Tejun reported stuttering and latency spikes on a system where random
tasks would enter direct reclaim and get stuck on dirty pages.  Around
50% of memory was occupied by tmpfs backed by an SSD, and another disk
(rotating) was reading and writing at max speed to shrink a partition.

: The problem was pretty ridiculous.  It's a 8gig machine w/ one ssd and 10k
: rpm harddrive and I could reliably reproduce constant stuttering every
: several seconds for as long as buffered IO was going on on the hard drive
: either with tmpfs occupying somewhere above 4gig or a test program which
: allocates about the same amount of anon memory.  Although swap usage was
: zero, turning off swap also made the problem go away too.
:
: The trigger conditions seem quite plausible - high anon memory usage w/
: heavy buffered IO and swap configured - and it's highly likely that this
: is happening in the wild too.  (this can happen with copying large files
: to usb sticks too, right?)

This patch (of 2):

The dirty_balance_reserve is an approximation of the fraction of free
pages that the page allocator does not make available for page cache
allocations.  As a result, it has to be taken into account when
calculating the amount of "dirtyable memory", the baseline to which
dirty_background_ratio and dirty_ratio are applied.

However, currently the reserve is subtracted from the sum of free and
reclaimable pages, which is non-sensical and leads to erroneous results
when the system is dominated by unreclaimable pages and the
dirty_balance_reserve is bigger than free+reclaimable.  In that case, at
least the already allocated cache should be considered dirtyable.

Fix the calculation by subtracting the reserve from the amount of free
pages, then adding the reclaimable pages on top.

[akpm@linux-foundation.org: fix CONFIG_HIGHMEM build]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Tejun Heo <tj@kernel.org>
Tested-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Prior to commit fe35004f ("mm: avoid swapping out with
swappiness==0") setting swappiness to 0, reclaim code could still evict
recently used user anonymous memory to swap even though there is a
significant amount of RAM used for page cache.

The behaviour of setting swappiness to 0 has since changed.  When set,
the reclaim code does not initiate swap until the amount of free pages
and file-backed pages, is less than the high water mark in a zone.

Let's update the documentation to reflect this.

[akpm@linux-foundation.org: remove comma, per Randy]
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Bryn M. Reeves <bmr@redhat.com>
Cc: Satoru Moriya <satoru.moriya@hds.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In the gen_pool_dma_alloc() the dma pointer can be NULL and while
assigning gen_pool_virt_to_phys(pool, vaddr) to dma caused the following
crash on da850 evm:

   Unable to handle kernel NULL pointer dereference at virtual address 00000000
   Internal error: Oops: 805 [#1] PREEMPT ARM
   Modules linked in:
   CPU: 0 PID: 1 Comm: swapper Tainted: G        W    3.13.0-rc1-00001-g0609e45-dirty #5
   task: c4830000 ti: c4832000 task.ti: c4832000
   PC is at gen_pool_dma_alloc+0x30/0x3c
   LR is at gen_pool_virt_to_phys+0x74/0x80
   Process swapper, call trace:
     gen_pool_dma_alloc+0x30/0x3c
     davinci_pm_probe+0x40/0xa8
     platform_drv_probe+0x1c/0x4c
     driver_probe_device+0x98/0x22c
     __driver_attach+0x8c/0x90
     bus_for_each_dev+0x6c/0x8c
     bus_add_driver+0x124/0x1d4
     driver_register+0x78/0xf8
     platform_driver_probe+0x20/0xa4
     davinci_init_late+0xc/0x14
     init_machine_late+0x1c/0x28
     do_one_initcall+0x34/0x15c
     kernel_init_freeable+0xe4/0x1ac
     kernel_init+0x8/0xec

This patch fixes the above.

