Ran into BUG() while doing madvise(REMOVE) testing.  If we are punching a
hole into shared memory segment using madvise(REMOVE) and the entire hole
is below the indirect blocks, we hit following assert.

	        BUG_ON(limit <= SHMEM_NR_DIRECT);
Signed-off-by: NBadari Pulavarty <pbadari@us.ibm.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Commit 2d7d2535 ("fix cond_resched() fix")
introduced an 'expected_preempt_count' parameter to __resched_legal() to
fix a bug where it was returning a false negative when called from
cond_resched_lock() and preemption was enabled.

Unfortunately this broke things for when preemption is disabled.
preempt_count() will always return zero, thus failing the check against any
value of expected_preempt_count not equal to zero.  cond_resched_lock() for
example, passes an expected_preempt_count value of 1.

So fix the fix for the cond_resched() fix by skipping the check of
preempt_count() against expected_preempt_count when preemption is disabled.

Credit should go to Sunil Mushran for spotting the bug during testing.
Signed-off-by: NMark Fasheh <mark.fasheh@oracle.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The VM event counters, enabled by CONFIG_VM_EVENT_COUNTERS, which provides
VM event counters in /proc/vmstat, has become more essential to
non-EMBEDDED kernel configurations than they were in the past.  Comments in
the code and the Kconfig configuration explanation were stale, downplaying
their role excessively.

Refresh those comments to correctly reflect the current role of VM event
counters.
Signed-off-by: NPaul Jackson <pj@sgi.com>
Acked-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add compile-time and run-time API versioning.
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This allows plan9 to get a little further booting.
Signed-off-by: NMichael Riepe <michael@mr511.de>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This allows opensolaris to boot on kvm/intel.
Signed-off-by: NMichael Riepe <michael@mr511.de>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Some msrs, such as MSR_STAR, are not available on all processors.  Exporting
them causes qemu to try to fetch them, which will fail.

So, check all msrs for validity at module load time.
Signed-off-by: NMichael Riepe <michael@mr511.de>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fixes sf bug 1614113 (segfaults in nbench).
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is necessary for linux guests.
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Consolidate the logic for checking whether a vcpu index is valid.  Also, use
likely(), as a valid value should be the overwhelmingly common case.
Signed-off-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Only (un)account for IO and page-dirtying for devices which have real backing
store (ie: not tmpfs or ramdisks).

Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The recent io scheduler allow_merge commit left the block layer with
no merging, oops. This patch fixes that up.

That means the CFQ change needs to be verified again, it might not fix
the original bug now.  But that's a seperate thing, I'll double check
that tomorrow.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

truncate presently invalidates the dirty page's buffer_heads then shoots down
the page.  But try_to_free_buffers() will now bale out because the page is
dirty.

Net effect: the LRU gets filled with dirty pages which have invalidated
buffer_heads attached.  They have no ->mapping and hence cannot be cleaned.
The machine leaks memory at an enormous rate.

Fix this by cleaning the page before running try_to_free_buffers(), so
try_to_free_buffers() can do its work.

Also, remember to do dirty-page-acoounting in cancel_dirty_page() so the
machine won't wedge up trying to write non-existent dirty pages.

Probably still wrong, but now less so.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

XFS appears to call clear_page_dirty to get the mapping tree dirty tag
set correctly at the same time the page dirty flag is cleared.  I note
that this can be done by set_page_writeback() if we clear the dirty flag
on the page first when we are writing back the entire page.

Hence it seems to me that the XFS call to clear_page_dirty() could
easily be substituted by clear_page_dirty_for_io() followed by a call to
set_page_writeback() to get the mapping tree tags set correctly after
the page has been marked clean.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The use by FUSE was just a remnant of an optimization from the time
when writable mappings were supported.

Now FUSE never actually allows the creation of dirty pages, so this
invocation of clear_page_dirty() is effectively a no-op.
Signed-off-by: NMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch removes some questionable code that attempted to make a
no-longer-used page easier to reclaim.

Calling metapage_writepage against such a page will not result in any
I/O being performed, so removing this code shouldn't be a big deal.

[ It's likely that we could have just replaced the "clear_page_dirty()"
  call with a call to "cancel_dirty_page()" instead, but in the
  meantime this is cleaner and simpler anyway, so unless there is some
  overriding reason (and Dave implies there isn't) I'll just use this
  patch as-is.			- Linus ]
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

They were horribly easy to mis-use because of their tempting naming, and
they also did way more than any users of them generally wanted them to
do.

A dirty page can become clean under two circumstances:

 (a) when we write it out.  We have "clear_page_dirty_for_io()" for
     this, and that function remains unchanged.

     In the "for IO" case it is not sufficient to just clear the dirty
     bit, you also have to mark the page as being under writeback etc.

