This patch changes iscsi-target to propagate iscsit_transport
->iscsit_queue_data_in() and ->iscsit_queue_status() callback
errors, back up into target-core.

This allows target-core to retry failed iscsit_transport
callbacks using internal queue-full logic.
Reported-by: NPotnuri Bharat Teja <bharat@chelsio.com>
Reviewed-by: NPotnuri Bharat Teja <bharat@chelsio.com>
Tested-by: NPotnuri Bharat Teja <bharat@chelsio.com>
Cc: Potnuri Bharat Teja <bharat@chelsio.com>
Reported-by: NSteve Wise <swise@opengridcomputing.com>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch fixes a set of queue-full response handling
bugs, where outgoing responses are leaked when a fabric
driver is propagating non -EAGAIN or -ENOMEM errors
to target-core.

It introduces TRANSPORT_COMPLETE_QF_ERR state used to
signal when CHECK_CONDITION status should be generated,
when fabric driver ->write_pending(), ->queue_data_in(),
or ->queue_status() callbacks fail with non -EAGAIN or
-ENOMEM errors, and data-transfer should not be retried.

Note all fabric driver -EAGAIN and -ENOMEM errors are
still retried indefinately with associated data-transfer
callbacks, following existing queue-full logic.

Also fix two missing ->queue_status() queue-full cases
related to CMD_T_ABORTED w/ TAS status handling.
Reported-by: NPotnuri Bharat Teja <bharat@chelsio.com>
Reviewed-by: NPotnuri Bharat Teja <bharat@chelsio.com>
Tested-by: NPotnuri Bharat Teja <bharat@chelsio.com>
Cc: Potnuri Bharat Teja <bharat@chelsio.com>
Reported-by: NSteve Wise <swise@opengridcomputing.com>
Cc: Steve Wise <swise@opengridcomputing.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The t_data_nents and t_bidi_data_nents are the numbers of the
segments, but it couldn't be sure the block size equals to size
of the segment.

For the worst case, all the blocks are discontiguous and there
will need the same number of iovecs, that's to say: blocks == iovs.
So here just set the number of iovs to block count needed by tcmu
cmd.
Tested-by: NIlias Tsitsimpis <iliastsi@arrikto.com>
Reviewed-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NXiubo Li <lixiubo@cmss.chinamobile.com>
Cc: stable@vger.kernel.org # 3.18+
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

If there has BIDI data, its first iov[] will overwrite the last
iov[] for se_cmd->t_data_sg.

To fix this, we can just increase the iov pointer, but this may
introuduce a new memory leakage bug: If the se_cmd->data_length
and se_cmd->t_bidi_data_sg->length are all not aligned up to the
DATA_BLOCK_SIZE, the actual length needed maybe larger than just
sum of them.

So, this could be avoided by rounding all the data lengthes up
to DATA_BLOCK_SIZE.
Reviewed-by: NMike Christie <mchristi@redhat.com>
Tested-by: NIlias Tsitsimpis <iliastsi@arrikto.com>
Reviewed-by: NBryant G. Ly <bryantly@linux.vnet.ibm.com>
Signed-off-by: NXiubo Li <lixiubo@cmss.chinamobile.com>
Cc: stable@vger.kernel.org # 3.18+
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch closes a race between se_lun deletion during configfs
unlink in target_fabric_port_unlink() -> core_dev_del_lun()
-> core_tpg_remove_lun(), when transport_clear_lun_ref() blocks
waiting for percpu_ref RCU grace period to finish, but a new
NodeACL mappedlun is added before the RCU grace period has
completed.

This can happen in target_fabric_mappedlun_link() because it
only checks for se_lun->lun_se_dev, which is not cleared until
after transport_clear_lun_ref() percpu_ref RCU grace period
finishes.

This bug originally manifested as NULL pointer dereference
OOPsen in target_stat_scsi_att_intr_port_show_attr_dev() on
v4.1.y code, because it dereferences lun->lun_se_dev without
a explicit NULL pointer check.

In post v4.1 code with target-core RCU conversion, the code
in target_stat_scsi_att_intr_port_show_attr_dev() no longer
uses se_lun->lun_se_dev, but the same race still exists.

