The recent comment:
commit 7e83ccbe
    md/raid10: Allow skipping recovery when clean arrays are assembled

Causes raid10 to skip a recovery in certain cases where it is safe to
do so.  Unfortunately it also causes a reshape to be skipped which is
never safe.  The result is that an attempt to reshape a RAID10 will
appear to complete instantly, but no data will have been moves so the
array will now contain garbage.
(If nothing is written, you can recovery by simple performing the
reverse reshape which will also complete instantly).

Bug was introduced in 3.10, so this is suitable for 3.10-stable.

Cc: stable@vger.kernel.org (3.10)
Cc: Martin Wilck <mwilck@arcor.de>
Signed-off-by: NNeilBrown <neilb@suse.de>

There is a bug in 'check_reshape' for raid5.c  To checks
that the new minimum number of devices is large enough (which is
good), but it does so also after the reshape has started (bad).

This is bad because
 - the calculation is now wrong as mddev->raid_disks has changed
   already, and
 - it is pointless because it is now too late to stop.

So only perform that test when reshape has not been committed to.
Signed-off-by: NNeilBrown <neilb@suse.de>

1/ If a RAID10 is being reshaped to a fewer number of devices
 and is stopped while this is ongoing, then when the array is
 reassembled the 'mirrors' array will be allocated too small.
 This will lead to an access error or memory corruption.

2/ A sanity test for a reshaping RAID10 array is restarted
 is slightly incorrect.

Due to the first bug, this is suitable for any -stable
kernel since 3.5 where this code was introduced.

Cc: stable@vger.kernel.org (v3.5+)
Signed-off-by: NNeilBrown <neilb@suse.de>

After last md.txt edits for sync_min/max, sync_max description became
doubled. Removing 1st copy, merging details into common
sync_min/sync_max section.
Signed-off-by: NRoman Ovchinnikov <coolthecold@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

MD:  Remember the last sync operation that was performed

This patch adds a field to the mddev structure to track the last
sync operation that was performed.  This is especially useful when
it comes to what is recorded in mismatch_cnt in sysfs.  If the
last operation was "data-check", then it reports the number of
descrepancies found by the user-initiated check.  If it was a
"repair" operation, then it is reporting the number of
descrepancies repaired.  etc.
Signed-off-by: NJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

RAID5 uses a 'per-array' value for the 'size' of each device.
RAID0 uses a 'per-device' value - it can be different for each device.

When converting a RAID5 to a RAID0 we must ensure that the per-device
size of each device matches the per-array size for the RAID5, else
the array will change size.

If the metadata cannot record a changed per-device size (as is the
case with v0.90 metadata) the array could get bigger on restart.  This
does not cause data corruption, so it not a big issue and is mainly
yet another a reason to not use 0.90.
Signed-off-by: NNeilBrown <neilb@suse.de>

It isn't really enough to check that the rdev is present, we need to
also be sure that the device is still In_sync.

Doing this requires using rcu_dereference to access the rdev, and
holding the rcu_read_lock() to ensure the rdev doesn't disappear while
we look at it.
Signed-off-by: NNeilBrown <neilb@suse.de>

As 'enough' accesses conf->prev and conf->geo, which can change
spontanously, it should guard against changes.
This can be done with device_lock as start_reshape holds device_lock
while updating 'geo' and end_reshape holds it while updating 'prev'.

So 'error' needs to hold 'device_lock'.

On the other hand, raid10_end_read_request knows which of the two it
really wants to access, and as it is an active request on that one,
the value cannot change underneath it.

So change _enough to take flag rather than a pointer, pass the
appropriate flag from raid10_end_read_request(), and remove the locking.

All other calls to 'enough' are made with reconfig_mutex held, so
neither 'prev' nor 'geo' can change.
Signed-off-by: NNeilBrown <neilb@suse.de>

The usage of strict_strtoul() is not preferred, because
strict_strtoul() is obsolete. Thus, kstrtoul() should be
used.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

When a device has failed, it needs to be removed from the personality
module before it can be removed from the array as a whole.
The first step is performed by md_check_recovery() which is called
from the raid management thread.

