On most gen2-4 platforms the GTT can be (or maybe always is?)
inside the stolen memory region. If that's the case, reduce the
size of the stolen memory appropriately to make make sure we
don't clobber the GTT.

v2: Deal with gen4 36 bit physical address
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=80151Acked-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We should keep DEVICE_READY bit set in the ULPS enter sequence. In
exit sequence also we should set DEVICE_READY, but thats causing
blankout for me. Also exit sequence is simplified as per hw team
recommendation.

This should fix -
[drm:intel_dsi_clear_device_ready] *ERROR* DSI LP not going Low

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=80818Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Tested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

While sending DPI SHUTDOWN command, we cannot wait for FIFO empty as
pipes are not disabled at that time. In case of MIPI we disable port
first and send SHUTDOWN command while pipe is still running and FIFOs
will not be empty, causing spurious error log
Signed-off-by: NShobhit Kumar <shobhit.kumar@intel.com>
Tested-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>

The Toshiba CB35 Chromebook (with Celeron 2955U CPU) has a controllable
backlight although its VBT reports otherwise. Apply quirk to ignore the
backlight presence check during backlight setup.

Patch tested by author on Toshiba CB35.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79813Signed-off-by: NScot Doyle <lkml14@scotdoyle.com>
CC: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org # 3.15 only
[danvet: Add cc: stable because the regressing commit is in 3.15.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The Acer C720 and C720P Chromebooks (with Celeron 2955U CPU) have a
controllable backlight although their VBT reports otherwise. Apply quirk
to ignore the backlight presence check during backlight setup.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79813Tested-by: NJames Duley <jagduley@gmail.com>
Tested-by: NMichael Mullin <masmullin@gmail.com>
Signed-off-by: NScot Doyle <lkml14@scotdoyle.com>
CC: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org # 3.15 only
[danvet: Add cc: stable because the regressing commit is in 3.15.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

commit c675949e
Author: Jani Nikula <jani.nikula@intel.com>
Date:   Wed Apr 9 11:31:37 2014 +0300

    drm/i915: do not setup backlight if not available according to VBT

caused a regression on machines with a misconfigured VBT. Add a quirk to
assert the presence of a controllable backlight. Use it to ignore the VBT
backlight presence check during backlight setup.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79813Tested-by: NJames Duley <jagduley@gmail.com>
Tested-by: NMichael Mullin <masmullin@gmail.com>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NScot Doyle <lkml14@scotdoyle.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Cc: stable@vger.kernel.org # 3.15 only
[danvet: Add cc: stable because the regressing commit is in 3.15.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Fixes for 3.16-rc3; most importantly Jesse brings back VGA he took away
on a bunch of machines. Also a vblank fix for BDW and a power workaround
fix for VLV.

* tag 'drm-intel-fixes-2014-07-03' of git://anongit.freedesktop.org/drm-intel:
  drm/i915: Drop early VLV WA to fix Voltage not getting dropped to Vmin
  drm/i915: only apply crt_present check on VLV
  drm/i915: Wait for vblank after enabling the primary plane on BDW

fix to a 3.15 commit.

* 'vmwgfx-fixes-3.16' of git://people.freedesktop.org/~thomash/linux:
  drm/vmwgfx: Fix incorrect write to read-only register v2:

mode fixes for tda998x.

* 'tda998x-fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-cubox:
  drm/i2c: tda998x: add some basic mode validation
  drm/i2c: tda998x: faster polling for edid
  drm/i2c: tda998x: move drm_i2c_encoder_destroy call

Pull ARM64 fixes from Catalin Marinas:
 - Exception level check at boot time (for completeness, not triggering
   any bug before)
 - I/D-cache synchronisation logic for huge pages
 - Config symbol typo

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: fix el2_setup check of CurrentEL
  arm64: mm: Make icache synchronisation logic huge page aware
  arm64: mm: Fix horrendous config typo

Pull md bugfixes from Neil Brown:
 "Two minor bugfixes for md in 3.16"

* tag 'md/3.16-fixes' of git://neil.brown.name/md:
  md: flush writes before starting a recovery.
  md: make sure GET_ARRAY_INFO ioctl reports correct "clean" status

