kcopyd should accumulate errors - otherwise I/O failures may be ignored
unintentionally.

And invert 'success' (used in a future patch), using a more intuitive
!(read_err || write_err).
Signed-off-by: NJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When a mirror is reduced in size, clear the part of the bitmap that is no
longer used.
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the 'sizeof' in the region log bitmap size calculation: it's uint32_t, not
unsigned long - this breaks on some archs.
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Refactor the code that creates the core and disk log contexts to avoid the
repeated allocation of clean_bits introduced by the last patch.
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

On-disk logs for dm-mirror devices are currently hard-coded to use 512 byte
hard-sector-sizes.  This patch fixes dm-log so it will work with devices with
non-512-byte hard-sector-sizes.

To maintain full compatibility, instead of moving the clean-bits bitset to a
bitset, and enlarges the disk-header buffer to encompass both the header and
the bitset.  The I/O routines for the bitset are removed, and the I/O routines
for the disk-header now also read/write the bitset.
Signed-off-by: NKevin Corry <kevcorry@us.ibm.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The table is indexed from 0, so an index equal to t->num_targets should be
rejected.

(There is no code in the current tree that would exercise this bug.)
Signed-off-by: NMilan Broz <mbroz@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The device-mapper core does not perform any remapping of bios before passing
them to the targets.  If a particular mapping begins part-way into a device,
targets obtain the sector relative to the start of the mapping by subtracting
ti->begin.

The dm-raid1 target didn't do this everywhere: this patch fixes it, taking
care to subtract ti->begin exactly once for each bio.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]
Signed-off-by: NNeil Brown <neilb@suse.de>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In alloc_dev(), we register the device with the block layer and then continue
to initialize the device.  But register_disk() makes the device available to
be opened before we have completed initialising it.

This patch moves the final bits of the initialization above the disk
registration.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The reference counting on dm-mod is zero if no mapped devices are open.  This
is incorrect, and can lead to an oops if the module is unloaded while mapped
devices exist.

This patch claims a reference to the module whenever a device is created, and
drops it again when the device is freed.

Devices must be removed before dm-mod is unloaded.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

To avoid races, _minor_lock must be held while changing mapped device
reference counts.

There are a few paths where a mapped_device pointer is returned before a
reference is taken.  This patch fixes them.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There is a chicken and egg problem between the block layer and dm in which the
gendisk associated with a mapping keeps a reference-less pointer to the
mapped_device.

This patch uses a new flag DMF_FREEING to indicate when the mapped_device is
no longer valid.  This is checked to prevent any attempt to open the device
from succeeding while the device is being destroyed.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

While removing a device, another another thread might attempt to resurrect it.

This patch replaces the _minor_lock mutex with a spinlock and uses
atomic_dec_and_lock() to serialize reference counting in dm_put().

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

idr_pre_get() can sleep while allocating memory.

The next patch will change _minor_lock into a spinlock, so this patch moves
idr_pre_get() outside the lock in preparation.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

One part of the system can attempt to use a mapped device before another has
finished initialising it or while it is being freed.

This patch introduces a place holder value, MINOR_ALLOCED, to mark the minor
as allocated but in a state where it can't be used, such as mid-allocation or
mid-free.  At the end of the initialization, it replaces the place holder with
the pointer to the mapped_device, making it available to the rest of the dm
subsystem.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Persistent snapshots currently store a private copy of the chunk size.
Userspace also supplies the chunk size when loading a snapshot.  Ensure
consistency by only storing the chunk_size in one place instead of two.

Currently the two sizes will differ if the chunk size supplied by userspace
does not match the chunk size an existing snapshot actually uses.  Amongst
other problems, this causes an incorrect 'percentage full' to be reported.

