When selecting an oom victim, we use the same heuristic for both memory
cgroup and global oom.  The only difference is the scope of tasks to
select the victim from.  So we could just export an iterator over all
memcg tasks and keep all oom related logic in oom_kill.c, but instead we
duplicate pieces of it in memcontrol.c reusing some initially private
functions of oom_kill.c in order to not duplicate all of it.  That looks
ugly and error prone, because any modification of select_bad_process
should also be propagated to mem_cgroup_out_of_memory.

Let's rework this as follows: keep all oom heuristic related code private
to oom_kill.c and make oom_kill.c use exported memcg functions when it's
really necessary (like in case of iterating over memcg tasks).

Link: http://lkml.kernel.org/r/1470056933-7505-1-git-send-email-vdavydov@virtuozzo.comSigned-off-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Though the time_before and time_after family of functions were nicely
extended to support jiffies64, so that the interface would be consistent,
it was forgotten to also extend the before/after jiffies functions to
support jiffies64.  This commit brings the interface to parity between
jiffies and jiffies64, which is quite convenient.

Link: http://lkml.kernel.org/r/20160929033319.12188-1-Jason@zx2c4.comSigned-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fanotify code has its own lock (access_lock) to protect a list of events
waiting for a response from userspace.

However this is somewhat awkward as the same list_head in the event is
protected by notification_lock if it is part of the notification queue
and by access_lock if it is part of the fanotify private queue which
makes it difficult for any reliable checks in the generic code.  So make
fanotify use the same lock - notification_lock - for protecting its
private event list.

Link: http://lkml.kernel.org/r/1473797711-14111-6-git-send-email-jack@suse.czSigned-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NLino Sanfilippo <LinoSanfilippo@gmx.de>
Cc: Miklos Szeredi <mszeredi@redhat.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>

notification_mutex is used to protect the list of pending events.  As such
there's no reason to use a sleeping lock for it.  Convert it to a
spinlock.

[jack@suse.cz: fixed version]
  Link: http://lkml.kernel.org/r/1474031567-1831-1-git-send-email-jack@suse.cz
Link: http://lkml.kernel.org/r/1473797711-14111-5-git-send-email-jack@suse.czSigned-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NLino Sanfilippo <LinoSanfilippo@gmx.de>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Cc: Miklos Szeredi <mszeredi@redhat.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>

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the underflow checks were added to workingset_node_shadow_dec(),
they triggered immediately:

  kernel BUG at ./include/linux/swap.h:276!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: isofs usb_storage fuse xt_CHECKSUM ipt_MASQUERADE nf_nat_masquerade_ipv4 tun nf_conntrack_netbios_ns nf_conntrack_broadcast ip6t_REJECT nf_reject_ipv6
   soundcore wmi acpi_als pinctrl_sunrisepoint kfifo_buf tpm_tis industrialio acpi_pad pinctrl_intel tpm_tis_core tpm nfsd auth_rpcgss nfs_acl lockd grace sunrpc dm_crypt
  CPU: 0 PID: 20929 Comm: blkid Not tainted 4.8.0-rc8-00087-gbe67d60b #1
  Hardware name: System manufacturer System Product Name/Z170-K, BIOS 1803 05/06/2016
  task: ffff8faa93ecd940 task.stack: ffff8faa7f478000
  RIP: page_cache_tree_insert+0xf1/0x100
  Call Trace:
    __add_to_page_cache_locked+0x12e/0x270
    add_to_page_cache_lru+0x4e/0xe0
    mpage_readpages+0x112/0x1d0
    blkdev_readpages+0x1d/0x20
    __do_page_cache_readahead+0x1ad/0x290
    force_page_cache_readahead+0xaa/0x100
    page_cache_sync_readahead+0x3f/0x50
    generic_file_read_iter+0x5af/0x740
    blkdev_read_iter+0x35/0x40
    __vfs_read+0xe1/0x130
    vfs_read+0x96/0x130
    SyS_read+0x55/0xc0
    entry_SYSCALL_64_fastpath+0x13/0x8f
  Code: 03 00 48 8b 5d d8 65 48 33 1c 25 28 00 00 00 44 89 e8 75 19 48 83 c4 18 5b 41 5c 41 5d 41 5e 5d c3 0f 0b 41 bd ef ff ff ff eb d7 <0f> 0b e8 88 68 ef ff 0f 1f 84 00
  RIP  page_cache_tree_insert+0xf1/0x100

