Impact: change (fix) the way the NTP PLL seconds offset is initialized/tracked

Fix a bug and do a micro-optimization:

When PLL is enabled we do not reset time_reftime. If the PLL
was off for a long time (for example after bootup), this is
arguably the wrong thing to do.

We already had a hack for the common boot-time case in
ntp_update_offset(), in form of:

	if (unlikely(time_status & STA_FREQHOLD || time_reftime == 0))
 		secs = 0;

But the update delta should be reset later on too - not just when
the PLL is enabled for the first time after bootup.

So do it on !STA_PLL -> STA_PLL transitions.

This changes behavior, as previously if ntpd was disabled for
a long time and we restarted it, we'd run from that last update,
with a very large delta.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup, no functionality changed

The time_reftime update in ntp_update_offset() to xtime.tv_sec
is a convoluted way of saying that we want to freeze the frequency
and want the 'secs' delta to be 0. Also make this branch unlikely.

This shaves off 8 bytes from the code size:

   text	   data	    bss	    dec	    hex	filename
   2504	    114	    136	   2754	    ac2	ntp.o.before
   2496	    114	    136	   2746	    aba	ntp.o.after
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup, no functionality changed

Change ntp_update_offset_fll() to delta logic instead of
absolute value logic. This eliminates 'freq_adj' from the
function.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup, no functionality changed

- introduce the ntp_update_offset_fll() helper
- clean up the flow and variable naming

kernel/time/ntp.o:

   text	   data	    bss	    dec	    hex	filename
   2504	    114	    136	   2754	    ac2	ntp.o.before
   2504	    114	    136	   2754	    ac2	ntp.o.after

md5:
   01f7b8e1a5472a3056f9e4ae84d46315  ntp.o.before.asm
   01f7b8e1a5472a3056f9e4ae84d46315  ntp.o.after.asm
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup, no functionality changed

Change ntp_update_frequency() from a hard to follow code
flow that uses global variables as temporaries, to a clean
input+output flow.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup, no functionality changed

Prepare a refactoring of ntp_update_frequency().

kernel/time/ntp.o:

   text	   data	    bss	    dec	    hex	filename
   2504	    114	    136	   2754	    ac2	ntp.o.before
   2504	    114	    136	   2754	    ac2	ntp.o.after

md5:
   41f3009debc9b397d7394dd77d912f0a  ntp.o.before.asm
   41f3009debc9b397d7394dd77d912f0a  ntp.o.after.asm
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup, no functionality changed

There's an ugly u64 typecase in the MAX_TICKADJ_SCALED definition,
this can be eliminated by making the MAX_TICKADJ constant's type
64-bit (signed).

kernel/time/ntp.o:

   text	   data	    bss	    dec	    hex	filename
   2504	    114	    136	   2754	    ac2	ntp.o.before
   2504	    114	    136	   2754	    ac2	ntp.o.after

md5:
   41f3009debc9b397d7394dd77d912f0a  ntp.o.before.asm
   41f3009debc9b397d7394dd77d912f0a  ntp.o.after.asm
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup, no functionality changed

Instead of a hierarchy of conditions, transform them to clean
gradual conditions and return's.

This makes the flow easier to read and makes the purpose of
the function easier to understand.

kernel/time/ntp.o:

   text	   data	    bss	    dec	    hex	filename
   2552	    170	    168	   2890	    b4a	ntp.o.before
   2552	    170	    168	   2890	    b4a	ntp.o.after

md5:
   eae1275df0b7d6290c13f6f6f8f05c8c  ntp.o.before.asm
   eae1275df0b7d6290c13f6f6f8f05c8c  ntp.o.after.asm
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup, no functionality changed

Make this file a bit more readable by applying a consistent coding style.

No code changed:

kernel/time/ntp.o:

   text	   data	    bss	    dec	    hex	filename
   2552	    170	    168	   2890	    b4a	ntp.o.before
   2552	    170	    168	   2890	    b4a	ntp.o.after

md5:
   eae1275df0b7d6290c13f6f6f8f05c8c  ntp.o.before.asm
   eae1275df0b7d6290c13f6f6f8f05c8c  ntp.o.after.asm
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Since the GENERIC_TIME changes landed, the adjtimex behavior changed
for struct timex.tick and .freq changed. When the tick or freq value
is set, we adjust the tick_length_base in ntp_update_frequency().
However, this new value doesn't get applied to tick_length until the
next second (via second_overflow).

