Writeback implements its own worker pool - each bdi can be associated
with a worker thread which is created and destroyed dynamically.  The
worker thread for the default bdi is always present and serves as the
"forker" thread which forks off worker threads for other bdis.

there's no reason for writeback to implement its own worker pool when
using unbound workqueue instead is much simpler and more efficient.
This patch replaces custom worker pool implementation in writeback
with an unbound workqueue.

The conversion isn't too complicated but the followings are worth
mentioning.

* bdi_writeback->last_active, task and wakeup_timer are removed.
  delayed_work ->dwork is added instead.  Explicit timer handling is
  no longer necessary.  Everything works by either queueing / modding
  / flushing / canceling the delayed_work item.

* bdi_writeback_thread() becomes bdi_writeback_workfn() which runs off
  bdi_writeback->dwork.  On each execution, it processes
  bdi->work_list and reschedules itself if there are more things to
  do.

  The function also handles low-mem condition, which used to be
  handled by the forker thread.  If the function is running off a
  rescuer thread, it only writes out limited number of pages so that
  the rescuer can serve other bdis too.  This preserves the flusher
  creation failure behavior of the forker thread.

* INIT_LIST_HEAD(&bdi->bdi_list) is used to tell
  bdi_writeback_workfn() about on-going bdi unregistration so that it
  always drains work_list even if it's running off the rescuer.  Note
  that the original code was broken in this regard.  Under memory
  pressure, a bdi could finish unregistration with non-empty
  work_list.

* The default bdi is no longer special.  It now is treated the same as
  any other bdi and bdi_cap_flush_forker() is removed.

* BDI_pending is no longer used.  Removed.

* Some tracepoints become non-applicable.  The following TPs are
  removed - writeback_nothread, writeback_wake_thread,
  writeback_wake_forker_thread, writeback_thread_start,
  writeback_thread_stop.

Everything, including devices coming and going away and rescuer
operation under simulated memory pressure, seems to work fine in my
test setup.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Jeff Moyer <jmoyer@redhat.com>

There's no user left.  Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Fengguang Wu <fengguang.wu@intel.com>

Writeback conversion to workqueue will be based on top of wq/for-3.10
branch to take advantage of custom attrs and NUMA support for unbound
workqueues.  Mainline currently contains two commits which result in
non-trivial merge conflicts with wq/for-3.10 and because
block/for-3.10/core is based on v3.9-rc3 which contains one of the
conflicting commits, we need a pre-merge-window merge anyway.  Let's
pull v3.9-rc5 into wq/for-3.10 so that the block tree doesn't suffer
from workqueue merge conflicts.

The two conflicts and their resolutions:

* e68035fb ("workqueue: convert to idr_alloc()") in mainline changes
  worker_pool_assign_id() to use idr_alloc() instead of the old idr
  interface.  worker_pool_assign_id() goes through multiple locking
  changes in wq/for-3.10 causing the following conflict.

  static int worker_pool_assign_id(struct worker_pool *pool)
  {
	  int ret;

  <<<<<<< HEAD
	  lockdep_assert_held(&wq_pool_mutex);

	  do {
		  if (!idr_pre_get(&worker_pool_idr, GFP_KERNEL))
			  return -ENOMEM;
		  ret = idr_get_new(&worker_pool_idr, pool, &pool->id);
	  } while (ret == -EAGAIN);
  =======
	  mutex_lock(&worker_pool_idr_mutex);
	  ret = idr_alloc(&worker_pool_idr, pool, 0, 0, GFP_KERNEL);
	  if (ret >= 0)
		  pool->id = ret;
	  mutex_unlock(&worker_pool_idr_mutex);
  >>>>>>> c67bf5361e7e66a0ff1f4caf95f89347d55dfb89

	  return ret < 0 ? ret : 0;
  }

  We want locking from the former and idr_alloc() usage from the
  latter, which can be combined to the following.

  static int worker_pool_assign_id(struct worker_pool *pool)
  {
	  int ret;

	  lockdep_assert_held(&wq_pool_mutex);

	  ret = idr_alloc(&worker_pool_idr, pool, 0, 0, GFP_KERNEL);
	  if (ret >= 0) {
		  pool->id = ret;
		  return 0;
	  }
	  return ret;
   }