So when a HOT_REMOVE ioctl arrives, wait briefly for md_check_recovery
to have run.  This increases the chance that the ioctl will succeed.
Signed-off-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NNeil Brown <nfbrown@suse.de>

This doesn't really need to be initialised, but it doesn't hurt,
silences the compiler, and as it is a counter it makes sense for it to
start at zero.
Signed-off-by: NNeilBrown <neilb@suse.de>

DM RAID:  Fix raid_resume not reviving failed devices in all cases

When a device fails in a RAID array, it is marked as Faulty.  Later,
md_check_recovery is called which (through the call chain) calls
'hot_remove_disk' in order to have the personalities remove the device
from use in the array.

Sometimes, it is possible for the array to be suspended before the
personalities get their chance to perform 'hot_remove_disk'.  This is
normally not an issue.  If the array is deactivated, then the failed
device will be noticed when the array is reinstantiated.  If the
array is resumed and the disk is still missing, md_check_recovery will
be called upon resume and 'hot_remove_disk' will be called at that
time.  However, (for dm-raid) if the device has been restored,
a resume on the array would cause it to attempt to revive the device
by calling 'hot_add_disk'.  If 'hot_remove_disk' had not been called,
a situation is then created where the device is thought to concurrently
be the replacement and the device to be replaced.  Thus, the device
is first sync'ed with the rest of the array (because it is the replacement
device) and then marked Faulty and removed from the array (because
it is also the device being replaced).

The solution is to check and see if the device had properly been removed
before the array was suspended.  This is done by seeing whether the
device's 'raid_disk' field is -1 - a condition that implies that
'md_check_recovery -> remove_and_add_spares (where raid_disk is set to -1)
-> hot_remove_disk' has been called.  If 'raid_disk' is not -1, then
'hot_remove_disk' must be called to complete the removal of the previously
faulty device before it can be revived via 'hot_add_disk'.
Signed-off-by: NJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

DM RAID:  Break-up untidy function

Clean-up excessive indentation by moving some code in raid_resume()
into its own function.
Signed-off-by: NJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

DM RAID: Add ability to restore transiently failed devices on resume

This patch adds code to the resume function to check over the devices
in the RAID array.  If any are found to be marked as failed and their
superblocks can be read, an attempt is made to reintegrate them into
the array.  This allows the user to refresh the array with a simple
suspend and resume of the array - rather than having to load a
completely new table, allocate and initialize all the structures and
throw away the old instantiation.
Signed-off-by: NJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

Pull ACPI fix from Rafael Wysocki:
 "This is an alternative fix for the regression introduced in 3.9 whose
  previous fix had to be reverted right before 3.10-rc5, because it
  broke one of the Tony's machines.

  In this one the check is confined to the ACPI video driver (which is
  the only one causing the problem to happen in the first place) and the
  Tony's box shouldn't even notice it.

   - ACPI fix for an issue causing ACPI video driver to attempt to bind
     to devices it shouldn't touch from Rafael J Wysocki."

* tag 'acpi-3.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / video: Do not bind to device objects with a scan handler

Pull x86 fixes from Peter Anvin:
 "Another set of fixes, the biggest bit of this is yet another tweak to
  the UEFI anti-bricking code; apparently we finally got some feedback
  from Samsung as to what makes at least their systems fail.  This set
  should actually fix the boot regressions that some other systems (e.g.
  SGI) have exhibited.

  Other than that, there is a patch to avoid a panic with particularly
  unhappy memory layouts and two minor protocol fixes which may or may
  not be manifest bugs"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Fix typo in kexec register clearing
  x86, relocs: Move __vvar_page from S_ABS to S_REL
  Modify UEFI anti-bricking code
  x86: Fix adjust_range_size_mask calling position

Pull RCU fixes from Paul McKenney:
 "I must confess that this past merge window was not RCU's best showing.
  This series contains three more fixes for RCU regressions:

   1.   A fix to __DECLARE_TRACE_RCU() that causes it to act as an
        interrupt from idle rather than as a task switch from idle.
        This change is needed due to the recent use of _rcuidle()
        tracepoints that can be invoked from interrupt handlers as well
        as from idle.  Without this fix, invoking _rcuidle() tracepoints
        from interrupt handlers results in splats and (more seriously)
        confusion on RCU's part as to whether a given CPU is idle or not.
        This confusion can in turn result in too-short grace periods and
        therefore random memory corruption.

