This patch converts a handful of iscsi_session statistics to type
atomic_long_t, instead of using iscsi_session->session_stats_lock
when incrementing these values.

More importantly, go ahead and drop the spinlock usage within
iscsit_setup_scsi_cmd(), iscsit_check_dataout_hdr(),
iscsit_send_datain(), and iscsit_build_rsp_pdu() fast-path code.

(Squash in Roland's  target: Remove write-only stats fields and lock
from struct se_node_acl)
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch converts the handful of se_device statistics to type
atomic_long_t, instead of using se_device->stats_lock when
incrementing these values.

More importantly, go ahead and drop the spinlock usage within
transport_lookup_cmd_lun() fast-path code.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch fixes a bug in delayed Task Aborted Status (TAS) handling,
where transport_send_task_abort() was not returning for the case
when the se_tfo->write_pending() callback indicated that last fabric
specific WRITE PDU had not yet been received.

It also adds an explicit cmd->scsi_status = SAM_STAT_TASK_ABORTED
assignment within transport_check_aborted_status() to avoid the case
where se_tfo->queue_status() is called when the SAM_STAT_TASK_ABORTED
assignment + ->queue_status() in transport_send_task_abort() does not
occur once SCF_SENT_DELAYED_TAS has been set.

Cc: <stable@vger.kernel.org> #3.2+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch adds a check to reject text commands with F_BIT=0 ||
C_BIT=1, as multi PDU text command sequences are currently
unsupported.

This avoids the case where a text command received with F_BIT=0,
was generating a text response with F_BIT=1 which is a protocol
error according to RFC-3720 Section 10.11.1.
Reported-by: Arshad Hussain <arshad.hussain@calsoftinc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch avoids a duplicate iscsit_increment_maxcmdsn() call for
ISER_IB_RDMA_WRITE within isert_map_rdma() + isert_reg_rdma_frwr(),
which will already be occuring once during isert_put_datain() ->
iscsit_build_rsp_pdu() operation.

It also removes the local conn->stat_sn assignment + increment,
and changes the third parameter to iscsit_build_rsp_pdu() to
signal this should be done by iscsi_target_mode code.
Tested-by: Moussa Ba <moussaba@micron.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch fixes a >= v3.10 regression bug with mutex_trylock() usage
within iscsit_increment_maxcmdsn(), that was originally added to allow
for a special case where ->cmdsn_mutex was already held from the
iscsit_execute_cmd() exception path for ib_isert.

When !mutex_trylock() was occuring under contention during normal RX/TX
process context codepaths, the bug was manifesting itself as the following
protocol error:

  Received CmdSN: 0x000fcbb7 is greater than MaxCmdSN: 0x000fcbb6, protocol error.
  Received CmdSN: 0x000fcbb8 is greater than MaxCmdSN: 0x000fcbb6, protocol error.

This patch simply avoids the direct ib_isert callback in lio_queue_status()
for the special iscsi_execute_cmd() exception cases, that allows the problematic
mutex_trylock() usage in iscsit_increment_maxcmdsn() to go away.
Reported-by: Moussa Ba <moussaba@micron.com>
Tested-by: Moussa Ba <moussaba@micron.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Target core does not depend on the block layer, only backstores that
use the block layer do.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

In addition to block size (already implemented), passing through
alignment offset, logical-to-phys block exponent, I/O granularity and
optimal I/O length will allow initiators to properly handle layout on
LUNs with 4K block sizes.

Tested with various weird values via scsi_debug module.

One thing to look at with this patch is the new block limits values --
instead of granularity 1 optimal 8192, Lio will now be returning whatever
the block device says, which may affect performance.
Signed-off-by: Andy Grover <agrover@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch changes isert_reg_rdma_frwr() to not use FRMR for single
dma entry requests from small I/Os, in order to avoid the associated
memory registration overhead.

Using DMA MR is sufficient here for the single dma entry requests,
and addresses a >= v3.12 performance regression.
Signed-off-by: Vu Pham <vu@mellanox.com>
Cc: <stable@vger.kernel.org> # v3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch adds a se_device->xcopy_lun that is used for local
copy offload I/O, instead of allocating + initializing a pseudo
se_lun for each received EXTENDED_COPY operation.