Pull sound fixes from Takashi Iwai:
 "This contains a few fixes for HD-audio: yet another Dell headset pin
  quirk, a fixup for Thinkpad T540P, and an improved fix for
  Haswell/Broadwell HDMI clock setup"

* tag 'sound-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda - restore BCLK M/N value as per CDCLK for HSW/BDW display HDA controller
  drm/i915: provide interface for audio driver to query cdclk
  ALSA: hda - Add a fixup for Thinkpad T540p
  ALSA: hda - Add another headset pin quirk for some Dell machines

Pull btrfs fixes from Chris Mason:
 "We've queued up a few fixes in my for-linus branch"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix crash when starting transaction
  Btrfs: fix btrfs_print_leaf for skinny metadata
  Btrfs: fix race of using total_bytes_pinned
  btrfs: use E2BIG instead of EIO if compression does not help
  btrfs: remove stale comment from btrfs_flush_all_pending_stuffs
  Btrfs: fix use-after-free when cloning a trailing file hole
  btrfs: fix null pointer dereference in btrfs_show_devname when name is null
  btrfs: fix null pointer dereference in clone_fs_devices when name is null
  btrfs: fix nossd and ssd_spread mount option regression
  Btrfs: fix race between balance recovery and root deletion
  Btrfs: atomically set inode->i_flags in btrfs_update_iflags
  btrfs: only unlock block in verify_parent_transid if we locked it
  Btrfs: assert send doesn't attempt to start transactions
  btrfs compression: reuse recently used workspace
  Btrfs: fix crash when mounting raid5 btrfs with missing disks
  btrfs: create sprout should rename fsid on the sysfs as well
  btrfs: dev replace should replace the sysfs entry
  btrfs: dev add should add its sysfs entry
  btrfs: dev delete should remove sysfs entry
  btrfs: rename add_device_membership to btrfs_kobj_add_device

The CurrentEL system register reports the Current Exception Level
of the CPU. It doesn't say anything about the stack handling, and
yet we compare it to PSR_MODE_EL2t and PSR_MODE_EL2h.

It works by chance because PSR_MODE_EL2t happens to match the right
bits, but that's otherwise a very bad idea. Just check for the EL
value instead.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
[catalin.marinas@arm.com: fixed arch/arm64/kernel/efi-entry.S]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The __sync_icache_dcache routine will only flush the dcache for the
first page of a compound page, potentially leading to stale icache
data residing further on in a hugetlb page.

This patch addresses this issue by taking into consideration the
order of the page when flushing the dcache.
Reported-by: NMark Brown <broonie@linaro.org>
Tested-by: NMark Brown <broonie@linaro.org>
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org> # v3.11+

The define ARM64_64K_PAGES is tested for rather than
CONFIG_ARM64_64K_PAGES. Correct that typo here.
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

For HSW/BDW display HD-A controller, hda_set_bclk() is defined to set BCLK
by programming the M/N values as per the core display clock (CDCLK) queried from
i915 display driver.

And the audio driver will also set BCLK in azx_first_init() since the display
driver can turn off the shared power in boot phase if only eDP is connected
and M/N values will be lost and must be reprogrammed.
Signed-off-by: NMengdong Lin <mengdong.lin@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

For Haswell and Broadwell, if the display power well has been disabled,
the display audio controller divider values EM4 M VALUE and EM5 N VALUE
will have been lost. The CDCLK frequency is required for reprogramming them
to generate 24MHz HD-A link BCLK. So provide a private interface for the
audio driver to query CDCLK.