This means some applications that do quick time tweaking do not see the
requested change made as quickly as expected.

I've run a few tests with this change, and ntpd still functions fine.
Signed-off-by: NJohn Stultz <johnstul@us.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list
  block: fix booting from partitioned md array
  block: revert part of 18ce3751
  cciss: PCI power management reset for kexec
  paride/pg.c: xs(): &&/|| confusion
  fs/bio: bio_alloc_bioset: pass right object ptr to mempool_free
  block: fix bad definition of BIO_RW_SYNC
  bsg: Fix sense buffer bug in SG_IO

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
  omap_hsmmc: Change while(); loops with finite version
  omap_hsmmc: recover from transfer failures
  omap_hsmmc: only MMC1 allows HCTL.SDVS != 1.8V
  omap_hsmmc: card detect irq bugfix
  sdhci: fix led naming
  mmc_test: fix basic read test
  s3cmci: Fix hangup in do_pio_write()
  Revert "sdhci: force high speed capability on some controllers"
  MMC: fix bug - SDHC card capacity not correct

Enhanced lockdep coverage of __GFP_NOFS turned up this new lockdep
assert:

[ 1093.677775]
[ 1093.677781] =================================
[ 1093.680031] [ INFO: inconsistent lock state ]
[ 1093.680031] 2.6.29-rc5-tip-01504-gb49eca1-dirty #1
[ 1093.680031] ---------------------------------
[ 1093.680031] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
[ 1093.680031] kswapd0/308 [HC0[0]:SC0[0]:HE1:SE1] takes:
[ 1093.680031]  (&inode->inotify_mutex){+.+.?.}, at: [<c0205942>] inotify_inode_is_dead+0x20/0x80
[ 1093.680031] {RECLAIM_FS-ON-W} state was registered at:
[ 1093.680031]   [<c01696b9>] mark_held_locks+0x43/0x5b
[ 1093.680031]   [<c016baa4>] lockdep_trace_alloc+0x6c/0x6e
[ 1093.680031]   [<c01cf8b0>] kmem_cache_alloc+0x20/0x150
[ 1093.680031]   [<c040d0ec>] idr_pre_get+0x27/0x6c
[ 1093.680031]   [<c02056e3>] inotify_handle_get_wd+0x25/0xad
[ 1093.680031]   [<c0205f43>] inotify_add_watch+0x7a/0x129
[ 1093.680031]   [<c020679e>] sys_inotify_add_watch+0x20f/0x250
[ 1093.680031]   [<c010389e>] sysenter_do_call+0x12/0x35
[ 1093.680031]   [<ffffffff>] 0xffffffff
[ 1093.680031] irq event stamp: 60417
[ 1093.680031] hardirqs last  enabled at (60417): [<c018d5f5>] call_rcu+0x53/0x59
[ 1093.680031] hardirqs last disabled at (60416): [<c018d5b9>] call_rcu+0x17/0x59
[ 1093.680031] softirqs last  enabled at (59656): [<c0146229>] __do_softirq+0x157/0x16b
[ 1093.680031] softirqs last disabled at (59651): [<c0106293>] do_softirq+0x74/0x15d
[ 1093.680031]
[ 1093.680031] other info that might help us debug this:
[ 1093.680031] 2 locks held by kswapd0/308:
[ 1093.680031]  #0:  (shrinker_rwsem){++++..}, at: [<c01b0502>] shrink_slab+0x36/0x189
[ 1093.680031]  #1:  (&type->s_umount_key#4){+++++.}, at: [<c01e6d77>] shrink_dcache_memory+0x110/0x1fb
[ 1093.680031]
[ 1093.680031] stack backtrace:
[ 1093.680031] Pid: 308, comm: kswapd0 Not tainted 2.6.29-rc5-tip-01504-gb49eca1-dirty #1
[ 1093.680031] Call Trace:
[ 1093.680031]  [<c016947a>] valid_state+0x12a/0x13d
[ 1093.680031]  [<c016954e>] mark_lock+0xc1/0x1e9
[ 1093.680031]  [<c016a5b4>] ? check_usage_forwards+0x0/0x3f
[ 1093.680031]  [<c016ab74>] __lock_acquire+0x2c6/0xac8
[ 1093.680031]  [<c01688d9>] ? register_lock_class+0x17/0x228
[ 1093.680031]  [<c016b3d3>] lock_acquire+0x5d/0x7a
[ 1093.680031]  [<c0205942>] ? inotify_inode_is_dead+0x20/0x80
[ 1093.680031]  [<c08824c4>] __mutex_lock_common+0x3a/0x4cb
[ 1093.680031]  [<c0205942>] ? inotify_inode_is_dead+0x20/0x80
[ 1093.680031]  [<c08829ed>] mutex_lock_nested+0x2e/0x36
[ 1093.680031]  [<c0205942>] ? inotify_inode_is_dead+0x20/0x80
[ 1093.680031]  [<c0205942>] inotify_inode_is_dead+0x20/0x80
[ 1093.680031]  [<c01e6672>] dentry_iput+0x90/0xc2
[ 1093.680031]  [<c01e67a3>] d_kill+0x21/0x45
[ 1093.680031]  [<c01e6a46>] __shrink_dcache_sb+0x27f/0x355
[ 1093.680031]  [<c01e6dc5>] shrink_dcache_memory+0x15e/0x1fb
[ 1093.680031]  [<c01b05ed>] shrink_slab+0x121/0x189
[ 1093.680031]  [<c01b0d12>] kswapd+0x39f/0x561
[ 1093.680031]  [<c01ae499>] ? isolate_pages_global+0x0/0x233
[ 1093.680031]  [<c0157eae>] ? autoremove_wake_function+0x0/0x43
[ 1093.680031]  [<c01b0973>] ? kswapd+0x0/0x561
[ 1093.680031]  [<c0157daf>] kthread+0x41/0x82
[ 1093.680031]  [<c0157d6e>] ? kthread+0x0/0x82
[ 1093.680031]  [<c01043ab>] kernel_thread_helper+0x7/0x10