The patch ensures consistency by only storing the chunk_size in one place,
removing it from struct pstore.  Some initialisation is delayed until the
correct chunk_size is known.  If read_header() discovers that the wrong chunk
size was supplied, the 'area' buffer (which the header already got read into)
is reinitialised to the correct size.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Do not mark sticon_startup() as __init
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Do not mark promcon_startup() and promcon_init_unimap() as __init
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

- move register ioremap from newport_startup() to newport_console_init()
- fonts are freed multiple times, do it only once
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Do not mark mdacon_startup __init.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The class device "fbcon" does not need to be a device file.  Do not create one
by passing a major and minor number of zero to
class_device_create()/destroy().
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

To enable this feature, CONFIG_VT_HW_CONSOLE_BINDING must be set to 'y'.  This
feature will default to 'n' to minimize users accidentally corrupting their
virtual terminals.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add sysfs control to the VT layer.  A new sysfs class, 'vtconsole', and class
devices 'vtcon[n]' are added.  Each class device file has the following
attributes:

/sys/class/vtconsole/vtcon[n]/name - read-only attribute showing the
                                     name of the current backend

/sys/class/vtconsole/vtcon[n]/bind - read/write attribute
             where: 0 - backend is unbound/unbind backend from the VT layer
                    1 - backend is bound/bind backend to the VT layer

In addition, if any of the consoles are in KD_GRAPHICS mode, binding and
unbinding will not succeed.  KD_GRAPHICS mode usually indicates that the
underlying console hardware is used for other purposes other than displaying
text (ie X).  This feature should prevent binding/unbinding from interfering
with a graphics application using the VT.

[akpm@osdl.org: warning fixes]
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The control for binding/unbinding is moved from fbcon to the console layer.
Thus the fbcon sysfs attributes, attach and detach, are also gone.

    1. Add a notifier event that tells fbcon if a framebuffer driver has been
       unregistered.  If no registered driver remains, fbcon will unregister
       itself from the console layer.

    2. Replaced calls to give_up_console() with unregister_con_driver().

    3. Still use take_over_console() instead of register_con_driver() to
       maintain compatibility

    4. Respect the parameter first_fb_vc and last_fb_vc instead of using 0 and
       MAX_NR_CONSOLES - 1. These parameters are settable by the user.

    5. When fbcon is completely unbound from the console layer, fbcon will
       also release (iow, decrement module reference counts to zero) all fbdev
       drivers. In other words, a bind or unbind request from the console layer
       will propagate down to the framebuffer drivers.

    6. If fbcon is not bound to the console, it will ignore all notifier
       events (except driver registration and unregistration) and all sysfs
       requests.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

The framebuffer console is now able to dynamically bind and unbind from the VT
console layer.  Due to the way the VT console layer works, the drivers
themselves decide when to bind or unbind.  However, it was decided that
binding must be controlled, not by the drivers themselves, but by the VT
console layer.  With this, dynamic binding is possible for all VT console
drivers, not just fbcon.

Thus, the VT console layer will impose the following to all VT console
drivers:

- all registered VT console drivers will be entered in a private list
- drivers can register themselves to the VT console layer, but they cannot
  decide when to bind or unbind. (Exception: To maintain backwards
  compatibility, take_over_console() will automatically bind the driver after
  registration.)
- drivers can remove themselves from the list by unregistering from the VT
  console layer. A prerequisite for unregistration is that the driver must not
  be bound.

The following functions are new in the vt.c:

register_con_driver() - public function, this function adds the VT console
driver to an internal list maintained by the VT console

bind_con_driver() - private function, it binds the driver to the console

take_over_console() is changed to call register_con_driver() followed by a
bind_con_driver().  This is the only time drivers can decide when to bind to
the VT layer.  This is to maintain backwards compatibility.

unbind_con_driver() - private function, it unbinds the driver from its
console.  The vacated consoles will be taken over by the default boot console
driver.

unregister_con_driver() - public function, removes the driver from the
internal list maintained by the VT console.  It will only succeed if the
driver is currently unbound.

con_is_bound() checks if the driver is currently bound or not

give_up_console() is just a wrapper to unregister_con_driver().

