UBIFS: correct mount message

When mounting an UBIFS R/W volume, we have the message:
UBIFS: mounted UBI device 0, volume 1, name "rootfs"(null)
With this patch, we'll have:
UBIFS: mounted UBI device 0, volume 1, name "rootfs"
Which is, I think, what was intended.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Cc: stable@vger.kernel.org [v3.7+]
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
init.h: remove __cpuinit sections from the kernel

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

As an interim step, we can dummy out the macros to be no-ops, and
this will allow us to avoid a giant tree-wide patch, and instead
we can feed in smaller chunks mainly via the arch/ trees.  This
is in keeping with commit 78d86c213f28193082b5d8a1a424044b7ba406f1
("init.h: Remove __dev* sections from the kernel")

We don't strictly need to dummy out the macros to do this, but if
we don't then some harmless section mismatch warnings may temporarily
result.  For example, notify_cpu_starting() and cpu_up() are arch
independent (kernel/cpu.c) and are flagged as __cpuinit.  And hence
the calling functions in the arch specific code are also expected
to be __cpuinit -- if not, then we get the section mismatch warning.

Two of the three __CPUINIT variants are not used whatsoever, and
so they are simply removed directly at this point in time.

[1] https://lkml.org/lkml/2013/5/20/589

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
modpost: remove all traces of cpuinit/cpuexit sections

Delete all audit rules that were checking how the .cpuXYZ
related sections were inter-operating with other __init
like sections, now that __cpuinit is gone.  Update the linker
script to not have any knowledge of .cpuinit sections.

[lds.h update courtesy of Ralf Baechle <ralf@linux-mips.org>]

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
ARM: dma-mapping: Get pages if the cpu_addr is out of atomic_pool

In __iommu_get_pages(), the cpu_addr is checked wheather in
atomic_pool range or not. So if the cpu_addr is in atomic_pool
range, it does not need to check twice.

Signed-off-by: YoungJun Cho <yj44.cho@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
ARM: dma-mapping: convert DMA direction into IOMMU protection attributes

IOMMU mappings take a prot parameter, identifying the protection bits
to enforce on the newly created mapping (READ or WRITE). The ARM
dma-mapping framework currently just passes 0 as the prot argument,
resulting in faulting mappings.

This patch infers the protection attributes based on the direction of
the DMA transfer.

Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
ARM: dma-mapping: NULLify dev->archdata.mapping pointer on detach

The current code only clobbers a local variable, so the device is left
with a stale mapping pointer.

Cc: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Hiroshi Doyu <hdoyu@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
ARM: DMA-mapping: mark all !DMA_TO_DEVICE pages in unmapping as clean

It is common for one sg to include many pages, so mark all these
pages as clean to avoid unnecessary flushing on them in
set_pte_at() or update_mmu_cache().

The patch might improve loading performance of applciation code a bit.

On the below test code to read file(~1GByte size) from usb mass storage
disk to buffer created with mmap(PROT_READ | PROT_EXEC) on
Pandaboard, average ~1% improvement can be observed with the patch on
10 times test.

unsigned int sum = 0;

static unsigned long tv_diff(struct timeval *tv1, struct timeval *tv2)
{
	return (tv2->tv_sec - tv1->tv_sec) * 1000000 +
		(tv2->tv_usec - tv1->tv_usec);
}

int main(int argc, char *argv[])
{
	char *mbuffer;
	int fd;
	int i;
	unsigned long page_size, size;
	struct stat stat;
	struct timeval t1, t2;

	page_size = getpagesize();
	fd = open(argv[1], O_RDONLY);
	assert(fd >= 0);

	fstat(fd, &stat);
	size = stat.st_size;
	printf("%s: file %s, file size %lu, page size %lu\n", argv[0],
		read_filename, size, page_size);

	gettimeofday(&t1, NULL);
	mbuffer = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_SHARED, fd, 0);
	for (i = 0 ; i < size ; i += page_size)
		sum += mbuffer[i];
	munmap(mbuffer, page_size);
	gettimeofday(&t2, NULL);
	printf("\tread mmaped time: %luus\n", tv_diff(&t1, &t2));

	close(fd);
}

Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
ARM: dma: Drop __GFP_COMP for iommu dma memory allocations

__iommu_alloc_buffer wants to split pages after allocation in order to
reduce the memory footprint. This does not work well with __GFP_COMP
pages, so drop this flag before allocation

One failure example is snd_malloc_dev_pages call dma_alloc_coherent with
__GFP_COMP.

