Similar to INQUIRY and MODE SENSE, construct the sense data in a
buffer and later copy it to the scatterlist.  Do not do anything,
but still clear a pending unit attention condition, if the allocation
length is zero.

However, SPC tells us that "If a REQUEST SENSE command is terminated with
CHECK CONDITION status [and] the REQUEST SENSE command was received on
an I_T nexus with a pending unit attention condition (i.e., before the
device server reports CHECK CONDITION status), then the device server
shall not clear the pending unit attention condition."  Do the
transport_kmap_data_sg early to detect this case.

It also tells us "Device servers shall not adjust the additional sense
length to reflect truncation if the allocation length is less than the
sense data available", so do not do that!  Note that the err variable
is write-only.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This was originally for helping fabrics to determine overflow/underflow
status, and has been superceeded by SCF_OVERFLOW_BIT + SCF_UNDERFLOW_BIT.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Many SCSI commands are defined to return a CHECK CONDITION / ILLEGAL
REQUEST with ASC set to LOGICAL BLOCK ADDRESS OUT OF RANGE if the
initiator sends a command that accesses a too-big LBA.  Add an enum
value and case entries so that target code can return this status.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Since we set se_session.sess_tearing_down and stop new commands from
being added to se_session.sess_cmd_list before we wait for commands to
finish when freeing a session, there's no need for a separate
sess_wait_list -- if we let new commands be added to sess_cmd_list
after setting sess_tearing_down, that would be a bug that breaks the
logic of waiting in-flight commands.

Also rename target_splice_sess_cmd_list() to
target_sess_cmd_list_set_waiting(), since we are no longer splicing
onto a separate list.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

The last functionality of the target processing thread is offloading possibly
long running task management requests from the submitter context.  To keep
TMR semantics the same we need a single threaded ordered queue, which can
be provided by a per-device workqueue with the right flags.

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

Remove this command submission path which is not used by any in-tree driver.
This also removes the now unused new_cmd_map fabtric method, which a few
drivers implemented despite never calling transport_generic_handle_cdb_map.

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

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

Remove the dead SCF_SE_ALLOW_EOO and SCF_DELAYED_CMD_FROM_SAM_ATTR
from se_cmd_flags_table.

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

Also remove the unused ref_task_lun field in struct se_tmr_req.

(nab: Add missing TASK_REASSIGN ref_lun vs. ref_cmd orig_fe_lun checks
      in iscsit_tmr_task_reassign)

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

Since "target: Drop se_device TCQ queue_depth usage from I/O path" we always
submit all commands (or back then, tasks) from __transport_execute_tasks.

That means the the execute list has lots its purpose, as we can simply
submit the commands that are restarted in transport_complete_task_attr
directly while we walk the list.  In fact doing so also solves a race
in the way it currently walks to delayed_cmd_list as well.

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