[akpm@linux-foundation.org: update kerneldoc]
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Nicolin Chen <b42378@freescale.com>
Cc: Joe Perches <joe@perches.com>
Cc: Sachin Kamat <sachin.kamat@linaro.org>
Cc: <stable@vger.kernel.org>	[3.13.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull MTD updates from Brian Norris:
 - Add me (Brian Norris) as an additional MTD maintainer (it'd be nice to get
   David's "ack" for this; I'm sure he approves, but he's been pretty silent
   lately)
 - Add Ezequiel Garcie as maintainer for the pxa3xx NAND driver
 - Last (?) round of pxa3xx improvements for supporting Armada 370/XP
 - Typical churn in driver boilerplate (OOM messages, printk()'s, devm_*, etc.)
 - Quad read mode support for SPI NOR driver (m25p80)
 - Update Davinci NAND driver to prepare for use on new platforms
 - Begin to kill off NAND_MAX_{PAGE,OOB}SIZE macros; more work is pending
 - Miscellaneous NAND device support (new IDs)
 - Add READ RETRY support for Micron MLC NAND
 - Support new GPMI NAND ECC layout device-tree binding
 - Avoid mapping stack/vmalloc() memory for GPMI NAND DMA

* tag 'for-linus-20140127' of git://git.infradead.org/linux-mtd: (151 commits)
  mtd: gpmi: add sanity check when mapping DMA for read_buf/write_buf
  mtd: gpmi: allocate a proper buffer for non ECC read/write
  mtd: m25p80: Set rx_nbits for Quad SPI transfers
  mtd: m25p80: Enable Quad SPI read transfers for s25fl512s
  mtd: s3c2410: Merge plat/regs-nand.h into s3c2410.c
  mtd: mtdram: add missing 'const'
  mtd: m25p80: assign default read command
  mtd: nuc900_nand: remove redundant return value check of platform_get_resource()
  mtd: plat_nand: remove redundant return value check of platform_get_resource()
  mtd: nand: add Intel manufacturer ID
  mtd: nand: add SanDisk manufacturer ID
  mtd: nand: add support for Samsung K9LCG08U0B
  mtd: nand: pxa3xx: Add support for 2048 bytes page size devices
  mtd: m25p80: Use OPCODE_QUAD_READ_4B for 4-byte addressing
  mtd: nand: don't use {read,write}_buf for 8-bit transfers
  mtd: nand: use __packed shorthand
  mtd: nand: support Micron READ RETRY
  mtd: nand: add generic READ RETRY support
  mtd: nand: add ONFI vendor block for Micron
  mtd: nand: localize ECC failures per page
  ...

Pull LED subsystem update from Bryan Wu:
 "Basically this cycle is mostly cleanup for LED subsystem"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds:
  leds: s3c24xx: Remove hardware.h inclusion
  leds: replace list_for_each with list_for_each_entry
  leds: kirkwood: Cleanup in header files
  leds: pwm: Remove a warning on non-DT platforms
  leds: leds-pwm: fix duty time overflow.
  leds: leds-mc13783: Remove unneeded mc13xxx_{un}lock
  leds: leds-mc13783: Remove duplicate field in platform data
  drivers: leds: leds-tca6507: check CONFIG_GPIOLIB whether defined for 'gpio_base'
  leds: lp5523: Support LED MUX configuration on running a pattern
  leds: lp5521/5523: Fix multiple engine usage bug
  LEDS: tca6507 - fix up some comments.
  LEDS: tca6507: add device-tree support for GPIO configuration.
  LEDS: tca6507 - fix bugs in parsing of device-tree configuration.

Pull serial fixes from Greg KH:
 "Here are tiny and assorted serial driver fixes that have been in a
  branch in my tree for a while and somehow did not get properly merged
  into my big TTY / Serial pull request for 3.14-rc1.  Sorry about that.

  All have been in linux-next for a while with no issues"

* tag 'tty-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: xuartps: Properly guard sysrq specific code
  serial: 8250: Fix initialisation of Quatech cards with the AMCC PCI chip
  serial: icom: dereference after free in load_code()
  serial: 8250_dw: add new ACPI IDs
  tty: serial: pch: don't crash if DMA enabled but not loaded
  serial: samsung: move clock deactivation below uart registration

Pull more clock framework changes from Mike Turquette:
 "The second half of the clock framework pull requeust for 3.14 is
  dominated by platform support for Qualcomm's MSM SoCs, DT binding
  updates for TI's OMAP-ish processors and additional support for
  Samsung chips.