Also, move declaration of struct se_lun + struct se_port_stat_grps
ahead of struct se_device.
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Now with percpu refcounting for se_lun in place, go ahead and drop
the legacy per se_cmd accounting for se_lun shutdown.

This includes __transport_clear_lun_from_sessions(), the associated
transport_lun_wait_for_tasks() logic, along with a handful of now
unused se_cmd structure members and ->transport_state bits.

Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch adds percpu refcounting for se_lun access that allows the
association of an se_lun + se_cmd in transport_lookup_cmd_lun() to
occur without an extra list_head for tracking outstanding I/O during
se_lun shutdown.

This effectively changes se_lun shutdown logic to wait for outstanding
I/O percpu references to complete in transport_lun_remove_cmd() using
se_lun->lun_ref_comp, instead of explicitly draining the per se_lun
command list and waiting for individual se_cmd descriptor processing
to complete.

Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch adds EXPORT_SYMBOL() for percpu_ref_init(),
percpu_ref_cancel_init() and percpu_ref_kill_and_confirm() so
that percpu refcounting can be used by external modules.

Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch changes iscsit_check_dataout_hdr() to no longer generate
REJECTs for zero-length DataOUTs, and instead simply ignore these
requests.

This follows RFC-3720, Section 10.7.7.  DataSegmentLength

  "This is the data payload length of a SCSI Data-In or SCSI Data-Out PDU.
   The sending of 0 length data segments should be avoided, but initiators
   and targets MUST be able to properly receive 0 length data segments."
Reported-by: Santosh Kulkarni <santosh.kulkarni@calsoftinc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch adds support for completion interrupt coalescing that
allows only every ISERT_COMP_BATCH_COUNT (8) to set IB_SEND_SIGNALED,
thus avoiding completion interrupts for every posted iser_tx_desc.

The batch processing is done using a per isert_conn llist that once
IB_SEND_SIGNALED has been set is saved to tx_desc->comp_llnode_batch,
and completion processing of previously posted iser_tx_descs is done
in a single shot from within isert_send_completion() code.

Note this is only done for response PDUs from ISCSI_OP_SCSI_CMD, and
all other control type of PDU responses will force an implicit batch
drain to occur.

Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

If demo_mode_discovery=0 and generate_node_acls=0 (demo mode dislabed) do
not return TargetName+TargetAddress unless a NodeACL exists.
Signed-off-by: Thomas Glanzmann <thomas@glanzmann.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Export symbol core_tpg_check_initiator_node_acl and move prototype from the
private drivers/target/target_core_internal.h to the public
include/target/target_core_fabric.h
Signed-off-by: Thomas Glanzmann <thomas@glanzmann.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Add a new TPG attribute demo_mode_discovery which is enabled by default.
Signed-off-by: Thomas Glanzmann <thomas@glanzmann.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Implement target reset by resetting the transport status.

(nab: Remove unused ret in tcm_loop_target_reset)
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Implement TCQ support, which enables us to do proper command
abort, too.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

No functional change.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Add attribute 'transport_status' to simulate link failure.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Just a dereference, don't need a macro.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

These just want to return a pointer instead of a value, but are otherwise
the same.

ISCSI_TPG_LUN macro was unused.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

These are all straightforward.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Remove a lingering macro that just hid a dereference.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Removing unused struct percpu_ida *pool from arguements of
alloc_local_tag, changed it's one use in percpu_ida.c

(nab: Fixed reference of idr.c -> percpu_ida.c)
Signed-Off-By: Nick Swenson <nks@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch converts tcm_fc to use transport_init_session_tags()
pre-allocation logic for struct ft_cmd descriptors using per-cpu
session tag pooling in order to effectively avoid memory allocation
+ release for each received I/O.

It adds percpu_ida_alloc() in ft_recv_cmd() to obtain an tag and
locate ft_cmd from se_sess->sess_cmd_map[], and percpu_ida_free()
in ft_free_cmd() to release the tag based upon se_cmd->map_tag id.

