linux-stable.git/include/target/target_core_backend.h, branch linux-3.16.y

target: Fix max_unmap_lba_count calc overflow

2016-11-20T01:16:55+00:00

commit ea263c7fada4af8ec7fe5fcfd6e7d7705a89351b upstream.

max_discard_sectors only 32bits, and some non scsi backend
devices will set this to the max 0xffffffff, so we can end up
overflowing during the max_unmap_lba_count calculation.

This fixes a regression caused by my patch:

commit 8a9ebe717a133ba7bc90b06047f43cc6b8bcb8b3
Author: Mike Christie 
Date:   Mon Jan 18 14:09:27 2016 -0600

    target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors

which can result in extra discards being sent to due the overflow
causing max_unmap_lba_count to be smaller than what the backing
device can actually support.

Signed-off-by: Mike Christie 
Reviewed-by: Bart Van Assche 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Ben Hutchings

target: Fix WRITE_SAME/DISCARD conversion to linux 512b sectors

2016-02-25T00:18:38+00:00

commit 8a9ebe717a133ba7bc90b06047f43cc6b8bcb8b3 upstream.

In a couple places we are not converting to/from the Linux
block layer 512 bytes sectors.

1.

The request queue values and what we do are a mismatch of
things:

max_discard_sectors - This is in linux block layer 512 byte
sectors. We are just copying this to max_unmap_lba_count.

discard_granularity - This is in bytes. We are converting it
to Linux block layer 512 byte sectors.

discard_alignment - This is in bytes. We are just copying
this over.

The problem is that the core LIO code exports these values in
spc_emulate_evpd_b0 and we use them to test request arguments
in sbc_execute_unmap, but we never convert to the block size
we export to the initiator. If we are not using 512 byte sectors
then we are exporting the wrong values or are checks are off.
And, for the discard_alignment/bytes case we are just plain messed
up.

2.

blkdev_issue_discard's start and number of sector arguments
are supposed to be in linux block layer 512 byte sectors. We are
currently passing in the values we get from the initiator which
might be based on some other sector size.

There is a similar problem in iblock_execute_write_same where
the bio functions want values in 512 byte sectors but we are
passing in what we got from the initiator.

Signed-off-by: Mike Christie 
Signed-off-by: Nicholas Bellinger 
[ luis: backported to 3.16:
  - dropped changes to attribute unmap_zeroes_data as 3.16 doesn't
    support LBPRZ
  - functions rename:
    * fd_execute_unmap -> fd_do_unmap
    * iblock_execute_unmap -> iblock_do_unmap
  - adjusted context ]
Signed-off-by: Luis Henriques

target: Report correct response length for some commands

2014-06-11T19:15:30+00:00

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/6515

Signed-off-by: Roland Dreier 
Tested-by: Christophe Vu-Brugier 
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Nicholas Bellinger

target/sbc: Add sbc_dif_read_strip software emulation

2014-04-07T08:48:57+00:00

Split up __sbc_dif_verify_read() so that VERIFY READ emulation can
perform target-core specific READ_STRIP, seperate from the existing
FILEIO/RAMDISK backend emulation code.

Also add sbc_dif_read_strip() in order to determine number of sectors
using cmd->prot_length, and skip the extra sbc_dif_copy_prot().

Reviewed-by: Sagi Grimberg 
Cc: Martin K. Petersen 
Cc: Or Gerlitz 
Cc: Quinn Tran 
Cc: Giridhar Malavali 
Signed-off-by: Nicholas Bellinger

target/sbc: Add sbc_dif_generate software emulation

2014-04-07T08:48:56+00:00

This patch adds WRITE_INSERT emulation within target-core
using TYPE1 / TYPE3 PI modes in sbc_dif_generate() code.