   2.   A fix to a subtle deadlock that could result due to RCU doing
        a wakeup while holding one of its rcu_node structure's locks.
        Although the probability of occurrence is low, it really
        does happen.  The fix, courtesy of Steven Rostedt, uses
        irq_work_queue() to avoid the deadlock.

   3.   A fix to a silent deadlock (invisible to lockdep) due to the
        interaction of timeouts posted by RCU debug code enabled by
        CONFIG_PROVE_RCU_DELAY=y, grace-period initialization, and CPU
        hotplug operations.  This will not occur in production kernels,
        but really does occur in randconfig testing.  Diagnosis courtesy
        of Steven Rostedt"

* 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
  rcu: Fix deadlock with CPU hotplug, RCU GP init, and timer migration
  rcu: Don't call wakeup() with rcu_node structure ->lock held
  trace: Allow idle-safe tracepoints to be called from irq

Pull s390 fixes from Martin Schwidefsky:
 "Three kvm related memory management fixes, a fix for show_trace, a fix
  for early console output and a patch from Ben to help prevent compile
  errors in regard to irq functions (or our lack thereof)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/pci: Implement IRQ functions if !PCI
  s390/sclp: fix new line detection
  s390/pgtable: make pgste lock an explicit barrier
  s390/pgtable: Save pgste during modify_prot_start/commit
  s390/dumpstack: fix address ranges for asynchronous and panic stack
  s390/pgtable: Fix guest overindication for change bit

Pull ASoC sound updates from Mark Brown:
 "Takashi is travelling at the minute and it'd be good to get the
  MAINTAINERS update in here merged so sending directly.

  As well as the usual driver specifics we've got a couple of core fixes
  here, one fixing capabilities for unidirectional streams and the other
  fixing suspend while audio streams are active.

  The suspend fix is a little involved but mostly as a result of
  removing some special casing that was doing the wrong thing."

* tag 'asoc-v3.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound:
  ASoC: tlv320aic3x: Remove deadlock from snd_soc_dapm_put_volsw_aic3x()
  ASoC: dapm: Treat DAI widgets like AIF widgets for power
  ASoC: arizona: Correct AEC loopback enable
  ASoC: pcm: Require both CODEC and CPU support when declaring stream caps
  MAINTAINERS: Remove myself from Wolfson maintainers
  ASoC: wm8994: Ensure microphone detection state is reset on removal
  ASoC: wm8994: Avoid leaking pm_runtime reference on removed jack race
  ASoC: cs42l52: fix hp_gain_enum shift value.
  ASoC: cs42l52: use correct PCM mixer TLV dB scale to match datasheet.

Pull md bugfixes from Neil Brown:
 "A few bugfixes for md

  Some tagged for -stable"

* tag 'md-3.10-fixes' of git://neil.brown.name/md:
  md/raid1,5,10: Disable WRITE SAME until a recovery strategy is in place
  md/raid1,raid10: use freeze_array in place of raise_barrier in various places.
  md/raid1: consider WRITE as successful only if at least one non-Faulty and non-rebuilding drive completed it.
  md: md_stop_writes() should always freeze recovery.

On platforms with C8-C10 support, the additional C-states cause
turbostat to overrun its output buffer of 128 bytes per CPU.  Increase
this to 256 bytes per CPU.

[ As a bugfix, this should go into 3.10; however, since the C8-C10
  support didn't go in until after 3.9, this need not go into any stable
  kernel. ]
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

 * More tweaking to the EFI variable anti-bricking algorithm. Quite a
   few users were reporting boot regressions in v3.9. This has now been
   fixed with a more accurate "minimum storage requirement to avoid
   bricking" value from Samsung (5K instead of 50%) and code to trigger
   garbage collection when we near our limit - Matthew Garrett.
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

There are cases where the kernel will believe that the WRITE SAME
command is supported by a block device which does not, in fact,
support WRITE SAME.  This currently happens for SATA drivers behind a
SAS controller, but there are probably a hundred other ways that can
happen, including drive firmware bugs.

After receiving an error for WRITE SAME the block layer will retry the
request as a plain write of zeroes, but mdraid will consider the
failure as fatal and consider the drive failed.  This has the effect
that all the mirrors containing a specific set of data are each
offlined in very rapid succession resulting in data loss.

