Generic code to provide new per cpu atomic features
this_cpu_cmpxchg
this_cpu_xchg
Fallback occurs to functions using interrupts disable/enable
to ensure correct per cpu atomicity.
Fallback to regular cmpxchg and xchg is not possible since per cpu atomic
semantics include the guarantee that the current cpus per cpu data is
accessed atomically. Use of regular cmpxchg and xchg requires the
determination of the address of the per cpu data before regular cmpxchg
or xchg which therefore cannot be atomically included in an xchg or
cmpxchg without segment override.
tj: - Relocated new ops to conform better to the general organization.
- This patch contains a trivial comment fix.
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
- include/linux/percpu.h: this_cpu_add_return() and friends were
located next to __this_cpu_add_return(). However, the overall
organization is to first group by preemption safeness. Relocate
this_cpu_add_return() and friends to preemption-safe area.
- arch/x86/include/asm/percpu.h: Relocate percpu_add_return_op() after
other more basic operations. Relocate [__]this_cpu_add_return_8()
so that they're first grouped by preemption safeness.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Use this_cpu operations to optimize access primitives for highmem.
The main effect is the avoidance of address calculations through the
use of a segment prefix.
V3->V4
- kmap_atomic_idx: Do not return a value.
- Use __this_cpu_dec without HIGHMEM_DEBUG
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Introduce generic support for this_cpu_add_return etc.
The fallback is to realize these operations with simpler __this_cpu_ops.
tj: - Reformatted __cpu_size_call_return2() to make it more consistent
with its neighbors.
- Dropped unnecessary temp variable ret__ from
__this_cpu_generic_add_return().
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
__get_cpu_var() can be replaced with this_cpu_read and will then use a
single read instruction with implied address calculation to access the
correct per cpu instance.
However, the address of a per cpu variable passed to __this_cpu_read()
cannot be determined (since it's an implied address conversion through
segment prefixes). Therefore apply this only to uses of __get_cpu_var
where the address of the variable is not used.
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Hugh Dickins <hughd@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Use this_cpu ops in various places to optimize per cpu data access.
Cc: Jason Baron <jbaron@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
* 'for-linus' of git://git.infradead.org/users/eparis/notify:
fanotify: fill in the metadata_len field on struct fanotify_event_metadata
fanotify: split version into version and metadata_len
fanotify: Dont try to open a file descriptor for the overflow event
fanotify: Introduce FAN_NOFD
fanotify: do not leak user reference on allocation failure
inotify: stop kernel memory leak on file creation failure
fanotify: on group destroy allow all waiters to bypass permission check
fanotify: Dont allow a mask of 0 if setting or removing a mark
fanotify: correct broken ref counting in case adding a mark failed
fanotify: if set by user unset FMODE_NONOTIFY before fsnotify_perm() is called
fanotify: remove packed from access response message
fanotify: deny permissions when no event was sent
* 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus: (28 commits)
MIPS: Add a CONFIG_FORCE_MAX_ZONEORDER Kconfig option.
MIPS: LD/SD o32 macro GAS fix update
MIPS: Alchemy: fix build with SERIAL_8250=n
MIPS: Rename mips_dma_cache_sync back to dma_cache_sync
MIPS: MT: Fix typo in comment.
SSB: Fix nvram_get on BCM47xx platform
MIPS: BCM47xx: Swap serial console if ttyS1 was specified.
MIPS: BCM47xx: Use sscanf for parsing mac address
MIPS: BCM47xx: Fill values for b43 into SSB sprom
MIPS: BCM47xx: Do not read config from CFE
MIPS: FDT size is a be32
MIPS: Fix CP0 COUNTER clockevent race
MIPS: Fix regression on BCM4710 processor detection
MIPS: JZ4740: Fix pcm device name
MIPS: Separate two consecutive loads in memset.S
MIPS: Send proper signal and siginfo on FP emulator faults.
MIPS: AR7: Fix loops per jiffies on TNETD7200 devices
MIPS: AR7: Fix double ar7_gpio_init declaration
MIPS: Rework GENERIC_HARDIRQS Kconfig.