This is a long-standing bug in the way shadow entries are accounted in
the radix tree nodes. The shrinker needs to know when radix tree nodes
contain only shadow entries, no pages, so node->count is split in half
to count shadows in the upper bits and pages in the lower bits.

Unfortunately, the radix tree implementation doesn't know of this and
assumes all entries are in node->count. When there is a shadow entry
directly in root->rnode and the tree is later extended, the radix tree
implementation will copy that entry into the new node and and bump its
node->count, i.e. increases the page count bits. Once the shadow gets
removed and we subtract from the upper counter, node->count underflows
and triggers the warning. Afterwards, without node->count reaching 0
again, the radix tree node is leaked.

Limit shadow entries to when we have actual radix tree nodes and can
count them properly. That means we lose the ability to detect refaults
from files that had only the first page faulted in at eviction time.

Fixes: 449dd698 ("mm: keep page cache radix tree nodes in check")
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reported-and-tested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This function is only used in a single place and no new users will be
added as all the devices other required GPIOs are already handled. As
such just merge the code back into the calling function.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>

The McPDM in OMAP4/5 is using the pdmclk from twl6040 as functional clock.
The twl6040-pdmclk driver provides a clock which can be used to make sure
that the pdmclk is active when the McPDM is in use.
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

There are no call sites for these functions.  Strip them out.
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Due to the lack of parity in the way array fields have been named/
numbered, a mistake was made where more debug fields were declared
than actually existed.  In doing so, 2 fields were added, which
although unclear, were already declared in the array.  The result
was that the latter declarations trashed the former ones.

This patch places the array back in the correct order and removes
the offending NULL entries.

While we're at it, let's ensure this doesn't happen again by naming
each field properly and add a new *_LAST define to describe how
many fields there should be.
Signed-off-by: NLee Jones <lee.jones@linaro.org>

When building with -Woverride-init, we get a warning about an incorrect
initializer:

drivers/mfd/rk808.c:244:8: error: initialized field overwritten [-Werror=override-init]
  [RK818_IRQ_DISCHG_ILIM] = {

This is clearly a mistake, as both RK818_IRQ_DISCHG_ILIM and RK818_IRQ_USB_OV
are defined as '7', but they refer to different register bits. Changing
RK818_IRQ_DISCHG_ILIM to 15 is consistent with how all other 14 interrupts are
handled here, so I'm assuming this is what it should have been.

Fixes: 2eedcbfc ("mfd: rk808: Add RK818 support")
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NAndy Yan <andy.yan@rock-chips.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

The mutex is not used, so remove it.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Add support for handling IRQs: power button, AC and USB power state
changes. Mask and interrupt bits are shared within one register, which
prevents us to use regmap_irq implementation. New irq_domain is created in
order to add interrupt handling for each tps65217's subsystem. IRQ
resources have been added for charger subsystem to be able to notify about
AC and USB state changes.
Signed-off-by: NMarcin Niestroj <m.niestroj@grinn-global.com>
Reviewed-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Tested-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

This patch adds common driver for the Top block of the Samsung Exynos
SoC Low Power Audio Subsystem.  This is a minimal driver which prepares
resources for IP blocks like I2S, audio DMA and UART and exposes
a regmap for the Top block registers.  Also system power ops are added
to ensure the Audio Subsystem is operational after system suspend/resume
cycle.
Signed-off-by: NInha Song <ideal.song@samsung.com>
Signed-off-by: NBeomho Seo <beomho.seo@samsung.com>
Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Tested-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Change my email address to kernel.org instead of Samsung one for the
purpose of any future contact.  The copyrights remain untouched and are
attributed to Samsung.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

set_bit() and clear_bit() take the bit number so this code is really
doing "1 << (1 << irq)" which is a double shift bug.  It's done
consistently so it won't cause a problem unless "irq" is more than 4.

