linux-stable.git/include/target/target_core_base.h, branch linux-3.19.y

target: Fix COMPARE_AND_WRITE with SG_TO_MEM_NOALLOC handling

2015-05-06T20:01:55+00:00

commit c8e639852ad720499912acedfd6b072325fd2807 upstream.

This patch fixes a bug for COMPARE_AND_WRITE handling with
fabrics using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.

It adds the missing allocation for cmd->t_bidi_data_sg within
transport_generic_new_cmd() that is used by COMPARE_AND_WRITE
for the initial READ payload, even if the fabric is already
providing a pre-allocated buffer for cmd->t_data_sg.

Also, fix zero-length COMPARE_AND_WRITE handling within the
compare_and_write_callback() and target_complete_ok_work()
to queue the response, skipping the initial READ.

This fixes COMPARE_AND_WRITE emulation with loopback, vhost,
and xen-backend fabric drivers using SG_TO_MEM_NOALLOC.

Reported-by: Christoph Hellwig 
Cc: Christoph Hellwig 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Fix PR_APTPL_BUF_LEN buffer size limitation

2015-03-18T13:10:57+00:00

commit f161d4b44d7cc1dc66b53365215227db356378b1 upstream.

This patch addresses the original PR_APTPL_BUF_LEN = 8k limitiation
for write-out of PR APTPL metadata that Martin has recently been
running into.

It changes core_scsi3_update_and_write_aptpl() to use vzalloc'ed
memory instead of kzalloc, and increases the default hardcoded
length to 256k.

It also adds logic in core_scsi3_update_and_write_aptpl() to double
the original length upon core_scsi3_update_aptpl_buf() failure, and
retries until the vzalloc'ed buffer is large enough to accommodate
the outgoing APTPL metadata.

Reported-by: Martin Svec 
Signed-off-by: Nicholas Bellinger 
Signed-off-by: Greg Kroah-Hartman

target: Drop left-over fabric_max_sectors attribute

2015-01-09T23:22:05+00:00

Now that fabric_max_sectors is no longer used to enforce the maximum
I/O size, go ahead and drop it's left-over usage in target-core and
associated backend drivers.

Cc: Christoph Hellwig 
Cc: Martin K. Petersen 
Cc: Roland Dreier 
Signed-off-by: Nicholas Bellinger

scsi: remove MSG_*_TAG defines

2014-12-04T08:58:33+00:00

For SPI drivers use the message definitions from scsi.h, and for target
drivers introduce a new TCM_*_TAG namespace.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Bart Van Assche 
Reviewed-by: Martin K. Petersen

target: Add force_pr_aptpl device attribute

2014-10-04T05:41:20+00:00

This patch adds a force_pr_aptpl device attribute used to force SPC-3 PR
Activate Persistence across Target Power Loss (APTPL) operation.  This
makes PR metadata write-out occur during state change regardless if new
PERSISTENT_RESERVE_OUT CDBs have their APTPL feature bit set.

This is useful during H/A failover in active/passive setups where all PR
state is being re-created on a different node, driven by configfs backend
device + export layout and pre-loaded $DEV/pr/res_aptpl_metadata.

Cc: Mike Christie 
Signed-off-by: Nicholas Bellinger

target: encapsulate smp_mb__after_atomic()

2014-10-01T21:39:06+00:00

The target code has a rather generous helping of smp_mb__after_atomic()
throughout the code base.  Most atomic operations were followed by one
and none were preceded by smp_mb__before_atomic(), nor accompanied by a
comment explaining the need for a barrier.

Instead of trying to prove for every case whether or not it is needed,
this patch introduces atomic_inc_mb() and atomic_dec_mb(), which
explicitly include the memory barriers before and after the atomic
operation.  For now they are defined in a target header, although they
could be of general use.

Most of the existing atomic/mb combinations were replaced by the new
helpers.  In a few cases the atomic was sandwiched in
spin_lock/spin_unlock and I simply removed the barrier.

I suspect that in most cases the correct conversion would have been to
drop the barrier.  I also suspect that a few cases exist where a) the
barrier was necessary and b) a second barrier before the atomic would
have been necessary and got added by this patch.

Signed-off-by: Joern Engel 
Signed-off-by: Nicholas Bellinger

target: Pass in transport supported PI at session initialization

2014-04-07T08:48:54+00:00

In order to support local WRITE_INSERT + READ_STRIP operations for
non PI enabled fabrics, the fabric driver needs to be able signal
what protection offload operations are supported.

This is done at session initialization time so the modes can be
signaled by individual se_wwn + se_portal_group endpoints, as well
as optionally across different transports on the same endpoint.

For iser-target, set TARGET_PROT_ALL if the underlying ib_device
has already signaled PI offload support, and allow this to be
exposed via a new iscsit_transport->iscsit_get_sup_prot_ops()
callback.

For loopback, set TARGET_PROT_ALL to signal SCSI initiator mode
operation.

For all other drivers, set TARGET_PROT_NORMAL to disable fabric
level PI.

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

target: Fix Task Aborted Status (TAS) handling

2014-04-07T08:48:50+00:00

This patch addresses three of long standing issues wrt to Task
Aborted Status (TAS) handling.

The first is the incorrect assumption in core_tmr_handle_tas_abort()
that TASK_ABORTED status is sent for the task referenced by TMR
ABORT_TASK, and sending TASK_ABORTED status for TMR LUN_RESET on
the same nexus the LUN_RESET was received.

The second is to ensure the lun reference count is dropped within
transport_cmd_finish_abort() by calling transport_lun_remove_cmd()
before invoking transport_cmd_check_stop_to_fabric().

The last is to fix the delayed TAS handling to allow outstanding
WRITEs to complete before sending the TASK_ABORTED status. This
includes changing transport_check_aborted_status() to avoid
processing when SCF_SEND_DELAYED_TAS has not be set, and updating
transport_send_task_abort() to drop the SCF_SENT_DELAYED_TAS
check.

Signed-off-by: Alex Leung 
Cc: Alex Leung 
Signed-off-by: Nicholas Bellinger

Target/core: Remove prot_handover use for now

2014-04-07T08:48:43+00:00

This is not going to be supported soon - so drop it.

Signed-off-by: Sagi Grimberg 
Signed-off-by: Nicholas Bellinger

Target/dif: Introduce protection-passthough-only mode

2014-04-07T08:48:42+00:00

Some transports (iSCSI/iSER/SRP/FC) support hardware INSERT/STRIP
capabilities while other transports like loopback/vhost-scsi need
perform this is software.

This patch allows fabrics using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC
to signal the early LUN scan handling case where PROTECT CDB bits
are set, but no fabric buffer has been provided.

For transports which use generic new command these buffers have yet
to be allocated.

Also this way, target may support protection information
against legacy initiators (writes are inserted and reads
are stripped).

(Only set prot_pto for loopback during early special case - nab)

Signed-off-by: Sagi Grimberg 
Signed-off-by: Nicholas Bellinger