 (b) when we actually remove a page due to it becoming inaccessible to
     users, notably because it was truncate()'d away or the file (or
     metadata) no longer exists, and we thus want to cancel any
     outstanding dirty state.

For the (b) case, we now introduce "cancel_dirty_page()", which only
touches the page state itself, and verifies that the page is not mapped
(since cancelling writes on a mapped page would be actively wrong as it
is still accessible to users).

Some filesystems need to be fixed up for this: CIFS, FUSE, JFS,
ReiserFS, XFS all use the old confusing functions, and will be fixed
separately in subsequent commits (with some of them just removing the
offending logic, and others using clear_page_dirty_for_io()).

This was confirmed by Martin Michlmayr to fix the apt database
corruption on ARM.

Cc: Martin Michlmayr <tbm@cyrius.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Andrei Popa <andrei.popa@i-neo.ro>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Gordon Farquharson <gordonfarquharson@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is preparatory work in our continuing saga on some hard-to-trigger
file corruption with shared writable mmap() after the dirty page
tracking changes (commit d08b3851 etc)
were merged.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fix the schedule_on_each_cpu() implementation: __queue_work() is now
stricter, hence set the work-pending bit before passing in the new work.

(found in the -rt tree, using Peter Zijlstra's files-lock scalability
patchset)
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

* master.kernel.org:/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes:
  [GFS2] Fix Kconfig
  [DLM] fix compile warning

Problem:
  sched_fork() has always called scheduler_tick() in some (unlikely)
  circumstances in order to update the current task in light of those
  circumstances.  It has always been the case that the work done by
  scheduler_tick() was more than was required to handle the problem in
  hand but no harm was done except for the waste of a few CPU cycles.

  However, the splitting of scheduler_tick() into two procedures in
  2.6.20-rc1 enables the wasted cycles to be saved as the new procedure
  task_running_tick() does all the work that is required to rectify the
  problem being handled.

Solution:
  Replace the call to scheduler_tick() in sched_fork() with a call to
  task_running_tick().
Signed-off-by: NPeter Williams <pwil3058@bigpond.com.au>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

if CONFIG_CALGARY_IOMMU is built into the kernel via
CONFIG_CALGARY_IOMMU_ENABLED_BY_DEFAULT, or is enabled via the
iommu=calgary boot option, then the detect_calgary() function runs to
detect the presence of a Calgary IOMMU.

detect_calgary() first searches the BIOS EBDA area for a "rio_table_hdr"
BIOS table. It has this parsing algorithm for the EBDA:

	while (offset) {
		...
		/* The next offset is stored in the 1st word. 0 means no more */
 		offset = *((unsigned short *)(ptr + offset));
	}

got that? Lets repeat it slowly: we've got a BIOS-supplied data
structure, plus Linux kernel code that will only break out of an
infinite parsing loop once the BIOS gives a zero offset. Ok?

Translation: what an excellent opportunity for BIOS writers to lock up
the Linux boot process in an utterly hard to debug place! Indeed the
BIOS jumped on that opportunity on my box, which has the following EBDA
chaining layout:

  384, 65282, 65535, 65535, 65535, 65535, 65535, 65535 ...

see the pattern? So my, definitely non-Calgary system happily locks up
in detect_calgary()!

the patch below fixes the boot hang by trusting the BIOS-supplied data
structure a bit less: the parser always has to make forward progress,
and if it doesnt, we break out of the loop and i get the expected kernel
message:

  Calgary: Unable to locate Rio Grande Table in EBDA - bailing!
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

one of my boxes didnt boot the 2.6.20-rc1-rt0 kernel rpm, it hung during
early bootup. After an hour or two of happy debugging i narrowed it down
to the CALGARY_IOMMU_ENABLED_BY_DEFAULT option, which was freshly added
to 2.6.20 via the x86_64 tree and /enabled by default/.

commit bff6547b claims:

    [PATCH] Calgary: allow compiling Calgary in but not using it by default

    This patch makes it possible to compile Calgary in but not use it by
    default. In this mode, use 'iommu=calgary' to activate it.

but the change does not actually practice it:

 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
        bool "Should Calgary be enabled by default?"
        default y
        depends on CALGARY_IOMMU
        help
          Should Calgary be enabled by default? if you choose 'y', Calgary
          will be used (if it exists). If you choose 'n', Calgary will not be
          used even if it exists. If you choose 'n' and would like to use
          Calgary anyway, pass 'iommu=calgary' on the kernel command line.
          If unsure, say Y.

it's both 'default y', and says "If unsure, say Y". Clearly not a typo.

disabling this option makes my box boot again. The patch below fixes the
Kconfig entry. Grumble.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