inotify_handle_get_wd() does idr_pre_get() which does a
kmem_cache_alloc() without __GFP_FS - and is hence deadlockable under
extreme MM pressure.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: MinChan Kim <minchan.kim@gmail.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

gpio_get_value() returns 0 or nonzero, but getmiso() expects 0 or 1.
Sanitize the value to a 0/1 boolean.
Signed-off-by: NMichael Buesch <mb@bu3sch.de>
Acked-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since I don't work for SUSE any more and the bwalle@suse.de address is
invalid, correct it in the copyright headers and documentation.
Signed-off-by: NBernhard Walle <bernhard.walle@gmx.de>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Build breaks when DELL_LAPTOP=y and POWER_SUPPLY=m.  DELL_LAPTOP needs to
depend on POWER_SUPPLY.

dell-laptop.c:(.text+0x1ef3c4): undefined reference to `power_supply_is_system_supplied'
dell-laptop.c:(.text+0x1ef45e): undefined reference to `power_supply_is_system_supplied'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Otherwise, these don't work when called from 32-bit userspace on 64-bit
kernels.

Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Submenus of the graphics support "Support for frame buffer devices" and
"Direct Rendering Manager (XFree86 4.1.0 and higher DRI support)" are
broken in half after latest changes for Intel 915 mode setting support.

The DRM subsection is broken because one option is put outside the choice
section it depends on.

The frame buffers part is broken then due to circular dependency.  Fix
this by make Intel frame buffers depend on CONFIG_INTEL_AGP.

Kconfigs are broken by d2f59357
("drm/i915: select framebuffer support automatically").

This is probably not only way to fix this.
Signed-off-by: NKrzysztof Helt <krzysztof.h1@wp.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The floppy driver requests an I/O port it doesn't need, and sometimes this
causes a conflict with a motherboard device reported by PNPBIOS.

This patch makes the floppy driver request and release only the ports it
actually uses.  It also factors out the request/release stuff and the
io-ports list so they're all in one place now.

The current floppy driver uses only these ports:

    0x3f2 (FD_DOR)
    0x3f4 (FD_STATUS)
    0x3f5 (FD_DATA)
    0x3f7 (FD_DCR/FD_DIR)

but it requests 0x3f2-0x3f5 and 0x3f7, which includes the unused port
0x3f3.

