Fix a bug reported by and diagnosed by Aaron Straus.

This is a regression intruduced into 2.6.26 by

    commit adc782da
    Author: Matt Mackall <mpm@selenic.com>
    Date:   Tue Apr 29 01:03:07 2008 -0700

        random: simplify and rename credit_entropy_store

credit_entropy_bits() does:

	spin_lock_irqsave(&r->lock, flags);
	...
	if (r->entropy_count > r->poolinfo->POOLBITS)
		r->entropy_count = r->poolinfo->POOLBITS;

so there is a time window in which this BUG_ON():

static size_t account(struct entropy_store *r, size_t nbytes, int min,
		      int reserved)
{
	unsigned long flags;

	BUG_ON(r->entropy_count > r->poolinfo->POOLBITS);

	/* Hold lock while accounting */
	spin_lock_irqsave(&r->lock, flags);

can trigger.

We could fix this by moving the assertion inside the lock, but it seems
safer and saner to revert to the old behaviour wherein
entropy_store.entropy_count at no time exceeds
entropy_store.poolinfo->POOLBITS.
Reported-by: NAaron Straus <aaron@merfinllc.com>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: <stable@kernel.org>		[2.6.26.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make PM_QOS and CPU_IDLE play nicer when run with the RT-Preempt kernel.

The purpose of the patch is to remove the spin_lock around the read in the
function pm_qos_requirement - since spinlocks can sleep in -rt and this
function is called from idle.

CPU_IDLE polls the target_value's of some of the pm_qos parameters from
the idle loop causing sleeping locking warnings.  Changing the
target_value to an atomic avoids this issue.

Remove the spinlock in pm_qos_requirement by making target_value an atomic
type.
Signed-off-by: Nmark gross <mgross@linux.intel.com>
Signed-off-by: NJohn Kacur <jkacur@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update rtc-cmos shutdown handling to leave RTC alarms active, resolving
http://bugzilla.kernel.org/show_bug.cgi?id=11411 on several boards.  There
are still some systems where the ACPI event handling doesn't cooperate.
(Possibly related to bugid 11312, reporting the spontaneous disabling of
RTC events.)

Bug 11411 reported that changes to work around some ACPI event issues
broke wake-from-S5 handling, as used for DVR applications.  (They like to
power off, then wake later to record programs.)

[yakui.zhao@intel.com: add shutdown for PNP devices]
[dbrownell@users.sourceforge.net: update comments]
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Cc: Stefan Bauer <stefan.bauer@cs.tu-chemnitz.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Document files in /sys/firmware/sgi_uv/.
Signed-off-by: NRuss Anderson <rja@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I got this patch through Red Hat's bugzilla from the bug submitter and
patch creator.  I have just fixed it up so it applies without fuzz to
upstream kernels.

Original patch and description from Shyam kumar Iyer:

The issue [ibft module not displaying targets with short names] is because
of an offset calculatation error in the iscsi_ibft.c code.  Due to this
error directory structure for the target in /sys/firmware/ibft does not
get created and so the initiator is unable to connect to the target.

Note that this bug surfaced only with an name that had a short section at
the end.  eg: "iqn.1984-05.com.dell:dell".  It did not surface when the
iqn's had a longer section at the end.  eg:
"iqn.2001-04.com.example:storage.disk2.sys1.xyz"

So, the eot_offset was calculated such that an extra 48 bytes i.e.  the
size of the ibft_header which has already been accounted was subtracted
twice.

This was not evident with longer iqn names because they would overshoot
the total ibft length more than 48 bytes and thus would escape the bug.
Signed-off-by: NShyam Kumar Iyer <shyam_iyer@dell.com>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Cc: Konrad Rzeszutek <konrad@virtualiron.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

commit 945185a6 ("rtc: rtc_time_to_tm: use
unsigned arithmetic") changed the some types in rtc_time_to_tm() to
unsigned:

 void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
 {
-       register int days, month, year;
+       unsigned int days, month, year;