Fixes: 70c6cce0 ('mfd: Support 88pm80x in 80x driver')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Remove incorrect e-mail addresses from the copyright header and
MODULE_AUTHOR() macro. These e-mail addresses are no longer in use.

The author names have not been changed, only the e-mail addresses have
been deleted from the source files.
Signed-off-by: NSteve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

This patch adds requesting of the clocks supplied on MCLK1, MCLK2 pins,
gating of the 32k clock is added to the arizona_clk32k_enable(),
arizona_clk32k_disable() helpers.

It's a temporary change until the CODEC's clock controller gets exposed
through the clk API and is helpful for board configurations where the
MCLK clocks are not provided by always on oscillators.
Signed-off-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

This introduces ncsi_stop_dev(), as counterpart to ncsi_start_dev(),
to stop the NCSI device so that it can be reenabled in future. This
API should be called when the network device driver is going to
shutdown the device. There are 3 things done in the function: Stop
the channel monitoring; Reset channels to inactive state; Report
NCSI link down.
Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: NJoel Stanley <joel@jms.id.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Edge-rate:
As system and networking speeds increase, a signal's output transition,
also know as the edge rate or slew rate (V/ns), takes on greater importance
because high-speed signals come with a price. That price is an assortment of
interference problems like ringing on the line, signal overshoot and
undershoot, extended signal settling times, crosstalk noise, transmission
line reflections, false signal detection by the receiving device and
electromagnetic interference (EMI) -- all of which can negate the potential
gains designers are seeking when they try to increase system speeds through
the use of higher performance logic devices. The fact is, faster signaling
edge rates can cause a higher level of electrical noise or other type of
interference that can actually lead to slower line speeds and lower maximum
system frequencies. This parameter allow the board designers to change the
driving strange, and thereby change the EMI behavioral.

Edge-rate parameters (vddmac, edge-slowdown) get from Device Tree.

Tested on Beaglebone Black with VSC 8531 PHY.
Signed-off-by: NRaju Lakkaraju <Raju.Lakkaraju@microsemi.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

That just generally kills the machine, and makes debugging only much
harder, since the traces may long be gone.

Debugging by assert() is a disease.  Don't do it.  If you can continue,
you're much better off doing so with a live machine where you have a
much higher chance that the report actually makes it to the system logs,
rather than result in a machine that is just completely dead.

The only valid situation for BUG_ON() is when continuing is not an
option, because there is massive corruption.  But if you are just
verifying that something is true, you warn about your broken assumptions
(preferably just once), and limp on.

Fixes: 22f2ac51 ("mm: workingset: fix crash in shadow node shrinker caused by replace_page_cache_page()")
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add the RoCE-specific LL2 logic [as well as GSI support] over
the 'generic' LL2 interface.
Signed-off-by: NRam Amrani <Ram.Amrani@caviumnetworks.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@caviumnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add slowpath configuration support for user, dma and memory
regions registration.
Signed-off-by: NRam Amrani <Ram.Amrani@caviumnetworks.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@caviumnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for the slowpath configurations of Queue Pair verbs
which adds, deletes, modifies and queries Queue Pairs.
Signed-off-by: NRam Amrani <Ram.Amrani@caviumnetworks.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@caviumnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for the configurations of the protection domain and
completion queues.
Signed-off-by: NRam Amrani <Ram.Amrani@caviumnetworks.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@caviumnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds the backbone required for the various HW initalizations
which are necessary for the qedr driver - FW notification, resource
initializations, etc.
Signed-off-by: NRam Amrani <Ram.Amrani@caviumnetworks.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@caviumnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adds a skeletal implementation of the qede RoCE driver -
The qedr has some dependencies of the state of the underlying base
interface. This adds some logic required with mutual registrations
and the ability to pass updates on 'intresting' events.
Signed-off-by: NRam Amrani <Ram.Amrani@caviumnetworks.com>
Signed-off-by: NYuval Mintz <Yuval.Mintz@caviumnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Other protocols beside the networking driver need the ability
of passing some L2 traffic, usually [although not limited] for the
purpose of some management traffic.
Signed-off-by: NYuval Mintz <Yuval.Mintz@caviumnetworks.com>
Signed-off-by: NRam Amrani <Ram.Amrani@caviumnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