Some BIOSes report 0x3f3 as a motherboard resource.  The PNP system driver
reserves that, which causes a conflict when the floppy driver requests
0x3f2-0x3f5 later.

Philippe reported that this conflict broke the floppy driver between
2.6.11 and 2.6.22.  His PNPBIOS reports these devices:

    $ cat 00:07/id 00:07/resources	# motherboard device
    PNP0c02
    state = active
    io 0x80-0x80
    io 0x10-0x1f
    io 0x22-0x3f
    io 0x44-0x5f
    io 0x90-0x9f
    io 0xa2-0xbf
    io 0x3f0-0x3f1
    io 0x3f3-0x3f3

    $ cat 00:03/id 00:03/resources	# floppy device
    PNP0700
    state = active
    io 0x3f4-0x3f5
    io 0x3f2-0x3f2

Reference:
    http://lkml.org/lkml/2009/1/31/162Signed-off-by: NBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: NPhilippe De Muyter <phdm@macqel.be>
Reported-by: NPhilippe De Muyter <phdm@macqel.be>
Tested-by: NPhilippe De Muyter <phdm@macqel.be>
Cc: Adam M Belay <abelay@mit.edu>
Cc: Robert Hancock <hancockrwd@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I have a Digi Neo 8 PCI card (114f:00b1) Serial controller: Digi
International Digi Neo 8 (rev 05)

that works with the jsm driver after using the following patch.
Signed-off-by: NAdam Lackorzynski <adam@os.inf.tu-dresden.de>
Cc: Scott H Kilau <Scott_Kilau@digi.com>
Cc: Wendy Xiong <wendyx@us.ibm.com>
Acked-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now, early_pfn_in_nid(PFN, NID) may returns false if PFN is a hole.
and memmap initialization was not done. This was a trouble for
sparc boot.

To fix this, the PFN should be initialized and marked as PG_reserved.
This patch changes early_pfn_in_nid() return true if PFN is a hole.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reported-by: NDavid Miller <davem@davemlloft.net>
Tested-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

What's happening is that the assertion in mm/page_alloc.c:move_freepages()
is triggering:

	BUG_ON(page_zone(start_page) != page_zone(end_page));

Once I knew this is what was happening, I added some annotations:

	if (unlikely(page_zone(start_page) != page_zone(end_page))) {
		printk(KERN_ERR "move_freepages: Bogus zones: "
		       "start_page[%p] end_page[%p] zone[%p]\n",
		       start_page, end_page, zone);
		printk(KERN_ERR "move_freepages: "
		       "start_zone[%p] end_zone[%p]\n",
		       page_zone(start_page), page_zone(end_page));
		printk(KERN_ERR "move_freepages: "
		       "start_pfn[0x%lx] end_pfn[0x%lx]\n",
		       page_to_pfn(start_page), page_to_pfn(end_page));
		printk(KERN_ERR "move_freepages: "
		       "start_nid[%d] end_nid[%d]\n",
		       page_to_nid(start_page), page_to_nid(end_page));
 ...

And here's what I got:

	move_freepages: Bogus zones: start_page[2207d0000] end_page[2207dffc0] zone[fffff8103effcb00]
	move_freepages: start_zone[fffff8103effcb00] end_zone[fffff8003fffeb00]
	move_freepages: start_pfn[0x81f600] end_pfn[0x81f7ff]
	move_freepages: start_nid[1] end_nid[0]

My memory layout on this box is:

[    0.000000] Zone PFN ranges:
[    0.000000]   Normal   0x00000000 -> 0x0081ff5d
[    0.000000] Movable zone start PFN for each node
[    0.000000] early_node_map[8] active PFN ranges
[    0.000000]     0: 0x00000000 -> 0x00020000
[    0.000000]     1: 0x00800000 -> 0x0081f7ff
[    0.000000]     1: 0x0081f800 -> 0x0081fe50
[    0.000000]     1: 0x0081fed1 -> 0x0081fed8
[    0.000000]     1: 0x0081feda -> 0x0081fedb
[    0.000000]     1: 0x0081fedd -> 0x0081fee5
[    0.000000]     1: 0x0081fee7 -> 0x0081ff51
[    0.000000]     1: 0x0081ff59 -> 0x0081ff5d

So it's a block move in that 0x81f600-->0x81f7ff region which triggers
the problem.