This doesn't work for all cases, because days is checked for < 0 later
on:

if (days < 0) {
	year -= 1;
	days += 365 + LEAP_YEAR(year);
}

I think the correct fix would be to keep days signed and do an appropriate
cast later on.
Signed-off-by: NJan Altenberg <jan.altenberg@linutronix.de>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If there are more then one graphics card handled by the tdfxfb driver the
name of the frame buffer overruns reserved size.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix memory detection on Voodoo3 cards with SDRAM memory.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It turns out that event 0x4 merely indcates that a hotkey has been
pressed, not which one.  A further query is required in order to determine
the actual keypress.  The following patch adds support for that along with
the known keycodes.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

hp-wmi currently changes the RFKill state by altering the struct members
rather than using the dedicated interface, meaning that update events
won't be pushed to userspace.  This patch fixes that, along with fixing
the declared type of the WWAN kill switch.  It also ensures that rfkill
interfaces are only registered for hardware that exists.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ivo van Doorn <ivdoorn@gmail.com>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update Documentation/filesystems/proc.txt: it describes the file
auto_msgmni intoduced to enable/disable msgmni automatic recomputing upon
memory add/remove (see thread http://lkml.org/lkml/2008/7/4/27).  Also
added a description for msgmni (this filex is only listed in
Documentation/sysctl/kernel.txt).
Signed-off-by: NNadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Quicklists store pages for each CPU as caches.  (Each CPU can cache
node_free_pages/16 pages)

It is used for page table cache.  exit() will increase the cache size,
while fork() consumes it.

So for example if an apache-style application runs (one parent and many
child model), one CPU process will fork() while another CPU will process
the middleware work and exit().

At that time, the CPU on which the parent runs doesn't have page table
cache at all.  Others (on which children runs) have maximum caches.

	QList_max = (#ofCPUs - 1) x Free / 16
	=> QList_max / (Free + QList_max) = (#ofCPUs - 1) / (16 + #ofCPUs - 1)

So, How much quicklist memory is used in the maximum case?

This is proposional to # of CPUs because the limit of per cpu quicklist
cache doesn't see the number of cpus.

Above calculation mean

	 Number of CPUs per node            2    4    8   16
	 ==============================  ====================
	 QList_max / (Free + QList_max)   5.8%  16%  30%  48%

Wow! Quicklist can spend about 50% memory at worst case.

My demonstration program is here
--------------------------------------------------------------------------------
#define _GNU_SOURCE

#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sched.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/wait.h>

#define BUFFSIZE 512

int max_cpu(void)	/* get max number of logical cpus from /proc/cpuinfo */
{
  FILE *fd;
  char *ret, buffer[BUFFSIZE];
  int cpu = 1;

  fd = fopen("/proc/cpuinfo", "r");
  if (fd == NULL) {
    perror("fopen(/proc/cpuinfo)");
    exit(EXIT_FAILURE);
  }
  while (1) {
    ret = fgets(buffer, BUFFSIZE, fd);
    if (ret == NULL)
      break;
    if (!strncmp(buffer, "processor", 9))
      cpu = atoi(strchr(buffer, ':') + 2);
  }
  fclose(fd);
  return cpu;
}

void cpu_bind(int cpu)	/* bind current process to one cpu */
{
  cpu_set_t mask;
  int ret;

  CPU_ZERO(&mask);
  CPU_SET(cpu, &mask);
  ret = sched_setaffinity(0, sizeof(mask), &mask);
  if (ret == -1) {
    perror("sched_setaffinity()");
    exit(EXIT_FAILURE);
  }
  sched_yield();	/* not necessary */
}

#define MMAP_SIZE (10 * 1024 * 1024)	/* 10 MB */
#define FORK_INTERVAL 1	/* 1 second */

main(int argc, char *argv[])
{
  int cpu_max, nextcpu;
  long pagesize;
  pid_t pid;

  /* set max number of logical cpu */
  if (argc > 1)
    cpu_max = atoi(argv[1]) - 1;
  else
    cpu_max = max_cpu();

  /* get the page size */
  pagesize = sysconf(_SC_PAGESIZE);
  if (pagesize == -1) {
    perror("sysconf(_SC_PAGESIZE)");
    exit(EXIT_FAILURE);
  }

  /* prepare parent process */
  cpu_bind(0);
  nextcpu = cpu_max;

loop:

  /* select destination cpu for child process by round-robin rule */
  if (++nextcpu > cpu_max)
    nextcpu = 1;

  pid = fork();

  if (pid == 0) { /* child action */

    char *p;
    int i;

    /* consume page tables */
    p = mmap(0, MMAP_SIZE, PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
    i = MMAP_SIZE / pagesize;
    while (i-- > 0) {
      *p = 1;
      p += pagesize;
    }

    /* move to other cpu */
    cpu_bind(nextcpu);
/*
    printf("a child moved to cpu%d after mmap().\n", nextcpu);
    fflush(stdout);
 */

    /* back page tables to pgtable_quicklist */
    exit(0);

  } else if (pid > 0) { /* parent action */

    sleep(FORK_INTERVAL);
    waitpid(pid, NULL, WNOHANG);

  }

  goto loop;
}
----------------------------------------

When above program which does task migration runs, my 8GB box spends
800MB of memory for quicklist.  This is not memory leak but doesn't seem
good.

