This is a reimplemention of commit
0119509c
from Matthew Garrett <mjg59@srcf.ucam.org>

This patch got removed because of a regression: ThinkPads with a
Intel graphics card and an Integrated Graphics Device BIOS implementation
stopped working.
In fact, they only worked because the ACPI device of the discrete, the
wrong one, got used (via int10). So ACPI functions were poking on the wrong
hardware used which is a sever bug.
The next patch provides support for above ThinkPads to be able to
switch brightness via the legacy thinkpad_acpi driver and automatically
detect when to use it.

Original commit message from Matthew Garrett:
    Vendors often ship machines with a choice of integrated or discrete
    graphics, and use the same DSDT for both. As a result, the ACPI video
    module will locate devices that may not exist on this specific platform.
    Attempt to determine whether the device exists or not, and abort the
    device creation if it doesn't.

http://bugzilla.kernel.org/show_bug.cgi?id=9614Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] Reserve elfcorehdr memory in CONFIG_CRASH_DUMP
  [IA64] fix boot panic caused by offline CPUs
  [IA64] reorder Kconfig options to match x86
  [IA64] Build VT-D iommu support into generic kernel
  [IA64] remove dead BIO_VMERGE_BOUNDARY definition
  [IA64] remove duplicated #include from pci-dma.c
  [IA64] use common header for software IO/TLB
  [IA64] fix the difference between node_mem_map and node_start_pfn
  [IA64] Add error_recovery_info field to SAL section header
  [IA64] Add UV watchlist support.
  [IA64] Simplify SGI uv vs. sn2 driver issues

IA64 kdump kernel failed to initialize /proc/vmcore in 2.6.28-rc2.
A bug was introduced in this patch commit:

  d9a9855d
  always reserve elfcore header memory in crash kernel

The problem was that the call to reserve_elfcorehdr() should be placed
in CONFIG_CRASH_DUMP rather than in CONFIG_CRASH_KERNEL, which does
not exist.
Signed-off-by: Jay Lan <jlan@sgi.com>
Acked-by: Simon Hormon <horms@verge.net.au>
Signed-off-by: Tony Luck <tony.luck@intel.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: fix range check on mmapped sysfs resource files
  PCI: remove excess kernel-doc notation
  PCI: annotate return value of pci_ioremap_bar with __iomem
  PCI: fix VPD limit quirk for Broadcom 5708S

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, xen: fix use of pgd_page now that it really does return a page

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: fine-tune SD_SIBLING_INIT
  sched: fine-tune SD_MC_INIT
  sched: fix memory leak in a failure path
  sched: fix a bug in sched domain degenerate

Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  xen: make sure stray alias mappings are gone before pinning
  vmap: cope with vm_unmap_aliases before vmalloc_init()

This triggers false bug reports as it does a bogus kmalloc with locks held
but is never really compiled into the kernel.

Closes #8329
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

As we've lost our trivial maintainer for the moment I'll send this
directly. Only touches a comment
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: add checksum calculation when clearing UNINIT flag in ext4_new_inode
  ext4: Mark the buffer_heads as dirty and uptodate after prepare_write
  ext4: calculate journal credits correctly
  ext4: wait on all pending commits in ext4_sync_fs()
  ext4: Convert to host order before using the values.
  ext4: fix missing ext4_unlock_group in error path
  jbd2: deregister proc on failure in jbd2_journal_init_inode
  jbd2: don't give up looking for space so easily in __jbd2_log_wait_for_space
  jbd: don't give up looking for space so easily in __log_wait_for_space

fine-tune the HT sched-domains parameters as well.

On a HT capable box, this increases lat_ctx performance from 23.87
usecs to 1.49 usecs:

 # before

 $ ./lat_ctx -s 0 2

   "size=0k ovr=1.89
    2 23.87

 # after

 $ ./lat_ctx -s 0 2

   "size=0k ovr=1.84
     2 1.49
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Tune SD_MC_INIT the same way as SD_CPU_INIT:
unset SD_BALANCE_NEWIDLE, and set SD_WAKE_BALANCE.

This improves vmark by 5%:

vmark         132102 125968 125497 messages/sec    avg 127855.66    .984
vmark         139404 131719 131272 messages/sec    avg 134131.66   1.033
Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

 # *DOCUMENTATION*

When initializing an uninitialized block group in ext4_new_inode(),
its block group checksum must be re-calculated.  This fixes a race
when several threads try to allocate a new inode in an UNINIT'd group.

There is some question whether we need to be initializing the block
bitmap in ext4_new_inode() at all, but for now, if we are going to
init the block group, let's eliminate the race.
Signed-off-by: Frederic Bohe <frederic.bohe@bull.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

We need to make sure we mark the buffer_heads as dirty and uptodate
so that block_write_full_page write them correctly.