This is useful in order for existing legacy fabrics that do not
support protection offloads to interact with backend devices that
currently have T10 PI enabled.

v2 changes:
   - Rename to sbc_dif_generate() (Sagi)

Cc: Martin K. Petersen 
Cc: Sagi Grimberg 
Cc: Or Gerlitz 
Cc: Quinn Tran 
Cc: Giridhar Malavali 
Signed-off-by: Nicholas Bellinger

target/sbc: Add DIF TYPE1+TYPE3 read/write verify emulation

2014-01-18T09:53:12+00:00

This patch adds support for DIF read/write verify emulation
for TARGET_DIF_TYPE1_PROT + TARGET_DIF_TYPE3_PROT operation.

This includes sbc_dif_verify_write() + sbc_dif_verify_read()
calls accessable by backend drivers to perform DIF verify
for SGL based data and protection information.

Also included is sbc_dif_copy_prot() logic to copy protection
information to/from backend provided protection SGLs.

Based on scsi_debug.c DIF TYPE1+TYPE3 emulation.

v2 changes:
  - Select CRC_T10DIF for TARGET_CORE in Kconfig (Fengguang)
  - Drop IP checksum logic from sbc_dif_v1_verify (MKP)
  - Fix offset on app_tag = 0xffff in sbc_dif_verify_read()

Cc: Martin K. Petersen 
Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Sagi Grimberg 
Cc: Or Gerlitz 
Signed-off-by: Nicholas Bellinger

target: Add DIF related base definitions

2014-01-18T09:52:34+00:00

This patch adds DIF related definitions to target_core_base.h
that includes enums for target_prot_op + target_prot_type +
target_prot_version + target_guard_type + target_pi_error.

Also included is struct se_dif_v1_tuple, along with changes
to struct se_cmd, struct se_dev_attrib, and struct se_device.

Also, add new se_subsystem_api->[init,format,free]_prot() callers
used by target core code to setup backend specific protection
information after the device has been configured.

Enums taken from Sagi Grimberg's original patch.

v2 changes:
  - Drop guard_type related definitions
  - Update target_prot_op + target_prot_ho definitions (Sagi)
  - Drop SCF_PROT + pi_prot_version flag
  - Add se_subsystem_api->format_prot() (Sagi)
  - Add hw_pi_prot_type device attribute

Cc: Martin K. Petersen 
Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Sagi Grimberg 
Cc: Or Gerlitz 
Signed-off-by: Nicholas Bellinger

target: Pass through I/O topology for block backstores

2013-11-12T21:44:54+00:00

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: Andy Grover 
Acked-by: Martin K. Petersen 
Signed-off-by: Nicholas Bellinger

target: Make helpers non static for EXTENDED_COPY command setup

2013-09-10T23:48:39+00:00

Both target_alloc_sgl() and transport_generic_map_mem_to_cmd() are
required by EXTENDED_COPY logic when setting up internally dispatched
command descriptors, so go ahead and make both of these non static.

Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Martin Petersen 
Cc: Chris Mason 
Cc: Roland Dreier 
Cc: Zach Brown 
Cc: James Bottomley 
Cc: Nicholas Bellinger 
Signed-off-by: Nicholas Bellinger

target: Allow sbc_ops->execute_rw() to accept SGLs + data_direction

2013-09-09T21:29:28+00:00

COMPARE_AND_WRITE expects to be able to send down a DMA_FROM_DEVICE
to obtain the necessary READ payload for comparision against the
first half of the WRITE payload containing the verify user data.

Currently virtual backends expect to internally reference SGLs,
SGL nents, and data_direction, so change IBLOCK, FILEIO and RD
sbc_ops->execute_rw() to accept this values as function parameters.

Also add default sbc_execute_rw() handler for the typical case for
cmd->execute_rw() submission using cmd->t_data_sg, cmd->t_data_nents,
and cmd->data_direction).

v2 Changes:
  - Add SCF_COMPARE_AND_WRITE command flag
  - Use sbc_execute_rw() for normal cmd->execute_rw() submission
    with expected se_cmd members.

Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Martin Petersen 
Cc: Chris Mason 
Cc: James Bottomley 
Cc: Nicholas Bellinger 
Signed-off-by: Nicholas Bellinger