However, just bouncing the request back up to the block layer isn't
ideal either, because the whole initial request-retry sequence should
be inside the write bitmap fence, which probably means that md needs
to do its own conversion of WRITE SAME to write zero.

Until the failure scenario has been sorted out, disable WRITE SAME for
raid1, raid5, and raid10.

[neilb: added raid5]

This patch is appropriate for any -stable since 3.7 when write_same
support was added.

Cc: stable@vger.kernel.org
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

Various places in raid1 and raid10 are calling raise_barrier when they
really should call freeze_array.
The former is only intended to be called from "make_request".
The later has extra checks for 'nr_queued' and makes a call to
flush_pending_writes(), so it is safe to call it from within the
management thread.

Using raise_barrier will sometimes deadlock.  Using freeze_array
should not.

As 'freeze_array' currently expects one request to be pending (in
handle_read_error - the only previous caller), we need to pass
it the number of pending requests (extra) to ignore.

The deadlock was made particularly noticeable by commits
050b6615 (raid10) and 6b740b8d (raid1) which
appeared in 3.4, so the fix is appropriate for any -stable
kernel since then.

This patch probably won't apply directly to some early kernels and
will need to be applied by hand.

Cc: stable@vger.kernel.org
Reported-by: NAlexander Lyakas <alex.bolshoy@gmail.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

md/raid1: consider WRITE as successful only if at least one non-Faulty and non-rebuilding drive completed it.

Without that fix, the following scenario could happen:

- RAID1 with drives A and B; drive B was freshly-added and is rebuilding
- Drive A fails
- WRITE request arrives to the array. It is failed by drive A, so
r1_bio is marked as R1BIO_WriteError, but the rebuilding drive B
succeeds in writing it, so the same r1_bio is marked as
R1BIO_Uptodate.
- r1_bio arrives to handle_write_finished, badblocks are disabled,
md_error()->error() does nothing because we don't fail the last drive
of raid1
- raid_end_bio_io()  calls call_bio_endio()
- As a result, in call_bio_endio():
        if (!test_bit(R1BIO_Uptodate, &r1_bio->state))
                clear_bit(BIO_UPTODATE, &bio->bi_flags);
this code doesn't clear the BIO_UPTODATE flag, and the whole master
WRITE succeeds, back to the upper layer.

So we returned success to the upper layer, even though we had written
the data onto the rebuilding drive only. But when we want to read the
data back, we would not read from the rebuilding drive, so this data
is lost.

[neilb - applied identical change to raid10 as well]

This bug can result in lost data, so it is suitable for any
-stable kernel.

Cc: stable@vger.kernel.org
Signed-off-by: NAlex Lyakas <alex@zadarastorage.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

__md_stop_writes() will currently sometimes freeze recovery.
So any caller must be ready for that to happen, and indeed they are.

However if __md_stop_writes() doesn't freeze_recovery, then
a recovery could start before mddev_suspend() is called, which
could be awkward.  This can particularly cause problems or dm-raid.

So change __md_stop_writes() to always freeze recovery.  This is safe
and more predicatable.
Reported-by: NBrassow Jonathan <jbrassow@redhat.com>
Tested-by: NBrassow Jonathan <jbrassow@redhat.com>
Signed-off-by: NNeilBrown <neilb@suse.de>

Pull networking update from David Miller:

 1) Fix dump iterator in nfnl_acct_dump() and ctnl_timeout_dump() to
    dump all objects properly, from Pablo Neira Ayuso.

 2) xt_TCPMSS must use the default MSS of 536 when no MSS TCP option is
    present.  Fix from Phil Oester.

 3) qdisc_get_rtab() looks for an existing matching rate table and uses
    that instead of creating a new one.  However, it's key matching is
    incomplete, it fails to check to make sure the ->data[] array is
    identical too.  Fix from Eric Dumazet.

 4) ip_vs_dest_entry isn't fully initialized before copying back to
    userspace, fix from Dan Carpenter.

 5) Fix ubuf reference counting regression in vhost_net, from Jason
    Wang.

 6) When sock_diag dumps a socket filter back to userspace, we have to
    translate it out of the kernel's internal representation first.
    From Nicolas Dichtel.

 7) davinci_mdio holds a spinlock while calling pm_runtime, which
    sleeps.  Fix from Sebastian Siewior.