of_gpiochip_add() and of_gpiochip_remove() are only used locally
in the gpio subsystem so move these functions to the local
header.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

skb_mpls_header is equivalent to mpls_hdr now. Use the existing helper
instead.
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This will be also used by openvswitch.
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Acked-by: NDavid Ahern <dsa@cumulusnetworks.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to be able to lock a rproc driver implementations only when
used by a client, we must differ between the dereference operation of a
client and the implementation itself.

This patch brings no functional change.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Add IB headers, defines, and accessors that are identical
in both qib and hfi1 into the core includes.

The accessors for be maintenance of __be64 fields since
alignment is potentially invalid and can differ based on
the presense of the GRH.

{hfi1,qib}_ib_headers will be ib_headers.
{hfi1,qib|_other_headers will be ib_other_headers.
Reviewed-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: NDon Hiatt <don.hiatt@intel.com>
Signed-off-by: NMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

Add a new INIT flag, FUSE_POSIX_ACL, for negotiating ACL support with
userspace.  When it is set in the INIT response, ACL support will be
enabled.  ACL support also implies "default_permissions".

When ACL support is enabled, the kernel will cache and have responsibility
for enforcing ACLs.  ACL xattrs will be passed to userspace, which is
responsible for updating the ACLs in the filesystem, keeping the file mode
in sync, and inheritance of default ACLs when new filesystem nodes are
created.
Signed-off-by: NSeth Forshee <seth.forshee@canonical.com>
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>

Only userspace filesystem can do the killing of suid/sgid without races.
So introduce an INIT flag and negotiate support for this.
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>

This fixes commit d76eebfa ("include/linux/property.h: fix build
issues with gcc-4.4.4").

With that commit we get the following compile error when using the
PROPERTY_ENTRY_INTEGER_ARRAY macro.

 include/linux/property.h:201:39: error: `u32_data' undeclared (first
                 use in this function)
  PROPERTY_ENTRY_INTEGER_ARRAY(_name_, u32, _val_)
                                       ^
 include/linux/property.h:193:17: note: in definition of macro
                 `PROPERTY_ENTRY_INTEGER_ARRAY'
  { .pointer = { _type_##_data = _val_ } },  \
                 ^

This needs a '.' to reference the union member.  It seems this was just
overlooked here since it is done correctly in similar constructs in
other parts of the original commit.

This fix is in preparation of upcoming commits that will use this macro.

Fixes: commit d76eebfa ("include/linux/property.h: fix build issues with gcc-4.4.4")
Link: http://lkml.kernel.org/r/2de3b929290d88a723ed829a3e3cbd02044714df.1475114627.git.johnyoun@synopsys.comSigned-off-by: NJohn Youn <johnyoun@synopsys.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Antonio reports the following crash when using fuse under memory pressure:

  kernel BUG at /build/linux-a2WvEb/linux-4.4.0/mm/workingset.c:346!
  invalid opcode: 0000 [#1] SMP
  Modules linked in: all of them
  CPU: 2 PID: 63 Comm: kswapd0 Not tainted 4.4.0-36-generic #55-Ubuntu
  Hardware name: System manufacturer System Product Name/P8H67-M PRO, BIOS 3904 04/27/2013
  task: ffff88040cae6040 ti: ffff880407488000 task.ti: ffff880407488000
  RIP: shadow_lru_isolate+0x181/0x190
  Call Trace:
    __list_lru_walk_one.isra.3+0x8f/0x130
    list_lru_walk_one+0x23/0x30
    scan_shadow_nodes+0x34/0x50
    shrink_slab.part.40+0x1ed/0x3d0
    shrink_zone+0x2ca/0x2e0
    kswapd+0x51e/0x990
    kthread+0xd8/0xf0
    ret_from_fork+0x3f/0x70

which corresponds to the following sanity check in the shadow node
tracking:

  BUG_ON(node->count & RADIX_TREE_COUNT_MASK);

The workingset code tracks radix tree nodes that exclusively contain
shadow entries of evicted pages in them, and this (somewhat obscure)
line checks whether there are real pages left that would interfere with
reclaim of the radix tree node under memory pressure.