* eb283428 ("workqueue: fix possible pool stall bug in
  wq_unbind_fn()") updated wq_unbind_fn() such that it has single
  larger for_each_std_worker_pool() loop instead of two separate loops
  with a schedule() call inbetween.  wq/for-3.10 renamed
  pool->assoc_mutex to pool->manager_mutex causing the following
  conflict (earlier function body and comments omitted for brevity).

  static void wq_unbind_fn(struct work_struct *work)
  {
  ...
		  spin_unlock_irq(&pool->lock);
  <<<<<<< HEAD
		  mutex_unlock(&pool->manager_mutex);
	  }
  =======
		  mutex_unlock(&pool->assoc_mutex);
  >>>>>>> c67bf5361e7e66a0ff1f4caf95f89347d55dfb89

		  schedule();

  <<<<<<< HEAD
	  for_each_cpu_worker_pool(pool, cpu)
  =======
  >>>>>>> c67bf5361e7e66a0ff1f4caf95f89347d55dfb89
		  atomic_set(&pool->nr_running, 0);

		  spin_lock_irq(&pool->lock);
		  wake_up_worker(pool);
		  spin_unlock_irq(&pool->lock);
	  }
  }

  The resolution is mostly trivial.  We want the control flow of the
  latter with the rename of the former.

  static void wq_unbind_fn(struct work_struct *work)
  {
  ...
		  spin_unlock_irq(&pool->lock);
		  mutex_unlock(&pool->manager_mutex);

		  schedule();

		  atomic_set(&pool->nr_running, 0);

		  spin_lock_irq(&pool->lock);
		  wake_up_worker(pool);
		  spin_unlock_irq(&pool->lock);
	  }
  }
Signed-off-by: Tejun Heo <tj@kernel.org>

workqueue: update sysfs interface to reflect NUMA awareness and a kernel param to disable NUMA affinity

Unbound workqueues are now NUMA aware.  Let's add some control knobs
and update sysfs interface accordingly.

* Add kernel param workqueue.numa_disable which disables NUMA affinity
  globally.

* Replace sysfs file "pool_id" with "pool_ids" which contain
  node:pool_id pairs.  This change is userland-visible but "pool_id"
  hasn't seen a release yet, so this is okay.

* Add a new sysf files "numa" which can toggle NUMA affinity on
  individual workqueues.  This is implemented as attrs->no_numa whichn
  is special in that it isn't part of a pool's attributes.  It only
  affects how apply_workqueue_attrs() picks which pools to use.

After "pool_ids" change, first_pwq() doesn't have any user left.
Removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Currently, an unbound workqueue has single current, or first, pwq
(pool_workqueue) to which all new work items are queued.  This often
isn't optimal on NUMA machines as workers may jump around across node
boundaries and work items get assigned to workers without any regard
to NUMA affinity.

This patch implements NUMA affinity for unbound workqueues.  Instead
of mapping all entries of numa_pwq_tbl[] to the same pwq,
apply_workqueue_attrs() now creates a separate pwq covering the
intersecting CPUs for each NUMA node which has online CPUs in
@attrs->cpumask.  Nodes which don't have intersecting possible CPUs
are mapped to pwqs covering whole @attrs->cpumask.

As CPUs come up and go down, the pool association is changed
accordingly.  Changing pool association may involve allocating new
pools which may fail.  To avoid failing CPU_DOWN, each workqueue
always keeps a default pwq which covers whole attrs->cpumask which is
used as fallback if pool creation fails during a CPU hotplug
operation.

This ensures that all work items issued on a NUMA node is executed on
the same node as long as the workqueue allows execution on the CPUs of
the node.

As this maps a workqueue to multiple pwqs and max_active is per-pwq,
this change the behavior of max_active.  The limit is now per NUMA
node instead of global.  While this is an actual change, max_active is
already per-cpu for per-cpu workqueues and primarily used as safety
mechanism rather than for active concurrency control.  Concurrency is
usually limited from workqueue users by the number of concurrently
active work items and this change shouldn't matter much.

v2: Fixed pwq freeing in apply_workqueue_attrs() error path.  Spotted
    by Lai.

v3: The previous version incorrectly made a workqueue spanning
    multiple nodes spread work items over all online CPUs when some of
    its nodes don't have any desired cpus.  Reimplemented so that NUMA
    affinity is properly updated as CPUs go up and down.  This problem
    was spotted by Lai Jiangshan.

v4: destroy_workqueue() was putting wq->dfl_pwq and then clearing it;
    however, wq may be freed at any time after dfl_pwq is put making
    the clearing use-after-free.  Clear wq->dfl_pwq before putting it.

v5: apply_workqueue_attrs() was leaking @tmp_attrs, @new_attrs and
    @pwq_tbl after success.  Fixed.