This patch:

Declaration of early_pfn_to_nid() is scattered over per-arch include
files, and it seems it's complicated to know when the declaration is used.
 I think it makes fix-for-memmap-init not easy.

This patch moves all declaration to include/linux/mm.h

After this,
  if !CONFIG_NODES_POPULATES_NODE_MAP && !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
     -> Use static definition in include/linux/mm.h
  else if !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
     -> Use generic definition in mm/page_alloc.c
  else
     -> per-arch back end function will be called.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: NDavid Miller <davem@davemlloft.net>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Li Zefan said:

Thread 1:
  for ((; ;))
  {
      mount -t cpuset xxx /mnt > /dev/null 2>&1
      cat /mnt/cpus > /dev/null 2>&1
      umount /mnt > /dev/null 2>&1
  }

Thread 2:
  for ((; ;))
  {
      mount -t cpuset xxx /mnt > /dev/null 2>&1
      umount /mnt > /dev/null 2>&1
  }

(Note: It is irrelevant which cgroup subsys is used.)

After a while a lockdep warning showed up:

=============================================
[ INFO: possible recursive locking detected ]
2.6.28 #479
---------------------------------------------
mount/13554 is trying to acquire lock:
 (&type->s_umount_key#19){--..}, at: [<c049d888>] sget+0x5e/0x321

but task is already holding lock:
 (&type->s_umount_key#19){--..}, at: [<c049da0c>] sget+0x1e2/0x321

other info that might help us debug this:
1 lock held by mount/13554:
 #0:  (&type->s_umount_key#19){--..}, at: [<c049da0c>] sget+0x1e2/0x321

stack backtrace:
Pid: 13554, comm: mount Not tainted 2.6.28-mc #479
Call Trace:
 [<c044ad2e>] validate_chain+0x4c6/0xbbd
 [<c044ba9b>] __lock_acquire+0x676/0x700
 [<c044bb82>] lock_acquire+0x5d/0x7a
 [<c049d888>] ? sget+0x5e/0x321
 [<c061b9b8>] down_write+0x34/0x50
 [<c049d888>] ? sget+0x5e/0x321
 [<c049d888>] sget+0x5e/0x321
 [<c045a2e7>] ? cgroup_set_super+0x0/0x3e
 [<c045959f>] ? cgroup_test_super+0x0/0x2f
 [<c045bcea>] cgroup_get_sb+0x98/0x2e7
 [<c045cfb6>] cpuset_get_sb+0x4a/0x5f
 [<c049dfa4>] vfs_kern_mount+0x40/0x7b
 [<c049e02d>] do_kern_mount+0x37/0xbf
 [<c04af4a0>] do_mount+0x5c3/0x61a
 [<c04addd2>] ? copy_mount_options+0x2c/0x111
 [<c04af560>] sys_mount+0x69/0xa0
 [<c0403251>] sysenter_do_call+0x12/0x31

The cause is after alloc_super() and then retry, an old entry in list
fs_supers is found, so grab_super(old) is called, but both functions hold
s_umount lock:

struct super_block *sget(...)
{
	...
retry:
	spin_lock(&sb_lock);
	if (test) {
		list_for_each_entry(old, &type->fs_supers, s_instances) {
			if (!test(old, data))
				continue;
			if (!grab_super(old))  <--- 2nd: down_write(&old->s_umount);
				goto retry;
			if (s)
				destroy_super(s);
			return old;
		}
	}
	if (!s) {
		spin_unlock(&sb_lock);
		s = alloc_super(type);   <--- 1th: down_write(&s->s_umount)
		if (!s)
			return ERR_PTR(-ENOMEM);
		goto retry;
	}
	...
}

It seems like a false positive, and seems like VFS but not cgroup needs to
be fixed.

Peter said:

We can simply put the new s_umount instance in a but lockdep doesn't
particularly cares about subclass order.

If there's any issue with the callers of sget() assuming the s_umount lock
being of sublcass 0, then there is another annotation we can use to fix
that, but lets not bother with that if this is sufficient.

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12673Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: NLi Zefan <lizf@cn.fujitsu.com>
Reported-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Menage <menage@google.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I found a problem of handling of modem status of atmel_serial driver.

