The "flags" member of "struct wait_queue_t" is used in several places in
the kernel code without beeing initialized by init_wait().  "flags" is
used in bitwise operations.

If "flags" not initialized then unexpected behaviour may take place.
Incorrect flags might used later in code.

Added initialization of "wait_queue_t.flags" with zero value into
"init_wait".
Signed-off-by: NEvgeny Kuznetsov <EXT-Eugeny.Kuznetsov@nokia.com>
[ The bit we care about does end up being initialized by both
   prepare_to_wait() and add_to_wait_queue(), so this doesn't seem to
   cause actual bugs, but is definitely the right thing to do -Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With all the recent module loading cleanups, we've minimized the code
that sits under module_mutex, fixing various deadlocks and making it
possible to do most of the module loading in parallel.

However, that whole conversion totally missed the rather obscure code
that adds a new module to the list for BUG() handling.  That code was
doubly obscure because (a) the code itself lives in lib/bugs.c (for
dubious reasons) and (b) it gets called from the architecture-specific
"module_finalize()" rather than from generic code.

Calling it from arch-specific code makes no sense what-so-ever to begin
with, and is now actively wrong since that code isn't protected by the
module loading lock any more.

So this commit moves the "module_bug_{finalize,cleanup}()" calls away
from the arch-specific code, and into the generic code - and in the
process protects it with the module_mutex so that the list operations
are now safe.

Future fixups:
 - move the module list handling code into kernel/module.c where it
   belongs.
 - get rid of 'module_bug_list' and just use the regular list of modules
   (called 'modules' - imagine that) that we already create and maintain
   for other reasons.
Reported-and-tested-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In order to be fully threadsafe we need to check that the drm_gem_object
refcount is still 0 after acquiring the mutex in order to call the free
function. Otherwise, we may encounter scenarios like:

Thread A:                                        Thread B:
drm_gem_close
unreference_unlocked
kref_put                                         mutex_lock
...                                              i915_gem_evict
...                                              kref_get -> BUG
...                                              i915_gem_unbind
...                                              kref_put
...                                              i915_gem_object_free
...                                              mutex_unlock
mutex_lock
i915_gem_object_free -> BUG
i915_gem_object_unbind
kfree
mutex_unlock

Note that no driver is currently using the free_unlocked vfunc and it is
scheduled for removal, hasten that process.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=30454Reported-and-Tested-by: NMagnus Kessler <Magnus.Kessler@gmx.net>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Avoid TLB flush IPIs for the cores in deeper c-states by voluntary leave_mm()
before entering into that state. CPUs tend to flush TLB in those c-states
anyways.

acpi_idle does this with C3-type states, but it was not caried over
when intel_idle was introduced.  intel_idle can apply it
to C-states in addition to those that ACPI might export as C3...
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

There were lots of places being inconsistent since handle count
looked like a kref but it really wasn't.

Fix this my just making handle count an atomic on the object,
and have it increase the normal object kref.

Now i915/radeon/nouveau drivers can drop the normal reference on
userspace object creation, and have the handle hold it.

This patch fixes a memory leak or corruption on unload, because
the driver had no way of knowing if a handle had been actually
added for this object, and the fbcon object needed to know this
to clean itself up properly.
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NLen Brown <len.brown@intel.com>

Fixes kernel bugzilla #16603

tcp_sendmsg() truncates iov_len to an 'int' which a 4GB write to write
zero bytes, for example.

There is also the problem higher up of how verify_iovec() works.  It
wants to prevent the total length from looking like an error return
value.

However it does this using 'int', but syscalls return 'long' (and
thus signed 64-bit on 64-bit machines).  So it could trigger
false-positives on 64-bit as written.  So fix it to use 'long'.
Reported-by: NOlaf Bonorden <bono@onlinehome.de>
Reported-by: NDaniel Büse <dbuese@gmx.de>
Reported-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hook the GEM vm open/close ops into the generic drm vm open/close so
that the private vma entries are created and destroy appropriately.
Fixes the leak of the drm_vma_entries during the lifetime of the filp.
Reported-by: NMatt Mackall <mpm@selenic.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Acked-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

as done in ip_route_connect()
Signed-off-by: NUlrich Weber <uweber@astaro.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Clean up a missing exit path in the ipv6 module init routines.  In
addrconf_init we call ipv6_addr_label_init which calls register_pernet_subsys
for the ipv6_addr_label_ops structure.  But if module loading fails, or if the
ipv6 module is removed, there is no corresponding unregister_pernet_subsys call,
which leaves a now-bogus address on the pernet_list, leading to oopses in
subsequent registrations.  This patch cleans up both the failed load path and
the unload path.  Tested by myself with good results.
Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>