 8) Timeout check in sh_eth_check_reset is off by one, from Sergei
    Shtylyov.

 9) If sctp socket init fails, we can NULL deref during cleanup.  Fix
    from Daniel Borkmann.

10) netlink_mmap() does not propagate errors properly, from Patrick
    McHardy.

11) Disable powersave and use minstrel by default in ath9k.  From Sujith
    Manoharan.

12) Fix a regression in that SOCK_ZEROCOPY is not set on tuntap sockets
    which prevents vhost from being able to use zerocopy.  From Jason
    Wang.

13) Fix race between port lookup and TX path in team driver, from Jiri
    Pirko.

14) Missing length checks in bluetooth L2CAP packet parsing, from Johan
    Hedberg.

15) rtlwifi fails to connect to networking using any encryption method
    other than WPA2.  Fix from Larry Finger.

16) Fix iwlegacy build due to incorrect CONFIG_* ifdeffing for power
    management stuff.  From Yijing Wang.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (35 commits)
  b43: stop format string leaking into error msgs
  ath9k: Use minstrel rate control by default
  Revert "ath9k_hw: Update rx gain initval to improve rx sensitivity"
  ath9k: Disable PowerSave by default
  net: wireless: iwlegacy: fix build error for il_pm_ops
  rtlwifi: Fix a false leak indication for PCI devices
  wl12xx/wl18xx: scan all 5ghz channels
  wl12xx: increase minimum singlerole firmware version required
  wl12xx: fix minimum required firmware version for wl127x multirole
  rtlwifi: rtl8192cu: Fix problem in connecting to WEP or WPA(1) networks
  mwifiex: debugfs: Fix out of bounds array access
  Bluetooth: Fix mgmt handling of power on failures
  Bluetooth: Fix missing length checks for L2CAP signalling PDUs
  Bluetooth: btmrvl: support Marvell Bluetooth device SD8897
  Bluetooth: Fix checks for LE support on LE-only controllers
  team: fix checks in team_get_first_port_txable_rcu()
  team: move add to port list before port enablement
  team: check return value of team_get_port_by_index_rcu() for NULL
  tuntap: set SOCK_ZEROCOPY flag during open
  netlink: fix error propagation in netlink_mmap()
  ...

Pull input layer bugfix from Jiri Kosina:
 "Memory leak regression fix from Benjamin Tissoires"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: multitouch: prevent memleak with the allocated name

Pull block layer fixes from Jens Axboe:
 "Outside of bcache (which really isn't super big), these are all
  few-liners.  There are a few important fixes in here:

   - Fix blk pm sleeping when holding the queue lock

   - A small collection of bcache fixes that have been done and tested
     since bcache was included in this merge window.

   - A fix for a raid5 regression introduced with the bio changes.

   - Two important fixes for mtip32xx, fixing an oops and potential data
     corruption (or hang) due to wrong bio iteration on stacked devices."

* 'for-linus' of git://git.kernel.dk/linux-block:
  scatterlist: sg_set_buf() argument must be in linear mapping
  raid5: Initialize bi_vcnt
  pktcdvd: silence static checker warning
  block: remove refs to XD disks from documentation
  blkpm: avoid sleep when holding queue lock
  mtip32xx: Correctly handle bio->bi_idx != 0 conditions
  mtip32xx: Fix NULL pointer dereference during module unload
  bcache: Fix error handling in init code
  bcache: clarify free/available/unused space
  bcache: drop "select CLOSURES"
  bcache: Fix incompatible pointer type warning

Merge misc fixes from Andrew Morton:
 "Bunch of fixes and one little addition to math64.h"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (27 commits)
  include/linux/math64.h: add div64_ul()
  mm: memcontrol: fix lockless reclaim hierarchy iterator
  frontswap: fix incorrect zeroing and allocation size for frontswap_map
  kernel/audit_tree.c:audit_add_tree_rule(): protect `rule' from kill_rules()
  mm: migration: add migrate_entry_wait_huge()
  ocfs2: add missing lockres put in dlm_mig_lockres_handler
  mm/page_alloc.c: fix watermark check in __zone_watermark_ok()
  drivers/misc/sgi-gru/grufile.c: fix info leak in gru_get_config_info()
  aio: fix io_destroy() regression by using call_rcu()
  rtc-at91rm9200: use shadow IMR on at91sam9x5
  rtc-at91rm9200: add shadow interrupt mask
  rtc-at91rm9200: refactor interrupt-register handling
  rtc-at91rm9200: add configuration support
  rtc-at91rm9200: add match-table compile guard
  fs/ocfs2/namei.c: remove unecessary ERROR when removing non-empty directory
  swap: avoid read_swap_cache_async() race to deadlock while waiting on discard I/O completion
  drivers/rtc/rtc-twl.c: fix missing device_init_wakeup() when booted with device tree
  cciss: fix broken mutex usage in ioctl
  audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE
  drivers/rtc/rtc-cmos.c: fix accidentally enabling rtc channel
  ...