This is a stopgap solution until a more generic interface between audio
and display drivers has been implemented.
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NMengdong Lin <mengdong.lin@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>

Pull USB bugfixes from Greg KH:
 "Here's a round of USB bugfixes, quirk additions, and new device ids
  for 3.16-rc4.  Nothing major in here at all, just a bunch of tiny
  changes.  All have been in linux-next with no reported issues"

* tag 'usb-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (33 commits)
  usb: chipidea: udc: delete td from req's td list at ep_dequeue
  usb: Kconfig: make EHCI_MSM selectable for QCOM SOCs
  usb-storage/SCSI: Add broken_fua blacklist flag
  usb: musb: dsps: fix the base address for accessing the mode register
  tools: ffs-test: fix header values endianess
  usb: phy: msm: Do not do runtime pm if the phy is not idle
  usb: musb: Ensure that cppi41 timer gets armed on premature DMA TX irq
  usb: gadget: gr_udc: Fix check for invalid number of microframes
  usb: musb: Fix panic upon musb_am335x module removal
  usb: gadget: f_fs: resurect usb_functionfs_descs_head structure
  Revert "tools: ffs-test: convert to new descriptor format fixing compilation error"
  xhci: Fix runtime suspended xhci from blocking system suspend.
  xhci: clear root port wake on bits if controller isn't wake-up capable
  xhci: correct burst count field for isoc transfers on 1.0 xhci hosts
  xhci: Use correct SLOT ID when handling a reset device command
  MAINTAINERS: update e-mail address
  usb: option: add/modify Olivetti Olicard modems
  USB: ftdi_sio: fix null deref at port probe
  MAINTAINERS: drop two usb-serial subdriver entries
  USB: option: add device ID for SpeedUp SU9800 usb 3g modem
  ...

Pull staging driver bugfixes from Greg KH:
 "Nothing major here, just 4 small bugfixes that resolve some issues
  reported for the IIO (staging and non-staging) and the tidspbridge
  driver"

* tag 'staging-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: tidspbridge: fix an erroneous removal of parentheses
  iio: of_iio_channel_get_by_name() returns non-null pointers for error legs
  staging: iio/ad7291: fix error code in ad7291_probe()
  iio:adc:ad799x: Fix reading and writing of event values, apply shift

Merge tag 'driver-core-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Well, one drivercore fix for kernfs to resolve a reported issue with
  sysfs files being updated from atomic contexts, and another lz4 bugfix
  for testing potential buffer overflows"

* tag 'driver-core-3.16-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  lz4: add overrun checks to lz4_uncompress_unknownoutputsize()
  kernfs: kernfs_notify() must be useable from non-sleepable contexts

Merge tag 'trace-fixes-v3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Oleg Nesterov found and fixed a bug in the perf/ftrace/uprobes code
  where running:

    # perf probe -x /lib/libc.so.6 syscall
    # echo 1 >> /sys/kernel/debug/tracing/events/probe_libc/enable
    # perf record -e probe_libc:syscall whatever

  kills the uprobe.  Along the way he found some other minor bugs and
  clean ups that he fixed up making it a total of 4 patches.

  Doing unrelated work, I found that the reading of the ftrace trace
  file disables all function tracer callbacks.  This was fine when
  ftrace was the only user, but now that it's used by perf and kprobes,
  this is a bug where reading trace can disable kprobes and perf.  A
  very unexpected side effect and should be fixed"

* tag 'trace-fixes-v3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Remove ftrace_stop/start() from reading the trace file
  tracing/uprobes: Fix the usage of uprobe_buffer_enable() in probe_event_enable()
  tracing/uprobes: Kill the bogus UPROBE_HANDLER_REMOVE code in uprobe_dispatcher()
  uprobes: Change unregister/apply to WARN() if uprobe/consumer is gone
  tracing/uprobes: Revert "Support mix of ftrace and perf"

Pull kbuild fix from Michal Marek:
 "There is one more fix for the relative paths series from -rc1: Print
  the path to the build directory at the start of the build, so that
  editors and IDEs can match the relative paths to source files"

* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  kbuild: Print the name of the build directory

Pull nfsd bugfixes from Bruce Fields:
 "By coincidence, two NFSv4 symlink bugs, one introduced in the 3.16 xdr
  encoding rewrite, the other a decoding bug that I think we've had
  since the start but that just doesn't trigger very often"

* 'for-3.16' of git://linux-nfs.org/~bfields/linux:
  nfs: fix nfs4d readlink truncated packet
  nfsd: fix rare symlink decoding bug

The 'sysret' fastpath does not correctly restore even all regular
registers, much less any segment registers or reflags values.  That is
very much part of why it's faster than 'iret'.