    Retry loop in wq_update_unbound_numa_attrs() isn't necessary as
    application of new attrs is excluded via CPU hotplug.  Removed.

    Documentation on CPU affinity guarantee on CPU_DOWN added.

    All changes are suggested by Lai Jiangshan.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Factor out lock pool, put_pwq(), unlock sequence into
put_pwq_unlocked().  The two existing places are converted and there
will be more with NUMA affinity support.

This is to prepare for NUMA affinity support for unbound workqueues
and doesn't introduce any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Factor out pool_workqueue linking and installation into numa_pwq_tbl[]
from apply_workqueue_attrs() into numa_pwq_tbl_install().  link_pwq()
is made safe to call multiple times.  numa_pwq_tbl_install() links the
pwq, installs it into numa_pwq_tbl[] at the specified node and returns
the old entry.

@last_pwq is removed from link_pwq() as the return value of the new
function can be used instead.

This is to prepare for NUMA affinity support for unbound workqueues.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Use kmem_cache_alloc_node() with @pool->node instead of
kmem_cache_zalloc() when allocating a pool_workqueue so that it's
allocated on the same node as the associated worker_pool.  As there's
no no kmem_cache_zalloc_node(), move zeroing to init_pwq().

This was suggested by Lai Jiangshan.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Break init_and_link_pwq() into init_pwq() and link_pwq() and move
unbound-workqueue specific handling into apply_workqueue_attrs().
Also, factor out unbound pool and pool_workqueue allocation into
alloc_unbound_pwq().

This reorganization is to prepare for NUMA affinity and doesn't
introduce any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Currently, an unbound workqueue has only one "current" pool_workqueue
associated with it.  It may have multple pool_workqueues but only the
first pool_workqueue servies new work items.  For NUMA affinity, we
want to change this so that there are multiple current pool_workqueues
serving different NUMA nodes.

Introduce workqueue->numa_pwq_tbl[] which is indexed by NUMA node and
points to the pool_workqueue to use for each possible node.  This
replaces first_pwq() in __queue_work() and workqueue_congested().

numa_pwq_tbl[] is currently initialized to point to the same
pool_workqueue as first_pwq() so this patch doesn't make any behavior
changes.

v2: Use rcu_dereference_raw() in unbound_pwq_by_node() as the function
    may be called only with wq->mutex held.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Move wq->flags and ->cpu_pwqs to the end of workqueue_struct and align
them to the cacheline.  These two fields are used in the work item
issue path and thus hot.  The scheduled NUMA affinity support will add
dispatch table at the end of workqueue_struct and relocating these two
fields will allow us hitting only single cacheline on hot paths.

Note that wq->pwqs isn't moved although it currently is being used in
the work item issue path for unbound workqueues.  The dispatch table
mentioned above will replace its use in the issue path, so it will
become cold once NUMA support is implemented.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Currently workqueue->name[] is of flexible length.  We want to use the
flexible field for something more useful and there isn't much benefit
in allowing arbitrary name length anyway.  Make it fixed len capping
at 24 bytes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Currently, when exposing attrs of an unbound workqueue via sysfs, the
workqueue_attrs of first_pwq() is used as that should equal the
current state of the workqueue.

The planned NUMA affinity support will make unbound workqueues make
use of multiple pool_workqueues for different NUMA nodes and the above
assumption will no longer hold.  Introduce workqueue->unbound_attrs
which records the current attrs in effect and use it for sysfs instead
of first_pwq()->attrs.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

When worker tasks are created using kthread_create_on_node(),
currently only per-cpu ones have the matching NUMA node specified.
All unbound workers are always created with NUMA_NO_NODE.

Now that an unbound worker pool may have an arbitrary cpumask
associated with it, this isn't optimal.  Add pool->node which is
determined by the pool's cpumask.  If the pool's cpumask is contained
inside a NUMA node proper, the pool is associated with that node, and
all workers of the pool are created on that node.