__set_irq_handler: Kill a bogus space
Signed-off-by: NGeert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

* 'for-linus' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [PATCH] block: document io scheduler allow_merge_fn hook
  [PATCH] cfq-iosched: don't allow sync merges across queues
  [PATCH] Fixup blk_rq_unmap_user() API
  [PATCH] __blk_rq_unmap_user() fails to return error
  [PATCH] __blk_rq_map_user() doesn't need to grab the queue_lock
  [PATCH] Remove queue merging hooks
  [PATCH] ->nr_sectors and ->hard_nr_sectors are not used for BLOCK_PC requests
  [PATCH] cciss: fix XFER_READ/XFER_WRITE in do_cciss_request
  [PATCH] cciss: set default raid level when reading geometry fails

* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  [libata] sata_svw, sata_vsc: kill iomem warnings
  [PATCH] libata: take scmd->cmd_len into account when translating SCSI commands
  [PATCH] libata: kill @cdb argument from xlat methods
  [PATCH] libata: clean up variable name usage in xlat related functions
  [libata] Move some PCI IDs from sata_nv to ahci
  [libata] pata_via: suspend/resume support fix
  [libata] pata_cs5530: suspend/resume support tweak

* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/driver-2.6:
  Driver core: proper prototype for drivers/base/init.c:driver_init()
  kobject: kobject_uevent() returns manageable value
  kref refcnt and false positives

* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/pci-2.6: (22 commits)
  acpiphp: Link-time error for PCI Hotplug
  shpchp: cleanup shpchp.h
  shpchp: remove shpchprm_get_physical_slot_number
  shpchp: cleanup struct controller
  shpchp: remove unnecessary struct php_ctlr
  PCI: ATI sb600 sata quirk
  PCI legacy resource fix
  PCI: don't export device IDs to userspace
  PCI: Be a bit defensive in quirk_nvidia_ck804() so we don't risk dereferencing a NULL pdev.
  PCI: Fix multiple problems with VIA hardware
  PCI: Only check the HT capability bits in mpic.c
  PCI: Use pci_find_ht_capability() in drivers/pci/quirks.c
  PCI: Add #defines for Hypertransport MSI fields
  PCI: Use pci_find_ht_capability() in drivers/pci/htirq.c
  PCI: Add pci_find_ht_capability() for finding Hypertransport capabilities
  PCI: Create __pci_bus_find_cap_start() from __pci_bus_find_cap()
  pci: Introduce pci_find_present
  PCI: pcieport-driver: remove invalid warning message
  rpaphp: compiler warning cleanup
  PCI quirks: remove redundant check
  ...

* master.kernel.org:/pub/scm/linux/kernel/git/gregkh/usb-2.6: (34 commits)
  USB Storage: remove duplicate Nokia entry in unusual_devs.h
  [PATCH] bluetooth: add support for another Kensington dongle
  [PATCH] usb serial: add support for Novatel S720/U720 CDMA/EV-DO modems
  [PATCH] USB: Nokia E70 is an unusual device
  USB: fix to usbfs_snoop logging of user defined control urbs
  USB: at91_udc: Additional checks
  USB: at91_udc: Cleanup variables after failure in usb_gadget_register_driver()
  USB: at91_udc: allow drivers that support high speed
  USB: u132-hcd/ftdi-elan: add support for Option GT 3G Quad card
  USB: at91_udc, misc fixes
  USB: at91 udc, support at91sam926x addresses
  USB: OHCI support for PNX8550
  USB: ohci handles hardware faults during root port resets
  USB: ohci at91 warning fix
  USB: ohci whitespace/comment fixups
  USB: MAINTAINERS update, EHCI and OHCI
  USB: gadget driver unbind() is optional; section fixes; misc
  UHCI: module parameter to ignore overcurrent changes
  USB: Nokia E70 is an unusual device
  USB AUERSWALD: replace kmalloc+memset with kzalloc
  ...

* 'merge' of master.kernel.org:/pub/scm/linux/kernel/git/paulus/powerpc:
  [POWERPC] Fix register save area alignment for swapcontext syscall
  [POWERPC] Fix PCI device channel state initialization
  [POWERPC] Update MTD OF documentation
  [POWERPC] Probe Efika platform before CHRP.
  [POWERPC] Fix build of cell zImage.initrd
  [POWERPC] iSeries: fix CONFIG_VIOPATH dependency
  [POWERPC] iSeries: fix viocons init
  [POWERPC] iSeries: fix viocd init
  [POWERPC] iSeries: fix iseries_veth init
  [POWERPC] iSeries: fix viotape init
  [POWERPC] iSeries: fix viodasd init
  [POWERPC] Workaround oldworld OF bug with IRQs & P2P bridges
  [POWERPC] powerpc: add scanning of ebc bus to of_platform
  [POWERPC] spufs: fix assignment of node numbers
  [POWERPC] cell: Fix spufs with "new style" device-tree
  [POWERPC] cell: Enable spider workarounds on all PCI buses
  [POWERPC] cell: add forward struct declarations to spu.h
  [POWERPC] cell: update cell_defconfig