  Additionally there are other smaller clock driver changes and several
  last minute fixes.  This pull request also includes the HiSilicon
  support that depends on the already-merged arm-soc pull request"

[ Fix up stupid compile error in the source tree with evil merge  - Grumpy Linus ]

* tag 'clk-for-linus-3.14-part2' of git://git.linaro.org/people/mike.turquette/linux: (49 commits)
  clk: sort Makefile
  clk: sunxi: fix overflow when setting up divided factors
  clk: Export more clk-provider functions
  dt-bindings: qcom: Fix warning with duplicate dt define
  clk: si5351: remove variant from platform_data
  clk: samsung: Remove unneeded semicolon
  clk: qcom: Fix modular build
  ARM: OMAP3: use DT clock init if DT data is available
  ARM: AM33xx: remove old clock data and link in new clock init code
  ARM: AM43xx: Enable clock init
  ARM: OMAP: DRA7: Enable clock init
  ARM: OMAP4: remove old clock data and link in new clock init code
  ARM: OMAP2+: io: use new clock init API
  ARM: OMAP2+: PRM: add support for initializing PRCM clock modules from DT
  ARM: OMAP3: hwmod: initialize clkdm from clkdm_name
  ARM: OMAP: hwmod: fix an incorrect clk type cast with _get_clkdm
  ARM: OMAP2+: clock: use driver API instead of direct memory read/write
  ARM: OMAP2+: clock: add support for indexed memmaps
  ARM: dts: am43xx clock data
  ARM: dts: AM35xx: use DT clock data
  ...

Pull second xfs update from Ben Myers:
 "Allow logical sector sized direct io on 'advanced format' 4k/512 disk"

* tag 'xfs-for-linus-v3.14-rc1-2' of git://oss.sgi.com/xfs/xfs:
  xfs: allow logical-sector sized O_DIRECT
  xfs: rename xfs_buftarg structure members
  xfs: clean up xfs_buftarg

The previous ceph-client merge resulted in ceph not even building,
because there was a merge conflict that wasn't visible as an actual data
conflict: commit 7221fe4c ("ceph: add acl for cephfs") added support
for POSIX ACL's into Ceph, but unluckily we also had the VFS tree change
a lot of the POSIX ACL helper functions to be much more helpful to
filesystems (see for example commits 2aeccbe9 "fs: add generic
xattr_acl handlers", 5bf3258f "fs: make posix_acl_chmod more useful"
and 37bc1539 "fs: make posix_acl_create more useful")

The reason this conflict wasn't obvious was many-fold: because it was a
semantic conflict rather than a data conflict, it wasn't visible in the
git merge as a conflict.  And because the VFS tree hadn't been in
linux-next, people hadn't become aware of it that way.  And because I
was at jury duty this morning, I was using my laptop and as a result not
doing constant "allmodconfig" builds.

Anyway, this fixes the build and generally removes a fair chunk of the
Ceph POSIX ACL support code, since the improved helpers seem to match
really well for Ceph too.  But I don't actually have any way to *test*
the end result, and I was really hoping for some ACK's for this.  Oh,
well.

Not compiling certainly doesn't make things easier to test, so I'm
committing this without the acks after having waited for four hours...
Plus it's what I would have done for the merge had I noticed the
semantic conflict..
Reported-by: Dave Jones <davej@redhat.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Guangliang Zhao <lucienchao@gmail.com>
Cc: Li Wang <li.wang@ubuntykylin.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ceph updates from Sage Weil:
 "This is a big batch.  From Ilya we have:

   - rbd support for more than ~250 mapped devices (now uses same scheme
     that SCSI does for device major/minor numbering)
   - crush updates for new mapping behaviors (will be needed for coming
     erasure coding support, among other things)
   - preliminary support for tiered storage pools

  There is also a big series fixing a pile cephfs bugs with clustered
  MDSs from Yan Zheng, ACL support for cephfs from Guangliang Zhao, ceph
  fscache improvements from Li Wang, improved behavior when we get
  ENOSPC from Josh Durgin, some readv/writev improvements from
  Majianpeng, and the usual mix of small cleanups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (76 commits)
  ceph: cast PAGE_SIZE to size_t in ceph_sync_write()
  ceph: fix dout() compile warnings in ceph_filemap_fault()
  libceph: support CEPH_FEATURE_OSD_CACHEPOOL feature
  libceph: follow redirect replies from osds
  libceph: rename ceph_osd_request::r_{oloc,oid} to r_base_{oloc,oid}
  libceph: follow {read,write}_tier fields on osd request submission
  libceph: add ceph_pg_pool_by_id()
  libceph: CEPH_OSD_FLAG_* enum update
  libceph: replace ceph_calc_ceph_pg() with ceph_oloc_oid_to_pg()
  libceph: introduce and start using oid abstraction
  libceph: rename MAX_OBJ_NAME_SIZE to CEPH_MAX_OID_NAME_LEN
  libceph: move ceph_file_layout helpers to ceph_fs.h
  libceph: start using oloc abstraction
  libceph: dout() is missing a newline
  libceph: add ceph_kv{malloc,free}() and switch to them
  libceph: support CEPH_FEATURE_EXPORT_PEER
  ceph: add imported caps when handling cap export message
  ceph: add open export target session helper
  ceph: remove exported caps when handling cap import message
  ceph: handle session flush message
  ...

