The intention of commit aae8679b0e
("pagemap: fix bug in add_to_pagemap, require aligned-length reads of
/proc/pid/pagemap") was to force reads of /proc/pid/pagemap to be a
multiple of 8 bytes, but now it allows to read 0 bytes, which actually
puts some data to user's buffer. According to POSIX, if count is zero,
read() should return zero and has no other results.
Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com>
Cc: Thomas Tuttle <ttuttle@google.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change page_mkwrite to allow implementations to return with the page
locked, and also change it's callers (in page fault paths) to hold the
lock until the page is marked dirty. This allows the filesystem to have
full control of page dirtying events coming from the VM.
Rather than simply hold the page locked over the page_mkwrite call, we
call page_mkwrite with the page unlocked and allow callers to return with
it locked, so filesystems can avoid LOR conditions with page lock.
The problem with the current scheme is this: a filesystem that wants to
associate some metadata with a page as long as the page is dirty, will
perform this manipulation in its ->page_mkwrite. It currently then must
return with the page unlocked and may not hold any other locks (according
to existing page_mkwrite convention).
In this window, the VM could write out the page, clearing page-dirty. The
filesystem has no good way to detect that a dirty pte is about to be
attached, so it will happily write out the page, at which point, the
filesystem may manipulate the metadata to reflect that the page is no
longer dirty.
It is not always possible to perform the required metadata manipulation in
->set_page_dirty, because that function cannot block or fail. The
filesystem may need to allocate some data structure, for example.
And the VM cannot mark the pte dirty before page_mkwrite, because
page_mkwrite is allowed to fail, so we must not allow any window where the
page could be written to if page_mkwrite does fail.
This solution of holding the page locked over the 3 critical operations
(page_mkwrite, setting the pte dirty, and finally setting the page dirty)
closes out races nicely, preventing page cleaning for writeout being
initiated in that window. This provides the filesystem with a strong
synchronisation against the VM here.
- Sage needs this race closed for ceph filesystem.
- Trond for NFS (http://bugzilla.kernel.org/show_bug.cgi?id=12913).
- I need it for fsblock.
- I suspect other filesystems may need it too (eg. btrfs).
- I have converted buffer.c to the new locking. Even simple block allocation
under dirty pages might be susceptible to i_size changing under partial page
at the end of file (we also have a buffer.c-side problem here, but it cannot
be fixed properly without this patch).
- Other filesystems (eg. NFS, maybe btrfs) will need to change their
page_mkwrite functions themselves.
[ This also moves page_mkwrite another step closer to fault, which should
eventually allow page_mkwrite to be moved into ->fault, and thus avoiding a
filesystem calldown and page lock/unlock cycle in __do_fault. ]
[akpm@linux-foundation.org: fix derefs of NULL ->mapping]
Cc: Sage Weil <sage@newdream.net>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On a linux-next allyesconfig build:
kernel/trace/ring_buffer.c:1726:
warning: passing argument 1 of 'atomic_cmpxchg' from incompatible pointer type
linux-next/arch/s390/include/asm/atomic.h:112:
note: expected 'struct atomic_t *' but argument is of type 'struct atomic64_t *'
atomic_long_cmpxchg and atomic_long_xchg are incorrectly defined for 64
bit architectures. They should be mapped to the atomic64_* variants.
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/serial/crisv10.c:4428: error: unknown field 'read_proc' specified in initializer
Commit 0f043a81eb ("proc tty: remove struct
tty_operations::read_proc") removes the read_proc entry from struct
tty_operations.
Rework the proc handling in the CRISv10 serial driver to use proc_fops
instead.
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
acpi_rs_get_pci_routing_table_length is not performing sufficient
validation on the package returned from _PRT. It assumes a package of
packages and fails/faults if this is not the case.
We should validate each subpackage when extracted from the parent
package, and not accept objects of the wrong type, since that will just
cause the scanning to fail (likely with a kernel oops).