With the commit 1ecc26 ("atmel_serial: split the interrupt handler"),
handling of modem status signal was splitted into two parts.  The
atmel_tasklet_func() compares new status with irq_status_prev, but
irq_status_prev is not correct if signal status was changed while the port
is closed.

Here is a sequence to cause problem:

1. Remote side sets CTS (and DSR).
2. Local side close the port.
3. Local side clears RTS and DTR.
4. Remote side clears CTS and DSR.
5. Local side reopen the port.  hw_stopped becomes 1.
6. Local side sets RTS and DTR.
7. Remote side sets CTS and DSR.

Then CTS change interrupt can be received, but since CTS bit in
irq_status_prev and new status is same, uart_handle_cts_change() will not
be called (so hw_stopped will not be cleared, i.e.  cannot send any data).

I suppose irq_status_prev should be initialized at somewhere in open
sequence.

Itai Levi pointed out that we need to initialize atmel_port->irq_status
as well here. His analysis is as follows:

> Regarding the second part of the patch (which resets irq_status_prev),
> it turns out that both versions of the patch (mine and Atsushi's)
> still leave enough room for faulty behavior when opening the port.
>
> This is because we are not resetting both irq_status_prev and
> irq_status in atmel_startup() to CSR, which leads faulty behavior in
> the following sequences:
>
> First case:
> 1. closing the port while CTS line = 1 (TX not allowed)
> 2. setting CTS line = 0 (TX allowed)
> 3. opening the port
> 4. transmitting one char
> 5. Cannot transmit more chars, although CTS line is 0
>
> Second case:
> 1. closing the port while CTS line = 0 (TX allowed)
> 2. setting CTS line = 1 (TX not allowed)
> 3. opening the port
> 4. receiving some chars
> 5. Now we can transmit, although CTS line is 1
>
> This reason for this is that the tasklet is scheduled as a result of
> TX or RX interrupts (not a status change!), in steps 4 above. Inside
> the tasklet, the atmel_port->irq_status (which holds the value from
> the previous session) is compared to atmel_port->irq_status_prev.
> Hence, a status-change of the CTS line is faultily detected.
>
> Both cases were verified on 9260 hardware.

[haavard.skinnemoen@atmel.com: folded with patch from Itai Levi]
Signed-off-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NHaavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Remy Bohmer <linux@bohmer.net>
Cc: Marc Pignat <marc.pignat@hevs.ch>
Cc: Itai Levi <itai.levi.devel@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The conversion of atmel-mci to dma_request_channel missed the
initialization of the channel dma_slave information.  The filter_fn passed
to dma_request_channel is responsible for initializing the channel's
private data.  This implementation has the additional benefit of enabling
a generic client-channel data passing mechanism.
Reviewed-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Acked-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for HP Pavilion dv5.

Since Intel-based models have an inverted x axis, while AMD-based models
have an inverted y axis, we introduce a new macro that special-cases axis
orientation based on two DMI entries: HP dv5 axis configuration is then
based on both the PRODUCT and BOARD name.
Signed-off-by: NGiuseppe Bilotta <giuseppe.bilotta@gmail.com>
Cc: Eric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@suse.cz>
Tested-by: NPalatis Tseng <palatis@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sensors responding with 0x3B to WHO_AM_I only have one data register per
direction, thus returning a signed byte from the position which is
occupied by the MSB in sensors responding with 0x3A.

Since multiple sensors share the reply to WHO_AM_I, we rename the defines
to better indicate what they identify (family of single and double
precision sensors).

We support both kind of sensors by checking for the sensor type on init
and defining appropriate data-access routines and sensor limits (for the
joystick) depending on what we find.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NGiuseppe Bilotta <giuseppe.bilotta@gmail.com>
Acked-by: NEric Piel <Eric.Piel@tremplin-utc.net>
Cc: Pavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds freefall handling to hp_accel driver.  According to HP, it
should just work, without us having to set the chip up by hand.