There is div64_long() to handle the s64/long division, but no mocro do
u64/ul division.  It is necessary in some scenarios, so add this
function.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NAlex Shi <alex.shi@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The lockless reclaim hierarchy iterator currently has a misplaced
barrier that can lead to use-after-free crashes.

The reclaim hierarchy iterator consist of a sequence count and a
position pointer that are read and written locklessly, with memory
barriers enforcing ordering.

The write side sets the position pointer first, then updates the
sequence count to "publish" the new position.  Likewise, the read side
must read the sequence count first, then the position.  If the sequence
count is up to date, it's guaranteed that the position is up to date as
well:

  writer:                         reader:
  iter->position = position       if iter->sequence == expected:
  smp_wmb()                           smp_rmb()
  iter->sequence = sequence           position = iter->position

However, the read side barrier is currently misplaced, which can lead to
dereferencing stale position pointers that no longer point to valid
memory.  Fix this.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reported-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NTejun Heo <tj@kernel.org>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: <stable@kernel.org>		[3.10+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The bitmap accessed by bitops must have enough size to hold the required
numbers of bits rounded up to a multiple of BITS_PER_LONG.  And the
bitmap must not be zeroed by memset() if the number of bits cleared is
not a multiple of BITS_PER_LONG.

This fixes incorrect zeroing and allocation size for frontswap_map.  The
incorrect zeroing part doesn't cause any problem because frontswap_map
is freed just after zeroing.  But the wrongly calculated allocation size
may cause the problem.

For 32bit systems, the allocation size of frontswap_map is about twice
as large as required size.  For 64bit systems, the allocation size is
smaller than requeired if the number of bits is not a multiple of
BITS_PER_LONG.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

audit_add_tree_rule() must set 'rule->tree = NULL;' firstly, to protect
the rule itself freed in kill_rules().

The reason is when it is killed, the 'rule' itself may have already
released, we should not access it.  one example: we add a rule to an
inode, just at the same time the other task is deleting this inode.

The work flow for adding a rule:

    audit_receive() -> (need audit_cmd_mutex lock)
      audit_receive_skb() ->
        audit_receive_msg() ->
          audit_receive_filter() ->
            audit_add_rule() ->
              audit_add_tree_rule() -> (need audit_filter_mutex lock)
                ...
                unlock audit_filter_mutex
                get_tree()
                ...
                iterate_mounts() -> (iterate all related inodes)
                  tag_mount() ->
                    tag_trunk() ->
                      create_trunk() -> (assume it is 1st rule)
                        fsnotify_add_mark() ->
                          fsnotify_add_inode_mark() ->  (add mark to inode->i_fsnotify_marks)
                        ...
                        get_tree(); (each inode will get one)
                ...
                lock audit_filter_mutex

The work flow for deleting an inode:

    __destroy_inode() ->
     fsnotify_inode_delete() ->
       __fsnotify_inode_delete() ->
        fsnotify_clear_marks_by_inode() ->  (get mark from inode->i_fsnotify_marks)
          fsnotify_destroy_mark() ->
           fsnotify_destroy_mark_locked() ->
             audit_tree_freeing_mark() ->
               evict_chunk() ->
                 ...
                 tree->goner = 1
                 ...
                 kill_rules() ->   (assume current->audit_context == NULL)
                   call_rcu() ->   (rule->tree != NULL)
                     audit_free_rule_rcu() ->
                       audit_free_rule()
                 ...
                 audit_schedule_prune() ->  (assume current->audit_context == NULL)
                   kthread_run() ->    (need audit_cmd_mutex and audit_filter_mutex lock)
                     prune_one() ->    (delete it from prue_list)
                       put_tree(); (match the original get_tree above)
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When we have a page fault for the address which is backed by a hugepage
under migration, the kernel can't wait correctly and do busy looping on
hugepage fault until the migration finishes.  As a result, users who try
to kick hugepage migration (via soft offlining, for example) occasionally
experience long delay or soft lockup.

