This patch refactors ISCSI_OP_NOOP handling within iscsi-target in
order to handle iscsi_nopout payloads in a transport specific manner.

This includes splitting existing iscsit_handle_nop_out() into
iscsit_setup_nop_out() and iscsit_process_nop_out() calls, and
makes iscsit_handle_nop_out() be only used internally by traditional
iscsi socket calls.

Next update iser-target code to use new callers and add FIXME for
the handling iscsi_nopout payloads.  Also fix reject response handling
in iscsit_setup_nop_out() to use proper iscsit_add_reject_from_cmd().

v2: Fix uninitialized iscsit_handle_nop_out() payload_length usage (Fengguang)
v3: Remove left-over dead code in iscsit_setup_nop_out() (DanC)
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Comment from original 2012 patch:
  In all our testing this function has never returned true.  However, the
  dropping of hardware_lock necessary to call this function seems to cause
  a use-after-free we manage to hit rather frequently.  Given this
  cost-benefit ratio, I'm willing to remove some 100 lines of code.

And since the same problem exists around shutdown_sess and put_sess,
this patch changes them from taking the hardware_lock to requiring the
hardware_lock to be taken.  In most cases the caller already had the
lock and had to drop it for the called method to reacquire it.  At best
that hurts performance and in rare instances it causes races with fatal
consequences.

We dropped the original 2012 patch when upgrading our kernel and it took
us nearly half a year to discover we still need it.

(nab: Fix qla_tgt_sess reference in tcm_qla2xxx_put_sess)
Signed-off-by: Joern Engel <joern@logfs.org>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Cc: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch coverts vhost/scsi to se_cmd->cmd_kref TARGET_SCF_ACK_KREF
usage, instead of assuming that vhost_scsi_free_cmd() is always called
before TCM processing is completed in the response fast path.

This includes adding vhost_scsi_check_stop_free() -> target_put_sess_cmd()
to perform the second se_cmd->cmd_kref put, and moving vhost_scsi_free_cmd()
resource release into tcm_vhost_release_cmd() that is invoked once the last
se_cmd->cmd_kref put occurs.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Asias He <asias@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch changes vhost_scsi_free_cmd() to call transport_generic_free_cmd()
with wait_for_tasks=false in order to avoid the extra se_cmd->t_state_lock
access for the wait_for_tasks=true case.

This is unnecessary because vhost_scsi_free_cmd() is only ever called by
vhost_scsi_complete_cmd_work() after TCM completion handoff, and by
vhost_scsi_handle_vq() exception code before TCM submission handoff, so
there is never a case where se_cmd is still active from TCM's perspective
when transport_generic_free_cmd() is called.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Asias He <asias@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Now with iscsi-target using modern se_cmd->cmd_kref accounting in
v3.10 code, it's safe to go ahead and drop the legacy release
codepath + se_cmd->check_release bit in transport_release_cmd()

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

In modern iscsi-target code, the setup and I/O submission is done within a
single process context, so there is no need to acquire se_cmd->t_state_lock while
checking SCF_SUPPORTED_SAM_OPCODE for determining when unsolicited data-out
should be dumped.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch drops the se_cmd->t_state_lock access around SCF_SUPPORTED_SAM_OPCODE
assignment within target_setup_cmd_from_cdb().

Original v4.0 target code required this as fabrics would be checking for
this values in different process contexts for setup and I/O submission.

Given that modern v4.1 target code performs setup and I/O submission
from the same process context, this t_state_lock access is no longer
required.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch makes target_execute_cmd() set CMD_T_BUSY|CMD_T_SENT while
holding se_cmd->t_state_lock, in order to avoid the extra aquire/release
in __target_execute_cmd().

It also clears these bits in case of a target_handle_task_attr()
failure.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch removes legacy se_cmd->t_fe_count usage in order to avoid
se_cmd->t_state_lock access within transport_put_cmd() during normal
fast path se_cmd descriptor release.

Also drop the left-over parameter usage within core_tmr_handle_tas_abort()

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch drops an unnecessary acquire/release of se_cmd->t_state_lock within
transport_lun_remove_cmd() when checking CMD_T_DEV_ACTIVE for invoking
target_remove_from_state_list().

