Remove the dead SCF_SE_ALLOW_EOO and SCF_DELAYED_CMD_FROM_SAM_ATTR
from se_cmd_flags_table.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas 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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas 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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

We don't need three flags to classifiy the CDB as we can check for a NULL S/G
list for a dataless command, and can infer from the absence of the data flag
that we deal with a control CDB.  Also remove the _SG_IO from the data CDB
flag as all I/O is dont on S/G lists now.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch adds support for ALUA MI_REPORT_TARGET_PGS extended header
format defined within SPC-4.  It changes target core ALUA emulation logic
within target_emulate_report_target_port_groups() to support both the
extended and original length only header formats.

It includes adding a new 'implict_trans_secs' attribute for each ALUA
target port group to control the value returned to the application client
for an recommended implict translation timeout in seconds.  By default
this value is currently set to zero, and limited up to 255 by virtue of
using a single byte in the extended header format.

This value is used by target_emulate_report_target_port_groups() within
the extended header logic to set IMPLICIT TRANSITION TIME as defined by
spc4r30.

Cc: Hannes Reinecke <hare@suse.de>
Cc: Rob Evers <revers@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch removes the original usage of dev_attr->max_sectors in favor of
dev_attr->hw_max_sectors that is now being enforced by target core from
within transport_generic_cmd_sequencer() for SCF_SCSI_DATA_SG_IO_CDB ops.

After the recent se_task removal patches from hch, this value for IBLOCK
backends being set via configfs by userspace from an saved max_sectors
value that is turning out to be problematic, so it makes sense to go ahead
and remove this now legacy attribute all-together.

This patch also continues to make se_dev_set_default_attribs() do
(sectors / block_size) alignment for what actually get used by
target_core_mod to be safe here, following the same alignment currently
used by fabric_max_sectors.
Reported-by: NAndy Grover <agrover@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Now that tasks are gone we are guaranteed to only get a single completion
per command, and thus don't need this counter.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Now that tasks are gone we are guaranteed to only get a single completion
per command, and thus don't need this counter.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Now that tasks are gone we are guaranteed to only get a single completion
per command, and thus don't need this counter.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

We can use struct se_cmd for everything it did.  Make sure to pass the S/G
list and data direction to the execution function to ease adding back BIDI
support later on.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

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

Now that we only have a single task per command we can use a direct pointer
to it instead of list.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Make CDB emulation work on commands instead of tasks again as a preparation
of removing tasks completely.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Remove the task_sectors field that isn't used anywhere.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Now that we don't split commands the size field in the task is always
equivalent to the one in the CDB, even in cases where we have two tasks
due to a BIDI transfer.  Just refer the the size in the command instead
of duplicating it in the task.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Now that we don't split commands the lba field in the task is always
equivalent to the one in the CDB, even in cases where we have two tasks
due to a BIDI transfer.  Just refer the the lba in the command instead
of duplicating it in the task.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Now that all fabrics are converted over to using se_cmd->t_data_sg
directly, we can drop the task sg chaining support.  With the modern
memory allocation in target core, task sg chaining is needless
overhead -- we would split up the main cmd sglist into pieces, and
then splice those pieces back together instead of just using the
original list directly.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The UASP protocol does not inform the target device upfront how much
data it should expect so we have to learn in from the CDB.  So in order
to handle this case, add a TARGET_SCF_UNKNOWN_SIZE to target_submit_cmd()
and perform an explictly assignment for se_cmd->data_length from the
extracted CDB size in transport_generic_cmd_sequencer().
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This was used at one time as a hack by FILEIO backend registration to
allow a struct block_device that was claimed with blkdev_get (by a local
filesystem mount for example) to be exported as read-only (SCSI WP=1).

Since FILEIO backend registration will no longer attempt to obtain
exclusive access to an underlying struct block_device here, this flag is
now obsolete.
Reported-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Turns an order-8 allocation into slab-sized ones, thereby preventing
allocation failures with memory fragmentation.

This likely saves memory as well, as the slab allocator can pack objects
more tightly than the buddy allocator.

(nab: Fix lio-core patch fuzz)
Signed-off-by: NJoern Engel <joern@logfs.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Turns an order-10 allocation into slab-sized ones, thereby preventing
allocation failures with memory fragmentation.