Signed-off-by: Richard Zhao <rizhao@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
tick: Make oneshot broadcast robust vs. CPU offlining

In periodic mode we remove offline cpus from the broadcast propagation
mask. In oneshot mode we fail to do so. This was not a problem so far,
but the recent changes to the broadcast propagation introduced a
constellation which can result in a NULL pointer dereference.

What happens is:

CPU0			CPU1
			idle()
			  arch_idle()
			    tick_broadcast_oneshot_control(OFF);
			      set cpu1 in tick_broadcast_force_mask
			  if (cpu_offline())
			     arch_cpu_dead()

cpu_dead_cleanup(cpu1)
 cpu1 tickdevice pointer = NULL

broadcast interrupt
  dereference cpu1 tickdevice pointer -> OOPS

We dereference the pointer because cpu1 is still set in
tick_broadcast_force_mask and tick_do_broadcast() expects a valid
cpumask and therefor lacks any further checks.

Remove the cpu from the tick_broadcast_force_mask before we set the
tick device pointer to NULL. Also add a sanity check to the oneshot
broadcast function, so we can detect such issues w/o crashing the
machine.

Reported-by: Prarit Bhargava <prarit@redhat.com>
Cc: athorlton@sgi.com
Cc: CAI Qian <caiqian@redhat.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1306261303260.4013@ionos.tec.linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
tick: Prevent uncontrolled switch to oneshot mode

When the system switches from periodic to oneshot mode, the broadcast
logic causes a possibility that a CPU which has not yet switched to
oneshot mode puts its own clock event device into oneshot mode without
updating the state and the timer handler.

CPU0				CPU1
				per cpu tickdev is in periodic mode
				and switched to broadcast

Switch to oneshot mode
 tick_broadcast_switch_to_oneshot()
  cpumask_copy(tick_oneshot_broacast_mask,
	       tick_broadcast_mask);

  broadcast device mode = oneshot

				Timer interrupt
						
				irq_enter()
				 tick_check_oneshot_broadcast()
				  dev->set_mode(ONESHOT);

				tick_handle_periodic()
				 if (dev->mode == ONESHOT)
				   dev->next_event += period;
				   FAIL.

We fail, because dev->next_event contains KTIME_MAX, if the device was
in periodic mode before the uncontrolled switch to oneshot happened.

We must copy the broadcast bits over to the oneshot mask, because
otherwise a CPU which relies on the broadcast would not been woken up
anymore after the broadcast device switched to oneshot mode.

So we need to verify in tick_check_oneshot_broadcast() whether the CPU
has already switched to oneshot mode. If not, leave the device
untouched and let the CPU switch controlled into oneshot mode.

This is a long standing bug, which was never noticed, because the main
user of the broadcast x86 cannot run into that scenario, AFAICT. The
nonarchitected timer mess of ARM creates a gazillion of differently
broken abominations which trigger the shortcomings of that broadcast
code, which better had never been necessary in the first place.

Reported-and-tested-by: Stehle Vincent-B46079 <B46079@freescale.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: John Stultz <john.stultz@linaro.org>,
Cc: Mark Rutland <mark.rutland@arm.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1307012153060.4013@ionos.tec.linutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
tick: Sanitize broadcast control logic

The recent implementation of a generic dummy timer resulted in a
different registration order of per cpu local timers which made the
broadcast control logic go belly up.

If the dummy timer is the first clock event device which is registered
for a CPU, then it is installed, the broadcast timer is initialized
and the CPU is marked as broadcast target.

If a real clock event device is installed after that, we can fail to
take the CPU out of the broadcast mask. In the worst case we end up
with two periodic timer events firing for the same CPU. One from the
per cpu hardware device and one from the broadcast.

Now the problem is that we have no way to distinguish whether the
system is in a state which makes broadcasting necessary or the
broadcast bit was set due to the nonfunctional dummy timer
installment.