For all fast path completion cases, transport_lun_remove_cmd() is always
called ahead of transport_cmd_check_stop(), and since transport_cmd_check_stop()
is calling target_remove_from_state_list() when remove_from_lists=true,
the t_state_lock usage in transport_lun_remove_cmd() can safely be removed.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch adds a new transport_cmd_check_stop() parameter for signaling
when TRANSPORT_WRITE_PENDING needs to be set.

This allows transport_generic_new_cmd() to avoid the extra lock acquire/release
of ->t_state_lock in the fast path for DMA_TO_DEVICE operations ahead of
transport_cmd_check_stop() + se_tfo->write_pending().

Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

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

Nobody should be expecting to read or write virtual_lun0.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Use bool params when appropriate.

Eliminate unneeded pr_reg_e and type variables.

Just one goto label, so rename to 'out' from 'out_put_pr_reg'.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Don't need goto, we can just do an if/else for sa_res_key behavior. Move
shorter case first. Slightly shorter b/c both cases can share a call to
update_and_write_aptpl() now.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Instead of taking the buffer and length, update_and_write_aptpl() will
allocate the buffer as needed, and then free it. Instead, the function
takes an 'aptpl' boolean parameter.

This enables us to remove memory alloc/frees from struct
t10_pr_registration and other spots.

There is a slight loss of functionality because each callsite doesn't get
its own pr_debug any more, but this info can be cleaned via ftrace if
necessary and I think the shorter code is worth it.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

aptpl_file_mutex seems to no longer exist.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

As mentioned in the comments in update_and_write_aptpl,
write_aptpl_to_file() calls strlen() on the buffer, and the length was
always being passed as zero.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

It's only ever set to PR_APTPL_BUF_LEN, so we don't need a variable.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

The __ version is only ever called from the regular version, so just
inline it. It's not too much more complex to handle both spinlocks in the
same function.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Simpler to just set buf in update_and_write_aptpl(), rather than passing
down to ____core_scsi3_update_aptpl_buf().
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

They're in emulate_pro_register, so change UNREGISTER to REGISTER.

The first one seems wrong -- sa_res_key could be 0 there, but it's testing
spec_i_pt.

Remove unneeded parens  in 2nd conditional.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

We use this function exclusively in debug prints. Instead of returning
0 or 1 if isid is present, just set buf to "" if it isn't there. This
saves callers from having to check the return value.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

core_scsi3_enulate_pro_register took an 'ignore_key' parameter that
really distinguished between REGISTER and REGISTER_AND_IGNORE_EXISTING_KEY
registration types, which was a little confusing. Same situation for
PREEMPT and PREEMPT_AND_ABORT. Use enums to add a little more
descriptiveness to the code.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch fixes warnings due to missing lock on write error path.

  WARNING: at fs/hpfs/hpfs_fn.h:353 hpfs_truncate+0x75/0x80 [hpfs]()
  Hardware name: empty
  Pid: 26563, comm: dd Tainted: P           O 3.9.4 #12
  Call Trace:
    hpfs_truncate+0x75/0x80 [hpfs]
    hpfs_write_begin+0x84/0x90 [hpfs]
    _hpfs_bmap+0x10/0x10 [hpfs]
    generic_file_buffered_write+0x121/0x2c0
    __generic_file_aio_write+0x1c7/0x3f0
    generic_file_aio_write+0x7c/0x100
    do_sync_write+0x98/0xd0
    hpfs_file_write+0xd/0x50 [hpfs]
    vfs_write+0xa2/0x160
    sys_write+0x51/0xa0
    page_fault+0x22/0x30
    system_call_fastpath+0x1a/0x1f
Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: stable@kernel.org  # 2.6.39+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull timer fixes from Thomas Gleixner:

 - Trivial: unused variable removal

 - Posix-timers: Add the clock ID to the new proc interface to make it
   useful.  The interface is new and should be functional when we reach
   the final 3.10 release.