This currently only makes difference for unbound worker pools with
cpumask contained inside single NUMA node, but this will serve as
foundation for making all unbound pools NUMA-affine.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Currently, all workqueue workers which have negative nice value has
'H' postfixed to their names.  This is necessary for per-cpu workers
as they use the CPU number instead of pool->id to identify the pool
and the 'H' postfix is the only thing distinguishing normal and
highpri workers.

As workers for unbound pools use pool->id, the 'H' postfix is purely
informational.  TASK_COMM_LEN is 16 and after the static part and
delimiters, there are only five characters left for the pool and
worker IDs.  We're expecting to have more unbound pools with the
scheduled NUMA awareness support.  Let's drop the non-essential 'H'
postfix from unbound kworker name.

While at it, restructure kthread_create*() invocation to help future
NUMA related changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

Unbound workqueues are going to be NUMA-affine.  Add wq_numa_tbl_len
and wq_numa_possible_cpumask[] in preparation.  The former is the
highest NUMA node ID + 1 and the latter is masks of possibles CPUs for
each NUMA node.

This patch only introduces these.  Future patches will make use of
them.

v2: NUMA initialization move into wq_numa_init().  Also, the possible
    cpumask array is not created if there aren't multiple nodes on the
    system.  wq_numa_enabled bool added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

The scheduled NUMA affinity support for unbound workqueues would need
to walk workqueues list and pool related operations on each workqueue.

Move wq_pool_mutex locking out of get/put_unbound_pool() to their
callers so that pool operations can be performed while walking the
workqueues list, which is also protected by wq_pool_mutex.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>

apply_workqueue_attrs() wasn't freeing temp attrs variable @new_attrs
in its success path.  Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Lai Jiangshan <laijs@cn.fujitsu.com>

29c91e99 ("workqueue: implement attribute-based unbound worker_pool
management") implemented attrs based worker_pool matching.  It tried
to avoid false negative when comparing cpumasks with custom hash
function; unfortunately, the hash and comparison functions fail to
ignore CPUs which are not possible.  It incorrectly assumed that
bitmap_copy() skips leftover bits in the last word of bitmap and
cpumask_equal() ignores impossible CPUs.

This patch updates attrs->cpumask handling such that impossible CPUs
are properly ignored.

* Hash and copy functions no longer do anything special.  They expect
  their callers to clear impossible CPUs.

* alloc_workqueue_attrs() initializes the cpumask to cpu_possible_mask
  instead of setting all bits and explicit cpumask_setall() for
  unbound_std_wq_attrs[] in init_workqueues() is dropped.

* apply_workqueue_attrs() is now responsible for ignoring impossible
  CPUs.  It makes a copy of @attrs and clears impossible CPUs before
  doing anything else.
Signed-off-by: Tejun Heo <tj@kernel.org>

8864b4e5 ("workqueue: implement get/put_pwq()") implemented pwq
(pool_workqueue) refcnting which frees workqueue when the last pwq
goes away.  It determined whether it was the last pwq by testing
wq->pwqs is empty.  Unfortunately, the test was done outside wq->mutex
and multiple pwq release could race and try to free wq multiple times
leading to oops.

Test wq->pwqs emptiness while holding wq->mutex.
Signed-off-by: Tejun Heo <tj@kernel.org>

Pull slave-dmaengine fixes from Vinod Koul:
 "Two fixes for slave-dmaengine.

  The first one is for making slave_id value correct for dw_dmac and
  the other one fixes the endieness in DT parsing"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dw_dmac: adjust slave_id accordingly to request line base
  dmaengine: dw_dma: fix endianess for DT xlate function

Pull media fixes from Mauro Carvalho Chehab:
 "For a some fixes for Kernel 3.9:
   - subsystem build fix when VIDEO_DEV=y, VIDEO_V4L2=m and I2C=m
   - compilation fix for arm multiarch preventing IR_RX51 to be selected
   - regression fix at bttv crop logic
   - s5p-mfc/m5mols/exynos: a few fixes for cameras on exynos hardware"

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] [REGRESSION] bt8xx: Fix too large height in cropcap
  [media] fix compilation with both V4L2 and I2C as 'm'
  [media] m5mols: Fix bug in stream on handler
  [media] s5p-fimc: Do not attempt to disable not enabled media pipeline
  [media] s5p-mfc: Fix encoder control 15 issue
  [media] s5p-mfc: Fix frame skip bug
  [media] s5p-fimc: send valid m2m ctx to fimc_m2m_job_finish
  [media] exynos-gsc: send valid m2m ctx to gsc_m2m_job_finish
  [media] fimc-lite: Fix the variable type to avoid possible crash
  [media] fimc-lite: Initialize 'step' field in fimc_lite_ctrl structure
  [media] ir: IR_RX51 only works on OMAP2

Pull block fixes from Jens Axboe:
 "Alright, this time from 10K up in the air.