While discussing ways how fuse might sneak pages into the radix tree
past the workingset code, Miklos pointed to replace_page_cache_page(),
and indeed there is a problem there: it properly accounts for the old
page being removed - __delete_from_page_cache() does that - but then
does a raw raw radix_tree_insert(), not accounting for the replacement
page.  Eventually the page count bits in node->count underflow while
leaving the node incorrectly linked to the shadow node LRU.

To address this, make sure replace_page_cache_page() uses the tracked
page insertion code, page_cache_tree_insert().  This fixes the page
accounting and makes sure page-containing nodes are properly unlinked
from the shadow node LRU again.

Also, make the sanity checks a bit less obscure by using the helpers for
checking the number of pages and shadows in a radix tree node.

Fixes: 449dd698 ("mm: keep page cache radix tree nodes in check")
Link: http://lkml.kernel.org/r/20160919155822.29498-1-hannes@cmpxchg.orgSigned-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reported-by: NAntonio SJ Musumeci <trapexit@spawn.link>
Debugged-by: NMiklos Szeredi <miklos@szeredi.hu>
Cc: <stable@vger.kernel.org>	[3.15+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CAI Qian <caiqian@redhat.com> pointed out that the semantics
of shared subtrees make it possible to create an exponentially
increasing number of mounts in a mount namespace.

    mkdir /tmp/1 /tmp/2
    mount --make-rshared /
    for i in $(seq 1 20) ; do mount --bind /tmp/1 /tmp/2 ; done

Will create create 2^20 or 1048576 mounts, which is a practical problem
as some people have managed to hit this by accident.

As such CVE-2016-6213 was assigned.

Ian Kent <raven@themaw.net> described the situation for autofs users
as follows:

> The number of mounts for direct mount maps is usually not very large because of
> the way they are implemented, large direct mount maps can have performance
> problems. There can be anywhere from a few (likely case a few hundred) to less
> than 10000, plus mounts that have been triggered and not yet expired.
>
> Indirect mounts have one autofs mount at the root plus the number of mounts that
> have been triggered and not yet expired.
>
> The number of autofs indirect map entries can range from a few to the common
> case of several thousand and in rare cases up to between 30000 and 50000. I've
> not heard of people with maps larger than 50000 entries.
>
> The larger the number of map entries the greater the possibility for a large
> number of active mounts so it's not hard to expect cases of a 1000 or somewhat
> more active mounts.

So I am setting the default number of mounts allowed per mount
namespace at 100,000.  This is more than enough for any use case I
know of, but small enough to quickly stop an exponential increase
in mounts.  Which should be perfect to catch misconfigurations and
malfunctioning programs.

For anyone who needs a higher limit this can be changed by writing
to the new /proc/sys/fs/mount-max sysctl.
Tested-by: NCAI Qian <caiqian@redhat.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

Previously, we used cp_version only to detect recoverable dnodes.
In order to avoid same garbage cp_version, we needed to truncate the next
dnode during checkpoint, resulting in additional discard or data write.
If we can distinguish this by using crc in addition to cp_version, we can
remove this overhead.

There is backward compatibility concern where it changes node_footer layout.
So, this patch introduces a new checkpoint flag, CP_CRC_RECOVERY_FLAG, to
detect new layout. New layout will be activated only when this flag is set.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Keep that call timeouts as ktimes rather than jiffies so that they can be
expressed as functions of RTT.
Signed-off-by: NDavid Howells <dhowells@redhat.com>