Pull exofs and ore fixes from Boaz Harrosh:
 "The main fix here, the first patch, is also destined for -stable.  The
  rest is small trivia and cosmetics.  The ORE patches effect both exofs
  and pnfs-objects very reproducible bugs"

[ ORE is "object raid engine", used by exofs and pnfs  - Linus ]

* 'for-linus' of git://git.open-osd.org/linux-open-osd:
  exofs: Print less in r4w
  exofs: Allow corrupted directory entry to be empty file
  exofs: Allow O_DIRECT open
  ore: Don't crash on NULL bio in _clear_bio
  ore: Fix wrong math in allocation of per device BIO

Use min_t(size_t, ...) instead of plain min(), which does strict type
checking, to avoid compile warning on i386.

Cc: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

PAGE_CACHE_SIZE is unsigned long on all architectures, however size_t
is either unsigned int or unsigned long.  Rather than change format
strings, cast PAGE_CACHE_SIZE to size_t to be in line with dout()s in
ceph_page_mkwrite().

Cc: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

Pull microblaze patches from Michal Simek:
 - add CCF support
 - fix BS=0 compilation
 - wire up defconfig
 - some minor cleanups and fixes

* tag 'microblaze-3.14-rc1' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Add missing v8.50.a version
  microblaze: Fix missing bracket in printk
  microblaze: Fix compilation error for BS=0
  microblaze: Disable stack protection from bootloader
  microblaze: Define read/write{b,w,l}_relaxed MMIO
  microblaze: timer: Do not initialized system timer twice
  microblaze: timer: Use generic sched_clock implementation
  microblaze: Add NOTES section to linker script
  microblaze: Add support for CCF
  microblaze: Simplify fcpu helper function
  microblaze/uapi: Use Kbuild logic to include <asm-generic/types.h>
  microblaze: Remove duplicate declarations of _stext[] and _etext[]
  microblaze: Remove _fdt_start casts
  microblaze: Wire up defconfig to mmu_defconfig

Pull s390 patches from Martin Schwidefsky:
 "A new binary interface to be able to query and modify the LPAR
  scheduler weight and cap settings.  Some improvements for the hvc
  terminal over iucv and a couple of bux fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/hypfs: add interface for diagnose 0x304
  s390: wire up sys_sched_setattr/sys_sched_getattr
  s390/uapi: fix struct statfs64 definition
  s390/uaccess: remove dead extern declarations, make functions static
  s390/uaccess: test if current->mm is set before walking page tables
  s390/zfcpdump: make zfcpdump depend on 64BIT
  s390/32bit: fix cmpxchg64
  s390/xpram: don't modify module parameters
  s390/zcrypt: remove zcrypt kmsg documentation again
  s390/hvc_iucv: Automatically assign free HVC terminal devices
  s390/hvc_iucv: Display connection details through device attributes
  s390/hvc_iucv: fix sparse warning
  s390/vmur: Link parent CCW device during UR device creation

Pull cris fix from Jesper Nilsson:
 "One include too much was removed"

* tag 'cris-correction-for-3.14' of git://jni.nu/cris:
  CRISv10: Readd missing header

Pull ext4 update from Ted Ts'o:
 "Bug fixes and cleanups for ext4.  We also enable the punch hole
  functionality for bigalloc file systems"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: delete "set but not used" variables
  ext4: don't pass freed handle to ext4_walk_page_buffers
  ext4: avoid clearing beyond i_blocks when truncating an inline data file
  ext4: ext4_inode_is_fast_symlink should use EXT4_CLUSTER_SIZE
  ext4: fix a typo in extents.c
  ext4: use %pd printk specificer
  ext4: standardize error handling in ext4_da_write_inline_data_begin()
  ext4: retry allocation when inline->extent conversion failed
  ext4: enable punch hole for bigalloc