  Collection of fixes that have been queued up since the merge window
  opened, hence postponed until later in the cycle.  The pull request
  contains:

   - A bunch of fixes for the xen blk front/back driver.

   - A round of fixes for the new IBM RamSan driver, fixing various
     nasty issues.

   - Fixes for multiple drives from Wei Yongjun, bad handling of return
     values and wrong pointer math.

   - A fix for loop properly killing partitions when being detached."

* tag 'for-linus-20130331' of git://git.kernel.dk/linux-block: (25 commits)
  mg_disk: fix error return code in mg_probe()
  rsxx: remove unused variable
  rsxx: enable error return of rsxx_eeh_save_issued_dmas()
  block: removes dynamic allocation on stack
  Block: blk-flush: Fixed indent code style
  cciss: fix invalid use of sizeof in cciss_find_cfgtables()
  loop: cleanup partitions when detaching loop device
  loop: fix error return code in loop_add()
  mtip32xx: fix error return code in mtip_pci_probe()
  xen-blkfront: remove frame list from blk_shadow
  xen-blkfront: pre-allocate pages for requests
  xen-blkback: don't store dev_bus_addr
  xen-blkfront: switch from llist to list
  xen-blkback: fix foreach_grant_safe to handle empty lists
  xen-blkfront: replace kmalloc and then memcpy with kmemdup
  xen-blkback: fix dispatch_rw_block_io() error path
  rsxx: fix missing unlock on error return in rsxx_eeh_remap_dmas()
  Adding in EEH support to the IBM FlashSystem 70/80 device driver
  block: IBM RamSan 70/80 error message bug fix.
  block: IBM RamSan 70/80 branding changes.
  ...

This reverts commit 6aa97070.

Commit 6aa97070 ("lockdep: check that no locks held at freeze time")
causes problems with NFS root filesystems.  The failures were noticed on
OMAP2 and 3 boards during kernel init:

  [ BUG: swapper/0/1 still has locks held! ]
  3.9.0-rc3-00344-ga937536b #1 Not tainted
  -------------------------------------
  1 lock held by swapper/0/1:
   #0:  (&type->s_umount_key#13/1){+.+.+.}, at: [<c011e84c>] sget+0x248/0x574

  stack backtrace:
    rpc_wait_bit_killable
    __wait_on_bit
    out_of_line_wait_on_bit
    __rpc_execute
    rpc_run_task
    rpc_call_sync
    nfs_proc_get_root
    nfs_get_root
    nfs_fs_mount_common
    nfs_try_mount
    nfs_fs_mount
    mount_fs
    vfs_kern_mount
    do_mount
    sys_mount
    do_mount_root
    mount_root
    prepare_namespace
    kernel_init_freeable
    kernel_init

Although the rootfs mounts, the system is unstable.  Here's a transcript
from a PM test:

  http://www.pwsan.com/omap/testlogs/test_v3.9-rc3/20130317194234/pm/37xxevm/37xxevm_log.txt

Here's what the test log should look like:

  http://www.pwsan.com/omap/testlogs/test_v3.8/20130218214403/pm/37xxevm/37xxevm_log.txt

Mailing list discussion is here:

  http://lkml.org/lkml/2013/3/4/221

Deal with this for v3.9 by reverting the problem commit, until folks can
figure out the right long-term course of action.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: <maciej.rutecki@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ben Chan <benchan@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull SCSI target fixes from Nicholas Bellinger:
 "This includes the bug-fix for a >= v3.8-rc1 regression specific to
  iscsi-target persistent reservation conflict handling (CC'ed to
  stable), and a tcm_vhost patch to drop VIRTIO_RING_F_EVENT_IDX usage
  so that in-flight qemu vhost-scsi-pci device code can detect the
  proper vhost feature bits.

  Also, there are two more tcm_vhost patches still being discussed by
  MST and Asias for v3.9 that will be required for the in-flight qemu
  vhost-scsi-pci device patch to function properly, and that should
  (hopefully) be the last target fixes for this round."