hpfall.c is example .c program that parks the disk when accelerometer
detects free fall.  It should work; for now, it uses fixed 20seconds
protection period.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Éric Piel <eric.piel@tremplin-utc.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Otherwise with INPUT=m, EEEPC_LAPTOP=y one gets

drivers/built-in.o: In function `input_sync':
eeepc-laptop.c:(.text+0x18ce51): undefined reference to `input_event'
drivers/built-in.o: In function `input_report_key':
eeepc-laptop.c:(.text+0x18ce73): undefined reference to `input_event'
drivers/built-in.o: In function `eeepc_hotk_check':
eeepc-laptop.c:(.text+0x18d05f): undefined reference to `input_allocate_device'
eeepc-laptop.c:(.text+0x18d10f): undefined reference to `input_register_device'
eeepc-laptop.c:(.text+0x18d131): undefined reference to `input_free_device'
drivers/built-in.o: In function `eeepc_backlight_exit':
eeepc-laptop.c:(.text+0x18d546): undefined reference to `input_unregister_device'
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Compilation of kprobes.c with CONFIG_PM unset is broken due to some broken
config dependncies.  Fix that.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Reported-by: NIngo Molnar <mingo@elte.hu>
Tested-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Acked-by: NPavel Machek <pavel@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In cgroup_kill_sb(), root is freed before sb is detached from the list, so
another sget() may find this sb and call cgroup_test_super(), which will
access the root that has been freed.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPaul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for
cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty).

Additionally, there is some inconsistency about when task_dirty_inc is
called.  It is used for dirty balancing, however it even gets called for
__set_page_dirty_no_writeback.

So rather than increment it in a set_page_dirty wrapper, move it down to
exactly where the dirty page accounting stats are incremented.

Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: NNick Piggin <npiggin@suse.de>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As requested by Michael, add a missing check for valid flags in
timerfd_settime(), and make it return EINVAL in case some extra bits are
set.

Michael said:
If this is to be any use to userland apps that want to check flag
support (perhaps it is too late already), then the sooner we get it
into the kernel the better: 2.6.29 would be good; earlier stables as
well would be even better.

[akpm@linux-foundation.org: remove unused TFD_FLAGS_SET]
Acked-by: NMichael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: NDavide Libenzi <davidel@xmailserver.org>
Cc: <stable@kernel.org>		[2.6.27.x, 2.6.28.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

My @suse.cz address will stop working some day, so put working one into
MAINTAINERS/CREDITS.  It would be cool to get this to 2.6.29...  it should
not really break anything.
Signed-off-by: NPavel Machek <pavel@ucw.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently seq_read assumes that the offset passed to it is always the
offset it passed to user space.  In the case pread this assumption is
broken and we do the wrong thing when presented with pread.

To solve this I introduce an offset cache inside of struct seq_file so we
know where our logical file position is.  Then in seq_read if we try to
read from another offset we reset our data structures and attempt to go to
the offset user space wanted.

[akpm@linux-foundation.org: restore FMODE_PWRITE]
[pjt@google.com: seq_open needs its fmode opened up to take advantage of this]
Signed-off-by: NEric Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Turner <pjt@google.com>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Separate FMODE_PREAD and FMODE_PWRITE into separate flags to reflect the
reality that the read and write paths may have independent restrictions.

A git grep verifies that these flags are always cleared together so this
new behavior will only apply to interfaces that change to clear flags
individually.

This is required for "seq_file: properly cope with pread", a post-2.6.25
regression fix.

[akpm@linux-foundation.org: add comment]
Signed-off-by: NPaul Turner <pjt@google.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc:  Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The css_set hash table was introduced in 2.6.26, so update the
documentation accordingly.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPaul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The Welland ME-747K-SI AoE target generates unsolicited AoE responses that
are marked as vendor extensions.  Instead of ignoring these packets, the
aoe driver was generating kernel messages for each unrecognized response
received.  This patch corrects the behavior.
Signed-off-by: NEd Cashin <ecashin@coraid.com>
Reported-by: <karaluh@karaluh.pl>
Tested-by: <karaluh@karaluh.pl>
Cc: <stable@kernel.org>
Cc: Alex Buell <alex.buell@munted.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We have get_vm_area_caller() and __get_vm_area() but not
__get_vm_area_caller()

On powerpc, I use __get_vm_area() to separate the ranges of addresses
given to vmalloc vs.  ioremap (various good reasons for that) so in order
to be able to implement the new caller tracking in /proc/vmallocinfo, I
need a "_caller" variant of it.

(akpm: needed for ongoing powerpc development, so merge it early)

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace the infinite 'while() ;' loops
with a finite loop version.
Signed-off-by: NJean Pihet <jpihet@mvista.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>