There are also 3 additional functions meant to be called only by the tty layer
for sysfs control:

	vt_bind() - calls bind_con_driver()
	vt_unbind() - calls unbind_con_driver()
	vt_show_drivers() - shows the list of registered drivers

Most VT console drivers will continue to work as is, but might have problems
when unbinding or binding which should be fixable with minimal changes.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add the ability to detach and attach the framebuffer console to and from the
vt layer.  This is done by echo'ing any value to sysfs attributes located in
class/graphics/fbcon.  The two attributes are:

      attach - bind fbcon to the vt layer
      detach - unbind fbcon from the vt layer

Once fbcon is detached from the vt layer, fbcon can be unloaded if compiled as
a module.  This feature is quite useful for developers who work on the
framebuffer or console subsystem.  This is also useful for users who want to
go to text mode or graphics mode without having to reboot.

Directly unloading the fbcon module is not possible because the vt layer
increments the module reference count for all bound consoles.  Detaching fbcon
decrements the module reference count to zero so unloading becomes possible.

Detaching fbcon may interfere with X and/or DRM.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

To detach fbcon, it must also clean up all resources it allocated.  This was
never done before because fbcon cannot be unloaded.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

In order for this feature to work, an interface will be needed.  The most
appropriate is sysfs.  However, the framebuffer console has no sysfs entry
yet.  This will create a sysfs class device entry for fbcon under
/sys/class/graphics.

Add a class_device entry 'fbcon' under class 'graphics'.  Console-specific
attributes which where previously under class/graphics/fb[x] are moved to
class/graphics/fbcon.  These attributes, 'con_rotate' and 'con_rotate_all',
are also renamed to 'rotate' and 'rotate_all' respectively.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Detaching fbcon allows individual drivers to be unloaded.  However several
drivers call pci_disable_device() upon exit.  This function will disable the
BAR's which will kill VGA text mode and/or affect X/DRM.

To prevent this, remove calls to pci_disable_device() from several drivers.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

To allow for detaching fbcon, it must be able to give up the console.
However, the function give_up_console() is plain broken.  It just sets the
entries in the console driver map to NULL, it leaves the vt layer without a
console driver, and does not decrement the module reference count.  Calling
give_up_console() is guaranteed to hang the machine..

To fix this problem, ensure that the virtual consoles are not left dangling
without a driver.  All systems have a default boot driver (either vgacon or
dummycon) which is never unloaded.  For those vt's that lost their driver, the
default boot driver is reassigned back to them.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

One of the limitations of the framebuffer console system is its inablity to
unload or detach itself from the console layer.  And once it loads, it also
locks in framebuffer drivers preventing their unload. Although the con2fbmap
utility does provide a means to unload individual drivers, it requires that at
least one framebuffer driver is loaded for use by fbcon.

With this change, it is possible to detach fbcon from the console layer. If it
is detached, it will reattach the boot console driver (which is permanently
loaded) back to the console layer so the system can continue to work.  As a
consequence, fbcon will also decrement its reference count of individual
framebuffer drivers, allowing all of these drivers to be unloaded even if
fbcon is still loaded.

Unless you use drivers that restores the display to text mode (rivafb and
i810fb, for example), detaching fbcon does require assistance from userspace
tools (ie, vbetools) for text mode to be restored completely.  Without the
help of these tools, fbcon will leave the VGA console corrupted. The methods
that can be used will be described in Documentation/fb/fbcon.txt.

Because the vt layer also increments the module reference count for each
console driver, fbcon cannot be directly unloaded.  It must be detached first
prior to unload.

Similarly, fbcon can be reattached to the console layer without having to
reload the module.  A nice feature if fbcon is compiled statically.

Attaching and detaching fbcon is done via sysfs attributes. A class device
entry for fbcon is created in /sys/class/graphics. The two attributes that
controls this feature are detach and attach. Two other attributes that are
piggybacked under /sys/class/graphics/fb[n] that are fbcon-specific,
'con_rotate' and 'con_rotate_all' are moved to fbcon.  They are renamed as
'rotate' and 'rotate_all' respectively.