It also uses a TCM_FC_DEFAULT_TAGS value of 512, that puts the
per se_sess->sess_cmd_map allocation at ~360K on 64-bit.

v2 changes:

  - Handle possible tag < 0 failure with GFP_ATOMIC

Cc: Mark Rustad <mark.d.rustad@intel.com>
Cc: Robert Love <robert.w.love@intel.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@daterainc.com>

Pull USB fixes from Greg KH:
 "Here are a number of USB driver fixes for 3.12-rc3.

  These are all for host controller issues that have been reported, and
  there's a fix for an annoying error message that gets printed every
  time you remove a USB 3 device from the system that's been bugging me
  for a while"

* tag 'usb-3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: dwc3: add support for Merrifield
  USB: fsl/ehci: fix failure of checking PHY_CLK_VALID during reinitialization
  USB: Fix breakage in ffs_fs_mount()
  fsl/usb: Resolve PHY_CLK_VLD instability issue for ULPI phy
  usb/core/devio.c: Don't reject control message to endpoint with wrong direction bit
  usb: chipidea: USB_CHIPIDEA should depend on HAS_DMA
  usb: chipidea: udc: free pending TD at removal procedure
  usb: chipidea: imx: Add usb_phy_shutdown at probe's error path
  usb: chipidea: Fix memleak for ci->hw_bank.regmap when removal
  usb: chipidea: udc: fix the oops after rmmod gadget
  USB: fix PM config symbol in uhci-hcd, ehci-hcd, and xhci-hcd
  USB: OHCI: accept very late isochronous URBs
  USB: UHCI: accept very late isochronous URBs
  USB: iMX21: accept very late isochronous URBs
  usbcore: check usb device's state before sending a Set SEL control transfer
  xhci: Fix race between ep halt and URB cancellation
  usb: Fix xHCI host issues on remote wakeup.
  xhci: Ensure a command structure points to the correct trb on the command ring
  xhci: Fix oops happening after address device timeout

Pull tty/serial fixes from Greg KH:
 "Here are some serial at tty driver fixes for 3.12-rc3

  The serial driver fixes some kref leaks, documentation is moved to the
  proper places, and the tty and n_tty fixes resolve some reported
  regressions.  There is still one outstanding tty regression fix that
  isn't in here yet, as I want to test it out some more, it will be sent
  for 3.12-rc4 if it checks out"

* tag 'tty-3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: ar933x_uart: move devicetree binding documentation
  tty: Fix SIGTTOU not sent with tcflush()
  n_tty: Fix EOF push index when termios changes
  serial: pch_uart: remove unnecessary tty_port_tty_get
  serial: pch_uart: fix tty-kref leak in dma-rx path
  serial: pch_uart: fix tty-kref leak in rx-error path
  serial: tegra: fix tty-kref leak

Pull staging fixes from Greg KH:
 "Here are some staging driver fixes, MAINTAINER updates, and a new
  device id.  All of these have been in the linux-next tree, and are
  pretty simple patches"

* tag 'staging-3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: r8188eu: Add new device ID
  staging: imx-drm: Fix probe failure
  staging: vt6656: [BUG] iwctl_siwencodeext return if device not open
  staging: vt6656: [BUG] main_usb.c oops on device_close move flag earlier.
  staging: vt6656: rxtx.c [BUG] s_vGetFreeContext dead lock on null apTD.
  Staging: rtl8192u: r819xU_cmdpkt: checking NULL value after doing dev_alloc_skb
  staging: usbip: Orphan usbip
  staging: r8188eu: Add files for new drive: Cocci spatch "noderef"
  staging: r8188eu: Cocci spatch "noderef"
  staging: octeon-usb: Cocci spatch "noderef"
  staging: r8188eu: Add files for new drive: Cocci spatch "noderef"
  MAINTAINERS: staging: dgnc and dgap drivers: add maintainer
  staging: lustre: Cocci spatch "noderef"

Merge tag 'driver-core-3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core / sysfs fixes from Greg KH:
 "Here are 2 fixes for 3.12-rc3.  One fixes a sysfs problem with
  mounting caused by 3.12-rc1, and the other is a bug reported by the
  chromeos developers with the driver core.