To solve this we need to keep track of the system state seperately and
provide a more detailed decision logic whether we keep the CPU in
broadcast mode or not.

The old decision logic only clears the broadcast mode, if the newly
installed clock event device is not affected by power states.

The new logic clears the broadcast mode if one of the following is
true:

  - The new device is not affected by power states.

  - The system is not in a power state affected mode

  - The system has switched to oneshot mode. The oneshot broadcast is
    controlled from the deep idle state. The CPU is not in idle at
    this point, so it's safe to remove it from the mask.

If we clear the broadcast bit for the CPU when a new device is
installed, we also shutdown the broadcast device when this was the
last CPU in the broadcast mask.

If the broadcast bit is kept, then we leave the new device in shutdown
state and rely on the broadcast to deliver the timer interrupts via
the broadcast ipis.

Reported-and-tested-by: Stehle Vincent-B46079 <B46079@freescale.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: John Stultz <john.stultz@linaro.org>,
Cc: Mark Rutland <mark.rutland@arm.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1307012153060.4013@ionos.tec.linutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
posix_cpu_timer: consolidate expiry time type

The posix cpu timer expiry time is stored in a union of two types: a 64
bits field if we rely on scheduler precise accounting, or a cputime_t if
we rely on jiffies.

This results in quite some duplicate code and special cases to handle the
two types.

Just unify this into a single 64 bits field.  cputime_t can always fit
into it.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Olivier Langlois <olivier@trillion01.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
posix_cpu_timers: consolidate timer list cleanups

Cleaning up the posix cpu timers on task exit shares some common code
among timer list types, most notably the list traversal and expiry time
update.

Unify this in a common helper.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Olivier Langlois <olivier@trillion01.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
posix_cpu_timers: consolidate expired timers check

Consolidate the common code amongst per thread and per process timers list
on tick time.

List traversal, expiry check and subsequent updates can be shared in a
common helper.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Olivier Langlois <olivier@trillion01.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
selftests: add basic posix timers selftests

Add some initial basic tests on a few posix timers interface such as
setitimer() and timer_settime().

These simply check that expiration happens in a reasonable timeframe after
expected elapsed clock time (user time, user + system time, real time,
...).

This is helpful for finding basic breakages while hacking
on this subsystem.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Olivier Langlois <olivier@trillion01.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
posix-timers: correctly get dying task time sample in posix_cpu_timer_schedule()

In order to re-arm a timer after it fired, we take a sample of the current
process or thread cputime.

If the task is dying though, we don't arm anything but we cache the
remaining timer expiration delta for further reads.

Something similar is performed in posix_cpu_timer_get() but here we forget
to take the process wide cputime sample before caching it.

As a result we are storing random stack content, leading every further
reads of that timer to return junk values.

Fix this by taking the appropriate sample in the case of process wide
timers.

This probably doesn't matter much in practice because, at this stage, the
thread is the last one in the group and we reached exit_notify().  This
implies that we called exit_itimers() and there should be no more timers
to handle for that task.

So this is likely dead code anyway but let's fix the current logic
and the warning that came along:

    kernel/posix-cpu-timers.c: In function 'posix_cpu_timer_schedule':
    kernel/posix-cpu-timers.c:1127: warning: 'now' may be used uninitialized in this function

Then we can start to think further about cleaning up that code.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Chen Gang <gang.chen@asianux.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Olivier Langlois <olivier@trillion01.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
posix_timers: fix racy timer delta caching on task exit

When a task exits, we perform a caching of the remaining cputime delta
before expiring of its timers.

This is done from the following places:

* When the task is reaped. We iterate through its list of
  posix cpu timers and store the remaining timer delta to
  the timer struct instead of the absolute value.
  (See posix_cpu_timers_exit() / posix_cpu_timers_exit_group() )

* When we call posix_cpu_timer_get() or posix_cpu_timer_schedule().
  If the timer's task is considered dying when watched from these
  places, the same conversion from absolute to relative expiry time
  is performed. Then the given task's reference is released.
  (See clear_dead_task() ).

