emulate_write_cache" is disabled.

This patch uses se_dev_check_wce() (previously named
spc_check_dev_wce) to invoke transport->get_write_cache() if the
device has a write cache or check the "emulate_write_cache" attribute
otherwise.
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NChristophe Vu-Brugier <cvubrugier@fastmail.fm>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch sets the missing LBPWS10 bit within spc_emulate_evpd_b2()
in order to signal WRITE_SAME (10) w/ UNMAP support, following the
existing LBPWS bit to signal WRITE_SAME (16) w/ UNMAP support.

Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch drops the arbitrary maximum I/O size limit in sbc_parse_cdb(),
which currently for fabric_max_sectors is hardcoded to 8192 (4 MB for 512
byte sector devices), and for hw_max_sectors is a backend driver dependent
value.

This limit is problematic because Linux initiators have only recently
started to honor block limits MAXIMUM TRANSFER LENGTH, and other non-Linux
based initiators (eg: MSFT Fibre Channel) can also generate I/Os larger
than 4 MB in size.

Currently when this happens, the following message will appear on the
target resulting in I/Os being returned with non recoverable status:

  SCSI OP 28h with too big sectors 16384 exceeds fabric_max_sectors: 8192

Instead, drop both [fabric,hw]_max_sector checks in sbc_parse_cdb(),
and convert the existing hw_max_sectors into a purely informational
attribute used to represent the granuality that backend driver and/or
subsystem code is splitting I/Os upon.

Also, update FILEIO with an explicit FD_MAX_BYTES check in fd_execute_rw()
to deal with the one special iovec limitiation case.

v2 changes:
  - Drop hw_max_sectors check in sbc_parse_cdb()
Reported-by: NLance Gropper <lance.gropper@qosserver.com>
Reported-by: NStefan Priebe <s.priebe@profihost.ag>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org # 3.4
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

For SPI drivers use the message definitions from scsi.h, and for target
drivers introduce a new TCM_*_TAG namespace.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com

This patch fixes an apparent cut and paste error in spc_emulate_evpd_b3(),
where lba_map_segment_size was being used twice for the Referrals VPD.

Go ahead and set the correct user data segment multiplier instead of
user data segment size.
Signed-off-by: NSebastian Herbszt <herbszt@gmx.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

When an initiator sends an allocation length bigger than what its
command consumes, the target should only return the actual response data
and set the residual length to the unused part of the allocation length.

Add a helper function that command handlers (INQUIRY, READ CAPACITY,
etc) can use to do this correctly, and use this code to get the correct
residual for commands that don't use the full initiator allocation in the
handlers for READ CAPACITY, READ CAPACITY(16), INQUIRY, MODE SENSE and
REPORT LUNS.

This addresses a handful of failures as reported by Christophe with
the Windows Certification Kit:

  http://permalink.gmane.org/gmane.linux.scsi.target.devel/6515Signed-off-by: NRoland Dreier <roland@purestorage.com>
Tested-by: NChristophe Vu-Brugier <cvubrugier@yahoo.fr>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NChristophe Vu-Brugier <cvubrugier@yahoo.fr>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Only expose the control modepage bit for Application Tag Owner (ATO)
if the session + fabric support DIX PASS operations.
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Only expose standard INQUIRY PROTECT=1 and EVPD=0x86 TYPE1/TYPE3
PI control bits if the session + fabric support DIX PASS operations.
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Commit fbfe858f ("target_core_spc: Include target device
descriptor in VPD page 83") added a new length variable, but (due to a
cut and paste mistake?) just checks scsi_name_len against 256 twice.
Fix this to check scsi_target_len for overflow too.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch updates spc_modesense_control() to set the Application
Tag Owner (ATO) bit when when DIF emulation is enabled by the
backend device.
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch updates spc_emulate_evpd_86() (extended INQUIRY) to
report GRD_CHK (Guard Check) and REF_CHK (Reference Check) bits
when DIF emulation is enabled by the backend device.
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch updates spc_emulate_inquiry_std() to set the
PROTECT bit when DIF emulation is enabled by the backend
device.
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch converts the temporary buffer in spc_emulate_inquiry() to
use dynamically allocated memory, instead of local stack memory.

