In case of hw iscsi offload, an host can have N-number of active
connections. There can be IO's running on some connections which
make host->host_busy always TRUE. Now if logout from a connection
is tried then the code gets into an infinite loop as host->host_busy
is always TRUE.

 iscsi_conn_teardown(....)
 {
   .........
    /*
     * Block until all in-progress commands for this connection
     * time out or fail.
     */
     for (;;) {
      spin_lock_irqsave(session->host->host_lock, flags);
      if (!atomic_read(&session->host->host_busy)) { /* OK for ERL == 0 */
	      spin_unlock_irqrestore(session->host->host_lock, flags);
              break;
      }
     spin_unlock_irqrestore(session->host->host_lock, flags);
     msleep_interruptible(500);
     iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
                 "host_busy %d host_failed %d\n",
	          atomic_read(&session->host->host_busy),
	          session->host->host_failed);

	................
	...............
     }
  }

This is not an issue with software-iscsi/iser as each cxn is a separate
host.

Fix:
Acquiring eh_mutex in iscsi_conn_teardown() before setting
session->state = ISCSI_STATE_TERMINATE.

Signed-off-by: John Soni Jose <sony.john@avagotech.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Chris Leech <cleech@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Bottomley <JBottomley@Odin.com>

Drop the now unused reason argument from the ->change_queue_depth method.
Also add a return value to scsi_adjust_queue_depth, and rename it to
scsi_change_queue_depth now that it can be used as the default
->change_queue_depth implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

All drivers use the implementation for ramping the queue up and down, so
instead of overloading the change_queue_depth method call the
implementation diretly if the driver opts into it by setting the
track_queue_depth flag in the host template.

Note that a few drivers validated the new queue depth in their
change_queue_depth method, but as we never go over the queue depth
set during slave_configure or the sysfs file this isn't nessecary
and can safely be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Venkatesh Srinivas <venkateshs@google.com>

Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth.  For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway.  The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

This just has iscsi_tcp support ISCSI_PARAM_LOCAL_PORT which
exports the local port being used by the iscsi connection.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Christoph Hellwig <hch@lst.de>

This patches fixes a potential buffer overrun in __iscsi_conn_send_pdu.
This function is used by iscsi drivers and userspace to send iscsi PDUs/
commands. For login commands, we have a set buffer size. For all other
commands we do not support data buffers.

This was reported by Dan Carpenter here:
http://www.spinics.net/lists/linux-scsi/msg66838.html

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

When a iscsi nop as ping timedout we were failing with the
common connection error code, ISCSI_ERR_CONN_FAILED. This
patch adds a new error code for this problem so can properly
track/distinguish in userspace.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Avoid taking the host-wide host_lock to check the per-host queue limit.
Instead we do an atomic_inc_return early on to grab our slot in the queue,
and if necessary decrement it after finishing all checks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Webb Scales <webbnh@hp.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Robert Elliott <elliott@hp.com>

The SCSI standard defines 64-bit values for LUNs, and large arrays
employing large or hierarchical LUN numbers become more and more
common.

So update the linux SCSI stack to use 64-bit LUN numbers.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Pull SCSI target updates from Nicholas Bellinger:
 "The highlights this round include:

   - Add support for T10 PI pass-through between vhost-scsi +
     virtio-scsi (MST + Paolo + MKP + nab)
   - Add support for T10 PI in qla2xxx target mode (Quinn + MKP + hch +
     nab, merged through scsi.git)
   - Add support for percpu-ida pre-allocation in qla2xxx target code
     (Quinn + nab)
   - A number of iser-target fixes related to hardening the network
     portal shutdown path (Sagi + Slava)
   - Fix response length residual handling for a number of control CDBs
     (Roland + Christophe V.)
   - Various iscsi RFC conformance fixes in the CHAP authentication path
     (Tejas and Calsoft folks + nab)
   - Return TASK_SET_FULL status for tcm_fc(FCoE) DataIn + Response
     failures (Vasu + Jun + nab)
   - Fix long-standing ABORT_TASK + session reset hang (nab)
   - Convert iser-initiator + iser-target to include T10 bytes into EDTL
     (Sagi + Or + MKP + Mike Christie)
   - Fix NULL pointer dereference regression related to XCOPY introduced
     in v3.15 + CC'ed to v3.12.y (nab)"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (34 commits)
  target: Fix NULL pointer dereference for XCOPY in target_put_sess_cmd
  vhost-scsi: Include prot_bytes into expected data transfer length
  TARGET/sbc,loopback: Adjust command data length in case pi exists on the wire
  libiscsi, iser: Adjust data_length to include protection information
  scsi_cmnd: Introduce scsi_transfer_length helper
  target: Report correct response length for some commands
  target/sbc: Check that the LBA and number of blocks are correct in VERIFY
  target/sbc: Remove sbc_check_valid_sectors()
  Target/iscsi: Fix sendtargets response pdu for iser transport
  Target/iser: Fix a wrong dereference in case discovery session is over iser
  iscsi-target: Fix ABORT_TASK + connection reset iscsi_queue_req memory leak
  target: Use complete_all for se_cmd->t_transport_stop_comp
  target: Set CMD_T_ACTIVE bit for Task Management Requests
  target: cleanup some boolean tests
  target/spc: Simplify INQUIRY EVPD=0x80
  tcm_fc: Generate TASK_SET_FULL status for response failures
  tcm_fc: Generate TASK_SET_FULL status for DataIN failures
  iscsi-target: Reject mutual authentication with reflected CHAP_C
  iscsi-target: Remove no-op from iscsit_tpg_del_portal_group
  iscsi-target: Fix CHAP_A parameter list handling
  ...