linux-toradex.git/drivers/target, branch v3.3-rc2

target: Set additional sense length field in sense data

2011-12-16T06:29:04+00:00

The target code was not setting the additional sense length field in the
sense data it returned, which meant that at least the Linux stack
ignored the ASC/ASCQ fields.  For example, without this patch, on a
tcm_loop device:

    # sg_raw -v /dev/sda 2 0 0 0 0 0

gives

        cdb to send: 02 00 00 00 00 00
    SCSI Status: Check Condition

    Sense Information:
     Fixed format, current;  Sense key: Illegal Request
      Raw sense data (in hex):
            70 00 05 00 00 00 00 00

while after the patch we correctly get the following (which matches what
a regular disk returns):

        cdb to send: 02 00 00 00 00 00
    SCSI Status: Check Condition

    Sense Information:
     Fixed format, current;  Sense key: Illegal Request
     Additional sense: Invalid command operation code
     Raw sense data (in hex):
            70 00 05 00 00 00 00 0a  00 00 00 00 20 00 00 00
            00 00

Signed-off-by: Roland Dreier 
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger

target: Remove legacy device status check from transport_execute_tasks

2011-12-14T11:53:29+00:00

This patch removes a legacy se_dev_check_online() check from within
transport_execute_tasks() that should no longer be necessary as
transport_lookup_cmd_lun() is already making this call.

Using transport_cmd_check_stop() from transport_execute_tasks() should
already be checking per se_cmd context for each descriptor upon active
I/O shutdown, so no need to acquire dev->dev_status_lock again while
executing se_task submission.

Cc: Christoph Hellwig 
Cc: Roland Dreier 
Cc: Joern Engel 
Signed-off-by: Nicholas Bellinger

target: Remove __transport_execute_tasks() for each processing context

2011-12-14T11:50:12+00:00

This patch removes the original usage of __transport_execute_tasks() ahead
of every transport_get_cmd_from_queue() call in transport_processing_thread().
This helps reduce se_device->execute_task_lock contention between qla2xxx wq
with target_submit_cmd() for READs and transport_processing_thread()
context servicing WRITEs with full payloads for I/O submission.

It also adds a __transport_execute_tasks() to kick the task queue again
without a *se_cmd descriptor with existing queue full logic, but this may
end up not being necessary.

Cc: Christoph Hellwig 
Cc: Roland Dreier 
Cc: Joern Engel 
Signed-off-by: Nicholas Bellinger

target: Remove extra se_device->execute_task_lock access in fast path

2011-12-14T11:48:46+00:00

This patch makes __transport_execute_tasks() perform the addition of
tasks to dev->execute_task_list via __transport_add_tasks_from_cmd()
while holding dev->execute_task_lock during normal I/O fast path
submission.

It effectively removes the unnecessary re-acquire of dev->execute_task_lock
during transport_execute_tasks() -> transport_add_tasks_from_cmd() ahead
of calling  __transport_execute_tasks() to queue tasks for the passed
*se_cmd descriptor.

(v2: Re-add goto check_depth usage for multi-task submission for now..)

Cc: Christoph Hellwig 
Cc: Roland Dreier 
Cc: Joern Engel 
Signed-off-by: Nicholas Bellinger

target: Drop se_device TCQ queue_depth usage from I/O path

2011-12-14T11:42:13+00:00

Historically, pSCSI devices have been the ones that required target-core
to enforce a per se_device->depth_left.  This patch changes target-core
to no longer (by default) enforce a per se_device->depth_left or sleep in
transport_tcq_window_closed() when we out of queue slots for all backend
export cases.

Cc: Christoph Hellwig 
Cc: Roland Dreier 
Cc: Joern Engel 
Signed-off-by: Nicholas Bellinger

target: Fix possible NULL pointer with __transport_execute_tasks

2011-12-14T11:42:12+00:00

This patch makes __transport_execute_tasks() use a local *se_dev
reference to prevent direct se_cmd->se_dev access after
transport_cmd_check_stop() -> transport_add_tasks_from_cmd()
has been called, as in the current implementation we can expect
__transport_execute_tasks() may be called from another context
that may have already completed the I/O.

Cc: Christoph Hellwig 
Signed-off-by: Nicholas Bellinger

tcm_fc: Convert ft_send_work to use target_submit_cmd

2011-12-14T11:42:08+00:00

This patch converts the main ft_send_work() I/O path to use
target_submit_cmd() with a single se_cmd->cmd_kref reference
that is released via the existing ft_check_stop_free() response
path callback.

It also makes ft_send_tm() use transport_init_se_cmd() and
target_get_sess_cmd() to also use single se_cmd->cmd_kref
reference.

Cc: Christoph Hellwig 
Cc: Kiran Patil 
Signed-off-by: Nicholas Bellinger

target: Add target_submit_cmd() for process context fabric submission

2011-12-14T11:40:56+00:00

This patch adds a target_submit_cmd() caller that can be used by fabrics
to submit an uninitialized se_cmd descriptor to an struct se_session +
unpacked_lun from workqueue process context.  This call will invoke the
following steps:

- transport_init_se_cmd() to setup se_cmd specific pointers
- Obtain se_cmd->cmd_kref references with target_get_sess_cmd()
- set se_cmd->t_tasks_bidi
- transport_lookup_cmd_lun() to setup struct se_cmd->se_lun from
  the passed unpacked_lun
- transport_generic_allocate_tasks() to setup the passed *cdb, and
- transport_handle_cdb_direct() handle READ dispatch or WRITE
  ready-to-transfer callback to fabric

v2 changes from hch feedback:

*) Add target_sc_flags_table for target_submit_cmd flags
*) Rename bidi parameter to flags, add TARGET_SCF_BIDI_OP
*) Convert checks to BUG_ON
*) Add out_check_cond for transport_send_check_condition_and_sense
   usage

v3 changes:

*) Add TARGET_SCF_ACK_KREF for target_submit_cmd into
   target_get_sess_cmd to determine when the fabric caller is expecting
   a second kref_put() from fabric packet acknowledgement.

Cc: Christoph Hellwig 
Cc: Roland Dreier 
Signed-off-by: Nicholas Bellinger

target: Make target_put_sess_cmd use target_release_cmd_kref

2011-12-14T11:38:29+00:00

This patch moves target_put_sess_cmd() to use a se_cmd->cmd_kref
callback target_release_cmd_kref when performing driver release of
fabric->se_cmd descriptor memory.  It sets the default cmd_kref
count value to '2' within target_get_sess_cmd() setup, and
currently assumes TFO->check_stop_free() usage.

It drops se_tfo->check_release_cmd() usage in the main
transport_release_cmd codepath.

Signed-off-by: Nicholas Bellinger

target: Set response format in INQUIRY response

2011-12-14T11:38:28+00:00

Current SCSI specs say that the "response format" field in the standard
INQUIRY response should be set to 2, and all the real SCSI devices I
have do put 2 here.  So let's do that too.

Signed-off-by: Roland Dreier 
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger