This patch adds the kernel module ib_srpt SCSI RDMA Protocol (SRP) target
implementation conforming to the SRP r16a specification for the mainline
drivers/target infrastructure.

This driver was originally developed by Vu Pham and has been optimized by
Bart Van Assche and merged into upstream LIO based on his srpt-lio-4.1
branch here:

   https://github.com/bvanassche/srpt-lio/commits/srpt-lio-4.1/

This updated patch also contains the following two changes from
lio-core-2.6.git/master.  One is to fix a bug with 1 >= task->task_sg[]
chained mappings in ib_srpt, and the other to convert the configfs control
plane to reference IB Port GUID and struct srpt_port directly following
mainline v4.x target_core_fabric_configfs.c convertion for ib_srpt
to work with rtslib/rtsadmin v2 code.

These seperate patches can be found here:

ib_srpt: Fix bug with chainged SGLs in srpt_map_sg_to_ib_sge
http://www.risingtidesystems.com/git/?p=lio-core-2.6.git;a=commitdiff;h=ea485147563b6555a97dbf811825fbb586519252

ib_srpt: Convert se_wwn endpoint reference to struct srpt_port->port_wwn
http://www.risingtidesystems.com/git/?p=lio-core-2.6.git;a=commitdiff;h=4e544a210acb227df1bb4ca5086e65bdf4e648ea

This also includes the following recent v1 -> v2 review changes:

ib_srpt: Fix potential out-of-bounds array access
ib_srpt: Avoid failed multipart RDMA transfers
ib_srpt: Fix srpt_alloc_fabric_acl failure case return value
ib_srpt: Update comments to reference $driver/$port layout
ib_srpt: Fix sport->port_guid formatting code
ib_srpt: Remove legacy use_port_guid_in_session_name module parameter
ib_srpt: Convert srp_max_rdma_size into per port configfs attribute
ib_srpt: Convert srp_max_rsp_size into per port configfs attribute
ib_srpt: Convert srpt_sq_size into per port configfs attribute

and v2 -> v3 review changes:

ib_srpt: Fix possible race with srp_sq_size in srpt_create_ch_ib
ib_srpt: Fix possible race with srp_max_rsp_size in srpt_release_channel_work
ib_srpt: Fix up MAX_SRPT_RDMA_SIZE define
ib_srpt: Make srpt_map_sg_to_ib_sge() failure case return -EAGAIN
ib_srpt: Convert port_guid to use subnet_prefix + interface_id formatting
ib_srpt: Make srpt_check_stop_free return kref_put status
ib_srpt: Make compilation with BUG=n proceed`
ib_srpt: Use new target_core_fabric.h include
ib_srpt: Check hex2bin() return code to silence build warning

Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Roland Dreier <roland@purestorage.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Vu Pham <vu@mellanox.com>
Cc: David Dillow <dillowda@ornl.gov>
Signed-off-by: Nicholas A. Bellinger <nab@risingtidesystems.com>

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

This patch removes a legacy se_dev_check_online() check from within
transport_execute_tasks() that should no longer be necessary as
transport_lookup_cmd_lun() is already making this call.

Using transport_cmd_check_stop() from transport_execute_tasks() should
already be checking per se_cmd context for each descriptor upon active
I/O shutdown, so no need to acquire dev->dev_status_lock again while
executing se_task submission.

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

This patch removes the original usage of __transport_execute_tasks() ahead
of every transport_get_cmd_from_queue() call in transport_processing_thread().
This helps reduce se_device->execute_task_lock contention between qla2xxx wq
with target_submit_cmd() for READs and transport_processing_thread()
context servicing WRITEs with full payloads for I/O submission.

It also adds a __transport_execute_tasks() to kick the task queue again
without a *se_cmd descriptor with existing queue full logic, but this may
end up not being necessary.

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

This patch makes __transport_execute_tasks() use a local *se_dev
reference to prevent direct se_cmd->se_dev access after
transport_cmd_check_stop() -> transport_add_tasks_from_cmd()
has been called, as in the current implementation we can expect
__transport_execute_tasks() may be called from another context
that may have already completed the I/O.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Remove the now unused target_core_fabric_ops->check_release_cmd() as
target_core handles this directly for se_cmd->cmd_kref objects now.

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch converts the main ft_send_work() I/O path to use
target_submit_cmd() with a single se_cmd->cmd_kref reference
that is released via the existing ft_check_stop_free() response
path callback.

It also makes ft_send_tm() use transport_init_se_cmd() and
target_get_sess_cmd() to also use single se_cmd->cmd_kref
reference.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Nicholas 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: Nicholas 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: Nicholas Bellinger <nab@linux-iscsi.org>

Current SCSI specs say that the "response format" field in the standard
INQUIRY response should be set to 2, and all the real SCSI devices I
have do put 2 here.  So let's do that too.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This includes:
- remove on _ in "__NAMELEN" in $fabric _make_tport
- target_fabric_configfs_init() returns an error pointer and not NULL
  anymore. Consider that.
- replace (!(var_name)) with (!var_name). The extra () are not required
- remove #ifdef MODULE. If the code is builtin it needs an init function
  or the code is useless
- put exit/clean functions into __exit
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch fixes TFO->release_cmd() and removes legacy pack_lun() usage
and new_cmd_failure when generating new TCM fabric skeleton from the
tcm_mod_builder.py script.
Reported-by: Stefan Bergstrand <stefan.bergstrand@sdsab.se>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

If we want dynamically allocated objects to be cacheline aligned we need
to tell that to the slab allocator by using the proper flags and not
by liberally sprinkling annotations onto all structures.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

There is not reason to artifically limit max_sectors in tcm_loop, set
it to UINT_MAX to allow stressing the large I/O handling in the target
core using the loopback driver.  Also remove various superflous defines
hiding the values set in the host template.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch strips the trailing newline from backend device udev_path and
alias attributes.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch makes chap_server_compute_md5() use proper unsigned long
usage for the CHAP_I (identifier) and check for values beyond 255 as
per RFC-1994.
Reported-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

A reader should spend an extra moment whenever noticing a cast,
because either something special is going on that deserves extra
attention or, as is all too often the case, the code is wrong.

These casts, afaics, have all been useless.  They cast a foo* to a
foo*, cast a void* to the assigned type, cast a foo* to void*, before
assigning it to a void* variable, etc.

In a few cases I also removed an additional &...[0], which is equally
useless.

Lastly I added three FIXMEs where, to the best of my judgement, the
code appears to have a bug.  It would be good if someone could check
these.
Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

- rename to target_check_cdb_and_preempt
- use non-safe list_for_each_entry
- move common check into callee (simplifying callers)
Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

And make it static afterwards.
Signed-off-by: Joern Engel <joern@logfs.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

The command
| echo rd_pages=32768 > ramdisk/control

Does not work because it writes "rd_pages=32768\n" and the parser which
matches for "rd_pages=%d" does not recognize it due to the \n. One way
of fixing this would be using "echo -n" instead.
This patch adds \n to the list of separators so we don't have to use the
-n argument which I find is more convinient.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

There is no need to make task_state_active an atomic_t given that it is
always set under the execute_task_lock so we can make it a simple bool.
Also rename it to t_state_active to be closer to the list it guards,
and make sure all checks before the list addion/removal actually happen
under execute_task_lock.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

We only reach transport_complete_task once per task, so the test and set on
task_error_status is never going to have an effect.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

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

This reorganized the headers under include/target into:

 - target_core_base.h stays as is with all target-wide data stuctures and defines
 - target_core_backend.h contains the whole interface to I/O backends
 - target_core_fabric.h contains the whole interface to fabric modules

Except for those only the various configfs macro headers stay around.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Create a new headers, drivers/target/target_core_internal.h that is supposed
to hold all target_core-internal prototypes.  Move all non-exported includes
from include/target to it, and merge the smaller prototype-only includes
inside drivers/target into it as well.  Mark functions that were found to
not be called outside their implementation file static.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