Normally that isn't a problem, because the normal ptrace() interface
catches the process using the signal handler infrastructure, which
always returns with an iret.

However, some paths can get caught using ptrace_event() instead of the
signal path, and for those we need to make sure that we aren't going to
return to user space using 'sysret'.  Otherwise the modifications that
may have been done to the register set by the tracer wouldn't
necessarily take effect.

Fix it by forcing IRET path by setting TIF_NOTIFY_RESUME from
arch_ptrace_stop_needed() which is invoked from ptrace_stop().
Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Jan points out that I forgot to make the needed fixes to the
lz4_uncompress_unknownoutputsize() function to mirror the changes done
in lz4_decompress() with regards to potential pointer overflows.

The only in-kernel user of this function is the zram code, which only
takes data from a valid compressed buffer that it made itself, so it's
not a big issue.  But due to external kernel modules using this
function, it's better to be safe here.
Reported-by: NJan Beulich <JBeulich@suse.com>
Cc: "Don A. Bailey" <donb@securitymouse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge fixes from Andrew Morton:
 "14 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  shmem: fix init_page_accessed use to stop !PageLRU bug
  kernel/printk/printk.c: revert "printk: enable interrupts before calling console_trylock_for_printk()"
  tools/testing/selftests/ipc/msgque.c: improve error handling when not running as root
  fs/seq_file: fallback to vmalloc allocation
  /proc/stat: convert to single_open_size()
  hwpoison: fix the handling path of the victimized page frame that belong to non-LRU
  mm:vmscan: update the trace-vmscan-postprocess.pl for event vmscan/mm_vmscan_lru_isolate
  msync: fix incorrect fstart calculation
  zram: revalidate disk after capacity change
  tools: memory-hotplug fix unexpected operator error
  tools: cpu-hotplug fix unexpected operator error
  autofs4: fix false positive compile error
  slub: fix off by one in number of slab tests
  mm: page_alloc: fix CMA area initialisation when pageblock > MAX_ORDER

Under shmem swapping load, I sometimes hit the VM_BUG_ON_PAGE(!PageLRU)
in isolate_lru_pages() at mm/vmscan.c:1281!

Commit 2457aec6 ("mm: non-atomically mark page accessed during page
cache allocation where possible") looks like interrupted work-in-progress.

mm/filemap.c's call to init_page_accessed() is fine, but not mm/shmem.c's
- shmem_write_begin() is clearly wrong to use it after shmem_getpage(),
when the page is always visible in radix_tree, and often already on LRU.

Revert change to shmem_write_begin(), and use init_page_accessed() or
mark_page_accessed() appropriately for SGP_WRITE in shmem_getpage_gfp().

SGP_WRITE also covers shmem_symlink(), which did not mark_page_accessed()
before; but since many other filesystems use [__]page_symlink(), which did
and does mark the page accessed, consider this as rectifying an oversight.
Signed-off-by: NHugh Dickins <hughd@google.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Prabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/printk/printk.c: revert "printk: enable interrupts before calling console_trylock_for_printk()"

Revert commit 939f04be ("printk: enable interrupts before calling
console_trylock_for_printk()").

Andreas reported:

: None of the post 3.15 kernel boot for me. They all hang at the GRUB
: screen telling me it loaded and started the kernel, but the kernel
: itself stops before it prints anything (or even replaces the GRUB
: background graphics).

939f04be is modest latency reduction.  Revert it until we understand
the reason for these failures.
Reported-by: NAndreas Bombe <aeb@debian.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The test fails in the middle when it is not run as root while accessing
/proc/sys/kernel/msg_next_id.  Changed it to check for root at the
beginning of the test and exit if not root.
Signed-off-by: NShuah Khan <shuah.kh@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Colin Ian King <colin.king@canonical.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are a couple of seq_files which use the single_open() interface.
This interface requires that the whole output must fit into a single
buffer.

E.g.  for /proc/stat allocation failures have been observed because an
order-4 memory allocation failed due to memory fragmentation.  In such
situations reading /proc/stat is not possible anymore.