MIPS: Alchemy: Add return value check for strict_strtoul()
...
The nvram_get function was never in the mainline kernel, it only existed in
an external OpenWrt patch. Use nvram_getenv function, which is in mainline
and use an include instead of an extra function declaration. et0macaddr
contains the mac address in text from like 00:11:22:33:44:55. We have to
parse it before adding it into macaddr.
nvram_parse_macaddr will be merged into asm/mach-bcm47xx/nvram.h through
the MIPS git tree and will be available soon. It will not build now without
nvram_parse_macaddr, but it hasn't before either.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
To: linux-mips@linux-mips.org
Cc: mb@bu3sch.de
Cc: netdev@vger.kernel.org
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Michael Buesch <mb@bu3sch.de>
Patchwork: https://patchwork.linux-mips.org/patch/1849/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: define separate EVIOCGKEYCODE_V2/EVIOCSKEYCODE_V2
Input: wacom - add another Bamboo Pen ID (0xd4)
Without this, gcc 4.5 won't compile xen-netfront and xen-blkfront, where
this is being used to specify array sizes.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: David Miller <davem@davemloft.net>
Cc: Stable Kernel <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To implement per event type optional headers we are interested in
knowing how long the metadata structure is. This patch slits the __u32
version field into a __u8 version and a __u16 metadata_len field (with
__u8 left over). This should allow for backwards compat ABI.
Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
[rewrote descrtion and changed object sizes and ordering - eparis]
Signed-off-by: Eric Paris <eparis@redhat.com>
The desire to keep old names for the EVIOCGKEYCODE/EVIOCSKEYCODE while
extending them to support large scancodes was a mistake. While we tried
to keep ABI intact (and we succeeded in doing that, programs compiled
on older kernels will work on newer ones) there is still a problem with
recompiling existing software with newer kernel headers.
New kernel headers will supply updated ioctl numbers and kernel will
expect that userspace will use struct input_keymap_entry to set and
retrieve keymap data. But since the names of ioctls are still the same
userspace will happily compile even if not adjusted to make use of the
new structure and will start miraculously fail in the field.
To avoid this issue let's revert EVIOCGKEYCODE/EVIOCSKEYCODE definitions
and add EVIOCGKEYCODE_V2/EVIOCSKEYCODE_V2 so that userspace can explicitly
select the style of ioctls it wants to employ.
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Acked-by: Jarod Wilson <jarod@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (75 commits)
pppoe.c: Fix kernel panic caused by __pppoe_xmit
WAN: Fix a TX IRQ causing BUG() in PC300 and PCI200SYN drivers.
bnx2x: Advance a version number to 1.60.01-0
bnx2x: Fixed a compilation warning
bnx2x: LSO code was broken on BE platforms
qlge: Fix deadlock when cancelling worker.
net: fix skb_defer_rx_timestamp()
cxgb4vf: Ingress Queue Entry Size needs to be 64 bytes
phy: add the IC+ IP1001 driver
atm: correct sysfs 'device' link creation and parent relationships
MAINTAINERS: remove me from tulip
SCTP: Fix SCTP_SET_PEER_PRIMARY_ADDR to accpet v4mapped address
enic: Bug Fix: Pass napi reference to the isr that services receive queue
ipv6: fix nl group when advertising a new link
connector: add module alias
net: Document the kernel_recvmsg() function
r8169: Fix runtime power management
hso: IP checksuming doesn't work on GE0301 option cards
xfrm: Fix xfrm_state_migrate leak
net: Convert netpoll blocking api in bonding driver to be a counter
...