 - Cure a false positive warning in the tick code introduced by the
   overhaul in 3.10

 - Fix for a persistent clock detection regression introduced in this
   cycle

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timekeeping: Correct run-time detection of persistent_clock.
  ntp: Remove unused variable flags in __hardpps
  posix-timers: Show clock ID in proc file
  tick: Cure broadcast false positive pending bit warning

Pull irqdomain bug fixes from Grant Likely:
 "This branch contains a set of straight forward bug fixes to the
  irqdomain code and to a couple of drivers that make use of it."

* tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux:
  irqchip: Return -EPERM for reserved IRQs
  irqdomain: document the simple domain first_irq
  kernel/irq/irqdomain.c: before use 'irq_data', need check it whether valid.
  irqdomain: export irq_domain_add_simple

The irqdomain core will report a log message for any attempted map call
that fails unless the error code is -EPERM. This patch changes the
Versatile irq controller drivers to use -EPERM because it is normal for
a subset of the IRQ inputs to be marked as reserved on the various
Versatile platforms.
Signed-off-by: Grant Likely <grant.likely@linaro.org>

The first_irq needs to be zero to get a linear domain and that
comes with special semantics. We want to simplify this going
forward but some documentation never hurts.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

Since irq_data may be NULL, if so, we WARN_ON(), and continue, 'hwirq'
which related with 'irq_data' has to initialize later, or it will cause
issue.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

All other irq_domain_add_* functions are exported already, and apparently
this one got left out by mistake, which causes build errors for ARM
allmodconfig kernels:

ERROR: "irq_domain_add_simple" [drivers/gpio/gpio-rcar.ko] undefined!
ERROR: "irq_domain_add_simple" [drivers/gpio/gpio-em.ko] undefined!
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

Pull ARM SoC fixes from Olof Johansson:
 "Another week, another batch of fixes for arm-soc platforms.

  Nothing controversial here, a handful of fixes for regressions and/or
  serious problems across several of the platforms.  Things are slowing
  down nicely on fix rates for 3.10"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: exynos: add debug_ll_io_init() call in exynos_init_io()
  ARM: EXYNOS: uncompress - print debug messages if DEBUG_LL is defined
  ARM: shmobile: sh73a0: Update CMT clockevent rating to 80
  sh-pfc: r8a7779: Don't group USB OVC and PENC pins
  ARM: mxs: icoll: Fix interrupts gpio bank 0
  ARM: imx: clk-imx6q: AXI clock select index is incorrect
  ARM: bcm2835: override the HW UART periphid
  ARM: mvebu: Fix bug in coherency fabric low level init function
  ARM: Kirkwood: TS219: Fix crash by double PCIe instantiation
  ARM: ux500: Provide supplies for AUX1, AUX2 and AUX3
  ARM: ux500: Only configure wake-up reasons on ux500 based platforms
  ARM: dts: imx: fix clocks for cspi
  ARM i.MX6q: fix for ldb_di_sels

Pull MIPS fixes from Ralf Baechle:
 "MIPS fixes across the field.  The only area that's standing out is the
  exception handling which received it's dose of breakage as part of the
  microMIPS patchset"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: ralink: add missing SZ_1M multiplier
  MIPS: Compat: Fix cputime_to_timeval() arguments in compat binfmt_elf.
  MIPS: OCTEON: Improve _machine_halt implementation.
  MIPS: rtlx: Fix implicit declaration of function set_vi_handler()
  MIPS: Trap exception handling fixes
  MIPS: Quit exposing Kconfig symbols in uapi headers.
  MIPS: Remove duplicate definition of check_for_high_segbits.

Pull m68knommu fix from Greg Ungerer:
 "A single fix for compilation breakage to many of the ColdFire CPU
  targets"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
  m68k: only use local gpio_request_one if not using GPIOLIB

Pull drm fixes from Dave Airlie:
 "Regression fixers for the big 3:

   - nouveau: hdmi audio, dac load detect, s/r regressions fixed
   - radeon: long standing system hang fixed, hdmi audio and rs780 fast
     fb fixes
   - intel: one old regression, a WARN removal, and a stop X dying fix