This likely saves memory as well, as the slab allocator can pack objects
more tightly than the buddy allocator.
Signed-off-by: NJoern Engel <joern@logfs.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Bump core version to v4.1.0-rc2-ml, and for versions from the
following mainline fabric modules:

loopback: v2.1-rc2
tcm_fc: v0.4
iscsi-target: v4.1.0-rc2
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch converts core_tpg_del_initiator_node_acl() shutdown from configfs
context to use se_node_acl->acl_kref and ->acl_free_comp in order to wait for
outstanding fabric callbacks to complete via transport_deregister_session()
callbacks before waking ->acl_free_comp from the last ->acl_kref put.

It also changes core_tpg_del_initiator_node_acl() to setup a local sess_list
with target_get_session() + acl->acl_stop = 1 for active sessions that will
be shutdown, and changes transport_deregister_session_configfs() to check
for ->acl_stop usage.

Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Joern Engel <joern@logfs.org>
Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch adds se_node_acl->acl_kref for use with ->acl_free_comp
during explict se_node_acl release.  It adds kref_init() during
se_node_acl setup, kref_get() during __transport_register_session()
-> target_put_nacl() with existing transport_deregister_session()
fabric callback usage.

It also moves transport_free_session() to release *se_sess memory
after target_put_nacl() execution in transport_deregister_session()

Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Joern Engel <joern@logfs.org>
Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Add se_node_acl->acl_free_comp for NodeACL release path to wait for outstanding
fabric session shutdown to complete in transport_deregister_session() before
finishing NodeACL release from configfs process context.

Also make transport_deregister_session() clear the comp_nacl bit
to skip se_node_acl->acl_free_comp completion for dynamically generated
NodeACL during fabric session shutdown.

Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Joern Engel <joern@logfs.org>
Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch adds basic se_session->sess_kref and get/put helpers for fabric
session reference counting.  It sets the initial kref in transport_init_session()
and adds a target_release_session() callback to invoke TFO->close_session()
for final session shutdown.

Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Joern Engel <joern@logfs.org>
Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

se_dev_attrib.max_sectors currently has two independent meanings:

 - It is reported in the block limits VPD page as the maximum transfer
   length, ie the largest IO that the front-end (fabric) can handle.
   Also the target core doesn't enforce this maximum transfer length.

 - It is used to hold the size of the largest IO that the back-end can
   handle, so we know when to split SCSI commands into multiple tasks.

Fix this by adding a new se_dev_attrib.fabric_max_sectors to hold the
maximum transfer length, and checking incoming IOs against that limit.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

If the initiator sends us an INQUIRY command with an allocation length
that's shorter than what we want to return, we're simply supposed to
truncate our response and return what the initiator gave us space for,
without signaling any error.  Current target code has various tests that
don't fill out the full response if the buffer is too short and
sometimes return errors incorrectly.

Fix this up by allocating a bounce buffer for INQUIRY responses if we
need to, ie if we have cmd->data_length too small as well as
SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC set in cmd->se_cmd_flags -- for most
fabrics, we always allocate at least a full page, but for tcm_loop we
may have a small buffer coming directly from the SCSI stack.

This lets us delete a lot of cmd->data_length checking, and also makes
our INQUIRY handling correct per SPC in a lot more cases.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

When TARGET_SCF_ACK_KREF is in use with target_submit_cmd() for
setting the extra acknowledgement reference to se_cmd->cmd_kref,
go ahead and set SCF_ACK_KREF in order to be used later by
abort task.
Reported-by: NRoland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Change the test for if a cmd is a tmr request to checking if
SCF_SCSI_TMR_CDB (a new flag) is set in cmd->se_cmd_flags.

Also remove se_tmr_req_cache usage in favor of kzalloc usage,
and make core_tmr_alloc_req() return int + setup se_cmd->se_tmr_req
directly and fix up various fabric module usages

Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NAndy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NAndy Grover <agrover@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

There is no reason to have a flag telling if a command is on the per-lun list,
we can simply do a list_empty check before removing it as long as we're careful
to always use list_del_init.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Replace various atomic_ts used as flags in struct se_cmd with a single
transport_state bitmap that requires t_state_lock to be held for modifications.

In the target core that assumption generally is true, but some recently added
code in the SRP target had to grow new lock calls.  I can't say I like the way
how it messes with the command state directly, but let's leave that for later.

(Re-add missing ib_srpt.c changes that nab dropped..)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

We need to handle >1 page control cdbs, so extend the code to do a vmap
if bigger than 1 page. It seems like kmap() is still preferable if just
a page, fewer TLB shootdowns(?), so keep using that when possible.

Rename function pair for their new scope.
Signed-off-by: NAndy Grover <agrover@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

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

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 <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Joern Engel <joern@logfs.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

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 <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Joern Engel <joern@logfs.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

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 <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

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: NNicholas Bellinger <nab@linux-iscsi.org>