% cat /proc/meminfo

MemTotal:        7701568 kB
MemFree:         4724672 kB
(snip)
Quicklists:       844800 kB

because

- My machine spec is
	number of numa node: 2
	number of cpus:      8 (4CPU x2 node)
        total mem:           8GB (4GB x2 node)
        free mem:            about 5GB

- Then, 4.7GB x 16% ~= 880MB.
  So, Quicklist can use 800MB.

So, if following spec machine run that program

   CPUs: 64 (8cpu x 8node)
   Mem:  1TB (128GB x8node)

Then, quicklist can waste 300GB (= 1TB x 30%).  It is too large.

So, I don't like cache policies which is proportional to # of cpus.

My patch changes the number of caches
from:
   per-cpu-cache-amount = memory_on_node / 16
to
   per-cpu-cache-amount = memory_on_node / 16 / number_of_cpus_on_node.
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Keiichiro Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Tested-by: NDavid Miller <davem@davemloft.net>
Acked-by: NMike Travis <travis@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Quicklists can consume several GB of memory.  We should provide a means of
monitoring this.

After this patch is applied, /proc/meminfo will output the following:

% cat /proc/meminfo

MemTotal:      7715392 kB
MemFree:       5401600 kB
Buffers:         80384 kB
Cached:         300800 kB
SwapCached:          0 kB
Active:         235584 kB
Inactive:       262656 kB
SwapTotal:     2031488 kB
SwapFree:      2031488 kB
Dirty:            3520 kB
Writeback:           0 kB
AnonPages:      117696 kB
Mapped:          38528 kB
Slab:          1589952 kB
SReclaimable:    23104 kB
SUnreclaim:    1566848 kB
PageTables:      14656 kB
NFS_Unstable:        0 kB
Bounce:              0 kB
WritebackTmp:        0 kB
CommitLimit:   5889152 kB
Committed_AS:   393152 kB
VmallocTotal: 17592177655808 kB
VmallocUsed:     29056 kB
VmallocChunk: 17592177626432 kB
Quicklists:     130944 kB
HugePages_Total:     0
HugePages_Free:      0
HugePages_Rsvd:      0
HugePages_Surp:      0
Hugepagesize:    262144 kB
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Keiichiro Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

During the use of a dev_cgroup, we should guarantee the corresponding
cgroup won't be deleted (i.e.  via rmdir).  This can be done through
css_get(&dev_cgroup->css), but here we can just get and use the dev_cgroup
under rcu_read_lock.

And also remove checking NULL dev_cgroup, it won't be NULL since a task
always belongs to a cgroup.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

1. Check if virtual resolution fits into memory.
   Otherwise, Linux hangs during panning.
2. When selected use all available memory to
    maximize yres_virtual to speed up panning
   (previously also xres_virtual was increased).
3. Simplify memory restriction calculations.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We don't change pid_ns->child_reaper when the main thread of the
subnamespace init exits.  As Robert Rex <robert.rex@exasol.com> pointed
out this is wrong.

Yes, the re-parenting itself works correctly, but if the reparented task
exits it needs ->parent->nsproxy->pid_ns in do_notify_parent(), and if the
main thread is zombie its ->nsproxy was already cleared by
exit_task_namespaces().

Introduce the new function, find_new_reaper(), which finds the new
->parent for the re-parenting and changes ->child_reaper if needed.  Kill
the now unneeded exit_child_reaper().

Also move the changing of ->child_reaper from zap_pid_ns_processes() to
find_new_reaper(), this consolidates the games with ->child_reaper and
makes it stable under tasklist_lock.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=11391Reported-by: NRobert Rex <robert.rex@exasol.com>
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NPavel Emelyanov <xemul@openvz.org>
Acked-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

zap_pid_ns_processes() sets pid_ns->child_reaper = NULL, this is wrong.

Yes, we have already killed all tasks in this namespace, and sys_wait4()
doesn't see any child.  But this doesn't mean ->children list is empty, we
may have EXIT_DEAD tasks which are not visible to do_wait().  In that case
the subsequent forget_original_parent() will crash the kernel because it
will try to re-parent these tasks to the NULL reaper.

Even if there are no childs, it is not good that forget_original_parent()
uses reaper == NULL.