 include/net/addrconf.h |    1 +
 net/ipv6/addrconf.c    |   11 ++++++++---
 net/ipv6/addrlabel.c   |    5 +++++
 3 files changed, 14 insertions(+), 3 deletions(-)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reset queue mapping when an skb is reentering the stack via a tunnel.
On second pass, the queue mapping from the original device is no
longer valid.
Signed-off-by: NTom Herbert <therbert@google.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fixes https://bugzilla.kernel.org/show_bug.cgi?id=19012

cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

rcu_dereference_bh() doesnt know yet about hard irq being disabled, so
lockdep can trigger in netpoll_rx() after commit f0f9deae (netpoll:
Disable IRQ around RCU dereference in netpoll_rx)
Reported-by: NMiles Lane <miles.lane@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Tested-by: NMiles Lane <miles.lane@gmail.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

This patch adds a workaround for an IOMMU BIOS problem to
the AMD IOMMU driver. The result of the bug is that the
IOMMU does not execute commands anymore when the system
comes out of the S3 state resulting in system failure. The
bug in the BIOS is that is does not restore certain hardware
specific registers correctly. This workaround reads out the
contents of these registers at boot time and restores them
on resume from S3. The workaround is limited to the specific
IOMMU chipset where this problem occurs.

Cc: stable@kernel.org
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

This fixes the regression caused by the commit 6fee48cd
("dma-mapping: arm: use generic pci_set_dma_mask and
pci_set_consistent_dma_mask").

ARM needs to clip the dma coherent mask for dmabounce devices. This
restores the old trick.

Note that strictly speaking, the DMA API doesn't allow architectures to do
such but I'm not sure it's worth adding the new API to set the dma mask
that allows architectures to clip it.
Reported-by: NKrzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a missing inline keyword for static function in linux/dmaengine.h to
avoid duplicate symbol definitions.
Signed-off-by: NMathieu Lacage <mathieu.lacage@sophia.inria.fr>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

This patch reduces namespace pollution by moving the "struct net" declaration
out of the userspace-facing portion of linux/netlink.h.  It has no impact on
the kernel.

(This came up because we have several C++ applications which use "net" as a
namespace name.)
Signed-off-by: NOllie Wild <aaw@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The lock structs are currently protected by the BKL, but are accessed by
code in fs/locks.c and misc file system and DLM code.  These stubs will
allow all users to switch to the new interface before the implementation
is changed to a spinlock.
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NSage Weil <sage@newdream.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The family parameter xfrm_state_find is used to find a state matching a
certain policy. This value is set to the template's family
(encap_family) right before xfrm_state_find is called.
The family parameter is however also used to construct a temporary state
in xfrm_state_find itself which is wrong for inter-family scenarios
because it produces a selector for the wrong family. Since this selector
is included in the xfrm_user_acquire structure, user space programs
misinterpret IPv6 addresses as IPv4 and vice versa.
This patch splits up the original init_tempsel function into a part that
initializes the selector respectively the props and id of the temporary
state, to allow for differing ip address families whithin the state.
Signed-off-by: NThomas Egerer <thomas.egerer@secunet.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We cannot use rcu_dereference_bh safely in netpoll_rx as we may
be called with IRQs disabled.  We could however simply disable
IRQs as that too causes BH to be disabled and is safe in either
case.

Thanks to John Linville for discovering this bug and providing
a patch.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If peer uses tiny MSS (say, 75 bytes) and similarly tiny advertised
window, the SWS logic will packetize to half the MSS unnecessarily.

This causes problems with some embedded devices.

However for large MSS devices we do want to half-MSS packetize
otherwise we never get enough packets into the pipe for things
like fast retransmit and recovery to work.

Be careful also to handle the case where MSS > window, otherwise
we'll never send until the probe timer.
Reported-by: Nツ Leandro Melo de Sales <leandroal@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

compat_alloc_user_space() expects the caller to independently call
access_ok() to verify the returned area.  A missing call could
introduce problems on some architectures.

This patch incorporates the access_ok() check into
compat_alloc_user_space() and also adds a sanity check on the length.
The existing compat_alloc_user_space() implementations are renamed
arch_compat_alloc_user_space() and are used as part of the
implementation of the new global function.