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

   - stable fix for an infinite loop in RPC state machine
   - stable fix for a use after free situation in the NFSv4 trunking discovery
   - stable fix for error handling in the NFSv4 trunking discovery
   - stable fix for the page write update code
   - stable fix for the NFSv4.1 mount time security negotiation
   - stable fix for the NFSv4 open code.
   - O_DIRECT locking fixes
   - fix an Oops in the pnfs file commit code
   - RPC layer needs finer grained handling of connection errors
   - more RPC GSS upcall fixes"

* tag 'nfs-for-3.14-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (30 commits)
  pnfs: Proper delay for NFS4ERR_RECALLCONFLICT in layout_get_done
  pnfs: fix BUG in filelayout_recover_commit_reqs
  nfs4: fix discover_server_trunking use after free
  NFSv4.1: Handle errors correctly in nfs41_walk_client_list
  nfs: always make sure page is up-to-date before extending a write to cover the entire page
  nfs: page cache invalidation for dio
  nfs: take i_mutex during direct I/O reads
  nfs: merge nfs_direct_write into nfs_file_direct_write
  nfs: merge nfs_direct_read into nfs_file_direct_read
  nfs: increment i_dio_count for reads, too
  nfs: defer inode_dio_done call until size update is done
  nfs: fix size updates for aio writes
  nfs4.1: properly handle ENOTSUP in SECINFO_NO_NAME
  NFSv4.1: Fix a race in nfs4_write_inode
  NFSv4.1: Don't trust attributes if a pNFS LAYOUTCOMMIT is outstanding
  point to the right include file in a comment (left over from a9004abc)
  NFS: dprintk() should not print negative fileids and inode numbers
  nfs: fix dead code of ipv6_addr_scope
  sunrpc: Fix infinite loop in RPC state machine
  SUNRPC: Add tracepoint for socket errors
  ...

Pull vfs updates from Al Viro:
 "Assorted stuff; the biggest pile here is Christoph's ACL series.  Plus
  assorted cleanups and fixes all over the place...

  There will be another pile later this week"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (43 commits)
  __dentry_path() fixes
  vfs: Remove second variable named error in __dentry_path
  vfs: Is mounted should be testing mnt_ns for NULL or error.
  Fix race when checking i_size on direct i/o read
  hfsplus: remove can_set_xattr
  nfsd: use get_acl and ->set_acl
  fs: remove generic_acl
  nfs: use generic posix ACL infrastructure for v3 Posix ACLs
  gfs2: use generic posix ACL infrastructure
  jfs: use generic posix ACL infrastructure
  xfs: use generic posix ACL infrastructure
  reiserfs: use generic posix ACL infrastructure
  ocfs2: use generic posix ACL infrastructure
  jffs2: use generic posix ACL infrastructure
  hfsplus: use generic posix ACL infrastructure
  f2fs: use generic posix ACL infrastructure
  ext2/3/4: use generic posix ACL infrastructure
  btrfs: use generic posix ACL infrastructure
  fs: make posix_acl_create more useful
  fs: make posix_acl_chmod more useful
  ...

The svinto architecture header was mistakenly removed,
leading to a compile error.
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>

The buffer pointer passed from the upper layer may points to
a buffer in the stack or a buffer allocated by vmalloc, and etc..

This patch adds more sanity check to this buffer.
After this patch, if we meet a buffer which is allocated by vmalloc or
a buffer in the stack, we will use our own DMA buffer @data_buffer_dma
to do the DMA operations. If the buffer is not the cases above, we will
map it for DMA operations directly.
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The @data_buffer_dma buffer is used for non ECC read/write.

Currently, the length of the buffer is PAGE_SIZE, but the NAND chip may
has 8K page or 16K page. So we have to extend it for the large page NAND
chips.

The gpmi_alloc_dma_buffer will be called twice. The first time is to
allocate a temporary buffer for scanning the NAND chip; The second time
is to allocate a buffer to store the real page content.

This patch allocates a buffer of PAGE_SIZE size for scanning the NAND
chip when gpmi_alloc_dma_buffer is called the first time, and allocates a
buffer of the real NAND page size for the second time gpmi_alloc_dma_buffer
is called.
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

When using the Quad Read opcode, SPI masters still use Single SPI
transfers, as spi_transfer.rx_nbits defaults to SPI_NBITS_SINGLE.
Use SPI_NBITS_QUAD to fix this.