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  target: Fix RESERVATION_CONFLICT status regression for iscsi-target special case
  tcm_vhost: Avoid VIRTIO_RING_F_EVENT_IDX feature bit

On some hardware configurations we have got the request line with the offset.
The patch introduces convert_slave_id() helper for that cases. The request line
base is came from the driver data provided by the platform_device_id table.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

As reported by Wu Fengguang's build robot tracking sparse warnings, the
dma_spec arguments in the dw_dma_xlate are already byte swapped on
little-endian platforms and must not get swapped again. This code is
currently not used anywhere, but will be used in Linux 3.10 when the
ARM SPEAr platform starts using the generic DMA DT binding.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The Adam Belay's e-mail address in MAINTAINERS under PNP SUPPORT
is not valid any more and I started to maintain that code in the
meantime as a matter of fact, so list myself as a maintainer of it
along with Bjorn and remove the Adam's entry from it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ceph fix from Sage Weil:
 "This fixes a regression introduced during the last merge window when
  mapping non-existent images."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: don't zero-fill non-image object requests

A result of ENOENT from a read request for an object that's part of
an rbd image indicates that there is a hole in that portion of the
image.  Similarly, a short read for such an object indicates that
the remainder of the read should be interpreted a full read with
zeros filling out the end of the request.

This behavior is not correct for objects that are not backing rbd
image data.  Currently rbd_img_obj_request_callback() assumes it
should be done for all objects.

Change rbd_img_obj_request_callback() so it only does this zeroing
for image objects.  Encapsulate that special handling in its own
function.  Add an assertion that the image object request is a bio
request, since we assume that (and we currently don't support any
other types).

This resolves a problem identified here:
    http://tracker.ceph.com/issues/4559

The regression was introduced by bf0d5f50.
Reported-by: Dan van der Ster <dan@vanderster.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-off-by: Sage Weil <sage@inktank.com>

Pull btrfs fixes from Chris Mason:
 "We've had a busy two weeks of bug fixing.  The biggest patches in here
  are some long standing early-enospc problems (Josef) and a very old
  race where compression and mmap combine forces to lose writes (me).
  I'm fairly sure the mmap bug goes all the way back to the introduction
  of the compression code, which is proof that fsx doesn't trigger every
  possible mmap corner after all.

  I'm sure you'll notice one of these is from this morning, it's a small
  and isolated use-after-free fix in our scrub error reporting.  I
  double checked it here."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: don't drop path when printing out tree errors in scrub
  Btrfs: fix wrong return value of btrfs_lookup_csum()
  Btrfs: fix wrong reservation of csums
  Btrfs: fix double free in the btrfs_qgroup_account_ref()
  Btrfs: limit the global reserve to 512mb
  Btrfs: hold the ordered operations mutex when waiting on ordered extents
  Btrfs: fix space accounting for unlink and rename
  Btrfs: fix space leak when we fail to reserve metadata space
  Btrfs: fix EIO from btrfs send in is_extent_unchanged for punched holes
  Btrfs: fix race between mmap writes and compression
  Btrfs: fix memory leak in btrfs_create_tree()
  Btrfs: fix locking on ROOT_REPLACE operations in tree mod log
  Btrfs: fix missing qgroup reservation before fallocating
  Btrfs: handle a bogus chunk tree nicely
  Btrfs: update to use fs_state bit

Commit 3e7fc708 ("ia64 idle: delete pm_idle") in 3.9-rc1 didn't
finish the job, leaving an un-initialized reference to (*idle)().

[ Haven't seen a crash from this - but seems like we are just being
  lucky that "idle" is zero so it does get initialized before we jump to
  randomland  - Len ]
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull arc architecture fixes from Vineet Gupta:
 "This includes fix for a serious bug in DMA mapping API, make
  allyesconfig wreckage, removal of bogus email-list placeholder in
  MAINTAINERS, a typo in ptrace helper code and last remaining changes
  for syscall ABI v3 which we are finally starting to transition-to
  internally.

  The request is late than I intended to - but I was held up with
  debugging a timer link list corruption, for which a proposed fix to
  generic timer code was sent out to lkml/tglx earlier today."