* 'drm-patches' of master.kernel.org:/pub/scm/linux/kernel/git/airlied/drm-2.6:
  drm: Stop defining pci_pretty_name
  drm: r128: comment aligment with drm git
  drm: make kernel context switch same as for drm git tree.
  drm: fixup comment header style
  drm: savage: compat fix from drm git.
  drm: Unify radeon offset checking.
  i915_vblank_tasklet: Try harder to avoid tearing.
  DRM: handle pci_enable_device failure
  drm: fix return value check

* 'linus' of master.kernel.org:/pub/scm/linux/kernel/git/perex/alsa: (30 commits)
  [ALSA] version 1.0.14rc1
  [ALSA] ac97: Identify CMI9761 chips.
  [ALSA] ac97_codec - trivial fix for bit update functions
  [ALSA] snd-ca0106: Fix typos.
  [ALSA] snd-ca0106: Add new card variant.
  [ALSA] sound: fix PCM substream list
  [ALSA] sound: initialize rawmidi substream list
  [ALSA] snd_hda_intel 3stack mode for ASUS P5P-L2
  [ALSA] Remove IRQF_DISABLED for shared PCI irqs
  [ALSA] Fix invalid assignment of PCI revision
  [ALSA] Fix races in PCM OSS emulation
  [ALSA] hda-codec - fix typo in PCI IDs
  [ALSA] ac97 - Fix potential negative array index
  [ALSA] hda-codec - Verbose proc output for PCM parameters
  [ALSA] hda-codec - Fix detection of supported sample rates
  [ALSA] hda-codec - Fix model for ASUS V1j laptop
  [ALSA] sound/core/control.c: remove dead code
  [ALSA] hda-codec - Add model for HP q965
  [ALSA] pcm core: fix silence_start calculations
  [ALSA] hda-codec - Fix a typo
  ...

* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (29 commits)
  [ARM] 4062/1: S3C24XX: Anubis and Osiris shuld have CONFIG_PM_SIMTEC
  [ARM] 4060/1: update several ARM defconfigs
  [ARM] 4061/1: xsc3: change of maintainer
  [ARM] 4059/1: VR1000: fix LED3's platform device number
  [ARM] 4022/1: iop13xx: generic irq fixups
  [ARM] 4015/1: s3c2410 cpu ifdefs
  [ARM] 4057/1: ixp23xx: unconditionally enable hardware coherency
  [ARM] 4056/1: iop13xx: fix resource.end off-by-one in flash setup
  [ARM] 4055/1: iop13xx: fix phys_io/io_pg_offst for iq81340mc/sc
  [ARM] 4054/1: ep93xx: add HWCAP_CRUNCH
  [ARM] 4052/1: S3C24XX: Fix PM in arch/arm/mach-s3c2410/Kconfig
  [ARM] Fix warnings from asm/system.h
  [ARM] 4051/1: S3C24XX: clean includes in S3C2440 and S3C2442 support
  [ARM] 4050/1: S3C24XX: remove old changelogs in arch/arm/mach-s3c2410
  [ARM] 4049/1: S3C24XX: fix sparse warning due to upf_t in regs-serial.h
  [ARM] 4048/1: S3C24XX: make s3c2410_pm_resume() static
  [ARM] 4046/1: S3C24XX: fix sparse errors arch/arm/mach-s3c2410
  [ARM] 4045/1: S3C24XX: remove old VA for non-shared areas
  [ARM] 4044/1: S3C24XX: fix sparse warnings in arch/arm/mach-s3c2410/s3c2442-clock.c
  [ARM] 4043/1: S3C24XX: fix sparse warnings in arch/arm/mach-s3c2410/s3c2440-clock.c
  ...

How many times are we going to merge this entry...
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Now that iomap merge is close to reality, and since the warnings and
issue have been around so long, we don't need a reminder on every build
that libata needs to be converted over to iomap.
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Add the stupid sco fixup quirk to yet another Broadcom/Kensington device.

Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add USB vendor/device IDs for Novatel Wireless S720 and U720 CDMA/EV-DO
modems to airprime.c.
Signed-off-by: NEric Smith <eric@brouhaha.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Taken from http://bugzilla.kernel.org/show_bug.cgi?id=7508

When the Nokia E70 Phone is plugged in to the USB port, I get:

end_request: I/O error, dev sda, sector 1824527
sd 0:0:0:0: SCSI error: return code = 0x10070000
end_request: I/O error, dev sda, sector 1824535
sd 0:0:0:0: SCSI error: return code = 0x10070000

The fix is to add these lines to drivers/usb/storage/unusual_devs.h:

Cc: <honkkis@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>