This fixes mmap corruptions that can occur in low memory situations.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Xen requires that all mappings of pagetable pages are read-only, so
that they can't be updated illegally.  As a result, if a page is being
turned into a pagetable page, we need to make sure all its mappings
are RO.

If the page had been used for ioremap or vmalloc, it may still have
left over mappings as a result of not having been lazily unmapped.
This change makes sure we explicitly mop them all up before pinning
the page.

Unlike aliases created by kmap, the there can be vmalloc aliases even
for non-high pages, so we must do the flush unconditionally.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Linux Memory Management List <linux-mm@kvack.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Xen can end up calling vm_unmap_aliases() before vmalloc_init() has
been called.  In this case its safe to make it a simple no-op.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Linux Memory Management List <linux-mm@kvack.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: fix rare memory leak in the sched-domains manual reconfiguration code

In the failure path, rd is not attached to a sched domain,
so it causes a leak.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Impact: re-add incorrectly eliminated sched domain layers

(1) on i386 with SCHED_SMT and SCHED_MC enabled
	# mount -t cgroup -o cpuset xxx /mnt
	# echo 0 > /mnt/cpuset.sched_load_balance
	# mkdir /mnt/0
	# echo 0 > /mnt/0/cpuset.cpus
	# dmesg
	CPU0 attaching sched-domain:
	 domain 0: span 0 level CPU
	  groups: 0

(2) on i386 with SCHED_MC enabled but SCHED_SMT disabled
	# same with (1)
	# dmesg
	CPU0 attaching NULL sched-domain.

The bug is that some sched domains may be skipped unintentionally when
degenerating (optimizing) sched domains.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  net: Fix recursive descent in __scm_destroy().
  iwl3945: fix deadlock on suspend
  iwl3945: do not send scan command if channel count zero
  iwl3945: clear scanning bits upon failure
  ath5k: correct handling of rx status fields
  zd1211rw: Add 2 device IDs
  Fix logic error in rfkill_check_duplicity
  iwlagn: avoid sleep in softirq context
  iwlwifi: clear scanning bits upon failure
  Revert "ath5k: honor FIF_BCN_PRBRESP_PROMISC in STA mode"
  tcp: Fix recvmsg MSG_PEEK influence of blocking behavior.
  netfilter: netns ct: walk netns list under RTNL
  ipv6: fix run pending DAD when interface becomes ready
  net/9p: fix printk format warnings
  net: fix packet socket delivery in rx irq handler
  xfrm: Have af-specific init_tempsel() initialize family field of temporary selector

Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  Revert "x86: default to reboot via ACPI"
  x86: align DirectMap in /proc/meminfo
  AMD IOMMU: fix lazy IO/TLB flushing in unmap path
  x86: add smp_mb() before sending INVALIDATE_TLB_VECTOR
  x86: remove VISWS and PARAVIRT around NR_IRQS puzzle
  x86: mention ACPI in top-level Kconfig menu
  x86: size NR_IRQS on 32-bit systems the same way as 64-bit
  x86: don't allow nr_irqs > NR_IRQS
  x86/docs: remove noirqbalance param docs
  x86: don't use tsc_khz to calculate lpj if notsc is passed
  x86, voyager: fix smp_intr_init() compile breakage
  AMD IOMMU: fix detection of NP capable IOMMUs

* master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] xsc3: fix xsc3_l2_inv_range
  [ARM] mm: fix page table initialization
  [ARM] fix naming of MODULE_START / MODULE_END
  ARM: OMAP: Fix define for twl4030 irqs
  ARM: OMAP: Fix get_irqnr_and_base to clear spurious interrupt bits
  ARM: OMAP: Fix debugfs_create_*'s error checking method for arm/plat-omap
  ARM: OMAP: Fix compiler warnings in gpmc.c
  [ARM] fix VFP+softfloat binaries

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  ieee1394: dv1394: fix possible deadlock in multithreaded clients
  ieee1394: raw1394: fix possible deadlock in multithreaded clients
  ieee1394: struct device - replace bus_id with dev_name(), dev_set_name()
  firewire: struct device - replace bus_id with dev_name(), dev_set_name()

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  Block: use round_jiffies_up()
  Add round_jiffies_up and related routines
  block: fix __blkdev_get() for removable devices
  generic-ipi: fix the smp_mb() placement
  blk: move blk_delete_timer call in end_that_request_last
  block: add timer on blkdev_dequeue_request() not elv_next_request()
  bio: define __BIOVEC_PHYS_MERGEABLE
  block: remove unused ll_new_mergeable()

* git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  [WATCHDOG] SAM9 watchdog - supported on all SAM9 and CAP9 processors
  [WATCHDOG] SAM9 watchdog - update for moved headers

* 'for-linus' of git://neil.brown.name/md:
  md: linear: Fix a division by zero bug for very small arrays.
  md: fix bug in raid10 recovery.
  md: revert the recent addition of a call to the BLKRRPART ioctl.