This patch assumes NULL will cause __get_user()/__put_user() to either
fail or access userspace on all architectures.  This should be
followed by checking the return value of compat_access_user_space()
for NULL in the callers, at which time the access_ok() in the callers
can also be removed.
Reported-by: NBen Hawkes <hawkes@sota.gen.nz>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NChris Metcalf <cmetcalf@tilera.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NTony Luck <tony.luck@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: James Bottomley <jejb@parisc-linux.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: <stable@kernel.org>

v2: Julien Cristau pointed out that @nondestructive results in
double-negatives and confusion when trying to interpret the parameter,
so use @force instead. Much easier to type as well. ;-)

And fix the miscompilation of vmgfx reported by Sedat Dilek.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Destructive load-detection is very expensive and due to failings
elsewhere can trigger system wide stalls of up to 600ms. A simple
first step to correcting this is not to invoke such an expensive
and destructive load-detection operation automatically.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=29536
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=16265Reported-by: NBruno Prémont <bonbons@linux-vserver.org>
Tested-by: NSitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

Update copyright notice and add Documentation/workqueue.txt.

Randy Dunlap, Dave Chinner: misc fixes.
Signed-off-by: NTejun Heo <tj@kernel.org>
Reviewed-By: NFlorian Mickler <florian@mickler.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>

There is a race between rpc_info_open and rpc_release_client()
in that nothing stops a process from opening the file after
the clnt->cl_kref goes to zero.

Fix this by using atomic_inc_unless_zero()...
Reported-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

Keep track of the link on the which the current request is in progress.
It allows support of links behind port multiplier.

Not all libata-sff is PMP compliant. Code for native BMDMA controller
does not take in accound PMP.

Tested on Marvell 7042 and Sil7526.
Signed-off-by: NGwendal Grignou <gwendal@google.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

For some mysterious reason, certain hardware reacts badly to usual EH
actions while the system is going for suspend.  As the devices won't
be needed until the system is resumed, ask EH to skip usual autopsy
and recovery and proceed directly to suspend.
Signed-off-by: NTejun Heo <tj@kernel.org>
Tested-by: NStephan Diestelhorst <stephan.diestelhorst@amd.com>
Cc: stable@kernel.org
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

mm: page allocator: calculate a better estimate of NR_FREE_PAGES when memory is low and kswapd is awake

Ordinarily watermark checks are based on the vmstat NR_FREE_PAGES as it is
cheaper than scanning a number of lists.  To avoid synchronization
overhead, counter deltas are maintained on a per-cpu basis and drained
both periodically and when the delta is above a threshold.  On large CPU
systems, the difference between the estimated and real value of
NR_FREE_PAGES can be very high.  If NR_FREE_PAGES is much higher than
number of real free page in buddy, the VM can allocate pages below min
watermark, at worst reducing the real number of pages to zero.  Even if
the OOM killer kills some victim for freeing memory, it may not free
memory if the exit path requires a new page resulting in livelock.

This patch introduces a zone_page_state_snapshot() function (courtesy of
Christoph) that takes a slightly more accurate view of an arbitrary vmstat
counter.  It is used to read NR_FREE_PAGES while kswapd is awake to avoid
the watermark being accidentally broken.  The estimate is not perfect and
may result in cache line bounces but is expected to be lighter than the
IPI calls necessary to continually drain the per-cpu counters while kswapd
is awake.
Signed-off-by: NChristoph Lameter <cl@linux.com>
Signed-off-by: NMel Gorman <mel@csn.ul.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Tests with recent firmware on Intel X25-M 80GB and OCZ Vertex 60GB SSDs
show a shift since I last tested in December: in part because of firmware
updates, in part because of the necessary move from barriers to awaiting
completion at the block layer.  While discard at swapon still shows as
slightly beneficial on both, discarding 1MB swap cluster when allocating
is now disadvanteous: adds 25% overhead on Intel, adds 230% on OCZ (YMMV).

Surrender: discard as presently implemented is more hindrance than help
for swap; but might prove useful on other devices, or with improvements.
So continue to do the discard at swapon, but make discard while swapping
conditional on a SWAP_FLAG_DISCARD to sys_swapon() (which has been using
only the lower 16 bits of int flags).

We can add a --discard or -d to swapon(8), and a "discard" to swap in
/etc/fstab: matching the mount option for btrfs, ext4, fat, gfs2, nilfs2.
Signed-off-by: NHugh Dickins <hughd@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Nigel Cunningham <nigel@tuxonice.net>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Please revert 2.6.36-rc commit d2997b10
"hibernation: freeze swap at hibernation".  It complicated matters by
adding a second swap allocation path, just for hibernation; without in any
way fixing the issue that it was intended to address - page reclaim after
fixing the hibernation image might free swap from a page already imaged as
swapcache, letting its swap be reallocated to store a different page of
the image: resulting in data corruption if the imaged page were freed as
clean then swapped back in.  Pages freed to si->swap_map were still in
danger of being reallocated by the alternative allocation path.

