Use the generic unmap object to unmap dma buffers.

Later we can push this unmap object up to the raid layer and get rid of
the 'scribble' parameter.

Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
[bzolnier: minor cleanups]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Use the generic unmap object to unmap dma buffers.

Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
[bzolnier: add missing unmap->len initialization]
[bzolnier: fix whitespace damage]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
[djbw: add DMA_ENGINE=n support]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Hang a common 'unmap' object off of dma descriptors for the purpose of
providing a unified unmapping interface.  The lifetime of a mapping may
span multiple descriptors, so these unmap objects are reference counted
by related descriptor.

Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Dave Jiang <dave.jiang@intel.com>
[bzolnier: fix IS_ENABLED() check]
[bzolnier: fix release ordering in dmaengine_destroy_unmap_pool()]
[bzolnier: fix check for success in dmaengine_init_unmap_pool()]
[bzolnier: use mempool_free() instead of kmem_cache_free()]
[bzolnier: add missing unmap->len initializations]
[bzolnier: add __init tag to dmaengine_init_unmap_pool()]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
[djbw: move DMAENGINE=n support to this patch for async_tx]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Add a hook for a common dma unmap implementation to enable removal of
the per driver custom unmap code.  (A reworked version of Bartlomiej
Zolnierkiewicz's patches to remove the custom callbacks and the size
increase of dma_async_tx_descriptor for drivers that don't care about
raid).

Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Dave Jiang <dave.jiang@intel.com>
[bzolnier: prepare pl330 driver for adding missing unmap while at it]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Copying from page to page (dma_async_memcpy_pg_to_pg) is the superset,
make the other two apis use that one in preparation for providing a
common dma unmap implementation.  The common implementation just wants
to assume all buffers are mapped with dma_map_page().

Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Make the driver DMA unmap also source buffers by itself
(currently it DMA unmaps only destination buffers) as
a preparation for introducing generic 'ummap' data.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Pull btrfs fix from Chris Mason:
 "Sage hit a deadlock with ceph on btrfs, and Josef tracked it down to a
  regression in our initial rc1 pull.  When doing nocow writes we were
  sometimes starting a transaction with locks held"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: release path before starting transaction in can_nocow_extent

Pull ACPI and power management fixes from Rafael Wysocki:

 - intel_pstate fix for misbehavior after system resume if sysfs
   attributes are set in a specific way before the corresponding suspend
   from Dirk Brandewie.

 - A recent intel_pstate fix has no effect if unsigned long is 32-bit,
   so fix it up to cover that case as well.

 - The s3c64xx cpufreq driver was not updated when the index field of
   struct cpufreq_frequency_table was replaced with driver_data, so
   update it now.  From Charles Keepax.

 - The Kconfig help text for ACPI_BUTTON still refers to
   /proc/acpi/event that has been dropped recently, so modify it to
   remove that reference.  From Krzysztof Mazur.

 - A Lan Tianyu's change adds a missing mutex unlock to an error code
   path in acpi_resume_power_resources().

 - Some code related to ACPI power resources, whose very purpose is
   questionable to put it lightly, turns out to cause problems to happen
   during testing on real systems, so remove it completely (we may
   revisit that in the future if there's a compelling enough reason).
   From Rafael J Wysocki and Aaron Lu.

* tag 'pm+acpi-3.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / PM: Drop two functions that are not used any more
  ATA / ACPI: remove power dependent device handling
  cpufreq: s3c64xx: Rename index to driver_data
  ACPI / power: Drop automaitc resume of power resource dependent devices
  intel_pstate: Fix type mismatch warning
  cpufreq / intel_pstate: Fix max_perf_pct on resume
  ACPI: remove /proc/acpi/event from ACPI_BUTTON help
  ACPI / power: Release resource_lock after acpi_power_get_state() return error

Pull x86 fixes from Ingo Molnar:
 "Two fixlets:

   - fix a (rare-config) build bug
   - fix a next-gen SGI/UV hw/firmware enumeration bug"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Update UV3 hub revision ID
  x86/microcode: Correct Kconfig dependencies

We can't be holding tree locks while we try to start a transaction, we will
deadlock.  Thanks,
Reported-by: Sage Weil <sage@inktank.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

* acpi-fixes:
  ACPI / PM: Drop two functions that are not used any more
  ATA / ACPI: remove power dependent device handling
  ACPI / power: Drop automaitc resume of power resource dependent devices
  ACPI: remove /proc/acpi/event from ACPI_BUTTON help
  ACPI / power: Release resource_lock after acpi_power_get_state() return error