Therefore change the seq_file code to fallback to vmalloc allocations
which will usually result in a couple of order-0 allocations and hence
also work if memory is fragmented.

For reference a call trace where reading from /proc/stat failed:

  sadc: page allocation failure: order:4, mode:0x1040d0
  CPU: 1 PID: 192063 Comm: sadc Not tainted 3.10.0-123.el7.s390x #1
  [...]
  Call Trace:
    show_stack+0x6c/0xe8
    warn_alloc_failed+0xd6/0x138
    __alloc_pages_nodemask+0x9da/0xb68
    __get_free_pages+0x2e/0x58
    kmalloc_order_trace+0x44/0xc0
    stat_open+0x5a/0xd8
    proc_reg_open+0x8a/0x140
    do_dentry_open+0x1bc/0x2c8
    finish_open+0x46/0x60
    do_last+0x382/0x10d0
    path_openat+0xc8/0x4f8
    do_filp_open+0x46/0xa8
    do_sys_open+0x114/0x1f0
    sysc_tracego+0x14/0x1a
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: NDavid Rientjes <rientjes@google.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Thorsten Diehl <thorsten.diehl@de.ibm.com>
Cc: Andrea Righi <andrea@betterlinux.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Stefan Bader <stefan.bader@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

These two patches are supposed to "fix" failed order-4 memory
allocations which have been observed when reading /proc/stat.  The
problem has been observed on s390 as well as on x86.

To address the problem change the seq_file memory allocations to
fallback to use vmalloc, so that allocations also work if memory is
fragmented.

This approach seems to be simpler and less intrusive than changing
/proc/stat to use an interator.  Also it "fixes" other users as well,
which use seq_file's single_open() interface.

This patch (of 2):

Use seq_file's single_open_size() to preallocate a buffer that is large
enough to hold the whole output, instead of open coding it.  Also
calculate the requested size using the number of online cpus instead of
possible cpus, since the size of the output only depends on the number
of online cpus.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Thorsten Diehl <thorsten.diehl@de.ibm.com>
Cc: Andrea Righi <andrea@betterlinux.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Stefan Bader <stefan.bader@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Until now, the kernel has the same policy to handle victimized page
frames that belong to kernel-space(reserved/slab-subsystem) or
non-LRU(unknown page state).  In other word, the result of handling
either of these victimized page frames is (IGNORED | FAILED), and the
return value of memory_failure() is -EBUSY.

This patch is to avoid that memory_failure() returns very soon due to
the "true" value of (!PageLRU(p)), and it also ensures that
action_result() can report more precise information("reserved kernel",
"kernel slab", and "unknown page state") instead of "non LRU",
especially for memory errors which are detected by memory-scrubbing.

Andi said:

: While running the mcelog test suite on 3.14 I hit the following VM_BUG_ON:
:
: soft_offline: 0x56d4: unknown non LRU page type 3ffff800008000
: page:ffffea000015b400 count:3 mapcount:2097169 mapping:          (null) index:0xffff8800056d7000
: page flags: 0x3ffff800004081(locked|slab|head)
: ------------[ cut here ]------------
: kernel BUG at mm/rmap.c:1495!
:
: I think what happened is that a LRU page turned into a slab page in
: parallel with offlining.  memory_failure initially tests for this case,
: but doesn't retest later after the page has been locked.
:
: ...
:
: I ran this patch in a loop over night with some stress plus
: the mcelog test suite running in a loop. I cannot guarantee it hit it,
: but it should have given it a good beating.
:
: The kernel survived with no messages, although the mcelog test suite
: got killed at some point because it couldn't fork anymore. Probably
: some unrelated problem.
:
: So the patch is ok for me for .16.
Signed-off-by: NChen Yucong <slaoub@gmail.com>
Acked-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: NAndi Kleen <andi@firstfloor.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When using trace-vmscan-postprocess.pl for checking the file/anon rate
of scanning, we can find that it can not be performed.  At the same
time, the following message will be reported:

  WARNING: Format not as expected for event vmscan/mm_vmscan_lru_isolate
  'file' != 'contig_taken' Fewer fields than expected in format at
  ./trace-vmscan-postprocess.pl line 171, <FORMAT> line 76.