  Otherwise one mgag200 fix, a couple of arm build fixes, and a core use
  after free fix."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/nv50/kms: use dac loadval from vbios, where it's available
  drm/nv50/disp: force dac power state during load detect
  drm/nv50-nv84/fifo: fix resume regression introduced by playlist race fix
  drm/nv84/disp: Fix HDMI audio regression
  drm/i915/sdvo: Use &intel_sdvo->ddc instead of intel_sdvo->i2c for DDC.
  drm/radeon: don't allow audio on DCE6
  drm/radeon: Use direct mapping for fast fb access on RS780/RS880 (v2)
  radeon: Fix system hang issue when using KMS with older cards
  drm/i915: no lvds quirk for hp t5740
  drm/i915: Quirk the pipe A quirk in the modeset state checker
  drm/i915: Fix spurious -EIO/SIGBUS on wedged gpus
  drm/mgag200: Add missing write to index before accessing data register
  drm/nouveau: use mdelay instead of large udelay constants
  drm/tilcd: select BACKLIGHT_LCD_SUPPORT
  drm: fix a use-after-free when GPU acceleration disabled

Pull slave-dmaengine fixes from Vinod Koul:
 "Fix from Andy is for dmatest regression reported by Will and Rabin has
  fixed runtime ref counting for st_dma40"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dmatest: do not allow to interrupt ongoing tests
  dmaengine: ste_dma40: fix pm runtime ref counting

Merge tag 'trace-fixes-v3.10-rc3-v3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "This contains 4 fixes.

  The first two fix the case where full RCU debugging is enabled,
  enabling function tracing causes a live lock of the system.  This is
  due to the added debug checks in rcu_dereference_raw() that is used by
  the function tracer.  These checks are also traced by the function
  tracer as well as cause enough overhead to the function tracer to slow
  down the system enough that the time to finish an interrupt can take
  longer than when the next interrupt is triggered, causing a live lock
  from the timer interrupt.

  Talking this over with Paul McKenney, we came up with a fix that adds
  a new rcu_dereference_raw_notrace() that does not perform these added
  checks, and let the function tracer use that.

  The third commit fixes a failed compile when branch tracing is
  enabled, due to the conversion of the trace_test_buffer() selftest
  that the branch trace wasn't converted for.

  The forth patch fixes a bug caught by the RCU lockdep code where a
  rcu_read_lock() is performed when rcu is disabled (either going to or
  from idle, or user space).  This happened on the irqsoff tracer as it
  calls task_uid().  The fix here was to use current_uid() when possible
  that doesn't use rcu locking.  Which luckily, is always used when
  irqsoff calls this code."

* tag 'trace-fixes-v3.10-rc3-v3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Use current_uid() for critical time tracing
  tracing: Fix bad parameter passed in branch selftest
  ftrace: Use the rcu _notrace variants for rcu_dereference_raw() and friends
  rcu: Add _notrace variation of rcu_dereference_raw() and hlist_for_each_entry_rcu()

Commit 9f29ab11 ("ACPI / scan: do not match drivers against objects
having scan handlers") introduced a boot regression on Tony's ia64 HP
rx2600.  Tony says:

  "It panics with the message:

   Kernel panic - not syncing: Unable to find SBA IOMMU: Try a generic or DIG kernel

   [...] my problem comes from arch/ia64/hp/common/sba_iommu.c
   where the code in sba_init() says:

        acpi_bus_register_driver(&acpi_sba_ioc_driver);
        if (!ioc_list) {

   but because of this change we never managed to call ioc_init()
   so ioc_list doesn't get set up, and we die."

Revert it to avoid this breakage and we'll fix the problem it attempted
to address later.
Reported-by: Tony Luck <tony.luck@gmail.com>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

From Shawn Guo, mxs fixes for 3.10:

- Since the time we move to MULTI_IRQ_HANDLER, the 0x7f polling for no
  interrupt in icoll_handle_irq() becomes insane, because 0x7f is an
  valid interrupt number, the irq of gpio bank 0.  That unnecessary
  polling results in the driver not detecting when irq 0x7f is active
  which makes the machine effectively dead lock.  The fix removes the
  interrupt poll loop and allows usage of gpio0 interrupt without an
  infinite loop.

* tag 'mxs-fixes-3.10' of git://git.linaro.org/people/shawnguo/linux-2.6:
  ARM: mxs: icoll: Fix interrupts gpio bank 0
Signed-off-by: Olof Johansson <olof@lixom.net>