To address the bug, go ahead and set se_lun>lun_shutdown as
early as possible in core_tpg_remove_lun(), and ensure new
NodeACL mappedlun creation in target_fabric_mappedlun_link()
fails during se_lun shutdown.
Reported-by: NJames Shen <jcs@datera.io>
Cc: James Shen <jcs@datera.io>
Tested-by: NJames Shen <jcs@datera.io>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch fixes a iscsi-target specific TMR reference leak
during session shutdown, that could occur when a TMR was
quiesced before the hand-off back to iscsi-target code
via transport_cmd_check_stop_to_fabric().

The reference leak happens because iscsit_free_cmd() was
incorrectly skipping the final target_put_sess_cmd() for
TMRs when transport_generic_free_cmd() returned zero because
the se_cmd->cmd_kref did not reach zero, due to the missing
se_cmd assignment in original code.

The result was iscsi_cmd and it's associated se_cmd memory
would be freed once se_sess->sess_cmd_map where released,
but the associated se_tmr_req was leaked and remained part
of se_device->dev_tmr_list.

This bug would manfiest itself as kernel paging request
OOPsen in core_tmr_lun_reset(), when a left-over se_tmr_req
attempted to dereference it's se_cmd pointer that had
already been released during normal session shutdown.

To address this bug, go ahead and treat ISCSI_OP_SCSI_CMD
and ISCSI_OP_SCSI_TMFUNC the same when there is an extra
se_cmd->cmd_kref to drop in iscsit_free_cmd(), and use
op_scsi to signal __iscsit_free_cmd() when the former
needs to clear any further iscsi related I/O state.
Reported-by: NRob Millner <rlm@daterainc.com>
Cc: Rob Millner <rlm@daterainc.com>
Reported-by: NChu Yuan Lin <cyl@datera.io>
Cc: Chu Yuan Lin <cyl@datera.io>
Tested-by: NChu Yuan Lin <cyl@datera.io>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch corrects the argument in usb_ep_free_request as it is
mistakenly set to ep_out. It should be ep_in for status request.
Signed-off-by: NManish Narani <mnarani@xilinx.com>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The new cmd_time_out configfs attribute for TCMU is allowed to
be disabled, so go ahead and drop the tcmu_cmd_time_out_store()
check.
Reported-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
signed-off-by: NGiridhar Malavali <giridhar.malavali@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Current driver wait for FW to be in the ready state before
processing in-coming commands. For Arbitrated Loop or
Point-to- Point (not switch), FW Ready state can take a while.
FW will transition to ready state after all Nports have been
logged in. In the mean time, certain initiators have completed
the login and starts IO. Driver needs to start processing all
queues if FW is already started.
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

For target mode, when new scsi command arrive, driver first performs
a look up of the SCSI Host. The current look up method is based on
the ALPA portion of the NPort ID. For Cisco switch, the ALPA can
not be used as the index. Instead, the new search method is based
on the full value of the Nport_ID via btree lib.
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NGiridhar Malavali <giridhar.malavali@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The Mailbox interface is currently over subscribed. We like
to reserve the Mailbox interface for the chip managment and
link initialization. Any non essential Mailbox command will
be routed through the IOCB interface. The IOCB interface is
able to absorb more commands.

Following commands are being routed through IOCB interface

- Get ID List (007Ch)
- Get Port DB (0064h)
- Get Link Priv Stats (006Dh)
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NAnil Gurumurthy <anil.gurumurthy@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Add routines to support T10 DIF tag.
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NAnil Gurumurthy <anil.gurumurthy@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

If the remote port have started the login process, then the
PLOGI and PRLI should be back to back. Driver will allow
the remote port to complete the process. For the case where
the remote port decide to back off from sending PRLI, this
local port sets an expiration timer for the PRLI. Once the
expiration time passes, the relogin retry logic is allowed
to go through and perform login with the remote port.
Signed-off-by: NQuinn Tran <quinn.tran@qlogic.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The main lock that needs to be held for CMD or TMR submission
to upper layer is the sess_lock. The sess_lock is used to
serialize cmd submission and session deletion. The addition
of hardware_lock being held is not necessary. This patch removes
hardware_lock dependency from CMD/TMR submission.

Use hardware_lock only for error response in this case.