* pm-fixes:
  cpufreq: s3c64xx: Rename index to driver_data
  intel_pstate: Fix type mismatch warning
  cpufreq / intel_pstate: Fix max_perf_pct on resume

Pull CIFS fixes from Steve French:
 "Five small cifs fixes (includes fixes for: unmount hang, 2 security
  related, symlink, large file writes)"

* 'for-linus' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: ntstatus_to_dos_map[] is not terminated
  cifs: Allow LANMAN auth method for servers supporting unencapsulated authentication methods
  cifs: Fix inability to write files >2GB to SMB2/3 shares
  cifs: Avoid umount hangs with smb2 when server is unresponsive
  do not treat non-symlink reparse points as valid symlinks

Merge tag 'driver-core-3.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fix from Greg KH:
 "Here is one fix for the hotplug memory path that resolves a regression
  when removing memory that showed up in 3.12-rc1"

* tag 'driver-core-3.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: Release device_hotplug_lock when store_mem_state returns EINVAL

Pull USB fixes from Greg KH:
 "Here are some USB fixes and new device ids for 3.12-rc6

  The largest change here is a bunch of new device ids for the option
  USB serial driver for new Huawei devices.  Other than that, just some
  small bug fixes for issues that people have reported (run-time and
  build-time), nothing major"

* tag 'usb-3.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: usb_phy_gen: refine conditional declaration of usb_nop_xceiv_register
  usb: misc: usb3503: Fix compile error due to incorrect regmap depedency
  usb/chipidea: fix oops on memory allocation failure
  usb-storage: add quirk for mandatory READ_CAPACITY_16
  usb: serial: option: blacklist Olivetti Olicard200
  USB: quirks: add touchscreen that is dazzeled by remote wakeup
  Revert "usb: musb: gadget: fix otg active status flag"
  USB: quirks.c: add one device that cannot deal with suspension
  USB: serial: option: add support for Inovia SEW858 device
  USB: serial: ti_usb_3410_5052: add Abbott strip port ID to combined table as well.
  USB: support new huawei devices in option.c
  usb: musb: start musb on the udc side, too
  xhci: Fix spurious wakeups after S5 on Haswell
  xhci: fix write to USB3_PSSEN and XUSB2PRM pci config registers
  xhci: quirk for extra long delay for S4
  xhci: Don't enable/disable RWE on bus suspend/resume.

Pull serial driver fixes from Greg KH:
 "Here are two serial driver fixes for your tree.  One is a revert of a
  patch that causes a build error, the other is a fix to provide the
  correct brace placement which resolves a bug where the driver was not
  working properly"

* tag 'tty-3.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: vt8500: add missing braces
  Revert "serial: i.MX: evaluate linux,stdout-path property"

Pull char/misc driver fixes from Greg KH:
 "Here are some small iio and w1 driver fixes for 3.12-rc6.

  There is also a hyper-v fix in here, which turned out to be incorrect,
  so it was reverted.  That will probably have to wait unto 3.13-rc1 to
  get accepted as it's still being discussed"

* tag 'char-misc-3.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Revert "Drivers: hv: vmbus: Fix a bug in channel rescind code"
  Drivers: hv: vmbus: Fix a bug in channel rescind code
  iio:buffer: Free active scan mask in iio_disable_all_buffers()
  iio: frequency: adf4350: add missing clk_disable_unprepare() on error in adf4350_probe()
  w1 - call request_module with w1 master mutex unlocked
  w1 - fix fops in w1_bus_notify

Pull sound fixes from Takashi Iwai:
 "All reasonably small fixes as rc6: a HD-audio mic fix, a us122l mmap
  regression fix, and kernel memory leak fix in hdsp driver.  Hopefully
  this will be the last pull request for 3.12..."

* tag 'sound-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hdsp - info leak in snd_hdsp_hwdep_ioctl()
  ALSA: us122l: Fix pcm_usb_stream mmapping regression
  ALSA: hda - Fix inverted internal mic not indicated on some machines

Pull apparmor fixes from James Morris:
 "A couple more regressions fixed"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  apparmor: fix bad lock balance when introspecting policy
  apparmor: fix memleak of the profile hash

Merge tag 'iio-fixes-for-3.12c' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into char-misc-linus

Jonathan writes:

Third set of IIO fixes for the 3.12 cycle.