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
  powerpc: Fix "unused variable" warning in pci_dlpar.c
  powerpc/cell: Fix compile error in ras.c
  powerpc/ps3: Fix compile error in ps3-lpm.c

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  net/9p: fix printk format warnings
  unsigned fid->fid cannot be negative
  9p: rdma: remove duplicated #include
  p9: Fix leak of waitqueue in request allocation path
  9p: Remove unneeded free of fcall for Flush
  9p: Make all client spin locks IRQ safe
  9p: rdma: Set trans prior to requesting async connection ops

Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: re-tune balancing
  sched: fix buddies for group scheduling
  sched: backward looking buddy
  sched: fix fair preempt check
  sched: cleanup fair task selection

__scm_destroy() walks the list of file descriptors in the scm_fp_list
pointed to by the scm_cookie argument.

Those, in turn, can close sockets and invoke __scm_destroy() again.

There is nothing which limits how deeply this can occur.

The idea for how to fix this is from Linus.  Basically, we do all of
the fput()s at the top level by collecting all of the scm_fp_list
objects hit by an fput().  Inside of the initial __scm_destroy() we
keep running the list until it is empty.
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix the hrtimer_add_expires_ns() function.  It should take a 'u64 ns' argument,
but rather takes an 'unsigned long ns' argument - which might only be 32-bits.

On FRV, this results in the kernel locking up because hrtimer_forward() passes
the result of a 64-bit multiplication to this function, for which the compiler
discards the top 32-bits - something that didn't happen when ktime_add_ns() was
called directly.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.infradead.org/mtd-2.6:
  [JFFS2] fix race condition in jffs2_lzo_compress()
  [MTD] [NOR] Fix cfi_send_gen_cmd handling of x16 devices in x8 mode (v4)
  [JFFS2] Fix lack of locking in thread_should_wake()
  [JFFS2] Fix build failure with !CONFIG_JFFS2_FS_WRITEBUFFER
  [MTD] [NAND] OMAP2: remove duplicated #include

blkcnt_t type depends on CONFIG_LSF. Use unsigned long long always for
printk().  But lazy to type it, so add "llu" and use it.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

i_pos is 64bits value, hence it's not atomic to update.

Important place is fat_write_inode() only, other places without lock
are just for printk().

This adds lock for "BITS_PER_LONG == 32" kernel.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mmu_private is 64bits value, hence it's not atomic to update.

So, the access rule for mmu_private is we must hold ->i_mutex.  But,
fat_get_block() path doesn't follow the rule on non-allocation path.

This fixes by using i_size instead if non-allocation path.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fat_get_cluster() assumes the requested blocknr isn't truncated during
read. _fat_bmap() doesn't follow this rule.

This protects it by ->i_mutex.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

FAT has the ATTR_RO (read-only) attribute. But on Windows, the ATTR_RO
of the directory will be just ignored actually, and is used by only
applications as flag. E.g. it's setted for the customized folder by
Explorer.

http://msdn2.microsoft.com/en-us/library/aa969337.aspx

This adds "rodir" option. If user specified it, ATTR_RO is used as
read-only flag even if it's the directory. Otherwise, inode->i_mode
is not used to hold ATTR_RO (i.e. fat_mode_can_save_ro() returns 0).
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If inode->i_mode doesn't have S_WUGO, current code assumes it means
ATTR_RO.  However, if (~[ufd]mask & S_WUGO) == 0, inode->i_mode can't
hold S_WUGO. Therefore the updated directory entry will always have
ATTR_RO.

This adds fat_mode_can_hold_ro() to check it. And if inode->i_mode
can't hold, uses -i_attrs to hold ATTR_RO instead.

With this, we don't set ATTR_RO unless users change it via ioctl() if
(~[ufd]mask & S_WUGO) == 0.

And on FAT_IOCTL_GET_ATTRIBUTES path, this adds ->i_mutex to it for
not returning the partially updated attributes by FAT_IOCTL_SET_ATTRIBUTES
to userland.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This adds three helpers:

fat_make_attrs() - makes FAT attributes from inode.
fat_make_mode()  - makes mode_t from FAT attributes.
fat_save_attrs() - saves FAT attributes to inode.

Then this replaces: MSDOS_MKMODE() by fat_make_mode(), fat_attr() by
fat_make_attrs(), ->i_attrs = attr & ATTR_UNUSED by fat_save_attrs().
And for root inode, those is used with ATTR_DIR instead of bogus
ATTR_NONE.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>