Path1
       CPU0                    CPU1
       ----                    ----
  lock(&(&ha->tgt.sess_lock)->rlock);
                               lock(&(&ha->hardware_lock)->rlock);
                               lock(&(&ha->tgt.sess_lock)->rlock);
  lock(&(&ha->hardware_lock)->rlock);

Path2/deadlock
*** DEADLOCK ***
Call Trace:
dump_stack+0x85/0xc2
print_circular_bug+0x1e3/0x250
__lock_acquire+0x1425/0x1620
lock_acquire+0xbf/0x210
_raw_spin_lock_irqsave+0x53/0x70
qlt_sess_work_fn+0x21d/0x480 [qla2xxx]
process_one_work+0x1f4/0x6e0

Cc: <stable@vger.kernel.org>
Cc: Bart Van Assche <Bart.VanAssche@sandisk.com>
Reported-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Normally, ABTS is sent to Target Core as Task MGMT command.
In the case of error, qla2xxx needs to send response, hardware_lock
is required to prevent request queue corruption.

Cc: <stable@vger.kernel.org>
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

When FW notify driver or driver detects low FW resource,
driver tries to send out Busy SCSI Status to tell Initiator
side to back off. During the send process, the lock was not held.

Cc: <stable@vger.kernel.org>
Signed-off-by: NQuinn Tran <quinn.tran@qlogic.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Cc: <stable@vger.kernel.org>
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Cc: <stable@vger.kernel.org>
Signed-off-by: NJoe Carnuccio <joe.carnuccio@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Instead of putting cmd_time_out under ../target/core/user_0/foo/control,
which has historically been used by parameters needed for initial
backend device configuration, go ahead and move cmd_time_out into
a backend device attribute.

In order to do this, tcmu_module_init() has been updated to create
a local struct configfs_attribute **tcmu_attrs, that is based upon
the existing passthrough_attrib_attrs along with the new cmd_time_out
attribute.  Once **tcm_attrs has been setup, go ahead and point
it at tcmu_ops->tb_dev_attrib_attrs so it's picked up by target-core.

Also following MNC's previous change, ->cmd_time_out is stored in
milliseconds but exposed via configfs in seconds.  Also, note this
patch restricts the modification of ->cmd_time_out to before +
after the TCMU device has been configured, but not while it has
active fabric exports.

Cc: Mike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

A single daemon could implement multiple types of devices
using multuple types of real devices that may not support
restarting from crashes and/or handling tcmu timeouts. This
makes the cmd timeout configurable, so handlers that do not
support it can turn if off for now.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This adds a helper to check if the dev was configured. It
will be used in the next patch to prevent updates to some
config settings after the device has been setup.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This fixes the following races:

1. core_alua_do_transition_tg_pt could have read
tg_pt_gp_alua_access_state and gone into this if chunk:

if (!explicit &&
        atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) ==
           ALUA_ACCESS_STATE_TRANSITION) {

and then core_alua_do_transition_tg_pt_work could update the
state. core_alua_do_transition_tg_pt would then only set
tg_pt_gp_alua_pending_state and the tg_pt_gp_alua_access_state would
not get updated with the second calls state.

2. core_alua_do_transition_tg_pt could be setting
tg_pt_gp_transition_complete while the tg_pt_gp_transition_work
is already completing. core_alua_do_transition_tg_pt then waits on the
completion that will never be called.

To handle these issues, we just call flush_work which will return when
core_alua_do_transition_tg_pt_work has completed so there is no need
to do the complete/wait. And, if core_alua_do_transition_tg_pt_work
was running, instead of trying to sneak in the state change, we just
schedule up another core_alua_do_transition_tg_pt_work call.

Note that this does not handle a possible race where there are multiple
threads call core_alua_do_transition_tg_pt at the same time. I think
we need a mutex in target_tg_pt_gp_alua_access_state_store.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Userspace target_core_user handlers like tcmu-runner may want to set the
ALUA state to transitioning while it does implicit transitions. This
patch allows that state when set from configfs.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The implicit transition time tells initiators the min time
to wait before timing out a transition. We currently schedule
the transition to occur in tg_pt_gp_implicit_trans_secs
seconds so there is no room for delays. If
core_alua_do_transition_tg_pt_work->core_alua_update_tpg_primary_metadata
needs to write out info to a remote file, then the initiator can
easily time out the operation.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

If tcmu-runner is processing a STPG and needs to change the kernel's
ALUA state then we cannot use the same work queue for task management
requests and ALUA transitions, because we could deadlock. The problem
occurs when a STPG times out before tcmu-runner is able to
call into target_tg_pt_gp_alua_access_state_store->
core_alua_do_port_transition -> core_alua_do_transition_tg_pt ->
queue_work. In this case, the tmr is on the work queue waiting for
the STPG to complete, but the STPG transition is now queued behind
the waiting tmr.