Two little ones this time:

1) A missing clk_unprepare in adf4350.
2) A missing free of the active_scan_mask when iio_disable_all_buffers is
called during an unexpected device removal.  This leak was introduced by
the fix
a87c82e4 iio: Stop sampling when the device is removed
and hence is a regression fix.

Commit 3fa4d734 (usb: phy: rename nop_usb_xceiv => usb_phy_gen_xceiv)
changed the conditional around the declaration of usb_nop_xceiv_register
from
	#if defined(CONFIG_NOP_USB_XCEIV) ||
		(defined(CONFIG_NOP_USB_XCEIV_MODULE) && defined(MODULE))
to
	#if IS_ENABLED(CONFIG_NOP_USB_XCEIV)

While that looks the same, it is semantically different. The first expression
is true if CONFIG_NOP_USB_XCEIV is built as module and if the including
code is built as module. The second expression is true if code depending on
CONFIG_NOP_USB_XCEIV if built as module or into the kernel.

As a result, the arm:allmodconfig build fails with

arch/arm/mach-omap2/built-in.o: In function `omap3_evm_init':
arch/arm/mach-omap2/board-omap3evm.c:703: undefined reference to
	`usb_nop_xceiv_register'

Fix the problem by reverting to the old conditional.

Cc: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 90d33f3e as it's not
the correct fix for this issue, and it causes a build warning to be
added to the kernel tree.

Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Two functions defined in device_pm.c, acpi_dev_pm_add_dependent()
and acpi_dev_pm_remove_dependent(), have no callers and may be
dropped, so drop them.

Moreover, they are the only functions adding entries to and removing
entries from the power_dependent list in struct acpi_device, so drop
that list too.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Previously, we wanted SCSI devices corrsponding to ATA devices to
be runtime resumed when the power resource for those ATA device was
turned on by some other device, so we added the SCSI device to the
dependent device list of the ATA device's ACPI node.  However, this
code has no effect after commit 41863fce (ACPI / power: Drop automaitc
resume of power resource dependent devices) and the mechanism it was
supposed to implement is regarded as a bad idea now, so drop it.

[rjw: Changelog]
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Merge misc fixes from Andrew Morton.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (21 commits)
  mm: revert mremap pud_free anti-fix
  mm: fix BUG in __split_huge_page_pmd
  swap: fix set_blocksize race during swapon/swapoff
  procfs: call default get_unmapped_area on MMU-present architectures
  procfs: fix unintended truncation of returned mapped address
  writeback: fix negative bdi max pause
  percpu_refcount: export symbols
  fs: buffer: move allocation failure loop into the allocator
  mm: memcg: handle non-error OOM situations more gracefully
  tools/testing/selftests: fix uninitialized variable
  block/partitions/efi.c: treat size mismatch as a warning, not an error
  mm: hugetlb: initialize PG_reserved for tail pages of gigantic compound pages
  mm/zswap: bugfix: memory leak when re-swapon
  mm: /proc/pid/pagemap: inspect _PAGE_SOFT_DIRTY only on present pages
  mm: migration: do not lose soft dirty bit if page is in migration state
  gcov: MAINTAINERS: Add an entry for gcov
  mm/hugetlb.c: correct missing private flag clearing
  mm/vmscan.c: don't forget to free shrinker->nr_deferred
  ipc/sem.c: synchronize semop and semctl with IPC_RMID
  ipc: update locking scheme comments
  ...

Revert commit 1ecfd533 ("mm/mremap.c: call pud_free() after fail
calling pmd_alloc()").

The original code was correct: pud_alloc(), pmd_alloc(), pte_alloc_map()
ensure that the pud, pmd, pt is already allocated, and seldom do they
need to allocate; on failure, upper levels are freed if appropriate by
the subsequent do_munmap().  Whereas commit 1ecfd533 did an
unconditional pud_free() of a most-likely still-in-use pud: saved only
by the near-impossiblity of pmd_alloc() failing.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Occasionally we hit the BUG_ON(pmd_trans_huge(*pmd)) at the end of
__split_huge_page_pmd(): seen when doing madvise(,,MADV_DONTNEED).

It's invalid: we don't always have down_write of mmap_sem there: a racing
do_huge_pmd_wp_page() might have copied-on-write to another huge page
before our split_huge_page() got the anon_vma lock.