While an earlier version of commit 3487a639
("drivers: mtd: m25p80: add quad read support") did this correctly, it was
forgotten in the version that got merged.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Spansion s25fl512s supports Quad SPI transfers, hence set the
M25P80_QUAD_READ flag.
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Merge misc updates from Andrew Morton:

 - a few hotfixes

 - dynamic-debug updates

 - ipc updates

 - various other sweepings off the factory floor

* akpm: (31 commits)
  firmware/google: drop 'select EFI' to avoid recursive dependency
  compat: fix sys_fanotify_mark
  checkpatch.pl: check for function declarations without arguments
  mm/migrate.c: fix setting of cpupid on page migration twice against normal page
  softirq: use const char * const for softirq_to_name, whitespace neatening
  softirq: convert printks to pr_<level>
  softirq: use ffs() in __do_softirq()
  kernel/kexec.c: use vscnprintf() instead of vsnprintf() in vmcoreinfo_append_str()
  splice: fix unexpected size truncation
  ipc: fix compat msgrcv with negative msgtyp
  ipc,msg: document barriers
  ipc: delete seq_max field in struct ipc_ids
  ipc: simplify sysvipc_proc_open() return
  ipc: remove useless return statement
  ipc: remove braces for single statements
  ipc: standardize code comments
  ipc: whitespace cleanup
  ipc: change kern_ipc_perm.deleted type to bool
  ipc: introduce ipc_valid_object() helper to sort out IPC_RMID races
  ipc/sem.c: avoid overflow of semop undo (semadj) value
  ...

Pull powerpc updates from Ben Herrenschmidt:
 "So here's my next branch for powerpc.  A bit late as I was on vacation
  last week.  It's mostly the same stuff that was in next already, I
  just added two patches today which are the wiring up of lockref for
  powerpc, which for some reason fell through the cracks last time and
  is trivial.

  The highlights are, in addition to a bunch of bug fixes:

   - Reworked Machine Check handling on kernels running without a
     hypervisor (or acting as a hypervisor).  Provides hooks to handle
     some errors in real mode such as TLB errors, handle SLB errors,
     etc...

   - Support for retrieving memory error information from the service
     processor on IBM servers running without a hypervisor and routing
     them to the memory poison infrastructure.

   - _PAGE_NUMA support on server processors

   - 32-bit BookE relocatable kernel support

   - FSL e6500 hardware tablewalk support

   - A bunch of new/revived board support

   - FSL e6500 deeper idle states and altivec powerdown support

  You'll notice a generic mm change here, it has been acked by the
  relevant authorities and is a pre-req for our _PAGE_NUMA support"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (121 commits)
  powerpc: Implement arch_spin_is_locked() using arch_spin_value_unlocked()
  powerpc: Add support for the optimised lockref implementation
  powerpc/powernv: Call OPAL sync before kexec'ing
  powerpc/eeh: Escalate error on non-existing PE
  powerpc/eeh: Handle multiple EEH errors
  powerpc: Fix transactional FP/VMX/VSX unavailable handlers
  powerpc: Don't corrupt transactional state when using FP/VMX in kernel
  powerpc: Reclaim two unused thread_info flag bits
  powerpc: Fix races with irq_work
  Move precessing of MCE queued event out from syscall exit path.
  pseries/cpuidle: Remove redundant call to ppc64_runlatch_off() in cpu idle routines
  powerpc: Make add_system_ram_resources() __init
  powerpc: add SATA_MV to ppc64_defconfig
  powerpc/powernv: Increase candidate fw image size
  powerpc: Add debug checks to catch invalid cpu-to-node mappings
  powerpc: Fix the setup of CPU-to-Node mappings during CPU online
  powerpc/iommu: Don't detach device without IOMMU group
  powerpc/eeh: Hotplug improvement
  powerpc/eeh: Call opal_pci_reinit() on powernv for restoring config space
  powerpc/eeh: Add restore_config operation
  ...

Pull powerpc mremap fix from Ben Herrenschmidt:
 "This is the patch that I had sent after -rc8 and which we decided to
  wait before merging.  It's based on a different tree than my -next
  branch (it needs some pre-reqs that were in -rc4 or so while my -next
  is based on -rc1) so I left it as a separate branch for your to pull.
  It's identical to the request I did 2 or 3 weeks back.