Note:
This bug will also be fixed by this patch:
http://www.spinics.net/lists/target-devel/msg14560.html
which switches the tmr code to use the system workqueues.

For both, I am not sure if we need a dedicated workqueue since
it is not a performance path and I do not think we need WQ_MEM_RECLAIM
to make forward progress to free up memory like the block layer does.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

We do not setup the LU group for pscsi devices, so if you write
a state to alua_access_state that will cause a transition you will
get a NULL pointer dereference.

This patch will fail attempts to try and transition the path
for backend devices that set the TRANSPORT_FLAG_PASSTHROUGH_ALUA
flag.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch allows passthrough backends to use the core/base LIO
ALUA setup and state checks, but still handle the execution of
commands.

This will allow the target_core_user module to execute STPG and RTPG
in userspace, and not have to duplicate the ALUA state checks, path
information (needed so we can check if command is executable on
specific paths) and setup (rtslib sets/updates the configfs ALUA
interface like it does for iblock or file).

For STPG, the target_core_user userspace daemon, tcmu-runner will
still execute the STPG, and to update the core/base LIO state it
will use the existing configfs interface. For RTPG, tcmu-runner
will loop over configfs and/or cache the state.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

We only were returing failure if the last opt to be parsed failed.
This has a return failure when we first detect a failure.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

tcmu hard codes the hw_max_sectors to 128 which is a litle small.
Userspace uses the max_sectors to report the optimal IO size and
some initiators perform better with larger IOs (open-iscsi seems
to do better with 256 to 512 depending on the test).

(Fix do not display hw max sectors twice - MNC)
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

All in-tree fabric drivers provide a tfo->check_stop_free(),
so there is no need to do the extra check within existing
transport_cmd_check_stop_to_fabric() code.

Just to be sure, add a check in target_fabric_tf_ops_check()
to notify any out-of-tree drivers that might be missing it.
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

As reported by Max, the Windows 2008 R2 chkdsk utility expects
VERIFY_16 to be supported, and does not handle the returned
CHECK_CONDITION properly, resulting in an infinite loop.

The kernel will log huge amounts of this error:

kernel: TARGET_CORE[iSCSI]: Unsupported SCSI Opcode 0x8f, sending
CHECK_CONDITION.
Signed-off-by: NMax Lohrmann <post@wickenrode.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The following fixes a divide by zero OOPs with TYPE_TAPE
due to pscsi_tape_read_blocksize() failing causing a zero
sd->sector_size being propigated up via dev_attrib.hw_block_size.

It also fixes another long-standing bug where TYPE_TAPE and
TYPE_MEDIMUM_CHANGER where using pscsi_create_type_other(),
which does not call scsi_device_get() to take the device
reference.  Instead, rename pscsi_create_type_rom() to
pscsi_create_type_nondisk() and use it for all cases.

Finally, also drop a dump_stack() in pscsi_get_blocks() for
non TYPE_DISK, which in modern target-core can get invoked
via target_sense_desc_format() during CHECK_CONDITION.
Reported-by: NMalcolm Haak <insanemal@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The value we read from the header is in network byte order, whereas
 EFX_POPULATE_QWORD_* takes values in host byte order (which it then
 converts to little-endian, as MCDI is little-endian).

Fixes: e9117e50 ("sfc: Firmware-Assisted TSO version 2")
Signed-off-by: NEdward Cree <ecree@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It confuses sparse, which thinks the size isn't constant.  Let's achieve
 the same thing with a BUILD_BUG_ON, since we know which one should be
 bigger and don't expect them ever to change.
Signed-off-by: NEdward Cree <ecree@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dma_sync_single_for_*() takes the direction in which the buffer
was mapped, not the direction of the sync.  We should sync XDP
buffers bidirectionally.

Fixes: ecd63a02 ("nfp: add XDP support in the driver")
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit c0f031bc ("nfp_net: use alloc_frag() and build_skb()")
we are allocating buffers which have to hold both the data and skb to
be created in place by build_skb().

FW should only be told about the buffer space it can DMA to, that
is without the build_skb() headroom and tailroom.  Note: firmware
applications should validate the buffers against both MTU and
free list buffer size so oversized packets would not pass through
the NIC anyway.

Fixes: c0f031bc ("nfp: use alloc_frag() and build_skb()")
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>