Revert "ext4: don't release page refs in ext4_end_bio()"

This reverts commit b43d17f319f2c502b17139d1cf70731b2b62c644.

Dave Jones reports that it causes lockups on his laptop, and his debug
output showed a lot of processes hung waiting for page_writeback (or
more commonly - processes hung waiting for a lock that was held during
that writeback wait).

The page_writeback hint made Ted suggest that Dave look at this commit,
and Dave verified that reverting it makes his problems go away.

Ted says:
 "That commit fixes a race which is seen when you write into fallocated
  (and hence uninitialized) disk blocks under *very* heavy memory
  pressure.  Furthermore, although theoretically it could trigger under
  normal direct I/O writes, it only seems to trigger if you are issuing
  a huge number of AIO writes, such that a just-written page can get
  evicted from memory, and then read back into memory, before the
  workqueue has a chance to update the extent tree.

  This race has been around for a little over a year, and no one noticed
  until two months ago; it only happens under fairly exotic conditions,
  and in fact even after trying very hard to create a simple repro under
  lab conditions, we could only reproduce the problem and confirm the
  fix on production servers running MySQL on very fast PCIe-attached
  flash devices.

  Given that Dave was able to hit this problem pretty quickly, if we
  confirm that this commit is at fault, the only reasonable thing to do
  is to revert it IMO."

Reported-and-tested-by: Dave Jones <davej@redhat.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ARM: pxa: fix build failure for regulator consumer in em-x270.c

Commit 737f360d5bef5e01c6cfa755dca0b449a154c1e0

"regulator: Remove support for supplies specified by struct device"

caused this file to break, since it was still relying on the
device field to be present.  Map it onto dev_name appropriately

Since there are two consumers with the name "reg-userspace-consumer",
we have to supply the ID as a suffix in the REGULATOR_CONSUMER calls.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
CC: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Merge tag 'cleanup2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull "ARM: cleanups of io includes" from Olof Johansson:
 "Rob Herring has done a sweeping change cleaning up all of the
  mach/io.h includes, moving some of the oft-repeated macros to a common
  location and removing a bunch of boiler plate.  This is another step
  closer to a common zImage for multiple platforms."

Fix up various fairly trivial conflicts (<mach/io.h> removal vs changes
around it, tegra localtimer.o is *still* gone, yadda-yadda).

* tag 'cleanup2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (29 commits)
  ARM: tegra: Include assembler.h in sleep.S to fix build break
  ARM: pxa: use common IOMEM definition
  ARM: dma-mapping: convert ARCH_HAS_DMA_SET_COHERENT_MASK to kconfig symbol
  ARM: __io abuse cleanup
  ARM: create a common IOMEM definition
  ARM: iop13xx: fix missing declaration of iop13xx_init_early
  ARM: fix ioremap/iounmap for !CONFIG_MMU
  ARM: kill off __mem_pci
  ARM: remove bunch of now unused mach/io.h files
  ARM: make mach/io.h include optional
  ARM: clps711x: remove unneeded include of mach/io.h
  ARM: dove: add explicit include of dove.h to addr-map.c
  ARM: at91: add explicit include of hardware.h to uncompressor
  ARM: ep93xx: clean-up mach/io.h
  ARM: tegra: clean-up mach/io.h
  ARM: orion5x: clean-up mach/io.h
  ARM: davinci: remove unneeded mach/io.h include
  [media] davinci: remove includes of mach/io.h
  ARM: OMAP: Remove remaining includes for mach/io.h
  ARM: msm: clean-up mach/io.h
  ...
ARM: pxa: fix build issue on cm-x300

arch/arm/mach-pxa/cm-x300.c:716:3: error: unknown field ‘dev’ specified
in initializer
make[1]: *** [arch/arm/mach-pxa/cm-x300.o] Error 1
make: *** [arch/arm/mach-pxa] Error 2

It's caused by 'dev' field removed from struct
regulator_consumer_supply.

Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
ARM: pxa: fix build issue on stargate2

arch/arm/mach-pxa/stargate2.c:155:3: error: unknown field ‘dev’
specified in initializer
arch/arm/mach-pxa/stargate2.c:155:3: warning: initialization from
incompatible pointer type [enabled by default]
arch/arm/mach-pxa/stargate2.c:155:3: warning: (near initialization for
‘stargate2_sensor_3_con[0].dev_name’) [enabled by default]
make[1]: *** [arch/arm/mach-pxa/stargate2.o] Error 1
make: *** [arch/arm/mach-pxa] Error 2

It's caused by 'dev' field removed from struct
regulator_consumer_supply.

Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x32 support for x86-64 from Ingo Molnar:
 "This tree introduces the X32 binary format and execution mode for x86:
  32-bit data space binaries using 64-bit instructions and 64-bit kernel
  syscalls.