Also bump SE_INQUIRY_BUF up to 1024 bytes to be safe when handling
multiple large SCSI name descriptors for EVPD=0x83.
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Add infrastructure for referrals.

v2 changes:

 - Fix unsigned long long division in core_alua_state_lba_dependent on
   32-bit  (Fengguang + Chen + Hannes)
 - Fix compile warning in core_alua_state_lba_dependent (nab)
 - Convert segment_* + sectors variables in core_alua_state_lba_dependent
   to u64 (Hannes)
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

We should be including a descriptor referring to the target device
to allow identification of different TCM instances.

(nab: Bump SE_INQUIRY_BUF to 1024 bytes to handle 2x 256 byte SCSI names)
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

scsi_name_len in spc_emulate_evpd_83 is calculated twice, with
the results of the first calculation discarded. So remove it.
And check for the maximum allowed length, too.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

In addition to block size (already implemented), passing through
alignment offset, logical-to-phys block exponent, I/O granularity and
optimal I/O length will allow initiators to properly handle layout on
LUNs with 4K block sizes.

Tested with various weird values via scsi_debug module.

One thing to look at with this patch is the new block limits values --
instead of granularity 1 optimal 8192, Lio will now be returning whatever
the block device says, which may affect performance.
Signed-off-by: NAndy Grover <agrover@redhat.com>
Acked-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Update copyright ownership/year information for target-core,
loopback, iscsi-target, tcm_qla2xx, vhost and iser-target.
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch adds the Third Party Copy (3PC) bit to signal support
for EXTENDED_COPY within standard inquiry response data.

Also add emulate_3pc device attribute in configfs (enabled by default)
to allow the exposure of this bit to be disabled, if necessary.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Zach Brown <zab@redhat.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: NNicholas Bellinger <nab@daterainc.com>

Setup up the se_cmd->execute_cmd() pointers for EXTENDED_COPY and
RECEIVE_COPY_RESULTS handling within spc_parse_cdb()

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Zach Brown <zab@redhat.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: NNicholas Bellinger <nab@daterainc.com>

This patch makes spc_parse_naa_6h_vendor_specific() available to
other target code, which is required by EXTENDED_COPY when comparing
the received NAA WWN device identifer for locating the associated
se_device backend.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Zach Brown <zab@redhat.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: NNicholas Bellinger <nab@daterainc.com>

This patch adds the MAXIMUM COMPARE AND WRITE LENGTH bit, currently
hardcoded to a single logical block (NoLB=1) within the Block Limits
VPD in spc_emulate_evpd_b0().

Also add emulate_caw device attribute in configfs (enabled by default)
to allow the exposure of this bit to be disabled, if necessary.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Martin Petersen <martin.petersen@oracle.com>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: James Bottomley <JBottomley@Parallels.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: NNicholas Bellinger <nab@daterainc.com>

This patch fixes spc_emulate_inquiry_std() to add trailing ASCII
spaces for INQUIRY vendor + model fields following SPC-4 text:

  "ASCII data fields described as being left-aligned shall have any
   unused bytes at the end of the field (i.e., highest offset) and
   the unused bytes shall be filled with ASCII space characters (20h)."

This addresses a problem with Falconstor NSS multipathing.
Reported-by: NTomas Molota <tomas.molota@lightstorm.sk>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

An empty parameter list (length == 0) is not an error, so succeed MODE
SELECT in this case.  If the parameter list length is too small,
return the correct sense code of PARAMETER LIST LENGTH ERROR.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch allows IBLOCK to check block hints in request_queue->flush_flags
when reporting current backend device WriteCacheEnabled status to a remote
SCSI initiator port.

This is done via a se_subsystem_api->get_write_cache() call instead of a
backend se_device creation time flag, as we expect REQ_FLUSH bits to possibly
change from an underlying blk_queue_flush() by the SCSI disk driver, or
internal raw struct block_device driver usage.

Also go ahead and update iblock_execute_rw() bio I/O path code to use
REQ_FLUSH + REQ_FUA hints when determining WRITE_FUA usage, and make SPC
emulation code use a spc_check_dev_wce() helper to handle both types of
cases for virtual backend subsystem drivers.