* 'for-curr' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: Fix the typo in event identifier flags used by ptrace
  arc: fix dma_address assignment during dma_map_sg()
  ARC: Remove SET_PERSONALITY (tracks cross-arch change)
  ARC: ABIv3: fork/vfork wrappers not needed in "no-legacy-syscall" ABI
  ARC: ABIv3: Print the correct ABI ver
  ARC: make allyesconfig build breakages
  ARC: MAINTAINERS update for ARC

A user reported a panic where we were panicing somewhere in
tree_backref_for_extent from scrub_print_warning.  He only captured the trace
but looking at scrub_print_warning we drop the path right before we mess with
the extent buffer to print out a bunch of stuff, which isn't right.  So fix this
by dropping the path after we use the eb if we need to.  Thanks,

Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

This patch fixes a regression introduced in v3.8-rc1 code where a failed
target_check_reservation() check in target_setup_cmd_from_cdb() was causing
an incorrect SAM_STAT_GOOD status to be returned during a WRITE operation
performed by an unregistered / unreserved iscsi initiator port.

This regression is only effecting iscsi-target due to a special case check
for TCM_RESERVATION_CONFLICT within iscsi_target_erl1.c:iscsit_execute_cmd(),
and was still correctly disallowing WRITE commands from backend submission
for unregistered / unreserved initiator ports, while returning the incorrect
SAM_STAT_GOOD status due to the missing SAM_STAT_RESERVATION_CONFLICT
assignment.

This regression was first introduced with:

commit de103c93
Author: Christoph Hellwig <hch@lst.de>
Date:   Tue Nov 6 12:24:09 2012 -0800

    target: pass sense_reason as a return value

Go ahead and re-add the missing SAM_STAT_RESERVATION_CONFLICT assignment
during a target_check_reservation() failure, so that iscsi-target code
sends the correct SCSI status.

All other fabrics using target_submit_cmd_*() with a RESERVATION_CONFLICT
call to transport_generic_request_failure() are not effected by this bug.
Reported-by: Jeff Leung <jleung@curriegrad2004.ca>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This patch adds a VHOST_SCSI_FEATURES mask minus VIRTIO_RING_F_EVENT_IDX
so that vhost-scsi-pci userspace will strip this feature bit once
GET_FEATURES reports it as being unsupported on the host.

This is to avoid a bug where ->handle_kicks() are missed when EVENT_IDX
is enabled by default in userspace code.

(mst: Rename to VHOST_SCSI_FEATURES + add comment)
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Asias He <asias@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

This reverts commit 18693050 ("mm: introduce VM_POPULATE flag to
better deal with racy userspace programs").

VM_POPULATE only has any effect when userspace plays racy games with
vmas by trying to unmap and remap memory regions that mmap or mlock are
operating on.

Also, the only effect of VM_POPULATE when userspace plays such games is
that it avoids populating new memory regions that get remapped into the
address range that was being operated on by the original mmap or mlock
calls.

Let's remove VM_POPULATE as there isn't any strong argument to mandate a
new vm_flag.
Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull USB fixes from Greg Kroah-Hartman:
 "Here are some USB fixes to resolve issues reported recently, as well
  as a new device id for the ftdi_sio driver."

* tag 'usb-3.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: ftdi_sio: Add support for Mitsubishi FX-USB-AW/-BD
  usb: Fix compile error by selecting USB_OTG_UTILS
  USB: serial: fix hang when opening port
  USB: EHCI: fix bug in iTD/siTD DMA pool allocation
  xhci: Don't warn on empty ring for suspended devices.
  usb: xhci: Fix TRB transfer length macro used for Event TRB.
  usb/acpi: binding xhci root hub usb port with ACPI
  usb: add find_raw_port_number callback to struct hc_driver()
  usb: xhci: fix build warning

Pull TTY/serial fixes from Greg Kroah-Hartman:
 "Here are some tty/serial driver fixes for 3.9.

  The big thing here is the fix for the huge mess we caused renaming the
  8250 driver accidentally in the 3.7 kernel release, without realizing
  that there were users of the module options that suddenly broke.  This
  is now resolved, and, to top the injury off, we have a backwards-
  compatible option for those users who got used to the new name since
  3.7.  Ugh, sorry about that.

  Other than that, some other minor fixes for issues that have been
  reported by users."

* tag 'tty-3.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Xilinx: ARM: UART: clear pending irqs before enabling irqs
  TTY: 8250, deprecated 8250_core.* options
  TTY: 8250, revert module name change
  serial: 8250_pci: Add WCH CH352 quirk to avoid Xscale detection
  tty: atmel_serial_probe(): index of atmel_ports[] fix