Change the code to set ->child_reaper = init_pid_ns.child_reaper instead.
We could use pid_ns->parent->child_reaper as well, I think this does not
really matter.  These EXIT_DEAD tasks are not visible to the new ->parent
after re-parenting, they will silently do release_task() eventually.

Note that we must change ->child_reaper, otherwise
forget_original_parent() will use reaper == father, and in that case we
will hit the (correct) BUG_ON(!list_empty(&father->children)).
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

At91_mci is abusing dma_free_coherent(), which may not be called with IRQs
disabled.  I saw "mkfs.ext3" on an MMC card objecting voluminously as each
write completed:

 WARNING: at arch/arm/mm/consistent.c:368 dma_free_coherent+0x2c/0x224()
 [<c002726c>] (dump_stack+0x0/0x14) from [<c00387d4>] (warn_on_slowpath+0x4c/0x68)
 [<c0038788>] (warn_on_slowpath+0x0/0x68) from [<c0028768>] (dma_free_coherent+0x2c/0x224)
  r6:00008008 r5:ffc06000 r4:00000000
 [<c002873c>] (dma_free_coherent+0x0/0x224) from [<c01918ac>] (at91_mci_irq+0x374/0x420)
 [<c0191538>] (at91_mci_irq+0x0/0x420) from [<c0065d9c>] (handle_IRQ_event+0x2c/0x6c)
 ...

This bug has been around for a LONG time.  The MM warning is from late
2005, but the driver merged a year later ...  so I'm puzzled why nobody
noticed this before now.

The fix involves noting that this buffer shouldn't be DMA-coherent; it's
just used for normal DMA writes.  So replace it with standard kmalloc()
buffering and DMA mapping calls.

This is the quickie fix.  A better one would not rely on allocating large
bounce buffers.  (Note that dma_alloc_coherent could have failed too, but
that case was ignored...  kmalloc is a bit more likely to fail though.)
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Acked-by: NPierre Ossman <drzeus-mmc@drzeus.cx>
Cc: Andrew Victor <linux@maxim.org.za>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Recent changes to tighten the check for UARTs that don't correctly
re-assert THRE (01c194d9: "serial 8250:
tighten test for using backup timer") caused problems when such a UART was
opened for the second time - the bug could only successfully be detected
at first initialization.  For users of this version of this particular
UART IP it is fatal.

This patch stores the information about the bug in the bugs field of the
port structure when the port is first started up so subsequent opens can
check this bit even if the test for the bug fails.

David Brownell: "My own exposure to this is that the UART on DaVinci
hardware, which TI allegedly derived from its original 16550 logic, has
periodically gone from working to unusable with the mainline 8250.c ...
and back and forth a bunch.  Currently it's "unusable", a regression from
some previous versions.  With this patch from Will, it's usable."
Signed-off-by: NWill Newton <will.newton@gmail.com>
Acked-by: NAlex Williamson <alex.williamson@hp.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Brownell <david-b@pacbell.net>
Cc: <stable@kernel.org>		[2.6.26.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NHenrik Rydberg <rydberg@euromail.se>
Cc: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

WARNING: vmlinux.o(.data+0x1f5c0): Section mismatch in reference from the variable contig_page_data to the variable .init.data:bootmem_node_data
The variable contig_page_data references
the variable __initdata bootmem_node_data
If the reference is valid then annotate the
variable with __init* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,
Signed-off-by: NMarcin Slusarz <marcin.slusarz@gmail.com>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: Sean MacLennan <smaclennan@pikatech.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The exit function neglects to remove debugfs entries, leading to a BUG
on reload.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: NRuss Dill <Russ.Dill@gmail.com>
Acked-by: NCarlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Dio write returns EIO when try_to_release_page fails because bh is
still referenced.

The patch

    commit 3f31fddf
    Author: Mingming Cao <cmm@us.ibm.com>
    Date:   Fri Jul 25 01:46:22 2008 -0700

        jbd: fix race between free buffer and commit transaction

was merged into 2.6.27-rc1, but I noticed that this patch is not enough
to fix the race.

I did fsstress test heavily to 2.6.27-rc1, and found that dio write still
sometimes got EIO through this test.

The patch above fixed race between freeing buffer(dio) and committing
transaction(jbd) but I discovered that there is another race, freeing
buffer(dio) and ext3/4_ordered_writepage.