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
ACPI / PM: Do not save/restore NVS on Sony Vaio VGN-NW130D
ACPI/HEST: adjust section selection
ACPI: eliminate unused variable warning for !ACPI_SLEEP
ACPI/PNP: avoid section mismatch warning
ACPI thermal: remove two unused functions
ACPI: fix a section mismatch
ACPI, APEI, use raw spinlock in ERST
ACPI: video: fix build for CONFIG_ACPI=n
ACPI: video: fix build for VIDEO_OUTPUT_CONTROL=n
ACPI: fix allowing to add/remove multiple _OSI strings
acpi: fix _OSI string setup regression
ACPI: EC: Add another dmi match entry for MSI hardware
ACPI battery: update status upon sysfs query
ACPI ac: update AC status upon sysfs query
ACPI / PM: Do not refcount power resources that can't be turned on
ACPI / PM: Check device state before refcounting power resources
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ALSA: HDA: Quirk for Dell Vostro 320 to make microphone work
ALSA: hda - Reset sample sizes and max bitrates when reading ELD
ALSA: hda - Always allow basic audio irrespective of ELD info
ALSA: hda - Do not wrongly restrict min_channels based on ELD
ASoC: Correct WM8962 interrupt mask register read
ASoC: WM8580: Debug BCLK and sample size
ASoC: Fix resource leak if soc_register_ac97_dai_link failed
ASoC: Hold client_mutex while calling snd_soc_instantiate_cards()
ASoC: Fix swap of left and right channels for WM8993/4 speaker boost gain
ASoC: Fix off by one error in WM8994 EQ register bank size
ALSA: hda: Use position_fix=1 for Acer Aspire 5538 to enable capture on internal mic
ALSA: hda - Enable jack sense for Thinkpad Edge 13
ALSA: hda - Fix ThinkPad T410[s] docking station line-out
ALSA: hda: Use model=lg quirk for LG P1 Express to enable playback and capture
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
NFS: Fix panic after nfs_umount()
nfs: remove extraneous and problematic calls to nfs_clear_request
nfs: kernel should return EPROTONOSUPPORT when not support NFSv4
NFS: Fix fcntl F_GETLK not reporting some conflicts
nfs: Discard ACL cache on mode update
NFS: Readdir cleanups
NFS: nfs_readdir_search_for_cookie() don't mark as eof if cookie not found
NFS: Fix a memory leak in nfs_readdir
Call the filesystem back whenever a page is removed from the page cache
NFS: Ensure we use the correct cookie in nfs_readdir_xdr_filler
In file included from drivers/gpu/drm/i915/intel_opregion.c:30:
include/acpi/video.h:22: warning: ‘struct acpi_device’ declared inside parameter list
...
include/acpi/video.h:24: error: ‘ENODEV’ undeclared (first use in this function)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Len Brown <len.brown@intel.com>
drivers/built-in.o: In function `acpi_video_bus_put_devices':
video.c:(.text+0x79663): undefined reference to
`video_output_unregister'
drivers/built-in.o: In function `acpi_video_bus_add':
video.c:(.text+0x7b0b3): undefined reference to `video_output_register'
Signed-off-by: Len Brown <len.brown@intel.com>
commit b0ed7a91(ACPICA/ACPI: Add new host interfaces for _OSI suppor)
introduced a regression that _OSI string setup fails.
There are 2 paths to setup _OSI string.
DMI:
acpi_dmi_osi_linux -> set_osi_linux -> acpi_osi_setup -> copy _OSI
string to osi_setup_string
Boot command line:
acpi_osi_setup -> copy _OSI string to osi_setup_string
Later, acpi_osi_setup_late will be called to handle osi_setup_string.
If _OSI string is "Linux" or "!Linux", then the call path is,
acpi_osi_setup_late -> acpi_cmdline_osi_linux -> set_osi_linux ->
acpi_osi_setup -> copy _OSI string to osi_setup_string
This actually never installs _OSI string(acpi_install_interface not
called), but just copy the _OSI string to osi_setup_string.
This patch fixes the regression.
Reported-and-tested-by: Lukas Hejtmanek <xhejtman@ics.muni.cz>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
The ATM subsystem was incorrectly creating the 'device' link for ATM
nodes in sysfs. This led to incorrect device/parent relationships
exposed by sysfs and udev. Instead of rolling the 'device' link by hand
in the generic ATM code, pass each ATM driver's bus device down to the
sysfs code and let sysfs do this stuff correctly.
Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rather than printing the message to the log, use a mib counter to keep
track of the count of occurences of time wait bucket overflow. Reduces
spam in logs.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
drm/i915: i915 cannot provide switcher services.
drm/radeon/kms: fix vram base calculation on rs780/rs880
drm/radeon/kms: fix formatting of vram and gtt info
drm/radeon/kms: forbid big bo allocation (fdo 31708) v3
drm: Don't try and disable an encoder that was never enabled
drm: Add missing drm_vblank_put() along queue vblank error path
drm/i915/dp: Only apply the workaround if the select is still active
drm/i915: Emit a request to clear a flushed and idle ring for unbusy bo
drm/i915/lvds: Always restore panel-fitter when enabling the LVDS
drm/i915/ringbuffer: Only print an error on the second attempt to reset head
drm/i915: announce to userspace that the bsd ring is coherent
agp/intel: Fix wrong kunmap in i830_cleanup()
drm/i915: Factor in pixel-repeat in FDI M/N calculation
drm/i915: Death to the unnecessary 64bit divide
drm/i915: Clean conflicting modesetting registers upon init
drm/i915: Apply a workaround for transitioning from DP on pipe B to HDMI.
drm/i915: Always set the DP transcoder config to 8BPC.
When a nfs_page is freed, nfs_free_request is called which also calls
nfs_clear_request to clean out the lock and open contexts and free the
pagecache page.
However, a couple of places in the nfs code call nfs_clear_request
themselves. What happens here if the refcount on the request is still high?
We'll be releasing contexts and freeing pointers while the request is
possibly still in use.
Remove those bare calls to nfs_clear_context. That should only be done when
the request is being freed.
Note that when doing this, we need to watch out for tests of req->wb_page.
Previously, nfs_set_page_tag_locked() and nfs_clear_page_tag_locked()
would check the value of req->wb_page to figure out if the page is mapped
into the nfsi->nfs_page_tree. We now indicate the page is mapped using
the new bit PG_MAPPED in req->wb_flags .
Reported-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
FAN_NOFD is used in fanotify events that do not provide an open file
descriptor (like the overflow_event).
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
When fanotify_release() is called, there may still be processes waiting for
access permission. Currently only processes for which an event has already been
queued into the groups access list will be woken up. Processes for which no
event has been queued will continue to sleep and thus cause a deadlock when
fsnotify_put_group() is called.
Furthermore there is a race allowing further processes to be waiting on the
access wait queue after wake_up (if they arrive before clear_marks_by_group()
is called).
This patch corrects this by setting a flag to inform processes that the group
is about to be destroyed and thus not to wait for access permission.
[additional changelog from eparis]
Lets think about the 4 relevant code paths from the PoV of the
'operator' 'listener' 'responder' and 'closer'. Where operator is the
process doing an action (like open/read) which could require permission.
Listener is the task (or in this case thread) slated with reading from
the fanotify file descriptor. The 'responder' is the thread responsible
for responding to access requests. 'Closer' is the thread attempting to
close the fanotify file descriptor.
The 'operator' is going to end up in:
fanotify_handle_event()
get_response_from_access()
(THIS BLOCKS WAITING ON USERSPACE)
The 'listener' interesting code path
fanotify_read()
copy_event_to_user()
prepare_for_access_response()
(THIS CREATES AN fanotify_response_event)
The 'responder' code path:
fanotify_write()
process_access_response()
(REMOVE A fanotify_response_event, SET RESPONSE, WAKE UP 'operator')
The 'closer':
fanotify_release()
(SUPPOSED TO CLEAN UP THE REST OF THIS MESS)
What we have today is that in the closer we remove all of the
fanotify_response_events and set a bit so no more response events are
ever created in prepare_for_access_response().
The bug is that we never wake all of the operators up and tell them to
move along. You fix that in fanotify_get_response_from_access(). You
also fix other operators which haven't gotten there yet. So I agree
that's a good fix.