  This allows applications whose working set fits into a 32 bits address
  space to make use of 64-bit instructions while using a 32-bit address
  space with shorter pointers, more compressed data structures, etc."

Fix up trivial context conflicts in arch/x86/{Kconfig,vdso/vma.c}

* 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
  x32: Fix alignment fail in struct compat_siginfo
  x32: Fix stupid ia32/x32 inversion in the siginfo format
  x32: Add ptrace for x32
  x32: Switch to a 64-bit clock_t
  x32: Provide separate is_ia32_task() and is_x32_task() predicates
  x86, mtrr: Use explicit sizing and padding for the 64-bit ioctls
  x86/x32: Fix the binutils auto-detect
  x32: Warn and disable rather than error if binutils too old
  x32: Only clear TIF_X32 flag once
  x32: Make sure TS_COMPAT is cleared for x32 tasks
  fs: Remove missed ->fds_bits from cessation use of fd_set structs internally
  fs: Fix close_on_exec pointer in alloc_fdtable
  x32: Drop non-__vdso weak symbols from the x32 VDSO
  x32: Fix coding style violations in the x32 VDSO code
  x32: Add x32 VDSO support
  x32: Allow x32 to be configured
  x32: If configured, add x32 system calls to system call tables
  x32: Handle process creation
  x32: Signal-related system calls
  x86: Add #ifdef CONFIG_COMPAT to <asm/sys_ia32.h>
  ...
dt: Linux DT usage model documentation

v2: 2nd draft
 - Editorial cleanups (Randy Dunlap and Stephen Warren)
 - Added missing Microblaze reference (Stephen Neuendorffer)
 - Make example of platform_device creation clearer (Shawn Guo)
 - Expand on PowerPC history and mention i2c mess (David Gibson)
 - convert to plain text (remove bits of html formating)

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cleanups from Peter Anvin:
 "The biggest textual change is the cleanup to use symbolic constants
  for x86 trap values.

  The only *functional* change and the reason for the x86/x32 dependency
  is the move of is_ia32_task() into <asm/thread_info.h> so that it can
  be used in other code that needs to understand if a system call comes
  from the compat entry point (and therefore uses i386 system call
  numbers) or not.  One intended user for that is the BPF system call
  filter.  Moving it out of <asm/compat.h> means we can define it
  unconditionally, returning always true on i386."

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Move is_ia32_task to asm/thread_info.h from asm/compat.h
  x86: Rename trap_no to trap_nr in thread_struct
  x86: Use enum instead of literals for trap values
Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux-2.6

Pull devicetree documentation update from Grant Likely.

* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  dt: Linux DT usage model documentation
  mtd: Move fdt partition documentation to a seperate file
tools turbostat: reduce measurement overhead due to IPIs

turbostat uses /dev/cpu/*/msr interface to read MSRs.
For modern systems, it reads 10 MSR/CPU.  This can
be observed as 10 "Function Call Interrupts"
per CPU per sample added to /proc/interrupts.

This overhead is measurable on large idle systems,
and as Yoquan Song pointed out, it can even trick
cpuidle into thinking the system is busy.

Here turbostat re-schedules itself in-turn to each
CPU so that its MSR reads will always be local.
This replaces the 10 "Function Call Interrupts"
with a single "Rescheduling interrupt" per sample
per CPU.

On an idle 32-CPU system, this shifts some residency from
the shallow c1 state to the deeper c7 state:

 # ./turbostat.old -s
   %c0  GHz  TSC    %c1    %c3    %c6    %c7   %pc2   %pc3   %pc6   %pc7
  0.27 1.29 2.29   0.95   0.02   0.00  98.77  20.23   0.00  77.41   0.00
  0.25 1.24 2.29   0.98   0.02   0.00  98.75  20.34   0.03  77.74   0.00
  0.27 1.22 2.29   0.54   0.00   0.00  99.18  20.64   0.00  77.70   0.00
  0.26 1.22 2.29   1.22   0.00   0.00  98.52  20.22   0.00  77.74   0.00
  0.26 1.38 2.29   0.78   0.02   0.00  98.95  20.51   0.05  77.56   0.00
^C
 i# ./turbostat.new -s
   %c0  GHz  TSC    %c1    %c3    %c6    %c7   %pc2   %pc3   %pc6   %pc7
  0.27 1.20 2.29   0.24   0.01   0.00  99.49  20.58   0.00  78.20   0.00
  0.27 1.22 2.29   0.25   0.00   0.00  99.48  20.79   0.00  77.85   0.00
  0.27 1.20 2.29   0.25   0.02   0.00  99.46  20.71   0.03  77.89   0.00
  0.28 1.26 2.29   0.25   0.01   0.00  99.46  20.89   0.02  77.67   0.00
  0.27 1.20 2.29   0.24   0.01   0.00  99.48  20.65   0.00  78.04   0.00

cc: Youquan Song <youquan.song@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
tools turbostat: harden against cpu online/offline

Sometimes users have turbostat running in interval mode
when they take processors offline/online.