* git://git.samba.org/sfrench/cifs-2.6:
  cifs: check for NULL last_entry before calling cifs_save_resume_key
  cifs: attempt to freeze while looping on a receive attempt
  cifs: Fix sparse warning when calling cifs_strtoUCS
  CIFS: Add descriptions to the brlock cache functions

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, efi: Calling __pa() with an ioremap()ed address is invalid
  x86, hpet: Immediately disable HPET timer 1 if rtc irq is masked
  x86/intel_mid: Kconfig select fix
  x86/intel_mid: Fix the Kconfig for MID selection

* 'spi/for-3.2' of git://git.pengutronix.de/git/wsa/linux-2.6:
  spi/gpio: fix section mismatch warning
  spi/fsl-espi: disable CONFIG_SPI_FSL_ESPI=m build
  spi/nuc900: Include linux/module.h
  spi/ath79: fix compile error due to missing include

* 'for-linus' of git://neil.brown.name/md:
  md: raid5 crash during degradation
  md/raid5: never wait for bad-block acks on failed device.
  md: ensure new badblocks are handled promptly.
  md: bad blocks shouldn't cause a Blocked status on a Faulty device.
  md: take a reference to mddev during sysfs access.
  md: refine interpretation of "hold_active == UNTIL_IOCTL".
  md/lock: ensure updates to page_attrs are properly locked.

* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  arch/tile: use new generic {enable,disable}_percpu_irq() routines
  drivers/net/ethernet/tile: use skb_frag_page() API
  asm-generic/unistd.h: support new process_vm_{readv,write} syscalls
  arch/tile: fix double-free bug in homecache_free_pages()
  arch/tile: add a few #includes and an EXPORT to catch up with kernel changes.

* 'iommu/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  MAINTAINERS: Update amd-iommu F: patterns
  iommu/amd: Fix typo in kernel-parameters.txt
  iommu/msm: Fix compile error in mach-msm/devices-iommu.c
  Fix comparison using wrong pointer variable in dma debug code

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Fix lost speaker volume controls
  ALSA: hda/realtek - Create "Bass Speaker" for two speaker pins
  ALSA: hda/realtek - Don't create extra controls with channel suffix
  ALSA: hda - Fix remaining VREF mute-LED NID check in post-3.1 changes
  ALSA: hda - Fix GPIO LED setup for IDT 92HD75 codecs
  ASoC: Provide a more complete DMA driver stub
  ASoC: Remove references to corgi and spitz from machine driver document
  ASoC: Make SND_SOC_MX27VIS_AIC32X4 depend on I2C
  ASoC: Fix dependency for SND_SOC_RAUMFELD and SND_PXA2XX_SOC_HX4700
  ASoC: uda1380: Return proper error in uda1380_modinit failure path
  ASoC: kirkwood: Make SND_KIRKWOOD_SOC_OPENRD and SND_KIRKWOOD_SOC_T5325 depend on I2C
  ASoC: Mark WM8994 ADC muxes as virtual
  ALSA: hda/realtek - Fix Oops in alc_mux_select()
  ALSA: sis7019 - give slow codecs more time to reset

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Do no try to schedule task events if there are none
  lockdep, kmemcheck: Annotate ->lock in lockdep_init_map()
  perf header: Use event_name() to get an event name
  perf stat: Failure with "Operation not supported"

In order to safely dereference current->real_parent inside an
rcu_read_lock, we need an rcu_dereference.
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Modify initialization of PCIe capability registers in Tsi721 mport driver:
 - change Completion Timeout value to avoid unexpected data transfer
   aborts during intensive traffic.
 - replace hardcoded offset of PCIe capability block by making it use the
   common function.

This patch is applicable to kernel versions starting from 3.2-rc1.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Bug fix for Tsi721 RapidIO mport driver: Tsi721 supports four RapidIO
mailboxes (MBOX0 - MBOX3) as defined by RapidIO specification.  Mailbox
resources has to be properly reported to allow use of all available
mailboxes (initial version reports only MBOX0).

This patch is applicable to kernel versions staring from 3.2-rc1.
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Replace the pair dma_alloc_coherent()+memset() with the new
dma_zalloc_coherent() added by Andrew Morton for kernel version 3.2
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>