[/additional changelog from eparis]
[remove additional changes to minimize patch size]
[move initialization so it was inside CONFIG_FANOTIFY_PERMISSION]
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
Unsetting FMODE_NONOTIFY in fsnotify_open() is too late, since fsnotify_perm()
is called before. If FMODE_NONOTIFY is set fsnotify_perm() will skip permission
checks, so a user can still disable permission checks by setting this flag
in an open() call.
This patch corrects this by unsetting the flag before fsnotify_perm is called.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
Since fanotify has decided to be careful about alignment and packing
rather than rely on __attribute__((packed)) for multiarch support.
Since this attribute isn't doing anything on fanotify_response we just
drop it. This does not break API/ABI.
Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
The existing gpio-keys driver can be usable only for GPIO lines with
interrupt support. Several devices have buttons connected to a GPIO
line which is not capable to generate interrupts. This patch adds a
new input driver using the generic GPIO layer and the input-polldev
to support such buttons.
[Ben Gardiner <bengardiner@nanometrics.ca: fold code to use more
of the original gpio_keys infrastructure; cleanups and other
improvements.]
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Tested-by: Ben Gardiner <bengardiner@nanometrics.ca>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM / Hibernate: Fix memory corruption related to swap
PM / Hibernate: Use async I/O when reading compressed hibernation image
There is a problem that swap pages allocated before the creation of
a hibernation image can be released and used for storing the contents
of different memory pages while the image is being saved. Since the
kernel stored in the image doesn't know of that, it causes memory
corruption to occur after resume from hibernation, especially on
systems with relatively small RAM that need to swap often.
This issue can be addressed by keeping the GFP_IOFS bits clear
in gfp_allowed_mask during the entire hibernation, including the
saving of the image, until the system is finally turned off or
the hibernation is aborted. Unfortunately, for this purpose
it's necessary to rework the way in which the hibernate and
suspend code manipulates gfp_allowed_mask.
This change is based on an earlier patch from Hugh Dickins.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Ondrej Zary <linux@rainbow-software.org>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: stable@kernel.org
Pavel Emelyanov tried to fix a race between sk_filter_(de|at)tach and
sk_clone() in commit 47e958eac2
Problem is we can have several clones sharing a common sk_filter, and
these clones might want to sk_filter_attach() their own filters at the
same time, and can overwrite old_filter->rcu, corrupting RCU queues.
We can not use filter->rcu without being sure no other thread could do
the same thing.
Switch code to a more conventional ref-counting technique : Do the
atomic decrement immediately and queue one rcu call back when last
reference is released.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Uk Kim <w0806.kim@samsung.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@kernel.org
Otherwise we can't really fix the abi-braindeadness of forcing
libva to manually wait for rendering when switching rings. Which
in turn makes implementing hw semaphores a pointless exercise
(at least for ironlake).
[Also added the relaxed fencing param to explain the jump in
numbering - relaxed fencing is in -next.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
* '2.6.37-rc4-pvhvm-fixes' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
xen: unplug the emulated devices at resume time
xen: fix save/restore for PV on HVM guests with pirq remapping
xen: resume the pv console for hvm guests too
xen: fix MSI setup and teardown for PV on HVM guests
xen: use PHYSDEVOP_get_free_pirq to implement find_unbound_pirq
Presently hwpoison is using lock_system_sleep() to prevent a race with
memory hotplug. However lock_system_sleep() is a no-op if
CONFIG_HIBERNATION=n. Therefore we need a new lock.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Suggested-by: Hugh Dickins <hughd@google.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On stock 2.6.37-rc4, running:
# mount lilith:/export /mnt/lilith
# find /mnt/lilith/ -type f -print0 | xargs -0 file
crashes the machine fairly quickly under Xen. Often it results in oops
messages, but the couple of times I tried just now, it just hung quietly
and made Xen print some rude messages:
(XEN) mm.c:2389:d80 Bad type (saw 7400000000000001 != exp
3000000000000000) for mfn 1d7058 (pfn 18fa7)
(XEN) mm.c:964:d80 Attempt to create linear p.t. with write perms
(XEN) mm.c:2389:d80 Bad type (saw 7400000000000010 != exp
1000000000000000) for mfn 1d2e04 (pfn 1d1fb)
(XEN) mm.c:2965:d80 Error while pinning mfn 1d2e04
Which means the domain tried to map a pagetable page RW, which would
allow it to map arbitrary memory, so Xen stopped it. This is because
vm_unmap_ram() left some pages mapped in the vmalloc area after NFS had
finished with them, and those pages got recycled as pagetable pages
while still having these RW aliases.