This is because pte_offset_map_lock() can't get a correct migration entry
or a correct page table lock for hugepage.  This patch introduces
migration_entry_wait_huge() to solve this.
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: NRik van Riel <riel@redhat.com>
Reviewed-by: NWanpeng Li <liwanp@linux.vnet.ibm.com>
Reviewed-by: NMichal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>	[2.6.35+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dlm_mig_lockres_handler() is missing a dlm_lockres_put() on an error path.
Signed-off-by: Njoyce <xuejiufei@huawei.com>
Reviewed-by: Nshencanquan <shencanquan@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The watermark check consists of two sub-checks.  The first one is:

	if (free_pages <= min + lowmem_reserve)
		return false;

The check assures that there is minimal amount of RAM in the zone.  If
CMA is used then the free_pages is reduced by the number of free pages
in CMA prior to the over-mentioned check.

	if (!(alloc_flags & ALLOC_CMA))
		free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);

This prevents the zone from being drained from pages available for
non-movable allocations.

The second check prevents the zone from getting too fragmented.

	for (o = 0; o < order; o++) {
		free_pages -= z->free_area[o].nr_free << o;
		min >>= 1;
		if (free_pages <= min)
			return false;
	}

The field z->free_area[o].nr_free is equal to the number of free pages
including free CMA pages.  Therefore the CMA pages are subtracted twice.
This may cause a false positive fail of __zone_watermark_ok() if the CMA
area gets strongly fragmented.  In such a case there are many 0-order
free pages located in CMA.  Those pages are subtracted twice therefore
they will quickly drain free_pages during the check against
fragmentation.  The test fails even though there are many free non-cma
pages in the zone.

This patch fixes this issue by subtracting CMA pages only for a purpose of
(free_pages <= min + lowmem_reserve) check.

Laura said:

  We were observing allocation failures of higher order pages (order 5 =
  128K typically) under tight memory conditions resulting in driver
  failure.  The output from the page allocation failure showed plenty of
  free pages of the appropriate order/type/zone and mostly CMA pages in
  the lower orders.

  For full disclosure, we still observed some page allocation failures
  even after applying the patch but the number was drastically reduced and
  those failures were attributed to fragmentation/other system issues.
Signed-off-by: NTomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Tested-by: NLaura Abbott <lauraa@codeaurora.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Tested-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Cc: <stable@vger.kernel.org>	[3.7+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The "info.fill" array isn't initialized so it can leak uninitialized stack
information to user space.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NRobin Holt <holt@sgi.com>
Acked-by: NDimitri Sivanich <sivanich@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There was a regression introduced by 36f55889 ("aio: refcounting
cleanup"), reported by Jens Axboe - the refcounting cleanup switched to
using RCU in the shutdown path, but the synchronize_rcu() was done in
the context of the io_destroy() syscall greatly increasing the time it
could block.

This patch switches it to call_rcu() and makes shutdown asynchronous
(more asynchronous than it was originally; before the refcount changes
io_destroy() would still wait on pending kiocbs).

Note that there's a global quota on the max outstanding kiocbs, and that
quota must be manipulated synchronously; otherwise io_setup() could
return -EAGAIN when there isn't quota available, and userspace won't
have any way of waiting until shutdown of the old kioctxs has finished
(besides busy looping).

So we release our quota before kioctx shutdown has finished, which
should be fine since the quota never corresponded to anything real
anyways.
Signed-off-by: NKent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Reported-by: NJens Axboe <axboe@kernel.dk>
Tested-by: NJens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>
Tested-by: NBenjamin LaHaise <bcrl@kvack.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for the at91sam9x5-family which must use the shadow
interrupt mask due to a hardware issue (causing RTC_IMR to always be
zero).
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Cc: Douglas Gilbert <dgilbert@interlog.com>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Ludovic Desroches <ludovic.desroches@atmel.com>
Cc: Robert Nelson <Robert.Nelson@digikey.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>