Overall, this feature is a great help for developers working in the
framebuffer or console layer.  There is not need to continually reboot the
kernel for every small change. It is also useful for regular users who wants
to choose between a graphical console or a text console without having to
reboot.

Example usage for x86:

/* start in text mode */
modprobe xxxfb
modprobe fbcon
/* graphical mode with fbcon using xxxfb */
echo 1 > /sys/class/graphics/fbcon/detach
/* back to text mode, will produce corrupt display unless vbetool is used */
rmmod xxxfb
modprobe yyyfb
/* back to graphical mode with fbcon using yyyfb */

Before trying out this feature, please read Documentation/fb/fbcon.txt.

This patch:

In order for fbcon to detach itself from the console layer, vgacon, which is a
boot console driver, must be fixed so it can retake the console multiple
times, not just during init.  The following needs to be done:

- remove __init from the vgacon_startup, this is called again by
  take_over_console().

- vc->rows and vc->cols are set manually by vgacon during init. After init,
  vc_resize() can be used

- make sure the scrollback_buffer is not reallocated
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Modify the sysfs description of a video mode such that modes are tagged with
their scan type, (p)rogessive, (i)nterlaced, (d)ouble scan.  For example,
U:1920x1080i-50.  This is useful to disambiguate some of the 'consumer' video
timings found in CEA-861 (especially those for EDTV).
Signed-off-by: NDaniel R Thompson <daniel.thompson@st.com>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds a new framebuffer driver for the Intel Based macs.  This
framebuffer is needed when booting from EFI to get something out the box.

[akpm: note: doesn't support modular building]

[akpm@osdl.org: cleanups]
Signed-off-by: NEdgar Hucek <hostmaster@ed-soft.at>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the following warning:

WARNING: drivers/video/aty/atyfb.o - Section mismatch: reference to
.init.text:aty_init_cursor from .text between 'aty_init' (at offset 0x241d)
and 'atyfb_blank'
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Fix the following warning:

WARNING: drivers/video/macmodes.o - Section mismatch: reference to
.init.text:mac_find_mode from __ksymtab after '__ksymtab_mac_find_mode' (at
offset 0x10)
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Logo drawing crashes or produces a corrupt display if the logo width and
height are not equal.  The dimensions are transposed prior to the actual
rotation and the width is used instead of the height in the actual rotation
code.  These produce a corrupt image.
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is a fix for the most annoying problem that remained with neofb:

After "setterm -powersave powerdown" the console blanker will disable the
backlight after the given timeout expires.  If this happens after the lid
has been shut, we read "LCD off" from the register and store that in the
driver.  Once the lid is opened, the backlight turns on, but any key press
that would awaken the blanked console will switch the backlight off again.

The workaround so far was to use the "display config toggle" Fn key combo -
once if no external display is attached, otherwise as often as required to
restore the desired display setup.

The following patch fixes the issue at least for the LCD-only case, with no
external monitor attached.  Other display setup permutations are pending
further testing, but so far I can guarantee at least no negative change in
behaviour, if any at all.
Signed-off-by: NChristian Trefzer <ctrefzer@gmx.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
Acked-by: N"Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Add power management support

[akpm@osdl.org: cleanup]
Signed-off-by: NRodolfo Giometti <giometti@linux.it>
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

CONFIG_FB = m and CONFIG_{BACKLIGHT:LCD}_CLASS_DEVICE = y is possible
resulting in link errors.  Fix by making backlight and lcd class also depend
on FB
Signed-off-by: NAntonino Daplas <adaplas@pol.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

regs.lcdcon1 was not updated on suspend.  The result was a garbaged display on
resume.  This bug was first noticed by Christer Weinigel.  This patch is a
modified version of the one he sent to me.
Signed-off-by: NArnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>