linux-toradex.git/drivers/target, branch v4.10-rc4

target: support XCOPY requests without parameters

2017-01-10T16:41:30+00:00

SPC4r37 6.4.1 EXTENDED COPY(LID4) states (also applying to LID1 reqs):
  A parameter list length of zero specifies that the copy manager shall
  not transfer any data or alter any internal state, and this shall not
  be considered an error.

This behaviour can be tested using the libiscsi ExtendedCopy.ParamHdr
test.

Signed-off-by: David Disseldorp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Bart Van Assche

target: check for XCOPY parameter truncation

2017-01-10T16:41:27+00:00

Check for XCOPY header, CSCD descriptor and segment descriptor list
truncation, and respond accordingly.

SPC4r37 6.4.1 EXTENDED COPY(LID4) states (also applying to LID1 reqs):
  If the parameter list length causes truncation of the parameter list,
  then the copy manager shall transfer no data and shall terminate the
  EXTENDED COPY command with CHECK CONDITION status, with the sense key
  set to ILLEGAL REQUEST, and the additional sense code set to PARAMETER
  LIST LENGTH ERROR.

This behaviour can be tested using the libiscsi ExtendedCopy.ParamHdr
test.

Signed-off-by: David Disseldorp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Bart Van Assche

target: use XCOPY segment descriptor CSCD IDs

2017-01-10T16:41:19+00:00

The XCOPY specification in SPC4r37 states that the XCOPY source and
destination device(s) should be derived from the copy source and copy
destination (CSCD) descriptor IDs in the XCOPY segment descriptor.

The CSCD IDs are generally (for block -> block copies), indexes into
the corresponding CSCD descriptor list, e.g.
=================================
EXTENDED COPY Header
=================================
CSCD Descriptor List
- entry 0
  + LU ID <--------------<------------------\
- entry 1                                   |
  + LU ID <______________<_____________     |
=================================      |    |
Segment Descriptor List                |    |
- segment 0                            |    |
  + src CSCD ID = 0 --------->---------+----/
  + dest CSCD ID = 1 ___________>______|
  + len
  + src lba
  + dest lba
=================================

Currently LIO completely ignores the src and dest CSCD IDs in the
Segment Descriptor List, and instead assumes that the first entry in the
CSCD list corresponds to the source, and the second to the destination.

This commit removes this assumption, by ensuring that the Segment
Descriptor List is parsed prior to processing the CSCD Descriptor List.
CSCD Descriptor List processing is modified to compare the current list
index with the previously obtained src and dest CSCD IDs.

Additionally, XCOPY requests where the src and dest CSCD IDs refer to
the CSCD Descriptor List entry can now be successfully processed.

Fixes: cbf031f ("target: Add support for EXTENDED_COPY copy offload")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=191381
Signed-off-by: David Disseldorp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Bart Van Assche

target: check XCOPY segment descriptor CSCD IDs

2017-01-10T16:41:13+00:00

Ensure that the segment descriptor CSCD descriptor ID values correspond
to CSCD descriptor entries located in the XCOPY command parameter list.
SPC4r37 6.4.6.1 Table 150 specifies this range as 0000h to 07FFh, where
the CSCD descriptor location in the parameter list can be located via:
16 + (id * 32)

Signed-off-by: David Disseldorp 
Reviewed-by: Christoph Hellwig 
[ bvanassche: inserted "; " in the format string of an error message
  and also moved a "||" operator from the start of a line to the end
  of the previous line ]
Signed-off-by: Bart Van Assche

target: simplify XCOPY wwn->se_dev lookup helper

2017-01-10T16:41:12+00:00

target_xcopy_locate_se_dev_e4() is used to locate an se_dev, based on
the WWN provided with the XCOPY request. Remove a couple of unneeded
arguments, and rely on the caller for the src/dst test.

Signed-off-by: David Disseldorp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Bart Van Assche

target: return UNSUPPORTED TARGET/SEGMENT DESC TYPE CODE sense

2017-01-10T16:41:09+00:00

Use UNSUPPORTED TARGET DESCRIPTOR TYPE CODE and UNSUPPORTED SEGMENT
DESCRIPTOR TYPE CODE additional sense codes if a descriptor type in an
XCOPY request is not supported, as specified in spc4r37 6.4.5 and 6.4.6.

Signed-off-by: David Disseldorp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Bart Van Assche

target: bounds check XCOPY total descriptor list length

2017-01-10T16:41:04+00:00

spc4r37 6.4.3.5 states:
  If the combined length of the CSCD descriptors and segment descriptors
  exceeds the allowed value, then the copy manager shall terminate the
  command with CHECK CONDITION status, with the sense key set to ILLEGAL
  REQUEST, and the additional sense code set to PARAMETER LIST LENGTH
  ERROR.

This functionality can be tested using the libiscsi
ExtendedCopy.DescrLimits test.

Signed-off-by: David Disseldorp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Bart Van Assche

target: bounds check XCOPY segment descriptor list

2017-01-10T16:40:58+00:00

Check the length of the XCOPY request segment descriptor list against
the value advertised via the MAXIMUM SEGMENT DESCRIPTOR COUNT field in
the RECEIVE COPY OPERATING PARAMETERS response.

spc4r37 6.4.3.5 states:
  If the number of segment descriptors exceeds the allowed number, the
  copy manager shall terminate the command with CHECK CONDITION status,
  with the sense key set to ILLEGAL REQUEST, and the additional sense
  code set to TOO MANY SEGMENT DESCRIPTORS.

This functionality is testable using the libiscsi
ExtendedCopy.DescrLimits test.

Signed-off-by: David Disseldorp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Bart Van Assche

target: use XCOPY TOO MANY TARGET DESCRIPTORS sense

2017-01-10T16:40:43+00:00

spc4r37 6.4.3.4 states:
  If the number of CSCD descriptors exceeds the allowed number, the copy
  manager shall terminate the command with CHECK CONDITION status, with
  the sense key set to ILLEGAL REQUEST, and the additional sense code
  set to TOO MANY TARGET DESCRIPTORS.

LIO currently responds with INVALID FIELD IN PARAMETER LIST, which sees
it fail the libiscsi ExtendedCopy.DescrLimits test.

Signed-off-by: David Disseldorp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Bart Van Assche

target: add XCOPY target/segment desc sense codes

2017-01-10T16:40:32+00:00

As defined in http://www.t10.org/lists/asc-num.htm. To be used during
validation of XCOPY target and segment descriptor lists.

Signed-off-by: David Disseldorp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Bart Van Assche