The relevance of this caching is questionable but this is another
and deeper debate.

The big issue here is that these two sources of caching don't mix
up very well together.

More specifically, the caching can easily be done twice, resulting
in a wrong delta as it gets spuriously substracted a second time by
the elapsed clock. This can happen in the following scenario:

1) The task exits and gets reaped: we call posix_cpu_timers_exit()
   and the absolute timer expiry values are converted to a relative
   delta.

2) timer_gettime() -> posix_cpu_timer_get() is called and relies on
   clear_dead_task() because  tsk->exit_state == EXIT_DEAD.
   The delta gets substracted again by the elapsed clock and we return
   a wrong result.

To fix this, just remove the caching done on task reaping time.  It
doesn't bring much value on its own.  The caching done from
posix_cpu_timer_get/schedule is enough.

And it would also be hard to get it really right: we could make it put and
clear the target task in the timer struct so that readers know if they are
dealing with a relative cached of absolute value.  But it would be racy.
The only safe way to do it would be to lock the itimer->it_lock so that we
know nobody reads the cputime expiry value while we modify it and its
target task reference.  Doing so would involve some funny workarounds to
avoid circular lock against the sighand lock.  There is just no reason to
maintain this.

The user visible effect of this patch can be observed by running the
following code: it creates a subthread that launches a posix cputimer
which expires after 10 seconds. But then the subthread only busy loops for 2
seconds and exits. The parent reaps the subthread and read the timer value.
Its expected value should the be the initial timer's expiration value
minus the cputime elapsed in the subthread. Roughly 10 - 2 = 8 seconds:

	#include <sys/time.h>
	#include <stdio.h>
	#include <unistd.h>
	#include <time.h>
	#include <pthread.h>

	static timer_t id;
	static struct itimerspec val = { .it_value.tv_sec = 10, }, new;

	static void *thread(void *unused)
	{
		int err;
		struct timeval start, end, diff;

		timer_create(CLOCK_THREAD_CPUTIME_ID, NULL, &id);
		if (err < 0) {
			perror("Can't create timer\n");
			return NULL;
		}

		/* Arm 10 sec timer */
		err = timer_settime(id, 0, &val, NULL);
		if (err < 0) {
			perror("Can't set timer\n");
			return NULL;
		}

		/* Exit after 2 seconds of execution */
		gettimeofday(&start, NULL);
	        do {
			gettimeofday(&end, NULL);
			timersub(&end, &start, &diff);
		} while (diff.tv_sec < 2);

		return NULL;
	}

	int main(int argc, char **argv)
	{
		pthread_t pthread;
		int err;

		err = pthread_create(&pthread, NULL, thread, NULL);
		if (err) {
			perror("Can't create thread\n");
			return -1;
		}
		pthread_join(pthread, NULL);
		/* Just wait a little bit to make sure the child got reaped */
		sleep(1);
		err = timer_gettime(id, &new);
		if (err)
			perror("Can't get timer value\n");
		printf("%d %ld\n", new.it_value.tv_sec, new.it_value.tv_nsec);

		return 0;
	}

Before the patch:

       $ ./posix_cpu_timers
       6 2278074

After the patch:

      $ ./posix_cpu_timers
      8 1158766

Before the patch, the elapsed time got two more seconds spuriously accounted.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Olivier Langlois <olivier@trillion01.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
md/raid5: allow 5-device RAID6 to be reshaped to 4-device.

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: NeilBrown <neilb@suse.de>
md/raid10: fix bug which causes all RAID10 reshapes to move no data.

The recent comment:
commit 7e83ccbecd608b971f340e951c9e84cd0343002f
    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: NeilBrown <neilb@suse.de>
metag: move EXPORT_SYMBOL(csum_partial) to metag_ksyms.c

Move EXPORT_SYMBOL(csum_partial) from lib/checksum.c into metag_ksyms.c
so that it doesn't get omitted by the static linker if it's not used by
any other statically linked code, which can result in undefined symbols
when building modules.

For example a randconfig caused the following error:
ERROR: "csum_partial" [fs/reiserfs/reiserfs.ko] undefined!

Signed-off-by: James Hogan <james.hogan@imgtec.com>