  Both have been in linux-next for a bit"

* tag 'driver-core-3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core : Fix use after free of dev->parent in device_shutdown
  sysfs: Allow mounting without CONFIG_NET

Pull char/misc driver fixes from Greg KH:
 "Here are some HyperV and MEI driver fixes for 3.12-rc3.  They resolve
  some issues that people have been reporting for them"

* tag 'char-misc-3.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Drivers: hv: vmbus: Terminate vmbus version negotiation on timeout
  Drivers: hv: util: Correctly support ws2008R2 and earlier
  mei: cancel stall timers in mei_reset
  mei: bus: stop wait for read during cl state transition
  mei: make me client counters less error prone

Pull perf revert from Ingo Molnar:
 "This fixes the 'perf top' regression Markus Trippelsdorf reported"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "perf symbols: Demangle cloned functions"

Pull drm fixes from Dave Airlie:
 "Nothing too major, radeon still has some dpm changes for off by
  default.

  Radeon, intel, msm:
   - radeon: a few more dpm fixes (still off by default), uvd fixes
   - i915: runtime warn backtrace and regression fix
   - msm: iommu changes fallout"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (27 commits)
  drm/msm: use drm_gem_dumb_destroy helper
  drm/msm: deal with mach/iommu.h removal
  drm/msm: Remove iommu include from mdp4_kms.c
  drm/msm: Odd PTR_ERR usage
  drm/i915: Fix up usage of SHRINK_STOP
  drm/radeon: fix hdmi audio on DCE3.0/3.1 asics
  drm/i915: preserve pipe A quirk in i9xx_set_pipeconf
  drm/i915/tv: clear adjusted_mode.flags
  drm/i915/dp: increase i2c-over-aux retry interval on AUX DEFER
  drm/radeon/cik: fix overflow in vram fetch
  drm/radeon: add missing hdmi callbacks for rv6xx
  drm/i915: Use a temporary va_list for two-pass string handling
  drm/radeon/uvd: lower msg&fb buffer requirements on UVD3
  drm/radeon: disable tests/benchmarks if accel is disabled
  drm/radeon: don't set default clocks for SI when DPM is disabled
  drm/radeon/dpm/ci: filter clocks based on voltage/clk dep tables
  drm/radeon/dpm/si: filter clocks based on voltage/clk dep tables
  drm/radeon/dpm/ni: filter clocks based on voltage/clk dep tables
  drm/radeon/dpm/btc: filter clocks based on voltage/clk dep tables
  drm/radeon/dpm: fetch the max clk from voltage dep tables helper
  ...

This reverts commit de95ab53.

Markus Trippelsdorf reported that this commit broke 'perf top':

 > I just see a gray screen with no text at all. Sometimes the
 > following error messages are printed:
 >
 >  *** Error in `perf': invalid fastbin entry (free): 0x00000000029b18c0
 >  ***
 >  *** Error in `perf': malloc(): memory corruption (fast): 0x0000000000ee0b10 ***

While this code is fixable, the commit itself fails on several levels:

 - it should have been a separate helper function
 - why the heck does it do strchr() twice
 - it casts a const char * over into char *
 - sloppy style
 - it's not even a regression fix!

So lets revert it and re-try the patch in v3.13.
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

A small fix + deal with fallout of iommu changes + use new
drm_gem_dumb_destroy helper.

* 'msm-fixes-3.12-rc2' of git://people.freedesktop.org/~robclark/linux:
  drm/msm: use drm_gem_dumb_destroy helper
  drm/msm: deal with mach/iommu.h removal
  drm/msm: Remove iommu include from mdp4_kms.c
  drm/msm: Odd PTR_ERR usage

Merge branches 'sched-urgent-for-linus', 'timers-urgent-for-linus' and 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler, timer and x86 fixes from Ingo Molnar:
 - A context tracking ARM build and functional fix
 - A handful of ARM clocksource/clockevent driver fixes
 - An AMD microcode patch level sysfs reporting fixlet

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  arm: Fix build error with context tracking calls

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: em_sti: Set cpu_possible_mask to fix SMP broadcast
  clocksource: of: Respect device tree node status
  clocksource: exynos_mct: Set IRQ affinity when the CPU goes online
  arm: clocksource: mvebu: Use the main timer as clock source from DT

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode/AMD: Fix patch level reporting for family 15h