Previously, turbostat would survive, but not gracefully.

Tighten up the error checking so turbostat notices
changesn sooner, and print just 1 line on change:

turbostat: re-initialized with num_cpus %d

Signed-off-by: Len Brown <len.brown@intel.com>
Merge branch 'fixes' of git://github.com/hzhuang1/linux into fixes

* 'fixes' of git://github.com/hzhuang1/linux:
  ARM: pxa: fix build issue on stargate2
  ARM: pxa: fix build issue on cm-x300
  ARM: pxa: fix build failure for regulator consumer in em-x270.c
  ARM: pxa: fix regulator related build fail in magician_defconfig
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull arm-soc fixes from Olof Johansson:
 "This is a first pass of some of the merge window fallout for ARM
  platforms.

  Nothing controversial:
   - A system.h fallout fix for OMAP
   - PXA fixes for breakage caused by the regulator struct changes
   - GPIO fixes for OMAP to properly deal with dynamic IRQ allocation
   - A mismerge in our arm-soc tree of an lpc32xx change for networking
   - A fix for USB setup on tegra
   - An undo of __init annotation of display mux setup on OMAP that's
     needed at runtime"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: pxa: fix build issue on stargate2
  ARM: pxa: fix build issue on cm-x300
  ARM: pxa: fix build failure for regulator consumer in em-x270.c
  ARM: LPC32xx: clock.c: Fix lpc-eth clock reference
  ARM: OMAP: pm: fix compilation break
  ARM: OMAP: Remove OMAP_GPIO_IRQ macro definition
  drivers: input: Fix OMAP_GPIO_IRQ with gpio_to_irq() in ams_delta_serio_exit()
  ARM: OMAP: boards: Fix OMAP_GPIO_IRQ usage with gpio_to_irq()
  ARM: pxa: fix regulator related build fail in magician_defconfig
  ARM: tegra: Fix device tree AUXDATA for USB/EHCI
  ARM: OMAP2+: Remove __init from DSI mux functions
cgroup: cgroup_attach_task() could return -errno after success

61d1d219c4 "cgroup: remove extra calls to find_existing_css_set" made
cgroup_task_migrate() return void.  An unfortunate side effect was
that cgroup_attach_task() was depending on that function's return
value to clear its @retval on the success path.  On cgroup mounts
without any subsystem with ->can_attach() callback,
cgroup_attach_task() ended up returning @retval without initializing
it on success.

For some reason, gcc failed to warn about it and it didn't cause
cgroup_attach_task() to return non-zero value in many cases, probably
due to difference in register allocation.  When the problem
materializes, systemd fails to populate /systemd cgroup mount and
fails to boot.

Fix it by initializing @retval to zero on declaration.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Jiri Kosina <jkosina@suse.cz>
LKML-Reference: <alpine.LNX.2.00.1203282354440.25526@pobox.suse.cz>
Reviewed-by: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Merge branch 'for-3.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull urgent cgroup fix from Tejun Heo:
 "Commit 61d1d219c4c0 ('cgroup: remove extra calls to
  find_existing_css_set') which was part of the rc1 cgroup pull request
  made writes to the cgroup "tasks" file return an uninitialized retval
  on success which can cause boot failures with systemd.

  The change stayed in linux-next for quite some time but gcc
  interestingly failed to emit warning about using uninitialized
  variable and the problem seems to materialize only for certain build
  combinations (probably depends on register allocation).

  It's just missing local variable initialization and the fix is trivial
  & safe.  As the problem is critical when it materializes, I'm
  fast-tracking it.  Also included is Li's email address change in
  MAINTAINERS."

* 'for-3.4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: cgroup_attach_task() could return -errno after success
  cgroup: update MAINTAINERS entry
sparc: fix fallout from system.h split

Fixes this build error:

kernel/signal.c: In function 'ptrace_stop':
kernel/signal.c:1860:3: error: implicit declaration of function 'synchronize_user_stack' [-Werror=implicit-function-declaration]

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
sparc: Fix even more fallout from system.h split.

jump_label.c needs asm/cacheflush.h to get flushi().
kgdb_64.c needs asm/cacheflush.h to get flushw_all().

Signed-off-by: David S. Miller <davem@davemloft.net>
ACPI: ec: Do request_region outside WARN()

WARN() is not supposed to have side effects, so move the request_regions
outside.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
ACPI: Make ACPI interrupt threaded

Some ACPI interrupt actions may need to wait, and it's easiest to
have a thread context for this. So turn the ACPI interrupt
into a threaded interrupt.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Input: wacom - check for allocation failure in probe()

We accidentally removed the check for NULL in 3aac0ef10b "Input: wacom -
isolate input registration".

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Chris Bagwell <chris@cnpbagwell.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>