(asias: Drop unnecessary comparsion operators)
Reported-by: Nmajianpeng <majianpeng@gmail.com>
Cc: majianpeng <majianpeng@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Some target drivers might need to access the inquiry data
directly, without sending out the actual command.
So export these functions.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Cc: Nicholas Bellinger <nab@risingtidesystems.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch fixes a regression introduced in v3.8-rc1 code where
a zero-length MODE_SENSE was no longer returning GOOD status, but
instead returning TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE to generate
a CHECK_CONDITION status.

This regression was introduced with the following commit:

  commit de103c93
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Tue Nov 6 12:24:09 2012 -0800

      target: pass sense_reason as a return value

and this patch has been tested with the following zero-length CDB:

  sg_raw /dev/sdd 5a 00 0a 00 00 00 00 00 00 00
  SCSI Status: Good

  Sense Information:
  sense buffer empty

Cc: Christoph Hellwig <hch@lst.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch fixes a minor regression introduced in v3.8-rc1 code
where a zero-length INQUIRY was no longer returning the correct
INVALID FIELD IN CDB additional sense code.

This regression was introduced with the following commit:

  commit de103c93
  Author: Christoph Hellwig <hch@lst.de>
  Date:   Tue Nov 6 12:24:09 2012 -0800

      target: pass sense_reason as a return value

and this patch has been tested with the following zero-length CDB:

  sg_raw /dev/sdd 12 00 83 00 00 00
  SCSI Status: Check Condition

  Sense Information:
   Fixed format, current;  Sense key: Illegal Request
   Additional sense: Invalid field in cdb

Cc: Christoph Hellwig <hch@lst.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

v2: Use correct target_core_stat.c 2006 copyright year
v3: Drop extra unnessary legal verbage from header (hch)

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch adds a new max_write_same_len device attribute for use with
WRITE_SAME w/ UNMAP=0 backend emulation.  This can be useful for
lowering the default backend value (IBLOCK uses 0xFFFF).

Also, update block limits VPD emulation code in spc_emulate_evpd_b0() to
report MAXIMUM WRITE SAME LENGTH, and enforce max_write_same_len during
sbc_parse() -> sbc_setup_write_same() CDB sanity checking for all emulated
WRITE_SAME w/ UNMAP=0 cases.

(Robert: Move max_write_same_len check in sbc_setup_write_same() to
         check both WRITE_SAME w/ UNMAP=1 and w/ UNMAP=0 cases)

Cc: Christoph Hellwig <hch@lst.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Pass the sense reason as an explicit return value from the I/O submission
path instead of storing it in struct se_cmd and using negative return
values.  This cleans up a lot of the code pathes, and with the sparse
annotations for the new sense_reason_t type allows for much better
error checking.

(nab: Convert spc_emulate_modesense + spc_emulate_modeselect to use
      sense_reason_t with Roland's MODE SELECT changes)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch fixes a new off-by-one bug in the hardcoded starting offset of
spc_emulate_modesense() code that causes BLOCK DESCRIPTOR to be incorrectly
written within the MEDIUM TYPE buffer area of the mode parameter header.

According to spc4r30, Section 7.5.4, BLOCK DESCRIPTOR for MODE_SENSE_10
starts at byte 3, and BLOCK_DESCRIPTOR for MODE_SENSE (6) starts at byte 2.

(roland: add MODE DATA LENGTH + MEDIUM TYPE offset comment)

Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This is another thing that compliance tests try, and it's easy to
implement on top of the MODE SENSE refactoring; since we don't claim
to support any changeable values, all we need to do is check that
the page contents sent by the initiator match what we would return.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The Windows SCSI compliance test asks for this mode page, and it's
easy to implement: we can just return all 0s to show we don't support
any of these features.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Convert spc_emulate_modesense() to use a table of mode pages, rather
than a switch statement.  This makes it possible to add more pages
sanely -- in particular we no longer need to make sure we keep the
0x3f (return all mode pages) case in sync.

While we're touching this code, make our MODE SENSE emulation a bit
better in a couple of ways:
 - When the initiator passes PC == 1 asking for changeable values,
   return all 0s to show we don't support setting anything.
 - Return a block descriptor for disk devices.

(nab: fix up device attribute references to use dev->dev_attrib
      in for-next code)
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>