Forget the BUG_ON, just go back and try again if this happens.
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: David Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix race between swapoff and swapon.  Swapoff used old_block_size from
swap_info outside of swapon_mutex so it could be overwritten by
concurrent swapon.

The race has visible effect only if more than one swap block device
exists with different block sizes (e.g.  /dev/sda1 with block size 4096
and /dev/sdb1 with 512).  In such case it leads to setting the blocksize
of swapped off device with wrong blocksize.

The bug can be triggered with multiple concurrent swapoff and swapon:
0. Swap for some device is on.
1. swapoff:
First the swapoff is called on this device and "struct swap_info_struct
*p" is assigned. This is done under swap_lock however this lock is
released for the call try_to_unuse().

2. swapon:
After the assignment above (and before acquiring swapon_mutex &
swap_lock by swapoff) the swapon is called on the same device.
The p->old_block_size is assigned to the value of block_size the device.
This block size should be the same as previous but sometimes it is not.
The swapon ends successfully.

3. swapoff:
Swapoff resumes, grabs the locks and mutex and continues to disable this
swap device. Now it sets the block size to value taken from swap_info
which was overwritten by swapon in 2.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reported-by: Weijie Yang <weijie.yang.kh@gmail.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Minchan Kim <minchan@kernel.org>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit c4fe2448 ("sparc: fix PCI device proc file mmap(2)") added
proc_reg_get_unmapped_area in proc_reg_file_ops and
proc_reg_file_ops_no_compat, by which now mmap always returns EIO if
get_unmapped_area method is not defined for the target procfs file,
which causes regression of mmap on /proc/vmcore.

To address this issue, like get_unmapped_area(), call default
current->mm->get_unmapped_area on MMU-present architectures if
pde->proc_fops->get_unmapped_area, i.e.  the one in actual file
operation in the procfs file, is not defined.
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently, proc_reg_get_unmapped_area truncates upper 32-bit of the
mapped virtual address returned from get_unmapped_area method in
pde->proc_fops due to the variable rv of signed integer on x86_64.  This
is too small to have vitual address of unsigned long on x86_64 since on
x86_64, signed integer is of 4 bytes while unsigned long is of 8 bytes.
To fix this issue, use unsigned long instead.

Fixes a regression added in commit c4fe2448 ("sparc: fix PCI device
proc file mmap(2)").
Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Toralf runs trinity on UML/i386.  After some time it hangs and the last
message line is

	BUG: soft lockup - CPU#0 stuck for 22s! [trinity-child0:1521]

It's found that pages_dirtied becomes very large.  More than 1000000000
pages in this case:

	period = HZ * pages_dirtied / task_ratelimit;
	BUG_ON(pages_dirtied > 2000000000);
	BUG_ON(pages_dirtied > 1000000000);      <---------

UML debug printf shows that we got negative pause here:

	ick: pause : -984
	ick: pages_dirtied : 0
	ick: task_ratelimit: 0

	 pause:
	+       if (pause < 0)  {
	+               extern int printf(char *, ...);
	+               printf("ick : pause : %li\n", pause);
	+               printf("ick: pages_dirtied : %lu\n", pages_dirtied);
	+               printf("ick: task_ratelimit: %lu\n", task_ratelimit);
	+               BUG_ON(1);
	+       }
	        trace_balance_dirty_pages(bdi,

Since pause is bounded by [min_pause, max_pause] where min_pause is also
bounded by max_pause.  It's suspected and demonstrated that the
max_pause calculation goes wrong:

	ick: pause : -717
	ick: min_pause : -177
	ick: max_pause : -717
	ick: pages_dirtied : 14
	ick: task_ratelimit: 0

The problem lies in the two "long = unsigned long" assignments in
bdi_max_pause() which might go negative if the highest bit is 1, and the
min_t(long, ...) check failed to protect it falling under 0.  Fix all of
them by using "unsigned long" throughout the function.
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Tested-by: Toralf Förster <toralf.foerster@gmx.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Richard Weinberger <richard@nod.at>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Export the interface to be used within modules.
Signed-off-by: Matias Bjorling <m@bjorling.me>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Buffer allocation has a very crude indefinite loop around waking the
flusher threads and performing global NOFS direct reclaim because it can
not handle allocation failures.

The most immediate problem with this is that the allocation may fail due
to a memory cgroup limit, where flushers + direct reclaim might not make
any progress towards resolving the situation at all.  Because unlike the
global case, a memory cgroup may not have any cache at all, only
anonymous pages but no swap.  This situation will lead to a reclaim
livelock with insane IO from waking the flushers and thrashing unrelated
filesystem cache in a tight loop.