This can only happen with a serious BIOS bug, and is accompanied by a
warning something like this:
ACPI Warning (nspredef-0949): \_SB_.PCI0.PEG4._PRT: Return Package type mismatch at index 0 - found Integer, expected Package [20090320]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6:
eCryptfs: Fix min function comparison warning
ecryptfs: fix printk format warning
A regression was introduced in hg changeset 33810c734a0d, which resulted in
a kernel panic whenever the device was disconnected from USB. The call to
4l2_device_register() was overwriting the pointer for usb_set_intfdata(), so
when au0828_usb_disconnect() was called, the usb_get_intfdata() returned a
pointer to the v4l2_device instead of the au0828_dev structure.
Signed-off-by: Devin Heitmueller <dheitmueller@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
set_modeready flag must be set before command sent to USB in
s2255_write_config.
Signed-off-by: Dean Anderson <dean@sensoray.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
* Return actual error values as returned by the i2c subsystem, rather
than 0 or 1.
* If the registration of the second bus fails, unregister the first one
before exiting, otherwise we are leaking resources.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Currently drivers/media drivers are linked very early - directly after
base, block, misc, and mfd and before ata, scsi, ide, input, firewire,
usb, and i2c. This breaks static build of video4linux drivers, that use
generic CPU i2c adapter drivers and the v4l2-subdev subsystem, because
during video4linux probing the v4l2-subdev core requires a struct
i2c_adapter context, which cannot be satisfied before the i2c subsystem is
initialised. Moving drivers/media after drivers/i2c fixes this problem.
The best way to trigger action is by submitting a patch:-) So, let's see
what comes out of it - on the one hand I don't see any reason why media
has to be linked this early, and nobody was able to give me one yesterday
as this problem has been discussed on linux-media, OTOH, maybe indeed it
would be better to move i2c the whole way up above media, but that'd be
much bigger of a change, I think.
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Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
I lowered the kfree(t) down a couple lines and removed the superflous
"t->vdev = NULL;"
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
I moved the kfree() down a couple lines. t->vdev is going to be in freed
memory so there is no point setting it to NULL. I added a kfree(t) on a
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
selecting ALSA module breaks if !SND. Just remove select.
While here, let's fix the whitespacing at the Kconfig.
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
A late v4l2_subdev framework change accidentally sent the audio input
routing value to the external multiplexer, instead of the muxer input routing
value to the external multiplexer. This change corrects that error.
Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (24 commits)
e100: do not go D3 in shutdown unless system is powering off
netfilter: revised locking for x_tables
Bluetooth: Fix connection establishment with low security requirement
Bluetooth: Add different pairing timeout for Legacy Pairing
Bluetooth: Ensure that HCI sysfs add/del is preempt safe
net: Avoid extra wakeups of threads blocked in wait_for_packet()
net: Fix typo in net_device_ops description.
ipv4: Limit size of route cache hash table
Add reference to CAPI 2.0 standard
Documentation/isdn/INTERFACE.CAPI
update Documentation/isdn/00-INDEX
ixgbe: Fix WoL functionality for 82599 KX4 devices
veth: prevent oops caused by netdev destructor
xfrm: wrong hash value for temporary SA
forcedeth: tx timeout fix
net: Fix LL_MAX_HEADER for CONFIG_TR_MODULE
mlx4_en: Handle page allocation failure during receive
mlx4_en: Fix cleanup flow on cq activation
vlan: update vlan carrier state for admin up/down
netfilter: xt_recent: fix stack overread in compat code
...
After experimenting with kexec with the last merges after 2.6.29, I've
had some problems when probing e100. It would not read the eeprom. After
some bisects, I realized this has been like that since forever (at least
2.6.18). The problem is that shutdown is doing the same thing that
suspend does and puts the device in D3 state. I couldn't find a way to
get the device back to a sane state in the probe function. So, based on
some similar patches from Rafael J. Wysocki for e1000, e1000e, and ixgbe,
I wrote this one for e100.
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Vitaly Mayatskikh
Nick Piggin
Heiko Carstens
Jesper Nilsson
Christoph Hellwig
Daisuke Nishimura
Florian Fainelli
Ian Kent
Johannes Weiner
Robert Moore
Linus Torvalds
Devin Heitmueller
Christopher Pascoe
Sascha Hauer
Dean Anderson
Jean Delvare
Guennadi Liakhovetski
Dan Carpenter
Mauro Carvalho Chehab
Andy Walls
Thadeu Lima de Souza Cascardo