I guess it inadvertently fixed slow SSD swap allocation for hibernation,
as reported by Nigel Cunningham: by missing out the discards that occur on
the usual swap allocation path; but that was unintentional, and needs a
separate fix.
Signed-off-by: NHugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ondrej Zary <linux@rainbow-software.org>
Cc: Andrea Gelmini <andrea.gelmini@gmail.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nigel Cunningham <nigel@tuxonice.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's been some recent confusion about error checking GPIO numbers.
briefly, it should be handled mostly during setup, when gpio_request() is
called, and NEVER by expectig gpio_is_valid to report more than
never-usable GPIO numbers.

[akpm@linux-foundation.org: terminate unterminated comment]
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Eric Miao" <eric.y.miao@gmail.com>
Cc: "Ryan Mallon" <ryan@bluewatersys.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace the arbitrary software-reset call from the device-probe
method, because:

- It is defective.  To work correctly, it should be two byte writes,
  not a single word write.  As it stands, it does nothing.

- Some devices with sx150x expanders installed have their NRESET pins
  ganged on the same line, so resetting one causes the others to reset -
  not a nice thing to do arbitrarily!

- The probe, usually taking place at boot, implies a recent hard-reset,
  so a software reset at this point is just a waste of energy anyway.

Therefore, make it optional, defaulting to off, as this will match the
common case of probing at powerup and also matches the current broken
no-op behavior.
Signed-off-by: NGregory Bean <gbean@codeaurora.org>
Reviewed-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The pte_same check is reliable only if the swap entry remains pinned (by
the page lock on swapcache).  We've also to ensure the swapcache isn't
removed before we take the lock as try_to_free_swap won't care about the
page pin.

One of the possible impacts of this patch is that a KSM-shared page can
point to the anon_vma of another process, which could exit before the page
is freed.

This can leave a page with a pointer to a recycled anon_vma object, or
worse, a pointer to something that is no longer an anon_vma.

[riel@redhat.com: changelog help]
Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Acked-by: NHugh Dickins <hughd@google.com>
Reviewed-by: NRik van Riel <riel@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add cgroup_attach_task_all()

The existing cgroup_attach_task_current_cg() API is called by a thread to
attach another thread to all of its cgroups; this is unsuitable for cases
where a privileged task wants to attach itself to the cgroups of a less
privileged one, since the call must be made from the context of the target
task.

This patch adds a more generic cgroup_attach_task_all() API that allows
both the source task and to-be-moved task to be specified.
cgroup_attach_task_current_cg() becomes a specialization of the more
generic new function.

[menage@google.com: rewrote changelog]
[akpm@linux-foundation.org: address reviewer comments]
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Tested-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NPaul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ben Blum <bblum@google.com>
Cc: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some macro parameter references inside typeof() operator are not enclosed
with parenthesis.  It should be safer to add them.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Acked-by: NStefani Seibold <stefani@seibold.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The introduction of support for SD combo cards breaks the initialization
of all CSR SDIO chips.  The GO_IDLE (CMD0) in mmc_sd_get_cid() causes CSR
chips to be reset (this is non-standard behavior).

When initializing an SDIO card check for a combo card by using the memory
present bit in the R4 response to IO_SEND_OP_COND (CMD5).  This avoids the
call to mmc_sd_get_cid() on an SDIO-only card.
Signed-off-by: NDavid Vrabel <david.vrabel@csr.com>
Acked-by: NMichal Mirolaw <mirq-linux@rere.qmqm.pl>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lg_lock_global() currently only acquires spinlocks for online CPUs, but
it's meant to lock all possible CPUs.  Lglock-protected resources may be
associated with removed CPUs - and, indeed, that could happen with the
per-superblock open files lists.

At Nick's suggestion, change for_each_online_cpu() to
for_each_possible_cpu() to protect accesses to those resources.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: NNick Piggin <npiggin@kernel.dk>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

So it can be used by all that need to check for that.
Signed-off-by: NStefan Bader <stefan.bader@canonical.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Alex Shi found a regression when doing ffsb test. The test has several threads,
and each thread creates a small file, write to it and then delete it. ffsb
reports about 20% regression and Alex bisected it to 43d2932d. The test
will call __mark_inode_dirty 3 times. without this commit, we only take
inode_lock one time, while with it, we take the lock 3 times with flags (
I_DIRTY_SYNC,I_DIRTY_PAGES,I_DIRTY). Perf shows the lock contention increased
too much. Below proposed patch fixes it.

fs is allocating blocks, which usually means file writes and the inode
will be dirtied soon. We fully dirty the inode to reduce some inode_lock
contention in several calls of __mark_inode_dirty.

Jan Kara: Added comment.
Signed-off-by: NShaohua Li <shaohua.li@intel.com>
Signed-off-by: NAlex Shi <alex.shi@intel.com>
Signed-off-by: NJan Kara <jack@suse.cz>