Use __GFP_NOFAIL allocations for buffers for now.  This makes sure that
any looping happens in the page allocator, which knows how to
orchestrate kswapd, direct reclaim, and the flushers sensibly.  It also
allows memory cgroups to detect allocations that can't handle failure
and will allow them to ultimately bypass the limit if reclaim can not
make progress.
Reported-by: azurIt <azurit@pobox.sk>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 3812c8c8 ("mm: memcg: do not trap chargers with full
callstack on OOM") assumed that only a few places that can trigger a
memcg OOM situation do not return VM_FAULT_OOM, like optional page cache
readahead.  But there are many more and it's impractical to annotate
them all.

First of all, we don't want to invoke the OOM killer when the failed
allocation is gracefully handled, so defer the actual kill to the end of
the fault handling as well.  This simplifies the code quite a bit for
added bonus.

Second, since a failed allocation might not be the abrupt end of the
fault, the memcg OOM handler needs to be re-entrant until the fault
finishes for subsequent allocation attempts.  If an allocation is
attempted after the task already OOMed, allow it to bypass the limit so
that it can quickly finish the fault and invoke the OOM killer.
Reported-by: azurIt <azurit@pobox.sk>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The err variable is intended to receive the timer_create() return before
checking it
Signed-off-by: Felipe Pena <felipensp@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

In commit 27a7c642 ("partitions/efi: account for pmbr size in lba")
we started treating bad sizes in lba field of the partition that has the
0xEE (GPT protective) as errors.

However, we may run into these "bad sizes" in the real world if someone
uses dd to copy an image from a smaller disk to a bigger disk.  Since
this case used to work (even without using force_gpt), keep it working
and treat the size mismatch as a warning instead of an error.
Reported-by: Josh Triplett <josh@joshtriplett.org>
Reported-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Acked-by: Davidlohr Bueso <davidlohr@hp.com>
Tested-by: Artem Bityutskiy <dedekind1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 11feeb49 ("kvm: optimize away THP checks in
kvm_is_mmio_pfn()") introduced a memory leak when KVM is run on gigantic
compound pages.

That commit depends on the assumption that PG_reserved is identical for
all head and tail pages of a compound page.  So that if get_user_pages
returns a tail page, we don't need to check the head page in order to
know if we deal with a reserved page that requires different
refcounting.

The assumption that PG_reserved is the same for head and tail pages is
certainly correct for THP and regular hugepages, but gigantic hugepages
allocated through bootmem don't clear the PG_reserved on the tail pages
(the clearing of PG_reserved is done later only if the gigantic hugepage
is freed).

This patch corrects the gigantic compound page initialization so that we
can retain the optimization in 11feeb49.  The cacheline was already
modified in order to set PG_tail so this won't affect the boot time of
large memory systems.

[akpm@linux-foundation.org: tweak comment layout and grammar]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: andy123 <ajs124.ajs124@gmail.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zswap_tree is not freed when swapoff, and it got re-kmalloced in swapon,
so a memory leak occurs.

Free the memory of zswap_tree in zswap_frontswap_invalidate_area().
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
From: Weijie Yang <weijie.yang@samsung.com>
Subject: mm/zswap: bugfix: memory leak when invalidate and reclaim occur concurrently

Consider the following scenario:
thread 0: reclaim entry x (get refcount, but not call zswap_get_swap_cache_page)
thread 1: call zswap_frontswap_invalidate_page to invalidate entry x.
	finished, entry x and its zbud is not freed as its refcount != 0
	now, the swap_map[x] = 0
thread 0: now call zswap_get_swap_cache_page
	swapcache_prepare return -ENOENT because entry x is not used any more
	zswap_get_swap_cache_page return ZSWAP_SWAPCACHE_NOMEM
	zswap_writeback_entry do nothing except put refcount
Now, the memory of zswap_entry x and its zpage leak.

Modify:
 - check the refcount in fail path, free memory if it is not referenced.

 - use ZSWAP_SWAPCACHE_FAIL instead of ZSWAP_SWAPCACHE_NOMEM as the fail path
   can be not only caused by nomem but also by invalidate.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If a page we are inspecting is in swap we may occasionally report it as
having soft dirty bit (even if it is clean).  The pte_soft_dirty helper
should be called on present pte only.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>