  This fixes crashes in mremap with THP on powerpc.

  The fix however requires a small change in the generic code.  It moves
  a condition into a helper we can override from the arch which is
  harmless, but it *also* slightly changes the order of the set_pmd and
  the withdraw & deposit, which should be fine according to Kirill (who
  wrote that code) but I agree -rc8 is a bit late...

  It was acked by Kirill and Andrew told me to just merge it via powerpc"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/thp: Fix crash on mremap

The GOOGLE_SMI Kconfig symbol depends on DMI and selects EFI.  This
causes problems on other archs when introducing DMI support that depends
on EFI, as it results in a recursive dependency:

  arch/arm/Kconfig:1845:error: recursive dependency detected!
  arch/arm/Kconfig:1845:	symbol DMI depends on EFI

Fix by changing the 'select EFI' to a 'depends on EFI'.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Mike Waychison <mikew@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 91c2e0bc ("unify compat fanotify_mark(2), switch to
COMPAT_SYSCALL_DEFINE") added a new unified compat fanotify_mark syscall
to be used by all architectures.

Unfortunately the unified version merges the split mask parameter in a
wrong way: the lower and higher word got swapped.

This was discovered with glibc's tst-fanotify test case.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reported-by: Andreas Krebbel <krebbel@linux.vnet.ibm.com>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Acked-by: "David S. Miller" <davem@davemloft.net>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: <stable@vger.kernel.org>	[3.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Functions like this one are evil:

void foo()
{
	...
}

Because these functions allow variadic arguments without
checking the arguments at all.

Original patch by Richard Weinberger.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Borislav Petkov <bp@alien8.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 7851a45c ("mm: numa: Copy cpupid on page migration") copies
over the cpupid at page migration time.  It is unnecessary to set it
again in alloc_misplaced_dst_page().
Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Reduce data size a little.
Reduce checkpatch noise.

$ size kernel/softirq.o*
   text	   data	    bss	    dec	    hex	filename
  11554	   6013	   4008	  21575	   5447	kernel/softirq.o.new
  11474	   6093	   4008	  21575	   5447	kernel/softirq.o.old
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use a more current logging style.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Possible speed improvement of __do_softirq() by using ffs() instead of
using a while loop with an & 1 test then single bit shift.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

vsnprintf() may let 'r' larger than sizeof(buf), in this case, if 'r' is
also less than "vmcoreinfo_max_size - vmcoreinfo_size" (left size of
destination buffer), next memcpy() will read the unexpected addresses.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

@splice_desc.total_len is 32 bit(unsigned int) which is used to store the
size passed from userspace which is 64 bit(size_t) so that the size is
unexpectedly truncated

That means vmsplice can not work if the size passed from userspace is >=
4G, for example, we noticed in vmsplice, splice-reader does not do
anything and splice-writer is waiting for available buffer forever if the
size is 4G

Fix it by extending @splice_desc.total_len to 64 bits as well
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Compat function takes msgtyp argument as u32 and passes it down to
do_msgrcv which results in casting to long, thus the sign is lost and we
get a big positive number instead.

Cast the argument to signed type before passing it down.
Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Reported-by: Gabriellla Schmidt <gsc@bruker.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Both expunge_all() and pipeline_send() rely on both a nil msg value and
a full barrier to guarantee the correct ordering when waking up a task.

While its counterpart at the receiving end is well documented for the
lockless recv algorithm, we still need to document these specific
smp_mb() calls.

[akpm@linux-foundation.org: fix typo, per Mike]
[akpm@linux-foundation.org: mroe tpyos]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This field is only used to reset the ids seq number if it exceeds the
smaller of INT_MAX/SEQ_MULTIPLIER and USHRT_MAX, and can therefore be
moved out of the structure and into its own macro.  Since each
ipc_namespace contains a table of 3 pointers to struct ipc_ids we can
save space in instruction text:

   text    data     bss     dec     hex filename
  56232    2348      24   58604    e4ec ipc/built-in.o
  56216    2348      24   58588    e4dc ipc/built-in.o-after
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Jonathan Gonzalez <jgonzalez@linets.cl>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Get rid of silly/useless label jumping.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>