: background_writeout()
     ->write_cache_pages()
       ->ext3_ordered_writepage()
     	   walk_page_buffers() -> take a bh ref
 	   block_write_full_page() -> unlock_page
		: <- end_page_writeback
                : <- race! (dio write->try_to_release_page fails)
      	   walk_page_buffers() ->release a bh ref

ext3_ordered_writepage holds bh ref and does unlock_page remaining
taking a bh ref, so this causes the race and failure of
try_to_release_page.

To fix this race, I used the approach of falling back to buffered
writes if try_to_release_page() fails on a page.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: NHisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Zach Brown <zach.brown@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I have gotten to the root cause of the hugetlb badness I reported back on
August 15th.  My system has the following memory topology (note the
overlapping node):

            Node 0 Memory: 0x8000000-0x44000000
            Node 1 Memory: 0x0-0x8000000 0x44000000-0x80000000

setup_zone_migrate_reserve() scans the address range 0x0-0x8000000 looking
for a pageblock to move onto the MIGRATE_RESERVE list.  Finding no
candidates, it happily continues the scan into 0x8000000-0x44000000.  When
a pageblock is found, the pages are moved to the MIGRATE_RESERVE list on
the wrong zone.  Oops.

setup_zone_migrate_reserve() should skip pageblocks in overlapping nodes.
Signed-off-by: NAdam Litke <agl@us.ibm.com>
Acked-by: NMel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the location of the NTFS homepage in several files.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
  ide/Kconfig: mark ide-scsi as deprecated
  ide-disk: remove stale init_idedisk_capacity() documentation
  palm_bk3710: improve IDE registration
  ide: fix hwif_to_node()
  IDE: palm_bk3710: fix compile warning for unused variable
  IDE: compile fix for sff_dma_ops

Mark ide-scsi as deprecated and remove stale/bogus documentation.
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Acked-by: NSergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* fix device tree ... don't forget to set the parent device

* let init/exit code be removed where practical
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
[bart: splitted it from bigger DaVinci patch, s/hw.parent/hw.dev/]
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

hwif_to_node() incorrectly assumes that hwif->dev always belongs to
a PCI device.  This results in ide-cs oopsing in init_irq() after
commit c56c5648 accidentally fixed
device tree registration for ide-cs.  Fix it by using dev_to_node().

Thanks to Martin Michlmayr and Larry Finger for help with debugging
the issue.
Reported-by: NMartin Michlmayr <tbm@cyrius.com>
Tested-by: NMartin Michlmayr <tbm@cyrius.com>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

The sff_dma_ops struct should be wrapped by BLK_DEV_IDEDMA_SFF instead
of BLK_DEV_IDEDMA_PCI.
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <bzolnier@gmail.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda - Add mic-boost controls to ALC662/663 auto configuration
  ALSA: hda - Fix ALC663 auto-probe
  ALSA: ASoC: fix pxa2xx-i2s clk_get call
  ALSA: hda: Distortion fix for dell_m6_core_init

* 'audit.b57' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
  [PATCH] audit: Moved variable declaration to beginning of function

* 'for-linus' of git://neil.brown.name/md:
  Fix problem with waiting while holding rcu read lock in md/bitmap.c
  Remove invalidate_partition call from do_md_stop.

With the new firmware infrastructure in 2.6.27, some files are generated and shouldn't be
diffed; add these 2 to the "dontdiff" file
Signed-off-by: NArjan van de Ven <arjan@Linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes a typo in commit 2a2a6471 "Disable MWAIT via DMI on broken Compal board".

It allows the nomwait dmi check to actually detect the Acer 5220.
Signed-off-by: NDennis Jansen <dennis.jansen@web.de>
Tested-by: NDennis Jansen <dennis.jansen@web.de>
Acked-by: NZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.infradead.org/users/dwmw2/random-2.6:
  [MTD] mtdchar.c: Fix regression in MEMGETREGIONINFO ioctl()
  dabusb_fpga_download(): fix a memory leak
  Remove '#include <stddef.h>' from mm/page_isolation.c
  Fix modules_install on RO nfs-exported trees.

* 'for-2.6.27' of git://linux-nfs.org/~bfields/linux:
  nfsd: fix buffer overrun decoding NFSv4 acl
  sunrpc: fix possible overrun on read of /proc/sys/sunrpc/transports
  nfsd: fix compound state allocation error handling
  svcrdma: Fix race between svc_rdma_recvfrom thread and the dto_tasklet

Fix operator precedence bug in atari_keyb_init, which caused a failure on CT60
Signed-off-by: NMichael Schmitz <schmitz@debian.org>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>