Removing those mappings immediately removes the Xen-visible aliases, and
so it has no problem with those pages being reused as pagetable pages.
Deferring the TLB flush doesn't upset Xen because it can flush the TLB
itself as needed to maintain its invariants.
When unmapping a region in the vmalloc space, clear the ptes
immediately. There's no point in deferring this because there's no
amortization benefit.
The TLBs are left dirty, and they are flushed lazily to amortize the
cost of the IPIs.
This specific motivation for this patch is an oops-causing regression
since 2.6.36 when using NFS under Xen, triggered by the NFS client's use
of vm_map_ram() introduced in 56e4ebf877 ("NFS: readdir with vmapped
pages") . XFS also uses vm_map_ram() and could cause similar problems.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'driver-core-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
uio: Change mail address of Hans J. Koch
driver core: prune docs about device_interface
driver core: the development tree has switched to git
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
serial: mfd: adjust the baud rate setting
TTY: open/hangup race fixup
TTY: don't allow reopen when ldisc is changing
NET: wan/x25, fix ldisc->open retval
TTY: ldisc, fix open flag handling
serial8250: Mark console as CON_ANYTIME
* 'usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6:
USB: fix autosuspend bug in usb-serial
USB: ehci: disable LPM and PPCD for nVidia MCP89 chips
USB: serial: ftdi_sio: Vardaan USB RS422/485 converter PID added
USB: yurex: add .llseek fop to file_operations
USB: ftdi_sio: Add ID for RT Systems USB-29B radio cable
usb: musb: do not use dma for control transfers
usb: musb: gadget: fix compilation warning
usb: musb: clear RXCSR_AUTOCLEAR before PIO read
usb: musb: unmap dma buffer when switching to PIO
xhci: Don't let the USB core disable SuperSpeed ports.
xhci: Setup array of USB 2.0 and USB 3.0 ports.
xhci: Fix reset-device and configure-endpoint commands
We need to ensure that the entries in the nfs_cache_array get cleared
when the page is removed from the page cache. To do so, we use the
freepage address_space operation.
Change nfs_readdir_clear_array to use kmap_atomic(), so that the
function can be safely called from all contexts.
Finally, modify the cache_page_release helper to call
nfs_readdir_clear_array directly, when dealing with an anonymous
page from 'uncached_readdir'.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFS needs to be able to release objects that are stored in the page
cache once the page itself is no longer visible from the page cache.
This patch adds a callback to the address space operations that allows
filesystems to perform page cleanups once the page has been removed
from the page cache.
Original patch by: Linus Torvalds <torvalds@linux-foundation.org>
[trondmy: cover the cases of invalidate_inode_pages2() and
truncate_inode_pages()]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
When remapping MSIs into pirqs for PV on HVM guests, qemu is responsible
for doing the actual mapping and unmapping.
We only give qemu the desired pirq number when we ask to do the mapping
the first time, after that we should be reading back the pirq number
from qemu every time we want to re-enable the MSI.
This fixes a bug in xen_hvm_setup_msi_irqs that manifests itself when
trying to enable the same MSI for the second time: the old MSI to pirq
mapping is still valid at this point but xen_hvm_setup_msi_irqs would
try to assign a new pirq anyway.
A simple way to reproduce this bug is to assign an MSI capable network
card to a PV on HVM guest, if the user brings down the corresponding
ethernet interface and up again, Linux would fail to enable MSIs on the
device.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