In trace-vmscan-postprocess.pl, (contig_taken, contig_dirty, and
contig_failed) are be associated respectively to (nr_lumpy_taken,
nr_lumpy_dirty, and nr_lumpy_failed) for lumpy reclaim.  Via commit
c53919ad ("mm: vmscan: remove lumpy reclaim"), lumpy reclaim had
already been removed by Mel, but the update for
trace-vmscan-postprocess.pl was missed.
Signed-off-by: NChen Yucong <slaoub@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a regression caused by 7fc34a62 ("mm/msync.c: sync only the
requested range in msync()").

xfstests generic/075 fail occured on ext4 data=journal mode because the
intended range was not syncing due to wrong fstart calculation.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAshish Sangwan <a.sangwan@samsung.com>
Reported-by: NEric Whitney <enwlinux@gmail.com>
Tested-by: NEric Whitney <enwlinux@gmail.com>
Acked-by: NMatthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
Tested-by: NLukas Czerner <lczerner@redhat.com>
Reviewed-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Alexander reported mkswap on /dev/zram0 is failed if other process is
opening the block device file.

Step is as follows,

0. Reset the unused zram device.
1. Use a program that opens /dev/zram0 with O_RDWR and sleeps
   until killed.
2. While that program sleeps, echo the correct value to
   /sys/block/zram0/disksize.
3. Verify (e.g. in /proc/partitions) that the disk size is applied
   correctly. It is.
4. While that program still sleeps, attempt to mkswap /dev/zram0.
   This fails: mkswap: error: swap area needs to be at least 40 KiB

When I investigated, the size get by ioctl(fd, BLKGETSIZE64, xxx) on
mkswap to get a size of blockdev was zero although zram0 has right size by
2.

The reason is zram didn't revalidate disk after changing capacity so that
size of blockdev's inode is not uptodate until all of file is close.

This patch should fix the BUG.
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Reported-by: NAlexander E. Patrakov <patrakov@gmail.com>
Tested-by: NAlexander E. Patrakov <patrakov@gmail.com>
Reviewed-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Acked-by: NJerome Marchand <jmarchan@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

on-off-test uses "$UID != 0" to test for root, but $UID is a construct
specific to bash.  Using /bin/sh that isn't bash results in the
following error (due to the "$UID" part expanding to nothing):

  ./on-off-test.sh: 9: [: !=: unexpected operator

Change Makefile to use bash instead.
Signed-off-by: NShuah Khan <shuah.kh@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

on-off-test uses "$UID != 0" to test for root, but $UID is a construct
specific to bash.  Using /bin/sh that isn't bash results in the
following error (due to the "$UID" part expanding to nothing):

  ./on-off-test.sh: 9: [: !=: unexpected operator

Change Makefile to use bash instead.
Signed-off-by: NShuah Khan <shuah.kh@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On strict build environments we can see:

  fs/autofs4/inode.c: In function 'autofs4_fill_super':
  fs/autofs4/inode.c:312: error: 'pgrp' may be used uninitialized in this function
  make[2]: *** [fs/autofs4/inode.o] Error 1
  make[1]: *** [fs/autofs4] Error 2
  make: *** [fs] Error 2
  make: *** Waiting for unfinished jobs....

This is due to the use of pgrp_set being used to indicate pgrp has has
been set rather than initializing pgrp itself.
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

min_partial means minimum number of slab cached in node partial list.
So, if nr_partial is less than it, we keep newly empty slab on node
partial list rather than freeing it.  But if nr_partial is equal or
greater than it, it means that we have enough partial slabs so should
free newly empty slab.  Current implementation missed the equal case so
if we set min_partial is 0, then, at least one slab could be cached.
This is critical problem to kmemcg destroying logic because it doesn't
works properly if some slabs is cached.  This patch fixes this problem.

Fixes 91cb69620284 ("slub: make dead memcg caches discard free slabs
immediately").
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: NVladimir Davydov <vdavydov@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>